MTBE: Overview
Why refiners still reach for this octane booster
What this tab covers What the chemical is, how big its market is, what it is used for (with shares, volumes, why it wins and what could replace it), and its chain from raw material to end user. Ends with three things to remember.MTBE is made by reacting methanol with isobutylene from refinery or cracker C4 streams, or from dehydrogenated butane. Blended at 5-15% into petrol it raises octane and adds oxygen. About 94% of MTBE goes into petrol (S&P Global, 2024). MTBE consumes about 11% of world methanol, implying roughly 30 Mt of MTBE a year (derived). Asia uses more than half, led by China. The US and Japan stopped using it over groundwater pollution; the US is now a big exporter to Mexico. Its future is tied to petrol demand, which electrification will erode.
Volume about 30-33 Mt a year (2024, indicative, basis: 10.8% of 111.8 Mt methanol at 0.364 t methanol per t MTBE; includes some TAME) Market value about $20 billion (indicative, basis: about 31 Mt x $630/t FOB China, Sep-Nov 2025) Growth follows global petrol demand; growth mainly from China (Energy Aspects); flat to falling in Europe as ETBE gains Energy Aspects MTBE insight (2026); S&P Global Platts (2025); derivedKey uses
| Use | Share | Annual volume | Why this commodity | Alternatives |
|---|---|---|---|---|
| Petrol octane booster and oxygenate | 94% | about 29-31 Mtbasis | MTBE has a blending octane of about 110-118 and blends without the water and vapour-pressure problems of ethanol. Refiners use it to meet octane specs as lead was removed and aromatics were capped. It is cheap where methanol and C4s are cheap. S&P Global CEH MTBE abstract (Jun 2025) | Ethanol ETBE (from bio-ethanol) Alkylate Reformate and aromatics |
| High-purity isobutylene (HPIB) for butyl rubber and polyisobutylene | 4% | about 1.2 Mtbasis | Cracking MTBE back to isobutylene gives very pure monomer for butyl rubber (tyre inner liners) and polyisobutylene (lubricant dispersants). S&P Global CEH (2025); indicative split | Direct isobutylene extraction with sulphuric acid TBA dehydration |
| Isobutylene for methyl methacrylate (C4 route) and other chemicals | 1% | about 0.3 Mtbasis | In Japan and parts of Asia, MMA for acrylic sheet is made by oxidising isobutylene, which can come from cracking MTBE. Antioxidants and tert-butyl chemicals also use it. indicative | Acetone cyanohydrin MMA route Ethylene-based MMA |
| Solvent and pharma uses | 1% | about 0.3 Mtbasis | MTBE is a stable ether solvent used in chemical and pharmaceutical extractions. indicative | Other ethers (CPME, 2-MeTHF) Diethyl ether |
From raw material to user
- C4 and isobutylene supply Isobutylene comes from refinery FCC C4s, steam-cracker raffinate-1, isobutane dehydrogenation or tert-butyl alcohol from PO/TBA plants; about 0.64 t per t MTBE (stoichiometry).
- Methanol About 0.364 t of methanol per t MTBE (stoichiometry).
- Etherification Isobutylene and methanol react over an acidic ion-exchange resin at 40-90 C, often in a catalytic distillation column; conversion above 99% (indicative).
- Shipping Shipped in product tankers; US exports to Mexico were 1.115 Mt in Jan-Aug 2025, 84% of US MTBE exports (USITC via S&P Global).
- Petrol blending Blended at 5-15% by volume at refineries and import terminals.
Made from (commodity table)
Gas Natural gasOil Crude oilThree things to know
- About 94% of MTBE goes into petrol (S&P Global, 2024).
- MTBE takes about 11% of world methanol, roughly 12 Mt a year (Energy Aspects, 2024).
- MTBE FOB China fell from $665-725/t in Sep-Nov 2024 to $620-640/t a year later amid Chinese overcapacity (S&P Global Platts).