A new hybrid gas separation process combining membrane permeation and pressure swing adsorption (PSA) is presented. An integrated model was formulated which successfully predicts all process characteristics. Our modeling work shows that the coupled process increases the efficiency of the pressurization and high-pressure adsorption steps, thereby improving the separation performance as compared to a standalone PSA. The new process has been applied successfully to the bulk separation of a mixture of 50/50 H-2/CH2 and preliminary results have been obtained for CO2/CH4 and H2/CO2/CH4 mixtures.