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Magazine articles
Effects of different soda loss measurement techniques on brownstock quality, TAPPI Journal July 2024
ABSTRACT: The efficiency of the kraft recovery plant, bleaching process, and paper machine are affected when black liquor carryover from the brownstock washers is not controlled well. Measuring soda loss within a mill can vary from using conductivity, either in-situ or with a lab sample of black liquor filtrate squeezed from the last stage washer, to measuring absolute sodium content with a lab sodium specific ion probe or spectrophotometer. While measuring conductivity has value in tracking trends in black liquor losses, it is not an acceptable method in reporting losses in absolute units, typically in lb/ton of pulp. This is further complicated when trying to benchmark soda loss performance across a fleet of mills with multiple washer lines. Not only do the testing methods vary, but the amount of bound soda on high kappa pulps can be significant. This variability creates inconsistent results, and studies are needed to understand the effect of different testing methods on the pulp quality. In this study, soda loss is expressed as sodium sulfate (Na2SO4). Four different methods to measure soda content in pulp off commercial brownstock washers were studied: full digestion (FD), washing soaking overnight and washing (WSW), soaking in boiling water and stirring 10-min (SW-10), and squeeze-no wash (Sq). Total, washable, and bound sodium sulfate calculations were determined for each soda content measuring technique using inductively coupled plasma-optical emission spectroscopy (ICP-OES). Results showed bound and washable sodium sulfate amounts significantly depend on which soda measurement technique was used. In addition, the soda results were correlated with the pulp kappa numbers. As the kappa number increases, bound soda increases, regardless of the soda measurement method used. Impacts of high sodium sulfate in brownstock are also discussed.
Magazine articles
Continuous dust measurement as an indication of sootblowing performance in a recovery boiler, TAPPI JOURNAL, May 2001, Vol. 84(5)
Continuous dust measurement as an indication of sootblowing performance in a recovery boiler, TAPPI JOURNAL, May 2001, Vol. 84(5)
Magazine articles
Treatment efficiency of eucalypt kraft pulp bleaching effluents: influence of dissolved organic matter, SOLUTIONS! & TAPPI JOURNAL, April 2002 (128KB)
Treatment efficiency of eucalypt kraft pulp bleaching effluents: influence of dissolved organic matter, SOLUTIONS! & TAPPI JOURNAL, April 2002 (128KB)
Magazine articles
Barbara Dalpke: insights from a recent graduate, TAPPI JOURN
Barbara Dalpke: insights from a recent graduate, TAPPI JOURNAL, August 2002, Vol. 1(6) (144KB)
Magazine articles
Deinking difficulties related to ink formulation, printing process, and type of paper, TAPPI JOURNAL, June 2000, Vol. 83(6)
Deinking difficulties related to ink formulation, printing process, and type of paper, TAPPI JOURNAL, June 2000, Vol. 83(6)
Magazine articles
Industry leaders: jukka harmala leads stora enso into new global age, TAPPI JOURNAL, May 2000, Vol. 83(5)
Industry leaders: jukka harmala leads stora enso into new global age, TAPPI JOURNAL, May 2000, Vol. 83(5)
Magazine articles
A personal mount st. helens experience, TAPPI JOURNAL, May 2000, Vol. 83(5)
A personal mount st. helens experience, TAPPI JOURNAL, May 2000, Vol. 83(5)
Magazine articles
Energy: recovering capital and cutting costs, TAPPI JOURNAL, November 2000, Vol. 83(11)
Energy: recovering capital and cutting costs, TAPPI JOURNAL, November 2000, Vol. 83(11)
Magazine articles
Reliability of stainless alloy equipment in chlorine dioxide bleaching, TAPPI JOURNAL, November 2000, Vol. 83(11)
Reliability of stainless alloy equipment in chlorine dioxide bleaching, TAPPI JOURNAL, November 2000, Vol. 83(11)
Magazine articles
What's new with tappi test methods?, TAPPI JOURNAL, September 2000, Vol. 83(9)
What's new with tappi test methods?, TAPPI JOURNAL, September 2000, Vol. 83(9)