Evaluation of hydrothermally carbonized alternative biomass (Lepironia articulata) as a source of alternative energy and adsorbent

Abstract

Lepironia articulata (LA) widely available wetland biomass was successfully converted into a solid coal-like material called hydrochar. Hydrothermal carbonization (HTC) being a technically-attractive thermal conversion process of biomass into hydrochar at mild conditions was adopted in this study. The effect of process parameters on the physicochemical properties and the yield of hydrochar was studied by varying carbonization temperature and residence time over the range of 180, 200, 220, 240 oC and 6, 12, 24 h, respectively. With an increase in temperature, the hydrochar yield decreased rapidly from 68.8% at 180 oC to 55.2% at 240 oC. In addition, the increase in carbon percentage was observed with an increase in temperature from 10.28% (180 oC) to 38.69 %( 240 oC). The H/C and O/C atomic ratios reduced from 1.392 and 0.541 to 1.072 and 0.271, respectively, which was typically related to decarboxylation, demethanation, and dehydration reactions. Hydrochar obtained was characterized appropriately, i.e., proximate analysis, TGA, HHV, FT-IR and BET. The highest surface area (SBET) of hydrochar obtained was 72.2 m2/g. The maximum iodine number calculated was 220 mg/g. HHV of hydrochar was in the range of 22.52 to 25.1 MJ/kg. Overall results conclude the effectiveness of LA in the field of environmental remediation, sustainable and alternative energy.