Abstract: The present invention relates generally to adsorbents for use in pressure swing adsorption (PSA) prepurification processes. The invention more particularly relates to the design of adsorbent zones to be used in PSA prepurification processes that are expected to provide for extensions in PSA cycle time, thereby reducing blowdown loss and operating costs associated with the process. One particular embodiment of the present invention includes a first adsorption zone containing activated alumina and a second adsorption zone of an alumina-zeolite mixture or composite adsorbent in which the volume of the first zone does not exceed 50% of the total volume of the first and second zone.