1. Department of Biomass Processing and ProductsVTT Technical Research Centre of Finland Ltd Visiokatu 4, P.O. Box 1300, FI‐33101 Tampere Finland
2. Department of Bioproducts and BiosystemsAalto School of Chemical Engineering Vuorimiehentie 1, P.O. Box 16300, FI‐00076 AALTO Espoo Finland
3. Department of PhysicsUniversity of Jyväskylä P.O. Box 35, FI‐40014 Jyväskylä Finland
4. Department of Biomass Processing and ProductsVTT Technical Research Centre of Finland Ltd Biologinkuja 7, P.O. Box 1000, 02044 VTT Espoo Finland