The SUNERGY regional meeting introduced technological solutions for defosilization

"Transition pathways toward sustainable fossil-free fuels and base chemicals" is the title of a conference that was jointly organized by the J. Heyrovský Institute of Physical Chemistry (Czech Academy of Sciences), the Association of the Czech Chemical Industry, and the European initiative SUNERGY. It was held at the J. Heyrovský Institute in Prague on the 14th and 15th of September 2023

The conference was a very interesting event that brought together people from academia, industry, as well as from organizations supporting Czech participation in Horizon Europe. The industry participation ranged from large companies such as ORLEN-Unipetrol and BASF to new startups, for example TailorMem (CZ) who specialize in developing and producing new types of membranes. Academic participation involved mostly scientists from the J. Heyrovský Institute and other institutes of the Czech Academy, as well as from the University of Chemistry and Technology in Prague.

Altogether, the meeting was attended by around 70 participants, mostly from the Czech Republic as well as from France, Poland, Finland, and Spain. Such a broad and diverse range of participants allowed for the presentation and discussion of a range of scientific, technical, economical, and political issues related to synthetic fuels. This included the topics of energy-rich chemical compounds (such as hydrocarbons, methanol, hydrogen, etc.) produced from abundant raw materials (CO2, water, nitrogen) with the aid of sunlight (solar fuels) or renewable electricity (e-fuels). Making such fuels from CO2 would make them carbon-neutral and their wide usage would become a basis for a circular economy of the future.

Scientific talks covered a broad range of topics, from the general need of synthetic fuels (their merits as well as their downsides) to particular processes and technical solutions which would produce and utilize various kinds of sustainable fuels and feedstock chemicals. Using detailed analysis and hard numbers quantifying energy requirements, it was clearly shown that liquid synthetic fuels will be an essential factor in the transition to fossil-free fuels, especially within the Czech Republic. This is not just for transportation purposes (while using the existing infrastructure) but also for the storage of intermittent renewable energy over  a long period of time, in order to maintain the stability and resilience of the energy network across Europe. Development of technologies for energy storage in chemical bonds of synthetic fuels should thus be regarded as the foremost strategic goal of European countries and the EU. It has been acknowledged that synthetic fuels must be primarily judged and evaluated on the basis of their energy efficiency. In other words, more energy must be gained by the consumer than what was spent on the production of the fuel.

Several talks have clearly discussed that currently known fuel-producing processes do not live up to  strict material and energy efficiency requirements and therefore entirely new approaches are needed. This conclusion mandates establishing strong research and development programs on national as well as European scales. As was presented by its deputy coordinator, Frédéric Chandezon, SUNERGY (one of the meeting organizers) is a European initiative (together with the Horizon Europe Coordination and Support Action SUNER-C) that  strives to build up an EU-wide community working on synthetic (solar) fuels, to promote them, and most importantly, to establish an EU large-scale research initiative. This initiative will most likely be a co-programmed partnership that will fund and coordinate European research, encourage technology development and transfer (as well as the upscaling and implementation of synthetic fuels) in the energy budget of EU countries and beyond.

To fulfil this goal, SUNER-C (supported by the broader SUNERGY community) is currently working on a roadmap (explained in a previous dedicated talk). It is an open document which responds to the latest scientific/technical developments surrounding the initiative, as well as to the associated evolving political and societal views. As it is too early to "pick winners" by deciding which synthetic fuels and production processes are most promising, the roadmap rightly stresses the need to pursue research and development down multiple avenues, even including emerging novel aspects of photon management, light-matter interactions, and photo- and electro-catalysis.

Some of the technical issues raised in the roadmap were addressed by specific scientific/technical talks. Water oxidation (either electro- or photochemical) complements all practically considered fuel-producing processes but also presents their limitations. The physical and chemical origins of the water-oxidation problem were analyzed in one of the talks that also outlined the solution (being theory-guided development of new catalytic materials). On the hydrogen-evolution and CO2 reduction side, there was a very interesting talk on nanostructured 2-dimensional catalytic materials, including metal-doped graphene and molybdenum and rhenium sulfides, where catalytic sites occur on nanosheet edges. Photoelectrochemical CO2 reduction to hydrocarbons was shown to occur catalytically on copper-doped polydopamine on hydroxylapatite sheets. Doped organic semiconductors and metal-organic frameworks (combining light-harvesting and catalytic sites) were presented among new promising systems for artificial photosynthesis. Photobiology presents an alternative approach, whereby immobilized cyanobacteria reduce nitrogen or CO2 by using electro- or photochemically supplied electrons. Talks on innovative technical solutions dealt with co-electrolysis of CO2 and steam on solid oxides. Other talks also described the new types of ion-exchange membranes that are currently being employed in electrocatalytic systems and batteries, as well as in novel systems producing electricity upon mixing sea and fresh water. Several talks also stressed the importance of designing photoreactors and electrolytic cells, aimed at improving energy and material efficiencies.

Progress toward synthetic fuels is to a large extent contingent upon advances in materials research that is producing new catalysts, separators, etc. On an EU level, energy-related material research is represented by the AMPEA program of the European Energy Research Alliance (EERA), whose activities were overviewed. Important activities take place also at the national level as was discussed by talks on the "CO2 Czech Solution Group" and "Strategy AV21" of the Czech Academy of Sciences. The CO2 Group explores ways to convert CO2 into feedstock chemicals for industry and aims to create a cooperative environment encompassing industry, R&D, as well as government. The group also aims to involve the Czech Republic in an international cooperation on low carbon initiatives and circular economies. Strategy AV21 outlines the principal research directions of the Czech Academy of Sciences and, in selected directions, fosters synergies between Academy institutes as well as disciplines. It also aims to improve public awareness and facilitate knowledge transfer to the educational and private sectors. The Strategy is organized into programs, of which "Sustainable Energy" is directly relevant to synthetic fuels. It focuses on hydrogen and "new fuels", CO2 capture, as well as on energy storage. Specific research projects in Academy institutes include, for example, the mechanism of (photo)electrochemical water oxidation; development of catalytic materials and membranes for electrolyzers; hydrogen storage; membranes for CO2 capture; methane-to-methanol and CO2-to-ethanol conversions; as well as unravelling fundamental principles of light harnessing and energy conversion.

Finally, a citation from the talk given by Ivan Souček, director of the Czech Industry Association: "…reducing greenhouse gas emissions, increasing resource efficiency and circularity, safety in the chemical industry …. will require new process technologies and their combination will be essential to achieve the EU's 2050 climate-neutrality objective."

Prof. Antonín Vlček