05/02115 An example of innovative application in fuel cell system development: CO2 segregation using molten carbonate fuel cells

2005 ◽  
Vol 46 (5) ◽  
pp. 312
Author(s):  
Sy A. Ali ◽  
Robert Moritz

High temperature fuel cell stacks of commercially significant power (>100 kW) have emerged during the last 10 years. Five US programs, two Molten Carbonate and three Solid Oxide were recently awarded feasibility study funding from US Department of Energy (DOE) to define products which could achieve at least 70% efficiency to electricity. The Department of Energy believes that these pressurized fuel cell systems will become an important part of the future power generation soruces. In support of these views, Rolls-Royce has joined fuel cell manufacturers to develop pressurized fuel cell plants which can be marketed successfully to end users. In selecting technology which should be supported, RR-Allison considered the following critical issues: technology with US business focus; technology with potential for near term commercialization; and technology which would lead into second generation fuel cell system development over long term. The Rolls-Royce plan is to join the DOE initiative through the pressurized Molten Carbonate program which has been funded as “Molten Carbonate Fuel Cell (MCFC) Product Design and Improvement.” The paper outlines the functional and commercial issues to be evaluated during the proof of concept tests of the first pressurized MCFC power generation package. The key factors to be evaluated during the test program in current order of priority are: • operational stability • power output and system availability • cost reduction potential • system simplification for commercial power generation application • enhanced reliability • power quality • grid interconnection


Author(s):  
K. Hemmes ◽  
M. Houwing ◽  
N. Woudstra

Direct carbon fuel cells (DCFCs) have great thermodynamic advantages over other high temperature fuel cells such as molten carbonate fuel cells (MCFCs) and solid oxide fuel cells. They can have 100% fuel utilization, no Nernst loss (at the anode), and the CO2 produced at the anode is not mixed with other gases and is ready for re-use or sequestration. So far, only studies have been reported on cell development. In this paper, we study the performance of a CO2-producing DCFC system model. The theoretically predicted advantages that are confirmed on a bench scale are also confirmed on a system level, except for the production of pure CO2. Net system efficiencies of around 78% were found for the developed system. An exergy analysis of the system shows where the losses in the system occur. If the cathode of the DCFC must be operated as a standard MCFC cathode, the required CO2 at the cathode is the reason why a large part of the pure CO2 from the anode is recycled and mixed with the incoming air and cannot be used directly for sequestration. Bench scale studies should be performed to test the minimum amount of CO2 needed at the cathode. This might be lower than in a standard MCFC operation due to the pure CO2 at the anode side that enhances diffusion toward the cathode.


Energy ◽  
2016 ◽  
Vol 117 ◽  
pp. 578-589 ◽  
Author(s):  
Liqiang Duan ◽  
Kun Xia ◽  
Tao Feng ◽  
Shilun Jia ◽  
Jing Bian

2006 ◽  
Vol 3 (4) ◽  
pp. 492-494 ◽  
Author(s):  
Sari Tasa ◽  
Teppo Aapro

Mobile device manufacturers would like to provide totally wireless solutions—including charging. Future multimedia devices need to have longer operation times as simultaneously they require more power. Device miniaturization leaves less volumetric space available also for the energy source. The energy density of the Li-ion batteries is high, and continuously developed, but not at the same speed as the demand from devices. Fuel cells can be one possible solution to power mobile devices without connection to the mains grid, but they will not fit to all use cases. The fuel cell system includes a core unit, fuel system, controls, and battery to level out peaks. The total energy efficiency is the sum of the performance of the whole system. The environmental performance of the fuel cell system cannot be determined yet. Regulatory and standardization work is on-going and driving the fuel cell technology development. The main target is in safety, which is very important aspect for energy technologies. The outcomes will also have an effect on efficiency, cost, design, and environmental performance. Proper water, thermal, airflow, and fuel management of the fuel cell system combined with mechanical durability and reliability are the crucial enablers for stable operation required from the integrated power source of a mobile device. Reliability must be on the same level as the reliability of the device the energy source is powering; this means years of continuous operation time. Typically, the end-users are not interested of the enabling technologies nor understand the usage limits. They are looking for easy to use devices to enhance their daily life. Fuel cell technology looks promising but there are many practical issues to be solved.


2017 ◽  
Vol 4 ◽  
pp. 76-86 ◽  
Author(s):  
Reece Cohen Woodley ◽  
Kane Yang ◽  
Geoffrey Bruce Tanner ◽  
Dennis Tran

This meta-study focuses on the research regarding the use of nanotechnology in traditional fuel cells in order to increase thermodynamic efficiency through the exploitation of various thermodynamic systems and theories. The use of nanofilters and nano-structured catalysts improve the fuel cell system through the means of filtering molecules from protons and electrons significantly increases the possible output of the fuel cell and the use of nano-platinum catalysts to lower the activation energy of the fuel cell chemical reaction a notable amount resulting in a more efficient system and smaller entropy in comparison to the use of macro sized catalysts.


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