Media releases & Case studies

Case Study: Helping Fortum to provide green heat and energy for Oslo


When leading clean-energy specialists, Fortum, faced agglomeration problems with a biomass boiler at one of its Norwegian CHP plants, Sibelco’s GREENFLOW® provided the optimal solution.

Fortum is the largest power generator in the Nordic countries and a leading heat producer globally. The company operates 11 plants in Oslo, serving up to 160,000 of the city’s homes. A biomass CFB* boiler at one of the Oslo CHP** plants was suffering from the effects of agglomeration, leading to lower output and frequent shutdowns.

Agglomeration is a common problem in CFB boilers, caused when a build-up of alkaline ash reacts with the boiler bed material, which in this case was silica sand. To solve the issue, the Fortum team were simply adding more bed material. Whilst this had a positive impact on the boiler’s output, it meant that the plant had to be stopped every 2 months for cleaning. Coupled with the need for frequent deliveries and storage of silica sand, it was proving to be a very costly solution.

When Fortum decided to switch fuel and repurpose the boiler, GREENFLOW® olivine has proven to be the best alternative bed material. As a magnesium iron silicate, GREENFLOW®has a much higher resistance to alkaline fuel sources than silica sand, therefore limiting the impact of reaction problems such as agglomeration, fouling and corrosion. Importantly, we were able to provide a customised grain size which eliminated the need for a costly reconfiguration of the boiler to accommodate a new type of bed material.

As well as reducing agglomeration, GREENFLOW® is now outperforming the plant’s previous silica sand bed in terms of combustion efficiency thanks to its higher heat capacity. This means that less volume of bed material is needed, whilst also providing transport, storage and environmental savings. The use of Greenflow® has therefore enhanced overall process efficiency.

We are proud of our association with Fortum which stretches back over 30 years, and excited that our material solutions are supporting a business that is driving the change to a cleaner world.

Case study PDF:

Helping Fortum to Provide Green Heat and Energy for Oslo

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