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Preparation of regenerated cellulose from rice straw lignocellulosic waste and its use for reinforced paper products, TAPPI Journal July 2021

ABSTRACT: Rice straw waste is a lignocellulosic waste produced by farmers in large quantities. In this study, regenerated cellulose (RC) from rice straw was prepared by dissolving rice straw holocellulose (HC) in NaOH/Urea/Thio-urea/Water solution by the freeze-thawing process. The crystallinity index of RC was calculated at 31%, which is out of the crystallinity range of 39%•69% that has been previously suggested.The study indicated that the RC is amorphous with a low degree of polymerization (638) and higher hydroxyl group content as compared to HC. The fiber length of RC was found to be 26.7% shorter; however, the width of RC was 21.2% higher as compared to HC. Reduced kinked fiber content was observed in the fraction of RC (18.3%) as compared with HC (39.1%), and a higher curl index of fiber was observed more so in HC (10.5%) than RC (5.6%). Because of the regeneration process, the fiber length was reduced and a fines element content of about 96% was observed in RC compared to the initial fines content of HC (56.9%). Irrespective of the high fines element content of RC, the composite paper of rice straw bleached pulp and RC fibers was developed with an increase in the tensile index from 41.4 N.m/g to 71.2 N.m/g and an increase in the burst index from 4.7 kPa.m2/g to 5.3 kPa.m2/g with the addition of 5% and 15% RC, respectively. However, enhanced tear index of paper was observed up to 5% and then it declined upon further addition of RC. The study revealed that regenerated cellulose can be used as a strength additive to overcome the shortcomings of low mechanical properties in paper products.

The Future of Sustainability at Pulp and Paper Mills, Paper360º November/December 2021

The Future of Sustainability at Pulp and Paper Mills, Paper360º November/December 2021

World’s Largest MVR Evaporation Plant for Sulphite Spent Liquor at Sappi Saiccor Pulp Mill, Paper360º July/August 2022

TAPPI Journal Summaries, Paper360º March/April 2019

TAPPI Journal Summaries, Paper360º March/April 2019

TAPPI Journal, Paper360º January/February 2023

TAPPI Journal Summaries, Paper360º March/April 2024

Mill experience of calcium carbonate scale formation in green liquor pipelines, TAPPI Journal August 2020

ABSTRACT: Experience of hard calcite (CaCO3) scale formation in green liquor pipelines at four kraft pulp mills was systematically investigated to determine if there is any correlation between the severity of the scaling problem at each mill and the design and operating conditions of its causticizing plant. The results show that the high degree of supersaturation of calcium ions (Ca2+) in the liquor is the main contributing factor. Mills that operate at a lower green liquor total titratable alkali (TTA), higher causticity, and a larger liquor temperature drop are more likely to produce a green liquor that is supersaturated with Ca2+, and thus experience more severe scaling problems. In order to minimize CaCO3 scaling, the green liquor handling equipment should be operated as steady as possible to avoid conditions that allow Ca2+ to be supersaturated. The strategies include minimizing variations in liquor TTA, insulating the green liquor pipelines to reduce temperature gradients, and adding lime mud to weak wash to provide seeds for precipitation to occur on mud particles instead of on metal substrate.

Machinery That Can Support Zero Landfill Goals, Paper360º January/February 2022

Machinery That Can Support Zero Landfill Goals, Paper360º January/February 2022

TAPPI Journal Summaries, Paper360º September/October 2023

TAPPI Journal Summaries, Paper360º September/October

TAPPI Journal Summaries, Paper360º September/October