Developing Best Practice for SRF/RDF

Grabbing an opportunity: the UK has witnessed a dramatic rise in the production of RDF This article addresses Solid Recovered Fuel (SRF) and Refuse Derived Fuel (RDF) best practice in terms of maximising the recovery of organic and recyclable materials from residual waste, as well as its preparation for use as a fuel through a shredding and drying process By Dr Stephen Wise & Dr Adam Read Refuse Derived Fuel (RDF) is the generic term used within the waste management sector to describe a fuel that has been manufactured from 'processing' either municipal or commercial waste via mechanical and/or biological treatment. Within this very broad definition of RDF - Solid Recovered Fuel (SRF) has been defined to a much stricter set of parameters and for which end users have much stricter requirements such as Calorific Value (CV) Moisture Content (MC%) and Chlorine (Cl). To achieve the European definition of SRF will require most waste material to undergo extensive mechanical and/or biological processing to meet the stricter quality parameters. This is in contrast to the broader definition of RDF for which there is no standard or processing requirements. This lack of a standard across the broader RDF market means that it is relatively easy for operators to produce an RDF with minimal processing and investment which has seen a dramatic rise in the production of RDF, for example in UK. This increased production coupled with a lack of standards has seen an increase in environmental and other issues through associated supply chain activities including storage and transportation. Therefore, any additional control on the quality of RDF also needs to take into account these downstream activities to ensure that best practice is achieved throughout the supply chain. Stacking up: a lack of UK capacity for SRF and RDF has led to the development of the export market RDF Market Development To illustrate how the RDF market can develop rapidly, its drivers and associated challenges the development of the UK market has been used. The UK waste market is estimated to be worth approximately £10.5 billion per year according to the Office of National Statistics (ONS). Up until recently the UK waste market has been dominated by the letting of Private Finance Initiative (PFI) contracts by local authorities to collect, treat and dispose of municipal waste. These contracts supported with funding from central government have resulted in the construction of large waste treatment facilities across the UK. This has included the construction of Mechanical Biological Treatment (MBT) facilities in various configurations to produce both RDF and SRF for use both within the UK and the overseas export market as fuel for energy production in dedicated energy recovery facilities or as part of industrial processes such as cement production. However, central government has now withdrawn its financial support from PFI for the letting and construction of any more waste treatment facilities. This was on the premise of believing that there is sufficient municipal waste treatment capacity within the UK to meet the 2020 landfill diversion target set by Europe. With the market for the development of new treatment infrastructure for the municipal sector stalling and the continued increase in landfill tax (as from April 1st 2015 it is £82.60 per tonne) there has been an increased focus on providing additional capacity to treat commercial and industrial (C&I) waste. This has resulted in an increase in the number of merchant facilities being proposed, many of which focus on the production of RDF. WtE plants may require lower input quality fuel than cement kilns due to stricter emission control As there is currently not sufficient capacity within the UK market for the end use of the SRF and RDF, the increase over recent years in the production of SRF and especially RDF has led to the development of the export market. This has led to export routes being developed to countries such as the Netherlands and Germany where there is currently over capacity in the energy from waste market especially in facilities designed to generate energy from municipal waste. As a result, the export market has grown from 0.8 million tonnes in 2012 to 1.6 million tonnes in 2013 and 2.4 million tonnes in 2014, based on information submitted to the Environment Agency. It is expected that this level of export will be maintained until additional energy from waste infrastructure comes on line within the UK offering competitive gate fees. However, this does not reflect the true growth of the RDF market. There is also quantities of RDF that is in storage but not destined for an end user – the grey market which is causing the rise in concerns over the RDF market. As the production of RDF has grown a number of concerns have been justifiably raised relating to the quality of the RDF and a rise in the number of reported environmental and other issues from subsequent storage and transportation both for use within the UK and for export. This includes the failure to extract recyclables such as ferrous, poor management and storage of the RDF such as unsuitable wrapping leading to odours, flies, leachate and more significantly fires. There is also a concern relating to the lack of entry barriers to the market and the subsequent failure and lack of enforcement against those not following the requirements leading to issues such as abandoned sites. A Drive for Quality and Best Practice Quality requirements for RDF are generally set by the end user. For example, if the final destination is a dedicated energy from waste facility the input quality criteria may be low with the waste not requiring pre-treatment. This is because the plant will be operated under strict regulations and be equipped with equipment for removing and cleaning emissions before release to atmosphere. This enables the plant to accept waste with more varied compositions while still achieving the strict emissions criteria as set out in the Industrial Emissions Directive. However, if the RDF is to be used for co-incineration or as part of an industrial process such as cement production then it is in the best interests of that plant to ensure that certain quality criteria are met. This is to avoid technical problems such as corrosion, negative impacts on product or unwanted emissions to atmosphere.It is these higher quality fuels that typically fall under the SRF banner and are likely to be produced under the European EN 15359 standard. However, this does not necessarily address the environmental, storage and transportation criteria but provides fit for use criteria under which the waste can be accepted. And even though this standard may be achieved the SRF is still classified as a waste and moved under the required regulations. It is highly unlikely that any form of European wide standard for RDF will be developed and implemented. As a result it will be down to end users to determine input quality in conjunction with limited and specific definitions such as that for SRF. Many waste to energy facilities within Europe are designed and set up to receive municipal and/or commercial waste with little or no pre treatment and are willing to accept RDF that has undergone minimal treatment. Therefore, they have no interest in implementing higher quality standards. The lack of standards and willingness to accept waste that has received minimal treatment has meant that it is relatively easy both technically and financially for operators to start up and enter the market to ‘treat' waste and produce an RDF. Call for Evidence In 2014 Defra put out a call for evidence in relation to the RDF market. One of the significant issues identified through this process was the lack of quality standards for the production and use of RDF. However, the industry response suggested that there was little appetite to introduce an all-encompassing minimum standard. It was suggested that it should be down to end users to develop and implement suitable specifications to make the waste fit for purpose for their specific requirement. However, a more generally held view within the sector was that it might be beneficial to introduce some form of minimum processing standard. Such a processing requirement would need to cover both municipal and commercial waste used in RDF production. This would potentially need to look at ensuring that the process extracted potentially valuable materials such as ferrous, non ferrous, glass, aggregates, biodegradable content such as organic fines and other potentially valuable materials. Industry feedback from a Defra call for evidence suggests not to introduce a standard for RDF Then more controversially would it need to be more prescriptive to look at elements such as shredding size to ensure a more consistent material is produced? However, approaching the issue just from this perspective fails to take into account the associated downstream issues with storage and transportation which is where most of the environmental issues are being caused. Any standard should therefore have as a core objective minimising the impact on the environment from the whole supply chain and not just one aspect. This would then introduce minimum acceptable standards for storage and transportation to prevent odour, flies, leachate and fires. This type of approach could be implemented more readily through the development of Best Practice Guidance taking into account the current regulations and standards as has been achieved in other industry sectors. However, any measures introduced would also need to be balanced against not introducing significant costs into the supply chain which could lead to waste being disposed of by other less effective methods that may also cause greater harm to the environment. If introduced, an all encompassing RDF standard would need to address the whole supply chain Based on the 2014 Call for Evidence Defra has taken the view that any definition, should it be developed and introduced, should be relatively simple and clear requiring some form of processing but without being overly prescriptive. This overarching approach could provide the basis for a suite of treatment standards such as EN 15359 aimed at specific uses and developed in conjunction with the end users of the fuel. The 'treatment' would also need to be at a level to reflect the change in European Waste Code from mixed municipal waste/ mixed commercial & industrial waste to RDF. As outlined above any standard would need to cover the whole supply chain including storage and transportation and not just be limited to RDF that is exported. Requiring exported RDF to meet standards which do not have to be met by waste generated in the receiving country and which enters the very same plant may simply increase costs for RDF producers with no benefit and could looked as a trade barrier. Supply Chain Perhaps a more successful way of tackling poor quality is to look at the whole supply chain and include production, storage and transportation. This would then provide a focus on other existing regulations such as waste crime, under which storage and transportation is covered. Requiring more stringent permitting or some form of financial guarantee/bond would also assist in improving the standards within the whole supply chain, reduce impact on the environment from issues such as odour and may help to prevent the rogue operators from entering the market and reduce the associated 'grey market'. The designation of incineration as 'recovery' means that waste can cross borders where destined for such plants and current. Non legally binding European Guidance on this allows for the heat used within the plant to be counted when assessing whether a plant qualifies for recovery or disposal meaning that R1 status can be achieved through electricity generation. Perhaps an alternative more challenging threshold based on the amount of heat and power exported and utilised would give greater confidence that where residual waste as RDF is exported for recovery the efficiency of the energy recovery and used would be higher. Conclusion The treatment of municipal and commercial waste to produce RDF is here to stay. However, we are likely to see in the long-term more RDF used within the UK market as additional energy from waste capacity becomes available. Where RDF has been manufactured to a high quality we have already seen its use exploited within the cement industry within the UK, Europe and beyond as a more sustainable alternative to fossil fuel. The RDF sector must look to identify, embrace and maximise these type of opportunities where RDF can become a more sustainable fuel source to support manufacturing and power generation. However, to do this the sector must ensure that it recognises that RDF must be produced in a manner which prevents harm from the environment all the way through the supply chain from production to storage and transportation. While there may be little appetite for more prescriptive standards which would also be difficult to implement it may be time to ensure that a joined up approach is used to develop and implement Best Practice across the RDF supply chain to protect the environment, increase standards and assist in preventing rogue operators from entering the market. Dr Stephen Wise is principal consultant at Ricardo-AEA and Dr. Adam Read is practice director – resource efficiency & waste Management at Ricardo-AEA. PROMOTION: Wrap or Wire? Now Choose Both Cross Wrap, manufacturer for CW Bale Wrappers and Bale Openers, is launching a new model of CW Direct Wrapper. In order to optimise the use of a twin ram baler and a CW Direct Wrapper, Cross Wrap is launching a new model, where the wire tier is combined to the wrapper. This allows the customer to choose if they want to wrap the bales with film not using the wires at all. Another option is to produce specific material bales without a wrap having the bales wired only. The new combination allows to bale recyclables like cardboard and paper, which only need the wiring and no plastic wrap at all and run them through the same line without wrapping so saving the film cost and the investment cost for other equipment. When the customer needs to bale materials like RDF and SRF, which need to wrapped because of the handling, shipping or storage, the wrapping can be chosen instead of wiring, so saving the wiring cost and time. Setting the CW Direct Wrapper combined with the wire tier behind the twin ram baler, the customer can run various type of materials with the same baling and wrapping machinery whether the materials demand only wires and not wrap at all. Choosing the option of only wrapping or only wiring is automatic and quick and can save time and money (www.crosswrap.com) More Waste Management World Articles Waste Management World Issue Archives