A process for the alkylation of isobutane is disclosed wherein isobutane is fed to two separate alkylation systems. The effluent from the first alkylation system is fed to an interim debutanizer where the C.sub.4's are separated from the alkylate product. The overhead C.sub.4 product is then fed to the second alkylation system to provide the isobutane. The effluent from the second alkylation system is fed to a traditional deisobutanizer to prevent any build up of normal butanes in the system.