Energy, Vol.179, 19-29, 2019
Potential power generation on a small-scale separated-type biomass gasification system
A small-scale separated-type biomass gasification system composed of a screw pyrolyzer, a steam tar reformer, an air-steam char fluidized bed gasifier, and a spent char combustor with heat carrier particles circulating is designed to convert woody biomass into combustible gas which can be applied for gas engine power generation. In this study, the simulation results of this system based on two biomass pyrolysis routes, i.e., fast and slow pyrolysis, are analyzed and compared. During the simulations, the empirical equations as well as the main experimental data from the published literature are applied to analyze the elemental, mass, and energy balances of each process by using sets of assumptions at a certain condition to predict final energy efficiency and the potential electricity generated from the system. As a result, 12.5 kg/h of wood biomass feeding to this system has power generation ability of 16.8 kWe and 16.3 kWe with cold gas efficiencies of 73.8% and 71.7% for the fast and slow pyrolysis routes respectively. Comparison of product yields and compositions obtained in the present system with the reported data shows that the prediction gives a reasonable accuracy which could indicate what occur within the system. The calculation methods presented in this study could be utilized for preliminary engineering design of comprehensive biomass thermal conversion processes. (C) 2019 Elsevier Ltd. All rights reserved.