A Dissolved Lignin Monitoring-based Model for End-point Control during Displacement Kraft Pulping

A novel mathematical model is reported for end-point control during displacement kraft pulping. The model was based on an on-line process that measured the dissolved lignin content in cooking liquor using an attenuated total reflection ultraviolet spectroscopy method that had been developed previously, from which a relationship between the pulp kappa number and integrated dissolved lignin content was established. The results showed that there was good agreement between the pulp kappa numbers measured by the presented model and TAPPI standard method. The presented method is straightforward and accurate and has the potential for on-line process control in mill operation.