POWERED BY PLANTS
Biodiesel is an alternative fuel that works in a similar way to petroleum. Whereas petroleum fuel comes from underground oil reserves formed out of the decomposed matter of plants and animals, biodiesel comes from the oil of plants and animals still on the surface. Typically, biodiesel oil is obtained from plants, including rapeseed, palm and soybean, and animal fats or tallow. Through a process known as transesterification, these oils are converted into a fuel source through several chemical reactions.
Biodiesel is then combusted in engines the same way as petroleum, resulting in the release of carbon dioxide into the atmosphere, albeit on a much lower level. However, the carbon dioxide that biodiesel emits is largely offset by the amount of carbon dioxide that biodiesel crops absorb during photosynthesis.
Although biodiesel is kinder to the environment in terms of reducing greenhouse gas production, there are many challenges involved in its production, such as fertiliserinduced land pollution, soil erosion and monopolising land use – to meet the current fuel demands of the US, 563,000 square miles of land would be required to grow enough biodiesel crops.