We use the EU's 'Best Available Techniques (‘BAT’) approach, and the philosophy to create more with less raw materials, water and energy. Our mills also produce a significant amount of bioenergy.
The same wood for pulp and bioenergy
Pulp is made from wood and the sawdust from our sawmills and plywood mills. The process for both hardwood and softwood pulp is nearly identical, the main differences being the structure of the wood, and some slight differences in the amounts of chemicals used during the bleaching process.
While our mills produce pulp from pine, spruce, birch and eucalyptus, they also use the same wood to produce a significant amount of bioenergy. Our mills produce more than 2% of all the electricity produced in Finland, while the UPM Fray Bentos pulp mill accounts for as much as 8% of the energy generated in Uruguay. Electricity generation in pulp mills does not produce fossil CO2.
How do we make pulp?
This is how pulp is made
1. Wood handling
Sustainably grown and sourced wood is first debarked and cut into small chips for more efficient pulping. In addition to wood chips, we use sawdust from sawmills and plywood mills for pulp making. The bark of trees is used for bioenergy production at the mill.
2. Fibre processing
The process for both hardwood and softwood is nearly identical, the only difference being the structure of the wood. Softwood consists mostly of cellulose and lignin, and it contains less hemicellulose than hardwood.
Cooking the wood chips in the presence of sodium hydroxide and sulfide liquor under high pressure removes the lignin and separates the wood into cellulose fibres. During the cooking process approximately half the wood dissolves. The pulp is then washed, screened for quality, and bleached.
The spent cooking chemicals and dissolved wood material is called black liquor. This substance is recovered and burned in a recovery boiler to produce energy that keeps the process running. In causticising, the cooking chemicals are processed for re-use.
3. Drying and baling
Washed and bleached pulp resembles fluffy white cotton balls.
The pulp is then dried, cut into sheets and baled for easier handling, warehousing and transportation. A standard export unit of pulp consists of eight 250 kilogram bales.
Now our pulp is ready to travel the world.