EPA approves Oberon DME as first biogas-based fuel under the RFS

By Katie Fletcher | September 04, 2014

Oberon Fuels Inc. was the first company to announce plans to commercialize biogas-based dimethyl ether (DME) fuel production in North America, and now, less than a year after submitting a pathway petition, its DME is the first biogas-based fuel approved by the U.S. EPA for inclusion under the renewable fuel standard (RFS). The DME is now eligible for high value D3 cellulosic and D5 advanced biofuel renewable identification numbers (RINs) under the RFS. “In addition to opening the market for DME, the EPA’s pathway determination and Oberon’s leadership are paving the way for the approval of future biogas-based fuels,” said Rebecca Boudreaux, president of Oberon Fuels.

The transportation industry, particularly the heavy-duty sector, has another choice for a domestically produced, renewable fuel with DME’s inclusion under the RFS. “Being able to generate RINs put DME on an even playing field with other biofuels already included,” Boudreaux said.

The company refers to DME as a simple fuel requiring a simple engine and simple infrastructure. “It is a clean-burning, non-toxic fuel with diesel-like performance and propane-like handling properties,” Boudreaux said.

The propane-like handling properties make for simple infrastructure, because it already exists in the U.S. “The only thing that would need to be changed are seals and gaskets because DME is a bit more corrosive, but it’s not a high-pressure storage fuel,” said Brittany Syz, vice president of business development and general counsel with Oberon. “It’s a liquid at 75 psi, which is fairly low.”

Syz also discussed how DME has diesel-like fueling times with no expensive, complicated cryogenics or high compression. The fuel ignites in a diesel engine without the use of spark plugs, and can be used in a base diesel engine with only modification to the fuel system; the injector pump, fuel tanks and onboard software, according to Syz.

DME also produces no particulate matter when it combusts in a diesel engine, therefore no diesel particulate filter (DPF) is required. According to Syz, this makes the design and the engineering of the trucks simple, because it is easier to deal with the minimal nitrogen oxides (NOx) coming out. “Because of its simplicity, DME has the potential to compete long-term with diesel, diversifying the fuel supply and offering customers a domestically produced option,” Boudreaux said.

The fuel is derived from biogas and other hydrocarbon rich waste-streams. Oberon produces DME from various methane and carbon dioxide sources. The company’s pilot plant in Brawley, California has been producing the first fuel-grade DME in North America for over a year, deriving it from methanol. The ASTM D7901 compliant fuel is currently being used for demonstrations of DME-powered Volvo trucks. This was Oberon’s “first steps in commercializing,” Syz said.

These demonstrations are expanding in a collaboration with the Volvo Group and Safeway Inc., an American supermarket chain. Last year Oberon Fuels was awarded a $500,000 San Joaquin Valley Air Pollution Control District grant in conjunction with Volvo and Safeway to test DME-powered trucks at Safeway’s central California distribution center.

Currently Oberon’s focus is to build, own and operate its small-scale DME plants. “We build small-scale plants, so as the market grows instead of building larger plants we’ll do more plants,” Syz said. “Because they are small-scale we can build them quickly and we can put several different plants in one area to fuel that market.”