The German industrial giants Siemens and Evonik have launched a joint project to build and run a test plant to make valuable chemicals from water and waste carbon dioxide using bacteria — a process known as artificial photosynthesis.
The test plant, which is currently under construction, will be based at Evonik’s site in Marl, Germany, and will be run purely on renewable energy.
Germany’s Federal Ministry of Education and Research has contributed €3.5M to help build the plant, which is due to begin operations in early 2020 and run until 2021. After this point the success of the experiment will be assessed and the future of the plant decided.
The project, named Rheticus II, builds on work the two collaborators did in an earlier iteration called Rheticus I. In the earlier project, Siemens and Evonik worked on developing the technology to perform ‘artificial photosynthesis’ — essentially using energy to produce chemicals from carbon dioxide and water in a similar way to plants.
The process used in Rheticus II first converts carbon dioxide and water into carbon monoxide and hydrogen using an electrolyzer. The second step involves specialized microbes in a bioreactor that can convert the hydrogen and carbon monoxide byproducts into different chemicals. Siemens has contributed its expertise by developing the specialized electrolyzers and Evonik has developed the bacterial strains and the bioreactor.
“The innovative technology used for Rheticus has the potential to contribute to the success of Germany’s energy transition,” said Thomas Haas who is responsible for the Rheticus project at Evonik.
“In the future, this platform could be installed anywhere CO2 is available — for example, at power plants or biogas plants.”
The test plant includes an 8 meter-high bioreactor with a capacity of 2,000 liters to house the microbes and the world’s first automated carbon dioxide electrolyzer. These two sections will soon be combined, as well as an additional unit to extract the desired chemicals.
Initially, the test plant will focus on producing butanol and hexanol, used as a starting point for making some plastics and food supplements. But the company stated that varying the bacterial strain and conditions in the plant could allow a variety of different chemicals to be produced in the future.
Images via Evonik