When that happens, Tao said, we will have to switch to using renewable resources. One of the potential alternatives to petroleum is common field crops, which could soon be developed into a fuel for practical use. Ethanol has been discussed for years as a biofuel replacement for petroleum, but it's not the only option. Plant oils and fats have the same base chemical structure as petroleum, meaning they could also be used as a natural fuel replacement. By manipulating these plant oils, it may be possible to create a petroleum substitute, Tao said.
Ethanol is a type of alcohol made by fermenting plant material, such as starch and sugar crops.
Although it makes a good fuel, it does have drawbacks. It doesn't explode like gasoline and it can absorb water, which could cause rust and corrosion. Both fossil fuels and plants are made up of chains of chemicals known as hydrocarbons . A hydrocarbon is a carbon atom surrounded by hydrogen atoms. The simplest hydrocarbon is methane , which is a single carbon atom surrounded by four hydrogen atoms.