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Sulphur-based pulping

VTT has the right tools – contact us!

​VTT develops kraft and sulphite processes for the production of paper and dissolving grade pulps by raw material screenings, process modification simulations, unit operation optimizations and technoeconomic feasibility studies.

Stricter legislation and demands for profitability force industry towards more sustainable and raw material and energy-efficient processes.

Recent references:

  • Selection of eucalyptus clones for kraft pulping (Botnia, UPM);
  • Development of a high yield reinforcement pulp process (Metsä Fibre, FIBIC); 
  • Pre-evaluation of new bleaching sequences or sequence changes in a pulp mill (Botnia, Metsä Fibre); 
  • Enzyme aided bleaching – proposal for process improvement based on mill data (Fibria); 
  • Creation of a quality index (Botnia FOX index) , which combines the theory of cooking and bleaching, mill data and the utilization of statistical mathematics (Metsä Fibre won the Quality Innovation competition in 2012) 

Our competence and the focus of research in the recent past

VTT utilizes its core competences including raw material knowledge, chemical pulping and bleaching technology, chemical characterization and analytics to develop pulping processes and pulps.¨

VTT can offer techno-economic feasibility studies and LCA evaluations of processes, and application and runnability testing.

Raw material efficient pulping processes are the most important research area in the resent past, due to the fact that in Nordic countries over 60% of pulp production costs comes from wood raw materials. 

Research facilities and networks

Besides experts in pulping, VTT has versatile semi-pilot scale laboratory equipment with which to perform cooking and bleaching research for a wide variety of different kinds of raw materials Liukosellujen testaukseen VTT:llä on regenerointi- ja märkäkehruuympäristöt


  • Labtium – physical testing and chemical characterization of paper grade pulps
  • Aalto University – dissolving and spinning using novel ionic liquid based regeneration processes

We have the most to offer the forest industry.