Process and apparatus for the production of pressurized gas by cryogenic distillation

摘要

A process for pressurised gas prodn. in a cryogenic sepn. plant, involving (a) cooling the fluid to be separated in a heat exchanger (9) and feeding to a distillation column (12) of the plant and (b) withdrawing a liq. stream from a column (14) of the plant and reheating in the heat exchanger (9), includes the novel steps of (c) adding top-up liq. (pref. of the same compsn.) to the withdrawn liq. stream (pref. an oxygen-, nitrogen-, argon- or methane-rich liq.) of step (b); (d) reheating and opt. vaporising the resulting mixt. by indirect heat exchange in the heat exchanger (9); and (e) recovering gas under pressure at the plant outlet. Also claimed is a corresponding installation including an arrangement (27) for adding top-up liq. to the withdrawn liq. upstream of the heat exchanger (9) and an arrangement for passing the resulting mixt. to the exchanger (9) to form the pressurised gas.