Mining landfill sites for previously discarded plastics to recover valuable chemicals and liquid fuels is the basis of research at Cranfield University.
Previous work at Cranfield has highlighted that plastic recovered from landfill is not typically suitable for conventional recycling routes. Work is now underway to apply pyrolysis, an advanced thermal treatment process, to produce base chemicals for use in manufacturing or as liquid fuels.
There are over 20,000 landfill sites across the UK. Plastics within closed household waste landfill sites account for around 15-20% of the total waste. However the value and viability of reclaimed plastics is not clear as it is typically low-grade and difficult to recycle economically. Enhanced landfill mining is an emerging area that aims to recover value from such excavated solid waste, a process known as ‘upcycling’.
The concept of enhanced landfill mining is promoted through the European Enhanced Landfill Mining Consortium, (EURELCO), which Cranfield is a founding member of. Maximum value is sought through excavating the waste, recovering value from materials (e.g. rare earth elements, secondary raw materials)and energy-rich commodities (plastic, textiles, paper and card) and by being able to use the resulting land space for further development. Understanding the potential for secondary raw material recovery was explored in a recent project funded by the European Union under the Horizon 2020 programme (SMART GROUND). The use of plastics for direct energy conversion is one option, however, work at Cranfield is seeking to develop more valuable products which would have a greater impact by substituting the use of fuels and chemicals derived from crude oil.
Dr Stuart Wagland, Senior Lecturer in Energy & Environmental Chemistry at Cranfield, said: “There are a number of potential advantages in recovering materials from closed landfill sites. These sites are a long-term environmental burden, requiring careful monitoring and management, with evidence showing that nearby groundwater can be affected. Enhanced landfill mining will effectively reduce this burden, recover valuable materials and enable the use of land for redevelopment.”
“In this project, we are looking at upcycling plastics into base compounds for manufacturing, or for liquid fuels to substitute fuels produced directly from crude oil.”
About Cranfield University
Cranfield is a specialist postgraduate university that is a global leader for education and transformational research in technology and management.
Energy and Power at Cranfield
Cranfield has been a leader in energy and power for 20 years. Our expertise includes low carbon energy supply, power generation, advanced fossil fuel technologies and transport systems. Our teaching and research covers offshore renewables, oil and gas engineering, the production and clean utilisation of fossil fuels, combustion and power generation through to bioenergy and the utilisation of wastes as fuel.
We have long-standing strategic partnerships with Alstom Power, BP, Centrica, Chevron, Doosan Babcock, Dong Energy, Petrofac, Rolls-Royce, Shell, Siemens and many others.
Our world-class facilities include the Structural Integrity Laboratory, which has a wide range of equipment to study the mechanical behaviour of components and material samples up to 250,000 tonnes and has machines unique to any university in Europe, and the Ocean Systems Test Laboratory, designed for model testing at the early stage of marine renewable projects.