Chemometric study on alkaline pre-treatments of wood chips prior to pulping

Abstract

Alkaline pre-treatments were performed for the production of organics-containing effluents from silver/white birch (Betula pendula/pubescens) and Scots pine (Pinus sylvestris) chips prior to chemical pulping. Pre-treatment conditions were varied with respect to time (from 30 min to 120 min), temperature (130 °C and 150 °C), and alkali charge (1, 2, 3, 4, 6, and 8% of NaOH on oven-dried wood). The analytical data (total content, weight average molar mass, and molar mass distribution) on dissolved lignin were subjected to principal component analysis to examine the relationship between molar mass and molar mass distributions in lignin removed from different wood species under varying alkaline pre-treatment conditions. Using this method, differences between the wood species and effects of the various pre-treatment process variables (i.e., time, temperature, and alkali charge) were determined.