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New kinetics and mechanisms of oxygen delignification .

New kinetics and mechanisms of oxygen delignification .

Abstract Special oxygen delignification experiments were performed in a differentially operated continuous stirred tank reactor (CSTR). Because the dissolved oxygen and alkali concentrations in the reactor are constant, the rate of lignin removal may be determined from the dissolved lignin content in the outflow stream measured by UV absorption. The delignification kinetics were determined at .

Pilot scale trials of a low consistency oxygen .

Pilot scale trials of a low consistency oxygen .

style of reactor for oxygen delignification that was designed to minimize mass transfer limitations in the reaction. By minimiz-ing mass transfer considerations,the reactions can be effective-ly conducted at low consistency, delivering results comparable to medium consistency conventional oxygen delignification.

Oxygen delignification kinetics: CSTR and batch reactor .

Oxygen delignification kinetics: CSTR and batch reactor .

In the past, oxygen delignification studies were mostly performed in batch reactors, whereby the caustic and dissolved oxygen concentrations are changing during the reaction. Also the lignin content and cellulose degradation of the pulp are only established at the end of an experiment when the sample is removed from the reactor. To overcome these deficiencies, a differential reactor system .

Continuous alkaline oxygen gas delignification of pulp .

Continuous alkaline oxygen gas delignification of pulp .

The pulp is passed through a high-pressure delignification reactor run (R 1-R 3) and then depressurized and heated with steam before being supplied to a reactor system (R 4) in a low-pressure run where the dwell time is greater than that in the high-pressure run. A continuous process for the alkaline oxygen gas delignification of cellulose pulp which has been cooked and optionally washed .

Extended oxygen delignification of high kappa softwood .

Extended oxygen delignification of high kappa softwood .

Oxygen delignification (O-delignification) is an important tool for improving yield, reducing lignin content of pulp and lowering the bleach chemical consumption in the pulp and paper industries. This process is designed after cooking to maximize the delignification rate in comparison to the final phase of Kraft cooking without sacing pulp .

Delignification - an overview | ScienceDirect Topics

Delignification - an overview | ScienceDirect Topics

Delignification, the process of extracting lignin from plant sources, can be done using a variety of methods. Its aim is the disintegration of the lignocellulosic structure into its fibrous components [20]. The delignification processes can be divided into two major classes: chemical and solvent processes. . Reactor configuration and reaction .

Influence of xylan content on the oxygen delignification .

Influence of xylan content on the oxygen delignification .

Abstract. Common metrics for evaluating the efficiency of oxygen delignification include the kappa number and Klason lignin content. As a change in xylan content often leads to a change in HexA content, the kappa number must be corrected for the HexA contribution before evaluating the degree of oxygen delignification when trying to understand the process in detail.

Oxygen Delignification - Kempulp

Oxygen Delignification - Kempulp

Oxygen delignification has historically been done using various concepts; in several ways, high consistency, medium consistency, one stage or two stages. The state of the art design today is the Kempulp DualOx ® system which offers better selectivity, lower .

Simulation Of An Oxygen Delignification Reactor In The .

Simulation Of An Oxygen Delignification Reactor In The .

The delignification reactor consists of an upflow pressurized vessel with a pulp distributor at the bottom and a pulp discharger at the top. Oxygen delignification is the stage at which cellulosic pulp in an alkali solution, is pressurized with oxygen and steam, and then fed into the reactor. .

Effect of oxygen delignification on the rate and extent of .

Effect of oxygen delignification on the rate and extent of .

The values reported for mill A and B are typical of those achieved by softwood pulp mills using medium consistency oxygen delignification reactors (Bennington and Pineault, 1999). The oxygen delignification reactor at mill C was a "mini O 2 " system which, at the time of sampling, was operating at sub-optimal temperature (80°C).

The Medium Consistency Process for Oxygen Delignification

The Medium Consistency Process for Oxygen Delignification

The reactor bottom may be conical or may have a rotary bottom, and the top is equipped with a discharger. These features, in conjunction with a proper reactor geometry, are required to minimize channelling in the reactor. Post-oxygen filtrate may be added to the top of the reactor to facilitate discharging of the pulp.

DualOx® Enhanced Oxygen Delignification - Kempulp

DualOx® Enhanced Oxygen Delignification - Kempulp

The oxygen delignification system is of the GL&V patented DUALOX type in two-reactors. The process was designed using reaction kinetic equations, which were translated into a mill context. The equations state that the oxygen delignification process proceeds via two different phases, a very rapid initial phase and a slow final phase.

Ozone delignification of pine and eucalyptus kraft pulps .

Ozone delignification of pine and eucalyptus kraft pulps .

The kinetics of ozone delignification of unbleached pine and eucalyptus kraft pulps is studied at ultralow consistency in a stirred reactor. Ozone consumption was monitored with sensors located in both the liquid and gas phases of the reacting medium, and the results confirm the .

EP0043342A1 - A method for the delignification of wood and .

EP0043342A1 - A method for the delignification of wood and .

delignification Prior art date 1980-06-20 Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.) Granted Application number EP81810246A Other languages German (de) French (fr) Other versions EP0043342B1 (en .

Oxygen Delignification - Buckman

Oxygen Delignification - Buckman

Accelerate your pulp mill's oxygen delignification process and get superior results with D-Lig 151 from Buckman. It doesn't change the chemistry of the process; it makes it more efficient, enhancing the mass transfer of oxygen to the fiber to achieve a significantly higher rate of lignin removal.

Ozone delignification of pine and eucalyptus kraft pulps .

Ozone delignification of pine and eucalyptus kraft pulps .

The kinetics of ozone delignification of unbleached pine and eucalyptus kraft pulps is studied at ultralow consistency in a stirred reactor. Ozone consumption was monitored with sensors located in both the liquid and gas phases of the reacting medium, and the results confirm the .

Simulation of an Oxygen Delignification Reactor in the .

Simulation of an Oxygen Delignification Reactor in the .

The delignification reactor consists of an upflow pressurized vessel with a pulp distributor at the bottom and a pulp discharger at the top. The simulation was performed in 2D axissimetric and 3D geometry. The mesh created for the simulation of the geometries was the free triangular, being refined sequentially until obtaining different degrees .

Ozone Delignification/Bleaching | Linde Gas

Ozone Delignification/Bleaching | Linde Gas

Fast reactions, a short retention time (as a small reactor) is sufficient. Possibility of recycling filtrates to chemical recovery. Efficient delignification of all types of chemical pulps. Ozone was introduced as a bleaching chemical on industrial scale in the beginning of the 1990s.

Oxygen Delignification | Linde Gas

Oxygen Delignification | Linde Gas

The delignification may vary in the range of 40-70% depending on the wood raw material and whether one or two reactors in series are used. Unbleached kraft (sulphate) pulp has a lignin content of 3-5%, which after oxygen delignification, can be decreased to about 1.5% or a kappa number of 8-10.

Ozone Delignification/Bleaching | Linde Gas

Ozone Delignification/Bleaching | Linde Gas

Fast reactions, a short retention time (as a small reactor) is sufficient. Possibility of recycling filtrates to chemical recovery. Efficient delignification of all types of chemical pulps. Ozone was introduced as a bleaching chemical on industrial scale in the beginning of the 1990s.

OXYGEN DELIGNIFICATION -

OXYGEN DELIGNIFICATION -

single reactor. Hardwood pulp needs two reactors if a kappa number reduction of over 35% is required. Table 1 shows typical conditions in oxygen delignification. Table 1. Conditions in oxygen delignification. First stage Second stage temperature (°C) 80 - 85 90 - 105 pressure (bar) 7 - 10 3 - 5 retention time (min) 20 - 40 60 - 80 Valves

Elemental Chlorine Free Delignification of Chemical Pulp .

Elemental Chlorine Free Delignification of Chemical Pulp .

Elemental Chlorine Free Delignification of Chemical Pulp in Flow Through Reactor: Yahya Hamzeh, Soheila Izadyar and Gerard Mortha: Abstract: Based on the known mechanisms of lignin degradation by ClO 2, it has been shown that in conventional ECF delignification stage a significant part of applied chlorine dioxide is consumed in secondary reactions without significant effect on beaching.

Oxygen Delignification Kinetics and Selectivity Improvement

Oxygen Delignification Kinetics and Selectivity Improvement

Oxygen delignification experiments were conducted on Northeast softwood Kraft pulps at different temperatures, sodium hydroxide charges, reaction times, and pretreatments.

Simulation Of An Oxygen Delignification Reactor In The .

Simulation Of An Oxygen Delignification Reactor In The .

Simulation Of An Oxygen Delignification Reactor In The Kraft Pulp Production Process 4th October 2018 • The objective of this work is to analyze alternatives for optimization of the delignification process with oxygen, by means of simulation, in the aspect of operating conditions, as well as of the fluid dynamics of the reactor. The

Joseph M. Genco - Chemical and Biomedical Engineering .

Joseph M. Genco - Chemical and Biomedical Engineering .

Process parameters controlling the size of the reactor are the pulp throughput and consistency, temperature, caustic charge, oxygen addition rate and oxygen pressure. Design calculations suggest that the delignification rate depend strongly on the temperature while the selectivity is primarily controlled by the caustic addition.

Oxygen Delignification - Convergence Training

Oxygen Delignification - Convergence Training

Oxygen delignification produces pulp with a higher yield than pulping to the same kappa number. Oxygen is generated by cryogenic air separation where it is separated from nitrogen and the other components in air. In a high consistency reactor, steam is added to pulp at the top of a downflow reactor. Course Details. Specs. Training Time: 17 minutes.

Topical Report on XL-2 Project at IP, Jay, Maine .

Topical Report on XL-2 Project at IP, Jay, Maine .

Maine. The delignification experiments were performed to separate the effects of the 15 minute pressurized reactor from the 60 minute atmospheric tower. An ancillary objective was to determine the effects of mixing on the level of reaction that could be achieved in the oxygen reactor. O2 Delignification System at IP-Jay.

Topical Report on XL-2 Project at IP, Jay, Maine .

Topical Report on XL-2 Project at IP, Jay, Maine .

Maine. The delignification experiments were performed to separate the effects of the 15 minute pressurized reactor from the 60 minute atmospheric tower. An ancillary objective was to determine the effects of mixing on the level of reaction that could be achieved in the oxygen reactor. O2 Delignification System at IP-Jay.

White liquor oxidation - Valmet

White liquor oxidation - Valmet

With the air-based system, oxidation takes place in a multi-stage reactor. The air is fed to the reactors from a rotary air blower. Primarily, partial oxidation takes place and the sulfide is converted into thiosulfate. The cost of operation is low as atmospheric air is used to supply the required oxygen.

Medium Consistency Oxygen Delignification Performed with .

Medium Consistency Oxygen Delignification Performed with .

gen delignification (LCOD) system using a reactor in the place of a high-pressure retention tower and high shear mixer was installed at a U.S. kraft mill. The system was run with both hardwood (HWD) and softwood (SWD) pulps. Several potential process variables were explored along with the affect of the reactor on fiber integrity. The LCOD .