Combustion Kinetics of Biochar Prepared by Pyrolysis of Macadamia Shells

Abstract

The use of macadamia shells (MSs) has become an active research direction because of increasing production. This paper considers the combustion characteristics of MSs and their biochars that were investigated with thermogravimetry analysis (TGA). Combustion thermographs were obtained at different heating rates, using isoconversional methods expressed by combustion kinetics. The Kissinger-Akahira-Sunose (KAS) method authenticated the MSs, MSs-300, and MSs-600 average activation energy at 91.6 kJ/mol, 60.5 kJ/mol, and 50.1 kJ/mol, respectively. The Flynn-Wall-Ozawa (FWO) method authenticated these at 97.1 kJ/mol, 68.7 kJ/mol, and 59.5, kJ/mol. The Coats-Redfern method verified the samples combustion via a complex multi-step mechanism; the first stage mechanism had different activation energies at different heating rates. With increased heating rates, the activation energies of biochar decreased, and the activation energies of MSs for the second combustion zone also decreased. At the same heating rate, MSs-600 had higher activation energy values than MSs-300. The TGA curves and kinetic parameters demonstrated the superiority of the biochar derived MSs as a fuel substrate over its precursor.

Preparation and properties of hydrochars from macadamia nut shell via hydrothermal carbonization

“…However, studies on the energy utilization of MNS are rarely reported. In these respects, a related study has been conducted [ 13 , 14 ]. The results show that prepared biochar from MNS offers an important application prospect.…”

Research on the optimum carbonization process of walnut shell based on dynamic analysis

“…Biomass pyrolysis technology is suitable for biomass carbonization because it considers the types, distribution characteristics, and economy of biomass resources, and the raw material of carbonization technology is mainly fruit shell waste. 28 Walnuts have a certain scale in the food processing industry. The output of walnut shells is large, unreasonably utilized, and treated as garbage, thereby subjecting these shells to incineration.…”

Pyrolysis mechanism and pyrolysis kinetics of yellow wine lees

“…Moreover, the weight loss rate at a given temperature point and the maximum rate of weight loss through pyrolysis increased in response to an increase in the heating rate; this nding is in agreement with the pyrolysis results of lees reported by Wang 56 et al, this is because the increased heat conduction between the sample and the reactor, which is induced by the accelerated heating rate, causes the interior of the lees to reach the maximum pyrolysis temperature more quickly when the pyrolysis process begins; volatile components precipitate rapidly, which in turn increases the rate at which weight is lost. 57,58 Analysis of pyrolysis kinetics of yellow wine lees…”