Waste heat from a biomass fueled gas turbine for power generation via an ORC or compressor inlet cooling via an absorption refrigeration cycle: A thermoeconomic comparison

The key factors in sustainable energy development are increasing the energy conversion efficiency in using available resources and decreasing the environmental impacts, where waste heat recovery is one practice of achieving these goals. In this work, a novel biomass fueled externally fired gas turbine with closed cycle is introduced. Then its exhaust heat is utilized for power generation via organic Rankine cycle or inlet cooling of gas compressor via an absorption cooling cycle. Comprehensive analysis and performance comparison is made for proposed two systems from thermoeconomic standpoint. The effects of key design variables are examined on their performance and two-objective optimization is accomplished by genetic algorithm procedure to determine the optimum operating points based on levelized cost of electricity and exergetic efficiency. The results indicted superiority of waste heat utilization for compressor inlet cooling than the use of it for power generation, for all the variety of operating/design conditions. It is found that, at multi-objective optimal points, the gas turbine system with inlet cooling has 11.2% higher exergy efficiency and 12.3% lower electricity cost than the gas turbine system combined with organic Rankine cycle.