Waste for energy, not for the oceans

Myles Kitcher, Peel NRE, part of Peel L&P, UK, looks at the UK’s energy from waste market and how the movement towards net zero is driving change within the industry.

Despite the technology having its critics, energy from waste (EfW) is still widely used across Europe to treat municipal waste. In 2019/2020 in the UK alone, more than 11 million t of waste was collected by local authorities as feedstock for EfW facilities. This was used to generate approximately 7769 GWh of energy, enough to power all the washing machines in the UK for a year.1 However, leading the way is Finland, where over half of the country’s municipal waste was treated in EfW facilities in 2019.2

What is energy from waste?

Put simply, EfW, or energy recovery, is a way of creating energy from material that is no longer useful. While it is generally used to create electricity, it can be used to generate other forms of energy such as hydrogen and syngas.

In addition to energy generation, the technology has benefits for the environment and waste management. It helps to avoid waste going to landfill, which produces methane – a greenhouse gas 25 times more potent than CO2. After treatment, the volume of the waste is significantly reduced, leaving only ash which can be used as an aggregate in the construction industry.

The changing landscape

It is clear that EfW will remain a vital means of managing non-recyclable waste and a source of low carbon energy for the foreseeable future.

However, the landscape is changing which is driving innovation in the sector. With legally binding net zero carbon emissions targets in 2050, it is inevitable that there will be some form of carbon tax introduced, with EfW likely captured by the UK Emissions Trading Scheme (ETS). Like the introduction of the landfill tax, this will drive change within the industry as greater efficiencies and an even lower carbon intensity are sought after.

A carbon tax would drive further innovation in the sector. Removing the non-biogenic fraction from the waste stream will become even more important and increase the focus on plastics. There will be added emphasis on the collection of all plastic, which will increase levels of recycling but also incentivise more effective means of recovering energy from the unrecyclable fraction.

A generation of EfW facilities will soon start coming to the end of their life and this capacity will need replacing, albeit with more efficient and more innovative facilities. This is even more important as the impacts of Brexit mean (quite rightly so) that the UK is dealing with more of its waste on its shores and not exporting the problem overseas. Technologies are still needed to treat waste that cannot be recycled. COVID-19 has highlighted the ongoing role that plastic will have to play in society, for example in PPE and other medical products. Even in a circular economy many products have a finite life.

Driving innovation

Figure 1. Aerial view of the Protos site in Cheshire, UK.

Figure 2. Artist’s impression of the Protos site. This innovation is already starting to happen. At Protos, Peel NRE’s strategic energy and resource hub in Ellesmere Port, Cheshire, UK, the company is developing its first Plastic Park which will deal with a wide range of plastic wastes, providing solutions for materials where recycling has not previously been a viable option. It will cluster together technologies to recycle different types of plastic and recover energy from plastic that has reached the end of its life.

The Protos Plastic Park is set to be the home of the UK’s first plastic-to-hydrogen facility. It will take plastic that would otherwise go to landfill and turn it into hydrogen that can be used in cars, buses, and HGVs, helping to improve local air quality. It will use pioneering DMG technology developed by Powerhouse Energy – a form of advanced thermal conversion technology that takes unrecyclable plastic and recovers the maximum amount of energy. First, the non-recyclable plastics are broken up and shredded into similar size pieces which are fed into a thermal conversion chamber. The plastic is then heated at high temperature in a reduced air environment which prevents combustion. The output at this stage is a clean syngas. Next, the longer chain hydrocarbons in the syngas are broken down into the constituents of methane, hydrogen, and carbon monoxide. The residue from this process is made up of inert material which can be used to construct roads and has the potential to support agriculture. Any remaining contaminants are washed and filtered out in the gas clean-up process, leaving a small volume of brine which can be treated as waste water. When the facility is in full hydrogen production mode, it can process approximately 40 tpd of waste plastic. This is just over one-third of the plastic waste generated in Liverpool, UK, in the same time period. Using this waste, it will generate approximately 2 t of hydrogen – enough fuel for 60 lorries to travel 250 - 300 miles. This is equivalent to 48 MWh which can power over 47 000 homes each day. Providing more front-end sorting and a more sustainable solution for unrecyclable plastics will improve the overall economics and therefore drive higher levels of recycling.

Figure 3. Artist’s impression of plastic-to-hydrogen facility.

The future of energy from waste?

Figure 4. Ince Bio Power – a waste wood gasification plant – at Protos.

Peel NRE has plans to roll out Plastic Parks and the Powerhouse Energy technology across the UK.

Generating low carbon energy

EfW is not going to make huge inroads into energy generation needs. In the first instance it is about finding ways to manage waste more sustainably. If this also creates electricity then great, but if there is a better alternative, such as creating transport fuel to offset diesel or even aviation fuel, then this should be the focus. This is where the circular economy meets net zero.

Increasing efficiency will also bring a greater focus on district heating. Approximately 20% of UK carbon emissions are created by heating buildings and it is simply not feasible to say all heating can be electrified. Combining EfW with district heating could improve the efficiency of a typical facility, while helping developers meet exacting new building regulations.

Carbon capture

Carbon capture and utilisation or storage is something also likely to be seen alongside EfW. The UK Government has committed to creating at least two carbon capture clusters by the mid-2020s and while the focus has been on how this could help industry decarbonise and kick start a hydrogen economy, the role it could play in EfW is starting to become part of the discussion.

Resources and waste management company, Viridor, recently announced that it plans to link into leading hydrogen and carbon capture project HyNet North West to capture carbon at its largest EfW facility in North West England. This is part of the company’s plans to become the first net negative emissions waste company in the UK by 2045.

Peel NRE has partnered with Bioenergy Infrastructure Group (BIG) on the Ince Bioenergy Carbon Capture and Storage project (InBECCS). The project was awarded £250 000 by the Department for Business, Energy & Industrial Strategy (BEIS) as part of the Net Zero Innovation Portfolio. It will fund the design of a carbon capture demonstration facility at Ince Bio Power, the largest waste wood gasification plant in the UK, which is located at Protos.

Ince Bio Power currently takes commercial waste wood which would otherwise go to landfill and uses it to generate enough energy to power over 42 500 homes. The project will use chemical technology from C-Capture to capture over 7000 tpy of carbon. The InBECCS project will pioneer the first negative emissions project in the North West and could be ready as early as 2025.

The EfW sector will continue to evolve. More new technologies will come to market which can maximise the value of waste and reduce the impact of waste management on the environment. As the sector evolves it is important that the industry is given time to prepare. Transitionary procedures, or at the very least, reasonable notice, will be essential to prevent any unintended consequences of an immediate step up in EfW gate fees, such as increased fly tipping. It cannot be forgotten that EfW is primarily there for good sanitation, so any change needs to be carefully managed to ensure that effective waste management is maintained.

Later this year the UK will host the 26th UN Climate Change Conference (COP26) in Glasgow, Scotland. As the first major economy to commit to net zero carbon emissions by 2050, all eyes will be on how the UK plans to deliver on this ambitious target. Home grown technologies such as Powerhouse Energy will demonstrate how the UK is leading, not only on more innovative and sustainable ways to manage waste but also in the production of clean fuels.

There is still a future for EfW but innovation and improvement must continue. If this is achieved, the value from resources will be maximised and it will play an important role in the net zero future.

References

1. Department for Business, Energy & Industrial Strategy, Energy Consumption in the UK (ECUK) 1970 to 2019, (October 2020). 2. Confederation of European Waste-to-Energy Plants, ‘Latest Eurostat Figures: Municipal Waste Treatment 2019’, (March 2021).

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