Search
Use the search bar or filters below to find any TAPPI product or publication.
Filters
Publications
Level of Knowledge
Collections
Journal articles
Magazine articles
Alternative “green” lime kiln fuels: Part I—Pulping/recovery byproducts, TAPPI Journal May 2020
ABSTRACT: This paper is the first of a two-part series on “green” lime kiln fuels. The first part of this work reviews the use of pulp mill and recovery byproducts as either full or partial replacement of oil or natural gas in the kiln. The second part reviews the use of various forms of woody biomass, bio-oils, gasification, and hydrogen as potential carbon neutral or carbon-free lime kiln fuels.
Journal articles
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
Editorial: TAPPI Journal 2019 Best Research Paper addresses hard scale formation in green liquor pipelines, TAPPI Journal March 2020
ABSTRACT: TAPPI and the TAPPI Journal (TJ) Editorial Board would like congratulate the authors of the 2019 TAPPI Journal Best Research Paper Award: Alisha Giglio, Vladimiros Papangelakis, and Honghi Tran. Their paper, “The solubility of calcium carbonate in green liquor handling systems,” appeared on p. 595 of the October 2019 issue. This kraft recovery cycle research was recognized by the TJ Editorial Board for its innovation, creativity, scientific merit, and clear expression of ideas.
Journal articles
Magazine articles
Understanding extensibility of paper: Role of fiber elongation and fiber bonding, TAPPI Journal March 2020
ABSTRACT: The tensile tests of individual bleached softwood kraft pulp fibers and sheets, as well as the micro-mechanical simulation of the fiber network, suggest that only a part of the elongation potential of individual fibers is utilized in the elongation of the sheet. The stress-strain curves of two actual individual pulp fibers and one mimicked classic stress-strain behavior of fiber were applied to a micromechanical simulation of random fiber networks. Both the experimental results and the micromechanical simulations indicated that fiber bonding has an important role not only in determining the strength but also the elongation of fiber networks. Additionally, the results indicate that the shape of the stress-strain curve of individual pulp fibers may have a significant influence on the shape of the stress-strain curve of a paper sheet. A large increase in elongation and strength of paper can be reached only by strengthening fiber-fiber bonding, as demonstrated by the experimental handsheets containing starch and cellulose microfibrils and by the micromechanical simulations. The key conclusion related to this investigation was that simulated uniform inter-fiber bond strength does not influence the shape of the stress-strain curve of the fiber network until the bonds fail, whereas the number of bonds has an influence on the activation of the fiber network and on the shape of the whole stress-strain curve.
Journal articles
Magazine articles
Effects of different ammonium lignosulfonate contents on the crystallization, rheological behaviors, and thermal and mechanical properties of ethylene propylene diene monomer/polypropylene/ammonium lignosulfonate composites, TAPPI Journal January 2020
ABSTRACT: Thermoplastic elastomer (TPE), made from ethylene propylene diene monomer (EPDM) and polypropylene (PP) based on reactive blending, has an excellent processing performance and characteristics and a wide range of applications. However, there are currently no reports in the literature regarding the usage of TPE in making composite boards. In this paper, EPDM, PP, and ammonium lignosulfonate (AL) were used as the raw materials, polyethylene wax was used as the plasticizer, and a dicumyl peroxide vulcanization system with dynamic vulcanization was used to make a new kind of composite material. This research studied the influences of the AL contents on the crystallization behaviors, rheological properties, thermal properties, and mechanical properties of the composites. The results showed that the AL content had a noticeable impact on the performance of the composite board. Accordingly, this kind of composite material can be used as an elastomer material for the core layer of laminated flooring.
Journal articles
Magazine articles
Wheat straw as an alternative pulp fiber, TAPPI Journal January 2020
ABSTRACT: The desire to market sustainable packaging materials has led to an interest in the use of various fiber types as a raw material. It has been suggested that the use of annual crops for partial replacement of wood fiber would result in more sustainable products. Several life cycle analyses (LCA) have been performed to evaluate these claims. These LCAs provided conflicting and contradictory results because of the local conditions and the specific pulping processes investigated. Selected LCAs are reviewed and the underlying reasons for these conflicting results are analyzed.
Journal articles
Magazine articles
The solubility of calcium carbonate in green liquor handling systems, TAPPI Journal October 2019
ABSTRACT: The formation of hard calcite (CaCO3) scale in green liquor handling systems is a persistent problem in many kraft pulp mills. CaCO3 precipitates when its concentration in the green liquor exceeds its solubility. While the solubility of CaCO3 in water is well known, it is not so in the highly alkaline green liquor environment. A systematic study was conducted to determine the solubility of CaCO3 in green liquor as a function of temperature, total titratable alkali (TTA), causticity, and sulfidity. The results show that the solubility increases with increased temperature, increased TTA, decreased causticity, and decreased sulfidity. The new solubility data was incorporated into OLI (a thermodynamic simulation program for aqueous salt systems) to generate a series of CaCO3 solubility curves for various green liquor conditions. The results help explain how calcite scale forms in green liquor handling systems.
Journal articles
Magazine articles
Prehydrolysis kraft pulping of jute cutting and caddis mixture for rayon production
ABSTRACT: Jute cutting, jute caddis, and cutting-caddis mixtures were prehydrolyzed by varying time and temperature to get about 90% prehydrolyzed yield. At the conditions of 170°C for 60 min of prehydrolysis, the yield for 100% jute cutting was 76.3%, while the same for jute caddis was only 67.9%. But with prehydrolysis at 150°C for 60 min, the yield was 90% for jute cutting, where 49.94% of original pentosan was dissolved and prehydrolysis of jute caddis at 140°C in 60 min yielded 86.4% solid residue. Jute cutting-caddis mixed prehydrolysis was done at 140°C for 30 min and yielded 92% solid residue for 50:50 cutting-caddis mixtures, where pentosan dissolution was only 29%. Prehydrolyzed jute cutting, jute caddis, and cutting-caddis mixtures were subsequently kraft cooked. Pulp yield was only 40.9% for 100% jute cutting prehydrolyzed at 170°C for 60 min, which was 10.9% lower than the prehydrolysis at 140°C. For jute cutting-caddis mixed prehydrolysis at 140°C for 45 min followed by kraft cooking, pulp yield decreased by 3.3% from the 100% cutting to 50% caddis in the mixture, but 75% caddis in the mixture decreased pulp yield by 6.7%. The kappa number 50:50 cutting-caddis mixture was only 11.3. Pulp bleachability improved with increasing jute cutting proportion in the cutting-caddis mixture pulp.
Journal articles
Magazine articles
A review of green liquor scale formation, TAPPI Journal October 2018
A review of green liquor scale formation, TAPPI Journal October 2018
Journal articles
Magazine articles
Does the kappa number method accurately reflect lignin content in nonwood pulps?, TAPPI Journal November 2018
Does the kappa number method accurately reflect lignin content in nonwood pulps?, TAPPI Journal November 2018