Cryogenic air separation process with excess turbine refrigeration

Abstract

A process for carrying out cryogenic air separation wherein liquid oxygen is pressurized and vaporized against condensing feed air to produce oxygen gas product wherein excess plant refrigeration is generated such that the aggregate warm end temperature difference of the process exceeds the minimum internal temperature difference of the primary heat exchanger by at least 2K.

Description

TECHNICAL FIELD [0001] This invention relates generally to cryogenic air separation and, more particularly, to cryogenic air separation to produce oxygen product. BACKGROUND ART [0002] The separation of air into its constituent components by distillation occurs at cryogenic temperatures, and requires some amount of refrigeration. This refrigeration is typically generated by the expansion of a process gas across a turbine. When designing air separation processes, the amount of refrigeration generated by expansion is typically kept at a minimum, as all forms of refrigeration generation are penal to the process, either by degrading the efficiency of the separation or by requiring more compression energy than is minimally required by the needs of the plant's distillation columns. The efficiency of refrigeration usage for a plant is reflected by the temperature difference between the streams entering and leaving the plant. This temperature difference is referred to as the aggregate warm ...

AI Technical Summary

Benefits of technology

[0008] As used herein, the term “column” means a distillation or fractionation column or zone, i.e. a contacting column or zone, wherein liquid and vapor phases are countercurrently contacted to effect separation of a fluid mixture, as for example, by contacting of the vapor and liquid phases on a series of vertically spaced trays or plates mounted within the column and/or on packing elements such as

Problems solved by technology

As such, when higher pressure oxygen is required as a product,

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