ENRICHMENT OF ETHYLENE FROM FCC OFF-GAS

摘要

A method and an apparatus for enrichment of ethylene from FCC(Fluid Catalytic Cracking) off-gas are provided to treat a large volume of off-gas by desorbing and recovering the ethylene using a desorbent after adsorbing ethylene onto an olefin selective adsorbent, and to protect an adsorbent used in the enrichment of ethylene by removing water contained in the off-gas through a pre-treatment adsorption process. A method for separating ethylene from FCC off-gas comprises: a pre-treatment process including an adsorption step of introducing FCC off-gas to adsorb water and a desorption step of introducing an ethylene removing stream exhausted from the ethylene separation process to clean and desorb the adsorbed water; and an ethylene adsorbing and separating process including an adsorption step of introducing the pre-treated FCC off-gas into an adsorption tower to adsorb ethylene, and sending non-adsorbed components and an adsorbent in the adsorption tower to a distillation tower for separating the ethylene removing stream and an adsorbent, an ethylene cleaning step of introducing a portion of high concentration olefin obtained from an ethylene enriched stream/desorbent distillation tower into the adsorption tower to increase the purity of ethylene, and a desorption step of introducing a desorbent into the adsorption tower to desorb ethylene and sending the desorbed ethylene to a distillation tower for separating a mixture of the ethylene enriched stream and the desorbent to produce an ethylene enriched stream.