scholarly journals Kinetics of Elementary Processes Relevant to Incipient Soot Formation

2008 ◽  
Author(s):  
M C Lin ◽  
M C Heaven
Keyword(s):  
Soot Formation ◽  
Elementary Processes ◽  
Kinetics Of

Kinetic study by controlled-transformation rate thermal analysis of the dehydroxylation of kaolinite

Clay Minerals ◽  
1998 ◽  
Vol 33 (2) ◽  
pp. 269-276 ◽  
Author(s):  
P. Dion ◽  
J.-F. Alcover ◽  
F. Bergaya ◽  
A. Ortega ◽  
P. L. Llewellyn ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Vapour Pressure ◽  
Reaction Rate ◽  
Diffusion Mechanism ◽  
Transformation Rate ◽  
Elementary Processes ◽  
Precise Control ◽  
First Order ◽  
Temperature And Pressure ◽  
Kinetics Of

AbstractAlthough the kinetics of the dehydroxylation of kaolinite have been widely studied, there is no definitive explanation of its mechanism due to its dependence on a variety of parameters. In this study, the dehydroxylation of kaolinite has been studied using controlled-transformation rate thermal analysis (CRTA), allowing precise control of the reaction rate, and thus of both the temperature and pressure above the sample. Modelling of the experimental results obtained by CRTA as well as those from TEM and MAS-NMR show that two elementary processes (diffusion and firstorder) can occur in competition. At the start of the decomposition the diffusion mechanism is predominant, but as the reaction progresses, the first-order mechanism prevails. It would seem that the importance of each process depends, in particular, on the presence of defects as well as on the local vapour pressure.

scholarly journals The Influence of the Distributed Reaction Regime on Fuel Reforming Conditions

2018 ◽  
Vol 140 (12) ◽  
Author(s):  
Richard Scenna ◽  
Ashwani K. Gupta
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
Soot Formation ◽  
Product Distribution ◽  
Fuel Reforming ◽  
Length Scales ◽  
Reaction Regime ◽  
Available Information ◽  
Kinetics Of ◽  
Reforming Reactions

Previous works have demonstrated that the distributed reaction regime improved the reformate product distribution, prevented soot formation, and favored higher hydrogen yields. The experimental data from these works and additional literature focusing on individual reactions provided an insight into how the distributed reaction regime influenced the reformate product composition. The distributed reaction regime was achieved through the controlled entrainment of hot reactive products (containing heat, carbon dioxide, steam and reactive radicals and species) into the premixed fuel air mixture, elongating the chemical time and length scales. High velocity jets enhanced mixing, while shortening the time and length scales associated with transport. As some steam and carbon dioxide will form in the reforming process, it was theorized that the mixing of the entrained flow (containing heat, carbon dioxide, and steam) into the premixed fuel air mixture promoted dry and steam reforming reactions, improving conversion. The available information on chemical kinetics of reformation is rather limited. In this work, the activity and timescales of these reactions were determined from the available experimental data. This was then used to assess which reactions were active under Distributed Reforming conditions. These data help in the design and development of advanced reformers using distributed reforming conditions.

On the Kinetics of Elementary Processes of Pressure Solution

1998 ◽  
Vol 152 (4) ◽  
pp. 667-683 ◽  
Author(s):  
V. Kruzhanov ◽  
B. Stöckhert
Keyword(s):  
Pressure Solution ◽  
Elementary Processes ◽  
Kinetics Of

Elementary processes and kinetics of H2plasmas for different technological applications

2002 ◽  
Vol 11 (3A) ◽  
pp. A7-A25 ◽  
Author(s):  
M Capitelli ◽  
R Celiberto ◽  
F Esposito ◽  
A Laricchiuta ◽  
K Hassouni ◽  
...  
Keyword(s):  
Elementary Processes ◽  
Kinetics Of

OXIDATION MECHANISM OF THE BUTADIYNYL RADICAL, C4H: ANALOGUE OF C2H OR NOT?

2013 ◽  
Vol 12 (06) ◽  
pp. 1340002
Author(s):  
WEI-WEI ZHU ◽  
SHAO-WEN ZHANG ◽  
YI-HONG DING
Keyword(s):  
Atomic Oxygen ◽  
Energy Surface ◽  
Soot Formation ◽  
Oxidation Mechanism ◽  
Carbon Chain ◽  
Exchange Product ◽  
Ethynyl Radical ◽  
Kinetics Of ◽  
Oxygen Conversion ◽  
Recent Attention

Reactions of the carbon-chain radicals are of great importance in the combustion and astrophysical processes. The kinetics of the butadiynyl radical, C 4 H , has received recent attention. While there has been sufficient knowledge concerning the oxidation of the ethynyl radical, C 2 H , oxidation of the higher even-numbered members C 2n H (n > 1) is hardly known. In this paper, to enrich the C 4 H -chemistry, we report the first study of the oxidation mechanism of C 4 H . At the CCSD(T)/aug-cc-pVTZ//B3LYP/6-311++G(d,p)+ZPVE level, the potential energy surface (PES) survey is presented covering various product channels P1( CO + HC 3 O ) (-152.7 kcal/mol), P2( C 3 H + CO 2) (-117.9), P3( HCO + C 3 O ) (-108.5), P4( HC 4 O +3 O ) (-45.2), and P5( OH + C 4 O ) (-33.2) accompanied by the master equation rate constant calculations. Despite the similarity in the PES, the kinetics of C 4 H +3 O 2 differs dramatically from that of the analogous C 2 H +3 O 2 reaction. For the C 4 H +3 O 2 reaction, the O -abstraction product P4( HC 4 O +3 O ) is almost the exclusive product, whereas the lowest C , O -exchange product P1( CO + HC 3 O ) and other products have little importance. By contrast, the C 2 H +3 O 2 reaction favors the C , O -exchange product HCO + CO . Being overall barrierless and mainly associated with the molecular → atomic oxygen conversion, the C 4 H +3 O 2 reaction should play an important role in the soot formation and interstellar chemistry where C 4 H is involved.

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