The crucial role of Waste-to-Energy technologies in enhanced landfill mining: a technology review

The novel concepts Enhanced Waste Management (EWM) and Enhanced Landfill Mining (ELFM) intend to place landfilling of waste in a sustainable context. The state of the technology is an important factor in determining the most suitable moment to valorize – either as materials (Waste-to-Product, WtP) or as energy (Waste-to-Energy, WtE) – certain landfill waste streams. The present paper reviews thermochemical technologies (incineration, gasification, pyrolysis, plasma technologies, combinations) for energetic valorization of calorific waste streams, with focus on municipal solid waste (MSW), possibly processed into refuse derived fuel (RDF). The potential and suitability of these thermochemical technologies for ELFM applications are discussed. From this review it is clear that process and waste have to be closely matched, and that some thermochemical processes succeed in recovering both materials and energy from waste. Plasma gasification/vitrification is a viable candidate for combined energy and material valorization, its technical feasibility for MSW/RDF applications (including excavated waste) has been proven on installations ranging from pilot to full scale. The continued advances that are being made in process control and process efficiency are expected to improve the commercial viability of these advanced thermochemical conversion technologies in the near future.