Inventory audit notice: TAPPI Press orders will not be processed from August 21–28 during our fiscal year-end inventory audit. Orders placed during this time will ship starting August 31, in the order received. Normal payment processing also resumes August 31.

Thanks for your patience — this helps us serve our members better.

Search

Use the search bar or filters below to find any TAPPI product or publication.

Showing 481–490 of 1,859 results (Duration : 0.055 seconds)

Filters

Industry

Topics

Content Type

Publications

Level of Knowledge

Committees

Collections

Journal articles
Magazine articles
Open Access
Model development for real oxygen delignification processes, TAPPI Journal October 2024

ABSTRACT: Previous extensive work has been done on modeling the 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 delignification in practice. Such issues include the mass transfer and consumption of oxygen, which defines the concentration of dissolved oxygen in the process, and the effect of that concentration on the delignification rate. In this paper, a new way to model the oxygen delignification process is used in which these parameters, among other smaller matters, are taken into account. The basic model and its parameters were defined by the information obtained from the literature, delignification made in the laboratory tests, and mill processes and mill tests. An essential aspect of these studies was the information obtained from the oxygen concentration measured in the residual gas obtained from the top of the reactor. With the aid of this measurement, it was possible to define more accurately the consumption of oxygen and partial pressure of oxygen that define the concentration of dissolved oxygen in the reactor. Using mill experiments, a model was formed that predicts the operation of the oxygen delignification process. The model was used to show how much the process could be improved by optimizing the charge of the oxygen. The mill experiments also confirmed that mass transfer of oxygen is modeled correctly enough, except when the charge of oxygen is very low and/or the mixing is not efficient enough. In that case, there is variation in the concentration of oxygen in the process that should be taken into account in the modeling.

Journal articles
Open Access
TRS inventories and air dispersion modeling for odor reduction at a kraft mill with an activated sludge treatment plant, TAPPI JOURNAL, April 2002 (281KB)

TRS inventories and air dispersion modeling for odor reduction at a kraft mill with an activated sludge treatment plant, SOLUTIONS! & TAPPI JOURNAL, April 2002 (281KB)

Journal articles
Open Access
Catalysis and activation of oxygen and peroxide delignification of chemical pulps: A review, TAPPI JOURNAL, April 2002 (38KB)

Catalysis and activation of oxygen and peroxide delignification of chemical pulps: A review, SOLUTIONS! & TAPPI JOURNAL, April 2002 (38KB)

Journal articles
Open Access
Oxygen delignification as a pretreatment for acetosolv pulps bleaching, TAPPI JOURNAL, April 2002, Vol. 1(2) (221KB)

Oxygen delignification as a pretreatment for acetosolv pulps bleaching, TAPPI JOURNAL, April 2002, Vol. 1(2) (221KB)

Journal articles
Open Access
Measurement of kappa number variability on the fiber level, Solutions! & TAPPI JOURNAL, December 2002, Vol. 1(10) (147KB)

Measurement of kappa number variability on the fiber level, Solutions! & TAPPI JOURNAL, December 2002, Vol. 1(10) (147KB)

Journal articles
Open Access
Using near-infrared multivariate image regression to predict pulp properties, Solutions! & TAPPI JOURNAL, May 2004, Vol. 3(5) (271KB)

Using near-infrared multivariate image regression to predict pulp properties, Solutions! & TAPPI JOURNAL, May 2004, Vol. 3(5) (271KB)

Journal articles
Open Access
Concentric mixing of hardwood pulp and water, TAPPI JOURNAL, Online Exclusive, May 2004, Vol. 3(5) (475KB)

Concentric mixing of hardwood pulp and water, TAPPI JOURNAL, Online Exclusive, May 2004, Vol. 3(5) (475KB)

Journal articles
Open Access
Sulfuric acid emissions from combination boilers, Solutions! & TAPPI JOURNAL, May 2004, Vol. 3(5) (128KB)

Sulfuric acid emissions from combination boilers, Solutions! & TAPPI JOURNAL, May 2004, Vol. 3(5) (128KB)

Journal articles
Open Access
NCASI technical studies of environmental issues affecting fiber supplies, TAPPI JOURNAL, November 2000, Vol. 83(11)

NCASI technical studies of environmental issues affecting fiber supplies, TAPPI JOURNAL, November 2000, Vol. 83(11)

Journal articles
Open Access
Influence of hexenuronic acids on us bleaching operations, TAPPI JOURNAL, November 2000, Vol. 83(11)

Influence of hexenuronic acids on us bleaching operations, TAPPI JOURNAL, November 2000, Vol. 83(11)

Inside this Section