Plastics for Climate Protection

31. Jul 2021 | climate neutral

Hermann Staudinger would probably be pretty impressed if he could see how modern industry has further developed his legacy. His research laid the foundation for many plastics that are essential for our nowadays’ life: Plastics make cars lighter and safer, keep food fresh longer and are indispensable in medicine in the form of syringes and needles. And more than this, plastics are often more sustainable than other materials since they are lighter, more durable and more efficient. In short: we can no longer imagine our modern lives without plastics.

Circular economy is key

Staudinger could not have known about the shadow side of plastics. The production of plastics still produces too large amounts of the climate-threatening greenhouse gas carbon dioxide (CO2). And even though plastics help to save CO2 emissions throughout their life, their disposal and recycling remains a challenge. Too much plastic waste still ends up in landfills or incineration. This is problematic: when landfilled, plastics are dumped into the environment where it takes decades, sometimes even centuries, for them to decompose. And incineration causes CO2 emissions by itself. What can be done? One approach: introduce a circular economy in which raw materials are conserved, plastic waste is reduced and the benefits of plastic are fully recognised. Producing plastics from alternative sources instead of fossil raw materials such as crude oil can be a step in the right direction as well.

Mechanisches Recycling Flakes aus zum Beispiel Plastikflaschen. © BASF

A holistic approach to recycling

A proven alternative to crude oil is the usage of recycled material in the production of plastics. Today, most recycling is done mechanically: for example, used plastic bottles are sorted, cleaned and then crushed into small pieces called flakes. The flakes can then be used to form new bottles: Turning old into new.

Impressive variety

But not all plastic waste can be shredded and reassembled. This applies to waste which consists of different types of plastic and for which further sorting is technically not possible or not economical.  Chemical recycling can therefore be a sensible addition. The technology involves various technical processes in which used plastics are broken down into their basic chemical building blocks. This process, known as pyrolysis, converts mixed plastic waste into pyrolysis oil by means of heat and the exclusion of oxygen. This oil then serves as a raw material for new products. The resulting products have exactly the same properties as those made from fossil raw materials.

Chemisches Recycling gewinnt durch Pyrolyse Kunststoff zurück. © BASF

The quest for alternatives

Alternatives to petroleum can also be found in nature. Namely in the form of biomass, which consists of renewable raw materials such as wood, grain or sugar. With the help of bacteria and enzymes, polylactic acids (PLA), can be formed from biomass. These polylactic acids are then the starting material for new, bio-based plastics. For example, there are already rubbish bags and coffee capsules based on corn or sugar. And the potential of renewable raw materials is enormous, since the share of bio-based plastics is currently estimated at only one percent.

 

CO2 kann beim chemischen Recycling als Rohstoff in der Kunststoffproduktion eingesetzt werden. © Covestro

CO2 as raw material

Speaking about alternatives, even the bad reputation of CO2 could soon be history. The gas, which we associate with climate change more than almost any other, can soon prove itself as a raw material in plastics production. Thanks to the latest processes, it can already be used to make sports floors and even mattresses. Firmly bound in plastic, CO2 will celebrate a comeback in many products of our daily lives in the future.

Which alternative raw materials would Hermann Staudinger prefer? We do not know. It is certain that Staudinger would also be committed to making the production of plastics more climate-neutral. This, however, is our mission for today.