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Journal articles
Viscosity control - a new way to improve pressure screen performance, TAPPI JOURNAL, September 2000, Vol. 83(9)
Viscosity control - a new way to improve pressure screen performance, TAPPI JOURNAL, September 2000, Vol. 83(9)
Journal articles
Dispersion of pulp slurries using carboxymethylcellulose, TAPPI JOURNAL, October 2000, Vol. 83(10)
Dispersion of pulp slurries using carboxymethylcellulose, TAPPI JOURNAL, October 2000, Vol. 83(10)
Journal articles
Infrared analysis for process control in the pulp and paper industry, TAPPI JOURNAL, October 2000, Vol. 83(10)
Infrared analysis for process control in the pulp and paper industry, TAPPI JOURNAL, October 2000, Vol. 83(10)
Journal articles
Pulp bleaching with manganese peroxidase and xylanase: a synergistic effect, TAPPI JOURNAL, October 2000, Vol. 83(10)
Pulp bleaching with manganese peroxidase and xylanase: a synergistic effect, TAPPI JOURNAL, October 2000, Vol. 83(10)
Journal articles
An image analysis method to quantify fibre separation in wood subjected to fatigue loading, TAPPI JOURNAL, December 2000, Vol. 83(12)
An image analysis method to quantify fibre separation in wood subjected to fatigue loading, TAPPI JOURNAL, December 2000, Vol. 83(12)
Journal articles
Application of polyallylamine as a dry strength agent for paper, TAPPI JOURNAL, December 2000, Vol. 83(12)
Application of polyallylamine as a dry strength agent for paper, TAPPI JOURNAL, December 2000, Vol. 83(12)
Journal articles
Pulping of aspen wood in acetic acid media: effect of operating conditions on yield and pulp properties, TAPPI JOURNAL, December 2000, Vol. 83(12)
Pulping of aspen wood in acetic acid media: effect of operating conditions on yield and pulp properties, TAPPI JOURNAL, December 2000, Vol. 83(12)
Journal articles
Magazine articles
Wheat straw as an alternative pulp fiber, TAPPI Journal December 2024
Author: Peter W. Hart | TAPPI J. 19(1): 41(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
Modeling the dynamics of evaporator wash cycles, TAPPI Journal July 2024
ABSTRACT: Kraft pulping is a process that utilizes white liquor, composed of sodium sulfide (Na2S) and sodium hydroxide (NaOH), for wood delignification and pulp production. This process involves washing the dissolved organics and spent chemicals from the pulp, resulting in the generation of black liquor. Prior to its use as fuel in the recovery boiler, the black liquor is concentrated in multiple-effect evaporators. During the evaporation process, the inorganic salts present in the liquor become supersaturated and undergo crystallization. Fluctuations in sodium, carbonate, sulfate, and oxalate can give rise to severe sodium salt scaling events, which significantly impact the thermal efficiency of the evaporators, and ultimately, pulp production. Dynamic modeling provides insights into fluctuations in liquor chemistry in the evaporators. The primary objective of this study was to employ dynamic modeling to evaluate the effects of wash liquor recovery from evaporator wash cycles. The dynamics associated with wash cycles encompass variations in the concentrations of salts and solids in the recovered wash liquor, changes in the flow rate of wash liquor recovery, and fluctuations in liquor volume within the liquor tanks. The dynamic model was developed using Matlab Simulink and applied to the evaporation plant of a pulp mill in South America. By utilizing one month of mill process data, the model enabled the evaluation of fluctuations in liquor chemistry due to evaporator wash cycles. The developed model has demonstrated the potential to estimate the concentration of key ions responsible for scaling and to contribute to enhancements in evaporator washing strategies.
Journal articles
Magazine articles
Factors affecting deposit formation in foul condensate stripping systems, TAPPI Journal June 2024
ABSTRACT: In kraft pulp mills, foul condensates are often steam-stripped to produce clean condensate for use as process water. The formation of organic deposits in the stripped condensate is a common problem. A systematic study was conducted to examine the deposit composition and the most likely operating parameters responsible for stripped condensate contamination experienced at a kraft mill in Brazil. Daily averaged data of 170 operating parameters over a 15-month period were analyzed by means of multivariate discriminant analysis and random forest classification analysis. The results showed that the deposit formation is related to high temperature, pressure, and dry solids operations in various evaporator effects. These conditions, combined with the poor demisting efficiency in these effects, may have increased black liquor carryover mist in the vapor. Deposit formation also appeared to be related to increased throughput of the foul condensate stripping system and increased pressure in the stripper. Results of Fourier transform infrared spectroscopy (FTIR) and pyrolysis-gas chromatography mass spectrometry (Py-GCMS) analyses show that the deposit consists of mostly organic matter that likely originated from wood extractives and lignin.