Preventing Aerosol Emissions in a CO2 Capture System: Combining Aerosol Formation Inhibition and Wet Electrostatic Precipitation.

Abstract

Aerosol emission from the CO2 capture system has raised great concern for causing solvent loss and serious environmental issues. Here, we propose a comprehensive method for reducing aerosol emissions in a CO2 capture system under the synergy of aerosol formation inhibition and wet electrostatic precipitation. The gas-solvent temperature difference plays a vital role in aerosol formation, with aerosol emissions of 740.80 mg/m3 at 50 K and 119.36 mg/m3 at 0 K. Different effects of SO2 and SO3 on aerosol formation are also found in this research; the aerosol mass concentration could reach 2341.25 mg/m3 at 20 ppm SO3 and 681.01 mg/m3 at 50 ppm SO2 with different aerosol size distributions. After the CO2 capture process, an aerosol removal efficiency of 98% can be realized by electrostatic precipitation under different CO2 concentrations. Due to the high concentration of aerosols and aerosol space charge generated by SO2 and SO3, the removal performance of the wet electrostatic precipitator decreases, resulting in a high aerosol emission concentration (up to 130.26 mg/m3). Thus, a heat exchanger is installed before the electrostatic precipitation section to enhance aerosol growth and increase aerosol removal efficiency. Under the synergy of aerosol formation inhibition and electrostatic precipitation, an aerosol removal efficiency of 99% and emission concentrations lower than 5 mg/m3 are achieved, contributing to global warming mitigation and environmental protection.