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Understanding the risks and rewards of using 50% vs. 10% strength peroxide in pulp bleach plants, TAPPI Journal November 2018
Authors: Alan W. Rudie and Peter W. Hart | ABSTRACT: The use of 50% concentration and 10% concentration hydrogen peroxide were evaluated for chemical and mechanical pulp bleach plants at storage and at point of use. Several dangerous occurrences have been documented when the supply of 50% peroxide going into the pulping process was not stopped during a process failure. Startup conditions and leaking block valves during maintenance outages have also contributed to explosions. Although hazardous events have occurred, 50% peroxide can be stored safely with proper precautions and engineering controls. For point of use in a chemical bleach plant, it is recommended to dilute the peroxide to 10% prior to application, because risk does not outweigh the benefit. For point of use in a mechanical bleach plant, it is recommended to use 50% peroxide going into a bleach liquor mixing system that includes the other chemicals used to maintain the brightening reaction rate. When 50% peroxide is used, it is critical that proper engineering controls are used to mitigate any risks.
Journal articles
Magazine articles
Using multistage models to evaluate how pulp washing after the first extraction stage impacts elemental chlorine-free bleach demand, TAPPI Journal November 2018
Using multistage models to evaluate how pulp washing after the first extraction stage impacts elemental chlorine-free bleach demand, TAPPI Journal November 2018
Journal articles
Magazine articles
Laboratory method for determining the source of brightness loss at a southern United States bleached paperboard mill, TAPPI Journal October 2018
Laboratory method for determining the source of brightness loss at a southern United States bleached paperboard mill, TAPPI Journal October 2018
Journal articles
Factors contributing to improved environmental performance in the Finnish kraft pulping industry, TAPPI JOURNAL, September 2007
Factors contributing to improved environmental performance in the Finnish kraft pulping industry, TAPPI JOURNAL, September 2007
Journal articles
Performance of a final hydrogen peroxide stage in the ECF bleaching of Eucalypt DOEOPD1 Kraft Pulps
Performance of a final hydrogen peroxide stage in the ECF bleaching of Eucalypt D0EOPD1 kraft pulps, TAPPI JOURNAL, August 2008
Journal articles
Gasification of Mixtures of Black Liquor and Secondary Sludge, TAPPI JOURNAL, March 2007
Gasification of Mixtures of Black Liquor and Secondary Sludge, TAPPI JOURNAL, March 2007
Journal articles
Experimental Investigation of Black Liquor Pyrolysis Using Single Droplet TGA, TAPPI JOURNAL, May 2007
Experimental Investigation of Black Liquor Pyrolysis Using Single Droplet TGA, TAPPI JOURNAL, May 2007
Journal articles
The polyelectrolyte behavior of randomly branched lignosulfonates, TAPPI JOURNAL , november 2007 07NOV10
The polyelectrolyte behavior of randomly branched lignosulfonates, TAPPI JOURNAL November 2007
Journal articles
The hemicellulose composition of pulp fibers and their ability to endure mechanical treatment, TAPPI JOURNAL, October 2007
The hemicellulose composition of pulp fibers and their ability to endure mechanical treatment, TAPPI JOURNAL, October 2007
Journal articles
Magazine articles
Kraft pulp bleaching with a P-stage catalyzed by both bicarbonate and TAED, TAPPI Journal July 2019
ABSTRACT: Peroxide bleaching of softwood and hardwood (eucalypt) kraft pulps was performed in solutions of sodium bicarbonate (NaHCO3), sodium carbonate (Na2CO3), and sodium hydroxide (NaOH). The conventional P stage (hydrogen peroxide + sodium hydroxide; H2O2 + NaOH) was the most effective brightening system without an additional activator. However, peroxide activation by bicarbonate anion (HCO3•) was obvious in all cases where NaHCO3 or Na2CO3 was used. When N,N,N’,N’-tetraacetylethylenediamine (TAED) was added to the bleaching sys-tem, Na2CO3 as the alkali source afforded equal or slightly higher bleached brightness compared to NaOH usage for both the softwood and hardwood pulps. This outcome is attributed to simultaneous peroxide activation by HCO3• and TAED. When applied to the eucalypt pulp, the H2O2/Na2CO3/TAED bleaching system also decreased the bright-ness loss due to thermal reversion.