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Journal articles
Image analytical monitoring of paper quality - a feasibility
Image analytical monitoring of paper quality - a feasibility study, TAPPI JOURNAL, November 2006
Journal articles
Use of enzymes for reduction in refining energy - laboratory
Use of enzymes for reduction in refining energy - laboratory studies, TAPPI JOURNAL, November 2006
Biphasic 1-butanol/water delignification of miscanthus for manufacturing papermaking pulp, TAPPI Journal August 2026
ABSTRACT: Miscanthus has emerged as a promising nonwoody fiber source for papermaking and fiber molding as the world has sought alternatives to wood-based products. A diverse range of chemistries have been explored at the laboratory scale to turn nonwoody biomass into fibers; however, few have been successful at pilot or commercial scales. An emerging organosolv delignification chemistry that has demonstrated previous technical success is butanol/water, having been shown to produce papers with similar properties to other, more conventional chemistries, but offering the benefit of a built-in sugar and lignin coproduct separation. While a range of fiber lengths were achieved (0.45–0.95 mm), addition of sodium hydroxide (NaOH) to the butanol/water delignification chemistry resulted in fiber lengths comparable to commercially available hardwood pulps (0.7–1.0 mm). Lignin concentration was reduced from 19.1 wt% in the raw miscanthus to under 3.5 wt% for most trials. The lowest lignin concentration (2.5 wt%) was achieved at 180°C for 180 min with 50:50 butanol:water and 2 wt% acetic acid. Yet, the high severity of this condition (and similar ones) resulted in a significant truncation of fiber length, which is detrimental for papermaking applications. The highest quality pulp for papermaking was generated at 180°C for 180 min with 50:50 butanol:water and 10 wt% NaOH. This pulp had one of the longest fiber lengths, the highest brightness, and the highest hemicellulose concentration. Thus, butanol/water delignification, especially with NaOH addition, resulted in the successful production of cellulose-rich pulps that have potential in commercial papermaking and fiber molding applications.
Investigating the causes of severe economizer tube thinning in a spent sulfite liquor (SSL) boiler, TAPPI Journal August 2026
ABSTRACT: In this study, the causes of tube thinning in the economizer of an ammonia-based spent sulfite liquor (SSL) boiler in a Canadian pulp mill are investigated. The tube thinning was most severe in the upper tube rows of the lowest economizer sections where the tube surface temperature ranges between about 180°C and 210°C. The location, the temperature range, and the results of a tube failure analysis indicate that some form of corrosion- erosion is the main cause for the tube thinning. The process is likely initiated by the formation of potassium bisulfate in tube deposits. We hypothesize that some areas in the economizer, including gaps in tube shields, have allowed for temporary buildup of deposits that were not fully removed by sootblowing. Potassium bisulfate is highly hygroscopic, so it readily absorbs moisture, forming an acidic solution leading to corrosion. The corrosion products are removed by the erosive effects of high velocity gas movement, causing the tube thinning. The high-speed fluid flow may be a result of sootblower action and/or enhanced flue gas velocity due to channeling. The tube thinning eventually leads to perforation and leakage.