Research at Cranfield University is working to understand the potential recovery of valuable chemicals from plastic-containing waste which is not currently recycled. This would divert low-grade plastic waste from landfill to produce chemicals for use in manufacturing or as liquid fuels.
Due to the under capacity of suitable refuse plants in the UK, over three million tonnes per annum (tpa) of potential refuse-derived fuels (RDF) are currently exported.
Locally sourced sustainable alternatives to fossil fuels are crucial as the UK, and the rest of the world, seeks to develop safe waste management and energy security. There is a significant interest in resource recovery, based around a circular economy. The University’s research will support producing high value materials from wastes otherwise destined for landfill or as use as direct energy conversion, that is, power from incineration.
Partnering with Syngas Products and WestAfricaENRG, the research team will demonstrate that RDF and wastes containing low-grade plastic materials, which are currently rejected by material recycling facilities (MRF), can be used in a town-scale pyrolysis plant. Developed by Syngas Products, the plants produce energy, alongside affordable and high-quality liquid fuels, for use as base chemicals in manufacturing. By adding additional processing to the existing Syngas Products technology for waste processing, this ‘upcycling’ approach could be a commercially viable option to solve both the low-grade plastic waste issues and dependency on fossil fuels for transport.
Dr Stuart Wagland, Senior Lecturer in Energy & Environmental Chemistry at Cranfield said: “RDF material is energy-rich and represents a loss-of-resource once it leaves the UK. Similarly, substantial quantities, around 340,000 tpa, of rejected and mixed low-grade plastics from UK MRFs are produced each year, as the market for recovering and recycling this material is not commercially viable. Our research to date shows that through smaller-scale advanced thermal treatment, pyrolysis in this case, products can be recovered in addition to the energy and power.
“To ensure the UK is at the forefront of flexible ATT (advanced thermal treatment) processes we are developing a business case for the commercialisation of the liquid fuels and chemical products in both the UK and internationally. ATT processes are not necessarily rivals with conventional energy from waste technology – combustion, larger-scale facilities play a key role in diverting waste from landfill. However, town-scale advanced thermal treatment facilities are key to developing a diverse and flexible resource management future in the UK.”
In Nigeria, the electricity connection is sporadic and unreliable, which is typical across many developing countries. Therefore, there is a necessity to rely on costly diesel back-up generators. There are low levels of landfill diversion, however, WestAfricaENRG is amongst the more progressive companies and has built and operates a 280,000 tpa MRF in Lagos - the first in West Africa. If rolled-out across Nigeria, the outputs of the waste pyrolysis would provide a 'greener' fuel for the generators, security of power supplies and reduce the reliance on pure fossil-fuels, in addition, stimulate the development of more MRFs in Nigeria.
There is a significant availability of plastic-containing mixed waste streams in the UK and in Nigeria, yet further development is needed to demonstrate ATT on a community scale and to outline a pathway to commercialisation of liquid fuel outputs.It is hoped the knowledge gained from this research could reduce transportation emissions by siting technology locally at a small modular scale, where the waste arises or where there is a need for fuel. It could prevent the use of fossil fuels by utilising the energy from non-recyclable waste, improve security of supply and provide a low cost and sustainable fuel, avoiding the volatility of the oil and gas industry.