Power Cycle Integration and Efficiency Increase of Molten Carbonate Fuel Cell Systems

2005 ◽  
Vol 3 (4) ◽  
pp. 375-383 ◽  
Author(s):  
Petar Varbanov ◽  
Jiří Klemeš ◽  
Ramesh K. Shah ◽  
Harmanjeet Shihn
Keyword(s):  
Fuel Cells ◽  
High Temperature ◽  
Fuel Cell ◽  
Gas Turbines ◽  
Waste Heat ◽  
Combined Cycle ◽  
Molten Carbonate Fuel Cell ◽  
Steam Turbines ◽  
Molten Carbonate ◽  
Carbonate Fuel Cell

A new view is presented on the concept of the combined cycle for power generation. Traditionally, the term “combined cycle” is associated with using a gas turbine in combination with steam turbines to better utilize the exergy potential of the burnt fuel. This concept can be broadened, however, to the utilization of any power-generating facility in combination with steam turbines, as long as this facility also provides a high-temperature waste heat. Such facilities are high temperature fuel cells. Fuel cells are especially advantageous for combined cycle applications since they feature a remarkably high efficiency—reaching an order of 45–50% and even close to 60%, compared to 30–35% for most gas turbines. The literature sources on combining fuel cells with gas and steam turbines clearly illustrate the potential to achieve high power and co-generation efficiencies. In the presented work, the extension to the concept of combined cycle is considered on the example of a molten carbonate fuel cell (MCFC) working under stationary conditions. An overview of the process for the MCFC is given, followed by the options for heat integration utilizing the waste heat for steam generation. The complete fuel cell combined cycle (FCCC) system is then analyzed to estimate the potential power cost levels that could be achieved. The results demonstrate that a properly designed FCCC system is capable of reaching significantly higher efficiency compared to the standalone fuel cell system. An important observation is that FCCC systems may result in economically competitive power production units, comparable with contemporary fossil power stations.

scholarly journals Study and performance test of 10 kW molten carbonate fuel cell power generation system

2021 ◽  
Author(s):  
Chengzhuang Lu ◽  
Ruiyun Zhang ◽  
Guanjun Yang ◽  
Hua Huang ◽  
Jian Cheng ◽  
...  
Keyword(s):  
Fuel Cells ◽  
High Temperature ◽  
Fuel Cell ◽  
Open Circuit Voltage ◽  
Open Circuit ◽  
Molten Carbonate Fuel Cell ◽  
Operating Voltage ◽  
Molten Carbonate ◽  
Fuel Cell Stack ◽  
Carbonate Fuel Cell

AbstractThe 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.

scholarly journals Coal Cell

2003 ◽  
Vol 125 (12) ◽  
pp. 42-44 ◽  
Author(s):  
Jeffrey Winters
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Power Plants ◽  
The United States ◽  
Combined Cycle ◽  
Molten Carbonate Fuel Cell ◽  
Molten Carbonate ◽  
Integrated Gasification Combined Cycle ◽  
Integrated Gasification ◽  
Carbonate Fuel Cell

This article focuses on coal mining that is incredibly disruptive, and coal is heavy and bulky, involving rumbling freight trains to transport it. The idea that fuel cells are every bit as clean as coal is dirty is just as widespread. Fuel cells, after all, take hydrogen and oxygen, and combine those elements to make electricity and water. The program, called the Clean Coal Technology Program, was, in part, an effort to promote commercial-scale integrated gasification combined-cycle (IGCC) coal power plants in the United States. Molten carbonate fuel cell stacks routinely weigh in at 250 kW. For the Wabash River demonstration, eight stacks will be combined for 2 MW. It will be the largest carbonate fuel cell power plant operating on coal in the world. FuelCell Energy has been planning for this sort of project for more than 20 years.

Numerical Analysis of a Molten Carbonate Fuel Cell Stack in Emergency Scenarios

2020 ◽  
Vol 142 (9) ◽  
Author(s):  
Arkadiusz Szczęśniak ◽  
Jarosław Milewski ◽  
Łukasz Szabłowski ◽  
Olaf Dybiński ◽  
Kamil Futyma
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Numerical Analysis ◽  
High Accuracy ◽  
Molten Carbonate Fuel Cell ◽  
Molten Carbonate ◽  
Fuel Cell Stack ◽  
Power Load ◽  
Emergency Scenarios ◽  
Carbonate Fuel Cell

Abstract Molten carbonate fuel cells (MCFCs) offer several advantages that are attracting an increasingly intense research and development effort. Recent advances include improved materials and fabrication techniques as well as new designs, flow configurations, and applications. Several factors are holding back large-scale implementation of fuel cells, though, especially in distributed energy generation, a major one being their long response time to changing parameters. Alternative mathematical models of the molten carbonate fuel cell stack have been developed over the last decade. This study investigates a generic molten carbonate fuel cell stack with a nominal power output of 1 kWel. As daily, weekly, and monthly variations in the electrical power load are expected, there is a need to develop numerical tools to predict the unit’s performance with high accuracy. Hence, a fully physical dynamic model of an MCFC stack was developed and implemented in aspen hysys 10 modeling software to enable a predictive analysis of the dynamic response. The presented model exhibits high accuracy and accounts for thermal and electrochemical processes and parameters. The authors present a numerical analysis of an MCFC stack in emergency scenarios. Further functionality of the model, which was validated using real operational data, is discussed.

Performance Analysis on SOFC-HCCI Engine Hybrid System

2012 ◽  
Author(s):  
Sung Ho Park ◽  
Young Duk Lee ◽  
Sang Gyu Kang ◽  
Kook Young Ahn
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Hybrid Systems ◽  
Hybrid System ◽  
Gas Turbines ◽  
Waste Heat ◽  
Metal Catalyst ◽  
Molten Carbonate ◽  
Hcci Engine ◽  
Ci Engines

Fuel cell systems are currently regarded as a promising type of energy conversion system. Various types of fuel cell have been developed and investigated worldwide for portable, automotive, and stationary applications. In particular, in the case of large-scale stationary applications, the high-temperature fuel cells known as the molten carbonate fuel cell (MCFC) and the solid oxide fuel cell (SOFC) have been used as a power source due to their higher efficiency compared to low-temperature fuel cells. Because SOFCs have many advantages, including a high power density, low corrosion, and operability without a metal catalyst, many efforts to develop a SOFC hybrid system have been undertaken. SOFC hybrid systems with a gas turbine or engine show improved system efficiency through their utilization of waste heat and unreacted fuel. Especially, the internal combustion engine has the advantage of robustness, easy maintenance, and a low cost compared to gas turbines, this type is more adaptable for use in a hybrid system with a SOFC. However, the engine should be operated stably at a high air fuel ratio because the SOFC anode exhaust gas has a low fuel concentration. The homogeneous charge compression ignition (HCCI) engine has both the advantages of SI and CI engines. Moreover, the lean burn characteristics of the HCCI engine make it a strong candidate for SOFC hybrid systems. The objective of this work is to develop a novel cycle composed of a SOFC and a HCCI engine. In order to optimize the SOFC-HCCI hybrid system, a system analysis is conducted here using the commercial software Aspen Plus®. The SOFC model is validated with experimental data. The engine model is developed based on an empirical equation that considers the ignition delay time. The performance of the hybrid system is compared with that of a SOFC stand-alone system to confirm the optimization of the system. This study will be useful for the development of a new type of hybrid system which uses a fuel cell and an optimized system.

scholarly journals Research on high-temperature compression and creep behavior of porous Cu–Ni–Cr alloy for molten carbonate fuel cell anodes

2015 ◽  
Vol 33 (2) ◽  
pp. 356-362 ◽  
Author(s):  
W. Li ◽  
J. Chen ◽  
H. Liang ◽  
C. Li
Keyword(s):  
High Temperature ◽  
Fuel Cell ◽  
Creep Behavior ◽  
Creep Resistance ◽  
Surface Deformation ◽  
Molten Carbonate Fuel Cell ◽  
Molten Carbonate ◽  
Deformation Bands ◽  
Fuel Cell Anodes ◽  
Carbonate Fuel Cell

AbstractThe effect of porosity on high temperature compression and creep behavior of porous Cu alloy for the new molten carbonate fuel cell anodes was examined. Optical microscopy and scanning electron microscopy were used to investigate and analyze the details of the microstructure and surface deformation. Compression creep tests were utilized to evaluate the mechanical properties of the alloy at 650 °C. The compression strength, elastic modulus, and yield stress all increased with the decrease in porosity. Under the same creep stress, the materials with higher porosity exhibited inferior creep resistance and higher steadystate creep rate. The creep behavior has been classified in terms of two stages. The first stage relates to grain rearrangement which results from the destruction of large pores by the applied load. In the second stage, small pores are collapsed by a subsequent sintering process under the load. The main deformation mechanism consists in that several deformation bands generate sequentially under the perpendicular loading, and in these deformation bands the pores are deformed by flattering and collapsing sequentially. On the other hand, the shape of a pore has a severe influence on the creep resistance of the material, i.e. every increase of pore size corresponds to a decrease in creep resistance.

An Investigation of DIR-MCFC Based Cooling, Heating and Power System

2003 ◽  
Author(s):  
Indraneel Samanta ◽  
Ramesh K. Shah ◽  
Ali Ogut
Keyword(s):  
Power Generation ◽  
Fuel Cell ◽  
Gas Turbines ◽  
Waste Heat ◽  
Hot Water ◽  
Molten Carbonate Fuel Cell ◽  
Molten Carbonate ◽  
Absorption Chiller ◽  
Internal Reforming ◽  
Cogeneration System

The fuel cell is an emerging technology for stationary power generation because of their higher energy conversion efficiency and extremely low environmental pollution. Fuel cell systems with cogeneration have even higher overall efficiency. Cogeneration can be defined as simultaneous production of electric power and useful heat from burning of single fuel. A fuel cell produces electrical energy by electrolytic process involving chemical reaction between H2 (fuel) and O2 (Air). Previous works have focussed on running the system in combination with gas turbines. We investigate the possibility of running an absorption chiller as a cogeneration system focussing on a 250 kW Direct Internal Reforming Molten Carbonate Fuel Cell (DIR-MCFC) powering a LiBr-Water absorption chiller. The objective of this work is to propose a cogeneration system capable of enhancing the profitability and efficiency of a MCFC for independent distributed power generation. Natural gas is used as fuel and O2 is used from atmospheric air. Two possibilities are evaluated to recover heat from the exhaust of the MCFC: (1) all waste heat available being used for providing hot water in the building and powering an absorption chiller in summer, and (2) hot water supply and space heating in winter. There is an increased cost saving for each case along with improved system efficiency. Based on these considerations payback period for each case is presented.

Efficiency Analyses of a Coal Gasification Molten Carbonate Fuel Cell With a Gas Turbine Combined Cycle Including CO2 Recovery

2008 ◽  
Author(s):  
F. Yoshiba ◽  
E. Koda
Keyword(s):  
Fuel Cell ◽  
Gas Turbine ◽  
Coal Gasification ◽  
Combined Cycle ◽  
Molten Carbonate Fuel Cell ◽  
Molten Carbonate ◽  
Coal Gas ◽  
Co2 Recovery ◽  
And Storage ◽  
Carbonate Fuel Cell

The efficiency of an integrated coal gasification system equipped with a molten carbonate fuel cell, a gas turbine and a steam turbine (IG/MCFC) is calculated. Coal is conveyed to a gasifier furnace by CO2 and changed to coal gas by adding oxygen; a methyldiethanolamine (MDEA) method is applied to initiate a cleanup procedure of the coal gas. A water-gas shift converter is employed to heat up the coal gas. The cathode gas of the MCFC is composed of CO2 and O2 with a composition of 66.7/33.3 (noble cathode gas composition). The magnitude of the system’s electrical power output is assumed to be that of a 300 MW class. The calculated net efficiency of the 2.2 MPa pressurised system reached a 60.1% high heating value (HHV) without CO2 recovery. The 2.2 MPa pressurised system, however, has a short lifetime limited by the shortening of electrodes. For this reason, a further 0.15 MPa pressurised system (low pressurised system) efficiency is recorded which has a more promising shortening time of the electrodes. The net efficiency of the low pressurised system is 51.9% HHV without CO2recovery. Since the coal is gasified using oxygen and the cathode gas of the MCFC is composed of CO2/O2, the system’s exhaust gas only includes CO2, thus the system is ready for the recovery and storage of carbon dioxide (Carbon Capture and Storage ready, CCS ready). For the purpose of estimating the net efficiency with CO2 recovery, a liquid form of CO2 with a pressure of 10MPa is assumed. Using the 2.2 MPa pressurised system, the net efficiency including the consumption of CO2 compression and liquefaction is evaluated at 58.2% HHV. Another simple CO2 closed system configuration without gas turbine is proposed; the net efficiencies of the 2.2 MPa and the 0.15 MPa system including the consumption of CO2 liquefaction are determined at 56.4% and 50.3% HHV, respectively. According to the calculation results, a high efficiency system with CO2 recovery is possible by applying the noble cathode gas in the IG/MCFC systems.

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