Current technologies for the management of municipal solid waste (MSW) are unsustainable, especially with escalating environmental concerns and resource depletion. The priority is to find sustainable and efficient methods to recover resources from waste. This research aims to investigate the potential of pyrolysis for value recovery from MSW. The study specifically focuses on the pyrolysis of solid recovered fuel (SRF), a more homogeneous form of MSW prepared by extracting recyclable materials, shredding, and mixing.
The methodology involved SRF characterisation, a series of laboratory-scale pyrolysis experiments and product analysis. These experiments investigated the relationship between SRF composition and the pyrolysis product. Thermal and microwave pyrolysis were investigated. Microwave pyrolysis demonstrated that it could overcome some limitations of thermal pyrolysis, by providing faster heat transfer and limiting secondary reactions. Key findings include that the plastic component of SRF improves the recovery potential of pyrolysis products, with the pyrolysis gas containing significant amounts of C2-C4 hydrocarbons, providing substantial energy content. The wax formation in the oil occurred under low heating rate pyrolysis and was found to contain BTEX and styrene, indicating enhanced potential for chemical recovery. The presence of inorganic elements in SRF, however, disrupted the pyrolysis process, reducing the value recovery potential.
The laboratory data were analysed within a circular economy framework, demonstrated that the multi-conversion of SRF components into pyrolysis products facilitates their downstream utilisation in value recovery, enhancing closed-loop resource management. Insights obtained from experiments were compiled into the fate of elements and compounds, summarising important reaction pathways during SRF pyrolysis.
This research confirmed that pyrolysis is a viable technology for the enhanced recovery of resources from SRF. The study highlighted the importance of optimising pyrolysis conditions and addressing the challenges posed by inorganic materials to maximise the recovery potential in waste management and thus achieving circular economy aspiration.