TY - JOUR
T1 - Pyrolysis of alkylcyclohexanes in or near the supercritical phase. Product distribution and reaction pathways
AU - Lai, Wei Chuan
AU - Song, Chunshan
N1 - Funding Information:
We are very grateful to Prof. H.H. Schobert of PSU for his encouragement, support, and helpful discussions. This project was jointly supported by the U.S. Department of Energy, Pittsburgh Energy Technology Center, and the U.S. Air Force Wright Laboratory/Aero Propulsion and Power Directorate, Wright-Patterson AFB. Funding was provided by the U.S. DOE under contract DE-FG22-92PC92104. We also thank Mr. W.E. Harrison III and Dr. D.M. Starch of WL and Dr. S. Rogers of PETC for their support.
PY - 1996/7
Y1 - 1996/7
N2 - Cyclohexane and seven n-alkylcyclohexanes (alkyl side-chain CmH2m + 1, m = 1, 2, 3, 4, 6, 8, 10) were pyrolyzed in or near the supercritical phase in a batch reactor at 450°C under relatively high (≥ 2 MPa) and continuously increasing pressure for 6-480 min. The thermal stability of alkylcyclohexanes decreases with increasing side-chain length. The major reaction pathways of alkylcyclohexanes are strongly dependent on the side-chain length. For cyclohexane and methyl-cyclohexane, the dominant reaction is isomerization to form alkylcyclopentanes via ring contraction. The tendency to isomerization decreases with increasing side-chain length. For alkylcyclohexanes with m ≥ 3, the major reaction at early decomposition stages is β-scission, leading to C-C bond cleavage in the side-chain at or near the ring followed by H-abstraction. The decomposition resulted in three pairs of most abundant products: cyclohexane plus 1-CmH2m, methylenecyclohexane plus n-C(m - 1)H2(m - 1)+ 2, and cyclohexene plus n-CmH2m + 2. Under the conditions used, alkylcyclohexanes do not undergo ring-opening cracking to any significant extent. An empirical equation was developed to correlate the rate constant with the molecular structure of alkylcyclohexanes using a group contribution method.
AB - Cyclohexane and seven n-alkylcyclohexanes (alkyl side-chain CmH2m + 1, m = 1, 2, 3, 4, 6, 8, 10) were pyrolyzed in or near the supercritical phase in a batch reactor at 450°C under relatively high (≥ 2 MPa) and continuously increasing pressure for 6-480 min. The thermal stability of alkylcyclohexanes decreases with increasing side-chain length. The major reaction pathways of alkylcyclohexanes are strongly dependent on the side-chain length. For cyclohexane and methyl-cyclohexane, the dominant reaction is isomerization to form alkylcyclopentanes via ring contraction. The tendency to isomerization decreases with increasing side-chain length. For alkylcyclohexanes with m ≥ 3, the major reaction at early decomposition stages is β-scission, leading to C-C bond cleavage in the side-chain at or near the ring followed by H-abstraction. The decomposition resulted in three pairs of most abundant products: cyclohexane plus 1-CmH2m, methylenecyclohexane plus n-C(m - 1)H2(m - 1)+ 2, and cyclohexene plus n-CmH2m + 2. Under the conditions used, alkylcyclohexanes do not undergo ring-opening cracking to any significant extent. An empirical equation was developed to correlate the rate constant with the molecular structure of alkylcyclohexanes using a group contribution method.
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U2 - 10.1016/0378-3820(96)01030-2
DO - 10.1016/0378-3820(96)01030-2
M3 - Article
AN - SCOPUS:0030181690
SN - 0378-3820
VL - 48
SP - 1
EP - 27
JO - Fuel processing technology
JF - Fuel processing technology
IS - 1
ER -