By 2035 EU Member States will be permitted to dispose of no more than 10% of their MSW to landfill, but large quantities remain unrecyclable. To ‘square this circle’, both ESWET and CEWEP have recently outlined the long-term need for waste to energy.
As Europe prepares to accelerate its move away from the landfilling of Municipal Solid Waste (MSW) and towards a more circular economy, the Confederation of European Waste-to-Energy Plants (CEWEP) unveiled its first ever ‘Waste-to-Energy Sustainability Roadmap’ to more than 100 European policymakers, stakeholders and industry representatives in Brussels. The document details how the industry provides essential services to society, and offers a vision for the sector to 2035.
“We cannot talk about the circular economy in 2035 without talking about how to keep the material cycles clean, how to make sure that all the waste that cannot be recycled is still treated securely and that all the value inherent in the residual waste, energy and materials is used,” explains Paul De Bruycker, the President of CEWEP. “In other words, as the waste to energy sector, we feel at home in the circular economy, we are and we will be needed.”
At the same event, fellow trade association the European Suppliers of Waste-to-Energy Technology (ESWET) launched its vision entitled ‘Waste-to-Energy 2050: clean technologies for sustainable waste management’. The document explains that when waste to energy technologies treat residual waste that is not fit for reuse or recycling, such as contaminated biomass including wood treated with preservatives, it combines the effects of landfill diversion, improved materials and energy recovery into a considerable sink for carbon emissions.
We Need to Talk About Residual Waste
In July this year, CEWEP launched its Circular Economy Calculation Tool (See WMW Story). It was accompanied by the tag line “Spoiler alert: residual waste will not disappear by 2035”– an unfortunate truth that will come as no surprise to anyone in the waste industry.
According to its calculations, if all the waste targets set by EU waste laws adopted in 2018 are reached on time, by 2035 Europe will still produce around 142 million tonnes of residual waste that will need treatment – not landfilling. Current waste to energy capacity is 90 million tonnes and the capacity for co-incineration is around 11 million tonnes. This leaves a gap of around 40 million tonnes.
The roadmap argues that many of the products used in society are not designed to be robust, easily repaired or upgraded and are often made from mixed materials which cannot be easily recycled. While everything should be done to adopt new technologies and policies which minimise waste creation, current production methods and consumption patterns will continue to generate residual waste which is contaminated or too low quality to recycle. While there are already some moves towards a more circular model, product design will not be reinvented overnight.
Both CEWEP and ESWET also point out difficulties in recycling some materials due to contamination with often low levels of potentially dangerous contaminants. For example, while plastic waste is not a desirable input from an environmental point of view, as it contributes to fossil CO2 emissions, WtE plants accept residual plastic waste as a service to society in order to help prevent landfilling and its exports to countries with lower environmental and social standards.
Plastic wastes can also contain toxic elements, e.g. phthalates, flame retardants, heavy metals and persistent organic pollutants, which can only be destroyed at high temperatures in controlled conditions. In these cases, WtE plants can act as a sink for pollutants by removing these substances from the circular economy. They also help avoid marine and soil pollution with nano-, micro- and macroplastics.
In the future, better and more widespread source-separated collection of waste is expected to help reduce mixed waste streams. European waste legislation supports this trend. However, taking into account the demographic and economic changes which will impact the amount of waste produced, it is unclear how much of a reduction in waste generation is truly feasible. This question is also raised in the recent World Bank publication ‘What a Waste 2.0: A Global Snapshot of Solid Waste Management to 2050’.
In addressing the continued challenges of residual waste, energy recovery will certainly have to provide essential treatment where recycling is not appropriate.
Bottom Ash – A Golden Opportunity
The recovery of metals from bottom ash is a well-trodden path to both additional environmental benefits and revenue from WtE. But that’s not where the story ends. Technological processes are advancing to the point where it is increasingly possible to recover significant amounts of materials from bottom ashes, including minerals and precious metals. According to ESWET, estimates show that, in the Netherlands alone, bottom ashes contain gold with a value of approximately €27 million. Tapping into such a source of precious metals would allow operators to increase their revenues by opening a new, local stream of secondary raw materials.
In its 2050 vision, the organisation highlights state-of-the-art bottom ash treatment at an HVC plant in Alkmaar in the Netherlands, which has implemented technology from Dutch soil and sediment washing specialist Boskalis Environmental to recover several materials in various fractions up to a very fine sand fraction. The fully integrated dry reprocessing and wet washing of bottom ash separates significantly higher amounts of ferrous and non-ferrous materials such as copper, gold, lead and aluminium, and produces a freely applicable building material from the sand and granulate that is separated.
However, while the recovered metals are counted towards recycling targets, the recycling of the mineral fraction of bottom ash does not have the same recognition, even though raw materials like sand and gravel that would be needed in various construction applications are replaced in this manner. CEWEP too is working with policymakers to have recovered minerals recognised in the same way as metals, which it says could help to address concerns raised by the United Nations Environment Programme (UNEP) about the high volume of virgin sand and gravel being extracted from the natural environment.
Decentralise and Decarbonise
ESWET’s vision for the future sees an increasingly decentralised network, with waste to energy plants able to process waste locally and deliver energy in the form of electricity, heating and cooling to local users. “The EU energy system will become more decentralised, decarbonised and more locally integrated and society will become more circular – in order to achieve a climate-neutral economy by 2050,” it says.
To negate the need to match energy generation to the demand of grid-connected users, some waste to energy plants will store the energy they produce in the form of fuels such as hydrogen, or through the desalination of water.
CEWEP offers the example of the German city of Wuppertal, where 10 new fuel cell powered buses took to the road in 2019. The vehicles use emission-free hydrogen gas produced locally, using electrolysers powered by the city’s AWG waste to energy plant with a hydrogen filling station located nearby. The development is an important first step towards diesel-free public transportation and electromobility as well as improving air quality. It’s not the first time AWG has aimed for better air quality and greater energy efficiency. In 2018, the district heating network in Wuppertal was connected to the WtE plant. At the same time, a coal-fired power plant in the Wuppertal valley was shut down. The combined effect was a considerable reduction in CO2 emissions and other pollutants.
There will also be greater implementation of carbon capture techniques. For example,
Dutch waste to energy firm AVR has recently completed an upgrade to cut the GHG emissions from its facility in Duiven by supplying a local horticultural greenhouse with CO2 to promote plant growth. It is the first waste to energy plant in Europe able to capture CO2 on such a large scale and emitted around 7500 fewer tonnes of carbon dioxide than usual over the past month.
Flue gases from incineration are fed to the new installation via a pipe. The CO2 is removed by means of a liquid that is then heated to release pure CO2, which can be cooled and compressed into a liquid for storage in one of four tanks. French industrial gas specialist Air Liquide transports that CO2 to the greenhouses, where it is used to boost the growth of crops such as tomatoes, fruit and flowers. Traditionally this has been produced by burning natural gas, but that is no longer necessary.
The Duiven waste to energy plant processes waste from 1.5 million households, releasing around 400,000 tonnes of CO2. With the new process AVR can now reuse 60,000 tonnes of this.
“Waste burners all over Europe are now looking at us,” says
AVR Manager Robert Hageman. “We notice that there is a lot of interest from Sweden, Switzerland, Denmark and Germany. They have already visited and are closely following our new installation. And we are more than willing to share our knowledge.”
A Call to Policymakers
Both ESWET and CEWEP offer a number of key calls to policymakers. First among these is the need to recognise waste to energy as an essential part of a circular economy, and to apply the waste hierarchy based on circular economy thinking. Diverting waste from landfills is an essential step in moving waste treatment up the waste hierarchy. Legislation also needs to set targets for landfill diversion and recycling for commercial and industrial waste.
Another recommendation is to increase trust in recycled products. The problem of substances polluting recycled products is often highlighted as a hindrance in their uptake. For example, ESWET cites a recent study from the Health and Environmental Alliance, ‘Toxic Soup – Dioxins in Plastic Toys’, which showed high levels of brominated dioxins in toys made of recycled plastic stemming from electronic waste. Quantitative recycling targets are therefore not enough to achieve a truly circular economy. They need to be complemented with qualitative targets in order to boost confidence in secondary raw materials, which still suffer from a poor reputation.
In this regard CEWEP recommends that further policy developments must “recognise WtE’s key role for treating waste that is contaminated with substances which are not fit for recycling.”
The organisations also agree on the need for new EU waste legislation to allow Member States to count the mineral fraction of the bottom ash against their recycling targets. EU-level incentives to allow the materials from bottom ash to re-enter the material loop are needed.
Perhaps most importantly, the organisations call for recognition of waste to energy’s role in mitigating climate change. ESWET notes that waste to energy offsets GHG emissions that would have been emitted by other sectors thanks to the diversion of waste from landfills, the production of energy that would otherwise be generated by fossil fuel-powered plants and the recycling of metals and minerals.
CEWEP meanwhile calculates that WtE plants could produce 190 TWh of energy by 2035, enough to supply more than 50 million people with heat and electricity and to replace 10% of the energy supplied by the coal sector today. In many European cities, WtE contributes significantly to district heating networks (about 90 TWh per year). There is a major opportunity for further improvement by linking more heat or process steam customers to WtE plants. The Heat Road Map Europe 2050 suggests that the potential is 200 TWh per year by 2050 for heat alone.
CEWEP says that its Sustainability Roadmap demonstrates the industry’s commitment to waste recovery and clean energy production, as well as its role in reducing environmental pollution and creating skilled jobs. Its goal is for a well-functioning circular economy by 2035 where quality recycling is steadily increasing and landfilling is minimised.
To achieve this, waste to energy has an essential function and must be recognised as an enabler of the circular economy.
“Our industry has made giant leaps towards sustainability in the past decades,” concludes ESWET President Edmund Fleck. “We see a bright future for waste to energy, where all by-products of our industry will be sent back to the economy in a low-carbon, circular way. We need policy support for that future to become a reality and such policies must ensure that basic waste management principles such as the waste hierarchy are safeguarded and a low carbon and clean circular economy emerges.”