Method for production of liquefied air and separation of air, involves cooling and liquefying air flow by indirect heat transfer with liquid nitrogen flow that is vaporized by indirect heat transfer to form nitrogen gas

摘要

The method involves utilizing a compressor (1) for compressing gas air, and purifying the compressed air by removing carbon dioxide and water by adsorption in a purification unit (7). The compressed air is divided into a set of purified air flows (9, 13). One air flow is cooled and is separated by cryogenic separation to form a fluid that is rich in nitrogen or oxygen. Another air flow is cooled and liquefied by indirect heat transfer with a liquid nitrogen flow (29). The liquid nitrogen flow is provided from a storage unit (27) and is vaporized by indirect heat transfer to form nitrogen gas. An independent claim is also included for an apparatus for production of liquefied air.