The Effect of Scalling-Up and Hydrodynamic Properties of Stirring System on the Kinetics of Vegetable Oil Hydrogenation

1993 ◽  
Vol 58 (2) ◽  
pp. 320-327
Author(s):  
Ivan Dědek
Keyword(s):  
Reaction Kinetics ◽  
Reaction Rate ◽  
Specific Effect ◽  
Scaling Up ◽  
Point Of View ◽  
Geometrical Parameters ◽  
Hydrodynamic Properties ◽  
Anchor Agitator ◽  
Kinetics Of ◽  
Limiting Value

The stirring system of classical turbine agitator beside the anchor agitation system was studied from the point of view of the effect of their hydrodynamic properties on the kinetics of sunflower oil hydrogenation, It was found out that the anchor agitator makes up a higher gas hold-up than the turbine one and its efficiency from the view of reaction kinetics is higher. On changing the geometrical parameters of anchor agitator - by reducing its blade height - its hydrodynamic properties change considerably, and its efficiency decreases. The scaling-up of the stirring system did not manifest itself in the reaction rate in case of the turbine agitator. With the anchor agitator, the scaling-up resulted in the confirmation of its specific effect on the reaction kinetics, viz., on exceeding the limiting value of stirring frequency, the dramatic loss in efficiency took place.

Enzymatic Reaction Kinetics of Papain-Extracted Collagen from Bighead Carp Scales

2015 ◽  
Vol 727-728 ◽  
pp. 56-60
Author(s):  
Min Li ◽  
Liu Meng Chen ◽  
Bo Quan Jiang
Keyword(s):  
Reaction Kinetics ◽  
Reaction Rate ◽  
Enzymatic Reaction ◽  
Raw Material ◽  
Bighead Carp ◽  
Fish Waste ◽  
Biomedical Material ◽  
Production Output ◽  
And Control ◽  
Kinetics Of

Collagen, as an important biomedical material, has been widely used in medical industry. Fish waste (scales, skins, bones, fins and swim bladders) is a kind of newly developed alternative collagen raw material.This paper uesd papain as enzyme and local bighead fish scales as raw material to extract collagen. More attention was paid to the study on enzymatic reaction kinetics of papain-extracted collagen. The results showed that two kinds of kinetic models(Michaelis-Menten equations and exponential type dynamic equations) at 20, 25 and 28°C were established, respectively and experimentally proved to be basically in agreement with the actual values. These models have a great significance to predict, adjust and control the reaction rate and production output under different conditions.

scholarly journals The oxidation kinetics of depleted uranium and its low-alloy molybdenum alloys in moist air

2019 ◽  
Vol 63 (3) ◽  
pp. 100-104
Author(s):  
T. Chmela ◽  
P. Krupička
Keyword(s):  
Relative Humidity ◽  
Reaction Kinetics ◽  
Oxidation Kinetics ◽  
Reaction Rate ◽  
Depleted Uranium ◽  
Rate Equations ◽  
Moist Air ◽  
Molybdenum Alloys ◽  
Exponential Behaviour ◽  
Kinetics Of

Abstract The oxidation kinetics of depleted uranium and its low-alloy molybdenum alloys (U-2wt.%Mo, U-5wt.%Mo) were measured in a moist air (75% relative humidity) at 60 and 75 ° C. Coefficients of reaction rate equations were determined for linear oxidation kinetics. In the oxidation of depleted uranium at 75 ° C, a change in reaction kinetics from linear to exponential behaviour was observed after about 2500 hours.

Effect of 1-D Nano-Confinement on the Kinetics of a Click-Chemistry Surface Reaction Used in Biosensors

2018 ◽  
Vol 282 ◽  
pp. 182-189
Author(s):  
Guy Vereecke ◽  
Haroen Debruyn ◽  
Quinten de Keyser ◽  
Rita Vos ◽  
Abhishek Dutta ◽  
...  
Keyword(s):  
Reaction Kinetics ◽  
Semiconductor Manufacturing ◽  
Reaction Rate ◽  
Surface Reaction ◽  
Double Layers ◽  
Planar Surface ◽  
Confined Spaces ◽  
Nano Structures ◽  
Water Structuring ◽  
Kinetics Of

In semiconductor manufacturing of 3-D nano-structures, modified kinetics have been encountered for the aqueous chemical etching of thin films in nano-confined spaces. A popular explanation relies on changes in reactant concentration from the overlap of electrostatic double layers (EDL) on opposite walls of the nano-structures. In this study, the cycloaddition of dibenzylcyclooctyne-PEG3-alcohol (DBCO) to a linear azide-terminated SAM was performed in nanochannels of width varying from 62 to 32 nm. ATR-FTIR was used to monitor the reaction kinetics, characterize water structuring and determine the pH in nanochannels. Reaction kinetics were slower in nanochannels as compared to a planar surface, while pH shifts were observed in absence of EDL overlap, with a significant influence of channel width. Actually only the overall decrease in reaction rate could be explained by EDL overlap. The discussion shows that the water structuring measured in nanochannels may play a significant role in the observed phenomena.

Retardation of the reaction kinetics of polymers due to entanglement in the post-gel stage in multi-chain slip-spring simulations

Soft Matter ◽  
2019 ◽  
Vol 15 (25) ◽  
pp. 5109-5115 ◽  
Author(s):  
Yuichi Masubuchi ◽  
Takashi Uneyama
Keyword(s):  
Reaction Kinetics ◽  
Reaction Rate ◽  
Network Formation ◽  
Coarse Grained ◽  
Coarse Grained Model ◽  
Kinetics Of ◽  
Standing Problem ◽  
Apparent Reaction Rate

The retardation in the apparent reaction rate in the network formation of polymers is a long-standing problem. We have tackled this issue by a coarse-grained model to clarify the effect of entanglement between polymers.

Microfluidic Chip Injection Photo Solidification Molding Study on Reaction Kinetics

2019 ◽  
Vol 814 ◽  
pp. 481-486
Author(s):  
Jin Ge Tong ◽  
Jian Yun He ◽  
Peng Cheng Xie ◽  
Jing Hui Zhang ◽  
Zeng Qiang Shen ◽  
...  
Keyword(s):  
Reaction Kinetics ◽  
Microfluidic Chip ◽  
Reaction Rate ◽  
Reaction System ◽  
Microfluidic Chips ◽  
Forming Efficiency ◽  
Chip Fabrication ◽  
On Line ◽  
Feeding Effect ◽  
Kinetics Of

Microfluidic chip injection photocuring is a new method for microfluidic chip fabrication. The accuracy of microfluidic chip photocuring has an important impact on the reliability of microfluidic chip. The reaction rate of photocuring system directly affects the final quality and efficiency of microfluidic chip. The rapid reaction rate of photocuring system will lead to poor feeding effect of the reaction system. The forming accuracy is affected, and the reaction rate is too slow, which will increase the forming time and affect the forming efficiency. In this paper, the conversion rate and reaction rate of different active monomers and oligomers used in the formulation system of microfluidic chips were measured on-line. The photocuring reaction kinetics of microfluidic chips was studied, and the influence of the formulation system on the photocuring reaction was explored, which laid a foundation for optimizing the formulation of microfluidic chips.

scholarly journals Reaction Kinetics of Carbon Dioxide in Aqueous Diethanolamine Solutions Using the Stopped-Flow Technique

2012 ◽  
Vol 19 (1) ◽  
pp. 55-66 ◽  
Author(s):  
Marta Siemieniec ◽  
Hanna Kierzkowska-Pawlak ◽  
Andrzej Chacuk
Keyword(s):  
Carbon Dioxide ◽  
Reaction Kinetics ◽  
Rate Constants ◽  
Reaction Rate ◽  
Reaction Rate Constant ◽  
Stopped Flow ◽  
First Order ◽  
Pseudo First Order ◽  
Kinetics Of ◽  
Good Agreement

Reaction Kinetics of Carbon Dioxide in Aqueous Diethanolamine Solutions Using the Stopped-Flow Technique The pseudo-first-order rate constants (kOV) for the reactions between CO2 and diethanolamine have been studied using the stopped-flow technique in an aqueous solution at 293, 298, 303 and 313 K. The amine concentrations ranged from 167 to 500 mol·m-3. The overall reaction rate constant was found to increase with amine concentration and temperature. Both the zwitterion and termolecular mechanisms were applied to correlate the experimentally obtained rate constants. The values of SSE quality index showed a good agreement between the experimental data and the corresponding fit by the use of both mechanisms.

Study on Oxidation Kinetics of Catalytic Oxidation of Magnesium Sulfite

2011 ◽  
Vol 391-392 ◽  
pp. 1350-1353
Author(s):  
Tong Zhu ◽  
Xiao Yan Qi ◽  
Zhong Yuan Wang ◽  
Fang Yu ◽  
An An Liu ◽  
...  
Keyword(s):  
Activation Energy ◽  
Reaction Kinetics ◽  
Oxidation Kinetics ◽  
Reaction Rate ◽  
Catalyst Concentration ◽  
Oxidation Process ◽  
Sulfate Concentration ◽  
Air Compressors ◽  
Kinetics Of ◽  
Temperature Time

This paper presented a study on the reaction kinetics of magnesium sulfite catalyzed by Catalyst TR. Used a Lib-scale Plexiglas reactor aerated by air compressors to research the oxidation process Influence by pH, catalyst concentration, aeration quantity, temperature, time, sulfate concentration. Through experiment concluded the activation energy, got the formula between reaction rate and sulfate concentration.

scholarly journals Controlled Kinetics of On-Surface Dehydrogenation using a Low-Energy Electron Beam

2021 ◽  
Author(s):  
Anton Makoveev ◽  
Pavel Procházka ◽  
Azin Shahsavar ◽  
Lukáš Kormoš ◽  
Tomáš Krajňák ◽  
...  
Keyword(s):  
Electron Beam ◽  
Reaction Kinetics ◽  
Chemical Reaction ◽  
Self Assembly ◽  
Reaction Rate ◽  
Low Energy ◽  
Energy Electron ◽  
Chemical Reaction Kinetics ◽  
Low Energy Electron ◽  
Kinetics Of

Abstract Self-assembly and on-surface synthesis are vital strategies used for fabricating surface-confined 1D or 2D supramolecular nanoarchitectures with atomic precision. In many systems, the resulting structure is determined by kinetics of processes involved, i.e., reaction rate, on-surface diffusion, nucleation, and growth, all of which are typically governed by temperature. However, other external factors have been only scarcely harnessed to control the on-surface chemical reaction kinetics and self-assembly. Here, we show that a low-energy electron beam can be used to steer chemical reaction kinetics and induce the growth of molecular phases unattainable by thermal annealing. The electron beam provides a well-controlled means of promoting the elementary reaction step, i.e., deprotonation of carboxyl groups. The reaction rate linearly increases with increasing electron beam energy beyond the threshold energy of 6 eV. Our results offer the novel prospect of controlling the self-assembly, enhancing the rate of reaction steps selectively, and thus altering the kinetic rate hierarchy.

scholarly journals Reaction Kinetics of Carbon Dioxide in Aqueous Blends of N-Methyldiethanolamine and L-Arginine Using the Stopped-Flow Technique

Processes ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 81 ◽  
Author(s):  
Nafis Mahmud ◽  
Abdelbaki Benamor ◽  
Mustafa Nasser ◽  
Muftah H. El-Naas ◽  
Paitoon Tontiwachwuthikul
Keyword(s):  
Carbon Dioxide ◽  
Reaction Kinetics ◽  
Reaction Rate ◽  
Carbon Dioxide Emission ◽  
Solution Concentration ◽  
Reaction Rate Constant ◽  
Stopped Flow ◽  
Promoting Effect ◽  
Absolute Deviation ◽  
Kinetics Of

: Reduction of carbon dioxide emission from natural and industrial flue gases is paramount to help mitigate its effect on global warming. Efforts are continuously deployed worldwide to develop efficient technologies for CO2 capture. The use of environment friendly amino acids as rate promoters in the present amine systems has attracted the attention of many researchers recently. In this work, the reaction kinetics of carbon dioxide with blends of N-methyldiethanolamine and L-Arginine was investigated using stopped flow technique. The experiments were performed over a temperature range of 293 to 313 K and solution concentration up to one molar of different amino acid/amine ratios. The overall reaction rate constant (kov) was found to increase with increasing temperature and amine concentration as well as with increased proportion of L-Arginine concentration in the mixture. The experimental data were fitted to the zwitterion and termolecular mechanisms using a nonlinear regression technique with an average absolute deviation (AAD) of 7.6% and 8.0%, respectively. A comparative study of the promoting effect of L-Arginine with that of the effect of Glycine and DEA in MDEA blends showed that MDEA-Arginine blend exhibits faster reaction rate with CO2 with respect to MDEA-DEA blend, while the case was converse when compared to the MDEA-Glycine blend.

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