Iggesund Paperboard, Sweden
Optimizing operations for the world’s top paperboard brands
Iggesund Paperboard manufactures two of the world’s leading paperboard brands – Invercote and Incada – which are used by some of the most demanding brand owners in the segment for their outstanding durability and versatility.
Iggesund Paperboard is part of the Holmen forestry group, which owns more than 1.3 million hectares of sustainably managed forest across Sweden. This allows Iggesund to manufacture unique paperboard products in technologically advanced mills, powered by renewable energy.
The challenge
Iggesund Paperboard recently invested in a new recovery boiler, steam turbine and related equipment to reduce the mill’s airborne emissions. At almost EUR 240 million, this was the largest ever investment made in the Iggesund mill.
The recovery boiler was built to withstand higher pressure than any other recovery boiler in Europe, thereby increasing the mill’s capacity to generate greater amounts of electricity. The new turbine supplies up to 520GWh of electricity per year, making Iggesund’s mill entirely self-sufficient in electricity for the longer-term.
The aim
We aimed to establish an overall operating strategy, which included both development of control philosophies, and the fine-tuning of control system settings to ensure that the operation of the new recovery boiler, the turbine, and existing biofuel boilers are optimized for the plant. The project included the development of engineering solutions, and operator training prior to commissioning.
The solution
Working closely with Iggesund Paperboard, we implemented a holistic program consisting of the following elements:
- Design of a steam distribution control philosophy for grid-connected and electrically islanded operations
- Simulator studies covering the mill’s steam distribution system and electrical system to ensure that the new plant – and its staff – are able to manage even the most challenging operating conditions, including service disruptions, without causing costly outages
- Island operation testing and tuning of turbine and generator control
- Operator training courses
This project was a multi-discipline project that involved several of Solvina’s areas of expertise:
- Process engineering
- Power systems engineering
- Control systems engineering
The control system that Solvina developed for this application was extensively tested and tuned by Solvina, with simulation results presented to the customer, prior to implementation and start-up.
The result
The start-up went smoothly, and avoided the need for time-consuming control system tuning and re-working – lengthy delays are typically a major risk associated with upgrading installations of this size and complexity. Similar projects elsewhere in Europe have experienced costly downtime periods amounting to between three and five per cent of annual production.
Solvina has given Iggesund the scope to adapt plant operation on an hourly basis to fuel and electricity prices on the spot market, thereby achieving the most energy efficient and profitable operational performance possible.
