Acrylics (PMMA): Production route
Four routes to MMA, one with a spent-acid problem
What this tab covers How it is made: the main production routes or, for product families, the main product types and technologies, compared on share of supply, inputs per tonne, plant scale, yield, co-products and unit cost.PMMA economics are mostly MMA economics. MMA is made by four main routes. The acetone cyanohydrin (ACH) route uses acetone and hydrogen cyanide with sulphuric acid and makes a large spent-acid stream. The C4 route oxidises isobutylene or tert-butanol and dominates in Japan and parts of Asia. Mitsubishi Chemical's Alpha route uses ethylene, CO and methanol. Röhm's LiMA route, started at Baytown in March 2025, uses ethylene, methanol and natural gas. MMA is then polymerised to sheet or moulding resin.
Routes compared
| Route | Share of supply | Inputs per tonne | Typical scale | Yield | Co-products | Unit cost |
|---|---|---|---|---|---|---|
| ACH (acetone cyanohydrin) route to MMA | about 45-50% of MMA (indicative) | about 0.68 t acetone, 0.32 t HCN, 0.35 t methanol and 1.4-1.6 t sulphuric acid (recycled) per t MMA (indicative) | 100-250 kt/yr; Mitsubishi Memphis 182 kt/yr (Chemical Week) | about 85-90% on acetone (indicative) | spent sulphuric acid or ammonium bisulphate | not published; acetone about $800/t (indicative, phenol tile) and acid regeneration are main costs |
| C4 (isobutylene or tert-butanol oxidation) | about 30-35% (indicative) | about 0.7-0.8 t isobutylene and 0.35 t methanol (indicative) | 50-250 kt/yr | not published | water and CO2 | not published |
| Ethylene-based routes: Alpha (Mitsubishi Chemical) and LiMA (Röhm) | about 15-20% and rising (indicative) | ethylene, CO and methanol; ratios not published | 250-350 kt/yr; Mitsubishi's planned 350 kt/yr Geismar Alpha plant was scrapped in January 2025 (Chemical Week) | not published | few | claimed lowest cost on US shale feed (indicative) |
| PMMA polymerisation: cast sheet, extruded sheet and moulding resin | sheet about half, moulding resin about half (indicative) | about 0.95-1.0 t MMA plus small comonomer (methyl acrylate) per t PMMA (indicative) | 20-150 kt/yr | about 95-98% (indicative) | trim scrap recycled | MMA plus about $300-800/t conversion depending on product (indicative) |
How each route works
ACH (acetone cyanohydrin) route to MMAAcetone reacts with HCN to acetone cyanohydrin, which is treated with sulphuric acid to methacrylamide sulphate and esterified with methanol. Spent acid must be regenerated by burning or sold as ammonium sulphate. HCN often comes as a co-product of acrylonitrile plants.
Mature and flexible; heavy acid handling and HCN hazard.
Chemical Week, May 2025; indicative C4 (isobutylene or tert-butanol oxidation)Isobutylene or tert-butanol is oxidised in two steps to methacrylic acid, then esterified with methanol, or oxidised directly in methanol (direct methylation). Common in Japan, Korea, Thailand, Singapore and China.
No HCN or spent acid; needs C4 supply from crackers or MTBE plants.
indicative Ethylene-based routes: Alpha (Mitsubishi Chemical) and LiMA (Röhm)Alpha makes methyl propionate from ethylene, CO and methanol, then condenses it with formaldehyde to MMA. Röhm's LiMA turns natural gas, methanol and ethylene into MMA; its 250 kt/yr Baytown plant started up in March 2025.
No sulphuric acid waste and cheap feeds; high capital cost.
Chemical Week, May 2025 PMMA polymerisation: cast sheet, extruded sheet and moulding resinCell casting polymerises MMA syrup between glass plates for high-quality sheet; continuous casting and extrusion make thinner sheet; bulk or suspension polymerisation makes pellets for injection moulding.
Cast sheet is best quality but slow; moulding resin is high volume.
indicative Unit economics are indicative ranges from the sources named; costs move with feedstock and energy prices, plant size and region.