A new mechanism of biopulping : attachment of acid groups on fiber

Abstract

We analyzed the physical properties of wood chips incubated with Ceriporiopsis subvermispora and cultural parameters of biopulping incubations of Phanerochaete chrysosporium and C. subvermispora. Dynamic mechanical analyses indicated a reduction in the modulus of elasticity (MOE) and loss modulus of spruce during the time where the biopulping energy savings effect takes place. The data from measurements of the MOE at different moisture contents indicated the fiber saturation point (FSP) of spruce increased from 29% to 42% during biopulping. Chips were made into pulp, which was washed, and the titratable acids attached to the fiber were determined. Titratable acid groups on spruce increased from 96 meq/kg for control pulps to 121 eq/kg for C. subvermispora treated spruce pulps. A 25 eq/kg of pulp would be expected to increase the FSP by 14%. Oxalate could be extracted from the biopulps by base in significantly greater amounts than by acid. Oxalate is bound to the pulp, probably through an ester linkage, in amounts that were in excess of the amount needed to explain the increase in FSP. A single esterification of oxalic acid would increase the acid content of the pulp, which should cause an increase in water content and softening of the chips.

Citation

Kenealy, William R.; Hunt, Chris; Horn, Eric; Houtman, Carl. 2004. A new mechanism of biopulping : attachment of acid groups on fiber. Ninth International Conference on Biotechnology in the Pulp and Paper Industry : Durban, South Africa, 10-14 October 2004. [S.l. : s.n.], 2004