Green Crude
Algae are a group of primitive plants best known to us as seaweeds and green pond scum. But algae are actually a large and diverse group-there are more than 30,000 species. And their uses by humans are legion. Seaweeds have been used as fertilizer for centuries, but over the past few decades, numerous other kinds of algae have been farmed commercially-
to produce fertilizer components,
to release hydrogen for energy production,
for pollution control (to mop up specific toxins),
to synthesize chemical laboratory aids,
for nutrition supplements,
for use in cosmetics, etc.
Their genetic makeup can be manipulated to make them complex biological factories. They can even be “taught” to produce fuel oils. Some species of algae have lipids (that is, fats and oils) amounting to as much as 40% of their dry weight.
In May 2008 a company in Sonoma, California-Sapphire Energy-announced that they had succeeded in producing the equivalent of petroleum crude oil from certain species of algae grown on non-arable land (dry, polluted wastelands). The process uses algae with chlorophyll to bind the energy of sunlight into long carbon chains, producing oils from carbon dioxide in the air.
This “green crude” is economical to produce and is fully equivalent to “black crude” petroleum. It can even be fed into the same refinery and transport infrastructure as black crude, and can produce gasoline with an octane rating of at least 91. Since it is grown on land that cannot be farmed for other purposes, it does not compete with food production (as growing corn for ethanol fuel does).
This may truly be a breakthrough in the production of fuel which is renewable (grown as needed) and non-polluting (the net carbon footprint is zero since it puts into the atmosphere only carbon it has previously removed from the atmosphere).
How about being able to get diesel fuel from trees?
Gliocladium roseum is a fungus recently discovered living inside trees in Patagonia. It represents a Holy Grail for molecular biologists because it synthesizes diesel from cellulose.
Most of the bulk of a tree-in fact, the vast majority of all the stiff, fibrous tissue found throughout the plant kingdom-is cellulose, consisting of long, polymerized chains of sugar molecules. Although most simple sugars are readily digested, the long chains cannot be broken down easily-which is why humans cannot eat wood. This takes special enzymes (termites have special bacteria in their gut than can digest the cellulose) or, in the laboratory, considerable heat, pressure, and the use of chemical catalysts.
Bio-fuels are usually made by fermenting the free (unpolymerized) sugars (for example, in corn) to produce alcohol. But this leaves the vast majority of the biomass in the corn as waste cellulose.
G. roseum is the first organism discovered in nature that can perform both the necessary steps. It can break the cellulose down into simple sugars, and from these it can synthesize hydrocarbons that closely resemble diesel fuel.