The case for decarbonising EfW

The concept of carbon capture alongside energy from waste is controversial but may, writes Kai Malloy, offer the only hope for the sector to hit net zero by 2050.

With its proponents claiming that carbon capture, utilisation and storage (CCUS) alongside energy from waste (EfW) will be key to the UK reaching net-zero and its opponents objecting to waste-to-energy in principle, the field of debate is unequivocally split. However, all will agree that reaching consensus will be critical to dealing with the ongoing problem of residual waste without contributing to the, some might say, more urgent issue of greenhouse gas (GHG) emissions.

Cardiff EfWThe Department of Business, Energy, and Industrial Strategy (BEIS) estimated that, in 2019, the waste sector was responsible for four per cent of the UK’s total GHG emissions. And, whilst the vast majority of these came from landfill, the Climate Change Committee (CCC) clarified that – in the same year – EfW accounted for around 16 per cent of GHG emissions for the whole waste industry. With the waste sector under mounting pressure to meet Net Zero targets, focus is zeroing in on EfW and how to reduce its considerable impact.

In its ‘Progress in reducing emissions 2021‘ report, the CCC also identified the decarbonisation of EfW as a field to be addressed with urgency, positioning the retrofit and installation of CCUS into incineration facilities as essential to achieving Net Zero in the UK. Eunomia agrees,
capitulating that CCUS ‘offers the only current viable solution to large-scale CO2 abatement of the UK EfW fleet’.

Taking a wider view, the International Energy Agency has claimed that CCUS deployment rate must increase by 50 per cent if the world is to reach Net Zero by 2050.

Conversely, the United Kingdom Without Incineration Network (UKWIN) opposes the entire premise of CCUS alongside EfW, referring to it not as carbon capture, but rather ‘carbon recapture’ – using energy and resources to extract newly created CO2 from the burning of waste that was already acting as a carbon store. The body naturally also opposes the additional energy required to compress, transport and store the carbon obtained, as well as the lock-in effect that comes with investing further into an undesirable solution, which might undermine efforts to minimise residual waste arisings. As such, UKWIN encourages the phasing out of incineration as part of a ‘coordinated and strategic incineration exit strategy’, in order for Net Zero goals to be achieved. The question is, do the two need to be mutually exclusive?

Many companies, including Eunomia, do not believe that CCUS makes EfW ‘desirable’ and are instead clear that CCUS should be seen ‘as a transitional technology until such time that EfW is not required’. Whilst residual waste remains an issue, they say, it continues to serve a purpose.

Implementing CCUS infrastructure must be seen alongside the transition towards a circular economy in order for Net Zero targets to be achieved. Eunomia cites legislation within the Environment Bill – such as Deposit Return Schemes and Extended Producer Responsibility – as the main impetus towards carbon neutrality; lessening the amount of material that needs to be burnt. Necessarily, therefore, the methods and costs associated with implementing CCUS at EfW facilities need to reflect the transitional nature of the ‘solution’.

The cost of capture

The two main ways of capturing carbon are, according to Eunomia, pre-combustion (where fossil fuel is reacted with oxygen, air or steam and then put through a catalytic process to remove the CO2) and post-combustion (where CO2 is removed from flue gases), with the latter most suitable for EfW as it can be retrofitted to existing facilities to capture approximately 90 per cent of the CO2 in the flue gas. The most promising technology of its kind, Eunomia states, is an absorption process that uses chemical solvents, such as monoethanolamine (MEA). The capture and subsequent compression of the CO2 does, however, incur an ‘energy loss’, which can be as much as 20 per cent of the output of the facility.

Once captured, carbon would be transported by pipeline, ship, truck and rail and injected into deep geological formations – such as saline aquifers and depleted oil and gas fields – for storage. The Sleipner Vest field – the world’s first offshore CCS plant – is an example of successful carbon sequestration, with the Norwegian facility having harboured over 20 MtCO2 since its opening.

Government policy anticipates that CCUS will initially be developed in ‘clusters’ around industrial emitters that have access to offshore storage locations, with 15 of the UK’s total 48 EfW facilities within 30km of one of the five planned clusters. A further 14 sit within 30km of one of the port hubs identified for CCUS development in the second phase of rollout. A final phase would see CCUS technology fitted to all remaining EfW facilities where deemed feasible. It should be possible, Eunomia states, to retrofit CCUS technology across all EfW facilities.

With regard to cost, Eunomia cites boiler efficiency, the use of combined heat and power (CHP), and the type of emission reduction equipment fitted as factors that could affect cost universally. On a site-specific level, the size and location of the plant have the largest financial impact. Eunomia estimates that the additional cost of CCUS ranges from £66/tCO2 to £110/tCO2 depending on proximity to transport and storage solutions.

Whilst conceding the benefit of long-term storage of carbon from a limited number of incinerators, UKWIN asserts that investment would be better directed towards the establishment of an incineration exit strategy in order to support the circular economy. In a report for Zero Waste Europe, Schlomo Dowen – national coordinator of UKWIN – says “CCS for municipal waste incinerators would come with significant opportunity costs, undermining more systemic change to resource and waste management, as well as creating perverse incentives to incinerate material that should otherwise be reduced, reused or recycled.”

Where are we now?

In spite of protestations from anti-incineration bodies, the Government has recently announced two clusters that will be used as pilots for public investment in CCUS. Users will share pipeline and sequestering capacity, with storage located 0.8 – 3km below sea level, in depleted gas reservoirs. The National Infrastructure Commission has said plans could be expanded beyond coastal clusters, to serve plants further inland.

It is clear that the early stages of UK CCUS development are well underway, though questions remain around how infrastructure will be scaled up to rival projects such as Sleipner. The CCSA states that upscaling will be highly dependent on ‘the development of a supportive policy environment that drives innovation and market scale adoption of technologies’. With the majority of EfWs being located near to the waste sources that they treat, far from CCUS clusters, expansion of carbon capture will meet logistical challenges without government intervention.

This article was taken from Issue 102

In spite of this, innovations being forged in the carbon capture industry are beginning to unpick these issues. Founded in 2009, Carbon Clean is a company that has developed cheaper and more accessible CCS technology. Their modular system is designed to be retrofitted and makes it much easier for facilities to scale up their CCS operations, bringing CCS ‘within reach of a greater number of EfW and industrial emitters’, according to the CCSA. Depending on the rollout of the appropriate regulatory and policy-based framework, scaleable CCS such as Carbon Clean, could be fitted to EfW facilities as early as 2025.

The potential

If carbon storage is scaled up to the degree anticipated by Eunomia in its ‘CCUS Development Pathway for the EfW Sector’ report, just under 5 million tCO2 will be captured by the end of the first phase (2030), when all EfW facilities in close proximity to CCUS clusters are assumed to be fitted with CCUS technology. By the end of the second phase (2040), targeting port hubs, this amount should reach 9.4 million tCO2. Once all operational and under construction EfWs are fitted with CCUS (by 2050), this figure should sit at 16.4 million tCO2. This, according to the CCC, represents roughly half the waste sector’s total emissions in 2018; significantly above EfW’s current 16 per cent share.

UKWIN remains sceptical of the ability for CCUS to be upscaled to this degree, citing ‘the technological uncertainties, the prohibitive costs, and the lack of social acceptance of anything that would perpetuate the current unsustainable level of incineration’ as forces that will limit carbon capture expansion to a small number of demonstrator projects.

However, if the potential to scale up CCUS to the extent envisaged by Eunomia is realised, with opponents reassured by a committed exit strategy to mitigate any lock-in effect, then a significant step towards achieving Net Zero across the resource sector could be made.