A research group at Chalmers University of Technology, Sweden, has developed an efficient process for breaking down any plastic waste at the molecular level. The resulting gasses morph into new plastics of high quality. This new process could change today’s plastic factories into recycling plants, with little change to their existing infrastructure.
Remaining and even collecting in our ecosystems is one of the main problems facing plastic production today. This is because plastics do not break down, causing massive environmental issues. Now, a research team headed by Henrik Thunman – Professor of Energy Technology at Chalmers – appears to have turned the corner in changing the lasting impact of plastic in the world.
The research team views the concept of circular usage. This is considered the solution to modern plastic being recycled easily as an exciting and practical option. This in turn creates value in collecting and recycling discarded plastic. Imagine the economic spin off, and the long-term prospects for much less plastic pollution everywhere.
Thunman states that the world should not lose sight of the massive contribution plastics have made since their introduction. The downside is society in general had no warning about the looming disaster that waste plastic would have right around the globe.
Thunman adds: “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. It has been cheaper to produce new plastics from oil and fossil gas than from reusing plastic waste”.
Experimenting with the steam-use of cracking plastic has been key. It has evolved into a highly effective process for converting used plastics into new products. This involves finding the correct temperature, around 850 Celsius. It also boils down to the right heating rate and dwell time.
The team has managed to show their method works at a scale where they convert 200 kg of plastic waste-an-hour into a reusable gas mixture. The result allows the gas to be recycled at the molecular level. In other words, new plastic of virgin quality.
Changing Rules of Engagement
Experiments conducted at the Chalmers Power Central site in Gothenburg stretch back to 2015. Some 350 million tons of plastic waste found worldwide resulted in the following:
#… 14 per cent was collected for material recovery;
#… 8 per cent was recycled into plastic of lower quality;
#… About 2 per cent was plastic of similar quality as the original;
#…Around 4 per cent was lost in the process.
So, around 40 per cent of global plastic waste in 2015 was re-processed after collection. This is mainly via incineration for energy recovery or volume reduction. This releases huge volumes of carbon dioxide into the atmosphere.
The remaining 60 per cent goes to landfill. The volume is a major environmental problem as the amount of plastic waste is so high overall. Moreover, the natural degradation of plastic is low, so it accumulates over time.
The proposed Swedish model for recycling plastic follows what is known as the ‘waste hierarchy’. This means the plastic is degraded many times to lower and lower quality before finally being burned for energy recovery.
Brand new plastics result from shattering fossil oil and gas fractions in a device known as a ‘cracker’ in petrochemical plants. Inside the cracker, building blocks of simple molecules are made. These combine in many different configurations, resulting in the wide variety of plastics we see today.