PROCESS FOR PRETREATING CRACKED GAS BEFORE CAUSTIC TOWER TREATMENT IN ETHYLENE PLANTS

摘要

An inline, high-shear mixer (20) is provided in a cracked gas stream (12)upstream of a caustic tower (38) in an ethylene productionunit. Spent caustic (52) is withdrawn from the bottom of the caustic tower(38) and pumped to the mixer (20), where the spent causticmixes with and absorbs acid gas components from the cracked gas stream (12).The spent caustic is separated from the cracked gas, forminga partially treated cracked gas stream (26). The partially treated cracked gasstream (26) is then fed to the caustic tower (38). Polymerdeposition in the caustic tower (38) is reduced because polymeric material isformed when the cracked gas stream is mixed with the spentcaustic and is removed before the cracked gas stream is fed to the caustictower (38).