On September 26, LyondellBasell (LYB) and Covestro permanently shut down the Propylene Oxide Styrene and Monomer (POSM) unit known as PO11 at their joint Maasvlakte site in the Netherlands. The plant had been in operation since 2003 and was regarded as one of the most advanced facilities of its kind.
The decision, announced in March 2025, was driven by global overcapacity, increasing imports from Asia, and high production costs in Europe. These factors made long-term profitable operation no longer feasible, despite investments of around €250 million in sustainability upgrades.
“While the decision to shut down the PO11 unit is difficult, we must ensure all assets within our portfolio are a long-term strategic fit,” said Aaron Ledet, executive vice president at LyondellBasell, in March this year. He added that the company prioritized assets central to technology differentiation and circularity.
Hermann-Josef Dörholt, head of Performance Materials at Covestro, also explained in March: “Due to global overcapacities, persistently weak demand, and high costs in Europe, we jointly decided with LYB to close the PO11 plant. We supported LYB in implementing this change as responsibly as possible. At the same time, we remain committed to the European market.”
The shutdown process will continue until the end of 2026, when the asset is scheduled to be dismantled. During this period, both companies will maintain communication with employees, suppliers, and customers to ensure business continuity in other product lines.
The closure reflects the broader pressures facing the European chemical industry, where competitiveness is challenged by high energy and operating costs compared with other regions.
The Maasvlakte site, a joint venture between LYB and Covestro. (Photo: Alex Lokker.)
