15 research outputs found
Computational fluid dynamic design of steam cracking reactors : simulation of dynamic coke growth
Detailed experimental and kinetic modeling study of cyclopentadiene pyrolysis and the effect of ethene as co-reactant
Mapping empires: 7th international symposium of the ICA commission on the history of cartography 2018
Detailed experimental and kinetic modeling study of cyclopentadiene pyrolysis in the presence of Ethene
Pressure dependent kinetic analysis of pathways to naphthalene from cyclopentadienyl recombination
Cyclopentadiene (CPD) and cyclopentadienyl radical (CPDyl) reactions are known to provide fast routes to
naphthalene and other polycyclic aromatic hydrocarbon (PAH) precursors in many systems. In this work, we combine literature quantum chemical pathways for the CPDyl + CPDyl recombination reaction and provide pressure dependent rate coefficient calculations and analysis. We find that the simplified 1-step global reaction leading to naphthalene and two H atoms used in many kinetic models is not an adequate description of this chemistry at conditions of relevance to pyrolysis and steam cracking. The C10H10 species is observed to live long enough to undergo H abstraction reactions to enter the C10H9 potential energy surface (PES). Rate coefficient expressions as functions of T and P are reported in CHEMKIN format for future use in kinetic modelin
Pressure dependent kinetic analysis of pathways to naphthalene from cyclopentadienyl recombination
Cyclopentadiene (CPD) and cyclopentadienyl radical (CPDyl) reactions are known to provide fast routes to naphthalene and other polycyclic aromatic hydrocarbon (PAH) precursors in many systems. In this work, we combine literature quantum chemical pathways for the CPDyl + CPDyl recombination reaction and provide pressure dependent rate coefficient calculations and analysis. We find that the simplified 1-step global reaction leading to naphthalene and two H atoms used in many kinetic models is not an adequate description of this chemistry at conditions of relevance to pyrolysis and steam cracking. The CââHââspecies is observed to live long enough to undergo H abstraction reactions to enter the CââHâ potential energy surface (PES). Rate coefficient expressions as functions of T and P are reported in CHEMKIN format for future use in kinetic modeling. Keywords:
Polycyclic aromatic hydrocarbons (PAH); Cyclopentadiene; Naphthalene; Pressure dependent kineticsUnited States. Department of Energy (Grant DE-SC0014901
Detailed Experimental and Kinetic Modeling Study of Cyclopentadiene Pyrolysis in the Presence of Ethene
A combined experimental
and kinetic modeling study is presented
to improve the understanding of the formation of polycyclic aromatic
hydrocarbons at pyrolysis conditions. The copyrolysis of cyclopentadiene
(CPD) and ethene was studied in a continuous flow tubular reactor
at a pressure of 0.17 MPa and a dilution of 1 mol CPD/1 mol ethene/10
mol N<sub>2</sub>. The temperature was varied from 873 to 1163 K,
resulting in cyclopentadiene conversions between 1 and 92%. Using
an automated reaction network generator, RMG, we present an elementary
step kinetic model for CPD pyrolysis that accurately predicts the
initial formation of aromatic products. The model is able to reproduce
the product yields measured during the pyrolysis of pure cyclopentadiene
and the copyrolysis of cyclopentadiene and ethene. The addition of
ethene as coreactant increases the benzene and toluene selectivity.
In the absence of ethene, benzene formation is initiated by addition
of a cyclopentadienyl radical to cyclopentadiene, following a complicated
series of isomerizations and loss of a butadienyl radical. In the
presence of ethene, the main pathway for the formation of benzene
+ CH<sub>3</sub> shifts to ethene + cyclopentadiene. Toluene formation
is initiated by vinyl radical addition to cyclopentadiene. Without
the addition of ethene, vinyl radicals are mainly formed by hydrogen
radical addition to ethyne. When ethene is added as coreactant, vinyl
radical production happens via hydrogen abstraction from ethene
Detailed Experimental and Kinetic Modeling Study of Cyclopentadiene Pyrolysis in the Presence of Ethene
A combined experimental
and kinetic modeling study is presented
to improve the understanding of the formation of polycyclic aromatic
hydrocarbons at pyrolysis conditions. The copyrolysis of cyclopentadiene
(CPD) and ethene was studied in a continuous flow tubular reactor
at a pressure of 0.17 MPa and a dilution of 1 mol CPD/1 mol ethene/10
mol N<sub>2</sub>. The temperature was varied from 873 to 1163 K,
resulting in cyclopentadiene conversions between 1 and 92%. Using
an automated reaction network generator, RMG, we present an elementary
step kinetic model for CPD pyrolysis that accurately predicts the
initial formation of aromatic products. The model is able to reproduce
the product yields measured during the pyrolysis of pure cyclopentadiene
and the copyrolysis of cyclopentadiene and ethene. The addition of
ethene as coreactant increases the benzene and toluene selectivity.
In the absence of ethene, benzene formation is initiated by addition
of a cyclopentadienyl radical to cyclopentadiene, following a complicated
series of isomerizations and loss of a butadienyl radical. In the
presence of ethene, the main pathway for the formation of benzene
+ CH<sub>3</sub> shifts to ethene + cyclopentadiene. Toluene formation
is initiated by vinyl radical addition to cyclopentadiene. Without
the addition of ethene, vinyl radicals are mainly formed by hydrogen
radical addition to ethyne. When ethene is added as coreactant, vinyl
radical production happens via hydrogen abstraction from ethene