A Massachusetts biotech company called Joule Unlimited claims it has hit upon a way to create biodiesel using sunlight, water and carbon dioxide. But there are some engineering challenges to overcome before the process becomes practical.
Biodiesel using genetically engineered algae has been tested from some years but so far has not proven to be practical on an industrial scale. The amount of acreage required to create the biodiesel has proven to be too large so far. Conventional biofuel processes also require a huge amount of biomass that has to be grown and then destroyed as waste material.
The Joule Unlimited process uses another cyanobacterium that it claims to be able to manufacture 15,000 gallons of diesel fuel per acre at about $30 a barrel, using very little biomass that has to be grown and then disposed of. If biodiesel can be created on such a scale, then fuel can be used for long-haul trucks, sports cars and airplanes on an industrial scale, which means there would be that much less that has to be refined from crude oil. Indeed, the biodiesel fuel factories could be co-located at coal-fired power plants, using the carbon dioxide emitted from those plants.
So far, so good. It looks like Joule Unlimited has created a win-win situation all around.
But there is an engineering challenge, according to one expert. That problem is how to extract the biodiesel from the water where the cyanobacterium will be. There will be a relatively small amount of biodiesel in a large amount of water. To create useable biodiesel on an industrial scale, Joule Unlimited will have to show it can extract the product from the water easily and cheaply.
The great stumbling block for a lot of alternative energy schemes is not that the technology can do what proponents say it can do. The problem is doing it on a scale and for a price that makes sense in the market. A biodiesel factory would not make economic sense unless it can create its product at a comparable cost to conventional methods that involve refining crude oil that has been pumped out of the ground.
The greenhouse gas angle might be illusionary as well as it might be true a Joule fuel factory would absorb carbon dioxide from a power plant. But anything burning the biodiesel would pump it right back into the atmosphere.
Still, the idea of making fuel at home instead of buying it from bad tempered foreigners is a beguiling one and likely something that bears watching as Joule Unlimited proceeds to the next step of proving industrial scale manufacturing.
