Dynamic modeling of carbohydrates degradation in kraft pulping of softwood

摘要

The degradation of carbohydrates during kraft pulping is related to pulp yield and pulp strength so it is of significant economic importance. In this work carbohydrate dissolution is estimated from batch kraft cooking of softwood (southern yellow pine) using a liquor analysis system. Near Infrared analysis (NIR) is used for the real time estimation of effective alkali, lignin and dissolved organic in the cooking liquor. A method to measure carbohydrate and total dissolved organic is developed by using a Total Organic Carbon (TOC) analyzer. This measurement is used to calibrate the NIR for on-line measurement of total dissolved organic and dissolved carbohydrate. A single model can be used to predict the carbohydrate dissolution during pulping. This model along with the delignification and effective alkali models already developed allows the optimization of the pulping process. Calibration methods for TOC, NIR and the model prediction results are also discussed.