Storing hydrogen directly in depleted gas reservoirs or converting it into methane
RAG’s Underground Sun Storage project (10% hydrogen fraction) has already demonstrated that hydrogen can be stored together with natural gas in underground gas storage facilities. The next step will be for RAG to study the storage of pure hydrogen in an additional, proprietary gas storage facility. Hydrogen can also be converted into naturally produced natural gas (“green gas”), through the admixture of carbon dioxide, in former gas reservoirs in a microbiological process. RAG has a international patent for this process, known as “hydrogenotrophic methanogenesis”.
Climate neutral production of hydrogen and carbon from methane
To reach agreed climate targets and reduce carbon emissions, a great deal more green gas will be needed than can be produced by current methods. RAG is therefore already committed to a wider perspective, and to carbon dioxide reduction across the entire energy market. It is looking at the potential of several cutting edge green gas technologies as replacements for fossil fuels in the moleculebased energy sector.
RAG is a hydrogen pioneer, and can draw on six years’ experience of water electrolysis. It is also involved in the highly promising climate and carbon neutral production of hydrogen by means of methane splitting/electrolysis. Both processes are free from carbon dioxide emissions. Methane splitting to produce hydrogen calls for just under one-fifth of the energy use as compared to water electrolysis, whilst yielding valuable resource carbon that can be used to make steel, batteries, carbon fibre, and numerous structures and materials, including fuel cells and electrical equipment. Carbon can also serve as a valuable soil conditioner that promotes plant growth. As methane splitting runs on renewable energy, the process is carbon dioxide neutral. Where methane from binding processes such as biogas production or Underground Sun Conversion technology is employed, carbon
dioxide is actually permanently recycled and bonded.
This innovative technology will make a significant contribution to Austria’s energy transformation whilst triggering a burst of innovation in industry, strengthening regional economies, and benefiting security of supply.