Algae vs. Yeast vs. Jatropha vs. Biomass

Algae biodiesel costs about $10 a gallon to produce, at best. So algae isn't ready for prime time. But given time, algae will be the most productive producer of biodiesel currently known.

Fungal fuel, or fuel from yeast, has a long history -- and will only get longer. Genetically altered yeast are now capable of producing complex hydrocarbons. Researchers are tweaking the genes of these yeast to make ever more valuable carbon based chemicals and fuels.

The company performed scores of genetic manipulations, inserting genes from land plants into yeast cells and targeting a dozen or so steps in the Acetyl CoA glycolitic pathway to polymerize hydrocarbons into chains of optimal lengths for fuels. Then, about two years ago, Amyris scientists peered into their first test tube filled with yeast-produced diesel. FungalFuel

So it looks like algae holds the greatest promise for biodiesel, but fungal fuels have a better start and may beat algae to the finish line. What about Jatropha? It takes longer to tweak the genetics of plants than for micro-organisms, but Jatropha produces high quality oil on marginal land at yields well above soy, rape, and maize. Unlike algae, Jatropha is already a player in the marketplace.

Jatropha curcas is a non-edible shrub that is native to Central America. Its seeds contain high amounts of oil that can be used for a variety of bio-based materials including biodiesel and feedstock substitutes for the petrochemical and aviation fuel industries. It can be effectively grown on abandoned lands that are unsuitable for other crops.

Jatropha oil produced by SG Biofuels has been independently evaluated for its biodiesel qualities and verified to be a clean, stable source of fuel for biodiesel that meets or exceeds European specifications. The company’s Latin American Jatropha recently outperformed palm, soy and Jatropha from India on two differentiating criteria: low temperature performance and long-term storage stability. _GCC

Biomass is another "ready for the market" energy technology that can only get better with time. Growing biomass on marginal soils, on saline soils along coasts, and in salt water, greatly expands the planet's capacity to produce human-useful energy. The limits for growth of biomass will not be reached before humans begin colonising the outer solar system and beyond. Biomass will benefit from the blooming biotechnology industry, with tweakable genetics. And while biomass is currently less energy-dense than fossil fuels, it is sustainable into the distant future. It can be made into electricity, liquid and gaseous fuels, plastics, industrial chemicals, structural material, and -- once nanotechnology comes of age -- we will truly begin to learn what biomass can create.