Standardization News

Oberon Fuels Inc., was founded in 2010 to convert waste streams to higher valued products such as DME (dimethyl ether), a clean-burning alternative to diesel. DME may not be familiar to many drivers today, but this remarkable fuel can power trucks or cars, can be produced with locally available resources (including waste and renewables), and offers the potential to lower overall cost of vehicle ownership.

There has only been one problem — engines that run on DME are not currently commercially produced for either heavy fleets or passenger cars. This has been both a curse and a blessing. A curse because it is challenging enough to introduce a new fuel, but an even more daunting task to require a new engine and fueling infrastructure. The blessing? We can purpose-build the supply chain, ensuring efficiencies and quality throughout and enabling a long-term sustainable model.

This process, which we and others in the DME industry started a few years ago, has required extensive coordination among fuel producers, engine manufacturers, infrastructure developers, and the fleet managers and consumers who will eventually purchase DME for their vehicles.

One essential step in establishing a foothold for DME is properly navigating regulatory hurdles, as all fuels must before they can be offered for sale. One such hurdle was creating chemical guidelines for DME under a widely respected organization that could provide confidence up and down the supply chain.

The Case for a New Fuel

In Oberon’s case, the importance of an ASTM specification was even greater in comparison to other renewable fuels with established customer bases. In addition to developing the DME fuel production technology, infrastructure, and engines, the DME fuel market also had to be created from scratch.
Fortunately, DME’s advantages make it very useful for a wide variety of customers. Fuel made with dimethyl ether:

• Is derived from a diversity of feedstocks;
• Has easy-handling properties combined with high performance characteristics;
• Is clean-burning and produces no soot or particulate matter and 68 percent fewer greenhouse gases than diesel fuel;  and
• Can be produced in a distributed manner with local resources.

Need for a Standard

The case for DME is strong from both an environmental and a performance standpoint, but one of Oberon’s initial challenges is encouraging the fuel’s adoption. To overcome this, Oberon is working closely with large auto manufacturers like Volvo and Ford to build DME engines and develop DME fueling infrastructure.

Yet, even with the development of DME engines, customers cannot use the fuel if it is not legal to use, and until recently, there were no guidelines for DME fuel on this front. As such, creating such a standard was a key component of Oberon’s early commercialization strategy. 

Oberon engaged with ASTM in 2012 because the state of California, unlike other states, required an international consensus standard for DME in order for it to be legally sold in the state as a fuel. After some initial consultations with ASTM’s committee on petroleum products, liquid fuels, and lubricants (D02), and several subcommittee leaders, Subcommittee D02.H0 on Liquefied Petroleum Gas was chosen as the most appropriate home for DME based on its diesel-like performance but propane-like handling properties.

I was fortunate to be able to head the ASTM task group that worked through the specification development. The standard, ASTM D7901, Specification for Dimethyl Ether for Fuel Purposes, was first published in February 2014.

Once the ASTM standard was published, the state of California began the process of modifying its code of regulations to allow for the the legal sale of DME as a fuel. That process was completed, and effective Jan. 1, 2015, DME could be legally sold as a fuel in the state, joining the other 49 states where DME fuel could already be sold. 

Since the publication of ASTM D7901, ISO 16861:2015 has also been published, providing another international guideline for DME. Its requirements are closely aligned with the ASTM purity requirements for DME.

As a small company with a big goal, Oberon came away impressed and humbled by the expertise that was applied to the DME specification development process. People with many years of experience in ASTM happily mentored our team, worked through challenges, solved problems, and put forward an ASTM specification with impressive speed and accuracy.

The speed and thoroughness of the specification would not have been possible without the help of task group members such as the chairman of Subcommittee D02.H0, Andy Pickard; James Simnick of BP; Bruce Swiecicki of the National Propane Gas Association; Allison Athey and Greg Shank of Volvo; and so many others. They all deserve great thanks and continue to be involved with the task group.

D7901 is already proving its value to the path toward commercializing this new transportation fuel. The standard is providing fuel producers, distributors, and engine manufacturers with the references they need for DME purity and fuel requirements. The publication of the ASTM standard also gave those engaged in the supply chain much-needed confidence that suitable DME regulations exist and that this fuel is ready for the market.

Results

Today, DME engines are being demonstrated in heavy-duty Volvo and Mack trucks, and the world’s first DME-powered passenger car is being built by Ford and a consortium of partners as part of a three-year project. Biogas-based DME is eligible under the U.S. Environmental Protection Agency’s Renewable Fuel Standard for Renewable Identification Number credits, and the state of Washington has qualified DME-powered trucks for tax incentives. 

Thanks to the hard work and diversity of the ASTM task group, DME now has a place in the U.S. market combined with greatly expanded legitimacy and also has increased interest around the world.

Besides the publication of the standard itself, the process of working with ASTM also has made DME “real” for many people. It is one thing to talk about a new fuel — its advantages and market potential — but it is another thing to become engaged in the actual development of a new fuel specification.

Over the past four years, the DME task force has continued to grow. More people are engaged, and more companies and organizations are considering the advantages of using DME in their own infrastructure, engines, and vehicles. It will not be long before we see DME powering cleaner, quieter, and more efficient vehicles on the road.

Rebecca Boudreaux, Ph.D., is the president of Oberon Fuels. She has a broad range of academic and industrial experience, having performed research at Princeton, Massachusetts Institute of Technology, and Lawrence Livermore National Laboratory, among others. She serves as chair of the International DME Association and is a member of ASTM’s petroleum and lubricants committee (D02).