OLEFIN PRODUCTION TECHNOLOGY WITH ADJUSTABLE PROPYLENE/ETHYLENE RATIO BY CATALYTIC CRACKING ROUTE

摘要

The well-known steam cracking is the major olefin production process worldwide. Light feedstock supply deficient and propylene/ethylene ratio imbalance impels the development of catalytic cracking processes to join the olefin production ranks. Catalytic cracking route based on different reaction mechanism is expected to raise the propylene/ethylene ratio. DCC is a commercialized technology using heavy hydrocarbons through mainly catalytic reaction differed from the solely thermal reaction in steam cracking. Its product propylene/ethylene ratio is 3.6 at a propylene yield of 24.8m% using an atmospheric residue under a reaction temperature of 829K, A new technology named CPP modified from DCC takes the advantages of both thermal and catalytic reactions for maximizing both ethylene and propylene production. A commercial trial with a throughput of 80kt/a showed that a propylene/ethylene ratio of 0.9 at an ethylene yield of 20.4m% under a cracking temperature of 913K with an atmospheric residue feedstock. Its propylene/ethylene ratio is adjustable in the range of 0.6-0.9, which is higher than that of steam cracking. CPP technology can be heat balance operated in a fluidized reaction/regeneration system.