Power-to-gas

Surplus energy from renewable energy generation is supposed to be stored in an appropriate way to deal with the usually intermittent availability of these forms of energy, for instance wind and sunlight. Chemical storage of the electrical energy by converting carbon dioxide into natural gas using green hydrogen is a promising pathway because the natural gas grid is already well established. Following this approach the carbon dioxide can either emerge from renewable sources or non-renewable sources such as biogas plants or industrial plants.

The methanation of carbon dioxide, especially in presence of methane, involves several main challenges that have to be addressed adequately:

• The applied reactor technology needs to optimally suit the required dynamic operating conditions of the heterogeneously catalyzed methanation process
• As the methanation is an exothermic equilibrium process an excellent heat management is required
• Applied catalysts need to feature a high selectivity for the methanation process largely avoiding the competing reverse water-gas shift reaction.
• Significant amounts of Sulphur species occurring in carbon dioxide from biogas plants need to be removed.
• Applied catalysts need to feature an improved stability against small amounts of Sulphur to retain their activity.

 "IMM methanation compact reactor technology and catalyst technology – robust and tailor-made for the reaction and dynamic operation“

Current larger scale methanation plants mostly rely on two-step fixed bed tube-bundle reactor technology. Specifically conceived for carbon dioxide from biogas plants, we have developed a two-stage catalytic methanation process. In a first step carbon dioxide is partially converted with the help of a monolithic reactor coated with high-temperature resistant catalysts. Downstream, the remaining carbon dioxide undertakes reaction in an oil-cooled heat exchanger reactor operated at a much lower temperature. Thus, more than 97 % conversion of the carbon dioxide contained in the process feed could be achieved. The optimum utilization of mass and heat flows as well as the heat integration allow for a highly dynamic operation.

Offer to our customers

Benefit from 20 years’ experience in catalyst development and reactor development for a large variety of reactions (fuel processing, combustion, fuel synthesis and many others). Long-term tests of our catalysts in lab scale demonstrated the high selectivity and stability, as well as strong resistance to the presence of traces of Sulphur-based compounds. The robustness of our plate heat exchanger reactor technology has been proven in practical applications under conditions of start-up, stationary operation and load changes for a variety of applications. Reactor fabrication can be performed by cost-efficient fabrication processes. Furthermore, the technology applied is appropriate for the construction of modular plants that can be easily coupled to other carbon dioxide sources, hence facilitating their assembly, installation and subsequent operation.