Air separating method for oxycombustion application in boiler, involves sending oxygen and nitrogen enriched liquids to low pressure column, removing oxygen enriched gas in condenser, and drawing nitrogen enriched gas from column

摘要

The method involves sending oxygen and nitrogen enriched flows from a medium pressure column (9) to a low pressure column (19). An oxygen enriched flow is sent from the column (9) to an intermediate pressure column (25). Gases containing nitrogen are sent to vessel vaporizers (50, 52) of the column (19), respectively. An oxygen enriched liquid is sent to an overhead condenser (31) of the column (25) or column (19). Oxygen and nitrogen enriched liquids are sent to the column (19). An oxygen enriched gas in the condenser is removed. A nitrogen enriched gas is drawn from the column (19). An independent claim is also included for an apparatus for separating air by cryogenic distillation.