Selective tertiary-butanol (tBA) dehydration to isobutylene has been demonstrated using a pressurized reactive distillation unit under mild conditions, wherein the reactive distillation section includes a bed of solid acid catalyst. Feeding tBA to the middle of the distillation section, anhydrous isobutylene product is recovered as an overhead fraction and co-product water as a bottoms fraction. Suitable solid acid catalysts include zeolite Beta, hydrogen-fluoride-treated beta -zeolites, and HF-treated montmorillonite clays. Quantitative tert-butanol conversions have been realized.