[Organic Chemicals] Understanding the MMA (methyl methacrylate) value chain in one go

[Organic Chemicals] Understanding the MMA (methyl methacrylate) value chain in one go

This is the fourth piece in a series on value chain analysis. The others are "Understanding the PVC value chain in one go," "Understanding the propylene value chain in one go," and "Understanding the styrene value chain in one go" — feel free to click through if you're interested.

I think value analysis is an important method for market analysis. It lets you quickly grasp the logic of how value is transmitted through an industrial chain, and from that transmission logic you can predict the direction of cost pass-through, which in turn helps you forecast where commodity prices are headed. Studying costs is a big part of that value chain work.

I'll keep doing value analysis on chemical industry chains, and I hope this kind of analysis helps the industry run in a healthier way and makes value distribution more reasonable.

MMA stands for methyl methacrylate. It's an important raw material for making polymethyl methacrylate (PMMA), which is what we commonly call acrylic. MMA gets a lot of industry attention because of the high-performance material properties of the downstream PMMA.

I've noticed that with the rapid growth of China's new materials industry, new materials used downstream in optics, electronics, and automotive have drawn much more attention, and they've really taken off in recent years. PMMA's properties in optical applications in particular have pushed its profile up a lot. PMMA can be used in LCD materials, automotive instrument and lighting materials, building decoration materials, advertising light box materials, and so on.

You could also say it's the growth of the PMMA industry that's pulling the MMA chain forward. According to what I've found, there are currently three mainstream MMA production processes: the acetone cyanohydrin route (ACH), the ethylene carbonylation route, and the isobutylene oxidation route (C4). Among Chinese producers right now, ACH and C4 dominate, and there's no commercial-scale plant using ethylene carbonylation.

ACH was the earliest industrialized MMA process. It uses hydrogen cyanide — a byproduct of acrylonitrile production — as a raw material. With an alkaline catalyst (diethylamine), acetone cyanohydrin forms. That reacts with sulfuric acid to produce methacrylamide sulfate, which after hydrolysis undergoes esterification with methanol to give crude MMA plus an acidic water-containing mixture. The crude MMA is distilled to get the MMA product, unreacted methanol is recovered and recycled, and the residual liquid goes to a recovery stage to reclaim ammonium bisulfate. In other words, ACH uses acetone and hydrogen cyanide as its raw materials.

The isobutylene route, or C4 route, first oxidizes isobutylene to methacrolein, then oxidizes that to methacrylic acid, and finally esterifies with methanol to make MMA.

Domestic C4 routes are all three-step processes. First, isobutylene/tert-butanol undergoes gas-phase oxidation with air over a Mo-Bi catalyst to form MA; isobutylene conversion exceeds 95%, and MA selectivity (mole fraction) is above 80%. Second, MA is oxidized to MAA using a phosphomolybdenum catalyst with alkali metals added to improve thermal stability, adjust activity, and increase surface area; through multi-stage oxidation, MA conversion can reach 98%. Third, MAA is esterified to MMA — the esterification can be either a liquid-phase or gas-phase reaction.