Optimizing the continuous cooking digesters at Stora Enso Imatra Mills

Stora Enso decided to build a new short-fiber pulp line (line 3) for birch cooking, and later to modernize and convert the existing pulp line 2 to long-fiber. Thus, there was the need to optimize the cooking process.

Production targets were exceed quickly after the start-up. The pulp from line 3 is very pure, which is essential for boards for the food industry, and the pulp from line 2 has improved its strength. Less pulp has to be purchased, thus reducing costs and enhancing pulp quality. The carbon dioxide emission from fossil fuels has been reduced, because the increased pulp production has lead to an increase in production of by-products, like black liquor and bark, which are used as fuel instead.