Producing Plastics from Carbon Dioxide
Researchers at Bayer MaterialScience and Bayer Technology Services are cooperating with RWE Power AG and the RWTH Aachen University on sustainable use of carbon dioxide. As part of the "Dream Production" project, a pilot plant in the Chempark Leverkusen was recently put into operation. The plant produces polyether polycarbonate polyols (PPP) that can be processed into polyurethanes. In the course of the process, CO2 is bound chemically and thus finds sustainable use as a starting material.
The key technology for the process is catalysis. The low reactivity of carbon dioxide previously stood as an impediment to its use as a starting material for polymers. The researchers have now achieved a breakthrough in catalyst technology. With the aid of a zinc-based catalyst, CO2 can be converted to high-value products energy-efficiently and economically.
The CO2 used in the process comes from a lignite-burning power plant in Niederaussem, where it is extracted from the flue gas by means of a CO2 scrubbing process. The CO2 scrubber is further equipped with a liquefying plant, permitting the carbon dioxide to be transported to Leverkusen.
To date, plastics have been produced primarily from fossil fuels and, after use, been incinerated (thermal recycling) in large quantities. With this new process, it might be possible to reverse the material stream: the fossil fuels are first used as a source of energy, after which the carbon dioxide contained therein is used as a starting material for other purposes. To a certain degree, this process mimics the creation of polymers in nature: it is known that plants absorb carbon dioxide from the atmosphere and convert it via photosynthesis into organic substances such as glucose.
The "Dream Production" process is being funded by the German federal government at a level of about €5 million. Taking the participation of Bayer and RWE into account, the total increases to about €9 million. If the testing phase is successful, industrial production of CO2 -based plastics is scheduled to begin in 2015.