A nursery in Australia will soon be growing a “diesel tree” also known as Copaifera langsdorfii. One tree is supposed to be able to produce up to 14 gallons of sap that is good enough to pour straight into your fuel tank.
I had never heard of this so I did some research and apparently this tree grows in South America and has been used for years. In 1982 an American scientist tried to mix a species of weed with this tree to allow it to grow in the less used arid parts of the country. The end result was to be the birth of “energy plantations”, but it seems like it didn’t get to far because I couldn’t find anything about it after that.
Maybe there will be renewed interest now from our friends down under and with changes in scinece and technology, since 1982, something more can be done with this source of fuel.