Abstract: A method for the preparation of isobutylene substantially free from tertiary butyl formate and peroxides from a tertiary butyl alcohol feedstock contaminated with tertiary butyl formate and peroxides wherein the feedstock is continuously brought into contact with a bed of a catalyst consisting essentially of sulfuric acid impregnated alumina under reaction conditions including a temperature of about 150.degree. to about 400.degree. C. and a pressure of about 0 to about 3000 psig. at the rate of about 0.5 to about 10 g of feedstock per hour per cc of catalyst, to form a reaction product substantially completely free from tertiary butyl formate and peroxides.

Abstract: A method for the separation of methanol from MTBE contained in a reaction mixture comprising water, methanol, TBA and MTBE which comprises distilling the reaction mixture in the presence of added water in order to provide a distillate fraction containing most of the MTBE and a heavier distillation fraction containing most of the tertiary-butanol, water and methanol charged to the distillation column.