A process for the sulfuric acid catalyzed alkylation of C3-C5 olefins with isobutane is disclosed wherein the requisite mixing is accomplished by the use of eductors within the reactor. In addition the alkylate product is subjected to primary and secondary coalescers for removal of entrained sulfuric acid. The vaporized unreacted C4's are recovered as liquid by absorption and desorption in an absorber oil.