ABB helps Stora Enso paper mill slash emissions

August 22, 2007
ABB
News

Summary

Zurich, Switzerland, August 22, 2007 - The Skoghall paper mill in central Sweden cut carbon dioxide emissions by about 170,000 tons a year following a two-year revamp costing 211 million euros ($290 million). "This was a very large project which was implemented without stopping production,” said Peter Olsson, engineering manager at Skoghall mill. “The demands placed on project planning were extremely high, as were the demands on equipment with regards to availability, security, user friendliness and energy efficiency, to ensure that the mill will be competitive for years to come." The Skoghall mill is gigantic: every day, 100 truck-loads and two train-loads of logs arrive at the mill to be chopped, processed to a pulp and turned into paper. Workers use bicycles to circulate in the cavernous hangars that house the two 300-meter long paper-making machines. In less than an hour, one of them can produce enough paper to make 2 million milk cartons. The big energy consumers are the boilers that produce steam to power turbines that generate electricity for the mill and it is these that Stora Enso rebuilt. ABB’s contribution to the project included:

High-efficiency motors

Variable-speed drives to help adjust the speed of the motors to the processes they are running. Many motors in industry waste energy by operating at full speed even when not required.

A motor management system that optimizes the coordinated operation of a whole set of motors running at constant speeds.

System 800xA Extended Automation to control the recovery boiler, where waste from the pulping process is burned to produce steam and chemicals are recovered. The system collects and analyzes data in real time from thousands of instruments fitted to equipment throughout the plant, helping operators adjust the settings to run operations at their optimal level to get the most out of the energy consumed.

Instruments to measure flows, temperatures and pressures on equipment around the plant and feed the data to the control system.

A MicroSCADA installation helps to prevent blackouts and disturbance, plan power consumption, and provide total control over the power supply with real-time data from the substations.The revamp of the recovery boiler and the conversion of the oil boiler into one that burns organic waste – mainly bark, sawdust and other waste wood - helped reduce oil consumption by the equivalent used in 30,000 Swedish homes with oil-based central heating. Discharges of oxygen-consuming substances from plant processes into the nearby lake were cut by 10 percent. And since boilers now produce up to 40 percent of the electricity Skoghall consumes, the mill's equipment must be as energy efficient as possible. The savings achieved at Skoghall make the mill more competitive, securing production and therefore jobs at the Swedish location, which is the world’s biggest plant for liquid packaging board, used to make drink cartons. ABB is a leader in power and automation technologies that enable utility and industry customers to improve performance while lowering environmental impact. The ABB Group of companies operates in around 100 countries and employs about 111,000 people. Photo Caption: Stora Enso's Skoghill paper mill is one of its most energy efficient and enivironmentally friendly, with help from ABB technologies. Learn More

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