Factors influencing the life cycle burdens of the recovery of energy from residual municipal waste

Abstract

a b s t r a c tA life cycle assessment was carried out to assess a selection of the factors influencing the environmental impacts and benefits of incinerating the fraction of municipal waste remaining after source-separation for reuse, recycling, composting or anaerobic digestion. The factors investigated were the extent of any metal and aggregate recovery from the bottom ash, the thermal efficiency of the process, and the conventional fuel for electricity generation displaced by the power generated. The results demonstrate that incineration has significant advantages over landfill with lower impacts from climate change, resource depletion, acidification, eutrophication human toxicity and aquatic ecotoxicity. To maximise the benefits of energy recovery, metals, particularly aluminium, should be reclaimed from the residual bottom ash and the energy recovery stage of the process should be as efficient as possible. The overall environmental benefits/burdens of energy from waste also strongly depend on the source of the power displaced by the energy from waste, with coal giving the greatest benefits and combined cycle turbines fuelled by natural gas the lowest of those considered. Regardless of the conventional power displaced incineration presents a lower environmental burden than landfill.

Methods for the Evaluation of Waste Treatment Processes

“…However, a stable demand for district heat (which requires appropriate infrastructure) or process steam is a prerequisite for the operation of a heatconducted WtE plant. The infrastructure and market for heat and steam are not available everywhere [40]. In contrast, electricity generated in a power-conducted plant can be easily transferred to the grid.…”

Using life cycle assessment in environmental engineering education

“…This flexibility contributes to the complexity of the tools, so the decision was taken to focus on a single activity. LCA is used in waste management to develop and improve waste management services and dedicated waste management LCA packages are available such as the UK's WRATE (Burnley, Coleman, & Peirce, 2015;Turner, Beaven, & Woodman, 2017), Denmark's EASETECH (Laurent et al, 2014) and the USA's DST (Kaplan, Ranjithan, & Barlaz, 2009). Therefore, waste management was selected for the teaching tool and this also meant that LCA could be taught in the context of an existing topic in most environmental engineering and environmental management programmes.…”

“…The model is based on results from the WRATE LCA tool developed by the Environment Agency (Burnley et al, 2015). A series of WRATE runs were carried out to assess the environmental impacts of landfill, incineration, recycling, composting, anaerobic digestion, waste collection and product transport.…”

A Life Cycle Assessment of Energy From Waste and Recycling in a Post-Carbon Future

“…The environmental advantages of EfW over landfill for non-recyclable rMSW have been demonstrated in many LCAs (for example Maalouf and El-Fadel, 2018;Hadzic et al, 2018) for the current energy supply situation. Recovering and recycling aluminium from the EfW ash accounts for a significant proportion of the environmental benefits of EfW (Burnley et al, 2015) and is becoming common practice. Therefore, it was considered necessary to consider the impacts of aluminium production and recycling under the two energy supply scenarios.…”