Emissions and Ambitions: EfW’s Carbon Conundrum in the Circular Economy
The waste management sector is at a crossroads, urgently seeking ways to contribute positively to the circular economy. The practice of simply incinerating waste exemplifies a linear economic model, where resources, once burned, cannot be reclaimed or reused. There will always be waste that is beyond redemption, and Energy from Waste (EfW) treatment remains the most appropriate and responsible solution for such materials. Nonetheless, in recent times, the strategy has broadly been to segregate Dry Mixed Recyclables (DMR) and incinerate the remainder. However, the looming application of the Emissions Trading Scheme (ETS) to the EfW sector has sharply drawn attention to the fossil carbon content in the residual waste stream and the sector’s responsibility for its emission into the atmosphere through EfW processes.
The Scale of the Problem
This situation undoubtedly poses a dilemma. The waste streams loaded with problematic carbon, such as textiles and plastics, are not recyclable in the conventional sense. If there were an easy solution or a ready market for these materials, the problem would already have been addressed.
In the UK in 2022, approximately 16 million tonnes of general waste were incinerated. Research by WRAP indicates that household residual waste is comprised of 38% organic material by weight, followed by 18% paper/card, with plastics making up 9%. In the Commercial & Industrial (C&I) waste stream, the proportion of organics is lower, while plastics constitute 23%. Considering these figures, it’s reasonable to estimate that the feedstock for UK EfW facilities includes between two and three million tonnes of plastic that the current recycling sector is unable or unwilling to process.
The Cost and Fate of Removing Plastics
Removing such plastics from waste streams introduces costs. Yet, the more pressing question remains: what becomes of these plastics? These are not clean PET bottles or HDPE trays mistakenly tossed into the waste stream. Rather, they are mixed-polymer laminates, food-contaminated containers, or plastic items with metallic components. Nappies, for example, contain polyethylene or polypropylene along with wood pulp or cotton, and this is before considering their use. Other hygiene products, high in plastic content, are similarly dismissed by traditional recycling operations.
It’s crucial for critics of the waste sector to acknowledge the significant challenges it faces and the pressing need for feasible technological solutions. Extracting 2.5 million tonnes of degraded plastic from the waste pile is one thing; deciding its fate is another. Resorting to landfill would be a step backward, directly contradicting the goals of sustainability. It is quite feasible that a hike in landfill taxes may be necessary to prevent such an outcome.
Innovative Pathways: SAF and Chemical Recycling
Sustainable Aviation Fuel (SAF), produced through pyrolysis to generate syngas which is distilled into jet fuel, represents one innovative pathway. Although this approach is still in its infancy, with three pilot plants underway in Teesside, Ellesmere Port, and Immingham, it signals a potential shift towards more sustainable waste management practices.
Chemical recycling, which includes gasification and pyrolysis to break down polymer chains, offers another enticing solution. These processes provide platform molecules for the plastics manufacturing sector, facilitating the circular economy. With pilot and demonstration plants either in operation or planning, the challenge lies in scaling up such innovations and the necessary investments. The anticipated Quantafuel site in Sunderland, aiming for an annual throughput of 110,000 tonnes, underscores the magnitude of the challenge in treating 2 to 3 million tonnes of waste.
Both SAF and chemical recycling hold the potential to address the issue of contaminated plastics currently destined for landfills or incineration. Yet, these technologies face significant environmental, commercial, and operational hurdles. The path to a truly circular economy is fraught with the failures of companies that have attempted to resolve complex waste issues through novel technologies, only to falter when transitioning from pilot to commercial scale.
Conclusion: Navigating Towards a Sustainable Future
With the implementation of ETS in the UK and Europe, the waste sector must prepare for significant transformations. The lack of a harmonised approach to these schemes could introduce turbulence, affecting waste-derived fuel exporters and the sector at large, necessitating a strategic and adaptable response to these impending regulatory changes.