“Waste contains enough carbon atoms to fulfil the demands of all world plastic manufacture. We can extrude new plastic goods from the availability of virgin fossil raw resources by using these atoms. If the process is powered by renewable energy, we also get plastic products which have a more than 95 per cent lower climate impact than those produced today, effectively resulting in negative emissions for the entire system,” says Henrik Thunman, Professor of Energy Technology at Chalmers University of Technology and one of the study’s authors.
To accomplish circular cycles, we must make greater use of the resources that are currently available in society. Henrik Thunman and his research team aim to focus on a critical resource that is frequently wasted today: the carbon atoms in our garbage, which are generally burnt or disposed of in landfills rather than recycled. This is made feasible by technologies that target the carbon in plastic, paper, and wood wastes, with or without food residues, to provide the raw material for the creation of polymers with the same range and quality as those now produced from fossil raw materials.
Just like nature
Current plastic recycling processes can only replace around 15-20% of the fossil raw material required to supply society’s need for plastic. The researchers’ improved approaches are based on thermochemical technology and entail heating the trash to 600-800 degrees Celsius. The waste is subsequently converted into a gas, which, when combined with hydrogen, may replace the building blocks of plastics. Using this recycling technology might decouple the supply of new fossil raw materials from the supply of new plastic goods.
The study’s researchers are working on a thermochemical recycling approach that creates a gas that can subsequently be utilised as a raw material in the same plants where plastic goods are now created from fossil oil or gas. At the Chalmers Power Central, various forms of waste, such as old plastic items and paper cups with or without food residues, are fed into the reactors.
“The key to more widespread recycling is to view leftover trash in a completely different light: as a raw material rich in valuable carbon atoms. The garbage gains value, and you can build economic mechanisms to gather and use the stuff as a raw material all over the world,” explains Henrik Thunman.
The process’s premise is based on the natural carbon cycle. When plants wither, they are broken down into carbon dioxide, and carbon dioxide, utilising the sun as an energy source and photosynthesis, makes new plants.
“However, our technique varies from how nature works in that we do not need to take the detour through the atmosphere to cycle the carbon in the form of carbon dioxide. All of the carbon atoms we require for plastic manufacture can be found in our garbage and regenerated using heat and power,” Henrik Thunman adds.
According to the researchers’ calculations, the energy used to power such operations may come from renewable sources such as solar, wind, hydropower, or biomass, and they will be more energy-efficient than current systems. Excess heat from recycling operations may also be extracted, which is a circular system that would compensate for the heat output now generated from waste incineration while removing the carbon dioxide emissions associated with energy recovery.
Can replace fossil raw materials
The study was conducted as part of the FUTNERC project. The researchers demonstrated the process’s viability in collaboration with plastics manufacturer Borealis in Stenungsund, Sweden, where they verified the results and demonstrated that the raw material can be used to make plastic, thereby replacing the fossil raw materials currently in use.
“Our objective is to build a plastics circular economy. Considering our plastic goods are critical to the transition to a sustainable society, we must fund studies like this. There are currently schemes in place to generate circularity for our plastic products, but additional solutions are required. As a consequence, we are thrilled with these good results, which will help us get closer to our target,” says Anders Fröberg, CEO of Borealis AB.
CEOforLIFE – We promote life. We support the SDGs
