A company that has developed a process for converting organic waste and other biomass into gasoline–Terrabon, based in Houston–recently announced a partnership with Waste Management, the giant garbage-collection and -disposal company based in Houston. The partnership could help Terrabon bring its technology to market.
Amid a profusion of new biofuels technologies, this one stands out because it will be relatively easy to scale up for producing millions of gallons of fuel, says James McMillan, the biochemical process R&D group manager at the National Renewable Energy Laboratory in Golden, CO, who is not connected to the company.
Most biofuels companies fall into one of two categories. Some use enzymes to break down biomass into simple sugars and a single organism to convert sugars into fuel, such as yeast. Others use high temperatures and pressure to break biomass down into basic chemical building blocks–carbon monoxide and hydrogen–which are then chemically processed into fuels. Terrabon has developed a process that combines the two. It uses a naturally occurring mixture of organisms to convert biomass, not into fuels, but into carboxylic acids. These can be converted into fuel and other chemicals using well-known chemical processes. Gary Luce, the company’s CEO, says Terrabon’s fuels can compete with petroleum-based fuels if prices are above $75 a barrel. (The price of oil is currently about $70 a barrel.)
The approach has an advantage over single-organism-based methods because the mixture of organisms used, collected from salt marshes, are adapted to survive in the wild. They don’t require the special sterile environments needed to prevent single-organism cultures from being contaminated, which brings down the cost of equipment.
These organisms naturally break down biomass into carboxylic acids, such as acetic acid, the key component of vinegar. These acids can serve as chemical precursors for a wide variety of chemicals and fuels, including gasoline and diesel, via processing steps that convert the acids into ketones and alcohols. The acids can be made without the expensive equipment required for high-pressure and -temperature processes. They can also then be processed into fuels using equipment at existing refineries, helping keep costs down.
Because the organisms don’t require special treatment and because the acids they produce can be converted to fuels at existing refineries, it should be relatively easy to ramp up production, McMillan says. Terrabon’s partnership with Waste Management should help, he says, since one of the biggest challenges with advanced biofuels is collecting the large amounts of biomass needed. Waste Management already has trucks and other equipment for collecting garbage and separating the organic waste.