Thermodynamic and Economic Analysis of a Conceptual System Combining Sludge Gasification, SOFC, Supercritical CO2 Cycle, and Organic Rankine Cycle

In order to reduce the environmental impact of conventional sludge treatment methods and to utilize the energy in sludge more effectively, a coupled system based on sewage sludge gasifier (SSG), solid oxide fuel cells (SOFC), supercritical CO2 cycle (S-CO2), and organic Rankine cycle (ORC) is proposed. The clean syngas obtained from sludge gasification is mixed with CH4 and then first utilized by the fuel cell. The exhaust gas from the fuel cell is fully combusted in the afterburning chamber and then enters the bottom cycle system consisting of S-CO2 ORC to generate electricity. To understand the performance of the system, thermodynamic and economic analyses were conducted to examine the project’s performance. The thermodynamics as well as the economics of the coupled system were analyzed to arrive at the following conclusions, the power production of the system is 37.34 MW; the exergy efficiency is 55.62