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Abstract: One of the most promising technologies for stationary power applications is the Molten Carbonate Fuel Cell (MCFC). This is due to its high efficiency, low emissions and the medium–high operating temperature. This high temperature allows for hybridization with other power generation technologies where the bottoming cycle recovers part of the heat in the fuel cell exhaust stream, hence resulting in highly efficient hybrid systems. The current MCFC hybrid system designs use microturbines as bottoming cycle. This paper presents the integration of a MCFC with a bottoming Humid Air Turbine (HAT) instead of the conventional microturbine. The HAT cycle, even if still under development, provides a relatively simple and inexpensive solution to increase the power output of the microturbine. An indirect integration between the MCFC and the HAT cycle is chosen aiming to simplify the layout and operation of the new system and considering that the necessary modifications to be performed in the microturbine are relatively simple (and therefore the additional equipment is expected to be relatively economical). The results presented in this paper show the potential of this MCFC–HAT combination with an increase of the net power output of 6 percentage points and an efficiency increase of 3 percentage points from the high efficiency conventional hybrid system (MCFC–MGT). An economic analysis as function of the MCFC investment cost is presented showing a break-even-cost of 2092 €/kW improving the estimated for the MCFC–MGT. [Copyright &y& Elsevier]

• A novel integrated gas turbine, MCFC and ORC system with CO 2 recovery is proposed. • The exergy utilization diagram (EUD) methodology is applied to reveal the energy conversion process more clearly. • The temperature matching of the new system is optimized in this paper. • When the CO 2 capture rate is 0.85, the thermal efficiency of the new system is 62.34% and the exergy efficiency is 60.08%. A huge amount of energy is consumed by recovering CO 2 in the gas turbine (GT) exhaust gas with the traditional method because of the low CO 2 concentration. A new system integrated with gas turbine, MCFC and ORC with CO 2 capture is proposed in this article. CO 2 in the gas turbine exhaust gas is concentrated by the MCFC electrochemical reaction. Compared with traditional CO 2 capture methods, it effectively decreases the energy consumption of CO 2 capture. The mid-temperature exhaust gas heat is recovered by two stages organic Rankine cycle systems. The influences of the major parameters on the new system performance are deeply studied. Also, the thermal and economic performances of the new system are compared with those of the reference system without CO 2 capture and with CO 2 capture based on the traditional mono-ethanol ammine (MEA) method. The results show that, when the CO 2 capture rate is 0.85, the thermal efficiency of the new system is 62.34%, 3 percentage points higher than that of the gas steam combined cycle system without CO 2 capture; and the exergy efficiency is 60.08%, 2.47 percentage points higher than that of the gas steam combined cycle system without CO 2 capture. Its economic performance will be improved with the reduction of the MCFC cost in the future. [ABSTRACT FROM AUTHOR]

In this paper the results of an on-site experimental analysis carried out on a Molten Carbonate Fuel Cell (MCFC) fed by different fuels (hydrogen, landfill gas and different mixtures of them) are presented. The examined MCFC is one of the experimental devices of an innovative power plant located at the urban landfill of Giugliano in Campania (Naples, Italy). Here, electricity is produced through four cogenerative reciprocating engines and one cogenerative gas turbine fed by landfill gas, operating since 2003. At the same site, two different fuel cells are installed for scientific purposes. During the considered experimental campaign, the MCFC is initially supplied by hydrogen for testing the system at the best operating conditions. Afterward, the fuel cell is fed by mixtures of different ratios of hydrogen and reformed landfill gas. For this reason, the system is equipped with an external reformer and a suitable gas cleaning. In order to analyse the system energy performance under varying electricity loads (obtained through an electronic device), several tests were carried out. In addition, several stress tests were also performed aiming at analysing the system endurance when fed by landfill gas. The experimental results concerning the produced electric currents and voltages show satisfactory performance of the system, while the obtained operating temperatures and cell reliability still need to be improved. [ABSTRACT FROM AUTHOR]