How engineered refuse-derived fuel is moving heavy industry away from fossil fuels
By Dominique Kuehner, Industry Director of Biomass, Waste & Industrial, ANDRITZ Feed & Biofuel
Special to The Digest
For decades, the relationship between heavy industry and waste was straightforward: waste was a cost to be managed, a liability to be disposed of as cheaply as possible. That thinking is shifting fast. The EU’s incoming ban on plastic waste exports is just the most visible sign of a broader squeeze: carbon pricing is rising, and the regulatory pressure on waste management – domestic and industrial – is tightening from multiple directions at once.
Materials that were once shipped offshore or sent to landfill are becoming valuable energy carriers. Putting them to work is increasingly a given – doing it well is the challenge.
From liability to fuel
Refuse-derived fuel (RDF) and solid recovered fuel (SRF) sit at the center of this shift. Produced from municipal or industrial solid waste after the removal of organics, metals and glass, these high-calorific materials are finding a growing role as fossil fuel substitutes in cement kilns, steel plants, industrial boilers and lime production. Alongside them, sewage sludge, animal manure and a range of industrial residues are moving in the same direction – from disposal problems to purposeful energy inputs.
The opportunity for energy-intensive industries is tangible. Cement and steel are among the most carbon-intensive sectors on the planet, and both have been using RDF and SRF as a direct coal substitute for years. But substitution rates remain constrained by the availability of prepared, specification-grade material rather than any lack of appetite. The economics are still not perfectly balanced; coal continues to avoid the full weight of its environmental cost, and carbon pricing alone has yet to fully close that gap. But the direction is clear, and the pressure is building.
Policy is following suit. Carbon border adjustment mechanisms (CBAM) are coming into force, and the EU Emissions Trading System is increasing, making the cost of fossil fuel use impossible to ignore. Waste that previously left the continent will need to be processed domestically, and the most logical destination for the high-calorific fraction is industrial energy recovery.
Consistency is everything
Substitution at scale requires consistency. A kiln running at up to 1,450°C cannot tolerate wild swings in calorific value or unexpected contaminants. This is where the chemistry of waste meets the precision of engineering, and where the preparation stage becomes as important as the combustion stage.
Raw municipal waste is, by nature, chaotic. It is variable and full of materials that have no business going near a burner. Turning it into a fuel that cement and steel operators can rely on means imposing order on that chaos, in the form of systematic removal of inert fractions, controlled downsizing, thermal or mechanical drying, and densification into a product with a defined specification. Done properly, the output is a material that efficiently been transported and existing industrial infrastructure can handle without expensive retrofits.
The preparation sequence – from material collection, reception and screening through to shredding, drying and bailing, pelletizing or briquetting – is where the quality of the end fuel is won or lost. A consistent moisture content, a reliable net calorific value, minimal chlorine, and a particle size suited to the target combustion system are the parameters that matter. Together, they determine whether a waste-derived fuel displaces fossil inputs or simply creates a new set of problems for the operators burning it.
A supply chain challenge as much as a technology one
Many industrial offtakers such as cement, steel, and lime are actively looking to increase alternative fuel substitution rates, and are constrained less by willingness than by the availability of prepared, specification-grade material. Closing that gap is a supply chain challenge as much as a technology one.
There is also a broader trajectory worth keeping in mind. The energy transition in waste-derived fuels follows a path that mirrors earlier shifts in the energy industry: from solids towards liquids and gases. RDF and engineered biomass pellets are today’s stepping stone; sustainable aviation fuel, bio-methanol and other advanced liquid or gaseous fuels are the horizon. But the foundational capability – reliably preparing heterogeneous raw materials into consistent, processable intermediates – carries through across all of these. You cannot gasify or liquefy what you have not first cleaned, dried and sized correctly.
The unglamorous work that matters
The infrastructure for waste preparation rarely attracts the same headlines as green hydrogen or carbon capture. But it is doing essential work that makes decarbonization in heavy industry practically achievable rather than theoretically desirable.
With carbon costs rising and fewer places for waste to go, the need for that engineering capability will only grow. The sectors that move early to secure reliable RDF supply chains, and the technology partners that help them build those chains, are positioning themselves well ahead of a changing market. Engineered correctly, waste has a place in the energy system. The infrastructure to put it there is what matters now.
Category: Thought Leadership
