Solid Oxide SOFC

Solid oxide fuel cells (SOFC) use a hard, non-porous ceramic compound as the electrolyte. Since the electrolyte is a solid, the cells do not have to be constructed in the plate-like configuration typical of other fuel cell types. SOFCs are expected to be around 50-60 percent efficient at converting fuel to electricity, however, calculations show that over 70 percent may be achievable. In applications designed to capture and utilize the system s waste heat (co-generation), overall fiiel use efficiencies could top 80-85 percent. 

Solid oxide fuel cellsoperateatvery high temperatures, around 1,000°C. High temperature operation removes the need for precious-metal catalyst, thereby reducing cost. It also allows SOFCs to reform fuels internally, which enables the use of a variety of fuels and reduces the cost associated with adding a reformer to the system. SOFCs are also the most sulphur-resistant fuel cell type they can tolerate several orders of magnitude more sulphur than other cell types. In addition, they are not poisoned by carbon monoxide (CO), which can even be used as fuel. This allows SOFCs to use gases made from coal. 

R D efforts directed at specific fuel cell type 

The PEM fuel cells offers an order of magnitude higher power density than any other fuel cell system, with the exception of the advanced aerospace AFC. Recent advances in performance and design offer the possibility of lower cost than any other fuel cell system. 

The EU s FURIM program targets the development of novel PEM membranes and related components for high temperature fuel cells and the testing of PEM stacks to evaluate their technical, economic and environmental impacts. Thirteen European partners are involved in the 4 million project. The EU s Hj-MINIPAC is focused on the development of micro PEM fuel cells using hydrogen as a fuel. 

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A number of strategic research topics were pursued for fuel cell systems in the EU funded projects, ranging from basic research to validation and demonstration activities for gaining field experience . All activities were targeting systems which could be commercially viable by 2020 for many applications, with focus on the high temperature technologies (mainly Solid Oxide, SOFC) and... 

Solid oxide (SOFC) CHP, power plants Solid oxide 875-1275... 

Several types of fuel cell are currently under development, using different electrolyte systems phosphoric acid (PAFC), alkaline, molten carbonate (MCFC), regenerative, zinc-air, protonic ceramic, (PCFC), proton exchange membrane (PEM), direct methanol (DMFC), and solid oxide (SOFC). The last four contain solid electrolytes. 

Solid Oxide (SOFC) These cells use a solid oxygen-ion-conducting metal oxide electrolyte. They operate at about 1000 °C, with an efficiency of up to 60%. They may find application in industrial and large-scale applications. 

Solid oxide (SOFC). The electrolyte is a ceramic oxide and operates at 1000°C and can consume hydrogen or hydrogen/carbon monoxide mixtures. A high electrical efficiency of over 50 per cent is reported. 

There are other types of fuel cells of which proton exchange membranes (PEMFC), molten carbonate (MCFC), and solid oxide (SOFC) are the most promising. These fuel cells are at various stages of technology demonstration and are not commercially available. Each type of fuel cell has its own preferred range... 

Solid Oxide (SOFC) Solid zirconium oxide to which a small amount of yttria is added 600-1000 Electric utility Higher efficiency, fuel flexibility, inexpensive catalysts. Solid electrolyte advantages like PEM... 

Solid oxide (SOFC) 500-1000°C Suitable for aU sizes of CHP systems, 2kW to multi-MW. 

Polymer electrolyte PEFC Phosphoric acid PAFC Molten carbonate MCFC Solid oxide SOFC... 

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