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Eucalyptus black liquor properties in a lignin extraction process: density, dry solids, viscosity, inorganic, and organic content, TAPPI Journal March 2023

ABSTRACT: Extracting lignin from black liquor is becoming more common, although only a few research papers discuss the impact of the process on the liquor’s primary properties. This work aims to determine the changes in black liquor properties as it undergoes a lignin extraction process using carbon dioxide (CO2). A diluted eucalyptus black liquor sample (DBL) was acidified with CO2 to a final pH of 8.5. After filtration, the kraft lignin was removed, and the filtrated lignin lean black liquor (LLBL) was collected. Five acidified black liquors (ABL) samples were collected during acidification at pH 10.5; 10.0; 9.5; 9.0; and 8.5. The samples were analyzed regarding lignin content in solution, sodium carbonate (Na2CO3), sodium sulfate (Na2SO4), density, dry solids content, and viscosity. While Na2SO4 remained almost constant, Na2CO3 presented an enormous increase in its concentration when comparing DBL with LLBL. As pH decreased, the lignin content in the solution was also reduced due to lignin precipitation. The results showed similar behavior for dry solids, density, and viscosity of the supernatant, but an increase in density was observed around pH 9.00. In light of this, the density of LLBL turns out to be closer to the one in the initial DBL. The significant increase in carbonate content could explain this behavior during acidification with CO2 once the inorganic content significantly influences the property. The viscosity was determined from 10 s-1 to 2000 s-1. We observed a Newtonian behavior for all samples. The increase in carbonate content in the sample is crucial information to the recovery cycle, especially for calculating the mass and energy balance when targeting the use of the LLBL.

TAPPI Journal Summaries, Paper360º January/February 2021

TAPPI Journal Summaries, Paper360º January/February 2021

TAPPI Journal Summaries, Paper360º January/February 2020

TAPPI Journal Summaries, Paper360º January/February 2020

Editorial: 2018 TAPPI Journal features diverse content, TAPPI Journal November 2018

Editorial: 2018 TAPPI Journal features diverse content, TAPPI Journal November 2018

TAPPI Journal Summaries, Paper360º November/December 2020

TAPPI Journal Summaries, Paper360º November/December 2020

TAPPI Journal Summaries,Paper360º July/August 2021

TAPPI Journal Summaries,Paper360º July/August 2021

TAPPI Journal Summaries, Paper360º September/October 2019

TAPPI Journal Summaries, Paper360º September/October 2019

TAPPI Journal, Paper360º January/February 2023

Considerations in managing wastewater odor at pulp and paper operations, TAPPI Journal March 2022

ABSTRACT: Many pulp and paper mills are, at least periodically, faced with the release of odors that can migrate offsite and be considered a nuisance by nearby residents. At chemical pulp mills, perceptible odors associated with reduced sulfur compounds (RSCs) are common, many of which are highly perceptible owing to their low odor thresholds. As releases of RSCs and other odorous substances from production processes are progressively controlled, the proportional contribution from wastewater treatment systems to areal odors can increase. This review paper summarizes important fundamentals of odor generation, source identification, and control. Common odorous substances are identified, and mechanisms for their generation are summarized. Approaches for measuring odorous substances are detailed to enable more effective management, and various odor control strategies are discussed.

Facing the Market, Paper360 May/June 2019

Facing the Market, Paper360 May/June 2019