Greenhouse gases headed for sustainability: How CO2 is turning into plastic

It is an undisputed fact that carbon dioxide is accelerating climate change. To combat the effects, emissions must be reduced – which means we must find other ways to apply CO2. Fraunhofer researchers have developed an approach that uses the greenhouse gas as a raw material to produce plastics.

Dr. Jonathan Fabarius is a member of the Fraunhofer research team. In this K-MAG interview he outlines the process that takes Co2 to the final raw material, describes the products that are best suited for this type of plastic and reveals when research will be ready to effectively benefit from these raw materials.

Jonathan Fabarius: The task requires a cascade process that combines multiple scientific disciplines. Carbon dioxide is a low energy compound that requires energy input as a first step using chemical or electrochemical processes. The reduction of CO2 leads to C1 compounds such as methanol or formic acid. The Fraunhofer IGB has successfully developed these types of processes, creating synthesis processes that are highly efficient. In a second step, the CO2-derived C1 compound is fed to microorganisms. Using a fermentation process, the microorganisms make the desired raw material to produce CO2-based plastics. This enables the production of polymer building blocks such as organic acids, amino acids, or diamines. We are also successful with this process step and already illustrated the concept with both methanol and formic acid as the substrate. The genetic modification of the applied microorganism and synthetic biology give us flexibility as it pertains to the conceivable products. Biotechnology has shown this many times using conventional sugar-based fermentation processes.

How are these raw materials subsequently used?

Fabarius: Product purification from the aqueous fermentation broth presents a challenge. Mandatory polymer purity is a major sticking point in this setting. The polymer building blocks are then ready for subsequent processing. 

Which products could be made from these plastics?

Fabarius: To take advantage of sustainability, these plastics can be used to make products requiring a longer life cycle. Thanks to the variety of polymer building blocks that can be created with the help of microorganisms, one can derive multiple polymers including polyamides or polyesters that are used in the production of films and fibers, for example.

How can you implement your research findings into industrial applications (in CO2-producing companies) in the future?

Fabarius: Our work aims to create a sustainable and CO2-based production route for a wide variety of chemical products. More specifically, we see the benefits of these processes in CO2 emissions reduction with simultaneous value creation. Since companies must now pay for their CO2 emissions, the respective costs can subsequently be reduced and capacity utilization improved at the same time, making this an exciting hot topic for carbon-emitting businesses. Obviously, the respective cascade processes must be economically efficient and profitable in this setting. We are working on making this a reality.

When will you be ready for implementation?

Fabarius: Our technical approaches still require some related development, which takes time and pertinent research funding. Collaborative relationships with interested industrial companies promote rapid technological leaps and targeted improvements to the concept thanks to know-how exchange. Of course, these leaps in innovation also hinge on the economic pressure that will increase considerably in the future thanks to the rising costs of offsetting carbon emissions. We project that our first processes will move into industrial application within 3 to 5 years, after the next funded project.

What's your take: Is CO2 the raw material for plastics in the future?

Fabarius: Well, if you put it that way, yes, it is! If you want to close the carbon cycle, the use of CO2 as a raw material is vital. Today we have access to more technology choices than you might think, enabling us to produce a wide range of products based on this new raw material in the future.