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Preparing prehydrolyzed kraft dissolving pulp via phosphotungstic acid prehydrolysis from grape branches, TAPPI Journal January 2022

ABSTRACT: Dissolving pulp was successful prepared via phosphotungstic acid (PTA) prehydrolysis kraft (PHK) cooking followed by an elementary chlorine-free (ECF) bleaching process from grape branches. The effects of prehydrolysis temperature, reaction time, and PTA concentration that potentially affect the quality of dissolving pulp product on chemical components of pulp were studied via an orthogonal experiment. The structure of lignin was activated during the PTA prehydrolysis phase, and lignin was easily removed during the following cooking process. Thus, relatively mild conditions (140°C, 100 min) can be used in the cooking process. During the prehydrolysis phase, temperature exhibited the most significant influence on the cellulose purity of the obtained pulp fiber, followed by reaction time and PTA concentration. The optimized prehydrolysis conditions were as follows: prehydrolysis temperature, 145°C; reaction time, 75 min; and PTA concentration, 1 wt%. Whether the excessively high prehydrolysis temperature or prolonging the reaction time did not favor the retention of long chain cellulose, the delignification selectivity for the cooking process could not be further improved by excessive PTA loading. Under these prehydrolysis conditions, 94.1% and 29.0% for a-cellulose content and total yield could be achieved after the given cooking and bleaching conditions, respectively. Moreover, the chemical structure and crystal form of cellulose were scarcely changed after PTA prehydrolysis, which could be confirmed by results from Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). PTA prehydrolysis could be considered as an alternative method for preparing PHK dissolving pulp under relatively mild cooking conditions.

Fundamental molecular characterization and comparison of the O, D0, and E stage effluents from hardwood pulp bleaching, TAPPI Journal 2019

ABSTRACT: The present study characterized effluents from the O, D0, and E stages using nuclear magnetic reso-nance (NMR) and gel permeation chromatography (GPC) techniques to better understand the chemical nature of the dissolved organics formed from the bleaching of a high-yield hardwood kraft pulp. Understanding the structures and molecular weight distribution of these organics is the first step in developing methods to mitigate these contam-inates in the discharged effluents. The results indicated that the molecular weight distribution (MWD) of the dis-solved organics from oxygen delignification effluent is broader than those from D0 and E stage effluents. In addition, the O stage filtrate contained considerable amounts of lignin and xylan fragments, which showed its efficiency in removing such materials. The effluent from the D0 stage contained a lower amount of high molecular weight frag-ments and a higher amount of low molecular weight fragments versus the O-stage filtrate. Aromatic structures were nearly absent in the D0 stage filtrate, but the degraded organic material, presumably from oxidized lignin, contained olefinic (C=C) and carbonyl (C=O) functional groups. Furthermore, higher molecular weight fragments were detected in the E-stage effluent, presumably due to the extensive solubilization and removal of the oxidized lignin generated from the D0 pulp.

Ink Detachment, Fragmentation and Alkali Darkening During Pulping of ONP/OMG Part II: Effects of Sodium Sulphite, 2007 TAPPI 8th Research Forum on Recycling

Ink Detachment, Fragmentation and Alkali Darkening During Pulping of ONP/OMG Part II: Effects of Sodium Sulphite, 2007 TAPPI 8th Research Forum on Recycling

Small Particle Migration Mechanisms in Consolidating Pigment Coating Layers, 2008 Advanced Coating Fundamentals Symposium

Small Particle Migration Mechanisms in Consolidating Pigment Coating Layers, 2008 Advanced Coating Fundamentals Symposium

An Alternate Approach to Flue Gas Heat Recovery, 2011 PEERS Conference

An Alternate Approach to Flue Gas Heat Recovery, 2011 PEERS Conference

Closed-Loop Vacuum Control in Papermaking: A Data-Driven Approach to Wet End Optimization, TAPPICon26

New improved quality inspection for food and liquid packaging board - innovative use of 3D detection for inspecting indents and outdents, and UV- technology for reliable inspection of oil, TAPPICon26

Is there Sulfuric Acid in Flue Gases in Biomass Combustion?

Is there Sulfuric Acid in Flue Gases in Biomass Combustion? Measurement Techniques and Results, 2016 PEERS

Ten Year Experience with Sustainable Composite Tubes in SCA

Ten Year Experience with Sustainable Composite Tubes in SCA High Efficiency Recovery Boiler in Östrand Sweden, 2016 PEERS

Generalized Steady-State Model for Chlorine Dioxide Brighten

Generalized Steady-State Model for Chlorine Dioxide Brightening of Hardwood Kraft Pulps, 2016 PEERS