Agriculture will give us energy security

24.5.2024

One of the biggest stars of the April Gas Fuel Forum in Warsaw was Dr. Rebecca Boudreaux, President of Oberon Fuels. In an interview with the Polish Liquid Gas Organization, she talked about the characteristics, advantages and challenges of using dimethyl bioether (DME) as a fuel. Dr Boudreaux stressed the importance of diversification of energy sources and the flexibility of DME, which can be produced from raw materials as diverse as agricultural waste, forestry or manure. Thanks to the use of existing LPG infrastructure, DME can significantly contribute to the decarbonisation of the Polish economy.

Dimethyl ether is not yet a widely known molecule, perhaps outside the aerosol industry. Why do we need it to generate energy, why not stay with the commonly known propane or renewable propane as a fuel?

When it comes to energy, diversification is important first and foremost. We do not want all our energy carriers to come from one raw material, one supplier, one production facility. DME is an energy carrier that has a low carbon footprint, can be produced from different raw materials, and uses a different production path, but allows the use of existing LPG infrastructure.

Renewable propane is a great source of energy, mixed today with fossil-derived propane. It is most often a by-product of renewable diesel (HVO) production, with less than 10% by weight of the production from this process being biopropane. As a result, in order to increase the volume of biopropane produced, it is necessary to simultaneously increase the production of liquid fuels.

DME is produced from a variety of raw materials, including other than those used for the production of renewable propane. We can produce it from raw materials such as manure, agricultural or forest waste, including residues from the wood and paper industry. Importantly, it can account for up to 100% of production - the production plant is optimized for the production of dimethyl ether, not diesel fuel.

DME is therefore a complement to renewable propane. We need different molecules to build a low-carbon, disruption-proof supply chain in the future.

It is about diversifying the risks... You often say that you change the world step by step, one molecule at a time. What is so attractive about DME? What are the most important characteristics of this fuel?

Yes... I am a chemist, I love all molecules! If I look back over the last 13-14 years, I can say with full confidence that at Oberon I focused on the commercialization of innovative solutions. We help manufacturing companies, but also countries, to reduce emissions, reduce waste and give them new business options. The main tool we use is to convert waste into dimethyl ether, although sometimes the final product is renewable methanol.

As for the attractiveness of DME, in my opinion the most important of its characteristics is the ability to use the existing LPG infrastructure while drastically reducing carbon emissions.

Well, that's right. In the course of its recent presentation in Warsaw you presented amazing CO reduction indicators2, some to a negative level. How is that even possible? Does it all depend on the raw material that is used in the production process?

You are absolutely right, it all depends on the raw material. Dimethyl ether can be produced from manure, sludge fraction from sewage treatment plants, agricultural waste, forest residues and others. As for the emission reduction rate, it all depends on how the waste is processed. Take the American dairy industry as an example. Many of these dairy farms use a flushing system to collect manure. Cattle droppings are regularly flushed into the tank, but this process leads to the release into the atmosphere of significant amounts of methane. The use of covered tanks and fermenter allows methane to be sequestered and used in our process. In this way, we have eliminated greenhouse gas emissions into the atmosphere.

This is very interesting because it means that we first reduce the emissions of methane, which is a very powerful greenhouse gas, and then - as I understand it - we can produce biogas. In the next step, we produce DME from biogas, right?

Yes, it is also interesting in the sense that a modular installation is possible, since you can use it as a distributed system. This is important from the point of view of energy security - let's take the example of the war outside the eastern border of Poland. Many small biogas plants can be created, which will then convert it into DME. In cases where such a farm is close to the gas pipeline, it may make more economic sense to purify biogas and introduce it into the gas network. If it is a smaller farm it may make more sense to produce biogas and generate electricity. But there are also cases, especially in larger plants remote from the transmission infrastructure, when it is economically justified to produce a molecule that is easy to store and transport. And this is where DME comes into play.

You said it was an alternative or complementary molecule to existing options like propane or biopropane. Can we mix them safely?

Yes, we can safely mix them. DME is an excellent solvent and has therefore been used extensively in the aerosol industry for decades. What does this mean for LPG infrastructure? For example, if you are dealing with 100% DME content, and in practice, if you have more than 20% DME in the mixture, you need to use special, reinforced gaskets. You need to use Teflon or similar material as a replacement for rubber gaskets. Dimethyl ether with a high concentration will simply dissolve the rubber. In this case, there are changes in the infrastructure, right? With a lower DME content in the mixture, no changes need to be made.

Well, that's right - you also mentioned mixtures below 20% DME. What about them? Do you need to replace the gaskets?

American Suburban Propane buys renewable dimethyl ether produced in Southern California from us and mixes it with fossil propane as a 4% blend. It is sold to 450 customers for use in forklifts and road vehicles, as autogas. The World Liquid Gas Association is currently collecting data on DME-propane mixtures and their compatibility with infrastructure and analyzing any technical issues that may arise. The WLGA has also conducted additional testing to examine any risks associated with the deployment of DME-propane blends on a global scale. In 2023, a recommendation was developed that a mixture of up to 12% can be safely used in all current propane applications without any modifications. The range of 12% to 20% is taken as the upper limit of material compatibility.

So below 12% as recommended by the World Liquid Gas Association, mixtures are completely safe even without reinforced gaskets?

That's right.

Poland is a member of the European Union with a strong agricultural sector, food processing and timber industry, with air quality problems. 85% of LPG is imported and used mainly in road transport. How can Poland use DME and how can we introduce it into our energy mix?

This is an opportunity for Poland, because Poland is rich in resources on the basis of which the production of renewable DME can be developed. This would strengthen energy security. Thinking about the raw materials you talked about, the developed agricultural industry, the poultry industry, the food processing, the wood industry, they can all be used to produce renewable DME. This is a serious asset. You can take advantage of the waste streams, which is not easy at the stage of targeting them properly, but it will create additional development opportunities for the industry that produces these streams. Poland's wealth of raw materials creates a great opportunity to produce its own renewable DME, reducing dependence on LPG imports. As if by the way, you would reduce greenhouse gas emissions by generating energy carriers with low CO emissions2. It is conceivable that with this wealth of raw materials, Poland would become an exporter of DME.

Innovation, as we have seen over the past 14 years at Oberon Fuels, alongside private investment, requires government support. It would be optimal to use the resources used to support fossil fuels to stimulate the production of renewable fuels. What are the market opportunities? Global supply chain for 3 billion customers worldwide. The human capital in the LPG industry is estimated at 4 million people globally who know how to handle gas safely. Poland has the necessary resources, both natural and human, that can be used in the production of renewable DME and help ensure energy independence and improve air quality.

In the previous year POGP conducted a public opinion survey, which show that about 54% of respondents have used LPG in the last three years, for cooking, heating, but mainly as autogas.

In the US, LPG is not widely used in transportation. However, thanks to support from the federal government, renewable DME is already approved for use in the transportation sector. However, it is worth noting that other sectors are not so supported by the US government.

Can you still comment on the topic of modularity of DME manufacturing technology? I have the impression that a distributed generation infrastructure offers some advantages in terms of energy security.

We build our production modules on skids and then they are transported from the manufacturing site to the production site once we have obtained the required permits and the preparatory work is completed. This allows us to optimize the investment time. When the module arrives on site, we still need to install and connect it, however, it is not built from scratch. Of course, they are not intended for regular transfer from place to place, but the format of the module on skids provides the possibility of moving the production plant if the need arises. Even storage tanks can be built on skids. When our customer decides to move or close the plant, our production assets may be moved to a new location. There again you need to do the preparatory work and get permits, but the module itself can be restarted.

Of course, the unit cost of a small modular plant per unit of production is higher than that of large plants using scale effects. However, the way to reduce costs is to build multiple installations at the same time. The module factory does not produce one installation - it builds 5-10 at a time at a time, for different locations.

It's like Small Modular Reactors (SMR) in nuclear power.

Yes, it is.

Thank you very much for the fascinating conversation and we invite you to the European Liquefied Gas Congress in Katowice in 2025.