Isoparaffin-olefin alkylation with HF alkylation and isomerization in a soaking zone

Claim 1

A process for producing an alkylation reaction product from an isoparaffin and an olefin, which comprises the steps of: a. reacting said olefin with said isoparaffin in admixture with a relatively low strength hydrogen fluoride catalyst containing 75 to 95 wt. percent HF at a catalyst to hydrocarbon volume ratio of 1:1 to 5:1; b. settling the resultant reaction mixture of step (a) to separate the same into a hydrocarbon phase and a catalyst phase; c. commingling with said hydrocarbon phase, without further addition of olefin, a relatively high strength catalyst of hydrogen fluoride and organic diluent containing 90 to 98 wt. percent HF, and 2 to 10 wt. percent of organic diluent, said catalyst having a higher strength than the catalyst utilized in step (a) and in a lower catalyst to hydrocarbon volume ratio than step (a); d. introducing the resulting mixture of step (c) into a soaking zone and therein isomerizing lower octane alkylate hydrocarbons to higher octane alkylate hydrocarbons, converting alkyl fluorides into high quality alkylate and HF acid, by maintaining said mixture in the soaking zone at a temperature of 50° to 120° F for 5 to 20 minutes; e. separating the effluent of the soaking zone into a second hydrocarbon phase and a second catalyst phase, and; f. recovering said alkylation reaction product from said second hydrocarbon phase.