Aalborg Energie Technik a/s Biomass Cogeneration Plant
Verdo Produktion, Randers, Denmark
The Task
The cogeneration plant in Randers originally consisted of two coal-fired CHP boilers, commissioned in 1982. The plant produces power to the national grid and district heating for the city of Randers, the 6th largest city in Denmark.
In the early 00’s, an idea was developed to re-use some of the industrial waste in the surrounding areas like meat and bone meal, olive stones, shea nuts, sunflower and bio- pellets in combination with coal. In 2008, Verdo Production decided to focus 100% on biomass and changed its name to Verdo to reflect the new green footprint. In both cases, AET was the supplier of choice for Verdo.
The Solutions
The first retrofit:
The 100% coal-fired boilers were converted to use up to 50% biomass pellets. AET re-designed the boiler plants to burn pellets with particles up to 5 - 10 mm.
AET converted the CHP plant by installing the AET Dust Firing System, the AET Fuel Handling System, the mechanical, instrumentation and electrical systems and by re-engineering the control systems and commissioning the plant.
The second retrofit:
By extending the furnace by 5 metres and lowering the grate, AET made it possible to utilise 100% biomass, 100% coal or any combination in between. AET supplied, installed and commissioned the full scope by including: AET Fuel Dosing Bins, AET Biomass Chutes, biomass fuel handling and AET Combi Spreaders for both biomass and coal. The economiser sections were refurbished and the AET Combustion Air System, ash handling system, key instrumentations and electrical systems were installed. A successful commissioning followed the re-engineering of the DCS control systems.
The AET Dust Firing System can utilise dusty and small particles up to 5 - 10 mm, while the AET Combi Spreader System utilises coal and biomass chips from separate fuel feeding systems.
Note that Verdo Production was previously Energi Randers.
Customer Statement
Henrik Bøgh Nielsen (Division Director), Verdo:
"The two retrofits have given us a large fuel flexibility to utilise what fuel is available on the market at a low price. The re-build of our boilers in 2008 - 2009 made by AET has been functioning to our full satisfaction and especially the long-term experience with AET Combi Spreaders."
