A study on kraft, bio-kraft, bio-kraft-aq, bio-polisulfur, and bio-kraft-sodium borhidrur pulping using Pinus brutia

Biotechnology finds several industrial utilization areas. In pulp industry, white rot fungi are in use to degrade lignin from the cell wall components prior to biopulping. In paper industry, biotechnology is currently in use to produce mechanical pulps (biomechanical pulping) while saving a significant amount of energy. The aim of this study is to examine the effects of kraft modifications (additives, biodelignification and combination of them) on pulp and paper properties. The experimental study was divided into two main sections. The first part evaluated the effects of biological pre-treatment (Ceriporiopsis subvermispora, FP-90031-sp) and second part experimented the effect of additives (AQ, PS and NaBH4), biodelignification of wood chips and combination of these approaches on pulp and paper properties. Chemical properties in term of holocellulose and lignin ratio on wood chips treated with C. subvermispora for a period of time resulted in that 4 weeks of treatment was found as the optimum incubation time. Kraft method is modified using additives of 0.1% AQ, 4% elemental sulfur and 2 and 4% NaBH4. Cooks with the same methods were also accomplished using bio-delignified chips and total 10 cooks were performed in this study. The obtained pulps were assessed on the basis of the pulp yield, viscosity, kappa number, optical and strength properties. It is found that bio-delignification of wood chips prior to chemical pulping gave higher pulp yield and viscosity and lower kappa number. When kraft method was modified by additives, pulps gave better optical properties. On the other hand, modifications generally resulted in lower pulp strength properties. It is considered that the decrease in the strength value versus the increase in the yield and viscosity as a result of modification of kraft method by the biological pre-treatment and/or using chemicals can be compensated in the fungal treatment and optimizing the quantities of the auxiliary chemical materials used. Keywords: Biopulping, kraft, AQ, PS, NaBH4, physical and optical properties.