Kinetics of hot hydrogen atoms from hydrogen sulfide photodissociation at 1850 A

1969 ◽  
Vol 73 (4) ◽  
pp. 1158-1160 ◽  
Author(s):  
L. E. Compton ◽  
J. L. Gole ◽  
Richard McKelvy Martin
Keyword(s):  
Hydrogen Sulfide ◽  
Hydrogen Atoms ◽  
Kinetics Of

KINETICS OF THE ABSTRACTION OF HYDROGEN ATOMS FROM HYDROGEN SULFIDE BY TRIFLUOROMETHYL RADICALS

1966 ◽  
Vol 44 (12) ◽  
pp. 1445-1449 ◽  
Author(s):  
N. L. Arthur ◽  
T. N. Bell
Keyword(s):  
Hydrogen Sulfide ◽  
Rate Constant ◽  
Hydrogen Sulphide ◽  
Hydrogen Atoms ◽  
Kinetics Of

Trifluoromethyl radicals generated from the photolysis of hexafluoroacetone abstract hydrogen atoms from hydrogen sulphide.[Formula: see text]The rate constant of this reaction measured by comparing the rate with that for the recombination of trifluoromethyl radicals (k = 2.3 × 1013 cc mole−1 s−1) is given by,[Formula: see text]

Hydrogen Sulfide Stress Cracking in a Q345R Welded Joint

2021 ◽  
Vol 1035 ◽  
pp. 486-491
Author(s):  
Yan Han ◽  
Jing Bin Luo ◽  
An Qing Fu ◽  
Cheng Xian Yin
Keyword(s):  
Hydrogen Sulfide ◽  
Welded Joint ◽  
Chemical Properties ◽  
Test Method ◽  
Hydrogen Atoms ◽  
Stress Cracking ◽  
Micro Cracks ◽  
Sulfide Stress ◽  
Macroscopic Observation ◽  
Metal Microstructure

In this paper the failure reason of Q345R Welded Joint was studied through macroscopic observation, chemical properties, metallurgical analysis, scanning electron microscope (SEM) and EDS test method. The results showed that there were a large number of micro-cracks in the fracture surface. The reason of cracking is severe banded structure in base metal microstructure, which provided opportunity for hydrogen atoms to enter into the internal of steel when contact with wet hydrogen sulfide environment. The existence of tensile stress promotes the entry of hydrogen atoms and the propagation of cracks. The welding products of this procedure are not suitable for use under sour conditions.

Reactions of hydrogen atoms with hexafluoroacetone

1978 ◽  
Vol 56 (20) ◽  
pp. 2638-2645 ◽  
Author(s):  
D. W. Grattan ◽  
K. O. Kutschke
Keyword(s):  
Rate Constant ◽  
Cross Sections ◽  
The Other ◽  
Hydrogen Atoms ◽  
Kinetics Of

Attempts were made to study the kinetics of the reaction of atomic H with (CF3)2CO vapour (HFA). Atomic H was generated from H2 by mercury photosensitization in the presence of C2H4 and HFA but the system was complicated by the loss of C2H5 radicals by addition to HFA and the kinetic results were intractable. When atomic H was generated from C3H8, the kinetics again were obscured by some unidentified reaction(s) which became more important at higher [HFA]/[C3H8]. An estimate of the rate constant for the addition of H to HFA obtained at low [HFA]/[C3H8] yielded k9 = 8.5 × 105 l mol−1 s−1. Trifluoroacetaldehyde was identified with some reliability but many of the other heavier products formed in the H2 + HFA reaction could not be identified. Quenching cross-sections were determined for C2H4, C3H8, C4H10, and HFA relative to that for N2O.

Reactions of free radicals with aromatic compounds in the gaseous phase. I. Kinetics of the reaction of methyl radicals with toluene

1964 ◽  
Vol 17 (12) ◽  
pp. 1329 ◽  
Author(s):  
MFR Mulcahy ◽  
DJ Williams ◽  
JR Wilmshurst
Keyword(s):  
Flow System ◽  
Methyl Radicals ◽  
Methyl Radical ◽  
Hydrogen Atoms ◽  
Methyl Group ◽  
Benzyl Radical ◽  
Toluene Molecule ◽  
Benzyl Radicals ◽  
Butyl Peroxide ◽  
Kinetics Of

The kinetics of abstraction of hydrogen atoms from the methyl group of the toluene molecule by methyl radicals at 430-540�K have been determined. The methyl radicals were produced by pyrolysis of di-t-butyl peroxide in a stirred-flow system. The kinetics ,agree substantially with those obtained by previous authors using photolytic methods for generating the methyl radicals. At toluene and methyl-radical concentrations of about 5 x 10-7 and 10-11 mole cm-3 respectively the benzyl radicals resulting from the abstraction disappear almost entirely by combination with methyl radicals at the methylenic position. In this respect the benzyl radical behaves differently from the iso-electronic phenoxy radical, which previous work has shown to combine with a methyl radical mainly at ring positions. The investigation illustrates the application of stirred-flow technique to the study of the kinetics of free-radical reactions.

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