Beneficial use of Fe-impregnated bentonite as a catalyst for pyrolysis of grass cut into syngas, bio-oil and biochar

Abstract

Fe-impregnated bentonite was employed in CO2-assisted pyrolysis of grass cut as a catalyst to improve syngas production, bio-oil quality, and biochar sorptive property. The gas analysis revealed that H2 and CO production was enhanced by 332 and 7,110%, respectively, by applying Fe-impregnated bentonite in pyrolysis of grass cut while untreated bentonite had a limited influence on syngas production. Bio-oil produced from Fe-impregnated bentonite and grass cut (Fe-BG) had more homogenized chemical species in bio-oil as compared to that produced from pyrolysis of grass cut, and contained methyl 1,1-methyl-dodecanoate (C14H28O2), one of the major components in biodiesel. The produced biochar had high surface area (69.2 m2 g−1) and possessed Fe0 and graphitic carbon structure, which was deemed to arise from reduction of Fe-oxides by syngas. Biochar also showed high As(V) adsorption capacity. The overall results of this work demonstrated the beneficial utility of Fe-impregnated bentonite in pyrolysis of biomass to improve syngas production as well as the quality of pyrogenic products.