Evonik and Siemens are planning to use electricity from renewable sources and bacteria to convert carbon dioxide (CO2) into specialty chemicals. The two companies are working on electrolysis and fermentation processes in a joint research project called Rheticus. The project was launched and is due to run for two years.

The first test plant is scheduled to go on stream by 2021 at the Evonik facility in Marl, Germany which produces chemicals such as butanol and hexanol, both feedstocks for special plastics and food supplements, for example. The next stage could see a plant with a production capacity of up to 20,000 tonnes a year. There is also potential to manufacture other specialty chemicals or fuels.

Some 20 scientists from the two companies are involved in the project. Siemens and Evonik are each contributing their own core competencies to this research collaboration. Siemens is providing the electrolysis technology, which is used in the first step to convert carbon dioxide and water into hydrogen and carbon monoxide (CO) using electricity.

Evonik is contributing the fermentation process, converting gases containing CO into useful products by metabolic processes with the aid of special micro-organisms. In the Rheticus project, these two steps ­ electrolysis and fermentation ­ are scaled up from the laboratory and combined in a technical test facility. Evonik and Siemens see great future potential in the Rheticus platform. It will make it simple to scale plants to the desired size ­ the chemical industry will be able to adapt them flexibly to local conditions.

In future, they could be installed anywhere where there is a source of CO2 ­ power plant waste gas or biogas for instance.