Xiaojian Ma

Thermal decomposition and kinetics of coal and fermented cornstalk using thermogravimetric analysis

The thermal behavior and kinetics of Yiluo coal (YC) and the residues of fermented cornstalk (FC) were investigated in this study. The Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO) methods were used for the kinetic analysis of the pyrolysis process. The results showed that the activation energy (Eα) was increased with the increase of the thermal conversion rate (α), and the average values of Eα of YC, FC and the blend (mYC/mFCu202f=u202f6/4) were 304.26, 224.94 and 233.46u202fkJ/mol, respectively. The order reaction model function for the blend was also developed by the master-plots method. By comparing the Ea and the enthalpy, it was found that the blend was favored to format activated complex due to the lower potential energy barrier. Meanwhile, the average value of Gibbs free energy of the blend was 169.83u202fkJ/mol, and the changes of entropies indicated that the pyrolysis process was evolved from ordered-state to disordered-state.

Effects of hot-washing process on structure and enzymatic hydrolysis of treated steam explosion corn stover

BackgroundCellulase adsorption of lignocellulosic materials is the key link during enzymatic hydrolysis. Hot-washing process (above lignin glass transition temperature) was used to change the physical structure of lignin, decrease covalent connection between cellulose and lignin, reduce the concentration of inhibitor, and explore the feasibility of enzymatic hydrolysis. The general objective of the paper was conducted to determine whether the hot-washing process has the potential to change the mechanism of lignin on enzyme hydrolysis.ResultsHot-washing was carried out at 151xa0°C for 20xa0min. The ratio of acid insoluble lignin to acid soluble lignin was increased, while the formation of spherical lignin droplets on the cell wall surface was decreased. Enzymatic digestibility of hot-washed filter cakes showed enhanced digestibility over the control samples. The concentration of fermentation inhibitor (acetic acid, formic acid, furfural and 5-hydroxymethylfurfural) obviously decreased after hot-washing process.ConclusionsHot-washing process significantly increased the adsorption ability of cellulase on the substrates and digestibility of biomass without removing much of the insoluble lignin content. Lignin distribution and/or physical property composition play a role.