Coal oxidation at low temperatures: oxygen consumption, oxidation products, reaction mechanism and kinetic modelling

2003 ◽  
Vol 29 (6) ◽  
pp. 487-513 ◽  
Author(s):  
Haihui Wang ◽  
Bogdan Z. Dlugogorski ◽  
Eric M. Kennedy
Keyword(s):  
Oxygen Consumption ◽  
Reaction Mechanism ◽  
Low Temperatures ◽  
Kinetic Modelling ◽  
Oxidation Products ◽  
Coal Oxidation

Kinetic Modelling of Phenol Oxidation in a Bioremediation Medium Using Fenton's Reagent

2011 ◽  
Vol 9 (1) ◽  
Author(s):  
Pardeep Kumar ◽  
Hossein Nikaktari ◽  
Mehdi Nemati ◽  
Gordon A. Hill
Keyword(s):  
Kinetic Modeling ◽  
Rate Constants ◽  
Maleic Acid ◽  
Kinetic Modelling ◽  
Pure Water ◽  
Chemical Oxidation ◽  
Phenol Oxidation ◽  
Oxidation Products ◽  
Increase With Increase ◽  
Oxidation Of Phenol

The present study is aimed at kinetic modeling of phenol oxidation using Fenton’s reagent in a medium suitable for bioremediation of organic pollutants. Batch experiments were conducted to study the effects of H2O2 concentration (29.26 to 146.31 mM), temperature (5 to 35°C), and to compare the oxidation of phenol in a bioremediation medium to that in pure water. The reaction mechanism used for kinetic modeling is based on the intermediate oxidation products identified in this study using LC-MS and ion chromatography. Progress of the chemical oxidation by Fenton’s reagent was monitored by determining the residual phenol concentration and concentrations of evolved intermediate compounds (catechol and hydroquinone) at regular time intervals. The rate of phenol oxidation and ultimate conversion of phenol were found to increase with increase in hydrogen peroxide concentration. The increase in temperatures has a positive effect on phenol oxidation and the rate of phenol oxidation was found to increase with temperature in the range of 5-35°C. Kinetic parameters, namely rate constants and activation energies for reactions involved, were determined by best-fitting the experimental data to the proposed reaction model. The values of the rate constants for oxidation of phenol and intermediate compounds, k1 (phenol to catechol), k2 (phenol to hydroquinone), k3 (catechol to maleic acid), k4 (hydroquinone to maleic acid) at 25°C were found to be 7.02x10-5±4.63x10-5, 7.22x10-4±6.09x10-4, 1.82x10-4±1.08x10-4, 1.68x10-3±1.29x10-3 L/mM min, respectively.

Study of the reaction mechanism between electroless Ni–P and Sn and its effect on the crystallization of Ni–P

2003 ◽  
Vol 18 (1) ◽  
pp. 4-7 ◽  
Author(s):  
Y. C. Sohn ◽  
Jin Yu ◽  
S. K. Kang ◽  
W. K. Choi ◽  
D. Y. Shih
Keyword(s):  
Reaction Mechanism ◽  
Solid State ◽  
Solid State Reaction ◽  
Crystallization Temperature ◽  
Low Temperatures ◽  
Transformation Temperature ◽  
The Self ◽  
Heat Of Reaction ◽  
Solder Reaction ◽  
Electroless Ni

The reaction mechanism between electroless Ni–P and Sn was investigated to understand the effects of Sn on solder reaction-assisted crystallization at low temperatures as well as self-crystallization of Ni–P at high temperatures. Ni3Sn4 starts to form in a solid-state reaction well before Sn melts. Heat of reaction for Ni3Sn4 was measured during the Ni–P and Sn reaction (241.2 J/g). It was found that the solder reaction not only promotes crystallization at low temperatures by forming Ni3P in the P-rich layer but also facilitates self-crystallization of Ni–P by reducing the transformation temperature and heat of crystallization. The presence of Sn reduces the self-crystallization temperature of Ni–P by about 10 °C. The heat of crystallization also decreases with an increased Sn thickness.

Regulation of Heat Production by Large Moths

1967 ◽  
Vol 47 (1) ◽  
pp. 21-33
Author(s):  
JAMES EDWARD HEATH ◽  
PHILLIP A. ADAMS
Keyword(s):  
Oxygen Consumption ◽  
Heat Loss ◽  
Low Temperatures ◽  
Cooling Curve ◽  
O2 Consumption ◽  
Internal Temperature ◽  
Warm Up ◽  
Temperature Changes ◽  
Thoracic Temperature ◽  
Silk Moth

1. Moths ‘warm-up’ prior to flight at mean rates of 4.06° C./min. in Celerio lineata and 2.5° C./min. in Rothschildia jacobae. The abdominal temperature rises only 2-3° C. during activity. 2. Oxygen consumption of torpid sphinx moths increases by a factor of 2.27 as temperature changes from 26° to 36° C. 3. Oxygen consumption during ‘warm-up’ increases with duration of ‘warm-up’ from about 1000 µl./g. min during the initial 30 sec. to nearly 1600µl./g. min. during the 3rd min. This increase compensates for increasing heat loss from the thorax during ‘warm-up‘. 4. When the moths are regulating thoracic temperature, oxygen consumption increases with decreasing air temperature from a mean of about 400µl./g. min at 31° C. to about 650µl./g. min. at 26° C 5. Values of O2 consumption calculated from the cooling curve of C. lineata are about 85% of the measured values of O2 consumption. 6. The giant silk moth, Rothschildia jacobae, regulates thoracic temperature during activity between about 32° and 36° C. at ambient temperature from 17° to 29° C. Moths kept at high temperatures are active longer, have more periods of activity and expend more energy for thermoregulation than moths kept at low temperatures. 7. Large moths increase metabolism during active periods to offset heat loss and thereby maintain a relatively constant internal temperature. In this regard they may be considered endothermic, like birds and mammals. 8. We estimate that male moths use 10% of their stored fat for thermoregulation, while females may use 50%.

Active chlorine mediated ammonia oxidation revisited: Reaction mechanism, kinetic modelling and implications

2018 ◽  
Vol 145 ◽  
pp. 220-230 ◽  
Author(s):  
Changyong Zhang ◽  
Di He ◽  
Jinxing Ma ◽  
T. David Waite
Keyword(s):  
Reaction Mechanism ◽  
Ammonia Oxidation ◽  
Kinetic Modelling ◽  
Active Chlorine

scholarly journals Kinetic modelling of hydrogen transfer deoxygenation of a prototypical fatty acid over a bimetallic Pd60Cu40 catalyst: an investigation of the surface reaction mechanism and rate limiting step

2020 ◽  
Vol 5 (9) ◽  
pp. 1682-1693
Author(s):  
Kin Wai Cheah ◽  
Suzana Yusup ◽  
Martin J. Taylor ◽  
Bing Shen How ◽  
Amin Osatiashtiani ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Reaction Mechanism ◽  
Hydrogen Transfer ◽  
Surface Reaction ◽  
Kinetic Modelling ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Cu Catalyst ◽  
P Application ◽  
Rate Limiting

Application of tetralin as a source of hydrogen for catalytic conversion of oleic acid to diesel-like hydrocarbons using a bimetallic Pd–Cu catalyst.

Well-defined nickel(II) tetrazole-saccharinate complex as homogeneous catalyst on the reduction of aldehydes: scope and reaction mechanism

2020 ◽  
Vol 92 (1) ◽  
pp. 151-166 ◽  
Author(s):  
Luís M. T. Frija ◽  
Bruno G. M. Rocha ◽  
Maxim L. Kuznetsov ◽  
Lília I. L. Cabral ◽  
M. Lurdes S. Cristiano ◽  
...  
Keyword(s):  
Experimental Data ◽  
Reaction Mechanism ◽  
Transition Metal ◽  
Dft Calculations ◽  
Microwave Power ◽  
Low Temperatures ◽  
Nickel Complex ◽  
Transition Metal Catalysts ◽  
Homogeneous Catalyst ◽  
First Time

AbstractA new (tetrazole-saccharin)nickel complex is shown to be a valuable catalyst for the hydrosilative reduction of aldehydes under microwave radiation at low temperatures. With typical 1 mol% content of the catalyst (microwave power range of 5–15 W) most reactions are complete within 30 min. The Ni(II)-catalyzed reduction of aldehydes, with a useful scope, was established for the first time by using this catalyst, and is competitive with the most effective transition-metal catalysts known for such transformation. The catalyst reveals tolerance to different functional groups, is air and moisture stable, and is readily prepared in straightforward synthetic steps. Supported by experimental data and DFT calculations, a plausible reaction mechanism involving the new catalytic system is outlined.

Le métabolisme aéroble de Vipera aspis et de Vipera berus (Reptilia: Viperidae) acclimatées à des conditions naturelles. Influence de la température et comparaison des deux espèces

1985 ◽  
Vol 6 (1) ◽  
pp. 71-81 ◽  
Author(s):  
Hubert Saint Girons ◽  
Marie-Louise Célérier ◽  
Guy Naulleau
Keyword(s):  
Oxygen Consumption ◽  
Low Temperatures ◽  
Aerobic Scope ◽  
Total Consumption ◽  
Distinctive Features ◽  
Absolute Value ◽  
Vipera Berus ◽  
The Difference ◽  
Average Consumption ◽  
Vipera Aspis

AbstractA study of the acute oxygen consumption of 16 young vipers (8 Vipera aspis and 8 V. berus) at temperatures of 10-15-20-25-30°C shows a number of distinctive features common to both species, and also specific differences. The oxygen consumption obviously increases with temperature, more or less irregularly for the average consumption which partly depends on the activities of each animal, while it follows an exponential progression for the minimum consumption and a linear progression for the maximum consumption. In the total consumption the part caused by the rather limited exploratory activities of our animals (routine aerobic scope) decreases as the temperature rises and it even decreases in absolute value between 25 and 30°C. At all temperatures, the oxygen consumption of V. berus is greater than that of V. aspis, the difference being globally significant. However, these differences are important only for the minimum consumption at low temperatures. These specific differences are discussed according to the ecology and the geographical distribution of the two species.

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