Aerosol emissions and mitigation of aqueous AMP/PZ solvent for postcombustion CO2 capture

Abstract

Aerosol emissions from the CO₂-capture process have a significant impact on both solvent depletion and environmental contamination. This work comprehensively investigated the emissions of AMP (2-amino-2-methyl-1propanol)/PZ (piperazine) from a bench-scale platform and a CO₂-capture pilot plant. The concentration of nuclei in flue gas is a key factor affecting aerosol emissions, and a high nuclei concentration leads to more serious aerosol emission problems. The amine emissions after the absorber in the three different scenarios (no added nuclei, nuclei added, and pilot plant) were 273, 1051, and 1347 mg/Nm³, respectively. Increasing the lean-solvent temperature promoted aerosol emissions, and increasing the liquid/gas ratio and CO₂ loading in the lean solvent suppressed aerosol emissions. In the pilot plant, the effects of four mitigation measures were evaluated, and it was found that dry bed and acid washing had better mitigation effects than did conventional water washing; amine emissions could be reduced to as low as 21 mg/Nm³ PZ and 25 mg/Nm³ AMP. This study provides a reference for the design and optimization of carbon-dioxide-capture systems, which can help to reduce the impact on the environment.