Process for the removal of ammonia from gases
AssigneeHoechst Aktiengesellschaft
InventorsThomas Staffel, Renate Adrian
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Abstract
In order to remove ammonia from water vapor-containing gases, in particular offgases, the gases are brought into intimate contact with warmed polyphosphoric acid, the polyphosphoric acid advantageously having a P.sub.2 O.sub.5 content of from 70 to 84% by weight and a temperature of from 120.degree. to 170.degree. C.
Claims6
A process for the removal of ammonia from water vapor-containing gases, which comprises introducing into a reaction zone being partially filled with warmed polyphosphoric acid having a P.sub.2 O.sub.5 content of from 70 to 88% by weight and a temperature of from 120.degree. to 170.degree. C. the ammonia- and water vapor-containing gases at a rate of from 50 to 200 l per hour and per l of polyphosphoric acid, withdrawing continuously polyphosphoric acid from the lower part of the reaction zone, and transferring the polyphosphoric acid withdrawn to a column the lower end of which being flow-connected to the reaction zone with the resultant formation of a gas being freed from ammonia and water vapor and an ammonia-saturated polyphosphoric acid.
A process for the removal of ammonia from water vapor-containing gases, which comprises allowing the ammonia- and water vapor-containing gases to bubble into warmed polyphosphoric acid having a P.sub.2 O.sub.5 content of from 70 to 88% by weight and a temperature of from 120.degree. to 170.degree. C. at a rate of from 20 to 80 l per hour and per l of polyphosphoric acid, said polyphosphoric acid being located in a stirred reaction zone with the resultant formation of a gas being freed from ammonia and water vapor and an ammonia-saturated polyphosphoric acid.
Dependencies are inferred from the claim text.