Experimental determination of the diffusion of monovalent cation into wood:Effects of micro-cracks,wood structure,impregnation time and temperature on local concentration profiles

Artikel i vetenskaplig tidskrift, 2014

A thorough understanding of the key phenomena that take place during the chemical transport of reactants into a wood matrix is critical for the success of today’s chemical pulp mills as well as future biorefinery operations. In the present article, our previous experimental methodology has been further developed to minimize the effect of micro-cracks present in wood pieces. The effects of wood structure (sapwood and heartwood), impregnation time, and temperature on local concentration profiles in Norway spruce wood were investigated using LiCl as a tracer substance. For experimental conditions of neutral/low pH, Li+ ion concentrations in the eluate of slices taken from the outer surface layers of an impregnated wood piece were found to be higher than the native anionic group content (i.e., the cationic exchange capacity) of the wood piece. The method gave reasonable results, but defects in the wood piece (micro-cracks) still existed and were detectable.