Life Cycle Assessment of Different Sorbents at Early Stage

Climate change caused by man-made carbon-dioxide emissions has become a global consensus. The studies of technologies for CO2 capture have received continuous attention over the past few decades. In our lab, we have developed different biomass sorbents in previous studies, compared to other biomass sorbents, which have more desirable performance for CO2 uptake. However, the application of these sorbents is still an emerging technology at the early stages of development. In order to optimize experimental design or develop large-scale production in the future, life cycle assessment has been employed to assess the environmental impacts of the sorbents prepared by different raw materials and conditions. According to the primary analysis on adsorption capacity and environmental benefits, five CO2 uptake sorbents which synthesized by glucose or wheat flour as the biomass source of carbon were selected in this study. The result shows that, from the environmental perspective, the 700-PC is the best CO2 uptake sorbent in five sorbents at ambient pressure, and the 800-N-PC is the best CO2 uptake sorbent at high pressure. For the source of the environmental burdens, the electricity production is the largest environmental burden in all sorbents, but it has obvious laboratory features and is easy to decreased with the proceeding of industrialization. The environmental burden of glucose is bigger than that of wheat flour. The environmental burden of sodium bicarbonate is lower than that of potassium hydroxide. The environmental benefit of N-doping is different in different conditions, at the ambient pressure, the sorbent without N-doping is better than that with N-doping, but it is opposite at high press. Additive of cobalt has great environmental benefits for sorbents. Meanwhile, we also found that some factors that have great impacts on environment have not been studied before. Hence, in order to get the best environmental friendship sorbents, the further research can be conducted on these issues.