Physico-chemical characterization of biomass, coal, and their chars using kinetics and electrochemistry

Abstract

The supply of sustainable and distributed energy becomes a concern. In this study, physico-chemical characterizations of coffee grounds, raw wood, composting sewage sludge, and raw comparable coal, as well as their chars were performed using carbonization/combustion kinetics and electrochemistry in order to promote the supply of sustainable and distributed energy. The carbonization kinetics of coffee grounds were faster than those of raw wood, composting sewage sludge, and raw coal because of the higher content of volatiles and potassium. The specific surface area of the wood char with steam activation was larger than those of the other chars, and that of the coffee grounds char with steam activation was also relatively larger. The graphitization degree of the wood char was similar to that of the coal char. The average potential of a direct carbon fuel cell (DCFC) using the composting sewage sludge char was higher than that of the other chars. Thus, the coffee grounds, wood, and composting sewage sludge chars may be better candidates for use as an adsorbent, heat source, and DCFC fuel, respectively.