Modelling of real oxygen delignification processes

Summary
Previously, extensive work has been done on the modelling of oxygen delignification process,
based on how the basic parameters i.e., temperature, kappa number, concentration of alkali and
concentration of oxygen affect the delignification rate. However, these models are not used
extensively to evaluate the performance of real processes primarily because they have not been
able to properly consider all the essential issues affecting to delignification in practice. Two
such issues are the mass transfer of oxygen, which defines the concentration of dissolved
oxygen in the process and effects of carry over. In this paper, we present a new way to model
the oxygen delignification process where these parameters, among other smaller things, are
taken into account. The basic model and its parameters are defined in the literature, aid of
delignifications and different laboratory tests, as well as essential information collected from
mill processes and mill tests. An essential part of these studies was the information obtained
from the oxygen dispersion in existing processes, measured with new continuous in-line bubble
size distribution measurement and usage in the modelling the diffusion theory-based equation,
which defines the connection between oxygen bubble size and mass transfer coefficient. This
presentation demonstrates how different parameters effect the delignification rate and critically
evaluates the accuracy of the modelling. This new approach provides the base to utilize
modelling to understand, improve and control the mill scale delignification processes. 

TAPPI conference proceedings and presentations, technical papers, and publication articles provide technical and management data and solutions on topics covering the Pulp, Paper, Tissue, Corrugated Packaging, Flexible Packaging, Nanotechnology and Converting Industries.

Simply select the quantity, add to your cart and your conference paper, presentation or article will be available for immediate download.