22 - Life-Cycle Assessment of Agricultural Waste-Based and Biomass-Based Adsorbents

Abstract

With the concept of circular bioeconomy, the conversion of agricultural and biomass wastes into valuable products plays an important role in sustainable resource utilization. Adaptation and evaluation of such waste products are necessary for the environmental impact as well as environmental benefits. This chapter reviews the environmental performance of agricultural waste- and biomass-based adsorbents through comparative life cycle assessment with commercial activated carbon production. Several residue utilization pathways of life cycle assessment showcase the potential of each residue from the perspectives of energy balance, GHG emission, and other impact categories. The conversion of biomass to bioenergy and biochar showed a better environmental performance than direct combustion. The adsorption efficiency of bioadsorbents increases through surface modification with different activation processes. Thermal processes were found to be more effective with the formation of biochar compared to other chemical processes. It has been reported that the reutilization of low cost agricultural- and biomass-based residues as adsorbents and subsequent utilization of the spent adsorbents in soil are the most preferred options from the perspectives of pollutants adsorption and carbon sequestration. Moreover, integration of production, utilization, and disposal of bioadsorbents in the scope of the life cycle assessment helps in deciding the best option for circular bioeconomical utilization of the bioadsorbents.