The Main problem in air drying unit is the adsorption and regeneration time. In a dryer adsorption continues for eight hours, after which the desiccant becomes saturated and cannot adsorb further moisture. In this study membrane systems are used to solve adsorption and regeneration problems in air drying unit. Instead of silica gel, different types of desiccants: activated alumina, zeolite, molecular sieves, activated carbon were used. Therefore membrane air dryer is more optimum for commercial processes than the other different dryers. Membrane dryer can be used for 24 hours for one week, so there is no need to standby this equipment.