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Exergy and sensibility analysis of each individual effect in a kraft multiple effect evaporator, TAPPI Journal October 2019
ABSTRACT: The multiple effect evaporator (MEE) is an energy intensive step in the kraft pulping process. The exergetic analysis can be useful for locating irreversibilities in the process and pointing out which equipment is less efficient, and it could also be the object of optimization studies. In the present work, each evaporator of a real kraft system has been individually described using mass balance and thermodynamics principles (the first and the second laws). Real data from a kraft MEE were collected from a Brazilian plant and were used for the estimation of heat transfer coefficients in a nonlinear optimization problem, as well as for the validation of the model. An exergetic analysis was made for each effect individually, which resulted in effects 1A and 1B being the least efficient, and therefore having the greatest potential for improvement. A sensibility analysis was also performed, showing that steam temperature and liquor input flow rate are sensible parameters.
Journal articles
Magazine articles
Critical parameters for tall oil separation I: The importance of ration of fatty acids to rosin acids, TAPPI Journal September 2019
ABSTRACT: Tall oil is a valuable byproduct in chemical pulping of wood, and its fractions have a large spectrum of applications as chemical precursors, detergents, and fuel. High recovery of tall oil is important for the economic and environmental profile of chemical pulp mills. The purpose of this study was to investigate critical parameters of tall oil separation from black liquor. To investigate this in a controlled way, we developed a model test system using a “synthetic” black liquor (active cooking chemicals OH- and HS- ions), a complete process for soap skimming, and determination of recovered tall oil based on solvent extraction and colorimetric analysis, with good reproducibility. We used the developed system to study the effect of the ratio of fatty acids to rosin acids on tall oil separation. When high amounts of rosin acids were present, tall oil recovery was low, while high content of fatty acids above 60% significantly promoted tall oil separation. Therefore, manipulating the content of fatty acids in black liquor before the soap skimming step can significantly affect the tall oil solubility, and hence its separation. The findings open up chemical ways to improve the tall oil yield.
Journal articles
Magazine articles
He’s Got the Pulp: Schalka Sets Record as LA CEO of the Year, Paper360º September/October 2019
He’s Got the Pulp: Schalka Sets Record as LA CEO of the Year, Paper360º September/October 2019
Journal articles
Magazine articles
IDEAS Digital Twin Technology for Evaporation Plants, Paper360º September/October 2019
IDEAS Digital Twin Technology for Evaporation Plants, Paper360º September/October 2019
Journal articles
Magazine articles
TAPPI Journal Summaries, Paper360º September/October 2019
TAPPI Journal Summaries, Paper360º September/October 2019
Magazine articles
Editor's Note: Collecting industry information that counts,
Editor's Note: Collecting industry information that counts, TAPPI JOURNAL April 2010
Magazine articles
Editor's Note: Monstrous marvels, TAPPI JOURNAL September 20
Editor's Note: Monstrous marvels, TAPPI JOURNAL September 2010
Magazine articles
Guest Editorial: Paul Wiegand: Environmental expert, TAPPI J
Guest Editorial: Paul Wiegand: Environmental expert, TAPPI JOURNAL August 2012
Magazine articles
Pulp bleaching and deinking pilot plants use chlorine-free processes, TAPPI JOURNAL, June 1997, Vol. 80(6)
Pulp bleaching and deinking pilot plants use chlorine-free processes, TAPPI JOURNAL, June 1997, Vol. 80(6)
Magazine articles
A reliable method to improve fabric life, TAPPI JOURNAL, March 1997, Vol. 80(3)
A reliable method to improve fabric life, TAPPI JOURNAL, March 1997, Vol. 80(3)