Electrochemical Carbon Separation in a SOFC–MCFC Polygeneration Plant With Near-Zero Emissions

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Luca Mastropasqua ◽  
Stefano Campanari ◽  
Jack Brouwer
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Power Systems ◽  
Carbon Capture ◽  
High Efficiency ◽  
Carbon Capture And Storage ◽  
Molten Carbonate Fuel Cell ◽  
Small Scale ◽  
Total Efficiency ◽  
Molten Carbonate

The modularity and high efficiency at small-scale make high temperature (HT) fuel cells an interesting solution for carbon capture and utilization at the distributed generation (DG) scale when coupled to appropriate use of CO2 (i.e., for industrial uses, local production of chemicals, etc.). The present work explores fully electrochemical power systems capable of producing a highly pure CO2 stream and hydrogen. In particular, the proposed system is based upon integrating a solid oxide fuel cell (SOFC) with a molten carbonate fuel cell (MCFC). The use of these HT fuel cells has already been separately applied in the past for carbon capture and storage (CCS) applications. However, their combined use is yet unexplored. The reference configuration proposed envisions the direct supply of the SOFC anode outlet to a burner which, using the cathode depleted air outlet, completes the oxidation of the unconverted species. The outlet of the burner is then fed to the MCFC cathode inlet, which separates the CO2 from the stream. This layout has the significant advantage of achieving the required CO2 purity for liquefaction and long-range transportation without requiring the need of cryogenic or distillation plants. Furthermore, different configurations are considered with the final aim of increasing the carbon capture ratio (CCR) and maximizing the electrical efficiency. Moreover, the optimal power ratio between SOFC and MCFC stacks is also explored. Complete simulation results are presented, discussing the proposed plant mass and energy balances and showing the most attractive configurations from the point of view of total efficiency and CCR.

Electrochemical Carbon Separation in a SOFC-MCFC Poly-Generation Plant With Near-Zero Emissions

2017 ◽  
Author(s):  
Luca Mastropasqua ◽  
Stefano Campanari ◽  
Jack Brouwer
Keyword(s):  
Fuel Cells ◽  
High Temperature ◽  
Fuel Cell ◽  
Carbon Capture ◽  
Large Scale ◽  
High Efficiency ◽  
Molten Carbonate Fuel Cell ◽  
Small Scale ◽  
Total Efficiency ◽  
Molten Carbonate

High temperature fuel cells have been studied as a suitable solution for Carbon Capture and Storage (CCS) purposes at a large scale (>100 MW). However, their modularity and high efficiency at small-scale make them an interesting solution for Carbon Capture and Utilisation at the distributed generation scale when coupled to appropriate use of CO2 (i.e., for industrial uses, local production of chemicals etc.). These systems could be used within low carbon micro-grids to power small communities in which multiple power generating units of diverse nature supply multiple products such as electricity, cooling, heating and chemicals (i.e., hydrogen and CO2). The present work explores fully electrochemical power systems capable of producing a highly pure CO2 stream and hydrogen. In particular, the proposed system is based upon integrating a Solid Oxide Fuel Cell (SOFC) with a Molten Carbonate Fuel Cell (MCFC). The use of these high temperature fuel cells has already been separately applied in the past for CCS applications. However, their combined use is yet unexplored. Moreover, both industry and US national laboratories have expressed their interest in this solution. The reference configuration proposed envisions the direct supply of the SOFC anode outlet to a burner which, using the cathode depleted air outlet, completes the oxidation of the unconverted species. The outlet of the burner is then fed to the MCFC cathode inlet which separates the CO2 from the stream. Both the SOFC and MCFC anode inlets are supplied with pre-reformed and desulfurized natural gas. The MCFC anode outlet, which is characterised by a high concentration of CO2, is fed to a CO2 separation line in which a two-stage Water Gas Shift (WGS) reactor and a PSA/membrane system respectively convert the remaining CO into H2 and remove the H2 from the exhaust stream. This has the significant advantage of achieving the required CO2 purity for liquefaction and long-range transportation without requiring the need of cryogenic or distillation plants. Moreover, the highly pure H2 stream can either be sold as transportation fuel or a valuable chemical. Furthermore, different configurations are considered with the final aim of increasing the Carbon Capture Ratio (CCR) and maximising the electrical efficiency. Moreover, the optimal power ratio between SOFC and MCFC stacks is also explored. Complete simulation results are presented, discussing the proposed plant mass and energy balances and showing the most attractive configurations from the point of view of total efficiency and CCR.

Comparative Analysis of Hybrid Cycles Based on Molten Carbonate and Solid Oxide Fuel Cells

2001 ◽  
Author(s):  
Stefano Campanari ◽  
Ennio Macchi
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Gas Turbines ◽  
Solid Oxide ◽  
Molten Carbonate Fuel Cell ◽  
Small Scale ◽  
Oxide Fuel ◽  
Molten Carbonate ◽  
Successful Operation ◽  
Hybrid Plants

High temperature fuel cells are experiencing an increasing amount of attention thanks to the successful operation of prototype plants, including a multi-MW Molten Carbonate Fuel Cell (MCFC) demonstration plant and a hybrid Solid Oxide Fuel Cell (SOFC) gas turbine power plant. Both MCFCs and SOFCs are currently considered attractive for the integration with gas turbines in more complex “hybrid” plants, with projected performances that largely exceed combined cycles efficiencies even at a small-scale size and with an extremely low environmental impact. This paper compares the performances of MCFC and SOFC hybrid cycles. The comparison shows some advantages for the SOFC hybrid cycle in terms of plant simplicity and moderately higher efficiency.

Molten Carbonate Fuel Cells for Carbon Capture From a Cogeneration System: A Comparative Analysis of Performance to Other Separation Technologies

2017 ◽  
Author(s):  
Marco Badami ◽  
Marco Cipriano ◽  
Gregory Kowalski ◽  
Armando Portoraro ◽  
Mansour Zenouzi
Keyword(s):  
Carbon Capture ◽  
Power Plants ◽  
Large Scale ◽  
Combustion Engine ◽  
Carbon Capture And Storage ◽  
Internal Heat ◽  
Molten Carbonate Fuel Cell ◽  
Small Scale ◽  
Molten Carbonate ◽  
Cogeneration System

This paper develops a mathematical model for the performance assessment and optimization of a small-scale molten carbonate fuel cell (MCFC) stack for the CO2 capture and liquefaction from the exhausts coming from an Internal Combustion Engine (ICE) cogenerator. An internal heat exchangers network has been developed for enhancing heat recovery, optimizing the efficiency of the global system. The model is innovative because, even though similar studies are reported in literature, they have never focused on a small-scale applications of a cogeneration system or compared the global performance to other means of carbon capture and storage (CCS). The energetic performance of the system has been compared to that of a monoethanolamine (MEA) adsorption system, which today is the most common technology for the carbon capture in large scale power plants. The results of the simulation show a carbon capture percent of about 81.3%, while the electrical output of the MCFC is around 280 kW with a conversion efficiency of 54%. The overall efficiency of the cogenerator and CCS system is about 37%. In the investigated MCFC technology the CCS system has a high carbon capture efficiency and produces a net power output unlike competing technologies.

Rodzaje ogniw paliwowych i ich potencjalne kierunki wykorzystania

Nafta-Gaz ◽  
2021 ◽  
Vol 77 (5) ◽  
pp. 332-339
Author(s):  
Urszula Żyjewska ◽  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Power Systems ◽  
Proton Exchange Membrane ◽  
Technical Specification ◽  
Proton Exchange ◽  
Molten Carbonate Fuel Cell ◽  
Motor Vehicles ◽  
Molten Carbonate ◽  
Exchange Membrane

Fuel cells are not a new technology, but they are gaining in popularity and are being intensively developed. The article presents and characterizes various types of fuel cells that are currently of interest to research and development centers dealing with environmental protection issues. These include: alkaline fuel cell (AFC), phosphoric acid fuel cell (PAFC), solid oxide fuel cell (SOFC), molten carbonate fuel cell (MCFC), proton exchange membrane fuel cell (PEMFC), including direct methanol fuel cell (DMFC). The operating parameters of the previously mentioned fuel cells were compared. The principle of operation of a fuel cell was described. The growing interest in devices using hydrogen as a fuel also results from the development of Power to Gas technology (P2G). Furthermore, the article presents the potential directions of development and use of fuel cells in various fields and sectors of the economy. Fuel cells can be used in transport. The characteristic of motor vehicles fleet by fuel type in usage in the European Union was presented. The technical specification of commercially available passenger cars using fuel cells with proton exchange membrane was presented. The possibility of using fuel cells in public transport (buses, trains) was discussed. The possibilities of operation of fuel cells in combined heat and power systems (CHP) were presented. Usage of fuel cell technology in large cogeneration units and micro systems was considered. One of the presented cogeneration systems is a combination of fuel cells with a gas turbine. Another possibility of using fuel cells is energy storage systems (EES). Interesting way of using fuel cells can also be Power to Power systems, which were briefly characterized.

Performance Evaluation of a Molten Carbonate Fuel Cell/Micro Gas Turbine Hybrid System With Oxy-Combustion Carbon Capture

2017 ◽  
Author(s):  
Ji Ho Ahn ◽  
Tong Seop Kim
Keyword(s):  
Carbon Dioxide ◽  
Fuel Cell ◽  
Gas Turbine ◽  
Hybrid System ◽  
Carbon Capture ◽  
Molten Carbonate Fuel Cell ◽  
Design Parameters ◽  
Molten Carbonate ◽  
Micro Gas Turbine ◽  
Carbonate Fuel Cell

Owing to the increasing consumption of fossil fuels and emission of greenhouse gases, interests in highly efficient and low carbon emitting power systems are growing fast. Several research groups have been suggesting advanced systems based on fuel cells and have also been applying carbon capture and storage technology to satisfy the demand for clean energy. In this study, the performance of a hybrid system, which is a combination of a molten carbonate fuel cell (MCFC) with oxy-combustion carbon capture and an indirectly fired micro gas turbine (MGT) was predicted. A 2.5MW MCFC system that is used in commercial applications was used as the reference system so that the results of the study could be applicable to practical situations. The ambient pressure type hybrid system was modeled by referring to the design parameters of an MGT that is currently being developed. A semi-closed type design characterized by flow recirculation was adopted for this hybrid system. A part of the recirculating gas is converted into liquefied carbon dioxide and captured for storage at the carbon separation unit. Almost 100% carbon dioxide capture is possible with this system. In these systems, the output power of the fuel cell is larger than in the normal hybrid system without carbon capture because the partial pressure of carbon dioxide increases. The increased cell power partially compensates for the power loss due to the carbon capture and MGT power reduction. The dependence of net system efficiency of the oxy-hybrid on compressor pressure ratio is marginal, especially beyond an optimal value.

Performance Evaluation of a Molten Carbonate Fuel Cell/Micro Gas Turbine Hybrid System With Oxy-Combustion Carbon Capture

2017 ◽  
Vol 140 (4) ◽  
Author(s):  
Ji Ho Ahn ◽  
Tong Seop Kim
Keyword(s):  
Carbon Dioxide ◽  
Fuel Cell ◽  
Gas Turbine ◽  
Hybrid System ◽  
Carbon Capture ◽  
Molten Carbonate Fuel Cell ◽  
Design Parameters ◽  
Molten Carbonate ◽  
Micro Gas Turbine ◽  
Carbonate Fuel Cell

Owing to the increasing consumption of fossil fuels and emission of greenhouse gases, interests in highly efficient and low carbon emitting power systems are growing fast. Several research groups have been suggesting advanced systems based on fuel cells and have also been applying carbon capture and storage technology to satisfy the demand for clean energy. In this study, the performance of a hybrid system, which is a combination of a molten carbonate fuel cell (MCFC) with oxy-combustion carbon capture and an indirectly fired micro gas turbine (MGT), was predicted. A 2.5 MW MCFC system that is used in commercial applications was used as the reference system so that the results of the study could be applied to practical situations. The ambient pressure type hybrid system was modeled by referring to the design parameters of an MGT that is currently being developed. A semi-closed type design characterized by flow recirculation was adopted for this hybrid system. A part of the recirculating gas is converted into liquefied carbon dioxide and captured for storage at the carbon separation unit (CSU). Almost 100% carbon dioxide capture is possible with this system. In these systems, the output power of the fuel cell is larger than in the normal hybrid system without carbon capture because the partial pressure of carbon dioxide increases. The increased cell power partially compensates for the power loss due to the carbon capture and MGT power reduction. The dependence of net system efficiency of the oxy-hybrid on compressor pressure ratio is marginal, especially beyond an optimal value.

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.

scholarly journals Effect of Cell Size on the Performance and Temperature Distribution of Molten Carbonate Fuel Cells

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1361 ◽  
Author(s):  
Jae-Hyeong Yu ◽  
Chang-Whan Lee
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Gas Flow ◽  
High Efficiency ◽  
Cross Flow ◽  
Current Density Distribution ◽  
Maximum Temperature ◽  
Similar Distribution ◽  
Molten Carbonate ◽  
Molten Carbonate Fuel Cells

Molten carbonate fuel cells (MCFCs) are high-operating-temperature fuel cells with high efficiency and fuel diversity. Electrochemical reactions in MCFCs are exothermic. As the size of the fuel cells increases, the amount of the heat from the fuel cells and the temperature of the fuel cells increase. In this work, we investigated the relationship between the fuel cell stack size and performance by applying computational fluid dynamics (CFD). Three flow types, namely co-flow, cross-flow, and counter-flow, were studied. We found that when the size of the fuel cells increased beyond a certain value, the size of the fuel cell no longer affected the cell performance. The maximum fuel cell temperature converged as the size of the fuel cell increased. The temperature and current density distribution with respect to the size showed a very similar distribution. The converged maximum temperature of the fuel cells depended on the gas flow condition. The maximum temperature of the fuel cell decreased as the amount of gas in the cathode size increased.

Performance Enhancement of a Molten Carbonate Fuel Cell/Micro Gas Turbine Hybrid System With Carbon Capture by Off-Gas Recirculation

2018 ◽  
Author(s):  
Ji Ho Ahn ◽  
Ji Hun Jeong ◽  
Tong Seop Kim
Keyword(s):  
Fuel Cell ◽  
Gas Turbine ◽  
Hybrid System ◽  
Carbon Capture ◽  
Molten Carbonate Fuel Cell ◽  
Human Society ◽  
Molten Carbonate ◽  
Micro Gas Turbine ◽  
Gas Recirculation ◽  
Carbonate Fuel Cell

The demand for clean energy continues to increase as the human society becomes more aware of environmental challenges such as global warming. Various power systems based on high-temperature fuel cells have been proposed, especially hybrid systems combining a fuel cell with a gas turbine, and research on carbon capture and storage technology to prevent the emission of greenhouse gases is already underway. This study suggests a new method to innovatively enhance the efficiency of a molten carbonate fuel cell/micro gas turbine hybrid system including carbon capture. The key technology adopted to improve the net cycle efficiency is off-gas recirculation. The hybrid system incorporating oxy-combustion capture was devised, and its performance was compared with that of a post-combustion system based on a hybrid system. A molten carbonate fuel cell system based on a commercial unit was modeled. Externally supplied water for reforming was not needed as a result of the presence of the water vapor in the recirculated anode off-gas. The analyses confirmed that the thermal efficiencies of all the systems (MCFC stand-alone, hybrid, hybrid with oxy-combustion capture, hybrid with post-combustion capture) were significantly improved by introducing the off-gas recirculation. In particular, the largest efficiency improvement was observed for the oxy-combustion hybrid system. Its efficiency is over 57% and is even higher than that of the post-combustion hybrid system.

Small Scale Reforming Separation Systems with Nanomembrane Reactors for Direct Fuel Cell Applications

2010 ◽  
Vol 12 ◽  
pp. 105-113 ◽  
Author(s):  
Savvas Vasileiadis ◽  
Zoe Ziaka
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Product Yield ◽  
Cell System ◽  
Membrane Reactors ◽  
Inorganic Membrane ◽  
Small Scale ◽  
Reaction Products ◽  
Molten Carbonate ◽  
Fuel Gas

Our recent communication focuses on small scale and nanoscale type engineering applications of alumina inorganic membrane reactors and reactor-permeator systems for the conversion of renewable and non-renewable hydrocarbons and methane rich streams into hydrogen rich gas for direct inner application and operation of fuel cell systems. This study elaborates on new nanomembrane reactors for the steam-methane/hydrocarbon reforming and water gas shift reactions, including work in the synthesis, manufacturing, modeling and operation of such microreaction systems. The projected small scale reactors, separators and overall reaction systems are of current significance in the area of multifunctional microreactor and nanoreactor design and operation in connection with the operation of fuel cells for transportation, stationary, and portable power generation applications. An added advantage of such systems is the reactive and separative operations of the fuel cell membrane-processor which are combined to convert the hydrocarbon with steam to valuable fuel gas for continuous fuel cell operation. Moreover, the nanomembrane systems under development have the unique characteristics to perform multiple operations per unit volume, such as to utilize beneficial equilibrium shift principles in reactant conversion and product yield through the removal of permselective species (i.e., hydrogen) via the inorganic membrane out of the conversion/reaction zone. In this way, improved hydrogen and product yields can be achieved which exceed the equilibrium calculated yields. Simultaneously, the reaction products, such as synthesis gas (i.e., H2, CO and CO2) at the reactor exit can be used as fuel in mostly solid oxide and molten carbonate fuel cells. The role of the alumina nanomembrane is also in the main conversion and upgrading sections of these feedstocks in order to overcome existing heat and mass transfer limitations and increase the overall efficiency of the microreactor-fuel cell system.

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