The doubling of substitute fuel deliveries from Prezero Spain to cement manufacturer Cemex marks more than just a bilateral business expansion. It exemplifies how the energy-intensive cement industry is repositioning itself under decarbonization pressure – and what technical requirements this creates for recycling technology. This is because substitute fuels made from processed waste are increasingly replacing fossil fuels in cement plants, which significantly increases demand for specialized processing plants, crushing machines and sorting technology.
Why cement manufacturers rely on substitute fuels
Cement production is one of the most energy-intensive industrial processes. Rotary kilns reach temperatures of over 1,400 degrees Celsius to burn clinker from limestone, clay and other raw materials – the basis for cement. Traditionally, coal, petroleum coke or natural gas were used for this. However, regulatory requirements for CO2 reduction, rising energy prices and tightened climate targets are forcing the industry to rethink.
Substitute fuels made from processed commercial and municipal waste offer a dual solution here: they reduce direct CO2 emissions compared to fossil fuels and simultaneously reduce energy costs. SBS typically consist of non-recyclable plastics, textiles, wood residues and other high-calorific fractions that can be used as fuel after mechanical processing. The biogenic portion – such as wood or paper – is counted as climate-neutral.
The development at Cemex and Prezero follows a Europe-wide trend. Cement plants in Germany, Austria and Switzerland are already achieving substitution rates of over 70 percent for fossil fuels. Southern European countries are now catching up, driven by EU regulations and national climate targets.
Technical requirements for SBS processing
The production of substitute fuels on an industrial scale places high demands on the technology used. Unlike material recycling, it is not about the purity of individual material fractions, but about defined physical and chemical properties: calorific value, particle size distribution, chlorine content and heavy metal concentration must be within narrow specifications so that cement plants can use the fuels without problems.
The processing chain begins with pre-sorting and removal of contaminants. Mobile and stationary recycling plants remove metals, inert materials and problematic components. This is followed by size reduction in several stages: primary crushers reduce bulky waste to manageable sizes, shredders and tear machines produce the actual fuel fraction with defined particle size.
Modern plants operate with multi-stage screening and air classification systems to separate the high-calorific fraction from mineral components. Magnetic separators and eddy current separators remove ferrous and non-ferrous metals. NIR sorters (near-infrared spectroscopy) enable precise separation by material type to control chlorine content – a critical parameter for cement plants, as excessive chlorine leads to buildup in the rotary kiln.
Quality control and homogenization
Cement plants require consistent fuel quality for stable production processes. Therefore, SBS processing plants include extensive homogenization and quality assurance systems. After processing, fuels are often pelletized or pressed into compact bales to facilitate transport and storage and enable uniform dosing at the cement plant.
These additional processing steps require specialized technology: baling presses with high pressing force, pelletizing systems and automated quality control systems with online analytics for calorific value and composition. Investment costs for a complete SBS processing plant range from single-digit to mid-double-digit million euros depending on capacity.
Which machinery manufacturers benefit
The growing SBS market creates demand in several segments of recycling and processing technology. Manufacturers of size reduction machines are seeing increased demand for robust shredders and crushers that can handle heterogeneous input streams. Machines with high availability and low operating costs are in demand, as margins in SBS production are under pressure due to competition and regulated disposal fees.
Sorting technology providers benefit from the need for precise material separation. Modern SBS plants are increasingly using sensor-based sorting to improve quality and reduce chlorine content. Manufacturers of NIR sorting systems, ballistic separators and air classifiers are accordingly seeing increased demand.
Providers of conveyor technology, screening machines and material handling systems are also in demand, as SBS plants require complex material flows with multiple processing stages. The integration of various components into functioning complete systems is becoming increasingly important – an advantage for systems providers over pure component manufacturers.
Mobile versus stationary solutions
An interesting aspect is the role of mobile processing technology. While large SBS producers like Prezero rely on stationary plants with high throughput, there is also demand for mobile solutions for decentralized pre-treatment or time-limited projects. Mobile crushers and shredders, as known from construction waste recycling, are also used in SBS pre-conditioning.
Technological development is moving towards automation and digitalization. Modern plants use process control systems that capture material properties in real time and automatically adjust machine parameters. Predictive maintenance reduces unplanned downtime – a critical factor when fulfilling long-term supply contracts like those between Prezero and Cemex.
Market development and regulatory drivers
The doubling of delivery volumes between Prezero and Cemex reflects a Europe-wide development. The EU taxonomy for sustainable investments, stricter emissions trading systems and national decarbonization targets increase pressure on the cement industry. At the same time, waste hierarchies and circular economy strategies promote the energetic utilization of non-recyclable waste compared to landfilling.
For recycling companies, this means new business models: instead of just collecting disposal fees, they become fuel suppliers with long-term supply contracts. However, this requires substantial investments in processing technology and quality assurance. Economic viability depends on several factors: disposal fees for input material, revenues from fuel sales, investment costs and operating costs of the plants.
Regulatory development remains an uncertainty factor. While energetic utilization in cement plants is currently considered advantageous compared to fossil fuels, stricter emission limits or changed climate accounting methods could affect economic viability. At the same time, improved mechanical and chemical recycling technologies could in future direct more materials to material recycling and reduce the input stream for SBS.
Outlook: Growth market with challenges
The partnership between Prezero and Cemex shows that the SBS market continues to grow. This creates opportunities for manufacturers of recycling and processing technology, though in an environment with high technical requirements and cost pressure. Success will come to those companies that can offer robust, efficient technology with low operating costs and high availability.
The integration of automation, sensors and digital process control will become a differentiating factor. Equally important is the ability to offer complete system solutions rather than just individual components. Technological development is likely to focus on improved separation precision, higher throughputs and better energy efficiency of machines.
For recycling plant operators, the SBS trend means new business opportunities, but also investment requirements and intensified competition. The quality requirements of the cement industry continue to rise, making modern processing technology indispensable. Those who want to succeed in this market need not only the right machinery, but also expertise in process control, quality management and logistics.
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