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Lignin carbohydrate complex studies during kraft pulping for producing paper grade pulp from birch, TAPPI Journal September 2020
ABSTRACT: Paper grade pulp production across the globe is dominated by the kraft process using different lignocellulosic raw materials. Delignification is achieved around 90% using different chemical treatments. A bottleneck for complete delignification is the presence of residual covalent bonds that prevail between lignin and carbohydrate even after severe chemical pulping and oxygen delignification steps. Different covalent bonds are present in native wood that sustain drastic pulping conditions. In this study, 100% birch wood was used for producing paper grade pulp, and the lignin carbohydrate bonds were analyzed at different stages of the kraft cook. The lignin carbohydrate bonds that were responsible for residual lignin retention in unbleached pulp were compared and analyzed with the original lignin-carbohydrate complex (LCC) bonds in native birch wood. It was shown that lignin remaining after pulping and oxygen delignification was mainly bound to xylan, whereas the lignin bound to glucomannan was for the most part degraded.
Journal articles
Magazine articles
Co-pulping of Trewia nudiflora and Trema orientalis, TAPPI Journal June 2023
ABSTRACT: Trewia nudiflora, a fast-growing species, was evaluated as a pulpwood. The a-cellulose content of this species was 40.4% with a Klason lignin of 21.5%. It was characterized by shorter fibers with a thin cell wall. The pulp yield was 40% with a kappa number of 16 at the conditions of 18% active alkali charge and 30% sulfidity for 2 h cooking at 170°C. T. nudiflora was similar to Trema orientalis in anatomical, morphological, and chemical composition; therefore, mixed chips at a 50:50 mixture ratio were cooked under optimum conditions. The pulp yield of mixed chip cooking was 45.4% with a kappa number of 19.4. The tensile and tear index of T. nudiflora pulps were 64.8 Nœm/g and 11.5 kPaœm2/g at 35 °SR, respectively. The mixed chips, T. nudiflora, and T. orientalis pulps showed above 81% brightness when bleached by D0(EP)D1 sequence using 20 kg chlorine dioxide (ClO2)/ton of pulp.
Journal articles
The influence of ph on the growth-linked biodegradation kinetics of selected resin acids found in pulp mill effluent, TAPPI JOURNAL, July 1999, Vol. 82(7)
The influence of ph on the growth-linked biodegradation kinetics of selected resin acids found in pulp mill effluent, TAPPI JOURNAL, July 1999, Vol. 82(7)
Journal articles
Fiber length fractionation of tmp using pressure screens, TAPPI JOURNAL, June 1999, Vol. 82(6)
Fiber length fractionation of tmp using pressure screens, TAPPI JOURNAL, June 1999, Vol. 82(6)
Journal articles
Paprican's process for polysulfide liquor production in kraft mill causticizers, part 1: batch trials and process optimization, TAPPI JOURNAL, October 1999, Vol. 82(10)
Paprican's process for polysulfide liquor production in kraft mill causticizers, part 1: batch trials and process optimization, TAPPI JOURNAL, October 1999, Vol. 82(10)
Journal articles
Lessons learned from gasifier operating experience, TAPPI JOURNAL, October 1999, Vol. 82(10)
Lessons learned from gasifier operating experience, TAPPI JOURNAL, October 1999, Vol. 82(10)
Journal articles
Comments on the measurement of cell wall water, TAPPI JOURNAL, September 1999, Vol. 82(9)
Comments on the measurement of cell wall water, TAPPI JOURNAL, September 1999, Vol. 82(9)
Journal articles
Black liquor gasification - operating experience at weyerhaeuser, new bern, nc, TAPPI JOURNAL, September 1999, Vol. 82(9)
Black liquor gasification - operating experience at weyerhaeuser, new bern, nc, TAPPI JOURNAL, September 1999, Vol. 82(9)
Magazine articles
Deinking Difficulties Related to Ink Formulation, Printing P
Deinking Difficulties Related to Ink Formulation, Printing Process and Type of Paper
Journal articles
Production of high yield bleached hardwood kraft pulp: Breaking the kraft pulp yield barrier,TAPPI Journal December 2024
Author: Peter W. Hart | TAPPI J. 10(9): 37(2011) - ABSTRACT: A modified kraft pulping process has been developed that successfully breaks the traditional hard-wood kraft pulp yield barrier. The process produces fully bleached, high brightness hardwood kraft pulp with a yield of greater than 53% on wood. Details of the development and processing steps, along with various recovery cycle impacts, are discussed.