Performance Prediction of Gasification of Biomass Briquettes Using Thermodynamic Equilibrium Model
DOI:
https://doi.org/10.26796/jenrm.v2i2.75Abstract
The gasification of biomass resources is considered a promising route for the production of clean energy fuels for the future. The product gas of partial combustion of biomass with air as the gasifying medium is the mixture of CO, H2, CH4, CO2, H2O and N2 called syngas. Syngas generation is now considered matured and acceptable technology compared to other biomass conversion technologies. In this study, a thermodynamic equilibrium model to determine syngas composition based on carbon, hydrogen and oxygen obtained from composite agricultural wastes was developed. For these materials, at preset gasification temperature of 750oC, the effects of changes in moisture content and air/fuel ratio on the quality syngas composition were modeled. The yields of combustible gases (H2, CO and CH4) from Rice husk briquette were observed to be generally higher than those of groundnut shell with sawdust briquette. The result with Groundnut shell and Sawdust briquette as input indicated that the fraction of H2, CO and CH4 gradually decreased, while the concentration of CO2 and H2O increased when moisture content increases from 0% to 45%. Similar trend was observed from the analysis of Rice husk briquette gasification in the model. The amount of Air per kmol of fuel varied from 0 to 1.0. As a result, the H2, CO and CH4 content of syngas for Groundnut shell and sawdust briquette decreased continuously; with CH4 approaching zero at air/fuel ratio of unity. Similar trend occurred in Rice husk briquette, but the values were higher than those observed for the groundnut shell & sawdust briquette. The amount of CO2 and H2O increased from 14.9742% and 20.6603% to 36.5886% and 57.3208% respectively for Groundnut shell briquette, while for Rice husk briquette the amount of CO2 and H2O rose from initial values of 2.8047% and 2.2552% at zero air/fuel ratios to 40.3272% and 45.6339% respectively. The results of this study would be useful for the engineering development of biomass gasification power generation technologies and in the selection of appropriate feedstock.
