Brian N Brogdon - Academia.edu (original) (raw)

Papers by Brian N Brogdon

Research paper thumbnail of Fundamentals and numerical modeling of unit operations in the forest products industries : 1999 AIChE Forest Products Symposium

American Institute of Chemical Engineers eBooks, 2000

Research paper thumbnail of Kraft pulp viscosity as a predictor of paper strength: Its uses and abuses

October 2023

For bleached kraft pulps, two factors govern paper strength: the individual fiber strength, and t... more For bleached kraft pulps, two factors govern paper strength: the individual fiber strength, and the bond strength that adheres the individual fibers together in the paper matrix. Inherent fiber strength is related to the length of the carbohydrate polymers, also known as the degree of polymerization (DP). Average DP (DP) is inferred by performing pulp viscosity measurements. Under certain circumstances during kraft pulping and bleaching, the average polymer lengths can be shortened, resulting in lower pulp viscosity, and may indicate fiber damage. Fiber damage typically manifests itself as a reduction in tear strength for well-bonded handsheets. This paper will review the literature on how pulp viscosity can predict paper/fiber strength and how it can be used as a diagnostic tool. It can be a means to monitor pulp quality during pulping and bleaching, as well as to alert when such operations approach a critical threshold. However, viscosity losses must be carefully and judiciously a...

Research paper thumbnail of Fundamental study of relative delignification efficiencies (II): Effects of phenols, carbohydrates, amines and reagent combinations during pulping

Reactions of a _-aryl ether lignin model compound (1) provide information on the relative rates o... more Reactions of a _-aryl ether lignin model compound (1) provide information on the relative rates of pulping reactions that involve quinone methides (QM). The lignin model was reacted with 2,6xylenol, 1,5-anhydrocellobiitol, amylose, reagent combinations, and amines. The results indicate that condensation reactions between QMs and phenolates or carbohydrates are much slower than fragmentation reactions with sulfide and anthrahydroquinone (AHQ). A sulfide/sulfite combination did not enhance 13-aryl ether fragmentation; however, a sulfide/AHQ combination increased fragmentation synergistically. The addition of amines to soda cooks substantially increased the conversion of model 1 to a vinyl ether (9).

Research paper thumbnail of New Insights into Lignin Modification During Chlorine Dioxide Bleaching Sequences (II): Modifications in Extraction (E) and Chlorine Dioxide Bleaching (D1)

Journal of Wood Chemistry and Technology, 2005

... Dr. Brian N. Brogdon a * , Douglas G. Mancosky b & Lucian A. Lucia b pages 221-237. .... more ... Dr. Brian N. Brogdon a * , Douglas G. Mancosky b & Lucian A. Lucia b pages 221-237. ... J. Chem. Phys. , 33: 1488 View all references as well as by Fitzpatrick and Steelink.2426. Fitzpatrick, JD and Steelink, S. 1972. The origin of the paramagnetic species in lignin solutions. ...

Research paper thumbnail of New Insights into Lignin Modification during Chlorine Dioxide Bleaching Sequences (IV): The Impact of Modifications in the (EP) and (EOP) Stages on the D1 Stage

Journal of Wood Chemistry and Technology, Jul 1, 2005

Abstract Peroxide‐reinforced extractions ((EP) or (EOP)) of D0 pulps lower both post‐extraction k... more Abstract Peroxide‐reinforced extractions ((EP) or (EOP)) of D0 pulps lower both post‐extraction kappa numbers and Klason lignins more than either E or (EO). An oxygen‐reinforced extraction (EO) results in lower kappa numbers, but affords comparable Klason ...

Research paper thumbnail of A fundamental study of a novel extraction stage for an organosolv-based bleaching sequence

Research paper thumbnail of Revised steady-state model for chlorine dioxide brightening that considers extraction washer carryover effects

Tappi Journal, Apr 1, 2016

Research paper thumbnail of Improved steady-state models for chlorine dioxide delignification sequences that include washer carryover effects

Tappi Journal, Mar 1, 2015

In previous studies, generalized steady-state models were proposed to approximate the chlorine di... more In previous studies, generalized steady-state models were proposed to approximate the chlorine dioxide demand needed for the delignification of softwood and hardwood pulps, where the kappa number entering the bleach plant can fluctuate. However, these expressions neglect the effect of dissolved solids with the stock that originate from incomplete pulp washing. In this study, the original elemental chlorine-free (ECF) models are modified to include the effects of carryover from brownstock or post-oxygen washing. The stoichiometric bleach consumption from carryover, based on its composition, was calculated from various literature sources. The majority of the bleach demand (about 70%) results from the dissolved lignin contained in the brownstock carryover, with the remainder resulting from the inorganic sulfur constituents (e.g., sulfide and thiosulfate). When the effect of brownstock carryover was taken into account, the modified models accurately predicted the amount of chlorine dioxide consumed for a given delignification level (about ±0.1% chlorine dioxide) vs. actual bleach plant data. The improved models can be used to gauge the level of washer carryover entering the bleach plant if this parameter is not regularly monitored by the mill. Additionally, these modified expressions could be integrated into advanced process control strategies for ECF bleaching where the washer carryover or dissolved lignin entrainment is measured with online sensors.

Research paper thumbnail of Bleachability of Kraft Pulps Treated by Ethanol-Based Chlorine Dioxide Delignification Sequences

Journal of Wood Chemistry and Technology, Aug 31, 2001

The institute of Paper Science and Technology is an independent graduate school, research organiz... more The institute of Paper Science and Technology is an independent graduate school, research organization, and information center for science and technology mainly concerned with manufacture and uses of pulp, paper, paperboard, and other forest products and byproducts. Established in 1929 as the Institute of Paper Chemistry, the Institute provides research and information services to the wood, fiber, and allied industries in a unique partnership between education and business. The Institute is supported by 52 North American companies. The purpose of the Institute is fulfilled through four missions, which are: l to provide a multidisciplinary graduate education to students who rise into leadership positions within the industry; who advance the science and technology of the industry and l to conduct and foster research that creates knowledge to satisfy the technological needs of the industry; l to provide the information, business performance; expertise, and interactive learning that enables customers to improve job knowledge and l to aggressively seek out technological collaboration with industry partners. opportu nities and facilitate the transfer and implementation of those tech nologies in ACCREDlTATlON The Institute of Paper Science and Technology is accredited by the Commission on Colleges of the Southern Association of Coileges and Schools to award the Master of Science and Doctor of Philosophy degrees. NOTICE AND DISCLAIMER The Institute of Paper Science and Technology (1PST) has provided a high standard of professional service and has put forth its best efforts within the time and funds available for this project. The information and conciusions are advisory and are intended only for internal use by any company who may receive this report. Each company must decide for itself the best approach to solving any problems it may have and how, or whether, this reported information should be considered in its approach. 1PST does not recommend particular products, procedures, materials, or service. These are included only in the interest of completeness within a laboratory context and budgetary constraint. Actual products, materials, and services used may differ and are peculiar to the operations of each company. In no event shaH lPST or its employees and agents have any obligation or liability for damages including, but not limited to, consequential damages arising out of or in connection with any company's use of or inabil'w to use the reported information. iPST provides no warranty or guaranty of results. The Institute of Paper Science and Technology assures equal opportunity to all qualified persons without regard to race, color, religion, sex, national origin, age, disability, marital status, or Vietnam era veterans status in the admission to, participation in, treatment of, or employment in the programs and activities which the Institute operates.

Research paper thumbnail of Electron Transfer Reactions in Pulping Systems (VII): Degradation Reactions of β-Methoxy Lignin Models

Journal of Wood Chemistry and Technology, Feb 1, 1994

(IPST) has provided a high standard of professional service and has put forth its best efforts wi... more (IPST) has provided a high standard of professional service and has put forth its best efforts within the time and funds available for this project. The information and conclusions are advisory and are intended only for internal use by any company who may receive this report. Each company must decide for itself the best approach to solving any problems it may have and how, or whether, this reported information should be considered in its approach. IPST does not recommend particular products, procedures, materials, or service. These are included only in the interest of completeness within a laboratory context and budgetary constraint. Actual products, procedures, materials, and services used may differ and are peculiar to the operations of each company. In no event shall IPST or its employees and agents have any obligation or liability for damages including, but not limited to, consequential damages arising out of or in connection with any company's use of or inability to use the reported information. IPST provides no warranty or guaranty of results.

Research paper thumbnail of Stoichiometric model of chlorine dioxide delignification of hardwood kraft pulps with oxidant-reinforced extraction effect

Tappi Journal, Mar 1, 2013

A generalized, steady-state model for hardwoods is proposed for predicting bleaching delignificat... more A generalized, steady-state model for hardwoods is proposed for predicting bleaching delignification and/or chlorine dioxide (ClO2) consumption for sequences that use oxidant-reinforced extraction. Published data for various hardwood species and mixtures were analyzed to develop the model. The kappa number data from these studies were normalized to their respective pre-D0 kappa number, and the normalized kappa numbers were plotted against the bleach demand. This mathematical transformation allowed for various brownstocks and oxygen-delignified pulps with different kappa numbers to be modeled as a single curve based on an empirical relationship with fitted equation parameters. One of the two equation parameters could be expressed as simple functions of oxidant-reinforced extraction conditions (i.e., peroxide dosage). The model forecasts ClO2 usage reasonably well (±0.20% ClO2 on pulp) for conventional ClO2 delignification with extraction. Attempts to incorporate modified bleaching delignification processes that eliminate hexenuronic acids into the model were unsuccessful; data were insufficient to develop a relationship. This straightforward stoichiometric model contains relatively few fitted parameters to be determined. The model could be used with other steady-state brightening-stage models to predict bleach usage.

Research paper thumbnail of Generalized steady-state model for chlorine dioxide brightening of hardwood kraft pulps

Research paper thumbnail of The Influence of the Bleaching Medium on Caustic Extraction Efficiency (II): Oxidized Lignin Solubility

Journal of Wood Chemistry and Technology, Nov 1, 1999

is an independent graduate school, research organization, and information center for science and ... more is an independent graduate school, research organization, and information center for science and technology mainly concerned with manufacture and uses of pulp, paper, paperboard, and other forest products and byproducts. Established in 1929, the Institute provides research and information services to the wood, fiber, and allied industries in a unique partnership between education and business. The Institute is supported by 52 North American companies. The purpose of the Institute is fulfilled through four missions, which are:

Research paper thumbnail of Stoichiometric model of chlorine dioxide delignification of softwood kraft pulps with oxidant-reinforced extraction

Tappi Journal, Apr 1, 2012

A generalized, steady-state model estimates bleaching delignification and/or chlorine dioxide con... more A generalized, steady-state model estimates bleaching delignification and/or chlorine dioxide consumption for sequences that employ oxidant-reinforced extraction. The model is based on Germgård’s stoichiometric expression for the D0E1 sequence, which relates chlorine dioxide uptake to post-extracted kappa number. Germgård’s integrated stoichiometric model was modified to normalize the extracted kappa number to the incoming kappa number. This mathematical transformation allows for various brownstocks and oxygen-delignified pulps with different kappa numbers to be modeled as a single curve whereby its shape is related to the stoichiometric parameter. From analyzing various softwood bleaching studies, it was determined that this stoichiometric parameter could be expressed as a simple function of oxidant-reinforced extraction conditions (e.g., extraction temperature and peroxide dosage). The generalized delignification model forecasts chlorine dioxide usage with small relative error from the experimental values, typically ±3% to ±10%. This model is relatively simple, with a minimum number of equation parameters to determined, and can be used with other steady-state brightening stage models to predict bleach usage.

Research paper thumbnail of The Influence of the Bleaching Medium on Chlorine Dioxide Delignification

Journal of Wood Chemistry and Technology, May 31, 2001

is an independent graduate school, research organization, and information center for science and ... more is an independent graduate school, research organization, and information center for science and technology mainly concerned with manufacture and uses of pulp, paper, paperboard, and other forest products and byproducts. Established in 1929 as the Institute of Paper Chemistry, the institute provides research and information services to the wood, fiber, and allied industries in a unique partnership between education and business. The Institute is supported by 52 North American companies. The purpose of the Institute is fulfilled through four missions, which are: * to provide a multidisciplinary graduate education to students who rise into leadership positions within the industry; who advance the science and tech nology of the industry and l to conduct and foster research that creates knowledge to satisfy the technological needs of the industry; 0 to provide the informatio business performance; expertise, and interactive learning that enables customers to improve job knowledge and l to aggressively seek out technological collaboration with industry partners. opportunities and facilitate the transfer and implementation of those technologies in ACCREDITATION The Institute of Paper Science and Technology is accredited by the Commission on Colleges of the Southern Association of Colleges and Schools to award the Master of Science and Doctor of Philosophy degrees. NOTICE AND DISCLAIMER The institute of Paper Science and Technology (IPST) has provided a high standard of professional service and has put forth its best efforts within the time and funds available for this project. The information and conclusions are advisory and are intended only for internal use by any company who may receive this report. Each company must decide for itself the best approach to solving any problems it may have and how, or whether, this reported information should be considered in its approach, IPST does not recommend particular products, procedures, materials, or service. These are included only in the interest of completeness within a taboratory context and budgetary constraint. Actual products, materials, and services used may differ and are peculiar to the operations of each company. In no event shall IPST or its employees and agents have any obligation or liability for damages including, but not limited to, consequential damages arising out of or in connection with any company's use of or inability to use the reported information. IPST provides no warranty or guaranty of results. The Institute of Paper Science and Technology assures equal opportunity to alf quatified persons without regard to race, color, religion, sex, national origin, age, disability, marital status, or Vietnam era veterans status in the admission to, participation in, treatment of, or employment in the programs and activities which the lnstitute operates.

Research paper thumbnail of Optimization of elemental chlorine-free bleaching for a softwood kraft pulp • part 2: economic analysis of chemical and steam consumption

Tappi Journal, Oct 1, 2010

Our previous investigation [1] re-analyzed the data from Basta and co-workers (1992 TAPPI Pulping... more Our previous investigation [1] re-analyzed the data from Basta and co-workers (1992 TAPPI Pulping Conference) to demonstrate how oxidative alkaline extraction can be augmented and how these changes affect chlorine dioxide consumption with elemental chlorine-free (ECF) sequences. The current study manipulates extraction delignification variables to curtail bleaching costs with a conventional U.S. Southern softwood kraft pulp. The economic advantages of ~0.35% to 0.65% H2O2 peroxide reinforcement in a 70°C (EOP)-stage versus 90°C (EO)-stage are predisposed to the brightness targets, to short or long bleach sequences, and to mill energy costs. Minimized bleaching costs are generally realized when a 90°C (EO) is employed in D0(EO)D1 bleaching, whereas a 70°C (EOP) is economically advantageous for D0(EOP)D1E2D2 bleaching. The findings we disclose here help to clarify previous ECF optimization studies of conventional softwood kraft pulps.

Research paper thumbnail of Fundamental Study of Relative Delignification Efficiencies (II): Combinations of Pulping Additives

Journal of Wood Chemistry and Technology, 1996

A specific model reaction has been developed that provides information on relative rates of pulpi... more A specific model reaction has been developed that provides information on relative rates of pulping reactions that involve quinone methides. The latter are key delignification intermediates. The lignin model 1 was reacted under soda, kraft, soda/anthraquinone (AQ), and sulfite conditions. All alkaline conditions displayed the same ligrdn model disappearance rate, verifying that quinone methide formation was the rate determining step for subsequent reactions. The results indicate that reactions of the pulping reagents and quinone methides are reversible in most cases and that anthrahydroquinone (AHQ) is the most effective reagent at promoting _-aryl ether cleavage-an important deligrdfication reaction. The product distribution for an alkaline sulfite reaction of lignin model 1 was similar to that from a soda cook; however, an c_-sulfonate (11) was the predominate product when the model was reacted under neutral sulfite conditions. Under alkaline conditions, the c_-sulfonate (11) reverted back to a quinone methide. An acid sulfite cook of model 1 gave a product distribution similar to an acid cook that contained no bisulfite. All of the sulfite cooks (acid, neutral, or alkaline) of model 1 showed only low levels of [_-aryl ether cleavage. The delignification efficiency of AHQ was improved in the presence of sulfite ions. This synergism may be because sulfite reduces AHQ radical ions to dianions or captures byproducts that otherwise consume AHQ ions.

Research paper thumbnail of Competing Reactions Affecting Delignification in Pulping Systems

Journal of Wood Chemistry and Technology, 1996

Research paper thumbnail of Fundamental Study of Relative Delignification Efficiencies (III): Organosolv Pulping Systems

Journal of Wood Chemistry and Technology, 1996

Research paper thumbnail of Fundamental study of relative delignification efficiencies (I): Sulfite pulping

A specific model reaction has been developed that provides information on relative rates of pulpi... more A specific model reaction has been developed that provides information on relative rates of pulping reactions that involve quinone methides. The latter are key delignification intermediates. The lignin model 1 was reacted under soda, kraft, soda/anthraquinone (AQ), and sulfite conditions. All alkaline conditions displayed the same ligrdn model disappearance rate, verifying that quinone methide formation was the rate determining step for subsequent reactions. The results indicate that reactions of the pulping reagents and quinone methides are reversible in most cases and that anthrahydroquinone (AHQ) is the most effective reagent at promoting _-aryl ether cleavage-an important deligrdfication reaction. The product distribution for an alkaline sulfite reaction of lignin model 1 was similar to that from a soda cook; however, an c_-sulfonate (11) was the predominate product when the model was reacted under neutral sulfite conditions. Under alkaline conditions, the c_-sulfonate (11) reverted back to a quinone methide. An acid sulfite cook of model 1 gave a product distribution similar to an acid cook that contained no bisulfite. All of the sulfite cooks (acid, neutral, or alkaline) of model 1 showed only low levels of [_-aryl ether cleavage. The delignification efficiency of AHQ was improved in the presence of sulfite ions. This synergism may be because sulfite reduces AHQ radical ions to dianions or captures byproducts that otherwise consume AHQ ions.

Research paper thumbnail of Fundamentals and numerical modeling of unit operations in the forest products industries : 1999 AIChE Forest Products Symposium

American Institute of Chemical Engineers eBooks, 2000

Research paper thumbnail of Kraft pulp viscosity as a predictor of paper strength: Its uses and abuses

October 2023

For bleached kraft pulps, two factors govern paper strength: the individual fiber strength, and t... more For bleached kraft pulps, two factors govern paper strength: the individual fiber strength, and the bond strength that adheres the individual fibers together in the paper matrix. Inherent fiber strength is related to the length of the carbohydrate polymers, also known as the degree of polymerization (DP). Average DP (DP) is inferred by performing pulp viscosity measurements. Under certain circumstances during kraft pulping and bleaching, the average polymer lengths can be shortened, resulting in lower pulp viscosity, and may indicate fiber damage. Fiber damage typically manifests itself as a reduction in tear strength for well-bonded handsheets. This paper will review the literature on how pulp viscosity can predict paper/fiber strength and how it can be used as a diagnostic tool. It can be a means to monitor pulp quality during pulping and bleaching, as well as to alert when such operations approach a critical threshold. However, viscosity losses must be carefully and judiciously a...

Research paper thumbnail of Fundamental study of relative delignification efficiencies (II): Effects of phenols, carbohydrates, amines and reagent combinations during pulping

Reactions of a _-aryl ether lignin model compound (1) provide information on the relative rates o... more Reactions of a _-aryl ether lignin model compound (1) provide information on the relative rates of pulping reactions that involve quinone methides (QM). The lignin model was reacted with 2,6xylenol, 1,5-anhydrocellobiitol, amylose, reagent combinations, and amines. The results indicate that condensation reactions between QMs and phenolates or carbohydrates are much slower than fragmentation reactions with sulfide and anthrahydroquinone (AHQ). A sulfide/sulfite combination did not enhance 13-aryl ether fragmentation; however, a sulfide/AHQ combination increased fragmentation synergistically. The addition of amines to soda cooks substantially increased the conversion of model 1 to a vinyl ether (9).

Research paper thumbnail of New Insights into Lignin Modification During Chlorine Dioxide Bleaching Sequences (II): Modifications in Extraction (E) and Chlorine Dioxide Bleaching (D1)

Journal of Wood Chemistry and Technology, 2005

... Dr. Brian N. Brogdon a * , Douglas G. Mancosky b & Lucian A. Lucia b pages 221-237. .... more ... Dr. Brian N. Brogdon a * , Douglas G. Mancosky b & Lucian A. Lucia b pages 221-237. ... J. Chem. Phys. , 33: 1488 View all references as well as by Fitzpatrick and Steelink.2426. Fitzpatrick, JD and Steelink, S. 1972. The origin of the paramagnetic species in lignin solutions. ...

Research paper thumbnail of New Insights into Lignin Modification during Chlorine Dioxide Bleaching Sequences (IV): The Impact of Modifications in the (EP) and (EOP) Stages on the D1 Stage

Journal of Wood Chemistry and Technology, Jul 1, 2005

Abstract Peroxide‐reinforced extractions ((EP) or (EOP)) of D0 pulps lower both post‐extraction k... more Abstract Peroxide‐reinforced extractions ((EP) or (EOP)) of D0 pulps lower both post‐extraction kappa numbers and Klason lignins more than either E or (EO). An oxygen‐reinforced extraction (EO) results in lower kappa numbers, but affords comparable Klason ...

Research paper thumbnail of A fundamental study of a novel extraction stage for an organosolv-based bleaching sequence

Research paper thumbnail of Revised steady-state model for chlorine dioxide brightening that considers extraction washer carryover effects

Tappi Journal, Apr 1, 2016

Research paper thumbnail of Improved steady-state models for chlorine dioxide delignification sequences that include washer carryover effects

Tappi Journal, Mar 1, 2015

In previous studies, generalized steady-state models were proposed to approximate the chlorine di... more In previous studies, generalized steady-state models were proposed to approximate the chlorine dioxide demand needed for the delignification of softwood and hardwood pulps, where the kappa number entering the bleach plant can fluctuate. However, these expressions neglect the effect of dissolved solids with the stock that originate from incomplete pulp washing. In this study, the original elemental chlorine-free (ECF) models are modified to include the effects of carryover from brownstock or post-oxygen washing. The stoichiometric bleach consumption from carryover, based on its composition, was calculated from various literature sources. The majority of the bleach demand (about 70%) results from the dissolved lignin contained in the brownstock carryover, with the remainder resulting from the inorganic sulfur constituents (e.g., sulfide and thiosulfate). When the effect of brownstock carryover was taken into account, the modified models accurately predicted the amount of chlorine dioxide consumed for a given delignification level (about ±0.1% chlorine dioxide) vs. actual bleach plant data. The improved models can be used to gauge the level of washer carryover entering the bleach plant if this parameter is not regularly monitored by the mill. Additionally, these modified expressions could be integrated into advanced process control strategies for ECF bleaching where the washer carryover or dissolved lignin entrainment is measured with online sensors.

Research paper thumbnail of Bleachability of Kraft Pulps Treated by Ethanol-Based Chlorine Dioxide Delignification Sequences

Journal of Wood Chemistry and Technology, Aug 31, 2001

The institute of Paper Science and Technology is an independent graduate school, research organiz... more The institute of Paper Science and Technology is an independent graduate school, research organization, and information center for science and technology mainly concerned with manufacture and uses of pulp, paper, paperboard, and other forest products and byproducts. Established in 1929 as the Institute of Paper Chemistry, the Institute provides research and information services to the wood, fiber, and allied industries in a unique partnership between education and business. The Institute is supported by 52 North American companies. The purpose of the Institute is fulfilled through four missions, which are: l to provide a multidisciplinary graduate education to students who rise into leadership positions within the industry; who advance the science and technology of the industry and l to conduct and foster research that creates knowledge to satisfy the technological needs of the industry; l to provide the information, business performance; expertise, and interactive learning that enables customers to improve job knowledge and l to aggressively seek out technological collaboration with industry partners. opportu nities and facilitate the transfer and implementation of those tech nologies in ACCREDlTATlON The Institute of Paper Science and Technology is accredited by the Commission on Colleges of the Southern Association of Coileges and Schools to award the Master of Science and Doctor of Philosophy degrees. NOTICE AND DISCLAIMER The Institute of Paper Science and Technology (1PST) has provided a high standard of professional service and has put forth its best efforts within the time and funds available for this project. The information and conciusions are advisory and are intended only for internal use by any company who may receive this report. Each company must decide for itself the best approach to solving any problems it may have and how, or whether, this reported information should be considered in its approach. 1PST does not recommend particular products, procedures, materials, or service. These are included only in the interest of completeness within a laboratory context and budgetary constraint. Actual products, materials, and services used may differ and are peculiar to the operations of each company. In no event shaH lPST or its employees and agents have any obligation or liability for damages including, but not limited to, consequential damages arising out of or in connection with any company's use of or inabil'w to use the reported information. iPST provides no warranty or guaranty of results. The Institute of Paper Science and Technology assures equal opportunity to all qualified persons without regard to race, color, religion, sex, national origin, age, disability, marital status, or Vietnam era veterans status in the admission to, participation in, treatment of, or employment in the programs and activities which the Institute operates.

Research paper thumbnail of Electron Transfer Reactions in Pulping Systems (VII): Degradation Reactions of β-Methoxy Lignin Models

Journal of Wood Chemistry and Technology, Feb 1, 1994

(IPST) has provided a high standard of professional service and has put forth its best efforts wi... more (IPST) has provided a high standard of professional service and has put forth its best efforts within the time and funds available for this project. The information and conclusions are advisory and are intended only for internal use by any company who may receive this report. Each company must decide for itself the best approach to solving any problems it may have and how, or whether, this reported information should be considered in its approach. IPST does not recommend particular products, procedures, materials, or service. These are included only in the interest of completeness within a laboratory context and budgetary constraint. Actual products, procedures, materials, and services used may differ and are peculiar to the operations of each company. In no event shall IPST or its employees and agents have any obligation or liability for damages including, but not limited to, consequential damages arising out of or in connection with any company's use of or inability to use the reported information. IPST provides no warranty or guaranty of results.

Research paper thumbnail of Stoichiometric model of chlorine dioxide delignification of hardwood kraft pulps with oxidant-reinforced extraction effect

Tappi Journal, Mar 1, 2013

A generalized, steady-state model for hardwoods is proposed for predicting bleaching delignificat... more A generalized, steady-state model for hardwoods is proposed for predicting bleaching delignification and/or chlorine dioxide (ClO2) consumption for sequences that use oxidant-reinforced extraction. Published data for various hardwood species and mixtures were analyzed to develop the model. The kappa number data from these studies were normalized to their respective pre-D0 kappa number, and the normalized kappa numbers were plotted against the bleach demand. This mathematical transformation allowed for various brownstocks and oxygen-delignified pulps with different kappa numbers to be modeled as a single curve based on an empirical relationship with fitted equation parameters. One of the two equation parameters could be expressed as simple functions of oxidant-reinforced extraction conditions (i.e., peroxide dosage). The model forecasts ClO2 usage reasonably well (±0.20% ClO2 on pulp) for conventional ClO2 delignification with extraction. Attempts to incorporate modified bleaching delignification processes that eliminate hexenuronic acids into the model were unsuccessful; data were insufficient to develop a relationship. This straightforward stoichiometric model contains relatively few fitted parameters to be determined. The model could be used with other steady-state brightening-stage models to predict bleach usage.

Research paper thumbnail of Generalized steady-state model for chlorine dioxide brightening of hardwood kraft pulps

Research paper thumbnail of The Influence of the Bleaching Medium on Caustic Extraction Efficiency (II): Oxidized Lignin Solubility

Journal of Wood Chemistry and Technology, Nov 1, 1999

is an independent graduate school, research organization, and information center for science and ... more is an independent graduate school, research organization, and information center for science and technology mainly concerned with manufacture and uses of pulp, paper, paperboard, and other forest products and byproducts. Established in 1929, the Institute provides research and information services to the wood, fiber, and allied industries in a unique partnership between education and business. The Institute is supported by 52 North American companies. The purpose of the Institute is fulfilled through four missions, which are:

Research paper thumbnail of Stoichiometric model of chlorine dioxide delignification of softwood kraft pulps with oxidant-reinforced extraction

Tappi Journal, Apr 1, 2012

A generalized, steady-state model estimates bleaching delignification and/or chlorine dioxide con... more A generalized, steady-state model estimates bleaching delignification and/or chlorine dioxide consumption for sequences that employ oxidant-reinforced extraction. The model is based on Germgård’s stoichiometric expression for the D0E1 sequence, which relates chlorine dioxide uptake to post-extracted kappa number. Germgård’s integrated stoichiometric model was modified to normalize the extracted kappa number to the incoming kappa number. This mathematical transformation allows for various brownstocks and oxygen-delignified pulps with different kappa numbers to be modeled as a single curve whereby its shape is related to the stoichiometric parameter. From analyzing various softwood bleaching studies, it was determined that this stoichiometric parameter could be expressed as a simple function of oxidant-reinforced extraction conditions (e.g., extraction temperature and peroxide dosage). The generalized delignification model forecasts chlorine dioxide usage with small relative error from the experimental values, typically ±3% to ±10%. This model is relatively simple, with a minimum number of equation parameters to determined, and can be used with other steady-state brightening stage models to predict bleach usage.

Research paper thumbnail of The Influence of the Bleaching Medium on Chlorine Dioxide Delignification

Journal of Wood Chemistry and Technology, May 31, 2001

is an independent graduate school, research organization, and information center for science and ... more is an independent graduate school, research organization, and information center for science and technology mainly concerned with manufacture and uses of pulp, paper, paperboard, and other forest products and byproducts. Established in 1929 as the Institute of Paper Chemistry, the institute provides research and information services to the wood, fiber, and allied industries in a unique partnership between education and business. The Institute is supported by 52 North American companies. The purpose of the Institute is fulfilled through four missions, which are: * to provide a multidisciplinary graduate education to students who rise into leadership positions within the industry; who advance the science and tech nology of the industry and l to conduct and foster research that creates knowledge to satisfy the technological needs of the industry; 0 to provide the informatio business performance; expertise, and interactive learning that enables customers to improve job knowledge and l to aggressively seek out technological collaboration with industry partners. opportunities and facilitate the transfer and implementation of those technologies in ACCREDITATION The Institute of Paper Science and Technology is accredited by the Commission on Colleges of the Southern Association of Colleges and Schools to award the Master of Science and Doctor of Philosophy degrees. NOTICE AND DISCLAIMER The institute of Paper Science and Technology (IPST) has provided a high standard of professional service and has put forth its best efforts within the time and funds available for this project. The information and conclusions are advisory and are intended only for internal use by any company who may receive this report. Each company must decide for itself the best approach to solving any problems it may have and how, or whether, this reported information should be considered in its approach, IPST does not recommend particular products, procedures, materials, or service. These are included only in the interest of completeness within a taboratory context and budgetary constraint. Actual products, materials, and services used may differ and are peculiar to the operations of each company. In no event shall IPST or its employees and agents have any obligation or liability for damages including, but not limited to, consequential damages arising out of or in connection with any company's use of or inability to use the reported information. IPST provides no warranty or guaranty of results. The Institute of Paper Science and Technology assures equal opportunity to alf quatified persons without regard to race, color, religion, sex, national origin, age, disability, marital status, or Vietnam era veterans status in the admission to, participation in, treatment of, or employment in the programs and activities which the lnstitute operates.

Research paper thumbnail of Optimization of elemental chlorine-free bleaching for a softwood kraft pulp • part 2: economic analysis of chemical and steam consumption

Tappi Journal, Oct 1, 2010

Our previous investigation [1] re-analyzed the data from Basta and co-workers (1992 TAPPI Pulping... more Our previous investigation [1] re-analyzed the data from Basta and co-workers (1992 TAPPI Pulping Conference) to demonstrate how oxidative alkaline extraction can be augmented and how these changes affect chlorine dioxide consumption with elemental chlorine-free (ECF) sequences. The current study manipulates extraction delignification variables to curtail bleaching costs with a conventional U.S. Southern softwood kraft pulp. The economic advantages of ~0.35% to 0.65% H2O2 peroxide reinforcement in a 70°C (EOP)-stage versus 90°C (EO)-stage are predisposed to the brightness targets, to short or long bleach sequences, and to mill energy costs. Minimized bleaching costs are generally realized when a 90°C (EO) is employed in D0(EO)D1 bleaching, whereas a 70°C (EOP) is economically advantageous for D0(EOP)D1E2D2 bleaching. The findings we disclose here help to clarify previous ECF optimization studies of conventional softwood kraft pulps.

Research paper thumbnail of Fundamental Study of Relative Delignification Efficiencies (II): Combinations of Pulping Additives

Journal of Wood Chemistry and Technology, 1996

A specific model reaction has been developed that provides information on relative rates of pulpi... more A specific model reaction has been developed that provides information on relative rates of pulping reactions that involve quinone methides. The latter are key delignification intermediates. The lignin model 1 was reacted under soda, kraft, soda/anthraquinone (AQ), and sulfite conditions. All alkaline conditions displayed the same ligrdn model disappearance rate, verifying that quinone methide formation was the rate determining step for subsequent reactions. The results indicate that reactions of the pulping reagents and quinone methides are reversible in most cases and that anthrahydroquinone (AHQ) is the most effective reagent at promoting _-aryl ether cleavage-an important deligrdfication reaction. The product distribution for an alkaline sulfite reaction of lignin model 1 was similar to that from a soda cook; however, an c_-sulfonate (11) was the predominate product when the model was reacted under neutral sulfite conditions. Under alkaline conditions, the c_-sulfonate (11) reverted back to a quinone methide. An acid sulfite cook of model 1 gave a product distribution similar to an acid cook that contained no bisulfite. All of the sulfite cooks (acid, neutral, or alkaline) of model 1 showed only low levels of [_-aryl ether cleavage. The delignification efficiency of AHQ was improved in the presence of sulfite ions. This synergism may be because sulfite reduces AHQ radical ions to dianions or captures byproducts that otherwise consume AHQ ions.

Research paper thumbnail of Competing Reactions Affecting Delignification in Pulping Systems

Journal of Wood Chemistry and Technology, 1996

Research paper thumbnail of Fundamental Study of Relative Delignification Efficiencies (III): Organosolv Pulping Systems

Journal of Wood Chemistry and Technology, 1996

Research paper thumbnail of Fundamental study of relative delignification efficiencies (I): Sulfite pulping

A specific model reaction has been developed that provides information on relative rates of pulpi... more A specific model reaction has been developed that provides information on relative rates of pulping reactions that involve quinone methides. The latter are key delignification intermediates. The lignin model 1 was reacted under soda, kraft, soda/anthraquinone (AQ), and sulfite conditions. All alkaline conditions displayed the same ligrdn model disappearance rate, verifying that quinone methide formation was the rate determining step for subsequent reactions. The results indicate that reactions of the pulping reagents and quinone methides are reversible in most cases and that anthrahydroquinone (AHQ) is the most effective reagent at promoting _-aryl ether cleavage-an important deligrdfication reaction. The product distribution for an alkaline sulfite reaction of lignin model 1 was similar to that from a soda cook; however, an c_-sulfonate (11) was the predominate product when the model was reacted under neutral sulfite conditions. Under alkaline conditions, the c_-sulfonate (11) reverted back to a quinone methide. An acid sulfite cook of model 1 gave a product distribution similar to an acid cook that contained no bisulfite. All of the sulfite cooks (acid, neutral, or alkaline) of model 1 showed only low levels of [_-aryl ether cleavage. The delignification efficiency of AHQ was improved in the presence of sulfite ions. This synergism may be because sulfite reduces AHQ radical ions to dianions or captures byproducts that otherwise consume AHQ ions.

Research paper thumbnail of Corrosion Control in Closed Mills

Corrosion Control in Closed Mills [A 390 Preparation for Research Problem (IPST PhD Entrance Exam Problem)], 1994

Closed mill (or effluent-free) technologies have received a lot of attention within the past few ... more Closed mill (or effluent-free) technologies have received a lot of attention within the past few years as a method of treating bleach plant effluent. One possible problem with the proposed closed mill scenarios is the build-up of non-process elements within the water recycling loops. These non-process elements have the potential of increasing the corrosion experienced by the bleach kraft mill. Increased chloride concentrations have been identified as a likely candidate for increasing mill-wide corrosion in an "effluent-free" mill. The presence of chlorides in an open bleach kraft mill has been known to promote the corrosion of bleach plant equipment as well as paper machine equipment. Little research. has been conducted to evaluate how increased chloride levels will impact the corrosion of various process equipment in a closed integrated bleach kraft mill. Research is needed to determine the effects of increased chlorides on the corrosion of mill process equipment. The knowledge gained from this research will aid in the material selection and corrosion mitigation for the future closed mill. This report has identified several key research areas where information is needed to evaluate how increased chloride levels will impact corrosion. The identified research areas were prioritized. One particular research area, chlorides in kraft process liquors, was chosen as a case study. Little information is known about how chlorides will affect corrosion in the kraft pulp mill. A research program was designed to investigate the effects of chlorides on the corrosivity of kraft process liquors on common construction materials used in the kraft pulp mill.