A process for the conversion of an alcohol mixture may include introducing into a reactor a stream including the alcohol mixture mixed with a stream including olefins having 4 carbon atoms or more. The process may include contacting the stream with a single catalyst at a temperature above 500° C. in the reactor at conditions effective to dehydrate isobutanol, forming C4+ olefins, and to catalytically crack the C4+ olefins. The single catalyst may be an acid catalyst adapted to cause both the dehydration and catalytic cracking. The process may include recovering an effluent including ethylene, propylene, and water, and fractionating the effluent.