Molten Carbonate Fuel Cell Power Research Articles

Investigation of a hybrid solar thermochemical water-splitting hydrogen production cycle and coal-fueled molten carbonate fuel cell power plant

Increasing electricity demand in the world’s energy portfolio and the focus on reducing carbon emission footprints has led to broad research into flexible and efficient energy conversion systems. The integration of various energy conversion systems is an efficient approach to meet sustainable energy technologies’ demand in the future. In this study, a brainchild integration process of the solar thermochemical water-splitting hydrogen production cycle and coal-fueled molten carbonate fuel cell coupled with a gas turbine is proposed, modeled, and simulated in AspenTech v9.1. The Zinc/Zinc-oxide thermochemical cycle directly utilizes the solar high-temperature reactor thereby avoiding the need for non-renewable power, thus increasing the efficiency of the system. The molten carbonate fuel cell feeds on the syngas produced by the coal gasification and the oxygen and hydrogen of the thermochemical cycle. The heat of the fuel cell is further exploited by a gas turbine. A sensitivity analysis is conducted to appraise cardinal parameters on system performance indicating the fuel cell pressure, voltage, and current density as the most influential parameters. The concentrated solar power provides 5.88 MW of heat for the thermochemical cycle encompassing 434 parabolic dishes. The molten carbonate fuel cell has a 63% and 61% LHV and HHV efficiency, respectively, and the system has a total efficiency of approximately 85%, producing 13.63 MW of electricity.

Study and performance test of 10\xa0kW molten carbonate fuel cell power generation system

The use of high-temperature fuel cells as a power technology can improve the efficiency of electricity generation and achieve near-zero emissions of carbon dioxide. This work explores the performance of a 10 kW high-temperature molten carbonate fuel cell. The key materials of a single cell were characterized and analyzed using X-ray diffraction and scanning electron microscopy. The results show that the pore size of the key electrode material is 6.5 µm and the matrix material is α-LiAlO2. Experimentally, the open circuit voltage of the single cell was found to be 1.23 V. The current density was greater than 100 mA/cm2 at an operating voltage of 0.7 V. The 10 kW fuel cell stack comprised 80 single fuel cells with a total area of 2000 cm2 and achieved an open circuit voltage of greater than 85 V. The fuel cell stack power and current density could reach 11.7 kW and 104.5 mA/cm2 at an operating voltage of 56 V. The influence and long-term stable operation of the stack were also analyzed and discussed. The successful operation of a 10 kW high-temperature fuel cell promotes the large-scale use of fuel cells and provides a research basis for future investigations of fuel cell capacity enhancement and distributed generation in China.

Hybrid molten carbonate fuel cell power plant and multiple-effect desalination system

In this work, an integrated system of simultaneous power generation, refrigeration and desalination cycle using a molten carbonate fuel cell, is developed and investigated. The process is simulated by HYSYS and MATLAB softwares. Molten carbonate fuel cell subsystem is the main power generation source, which produces 72000 kW power. Absorption refrigeration cycle with ammonia-water mixture as the working fluid is utilized for providing the required refrigeration. The required heat duty is supplied by exhaust heat from the power plant. This absorption refrigeration cycle can provide 32090 kW refrigeration with coefficient of performance of 0.4915. Four stage multiple-effect desalination subsystem produces 118944 kg/h fresh water. The proposed process is assessed by conventional exergy analysis method in order to evaluate performance of the process. Results of the energy analysis illustrate that overall thermal efficiency based on higher heating value (HHV) and lower heating value (LHV) are 54.37% and 60.32%, respectively. Results of the exergy analysis show that molten carbonate fuel cell with 91062 kW has the most exergy destruction rate. Also, generator has the most exergy efficiency (98.67%) and overall exergy efficiency of the process is 88.95%. Finally, a sensitivity analysis is applied on the major operating parameters of the system to demonstrate their effects on the performance of the process.

Techno-economic optimization of the integration of an organic Rankine cycle into a molten carbonate fuel cell power plant

This study proposes a simple economic model to optimize the integration of an organic Rankine cycle into a molten carbonate fuel cell power plant. The optimization was conducted with five different types of working fluids, and an exergetic optimization was also done for comparison. In addition, sensitivity analysis was conducted to provide better insight into the behavior of the ORC system. The optimization results show that the optimum economic point and the optimum exergetic point are different, and a maximum profit can be achieved for the ORC system with economic optimization. Overall, in most cases, the profit is highest when the ORC system uses n-butane; however, R152a yields better profit when the ambient temperature is below 5 °C. In addition, all ORC systems show positive profit when the price of electricity is above 0.05 USD/kWh. For sensitivity analysis, two simulation experiments were conducted to observe the effect of changes in the feed gas temperature and the sales price of electricity on the optimization results. As a result, changes in the sale price of electricity are very critical, but changes in the feed gas temperature are not important.

FuelCell Energy sells Trinity College project in Connecticut to AEP

In Connecticut, Danbury-based FuelCell Energy has sold the project company that owns the 1.4 MW molten carbonate fuel cell power plant at Trinity College in Hartford, to AEP OnSite Partners, part of American Electric Power. This project has been developed and constructed by FCE, and will be placed into commercial operation following the sale.

US Navy sub base breaks ground on FCE fuel cell microgrid

The US Naval Submarine Base New London (SUBASE) in Groton, Connecticut has begun construction of its 7.4 MW fuel cell park, which features two SureSource 4000™ molten carbonate fuel cell power plants from FuelCell Energy to generate power for the base and local power grid.

FuelCell Energy signs service agreement with Korea Southern Power

US-based FuelCell Energy has announced a 20-year service agreement for the recently completed 20 MW fuel cell project with Korea Southern Power (KOSPO). The eight SureSource 3000™ molten carbonate fuel cell power plants in this installation produce clean electricity and thermal energy to support a district heating system adjacent to the existing 1.8 GW Sinincheon combined cycle power plant owned by KOSPO in Incheon, near Seoul.

FuelCell Energy to sell Tulare water treatment project to NRG Yield

Connecticut-based FuelCell Energy has entered into a definitive agreement to sell the project company that owns the 2.8 MW molten carbonate fuel cell power plant project at the Tulare Waste Water Treatment Facility in California to NRG Yield.

Second FCE onsite biogas product wins CARB DG certification

Connecticut-based FuelCell Energy reports that its SureSource 3000™ molten carbonate fuel cell power plant, operating on anaerobic digester gas (ADG), has received the California Air Resources Board's Distributed Generation (DG) Certification to the 2013 Waste Gas Standard. The SureSource power plant solutions include FuelCell Energy's proprietary biogas treatment technology.

Process development and exergy cost sensitivity analysis of a hybrid molten carbonate fuel cell power plant and carbon dioxide capturing process

An integrated power plant with a net electrical power output of 3.71 × 105 kW is developed and investigated. The electrical efficiency of the process is found to be 60.1%. The process includes three main sub-systems: molten carbonate fuel cell system, heat recovery section and cryogenic carbon dioxide capturing process. Conventional and advanced exergoeconomic methods are used for analyzing the process. Advanced exergoeconomic analysis is a comprehensive evaluation tool which combines an exergetic approach with economic analysis procedures. With this method, investment and exergy destruction costs of the process components are divided into endogenous/exogenous and avoidable/unavoidable parts. Results of the conventional exergoeconomic analyses demonstrate that the combustion chamber has the largest exergy destruction rate (182 MW) and cost rate (13,100 $/h). Also, the total process cost rate can be decreased by reducing the cost rate of the fuel cell and improving the efficiency of the combustion chamber and heat recovery steam generator. Based on the total avoidable endogenous cost rate, the priority for modification is the heat recovery steam generator, a compressor and a turbine of the power plant, in rank order. A sensitivity analysis is done to investigate the exergoeconomic factor parameters through changing the effective parameter variations.

Introducing a hybrid multi-generation fuel cell system, hydrogen production and cryogenic CO2 capturing process

A combined system containing molten carbonate fuel cell power plant, coal gasification, hydrogen production cryogenic CO2 capture, Rankine steam cycle and ammonia-water absorption refrigeration system is introduced and analyzed. In this process, power, heat and cooling are produced. An electrochemical model is developed to validate the experimental results of the fuel cell. In this system at first coal burn with oxygen and produce synthesis gas which is primary fuel for molten carbonate fuel cell and hydrogen production. Outlet gases which contain carbon dioxide are sent to the cryogenic CO2 capture system and hydrogen is separated from CO2. Effect of key parameters on performance of the process is investigated. The power output from the system is 6.55MW which 6MW is gained from the fuel cell and 0.55MW from the heat recovery and steam cycle. Also, this process produce 90kmol/h hydrogen and 90% of the produced CO2 is captured. Electrical efficiency of the hybrid system is 58% (LHV). Refrigeration duty (−30°C) and the recovered heat are 101.2kW and 22.11kW respectively.

FCE unit running on biogas at Riverside wastewater plant

A megawatt-class molten carbonate fuel cell power plant supplied by Connecticut-based FuelCell Energy has been constructed and begun commercial operation at the Riverside Regional Water Quality Control Plant in Riverside, California. Under this turnkey solution, FuelCell Energy has installed and will operate and maintain the fuel cell power plant, while the city simply pays for the power produced.

Study on a novel pressurized MCFC hybrid system with CO2 capture

Based on the benchmark pressurized molten carbonate fuel cell hybrid system without CO2 capture, this paper proposes a novel pressurized molten carbonate fuel cell hybrid system with CO2 capture. Firstly, the benchmark system is optimized to obtain the optimum fuel cell operating pressure, under the same pressure the performance of the new system is investigated and compared with that of the benchmark system. In addition, the sensitivity and economic performance analyses of the new system are made. Results show the benchmark system can achieve the highest efficiency of 69.34% when the molten carbonate fuel cell operates at 0.6 MPa, under the same operating pressure, the efficiency of the new system is only 0.91% lower than that of the benchmark system when capturing 90% of the emitted CO2. When the natural gas price is 6.7 $/GJ and the cost of molten carbonate fuel cell is 2700 $/kW, the cost of electricity for the proposed new system is 16.43 cents/kWh. The specific capital cost is still too high, the cost of the molten carbonate fuel cell needs to be further reduced. Achievements from this paper will provide valuable references for capturing CO2 from molten carbonate fuel cell power system with lower energy consumption.

Development of Solid Oxide Fuel Cells at Versa Power Systems & FuelCell Energy

Versa Power Systems (VPS) is a developer of solid oxide fuel cells (SOFCs) for clean power generation and is a wholly owned subsidiary of FuelCell Energy (FCE). FCE is a global leader in the design, manufacture and distribution of Molten Carbonate Fuel Cell (MCFC) power plants. From an economic perspective, MCFCs scale-up very well and as a result FCE’s MCFC products are in the multi-megawatt size range. SOFCs are complementary because they scale-down well and hence are suited to submegawatt applications. This paper highlights the status of VPS and FCE’s SOFC technology in the areas of cell, stack and system development.

Study on CO2 capture from molten carbonate fuel cell hybrid system integrated with oxygen ion transfer membrane

Based on the benchmark MCFC (molten carbonate fuel cell) hybrid system without CO2 capture, a novel ITM (oxygen ion transfer membrane)-integrated MCFC hybrid system with CO2 capture is proposed, which uses ITM to produce the needed oxygen for the oxy-fuel combustion in the afterburner. With the Aspen plus software, the system model is established and then the system performance is investigated. In addition, the sensitivity analysis of the key parameters and the exergy analysis of the overall new system are also studied. Results show the efficiency of the benchmark hybrid system without CO2 capture is 63.36%, in comparison when capturing 85% of the CO2 emissions, the efficiency of the system integrated with the cryogenic air separation unit is 60.94%, 2.42% lower than that of the benchmark system, while capturing the same amount of CO2 emissions, the efficiency of the new system integrated with ITM is 62.68%, only 0.68% lower than that of the benchmark system, in addition the specific energy consumption of capturing per mole CO2 (SPECCA) of the new system is nearly a quarter of the system integrated with the cryogenic air separation unit. Achievements from this paper will provide valuable references for capturing CO2 from MCFC power plants with lower energy consumption.

Development of Solid Oxide Fuel Cells at Versa Power Systems and FuelCell Energy

Versa Power Systems (VPS) is a developer of solid oxide fuel cells (SOFCs) for clean power generation and is a wholly owned subsidiary of FuelCell Energy (FCE). FCE is a global leader in the design, manufacture and distribution of Molten Carbonate Fuel Cell (MCFC) power plants. From an economic perspective, MCFCs scale-up very well and as a result FCE’s MCFC products are in the multi-megawatt size range. SOFCs are complementary because they scale-down well and hence are well suited to sub-megawatt applications. This paper highlights the status of VPS and FCE’s SOFC technology in the areas of cell, stack and system development.

Development of Solid Oxide Fuel Cells at Versa Power Systems and FuelCell Energy

Versa Power Systems (VPS) is a developer of solid oxide fuel cells (SOFCs) for clean power generation and is a wholly owned subsidiary of FuelCell Energy (FCE). FCE is a global leader in the design, manufacture and distribution of Molten Carbonate Fuel Cell (MCFC) power plants. From an economic perspective, MCFCs scale-up very well and as a result FCE’s MCFC products are in the multi-megawatt size range. SOFCs are complementary because they scale-down well and hence are suited to sub-megawatt applications. This paper highlights the status of VPS and FCE’s SOFC technology in the areas of cell, stack and system development.

Energy and exergy analysis and optimal design of the hybrid molten carbonate fuel cell power plant and carbon dioxide capturing process

A hybrid molten carbonate fuel cell power plant and carbon dioxide capturing process is investigated through the exergy and advanced exergy analysis. The results show that the greatest exergy destruction (181MW) occurs in the combustion chamber. It is because of irreversibility of the chemical reactions in the combustion process. Also the lowest exergy efficiency is related to the fuel cell. Advanced exergy analysis shows that the most portion of the exergy destruction is avoidable (more than 65%). Optimal design of the process is done by adjusting the effective operating conditions for reducing the power consumption and carbon dioxide emission of the process. Results of the optimization shows that the power consumption in the compressors can be reduced up to 33%.

An efficient scenario-based stochastic programming for optimal planning of combined heat, power, and hydrogen production of molten carbonate fuel cell power plants

In this paper, a stochastic model is proposed for planning the location and operation of Molten Carbonate Fuel Cell Power Plants (MCFCPPs) in distribution networks when used for Combined Heat, Power, and Hydrogen (CHPH) simultaneously. Uncertainties of electrical and thermal loads forecasting; the pressures of hydrogen, oxygen, and carbon dioxide imported to MCFCPPs; and the nominal temperature of MCFCPPs are considered using a scenario-based method. In the method, scenarios are generated using Roulette Wheel Mechanism (RWM) based on Probability Distribution Functions (PDF) of input random variables. Using this method, probabilistic specifics of the problem are distributed and the problem is converted to a deterministic one. The type of the objective functions, placement, and operation of MCFCPPs as CHPH change this problem to a mixed integer nonlinear one. So, multi-objective Modified Firefly Algorithm (MFA) and Pareto optimal method are employed for solving the multi-objective problem and for compromising between the objective functions. During the simulation process, a set of non-dominated solutions are stored in a repository. The 69-bus distribution system is used for evaluating the proper function of the proposed method.

Development of Solid Oxide Fuel Cells at Versa Power Systems and Fuel Cell Energy

Versa Power Systems (VPS) is a developer of solid oxide fuel cells (SOFCs) for clean power generation and was recently acquired by FuelCell Energy (FCE). FCE is a global leader in the design, manufacture and distribution of Molten Carbonate Fuel Cell (MCFC) power plants. From an economic perspective, MCFCs scale-up very well and as a result FCE’s MCFC products are in the multi-megawatt size range. SOFCs are complementary because they scale-down well and hence are well suited to sub-megawatt applications. This paper highlights the status of VPS and FCE’s SOFC technology in the areas of cell, stack and system development.