The dawn of the microfactory
E-waste is the world’s fastest growing waste stream. Globally, about 50 million tonnes of e-waste is expected to be dumped this year, according to the United Nations (UN) Environment Program.
To give you an idea of how valuable this is, a UN investigation into e-waste calculated that an estimated 42 million tonnes of e-waste was thrown away worldwide in 2014 alone, representing a loss to the global economy, in terms of embedded resources, of approximately US $52 billion.
It is, however, difficult to precisely quantify the volumes of e-waste discarded, and its fate, as various loopholes in national and regional waste regulations and controls permit the export of e-waste from developed to developing countries, where dangerous, informal processing takes place.
Volumes processed in this way are largely undocumented. It is well-known, however, that informal processing, like open burning, has serious negative impacts on human health and local environments.
These methods include dismantling e-waste by hand, open burning of printed circuit boards (PCBs), plastic chipping and melting, burning wires to recover copper, acid and cyanide salt leaching and inadequate metallurgical treatments. Low temperature (up to 700 degrees Celsius) pyro-metallurgical approaches, including open burning, incineration and pyrolysis, are known to have a significant environmental impact in terms of hazardous and/or toxic emissions and secondary wastes generated.
At the same time, most of us have various devices just lying around; there are literally millions upon millions of outdated mobile phones in drawers and bags, and old TVs in sheds, all of which contain both valuable resources and potential toxins. So we need safer, cost-effective ways of ensuring we can process e-waste to recover the resources, without putting some of the poorest communities in the world at risk.
So are we doing enough to unlock the residual value from e-waste? Definitely not! We are talking about huge quantities of secondary resources currently locked up in landfills or waste stockpiles/dumps. It is sometimes easiest to look at the issue close up – one tonne of mobile phones (about 6000 handsets), for example, contains about 130 kilograms of copper, 3.5 kilograms of silver, 340 grams of gold and 140 grams of palladium, worth tens of thousands of dollars. E-waste contains between 10 and 20 percent copper, which is at higher concentrations than in virgin ore, so in many circumstances it makes real sense to ‘mine’ waste.
THE MICROFACTORY – HOW DID IT COME ABOUT?
A microfactory is a custom designed small scale unit set up to transform waste into valuable added resources, materials or products. UNSW’s researchers have developed these cost-effective solutions that can be readily sited almost anywhere.
At UNSW, our pilot microfactory on campus is already safely processing potentially toxic e-waste into valuable new products, such as plastic filament for 3D printers. UNSW’s microfactories can also be configured to handle a wide range of mixed and complex wastes that would otherwise go to landfill. Glass that currently cannot be recycled, like laminated safety glass and tempered glass, waste plastics, wood and used textiles are already being used as resources to produce a new range of attractive high quality building products, such as benchtops, flooring and building panels and boards, at a fraction of the cost of conventional products.
As UNSW’s microfactory technology requires minimal training, it offers communities everywhere new opportunities to generate income from waste and to create local jobs, while delivering local and global environmental benefits.
The microfactory concept for e-waste was developed as part of my current ARC Laureate Fellowship. This project focuses on discoveries relating to all types of materials in e-waste and their interactions and micro-recycling science and technologies – which will be translated into world-first microfactories for e-waste recycling.
However, I have been thinking about e-waste solutions for a long time. Growing up in Mumbai,
I used to walk past huge mountains of garbage on the way to school, which supported communities
of rubbish pickers. I imagined what it would take to convert ‘rubbish’ into something more valuable, like resources for industries.
India is one of the big destinations for e-waste for informal processing and really suffers in terms of serious environmental contamination and health risks. So, I have always wanted to develop a new process that could be deployed anywhere e-waste was stockpiled. In effect, I wanted to be able to take the solution to the problem for the first time, virtually anywhere in the world.
This was important for numerous reasons, including giving the poor communities who are carrying out informal processing a new, clean technology that will enable them to safely generate income from e-waste locally. We need to get away from the notion that these communities are mere ‘waste pickers’ and think about the economic and environmental services they do for the planet by recovering waste. With support, and the right kind of technology, their lives could be transformed. The microfactory model and its technology is, of course, just as suitable for major cities with large local supplies of e-waste, municipal regions or remote towns in inland Australia.
The science behind the e-waste microfactory is that by precisely controlling high temperature reactions the various valuable metals alloys can be produced through selective thermal transformation. As we are recycling e-waste in its entirety – as a complex waste mix – we have to take into account the plastics and glass and other impurities, so our target metal products are alloys. As I’ve already mentioned, we are also producing plastic filament for 3D printers from plastic cases, which make up a large proportion of e-waste. The key is to work outside the temperature range at which toxins like furans and dioxins are formed, so the process is safe.
LEARNINGS FROM THE PILOT PROGRAM
We’ve learned that it is possible to recycle e-waste in its entirety using a relatively small furnace that can be deployed almost anywhere, so it is possible to truly clean up e-waste.
We have also learned how important and valuable it is to work in collaboration with businesses and industries. At the SMaRT Centre we now have 22 industry partners; by working closely with them we can understand real world circumstances and markets to deliver practical and commercially viable solutions.
By taking business and industry’s needs into account at the beginning of the innovation chain we build in the momentum that will ensure great discoveries are translated into real world benefits; in our case we are always seeking to marry the economic benefits of a reduction in costs to producers via the use of waste as inputs, with environmental and social gains.
At this stage, the information about levels of investment required to take this forward is currently confidential as licences are being arranged via UNSW’s commercial arm, UNSW Innovations. Anyone interested in setting up a microfactory can, of course, find out more via UNSW Innovations.
My overriding goal is to transform waste to value – this means any and all waste. This sounds ambitious, but what does it mean?
Conventional recycling involves laboriously sorting through the world’s rubbish to extract single streams of the same materials, then reprocessing them back into the same form, such as recycling glass back into more glass. However, as our waste is becoming more and more complex (and toxic) – like waste tyres, mixed plastics, e-waste and auto waste, for example – much of it simply cannot be recycled using such conventional approaches.
We are overcoming the technical and cost barriers of conventional recycling – and so revolutionising recycling science — by looking at waste at its elemental level.
The world’s waste mountains are packed with useful elements like carbon, hydrogen, silicon, titanium and materials like silicon dioxide, titanium dioxide and various metals, that we would otherwise source via mining raw materials, which then need processing. When you look at waste this way, we find we have a previously unimaginable opportunity to transform it into a multitude of new value-added resources for industry, materials for building or manufacturing, and waste-based products.
This ‘urban mining’ approach is especially relevant to cities, as we currently spend huge amounts of money and energy in collecting and trucking or transporting waste away from cities. Instead, we could reprocess much of our waste locally and redirect these resources into industries. That way we would also reduce the need for extractive industries that, likewise, require long distant transport to bring materials to factories.
Our challenge at the SMaRT Centre is to ‘do the science’. This involves building an entirely new portfolio of knowledge, as the success of our processes relies on a precise understanding of how the various elements in waste react at different temperatures, and only with this new knowledge can we control those reactions to achieve our target materials or products.
However, as we progress, ideas build on each other, and new insight gained in one project inform the next project. We now have 22 industry partners – and this is increasing every month. We also have approval and funding for the installation, later this year, of a new demonstration e-waste microfactory on campus at UNSW, the next step on from our current pilot facility.
Veena Sahajwalla is director of Sustainable Materials Research and Technology (SMaRT@UNSW) at UNSW Australia.
This article also appears in Issue 6 of CWS magazine. Get your free, obligation-free trial of the mag here.