They ♥ DME, yeah yeah yeah: NREL, Enerkem advance BIO-DME to commercialization

Poor DME. it burns like natural gas, handles like LPG, powers like diesel, and it’s as well-known as a good place for sewing machine repair in Burundi.

San Diego-based Oberon Fuels has been the one consistent champion on the “what are we doing about energy security?” circuit. It’s the drop-in that gets dropped out, and for no set of good reasons.  NREL’s been a champion, Volvo’s been backing it without blinking, and Enerkem too — but they each have such as basket of projects and ‘we’re-working-on-its that DME rarely gets its day in the sun.

It might as well decode it, DME that is, as Despite Massive Evidence, Doubt Market Enthusiasm.  As Robert Rapier observed in the Digest in 2013, “Methanol can be converted into di-methyl-ether, which gets around methanol’s toxicity and corrosivity issues. DME can be used as fuel in either a gasoline or a diesel engine, which makes the potential market huge. DME is a gas at room temperature, but compresses to a liquid under mild pressures.”

But from Washington, a booster. The U.S. Department of Energy announced nearly $16 million in funding through the Technology Commercialization Fund to help move technologies from DOE’s National Laboratories to the marketplace. Overall 54 projects at 12 national labs involving 52 private-sector partners were selected for support.

The first trend — there’s precious little across the bioenergy spectrum.  Three projects for solid oxide fuel cells received support, which Nissan’s recent announce on ethanol SOFCs makes relevant. There was a carbon capture project from Oak Ridge – good for algae. And, hydrogen was the focus in a relatively massive $431,995 award to Lawrence Livermore for its Cryo-Compressed Hydrogen Tank Technology.

But there’s DME, lonely DME. All by its onesey. But it is among the biggest plums of all, $740,000 for an NREL project for Scaled Production Of High Octane Biofuel From Biomass-Derived Dimethyl Ether,. That’s in partnership with Enerkem.

Let’s take a look at DME fuel.

The DME option

The major player in the DME movement as headlined above is Oberon Fuels, which produces DME from syngas via methanol. But now along comes Enerkem — which in many ways is following a similar path. The Oberon production units use various feedstocks—such as biogas (animal and food waste, wastewater treatment, landfills), natural gas, and stranded gas—and they produce 3,000–10,000 gallons of DME per day.

Enerkem has been famously focused on MSW as a feedstock and has a small commercial-scale facility operating in Edmonton, Alberta.

Stable pricing

As we observed last summer in the Digest, the “Oberon process cost-effectively converts methane to DME, resulting in stable pricing (not dependent on crude oil), at a price that is competitive with diesel. The modular design can be deployed to remote stranded-gas locations that can be difficult and expensive to harvest, and to industrial operations where our units can monetize waste CO2 streams.”

A value lift

Right now, for Oberon the substantial value lift is concerting methane to methanol, where low-cost natural gas (available in the $3/MMBTU range) can be converted into $19/MMBTU methanol. The math is not quite as rosy in converting methanol to a diesel substitute right now — because fossil diesel is priced at $11.75/MMBTU at this time, and the up-conversion only makes sense if the methanol has no place to go.

How does Enerkem do it?

As Enerkem related in $2.7M project application with Natural resources Canada:

The biomass-rich waste conversion strategy into olefins and drop-in fuels begun to be developed experimentally on April 22, 2013. In such strategy, synthesis gas produced by gasification of the waste is converted into DME by two approaches: (1) the syngas is converted into methanol and the latter is converted into DME; (2) the methanol synthesis and the dehydration reaction are carried out simultaneously in the same reactor yielding directly the DME and shifting the equilibrium to a higher conversion of methanol in one pass.  The work related with DME synthesis by both routes (1) and (2) is now completed. Bench tests related to the transformation of DME to propylene were started during the summer of 2014, with ZSM-5 zeolite as the active catalyst which was prepared as an extrudate (i.e. a pellet).

Testing to date

In 2013, Pennsylvania State University, Volvo, and Oak Ridge National Laboratory completed field testing of a prototype DME truck. The heavy-duty truck performed well under real-world driving conditions, achieving comparable efficiency to a conventional diesel truck. Test results indicated that particulate matter emission standards could be met without the use of a diesel particulate filter. As with conventional diesel vehicles, oxides of nitrogen (NOx) emissions reductions can be handled with standard NOx after-treatment systems. Alternatively, the engine can be calibrated in such a way to negate the need for such a system, but this reduces efficiency.

NREL ♥ DME

If you can imagine an 177-page love letter, but written in  the form of process description, diagrams and High Technoeconomicese, that’s this one.

Process Design and Economics for the Conversion of Lignocellulosic Biomass to Hydrocarbons via Indirect Liquefaction: Thermochemical Research Pathway to High-Octane Gasoline Blendstock Through Methanol/Dimethyl Ether Intermediates

A cautionary note

Before we break out the bubbly, consider these sober words from Zhihong Yuan and Mario R. Eden of Auburn University, together with Rafiqul Gani at the Technical University of Denmark, writing in I&EC Research, here.

Although the importance of hydrogenation of CO2 to CH4 has been emphasized in several reviews and perspectives, the current low natural gas price and the high capital/operating cost of the methanation process prohibits the thermodynamically favorable hydrogenation of CO2 from being implemented economically on a large scale. Using an optimiztic estimation, where the selectivity and conversion rate of the methanation catalyst is assumed as 100% and 50% and the renewable H2 production cost is assumed as 2 US$/kg of H2, producing 1 kg of methane will cost at least 2 US$ for the required H2. Clearly, producing high-volume-low-value liquid fuels and high-value-low-volume chemicals from the hydrogenation of CO2 may offer more economical benefit. Nevertheless, no matter which production route will be adopted, two simple principles should be kept in mind when deciding on the products and designing the process for CO2 conversion: using more energy to produce a lower energy content material makes no sense; and the CO2 emissions from the entire conversion process must be less than the amount of converted CO2.

But the authors are not completely pessimistic. They add:

Compared with the CO2-derived methanol synthesis process MegaMethanol, under similar conditions, the CO2-derived DME synthesis process MegaDME shows lower productivities, but also lower byproduct contents.(181) Furthermore, this DME synthesis process is ready for large-scale implementation and therefore provides a promising alternative for large-scale CO2conversion.

Two Multi-Slide Guides

Simple Fuel, Engine, Infrastructure: The Digest’s 2016 Multi-Slide Guide to Oberon Fuels
The DME Option: The Digest’s 2016 Multi-Slide Guide to DME as a fuel

Two Key Reports

Here’s the skinny from California on how they see DME shaping up: California Dimethyl Ether Multimedia Evaluation: Final Tier I Report

From Oak Ridge National Laboratory, SAE and Volvo:Emissions and Performance Benchmarking of a Prototype Dimethyl Ether-Fueled Heavy-Duty Truck (PDF)

More about the Technology Commercialization Fund

The TCF is administered by DOE’s Office of Technology Transitions, which received 104 applications from across the laboratory system, including  projects for which additional technology maturation is needed to attract a private partner; and cooperative development projects between a lab and industry partners,

“Deploying new clean energy technologies is an essential part of our nation’s effort to lead in the 21st century economy and in the fight against climate change,” said Lynn Orr, DOE’s Under Secretary for Science and Energy. “The funds announced today will help to accelerate the commercialization of cutting-edge energy technologies developed in our national labs, making them more widely available to American consumers and businesses.”

“The great work at the national labs and across DOE’s program make the Department one of the largest supporters of technology transfer within the federal government” said Jetta Wong, Director of the Office of Technology Transitions. “These TCF selections will further strengthen DOE’s important mission to transition technologies to the market.”