Strategic use of biochar for CO₂ capture and sequestration

Dramatic increase of CO₂ emissions to sate the global carbon demand for chemicals, goods, and fuels has been regarded as one of the main contributors triggering global warming. Note that CO₂ emissions are over the Earth's full capacity to assimilate carbons via the natural carbon cycle. In these respects, CO₂ capture and sequestration have been considered as one of the strategic principles to cancel out CO₂ release from the anthropogenic activities in line with the use of fossil fuels. Thus, it is desirable to develop the efficient CO₂ sorptive materials that are economically viable. Among CO₂ sorptive materials, biochar (i.e., porous carbon-based materials) has been considered as one of the promising candidates. Indeed, a great deal of researches on biomass has been performed. Based on these rationales, this review laid great emphasis on informing the recent studies of activated biochars for CO₂ adsorption, which were fabricated from various biomasses. Also, this review offered the up-to-date knowledge on the physicochemical properties of activated biochars in line with their synthesis procedures. Lastly, the effects of biochar properties on CO₂ capture and separation was summarized with in-depth assessment of the activated biochars.