Borger Multicrusher introduced to award-winning Scottish biogas project
The Creed Integrated Waste Management Facility on the Isle of Lewis processes salmon waste into biogas using anaerobic digestion. The facility manages waste from the island's 22,000 inhabitants and has grown to include a combined heat and power plant, electric boiler and thermal store, alongside the biogas plant, a wind turbine and a hydrogen system. The IWMF won the Scottish Environment business VIBES award for its innovative practices in 2019.
The Borger Multicrusher chops a 7-cubic-tonne batch per shift of coarse waste salmon. The machinery has enabled the Creed facility to integrate the fish with household food waste and garden waste for its biogas process. The technology guarantees the shred of waste salmon to meet stringent regulations for the safe use of digestate as a renewable fertiliser, by cutting the waste to the required maximum particle size of 12mm.
Donnie Macmillan, plant manager at the Creed facility, said: "Borger's Multicrusher works extremely well for us in a very harsh environment. Some salmon waste can be quite tough and abrasive so understandably we see wear on the cutters during our inspections, but that's perfectly understandable.
"Importantly, the Borger unit helps us meet all of our PAS 110 requirements, which is all part of what we set out to achieve here - optimising the methods of managing waste - in this case not sending waste salmon to landfill sites, and not having to have it transported off the island."
"We are very proud to play our part at Creed," commented David Brown, Borger's UK managing director. "It rightly deserves all the praise it gets for showing what can be done to protect the environment and reduce carbon footprint with good practice, forward-thinking and hard work."
Some of the electricity generated by the CHP is used to produce hydrogen and oxygen. This is captured, compressed and delivered to the salmon hatchery, where oxygenation is essential. The hydrogen is used in a small fuel cell to provide electricity to the remote site, which can suffer from electrical network failures. The hydrogen system at Creed also includes a refuelling station, where some of the hydrogen is used to refill a dual-fuel refuse collection vehicle.