Although, biofuels may not yet be part of the Ooooby (out of our own backyard) movement, many supporters of biofuels share the Ooooby principle that people try and cultivate their own resources. Here, Madison, who typically writes about biology and practical uses for biology programmes, kicks off a new Renewable Enery Focus series on the Biology and Economics of Biofuels by taking a closer look at how biofuels stack up to fossil fuels.

Touted for both energy efficiency and reduced carbon emissions, biofuels have received worldwide attention in recent years as a viable solution to the global oil crisis. While these positive qualities have been reinforced by numerous scientific studies, biofuels still have critics who say cost-ineffectiveness and poor vehicular performance greatly hinder its perceived economic value.

A biofuel is any fuel source derived from naturally occurring biological processes:

• Ethanol, for instance, can be derived from crops such as corn, rye and sugarcane.
• Another example is biodiesel, which is rendered from organic oils and fats found in both plants and animals.
• Biogas, a methane-based substance, is generated by organic decomposition of botanical matter, herbivorous animal feces and other forms of biological waste.
• In addition, scientists have experimented with microalgae, woody biomass and other materials with potential to produce fuel sources. 

Biofuels have garnered worldwide support from environmentalists as a key factor in the energy crisis. One reason for this is biofuels’ ability to drastically reduce carbon emissions. Pure biodiesel cuts carbon monoxide, carbon dioxide, sulfur, hydrocarbons and smog-causing particulate by a significant degree (typically 50-90%).

Ethanol records a similarly impressive reduction of emissions; corn-based ethanol typically reduces GHG emissions by 20-30%, while cellulose-based ethanol – a product currently in development – is expected to reduce the same emissions by as much as 86%.

These characteristics effectively address and mitigate two global environmental challenges: the rise of global warming due to high emission levels, and the steady diminishment of fossil fuel reserves.         

Unfortunately, several factors have prevented biofuels from receiving worldwide support. The largest perceived drawback is relatively poor fuel economy. Biodiesel, for instance, is outperformed by petroleum diesel in terms of volumetric efficiency – a measure more commonly known as ‘miles per gallon’.

Since biodiesel’s energy content is roughly 11% lower than that of standard diesel, vehicles powered by the former do not travel as far as the latter on the same amount of fuel. Ethanol has recorded similar deficiencies. Though it can be cheaper per gallon than gasoline by as much as a dollar, the US Department of Energy notes that miles per gallon are reduced by 20-30%.

Technical drawbacks have also hurt the reputation of biofuels.

One problem is temperature. Biodiesel performs poorly in cold, wintry conditions because low temperatures cause wax crystals to form in the fuel. This can lead to clogged fuel lines and filters within the vehicle’s fuel processing system.

Another problem is incompatibility with other vehicles, which has been displayed by both biodiesel and ethanol. Since biodiesel has solvent properties, it will not function properly with certain parts used in older vehicles and machinery. As for ethanol, it can only be used in flex-fuel vehicles. In addition, long-term ethanol use causes engine corrosion, which can ultimately cost the owner thousands of dollars.

Fortunately, the science of biofuel technology is still in its infant stages. As researchers continue to develop these alternative fuel sources, steps will be taken to improve fuel economy and technical drawbacks – and retain the fuels’ positive, environmentally friendly attributes.

Biofuels might not be the most viable solution to the energy crisis yet, but many proponents believe it is only a matter of time until they will merit serious worldwide consideration.

Madison Jones writes about biology and practical uses for biology programmes.