Cement manufacturing is one of the most energy-intensive sectors, next to iron and steel, and chemicals, consuming approximately 12 EJ globally, which is about 3% of global energy consumption (Source: IEA, 2023). The cement sector also accounts for 7-8% of global GHG emissions, emitting roughly 2.6-2.8 GtCO2 annually. The largest sources of emissions are the calcination process to produce clinker and the fuel combustion to generate the high temperatures required in kilns. The chemical process of calcination accounts for 53% of the total emissions of cement production, while the thermal energy use contributes to 35% (Source McKinsey 2020).
In order to meet this huge energy supply need, producing Refuse-Derived Fuel (RDF) from Municipal Solid Waste (MSW) to substitute fossil fuels in the cement manufacturing plants makes great sense but there are technical limitations:
- Energy content RDF must provide a minimum Net Calorific Value (NCV) to reach a targeted temperature, for example, min. 1,450°C for the main burner of a cement plant, and min. 950°C in the calciner.
- Moisture content: RDF needs to be as dry as possible, for high energy density and ease of grinding and pulverisation and better overall combustion properties.
- Contaminating elements content which may react during the process and impact either the quality of the product or the efficiency of the process. Chlorine may cause coating, blockages in the ducts, refractories damage or corrosion. Sulphur primarily causes operational and environmental headaches, while phosphorus directly threatens the chemical quality and strength of the final cement. Ashes may contain reactive elements such as metal oxides that can affect the quality of cement in the cement industry.
- Polluting elements content which may impact emissions levels. For the most part the heavy metals are hereby incorporated into the cement clinker chemically and mineralogically. The only concern is mercury, which is highly volatile.
In order to harmonise the RDF market, the EU adopted the EN ISO 21640:2021 standards. RDF can be classified as a Solid Recovered Fuel (SRF) if it meets the requirements set out in the table below.ere (e.g. ‘because it destroys pollutants and leaves no residue for landfill’) would resolve it if you’d rather not wait.
Globally, the Thermal Substitution Rate (TSR) — meaning the share of kiln energy coming from alternative fuels rather than coal/petcoke — sits at roughly 8% as a straight global average (source World Economic Forum, 2020). In Europe, the average TSR was around 35% back in 2012 and is now considerably higher, with individual plants in Austria and the Czech Republic operating at close to 100% alternative fuels. This is linked to the introduction of carbon pricing mechanisms and landfilling taxes.
On the other hand developing regions operate on variable scales but lower than in Europe. It is caused by infrastructure and sorting hurdles even if it creates a dual-win solution by tackling two massive challenges simultaneously: municipal solid waste management crises and heavy industrial energy demands. The table below summarises advantages and challenges
| Advantages | Challenges |
| Urban waste crises: many developing countries struggle with overflowing landfills, open dumping, and informal burning of municipal solid waste (MSW). RDF facilities divert non-recyclable combustible materials (plastics, paper, textiles, biomass) away from dumpsites Fossil fuel dependence. RDF offers a cheaper, locally sourced alternative fuel that helps insulate local plants from global fossil fuel price volatility. Carbon Footprint: Because a significant portion of RDF consists of biogenic waste, its use helps lower net greenhouse gas emissions. Job Creation & Formalization: Setting up waste-sorting and RDF preprocessing streams creates formal green jobs, often integrating and upgrading the livelihoods of informal waste pickers into a structured supply chain. | Waste Heterogeneity: municipal waste in developing nations is often unsegregated, high in moisture (due to organic food waste), and contains impurities like glass, grit, and high chlorine content (from PVC plastics) High Upfront Capital Investment: Without subsidies, green climate funds, or international development bank backing, local municipalities or private operators may find the initial investment hard to justify. Economic Competition with Cheap Fossil Fuels: If a developing country heavily subsidizes fossil fuels (such as natural gas or coal), RDF may struggle to compete on raw cost alone unless waste-handling tariffs (gate fees) are introduced to generate alternative revenue streams. Regulatory & Monitoring Gap: Cement plants must strictly monitor air emissions (such as NOx, SOx, heavy metals, and dioxins/furans) when co-processing waste. Weak environmental enforcement or a lack of continuous emission monitoring systems (CEMS) can lead to unintended pollution problems. |
However, the global RDF market is expanding at roughly 8% annually driven by the following factors:
- Emergence of Mandatory Legal Frameworks: Developing nations are moving away from voluntary guidelines toward strict national mandates. For instance, in India, the Solid Waste Management Rules mandate that non-recyclable waste with calorific value above 12,500 kJ/kg should be converted into RDF and supplied to cement plants. Furthermore, from 2031, cement plants located within a 400-kilometre radius of an RDF facility are required to meet at least 15% of their fuel needs through RDF, aligning with the broader objective of transitioning to low-carbon industrial practices.
- Volatile Fossil Fuel Economics: With traditional fossil fuels (coal and petcoke) subject to severe price spikes and heavy import dependencies, cement producers look to RDF not just for green credentials, but as a critical buffer for operational cost control. RDF can deliver a reliable cost advantage over imported coal, particularly as local “tipping fees” (charges for accepting waste) become more common.
- Carbon Pricing and ESG Compliance: As international trade mechanisms—such as the European Union’s Carbon Border Adjustment Mechanism (CBAM)—indirectly penalize carbon-heavy exports from developing countries, local cement makers face immense pressure to lower their clinker-to-cement ratios and cut emissions. Co-processing biogenic-rich RDF is one of the fastest pathways to meet these export compliance standards.
- Technological Maturation: Modular, highly automated mechanical-biological treatment (MBT) plants are becoming cheaper and more accessible. This allows developing regions to bypass building massive, centralized facilities, opting instead for localized waste-sorting modules tailored specifically to cement plant requirements.
Over the next 10 years, the cement industry will probably change quite a lot because of the pressure for decarbonisation. In order to achieve this transformation towards increased resource efficiency, emphasis should be placed on two critical success factors:
- Spatial planning: Because RDF production and co-processing sit at the intersection of municipal waste management and heavy industry, poor geographic alignment can easily kill an otherwise economically viable project. Key leverages points are 1) Managing Transport Logistics and Haulage, Economics 2) Sourcing and Consolidating Waste Feeds, 3) Industrial symbiosis and eco-industrial zones
- Segregated collection: If it proves to be feasible despite the logistic impact and the difficulty to change the residents’ behaviour, implementing segregated waste collection has a transformative and overwhelmingly positive impact on the RDF production in developing countries. Key advantages are: 1) Dramatic Boost in Calorific Value, 2) Lower Capital and Operating Costs, 3 )Enhanced Quality and Environmental Safety 4) Increased RDF yield
In conclusion, RDF co-processing is certainly a sensible option for developing countries. Compared to incineration, it leaves no bottom ashes and is highly effective to destroy organic pollutants because of the higher temperature and the longer time residence. The NIMBY syndrome is often less pronounced. Nevertheless, RDF production should not be a one-size-fits-all solution. It must work jointly with other recovery schemes and should not jeopardize the effort invested in waste sorting and material recovery of the most valuable MSW fractions.
Reading list
- GIZ, “Waste to Energy: A Guide for Decision Makers in Developing and Emerging Countries” (2017 -link)
- Global Cement, “The future of alternative fuels” (2023-link)
- World Economic Forum, “Net-Zero Industry Tracker / Cement” (2024- link)
- European Investment Bank, “Managing refuse-derived and solid recovered fuels” (2024 – link)
- INTECUS GmbH, “Preparation of Refuse-Derived Fuels (RDF) for use in the Cement Industry in Turkey” (2021-link)
