Conversion of Syngas From Biomass in Solid Oxide Fuel Cells

2009 ◽  
Vol 6 (2) ◽  
Author(s):  
Jurgen Karl ◽  
Nadine Frank ◽  
Sotirios Karellas ◽  
Mathilde Saule ◽  
Ulrich Hohenwarter
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Liquid Metal ◽  
Waste Heat ◽  
Heat Pipes ◽  
Solid Oxide ◽  
Small Scale ◽  
Oxide Fuel ◽  
Cell Systems ◽  
Integrated Gasification

Conversion of biomass in syngas by means of indirect gasification offers the option to improve the economic situation of any fuel cell system due to lower costs for feedstock and higher power revenues in many European countries. The coupling of an indirect gasification of biomass and residues with highly efficient solid oxide fuel cell (SOFC) systems is therefore a promising technology for reaching economic feasibility of small decentralized combined heat and power production (CHP).The predicted efficiency of common high temperature fuel cell systems with integrated gasification of solid feedstock is usually significantly lower than the efficiency of fuel cells operated with hydrogen or methane. Additional system components like the gasifier as well as the gas cleaning reduce this efficiency. Hence common fuel cell systems with integrated gasification of biomass will hardly reach electrical efficiencies above 30%. An extraordinary efficient combination is achieved in case that the fuel cells waste heat is used in an indirect gasification system. A simple combination of a SOFC and an allothermal gasifier enables then electrical efficiencies above 50%. However, this system requires an innovative cooling concept for the fuel cell stack. Another significant question is the influence of impurities on the fuel cell degradation. The European Research Project “BioCellus” focuses on both questions—the influence of the biogenous syngas on the fuel cells and an innovative cooling concept based on liquid metal heat pipes. First experiments showed that, in particular, higher hydrocarbons—the so-called tars—do not have any significant influence on the performance of SOFC membranes. The innovative concept of the TopCycle comprises to heat an indirect gasifier with the exhaust heat of the fuel cell by means of liquid metal heat-pipes. Internal cooling of the stack and the recirculation of waste heat increases the system efficiency significantly. This concept promises electrical efficiencies of above 50% even for small-scale systems without any combined processes.

Conversion of Syngas From Biomass in Solid Oxide Fuel Cells

2006 ◽  
Author(s):  
Ju¨rgen Karl ◽  
Nadine Frank ◽  
Sotiris Karellas ◽  
Mathilde Saule ◽  
Ulrich Hohenwarter
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Liquid Metal ◽  
Waste Heat ◽  
Heat Pipes ◽  
Economic Feasibility ◽  
Small Scale ◽  
Cell Systems ◽  
Exhaust Heat ◽  
Integrated Gasification

Conversion of biomass in syngas by means of indirect gasification offers the option to improve the economic situation of any fuel cell systems due to lower costs for feedstock and higher power revenues in many European countries. The coupling of an indirect gasification of biomass and residues with highly efficient SOFC systems is therefore a promising technology for reaching economic feasibility of small decentralized combined heat and power production (CHP). The predicted efficiency of common high temperature fuel cell systems with integrated gasification of solid feedstock is usually significantly lower than the efficiency of fuel cells operated with hydrogen or methane. Additional system components like the gasifier, as well as the gas cleaning reduce this efficiency. Hence common fuel cell systems with integrated gasification of biomass will hardly reach electrical efficiencies above 30 percent. An extraordinary efficient combination is achieved in case that the fuel cells waste heat is used in an indirect gasification system. A simple combination of a SOFC and an allothermal gasifier enables then electrical efficiencies above 50%. But this systems requires an innovative cooling concept for the fuel cell stack. Another significant question is the influence of impurities on the fuel cells degradation. The European Research Project ‘BioCellus’ focuses on both questions — the influence of the biogenious syngas on the fuel cells and an innovative cooling concept based on liquid metal heat pipes. First experiments showed that in particular higher hydrocarbons — the so-called tars — do not have an significant influence on the performance of SOFC membranes. The innovative concept of the TopCycle comprises to heat an indirect gasifier with the exhaust heat of the fuel cell by means of liquid metal heat pipes. Internal cooling of the stack and the recirculation of waste heat increases the system efficiency significantly. This concept promises electrical efficiencies of above 50 percent even for small-scale systems without any combined processes.

Performance Comparison of Internal Reforming Against External Reforming in a Solid Oxide Fuel Cell, Gas Turbine Hybrid System

2005 ◽  
Vol 127 (1) ◽  
pp. 86-90 ◽  
Author(s):  
Eric A. Liese ◽  
Randall S. Gemmen
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Hybrid System ◽  
Waste Heat ◽  
Performance Comparison ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Internal Reforming ◽  
Hybrid Configuration

Solid Oxide Fuel Cell (SOFC) developers are presently considering both internal and external reforming fuel cell designs. Generally, the endothermic reforming reaction and excess air through the cathode provide the cooling needed to remove waste heat from the fuel cell. Current information suggests that external reforming fuel cells will require a flow rate twice the amount necessary for internal reforming fuel cells. The increased airflow could negatively impact system performance. This paper compares the performance among various external reforming hybrid configurations and an internal reforming hybrid configuration. A system configuration that uses the reformer to cool a cathode recycle stream is introduced, and a system that uses interstage external reforming is proposed. Results show that the thermodynamic performance of these proposed concepts are an improvement over a base-concept external approach, and can be better than an internal reforming hybrid system, depending on the fuel cell cooling requirements.

Optimization of an Integrated SOFC-Fuel Processing System for Aircraft Propulsion

2012 ◽  
Vol 9 (4) ◽  
Author(s):  
Thomas E. Brinson ◽  
Juan C. Ordonez ◽  
Cesar A. Luongo
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Processing System ◽  
Solid Oxide ◽  
System Level ◽  
Small Scale ◽  
Oxide Fuel ◽  
Fuel Processing ◽  
Aircraft Propulsion

As fuel cells continue to improve in performance and power densities levels rise, potential applications ensue. System-level performance modeling tools are needed to further the investigation of future applications. One such application is small-scale aircraft propulsion. Both piloted and unmanned fuel cell aircrafts have been successfully demonstrated suggesting the near-term viability of revolutionizing small-scale aviation. Nearly all of the flight demonstrations and modeling efforts are conducted with low temperature fuel cells; however, the solid oxide fuel cell (SOFC) should not be overlooked. Attributing to their durability and popularity in stationary applications, which require continuous operation, SOFCs are attractive options for long endurance flights. This study presents the optimization of an integrated solid oxide fuel cell-fuel processing system model for performance evaluation in aircraft propulsion. System parameters corresponding to maximum steady state thermal efficiencies for various flight phase power levels were obtained through implementation of the particle swarm optimization (PSO) algorithm. Optimal values for fuel utilization, air stoichiometric ratio, air bypass ratio, and burner ratio, a four-dimensional optimization problem, were obtained while constraining the SOFC operating temperature to 650–1000 °C. The PSO swarm size was set to 35 particles, and the number of iterations performed for each case flight power level was set at 40. Results indicate the maximum thermal efficiency of the integrated fuel cell-fuel processing system remains in the range of 44–46% throughout descend, loitering, and cruise conditions. This paper discusses a system-level model of an integrated fuel cell-fuel processing system, and presents a methodology for system optimization through the particle swarm algorithm.

Efficiency gain of solid oxide fuel cell systems by using anode offgas recycle – Results for a small scale propane driven unit

2011 ◽  
Vol 196 (17) ◽  
pp. 7152-7160 ◽  
Author(s):  
Ralph-Uwe Dietrich ◽  
Jana Oelze ◽  
Andreas Lindermeir ◽  
Christian Spitta ◽  
Michael Steffen ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Solid Oxide ◽  
Small Scale ◽  
Efficiency Gain ◽  
Oxide Fuel ◽  
Cell Systems

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.

Advances in Development of Coal-Based Integrated Gasification Fuel Cell Systems Utilizing Solid Oxide Fuel Cell Technology

2019 ◽  
Vol 30 (1) ◽  
pp. 157-165 ◽  
Author(s):  
Hossein Ghezel-Ayagh ◽  
Richard Way ◽  
Peng Huang ◽  
Jim Walzak ◽  
Steven Jolly ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Cell Systems ◽  
Cell Technology ◽  
Fuel Cell Technology ◽  
Integrated Gasification

Optimization of an Integrated SOFC-Fuel Processing System for Aircraft Propulsion

2011 ◽  
Author(s):  
Thomas E. Brinson ◽  
Juan C. Ordonez ◽  
Cesar A. Luongo
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Processing System ◽  
Solid Oxide ◽  
System Level ◽  
Small Scale ◽  
Oxide Fuel ◽  
Fuel Processing ◽  
Aircraft Propulsion

As fuel cells continue to improve in performance and power densities levels rise, potential applications ensue. System-level performance modeling tools are needed to further the investigation of future applications. One such application is small-scale aircraft propulsion. Both piloted and unmanned fuel cell aircrafts have been successfully demonstrated suggesting the near-term viability of revolutionizing small-scale aviation. Nearly all of the flight demonstrations and modeling efforts are conducted with low temperature fuel cells; however, the solid oxide fuel cell (SOFC) should not be overlooked. Attributing to their durability and popularity in stationary applications, which require continuous operation, SOFCs are attractive options for long endurance flights. This study presents the optimization of an integrated solid oxide fuel cell-fuel processing system model for performance evaluation in aircraft propulsion. System parameters corresponding to maximum steady state thermal efficiencies for various flight phase power levels were obtained through implementation of the PSO algorithm (Particle Swarm Optimization). Optimal values for fuel utilization, air stoichiometric ratio, air bypass ratio, and burner ratio, a 4-dimensional optimization problem, were obtained while constraining the SOFC operating temperature to 650–1000 °C. The PSO swarm size was set to 35 particles and the number of iterations performed for each case flight power level was set at 40. Results indicate the maximum thermal efficiency of the integrated fuel cell-fuel processing system remains in the range of 44–46% throughout descend, loitering, and cruise conditions. This paper discusses a system-level model of an integrated fuel cell - fuel processing system, and presents a methodology for system optimization through the particle swarm algorithm.

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