As sustainability becomes more prominent in the public consciousness, the need for smarter ways to recycle our resources is growing. Especially when it comes to tin cans. The cans are made of steel and tin, which is a scarce resource.
In order to separate the two metals, the cans must be clean, which is difficult as they often contain food residues that make the recycling process difficult.
That’s why Anders from ERA Recycling, in the knowledge bridge project Urban Tin Mining, set out to investigate how enzymes can make cleaning more efficient, reduce waste, and create a greener future.
Research and industry join forces for smarter recycling
Together with DTU Engineering Technology, ERA Recycling has gained new knowledge where DTU has brought their expertise into play. DTU has taken a theoretical approach to the project, analyzing the chemical and physical processes, while ERA Recycling has contributed with practical experience from the recycling industry.
Experiments were conducted where up to 10kg of cans were cleaned at a time. The trials showed that factors such as agitation, heat, water volume, and enzyme dosage have a major impact on how effective the cleaning process is.
We looked at how to clean these cans when they come from sorting. We looked at how we can use enzymes and detergents to get the cans clean enough. We learnt how much is needed – how much agitation, how much heat, the amount of water and the amount of enzymes, says Anders Alding from ERA Recycling.
However, the measurements have proved technically challenging, which has shifted the focus to larger batch trials where the processes can be tested under more realistic conditions.
From idea to reality
The practical testing of the defrosting of the cans has provided valuable insights, which are now summarised in a report. Based on the results, ERA Recycling is continuing to optimize the technology and investigate how it can be implemented on a larger scale.
Urban Tin Mining shows how much potential there is in rethinking waste management and the circular economy.
The project proves that with the right technological solutions we can take an important step towards a more sustainable future, says Anders Alding from ERA Recycling.
It’s a strong example of how research and industry can work together to create solutions that are not only good for the environment – but also make economic sense.
The Knowledge Bridge project was co-financed by the Danish Agency for Higher Education and Science.
