Biochar from Agro-Forest Residue: Application Perspective Based on Decision Support Analysis

Abstract

The present work aims at (a) carbonizing agriculture biomass residue; (b) characterizing the obtained biochar; and (c) exploring its potential use for energy/resource recovery purposes. Six types of biomass were carbonized. The biochar was investigated through scanning electron microscopy with energy dispersive X-ray spectroscopy detector, thermogravimetric (TGA), proximate, ultimate, and Brunauer–Emmett–Teller analyses, along with bulk density, pH, electrical conductivity, and salt content measurements. The results served as input data for multi-criteria, multi-objective decision analysis of biochar, aiming to evaluate its best application prospective. The TGA identified two general stages: devolatilization (stage 2: 180–560 °C), and combustion (stage 3: 560–720 °C). The activation energy of stage 2 decreased with an increasing heating rate, but the opposite trend was observed for stage 3. The biochar CO2 adsorption suggested possible applications beyond energy conversion technologies. The decision support analysis revealed that peach stones, cherry stones, and grape pomace biochar achieved the most promising results for all evaluated applications (biofuel; catalyst; CO2 sequestration and soil amendment; supercapacitor) in contrast to colza, softwood, or sunflower husks char.