Cleaner energy from waste

Chris Hudson, Associate Waste Consultant at Stantec

In the UK, nearly 15 million tonnes of residual waste are turned into around 8.6 Terawatts-per-hour (TWh) of electricity every year. This amount of energy registers at just under 3% of our total generation capacity. The process also releases nearly 10 million tonnes of carbon dioxide into the atmosphere.

If we are serious about reaching net zero, we need to cut these carbon emissions in the waste sector. Decarbonisation should certainly focus on reducing the amount of residual waste as well as the amount of fossil carbon through removing plastics for recycling. But the Environmental Services Association (ESA) and individual waste management companies have identified the installation of carbon capture on Energy from Waste (EfW) facilities as an essential component in the fight.

The barriers to the uptake of carbon capture, utilisation, and storage (CCUS) can be split intothree main challenges:Technology, cost, and markets. To date, we don’t have any carbon capture plants developed on EfWs in the UK—and only limited examples overseas—because of these barriers.

Adapting the technology

The technology needed for capturing carbon is well established in the oil and gas sector, but we need to adapt it for installation on EfWs. This can be achieved with a good understanding of the nature of the flue gases and the engineering installation requirements. And while the market for equipment is still emerging, there are other options available. These range from modular predesigned systems to fully bespoke stick-built construction methods.

Installing CCUS processing on individual facilities is more of a technically challenging hurdle to ensure that tapping off and reinjecting gases doesn’t affectthe EfW process. This process amendment requires careful planning and added facility downtime to complete.

Adding a CCUS stage also means we need extra space on site or in surrounding areas, both for physical installation and for any transport links for site servicing and removing the captured carbon.

Incentivising the development of CCUS

CCUS processing is expensive, and the operation needs a large amount of energy. This reduces the amount of electricity we can export and impacts the overall cost of a facility. As a result, CCUS developments have stalled. The Department for Business, Energy & Industrial Strategy (BEIS) has received nine applications for funding, which shows that removing the cost barrier could be the catalyst for CCUS development in the UK.

The recently released consultation on the UK Emissions Trading Scheme (UK ETS) considers bringing EfWs within its remit to reduce or reverse the cost difference. This is so the market can be levelled, and carbon capture is incentivised. This is a notable legislative change and should ensure that facilities with CCUS can compete with non-equipped EfWs.

“Installing CCUS—or having to manage emissions through the ETS— will add to the cost of residual waste management. As difficult as this may be, we need to change how we manage our waste to reach net zero”

However, it is not without its issues. The majority of the EfW fleet serves local authorities under long-term contracts, whose terms will dictate the ability to manage increased costs. Negotiations might be needed to understand how any amendments can pinpoint and distribute risks accordingly. Without accompanying landfill tax increases, this could perversely incentivise driving residual waste down the waste hierarchy—reducing the environmental benefit.

Installing CCUS—or having to manage emissions through the ETS—will add to the cost of residual waste management. As difficult as this may be, we need to change how we manage our waste to reach net zero. But this added cost can only be worthwhile if it supports the decarbonisation of the waste sector and developing markets for captured CO₂.

Developing our markets 

BEIS is supporting two CCUS clusters: Northern Endurance Partnership’s East Coast Cluster covering the industrial areas around the Humber and Tees estuaries; and HyNet North-West cluster, covering the Mersey and Deeside industrial areas. Phase 1 supported developing infrastructure to transport, compress, and store captured carbon. For the EfWs located around these clusters, there is relatively robust infrastructure and sites for captured carbon, as well as potential for connecting pipelines.

For the vast majority of EfW facilities found elsewhere, their location could be a problem and limits their ability to connect to the cluster. The clusters’ capacity to deal with facilities from outside their regions is also limited. We could look at developing further cluster locations in the future(such as potentially Aberdeen), however there are limited suitable locations for injecting carbon dioxide—and these do not necessarily align with EfW locations.

But finding outlets to store our captured CO₂ is a major consideration when we explore future implementation at EfW sites. Securing permanent or long-term sequestration is essential. The most prevalent form of storage is injecting CO₂ into hydrocarbon reservoirs to increase oil and gas yields. However, this contradicts our intention to reduce atmospheric CO₂ as we lose the benefit of sequestered carbon through the processing and use of the added yield.

There are other uses being developed for CO_2, such as mineralisation, that could be commercially viable. Other options tend to be stymied by either being too early in development (carbon nanotubes); excessively expensiveor relative costs(methanol replacement); low volume and therefore less reliable as a firm market (food & drinks); or only temporary storage (alternative fuels).

Uses of Carbon Dioxide

Breaking down barriers

The barriers to developing CCUS on a wider scale are breaking down steadily. We understand the technology issues relatively welland legislative change is flattening the cost difference.

The greatest barrier to adopting EfW will be identifying how we use the carbon we capture. As CCUS moves from ‘something we should consider’ to ‘considering how we do it’, we need to find uses for CO₂ that are commercially viable and scalable to maintain interest and momentum. If not, the waste industry could be left with a series of ETS targets that it may not be able to meet.

By considering sites, engineering, and consenting challenges within a comprehensive feasibility study or business case, we can get easier access to funding and CO₂ markets. Organisations will be able to react faster to market developments where there is a firm underpinning and support for them. They could also gain competitive advantage in securing what may be limited capacity for CO₂ offtake.

Storage

Construction