Rheticus: Evonik and Siemens launch phase II

Evonik and Siemens have launched their joint research project Rheticus II, which seeks to develop an efficient and powerful test plant that will develop speciality chemicals from CO₂, water, renewable electricity and bacteria. The facility should start operating in early 2020 and will run until 2021, aided by around €3.5 million in funding from Germany’s Federal Ministry of Education & Research (BMBF).

“In the future, this platform could be installed anywhere CO2 is available - for example, at power plants or biogas plants,” said Thomas Haas, who heads the project for Evonik. “We use available CO₂ as the raw material for the production of high-value chemicals using artificial photosynthesis.”

This all follows two years of work in Rheticus I to develop a technically feasible basis for artificial photosynthesis using a bioreactor and electrolysers, the former and related technology being supplied by Evonik, the latter by engineering and technology giant Siemens. In the newly developed facility, CO₂ and water are converted in combined chemical and biological steps, using electricity, into CO and hydrogen. The two previously separate plants are being combined in a test facility at Evonik’s Marl site in Germany.

In the coming months, the 8-metre high, 2,000L stainless steel bioreactor will be combined with a fully automated CO₂ electrolyser, which was integrated into a container over the summer. This comprises ten cells and the electrodes have a total surface area of 3,000 cm². It will release CO that will deliver nutrients for the bacteria or microorganisms in the bioreactor when in contact with hydrogen A unit to process the liquid from the bioreactor is also being built to obtain pure chemicals. The first products are to be butanol and hexanol, which will be used for research but, Evonik said, “other speciality chemicals are conceivable, depending on the bacterial strain and conditions”.