Is CO2 The New Oil?

2023 Author : Hannah Pearcy | [email protected] . Last modified: 2023-06-05 00:21

Whether in traffic, in industry or in power plants, wherever fossil substances are burned or processed, large amounts of carbon dioxide (CO ₂ ) are emitted. In return, carbon, a component of the greenhouse gas CO ₂ , is needed in the chemical industry as a central building block for numerous products such as plastics. It is usually obtained from oil, natural gas or coal. The team from science and industry from RWTH Aachen, the Max Planck Society and Covestro AG has taken a first step with this project to close this carbon cycle by using part of the emitted carbon dioxide for industrial production instead.

5000 tons of polyol a year

In the new process, part of the petroleum-based raw material for chemical production is replaced by CO ₂ . Up to 5000 tons of polyol can already be produced annually in a pilot plant of Covestro AG. This substance is further processed into polyurethanes , which are used, for example, as foams in mattresses. Other fields of application for polyurethanes are, for example, as soft foams in car seats or as hard foams in insulating materials.

The use of CO _{2 was made} possible by a breakthrough in catalysis research. Since CO _{2 is} chemically inert and only with great difficulty forms chemical compounds with other substances, a tailor-made catalyst was required to control the reaction in such a way that it was economical and efficient. A catalyst causes the reactants to form compounds by lowering the activation energy for the conversion and directing it in a desired direction. The experts from RWTH and Covestro have found a suitable catalyst for the incorporation of CO ₂ into the polyol.

World recycling day

For the “World Recycling Day” on March 18, 2020, German Environment Aid (DUH) is asking Federal Environment Minister Svenja Schulze to make the recycling capability of packaging and products as mandatory as the use of recycling material. The “World Recycling Day” was launched in 2017 to draw attention to the wasteful use of natural resources.

"The new process illustrates how chemistry can contribute to a sustainable future with closed carbon cycles," says Walter Leitner, holder of the RWTH Chair for Technical Chemistry and Petroleum Chemistry and director at the Max Planck Institute for Chemical Energy Conversion. The collaboration with Covestro as part of the CAT Catalytic Center at RWTH Aachen is a prime example of cooperation models between basic academic research and industrial innovation. "Together with Christoph Gürtler and Berit Stange, we represent many colleagues and employees who have contributed to this success with creativity, competence and commitment," explains Walter Leitner. Christoph Gürtler is responsible for the New Processes and Products division at Covestro AG and Berit Stange for the Polyurethane Recycling Management division.

Recycle plastics

A distinction is made between recycling materials and chemical recycling for recycling plastics.

Material recycling is a multi-stage process (sorting, shredding, cleaning, drying, regranulation), in which the polymer structure of the plastic is not or only slightly influenced.

Chemical recycling, on the other hand, breaks down the polymer structure into monomeric building blocks. These are then rebuilt into a polymer by a synthesis process. Chemical recycling is generally considered when material recycling is not possible. If chemical recycling does not appear to make sense either, energetic recycling remains, which is the most sensible variant under these circumstances.