Foreword
Ever since the invention of farming, crops have been produced mainly to feed people and livestock. Now that’s changing in response to concerns about pollution, air quality, and the price and availability of oil. Biofuels — fuels derived from organic matter, usually plants — are increasingly being used as an alternative to fossil fuels — coal, natural gas, and oil. The most common biofuels are ethanol, usually produced from corn and sugar, and biodiesel, made by combining alcohol with vegetable oil. The United States is the world’s largest producer of ethanol, followed by Brazil. According to the Renewable Fuels Association,…
