Recycling CO₂ – the efficient wayInnovative dry reforming process saves valuable energy.

A mixture of hydrogen and carbon monoxide, synthesis gas is used in many different chemical processes. For example, this gas mixture is a feedstock for many chemicals, polymers and fuels such as dimethyl ether. Linde has developed a dry reforming technology that feeds carbon dioxide (CO₂) into the synthesis gas production process, thus enabling industry to put recycled CO₂ to good use. To achieve this, experts from Linde collaborated with partners at BASF and its subsidiary hte as well as with researchers from the Karlsruhe Institute of Technology, the Technical University of Munich , the University of Leipzig and DECHEMA Gesellschaft für Chemische Technik und Biotechnologie e.V. to develop an innovative technology capable of activating CO₂, which is an inert gas. Initially, the team developed two different catalysts to enable the chemical reaction. This involved converting natural gas, steam and carbon dioxide into hydrogen and carbon monoxide.

Once the reaction had been resolved, the experts focused on optimising the process flow. Temperatures can reach 1,000 degrees Celsius inside the catalyst-filled tube reactor. Despite this, the engineers were able to make the new process significantly more energy-efficient. This is because, depending on the product composition, the steam to carbon ratio is reduced to around one tenth of the ratio required for conventional steam reforming. And less steam means lower energy consumption.

What’s more, this process allows large volumes of CO₂ emitted by other production processes to be fed back into industry rather than being released. Linde’s model calculations indicate that dry reforming has the potential to reduce CO₂ emissions by around 100,000 tonnes every year based on a dimethyl ether production plant with an annual capacity of about one million tonnes. This is the equivalent of 80 million car kilometres travelled. Using the pilot plant and its measuring technology, Linde experts are able to extensively test dry reforming processes and technologies, and collect data for future designs.