What is driving o-xylene price spikes and downstream phthalic anhydride costs?

What is driving o-xylene price spikes and downstream phthalic anhydride costs?
Ortho-xylene is overwhelmingly consumed in phthalic anhydride production, so the two markets move together. When OX hit a multi-year high near 9,600 yuan per tonne, phthalic anhydride followed to around 10,450 yuan per tonne, up more than 20 percent in a month. The mechanism is straightforward: OX is the dominant cost component in phthalic anhydride, and when OX supply tightens, phthalic anhydride producers have little choice but to pass costs through. Port inventories of OX have run low, keeping the feedstock tight. Downstream, phthalic anhydride operating rates below 50 percent reflect both margin pressure and limited OX availability, reinforcing the upward price spiral.