Inventory audit notice: TAPPI Press orders will not be processed from August 21–28 during our fiscal year-end inventory audit. Orders placed during this time will ship starting August 31, in the order received. Normal payment processing also resumes August 31.

Thanks for your patience — this helps us serve our members better.

Search

Use the search bar or filters below to find any TAPPI product or publication.

Showing 281–290 of 564 results (Duration : 0.007 seconds)

Filters

Industry

Topics

Content Type

Publications

Level of Knowledge

Committees

Collections

Journal articles
Open Access
Pulping and Papermaking Properties of Managed Second-Growth

Pulping and Papermaking Properties of Managed Second-Growth Softwoods, 1995 Pulping Conference Proceedings

Journal articles
Open Access
Qualification of Welding Procedures for Duplex Stainless Ste

Qualification of Welding Procedures for Duplex Stainless Steels, 1999 Engineering Conference Proceedings

Journal articles
Magazine articles
Open Access
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
Open Access
Non-process elements in the recovery cycle of six Finnish kraft pulp mills, TAPPI Journal March 2023

ABSTRACT: In this work, the aim was to study the distribution and accumulation of the non-process elements (NPEs) in the recovery cycle of Finnish pulp mills and look at whether the geographical location (North vs. South) correlates with the current Finnish NPE levels. In addition, a comparison to older similar Finnish measurements was made with an attempt to analyze the reasons behind differences in the most typical non-process elements, aluminum (Al), silicon (Si), calcium (Ca), phosphorus (P), magnesium (Mg), manganese (Mn), chlorine (Cl), and potassium (K), taking into account the main elements in the white liquor, sodium (Na) and sulfur (S). The extensive laboratory results gained in this study are from seven sampling points at six pulp mills and present analytical data of metal concentrations. The data obtained presents an update to previous NPE studies. The levels found did not statistically differ between North and South Finland. The NPE levels, apart from phosphorus, found in Finnish pulp mills today have not changed considerably compared to the levels in earlier investigations in the 1990s. In the newest data, the phosphorus concentration was consistently higher in the as fired black liquor, electrostatic precipitator (ESP) ash, lime mud, and green liquor than in the previous results. In addition, the levels of Al, Si, Ca, P, and Mg in recovery boiler ESP ash were consistently higher compared to the older results. As the mills start to close their systems more, a stronger accumulation of NPEs can be expected, increasing the likelihood of more operational problems in the process. Further understanding of where the NPEs accumulate and how they can be most effectively removed will be valuable knowledge in the future.

Journal articles
Open Access
Evaluation of Various Mechanical Pulping Processes for Mature and Juvenile Loblolly Pine in Lightweight Coated Paper, TAPPI JOURNAL March 2009

Evaluation of Various Mechanical Pulping Processes for Mature and Juvenile Loblolly Pine in Lightweight Coated Paper, TAPPI JOURNAL March 2009

Journal articles
Open Access
Prediction of the Solubility of Recovery Boiler Precipitator Ash, TAPPI JOURNAL May 2009

Prediction of the Solubility of Recovery Boiler Precipitator Ash, TAPPI JOURNAL May 2009

Journal articles
Open Access
Linking Pulp Variations to TMP Operation by Better Selection

Linking Pulp Variations to TMP Operation by Better Selection and Treatment of Process Data

Journal articles
Open Access
The influence of pigment particle shape on the in-plane tensile strength properties of kaolin-based coating layers, TAPPI JOURNAL

The influence of pigment particle shape on the in-plane tensile strength properties of kaolin-based coating layers, TAPPI JOURNAL

Journal articles
Magazine articles
Open Access
Lignin-based resins for kraft paper applications, TAPPI Journal November 2019

ABSTRACT: We investigated miscanthus (MS) and willow (W) lignin-furfural based resins as potential reinforce-ment agents on softwood and hardwood kraft paper. These resins might be sustainable alternatives to the commercial phenolformaldehyde (PF) resins. Phenol is a petrochemical product and formaldehyde has been classified as a carcinogen by the U.S. Environmental Protection Agency. The lignin used in this study was derived from hot water extraction (160ºC, 2 h) of MS and W biomass, and may be considered sulfur-free. These biorefinery lignins were characterized for their chemical composition and inherent properties via wet chemistry and instrumental techniques. The resin blends (MS-resin and W-resin) were characterized for their molecular weight, thermal behavior, and mechanical properties. Mechanical properties were measured by the resin’s ability to reinforce softwood and hard-wood kraft papers. The effect of adding hexamethylenetetramine (HMTA), a curing agent, to the resin was also examined. Mixtures of PF and lignin-based resins were investigated to further explore ways to reduce use of non-renewables, phenol, and carcinogenic formaldehyde. The results show that lignin-based resins have the potential to replace PF resins in kraft paper applications. For softwood paper, the highest strength was achieved using W-resin, without HMTA (2.5 times greater than PF with HMTA). For hardwood paper, MS-resin with HMTA gave the highest strength (2.3 times higher than PF with HMTA). The lignin-based resins, without HMTA, also yielded mechanical properties comparable to PF with HMTA.

Journal articles
Open Access
Comparative annual cost efficiency between thermal and chemical oxidation of TRS in kraft mills, TAPPI JOURNAL, July 2005, Vol. 4(7) (200 KB)

Comparative annual cost efficiency between thermal and chemical oxidation of TRS in kraft mills, TAPPI JOURNAL, July 2005, Vol. 4(7) (200 KB)

Inside this Section