Study on removing marine multiple pollutants in raw exhaust gas with a novel composited method combined with pre-agglomeration and wet scrubbing technology.

Abstract

Most of the existing oxidation denitrification methods need longer residence time to obtain higher NOx removal efficiency. In this study, urea peroxide (CO(NH2)2·H2O2) was first used for removing SO2 and NOx on diesel engine bench. The addition of ferrous sulfate can enhance the oxidant capacity of the solution. The better removal efficiency and lower nitrate content in liquid can be achieved in short exhaust gas residence time. The raw gas flow and residence time contained the actual application situation in ships and have high reference value. The removal efficiency decreased with the increase of gas flow, and the reaction temperature, urea peroxide concentration, liquid-gas ratio were the main factors. The optimal Fe2+ concentration of 50mmol/L and pH value of 4 were determined. The urea peroxide concentration, reaction temperature, and liquid-gas ratio were 9%, 70℃, and 10L/m3 respectively. The maximum gas treatment capacity was about 100L/min, and residence time was close to 10s for the scrubber. The pre-agglomerating method were used to improve the particle capturing efficiency combined with spray technology. The composited method can realize the synchronous and efficient removal of multiple pollutants in a single scrubber. The possibility of application on ship was further increased.