The novel coronavirus pandemic boosted the consumption of single-use plastic and highlighted the danger of uncontrolled dumping and open burning, which is the most common waste management practice in Africa and the Middle East. Unmanaged landfills cause the release of toxins and CO2 in the environment. Moreover, open dumps might contaminate water resources and attract animal vectors, leading to the secondary transmission of disease to humans.
In the Middle East and Africa, 53 percent of waste is openly dumped and only about 10 percent is disposed of in a sanitary landfill1. In Sub-Saharan Africa only 1.2 percent of waste ends up in a managed site. The Middle East and Africa still produce less waste compared to other regions; however, waste generation in the MENA region is set to double, and in Sub-Saharan Africa, even triple by 2050. Food and green waste, at 40-60 percent, are the most prominent waste streams in the Middle East and Africa1a.
Together with plastic, the organic fraction makes up 70 percent of the total waste and has a severe negative impact on mankind – by contaminating food worldwide and accelerating global warming. The decay of degradable waste releases a large amount of methane and other green-house-gases (GHGs), which can be converted into equivalent amounts of CO2 emission.
Taking back this significant amount of organic waste and other non-recyclable plastic materials in the framework of circular economy is quite challenging. Compost production from mixed MSW is not advisable as it will be highly contaminated by the glass, plastic pieces, and heavy metals besides others. Only very sophisticated refinement can remove the contaminants.
Biogas production is well proven, but unfortunately, it is a capital-intensive technology. It will harvest energy from the waste; however, there remains the problem of organic fraction disposal, as the total mass is not significantly reduced during the process. More energy can be produced, if the organic fraction together with other combustible parts is transformed into Refuse Derived Fuel (RDF), which can replace fossil fuel for cement or power production.
Cement producers in the MENA region already resort to RDF to reduce fossil fuel dependency and lower CO2 emissions. For instance, it has been calculated that the RDF currently produced in Egypt has a CO2 emission factor that is 37 percent lower as compared to that from coal2. Unfortunately, the quantity of RDF produced in the MENA region is still limited, as RDF is produced by inadequate mechanical means.
Eggersmann Fuel is a new plant concept engineered to divert over 80 percent of MSW from landfills and produce reliable quality RDF. The aim of Eggersmann Fuel is to be sustainable and affordable – first, by converting all the combustible fraction into RDF, including the organic fraction; secondly, by increasing the calorific value of RDF through biological drying and mechanical refinement; and finally reaching an optimal price-quality ratio of the RDF, keeping the process simple.
After pre-shredding to 300 mm, the MSW is transported to the respective bio-drying lane and covered by a special membrane. Biological drying is a drying process that benefits from the natural biodegradation of organic matter by microorganisms that exist in waste. When organic matter is decomposed, heat is produced as part of the metabolic activities.
Eggersmann Fuel uses this natural process, together with membrane cover, pressure aeration, and other components to remove moisture efficiently and reliably from process material in a controlled environment with low energy input. Moreover, biological drying helps prevent SARS-CoV-2 transmission, reaching the sanitisation temperature of 60° Celsius for sufficient duration and protecting waste from animal vectors as well.
For large capacities, the process is enhanced and automated by a Backus Convaero windrow turner that mixes the waste and handles the membrane. After the biological drying, the material is further refined with mechanical screens, metal separators, and density separation to remove any inert and non-combustible matter. Finally, the RDF is shredded to 80 or 50 mm according to the client’s requirements, ready to be co-processed.
The inclusion of organic fraction in RDF helps reduce landfill waste, and it also supports the final user in reducing CO2 emissions, as the combustion of organic matter has zero global warming impact. Calculation with IPCC3 data shows that if a cement producer replaces around 75,000 tons of coal with RDF - generated from 1,500 tons per day of MSW - approximately 800,000 tons per year of CO2 emissions will be saved. The quantity of the CO2 emission equivalent to a city with around 160,000 inhabitants, taking into consideration a worldwide average CO2 production per capita of 4.88 metric tons per year4.
Waste incineration and power generation plants can use RDF produced by Eggersmann Fuel system as well. Biological drying helps to significantly reduce the mass of MSW to be processed and increase the efficiency of the facility.
In 2018, an Eggersmann Fuel Plant with a capacity of 100 tons of MSW per day was installed in Cilacap, Indonesia. The concept is scalable for larger capacities, such as the facility that is currently under commissioning at Sulaymaniyah municipality in Iraq. The plant has been designed to process 1,040 tons of MSW per day and produce around 300 tons RDF per day, reaching an overall landfill diversion up > 80 percent through the inclusion of biological drying. The client, a local cement producer, negotiated a 20-year agreement for receiving waste from the municipality at the agreed tipping fee per ton.
The Sulaymaniyah project is a true example of sustainability, which benefits the overall system. The civil society and municipality can rely on an affordable solution to fight waste accumulation in landfills and groundwater contamination; and the cement producer on reliable quality of RDF, reducing fossil fuel dependency, energy cost and CO2 emissions.
For more information, please contact Sara Dallasta – Sales Manager for Africa & Middle East, Eggersmann Group: s.dallasta@f-e.de.
References
1 & 1a. Kaza, S., Bhada-Tata, P., & Van Woerden, F. (2018). What a Waste: A Global Snapshot of Solid Waste Management to 2050. Washington DC: World Bank.
2. Schwarzböck, T., Lederer, J., Munawar, E., & Fellner, J. (2018). Refuse-Derived Fuels – A Means to Reduce Fossil CO2-Emissions from Cement Plants? "ISWA 2018 World Congress” (pp. 16-17). Kuala Lumpur: Waste Management Association, Malaysia.
3. Intergovernmental Panel on Climate Change (2006). 2006 IPCC Guidelines for National Greenhouse Gases Inventories - Volume 5 - Waste. Hayama: IPCC. & Volume 2 – Energy. Hayama: IPCC.
4. Our World in Data (2019). Per Capita CO2 Emission. Retrieved from Our World in Data: https://ourworldindata.org/grapher/co-emissions-per-capita?tab=chart&country=AUS~CAN~USA~OWID_WRL