SODA-ANTHRAQUINONE PULPING OF A SOFTWOOD MIXTURE - APPLYING A PSEUDO-KINETIC SEVERITY PARAMETER

Experimental and published data about lignin solubilization during the soda-anthraquinone pulping of a softwood mixture were successfully de scribed with the aid of a generalized severity parameter K . R-OH. Bas ed on a first-order decay process and a time-dependent rate constant, the K . R-OH concept combines the main operation variables (temperatur e, time and chemical loads) into a single reaction ordinate which is t hen used to summarize the changes in chemical composition and physical properties of the resulting pulp. The product K . R-OH proved to be a valuable tool which provides an absolute scale that enables different biomass species treated in different conditions to be compared. (C) 1 997 Elsevier Science Ltd.