Papers by Keyword: Kinetic

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Authors: Peng Fei Yang
Abstract: Phenyl isocyanate is used to react with 1,3-butanediol at different temperatures. Toluene is used as solvent and 1,4-diazabicyclo[2,2,2]octane is used as catalyst. In-situ FT-IR is used to monitor the reaction to work out rate constant, Arrhenius equation and Eyring equation. The urethane reaction has been found to be a second order reaction, and the rate constant seems different between initial stage and final stage. The activation energy (Ea), activation enthalpy (ΔH) and activation entropy (ΔS) for the urethane reaction of primary hydroxyl group are calculated out, which are 26.4 kJ•mol-1, 23.6 kJ•mol-1 and -186.6 J•mol-1•k-1, respectively. They are very useful to reveal the reaction mechanism.
2223
Authors: Peng Fei Yang
Abstract: Phenyl isocyanate is used to react with 1,2-propanediol in different temperatures. Toluene is used as solvent and triethylamine is used as catalyst. In-situ FT-IR is used to monitor the reaction to work out rate constant, Arrhenius equation and Eyring equation. The urethane reaction has been found to be a second order reaction, and the rate constant seems different between initial stage and final stage. The activation energy (Ea), activation enthalpy (ΔH) and activation entropy (ΔS) for the urethane reaction are calculated out, which are 74.1 kJ•mol-1, 71.3 kJ•mol-1 and -30.5 J•mol-1•k-1, respectively. They are very useful to reveal the reaction mechanism.
131
Authors: Peng Fei Yang
Abstract: Benzyl alcohol is used to react with isophorone diisocyanate at different temperatures. Dibutyltin dilaurate is used as catalyst. In-situ FT-IR is used to monitor the reaction to work out rate constant, Arrhenius equation and Eyring equation. The urethane reaction has been found to be a second order reaction, and the rate constant seems different between initial stage and final stage. The activation energy (Ea), activation enthalpy (ΔH) and activation entropy (ΔS) for the urethane reaction of different isocyanates groups are respectively calculated out, which are very useful to reveal the reaction mechanism.
2197
Authors: Peng Fei Yang
Abstract: Phenyl isocyanate is used to react with 1,3-butanediol at different temperatures. Dimethylformamide is used as solvent. In-situ FT-IR is used to monitor the reaction to work out rate constant, Arrhenius equation and Eyring equation. The urethane reaction has been found to be a second order reaction, and the rate constant seems different between initial stage and final stage. The activation energy (Ea), activation enthalpy (ΔH) and activation entropy (ΔS) for the urethane reaction of primary hydroxyl group are calculated out, which are 90.9 kJ•mol-1, 88.2 kJ•mol-1 and 20.2 J•mol-1•k-1, respectively. They are very useful to reveal the reaction mechanism.
1911
Authors: Peng Fei Yang
Abstract: Phenyl isocyanate is used to react with 3-methyl-1,3-butanediol at different temperatures. Dimethylformamide is used as solvent. In-situ FT-IR is used to monitor the reaction to work out rate constant, Arrhenius equation and Eyring equation. The urethane reaction has been found to be a second order reaction, and the rate constant seems different between initial stage and final stage. The activation energy (Ea), activation enthalpy (ΔH) and activation entropy (ΔS) for the urethane reaction of tertiary hydroxyl group are calculated out, which are 75.2 kJ•mol-1, 72.4 kJ•mol-1 and -44.8 J•mol-1•k-1, respectively. They are very useful to reveal the reaction mechanism.
1743
Authors: Shan Yu, Chang Hai Li, Dong Mei Jia
Abstract: The hydroxyl alumina impregnated weakly basic resin composite (D301Al) successfully prepared through incorporation of hydroxyl alumina into the D301 resin for 2-naphthalenesulfonic acid (2-NSA) removal from aqueous solution. The structure of D301Al was examined using scanning electron microscopy and Fourier transform infrared spectroscopy. The adsorption behaviors of 2-NSA on D301Al were investigated by static adsorption experiments. Effects of pH of solution, temperature and contact time were determined. The results indicated D301Al reached the maximum adsorption capacity to 2-NSA with pH 2.4. Nonlinear regression was used to estimate of Langmuir and Freundlich model parameters. And the Langmuir model can give a satisfactory fit of the experimental equilibrium data. The kinetic studies indicated that the adsorption of D301Al for 2-NSA can establish adsorption equilibrium at 8 h. The pseudo-first-order and pseudo-second-order rate models could characterize the kinetic data of 2-NSA adsorption on D301Al.
34
Authors: Ying Ling Bao, Li Chen, Hong Lin Wang, Zong Cheng Yan
Abstract: A suitable starch hydrolysis strategy is crucial for conversion of starch into fermentable sugar, both with regard to reducing hydrolysis cost and increasing hydrolysis efficiency. A mathematical model for starch hydrolysis has been developed to predict sugar released curves based on experimental data from starch cold enzyme hydrolysis. At the first part of cold enzyme hydrolysis, starch was hydrolyzed by α-amylase (EC 3.2.1.1) and conversion into dextrin and glucose. Secondly, the residual starch and dextrin were second hydrolysis by glucoamylase (EC 3.2.1.3) into glucose. Fitting of experimental data was made by non-linear regression. Parameters values calculate were obtain from previous studies or experiments. Though mathematic formulation, the kinetic model was able to fit experiment with very good agreement. This model can be used for simulation of the industrial process and for faults detection. It can also be utilized for the optimization and even for the supervised control of the process.
2918
Authors: Zhi Qiang Wu, Shu Zhong Wang, Qi Xing Guo, Jun Zhao, Lin Chen, Hai Yu Meng
Abstract: Co-utilization of coal and biomass has been shown as an effective way to reduce the carbon footprint. Pyrolysis technology not only transform carbonaceous materials such as coal and biomass into various chemical compounds and fuels, but also as the initial step of the thermochemical conversation. For the sake of a better understanding of the co-thermal conversation, it is very necessary to get a intensive study on the co-pyrolysis of coal and biomass. In this paper the co-pyrolysis characteristics of coal and spent mushroom compost (SMC) were investigated through an thermogravimetry analyzer from ambient temperature to 950 °C at different heating rates (10, 20 and 40 °C/min) under nitrogen condition. Kinetic parameters were determined by the by the Flynn-Wall-Ozawa (FWO) method. It was found that the activation energy decreased with the increasing of the biomass mass ratio, but with the biomass ratio reached 0.75 the activation energy increased again. This may be involved with the negative synergies between the biomass and coal. The results could provide useful information for the further study on the co-pyrolysis of coal and MSC.
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