Industry juggernaut Waste Management is convinced there’s a future in sewage-to-biofuel, and to prove it the company has just joined with the largest refiner in the U.S., Valero Energy Corp., to blend wastewater “crude” into gasoline. The two companies have invested in Terrabon LLC, which was formed in the 1990′s to commercialize three technologies including a biofuel process called MixAlco. With a half-billion people (and counting) contributing to the feedstock in the U.S. alone, it looks like sewage could be the answer to the search for a truly sustainable biofuel.
Terrabon, LLC and Biofuel
Terrrabon’s MixAlco biofuel technology is an acid fermentation process that was developed at Texas A&M university by Dr. Mark T. Holtzapple and Dr. Cesar B. Granda. The process can be applied to sewage sludge, municipal solid waste, forest by-products such as wood chips and wood molasses, and to non-food crops like sorghum. It converts the biomass into organic salts called carboxylic acids, which can then be converted to ketones (common industrial solvents), then refined through existing, conventional processes to produce gasoline, jet fuel, or diesel. According to the company, gasoline from MixAlco has a higher energy value than ethanol. The company announced a successful production run at its research facility in Bryan, Texas in July.
Waste Management, Valero Energy, and Biofuel
Until now, the sewage-to-biofuel picture has been somewhat modest. Norway is experimenting with biomethane busses, San Antonio has a sewage biomethane program, and sewage grease is being tapped as a potential fuel. The partnership between Waste Management and Valero takes it a giant step further into the mass market. It means that Terrabon will have access to a high volume of organic waste as a feedstock for the process, along with a major customer to receive the organic salts and convert them to biofuel. Given the national scope of these operations, looks like it’s finally showtime for sewage.
Image: Hryck. on flickr.
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Tina Casey specializes in military and corporate sustainability, advanced technology, emerging materials, biofuels, and water and wastewater issues. Tina’s articles are reposted frequently on Reuters, Scientific American, and many other sites. You can also follow her on Twitter @TinaMCasey and Google+.