Activated carbon from biomass: Preparation, factors improving basicity and surface properties for enhanced CO2 capture capacity – A review

There has been a concerted and continued effort to enhance the CO2 capture capacity of activated carbon (AC) by adopting various physical and chemical treatments on the AC materials. This review is aimed for the compilation of works performed by various researchers on the synthesis of AC from biomass and two major modification works performed on them to improve their basicity for the application towards CO2 adsorption. The different methods of preparation of ACs utilizing biomass as starting materials have been reviewed. The effects of carbonization and activation on the surface properties of the ACs were discussed. Basicity of AC plays a vital role in the adsorption of CO2 along with the activation of carbon obtained from the carbonization of biomass. The improvement of basicity of ACs by i) nitrogen incorporation and ii) metal oxide impregnation, the various methods adopted to incorporate the above components and their effect on CO2 capture have been discussed in detail.