Selective Hydrogenation Catalysts of Acetylene in an Olefin Rich Stream

摘要

Ethylene is an important raw material for polyethylene production, which is often produced by the thermal or catalytic cracking of saturated or higher hydrocarbons. Ethylene produced in this method usually contains small proportions of acetylene. The acetylene must be removed from the stream because such an impurity is the poison of polyethylene catalyst, and influence the polymerization of ethylene. In polymer grade ethylene, it is generally preferred that the acetylene content be less than about 1 ppm, most preferably less than about 0.1 ppm. One of the techniques that have been used for removal acetylene in an ethylene stream has involved selective hydrogenation using a catalyst comprising palladium. The acetylene removal units are operated either "back-end" or "front-end" reactors.