Dependency of the combustion behavior of energy grass and three other types of biomass upon lignocellulosic composition

Abstract

The combustion characteristics of four kinds of biomass fuels (energy grass, sawdust, corn cob, and walnut shell) are investigated in this article. All the samples are heated from room temperature to 800°C at multiple heating rates of 10, 20, and 30°C/min. The effect of hemicellulose, cellulose, and lignin components on the pyrolysis and combustion processes of energy grass is explored by comparison to those of the other three types of biomass. The hemicellulose and cellulose content of samples could improve the devolatilization performance during biomass combustion. Furthermore, the comprehensive combustion index suggested herein indicates that the combustion performance of energy grass or walnut shell is limited by their high ash content or their low ratio of cellulose to lignin. Kinetic parameters are obtained by combining the isoconversional method (OFW and KAS models) and the method of master‐plots. The apparent activation energy of the devolatilization stage is higher than that of the char oxidization stage, which is mainly influenced by the lignocellulosic composition. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 815–823, 2018

Assessing the Importance of Pyrolysis Process Conditions and Feedstock Type on the Combustion Performance of Agricultural-Residue-Derived Chars

“…The positive effect of Cel on the combustion performance index seems to be in disagreement with the results by Pang et al, 15 who reported a decrease in combustion reactivity for chars produced from some cellulose-rich biomass sources. Nevertheless, Ma et al 46 observed that biomass sources having relatively low cellulose to lignin content ratios exhibited poorer combustion performances. In accordance with the argument made by Yan et al, 17 a relatively low content of lignin could result in a lower insulation of cellulose, which could then easily decompose and lead to chars with enhanced ignition characteristics.…”