Comparison of waste heat recovery from a Proton Exchange Membrane fuel cell by gas turbine or Organic Rankin Cycle: a display of 3E analysis

One of the most important methods for efficient hydrogen utilization is the proton exchange membrane fuel cell (PEMFC) because of its low environmental impact and easy maintenance. Depletion of fossil fuels along with global warming is all the more reason for researchers to seek new methods to convert primary energy into power, heating, etc. In the meantime, fuel cells are a promising method to convert energy into usable power. In this study, a proton exchange membrane fuel cell utilizing hydrogen as a fuel is proposed as the main component of a power generation system. The waste heat of the fuel cell is then recovered via two scenarios, using the waste heat as the heat source of an organic Rankin cycle (ORC) or using it to be expanded in the gas turbine. A comprehensive energy and exergy analysis are carried out to find the effectiveness of the system along with the adverse conditions of the components. Results demonstrate that at operation conditions, the system integrated with a gas turbine performs better in terms of energy and exergy efficiencies by 45% and 33%, respectively. Also, Fuel cell, and afterburner has the highest exergy destruction ranks amongst other elements, since they have all three main source of irreversibility. Furthermore, the economic study results show that the PEMFC/GT has a lower Levelized cost of electricity compared to the PEMFC/ORC.