The Kinetics of Oxygen Delignification of Reed Kraft Pulp (I)-Kinetics of Delignification

2011 ◽  
Vol 236-238 ◽  
pp. 1420-1424
Author(s):  
Xiao Feng Pan ◽  
Le Fan Ma ◽  
Qin Qin Qu ◽  
Jia Liang Lan ◽  
Li Hong Tan
Keyword(s):  
Activation Energy ◽  
Reaction Time ◽  
Oxygen Pressure ◽  
Kraft Pulp ◽  
Reaction Order ◽  
Frequency Factor ◽  
Kappa Number ◽  
Alkali Concentration ◽  
Oxygen Delignification ◽  
Kinetics Of

The 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. The reaction order fitted is 6.72 for delignification (a), 0.87 for alkali concentration (b), and 0.62 for oxygen pressure(c), respectively. The activation energy E is 80.96KJ/mol and frequency factor A 1.5×104.

Study on the Kinetics of Wet Flue Gas Desulfurization by Carbide Slag

2011 ◽  
Vol 322 ◽  
pp. 252-255
Author(s):  
Sheng Yu Liu ◽  
Li Chao Nengzi ◽  
Cheng Wei Lu ◽  
Wei Qiu ◽  
Yun Ming Hu
Keyword(s):  
Activation Energy ◽  
Chemical Reaction ◽  
Flue Gas ◽  
Reaction Order ◽  
Frequency Factor ◽  
Reaction Model ◽  
Flue Gas Desulfurization ◽  
Economic Costs ◽  
Carbide Slag ◽  
Kinetics Of

Current industrial desulfurization processes involve in economic costs, if carbide slag can be used in those processes, the costs will be reduced and the goal treating waste with waste can be achieved. A mathematic reaction model was built based on the chemical reaction of desulfurization by carbide slag, the overall reaction order n=α+β=1.74, the activation energy Ea=21749.56173J/mol and the frequency factor k0=0.349533643 .

Dynamic Model of Rapeseed Oil Hydrolysis Reaction in Sub-Critical Water

2013 ◽  
Vol 860-863 ◽  
pp. 510-513 ◽  
Author(s):  
Yi Zhe Li ◽  
Hua Wang ◽  
Gui Rong Bao
Keyword(s):  
Activation Energy ◽  
Reaction Time ◽  
Dynamic Model ◽  
Rapeseed Oil ◽  
Reaction Order ◽  
Volume Ratio ◽  
Hydrolysis Reaction ◽  
Water Volume ◽  
Oil Water ◽  
Oil Hydrolysis

Experiments of Rapeseed Oil Hydrolysis Reaction in Sub-Critical Water (250-300°C, 5-60min) are Conducted in this Paper. Results Show that the Best Conditions for Rapeseed Oil Hydrolysis are Reaction Temperature 290°C, Oil-Water Volume Ratio 1:3, Reaction Time 40min, and Conversion Rate 98.9%. Meanwhile, Kinetic Analysis of this Hydrolysis Reaction is Presented. we Learn that Hydrolysis Reaction Order is 0.7778, Activation Energy is 55.34kJ/mol and the Dynamic Model is .

scholarly journals Investigation of the pyrolysis characteristics and kinetics of oil-palm solid waste by using Coats–Redfern method

2019 ◽  
Vol 38 (1) ◽  
pp. 298-309
Author(s):  
Fredy Surahmanto ◽  
Harwin Saptoadi ◽  
Hary Sulistyo ◽  
Tri A Rohmat
Keyword(s):  
Activation Energy ◽  
Solid Waste ◽  
Oil Palm ◽  
Frequency Factor ◽  
Nitrogen Atmosphere ◽  
Empty Fruit Bunch ◽  
Pyrolysis Kinetics ◽  
Pyrolysis Characteristics ◽  
Kinetics Of

The pyrolysis kinetics of oil-palm solid waste was investigated by performing experiments on its individual components, including empty fruit bunch, fibre, shell, as well as the blends by using a simultaneous thermogravimetric analyser at a heating rate of 10°C/min under nitrogen atmosphere and setting up from initial temperature of 30°C to a final temperature of 550°C. The results revealed that the activation energy and frequency factor values of empty fruit bunch, fibre, and shell are 7.58–63.25 kJ/mol and 8.045E-02–4.054E + 04 s−1, 10.45–50.76 kJ/mol and 3.639E-01–5.129E + 03 s−1, 9.46–55.64 kJ/mol and 2.753E-01–9.268E + 03, respectively. Whereas, the corresponding values for empty fruit bunch–fibre, empty fruit bunch–shell, fibre–shell, empty fruit bunch–fibre–shell are 2.97–38.35 kJ/mol and 1.123E-02–1.326E + 02 s−1, 7.95–40.12 kJ/mol and 9.26E-02–2.101E + 02 s−1, 9.14–50.17 kJ/mol and 1.249E-01–2.25E + 03 s−1, 8.35–45.69 kJ/mol and 1.344E + 01–4.23E + 05 s−1, respectively. It was found that the activation energy and frequency factor values of the blends were dominantly due to the role of the components with a synergistic effect occurred during pyrolysis.

scholarly journals Kinetic study of wood pyrolysis in presence of metal halides

2014 ◽  
Vol 12 (12) ◽  
pp. 1294-1303 ◽  
Author(s):  
Vladimir Beliy ◽  
Elena Udoratina
Keyword(s):  
Activation Energy ◽  
Lewis Acids ◽  
Alkaline Earth ◽  
Reaction Order ◽  
Earth Metal ◽  
Inorganic Salts ◽  
Alkaline Earth Metal ◽  
Metal Halides ◽  
Wood Pyrolysis ◽  
Kinetics Of

AbstractThe purpose of this work was to study the kinetics of wood pyrolysis in the presence of inorganic salts, representatives of classes of alkali and alkaline earth metal halides (NaCl, KCl, KBr, CaCl2, BaCl2·2H2O) and Lewis acids (AlCl3·6H2O, FeCl3·6H2O, CuCl2, CuBr2, ZnCl2·1.5H2O, NiCl2·6H2O, SnCl2·2H2O) using TG-DSC. The activity of these catalysts was estimated by the temperature of the beginning of pyrolysis, charcoal yield and kinetic parameters, such as energy of activation and reaction order. Using the Lewis acids as catalysts for pyrolysis leads to a decrease in the temperature of the process beginning and the activation energy. In the presence of other catalysts activation energy does not significantly change. The increase of a seeming reaction order in the presence of Lewis acids possibly is a consequence of complication of the thermodestruction mechanism, with the appearance of new parallel competing stages.

Changes in the lignin-carbohydrate complex in softwood kraft pulp during kraft and oxygen delignification

Holzforschung ◽  
2004 ◽  
Vol 58 (6) ◽  
pp. 603-610 ◽  
Author(s):  
Martin Lawoko ◽  
Rickard Berggren ◽  
Fredrik Berthold ◽  
Gunnar Henriksson ◽  
Göran Gellerstedt
Keyword(s):  
Kraft Pulp ◽  
Kappa Number ◽  
Kraft Pulps ◽  
Residual Lignin ◽  
Oxygen Delignification ◽  
Number Range ◽  
Morphological Aspects ◽  
Carbohydrate Complex ◽  
Softwood Kraft Pulp ◽  
Hydrolysis Of

Abstract Three kraft pulps in the kappa number range between 50 and 20 and the same pulps oxygen-delignified to similar lignin contents (kappa approximately 6) were analyzed for lignin-carbohydrate complexes (LCC) by a method based on selective enzymatic hydrolysis of the cellulose, and quantitative fractionation of the LCC. Between 85 and 90% of residual lignin in the unbleached kraft pulp and all residual lignin in the oxygen-delignified pulps were isolated as LCC. Three types of complexes were found; viz., xylan-lignin, glucomannan-lignin-xylan and glucanlignin complexes. After pulping to a high kappa number, most of the residual lignin was linked to xylan. Different delignification rates were observed so that most of the residual lignin was linked to glucomannan when the pulping was extended to a low kappa number. With increasing degree of oxygen delignification, a similar trend in the delignification rates of LCC was observed so that the residual lignin was increasingly linked to glucomannan. Complex LCC network structures seemed to be degraded into simpler structures during delignification. The differences in delignification rates are discussed with reference to the solubility properties and structural differences of LCC, and to morphological aspects of the pulp.

Synthesis and Determination of the Kinetic Parameters for Non-Isothermal Decomposition of Complexes Ln(thd)3phen

2006 ◽  
Vol 530-531 ◽  
pp. 506-512 ◽  
Author(s):  
Wilton Silva Lopes ◽  
Crislene Rodrigues da Silva Morais ◽  
A.G. de Souza
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Lanthanide Complexes ◽  
Reaction Order ◽  
Decomposition Reaction ◽  
Cylindrical Symmetry ◽  
Boundary Reaction ◽  
Phase Boundary Reaction ◽  
Kinetics Of

In this work the kinetics of the thermal decomposition of two ß-diketone lanthanide complexes of the general formula Ln(thd)3phen (where Ln = Nd+3 or Tm+3, thd = 2,2,6,6- tetramethyl-3,5-heptanodione and phen = 1,10-phenantroline) has been studied. The powders were characterized by several techniques. Thermal decomposition of the complexes was studied by non-isothermal thermogravimetry techniques. The kinetic model that best describes the process of the thermal decomposition of the complexes it was determined through the method proposed by Coats-Redfern. The average values the activation energy obtained were 136 and 114 kJ.mol-1 for the complexes Nd(thd)3phen and Tm(thd)3phen, respectively. The kinetic models that best described the thermal decomposition reaction the both complexes were R2. The model R2 indicating that the mechanism is controlled by phase-boundary reaction (cylindrical symmetry) and is defined by the function g(α) = 2[1-(1-a)1/2], indicating a mean reaction order. The values of activation energy suggests the following decreasing order of stability: Nd(thd)3phen > Tm(thd)3phen.

scholarly journals The Optimum Reaction Time, Activation Energy and Frequency Factor of Methyl Ricinoleate Nitration

2013 ◽  
Vol 13 (1) ◽  
pp. 36-40 ◽  
Author(s):  
Abdullah Abdullah ◽  
Triyono Triyono ◽  
Wega Trisunaryanti ◽  
Winarto Haryadi
Keyword(s):  
Activation Energy ◽  
Reaction Time ◽  
Methyl Ricinoleate ◽  
Frequency Factor ◽  
Optimum Reaction

Determination of the optimum reaction time, activation energy (Ea) and frequency factor (A) of methyl ricinoleate nitration has been done. The nitration was conducted with the mole ratio of methyl ricinoleate to HNO3 of 1:15. The reaction was conducted at temperatures of 29 and 64 °C with a variation of reaction time for 10, 20, 30, 60, 90, 120, and 150 min. Determination of activation energy and frequency factor was performed in a temperature of 29, 33, 38, 44, 49, 57 and 64 °C. The results showed that the optimum reaction time is 90 min. The activation energy (Ea) and frequency factor (A) was 44.5 kJ/mol and 4.780 x 103 sec-1, respectively.

scholarly journals CO2 Gasification Kinetics of Shenhua Bituminous Coal by Isothermal Thermo-Gravimetric Analysis

2020 ◽  
Author(s):  
Jinzhi Zhang ◽  
Zhiqi Wang ◽  
Ruidong Zhao ◽  
Jinhu Wu
Keyword(s):  
Activation Energy ◽  
Bituminous Coal ◽  
Thermo Gravimetric Analysis ◽  
Correlation Coefficients ◽  
Mathematical Expression ◽  
Frequency Factor ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
Kinetics Of ◽  
Compensation Relationship

Abstract This research performed the gasification kinetics of three Shenhua coal under CO2 atmosphere using isothermal thermogravimetry. Results showed that isothermal gasification curves for three different coal samples revealed different gasification behaviour. Among the eleven kinetic models, A2 was the most suitable one to describe the gasification kinetics of three coal samples, because it can reproduce the experimental data very well with reasonable correlation coefficients. The activation energy for sample A, B and C were 95.9, 79.1, and 69.4 kJ mol-1, respectively. The activation energy decreased with the increase of the particle size. The compensation relationship was observed between activation energy and frequency factor, and the mathematical expression was lnA=0.1041 E+0.54028 with the correlation coefficients of 0.999.

scholarly journals Kinetics Study of Thermal Degradation of Resin Derived from Salicylaldehyde, Ethylenediamine and Formaldehyde

2010 ◽  
Vol 7 (2) ◽  
pp. 564-568 ◽  
Author(s):  
Dhanraj. T. Masram ◽  
N. S. Bhave ◽  
K. P. Kariya
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Free Energy ◽  
Thermal Degradation ◽  
Frequency Factor ◽  
Entropy Change ◽  
Energy Change ◽  
Kinetics Study ◽  
Degradation Studies ◽  
Kinetics Of

The present paper reports the synthesis and kinetics of thermal degradation studies of resin salicylicldehyde -ethylenediamine -formaldehyde (SdEDF) derived by the condensation of salicylicldehyde and ethylenediamine with formaldehyde in the presence of catalyst hydrochloric acid in 1:1:2 molar proportions of reactants. Detailed thermal degradation studies of the SdEDF resin has been carried out to ascertain its thermal stability. Thermal degradation curve has been discussed in order to determine their mode of decomposition, order of reaction, apparent activation energy, frequency factor, free energy change, entropy change, and apparent energy change. Freeman - Carroll and Sharp- Wentworth methods have been applied for the calculation of kinetic parameters while the data from the Freeman - Carroll methods have been used to determine various thermodynamic parameters.

MODEL FREE KINETICS ANALYSIS OF IMPERATA CYLINDRICA (LALANG)

2016 ◽  
Vol 78 (8-3) ◽  
Author(s):  
Olagoke Oladokun ◽  
Arshad Ahmad ◽  
Tuan Amran Tuan Abdullah ◽  
Bemgba Bevan Nyakuma ◽  
Syie Luing Wong
Keyword(s):  
Activation Energy ◽  
Biomass Conversion ◽  
Frequency Factor ◽  
Isoconversional Methods ◽  
Green Energy ◽  
Imperata Cylindrica ◽  
Heating Rates ◽  
Model Free ◽  
Solid Biofuel ◽  
Kinetics Of

This study is the first attempt at investigating the solid state decomposition and the devolatilization kinetics of Imperata cylindrica (lalang) grass termed the “farmer’s nightmare weed” as a potential solid biofuel of the future. Biomass conversion technologies such as pyrolysis and gasification can be utilized for future green energy needs. However an important step in the efficient utilization and process optimizing of biomass conversion processes is understanding the thermal decomposition kinetics of the feedstock. Consequently, thermogravimetric analysis (TGA) of Imperata cylindrica was carried out in the temperature range of 30-1000 °C at four heating rates of 5, 10, 15, and 20 K min-1 using Nitrogen at a flow rate of 20 L min-1 as purge gas. Using the TGA results, the kinetic parameters activation energy (Ea) and pre-exponential frequency factor (ko) of the grass were estimated via the model free or isoconversional methods of Kissinger and Starink. The results obtained for Kissinger model were 151.36 kJ moI-1 and 5.83 x 109 min-1 for activation energy and pre-exponential frequency factor respectively. However, Starink model activation energy and pre-exponential frequency factor were a function of conversion (α) with average values of 159.93 kJ mol-1 and 6.33 x 1022 min-1 respectively. 

Sign in / Sign up

Export Citation Format

Share Document