ABSORPTIONSVERFAHREN ZUR GEWINNUNG VON ÄTHYLEN UND WASSERSTOFF

摘要

A continuous process is described for contacting an olefins-containing feed gas stream, which has been freed of CO2 and sulfur compounds, compressed, cooled, and dried, with a solvent in an intercooled and reboiled demethanizing absorber to produce a rich solvent bottom stream containing ethylene and heavier hydrocarbons and an absorber overhead stream which is fed to a methane absorber which recovers a hydrogen product stream as overhead and produces a rich solvent stream as bottoms. When recovering up to 50% of the incoming hydrogen, this rich solvent stream from the methane absorber is fed to the demethanizing absorber, but when recovering from 20% to 100% of the incoming hydrogen, this rich solvent stream is recycled in part to the demethanizing absorber and in part is fed to a methane stripper which sends its bottoms to the methane absorber and its overhead to an auto refrigerated recovery unit which removes H2, CH4, and CO as a fuel gas product and produces an ethylene and heavier stream. The rich solvent stream from the demethanizing absorber is separated in a solvent regenerator into an overhead stream of ethylene and heavier hydrocarbons and a bottom lean solvent stream for recycle to the methane absorber and then to the demethanizing absorber. The bottom stream of the recovery unit and the overhead stream of the solvent regenerator are combined to form an ethylene and heavier product stream.