Which MMA production route is most cost-competitive in China today?

Which MMA production route is most cost-competitive in China today?
Route economics vary widely in China. From 2020 to mid-2023, ethylene-based MMA showed the lowest theoretical cost, averaging about 6,088 yuan/t in early 2023, versus higher costs for ACH and C4 routes. However, China has no commercial ethylene-based plant yet; the first, a 300 kt/y unit using ionic-liquid catalysis at Henan Zhongke Puyuan, started construction in July 2022 and is expected to start up around 2024. A second ethylene-based plant in Shandong is in early approval. The C4 route dominates domestic production but yields many byproducts, while ACH relies on toxic hydrogen cyanide. A novel coal-based methanol-acetic acid route, the world's first, began stable operation in September 2022. Ethylene-based technology offers higher atom efficiency above 64%, lower corrosion and longer run lengths, but requires integrated ethylene supply and is technically hard to license.