ISOPARAFFIN-OLEFIN ALKYLATION

An isoparafin-olefin alkylation process comprising the sequential steps of ( a) alkylating a mixed isoparaffin-olefin feed (10) in th e presence of an alkylation catalyst (12) comprising HF and sulfolane in a ris er reactor (20), whereby acid soluble oligomers (ASO) ar e formed; (b) gravitationally separating the effluent (22) in separator (30) i nto a less dense stream (38) containing the alkylate and unreacted isoparaffin and a more dense stream (32) containing sulfolane, ASO and HF, p art (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 str eam (32) in a multi-step stipping column (50) with a str ipping isoparaffin fluid (52) to obtain a stripped bottom stream (54) containing le ss than 30 % HF and an overhead stream (58) containing H F, isoparaffin, and a fraction of low-boiling ASO; (d) gravitationally separati ng the stripped bottom (54) in a separator (70) into a m ore dense sulfolane-enriched stream (78) and a less dense ASO-enriched stream (76); (e ) charging the stripper overhead stream (56) into an alk ylate fractionator (90) to obtain an overhead stream (92) containing isoparaffin a nd HF; (f) condensing the overhead stream (92) in overhe ad accumulator (100), a part (103) of which is recycled as reflux to thefractio nator (90) and the rest (105) is recycled as isoparaffi n stream to the riser reactor (20); (g) recycling the acid phase (104) condensate in ove rhead accumulator (100) back to the riser reactor (20) a s catalyst; (b) and recovering an alkylate product (96) and an n-butane product (98). 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