Hydrogenation Kinetics of N-Ethylcarbaozle as a Heteroaromatic Liquid Organic Hydrogen Carrier

2014 ◽  
Vol 953-954 ◽  
pp. 981-984 ◽  
Author(s):  
Ming Yang ◽  
Yuan Dong ◽  
Han Song Cheng

The catalytic hydrogenation kinetics of N-ethylcarbazole over 5 wt% Ru/Al2O3 was investigated at various temperatures. The results shows that the hydrogenation reaction was exothermic and high temperature is unfavorable for the reaction rate. Fully hydrogenation was achieved within 1 hour under the best reaction temperature of 170 °C. The kinetics of N-ethylcarbazole follows the first-order kinetics in terms of the reactant concentration but independent of hydrogen pressure, which was maintained as a constant in the reaction process. The apparent activation energy of N-ethylcarbazole hydrogenation reaction at 150-180 °C was found to be 71.2 kJ/mol.

2010 ◽  
Vol 113-116 ◽  
pp. 1814-1817 ◽  
Author(s):  
Hui Ling Guo ◽  
Jun Lin Xie

The formation kinetics of sulphoaluminate calcium was studied by variations of sulfur release with time from SC-132 based on competitive reactions, the generation of sulphoaluminate calcium and the decomposition of CaSO4. Experimental investigations and theoretical derivations show that the formation rate of sulphoaluminate calcium can be described as first-order kinetics at high temperature, and it belongs to the mechanism of random nucleus growth. The apparent activation energy is 456.37 KJ•mol-1 and pre-exponential factor is 1.545×1012.


1956 ◽  
Vol 103 (3) ◽  
pp. 285-293 ◽  
Author(s):  
Myron A. Leon ◽  

Quantitative methods have been developed for the estimation of C'3 and properdin. With these methods, the kinetics of the over-all reaction between properdin, zymosan, and C'3 were investigated. The reaction followed first order kinetics, provided zymosan was in excess, and the serum not diluted beyond 1/4. The reaction rate was proportional to the temperature, and an activation energy of 20,500 calories/mole was found. The distinction between total properdin and available serum properdin is discussed.


The kinetics of the thermal decomposition of benzylamine were studied by a flow method using toluene as a carrier gas. The decomposition produced NH 3 and dibenzyl in a molar ratio of 1:1, and small quantities of permanent gases consisting mainly of H 2 . Over a temperature range of 150° (650 to 800° C) the process was found to be a homogeneous gas reaction, following first-order kinetics, the rate constant being expressed by k = 6 x 10 12 exp (59,000/ RT ) sec. -1 . It was concluded, therefore, that the mechanism of the decomposition could be represented by the following equations: C 6 H 5 . CH 2 . NH 2 → C 6 H 5 . CH 2 • + NH 2 •, C 6 H 5 . CH 3 + NH 2 •→ C 6 H 5 . CH 2 • + NH 3 , 2C 6 H 5 . CH 2 •→ dibenzyl, and the experimentally determined activation energy of 59 ± 4 kcal./mole is equal to the dissociation energy of the C-N bond in benzylamine. Using the available thermochemical data we calculated on this basis the heat of formation of the NH 2 radical as 35.5 kcal./mole, in a fair agreement with the result obtained by the study of the pyrolysis of hydrazine. A review of the reactions of the NH 2 radicals is given.


2003 ◽  
Vol 1 (3) ◽  
pp. 233-241 ◽  
Author(s):  
Dumitru Oancea ◽  
Mihaela Puiu

AbstractThe kinetics of the auto-oxidation of 2-aminophenol (OAP) to 2-amino-phenoxazin-3-one (APX) was followed in air-saturated aqueous solutions and the influence of temperature and pH on the auto-oxidation rate was studied. The kinetic analysis was based on a spectrophotometric method following the increase of the absorbance of APX. The process follows first order kinetics according to the rate law—d[OAP]/dt=k′[OAP]. The experimental data, within the pH range 4–9.85, were analyzed using both differential and incremental methods. The temperature variation of the overall rate constant was studied at pH=9.85 within the range 25–50°C and the corresponding activation energy was evaluated.


RSC Advances ◽  
2016 ◽  
Vol 6 (85) ◽  
pp. 82138-82149 ◽  
Author(s):  
Anushree Dutta ◽  
Anumita Paul ◽  
Arun Chattopadhyay

Temperature dependent aggregation reaction of partially bare gold nanoparticles showed a first order kinetics and prevalence of reaction limited colloidal aggregation with an activation energy equal to 36.2 ± 3.0 kJ mol−1.


2018 ◽  
Vol 17 (2) ◽  
pp. 167-173
Author(s):  
Md Mokaram Hossain ◽  
Reza Ul Jalil ◽  
Mohammad A Rashid

Ramosetron hydrochloride is the hydrochloride salt of ramosetron, a selective serotonin (5-HT3) receptor antagonist with potential antiemetic activity. Upon administration, ramosetron selectively binds to and blocks the activity of 5-HT subtype 3 (5-HT3) receptors located in the vagus nerve terminal and the vomiting center of central nervous system (CNS), suppressing chemotherapy-induced nausea and vomiting. Degradation of Ramosetron HCl was conducted with 0.1N NaOH at 60°C, 70°C and 80°C to study the reaction kinetics. The reaction rate constants (k) for degradation at 60°C, 70°C and 80°C were -2.2680 molL-1s-1 , -3.3714 molL-1s-1 and -5.3686 molL-1s-1 for zero order and -1.05 x 10-2s-1, -1.60 x 10-2s-1 and -2.70 x 10-2s-1 for first order kinetics, respectively. The activation energy of Ramosetron HCl was found as 10.05 kcalmol-1 by using Arrhenius equation. Dhaka Univ. J. Pharm. Sci. 17(2): 167-173, 2018 (December)


2011 ◽  
Vol 396-398 ◽  
pp. 1044-1047 ◽  
Author(s):  
Tao Yan Mao ◽  
Cheng Zheng ◽  
Jimmy Yu

The reaction kinetics of the synthesis of quaternary ammonium salt under two sets of different reaction conditions, including microwave irradiation condition and conventional heating condition, were studied. In order to make sure that the microwave would not be interrupted, the reaction temperature was maintained at the boiling point of reaction solvents. The results showed that the reaction was a first-order reaction under both set of conditions and microwave irradiation changed the value of the activation energy of the reaction, indicating a change in the reaction mechanism. The activation energy was 41.44 kJ/mol under microwave irradiation condition, and 61.21 kJ/mol under conventional condition.


2005 ◽  
Vol 23 (5) ◽  
pp. 399-406 ◽  
Author(s):  
Riaz Qadeer

The temperature dependence of the kinetics of the adsorption of neodymium ions from aqueous solution onto activated charcoal has been studied. The results obtained indicate that a form of equilibration appears to be attained after ca. 30 min although further very slow changes may occur over a much longer period. The adsorption process is controlled by the diffusion of neodymium ions into the pores of the activated charcoal. Adsorption follows first-order kinetics with an activation energy of 13.09 kJ/mol. Values of the equilibrium constant for the adsorption of neodymium ions onto activated charcoal increase with increasing temperature, thereby indicate the endothermic nature of the process.


Author(s):  
Somayeh Ebrahimi ◽  
Jafarsadegh Moghaddas

The coking process includes two dynamic and isothermal steps. In this process, some factors control the coke formation kinetics. In this research, effects of some important and effective parameters of feed on the quality of petroleum coke were studied. Two hydrocarbon residue feeds; Cracked Fuel Oil (CFO) and Styrene Monomer Tar (SMTAR) were used at 500°C with atmospheric pressure of nitrogen used as an inert gas. Rate of weight loss and gas evolution from these feeds were considered by data of thermal analysis TG (thermogravimetry) and DTG (derivative thermogravimetry). Based on the results, CFO was assigned as the better feed. After selecting better feed, simultaneous thermogravimetry-differential analysis (TG-DTA) was used to study the pyrolysis kinetics of CFO. Samples were heated in a TG-DTA apparatus in nitrogen atmosphere at a temperature range of 37-600°C. The activation energy (Ea) and pre-exponential factor (A) were calculated from the experimental results by using a three stage Arrhenius-type kinetic model and showed that CFO pyrolysis kinetics at temperature ranges 37-285, 320-450 and 467-600°C follows first, second and first order kinetics, respectively. Attentive to temperature increase and reaction progress, activation energy and pre-exponential factor indicated different values at each stage. Also, kinetics of the isothermal step of coke formation was studied during heating of CFO. Samples were reacted in a tube furnace at 450°C and with nitrogen atmosphere. The kinetics of coke formation for petroleum residue was followed by solvent extraction (insolubility in hexane (HI), toluene (TI)) and a development of TI approximate to apparent first order kinetics. The rate constant at this temperature was calculated and it was also observed that the coke formation had been started at a temperature below 450°C.


2014 ◽  
Vol 27 (4) ◽  
pp. 213-216 ◽  
Author(s):  
Maria Zun ◽  
Dorota Dwornicka ◽  
Katarzyna Wojciechowska ◽  
Katarzyna Swiader ◽  
Regina Kasperek ◽  
...  

Abstract In this study, the stability of 10% hydrogen peroxide aqueous and non-aqueous solutions with the addition of 6% (w/w) of urea was evaluated. The solutions were stored at 20°C, 30°C and 40°C, and the decomposition of hydrogen peroxide proceeded according to first-order kinetics. With the addition of the urea in the solutions, the decomposition rate constant increased and the activation energy decreased. The temperature of storage also affected the decomposition of substance, however, 10% hydrogen peroxide solutions prepared in PEG-300, and stabilized with the addition of 6% (w/w) of urea had the best constancy.


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