Besides, fossil fuels are a nonrenewable resource – once they’re gone, they’re gone. So the search continues for better sources of energy – “perpetual” resources like solar and tidal energy, or “renewable” resources like biofuels.
Biofuels aren’t new – they’ve been around in one form or another for a long, long time. In its simplest form, biofuel is just combustible bits of animal or plant waste. They can be solids, which are burned directly (biomass fuels) like wood, charcoal, or dried manure; or they can be converted to gaseous or liquid forms (synthetic fuels, or synfuels), like biogas, methanol, and ethanol. Over much of the world, burning wood or animal dung is common practice, but is it really workable in an industrialized country like the US? Well, sort of. Brazil reportedly runs half its automotive fleet on ethanol manufactured from sugar cane. And gasohol, a mixture of gasoline and ethanol, is being used in the US now in internal combustion engines. And as a fuel source, there is potential for forested countries like the US. It’s estimated that US agriculture and forestry wastes, converted to fuel, would probably be equivalent to 1/3 of the annual commercial energy use here. So while it’s unlikely that biofuels will ever become the primary fuel source for industrialized nations, it certainly has potential to be a significant source of energy.
Like fossil fuels, biofuels are ultimately burned in order to produce electricity, run an internal combustion engine, or cook dinner. But burning biofuels produces less sulfur and nitrogen compounds than burning traditional fuels, which means there’s less air pollution associated with it. And while biofuel use does produce carbon dioxide and so contributes to greenhouse gas emissions, the increase is offset when carbon dioxide is taken from the atmosphere by the growing plants that are replacing the harvested ones.
Outside industrialized nations, it’s still common to burn wood or animal waste for cooking and home heating. Almost half of the wood harvested worldwide every year is burned as fuel. But most of the heat produced by open fires is wasted, so it’s an inefficient use of resources. And in many countries, wood is a precious commodity, and in some areas, could cost up to 25% of an urban family’s income. Animal dung, which in some tree-poor agricultural nations is collected, dried and burned, would be put to better use left on the fields as fertilizer, thus increasing crop yields and producing more food. But for forested countries in temperate climates, biofuels presents an attractive option for reducing our dependence on nonrenewable fossil fuel energy.
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