A study in Japan by Tohoku University researchers have discovered that big savings can be made on recycled car parts.
Sorting end-of-life car parts into 8 classes could increase recycling rates of alloy elements to over 97% in Japan.
Their analysis found that optimising recycling could save Japanese steelmakers 31.6 billion yen (£207.5 million) on raw materials, and cut greenhouse gas emissions associated with obtaining new material by more than 28 per cent.
While Japan mandates automobile recycling, scrap car parts are usually lumped together for iron, according to the study published in the journal Environmental Science & Technology (www.pubs.acs.org). This means specific alloy elements present in the scrap, such as manganese, chromium, nickel, and molybdenum, are not optimally recycled.
The researchers analysed the composition of scrap car parts and what they could be reused for and found they are best suited for nine steel alloys. The analysis found that between 94 and 99 per cent of the alloy elements could be recycled from the scrap car parts. The scrap metal would be melted down in electric arc furnaces and remade into steel products, such as coils, plates and bars. The recycled alloy elements could replace about 10 per cent of the new material used by electric arc furnace (EAF) steelmakers.
While it sounds like a small portion of the raw material, that translates to huge savings—steelmakers would save up to 15.2 per cent spent on alloys. It would also reduce greenhouse gas emissions associated with the new material by 28.3 per cent.
As part of their analysis, the researchers compared the tradeoffs between reducing costs versus emissions. They found that a small compromise on price could yield almost the greatest emission reduction. They were even able to identify which recycled alloy elements contributed the most to this equation, for the maximum benefit.
The authors note that their methodology can be applied globally and to other industries, helping find the optimal balance between costs and emissions to make the most of recycling efforts. This methodology will also help advance efforts to establish a circular economy, one that addresses products from cradle to grave and minimises harmful environmental impacts.
Despite the potential savings, the authors anticipate that improving car scrap recycling systems will likely require policymakers to support the development of new automatic sorting technologies for recyclers, as well as incentivise steelmakers to purchase sorted scrap at fair prices.