622Molten Carbonate

The electrolyte in a molten carbonate fuel cell (MCFC) is an alkali carbonate (sodium, potassium, or lithium salts, Na2CO3, K2CO2, or Li2CO3) or a combination of alkali carbonates that is retained in a ceramic matrix of lithium aluminum oxide (LiAlO2). An MCFC operates at 600 to 700°C where the alkali carbonates form a highly conductive molten salt with carbonate ions (CO3) providing ionic conduction through the electrolyte matrix. Relatively inexpensive nickel (Ni) and nickel oxide (NiO) are adequate to promote reaction on the anode and cathode, respectively, at the high operating temperatures of an MCFC (Baker, 1997).

MCFCs offer higher fuel-to-electricity efficiencies than lower temperature fuel cells, approaching 60%, and greater fuel flexibility. The higher operating temperatures of MCFCs make them candidates for combined-cycle applications in which the exhaust heat is used to generate additional electricity. When the waste heat is used for cogeneration, total thermal efficiencies can approach 85%.

The two leading U.S. MCFC developers are Fuel Cell Energy (Connecticut) and M-C Power Corporation (Illinois). In addition to the U.S. developers, MCFC technology is being developed in both Europe and Japan. Demonstration plants of up to 2 MW have been designed, constructed, and tested.

Solar Stirling Engine Basics Explained

Solar Stirling Engine Basics Explained

The solar Stirling engine is progressively becoming a viable alternative to solar panels for its higher efficiency. Stirling engines might be the best way to harvest the power provided by the sun. This is an easy-to-understand explanation of how Stirling engines work, the different types, and why they are more efficient than steam engines.

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