Better recycling for LEDs
The EU-funded project CYCLED (Cycling resources embedded in systems containing light emitting diodes) was established to optimise the efficient use and recycling of indium, gallium, rare earth elements (REE), the target metals (TMs) without compromising the well-established recycling paths for precious metals. Project partners therefore investigated ways to save scarce metals in the manufacturing of LEDs and increase the lifetime of LED products. They also explored ways of improving LED design and construction to enable recycling of target metals from end of life LED products. A toolbox was designed to help the resource-efficient design of LED products by providing supporting tools for various design stages ranging from technical design to environmental assessment. Business models were also developed for the valorization of the resource and energy efficient demonstrators developed. Research into the mass flows of TMs identified the rare earth elements (REEs) yttrium and lutetium together with precious metals as the most important elements within white LEDs. They also noted that the recycling of indium and gallium in LED chip production should be promoted, while recycling of these metals from LED products is neither viable nor necessary due to their extremely low concentrations in LED products and the resulting overall very low quantities used in LED products globally. The REE are concentrated in the converters of white LEDs. The consortium found a way to separate the converters from the LED chips. The chips can be processed in the established recycling paths to recycle in particular precious metals and copper. After a pre-treatment removing the organic parts, REE can be recycled in an already existing recycling process from the converters. The cost-benefit analyses of various end-of-life options showed that the REE recycling path can only be profitable for LED products that contain only extremely expensive lutetium converters, while in all other cases, which in practice can hardly be achieved. Overall, REE recycling requires additional funding as otherwise recyclers will not follow this process route. These findings will be used to guide further research and help policymakers to address the relevant waste stream in order to increase the resource efficiency of LED lighting. This will help to preserve valuable resources for other technologies, such as solar power. Studies into the main failure mechanisms of LED products will allow products to have a longer life time, thereby reducing resource consumption. Results of the technical and end-of-life research were used in four demonstrators, involving domestic/ atmospheric lighting, public lighting, industrial lighting and lighting in harsh environments. These were used to show the feasibility of the research result and for disseminating knowledge. The business models supporting the successful commercialisation of the demonstrator products and a generic business model is available to manufacturers of eco-innovative products. The models, toolbox and the technical approaches were brought together in an eco-innovation framework to guide producers of LED products. CYCLED will pave the way towards commercially successful resource-efficient products, create jobs and enable Europe to become a leader in LED technology.
Keywords
Light emitting diodes, CYCLED, target metals, rare earth elements, yttrium, lutetium, waste stream