Feasibility and Economic Issues of Biomass Pyrolysis-Gasification: the Effect of Moisture Content of Raw Material

Abstract

The use of various wastes, such as biomass as a raw material, has significant benefits from both an emission and economic point of view. The products yield and composition, as well as the feasibility of the process, are influenced by several factors. However, the moisture content can also play an important role, because the presence of water greatly influences the chemical processes taking place and their economic characteristics. In this work, the pyrolysis and gasification of biomass were investigated at different temperatures using different moisture content (0%, 20% and 40%) of raw material, with and without steam and catalyst. The composition of the gas products was determined by GC-FID and GC-TCD methods, and that of the solid product by CHNS analysis. In addition, using given technological layout, the process and its economic issues on the basis of feasibility were also investigated with Aspen Plus V11 software. It was found, that the moisture content of the raw material has increased the yield of hydrogen and H2/CO ratio. Besides, with the increment of temperature the CO/CO2 yield was increased as well. Furthermore, steam added by externally has a beneficial effect on the hydrogen and syngas yield, but it requires significant additional costs. Keywords: biomass, pyrolysis, gasification, synthesis gas, feasib