An electronic waste recycling process that is kinder to the planet – and uses pioneering technology developed at the University of Leicester – has attracted a £1.2 million grant and national awards recognition.
Recycling e-waste, such as discarded mobile phones, laptops and anything with an electronic circuit board, can cause significant environmental problems. This is because the critical metals in circuit boards are difficult to recycle, with the process requiring large and expensive, polluting, smelting facilities. New alternative chemistry based techniques are on the horizon, but the vast majority of these require the use of highly dangerous acids and oxidisers that are consumed in the process and need replacing on a regular basis, meaning more transport of hazardous materials on the roads and a high CO2 footprint which comes from the necessary neutralisation of these chemicals after their use.
But, there is a potentially zero carbon, clean chemical solution, based on the environmentally benign Deep Eutectic Solvents (DES) – a class of chemistry developed by Leicester scientists in the early 2000s.
The DES recycling process sees the solvents dissolve the target metals into a solution without the need for toxic chemicals or high temperatures. The solution is also not consumed within the process and can itself be recycled and used again.
UK based company Descycle, is using the DES chemistry to develop a commercially viable recycling plant that will be hosted by joint venture partner Gap Group, a fully accredited recycling specialist, which will supply approximately 5000 tonnes of high grade e-waste per year to be recycled using the DES chemistry.
The global e-waste market is currently worth over $65 billion with less than 20% being actually collected and recycled by being shipped to large global smelters. Descycle is currently engaging with several other recyclers outside of the UK, in the US, Europe, Australia and Asia, with the aim to announce more joint ventures using the technology in the coming months.
Descycle is also working with waste company GAP, to build a waste electrical and electronic equipment recycling facility in the north-east of England, which uses DES chemistry.
Chief technology officer is Dr Rob Harris, who is also a researcher at the university and is working on making the technology commercially viable.
Dr Harris said, ‘The technology we have developed to tackle the e-waste challenge is very exciting and potentially a real game changer. I feel incredibly honoured and excited to have expert validation in the technology and what we are doing at Descycle.’
Professor Sarah Davies, head of the College of Science and Engineering, commented: ‘Revolutionary chemistry research over the last 20 years at Leicester underpins these new processing technologies that are enabling us to tackle major issues of global significance. Dr Harris’s work demonstrates how the University’s world leading research is making a difference in the world.’
How rhubarb and chicken feed led to e-waste solution
The Deep Eutectic Solvents (DES) class of chemistry, which was developed by University of Leicester scientists in the early 2000s, are a class of non toxic solvents which have high applicability in a wide variety of materials processing, in particular metals. Some of the early combinations included choline chloride, a common chicken feed additive, rhubarb extract and common fertiliser ingredients.
One of the first documented cases of DES having applications in e-waste was when University of Leicester geologists approached the DES inventors at Leicester to design a DES chemistry to recover gold from fossils which had been coated to enable enhanced microscopic visualisation of the fossils’ features, without damaging the underlying fossil. Researchers at the university devised a DES combination which dissolved the gold which left the fossil intact. Since then, these DES chemistries have been tested on a variety of gold concentrates and ores as an alternative cyanide and mercury leaching to great success.
These DES chemistries are now being explored by a number of mining companies seeking a cleaner chemical compound to extract metals, without the risk of the highly pollutive methods traditional mining poses.
Descycle is also actively developing new DES based solutions to a number of metals processing challenges and successful operation of the first commercial DES process for e-waste, will see the DES platform springboarded in mass adoption in these areas, creating new opportunities for exploitation and commercialisation beyond e-waste.