Fiskeby’s specific use of electricity is among the very lowest in the industry. At normal production our energy plant produces up to 30% of our entire need for electricity. To be able to compare ourselves to others we use the measurement MWh per tonne of product.
A crucial process in paper production is drying which is performed with the aid of steam. All paper has a natural moisture content of about 6–7% and that is what we strive to achieve. Stock from recovered paper can be dewatered by almost 50% which is about 10% better than stock from virgin fibre. This gives us a low consumption of steam per tonne of product. Of the total volume of energy that we consume, heating energy (steam) accounts for two-thirds.
Outgoing air and water from the process exchanges heat with incoming air and water, allowing the heat to be used one more time.
Low-value waste heat from process industries is usually difficult to exploit. In our biogas plant, the energy from the mill’s waste water is used to give the microorganisms the optimal temperature for gas production. Thanks to the choice of efficient technology and careful insulation of tanks, the biogas is produced within 3–4 hours without any added heat or stirring. This can be compared with conventional digestion processes which require district heating for about 35 days.