Landfill gas and an ORC help future proof Häradsudden
In Sweden, waste management major Ragn-Sells Group converted a diesel-powered waste sorting line at its Häradsudden site in Norrköping to an all-electric one thereby reducing carbon dioxide (CO2) emissions by approximately 150 tonnes annually. The electricity is produced on-site using landfill gas (LFG) as fuel and future-proofed with an Organic Rankine Cycle (ORC) turbine.
Häradsudden outside Norrköping is one of Sweden’s largest privately-held commercial and municipal waste recycling and processing facilities. With the exception of medical– and hazardous wastes, Häradsudden has a permit to handle all kinds of solid commercial, industrial and household waste such as contaminated soil, organic materials, bottom ash, paper, wood, and plastic, scrap metals, glass, construction and demolition (C&D) waste.
The site is also a landfill, in operation since 1977 when it was owned by the municipality. Following several owners and operators in-between, it was acquired by Ragn-Sells in 2015 and is one of three facilities operated within the company’s Treatment & Detox business division. Site Manager Erik Gustafsson has been at Häradsudden since the start.
– We were six people at the start in 2015 tasked with transforming a typical landfill that nobody viewed as a resource into an environmentally and economically sound materials recovery facility complete with infrastructure, equipment, and buildings. We have grown almost fivefold since 2015 and now around the site employs about 30 people some of whom are third-party staff, explained Erik Gustafsson.
A hard-surfaced road network, temporary work halls, and new permanent office buildings at the entrance overlooking the entire site, Häradsudden is much more reminiscent of an orderly, well-maintained site preparation on a construction site than a landfill.
No odour, no muddy tracks with perilous sinkholes, no refuse trucks spilling their contents onto the ground to a cacophony of shrieking seagulls and drone of diesel-powered compactors.
Yet Ragn-Sells Häradsudden sees some 100 – 150 trucks per day and handles around a quarter of million tonnes of residual material per annum. Some of this traffic and volume is transitory as the site functions as a transfer and storage station for municipal household waste and recycling collection, both for Ragn-Sells and other third-party operators.
– In this way, supply logistics are optimised so that material recyclers receive full truckloads to their facilities. We have two full 24 metre weighbridges for trucks, we built a covered transfer station as well as wash-plate with an oil separator in the machine hall, all of which improves the working environment for operators, said Erik Gustafsson.
Urban mining repository
Erik Gustafsson is a well-respected figure in Swedish waste management circles, having worked with a government agency on both regional and national landfill permitting and other regulatory issues prior to joining Ragn-Sells in 2015. If anyone has an idea of what a landfill should be and look like then it would be him.
– For example, to avoid landfill tax, boiler ash is often diverted for use in roads and pavements. While it is good that it is used, it would be better it was used after various material fractions were removed first. That the boiler ash is landfilled doesn’t mean it can’t be mined again and much easier than digging up streets and roads, Erik Gustafsson explained.
Material recovery from boiler ash is something Ragn-Sells is adept at. At Härldsudden the company treats around 60 000 tonnes per annum of bottom ash from waste-to-energy plants and pulp- and paper industries.
Some 8 to 10 material fractions of ferrous and non-ferrous metals, down to 0-2 mm in size, are recovered from the ash. While Erik Gustafsson remained tight-lipped about the volume of materials recovered, the value is significant, double-digit SEK millions on an annual basis.
– The cleaner the fraction, the higher the value. A clean fraction of metal X is typically worth double compared to metal X in a mixed fraction of X and Y. So, you can understand why we all put so much effort into fine-tuning our systems and equipment. It’s about extracting as much value as possible per tonne of material, and not how many tonnes per hour, explained Erik Gustafsson.
Emission- and cost reductions
The site has developed another onsite production line consisting of equipment such as shredders, crushers, screens, and electro-magnets to recover other recyclable materials and produce refuse-derived fuels (RDF).
In 2018, Ragn-Sells began to look at the possibility of replacing the diesel-powered equipment units with electric-powered counterparts with the same production capacity and output. The equipment supplier Norditek was contacted to open up a collaboration.
Continue reading this article in Bioenergy International no. 3-2020. Note that as a magazine subscriber you get access to the e-magazine and articles like this before the print edition reaches your desk!