ISOPARAFFIN-OLEFIN ALKYLATION

摘要

An isoparafin-olefin alkylation process comprising the sequential steps of (a) alkylating a mixed isoparaffin-olefin feed (10) in the presence of an alkylation catalyst (12) comprising HF and sulfolane in a riser reactor (20), whereby acid soluble oligomers (ASO) are formed; (b) gravitationally separating the effluent (22) in separator (30) into a less dense stream (38) containing the alkylate and unreacted isoparaffin and a more dense stream (32) containing sulfolane, ASO and HF, part (36) of which is recycled into the riser reactor (20) as the acid catalyst; (c) stripping HF from the rest (34) of the more dense stream (32) in a multi-step stipping column (50) with a stripping isoparaffin fluid (52) to obtain a stripped bottom stream (54) containing less than 30 % HF and an overhead stream (58) containing HF, isoparaffin, and a fraction of low-boiling ASO; (d) gravitationally separating the stripped bottom (54) in a separator (70) into a more dense sulfolane-enriched stream (78) and a less dense ASO-enriched stream (76); (e) charging the stripper overhead stream (56) into an alkylate fractionator (90) to obtain an overhead stream (92) containing isoparaffin and HF; (f) condensing the overhead stream (92) in overhead accumulator (100), a part (103) of which is recycled as reflux to the fractionator (90) and the rest (105) is recycled as isoparaffin stream to the riser reactor (20); (g) recycling the acid phase (104) condensate in overhead accumulator (100) back to the riser reactor (20) as catalyst; (h) and recovering an alkylate product (96) and an n-butane product (98).