Biofuels: Renewable, but Clean?

Because most cars currently run on tangible fuels, many supporters of renewable energy have advertised biofuels, which are fuels generally created from plants. Since plants can reproduce to grow more plants, the supply of potential biofuels is virtually unlimited. The most familiar biofuel is ethanol, an alcohol that is mostly produced from corn sugars. Plants, however, are carbon-based, and this also applies for ethanol, meaning that carbon dioxide, a greenhouse gas, will still be produced when ethanol is burned. However, ethanol can cut greenhouse gas emissions by up to twenty percent, and an energy law passed last year demands a fourfold increase in ethanol production by 2022. Ethanol, though, still requires at least 15% gasoline for effective burning, has only two-thirds the energy content of gasoline, and may increase smog concentrations in urban areas. Despite these drawbacks, ethanol is blended into approximately sixty percent of gasoline, and eighteen percent of the corn in the United States was used to make ethanol last year, with the energy law making continued growth of that figure almost certain. In fact, one hundred and thirty-four ethanol power plants are currently operational in twenty-six states, and seventy-seven additional ethanol power plants are under construction. However, the intense consumption of American corn, which will only increase from these new power plants, has driven corn prices to records or near-records. A new type of ethanol, called cellulosic ethanol, now promises to erase many of ethanol's weaknesses, but faces technological hurdles in mass-production. Cellulosic ethanol does not require corn for production, could generate more energy than gasoline, and would also lower greenhouse gas emissions. This new form of ethanol may still impact global warming, but may keep global warming at bay long enough to develop other renewable energy sources.

Ethanol may be the best known biofuel, but there is another type of biofuel - biodiesel. Biodiesel, as the name suggests, is a diesel alternative, but is mostly made from soybeans and oils, particularly used cooking oil. Given the prevalence of cooking oils in restaurant and fast-food chains, this fuel type is appealing, but suffers from a few difficulties. Biodiesel may contain a higher energy content than gasoline, but has a lower energy content than regular diesel. Furthermore, biodiesel may also reduce greenhouse gas emissions, but the fuel may increase pollutant levels. Finally, biodiesel can damage cars at low temperatures. Biodiesel may be renewable, but the fuel offers very few benefits, and will likely never be distributed on a large scale.

Corn, soybeans, and oils are generally thought to be the major contributors to biofuel supplies. Many other fuel sources, though, can be used for biofuel production. Poppies, for instance, can be used to create biodiesel, and a power plant in Tasmania, Australia is already operational. Kudzu, the most invasive plant in the United States, could be used to generate two hundred and seventy gallons of ethanol per acre of kudzu, a comparable figure to corn's productivity of three hundred and thirty gallons per acre. Algae, another unknown biofuel source, in contrast, can produce ten thousand gallons of ethanol per acre. In fact, the first algae power plant, located in Texas, opened in April of this year, despite the incredible cost of twenty dollars per gallon for ethanol created by algae. The most intriguing source of ethanol, however, is not a plant, but instead, garbage. In fact, in a week, the garbage New York City disposes of could be used to fill the gas tanks of seven hundred and fifty thousand vehicles that can burn ethanol, and the United States and Canada have already approved power plants that process garbage. These discoveries are very intriguing, and some of these biofuel sources may even power a part of the world for a time.

Biofuels, however, still suffer from their fundamental flaw - their impact on the environment. No matter how innovative many of the discoveries regarding biofuels are, biofuels still contribute to global warming with carbon dioxide. Ethanol may serve as a temporary fuel for the world until the world can adapt to other renewable energy sources, but because of ethanol's contributions to global warming, the fuel cannot be permanent. Many renewable energy sources do not contribute to global warming, and society should pursue these to keep the Earth safe.