A research group at Chalmers University of Technology, Sweden, has developed an efficient process for breaking down any plastic waste to a molecular level. The resulting gases can then be transformed back into new plastics – of the same quality as the original. The new process could transform today’s plastic factories into recycling refineries, within the framework of their existing infrastructure.
?The fact that plastics do not break down, and therefore accumulate in our ecosystems, is one of our major environmental problems. But at Chalmers, a research group led by Henrik Thunman, Professor of Energy Technology, sees the resilience of plastic as an asset. The fact that it does not degrade makes it possible for circular usage, creating a true value for used plastic, and therefore an economic impetus to collect it.
“We should not forget that plastic is a fantastic material – it gives us products that we could otherwise only dream of. The problem is that it is manufactured at such low cost, that it has been cheaper to produce new plastics from oil and fossil gas than from reusing plastic waste,” says Henrik Thunman.
Now, through experimenting with chemical recovery via steam cracking of plastic, the researchers have developed an efficient process for turning used plastics into plastics of virgin quality.
“Through finding the right temperature – which is around 850 degrees Celsius – and the right heating rate and residence time, we have been able to demonstrate the proposed method at a scale where we turn 200 kg of plastic waste an hour into a useful gas mixture. That can then be recycled at the molecular level to become new plastic materials of virgin quality,” says Henrik Thunman.
The experiments were carried out at the Chalmers Power Central facility in Gothenburg.
In 2015, around 350 million tonnes of plastic waste were generated worldwide. In total, 14 per cent was collected for material recovery – 8 per cent was recycled into plastic of lower quality, and 2 per cent to plastics of similar quality as the original. Around 4 per cent was lost in the process.
Overall, around 40 per cent of global plastic waste in 2015 was processed after collection, mainly through incineration for energy recovery or volume reduction – releasing carbon dioxide into the atmosphere.
The rest – about 60 per cent – went to landfill. Only around 1 per cent was left uncollected and leaked into natural environments. Though only a small percentage, this nevertheless represents a significant environmental problem, since the amount of plastic waste is so high overall, and since the natural degradation of plastic is so slow, it accumulates over time.
The current model for recycling plastic tends to follow what is known as the ‘waste hierarchy’. This means the plastic is repeatedly degraded, to lower and lower quality before finally being burned for energy recovery.
“Instead of this, we focused on capturing the carbon atoms from the collected plastic and using them to create new plastic of original quality – that is, back to the top of the waste hierarchy, creating real circularity.”
Today, brand new plastics are made by shattering fossil oil and gas fractions in a device known as a ‘cracker’ in petrochemical plants. Inside the cracker, building blocks consisting of simple molecules are created. These can then be combined in many different configurations, resulting in the enormous variety of plastics we see in our society.
To do the same from collected plastics, new processes need to be developed. What the Chalmers researchers now present are the technical aspects of how such a process could be designed and integrated into existing petrochemical plants, in a cost-effective way. Eventually, this kind of development could enable a hugely significant transformation of today’s petrochemical plants into recycling refineries of the future.
The researchers are continuing their work on the process.
“We are now moving on from the initial trials, which aimed to demonstrate the feasibility of the process, to focusing on developing more detailed understanding. This knowledge is needed to scale up the process from a few tonnes of plastic a day, to hundreds of tonnes. That is when it becomes commercially interesting,” says Henrik Thunman.
Learn more: All plastic waste could be recycled into new plastic
The Latest on: Recycling plastics
[google_news title=”” keyword=”recycling plastics” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]
via Google News
The Latest on: Recycling plastics
- How invisible barcodes could increase plastic recyclingon May 18, 2024 at 9:27 pm
A pan-industry scheme is testing invisible barcodes on plastic packaging to boost recycling rates. Video by Adrienne Murray, James Brooks and Dougal Shaw Spirit AeroSystems supplied Boeing with faulty ...
- NYS legislation would shift the onus of recycling packaging to businesseson May 18, 2024 at 5:03 am
The proposal would improve recycling infrastructure, reduce toxins in packaging and shift the onus and cost of recycling to manufacturers.
- Giant Heaps of Plastic Are Helping Vegetables Growon May 17, 2024 at 6:28 am
Plastic allows farmers to use less water and fertilizer. But at the end of each season, they’re left with a pile of waste.
- Analysis: Chemical recycling’s ‘inflection point’ nearingon May 16, 2024 at 5:00 pm
An analysis of nearly 170 chemical (also known as advanced) recycling installations globally says in part that 2024 and 2025 mark “a key inflection point” as to how and whether pyrolysis systems in ...
- Proposed Plastics Law Could Slash Wasteful Packagingon May 16, 2024 at 5:00 pm
Recycling rates would also have to increase to 75 percent of packing material, including plastic, to be reused or recycled in 2050. Assemblymember Deborah Glick, a Democrat from Manhattan, said there ...
- Dow and SCGC Partner to Change 200KTA of Plastic Waste Into Circular Productson May 16, 2024 at 5:24 am
Dow (NYSE: DOW) and SCG Chemicals or SCGC, today announced the signing of a first-of-its kind memorandum of understanding (MOU) circularity partnership in the Asia Pacific region to transform 200KTA ...
- M&S teams up with recycling tech group to trace plastic packagingon May 15, 2024 at 3:26 pm
Polytag system prints invisible tag on to containers, which can be picked up by readers located at recycling centres ...
- Florida is one of America's highest generators of plastic wasteon May 15, 2024 at 2:20 am
Editorial: Why Floridians should give a hoot about all the plastic waste polluting beaches, natural habitats, open land and once pristine waterways ...
- Mechanical recycling: A look inside one of many ways to recycle plasticon May 14, 2024 at 1:30 pm
You've probably seen bins where you can recycle your plastic. But what happens to that plastic bottle after you drop it in?
- How Politics And Litigation Impede Innovation In Plastics Recyclingon May 9, 2024 at 5:21 am
Plastics recycling has long been one of society's most intractable problems. A planned new set of court actions seems set to only delay real solutions.
via Bing News