Removal of undesired gaseous components from hot waste gases

Abstract

For removing undesired gaseous components, e.g., SO.sub.2, from hot combustion gases (from carbonaceous fuels) by scrubbing with a regenerable absorbent, the scrubbing is conducted with a liquid physical absorbent, e.g., dimethylformamide, at a temperature less than 0.degree. C. The cooling requirements of the scrubbing process are supplied by an absorption type refrigeration unit. The hot combustion gases, prior to scrubbing, are cooled in indirect heat exchange, first with air in an upper temperature range cooling zone, and then with cold combustion gas purified by the scrubbing in a lower temperature range cooling zone. The resultant heated air is used in part as (a) air for combustion and in part as (b) an energy source for the operation of the refrigeration unit. A heat pump may be used to supplement the absorption type refrigeration unit. Other aspects include, for example, special regenerator design and absorbent regeneration steps.

Dependencies are inferred from the claim text.