They can be from a variety of naturally occurring substances. Most commercial biofuels are manufactured from grain plants. But things such as adipose tissue could make biofuel, as well. In Sweden,...
Depending on what you mean by "natural waste", it can certainly be made into biofuel. Many companies are now working on more economically viable ways to convert plant cellulose (sawdust, timber...
bio fuels are being made because the reserves of fossil fuels are running out.
fossil fuels take millions of years to form, if we run out, we need to find an alternative fuel in which to run our...