Introduction
Solid waste affects every single person on the planet. As nations and cities urbanize, develop economically and grow in terms of populations, their residues increase too. The World Bank estimates that waste generation will increase from 2.01 billion tonnes in 2016 to 3.40 billion in 2030. Of this waste, at least 33% is mismanaged through open dumping or burning. Disposing waste in open dumps and landfills without landfill gas collection systems make up for 2% of the total CO2eq produced worldwide. [1]
Poorly managed waste has far-reaching consequences, crossing borders to contaminate groundwater, surface water, land ecosystems, livestock, crops and the air we all share. These pollutants accumulate in the food chain and breast milk, potentially causing effects that span multiple generations. Each year, between 400,000 and 1 million people in the Global South die from diseases linked to improper waste management. [2]
To reduce the production and disposal of waste, the EU has implemented policies to prevent waste generation, promote recycling and reusing, while also setting strict standards for responsible disposal. [3] However, can this waste be used to produce energy or valuable products, giving it a second life? Beyond transforming waste into hydrogen, as seen in earlier discussions, what other pathways exist?
Reutilisation of waste
One promising solution to the waste problem lies in adopting a circular economy. The circular economy seeks to design waste out of the system by keeping materials in use for as long as possible through reuse, recycling, and regeneration. There are currently a few initiatives to revalorise and reuse waste, we can reduce disposal rates and recover valuable resources.
The EU has established a waste policy aimed at maximizing product usage and enforcing stringent guidelines for their proper disposal. This includes the WASTE Framework Directive, which outlines fundamental concepts and definitions related to waste management, such as what constitutes waste, as well as the processes of recycling and recovery. Also, as shown in the image below, it provides a detailed explanation of waste management hierarchy, emphasizing prevention as the preferred option, and sending waste to landfill as the last resort.
In the EU, several initiatives illustrate how the principles of revalorization are applied across sectors. Second-hand shops and reuse centres give consumer goods such as like furniture, clothes, and toys a second life, extending their life cycles and reducing the demand for new production. Secondary materials, including wood, cement, and metals, can be recovered and repurposed for new projects, while, electronic devices are dismantled to recover valuable metals like those in batteries, which are then reused in the manufacturing of new devices. Finally, biowaste produced mostly in the agriculture and food sector is turned into biogas and fertilizers thanks to processes like anaerobic digestion and pyrolysis among others. The next section explores biowaste in more detail, focusing on its potential as a key resource within the broader category of organic waste.
What is organic waste?
Within the broader context of waste management, organic waste stands out due to its inherent value as a source of energy and nutrients. Defined as biodegradable material derived from plants and animals, organic waste (OW) accounts for a significant portion of municipal, agricultural, and industrial waste streams. In the European Union, bio-waste constitutes approximately 34% of municipal waste. [4] This diverse category includes materials such as municipal organic waste, agro-industrial residues, animal manures, and sewage sludge. Its composition varies depending on its source, but it is typically rich in organic compounds, particularly carbon and nitrogen. [5]
Its high biodegradability also means that when mismanaged, OW can quickly decompose, releasing methane, a potent greenhouse gas. Leachates from organic waste can contaminate soil and water, while improper disposal methods, such as burning, contribute to air pollution. Addressing these issues requires innovative solutions that go beyond reducing these risks. If we manage them wisely, we can turn them into new resources.
Organic waste can be transformed into valuable resources through various sustainable technologies:
- Composting is a primary strategy for recycling OW, where organic matter is decomposed into nutrient-rich compost, enhancing soil fertility and structure.
- Thermal treatment such as pyrolysis and gasification convert OW into energy-dense products like biochar and syngas, which have application in agriculture and energy production. It reduces reliance on fossil fuels and lowers greenhouse gas emissions.
- Anaerobic digestion processes OW in oxygen-free environments, generating biogas for renewable energy and digestate for use as a biofertilizer.
- Fermentation is another powerful pathway, converting OW, particularly food and agro-industrial residues, into industrial chemicals such as ethanol or lactic acid.
Through these methods, organic waste is reintegrated into the economy, reducing its environmental impact while contributing to sustainable production cycles.
What is HYIELD going to use?
Effectively valorizing organic waste requires a detailed understanding of its composition, availability, and management challenges. HYIELD addresses these needs through its approach to converting organic waste into green hydrogen. A core aspect of the project involves Work Package 3, which focuses on identifying, characterizing, and managing diverse waste streams to ensure compatibility with HYIELD’s multi-stage gasification technology. This system integrates multiple stages to recover energy efficiently, reduce external heat demands, and produce hydrogen with high purity.
By utilizing diverse organic feedstocks and optimizing energy recovery, HYIELD offers a scalable and cost-effective solution for hydrogen production. The system’s ability to process a wide range of waste streams makes it particularly suitable for industrial applications, offering a dual solution to waste reduction and the transition to cleaner industrial processes.
References
[1] https://datatopics.worldbank.org/what-a-waste/
[2] https://www.unep.org/interactives/beat-waste-pollution/#!
[3] https://www.eea.europa.eu/en/topics/in-depth/waste-and-recycling?size=n_10_n&filters%5B0%5D%5Bfield%5D=readingTime&filters%5B0%5D%5Btype%5D=any&filters%5B0%5D%5Bvalues%5D%5B0%5D%5Bname%5D=All&filters%5B0%5D%5Bvalues%5D%5B0%5D%5BrangeType%5D=fixed&filters%5B1%5D%5Bfield%5D=issued.date&filters%5B1%5D%5Btype%5D=any&filters%5B1%5D%5Bvalues%5D%5B0%5D=Last+5+years&filters%5B2%5D%5Bfield%5D=language&filters%5B2%5D%5Btype%5D=any&filters%5B2%5D%5Bvalues%5D%5B0%5D=en&activeTab=07e50b68-8bf2-4641-ba6b-eda1afd544be
[4] https://www.eea.europa.eu/highlights/reducing-and-recycling-food-and
[5] https://www.sciencedirect.com/science/article/pii/S2589014X23003134
Writer: Zoe Cardell
Editorial: Lucía Salinas
December, 2024
