PRECOOLING FOR ETHYLENE RECOVERY IN DUAL DEMETHANIZER FRACTIONATION SYSTEMS

摘要

Ethylene-containing feed gas to a cryogenic ethylene recovery system is cooled and condensed, prior to fractionation, by an improved method which utilizes a combination of one or more partial condensers followed by one or more dephlegmators. The improved method simplifies heat exchange equipment and reduces capital cost, and is particularly suited for processing a pressurized precooled feed gas from ethane cracking which contains less than about 1 mole% of propane plus propylene.