Technical University of Denmark: Upgraded biogas to replace natural gas
Biogas is a necessary resource in the energy supply of the future—also for heating private homes. This is the assessment of Associate Professor Philip Fosbøl from DTU Chemical Engineering, who researches technology to upgrade biogas and remove CO2 and unwanted substances such as sulphur before it is sent into the natural gas grid.
According to the trade association Biogas Danmark, Danish biogas has displaced Russian gas of DKK 3.7 billion in the first eight months of the year. This means that biogas currently takes up 40 per cent of the methane in the natural gas grid supplied to companies and private customers. According to the Danish Energy Agency’s forecast, biogas will account for 72 per cent of the gas flowing in the natural gas grid by 2030.
Philip Fosbøl estimates that the current crisis in the natural gas market will ease within the next two to three years. Subsequently, the natural gas supply in Denmark will continue to be a resource required to produce power in CHP plants when wind turbines and solar energy cannot provide power.
“Already from 2024, when the Thyra gas field reopens, we will be able to produce the gas we need in Denmark. This will cause prices to fall again, and when biogas production is scaled up, we will be able to completely phase out fossil gas by 2030,” says Philip Fosbøl.
Hydrogen in the natural gas grid
Philip Fosbøl estimates that in a few years, the natural gas grid in Denmark will be used as infrastructure to supply Denmark with both methane produced from biogas and with hydrogen produced in Power-to-X plants, where wind power meets water and is converted into liquid hydrogen through electrolysis.
“In the future, it will be a mixture of methane and hydrogen that we burn both in natural gas boilers in private homes and in industry,” says Philip Fosbøl.
He points out that the current energy crisis with a lack of natural gas is a European problem triggered by Russia’s stopping their natural gas supply, combined with the fact that Europe does not have an infrastructure that can be quickly converted to supply gas from ships and refuelling facilities in the major ports.
DTU has a number of research projects within the upgrading of biogas and three demonstration plants where researchers test different technologies to improve biogas use. One of the projects, Bio-ReFuel, focuses on converting biogas into the liquid fuel methanol. The plant will have the capacity to process 240 m3 of biogas daily.
Another project BioCO2 which focuses on utilizing CO2 in biogas to achieve an improved quality with low energy consumption. In addition, the BE-CLEAN project uses a successful Power-to-X technology to reduce costs by removing impurities from the biogas.
The projects actively contribute to improving the core technologies that are part of the green transition of energy supply in Denmark.