Making renewable methane from green hydrogen makes sense – here’s why
Much of the production potential of biogas is still untapped, but an even greater potential lies in renewable synthetic methane, or e-methane, produced from green hydrogen. Unlike hydrogen, e-methane is easy to store and transport. In addition, it uses the same infrastructure and technology as other methane-based gas fuels, making it technically interchangeable with biogas and natural gas.
In its strategy, Gasum has set the goal of delivering seven terawatt hours (TWh) of renewable biogas to the market annually by 2027. The target is ambitious, and a major part of the increase comes from investments in new biogas plants and purchases from trusted producers in Europe.
However, beyond biogas, even greater potential lies in renewable synthetic methane, also called e-methane, which is connected to the hydrogen economy that is just now developing.
Green hydrogen is produced by electrolysis from renewable electricity and water. This process is called a P2G (Power-to-Gas) solution. However, as a molecule, hydrogen is challenging. It is difficult to store and transport, and there is no infrastructure for it.
Green hydrogen can be further processed into e-methane with the help of catalytic and biological methanation, i.e. by combining hydrogen with carbon obtained from carbon dioxide.
"Synthetic and fully renewable e-methane can be easily utilized in the green transition of industry, shipping and heavy road transport. It is technically interchangeable with biogas and natural gas, which means that there is already both an entire infrastructure as well as the technology for its transfer and use," says Mikko Syrjänen, Gasum's Director, Business Development.
The production potential of e-methane from renewable carbon dioxide sources in Finland, Sweden and Norway is up to 207 TWh per year. Renewable carbon dioxide can be recovered, for example, from the forest industry, the burning of waste from power plants, or the side streams of biogas plants, which means it is carbon dioxide that is already in circulation.
There is a need for methane in transport
The green transition and the regulation that promotes it require a transition away from fossil energy sources. For this reason, for example, electricity is planned as the main power source for passenger cars.
However, using electricity is not possible everywhere. For example, the electrification of heavy road transport is still very limited, and it is not suitable for all industries.
"One of the most obvious uses for methane is shipping, to which the EU has introduced mandatory emission reduction regulations for the first time. Electrifying shipping is not possible with current technology due to its high energy demand. It’s simply not possible to fit large enough batteries on ships", says Mikko Syrjänen.
Hydrogen can also be used in the production of methanol or ammonia, but both have their own limitations. Ammonia is a very toxic substance, and there is no technology that can be used on a large scale to use it as an energy source. Methanol is easier to use than ammonia due to its properties, but there are no technological solutions for its use in road traffic or industry yet.
Methanation is a way to store and transfer large amounts of renewable energy
Converting renewable electricity into fuel, such as e-methane, makes it possible to store and transfer energy on a large scale. With methanation, fuel can be produced where large amounts of renewable electricity are available and thus transfer clean energy to applications where direct electrification is not possible or to places where there is insufficient local renewable energy production capacity.
"When producing e-methane and other electric fuels, some energy is lost in the process, but their advantage is the storage and mobility of large amounts of energy that would not be practical or profitable to store and transfer as electricity," says Syrjänen.
The production of e-methane is particularly profitable due to the variability of renewable electricity production. When the conditions are favorable, a surplus of electricity is created, and it is beneficial to be able to store and use it.
"The surplus also affects electricity price, making it negative. In this case, it can be favorable to use electricity to produce hydrogen and further methane," says Marika Kokko, Associate Professor at Faculty of Engineering and Natural Sciences, Tampere University.
Kokko is researching biological methanation in the HYGCEL (Hydrogen and Carbon Value Chains in Green Electrification) research project funded by Business Finland. HYGCEL focuses on identifying and developing the hydrogen and carbon value chains of the electric fuel or P2X market (Power-to-X), which includes the value chains of the P2G solution. Gasum is also involved in the project.
Europe takes the lead in electric fuels
Finland and the other Nordic countries are particularly suitable areas for hydrogen production, as a lot of renewable electricity production is planned here.
In terms of green hydrogen production and methanation, the most important thing is to build a profitable and smooth value chain, where the different pieces of the process meet in the right places. This provides the greatest benefit to the end user of methane.
"It is essential to think about where the renewable electricity and carbon dioxide needed for green methane are produced. Methanation as a field is currently developing at a fast pace, and Europe is a pioneer in this," says Marika Kokko.
The continuous development of the technology for methane utilization is also essential for the sustainable use of methane. For example, preventing fugitive emissions of methane, i.e. methane slips, in the entire value chain is of primary importance.
"The EU has recently defined precise regulations that define which electric fuels are considered renewable. Now that the rules of the game are clear, we can work on the concrete steps of bringing sustainable and renewable e-methane to the market", says Gasum's Mikko Syrjänen.