To the editor:
David Kerr (August 17 letter to the editor) states that “The movement to completely eliminate fossil fuels is rooted in profound stupidity and ignorance.” What we want from fossil fuels is the services they provide, such as the example given by Mr Kerr of diesel used to harvest grain. What we want is to harvest grain. Renewable fuels, biodiesel or renewable diesel, made from vegetable oils and fats, can be substituted for fossil-based diesel. Biodiesel can be substituted up to 20% of petroleum diesel and renewable diesel up to 100% of petroleum diesel. With renewable diesel, one could completely replace petroleum diesel. Ethanol can be used to substitute for gasoline.
Currently nearly all gasoline in the U.S. has 10% ethanol, and up to 15% ethanol in gasoline is approved for most automobiles. There are advantages to using higher blends of ethanol with gasoline (25 to 40%) both in terms of air pollutants and greenhouse gases. Ethanol only has about two thirds of the energy. However, automobile engines could be modified (in new automobiles) to take advantage of ethanol’s higher octane (than gasoline) so that the miles per gallon of the higher ethanol blend is the same as gasoline. Manure from livestock and poultry can be collected and turned into biogas in an anaerobic digester. The biogas can be burned to produce electricity or upgraded and substituted for natural gas.
There are limits to currently available feedstock to make renewable/biodiesel, but there are means of increasing the supply. CO2 is a byproduct from the production of ethanol and researchers are working on ways to turn this CO2 into ethanol. With conversion of the CO2 from the currently produced 16 billion gallons of ethanol, ethanol production would become 24 billion gallons. Using biomass resources will not completely eliminate fossil fuels, but can significantly reduce fossil fuels use, reduce greenhouse gas emissions, and improve air quality. With renewable fuels we can still harvest the grain. Substituting renewable fuels for fossil fuels is not only feasible, but smart — not stupid. Alas, Mr Kerr is the ignorant one.