Simulation of an atmospheric SOFC and gas turbine hybrid system using Aspen Plus software

Fuel cell is an energy conversion device that transforms the chemical energy of a fuel gas directly into electrical energy without direct combustion as an intermediate step. One type of fuel cell is the solid oxide fuel cell (SOFC) with the operation temperature of around 1273 degrees K. The high operating temperature of the SOFC also provides excellent possibilities for feeding into a gas turbine (GT) to generate additional electricity. In this paper, an atmospheric SOFC and GT hybrid system have been simulated by application of Aspen Plus existing functions and unit operation modules. The study has shown that the system efficiency and voltage reduce continuously as the current density increases due to increase of Ohmic and concentration losses. However, the output power increases due to enhancement of the current density. Therefore, the system should operate at low current density if the goal is to generate power at higher efficiency. Moreover, if the goal is to produce more power, the system should operate at high current density. The simulation results indicate that the cycle can achieve high electrical generation efficiency (68.2%), which is very attractive compared to the ideal efficiency of combined cycle power plants around 50%. Moreover, a parametric analysis has been performed to assess the effects of the several operating condition variation on the system performance. Copyright (c) 2011 John Wiley & Sons, Ltd.