摘要 |
For removing undesired gaseous components, e.g., SO2, 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 DEG C. The cooling requirements of the scrubbing process are supplied by means of 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/or in part as (b) an energy source for the operation of the absorption-type refrigeration unit. A heat pump may be used to supplement the said refrigeration unit. Additionally, the resultant heated air can also be used in part as (c) an admixture to the scrubbed combustion gas mixed, and/or in part as (d) a purging gas for regenerating dessicators arranged in the undesired gaseous components (e.g. SO2) stream from a regenerator wherein the liquid physical absorbent is regenerated to be recycled to the scrubbing stage.
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