Diesel Trees
Just as cows give drinkable milk, trees can yield fuel pure enough to be burned in diesel engines. Dubbed the diesel tree, Brazil's Cobaifera tree is the Guernsey of the forest, each mature tree being able to produce 30 to 40 liters (8 to 10 U.S. gallons) per year.
Though not likely to become a significant source of diesel fuel in temperate climates, in the tropics Cobaifera plantations might produce as much as 25 barrels of fuel per year. Still, Cobaifera relatives in the same genus, Euphorbia, are producing 10 barrels per acre in northern California.
The hydrocarbons produced by these trees are called terpenes. Terpenes are made by plants from isoprene, a five-carbon-atom building block, so they always contain carbon atoms in multiples of five. Pinene is one of several useful 10-carbon terpenes. It is commonly known as turpentine. Heated up, terpenes break down into methanol (CH 3 OH) and other simple compounds useful for fuel and as raw materials in the chemical industry.
Preliminary tests in our laboratories at the Institute of Marine Science have shown that we can use water to wash terpenes and similar hydrocarbons out of white spruce foliage. Now we wish to make more extensive tests over a long time period to see what sort of terpene production might be achieved from northern forests.
It's probably a bit too much to hope for, but perhaps someday we might view cutting a tree as killing the goose that laid....
