TY - JOUR
T1 - Co-oxidation of methane (CH
4
) and carbon disulfide (CS
2
AU - Zeng, Zhe
AU - Dlugogorski, Bogdan Z.
AU - Oluwoye, Ibukun
AU - Altarawneh, Mohammednoor
PY - 2019/1/1
Y1 - 2019/1/1
N2 -
Sulfur-containing species persist as important impurities in fossil fuels, affecting the combustion process of constituent hydrocarbons. This contribution reports the promotion effects of carbon disulfide (CS
2
) on oxidation of methane (CH
4
), with experiments conducted in a jet-stirred reactor (JSR), and explains the experimental findings from comprehensive kinetic modelling of CH
4
/CS
2
/O
2
systems. This includes neat oxidation of CH
4
/O
2
and CS
2
/O
2
under stoichiometric conditions, as compared with co-oxidation of CH
4
/CS
2
/O
2
, containing different measures of CS
2
. Addition of small amounts of CS
2
(50?ppm and 100?ppm) enhances the oxidation of CH
4
(500?ppm) as characterised by a lower onset temperature (1300?K versus 1200?K and 1060?K). In contrast, the presence of CH
4
delays the process of CS
2
oxidation. Considering the similarity in the core charge of O and S, we propose the reactivity of S
2
, SO and in particular S towards CH
4
to be responsible for the observed behaviours, in addition to an important effect of O radicals generated in oxidation of CS
2
on engendering the oxidation of CH
4
. As reported in the literature, in analogy to O
2
and O which oxidise CH
4
into CO
2
, the S/S
2
/SO could also 'sulfurdise' CH
4
into CS
2
or COS under oxygen-lean conditions. Quantum chemistry calculations of the CH
4
?+?O, CH
4
?+?S, CH
4
?+?S
2
, CH
4
?+?SO and CH
4
?+?O
2
reactions further reveal the reactivity of O, O
2
, S, S
2
and SO towards H abstraction from CH
4
. The sensitivity analysis of the kinetic modelling of the proposed co-oxidation reactions indicates that, the radicals formed during the CS
2
conversion process promote the oxidation of CH
4
at lower temperatures. However, the consumption of radicals in the CH
4
oxidation also inhibits the decomposition of CS
2
as observed in the experiments.
AB -
Sulfur-containing species persist as important impurities in fossil fuels, affecting the combustion process of constituent hydrocarbons. This contribution reports the promotion effects of carbon disulfide (CS
2
) on oxidation of methane (CH
4
), with experiments conducted in a jet-stirred reactor (JSR), and explains the experimental findings from comprehensive kinetic modelling of CH
4
/CS
2
/O
2
systems. This includes neat oxidation of CH
4
/O
2
and CS
2
/O
2
under stoichiometric conditions, as compared with co-oxidation of CH
4
/CS
2
/O
2
, containing different measures of CS
2
. Addition of small amounts of CS
2
(50?ppm and 100?ppm) enhances the oxidation of CH
4
(500?ppm) as characterised by a lower onset temperature (1300?K versus 1200?K and 1060?K). In contrast, the presence of CH
4
delays the process of CS
2
oxidation. Considering the similarity in the core charge of O and S, we propose the reactivity of S
2
, SO and in particular S towards CH
4
to be responsible for the observed behaviours, in addition to an important effect of O radicals generated in oxidation of CS
2
on engendering the oxidation of CH
4
. As reported in the literature, in analogy to O
2
and O which oxidise CH
4
into CO
2
, the S/S
2
/SO could also 'sulfurdise' CH
4
into CS
2
or COS under oxygen-lean conditions. Quantum chemistry calculations of the CH
4
?+?O, CH
4
?+?S, CH
4
?+?S
2
, CH
4
?+?SO and CH
4
?+?O
2
reactions further reveal the reactivity of O, O
2
, S, S
2
and SO towards H abstraction from CH
4
. The sensitivity analysis of the kinetic modelling of the proposed co-oxidation reactions indicates that, the radicals formed during the CS
2
conversion process promote the oxidation of CH
4
at lower temperatures. However, the consumption of radicals in the CH
4
oxidation also inhibits the decomposition of CS
2
as observed in the experiments.
KW - Co-oxidation of CS and CH
KW - Enhanced ignition of CH by CS
KW - Jet-stirred reactor
KW - Kinetic model
KW - Sulfur-bearing radicals
UR - http://www.scopus.com/inward/record.url?scp=85052486317&partnerID=8YFLogxK
U2 - 10.1016/j.proci.2018.08.011
DO - 10.1016/j.proci.2018.08.011
M3 - Article
AN - SCOPUS:85052486317
VL - 37
SP - 677
EP - 685
JO - Proceedings of the Combustion Institute
JF - Proceedings of the Combustion Institute
SN - 0082-0784
IS - 1
ER -