The recycling of carbon dioxide (CO₂) is a promising approach to reducing industrial emissions and, at the same time, using CO₂ as a raw material for the production of valuable chemicals.

Two container plants are used for this purpose: a carbon capture unit for capturing CO₂ and a power-to-methanol plant for converting the CO₂ obtained into methanol. Both container plants can be flexibly connected to local CO₂ sources in order to convert emissions into usable products directly on site.

In the first step, the CO₂ is selectively separated from an exhaust gas stream in the carbon capture container plant using an amine scrubber. The system is designed for a throughput of up to 100 Nm³/h and thus enables the processing of large exhaust gas volumes.

The separated CO₂ is then mixed with hydrogen from an electrolysis unit in the power-to-methanol container plant and converted into methanol in a closed-loop process. The plant achieves a production capacity of up to 40 liters of raw methanol per day.

A central goal of the plant operation is the experimental investigation of the flexibility and dynamics of the overall process. The plants should be able to react quickly to fluctuating CO₂ quantities from industrial sources and to variable electricity prices. This enables a realistic evaluation of operating strategies under the conditions of an increasingly volatile energy market and represents an important step towards an adaptable and economically viable Power-to-X system.

Model-based simulation methods are also used to design and optimize the processes and reactors. These include stationary and dynamic process simulations with Aspen Plus, the programming and evaluation of complex process logic with Python and computational fluid dynamics (CFD) simulations for the detailed analysis of reaction-related processes in the reactor.

In addition to the large-scale examination of the overall process, specific detailed investigations are carried out in several smaller test stands in order to further optimize process control and evaluate operational safety.

A key focus is on the stability of different amines that are used in CO₂ separation by means of amine scrubbing. In particular, their resistance to elevated temperatures and pressures is being investigated, as well as the influence of impurities in the exhaust gas stream, such as sulphur dioxide (SO₂), on performance and long-term stability. In addition, material compatibility between process media and various stainless steels is tested in long-term tests in order to detect potential corrosion phenomena or material changes under real conditions.

In an additional test stand, we are investigating how the conversion of equilibrium-limited methanol synthesis can be increased. A promising approach here is the use of a water-permeable membrane that removes water from the reaction zone in situ during the reaction. The continuous separation of this reaction by-product shifts the chemical equilibrium towards product formation according to Le Chatelier's principle, which can enable a significant increase in methanol yield. This membrane-based reactor approach thus opens up new perspectives for a more efficient and economical design of methanol synthesis under real process conditions.