Sometimes, carbon dioxide emissions aren’t the enemy. Florida-based startup Algenol Biofuels and Dow Chemical Co. are building a Freeport, Texas algae-based biorefinery pilot plant to turn CO2 into ethanol. The 24 acre plant, which will contain 3,100 bioreactors that can produce up to 100,000 gallons of algae yearly, will be fed carbon emissions from a nearby Dow facility.
Algenol’s process consists of algae grown inside bioreactors (clear chambers filled with salt water solution) that use photosynthesis to turn CO2 into oxygen and ethanol. It’s a different approach to turning algae into fuel than other startups take–most algae startups process algae into fuel, but Algenol collects ethanol vapors from the algae without killing it or using a pricey refining process.
Dow initially plans to use ethanol produced from the pilot plant as a feedstock for plastic (replacing natural gas), but Algenol eventually wants to use its process in coal-burning power plants. In that scenario, oxygen from the process could be used in the coal plant’s combustion chamber to increase efficiency. Coal burned in oxygen makes exhaust that contains large amounts of CO2, which could go into the bioreactors to produce more algae.
Algenol’s plant will employ 300 people and consume two tons of CO2 each day, or enough to produce 120 to 140 gallons of ethanol. If successful, it could raise the profile of cheap, non food-based biofuels.