About Rheticus

Artificial photosynthesis - a contribution to the energy transition

From the idea to innovation - CO2-based specialty chemicals

Just as plants use solar energy to produce sugar, for example, from carbon dioxide (CO2) and water in several steps, artificial photosynthesis uses renewable energy to generate valuable chemicals from CO2 and water through electrolysis with the help of bacteria.

It was already successfully demonstrated a few years ago that artificial photosynthesis works in the laboratory (Haas et al., 2018). Another milestone on the way to industrial implementation was reached at the end of 2020: the test facility at Evonik's Marl site, funded by the German Federal Ministry of Education and Research (BMBF), was put into operation. It uses electricity from renewable sources, CO2 and H2O to produce chemicals and thus shows for the first time that artificial photosynthesis also works on a larger scale.

The test facility in Marl consists of a water electrolyser and the bioreactor with expertise from Evonik. In the first step, electricity is used in the electrolyser to convert water into hydrogen (H2). CO2 and H are used by special microorganisms to produce chemicals, e. g. hexanoic acid. These specialty chemicals are starting materials for example for lubricants or the cosmetics industry.

Since commissioning, the team has made significant progress by adding a down-stream processing unit to the plant, establishing continuous 24-hour operation and starting application tests with potential customers.

Even after the completion of the funding project, Evonik continues to push ahead work on the unique platform technology under the name Rheticus, thus creating access to specialty chemicals from CO2 and H2 – sustainable, modular, and flexible.

„Climate protection is not possible without chemistry, because our industry supplies and develops solutions for the energy turnaround. Research projects such as Rheticus are a motivation and innovation driver for a sustainable society.“

„The innovative technology used for Rheticus has the potential to contribute to the success of Germany's energy transition. In the future, this platform could be installed anywhere CO2 is available - for example, at power plants or biogas plants.“

„With Rheticus, we are showing how we can set up climate-friendly production processes in the chemical industry and at the same time manufacture new innovative products. And this works not only here in Germany, but potentially all over the world. This opens promising opportunities for technology exports. We want to promote effective climate protection and continue to have a strong industrial base in Germany. I am firmly convinced that we can succeed in both“


Evonik and Siemens Energy are researching a green future: They want to convert carbon dioxide into specialty chemicals - with the help of green electricity and bacteria in an artificial photosynthesis. In the Rheticus research project, they are driving the energy transition forward.


Two steps to green chemistry 

Bayerischer Energiepreis 2020

Winner in the category Products and Applications

Commissioning of the Rheticus test plant in Marl