Novel Algae Fuel-Farming Method Gets Big Backing

Al writes "Dow Chemical has given its backing to a Florida startup called Algenol Biofuels that hopes to produce commercial quantities of ethanol directly from algae without the need for fresh water or agricultural lands. Dozens of companies are trying to produce biofuels from algae, mostly by growing and harvesting the microorganisms to extract their oil. Algenol has chosen instead to genetically enhance certain strains of blue-green algae, also known as cyanobacteria, to convert as much carbon dioxide as possible into ethanol using a process that doesn't require harvesting to collect the fuel. Algenol's bioreactors are troughs covered by a dome of semitransparent film and filled with salt water that has been pumped in straight from the ocean. The photosynthetic algae growing inside are exposed to sunlight and fed a stream of carbon dioxide from Dow's chemical production units. The goal is to produce 100,000 gallons of ethanol annually."

Comments

Water/Coastal towns, sewage, animal feed?

[wonkavader]

From TFA: "Every gallon of ethanol made creates one gallon of fresh water out of salt water."

This sounds interesting. If this can be cheaply scaled up, it sounds like coastal towns all over the developing world would want to become gas providers for more inland towns -- it solves their water problem at the same time as it solves their cash flow problem.

I suspect there is a lot of distillation in the process as well, to purify the alcohol. So this sort of system would couple well with hot equator sun and passive solar systems.

All this makes me wonder: how much human waste can you pour into the system to fertilize the algae? Can this system be used to solve that problem, too?

And what do you do with the algae? Once you have a full tank, you just want to maintain the status quo, but the algae will continue to reproduce. Could the excess turn into an animal feed?