information transfer makes power plant effective

By Soili Städter* O

ne of the world’s largest biomass power plants, Alholmens Kraft in

Pietarsaari, Finland, has already been in commercial operation for about 15 years. The company highlights the combination of Valmet’s Circulating Fluidised Bed (CFB) boiler and Valmet DNA automation to operate the huge plant.

The biomass power plant has been in use since January, 2002, and Alholmens Kraft has won several international awards for its sustainable energy production since the plant is a good model for sustainable business.

The plant delivers 215 MWe of electricity on the open market to the Nordic countries and 60 MWth of district heating to inhabitants in the city of Pietarsaari, as well as 100 MWth of process steam to the UPM paper mill at the same site. The steam capacity of the plant is 550 MW.

Quick changes

Since the start-up of the plant, the energy business has changed dramatically. The price of electricity has fallen, so the management has had to consider carefully when to use the AK2 biomass boiler. If there has not been sufficient need for electricity, the smaller AK1 boiler, also supplied by Valmet, is used.

Sami Lassila, Production 10 Spring 2018


Supervisor at Alholmens Kraft, has known both the boiler and Valmet’s automation since the very beginning. He has also seen the change in the energy business. “It is very challenging for the whole plant to have frequent starts and stops, but even in those demanding conditions, Valmet’s technology has met the requirements,” he agreed. “Sometimes, the plant has to be started to full capacity within a few hours.”

Valmet DNA provides detailed technical descriptions on how to start and stop the operation. The meaning of a properly functioning automation system soon becomes apparent through the quick changes that are possible. “The plant is large in size and very complicated. There are plenty of conveyors around and many types of fuels in use. To master all this, a reliable system is required,” he added

In the control room, four operators run the process, yet Sami Lassila can easily follow the process – even from his office.

Fuel flexibility

The design of the plant allows fuel flexibility. Today, besides biomass, sometimes burnable waste known as recovered fuel (REF) and coal are also incinerated, so the raw material can be very diverse. “The boiler makes it possible to burn several raw materials in a


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24