The components in liquid and gas products from torrefaction of lignocellulosic biomass: Contribution from hemicellulose, cellulose and lignin

摘要

Torrefaction is a low temperature thermal treatment for lignocellulosic biomass to improve its energy density. Since the main product of this process is used as solid fuels, rather cheap products, any additional benefits must be considered in order to improve economical feasibility. From this viewpoint, it is important to identify the by-products from torrefaction. In the present study, torrefaction of empty fruit bunches (EFB) and palm kernel shell (PKS) was carried out by using a fixed-bed tubular reactor at 473-573 K for 30 min under nitrogen atmosphere. The representative by-products identified in the present study included carbon dioxide, carbon monoxide, water, acetic acid and phenol. In gas phase, also minor hydrogen and methane were detected. In liquid phase, fifteen types of minor organics were detected. Firstly, pyrolysis products from hemicellulose, cellulose and lignin were listed up from previous studies. Then by-products detected in the present study were correlated to possible sources, such as hemicellulose, cellulose and lignin. Secondly, the yields of major by-products were estimated by summing up the contributions from hemicellulose, cellulose and lignin, and compared with the observed yields.