Research on renewable and environmentally sustainable fuels has received a lot of impetus in recent years. With oil at high prices, alternative renewable energy has become very attractive. Many of these technologies are eco-friendly. Besides ethanol, other environmentally sustainable fuels include biodiesel and biobutanol.

A recent United Nations report urges governments to beware the human and environmental impacts of switching to energy derived from plants. There should a healthy debate about turning food crops or animal feed into fuel and the conse­quences of the switch to biofuels needs to be carefully thought out. Thus the focus of biofuel production needs to be on non-edible and waste sources. In the case of biodiesel, these include restaurant grease, non-edible sources like Jatropha as well as microalgae. Biobutanol is a renewable, biodegradable, alternative fuel, which can be used neat or blended with gasoline. Properties such as energy density, octane value, and Reid vapor pressure (RVP) are similar to gasoline; hence current vehicles can use biobutanol without any engine modifications. Biobutanol can be produced from biomass by the fermentation of sugars and starches or by thermochemical routes using gasification.

Ethanol is made through the fermentation of sugars, and sugar cane offers many advantages. Unlike corn-based fuels, sugarcane requires no fossil fuels to process. Cellulosic ethanol, derived from a range of crops, such as switchgrass and crop waste, is more economical than corn ethanol because it requires far less energy. While there is no single magic bullet that can completely replace our dependence of petroleum, the focus needs to shift on fuels that can not only alleviate our dependence on petroleum but are also renewable and environmentally sustainable.