The potential of biocarbon as CO2 adsorbent in VPSA unit

Abstract

The best solution to the main environmental problem seems to be CO2 capture to reduce greenhouse gas emissions. The activated carbons derived from biomass have attracted extensive attention as solid adsorbent for carbon dioxide capture process. In this work, we focus on examining the properties of biochar (non-activated porous carbon) produced from biomass. Physicochemical properties of the biochar were investigated by thermogravimetric analysis (TG), Fourier transform infrared spectroscopy, scanning electron microscopy and N2 adsorption–desorption at 77 K. In order to evaluate the possibility of using biocarbons for CO2 adsorption in large-scale VPSA units, investigations of these adsorbents in laboratory are necessary. The paper present the potential of biochar for CO2 capture in VPSA unit. The examination of the CO2 sorptive capability, stability and regeneration performance of biochar was carried out using a Mettler-Toledo TGA/SDTA 851e thermobalance and TG-Vacuum system. The sorption of CO2 was carried out isothermally in a flow of a mixture of gasses: CO2 (100 vol.%) and CO2 (16 vol.%)/N2 (84 vol.%). The commercial biochar showed a sorption performance for CO2 up to 26.4 mg CO2 g−1 adsorbent at 30 °C and 30 bar. Repeated use of the adsorbent in the sorption/desorption cycle did not affect its performance, which indicates high sorption stability.