Poly dimethyl siloxane (PDMS) membrane was used to separate a synthetic mixture consisting of isopropanol, ethanol, 2-butanol, and n-butanol using the pervaporation. separation technique. These alcohols are found to occur in naphtha reformate as a result of vapor-phase reaction of the alkenes in the presence of water and a catalyst. In this work the pervaporation separation efficiency of PDMS membrane toward different alcohols was evaluated by estimation of fluxes and separation factors at different temperatures and pressures. The coupling effect resulting from the presence of identical functional groups was investigated. The activation energies for the transport of each of these alcohols through the membrane were also evaluated.