Thermodynamic and exergetic assessment of a biomass derived syngas fueled gas turbine powered trigeneration system

Abstract

Processing of waste materials for the generation of renewable fuels, and the development of trigeneration systems are known as the sustainable procedure for satisfying the diverse energy demands. In this regard, this study aims at developing and analyzing a trigeneration system which consists of a gasifier, combined power cycle, and a vapor absorption refrigeration (VAR) system. A model based on equilibrium thermodynamics was developed which has considered the tar formation and char conversion, and accordingly, composition of biomass derived syngas was predicted by employing the MATLAB software. The gasifier operating performance is assessed for the effect of change in gasification equivalence ratio (GER), steam-to-biomass ratio (SBR), and type of biomass feed. Increase in GER from 0.3 to 0.6 for saw dust gasification reduces the energy and exergy efficiencies of gasifier from 44% to 27.5%, and from 51% to 34%, respectively. Finally, a computational method for the energetic and exergetic assessment of the trigeneration was developed using the EES software and a parametric analysis was conducted. CCHP system efficiencies are found considerably influenced by change in SBR and type of biomass feed. Having 40% second law efficiency gasifier has been determined as the most exergy destructive component in the system proposed.

Keywords

• Biomass derived syngas
• Trigeneration system
• Energy
• Chemical exergy
• Second law efficiency