ISSN Online: 2688-7231
ISBN Flash Drive: 978-1-56700-497-7
ISBN Online: 978-1-56700-496-0
Proceedings of the 25th National and 3rd International ISHMT-ASTFE Heat and Mass Transfer Conference (IHMTC-2019)
Mathematical model for energy and exergy analysis of Underground coal gasification
Underground Coal Gasification (UCG) is an important emerging environment friendly technology which can enable us to extract energy from coal seams at the greater depth inside earth's surface. Efficient gasification of coal depends on many factors of which the dominant are coal properties, oxidant properties and reaction properties. In the present study a numerical model is built based on thermodynamic equilibrium approach for exergy analysis of UCG process. Syngas composition is obtained by solving mass balance equations and equations relating mole fraction of chemical species with equilibrium constants. The gasification temperature is determined by solving the energy balance equations. Using the mole fractions of the chemical species and gasification temperature exergy analysis has been carried and second law efficiency for the process is determined. Effects of oxidant supply on second law efficiency is studied where it is found that the exergy efficiency for gasification is high at lower supply rates of air and steam.