GB824181A - Improvements in alkylation of hydrocarbons - Google Patents

Abstract

<PICT:0824181/IV (b)/1> <PICT:0824181/IV (b)/2> A liquid phase alkylation process comprises introducing an alkylatable hydrocarbon and a liquid alkylation catalyst into the lower portion of a confined reaction zone contained within a contacting zone, emulsifying, introducing an olefin, passing the emulsion upwardly at high velocity in confined streams within the reaction zone, withdrawing emulsion from the lower portion of the reaction zone into the contacting zone and venting vapours comprising alkylatable hydrocarbon from the reaction zone into and thence from the contacting zone, the passage of vapours being maintained through the upper portion of the contacting zone remote from the passage of emulsion and the vapours being vented from the reaction zone in a direction away from the vapour vent means in the contacting zone. Fig. 1 represents an alkylation contactor having three contacting zones 39, 39a and 39b in each of which is a mixing pump 45, 45a and 45b, shown in Fig. 2. The hydrocarbon to be alkylated enters the inlet chamber 37 through line 33. Acid catalyst enters through line 63 and may also be passed through lines 35. The liquid is cooled in each zone by removing vapours through lines 59, 59a and 59b and these are returned to the contactor after the last contacting zone. Mixed acid and hydrocarbon is sucked into the reactor 29 by the propeller 13. Olefine, supplied through lines 57, 57a and 57b, enters the reactor by passing down the hollow shaft casing 3 and through the holes 21. The mixture passes upwards at high velocity through the reaction tubes 28 and overflows into the shell of the reactor. The liquid is removed from the lower portion of the reactor through holes 31 into the contacting zone while vapours with entrained liquid are removed at a remote point through holes 73 which point away from the vapour vents (59a, 59b) from the contacting zones; the path of vapours through the contacting zone is thereby increased giving longer time for liquid to separate from the vapours. The liquid from each contacting zone is removed from the top where the greater proportion of hydrocarbon is and added to the bottom of the succeeding zone. The emulsion is broken in zone 43, the heavy acid layer is withdrawn and recycled and hydrocarbon, including alkylate product, overflows baffle 51 and is withdrawn by line 55. Vapours are withdrawn overhead, liquid separated and returned and the vapours compressed and cooled before recycling to line 33. Reaction conditions may be 0-150 DEG F. and 0-100 p.s.i.g., with a molar ratio of alkylatable hydrocarbon to olefine of 2 to 20:1. Specified catalysts are sulphuric, hydrofluoric, chlorosulphonic, and fluorosulphonic acids and Friedel-Craft metal halidehydrocarbon or -acid complexes.