An Investigation into the Conversion of Propylene Glycol to 2,4-dimethyl-1,3-dioxolane over an Acid Catalyst Using Gas Chromatography

2013 ◽  
Vol 850-851 ◽  
pp. 82-85
Author(s):  
Zuo You Zhang ◽  
Hui Chen ◽  
Xia Li ◽  
Zhao Hui Yang ◽  
Bao Chen Liang
Keyword(s):  
Aqueous Solution ◽  
Reaction Rate ◽  
Acid Catalyst ◽  
Reaction Rate Constant ◽  
Order Reaction ◽  
Molar Ratio ◽  
Temperature Reaction ◽  
Gas Chromatograph ◽  
Second Order Reaction ◽  
Operational Parameters

In the presence of an acid catalyst, PG react reversibly with acetaldehyde to form 2,4-dim-ethyl-1,3-dioxolane (24DMD). The effects of different operational parameters on PG conversion had been analyzed in paper, parameters included temperature, reaction time, amount of catalyst and aqueous acetaldehyde/PG molar ratio. Under optimal condition, 85% conversion of PG in aqueous solution was achieved within 180 min of reaction. The analysis of PG was conducted by gas chromatograph. Furthermore, reaction followed the second-order reaction kinetics, and the reaction rate constant was found to be 29.68min-1.

scholarly journals The alcoholysis of 1,2,2-trimethylpropyl-methylfluorophosphonate

2000 ◽  
Vol 65 (12) ◽  
pp. 857-866
Author(s):  
Mladjen Micevic ◽  
Slobodan Petrovic
Keyword(s):  
Kinetic Data ◽  
Reaction Rate ◽  
Frequency Factor ◽  
Reaction Rate Constant ◽  
Order Reaction ◽  
Activation Entropy ◽  
Second Order Reaction ◽  
Third Order ◽  
First Order ◽  
Kinetics Of

The alcoholysis of 1,2,2-trimethylpropyl-methylfluorophosphonate (soman) was examined with a series of alkoxides and in corresponding alcohols: methanol, ethanol, 1-propanol, 2-propanol, 2-methoxyethanol and 2-ethoxyethanol. Soman reacts with the used alkoxides in a second order reaction, first order in each reactant. The kinetics of the reaction between 1,2,2-trimethylpropyl-methylfluorophosphonate and ethanol in the presence of diethylenetriamine was also examined. A third order reaction rate constant was calculated, first order in each reactant. The activation energy, frequency factor and activation entropy were determined on the basis of the kinetic data.

scholarly journals Mechanistic study of CBT-Cys click reaction and its application for identifying bioactive N-terminal cysteine peptides in amniotic fluid

2017 ◽  
Vol 8 (1) ◽  
pp. 214-222 ◽  
Author(s):  
Zhen Zheng ◽  
Peiyao Chen ◽  
Gongyu Li ◽  
Yunxia Zhu ◽  
Zhonghua Shi ◽  
...  
Keyword(s):  
Amniotic Fluid ◽  
Rate Constant ◽  
Reaction Rate ◽  
Click Reaction ◽  
Condensation Reaction ◽  
Reaction Rate Constant ◽  
Order Reaction ◽  
Mechanistic Study ◽  
Second Order Reaction ◽  
Wide Applicability

CBT-Cys click condensation reaction has a high second-order reaction rate constant and has found wide applicability in recent years.

Photochemical reaction of superoxide radicals with 1-naphthol

2021 ◽  
Author(s):  
Ying Liu ◽  
Mengyu Zhu ◽  
Yadong Hu ◽  
Yijun Zhao ◽  
Chengzhu Zhu
Keyword(s):  
Photochemical Reaction ◽  
Reaction Rate ◽  
Surface Reaction ◽  
Atmospheric Model ◽  
Bulk Water ◽  
Reaction Rate Constant ◽  
Photochemical Reactions ◽  
Order Reaction ◽  
Reaction Pathways ◽  
Second Order Reaction

he photochemical reactions between 1-naphthol (1-NP) and superoxide anion radical (O2•−) were investigated in detail by using 365 nm UV irradiation. The results showed that the conversion rate of 1-naphthol decreased with the increase of the initial concentration of 1-naphthol, while the raising pH and riboflavin concentration accelerated the photochemical reaction. The second-order reaction rate constant was estimated to be (3.64 ± 0.17) × 108 L mol−1 s−1. The major photolysis products identified by using gas chromatography-mass spectrum (GC-MS) were 1, 4-naphquinone and 2, 3-epoxyresin-2, 3-dihydro-1, 4-naphquinone, and their reaction pathways were also discussed. An atmospheric model showed that both bulk water reaction and heterogeneous surface reaction deserved attentions in atmospheric aqueous chemistry.

Effect of Ozone Oxidation on the Molecular and Kinetic Properties of Effluent Organic Matter

2008 ◽  
Vol 11 (3) ◽  
Author(s):  
Fernando L. Rosario-Ortiz ◽  
Stephen P. Mezyk ◽  
Eric C. Wert ◽  
Devin F. R. Doud ◽  
Manu K. Singh ◽  
...  
Keyword(s):  
Organic Matter ◽  
Hydroxyl Radical ◽  
Rate Constant ◽  
Reaction Rate ◽  
Reaction Rate Constant ◽  
Order Reaction ◽  
Kinetic Properties ◽  
Second Order Reaction ◽  
Effluent Organic Matter ◽  
Ozone Oxidation

AbstractThe effect of ozone oxidation on the second order reaction rate constant between effluent organic matter (EfOM) and hydroxyl radical (

Kinetics of the reaction of methyl iodide with sulfite and thiosulfate ions in aqueous solution

1969 ◽  
Vol 47 (24) ◽  
pp. 4537-4541 ◽  
Author(s):  
R. A. Hasty ◽  
S. L. Sutter
Keyword(s):  
Activation Energy ◽  
Methyl Iodide ◽  
Reaction Rate ◽  
Reaction Rate Constant ◽  
Order Reaction ◽  
Second Order Reaction ◽  
Kcal Mole ◽  
Rate Of Reaction ◽  
Kinetics Of ◽  
Sulfite Ion

The rate of reaction of methyl iodide with sulfite ion is determined. In addition, the rate of reaction of methyl iodide with thiosulfate ion is reexamined and the rate of reaction of methyl iodide with bisulfite ion is estimated. A pronounced effect of ionic strength on the reaction rate in the methyl iodide – sulfite ion system is observed, this effect does not occur in the methyl iodide – thiosulfate ion system. The second order reaction rate constant and activation energy for the reaction of methyl iodide with the respective nucleophiles are: SO32−, 4.4 × 10−2M−1 s−1, 18.6 kcal mole−1; HSO3−, 1 × 10−3M−1 s−1, 18.4 kcal mole−1; and S2O32− 3.1 × 10−2M−1 s−1, 19.4 kcal mole−1.

scholarly journals Determination of exothermic batch reactor specific model parameters

2019 ◽  
Vol 292 ◽  
pp. 01063
Author(s):  
Lubomír Macků
Keyword(s):  
Rate Constant ◽  
Reaction Rate ◽  
Batch Reactor ◽  
Specific Model ◽  
Reaction Rate Constant ◽  
Order Reaction ◽  
First Order Reaction ◽  
Model Parameters ◽  
Reactor Model ◽  
First Order

An alternative method of determining exothermic reactor model parameters which include first order reaction rate constant is described in this paper. The method is based on known in reactor temperature development and is suitable for processes with changing quality of input substances. This method allows us to evaluate the reaction substances composition change and is also capable of the reaction rate constant (parameters of the Arrhenius equation) determination. Method can be used in exothermic batch or semi- batch reactors running processes based on the first order reaction. An example of such process is given here and the problem is shown on its mathematical model with the help of simulations.

Performance of Photocatalytic Microfiltration with Hollow Fiber Membrane

2007 ◽  
Vol 544-545 ◽  
pp. 95-98 ◽  
Author(s):  
Jong Tae Jung ◽  
Jong Oh Kim ◽  
Won Youl Choi
Keyword(s):  
Heavy Metals ◽  
Humic Acid ◽  
Rate Constant ◽  
Hollow Fiber ◽  
Reaction Rate ◽  
Hollow Fiber Membrane ◽  
Membrane Surface ◽  
Reaction Rate Constant ◽  
Operational Parameters ◽  
Tio2 Particles

The purpose of this study is to investigate the effect of the operational parameters of the UV intensity and TiO2 dosage for the removal of humic acid and heavy metals. It also evaluated the applicability of hollow fiber microfiltration for the separation of TiO2 particles in photocatalytic microfiltration systems. TiO2 powder P-25 Degussa and hollow fiber microfiltration with a 0.4 μm nominal pore size were used for experiments. Under the conditions of pH 7 and a TiO2 dosage 0.3 g/L, the reaction rate constant (k) for humic acid and heavy metals increased with an increase of the UV intensity in each process. For the UV/TiO2/MF process, the reaction rate constant (k) for humic acid and Cu, with the exception of Cr in a low range of UV intensity, was higher compared to that of UV/TiO2 due to the adsorption of the membrane surface. The reaction rate constant (k) increased as the TiO2 dosage increased in the range of 0.1~0.3 g/L. However it decreased for a concentration over 0.3 g/L of TiO2. For the UV/TiO2/MF process, TiO2 particles could be effectively separated from treated water via membrane rejection. The average removal efficiency for humic acid and heavy metals during the operational time was over 90 %. Therefore, photocatalysis with a membrane is believed to be a viable process for humic acid and heavy metals removal.

Photocatalytic Degradation of Methyl Orange by TiO2/Schorl Photocatalyst: Kinetics and Thermodynamics

2015 ◽  
Vol 713-715 ◽  
pp. 2789-2792
Author(s):  
Huan Yan Xu ◽  
Xue Li ◽  
Yan Li ◽  
Ping Li ◽  
Wei Chao Liu
Keyword(s):  
Methyl Orange ◽  
Reaction Rate ◽  
Reaction Kinetic ◽  
Kinetic Studies ◽  
Reaction Rate Constant ◽  
Order Reaction ◽  
Solution Ph ◽  
Kinetics And Thermodynamics ◽  
Hoff Equation ◽  
Degradation Of Methyl Orange

An active dye, Methyl Orange (MO) was employed as the target pollutant to evaluate the photocatalytic activity of TiO2/schorl composite and the kinetics and thermodynamics of this process was emphasized in this work. Langmuir–Hinshelwood kinetic model was employed for the kinetic studies and the results revealed that the process of MO photocatalytic discoloration by TiO2/schorl composite followed one order reaction kinetic equation under different conditions. The reaction rate constant (k) increased with initial MO concentration decreasing. When the catalyst dosage or solution pH increased,kvalues increased and then decreased. The possible reasons for these phenomena were discussed. Finally, the thermodynamic parameters ΔG, ΔH, ΔSwere obtained by the classical Van't Hoff equation.

scholarly journals Enhanced Heterogeneous Photodegradation of Organic Pollutants by a Visible Light Harvesting CoO@meso–CN@MoS2 Nanocomposites

Catalysts ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 722
Author(s):  
Linjer Chen ◽  
Thanh Binh Nguyen ◽  
Yi-Li Lin ◽  
Chung-Hsin Wu ◽  
Jih-Hsing Chang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Visible Light ◽  
Reaction Rate ◽  
Weight Ratio ◽  
Reaction Rate Constant ◽  
Pollutant Degradation ◽  
New Approach ◽  
Apparent Reaction Rate Constant ◽  
Apparent Reaction Rate

Developing simple and effective synthetic strategies regarding the formation of heterostructure photocatalytic semiconductors remains an intense challenge in research matters. Uniform heterostructure cobalt oxide@meso–CN@MoS2 (CoO@meso–CN@MoS2) photocatalyst exhibits excellent photocatalytic redox performance for pollutant degradation under visible light. By adjusting the weight ratio of CoO@meso–CN and MoS2, we fabricated a CoO@meso–CN@MoS2 heterostructure photocatalyst, and the established heterostructure between CoO@meso–CN and MoS2 was indicated by various physicochemical and morphological characterizations. The photocatalytic response to the fabricated hybrid was determined by rodamine B (RhB), methylene blue (MB), and congo red (CR) degradation in aqueous solution under visible light, and the nanocomposites with a slight content consisting of CoO@meso–CN achieved better catalysis than pure MoS2. This finding confirmed the propriety of this heterostructure as a valuable photocatalyst. The experimental results demonstrated that the apparent reaction rate constant of the 3 wt% CoO@meso–CN modified MoS2 was about two times higher than that of pure MoS2. The present work serves as a new approach for designing highly efficient visible light-induced heterostructure-based photocatalysts for environmental applications in the future.

scholarly journals Esterification of Waste Cooking Oil Using Ultrasonic: Kinetic Study

2019 ◽  
Vol 20 (2) ◽  
pp. 57-68
Author(s):  
Egi Agustian ◽  
Jessica Jessica ◽  
Pudji Untoro ◽  
Anny Sulaswatty
Keyword(s):  
Phosphoric Acid ◽  
Conventional Method ◽  
Acid Catalyst ◽  
Waste Cooking Oil ◽  
Reaction Rate Constant ◽  
Order Reaction ◽  
Second Order ◽  
Raw Material ◽  
Irreversible Reaction ◽  
Cooking Oil

Waste cooking oil (WCO) have a great potential as an alternative raw material for producing biodiesel. The literatures kinetic of the esterification of WCO in the presence of phosphoric acid catalyst with ultrasonic assisted are rare and most literatures used conventional method. This study aims to determine the optimum condition and the parameters of first and second order kinetics of the WCO esterification which was assisted by ultrasonic bath. Variables that used in this study are methanol/oil mole ratio, acid catalyst concentration and reaction temperature. The highest conversion was 42.08% with methanol/oil mole ratio of 15:1, a catalyst (phosphoric acid) concentration of 9% wt and temperature of 50oC within 90 minutes. The reaction time was reduced to 3 times (minute) compare to conventional method and fatty acid reduced 42%. Kinetic parameters were calculated with assumption that the esterification was the irreversible reaction. The reaction rate constant increasing with temperature. The value of activation energy for esterification of WCO is 42.94 kJ/mol for first order reaction and 35.30 kJ/mol for second order reaction.

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