AIR SEPARATION PROCESS WITH WASTE RECYCLE FOR NITROGEN AND OXYGEN PRODUCTION

摘要

The present invention is an improved process for the production of nitrogen and oxygen that uses a double distillation column arrangement. The improvement to the process is the recycling of at least a portion of the oxygen-enriched waste stream to the bottom of the high pressure column. As a result of this improvement, the process is capable of making a nitrogen product with high purity (e.g., 5 ppm oxygen product) at high pressures (e.g., 40 to 150 psia) while simultaneously producing high purity oxygen (e.g., 99.6% oxygen). Nitrogen is produced only from the high pressure column.