Smoke engulfs a distillation device at the Dalian Petrochemical Company of PetroChina, a leading onshore oil producer of the nation, in Dalian, Northeast China's Liaoning province, July 16, 2011. [Photo/Xinhua] 

Smoke engulfs a distillation device at the Dalian Petrochemical Company of PetroChina, a leading onshore oil producer of the nation, in Dalian, Northeast China's Liaoning province, July 16, 2011. [Photo/Xinhua] 

People watch as fire and smoke engulf a distillation device at the Dalian Petrochemical Company of PetroChina, a leading onshore oil producer of the nation, in Dalian, Northeast China's Liaoning province, July 16, 2011. [Photo/Xinhua]