Integration of biomass gasification with a supercritical CO2 and Kalina cycles in a combined heating and power system: A thermodynamic and exergoeconomic analysis

Abstract

A novel cogeneration system based on a combination of a gas turbine cycle, a supercritical CO2 cycle, and a Kalina cycle is devised for heating and power generation. Energy, exergy, and exergoeconomic analysis are performed to assess the system’s performance and feasibility. According to the findings, the energy and exergy efficiencies of the system are obtained by 78.15% and 40.97%, respectively. In addition, heating capacity enhanced with the increment of air preheater’s terminal temperature difference (ΔTAP), air compressor’s pressure ratio (r1p), and pressure ratio of S–CO2 compressor (r2p). The system’s sum unit cost of the product (SUCP) decreased with the increment of ΔTAP and with the decrement of ammonia concentration. Besides, the minimum value of SUCP is obtained at the air compressor pressure ratio of r1p=13.24 and r2p=2.63. The maximum value of exergy efficiency is evaluated at ΔTAP=262K, r1p=14.5, and r2p=4.21. Moreover, the maximum net output power is obtained where the design parameters are set as ΔTAP=262K, r1p=14.5, and r2p=3.5. Furthermore, the economic analysis revealed that the payback period and net present value are evaluated to be 6.9 years and 5.374×10+6 $, respectively, for the electricity price of 0.07 $/kWh and fuel cost of 2 $/GJ.