We generate large amounts of bioheat and bioelectricity in a cogeneration plant for heat and electricity. Only half of the wood is used to produce pulp and biochemicals. The other part of the valuable biomass is utilised for the generation of bioenergy.
Zellstoff Stendal generates 135 MW of electric bioenergy at all times. This makes us the largest biomass plant working with solid biomass in Germany. Zellstoff Stendal and its sister factory in Blankenstein produce approximately one fifth of all electric energy generated from solid biomass in Germany.
Zellstoff Stendal is completely self-sufficient in terms of electricity. The plant generates much more energy than it needs to operate its plants. Between 40 and 50 per cent of the generated electricity is fed into the public power grid every year. The amount of electricity produced annually by Zellstoff Stendal could supply more than 250,000 private households. It replaces electricity volumes that are generated on the basis of fossil fuels, thus preventing approximately 800,000 tonnes of CO2 emissions.
This technically rather difficult “cascaded use” of wood aims to ensure maximum value creation and the most efficient use of this increasingly rare raw material.
By using residual heat as efficiently as possible, this type of pulp industry generates “perfect” renewable energy. Over the course of the production process, the remaining wood, dissolved in black liquid, is burned in two modern recovery boilers. This generates heat and steam. This steam is first used to generate electricity and then fed to the production process: cogeneration of heat and electricity in perfect form. Another advantage of this process is: during this combustion process, the utilized chemicals are recovered and can be reused for production.
The method of green-energy generation used by our pulp plants is unparalleled in its efficiency: it has a total utilisation ratio of more than 60 per cent in terms of the biomass used, while more than 70 per cent of the electricity is cogenerated.