Optimization and Characterization of Biochar Obtained from the Weedy Biomass of Calotropis gigantea Using Vacuum Pyrolysis

Abstract

The excessive growth of invasive weeds causes adverse economic and environmental effects. In the present study, invasive weed Calotropis gigantea was pyrolyzed under optimized parameters of 450° and 50-100 mm particle size for 1.00 hour of reaction time for biochar production. The biochar was characterized by the presence of a high carbon content of 64.65% and low H/C and O/C molar ratios of 0.08 and 0.15, respectively. The biochar was observed with high surface area of 99.91m2/g and pore volume of 0.0398cm3/g along with mineral fractions such as K-1.33%, Na-1.17%, Mg-1.05%. Strong FTIR bands were observed at 1994.1 cm-1, 1110 cm-1, and 745 cm-1, representing allenes (R 2C=C=CR 2), aryl alkyl ethers (R – O – R), and aromatic (C–H) bending. All these parameters indicate its potential in the applications such as carbon sequestration, climate change mitigation, environment pollutants adsorption (both organic and inorganic), and soil improvement.