Thermal Properties of Biochars Derived from Waste Biomass Generated by Agricultural and Forestry Sectors

Abstract

Waste residues produced by agricultural and forestry industries can generate energy and are regarded as a promising source of sustainable fuels. Pyrolysis, where waste biomass is heated under low-oxygen conditions, has recently attracted attention as a means to add value to these residues. The material is carbonized and yields a solid product known as biochar. In this study, eight types of biomass were evaluated for their suitability as raw material to produce biochar. Material was pyrolyzed at either 350 • C or 500 • C and changes in ash content, volatile solids, fixed carbon, higher heating value (HHV) and yield were assessed. For pyrolysis at 350 • C, significant correlations (p < 0.01) between the biochars' ash and fixed carbon content and their HHVs were observed. Masson pine wood and Chinese fir wood biochars pyrolyzed at 350 • C and the bamboo sawdust biochar pyrolyzed at 500 • C were suitable for direct use in fuel applications, as reflected by their higher HHVs, higher energy density, greater fixed carbon and lower ash contents. Rice straw was a poor substrate as the resultant biochar contained less than 60% fixed carbon and a relatively low HHV. Of the suitable residues, carbonization via pyrolysis is a promising technology to add value to pecan shells and Miscanthus.

Effect of Temperature on the Structural and Physicochemical Properties of Biochar with Apple Tree Branches as Feedstock Material

“…Various types of biomass (wood materials, agricultural residues, dairy manure, sewage sludge, et al) have been used to produce biochars under different pyrolysis conditions [9,10]. During pyrolysis, biomass undergoes a variety of physical, chemical and molecular changes [11].…”

Energy Recovery Efficiency of Poultry Slaughterhouse Sludge Cake by Hydrothermal Carbonization

“…Anderson et al [32] also reported that biochars derived from woody plants had higher calorific values. In a recent study, bamboo sawdust biochar pyrolysis at 500 • C had a high colorific value of 32.4 MJ/kg [33], which was comparable to the calorific value (31.2 MJ/kg for 220 • C) of HTC-biochar in this study. Therefore, the HTC technique is effective in creating a high quality biochar from sludge cake at lower temperatures as compared to lignocellulosic feedstocks.…”

Chemical Characteristics and NaCl Component Behavior of Biochar Derived from the Salty Food Waste by Water Flushing

“…The temperature in the furnace increased to the target temperature of 300 °C, 400 °C, and 500 °C, and the samples in the sample chamber were then added. The mass yield of biochar at each temperature is 0.56, 0.38, and 0.32 as the pyrolysis temperature increases 300 to 500 °C, and the biochar yields are decreased as the pyrolysis temperature increases [22]. After pyrolysis, the samples were removed, cooled to room temperature, weighed, and ground.…”