The reformer unit, which processes naphtha into aromatics, is the world's single-largest facility of its kind, the company claimed.

Zhejiang Petrochemical,based in Zhoushan of Zhejiang province, started test runs at a 200,000-barrels-per-day crude oil refinery in May, the company said.

The complex includes a second 200,000-bpd crude unit, a 1.4 million-tonnes-per-year ethylene and a 4 million-tonnes-per-year paraxylene plant. All facilities are expected to start operating next year, industry sources said.

(Reporting by Chen Aizhu, Editing by Sherry Jacob-Phillips)