ALIGN innovation: can methanol-based synthetic fuels drive an energy revolution?

Interview with Prof. Dr. Ralf Peters (left), Head Fuel Processing and Systems, Forschungszentrum Jülich.

By Tom Mikunda, TNO

One of the most ambitious goals of the ALIGN-CCUS project is delivering the world’s first full carbon capture and utilisation (CCU) chain, which means creating an integrated system that captures and then uses man-made carbon dioxide to make useful products.

The project’s dissemination team recently caught up with Prof Ralf Peters, head of Forschungszentrum Jülich’s Department of Fuel Processing and Systems at the Institute of Energy and Climate Research, in Germany, who leads the team of experts at the forefront of this innovative work. We asked for his views on the role of methanol-based synthetic fuels in the global energy transition, and the significance of the ALIGN-CCUS project’s aims.

  • What is the role of methanol-based synthetic fuels in the energy transition?

Prof Ralf Peters: With the expected growth of renewable energies, such as sun and wind, in future power systems, we will have to develop ways to manage the inherent intermittency of such forms of electricity generation. Solutions will be needed to balance the demand and supply of power. Electricity can be stored in batteries, but this has limits in terms of scalability and unavoidable voltage losses during long-term storage. One option could be to produce hydrogen via electrolysis, which can be stored and used directly in a range of commercial and industrial applications. Or the hydrogen could be used as a feedstock to produce a number of chemical products for use in other sectors, in a concept commonly referred to as “power-to-X”.

In ALIGN-CCUS, we’re looking at producing dimethyl ether and oxymethylene ether [better known as DME and OME], which are potential transportation fuels. What is unique about the ALIGN-CCUS project is that the CO2, which is needed to produce these fuels, is captured from a coal-fired power station. Therefore, not only are these products a form of energy storage, but they also reuse CO2 [and] prevent further combustion of fossil fuel. Very importantly, DME and OME have the added environmental benefit that they combust soot-free in a diesel-type of engine.

  • Does this form of CCU have a positive climate impact and, if so, how can this be optimised?

Compared to the usual methods of producing DME and OME, the reuse of CO2 from fossil sources and renewable hydrogen can decrease the full life-cycle emissions of these fuels by around 40%. The climate impact of this CCU process is undeniably limited due to the carbon intensity of the coal-fired power plant. However, the reuse of CO2 not only has potential for the power sector but also some of the unavoidable process emissions from the steel and cement sector. Germany’s steel and cement industries emit process-related CO2 each year of around 16 and 13 megatonnes, respectively. CCU has considerable potential for reducing these emissions. The “Holy Grail” would be the use of “green” CO2 from the biogas industry, and renewable hydrogen – this would produce almost climate-neutral transport fuels!

  • How is ALIGN-CCUS supporting innovation in the field of synthetic fuel production?

A huge step in the field of synthetic fuel production is the utilisation of renewable hydrogen on one side and the direct usage of the captured anthropogenic CO2 on the other. But the project is also aiming to advance the production process of DME synthesis. The conventional route of DME production is a two-stage process. You first produce methanol, which is then dehydrated to form DME. What we are trying to do is to produce DME in a single-stage process, where both reactions take place in a single reactor. This development is very attractive because of the lower thermodynamic limitations, as well as the lower capital and operational costs associated with a single reactor. ALIGN-CCUS will contribute to advancing this process through the testing and development of a bifunctional catalyst.    

  • What are the key challenges the project will face over the next three years?

Not only the successful design and construction of the integrated CCU pilot, but its reliable operation for extended periods is likely to be the greatest challenge for the project. We’ll consider the pilot to be a success when we manage to achieve a long-term test of over 100 hours with constant settings. Pushing the boundaries of innovation can always lead to unexpected consequences, but the cooperation so far between the pilot project participants RWE, MHPSE and Asahi Kasei certainly gives me confidence.

Prof Peters and his team are working with RWE, MHPSE and Asahi Kasei on Work Package 4 – CO2 Re-use – of the ALIGN-CCUS project. Forschungszentrum Jülich is also involved in Work Package 5 (Industrial clusters) and Work Package 6 (Society).

Main photo @Ron Jautz 2017 from International DME Association website.