Modeling and Analysis of a Solid Oxide Fuel Cell Based Trigeneration System with an Oxygenated Fuel by Using an Exergoeconomic Methodology for Power, Heating and Cooling Production

In the present study, thermo-economic analysis of a combined solid oxide fuel cell (SOFC) with a gas turbine, a generator-absorber heat exchanger (GAX) and heating process heat exchanger for heating, cooling and power production as a tri-generation system is conducted. Also, an external steam reformer is applied to convert methanol as oxygenated fuel to hydrogen for the electrochemical process of the SOFC. The influence of the primary design parameters (anode inlet temperature and current density) on several variables (energy and exergy efficiencies, exergy destruction, SUCP and unit costs of the products) are examined. Results showed that energy efficiency of proposed system was 55% higher than standalone SOFC. It was found that the maximum exergy destructions occurred in fuel and water mixer, after burner and SOFC. Unit cost of cooling was higher than the other products in the proposed system. It was equal to $220.3/GJ at a specific condition, while unit cost of power and heating were $34.22/GJ and $1.24/GJ, respectively. That was because cooling system needed more components than other systems.