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 described with the aid of a generalized severity parameter, K•ROH. Based on a first-order decay process and a time-dependent rate constant, the K•ROH concept combines the main operation variables (temperature, time and chemical loads) into a single reaction ordinate which is then used to summarize the changes in chemical composition and physical properties of the resulting pulp. The product K•ROH proved to be a valuable tool which provides an absolute scale that enables different biomass species treated in different conditions to be compared.