Comparison of removal efficiencies of carbon dioxide between aqueous ammonia and NaOH solution in a fine spray column

Experimental studies on carbon dioxide capture in a spray column were carried out. Fine spray of aqueous ammonia and NaOH solution were used as CO2 absorbent. Effects of different operating and design parameters, including concentration of aqueous ammonia solution and NaOH solution, absorbent solution volume flow rate and total gas flow rate on CO2 removal efficiency were investigated. Experimental results showed that the higher concentration of aqueous ammonia solution and NaOH solution, the larger volume flow rate of absorbent solution and the lower flow rate of total gas mixture of nitrogen and CO2 were beneficial to promote CO2 removal efficiency. In order to have high removal efficiency of CO2, the mole ratios of absorbents to CO2 should be larger than certain values for aqueous ammonia solution and NaOH solution, respectively.