| abstract |
The present invention utilizes a dual column cryogenic air separation system to cool and purify a portion of compressed air from a combustion turbine compressor, to expand the first portion of the resulting cooling air, and to expand the expanded air into a low pressure column. It relates to a high pressure combustion turbine which is integrated by inflow. The resulting cooling air is recooled, flow suppressed and introduced into the high pressure column. The nitrogen product stream is returned to the turbine combustor where a portion of the nitrogen product stream is optionally cooled, flow inhibited and recycled to the high pressure column. Preferably, the high pressure column is operated at an absolute pressure in which the absolute pressure of the compressed air from the combustion turbine air compressor is in the range of about 20% to about 85%. Optionally, the high concentration oxygen liquid or high concentration nitrogen liquid exits and is stored from the high pressure column during periods of low nitrogen product receipt, and from the reservoir for additional feed to the low pressure column during periods of high nitrogen product reception. Alternatively, high purity liquid oxygen is discharged and stored from the low pressure column during periods of low demand of the oxygen product, and from the reservoir during periods of high demand of oxygen product to replenish the oxygen product discharged from the high pressure column. |