Solid recovered fuels 2.0 – ‘what’s new?’

‘What’s new about solid recovered fuels (SRF)? Is it worthwhile to dedicate a special issue of Waste Management & Research to this topic?’ – These were questions posed to us in the course of compiling this special issue. As a starting point, it helps to refer back on the origins of using waste as a fuel (→ solid recovered fuel) to produce energy and the changes in both the needs for and methods of applying energy from waste technology. The traditional use (or more often the misuse) of garbage or household waste as domestic fuel for kitchen stoves and other house stoves for room heating was commonly practiced in all parts of the world. (Indeed, families still use waste as a fuel in many rural areas of developing countries to this day.) In Europe and other developed countries, the use of solid fuels (mainly coal and wood) for domestic heat supply is declining in favour of increased use of gas and oil as well as heat supply via district heating systems and renewable sources of energy (such as for example on-site solar energy systems or geothermal energy). These changes reduce the potential for misusing waste as solid fuel in domestic appliances for heat supply. Besides the implementation of a few incinerators for municipal solid waste (MSW) starting more than 100 years ago in Europe (aiming at mass and volume reduction of waste but not yet optimized for energy recovery from waste) an approach of large-scale recovery of fuel from waste could be observed in the late 1970s. Around 1980, the prevailing concept in waste management in Middle Europe was to implement and propagate the separate collection of recyclable waste materials and to process the left-over residual waste into scrap iron, waste-derived fuel and materials for composting. In German-speaking countries the waste-derived fuel at that time was known as ‘Brennstoff aus Müll” (BRAM) (i.e. ‘fuel from waste’). In fact, many actors thought to concurrently contribute to environmental protection and save money by producing homemade ‘bio-briquettes’ out of garbage, using simple hand-operated presses. Quite a number of industrial-scale mechanical sorting and separating plants for production of BRAM (e.g. the RINTER plant in Vienna/Austria or the Byker plant in the UK) and other waste fuels started their operations in the early 1980s, but all of them ultimately failed and disappeared from the market. [The situation at that time is thoroughly described in: Brennstoff aus Müll (ThoméKozmiensky, K.J. (ed.)), which was published in 1984, (ISBN 3-924511-00-4)]. Looking back from the present state of the art in modern waste management technologies, the main reasons for failure of the early BRAM-concept become evident. Unrealistic expectations