Abstract: The invention relates to a group of heat exchangers for compressed gas refrigeration dryers, in which the heat exchangers (20,30) comprise a series of finned, closely spaced plates (21, 31), creating a series of passages for the countercurrent flow of fluids, and in which the gas/gas heat exchanger (20) is positioned beside the evaporator (30), so that an outlet zone (28) of a pre-cooling section (22) of the gas/gas heat exchanger (20) directs the mixture of compressed gases directly to an inlet zone (36) of a cooling section (32) of the evaporator (30).

Abstract: A system for producing carbon dioxide, particularly from a feed which contains significant levels of light contaminants, wherein light overhead from a distillation column is partially condensed against heat exchange fluid containing both carbon dioxide and light contaminants and the resulting heat exchange fluid passed into the feed for the distillation column.