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Process for producing acetic acid in hardwood kraft pulp mil
Process for producing acetic acid in hardwood kraft pulp mills, TAPPI JOURNAL May 2017
Journal articles
Magazine articles
Editorial: Celebrating Wayne Carr
Editorial: Celebrating Wayne Carr: A true recycling visionary, TAPPI JOURNAL November 2017
Journal articles
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The Chinese ban on recovered paper imports
The Chinese ban on recovered paper imports: An international disruption, TAPPI JOURNAL November 2017
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Deinking process water flotation
Deinking process water flotation: An innovative solution to improve deinking and papermaking processes efficiency, TAPPI JOURNAL November 2017
Journal articles
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Editorial: To paper and beyond at the University of Minnesot
Editorial: To paper and beyond at the University of Minnesota, TAPPI JOURNAL October 2017
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Lignin value prior to pulping (LVPP): An advanced pulping c
Lignin value prior to pulping (LVPP): An advanced pulping concept, TAPPI JOURNAL October 2017
Journal articles
Magazine articles
Degradation of 2,4-dichlorophenol by melamine amine cellulos
Degradation of 2,4-dichlorophenol by melamine amine cellulose- immobilized lacasses, TAPPI JOURNAL October 2017
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Formation mechanisms of “jellyroll” smelt in kraft recovery
Formation mechanisms of “jellyroll” smelt in kraft recovery boilers, TAPPI JOURNAL October 2017
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Magazine articles
How to use total dissolved solids measurements to evaluate the performance of diffuser washers—A mill study, TAPPI Journal April 2020
ABSTRACT: Various types of pulp washing equipment are available. Each washing device has a unique mechanical construction, and the washing principle is often a combination of dilution, thickening, and displacement washing. In this work, the performance of the pressure diffuser washer is studied. In stepwise trials, the effect of the feed and discharge consistencies on the performance of the diffuser was studied. The effect of the downward velocity of the screen on the pressure diffuser’s washing efficiency was also studied. The measurement of total dissolved solids (TDS) by a process refractometer was used as a wash loss measurement unit and the refractometer’s results were used in the calculations of standardized Nordén efficiency (E10) values. The chemical oxygen demand (COD) and conductivity values were also measured and their results compared to the TDS results.The results indicated that feed consistency has a significant effect on the performance and effectiveness of the diffuser washers in the mill. It can also be stated that when the downward velocity of the screen is adjusted to too high a level, the washing efficiency of the pressure diffuser decreases. As a conclusion from the mill tests, it can be stated that even small process parameter changes can provide enhanced diffuser washing at the beginning of the washing line, which has a direct effect on the performance of post-oxygen washing.
Journal articles
Magazine articles
A novel unit operation to remove hydrophobic contaminants, TAPPI Journal April 2020
ABSTRACT: For mills making paper with recovered fiber, removal of hydrophobic contaminants is essential for trouble-free operation of paper machines. Significant cost savings on paper machine operation can be achieved by reducing deposits, which results in better quality, reduced downtime, increased fiber yield, and reduced energy consumption. Bubble nucleation separation (BNS) is a relatively new process for removing hydrophobic particles. When vacuum is applied to a slurry, dissolved gas bubbles nucleate on hydrophobic particles and drag them to the surface for easy removal. We constructed a 16-L batch unit to evaluate the effect of operating parameters on removal of hydrophobic particles, using statistical design of experiments. These results were used to guide our design of a 16-L continuous unit. We tested this unit on laboratory and mill samples. The removal of 60%•80% of hydrophobic particles was achieved with a low reject rate of < 2%.Following on this success, we built a 200-L pilot unit and tested it in our pilot plant. With promising results there, we installed the pilot unit at a commercial paper recycling mill. Over the course of several mill trials, we showed that it was possible to remove a considerable amount of suspended solids from paper machine white water with less than 2% rejects. Unfortunately, due to the unit only treating 50 L/min and the mill flow being 12000 L/min, we were not able treat a sufficient portion of the white water to know whether a large-scale implementation of BNS would improve paper machine runnability.