Abstract:
Biomass gasification is an emerging technology for the production of synthesis gas. A
robust mechanism for evaluating its energy efficiency is vital to realize the biomass
gasification process’s efficient operation. In this context, exergy based analysis has been
getting more attention from researchers over conventional energy-based analysis because
of its capability to encompasses the effect of all the irreversibilities present in a process.
In this study, the exergy analysis of the biomass gasifier was performed in computational
fluid dynamics (CFD) environment. For the model development, the designed
specifications of a lab-scale downdraft biomass gasifier were used. The reaction sets were
imported from the species transport model. A code for exergy analysis was written in a
custom field function (CFF). The designed model achieved better syngas composition and
gasification temperature compared to reported work in literature. The algorithm for exergy
analysis also helped in evaluating the downdraft biomass gasifier’s performance by
analyzing all three types of exergies, chemical exergy, physical exergy, and mixing
exergy.
