Energy and exergy analysis of steam gasification of biomass materials: a comparative study

Abstract

Conversion of solid biomass to gaseous fuel by thermo-chemical method is an efficient and feasible way for bio-hydrogen production. This article presents energy and exergy analyses of steam gasification of four biomass materials found plenty in southern part of Indian subcontinent. The biomass materials are coconut shell, coir pith, bamboo and eucalyptus. For the analysis, an exergy model is formulated based on a Redlich–Kwong real gas equilibrium model. Parametric variations with steam-to-biomass ratio and gasification temperature are presented for energy and exergy efficiencies of gasification. The biomass materials are compared based on exergy destruction, associated entropy generation and exergy efficiency of the gasification process. Comparison of the predicted results with the existing literature is done for validation. It is found that the least irreversible gasification process is for coir pith, followed by coconut shell, bamboo and eucalyptus with the corresponding exergetic efficiencies of 79.2%, 77.5%, 74.4% and 68.3%, respectively.