Why does China's methanol cost structure hinge on coal prices and oil prices simultaneously?

Why does China's methanol cost structure hinge on coal prices and oil prices simultaneously?
China produces roughly 78-80% of its methanol from coal, making domestic pricing far more sensitive to coal costs than to international gas benchmarks. Yet the demand side is tied to oil-linked downstream products such as olefins, acetic acid and DMF. When Brent stays above $80, coal-to-methanol operators like Hualu Hengsheng enjoy a wide spread because their feedstock is cheap coal while their output is priced against oil-based chemicals. At $50-80 oil, margins compress but remain workable; below $45, coal-based economics lose their edge. This dual dependency means Chinese methanol prices are not simply a function of domestic coal supply, but also of global crude trends that shape end-product values.