Thermal decomposition of aromatics substituted by a long aliphatic chain

Abstract

The behavior of aromatics substituted by a long aliphatic chain, such as are liable to be present in vacuum distillates used to replace naphtha during the supplying of steam cracking units, was examined in a micropilot plant at 800 °C in the presence of n-decane. The decomposition of dodecylbenzene, tetradecylphenanthrene, octadecylnaphthalene, and docosylbenzene, when available in sufficient quantity, led to a better assessment of the contribution to steam cracking of the different parts of this type of molecule. The simplified reaction mechanism of the thermal decomposition of dodecylbenzene leads to six principal

Experimental study of hydrocarbon structure effects on the composition of its pyrolysis products

“…the results for tetrahydronaphthalene are in general agreement with the results of theoretical study published by Poutsma [41], or the dominant yields of styrene obtained by alkyl benzenes pyrolysis correspond to the results published by Billaud [51].…”

Autocatalysis and aryl-alkyl bond cleavage in 1-dodecylpyrene pyrolysis

“…The pyrolysis of long-chain alkyl aromatics containing more than one aromatic ring has received considerably less attention. The work of Billaud et al (1988), who studied the steam cracking of tetradecylphenanthrene and octadecylnaphthalene in decane at 800 °C, and Javanmardian et al (1988), who reported preliminary results from our present study of dodecylpyrene pyrolysis, are the only previous accounts of the pyrolysis of long-chain, polycyclic n-alkyl aromatics. Billaud et al (1988) reported the presence of vinyl-, ethyl-, and methyl-substituted aromatics as major reaction products.…”

“…The literature provides several accounts of the pyrolysis of long-chain (>C10) alkylbenzenes (Billaud et al, 1988;Blouri et al, 1985; Mushrush and Hazlett, 1984; Savage and Klein, 1987aand Klein, ,b, 1989. These investigations revealed that the major primary products from the pyrolysis of an alkylbenzene with an aliphatic chain containing N carbon atoms were toluene plus an -olefin with N -1 carbon atoms and styrene plus an n-alkane with N -2 carbon atoms.…”

The relationship between chemical structure and reactivity of alberta bitumens and heavy oils

“…This hypothesis is strongly supported by low-pressure pyrolysis of alkyl aromatics as model compounds. Alkyl benzenes gave toluene or styrene (via 0 and y scission) as the aromatic products, and the corresponding n-alkane or alkene (Billaud et al, 1988;Blouri et al, 1985;Savage and Klein, 1987). Pyrolysis of 1 -dodecy lpyrene gave pyrene and n-dodecane as the major products when the conversion was over 50%, indicating an autocatalytic breakage of the Car-Caliph bond in the aposition (Savage et al, 1989).…”