Flexible Coproduction of Hydrogen and Power Using Internal Reforming Solid Oxide Fuel Cells System

2008 ◽  
Vol 5 (4) ◽  
Author(s):  
Kas Hemmes ◽  
Anish Patil ◽  
Nico Woudstra
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Hydrogen Production ◽  
Natural Gas ◽  
Cell System ◽  
Solid Oxide ◽  
Flow Sheet ◽  
Oxide Fuel ◽  
Internal Reforming ◽  
Wide Range

Within the framework of the Greening of Gas project, in which the feasibility of mixing hydrogen into the natural gas network in the Netherlands is studied, we are exploring alternative hydrogen production methods. Fuel cells are usually seen as the devices that convert hydrogen into power and heat. It is less well known that these electrochemical energy converters can produce hydrogen, or form an essential component in the systems for coproduction of hydrogen and power. In this paper, the coproduction of hydrogen-rich syngas (that can be converted into hydrogen) and power from natural gas in an internal reforming fuel cell is worked out by flow sheet calculations on an internal reforming solid oxide fuel cell system. The goal of this paper is to study the technical feasibility of such a system and explore its possibilities and limitations for a flexible coproduction. It is shown that the system can operate in a wide range of fuel utilization values at least down to 60% representing highest hydrogen production mode up to 95% corresponding to standard FC operation mode.

Performance Comparison of Internal and External Reforming for Hybrid SOFC-GT Applications by Using 1D Real-Time Fuel Cell Mode

2019 ◽  
Author(s):  
Hao Chen ◽  
Chen Yang ◽  
Nana Zhou ◽  
Nor Farida Harun ◽  
David Tucker
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Natural Gas ◽  
Solid Oxide Fuel Cells ◽  
Real Time ◽  
Hybrid System ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Fuel Utilization ◽  
Internal Reforming

Abstract Solid oxide fuel cells integrated with gas turbine (SOFC-GT) systems are considered among the most promising power generation units, not only because of the high efficiency, low emissions and carbon capture ability, but also the flexibility to use different kinds of fuels such as natural gas, syngas and biogas directly. In the case of natural gas, Previous researches have demonstrated that solid oxide fuel cells possess the ability to utilize natural gas directly by reforming it inside the anode because of the high operating temperature. But the major problem of internal reforming is that it increases the temperature gradient at the leading edge of fuel cell which may lead to high thermal stress and damage the cells. On the other side, external reforming requires an additional reformer outside of fuel cell, which may increase the investment costs. Also, the amount of air needed to cool the fuel cell is doubled, compared with internal reforming. A full comparison between internal reforming and external reforming of the pressurized SOFC is needed for the hybrids application. In this paper, a real time equilibrium reformer model based on minimization of Gibbs free energy was built to couple with 1D real time solid oxide fuel cell model. An internal on-anode reforming SOFC stack configuration for hybrid SOFC-GT system application was compared with external reforming configurations with 800K, 900K and 1000K reforming temperatures. The results show that internal reforming provides better performance of SOFC stack in the case of high fuel utilization. However, the external reforming showed a higher stack efficiency and smaller stack size compared with on-anode reforming when keeping a relatively lower SOFC stack fuel utilization, necessarily for high hybrid efficiency. Results indicated that external and internal reforming of fuel needs to be optimized depending on different design conditions of the entire hybrid system in terms of efficiency and investment cost. This paper shows that the hybrid system provides the opportunities for thermal integration on performance and efficiency improvement over fuel cell anode reforming.

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.

Solid Oxide Fuel Cell System and the Economical Feasibility

2006 ◽  
Vol 3 (3) ◽  
pp. 242-253 ◽  
Author(s):  
Erkko Fontell ◽  
Tho Phan ◽  
Timo Kivisaari ◽  
Kimmo Keränen
Keyword(s):  
Fuel Cell ◽  
Natural Gas ◽  
Solid Oxide Fuel Cell ◽  
Cell System ◽  
Solid Oxide ◽  
Maintenance Cost ◽  
Oxide Fuel ◽  
Market Conditions ◽  
The Impact ◽  
Economical Feasibility

In the paper, a solid oxide fuel cell (SOFC) system is briefly described and its economical feasibility in three different applications is analyzed. In the feasibility analysis, the SOFC system is part of commercial applications where energy is used for power and heat generation. In the economical analysis, the three applications have different load profiles which are studied separately at different geographical locations with associated local energy market conditions. The price for natural gas and electricity varies by location, leading to a different feasibility condition for stationary fuel cell application as well as for other distributed generation equipment. In the study, the spark spread of natural gas and electricity is used as a base variable for the analysis. The feasibility is analyzed in the case of an electricity-only application as well as with two combined heat and power applications, where an economical value is assigned to the produced and consumed heat. The impact on economical competitiveness of possible incentives for the generated fuel cell power is estimated. A sensitivity analysis with different fuel cell-units’ electrical efficiency, maintenance cost, and payback period is presented. Finally, the maximum allowed investment cost levels for the SOFC system at different locations and market conditions is presented.

Numerical Simulations of Solid Oxide Fuel Cells Operating on Coal Syngas: A Parametric Study

2009 ◽  
Author(s):  
Francisco Elizalde-Blancas ◽  
S. Raju Pakalapati ◽  
F. Nihan Cayan ◽  
Ismail B. Celik
Keyword(s):  
Carbon Monoxide ◽  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Numerical Simulations ◽  
Alternative Fuels ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Coal Syngas ◽  
Internal Reforming ◽  
Wide Range

Fuel cells are considered to be one of the main sources of future power supply around the world because of their many desirable features; technology virtually free of pollution, the ability to use alternative fuels other than fossil fuels, and higher efficiencies than combustion engines. Solid Oxide Fuel Cells (SOFCs) can operate on a wide range of fuels, particularly with coal syngas. However, several issues have to be solved before SOFC’s operating on coal syngas can be introduced into the market as a reliable and cost viable technology. Numerical simulations can be used in conjunction with experiments to assist in resolution of such barriers. In the present work, a three-dimensional model is used to study the performance of a SOFC running on coal syngas operating at various conditions. The code is capable of simulating several species in the fuel stream, such as methane, steam, carbon monoxide, hydrogen, carbon dioxide. Due to the presence of hydrogen and carbon monoxide, simultaneous electrochemical oxidation of both fuels is considered. Internal reforming and water gas shift reaction are other processes that are taken into account. Simulations of typical anode-supported button cells are performed to assess the effects of cell operating temperature, fuel composition and CO electrochemistry on the performance of the button SOFCs.

Internal Reforming SOFC System for Flexible Coproduction of Hydrogen and Power

2005 ◽  
Author(s):  
Kas Hemmes ◽  
Anish Patil ◽  
Nico Woudstra
Keyword(s):  
Fuel Cell ◽  
Hydrogen Production ◽  
Natural Gas ◽  
Total System ◽  
Flow Sheet ◽  
Content Increase ◽  
Fuel Utilization ◽  
Production Mode ◽  
Internal Reforming ◽  
Production Of Hydrogen

In the framework of the project Greening of Gas, in which the feasibility of mixing hydrogen into the natural gas network in the NL is studied, we are exploring alternative hydrogen production methods. Fuel cells are usually only seen as devices that convert hydrogen into power and heat. It is less well known that these electrochemical energy converters can produce hydrogen, or form an essential component in systems for co-production of hydrogen and power. Co-production of hydrogen and power from NG in an Internal reforming fuel cell (IR FC) is worked out by flow sheet calculations on an Internal reforming Solid Oxide fuel cell (IR-SOFC) system. It is shown that the system can operate in a wide range of fuel utilization values at least from 60% representing highest hydrogen production mode to 95% corresponding to ‘normal’ fuel cell operation mode. For the atmospheric pressure system studied here hydrogen and CO content increase up to 22.6 and 13.5 % respectively at a fuel utilization of 60%. Total system efficiency (power + H2/CO) is increasing significantly at lower fuel utilization and can reach 94 %. Our study confirms that the calculations of Vollmar et al1) on an IR-SOFC stack also hold for a complete FC system. Notably that paradoxically a system with the same fuel cell stack when switched to hydrogen production mode can yield more power in addition to the H2 and CO produced. This is because the hydrogen production mode allows for operation at high current and power densities. The same system can double its power output (e.g. from 1.26 MW to 2.5 MW) while simultaneously increasing the H2 /CO output to 3.1MW). Economics of these systems is greatly improved. These systems can also be considered for hydrogen production for the purpose of mixing it with natural gas in the natural gas grid in order to reduce CO2 emissions at the end users, because of the ability to adopt the system rapidly to fluctuations in natural gas/hydrogen demand.

Numerical Simulation of an Internal Reforming Solid Oxide Fuel Cell Unit Fueled with Hydrogen-Natural Gas Mixtures

2021 ◽  
Vol MA2021-03 (1) ◽  
pp. 163-163
Author(s):  
Junhua Fan ◽  
Yuqing Wang ◽  
Jixin Shi ◽  
Yixiang Shi ◽  
Haishan Cao ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Fuel Cell ◽  
Natural Gas ◽  
Solid Oxide Fuel Cell ◽  
Gas Mixtures ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Internal Reforming
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