Advantages of high-temperature fuel cells

A significant advantage of high-temperature fuel cells such as MCFCs is their ability to use CO as a fuel. The anodic oxidation of CO in an operating MCFC is slow compared to the anodic oxidation of H2 thus, the direct oxidation of CO is not favored. However, the water gas shift reaction... 

It is the great advantage of high-temperature fuel cells that not only hydrogen but also hydrocarbons as well as carbon monoxide (a coal processing product) can directly be used as fuel. High-temperature fuel cells are primarily intended for large power... 

An inherent advantage of high temperature fuel cells is that hydrocarbons such as methane may be internally reformed directly in the cell according to the following cell reactions ... 

Together with the solid-oxide fuel cells (SOFCs) considered in Chapter 8, molten-carbonate fuel cells (MCFCs) are representatives of a class of high-temperature fuel cells that have a working temperature of more than 600°C. High-temperature fuel cells have a number of advantages over other fuel cell types ... 

Fuel cells such as the one shown on Fig. 3.4a convert H2 to H20 and produce electrical power with no intermediate combustion cycle. Thus their thermodynamic efficiency compares favorably with thermal power generation which is limited by Carnot-type constraints. One important advantage of solid electrolyte fuel cells is that, due to their high operating temperature (typically 700° to 1100°C), they offer the possibility of "internal reforming" which permits the use of fuels such as methane without a separate external reformer.33 36... 

The fact that these cells can operate with many different fuels is one advantage of high-temperature operation. However, there is at present much research directed toward lowering the operating temperature for cost reasons. 

Appendix A shows that for equilibrium fuel cells, high-temperature operation offers no advantage, but indeed a theoretical disadvantage. However, in a practical non-equilibrium set-up, where unused fuel and unconsumed oxygen are features and these have to be combusted in a gas turbine, the high-temperature fuel cell is likely to be at an advantage. Further discussion appears on this point in Chapters 4 and 5, in respect of the SOFC and the MCFC. The PEFC (Chapter 6) must, for... 

The direct methanol fuel cell is a special form of low-temperature fuel cells based on PEM technology. In the DMFC, methanol is directly fed into the fuel cell without the intermediate step of reforming the alcohol into hydrogen. Methanol is an attractive fuel option because it can be produced from natural gas or renewable biomass resources. It has the advantage of a high specific energy density, since it is liquid at operation conditions. The DMFC can be operated with liquid or gaseous methanoFwater mixtures. 

High-temperature fuel cells have a number of advantages in comparison to other fuel cell types ... 

The sulphur resistance of the CPO process is in particular an advantage when using heavy fuels (diesel) as feedstock. These will contain sulphur compounds, which are difficult to remove at low pressure. This is crucial for the operation of low-temperature fuel cells, but may not be the case for high-temperature fuel cells, as demonstrated by results on a SOFC stack [421]. 

Molten carbonate fuel cells (MCFCs) are one of the two most common high temperature fuel cells, operating at 600 to 700°C. The key advantage... 

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