How Waste to Energy can Complement Circularity

By 2050, if current practices are unchecked, municipal solid waste generation per year will nearly double from 2.1 billion tonnes to 3.8 billion tonnes, reports the United Nations Environmental Programme (UNEP). Even more worrisome is that 40 per cent of all this waste is “uncontrolled”, i.e. either dumped into the environment or openly burned, generating planet-warming methane gas and threatening the health and safety of surrounding areas. Fast-growing economies, particularly in Asia and the African continent^*2 with rapidly growing population and consumption, are expected to face particularly acute challenges from mismanaged waste. Horrifying news reports of towering landfills catching fire or collapsing onto nearby residents are unfortunately likely to increase at this rate.

In an ideal world, such landfills will become things of the past as we perfect systems to reduce, reuse, and recycle. But as of today, even with the best technologies, recycling may not be technically and economically feasible for many household rubbish. Such “residual waste” can be brought to landfills, but even when perfectly managed to reduce methane emissions or toxic leakages, they will take up valuable land space, near land-hungry cities. Or they can be brought to waste-to-energy (WtE) plants where rubbish is incinerated, reduced in volume, and turned into resources.

As a European assoication of WtE technologies argue: “Waste-to-Energy offers a holistic approach to resource recovery from non-recyclable, non-hazardous waste; it diverts those wastes from landfills, recovers metals and minerals, and produces renewable energy (from the biodegradable fraction of waste).” ^*3

Although some critics argue that WtE plants can reduce incentives to reduce waste production, the alternatives of mismanaged landfill and open dumping, widespread in many developing countries, are much worse. As a UNEP 2020 report “Waste to Energy: Considerations for Informed Decision-making” points out: “Diverting waste to WtE plants from these landfills, open dumps and open burning can reduce methane generated from waste decomposition.”^*4

There are also concerns that such plants generate health risks when incinerating waste. The UNEP report points out, however, that with advances in modern emission control technologies, harmful air pollutants can be reduced with minimal public health impacts.

Indeed, most of the 1,800 WtE plants in the world can be found in developed countries, particularly ones with relatively high levels of recycling and stringent pollution laws such as Sweden, Germany and Japan. Sweden, for example, sends only 1 per cent of its household waste to landfill. It recycles the remaining half and burns the rest in WtEs to generate district heating to 1.5 million households and 780,000 with electricity, in a population of some 10 million.^*5

For Yokogawa, finding ways to further improve the efficiency of WtE and biomass energy plants has long been an important part of its business and commitment to a carbon-neutral and more circular global economy. Yokogawa’s measurement and control technologies are deployed to improve safety in starting up boilers, ensure efficiency during combustion, optimally mix fuels to stabilize steam production, and eliminate harmful emissions, among other things. They are used not just in WtE plants but in biomass plants which burn, for example, ground rice husks in Thailand, woodchips in Hungary, and poultry litter in Japan to generate electricity.

The company has a track record of providing various control, monitoring and maintenance system solutions for waste and biomass power plants which generate a total of 3 GW of power across the world. It is now expanding its line-up of solutions to meet the need for more efficient plants.

In 2022, Yokogawa purchased Dublix Technology ApS, acquiring the Danish company’s technology for WtE and biomass energy plants. Dublix solutions enhance combustion control and boiler performance, including its “FuzEvent” a combustion-control software solution which enables plants to operate at optimal efficiency around-the-clock.

Such optimization of combustion is particularly useful to overcome the technical challenge of the varying calorific value and moisture content of household waste which leads to fluctuating amounts of steam to turn the turbine, resulting in unstable power generation. Household waste in developing countries have even lower calorific value and higher moisture content than in develop countries, which means Yokogawa and Dublix’s solution will be vital in these growing markets.

Dublix also has jet-based technology – the “DD-Jet system” – to effectively clean the open pass sections of boilers to remove deposits even during operation. Such cleaning improves efficiency while also reducing corrosion, increasing the lifespan, and decreasing unplanned shutdowns for plants. All of these and other solutions can contribute to greater efficiency and more profitable operations of these plants.^*6

In 2023, Yokogawa successfully conducted a performance test at Poland’s largest WtE plant in Krakow where it demonstrated a 2.5 per cent (equivalent to 5,500 tons annually if the plant operates at full capacity) increase in waste incineration, while keeping emissions within government-set limits and ensuring optimal operation of the steam turbine. By increasing plant efficiencies, the Krakow plant has been able to increase its operational availability and profits generated from processing fees based on the volume of waste incinerated.

Dealing with growing waste requires not just better managed landfills or more efficient WtE plants, but a holistic approach. One such is “integrated solid waste management” – a comprehensive, sustainable, and strategic approach to managing all aspects of solid wastes to maximise resource use. Such an approach is expected to bring cleaner and safer neighborhoods, higher resource use efficiency, and savings in waste management costs due to reduced levels of final waste for disposal, among other things, according to a UNEP researcher.^*7

Here too, Yokogawa is working in the field to provide solutions in important markets like India which is tackling its waste challenges in earnest. In 2023, Yokogawa bought a minor stake in Singaporean Ideation 3X, a waste management company with a track record of sorting and recycling of waste as well as generating high-quality alternative fuels from plastics in India.

The two companies hope to deliver more integrated solutions for municipal waste in India. The country has set aside over 500 million USD to clean up at some 3,000 existing legacy landfills in the country and to install new waste facilities and disposal methods based on circular economy principles.^*8 This includes plans for WtE and biomass energy plants which can reduce waste volumes hygienically and with less climate impact, while easing the country’s power shortages.^*9 The Indian government estimates that there is potential in the country for WtE plant capacity of 5 GW, almost 30 times more than the capacity installed today.^*10

Although hurdles remain in widespread adoption of WtE plants – including it being a costly option for waste disposal, particularly in developing countries, and a complicated business model involving establishment of feedstock, advanced technologies, and appropriate regulatory oversight – it remains an important option for many countries fighting runaway waste issues.

As Yonping Zhai, Chief of Energy Sector Group Sustainable Development and Climate Change Department at the Asian Development Bank notes in a 2020 report: “Waste to energy is one of the circular economy solutions that can have economic, social, and environmental co-benefits through efficient use of natural resources, reduced emissions, job creation, and fostering innovation. While advanced thermal technologies provide a high level of sanitation and baseload energy, two-thirds of common municipal waste can be converted to other forms of energy, fuels, chemicals, and fertilizers for higher economic and social impact.”^*11

Working towards this vital impact, Yokogawa’s global network is connecting technologies to meet needs for a smarter and more circular planet.

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References

*1 European Parliament: https://www.europarl.europa.eu/topics/en/article/20151201STO05603/circular-economy-definition-importance-and-benefits#:~:text=The%20circular%20economy%20is%20a,reducing%20waste%20to%20a%20minimum 
*2 UN Environment Programme: https://www.unep.org/resources/global-waste-management-outlook-2024 
*3 ESWET: https://eswet.eu/how-waste-to-energy-contributes-to-the-circular-economy/ 
*4 UN Environment Programme: https://www.unep.org/ietc/resources/publication/waste-energy-considerations-informed-decision-making#:~:text=Landfill%20and%20open%20dumping%20are,methane%20generated%20from%20waste%20decomposition 
*5 Earth Org: https://earth.org/sweden-waste-to-energy/ 
Avfall Sverige: https://www.avfallsverige.se/media/vtldhtom/2021-09-kort-eng.pdf  , https://www.avfallsverige.se/in-english/swedish-waste-management/treatment-methods/#:~:text=Landfill%20is%20the%20treatment%20method,sent%20to%20landfill%20each%20year 
Reasons to be Cheerful: https://reasonstobecheerful.world/waste-to-energy-sweden-power-plants/ 
*6 UN Environment Programme: https://www.unep.org/ietc/resources/publication/waste-energy-considerations-informed-decision-making 
*7 UN Environment Programme: https://sustainabledevelopment.un.org/content/dsd/csd/csd_pdfs/csd-19/learningcentre/presentations/May%202%20am/1%20-%20Memon%20-%20ISWM.pdf 
*8 Bloomberg: https://www.bloomberg.com/features/2022-methane-landfills-south-asia-climate-health-hazard/ 
*9 Reuters: https://www.reuters.com/business/energy/india-projects-biggest-power-shortfall-14-years-june-2024-05-09/ 
*10 Bloomberg: https://www.bloomberg.com/news/features/2023-12-05/how-cop28-could-impact-india-s-waste-to-energy-industry 
*11 Asian Development Bank: https://www.adb.org/sites/default/files/institutional-document/659981/waste-energy-circular-economy-handbook.pdf