Conversion of Sweet Sorghum Bagasse into Value-Added Biochar

Abstract

Sweet sorghum bagasse is an untapped resourceful carbon-rich material that can be thermochemically converted into value-added biochars. These biochars can be applied to the field as soil amendment for soil health enhancement, improved soil carbon content, water holding capacity, soil drainage and aeration, and plant and sugar yields. This study looked at four different varieties of sweet sorghum and processed their bagasse into biochars at low and high temperature (350 °C and 700 °C). The feedstock materials and respective biochars were chemically characterized for their nutrient content. Several physicochemical and adsorptive properties were also determined to ascertain their potential use as either adsorbents, soil amendment materials or as fuel sources, and compared with other plant and refinery wastes. No major differences were observed among the varieties in terms of resulting properties of the biochar; however, pyrolysis temperature affected biochar properties. Fuel value, fixed carbon, ash content and surface area increased with pyrolysis temperature. However, low-temperature biochars were better candidates as copper ion sorbents. Benefits of using sweet sorghum bagasse as value-added material are expected to help both sweet sorghum growers and processors through the production of value-added pyrolysis products, as well as enhancing the sweet sorghum industry’s role in renewable energy markets.