ATMP pulping of Norway spruce – pulp property development and energy efficiency
Jan Hill, Lars Johansson and Kathrin Mörseburg
ATMP pilot refining trials on Norway spruce were conducted. The ATMP configuration consists of selective wood disintegration and targeted application of chemicals when defibration already is initiated in order to achieve energy-efficient final fibre separation and development. ATMP was compared to TMP and RTS.
The TMP like character was maintained despite of differences in pre-treatment, chemicals and primary stage refining energies. The fractional composition of the pulps was, however, altered. Bauer McNett R14 fraction exhibited the largest differences followed by P200 fraction. Thus different process alternatives produced pulps with different fingerprints. The amount of the R14 fibres is important as these tend to cause surface roughness impairing printability.
Regardless of strategy, the ATMP pulp properties at equal tensile index (44 Nm/g) were equal or superior to those achieved by TMP or RTS refining. The main difference was the required specific energy input, ranging from 1.71 (TMP) to 1.05 MWh/BDT (ATMP with bisulphite addition).
Primary stage refining was explored from multiple trials with the same process configuration and chemistry. The higher the specific energy applied the better is the energy efficiency. Furthermore established refining theories appear inadequate in describing the differences between process alternatives with respect to energy efficiency and pulp property development.
Nordic Pulp & Paper Research Journal (NPPRJ) is an international scientific magazine covering science and technology for the areas of wood or bio-mass constituents, pulp and paper and including new fiber-based materials, recovery and by-products from pulping processes, bio-refining and energy issues. Articles meeting required scientific standards are accepted from any continent. Open Access: Articles not available through Gold Open Access may be purchased by credit card as a pdf file, to be downloaded within 24 h after ordering, at a price of 22 EUR per article. (Value added tax may apply depending on your location, which you enter at payment logout.) Such articles have Green Open Access, i.e. authors may share articles on their personal non-commerical homepage immediately after publication on the website and download them to non-commercial hosting platforms one year after publication in a full issue of NPPRJ. ISSN: 0283-2631