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Journal articles
Influence of the oxidative thermochemical treatment on the chemical composition of hardwood kraft black liquor, TAPPI JOURNAL, December 2002, Vol. 1(10) (182KB)
Influence of the oxidative thermochemical treatment on the chemical composition of hardwood kraft black liquor, Solutions! & TAPPI JOURNAL, December 2002, Vol. 1(10) (182KB)
Journal articles
Behavior of certain components in the vacuum drum washer after the first D stage in ECF bleaching, TAPPI JOURNAL, September 2003, Vol. 2(9) (172KB)
Behavior of certain components in the vacuum drum washer after the first D stage in ECF bleaching, Solutions! & TAPPI JOURNAL, September 2003, Vol. 2(9) (172KB)
Journal articles
Factors contributing to calcium oxalate scale at the Simpson Tacoma Kraft mill, TAPPI JOURNAL, February 2003, Vol. 2(2) (247KB)
Factors contributing to calcium oxalate scale at the Simpson Tacoma Kraft mill, Solutions! & TAPPI JOURNAL, February 2003, Vol. 2(2) (247KB)
Journal articles
Dust and flue gas chemistry during rapid changes in the operation of black liquor recovery boilersâ??Part 3: Gaseous emissions, TAPPI JOURNAL, September 2002 (195KB)
Dust and flue gas chemistry during rapid changes in the operation of black liquor recovery boilers—Part 3: Gaseous emissions, Solutions! & TAPPI JOURNAL, September 2002 (195KB)
Journal articles
Pulp yield loss in alkaline peroxide bleaching of aspen CTMP Part 1: Estimation and impacts, TAPPI JOURNAL, September 2003, Vol. 2(9) (145KB)
Pulp yield loss in alkaline peroxide bleaching of aspen CTMP Part 1: Estimation and impacts, Solutions! & TAPPI JOURNAL, September 2003, Vol. 2(9) (145KB)
Journal articles
Substitution of aspen high-yield pulp for hardwood kraft pulp in fine papers and its effect on AKD sizing, Solutions! & TAPPI JOURNAL, August 2004, Vol. 3(8) (186KB)
Substitution of aspen high-yield pulp for hardwood kraft pulp in fine papers and its effect on AKD sizing, Solutions! & TAPPI JOURNAL, August 2004, Vol. 3(8) (186KB)
Journal articles
Deinking of recycled mixed office paper using two endo-glucanases, celb and cele, from the anaerobic fungus orpinomyces pc-2, TAPPI JOURNAL, July 2003, Vol. 2(7) (108KB)
Deinking of recycled mixed office paper using two endo-glucanases, celb and cele, from the anaerobic fungus orpinomyces pc-2, Solutions! & TAPPI JOURNAL, July 2003, Vol. 2(7) (108KB)
Journal articles
Magazine articles
Recovery boiler back-end heat recovery, TAPPI Journal March 2023
ABSTRACT: Sustainability and efficient use of resources are becoming increasingly important aspects in the operation of all industries. Recently, some biomass-fired boilers have been equipped with increasingly complex condensing back-end heat recovery solutions, sometimes also using heat pumps to upgrade the low-grade heat. In kraft recovery boilers, however, scrubbers are still mainly for gas cleaning, with only simple heat recovery solutions. In this paper, we use process simulation software to study the potential to improve the power generation and energy efficiency by applying condensing back-end heat recovery on a recovery boiler. Different configurations are considered, including heat pumps. Potential streams to serve as heat sinks are considered and evaluated. Lowering the recovery boiler flue gas temperature to approximately 65°C significantly decreases the flue gas losses. The heat can be recovered as hot water, which is used to partially replace low-pressure (LP) steam, making more steam available for the condensing steam turbine portion for increased power generation. The results indicate that in a simple condensing plant, some 1%•4% additional electricity could be generated. In a Nordic mill that provides district heating, even more additional electricity generation, up to 6%, could be achieved. Provided the availability of sufficient low-temperature heat sinks to use the recovered heat, as well as sufficient condensing turbine swallowing capacity to utilize the LP steam, the use of scrubbing and possibly upgrading the heat using heat pumps appears potentially useful.
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.
Journal articles
Magazine articles
On the usage of online fiber measurements for predicting bleached eucalyptus kraft pulp tensile index — an industrial case, TAPPI Journal July 2022
ABSTRACT: Cellulose pulp’s physical-mechanical properties are determined by laboratory tests obtained from prepared handsheets. However, this procedure is time intensive and presents a lead time until the results are available, hindering its utilization for monitoring and decision-making in a pulp mill. In this context, developing real-time solutions for physical-mechanical properties prediction is fundamental. This work applied a mathematical modeling approach to develop a soft sensor for tensile index monitoring. The mathematical model considers online morphology measurements obtained from the last bleaching stage outlet stream and important process variables for tensile index prediction. The results obtained are satisfactory compared to laboratory results, presenting a mean absolute percentual error of 2.5%, which agrees with the laboratory testing method’s reproducibility.