Isobutane alkylation plays an important role in modern FCC-based refineries, where it serves the dual purpose of disposing of the LPG cut from the FCC and providing a source of highly desirable stock for gasoline blending. Concern about the processes used in the refineries today has resulted in the development of the fixed-bed alkylation TBA) technology, which is a compromise between the chemistry of isobutane alkylation and the desire for safe catalyst handling. The FBA reactor uses an SLP-type catalyst, which consists of a strong Bronsted acid supported on a fixed support bed in a well-defined catalyst zone. The acid slowly migrates through the support bed as the reaction progresses. Such reactors have been tested in three differently sized pieces of equipment, including a 10 bpd scale-up pilot, which was used to demonstrate the feasibility of scaling up of the reactor. Together with the FBA reactor technology, a new on-site catalyst recovery technology centered around a stripping tower and new reactor effluent treatment technology have been developed. The FBA technology is sturdy and flexible with respect to both operating conditions and feedstock and can also be adapted to make products other than alkylate gasoline, thereby expanding the use of alkylation beyond gasoline production into the production of middle distillates for jet and diesel fuels.