Oxygen production by molten alkali metal salts

Abstract

A continuous process for separating oxygen from air by means of a reversible chemical reaction wherein air is reacted with an oxygen acceptor which is subsequently decomposed to yield the product oxygen, and then recycled. The only energy input required is a conventional combustible fuel, and one object of the process is to reduce the amount of fuel energy required for oxygen production. The oxygen acceptor is a molten solution of alkali metal salt comprised predominantly of sodium nitrate and potassium nitrate. An efficient process is achieved with this salt by conducting oxygen absorption in multiple countercurrent stages. The compression energy requirement is minimized by combining isothermal and adiabatic compression, and the recovery of compression energy is maximized by processing the exhaust in the sequence combustion, partial expansion, heat exchange, and completion of expansion. Salt-to-salt heat exchange between reaction regions minimizes the pumping requirements.

Dependencies are inferred from the claim text.