Process Control and Quality, Vol.11, No.5, 407-417, 2000
A simple and practical pulp kappa test method for process control in pulp production
Through permanganate measurements, this study demonstrates a simple, rapid, practical, and direct spectrophotometric pulp kappa test method through one calibration with a standard pulp sample of known kappa number. Two permanganate absorption measurements were made in both the testing and standard pulp-permanganate reacting solutions for kappa calculation, one at the beginning of the reaction and the other at about 2-3 min into the reaction. The measured kappa numbers of 13 blended hardwood pulps and another 45 pulps from laboratory pulping of 10 hardwood and softwood species in a kappa number range of 10-70 are reported. The results showed excellent agreement with those obtained by the standard TAPPI kappa method. The effect of the pulp-permanganate reaction temperature on measured kappa number using the present method is also presented. The method has the potential for on-line kappa monitoring in pulp production.
Keywords:kappa number;pulp;spectrophotometry;permanganate;lignin;hexenuronic acids;spectrochemical analysis;measuring instruments