Polyetherimide/γ-alumina composite membrane has been prepared by dipping method for further reactor application. Separation factors and permeances for a quaternary acetic acid-ethanol-ethyl acetate-water equilibrium feed mixture have been measured on the composite membrane in the range of temperature from 303 K up to 343 K and space time from 27 sec to 27,000 sec at a permeate-side pressure of 2.67 × 10^-3 bar. Fluxes for the all four components increase as temperature inicreases due to the increase of free volume within polymer chains. Apparent activation energies have been measured for the four components. The flux change for acetic acid is the most sensitive on the temperature change. The composite membrane shows a good dehydration capability with reasonable separation characteristics, as well as thermal and mechanical stability in desired conditions.