System and method for integrated air separation and liquefaction
OwnerHenry E. Howardinventor
Life of this patent
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Abstract
A high efficiency and high volume air liquefaction system and method is disclosed wherein the cryogenic air separation plant includes a warm gas turbo-expansion cycle to supply the supplemental refrigeration required to produce liquid products in excess of about 15% of the incoming feed air.
Claims18
A method of separating a feed mixture comprised of air components in a cryogenic separation plant to produce liquid products, the cryogenic separation plant having a main heat exchanger and a distillation column system, the method comprising the steps of:
- producing a pressurized and purified feed stream;
- directing a first portion of the compressed and purified feed stream to the main heat exchanger to cool the first portion of the compressed and purified feed stream;
- liquefying the cooled first portion of the compressed and purified feed stream to produce a liquid feed stream suitable for rectification in the distillation column system;
- diverting a second portion of the compressed and purified feed stream to a turbo- expander section of the cryogenic separation plant;
- partially cooling at least a portion of the second compressed and purified feed stream in the main heat exchanger;
- expanding the partially cooled second portion of the compressed and purified feed stream in a turbo-expander to produce work and a gaseous exhaust stream at a pressure suitable for the rectification in the distillation column system;
- conducting a cryogenic distillation process to separate the first and second portions in the distillation column system thereby producing at least one liquid product stream;
- compressing a working fluid in a supplemental refrigeration circuit using the work produced by the turbo-expansion of the partially cooled second portion of the compressed and purified feed stream;
- cooling and expanding the compressed working fluid in a turbo-expander disposed within the supplemental refrigeration circuit;
- warming the expanded working fluid by way of heat exchange with at least a portion of the feed stream to impart a portion of the refrigeration required by the cryogenic separation plant;
- and
- recirculating at least a portion of the warmed working fluid to a compressor section within the supplemental refrigeration circuit after having been warmed by way of said heat exchange.
A supplemental refrigeration system for producing liquefied products in a cryogenic separation plant comprising:
- an intake conduit configured to receive a working fluid;
- a first compressor coupled to the intake conduit and configured to compress the working fluid, the first compressor mechanically coupled to a first turboexpander of the cryogenic separation plant and using the work produced by the first turboexpander of the cryogenic separation plant;
- a second compressor coupled to the first compressor and configured to further compress the compressed working fluid;
- a second turboexpander operatively coupled to the second compressor configured to expand the further compressed working fluid to generate an expanded working fluid;
- a heat exchanger configured to receive the expanded working fluid from the second turboexpander and warm the expanded working fluid to impart a portion of the refrigeration required by the cryogenic separation plant;
- and
- a recirculating conduit configured to return the warmed expanded working fluid from the heat exchanger to the first compressor section.
Dependencies are inferred from the claim text.