Energy, fuel types ethanol

Although most ethanol is now produced from corn, research has been done on producing this type of alcohol fuel from cellulosic biomass products including energy crops, forest and agricultural residues, and MSW, which would provide much cheaper feedstocks. The process of chemically converting these cellulosic biomass feedstocks is more involved and until this process can be simplified the price of ethanol will remain high. 

Hydrogen is not the only energy source for fuel cells. There are many different types of fuel cells (e.g., solid oxide fuel cells and direct ethanol fuel cells) which do not use hydrogen. 

One type of genuine fuel cell that does hold promise in the very long term is the biological fuel cell. These would normally use an organic fuel, such as methanol or ethanol. However, the distinctive biological aspect is that enzymes, rather than conventional chemical catalysts such as platinum, promote the electrode reactions. Such cells replicate nature in the way that energy is derived from organic fuels. However, this type of cell is not yet anywhere near commercial application, and is not yet suitable for detailed consideration in an application-oriented book such as this. 

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