Chemical Absorption of Ammonia from Air in a Packed Tower

Several methods are available for cleaning ammonia gas from the air stream. It seems that acid scrubbing by packed column is more successful than other methods. In this study, the possibility of removal of ammonia gas with sulfuric acid scrubbing liquid by a packed column was investigated. A packed column with 20 cm diameter was randomly packed in 30 cm with ceramic raschig rings. Acidic scrubbing liquid in three liquid flow rates and three pH of scrubbing liquid including 5, 6, and 7 were used to scrub the gas with three concentrations as well as three air flow rates. The pH values of scrubbing liquid were controlled by using sulfuric acid and monitored with a pH meter. Ammonia gas was measured by using a direct reading sampler. All measuring instruments were calibrated by the researcher or local manufactures representative. The results were analyzed by SPSS version 16 software package. The findings of this study showed that with decreasing the pH of scrubbing liquid from 7 to 6theremoval efficiency of column increased but it was not significant. Also with decreasing the pH of scrubbing liquid from 6 to 5theremoval efficiency of column increased but it was not significant. However, the removal efficiency of column increased significantly (p<0.01) as the pH of scrubbing liquid was reduced from 7 to 5. Chemical absorption was increased the removal efficiency of ammonia gas significantly. Gas removal efficiency was increased with the decreasing of scrubbing liquid pH values.