FAQs

• C&I – Commercial and Industrial
• CO₂e – Carbon Dioxide Equivalent
• EfW – Energy from Waste
• GHG – Greenhouse Gas
• IBA – Incinerator Bottom Ash
• LCA – Life Cycle Assessment
• RDF – Refuse Derived Fuel
• SRF – Solid Recovered Fuel
• TFS – TransFrontier Shipment of Waste
• WDF – Waste-Derived Fuel

Waste derived fuel (WDF) is a generic term used to describe waste from municipal solid waste (MSW) or commercial sources that is residual (i.e. non-recyclable mixed waste) and has undergone some processing that allows it to be burnt as a fuel to produce energy. WDF is commonly classified into two main categories: Refuse Derived Fuel (RDF); and Solid Recovered Fuel (SRF); both of which undergo a treatment process to meet specific requirements for their end uses. This processing can range from minimal sorting to more complex mechanical and/or biological treatment.

Whilst the RDF Industry Group references RDF in its name, the Group covers all types of WDF including RDF and SRF.

While RDF and SRF share similarities, there are some differences between the two.

RDF typically consists of a mix of non-recyclable waste materials, which have been separated from the general waste stream. The production of RDF involves shredding and sometimes drying to produce a fuel with a relatively consistent energy content.

SRF on the other hand, undergoes a more rigorous sorting and processing such as screening, sorting, and possibly further treatment to remove contaminants and enhance its suitability for use as a fuel. SRF is often more homogenous and contains a higher proportion of combustible materials. It subsequently has a higher quality and energy content compared to RDF.

MSW is collected from households, businesses, and industries and then transported to a sorting facility. Here the waste is separated into different categories. The organic and combustible portions of the waste are shredded into smaller pieces to enhance combustion efficiency. This waste is often dried to reduce the moisture content, as wet waste can be challenging to burn efficiently. Further processing may take place at this point, to remove any remaining non-combustible materials, ensuring a more uniform and consistent product. Quality control measures are employed to ensure that the RDF/SRF meets specific standards for calorific value and moisture content, among other parameters.

The final form taken can vary depending on the specific processing methods used, these can range from loose shredded material to more compacted forms such as pellets or briquettes, which are easier to handle, transport, and store.

See below for a more detailed overview of the supply chain.

Both RDF and SRF are used as alternative fuels in energy from waste (EfW) plants, cement kilns, and industrial boilers to replace traditional fossil fuels. However, SRF is often preferred in applications where higher quality and more consistent fuel characteristics are required, such as in cement production.

Incineration and EfW both refer to the burning of waste. However, EfW goes beyond simple incineration and harnesses the energy expelled during the burning process, to be used for the generation of efficient district heating and/or electricity. As such, EfW has a significant environmental advantage over incineration without energy recovery.

Life Cycle Assessment (LCA) is an evaluation process that allows the environmental impacts and benefits of providing and using goods and services to be determined.  Generally, the results of a range of waste management LCAs show the benefits of material recycling, and that a well-operated EfW has distinct environmental advantages over landfill. The negative impacts of EfW come from the emissions produced during its processes: through the use of energy in the facility itself and direct stack (chimney) emissions to the air.

The environmental benefits of EfW come from a range of different areas. EfW facilities produce energy in the form of electricity and for many facilities, also in the form of heat. This creates a greenhouse gas (GHG) benefit as it displaces carbon-intensive sources of energy production such as coal or gas. In recent years, improvements have additionally been made in the thermal efficiency of EfW, which furthers the environmental contribution of EfW. Some facilities also undertake pre-treatment of the waste before it enters the EfW process, diverting plastics and metals from the residual stream into recycling and shifting this material up the waste hierarchy. The recycling of this material also has a GHG benefit, as it reduces the demand for virgin materials and subsequently the energy needed to create new products. Manufacturing materials from recyclate is often far less energy intensive than manufacturing that begins with raw, generally non-renewable materials. Metals are also recovered and recycled from the incinerator bottom ash (IBA), (the material left once the EfW process is complete), which can also be used in the construction industry.

Nevertheless, waste hierarchy principles must be maintained whereby landfill is the least preferred waste management method and reuse is the most. EfW sits above landfill in the hierarchy, it provides an essential sanitary treatment route for residual waste which otherwise would be landfilled. It is therefore important to consider an LCA approach which not only looks at the overall net benefit of GHG emissions from an EfW facility, but also to compare this to what would otherwise happen to the waste.

By definition, RDF/SRF consists of non-recyclable mixed waste. However, currently in most cases RDF/SRF does contain some recyclable material. This is due to the limited capacity of sorting and separation technology. As these technologies develop into the future, a greater focus on the extraction of recyclable material from the waste stream should be made, to ensure RDF/SRF entering EfW is exclusively non-recyclable.

Residual waste will always be left over from the separation of material for recycling, and incineration with EfW moves this non-recyclable residual material out of landfill. Many Member States do not have sufficient non-landfill residual waste treatment capacity, and as such transport waste to other Member States with excess capacity for EfW. Indeed, this practice is fully supported by the European Commission in its communication on Waste-to-Energy and the circular economy.

Furthermore, the export of waste for efficient recovery as electricity or heat, provides countries with a management stream for this waste, that removes the need for the construction of national capacity. This not only has a negative GHG benefit from the use of construction material, but these facilities will most likely become redundant in a low-waste future.

European Commission, ‘Communication from the Commission to the European Parliament, the Council, European Economic and Social Committee and the Committee of the Regions. The Role of Waste-to Energy in the Circular Economy.’

RDF/SRF is often transported by trucks, especially for shorter distances. For longer distances or large quantities of RDF, rail transport can be more efficient and cost-effective. For international movement of waste, RDF/SRF can be transported via ships, barges or cargo ships carry large quantities of RDF/SRF to ports where it can be further transported by other means.

WDF can be exported under the following European Waste Codes:

• 19 12 10 (Combustible waste – Refuse Derived Fuel); and
• 19 12 12 (other wastes (including mixtures of materials) from mechanical treatment of wastes other than those mentioned in 19 12 11 (hazardous)).

Shipments of WDF are highly controlled and subject to prior written notification and consent in accordance with EU Waste Shipment Regulations. The TransFrontier Shipment of Waste (TFS) system establishes principles of liability and responsibility for waste shipments, ensuring that such movements are conducted in an environmentally sound and legally compliant manner.

Under the TFS system, countries must notify and obtain consent from the importing and transit countries before shipping waste across their borders. This notification and consent procedure helps ensure that all parties involved are aware of, and agree to, the waste shipment and allows importing countries to assess whether they have the capacity to manage the waste safely. Waste shipments under the TFS system require comprehensive documentation, including information about the type and quantity of waste being shipped, its origin and destination, and the method of treatment or disposal. This documentation facilitates tracking and monitoring of waste shipments to ensure they reach their intended destination and are managed in accordance with applicable regulations.

In some Member States, the success of domestic recycling initiatives has led to a reduction in residual waste. As a result, these nations find themselves in a landscape of overcapacity, where facilities previously built to treat higher waste volumes, no longer have the feedstock to support their operations. As such, these Member States import waste from nations with under capacity to ensure this waste is diverted from landfill and managed in a more environmentally preferential manner.

The export of residual waste, that otherwise would have been landfilled, allows a significant amount of material to be moved up the waste hierarchy – a principle enshrined within both UK and EU law.

The movement of WDF allows countries that have insufficient residual waste treatment capacity, to avoid landfill and use energy recovery capacity available in other nations. The additional transport required for WDF is (contrary to popular opinion), only a very small proportion of the overall carbon saved through landfill diversion. Studies have shown that exporting waste for EfW, and keeping it out of landfill, even over distances up to 9,000 km, helps to reduce net greenhouse gas (GHG) emissions. For every tonne of waste that is landfilled in the UK instead of incinerated for electricity and heat in Dutch facilities, an additional 261kg CO₂e is emitted. EfW is therefore not only providing an essential sanitary service to society, but contributing to an overall decrease in emissions when the whole waste management sector is considered.

Furthermore, the export of waste for efficient recovery provides countries with a management stream for this waste, that removes the need for the construction of national capacity. This not only has a negative GHG benefit from the use of construction material, but these facilities will most likely become redundant in a low-waste future.

The RDFIG supports the RDF industry and trade owing to the fact the WDF supply chain plays an important role in helping to solve three major environmental challenges. These include;

• Reducing levels of methane and CO₂ emissions to limit the rate of climate change;
• Ensuring resources are used in a circular (rather than a linear) way so their full value is realised; and
• Reducing fossil energy consumption and supporting energy security.

Methane is responsible for 30% of global warming. A significant source of methane in Europe is landfill, which is responsible for emitting ~80Mt CO₂e annually. The greatest potential for methane reduction in Europe is better solid waste management, with landfill diversion into EfW and recycling as the priority. Although small amounts of landfill capacity will always be needed for some specific waste streams (such as contaminated soils), progress towards the Landfill Directive targets is extremely patchy across Europe. Effective enforcement of existing policy must be prioritised to ensure the Landfill Directive meets its aims and objectives before effort is spent designing new policies. Failure to do so risks new policies having a limited impact due to inadequate enforcement.

The EU (both as a whole political entity, and every individual Member State) has committed to carbon reduction targets under the Paris Agreement, while all EU Member States signed the Global Methane Pledge. Achieving these targets require European and global commitment, demanding a collaborative approach.

The RDF industry offers a means of achieving this however, it must be noted all waste that can be recycled should be, with the remaining non-recyclable waste sent to EfW and kept out of landfill. This should encompass all waste types beyond MSW, including commercial and industrial (C&I) waste.