Results 171 to 180 of about 2,238 (210)

On the role of carbohydrates in oxygen delignification

Nordic Pulp & Paper Research Journal, 2005
The long-term trend regarding wood is an increase in price. Because wood contributes to a large part of production costs, the efficient utilisation of wood is greatly desired to reduce production costs for kraft pulp producers. During the 1990s, the development of improved modified kraft cooking began, which led to higher yields. There was also a trend
Helena Wedin, Mikael E. Lindström, Martin Ragnar   +2 more
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Addition of ammonia and/or oxygen to an ionic liquid for delignification of miscanthus

Bioresource Technology, 2011
Ammonia and/or oxygen were used to enhance the delignification of miscanthus dissolved in 1-ethyl-3-methylimidazolium acetate at 140°C. After dissolution of the gas at 9 bar, water was added as antisolvent to regenerate the dissolved biomass. In a next step, an acetone/water mixture was used to remove carbohydrate-free lignin from the regenerated ...
Héctor, Rodríguez, Sasisanker, Padmanabhan, Geoffrey, Poon, John M, Prausnitz   +3 more
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Effects of lignin chemistry on oxygen delignification performance

TAPPI Journal, 2018
The present work focused on characterizing the chemical and structural properties of isolated lignin from six hardwoods and their kraft pulps in an attempt to better understand the relationship between lignin’s chemical properties and resultant oxygen delignification performance.
Valeria Juste Gomes, Hasan Jameel, Hou-Min Chang, Robert Narron, Jorge Colodette, Peter Hart   +5 more
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Alternatives for Lignocellulosic Pulp Delignification Using Polyoxometalates and Oxygen: A Review

ChemInform, 2007
AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Armindo R. Gaspar, Jos? A. F. Gamelas, Dmitry V. Evtuguin, Carlos Pascoal Neto   +3 more
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Study of vanillin formation under oxygen delignification process

2018 IEEE 5th International Conference on Engineering Technologies and Applied Sciences (ICETAS), 2018
The production of vanillin during an alkaline oxygen delignification process was evaluated in this study. The degradation of lignin does not directly occur by oxygen but by the active oxygen species (AOS) generated in the system. These AOS occur by the attack of oxygen on the lignin phenolic side-chain leads to the cleavage of the lignin bond.
Napat Viseshsin, Pimwalun Sukhitkul, Rangsalid Panyadee, Chularat Sakdaronnarong, Pattaraporn Posoknistakul   +4 more
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A comparative study of the impact of the cooking process on oxygen delignification

Nordic Pulp & Paper Research Journal, 1997
The impact of oxygen delignification on chemical pulps of a given kappa number manufactured in different ways (using kraft, prehydrolysis kraft and magnesium sulphite cooking) has been investigated. The prehistory of the pulps proves to be a very important factor in determining the response to oxygen delignification, i.e. the degree of delignification.
Stefan Antonsson, Mikael E. Lindstrom, Martin Ragnar   +2 more
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Nitrogen-Centered Activators of Peroxide-Reinforced Oxygen Delignification

Industrial & Engineering Chemistry Research, 2004
In an effort to augment the efficiency of an oxygen delignification stage, we examined the effectiveness of various heterocyclic aromatic nitrogen compounds as possible activators of such a stage. It was shown that a variety of such compounds may act as activators in the presence of hydrogen peroxide, improving the delignification efficiency of oxygen ...
Dimitris S. Argyropoulos, Miro Suchy, Leonid Akim   +2 more
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Mass transfer and kinetics in oxygen delignification

2020
ABSTRACT MASS TRANSFER AND KINETICS IN OXYGEN DELIGNIFICATION Doğan, Ismail Ph.D., Department of Chemical Engineering Supervisor : Prof. Dr. Hayrettin Yücel Co-Supervisor : Prof. Dr. Güniz Gürüz November 2004, 147 pages In this study, the kinetic analysis of oxygen delignification of Turkish southern hardwood Kraft pulp was carried out.
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Modelling oxygen delignification in pulp processing operations

2009
A mathematical model of oxygen delignification for pulp processing operations has been developed to predict the kappa number (lignin content) and pulp strength (CED viscosity) as a function of system operation variables. The model incorporates a set of appropriate chemical reaction kinetics chosen from those available in the literature and gas-liquid ...
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Oxygen delignification as a pretreatment for the enzymatic hydrolysis of lignocellulosic material

2009
With the increasing importance of environmental conservation and the inevitable depletion of the world's fossil fuel supplies, it is necessary to develop renewable and clean sources of energy. Bioconversion, the process of converting plant biomass to fuel grade ethanol, is one process that addresses these concerns.
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