Results 181 to 190 of about 6,920 (226)
Some of the next articles are maybe not open access.
Oxygen Delignification Chemistry and Its Impact on Pulp Fibers
Journal of Wood Chemistry and Technology, 2003Abstract Two southern pine kraft pulps with kappa numbers of 30.0 (SW1-0) and 48.0 (SW2-0) were oxygen delignified by 30–60% by varying the reaction temperature (78–110°C) and charge of sodium hydroxide (1.6–4.4%). O-bleachability was found to be correlated to the incoming kappa number and charge of sodium hydroxide employed. In general, a lower charge
Lucian A Lucia +2 more
exaly +2 more sources
Gas dispersion in the oxygen delignification process
TAPPI Journal, 2021There has been very little knowledge about the state of gas dispersion in the oxygen delignification process, even though this has a major impact on the performance of the reactor. This paper presents a new continu-ous inline method for measuring oxygen bubble size distribution in the reactor, as well as results from studies con-ducted in softwood and ...
JARI KAYHKO +4 more
openaire +2 more sources
The role of gas dispersion in the oxygen delignification process
TAPPI Journal, 2021Oxygen delignification is an essential part of the pulp production process. Delignification occurs with the aid of alkali and dissolved oxygen. Dissolved oxygen is obtained by dispersing oxygen gas into the pulp suspension by using efficient mixers.
JARI KAYHKO +6 more
openaire +2 more sources
On the role of carbohydrates in oxygen delignification
Nordic Pulp & Paper Research Journal, 2005The 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 +2 more
openaire +1 more source
The Kinetics of Oxygen Delignification of Reed Kraft Pulp (I)-Kinetics of Delignification
Advanced Materials Research, 2011The kinetics of reed kraft pulp oxygen delignification process is studied, suitable kinetics model determined is -dk/dt=Aexp(-E/RT) [OH-]b[PO2]cKa, and the parameters in the model is calculated. The function for estimation of the kappa number at different reaction time is established for the reed kraft pulp oxygen delignification process.
Xiao Feng Pan +4 more
openaire +1 more source
Addition of ammonia and/or oxygen to an ionic liquid for delignification of miscanthus
Bioresource Technology, 2011Ammonia 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 +3 more
openaire +2 more sources
Effects of lignin chemistry on oxygen delignification performance
TAPPI Journal, 2018The 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 +5 more
openaire +1 more source
Reduced brightness variations by extended oxygen delignification
Nordic Pulp & Paper Research Journal, 2000The kappa number reduction for softwood kraft pulps in an alkaline environment was studied with and without oxygen present. It was shown that the major part of the kappa number reduction in oxygen delignification stages is due to the reaction chemistry but the importance of effective extraction washing was also proved in experiments with subsequent ...
Camilla Rööst +2 more
openaire +1 more source
Alternatives for Lignocellulosic Pulp Delignification Using Polyoxometalates and Oxygen: A Review
ChemInform, 2007AbstractChemInform 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 +3 more
openaire +1 more source
Pulp delignification with oxygen and copper(II)-polyimine complexes
Holzforschung, 2013Abstract Ten Cu(II)-polyimine complexes were tested as potential catalysts in oxygen delignification of softwood kraft pulps. The ligands were chosen from the terpyridine and the phenanthroline families, including several neocuproines. One diamine-phenanthrene (daphen) was also investigated.
Gueneau, Basile +3 more
openaire +2 more sources