scholarly journals A comparative analysis of empirical equations describing pressure dependence of equilibrium and reaction rate constants

2017 ◽  
Vol 95 (2) ◽  
pp. 149-161 ◽  
Author(s):  
Jacob Spooner ◽  
Noham Weinberg
Keyword(s):  
Experimental Data ◽  
Reaction Rate ◽  
Equilibrium Constants ◽  
Simulated Data ◽  
Diels Alder ◽  
Empirical Equations ◽  
Reaction Rate Constants ◽  
Analytical Functions ◽  
Experimental Errors ◽  
Reaction Volumes

General properties of the empirical analytical functions used to describe the effect of pressure on rate and equilibrium constants in solution are reviewed, and the effects of experimental errors on the accuracy of activation and reaction volumes predicted by these equations are compared. When the error levels are low (1%–2%) and pressure ranges are small (0–1 kbar), all functions perform well, but when fitting data with high error or extending to higher pressures, special care must be taken to obtain reliable results. Analysis of the results from fitting the equations to simulated data, as well as experimental data for Diels–Alder, Menshutkin, and methanolysis reactions, allows us to propose a set of general recommendations when using these equations as a tool for obtaining accurate activation and reaction volumes.

Enhanced Oxidation of Air Contaminants on an Ultra-Low Density UV-Accessible Aerogel Photocatalyst

1996 ◽  
Vol 454 ◽  
Author(s):  
M. Dreyer ◽  
G. K. Newman ◽  
L. Lobban ◽  
S. J. Kersey ◽  
R. Wang ◽  
...  
Keyword(s):  
Reaction Rate ◽  
Adsorption Equilibrium ◽  
Uv Light ◽  
Equilibrium Constants ◽  
Main Stream ◽  
Low Density ◽  
Air Contaminants ◽  
Reaction Rate Constants ◽  
Air Contaminant ◽  
Type Rate

ABSTRACTThis research developed new forms of photocatalysts that could potentially move photocatalytic degradation of air contaminants into the main stream of industrially used remediation technologies. Tests of the photocatalytic activity of the TiO2 aerogel catalysts have been carried out using both acetone and methane as the air contaminant. For comparison, the same tests were carried out on a standard (non-aerogel) anatase powder. Despite having very low crystallinity, the aerogel decontaminates the air far more effectively than an equal volume of the anatase powder which indicates that a much larger fraction of the aerogel is activated by the UV light. Experimental data were used to determine adsorption equilibrium constants for acetone, and to determine reaction rate constants assuming a Langmuir-Hinshelwood type rate expression.

Simulation of Crosslink and Graft Mechanism of Hydrogenated-NBR/ZINC Di-Methacrylate Composites by Moving Die Rheometer

2002 ◽  
Vol 75 (5) ◽  
pp. 943-954 ◽  
Author(s):  
Takashi Sato ◽  
Akio Fujino ◽  
Sachio Hayashi ◽  
Motofumi Oyama ◽  
Katsumichi Ono
Keyword(s):  
Experimental Data ◽  
Genetic Algorithm ◽  
Rate Constants ◽  
Reaction Rate ◽  
Addition Reaction ◽  
Algorithm Optimization ◽  
Reaction Rate Constants ◽  
Data Comparison ◽  
Graft Reaction ◽  
Comparison With Experimental Data

Abstract This paper studies the crosslink and graft mechanism of hydrogenated-NBR/zinc di-methacrylate (HNBR/ZDMA) composites. The experiments to determine the rate constants of crosslink and graft reaction formulas are from Moving Die Rheometer (MDR) data. Comparison with experimental data and the solution of simultaneous ordinary differential equations for the crosslink and graft reactions are performed. Genetic algorithm optimization of the reaction rate constants allowed for simulation of crosslinking and graft reaction process. This simulation predicts that the HNBR/peroxide cure system will contain 0.1052-mole/l crosslink between matrix HNBR polymer at 2 phr.-peroxide concentration. The crosslink concentration of 0.1052-mole/l is composed of 0.0308-mole/l-addition reaction and 0.0744-mole/l-termination reaction. Moreover, the HNBR/ZDMA cure system contains 0.0148-mole/l graft of poly-ZDMA to HNBR and 0.0903-mole/l crosslink between matrix HNBR polymer at a 2 phr.-peroxide concentration.

scholarly journals Aromatization of light naphtha fractions on zeolites 1: Kinetic model

2003 ◽  
Vol 57 (9) ◽  
pp. 399-403 ◽  
Author(s):  
Svetlana Rovenskaja ◽  
Nikolaj Ostrovski
Keyword(s):  
Experimental Data ◽  
Kinetic Model ◽  
Rate Constants ◽  
Reaction Rate ◽  
Reaction Scheme ◽  
Activation Energies ◽  
Modeling And Optimization ◽  
Light Naphtha ◽  
Reaction Rate Constants

On the basis of analyzing kinetic experimental data performed in laboratory integral reactors a lumping kinetic model of the "Zeoforming" process was developed. A reaction scheme of the lumped components was proposed, that was adapted to the technological requirements. The reaction rate constants and activation energies were estimated, that are valid for certain feed compositions. The model is intended for further modeling and optimization of the process.

Theory of CO2 Exchange in Trout Gills

1974 ◽  
Vol 60 (1) ◽  
pp. 183-194
Author(s):  
JAMES N. CAMERON ◽  
JOHN A. POLHEMUS
Keyword(s):  
Experimental Data ◽  
Computer Simulation ◽  
Water Flow ◽  
Reaction Rate ◽  
Co2 Exchange ◽  
Co2 Efflux ◽  
Flow Rates ◽  
Reaction Rate Constants ◽  
Co2 Output ◽  
Extreme Sensitivity

1. A computer simulation of countercurrent CO2 exchange in fish gills was constructed to examine effects of variations in blood and water flow rates. 2. CO2 output was sensitive to both blood and water flow rates, contrary to experimental data. 3. Various explanations of the contradiction are discussed, including patterns of gill perfusion and possible shunting of blood. 4. A simplified version of the model was also used to demonstrate extreme sensitivity of CO2 efflux to variations of the residence time of blood in the gills. 5. Data from the literature on reaction rate constants for the CO2/carbonate/ bicarbonate system are summarized, and the importance of some of these reactions is examined.

Investigation Of Kinetic Regularities For Obtaining Methyl-1,3,4- Trimethylcyclohex-3-Encarboxylate By Reaction Of Diels-Alder

2019 ◽  
Vol 14 (4) ◽  
pp. 208-215
Author(s):  
I.S. Kostiv ◽  
R.I. Havryliv
Keyword(s):  
Rate Constants ◽  
Reaction Rate ◽  
Activation Parameters ◽  
Product Yield ◽  
Alder Reaction ◽  
Diels Alder ◽  
Molar Ratio ◽  
Target Product ◽  
Reaction Rate Constants ◽  
Diels Alder Reaction

Kinetics of the reaction of the cycloaddition of 2,3-dimethylbuta-1,3-diene (DMB) and methylmethacrylate (MMA) by the Diels-Alder reaction was studied. Reaction rate constants k = 4.4∙10-6 l/(mol∙s) at T = 403 K; k = 10.0∙10-6 l/(mol∙s) at T = 413 K; k = 15.8∙10-6 l/(mol∙s) at T = 423 K; k = 19.4∙10-6 l/(mol∙s) at T = 433 K and the activation parameters of the reaction Eakt = 75.2 kJ/mol, ΔS = -146.8 J/(mol∙K), ΔH = 73.9 kJ/mol were determined. Influence of temperature, molar ratio of reagents on the yield of the target product was investigated. At temperature increase from 403 to 433 K, methyl-1,3,4-trimethylcyclohex-3-encarboxylate (MTMCHC) yield increases from 78 % to 92 %. With further increase in temperature, DMB boils and MMA remains in a liquid state, accordingly it is not expected that the target product yield will materially increase. An increase in the excess of DMB: МMA from 1:1 to 2.5:1 makes it possible to increase yield of MTMCHC from 65 % to 92 %. The production of methyl-1,3,4-trimethylcyclohex-3-encarboxylate at the optimal conditions was established: temperature of 423−433 K and molar ratio of reagents DMB:MMA = 1.5:1, the yield of MTMCHC reaches 89−92 % at productivity of 101−105 g/(l·h). Based on the obtained reaction rate constants and the activation parameters of the [4+2]-cyclic addition of 2,3-dimethylbuta-1,3-diene and methylmethacrylate, it was found that the reaction under study is subject to the kinetic law of the second order.

scholarly journals The influence of the catalyst on the kinetics of ethyl metacrylate synthesis

2007 ◽  
Vol 9 (1) ◽  
pp. 7-9
Author(s):  
Mirosław Grzesik ◽  
Teresa Witczak
Keyword(s):  
Liquid Phase ◽  
Integral Method ◽  
Reaction Rate ◽  
Reaction Order ◽  
Equilibrium Constants ◽  
Chemical Compounds ◽  
Rate Equations ◽  
Reaction Rate Constants ◽  
Kinetic Relations ◽  
Kinetics Of

The influence of the catalyst on the kinetics of ethyl metacrylate synthesis The synthesis of ethyl metacrylate in the liquid phase was studied. Tungstophosphoric and molybdophosphoric acids, which belong to heteropolyacids group, were used as a catalyst. The chemical compounds from this group are often utilized in the catalysis with regard to their activity and selectivity. The rate equations, reaction rate constants and equilibrium constants have been determined. The reaction order and the kinetic parameters of the kinetic relations were determined by the integral method. All rate equations are formulated with activities taking the non ideal effects of the compounds into consideration. It was found that the kinetics of the esterification of the presented reactions was non-elementary

scholarly journals N-hexylpyridinium bis(trifluoromethylsulfonyl)imide and Lewis acids — catalytic systems for Diels-Alder reaction

2011 ◽  
Vol 9 (1) ◽  
pp. 192-198 ◽  
Author(s):  
Bożena Bittner ◽  
Ewa Janus ◽  
Eugeniusz Milchert
Keyword(s):  
Ionic Liquid ◽  
Rate Constants ◽  
Lewis Acids ◽  
Reaction Rate ◽  
Alder Reaction ◽  
Diels Alder ◽  
Catalytic Systems ◽  
Reaction Rate Constants ◽  
Diels Alder Reaction ◽  
Reaction Media

AbstractA comparative study of the Diels-Alder reactions between cyclopentadiene (1) and dienophiles (2 a–c) in N-hexylpyridinium bis(trifluoromethylsulfonyl)imide in a temperature range of 20–45°C is reported. The reaction rate constants and activation energies were calculated. Moreover, the catalytic systems based on N-hexylpyridinium bis(trifluoromethylsulfonyl)imide and Lewis acids were tested as a reaction media to perform the Diels-Alder reaction. Yb, Y, Mg, Zn triflates and chlorides (0.005 to 0.1 mmol) were used as catalysts. The recycling of catalytic system consisted of YCl3 and ionic liquid was performed.

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