Abstract:

The pipe blockage problems during operation of PX combination plant in Zhenhai Petrochemical Co. when processing purchased C8A were analyzed. It is concluded that the coke formation due to olefin polymerization induced by the small amount of oxygen dissolved in C8A during storage and transportation is the main cause. Coking rate is positively correlated with the temperature and bromine index of the purchased C8A. A simple and cheap coking adsorption method was suggested and proved to be effective for solving the blockage problems during processing purchased C8A. It can be used for similar equipment to solve or to prevent similar problems.

Key words: para-xylene, dissolved oxygen, coking, blockage