| Abstrakt: |
Biomass utilization has attracted great attention for decades, and the dried distiller's grains with solubles (DDGs) is an important source which is the by-product of brewing industries, as fermented from raw biomass such as rice, wheat and sorghum. Currently, there are a few studies on the kinetics and thermodynamics of distiller's grains biomass. Therefore, the physicochemical characterization, kinetic and thermodynamic analyses of DDGs and DDGs-biochar were studied. The characterization results confirmed that DDGs had high volatile matter (81.6%) and higher heating value (21.3 MJ kg−1). The pyrolysis kinetics of DDGs and DDGs-biochar at four heating rates of 5, 10, 20 and 40 K min−1 were investigated by non-isothermal thermogravimetric analysis. The isoconversional method such as Kissinger-Akahira-Sunose (KAS), analysis showed that the effective activation energy varied with the change in the conversion rates. For DDGs, it was 122–159 kJ mol−1 (α: 0.1–0.2), 160 ± 6.20 kJ mol−1 (α: 0.20–0.75) and 179–194 kJ mol−1 (α > 0.75), corresponded to thermal decomposition of hemicellulose, cellulose and part of lignin, and remaining lignin respectively; as to combustion of DDGs-biochar, it was 152 to 60.1 kJ mol−1 (α: 0.1–0.9) indicated that some of the more complicated structures in DDGs had been carbonized, making as-obtained biochar easier to burn owing to the lower activation energy. The changes in enthalpy, Gibbs free energy and entropy of DDGs and DDGs-biochar were calculated, and the results were helpful to evaluate the conversion efficiency and technical feasibility of DDGs pyrolysis and DDGs-biochar combustion processes. [ABSTRACT FROM AUTHOR] |
