COLLECTIVE ADSORBING METHOD FOR RECOVERING HYDROGEN AND HYDROCARBON BY EMPLOYING TEMPERATURE SWING STAGE BEFORE PRESSURE SWING STAGE

摘要

PURPOSE: To effectively recover light hydrocarbons by directing a feed stream through a first adsorption zone which adsorbs heavy hydrocarbon, directing the feed stream through a second adsorption zone which adsorbs light hydrocarbons and directing an effluent of the stream through the first adsorption zone heated to a temperature at which heavy hydrocarbons are desorbed. CONSTITUTION: A feed stream containing hydrogen, benzene and methane is directed under pressure to a cryogenic apparatus 102 to be cooled and then to a flushing chamber 103 to be separated into a liquid phase including benzene and a gaseous phase including hydrogen, methane and the residual benzene. The gaseous phase is directed to a first adsorption zone containing adsorption beds 104 and 107 which adsorb benzene. The first adsorption zone effluent stream from which benzene is removed is withdrawn from the adsorption bed 104 and directed to a second adsorption zone which adsorbs methane. The second adsorption zone effluent stream from which methane is removed is directed to a heat exchanger 106 to be heated and then to the first adsorption zone 107 where adsorbed benzene is desorbed. Thereby methane can be effectively recovered.