Giving green tech a new life

The waste industry is increasingly finding itself at the centre of a great many carbon-reduction strategies, from resource recycling to power production. Chris Smith finds out more. 

Sometimes it’s hard not to be gloomy about the environment, especially when scientists are talking about a climate emergency. But beyond the headlines is some good news: across the waste and resource industries, organisations big and small are already using innovation to help meet net zero targets.

At the most obvious level – and nearer the top of the resource hierarchy –  the waste sector can help a wide range of industries reduce their greenhouse gas (GHG) emissions by providing them with recycled or refurbished materials. In almost all cases, this results in a smaller carbon footprint, although achieving this idyll can be challenging when, frustratingly, it’s sometimes cheaper to mine, process and ship virgin materials instead. But markets are constantly changing and the political and social will to make recycled resources the first choice is certainly there.

When it comes to non-recyclables and materials that have reached the end of their life, we can still help reduce GHG emissions through energy from waste (EfW). It’s a controversial topic: EfW involves burning waste, so despite claims it’s an environmentally friendly power source, in reality it still generates emissions.

Industry leaders say this is still better than sending the material to landfill, where it can decompose and give off methane – a far more potent GHG. Or, worse still, end up in the oceans. Furthermore, emissions limits and monitoring standards are set by the Industrial Emissions Directive (2010/75/EU).

The UK government wants to capture 20-30 million tonnes of CO2 per year by 2030, which is about four to six per cent of our emissions. But, so far, progress has been frustratingly slow.

It’s certainly true that CO2 is generated from incineration, but this is an emission that would have happened anyway, and each megawatt produced in this way is a megawatt that doesn’t have to be produced from a fossil fuel. The perfect solution it is not, but EfW has a role to play in a world where attitudes towards waste and energy are changing at pace. 

A useful adaptation to EfW is adding carbon capture and storage (CCS), so the CO2 produced by EfW can be stored safely and prevented from getting into the atmosphere. It’s something the government has talked about for more than a decade and the UK’s Committee on Climate Change (CCC) agrees that the targets for greenhouse gas emissions – set out in the Paris Agreement – cannot be met without CCS.

The UK government wants to capture 20-30 million tonnes of CO2 per year by 2030, which is about four to six per cent of our emissions. But, so far, progress has been frustratingly slow. CCS is a new technology and difficult to scale. Achieving it needs investment in infrastructure and lots of seed money to create the organisations to do it. The good news is the government published an investor roadmap in April setting out how this is going to happen. We’ll be keeping an eye on this, and will be reporting on its progress. 

There are other ways to mitigate the effects of GHGs produced by waste – even waste that was processed in less enlightened times. Waste disposal firm Biffa is targeting landfill gas as an energy source – methane produced by waste that was disposed of in landfill sites often many years ago. It’s identical to the natural gas in domestic supplies and can be used as a drop-in replacement. 

Again, it’s not a perfect solution – burning landfill gas also emits CO2 but this is not as harmful as methane would have been if vented into the air. And, as with EfW, it stops fossil fuels from being used instead.

Biffa operates more than 90MW of installed generation capacity at 34 sites and is the second-largest generator of electricity from landfill gas in the UK, producing an output of 530GWh in the last financial year. 

Enthusiastic about plastic

Even the most vilified material in the waste industry also has the potential to help lower GHG emissions. Plastic is a big challenge for recyclers, with 1.2 million tonnes still going to landfill every year because scientists have yet to devise ways to break it down faster.

But one innovator is focusing on hydrogen production from plastic that can be used for, among other things, zero-emission vehicles such as waste collection trucks.

Peel NRE, part of Peel L&P, has signed a partnership agreement with low-carbon energy start-up Powerhouse Energy to develop 11 plastic-to-hydrogen facilities across the UK. The first will be built at Peel NRE Protos site at Ellesmere Port in Cheshire.

Richard Barker, development director at Peel NRE says: ‘It’s imperative we deliver creative solutions to the UK’s plastic problem. It’ll mean we can cut down on vehicle movements, create 147 new jobs and deliver essential infrastructure to underpin a North West circular economy that’s much more sustainable.’

Building it big

The big villain in the GHG world is construction, which emits way more CO2 than domestic activity. The construction industry in the UK accounts for the use of 295 million tonnes of virgin material per year, displaces 22 million tonnes of industrial ‘by-product’ and produces approximately 150 million tonnes of construction and demolition waste annually. 

According to the Mineral Products Association, less than a third of this waste (46 million tonnes) is recycled – often as aggregate or hardcore in other building products, such as road construction or land reclamation. While this reduces the amount of material that is landfilled, and reduces the need for virgin materials in new construction, there is definitely room to do better. And the industry knows it.

The construction industry in the UK accounts for the use of 295 million tonnes of virgin material per year…

Noushin Khosravi, sustainable construction manager at The Concrete Centre, says the industry has moved on and is making improvements – from better separation to starting recycling processes earlier in a material’s life-cycle. ‘It’s complex,’ she says.

‘The UK is a very good source of natural aggregate sites. And the carbon is in the cement mix, not the aggregate. The good news is that concrete can be reused as a sub-base for roads and in construction. Transport means emissions so the key is to plan for local re-use.’

She reveals some less well-known innovations: ‘Crushing concrete absorbs a lot of CO2. It’s one of the big developments for the industry. We’re also using a lot of substitutes in cement that come from recycled materials like ash coal from steel blast furnaces.‘

London calling

When it comes to the UK’s biggest city, the Mayor of London and his team are using waste-industry contracting to reduce the carbon footprint of those living in the capital. 

‘The Mayor is determined for London to lead the way in tackling the climate crisis and aims to make London a zero-waste city,’ says a spokesperson. 

‘This means ensuring London sends no biodegradable or recyclable waste to landfill by 2026, and ensuring 65 per cent of London’s waste is recycled by 2030.

‘The Mayor is promoting better public awareness through the London-wide campaign London Recycles and is working closely with the boroughs to increase their recycling rates, as well as improving recycling facilities for Londoners living in flats.’ 

Whether it’s energy or resources, plastic or concrete, the waste industry is involved in so many of the strategies being used to reduce our carbon footprint and tackle the climate emergency that is threatening the future of our planet. The whole system approach is here – and delivering results and setting a standard for other sectors to follow.

As Khosravi says: ‘More industries need to embrace this approach. It’s a really good time to be thinking about this and working together to achieve it.’

This feature first appeared in the Nov/Dec 2022 issue of Circular.

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