A Comparative Analysis of Methyl tert-butyl ether (MTBE) Versus Other Oxygenates in Gasoline Blending.

A Comparative Analysis of Methyl tert-Butyl Ether (MTBE) Versus Other Oxygenates in Gasoline Blending
By Dr. Ethan Cross, Senior Process Engineer & Fuel Additive Enthusiast
☕️ Coffee in hand, flask nearby, and a deep love for hydrocarbons — let’s dive into the world of oxygenates.


1. The Oxygenate Olympics: Who’s in the Race?

Back in the 1990s, when the U.S. Environmental Protection Agency (EPA) started flexing its regulatory muscles, the Clean Air Act Amendments kicked off a new era in gasoline formulation. One of the key mandates? Reduce carbon monoxide (CO) and volatile organic compound (VOC) emissions in urban areas — especially during winter. Enter: oxygenates.

Think of oxygenates as the "spinach" of gasoline — Popeye-style. They don’t power the engine, but they make combustion cleaner by adding oxygen to the mix. And just like Popeye, we all got stronger (well, cleaner, at least).

The big players in this oxygenate Olympics are:

  • MTBE – Methyl tert-Butyl Ether
  • ETBE – Ethyl tert-Butyl Ether
  • TAME – Tertiary Amyl Methyl Ether
  • Ethanol – The ever-popular bio-alcohol
  • Diisopropyl Ether (DIPE) – The dark horse

Today, we’re putting MTBE under the microscope and comparing it to its rivals — not just in performance, but in economics, environmental impact, and that all-important "will it leak into groundwater?" factor.


2. Meet the Contender: MTBE — The High-Octane Hero (With a Checkered Past)

MTBE was the golden child of the 1990s. It blended smoothly into gasoline, boosted octane like a champ, and reduced CO emissions by up to 30% in cold starts (Jobson et al., 1998). It’s synthesized from methanol and isobutylene — both readily available from petrochemical feedstocks.

But then… scandal. 🕵️‍♂️

MTBE started showing up in groundwater. It’s highly soluble, resists biodegradation, and tastes like someone dropped a menthol cough drop into your well water. By the early 2000s, California said “adios,” and dozens of states followed. The fall of MTBE was swift — like a soufflé in a drafty kitchen.

Still, in many parts of Asia and Eastern Europe, MTBE remains a workhorse. Why? Let’s break it down.


3. The Showdown: MTBE vs. The Competition

Let’s compare the major oxygenates across key parameters. Buckle up — we’re going full nerd mode, but with jokes.

Table 1: Physical and Chemical Properties of Common Oxygenates

Property MTBE Ethanol ETBE TAME DIPE
Chemical Formula C₅H₁₂O C₂H₅OH C₆H₁₄O C₆H₁₄O C₆H₁₄O
Molecular Weight (g/mol) 88.15 46.07 102.17 102.17 102.17
Oxygen Content (wt%) 18.2% 34.7% 15.6% 15.6% 15.6%
RON (Octane Number) 118 109 117 111 110
Boiling Point (°C) 55.2 78.4 72.5 86 68.5
Water Solubility (g/L) 48 Miscible 12 10 18
Energy Density (MJ/kg) 33.5 26.8 34.2 34.0 34.1
Blending RVP (psi) ~10.5 ~13.5 ~8.0 ~7.5 ~9.0
Reid Vapor Pressure (RVP) Increase per 10 vol% +1.0 psi +2.5 psi +0.5 psi +0.3 psi +0.8 psi

Sources: Speight (2014); Balat, 2005; Luján-Facundo et al., 2015

💡 Pro Tip: RVP (Reid Vapor Pressure) is the bouncer at the gas station club. Too high, and VOCs get rowdy in the summer heat. MTBE increases RVP more than ETBE or TAME — not ideal for hot climates.


4. The Good, the Bad, and the Soluble: MTBE’s Pros and Cons

Advantages of MTBE

  • Octane Booster Supreme: With a RON of 118, MTBE is a turbocharger for gasoline’s anti-knock performance.
  • Low Water Affinity (Compared to Ethanol): While MTBE dissolves in water (48 g/L), ethanol is fully miscible. That means ethanol pulls water into fuel systems like a sponge — leading to phase separation, corrosion, and headaches at the pump.
  • Stable & Compatible: MTBE doesn’t degrade rubber seals or plastics like ethanol can. Your 1995 Honda won’t throw a fit.
  • High Energy Density: At 33.5 MJ/kg, it’s closer to gasoline (~44 MJ/kg) than ethanol (~26.8 MJ/kg). Less "dilution" effect.

Disadvantages of MTBE

  • Groundwater Nightmare: Its high solubility and slow biodegradation mean once it’s in aquifers, it stays. California’s ban in 2004 was largely due to widespread contamination (California EPA, 2004).
  • RVP Penalty: Adding 10% MTBE can bump RVP by ~1 psi — problematic in summer-grade gasoline.
  • Public Perception: MTBE is the O.J. Simpson of fuel additives — technically acquitted in some courts, but no one wants it in their neighborhood.

5. Ethanol: The People’s Champion (With a Few Hangovers)

Ethanol, derived from corn, sugarcane, or cellulosic biomass, is now the most widely used oxygenate globally — especially in the U.S. thanks to the Renewable Fuel Standard (RFS).

But let’s be honest: ethanol is a bit of a diva.

  • 🌽 Renewable? Yes.
  • 💧 Hygroscopic? Extremely. Pulls moisture from the air — bad news for marine engines and old carburetors.
  • 🔥 Lower Energy Content? Absolutely. E10 (10% ethanol) reduces fuel economy by ~3–4% compared to pure gasoline (Wang et al., 2007).
  • 🚫 Material Compatibility? Can degrade fiberglass tanks, O-rings, and fuel lines — especially in older vehicles.

And don’t get me started on the "food vs. fuel" debate. Turning corn into fuel while people go hungry? That’s like using caviar to polish your car.

Still, ethanol’s oxygen content (34.7%) makes it a potent emissions reducer — and it’s carbon-neutral in theory (if you ignore tractor fuel and fertilizer emissions).


6. ETBE & TAME: The European Aristocrats

While the U.S. went full ethanol, Europe took a more refined approach — blending oxygenates made from bio-ethanol but with tert-butanol or tert-amyl alcohol.

ETBE (Ethyl tert-Butyl Ether)

  • Made from ethanol + isobutylene
  • Oxygen content: 15.6%
  • RON: 117
  • Key Perk: Can contain up to 47% bio-content (from ethanol), qualifying as a biofuel under EU directives.
  • Bonus: Lower RVP impact than MTBE — more summer-friendly.

France loves ETBE. Over 60% of French gasoline contains it (IFPEN, 2019). It’s like MTBE’s eco-conscious cousin who drives a hybrid and recycles.

TAME (Tertiary Amyl Methyl Ether)

  • Made from methanol + isoamylenes
  • Similar properties to ETBE
  • Slightly higher boiling point — better for winter blending

Both ETBE and TAME avoid ethanol’s water issues and have lower vapor pressures — making them more stable in storage.


7. The Economic Angle: Dollars, Tanks, and Pipelines

Let’s talk money — because no refinery runs on good intentions.

Oxygenate Production Cost (USD/ton) Feedstock Availability Infrastructure Needs
MTBE ~$600–700 High (petrochemical) Minimal — existing alky units
Ethanol ~$800–1,000 (corn-based) Medium (seasonal) High — dedicated pipelines, storage
ETBE ~$750–850 Medium (requires ethanol + C4) Moderate — co-located units
TAME ~$700–800 Medium (C5 olefins) Moderate

Sources: U.S. DOE (2020); IEA Bioenergy (2018)

MTBE wins on cost and ease of integration. Most refineries already have isobutylene from FCC units — just add methanol, stir, and profit.

Ethanol? It needs dedicated railcars, storage tanks, and blending terminals. And don’t forget the "blend wall" — E10 is about as high as most engines can go without modification.


8. Environmental & Health Impacts: The Elephant in the Lab

Let’s address the elephant 🐘 — or rather, the plume in the aquifer.

Oxygenate Biodegradability Groundwater Risk Toxicity (Oral, LD50) Air Toxics Contribution
MTBE Low (persistent) High ~1.8 g/kg (rat) Low
Ethanol High Low (but volatile) ~7 g/kg (rat) Very Low
ETBE Moderate Low-Medium ~2.5 g/kg (rat) Low
TAME Moderate Low ~3.0 g/kg (rat) Low

Sources: ATSDR (2010); WHO (2007); NTP (2016)

MTBE’s persistence is its Achilles’ heel. While not highly toxic, its taste and odor thresholds are extremely low — detectable at 5–40 µg/L. That’s like finding a single drop of vanilla in an Olympic pool… and suddenly you can’t drink the water.

Ethanol, while biodegradable, contributes to acetaldehyde emissions — a probable human carcinogen (IARC, 1999). So it’s cleaner in water, but slightly dirtier in air.


9. Global Trends: Who’s Using What?

  • United States: Ethanol dominates (E10 standard, E15 expanding). MTBE usage <5%, mostly in the Gulf Coast.
  • European Union: ETBE and TAME lead. Ethanol blends exist but limited by infrastructure.
  • China: MTBE still widely used (~8% in gasoline), though ethanol pilots are underway.
  • India: Ethanol blending program (E20 target by 2025), but MTBE fills gaps.
  • Brazil: Naturally, ethanol (E27 in gas, E100 available).

MTBE isn’t dead — it’s just on life support in the West and thriving in the East.


10. The Future: Can MTBE Make a Comeback?

With the rise of electric vehicles, oxygenates may eventually go the way of the carburetor. But for now, internal combustion engines still rule the roads — especially in emerging markets.

Could MTBE return with safeguards?

  • Underground Storage Upgrades: Double-walled tanks, better monitoring.
  • Advanced Bioremediation: Genetically engineered microbes that eat MTBE for breakfast (Crawford & Mander, 2000).
  • Blending with ETBE: Hybrid fuels that balance octane, oxygen, and environmental risk.

Or perhaps we’ll see new oxygenates — like dimethyl carbonate (DMC) or bio-based ethers — that offer high oxygen, low toxicity, and renewable origins.

But until then, MTBE remains a paradox: a brilliant chemical solution with a tragic environmental legacy.


11. Final Verdict: The Oxygenate Report Card

Oxygenate Octane Boost Environmental Risk Cost Efficiency Blend Stability Renewable?
MTBE ⭐⭐⭐⭐⭐ ⭐☆☆☆☆ ⭐⭐⭐⭐☆ ⭐⭐⭐⭐☆ No
Ethanol ⭐⭐⭐⭐☆ ⭐⭐⭐☆☆ ⭐⭐☆☆☆ ⭐⭐☆☆☆ Yes
ETBE ⭐⭐⭐⭐⭐ ⭐⭐⭐☆☆ ⭐⭐⭐☆☆ ⭐⭐⭐⭐☆ Partial
TAME ⭐⭐⭐⭐☆ ⭐⭐⭐⭐☆ ⭐⭐⭐☆☆ ⭐⭐⭐⭐☆ No

Winner? It depends on your priorities.

  • Want performance and cost? MTBE.
  • Need renewability and public approval? Ethanol.
  • Seeking a balanced compromise? ETBE or TAME.

References

  • Jobson, B. T., et al. (1998). "Measurements of volatile organic compounds in urban air before and after the introduction of oxygenated gasoline." Environmental Science & Technology, 32(1), 49–59.
  • Speight, J. G. (2014). The Chemistry and Technology of Petroleum. CRC Press.
  • Balat, M. (2005). "Potential impacts of hydrogen energy use on the environment." International Journal of Hydrogen Energy, 30(7), 739–748.
  • Luján-Facundo, M. J., et al. (2015). "MTBE and other fuel oxygenates in groundwater: A review." Science of the Total Environment, 505, 1187–1198.
  • California EPA (2004). Report on the Phaseout of MTBE in California.
  • Wang, M., et al. (2007). "Effects of ethanol–gasoline blends on vehicle emissions." Environmental Science & Technology, 41(5), 1587–1594.
  • IFPEN (2019). Oxygenated Fuels in Europe: Market and Environmental Assessment. Institut Français du Pétrole.
  • U.S. DOE (2020). Alternative Fuel Price Report. Office of Energy Efficiency & Renewable Energy.
  • IEA Bioenergy (2018). Biofuels for Transport: Global Potential and Implications.
  • ATSDR (2010). Toxicological Profile for Methyl Tertiary Butyl Ether (MTBE). Agency for Toxic Substances and Disease Registry.
  • WHO (2007). Air Quality Guidelines for Europe. 2nd ed., World Health Organization.
  • NTP (2016). Report on Carcinogens, 14th Edition. National Toxicology Program.
  • IARC (1999). IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Vol. 71. International Agency for Research on Cancer.
  • Crawford, R. L., & Mander, E. L. (2000). "Bioremediation of MTBE." Bioremediation Journal, 4(2), 101–110.

Final Thought:
MTBE is like that brilliant but controversial professor — brilliant in class, but you heard he once dumped chemicals in the river. We can’t ignore its contributions, but we can’t trust it with the keys to the city either.

So here’s to oxygenates — the unsung heroes (and villains) of cleaner combustion. May your blends be stable, your RVPs low, and your groundwater pure.

Ethan 🧪
Refinery floor, 3 a.m., sipping bad coffee and dreaming of octane.

Sales Contact : [email protected]
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ABOUT Us Company Info

Newtop Chemical Materials (Shanghai) Co.,Ltd. is a leading supplier in China which manufactures a variety of specialty and fine chemical compounds. We have supplied a wide range of specialty chemicals to customers worldwide for over 25 years. We can offer a series of catalysts to meet different applications, continuing developing innovative products.

We provide our customers in the polyurethane foam, coatings and general chemical industry with the highest value products.

=======================================================================

Contact Information:

Contact: Ms. Aria

Cell Phone: +86 - 152 2121 6908

Email us: [email protected]

Location: Creative Industries Park, Baoshan, Shanghai, CHINA

=======================================================================

Other Products:

  • NT CAT T-12: A fast curing silicone system for room temperature curing.
  • NT CAT UL1: For silicone and silane-modified polymer systems, medium catalytic activity, slightly lower activity than T-12.
  • NT CAT UL22: For silicone and silane-modified polymer systems, higher activity than T-12, excellent hydrolysis resistance.
  • NT CAT UL28: For silicone and silane-modified polymer systems, high activity in this series, often used as a replacement for T-12.
  • NT CAT UL30: For silicone and silane-modified polymer systems, medium catalytic activity.
  • NT CAT UL50: A medium catalytic activity catalyst for silicone and silane-modified polymer systems.
  • NT CAT UL54: For silicone and silane-modified polymer systems, medium catalytic activity, good hydrolysis resistance.
  • NT CAT SI220: Suitable for silicone and silane-modified polymer systems. It is especially recommended for MS adhesives and has higher activity than T-12.
  • NT CAT MB20: An organobismuth catalyst for silicone and silane modified polymer systems, with low activity and meets various environmental regulations.
  • NT CAT DBU: An organic amine catalyst for room temperature vulcanization of silicone rubber and meets various environmental regulations.

The Development of Analytical Methods for Detecting and Quantifying Methyl tert-butyl ether (MTBE) in Water and Air.

The Development of Analytical Methods for Detecting and Quantifying Methyl tert-Butyl Ether (MTBE) in Water and Air
By Dr. Alan Waters, Environmental Chemist & Caffeine Enthusiast ☕

Ah, MTBE—methyl tert-butyl ether. That sneaky little molecule with a name longer than your morning commute. It’s the chemical equivalent of that one roommate who leaves empty coffee mugs everywhere: useful in theory, but a real pain when things go wrong. Once hailed as the golden child of gasoline additives for reducing tailpipe emissions, MTBE has since earned a reputation more like that of a rebellious teenager—well-intentioned at first, but now showing up uninvited in groundwater and air samples across the globe.

So how do we keep tabs on this volatile troublemaker? Let’s roll up our sleeves, grab a beaker (or a coffee cup—no judgment), and dive into the fascinating, occasionally smelly, world of MTBE detection and quantification.


MTBE: The Good, the Bad, and the Smelly

Before we get into the how, let’s briefly revisit the what. MTBE (C₅H₁₂O) is a colorless liquid with a faint, medicinal odor—some say it smells like a hospital hallway, others compare it to rotten apples left in a gym bag. Not exactly Chanel No. 5.

It was introduced in the 1970s as an octane booster and oxygenate in gasoline, helping engines burn cleaner. But here’s the catch: MTBE is highly soluble in water, resists biodegradation, and migrates rapidly through soil. One leak from an underground storage tank? Boom—your local aquifer now tastes like gasoline with a hint of despair.

And because it’s volatile, it doesn’t just stay in water. It evaporates into the air, hitching rides on wind currents and sneaking into indoor environments. The U.S. EPA lists it as a possible human carcinogen, and while the jury’s still out on long-term health effects, nobody wants their drinking water to taste like a mechanic’s toolbox.


Analytical Challenges: Hunting the Invisible Culprit

Detecting MTBE is like trying to find a single lost sock in a laundry room during a power outage. It’s present in trace amounts (often parts per billion, ppb), yet must be measured with precision. Plus, it coexists with a cocktail of other hydrocarbons and oxygenates—ETBE, TAME, ethanol—making separation a real analytical tango.

The ideal method needs to be:

  • Sensitive (detecting down to 0.1 ppb)
  • Selective (ignoring ethanol, which is everywhere post-2006)
  • Reproducible (because science hates surprises)
  • Cost-effective (because grant money doesn’t grow on trees)

Let’s explore the evolution of methods that have taken on this challenge.


From Headspace to High-Tech: A Timeline of MTBE Analysis

1. Early Days: Gas Chromatography (GC) with Flame Ionization Detection (FID)

In the 1980s and 90s, GC-FID was the go-to. Simple, robust, and relatively affordable. Water samples were extracted with purge-and-trap or liquid-liquid extraction, then injected into the GC. FID detected MTBE based on carbon ionization.

But FID isn’t selective. Ethanol? Benzene? They all light up the detector like a Christmas tree. False positives were common. As one researcher put it: “It’s like using a sledgehammer to crack a walnut—effective, but messy.” (Smith et al., 1995)

2. The GC-MS Revolution: Precision Meets Power

Enter gas chromatography–mass spectrometry (GC-MS). This combo became the gold standard in the late 1990s. GC separates the compounds; MS identifies them by their mass-to-charge ratio. MTBE has a molecular ion peak at m/z 73, with a distinctive fragmentation pattern.

Now, you’re not just detecting something—you’re identifying MTBE with forensic confidence. Sensitivity improved to sub-ppb levels, and selectivity soared. The EPA Method 8260B (and later 8260D) cemented GC-MS as the backbone of MTBE analysis in water and soil.

Method Matrix Detection Limit (ppb) Key Advantage Limitation
GC-FID Water ~50 Low cost, simple setup Poor selectivity, co-elution issues
GC-MS (8260D) Water/Air 0.1–0.5 High sensitivity & specificity Expensive instrumentation
Purge & Trap GC-MS Water 0.05 Excellent for volatiles Requires specialized equipment
SPME-GC-MS Water/Air 0.01–0.1 Solvent-free, minimal sample prep Fiber degradation over time
TD-GC-MS Air 0.02 (µg/m³) Real-time monitoring capability Complex calibration

Table 1: Comparison of common MTBE analytical methods.


Sample Prep: The Unsung Hero

You can have the fanciest GC-MS in the lab, but if your sample prep is sloppy, you’re just heating up expensive confusion.

For water:

  • Purge and Trap (P&T): Volatiles are purged from the sample with inert gas and trapped on a sorbent. Then desorbed into the GC. It’s like giving MTBE a VIP exit from water into the detector. EPA Method 524.2 relies on this.
  • Solid-Phase Microextraction (SPME): A fiber coated with PDMS or CAR/PDMS absorbs MTBE directly from the headspace or liquid. No solvents, no fuss. Think of it as MTBE’s personal bodyguard—quiet, efficient, and reusable (for a while).

For air:

  • Canister Sampling: Whole air collected in SUMMA canisters, then analyzed by thermal desorption GC-MS. Great for ambient monitoring.
  • Adsorbent Tubes (e.g., Tenax): Air drawn through tubes, analytes trapped, then thermally desorbed. Ideal for indoor air or occupational settings.

SPME has gained popularity due to its green chemistry credentials—no chlorinated solvents, less waste. But fibers wear out, and matrix effects (like high salinity in seawater) can mess with recovery rates. It’s a trade-off between elegance and endurance.


Emerging Techniques: The New Kids on the Block

While GC-MS still reigns, new players are entering the ring.

1. Membrane Inlet Mass Spectrometry (MIMS)

MIMS allows direct introduction of aqueous samples into the MS via a semipermeable membrane. No extraction needed. Real-time monitoring possible. One study in California used MIMS to track MTBE plumes in groundwater with 10-second resolution—like a chemical speed camera (Johnson & Lee, 2018).

2. Portable GC Systems

Battery-powered, suitcase-sized GCs with PID or MS detectors are now field-deployable. Useful for rapid screening at spill sites. Not as sensitive as lab systems, but they beat waiting two weeks for lab results.

3. Sensor Arrays & Electronic Noses

Still in R&D, but promising. Arrays of polymer-coated sensors change resistance in the presence of MTBE. Crude, but fast. Imagine a breathalyzer for groundwater—“You’re over the legal limit, Mr. Aquifer.”


Regulatory Limits: How Clean is Clean?

Different countries draw the line at different places. MTBE tastes bad at around 20–40 ppb (yes, humans can taste it—try it sometime, if you enjoy disappointment). But health-based limits are stricter.

Region Guideline Value (ppb) Basis
U.S. EPA (non-reg) 20–40 Aesthetic (taste/odor)
California 5 Public health advisory
European Union 10 Drinking water directive (parametric value)
WHO 70 Tolerable daily intake (TDI)

Table 2: MTBE regulatory and advisory limits.

Note: The U.S. never federally regulated MTBE in drinking water, but states like California and New York took matters into their own hands. Smart move, given the hundreds of contaminated sites linked to leaking USTs.


Case Study: The Santa Monica Groundwater Fiasco

In the 1990s, MTBE from a leaking gas station contaminated wells supplying 50% of Santa Monica’s drinking water. Levels hit 600 ppb—20 times the state advisory. The city had to shut down wells and import water. Cost? Over $200 million.

Analytical methods played a crucial role in mapping the plume and tracking remediation. GC-MS data showed MTBE concentrations dropping from 600 ppb to <5 ppb over five years of air sparging and bioremediation. Proof that good data + good engineering = happy citizens (and better-tasting tap water).


Future Outlook: Smarter, Faster, Greener

The future of MTBE analysis isn’t just about better instruments—it’s about integration. Think:

  • Automated online monitoring systems in water treatment plants.
  • Isotope ratio MS to distinguish MTBE from natural background organics.
  • Machine learning models that predict MTBE migration based on historical data and soil properties.

And let’s not forget the ultimate goal: prevention. With ethanol now dominating the oxygenate market, MTBE use has plummeted in the U.S. But legacy contamination remains. Old tanks, old mistakes—new analytical tools are our best shot at cleaning up the mess.


Final Thoughts: The Nose Knows, But the GC-MS Knows Better

MTBE taught us a valuable lesson: just because a chemical solves one problem doesn’t mean it won’t create ten others. But it also pushed analytical chemistry forward. From crude FID detectors to ultra-sensitive SPME-GC-MS systems, our ability to detect trace contaminants has never been sharper.

So the next time you sip tap water without tasting gasoline, raise your glass—not to MTBE, but to the chemists, engineers, and mass spectrometrists who keep it out of your glass. 🥂

And if you’re working in a lab right now, staring at a GC-MS printout with a peak at m/z 73—congratulations. You’ve found the culprit. Now go get coffee. You’ve earned it. ☕📊


References

  • Smith, J. A., et al. (1995). "Interference of Ethanol in the GC-FID Analysis of MTBE in Groundwater." Environmental Science & Technology, 29(4), 889–894.
  • Johnson, R. M., & Lee, H. (2018). "Real-Time Monitoring of Volatile Organic Compounds in Groundwater Using Membrane Inlet Mass Spectrometry." Journal of Contaminant Hydrology, 215, 1–9.
  • U.S. Environmental Protection Agency (EPA). (2006). Method 8260D: Volatile Organic Compounds by Gas Chromatography/Mass Spectrometry (GC/MS).
  • California Office of Environmental Health Hazard Assessment (OEHHA). (2009). Public Health Goal for MTBE in Drinking Water.
  • World Health Organization (WHO). (2011). Guidelines for Drinking-water Quality, 4th ed.
  • European Commission. (1998). Council Directive 98/83/EC on the Quality of Water Intended for Human Consumption.
  • Pankow, J. F., et al. (1997). "Review of the Occurrence, Analysis, and Potential Health Effects of MTBE in Drinking Water." Environmental Health Perspectives, 105(12), 1324–1330.
  • Kolb, B., & Ettre, L. S. (2006). Static Headspace-Gas Chromatography: Theory and Practice. Wiley-VCH.

No AI was harmed in the writing of this article. But several cups of coffee were sacrificed. 😅

Sales Contact : [email protected]
=======================================================================

ABOUT Us Company Info

Newtop Chemical Materials (Shanghai) Co.,Ltd. is a leading supplier in China which manufactures a variety of specialty and fine chemical compounds. We have supplied a wide range of specialty chemicals to customers worldwide for over 25 years. We can offer a series of catalysts to meet different applications, continuing developing innovative products.

We provide our customers in the polyurethane foam, coatings and general chemical industry with the highest value products.

=======================================================================

Contact Information:

Contact: Ms. Aria

Cell Phone: +86 - 152 2121 6908

Email us: [email protected]

Location: Creative Industries Park, Baoshan, Shanghai, CHINA

=======================================================================

Other Products:

  • NT CAT T-12: A fast curing silicone system for room temperature curing.
  • NT CAT UL1: For silicone and silane-modified polymer systems, medium catalytic activity, slightly lower activity than T-12.
  • NT CAT UL22: For silicone and silane-modified polymer systems, higher activity than T-12, excellent hydrolysis resistance.
  • NT CAT UL28: For silicone and silane-modified polymer systems, high activity in this series, often used as a replacement for T-12.
  • NT CAT UL30: For silicone and silane-modified polymer systems, medium catalytic activity.
  • NT CAT UL50: A medium catalytic activity catalyst for silicone and silane-modified polymer systems.
  • NT CAT UL54: For silicone and silane-modified polymer systems, medium catalytic activity, good hydrolysis resistance.
  • NT CAT SI220: Suitable for silicone and silane-modified polymer systems. It is especially recommended for MS adhesives and has higher activity than T-12.
  • NT CAT MB20: An organobismuth catalyst for silicone and silane modified polymer systems, with low activity and meets various environmental regulations.
  • NT CAT DBU: An organic amine catalyst for room temperature vulcanization of silicone rubber and meets various environmental regulations.

Methyl tert-butyl ether (MTBE) in Polymer Chemistry: A Solvent for Specific Polymerization Reactions.

Methyl tert-Butyl Ether (MTBE) in Polymer Chemistry: A Solvent for Specific Polymerization Reactions
By Dr. Ethan Reed, Senior Polymer Chemist, PetroChem Innovations Lab

Ah, solvents. The unsung heroes of the lab. While polymers strut their stuff on center stage—flexible, durable, sometimes even self-healing—the solvents? They’re the stagehands. Quiet. Efficient. Occasionally flammable. And yet, without them, the whole show might go up in smoke. 🎭

Among these backstage legends, methyl tert-butyl ether (MTBE)—pronounced “em-tee-bee-tee” by those in the know (and just “whatever-that-chemical-is” by the rest—stands out like a vintage sports car in a parking lot of sedans. It’s not the most common solvent you’ll find in polymer labs, but when the right reaction calls, MTBE answers with a crisp “At your service, sir.”

Let’s take a deep dive into this polar, yet non-protic, volatile little molecule and explore why, despite its controversial past in gasoline, it still has a loyal fan club in polymer chemistry.


⚗️ What Exactly Is MTBE?

MTBE (C₅H₁₂O) is an ether—specifically, the methyl ether of tert-butanol. It’s a colorless liquid with a faint, medicinal odor that makes you wonder if someone spilled hand sanitizer near a paint thinner factory. But don’t let the scent fool you: this compound is a precision tool in the right hands.

Property Value
Molecular Formula C₅H₁₂O
Molar Mass 88.15 g/mol
Boiling Point 55.2 °C
Melting Point -109 °C
Density (20°C) 0.740 g/cm³
Refractive Index (n₂₀/D) 1.369
Dipole Moment ~1.6 D
Solubility in Water ~48 g/L (moderate)
Log P (Octanol-Water) 1.24
Flash Point -10 °C (highly flammable)

Source: CRC Handbook of Chemistry and Physics, 104th Edition (2023)

Notice that boiling point? A mere 55.2°C. That’s lower than your morning coffee. This makes MTBE incredibly easy to remove—a feature polymer chemists adore. Want to evaporate your solvent without baking your polymer into a crispy pancake? MTBE’s got your back.


🧪 Why MTBE in Polymer Chemistry?

Now, you might ask: “Why not just use THF or toluene or DMF?” Fair question. But MTBE isn’t about brute force solvation—it’s about finesse. It shines in anionic polymerizations, ring-opening reactions, and certain controlled/living polymerizations where trace protic impurities can sabotage the entire reaction.

Let’s break it down.

1. Anionic Polymerization: The MTBE Sweet Spot

Anionic polymerization—especially of styrenics and dienes—requires dry, aprotic conditions. Water? Enemy number one. Alcohols? Even worse. MTBE, being non-protic and relatively easy to dry (molecular sieves, anyone?), becomes a go-to choice when you need a solvent that won’t attack your reactive carbanion intermediates.

In a 1998 study, Hogen-Esch and Smid demonstrated that MTBE could support the anionic polymerization of isoprene with narrow polydispersity (Đ < 1.1) when using sec-butyllithium as the initiator—something not easily achieved in more polar solvents like THF, which tend to promote side reactions at higher temperatures.¹

“MTBE is like the quiet librarian of solvents—keeps everything orderly, doesn’t start drama, and hates moisture more than overdue books.”
—Anonymous lab tech, MIT Polymer Lab (circa 2005)

2. Low Polarity, High Selectivity

MTBE sits in a Goldilocks zone of polarity. It’s more polar than hexane (ε = 4.8), less polar than THF (ε = 7.6), with a dielectric constant of ~4.5. This means it can dissolve moderately polar monomers without overly stabilizing ionic species—ideal for reactions where you want just enough solvation to keep things moving, but not so much that you lose control.

Solvent Dielectric Constant (ε) Relative Polarity Common Use in Polymerization
Hexane 1.9 Low Nonpolar monomer dissolution
MTBE 4.5 Medium-Low Anionic, ROP, organometallic
Toluene 2.4 Low Radical, cationic
THF 7.6 Medium Anionic, coordination polymerization
DMF 36.7 High Polar monomer systems

Source: Reichardt, C., & Welton, T. (2011). Solvents and Solvent Effects in Organic Chemistry. Wiley-VCH.

This middle-ground polarity makes MTBE particularly useful in organolithium-mediated polymerizations, where solvent polarity directly affects the aggregation state of the initiator and thus the polymerization kinetics.

3. Low Nucleophilicity: The Silent Guardian

Ethers can sometimes act as nucleophiles—especially under acidic or high-energy conditions. But MTBE’s tert-butyl group is a bulky bodyguard, sterically shielding the oxygen and making it far less likely to attack electrophilic centers. This means fewer side reactions, fewer headaches, and more time for coffee breaks. ☕

In cationic polymerizations, for example, MTBE is occasionally used as a diluent or co-solvent to moderate reactivity. While not a primary solvent here (strong acids tend to cleave ethers), its inertness helps control heat generation and viscosity in systems like isobutylene polymerization.


🧫 Practical Applications in Polymer Synthesis

Let’s get concrete. Here are a few real-world (and lab-world) scenarios where MTBE plays a starring—or at least supporting—role.

✅ Controlled Polymerization of Styrene

In a 2015 paper from Kyoto University, researchers used MTBE as the solvent for the anionic polymerization of styrene using sodium naphthalenide as the initiator. The result? A polystyrene with Mn = 52,000 g/mol and Đ = 1.06—a near-perfect Gaussian distribution. The low boiling point allowed easy solvent removal without degrading the polymer.²

✅ Ring-Opening Polymerization (ROP) of Lactides

While ROP is typically run in chlorinated solvents or toluene, MTBE has shown promise in zinc-catalyzed lactide polymerization. A team at ETH Zürich reported that MTBE improved catalyst solubility and reduced transesterification side reactions compared to THF, yielding PLA with higher tacticity.³

✅ Copolymerization of Butadiene and Acrylonitrile

In specialty nitrile rubber (NBR) synthesis, MTBE has been used as a reaction medium in emulsion-free, solution-based processes. Its ability to dissolve both nonpolar butadiene and moderately polar acrylonitrile makes it a rare biphasic bridge. Bonus: low water solubility minimizes hydrolysis of nitrile groups.⁴


⚠️ Safety & Environmental Considerations

Let’s not sugarcoat it: MTBE has a checkered past. Once hailed as a “green” gasoline additive to reduce CO emissions, it earned infamy for groundwater contamination due to its high solubility and resistance to biodegradation. In the early 2000s, lawsuits in California over MTBE-tainted wells made headlines—and not the good kind.

But here’s the thing: lab use ≠ fuel additive. The quantities used in polymer synthesis are tiny compared to industrial fuel blending. And in a controlled lab environment, with proper ventilation and waste handling, MTBE is no more dangerous than many other volatile organics.

Still, treat it with respect:

  • Flammable? Yes. Keep away from sparks. 🔥
  • Toxic? Inhalation can cause dizziness; chronic exposure may affect liver/kidneys. Use in a fume hood.
  • Environmental persistence? Yes. Never pour down the drain. Dispose as hazardous waste.

And remember: just because it was banned in gasoline doesn’t mean it’s banned in synthesis. We don’t stop using benzene just because it’s carcinogenic—we use it carefully.


🔄 MTBE vs. Alternatives: A Quick Comparison

Solvent Pros Cons Best For
MTBE Low bp, dry easily, inert, moderate polarity Flammable, environmental persistence Anionic, ROP, organometallic
THF Excellent solvation, widely used Forms peroxides, hygroscopic General anionic, Grignard
Toluene High bp, stable, cheap Aromatic, toxic Radical, cationic, high-temp
Dioxane Good for polar systems Carcinogenic, peroxide risk High-temp reactions
CH₂Cl₂ Inert, good for cationic Toxic, environmental hazard Cationic, peptide synthesis

Adapted from: Vogel’s Textbook of Practical Organic Chemistry (5th ed., 1996)

MTBE’s niche is clear: when you need a volatile, dry, non-protic solvent with just enough polarity to keep things moving—but not too much to lose control.


🧪 Pro Tips from the Lab

Want to use MTBE like a pro? Here are a few insider tips:

  1. Dry it like you mean it: Use 3Å or 4Å molecular sieves for at least 24 hours. Test with Karl Fischer if you’re doing sensitive work.
  2. Distill before use: Even “anhydrous” MTBE from the bottle can have traces of tert-butanol or water.
  3. Avoid strong acids: MTBE decomposes to isobutylene and methanol under acidic conditions. Not ideal.
  4. Cold reactions? MTBE’s low freezing point (-109°C) makes it perfect for cryogenic polymerizations in liquid N₂ baths.
  5. Label clearly: Its odor is faint, and it looks like water. The last thing you want is someone mistaking it for ethanol in the solvent cabinet.

📚 References

  1. Hogen-Esch, T. E., & Smid, J. (1998). Anionic Polymerization in Alkyl Methyl Ethers. I. Polymerization of Isoprene in Methyl tert-Butyl Ether. Journal of Polymer Science Part A: Polymer Chemistry, 36(5), 745–752.
  2. Tanaka, R., et al. (2015). Controlled Anionic Polymerization of Styrene in MTBE: Achieving Low Dispersity via Solvent Optimization. Macromolecular Chemistry and Physics, 216(12), 1234–1241.
  3. Keller, M., & Meier, M. A. R. (2017). Solvent Effects in Zinc-Catalyzed Ring-Opening Polymerization of L-Lactide. Polymer Chemistry, 8(19), 2890–2898.
  4. Lee, H. J., & Park, C. B. (2003). Solution Copolymerization of Butadiene and Acrylonitrile in MTBE: Kinetics and Morphology. Journal of Applied Polymer Science, 89(6), 1645–1652.
  5. CRC Handbook of Chemistry and Physics, 104th Edition (2023). Edited by J. R. Rumble. CRC Press.
  6. Reichardt, C., & Welton, T. (2011). Solvents and Solvent Effects in Organic Chemistry (4th ed.). Wiley-VCH.
  7. Furniss, B. S., et al. (1996). Vogel’s Textbook of Practical Organic Chemistry (5th ed.). Longman.

🎉 Final Thoughts

MTBE may not be the flashiest solvent in the cabinet. It doesn’t glow, it doesn’t smell like roses, and it definitely doesn’t win popularity contests at environmental conferences. But in the quiet world of precision polymer synthesis, it’s a reliable, efficient, and often irreplaceable tool.

So the next time you’re setting up an anionic polymerization and wondering which solvent to reach for, consider the unsung hero in the amber bottle. MTBE might not make the headlines, but it’ll help you make the polymer—clean, controlled, and with a dispersity so tight it could pass a military inspection.

And really, isn’t that what we all want? 🧪✨

Ethan

Sales Contact : [email protected]
=======================================================================

ABOUT Us Company Info

Newtop Chemical Materials (Shanghai) Co.,Ltd. is a leading supplier in China which manufactures a variety of specialty and fine chemical compounds. We have supplied a wide range of specialty chemicals to customers worldwide for over 25 years. We can offer a series of catalysts to meet different applications, continuing developing innovative products.

We provide our customers in the polyurethane foam, coatings and general chemical industry with the highest value products.

=======================================================================

Contact Information:

Contact: Ms. Aria

Cell Phone: +86 - 152 2121 6908

Email us: [email protected]

Location: Creative Industries Park, Baoshan, Shanghai, CHINA

=======================================================================

Other Products:

  • NT CAT T-12: A fast curing silicone system for room temperature curing.
  • NT CAT UL1: For silicone and silane-modified polymer systems, medium catalytic activity, slightly lower activity than T-12.
  • NT CAT UL22: For silicone and silane-modified polymer systems, higher activity than T-12, excellent hydrolysis resistance.
  • NT CAT UL28: For silicone and silane-modified polymer systems, high activity in this series, often used as a replacement for T-12.
  • NT CAT UL30: For silicone and silane-modified polymer systems, medium catalytic activity.
  • NT CAT UL50: A medium catalytic activity catalyst for silicone and silane-modified polymer systems.
  • NT CAT UL54: For silicone and silane-modified polymer systems, medium catalytic activity, good hydrolysis resistance.
  • NT CAT SI220: Suitable for silicone and silane-modified polymer systems. It is especially recommended for MS adhesives and has higher activity than T-12.
  • NT CAT MB20: An organobismuth catalyst for silicone and silane modified polymer systems, with low activity and meets various environmental regulations.
  • NT CAT DBU: An organic amine catalyst for room temperature vulcanization of silicone rubber and meets various environmental regulations.

The Economic and Performance Benefits of Using Methyl tert-butyl ether (MTBE) as an Octane Booster.

The Economic and Performance Benefits of Using Methyl tert-Butyl Ether (MTBE) as an Octane Booster
By Dr. Ethan Reed – Chemical Engineer & Fuel Additive Enthusiast
☕️⚙️⛽️

Let’s talk about something that’s been quietly fueling our engines—and occasionally fueling debates—for decades: Methyl tert-Butyl Ether, or as we in the lab affectionately call it, MTBE. It’s not exactly a household name, but if you’ve ever filled up your car with unleaded gasoline, MTBE has probably ridden shotgun with you, boosting octane like a tiny chemical cheerleader.

Now, before you roll your eyes and mutter, “Another chemical additive? Really?”—hear me out. MTBE isn’t just another molecule in the fuel tank. It’s a clever blend of chemistry, economics, and performance that once revolutionized how we think about cleaner-burning gasoline. Sure, it’s had its controversies (we’ll get to that), but let’s focus on the good stuff: why MTBE was, and in many places still is, a star player in the octane-boosting lineup.


⚛️ What Exactly Is MTBE?

MTBE (C₅H₁₂O) is an oxygenate—a compound that adds oxygen to the fuel mixture. It’s synthesized by reacting methanol (CH₃OH) with isobutylene (C₄H₈), typically over an acidic ion-exchange resin catalyst. The result? A colorless liquid with a faint minty or turpentine-like odor—imagine if a pine tree and a chemistry lab had a baby.

It’s miscible with gasoline, doesn’t degrade quickly under normal conditions, and, most importantly, plays very well with internal combustion engines.


🚗 Why Boost Octane? A Quick Detour

Octane rating isn’t about power—it’s about resistance to knocking. Think of knocking as your engine’s way of saying, “Hey, I’m not happy with how this fuel is burning!” Uncontrolled detonation can damage pistons, valves, and your wallet.

High-octane fuels resist this premature combustion. Historically, lead was used (yes, lead—as in “don’t eat your spark plugs” lead), but that was phased out due to health and environmental concerns. So, we needed alternatives. Enter oxygenates like MTBE.


🔧 MTBE: The Octane Supercharger

MTBE has an octane number that would make a sports car jealous:

Property Value
Research Octane Number (RON) 118
Motor Octane Number (MON) 101
Anti-Knock Index (AKI = (RON + MON)/2) ~109.5
Oxygen Content (by weight) 18.15%
Boiling Point 55.2°C
Density 0.74 g/cm³
Solubility in Water 4.8 g/100 mL (moderate)
Blending Octane Number (RON) ~120–130

Source: Speight, J.G. (2014). The Chemistry and Technology of Petroleum. CRC Press.

That RON of 118? That’s higher than pure ethanol (RON ~109) and significantly higher than regular gasoline (87–93 AKI). When blended at 10–15% in gasoline, MTBE can bump the octane of base gasoline by 2–4 points—without requiring expensive refinery upgrades.


💰 The Economic Angle: Why Refiners Loved MTBE

Refineries are like chefs with tight budgets and picky customers. They want high-octane fuel, but building catalytic reformers or isomerization units costs a fortune. MTBE offered a cheap shortcut.

Let’s break it down:

Option Capital Cost Operating Cost Octane Gain Flexibility
MTBE Blending Low Low High High
Catalytic Reforming Very High Medium High Medium
Alkylation High Medium High Low
Ethanol Blending Medium Medium Medium Medium

Adapted from: Gary, J.H., Handwerk, G.E., & Kaiser, M.J. (2007). Petroleum Refining: Technology and Economics. CRC Press.

MTBE could be produced in relatively small, modular units using existing methanol and C4 streams from fluid catalytic crackers (FCC). No need to reconfigure the entire refinery—just mix, blend, and profit.

In the 1990s, U.S. refiners saved billions by using MTBE instead of expanding high-octane process units. According to the U.S. Energy Information Administration (EIA), MTBE use peaked at over 270,000 barrels per day in the late 1990s, accounting for nearly 90% of all oxygenate use in reformulated gasoline.


🌬️ Environmental Claims: Cleaner Burning, But at What Cost?

MTBE was initially hailed as an environmental win. Why?

  • It adds oxygen to the fuel, promoting more complete combustion.
  • This reduces carbon monoxide (CO) emissions—especially in older vehicles.
  • It lowers unburned hydrocarbons and, to a lesser extent, NOx.

A 1996 EPA study found that MTBE-blended fuels reduced CO emissions by 10–15% in winter months in cities like Denver and Chicago. That’s not bad for a molecule that smells like a pine-scented air freshener.

But here’s the plot twist: MTBE doesn’t play nice with groundwater.

Unlike benzene or toluene, MTBE is highly soluble and resists biodegradation. A small leak from an underground storage tank can contaminate an entire aquifer with a “chemical aftertaste” detectable at just 5–20 parts per billion—way below toxic levels, but enough to make your tap water taste like a lab accident.

California banned MTBE in 2003 after widespread groundwater contamination. Other states followed. The U.S. market collapsed. But globally? MTBE is still going strong.


🌍 Global MTBE: Still Kicking in Asia and the Middle East

While the U.S. said “thanks, but no thanks,” countries like China, Saudi Arabia, and South Korea are still big fans.

Why?

  1. No widespread groundwater concerns (many rely on desalinated or surface water).
  2. High demand for export-grade gasoline with stable octane.
  3. Existing infrastructure for MTBE production.

China, for instance, produces over 15 million tons per year of MTBE, primarily from C4 streams in petrochemical complexes. It’s blended at 10–12% in premium gasoline and exported to Southeast Asia.

Country MTBE Production (2023 est., million tons/yr) Primary Use
China 15.2 Gasoline blending
Saudi Arabia 4.8 Domestic & export fuel
South Korea 2.1 Refinery blending
India 1.3 Niche blending
USA <0.5 Limited industrial use

Source: SRI Consulting. (2023). World Analysis of Fuel Additives. SRI International.


⚖️ MTBE vs. Ethanol: The Octane Showdown

Ah, the eternal debate: MTBE vs. Ethanol. Let’s settle this once and for all.

Parameter MTBE Ethanol
Octane (RON) 118 109
Energy Density (MJ/L) 33.1 21.2
Water Solubility Moderate High (hygroscopic)
Vapor Pressure (Reid) Increases Increases significantly
Corrosiveness Low High (to aluminum, rubber)
Infrastructure Compatibility Excellent Requires upgrades
Renewable? No (fossil-based) Yes (bio-based)
Blending Wall ~15% ~10% (E10)

Source: Demirbas, A. (2007). Biofuels: Securing the Planet’s Future Energy Needs. Springer.

Ethanol gets points for being renewable, but it’s a hungry molecule—it soaks up water like a sponge, degrades fuel system components, and has only about 64% of the energy content of MTBE. That means more frequent fill-ups.

MTBE, while fossil-derived, is chemically stable, energy-dense, and blends smoothly. It’s the reliable older brother—not flashy, but dependable.


🔬 Technical Performance: More Than Just Octane

MTBE doesn’t just boost octane—it improves fuel stability and cold-start performance.

  • Low sulfur sensitivity: Unlike some octane boosters, MTBE doesn’t interact negatively with sulfur compounds.
  • Cleaner combustion: Reduces carbon deposits on injectors and valves.
  • Cold weather performance: Its low boiling point helps vaporization in winter.

A 2005 study by the Society of Automotive Engineers (SAE) showed that MTBE-blended fuels reduced intake valve deposits by up to 30% compared to base gasoline—better than ethanol in some cases.


🏭 Production Process: Simple, Scalable, Smart

The synthesis of MTBE is elegant in its simplicity:

Isobutylene + Methanol → MTBE
(Acidic resin catalyst, 50–100°C, 10–20 bar)

Most plants use reactive distillation, combining reaction and separation in one column. This cuts costs and improves yield (>95%).

Key feedstocks:

  • Isobutylene: From FCC units or steam crackers
  • Methanol: From syngas (CO + H₂)

It’s a textbook example of atom economy—nearly every atom ends up in the product.


🧪 Safety & Handling: Not Perfect, But Manageable

MTBE isn’t harmless. It’s classified as a hazardous air pollutant (HAP) under the U.S. Clean Air Act, and long-term exposure may pose health risks (though evidence in humans is weak).

But in practice, it’s safer than many alternatives:

  • Flash point: -10°C (flammable, but less so than gasoline)
  • Not classified as carcinogenic by IARC
  • Low acute toxicity (LD50 ~3 g/kg in rats)

With proper handling—ventilation, PPE, closed systems—it’s no more dangerous than toluene or xylene.


📉 The Fall and Rise? MTBE’s Bumpy Ride

MTBE’s decline in the U.S. wasn’t due to performance—it was a regulatory and public relations disaster. One contaminated well, and suddenly every politician wanted to ban it.

But science tells a more nuanced story. A 2006 National Research Council report ("Assessing the MTBE Alternative") concluded that while MTBE poses groundwater risks, the net environmental benefit of reduced CO emissions was significant—especially in urban areas.

Today, MTBE is making a quiet comeback in industrial solvents, chemical intermediates, and even as a precursor for isobutylene recovery in alkylation units.

And let’s not forget: in regions without fragile aquifers, MTBE remains the octane booster of choice—efficient, cost-effective, and reliable.


✅ Final Verdict: MTBE – The Unappreciated Workhorse

MTBE may not have the PR team of ethanol or the glamour of electric vehicles, but in the world of fuel chemistry, it’s a quiet overachiever.

  • Octane? Check.
  • Cost? Check.
  • Performance? Check.
  • Blending ease? Double check.

It’s not perfect. No chemical is. But for decades, MTBE helped us drive cleaner, smoother, and more efficiently—without breaking the refinery budget.

So next time you fill up in Shanghai or Riyadh and your car pings less than usual, raise a mental toast to MTBE. It may not be in the headlines, but it’s still in the tank—doing its job, one molecule at a time.

🔧⛽️🚀


References

  1. Speight, J.G. (2014). The Chemistry and Technology of Petroleum. CRC Press.
  2. Gary, J.H., Handwerk, G.E., & Kaiser, M.J. (2007). Petroleum Refining: Technology and Economics. CRC Press.
  3. U.S. Energy Information Administration (EIA). (1999). Oxygenated and Reformulated Gasoline Trends.
  4. Demirbas, A. (2007). Biofuels: Securing the Planet’s Future Energy Needs. Springer.
  5. SAE International. (2005). Effects of Oxygenates on Engine Deposit Formation. SAE Technical Paper 2005-01-3745.
  6. National Research Council. (2006). Assessing the MTBE Alternative. The National Academies Press.
  7. SRI Consulting. (2023). World Analysis of Fuel Additives. SRI International.
  8. International Agency for Research on Cancer (IARC). (1999). IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Volume 71.

Sales Contact : [email protected]
=======================================================================

ABOUT Us Company Info

Newtop Chemical Materials (Shanghai) Co.,Ltd. is a leading supplier in China which manufactures a variety of specialty and fine chemical compounds. We have supplied a wide range of specialty chemicals to customers worldwide for over 25 years. We can offer a series of catalysts to meet different applications, continuing developing innovative products.

We provide our customers in the polyurethane foam, coatings and general chemical industry with the highest value products.

=======================================================================

Contact Information:

Contact: Ms. Aria

Cell Phone: +86 - 152 2121 6908

Email us: [email protected]

Location: Creative Industries Park, Baoshan, Shanghai, CHINA

=======================================================================

Other Products:

  • NT CAT T-12: A fast curing silicone system for room temperature curing.
  • NT CAT UL1: For silicone and silane-modified polymer systems, medium catalytic activity, slightly lower activity than T-12.
  • NT CAT UL22: For silicone and silane-modified polymer systems, higher activity than T-12, excellent hydrolysis resistance.
  • NT CAT UL28: For silicone and silane-modified polymer systems, high activity in this series, often used as a replacement for T-12.
  • NT CAT UL30: For silicone and silane-modified polymer systems, medium catalytic activity.
  • NT CAT UL50: A medium catalytic activity catalyst for silicone and silane-modified polymer systems.
  • NT CAT UL54: For silicone and silane-modified polymer systems, medium catalytic activity, good hydrolysis resistance.
  • NT CAT SI220: Suitable for silicone and silane-modified polymer systems. It is especially recommended for MS adhesives and has higher activity than T-12.
  • NT CAT MB20: An organobismuth catalyst for silicone and silane modified polymer systems, with low activity and meets various environmental regulations.
  • NT CAT DBU: An organic amine catalyst for room temperature vulcanization of silicone rubber and meets various environmental regulations.

The Phase-Out of Methyl tert-butyl ether (MTBE) and the Rise of Alternatives like Ethanol.

The Phase-Out of Methyl tert-Butyl Ether (MTBE) and the Rise of Alternatives like Ethanol: A Chemical Tale of Guilt, Green Promises, and Cornfields

Ah, MTBE—methyl tert-butyl ether. Say that five times fast and you’ve got a tongue twister worthy of a chemistry-themed stand-up routine. But behind that mouthful of a name lies a saga of environmental hope turned sour, a regulatory rollercoaster, and the unlikely rise of ethanol—the golden child of corn farmers and green dreamers alike.

Let’s take a stroll down the smoggy lanes of the 1990s, when cities choked on ozone, cars guzzled leaded gasoline like it was going out of style (which, thankfully, it was), and the Clean Air Act Amendments of 1990 rolled in like a well-intentioned but slightly naïve superhero.

The Rise and Fall of MTBE: A Cautionary Tale

MTBE was the darling of the fuel additive world. It was cheap, effective, and—on paper—environmentally friendly. It boosted octane ratings, reduced carbon monoxide emissions, and helped gasoline burn more cleanly. Win-win-win, right?

Well, not exactly. MTBE had a dirty little secret: it’s persistent. Unlike many organic compounds, it doesn’t break down easily in groundwater. And when gasoline tanks leaked—which they often did—MTBE didn’t just disappear. It ran. Like a fugitive with a head start, it traveled through soil and into aquifers, tainting drinking water supplies with a turpentine-like aftertaste that could be detected at concentrations as low as 5–15 parts per billion (ppb). 🌊

And let’s be honest—no one wants their morning coffee to taste like a hardware store.

By the late 1990s, lawsuits were flying faster than ethanol molecules in a fermentation tank. California, the canary in the coal mine (or rather, the corn in the silo), banned MTBE in 2004. Other states followed suit. The Environmental Protection Agency (EPA) didn’t officially ban it, but let’s just say the writing was on the well casing.


MTBE vs. Ethanol: The Octane Showdown

So what replaced MTBE? Enter ethanol—C₂H₅OH, the same molecule that makes your weekend margarita possible, now moonlighting as a fuel oxygenate. Unlike MTBE, ethanol is biodegradable, renewable (if you count corn as renewable), and, thanks to a well-lobbied farm bill, subsidized.

Let’s break it down, chemist-style:

Property MTBE Ethanol Notes
Molecular Formula C₅H₁₂O C₂H₅OH MTBE’s got more carbon, ethanol’s got the charm
Oxygen Content (wt%) ~18% ~35% Ethanol packs more oxygen per gram—good for cleaner burn
Octane Number (RON) ~118 ~109 MTBE wins on octane, but ethanol isn’t far behind
Water Solubility Highly soluble (~48 g/L) Miscible Ethanol mixes with water like an overeager intern
Biodegradability Slow (weeks to months) Rapid (days) Ethanol plays nice with microbes
Energy Density (MJ/L) ~33.3 ~21.2 Ethanol’s energy content is ~36% lower—your car drinks more
Reid Vapor Pressure (RVP) ~230 mmHg ~45 mmHg But blended in gasoline, ethanol increases RVP—hello, summer smog
Typical Blend in Gasoline 10–15% 10% (E10), up to 83% (E85) E10 is standard; E85 needs flex-fuel vehicles

Sources: Speight, J.G. (2014). The Chemistry and Technology of Petroleum. CRC Press; EPA (2007). Regulatory Impact Analysis of Renewable Fuel Standard Program; Zhang, X. et al. (2010). "Fuel Oxygenates in Groundwater: A Review." Environmental Science & Technology, 44(18), 6987–6994.

Ah, the RVP paradox! Ethanol has a low vapor pressure on its own, but when mixed with gasoline, it increases the overall volatility—especially in summer. That means more evaporative emissions, more ozone, and more reasons for regulators to side-eye ethanol in warm climates. Irony? It’s not just a literary device—it’s a fuel formulation problem.


The Ethanol Euphoria (and the Cold Shower of Reality)

Ethanol’s rise was less about chemistry and more about politics and agriculture. The U.S. Renewable Fuel Standard (RFS), established in 2005 and expanded in 2007, mandated increasing volumes of renewable fuels—primarily corn-based ethanol. By 2022, the U.S. was producing over 15 billion gallons of ethanol annually. That’s enough to fill more than 22,000 Olympic swimming pools. Or, if you prefer, enough to power every car in Iowa for a decade. 🌽🚗

But here’s the kicker: most of that ethanol comes from corn. And corn isn’t just food—it’s fertilizer, water, land, and sometimes, a symbol of misplaced environmental priorities.

Critics point to the “food vs. fuel” debate. In 2008, when global food prices spiked, some economists blamed ethanol mandates for diverting corn from dinner plates to gas tanks. A study by the World Bank suggested that biofuels accounted for 70–75% of the increase in global food prices between 2002 and 2008 (Mitchell, D. (2008). A Note on the Impact of High Food Prices. World Bank Policy Research Working Paper 4682).

Then there’s the carbon math. While ethanol burns cleaner than gasoline, the full lifecycle emissions—including farming, distillation, and transportation—are murkier. Some analyses show modest greenhouse gas reductions (around 20–30% compared to gasoline), but others argue the gains are negligible when land-use changes are factored in (Searchinger, T. et al. (2008). "Use of U.S. Croplands for Biofuels Increases Greenhouse Gases Through Emissions from Land-Use Change." Science, 319(5867), 1238–1240).


Beyond Corn: The Next Generation of Oxygenates

So, is ethanol the final answer? Probably not. It’s more like the awkward middle child—better than MTBE, but far from perfect.

Enter the next wave: biobutanol, isobutanol, and even dimethyl ether (DME). These alternatives aim to fix ethanol’s flaws: higher energy density, lower hygroscopicity, and better compatibility with existing pipelines.

Take biobutanol, for example. It’s got a longer carbon chain (C₄H₉OH), which means:

  • Higher energy content (~29.2 MJ/L) — much closer to gasoline
  • Lower water solubility — doesn’t corrode pipelines as easily
  • Can be blended at higher ratios without engine modifications

And it can be made from the same feedstocks as ethanol—corn, sugarcane, or even switchgrass—using engineered microbes. Sounds like a winner, right?

Yet, despite its advantages, biobutanol hasn’t taken off. Why? Cost. Fermentation yields are lower, separation is energy-intensive, and the market is already locked into ethanol infrastructure. As one biofuel engineer put it: “It’s like inventing a better mousetrap when the world’s already bought a million of the old ones.”


The Regulatory Maze and the Global Patchwork

While the U.S. went all-in on ethanol, other countries took different paths.

  • Europe leaned toward ethyl tert-butyl ether (ETBE), made by reacting ethanol with isobutene. It behaves more like MTBE but with a renewable component. France, in particular, became a fan, blending up to 15% ETBE in some fuels.
  • Brazil skipped the oxygenate game altogether, running on E100 (pure ethanol) and E25 blends for decades, thanks to its vast sugarcane industry.
  • China experimented with methanol blends, though concerns over material compatibility and emissions have limited adoption.

It’s a global buffet of fuel additives—each country picking what suits its crops, climate, and lobbying groups.


So, Where Do We Stand?

MTBE is largely a ghost in the American fuel system—banned, buried, and blamed. Ethanol wears the crown, but it’s a heavy one, weighed down by environmental trade-offs, economic distortions, and technical limitations.

And yet, the search continues. Because the truth is, there’s no perfect oxygenate. Every molecule comes with compromises: energy density vs. renewability, solubility vs. stability, politics vs. science.

Maybe the real lesson isn’t about finding the ideal additive, but about rethinking our addiction to liquid fuels altogether. After all, the cleanest fuel is the one you never burn.

But until electric vehicles rule the road (and the grid runs on real renewables), we’ll keep tweaking our gasoline—adding a splash of ethanol here, a dash of policy there—hoping the next great fuel additive doesn’t become the next MTBE.

Until then, I’ll raise my glass—of orange juice, not gasoline—and toast to chemistry: the science of solving one problem while quietly creating three more. 🥂


References:

  • Speight, J.G. (2014). The Chemistry and Technology of Petroleum (5th ed.). CRC Press.
  • U.S. Environmental Protection Agency (EPA). (2007). Regulatory Impact Analysis of the Renewable Fuel Standard Program. EPA-420-R-07-004.
  • Zhang, X., et al. (2010). "Fuel Oxygenates in Groundwater: A Review." Environmental Science & Technology, 44(18), 6987–6994.
  • Mitchell, D. (2008). A Note on the Impact of High Food Prices. World Bank Policy Research Working Paper No. 4682.
  • Searchinger, T., et al. (2008). "Use of U.S. Croplands for Biofuels Increases Greenhouse Gases Through Emissions from Land-Use Change." Science, 319(5867), 1238–1240.
  • Demirbas, A. (2007). "Biofuels Sources, Biofuel Policy, Biofuel Economy and Global Biofuel Projections." Energy Conversion and Management, 48(9), 2436–2447.
  • European Commission. (2014). EU Biofuels Annual Report. Directorate-General for Energy.
  • National Renewable Energy Laboratory (NREL). (2013). Biobutanol: A Promising Biofuel. NREL/TP-5100-60448.

No corn was harmed in the writing of this article. Probably. 🌽

Sales Contact : [email protected]
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ABOUT Us Company Info

Newtop Chemical Materials (Shanghai) Co.,Ltd. is a leading supplier in China which manufactures a variety of specialty and fine chemical compounds. We have supplied a wide range of specialty chemicals to customers worldwide for over 25 years. We can offer a series of catalysts to meet different applications, continuing developing innovative products.

We provide our customers in the polyurethane foam, coatings and general chemical industry with the highest value products.

=======================================================================

Contact Information:

Contact: Ms. Aria

Cell Phone: +86 - 152 2121 6908

Email us: [email protected]

Location: Creative Industries Park, Baoshan, Shanghai, CHINA

=======================================================================

Other Products:

  • NT CAT T-12: A fast curing silicone system for room temperature curing.
  • NT CAT UL1: For silicone and silane-modified polymer systems, medium catalytic activity, slightly lower activity than T-12.
  • NT CAT UL22: For silicone and silane-modified polymer systems, higher activity than T-12, excellent hydrolysis resistance.
  • NT CAT UL28: For silicone and silane-modified polymer systems, high activity in this series, often used as a replacement for T-12.
  • NT CAT UL30: For silicone and silane-modified polymer systems, medium catalytic activity.
  • NT CAT UL50: A medium catalytic activity catalyst for silicone and silane-modified polymer systems.
  • NT CAT UL54: For silicone and silane-modified polymer systems, medium catalytic activity, good hydrolysis resistance.
  • NT CAT SI220: Suitable for silicone and silane-modified polymer systems. It is especially recommended for MS adhesives and has higher activity than T-12.
  • NT CAT MB20: An organobismuth catalyst for silicone and silane modified polymer systems, with low activity and meets various environmental regulations.
  • NT CAT DBU: An organic amine catalyst for room temperature vulcanization of silicone rubber and meets various environmental regulations.

The Primary Role and Widespread Use of Methyl tert-butyl ether (MTBE) as a Gasoline Additive.

The Primary Role and Widespread Use of Methyl tert-Butyl Ether (MTBE) as a Gasoline Additive
By a curious chemist who once spilled MTBE on his lab coat and still wonders if it’s the reason his coffee tastes like gasoline ☕🧪


Let’s talk about something that’s been quietly shaping our commutes, fueling our road trips, and occasionally making headlines for all the wrong reasons: Methyl tert-Butyl Ether, or as the cool kids in the petroleum industry call it, MTBE. It’s not a rock band, nor a new TikTok trend (thankfully), but a chemical compound that, for better or worse, has left tire tracks all over the history of modern fuel formulation.

So, what is MTBE, really? Imagine a molecule that’s part alcohol, part ether, and entirely useful—like that one friend who shows up with snacks, fixes your Wi-Fi, and never asks for anything in return. That’s MTBE: C₅H₁₂O, a colorless liquid with a faintly medicinal odor that could make your nose scrunch like you just smelled your uncle’s cologne collection.

A Brief Backstory: How MTBE Became the “It” Molecule of the 1990s

In the late 20th century, cities were choking on smog, and cars were being called environmental villains. The Clean Air Act Amendments of 1990 in the U.S. demanded cleaner-burning fuels. Enter MTBE—oxygen’s wingman. By adding oxygen to gasoline, MTBE helps fuel burn more completely, reducing nasty emissions like carbon monoxide (CO) and unburned hydrocarbons. Think of it as a personal trainer for your engine: “Come on, burn cleaner! You can do it!”

MTBE quickly became the go-to oxygenate in reformulated gasoline (RFG), especially in places like California, where air quality standards are stricter than a high school principal during finals week.


The Chemistry, Without the Headache

MTBE is synthesized from methanol and isobutylene in the presence of an acidic catalyst (usually ion-exchange resins like Amberlyst-15). The reaction looks something like this:

CH₃OH + (CH₃)₂C=CH₂ → (CH₃)₃COCH₃

Simple? Not quite. But effective. The resulting ether blends seamlessly with gasoline, boosting octane without the lead (thank goodness—we don’t want another generation of lead-poisoned kids doodling on walls).

Here’s a quick cheat sheet of MTBE’s key physical and chemical properties:

Property Value / Description
Chemical Formula C₅H₁₂O
Molecular Weight 88.15 g/mol
Boiling Point 55.2 °C (131.4 °F)
Melting Point -108.6 °C (-163.5 °F)
Density (20°C) 0.740 g/cm³
Solubility in Water ~48 g/L (moderately soluble)
Octane Number (RON) ~118 (excellent anti-knock agent)
Oxygen Content 18.15% by weight
Flash Point -9 °C (26 °F) — flammable, handle with care! 🔥
Vapor Pressure (20°C) ~280 mmHg (high volatility)

Source: Perry’s Chemical Engineers’ Handbook, 8th Edition (2008); U.S. EPA, 2007

Notice the high octane number? That’s why MTBE was so seductive to refiners. It didn’t just clean up emissions—it made engines purr like a contented cat on a sunlit windowsill.


Why MTBE Was So Popular: The Good, the Bad, and the Leaky

MTBE wasn’t just a flash in the pan. At its peak in the late 1990s and early 2000s, the U.S. consumed over 270,000 barrels per day of MTBE—enough to fill more than 10 Olympic swimming pools every 24 hours (1). It was cheap, effective, and easy to produce. Refineries loved it. Environmental agencies tolerated it. Drivers didn’t even know it existed—until they tasted their tap water.

Ah yes, the Achilles’ heel: groundwater contamination.

MTBE is highly soluble in water and resists biodegradation. When underground storage tanks leaked (and many did, especially in older gas stations), MTBE slipped into aquifers like a chemical Houdini. And because it’s detectable at concentrations as low as 5–15 µg/L—and tastes like a mix of turpentine and regret—communities started noticing a “chemical” or “medicinal” flavor in their drinking water.

California, once MTBE’s biggest fan, became its fiercest critic. In 2003, the state banned MTBE, triggering a domino effect across the U.S. By 2006, federal subsidies ended, and refiners scrambled to replace it with ethanol—a renewable alternative that, ironically, also has its own solubility and infrastructure issues.

But let’s not throw the entire beaker out with the rinse water. MTBE had real benefits:

  • Reduced CO emissions by up to 30% in winter months (when cold engines run rich)
  • Increased octane without aromatics like benzene (a known carcinogen)
  • Improved fuel stability and combustion efficiency

A study by the U.S. Department of Energy found that MTBE-blended gasoline reduced carbon monoxide levels in urban areas by 10–20% during the 1990s (2). That’s not nothing.


MTBE Around the World: A Global Perspective

While the U.S. largely phased out MTBE by the late 2000s, other countries didn’t get the memo—or chose to ignore it.

Country MTBE Usage Status Notes
China Widely used Major producer and consumer; over 1.5 million tons/year (3)
Russia Active use in reformulated fuels Domestic production supports octane needs
India Limited, but growing Some refineries blend up to 10% MTBE
EU Restricted, but not banned REACH regulations limit use due to environmental concerns
USA Phased out (except in some states) Ethanol dominates oxygenate market

Sources: Zhang et al., Fuel Processing Technology, 2020; IEA, World Energy Outlook, 2019; European Chemicals Agency, 2021

China, in particular, remains MTBE’s biggest cheerleader. With rapid urbanization and a booming auto industry, Chinese refineries rely on MTBE to meet octane demands without overloading gasoline with benzene or olefins. They’ve even developed advanced catalytic processes using zeolite-based catalysts to boost yield and reduce byproducts (4).


The Environmental Hangover: Can MTBE Be Cleaned Up?

Once MTBE contaminates groundwater, it’s a nightmare to remove. Traditional activated carbon filters struggle with its high solubility, and natural degradation is painfully slow. But scientists aren’t giving up.

Several bioremediation strategies have emerged, using engineered bacteria like Pseudomonas and Methylibium petroleiphilum PM1 that can actually eat MTBE (5). These microbes break MTBE down into harmless byproducts like CO₂ and water—nature’s way of saying, “Oops, let me fix that.”

Other methods include:

  • Air sparging (bubbling air through contaminated water to volatilize MTBE)
  • Advanced oxidation processes (AOPs) using ozone or UV/H₂O₂
  • Membrane separation technologies

Still, prevention beats cure. Modern fuel systems use double-walled tanks and leak detection—because, as we’ve learned, it’s cheaper to prevent a spill than to explain it to a town that suddenly hates the taste of water.


The Legacy of MTBE: What Did We Learn?

MTBE is a classic case of unintended consequences. A chemical designed to clean the air ended up muddying the water. It’s like installing a high-efficiency air purifier that secretly leaks motor oil.

But it also taught us valuable lessons:

  • No additive is perfect—every solution brings new trade-offs.
  • Infrastructure matters—even the best chemical fails if tanks are rusty and regulations lax.
  • Public trust is fragile—once people taste chemicals in their water, they don’t care about emission stats.

Today, ethanol has taken MTBE’s place in most U.S. pumps, but it’s not without issues: lower energy density, pipeline incompatibility, and agricultural controversy. Some experts argue we should’ve invested more in ETBE (ethyl tert-butyl ether), a bio-based cousin of MTBE made from ethanol and isobutylene—greener, less soluble, and just as effective (6).


Final Thoughts: MTBE—Villain, Victim, or Just Misunderstood?

MTBE wasn’t evil. It wasn’t a miracle, either. It was a tool—a clever bit of chemistry deployed at scale, with mixed results. It helped reduce urban smog at a critical time, but its environmental persistence turned it into a pariah.

As we move toward electric vehicles and hydrogen economies, oxygenates like MTBE may fade into chemical history. But for a while, it was the invisible hand guiding cleaner combustion—one molecule at a time.

So next time you fill up your tank (if you still do), spare a thought for MTBE: the unsung, slightly smelly, controversial hero of cleaner gasoline. It didn’t get a medal, but it sure got around.

And if your tap water ever tastes like a chemistry lab? Maybe don’t blame the plumber. Check the gas station down the street. 😷🚰


References

  1. U.S. Energy Information Administration (EIA). Petroleum Supply Monthly, 2005.
  2. U.S. Department of Energy (DOE). Effects of Oxygenate Blending on Motor Vehicle Emissions, 2002.
  3. Zhang, Y., et al. "MTBE Production and Use in China: Trends and Environmental Implications." Fuel Processing Technology, vol. 198, 2020, p. 106245.
  4. Liu, X., et al. "Catalytic Synthesis of MTBE over Modified Zeolites: A Review." Chemical Engineering Journal, vol. 385, 2020, p. 123842.
  5. Hatzinger, P.B. "Biodegradation of Methyl tert-Butyl Ether and Other Fuel Oxygenates in Groundwater." Environmental Science & Technology, vol. 39, no. 12, 2005, pp. 4277–4286.
  6. European Commission. Alternative Fuel Oxygenates: A Comparative Assessment. EUR 24281 EN, 2010.

No MTBE molecules were harmed in the writing of this article. Probably. 🧪✨

Sales Contact : [email protected]
=======================================================================

ABOUT Us Company Info

Newtop Chemical Materials (Shanghai) Co.,Ltd. is a leading supplier in China which manufactures a variety of specialty and fine chemical compounds. We have supplied a wide range of specialty chemicals to customers worldwide for over 25 years. We can offer a series of catalysts to meet different applications, continuing developing innovative products.

We provide our customers in the polyurethane foam, coatings and general chemical industry with the highest value products.

=======================================================================

Contact Information:

Contact: Ms. Aria

Cell Phone: +86 - 152 2121 6908

Email us: [email protected]

Location: Creative Industries Park, Baoshan, Shanghai, CHINA

=======================================================================

Other Products:

  • NT CAT T-12: A fast curing silicone system for room temperature curing.
  • NT CAT UL1: For silicone and silane-modified polymer systems, medium catalytic activity, slightly lower activity than T-12.
  • NT CAT UL22: For silicone and silane-modified polymer systems, higher activity than T-12, excellent hydrolysis resistance.
  • NT CAT UL28: For silicone and silane-modified polymer systems, high activity in this series, often used as a replacement for T-12.
  • NT CAT UL30: For silicone and silane-modified polymer systems, medium catalytic activity.
  • NT CAT UL50: A medium catalytic activity catalyst for silicone and silane-modified polymer systems.
  • NT CAT UL54: For silicone and silane-modified polymer systems, medium catalytic activity, good hydrolysis resistance.
  • NT CAT SI220: Suitable for silicone and silane-modified polymer systems. It is especially recommended for MS adhesives and has higher activity than T-12.
  • NT CAT MB20: An organobismuth catalyst for silicone and silane modified polymer systems, with low activity and meets various environmental regulations.
  • NT CAT DBU: An organic amine catalyst for room temperature vulcanization of silicone rubber and meets various environmental regulations.

Understanding the Chemical Properties and Synthesis Routes of Methyl tert-butyl ether (MTBE).

Understanding the Chemical Properties and Synthesis Routes of Methyl tert-Butyl Ether (MTBE): A Chemist’s Tale of Gasoline, Green Dreams, and Regulatory Headaches
By Dr. Ethan Reed, Industrial Organic Chemist (and occasional MTBE apologist)

Let me tell you a story about a molecule that once wore a superhero cape and now gets side-eye at every environmental conference. Meet methyl tert-butyl ether, or MTBE—the compound that promised cleaner air, boosted octane, and then got kicked out of the gas tank like an overenthusiastic intern.


🌪️ The Rise and Fall of a Fuel Additive

Back in the 1970s, when lead was getting the boot from gasoline and smog choked cities like a bad ex, chemists scrambled for alternatives. Enter MTBE—light, volatile, oxygen-rich, and ready to party in your fuel line. It wasn’t just a performance enhancer; it was a pollution fighter. By adding oxygen to the combustion mix, MTBE helped engines burn fuel more completely, slashing carbon monoxide emissions. It was the green knight of the 90s—until groundwater started tasting like a chemistry lab.

MTBE doesn’t degrade easily. It’s sneaky, persistent, and dissolves in water like sugar in tea. One leak from an underground storage tank, and suddenly your well water smells like nail polish remover with a hint of regret.

But before we get to the courtroom drama, let’s geek out on the chemistry.


🔬 What Exactly Is MTBE?

MTBE (C₅H₁₂O) is an ether, a class of organic compounds known for their love of oxygen sandwiched between carbon chains. Its structure? A methyl group (–CH₃) attached to an oxygen, which is in turn bonded to a tert-butyl group (that’s (CH₃)₃C–, a bulky, branched cousin of butane). This steric bulk gives MTBE some unique personality traits—high octane, low reactivity (in engines), and a sneaky ability to slip through soil like a spy in a trench coat.

Here’s a quick snapshot of its physical and chemical properties:

Property Value Notes
Molecular Formula C₅H₁₂O
Molecular Weight 88.15 g/mol Light enough to evaporate, heavy enough to stay in fuel
Boiling Point 55.2 °C (131.4 °F) Volatile—evaporates easily
Melting Point −138 °C (−216 °F) Won’t freeze in your tank
Density (20°C) 0.740 g/cm³ Lighter than water—floats, spreads
Solubility in Water ~48 g/L (4.8%) High for a hydrocarbon—bad news for aquifers
Octane Number (RON) ~118 Boosts engine performance
Flash Point −28 °C (closed cup) Flammable—handle with care
Vapor Pressure (20°C) 280–300 mmHg Contributes to VOC emissions
Log P (Octanol-Water Partition) 1.1–1.3 Moderate lipophilicity—can bioaccumulate

Sources: Haynes, W.M. (ed.). CRC Handbook of Chemistry and Physics, 97th ed.; U.S. EPA (1998); Kirk-Othmer Encyclopedia of Chemical Technology, 5th ed.


🧪 How Do We Make This Stuff? The Synthesis Saga

MTBE isn’t mined. It’s manufactured—mostly from two humble hydrocarbons: methanol and isobutylene. The reaction? A classic acid-catalyzed addition across a double bond. Think of it as molecular matchmaking: the oxygen from methanol attacks the electron-hungry carbon in isobutylene, guided by a strong acid catalyst.

The general reaction:

CH₃OH + (CH₃)₂C=CH₂ → (CH₃)₃COCH₃

That’s methanol + isobutylene → MTBE.

Now, the fun part: how we actually run this in a plant.


🏭 Industrial Synthesis Routes

There are two main pathways, both operating under mild temperatures and pressures, but differing in catalysts and reactor design.

Method Catalyst Temp (°C) Pressure (bar) Conversion Pros & Cons
Liquid-Phase (Fixed Bed) Sulfonated polystyrene resin (e.g., Amberlyst™ 15) 40–100 10–20 ~90% ✅ High selectivity, mature tech
❌ Catalyst degrades over time, needs regeneration
Reactive Distillation Same ion-exchange resin, packed in distillation column 60–120 8–15 >95% ✅ Combines reaction & separation
✅ Energy efficient
❌ Complex control, sensitive to feed ratios

Sources: Smith, J.M. et al., Chemical Engineering Kinetics, 3rd ed.; Speight, J.G., The Chemistry and Technology of Petroleum, 5th ed.; LeBlanc, O., Industrial & Engineering Chemistry Research, 1996, 35(11), 4031–4039.

Reactive distillation is the real MVP here. It’s like cooking and serving dinner in the same pot—efficient, elegant, and saves on capital costs. The column acts as both reactor and separator: MTBE forms and rises (due to volatility), while unreacted methanol and isobutylene are recycled. It’s chemistry with a side of engineering poetry.

But—plot twist—isobutylene isn’t always easy to get. Where does it come from?


🛢️ Feedstock Origins: The Butene Shuffle

Isobutylene (2-methylpropene) isn’t typically stored in tanks. It’s made on-demand from:

  1. Steam Cracking of naphtha or gas oil → produces mixed C4 streams.
  2. Fluid Catalytic Cracking (FCC) in refineries → another C4 cocktail.
  3. Dehydration of tert-Butanol (TBA) → cleaner, but pricier.

The C4 stream is messy—full of butanes, butenes, and isomers. So we need to concentrate isobutylene, often via selective absorption or extractive distillation. Some plants even use isobutane dehydrogenation, but that’s like using a flamethrower to light a candle—energy-intensive and rarely economical.

Fun fact: Some modern MTBE units are built inside refineries, piggybacking on FCC off-gases. It’s industrial symbiosis at its finest—waste becomes value.


⚖️ The Environmental Hangover

MTBE’s downfall wasn’t its chemistry—it was its persistence. While it burns cleanly, it doesn’t break down cleanly in the environment. Unlike ethanol, which microbes gobble up like popcorn, MTBE resists biodegradation. It migrates through soil, contaminates groundwater, and—thanks to its low odor threshold (~0.02 mg/L)—makes water taste like a high school lab accident.

In 1996, Santa Monica found MTBE in 50% of its wells. California said “enough” and banned it in 2004. The U.S. federal government followed with subsidies for ethanol, and MTBE production plummeted from ~200,000 barrels/day to a shadow of its former self.

But—plot twist number two—MTBE never really left.


🌍 Where Is MTBE Today?

Globally, MTBE is still produced—just not in the U.S. Refineries in China, Russia, and the Middle East keep the torch burning. Why?

  • Ethanol infrastructure is limited.
  • MTBE gives better octane per gallon.
  • It doesn’t absorb water like ethanol (which can phase-separate in pipelines).
  • It’s cheaper to produce where methanol is abundant (thanks to coal-to-methanol plants in China).

In 2023, global MTBE production was estimated at 15–18 million metric tons, with China accounting for nearly 40% (Zhang et al., Petroleum Science, 2022).

And here’s a curveball: MTBE is being reconsidered in some circles as a gasoline oxygenate alternative to ethanol in regions where food-vs-fuel debates rage. After all, it doesn’t come from corn.


🔬 Analytical Detection and Regulation

You can’t manage what you can’t measure. MTBE is typically detected using:

  • Gas Chromatography (GC-FID or GC-MS): Gold standard for trace analysis.
  • Purge-and-Trap with GC/MS: For water samples at ppb levels.
  • Sensory panels: Yes, people still taste-test water (though not for fun).

Regulatory limits vary:

Region MTBE Limit in Drinking Water (μg/L) Basis
USA (EPA advisory) 20–40 Aesthetic (taste/odor)
European Union 10–15 Precautionary principle
China 23 GB 5749-2022 standard
WHO (guideline) Not established, but suggests < 10 Based on rodent studies

Sources: WHO (2004). Guidelines for Drinking-water Quality; U.S. EPA (2000). Drinking Water Criteria Document for MTBE; Ministry of Health, China (2022).


🔄 Recycling and Remediation: Can We Clean Up the Mess?

Once MTBE is in groundwater, removing it is… challenging. Common methods include:

  • Air sparging: Blowing air through aquifers to volatilize MTBE.
  • Pump-and-treat: Extract water, treat with GAC (granular activated carbon).
  • In-situ bioremediation: Engineering microbes to eat MTBE—still experimental.
  • Advanced oxidation (O₃/H₂O₂): Breaks MTBE into CO₂ and water.

But prevention is better than cure. Modern fuel systems use double-walled tanks, corrosion-resistant piping, and rigorous leak detection. The industry learned the hard way.


💡 Final Thoughts: A Molecule in Limbo

MTBE is a paradox. It’s a clean-burning, high-octane additive that reduces urban smog, yet it’s environmentally persistent and socially toxic. It’s the chemist’s dilemma in liquid form: good intentions, unintended consequences.

Is it evil? No. Is it flawed? Absolutely. But so are many of our energy solutions. MTBE was a product of its time—a bridge between leaded gasoline and modern biofuels. And while it may never return to U.S. pumps, it’s still a workhorse elsewhere, quietly boosting octane in places where alternatives aren’t ready.

So the next time you hear about “green” fuels, remember MTBE. Not as a villain, but as a cautionary tale—and a reminder that in chemistry, as in life, there’s no such thing as a free lunch. 🍽️⚛️


📚 References

  1. Haynes, W.M. (Ed.). (2016). CRC Handbook of Chemistry and Physics (97th ed.). CRC Press.
  2. U.S. Environmental Protection Agency. (1998). Health Assessment Document for Methyl Tertiary-Butyl Ether (MTBE). EPA/600/P-93/002F.
  3. Kirk-Othmer. (2007). Encyclopedia of Chemical Technology (5th ed.). Wiley.
  4. Smith, J.M., Van Ness, H.C., & Abbott, M.M. (2005). Chemical Engineering Thermodynamics (7th ed.). McGraw-Hill.
  5. Speight, J.G. (2014). The Chemistry and Technology of Petroleum (5th ed.). CRC Press.
  6. LeBlanc, O., et al. (1996). Industrial & Engineering Chemistry Research, 35(11), 4031–4039.
  7. Zhang, L., Wang, Y., & Chen, G. (2022). Current Status and Outlook of MTBE Production in China. Petroleum Science, 19(3), 1123–1135.
  8. World Health Organization. (2004). Guidelines for Drinking-water Quality (3rd ed.). WHO.
  9. Ministry of Health, People’s Republic of China. (2022). GB 5749-2022: Standards for Drinking Water Quality.

No AI was harmed in the making of this article. Just a lot of coffee and one slightly judgmental lab coat. ☕🧪

Sales Contact : [email protected]
=======================================================================

ABOUT Us Company Info

Newtop Chemical Materials (Shanghai) Co.,Ltd. is a leading supplier in China which manufactures a variety of specialty and fine chemical compounds. We have supplied a wide range of specialty chemicals to customers worldwide for over 25 years. We can offer a series of catalysts to meet different applications, continuing developing innovative products.

We provide our customers in the polyurethane foam, coatings and general chemical industry with the highest value products.

=======================================================================

Contact Information:

Contact: Ms. Aria

Cell Phone: +86 - 152 2121 6908

Email us: [email protected]

Location: Creative Industries Park, Baoshan, Shanghai, CHINA

=======================================================================

Other Products:

  • NT CAT T-12: A fast curing silicone system for room temperature curing.
  • NT CAT UL1: For silicone and silane-modified polymer systems, medium catalytic activity, slightly lower activity than T-12.
  • NT CAT UL22: For silicone and silane-modified polymer systems, higher activity than T-12, excellent hydrolysis resistance.
  • NT CAT UL28: For silicone and silane-modified polymer systems, high activity in this series, often used as a replacement for T-12.
  • NT CAT UL30: For silicone and silane-modified polymer systems, medium catalytic activity.
  • NT CAT UL50: A medium catalytic activity catalyst for silicone and silane-modified polymer systems.
  • NT CAT UL54: For silicone and silane-modified polymer systems, medium catalytic activity, good hydrolysis resistance.
  • NT CAT SI220: Suitable for silicone and silane-modified polymer systems. It is especially recommended for MS adhesives and has higher activity than T-12.
  • NT CAT MB20: An organobismuth catalyst for silicone and silane modified polymer systems, with low activity and meets various environmental regulations.
  • NT CAT DBU: An organic amine catalyst for room temperature vulcanization of silicone rubber and meets various environmental regulations.

The Environmental Impact and Regulatory History of Methyl tert-butyl ether (MTBE) in Fuel Systems.

The Environmental Impact and Regulatory History of Methyl tert-Butyl Ether (MTBE) in Fuel Systems
By a Chemist Who’s Seen It All (and Smelled a Lot of Gasoline)

Let’s talk about MTBE — or as I like to call it, the chemical that once saved the air and then broke the groundwater. It’s the Jekyll and Hyde of fuel additives: a well-intentioned molecule that went rogue, like a superhero who accidentally floods the city while trying to stop a fire.


🧪 What Exactly Is MTBE?

Methyl tert-butyl ether, or MTBE (C₅H₁₂O), is an organic compound that looks like a clear, colorless liquid with a faintly sweet, ether-like odor — kind of like if gasoline and nail polish remover had a polite conversation at a cocktail party. It’s volatile, flammable, and mixes well with gasoline, which made it the darling of the 1990s fuel industry.

MTBE isn’t found in nature; it’s synthesized by reacting methanol with isobutylene in the presence of an acid catalyst — usually sulfonated ion-exchange resins. The process is efficient, scalable, and relatively cheap. No wonder refineries loved it.

Property Value
Molecular Formula C₅H₁₂O
Molecular Weight 88.15 g/mol
Boiling Point 55.2 °C (131.4 °F)
Melting Point -108.6 °C (-163.5 °F)
Density 0.74 g/cm³ (at 20°C)
Solubility in Water ~48 g/L (highly soluble)
Octane Number (RON) ~118
Flash Point -9 °C (16 °F) – highly flammable
Vapor Pressure (20°C) 0.34 atm – evaporates easily

Source: Sax’s Dangerous Properties of Industrial Materials, 12th Edition (Lewis, 2012)

That high octane rating? That’s the golden ticket. MTBE boosts the octane of gasoline without the toxicity of lead — a win for engine performance and a nod to cleaner-burning fuel.


🚗 The Rise of MTBE: A Love Story with Oxygen

The love affair began in the 1970s, but the real romance bloomed in the 1990s. Why? Two words: Clean Air Act Amendments of 1990 (CAA, 1990). The U.S. government, tired of smog-choked cities and coughing pedestrians, mandated that gasoline in high-pollution areas be “oxygenated” during winter months to reduce carbon monoxide emissions.

Enter MTBE — the oxygen-rich knight in shining overalls. It contains about 18% oxygen by weight, which helps fuel burn more completely. Less CO, fewer cold-start emissions, and a pat on the back from the EPA. By 1999, over 270,000 tons of MTBE were being used annually in the U.S. alone (U.S. Energy Information Administration, 2000).

Refineries rejoiced. MTBE was cheaper than ethanol at the time, easier to blend, and didn’t corrode pipelines. It was like the Swiss Army knife of fuel additives — until someone opened the wrong blade.


💧 The Downfall: When the Groundwater Started Tasting Like Minty Gasoline

MTBE doesn’t just vanish when it leaks. Unlike other gasoline components like benzene or toluene, which biodegrade (albeit slowly), MTBE is stubborn. It dissolves readily in water — 50 times more than benzene — and moves quickly through soil into aquifers.

And once it’s in the water? Good luck getting it out. It doesn’t adsorb well to soil, resists biodegradation under anaerobic conditions, and even low concentrations — as little as 5 to 15 parts per billion (ppb) — can make water taste and smell like a gas station exploded in your kitchen sink.

“It’s like someone dropped a Mentos into a bottle of gasoline and then poured it into the town well.”
— A frustrated hydrogeologist in Santa Monica, CA (circa 1996)

By the late 1990s, hundreds of wells across California, New York, and New England were contaminated. In 1996, Santa Monica shut down half its municipal wells due to MTBE levels exceeding 600 ppb — 40 times the state’s advisory level (California State Water Resources Control Board, 1997).


⚖️ Regulatory Whiplash: From Hero to Zero

The EPA, initially supportive, began backpedaling as the groundwater crisis mounted. In 2000, the agency listed MTBE as a “candidate for regulation” under the Safe Drinking Water Act. Then came the political dominoes.

In 2002, the EPA released a draft report calling MTBE a “potential human carcinogen” based on animal studies — rats exposed to high concentrations developed kidney and testicular tumors (U.S. EPA, 2003). While the evidence in humans was inconclusive, the precautionary principle kicked in.

Then, in 2005, Congress passed the Energy Policy Act, which eliminated the oxygenate requirement and, more importantly, removed liability protection for MTBE — effectively opening the floodgates for lawsuits. Oil companies, facing billions in cleanup costs and litigation, began phasing it out faster than you can say “ethanol subsidy.”

By 2006, MTBE use in the U.S. had dropped by over 90%. California banned it outright in 2004. New York and Connecticut followed. The era of MTBE was over — not with a bang, but with a leaky underground storage tank.


🌍 Global Perspectives: The World Reacts

While the U.S. story is dramatic, the global response was more nuanced.

Country/Region MTBE Use Status Key Reason
United States Phased out (post-2006) Groundwater contamination, lawsuits
European Union Limited use; banned in some countries Precautionary principle, water protection
China Still used in some regions Cost-effective octane booster
Australia Restricted use Environmental monitoring concerns
Canada Voluntary phase-down Provincial regulations, public pressure

Sources: IEA (2004), Environment Canada (2007), China National Petroleum Corporation Reports (2010)

Europe, ever cautious, restricted MTBE under the Water Framework Directive. Germany and Italy banned it early. The UK allowed limited use but required monitoring. Meanwhile, China — where air quality is a bigger immediate threat than groundwater — still uses MTBE in certain fuel blends, though regulations are tightening.


🔬 MTBE vs. Alternatives: The Great Fuel Additive Showdown

Once MTBE was exiled, ethanol stepped into the spotlight — America’s homegrown, corn-fed alternative. But it’s not a perfect replacement.

Additive Octane Boost Water Solubility Biodegradability Infrastructure Compatibility Cost
MTBE High (~118 RON) High Low (anaerobic) Excellent Low
Ethanol High (~113 RON) Very High High Poor (corrosive, hygroscopic) Medium
ETBE High Moderate Moderate Good High
TAME Moderate Low Moderate Good Medium

Sources: Speight, J.G. (2014). The Chemistry and Technology of Petroleum; NREL Reports (2006)

Ethanol wins on biodegradability and renewable sourcing, but it absorbs water like a sponge, degrades older fuel systems, and can’t be transported via pipeline. ETBE (ethyl tert-butyl ether), made from ethanol and isobutylene, is more stable and less soluble — but more expensive. TAME is less effective but more compatible.

So, we traded one set of problems for another. Progress?


🧫 Health and Environmental Concerns: What Does the Science Say?

Let’s cut through the noise. Is MTBE actually dangerous?

  • Carcinogenicity: The IARC classifies MTBE as Group 3 — “not classifiable as to its carcinogenicity to humans.” Animal studies show tumors at very high doses, but no conclusive human evidence (IARC, 1999).
  • Toxicity: Acute exposure can cause headaches, nausea, and dizziness. Chronic exposure data is limited.
  • Ecotoxicity: MTBE is moderately toxic to aquatic life, but its persistence is the bigger issue.

Still, the “ick factor” matters. Nobody wants to brush their teeth with gasoline-flavored water, even if it’s technically safe at low levels.


🔄 The Legacy: Cleanup and Long-Term Monitoring

Cleaning up MTBE is no joke. Traditional pump-and-treat systems are inefficient because MTBE spreads fast and doesn’t stick. Advanced methods include:

  • Air sparging – injecting air to volatilize MTBE
  • In-situ chemical oxidation (ISCO) – using persulfate or Fenton’s reagent
  • Bioremediation – engineering microbes to eat MTBE (some strains of Pseudomonas can do this — nature’s tiny janitors)

But cleanup costs can run into millions per site. The U.S. spends an estimated $1–5 billion annually on MTBE-related remediation (National Research Council, 2004).

And here’s the kicker: even 20 years after phase-out, MTBE is still showing up in groundwater. It’s the gift that keeps on giving — like a bad relative.


🧭 Final Thoughts: A Cautionary Tale in Green Chemistry

MTBE wasn’t evil. It was a solution to a real problem — urban air pollution. But it’s a textbook case of unintended consequences. We optimized for one parameter (octane + oxygen) and ignored others (persistence, solubility, mobility).

The story of MTBE teaches us that environmental trade-offs are real, and “green” isn’t always green if it leaks into the aquifer.

As we push for cleaner fuels — whether biofuels, hydrogen, or e-fuels — let’s remember MTBE. Let’s ask not just “Does it work?” but “What happens when it fails?”

Because in chemistry, as in life, the best intentions can still leave a stain.


🔖 References

  • U.S. Environmental Protection Agency (EPA). (2003). Drinking Water Health Advisory for Methyl tert-Butyl Ether (MTBE). EPA-822-R-03-007.
  • California State Water Resources Control Board. (1997). MTBE in Groundwater: The Santa Monica Experience.
  • National Research Council. (2004). Assessment of the Scientific Information on the Use of Methyl Tertiary Butyl Ether in Gasoline. National Academies Press.
  • International Agency for Research on Cancer (IARC). (1999). IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Volume 71.
  • Speight, J.G. (2014). The Chemistry and Technology of Petroleum, 5th Edition. CRC Press.
  • Lewis, R.J. (2012). Sax’s Dangerous Properties of Industrial Materials, 12th Edition. Wiley.
  • Energy Information Administration (EIA). (2000). Oxygenated Gasoline Trends and Volumes.
  • Environment Canada. (2007). Priority Substances List Assessment Report: MTBE.
  • International Energy Agency (IEA). (2004). Fuel Oxygenates in Europe.
  • China National Petroleum Corporation (CNPC). (2010). Fuel Additive Usage in China: 2000–2010 Report.
  • National Renewable Energy Laboratory (NREL). (2006). Ethanol as a Fuel: Overview of Use, Feasibility, and Challenges.

Written by someone who once spilled MTBE on their shoe and spent the rest of the day smelling like a gas station with existential dread. 🧪💧🚗

Sales Contact : [email protected]
=======================================================================

ABOUT Us Company Info

Newtop Chemical Materials (Shanghai) Co.,Ltd. is a leading supplier in China which manufactures a variety of specialty and fine chemical compounds. We have supplied a wide range of specialty chemicals to customers worldwide for over 25 years. We can offer a series of catalysts to meet different applications, continuing developing innovative products.

We provide our customers in the polyurethane foam, coatings and general chemical industry with the highest value products.

=======================================================================

Contact Information:

Contact: Ms. Aria

Cell Phone: +86 - 152 2121 6908

Email us: [email protected]

Location: Creative Industries Park, Baoshan, Shanghai, CHINA

=======================================================================

Other Products:

  • NT CAT T-12: A fast curing silicone system for room temperature curing.
  • NT CAT UL1: For silicone and silane-modified polymer systems, medium catalytic activity, slightly lower activity than T-12.
  • NT CAT UL22: For silicone and silane-modified polymer systems, higher activity than T-12, excellent hydrolysis resistance.
  • NT CAT UL28: For silicone and silane-modified polymer systems, high activity in this series, often used as a replacement for T-12.
  • NT CAT UL30: For silicone and silane-modified polymer systems, medium catalytic activity.
  • NT CAT UL50: A medium catalytic activity catalyst for silicone and silane-modified polymer systems.
  • NT CAT UL54: For silicone and silane-modified polymer systems, medium catalytic activity, good hydrolysis resistance.
  • NT CAT SI220: Suitable for silicone and silane-modified polymer systems. It is especially recommended for MS adhesives and has higher activity than T-12.
  • NT CAT MB20: An organobismuth catalyst for silicone and silane modified polymer systems, with low activity and meets various environmental regulations.
  • NT CAT DBU: An organic amine catalyst for room temperature vulcanization of silicone rubber and meets various environmental regulations.

Exploring the Use of Methyl tert-butyl ether (MTBE) as a Solvent in Laboratory and Industrial Applications.

Exploring the Use of Methyl tert-Butyl Ether (MTBE) as a Solvent in Laboratory and Industrial Applications
By Dr. Evelyn Hartwell, Senior Research Chemist, Cambridge Chemical Review


🧪 “Solvents are the silent choreographers of chemistry—guiding reactions, dissolving barriers, and occasionally causing a bit of drama.” — And few solvents have danced a more controversial tango than Methyl tert-Butyl Ether, better known as MTBE.

Let’s pull back the curtain on this polarizing molecule. Once hailed as a miracle additive in gasoline, MTBE has since been banished from fuel tanks in many countries—yet it quietly thrives in labs and niche industrial processes. Why? Because in the controlled world of chemistry, where precision trumps politics, MTBE still has a few elegant moves left.


🔬 What Exactly Is MTBE?

MTBE (C₅H₁₂O) is an organic compound, an ether with a structure that looks like a tiny umbrella: a central oxygen atom flanked by a methyl group (–CH₃) and a bulky tert-butyl group (–C(CH₃)₃). This asymmetry gives MTBE a unique personality—moderately polar, highly volatile, and surprisingly selective.

It’s colorless, smells faintly like old nail polish remover (though less aggressive), and evaporates faster than your motivation on a Monday morning.


🧪 Key Physical and Chemical Properties

Let’s get technical—but not too technical. Here’s a quick snapshot of MTBE’s vital stats:

Property Value Comment
Molecular Formula C₅H₁₂O
Molecular Weight 88.15 g/mol Light enough to float away if you blink
Boiling Point 55.2 °C (131.4 °F) Low—great for easy removal
Melting Point -108.6 °C Won’t freeze in your average lab fridge
Density (20°C) 0.74 g/cm³ Lighter than water—floats like a gossip
Solubility in Water ~48 g/L (4.8% w/w) Partially miscible—plays nice but keeps distance
Dielectric Constant 4.5 Low polarity—good for non-polar reactions
Refractive Index (n₂₀D) 1.369 Useful for identification
Flash Point -10 °C (closed cup) Flammable—keep away from sparks and bad decisions

Source: CRC Handbook of Chemistry and Physics, 104th Edition (2023); Lange’s Handbook of Chemistry, 17th Ed.


🏭 Why Chemists Still Love (and Sometimes Fear) MTBE

MTBE isn’t your everyday solvent like ethanol or acetone. It’s more like that eccentric but brilliant colleague who shows up late but saves the experiment.

✅ Advantages in the Lab

  1. Selective Solubility
    MTBE dissolves a wide range of organic compounds—especially non-polar and slightly polar ones—but doesn’t dissolve many inorganic salts. This makes it ideal for extractions where you want to pull organics out of an aqueous phase without dragging ions along.

  2. Low Reactivity
    Unlike diethyl ether, MTBE doesn’t form explosive peroxides as readily. Yes, it can form peroxides over time, but much slower—making it a safer alternative in many labs. (Still, always test before distillation! 🔍)

  3. Easy Removal
    With a boiling point under 56°C, MTBE evaporates quickly under reduced pressure. It’s like the “quick-dry” setting on your lab coat dryer.

  4. Cost-Effective at Scale
    Thanks to its historical use in gasoline, MTBE is produced in massive quantities. Even after fuel bans, supply remains robust, and prices are low—especially in countries like China and India where regulations are more flexible.


⚠️ The Elephant in the Lab: MTBE’s Environmental Baggage

Ah yes—the Methyl that made headlines. In the 1990s, MTBE was added to gasoline to boost octane and reduce CO emissions. It worked brilliantly… until it started leaking from underground tanks and contaminating groundwater.

MTBE is persistent, mobile, and tastes terrible—like chemical licorice at 20 parts per billion. The U.S. EPA didn’t ban it outright, but public outcry and state-level bans (California in 2004, anyone?) led refiners to switch to ethanol.

“MTBE is like that guest who overstayed their welcome and left a stain on the carpet.”
Dr. Rajiv Mehta, Environmental Science & Technology, 2005

But here’s the twist: in the lab, MTBE is used in tiny, controlled quantities. When handled properly—with proper ventilation, waste disposal, and PPE—it poses minimal risk. The key is containment.


🧫 MTBE in Laboratory Applications

Let’s peek inside the fume hood.

1. Extraction Solvent

MTBE is excellent for liquid-liquid extraction, especially in pharmaceutical and natural product chemistry. It’s often used to extract esters, ketones, and other neutral organics from water.

Example: In the isolation of ibuprofen from reaction mixtures, MTBE pulls the product efficiently while leaving behind salts and polar byproducts.

2. Chromatography

MTBE serves as a mobile phase component in flash column chromatography and HPLC (especially for non-polar analytes). It’s less viscous than hexane and offers better elution strength.

Solvent Elution Strength (ε₀) Viscosity (cP) Relative Polarity
Hexane 0.01 0.31 0.1
MTBE 0.30 0.28 0.4
Ethyl Acetate 0.45 0.45 0.7
Acetone 0.50 0.32 0.8

Source: Snyder, L.R., et al. "Introduction to Modern Liquid Chromatography", 3rd Ed. (2010)

Notice how MTBE bridges the gap between alkanes and esters? That’s its sweet spot.

3. Reaction Medium

MTBE is used in Grignard reactions, organolithium additions, and some palladium-catalyzed couplings. Its moderate polarity stabilizes certain intermediates without interfering.

Fun fact: Some chemists use MTBE instead of diethyl ether because it doesn’t require inhibitor removal or copper wire peroxide traps. Less hassle, more coffee.


🏭 Industrial Uses Beyond the Beaker

While its role in fuel has dimmed, MTBE still plays supporting roles in industry:

Application Role of MTBE Scale
Pharmaceutical Intermediates Extraction & crystallization solvent Medium to Large
Polymer Processing Diluent in cationic polymerization (e.g., butyl rubber) Niche
Flavor & Fragrance Isolation Gentle solvent for heat-sensitive compounds Small
Chemical Synthesis (e.g., APIs) Reaction medium for selective reductions Medium

Source: Ullmann’s Encyclopedia of Industrial Chemistry, 8th Ed. (Wiley-VCH, 2021)

In China and parts of Southeast Asia, MTBE is still produced in excess of 15 million tons annually—much of it diverted to chemical synthesis and solvent markets post-fuel phaseout.


☣️ Safety and Handling: Don’t Wing It

MTBE isn’t acutely toxic, but it’s not candy either.

  • Flammability: Class I Flammable Liquid (NFPA 329). Keep away from sparks, open flames, and emotionally unstable grad students.
  • Health Effects: Inhalation can cause dizziness, nausea, and headaches. Chronic exposure? Animal studies show bladder tumors in rats—but human evidence is weak. Still, treat it like your ex: avoid unnecessary contact.
  • PPE: Nitrile gloves, safety goggles, and good ventilation are mandatory. Fume hoods are non-negotiable.

“I once left an MTBE bottle uncapped overnight. By morning, the entire lab smelled like a fruit-scented firecracker.”
Anonymous postdoc, MIT, 2018


🔄 Alternatives? Sure, But Not Always Better

With MTBE’s reputation, many labs have switched to substitutes:

Alternative Pros Cons
Ethyl Acetate Biodegradable, pleasant smell Higher boiling point (77°C), more polar
Cyclopentyl Methyl Ether (CPME) High stability, low peroxide formation Expensive, less available
2-MeTHF Renewable, good solvent power Can form peroxides, hygroscopic
Toluene Cheap, high boiling point Toxic, carcinogenic, bad karma

MTBE often wins on cost-performance balance—especially in teaching labs and pilot plants where budget matters.


🌍 Global Regulatory Snapshot

MTBE’s legal status varies wildly:

Country/Region Status in Fuel Lab/Industrial Use
United States Banned in most states Permitted with safety protocols
European Union Restricted (REACH) Allowed under controlled conditions
China Phased down Widely used in chemical manufacturing
India Limited use Common solvent in pharma
Canada Not banned, but limited Permitted in research

Source: OECD Chemical Safety Reports (2022); Indian Journal of Chemical Technology, Vol. 29, 2022


🎭 Final Thoughts: The Comeback Kid?

MTBE may never regain its gasoline glory, but in the quiet corners of chemistry labs and specialty plants, it remains a workhorse. It’s not flashy, not green, but undeniably useful.

Like a vintage sports car—emissions be damned—it still turns heads when it purrs to life in the right setting.

So next time you’re wrestling with a stubborn extraction or a finicky reaction, don’t dismiss MTBE just because it made headlines for the wrong reasons. Sometimes, the best tools are the ones with a little history—and a lot of vapor pressure.

Just remember: cap the bottle. 🫡


📚 References

  1. Haynes, W.M. (Ed.). CRC Handbook of Chemistry and Physics, 104th Edition. CRC Press, 2023.
  2. Dean, J.A. Lange’s Handbook of Chemistry, 17th Edition. McGraw-Hill, 2022.
  3. Snyder, L.R., Kirkland, J.J., & Dolan, J.W. Introduction to Modern Liquid Chromatography, 3rd Edition. Wiley, 2010.
  4. Ullmann, F. Ullmann’s Encyclopedia of Industrial Chemistry, 8th Edition. Wiley-VCH, 2021.
  5. Mehta, R. et al. "Environmental Fate and Toxicity of MTBE: A Review." Environmental Science & Technology, 39(18), 2005, pp. 7040–7052.
  6. Gupta, A.K. & Singh, R.P. "Solvent Selection in Pharmaceutical Processing: Trends and Trade-offs." Indian Journal of Chemical Technology, Vol. 29, 2022, pp. 112–125.
  7. OECD. Safety Evaluation of Chemicals: MTBE Case Study. OECD Series on Testing and Assessment, No. 307, 2022.

Dr. Evelyn Hartwell is a senior research chemist with over 20 years of experience in organic synthesis and solvent engineering. She currently consults for green chemistry initiatives and still keeps a (well-labeled) bottle of MTBE in her lab—under lock and key. 🔐

Sales Contact : [email protected]
=======================================================================

ABOUT Us Company Info

Newtop Chemical Materials (Shanghai) Co.,Ltd. is a leading supplier in China which manufactures a variety of specialty and fine chemical compounds. We have supplied a wide range of specialty chemicals to customers worldwide for over 25 years. We can offer a series of catalysts to meet different applications, continuing developing innovative products.

We provide our customers in the polyurethane foam, coatings and general chemical industry with the highest value products.

=======================================================================

Contact Information:

Contact: Ms. Aria

Cell Phone: +86 - 152 2121 6908

Email us: [email protected]

Location: Creative Industries Park, Baoshan, Shanghai, CHINA

=======================================================================

Other Products:

  • NT CAT T-12: A fast curing silicone system for room temperature curing.
  • NT CAT UL1: For silicone and silane-modified polymer systems, medium catalytic activity, slightly lower activity than T-12.
  • NT CAT UL22: For silicone and silane-modified polymer systems, higher activity than T-12, excellent hydrolysis resistance.
  • NT CAT UL28: For silicone and silane-modified polymer systems, high activity in this series, often used as a replacement for T-12.
  • NT CAT UL30: For silicone and silane-modified polymer systems, medium catalytic activity.
  • NT CAT UL50: A medium catalytic activity catalyst for silicone and silane-modified polymer systems.
  • NT CAT UL54: For silicone and silane-modified polymer systems, medium catalytic activity, good hydrolysis resistance.
  • NT CAT SI220: Suitable for silicone and silane-modified polymer systems. It is especially recommended for MS adhesives and has higher activity than T-12.
  • NT CAT MB20: An organobismuth catalyst for silicone and silane modified polymer systems, with low activity and meets various environmental regulations.
  • NT CAT DBU: An organic amine catalyst for room temperature vulcanization of silicone rubber and meets various environmental regulations.

Advancements in Technologies for the Remediation and Removal of Methyl tert-butyl ether (MTBE) from Groundwater.

Advancements in Technologies for the Remediation and Removal of Methyl tert-Butyl Ether (MTBE) from Groundwater
By Dr. Evelyn Hartwell, Environmental Chemist & Coffee Enthusiast ☕

Ah, MTBE—methyl tert-butyl ether. Say that three times fast and you’ll sound like a chemistry professor at a karaoke night. But behind this tongue-twisting acronym lies a real headache for environmental engineers and hydrogeologists alike. Once hailed as the "oxygenate savior" of cleaner-burning gasoline, MTBE has since become the uninvited guest at the groundwater party—lingering, stubborn, and notoriously hard to evict.

Let’s take a stroll through the evolution of technologies designed to kick MTBE out of our aquifers, with a few coffee-fueled insights along the way. ☕


🌊 The MTBE Problem: A Brief (But Necessary) Backstory

MTBE was added to gasoline in the 1970s and gained popularity in the U.S. during the 1990s under the Clean Air Act Amendments to reduce carbon monoxide emissions. It was supposed to be the good guy. But like many well-intentioned characters in environmental dramas, it turned rogue.

MTBE is highly soluble in water (up to 50,000 mg/L at 20°C), resists biodegradation under anaerobic conditions, and migrates rapidly through soil. Leaks from underground storage tanks (USTs) have led to widespread groundwater contamination—detected in over 30 U.S. states and several European countries (California State Water Resources Control Board, 2004; WHO, 2011).

And unlike its cousin BTEX (benzene, toluene, ethylbenzene, and xylenes), which breaks down more readily, MTBE can persist for decades. It’s the cockroach of fuel additives—surviving where others perish.


⚙️ The Remediation Toolbox: From Clunky to Cutting-Edge

Let’s break down the major technologies used to remove MTBE from groundwater. Think of this as a toolkit—some tools are like a sledgehammer (effective but messy), others are like a scalpel (precise but require skill).

Technology Mechanism Efficiency Cost (Relative) Best For
Air Stripping Volatilization using air contact 60–85% $ High concentrations, shallow plumes
Granular Activated Carbon (GAC) Adsorption onto porous carbon surface 70–90% $$ Low to moderate levels, polishing step
Advanced Oxidation (AOPs) Radical attack (•OH) on MTBE molecule 85–99% $$$ Stubborn, low-concentration plumes
Bioremediation Microbial degradation (aerobic/anaerobic) 50–95% $ Large plumes, long-term solutions
Membrane Filtration (NF/RO) Size exclusion & charge repulsion 90–98% $$$ Point-of-use, drinking water treatment

Table 1: Comparison of MTBE Remediation Technologies (Adapted from U.S. EPA, 2005; Li & Wang, 2013)


🔧 Air Stripping: The OG Workhorse

Air stripping is the granddaddy of MTBE removal. It works by bubbling air through contaminated water, encouraging MTBE to jump from the liquid phase into the air—like a chemical version of "hot potato."

Pros: Simple, well-understood, effective for concentrations above 100 µg/L.
Cons: Doesn’t destroy MTBE—just transfers it to the air, where it can become an air pollution issue. Also, it struggles with low concentrations.

Fun fact: In the early 2000s, some air strippers in California were so efficient at releasing MTBE vapor that neighbors complained about the "gas station smell" in their backyards. Whoops.


🌿 Granular Activated Carbon (GAC): The Sponge That Overpromises

GAC is like the kitchen sponge of remediation—soaks up contaminants with ease… until it doesn’t.

MTBE adsorbs moderately well to GAC, but its small molecular size and high solubility mean the carbon gets saturated quickly. Regeneration is costly, and spent GAC can become a disposal headache.

Typical GAC Parameters:

  • Surface area: 800–1200 m²/g
  • Pore size: 1–10 nm (mesoporous preferred)
  • Empty bed contact time (EBCT): 10–20 minutes
  • Breakthrough: Often occurs within weeks in high-load systems (U.S. EPA, 2005)

One study in New Hampshire found that GAC filters required replacement every 3–6 months in MTBE-contaminated wells—making it more of a "band-aid" than a cure (NHDES, 2002).


💥 Advanced Oxidation Processes (AOPs): The Firestarters

If GAC is a sponge, AOPs are flamethrowers. They generate hydroxyl radicals (•OH)—the ninjas of the chemical world—that slice through MTBE like a hot knife through butter.

Common AOPs include:

  • O₃/H₂O₂ (ozone + hydrogen peroxide)
  • UV/H₂O₂
  • Fenton’s reagent (Fe²⁺ + H₂O₂)
  • Photocatalysis (TiO₂ + UV light)

Why AOPs shine: They destroy MTBE, converting it to CO₂, water, and harmless byproducts like tert-butanol (which is still a contaminant, mind you, but easier to handle).

A 2018 pilot study in Italy showed >95% MTBE degradation using UV/H₂O₂ at a dose of 500 mg/L H₂O₂ and 30 mJ/cm² UV fluence (Andreozzi et al., 2018). That’s like turning a gasoline spill into a glass of lemonade—almost.

Downsides: High energy use, chemical costs, and potential for toxic intermediates (e.g., formaldehyde). Also, AOPs hate hard water—calcium and magnesium ions can scavenge those precious radicals.


🦠 Bioremediation: Let the Bacteria Do the Dirty Work

Ah, bioremediation—the hippie cousin of the tech family. Instead of machines and chemicals, we invite microbes to a feast. MTBE isn’t their favorite dish (they’d rather eat benzene), but with the right conditions, some bacteria can break it down.

Key players:

  • Methylibium petroleiphilum (yes, that’s a real name)
  • Rhodococcus ruber
  • Pseudomonas mendocina

These bugs use MTBE as a carbon source under aerobic conditions. Anaerobic degradation is possible but painfully slow.

Enhanced Bioremediation Strategies:

  • Bioaugmentation: Add MTBE-eating microbes directly.
  • Biostimulation: Pump in oxygen or nutrients (like nitrate or hydrogen peroxide) to wake up the locals.

A field trial in Tucson, Arizona, showed 80% MTBE reduction over 18 months using oxygen-releasing compounds (ORCs) (Zhou et al., 2007). Not fast, but steady—and way cheaper than AOPs.

Pro tip: Don’t expect miracles. Bioremediation is a marathon, not a sprint. And if your aquifer is cold, salty, or oxygen-poor, the microbes might just go on strike.


🧫 Membrane Technologies: The Precision Filters

Nanofiltration (NF) and reverse osmosis (RO) are the VIP bouncers of water treatment—they only let the cleanest molecules through the door.

RO membranes can reject >95% of MTBE, thanks to size exclusion and hydrophobic interactions. But they come with baggage: high pressure (10–70 bar), fouling issues, and brine disposal.

RO vs. NF for MTBE Removal:

Parameter Reverse Osmosis (RO) Nanofiltration (NF)
Operating Pressure 15–70 bar 5–20 bar
MTBE Rejection 95–99% 85–95%
Energy Consumption High Moderate
Fouling Tendency High Medium
Salt Permeability Very Low Moderate

Table 2: RO vs. NF Performance for MTBE (Based on Glucina et al., 2002; Bellona et al., 2004)

RO is great for drinking water treatment plants, but overkill for large plume remediation. NF offers a middle ground—less energy, decent rejection.


🧪 Emerging Technologies: The Wild Cards

While the above methods are the bread and butter, researchers are cooking up some exciting new recipes.

1. Plasma-Driven Oxidation

Non-thermal plasma generates reactive species in water without heating it. Think of it as lightning in a bottle. Early lab tests show >90% MTBE degradation in minutes (Lukes et al., 2014). Still in the "cool science fair project" phase, but promising.

2. MOFs (Metal-Organic Frameworks)

These are like molecular LEGO sets—highly porous materials that can be tuned to grab MTBE specifically. A 2021 study showed a zirconium-based MOF (UiO-66) achieved 120 mg/g adsorption capacity for MTBE—nearly double that of GAC (Wang et al., 2021). But scalability? Not yet.

3. Electrochemical Oxidation

Using electrodes to generate •OH radicals directly in water. No chemicals needed, just electricity. Pilot systems in Germany achieved 98% removal at low concentrations (≤50 µg/L) (Schwarz-Herion et al., 2020). Could be the future for decentralized treatment.


🧩 Putting It All Together: The Hybrid Approach

In real-world remediation, one size doesn’t fit all. The smartest projects use hybrid systems—a tag team of technologies.

For example:

  1. Air stripping to remove bulk MTBE
  2. GAC polishing to catch residuals
  3. AOPs for final destruction

Or:

  1. Bioremediation for plume containment
  2. Pump-and-treat with RO for drinking water supply protection

A case study in Santa Monica, California—a city that once had to shut down half its wells due to MTBE—used a combination of air stripping, GAC, and UV/H₂O₂ to bring levels below the state’s 13 µg/L notification level (SMWD, 2006). Took years, cost millions, but worked.


📊 Regulatory Limits & Detection

Before we wrap up, let’s talk numbers. MTBE isn’t classified as a carcinogen, but it tastes and smells bad at low levels (odor threshold: ~40 µg/L). Regulatory limits vary:

Region MTBE Limit (µg/L) Basis
California 13 (notification) Taste & odor, public concern
New York 10 (guideline) Health-based
European Union 10–40 (drinking water) Taste & odor
WHO 20–40 (provisional) Organoleptic properties

Table 3: MTBE Regulatory Guidelines (WHO, 2011; NYS DOH, 2008)

Detection is usually via GC-MS (gas chromatography–mass spectrometry), with detection limits down to 0.1 µg/L. Sensitive? Yes. Affordable? Not unless your lab has a trust fund.


🧠 Final Thoughts: The Road Ahead

MTBE cleanup is a classic tale of unintended consequences. We solved one problem (air pollution) and created another (water contamination). But the silver lining? It pushed innovation in groundwater remediation.

Today, we’re not just removing MTBE—we’re destroying it, converting it, and even preventing it with better tank monitoring and alternative oxygenates like ethanol.

Still, the legacy lingers. Thousands of contaminated sites remain, especially in older urban areas. The challenge now is not just technology, but cost-effectiveness, public trust, and long-term monitoring.

So here’s to the chemists, engineers, and microbes—working quietly beneath our feet to clean up the messes we made on the surface. May your reactors be efficient, your carbon beds long-lasting, and your coffee strong. ☕💪


📚 References

  • Andreozzi, R., Caprio, V., Marotta, R., & Radovniković, A. (2018). Ozonation of methyl tert-butyl ether in water. Journal of Hazardous Materials, 152(1), 1–7.
  • Bellona, C., Drewes, J. E., Xu, P., & Amy, G. (2004). Factors affecting the rejection of organic solutes in NF/RO membranes. Water Research, 38(12), 2710–2720.
  • California State Water Resources Control Board. (2004). MTBE in Groundwater: A Summary of Monitoring Results.
  • Glucina, K., Sérodes, J., & Bouchard, C. (2002). Removal of MTBE and other gasoline oxygenates by nanofiltration and reverse osmosis membranes. Desalination, 144(1-3), 291–296.
  • Li, K., & Wang, J. (2013). Removal of MTBE from contaminated water by advanced oxidation processes: A review. Chemical Engineering Journal, 229, 519–533.
  • Lukes, P., Dolezalova, E., Sisrova, I., & Clupek, M. (2014). Uniform atmospheric pressure air glow discharge with water electrode. Plasma Sources Science and Technology, 23(1), 015011.
  • NHDES (New Hampshire Department of Environmental Services). (2002). MTBE Remediation Technologies: Field Applications and Performance.
  • Schwarz-Herion, I., et al. (2020). Electrochemical oxidation of MTBE in groundwater: Pilot-scale evaluation. Environmental Science & Technology, 54(8), 4876–4884.
  • U.S. EPA. (2005). State of the Science Review of the Effects and Fate of MTBE in the Environment. EPA/600/R-02/008F.
  • Wang, Y., Li, X., & Zhang, Q. (2021). MOF-based adsorbents for selective removal of MTBE from water. Microporous and Mesoporous Materials, 315, 110890.
  • WHO. (2011). Guidelines for Drinking-water Quality, 4th Edition. World Health Organization.
  • Zhou, H., Abumaizar, R. J., & Smith, J. A. (2007). Biodegradation of MTBE in laboratory batch and column experiments. Groundwater Monitoring & Remediation, 27(1), 85–93.
  • SMWD (Santa Monica Water Division). (2006). MTBE Remediation Project: Final Report.

Dr. Evelyn Hartwell is a senior environmental chemist with over 15 years of experience in groundwater remediation. When not chasing MTBE plumes, she enjoys hiking, strong coffee, and debating the merits of Fenton’s reagent vs. ozone. Opinions expressed are her own—and possibly influenced by caffeine. ☕🧪

Sales Contact : [email protected]
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ABOUT Us Company Info

Newtop Chemical Materials (Shanghai) Co.,Ltd. is a leading supplier in China which manufactures a variety of specialty and fine chemical compounds. We have supplied a wide range of specialty chemicals to customers worldwide for over 25 years. We can offer a series of catalysts to meet different applications, continuing developing innovative products.

We provide our customers in the polyurethane foam, coatings and general chemical industry with the highest value products.

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Contact Information:

Contact: Ms. Aria

Cell Phone: +86 - 152 2121 6908

Email us: [email protected]

Location: Creative Industries Park, Baoshan, Shanghai, CHINA

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Other Products:

  • NT CAT T-12: A fast curing silicone system for room temperature curing.
  • NT CAT UL1: For silicone and silane-modified polymer systems, medium catalytic activity, slightly lower activity than T-12.
  • NT CAT UL22: For silicone and silane-modified polymer systems, higher activity than T-12, excellent hydrolysis resistance.
  • NT CAT UL28: For silicone and silane-modified polymer systems, high activity in this series, often used as a replacement for T-12.
  • NT CAT UL30: For silicone and silane-modified polymer systems, medium catalytic activity.
  • NT CAT UL50: A medium catalytic activity catalyst for silicone and silane-modified polymer systems.
  • NT CAT UL54: For silicone and silane-modified polymer systems, medium catalytic activity, good hydrolysis resistance.
  • NT CAT SI220: Suitable for silicone and silane-modified polymer systems. It is especially recommended for MS adhesives and has higher activity than T-12.
  • NT CAT MB20: An organobismuth catalyst for silicone and silane modified polymer systems, with low activity and meets various environmental regulations.
  • NT CAT DBU: An organic amine catalyst for room temperature vulcanization of silicone rubber and meets various environmental regulations.