Energy efficient VPSA system with direct drive high speed centrifugal compressors

The present invention relates to a method and system for improving VPSA plant energy and capital efficiency through optimizing direct drive variable speed centrifugal feed, vacuum, and/or product compressors to achieve lower unit gas product production cost. More specifically, the present invention relates to a new energy efficient VPSA process and system which employs high speed direct drive centrifugal compressors to achieve wider production range. Significant lower energy consumption can be achieved over the plant operation life by employing compressors sized with average ambient and production demand, utilizing direct drive variable high speed centrifugal compressors' speed and operating range to meet the desired production demand. Since majority of the plants tend to run at below peak production most of operating life of the plant. In addition, the smaller size machine offers plant capital savings from the initial investment.