1070-4272/01/7406-1047 $25.00 C 2001 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 74, No. 6, 2001, pp. 1047!1052. Translated from Zhurnal Prikladnoi Khimii, Vol. 74, No. 6, 2001,
Original Russian Text Copyright + 2001 by Platonov, Proskuryakov, Ryl’tsova, Popova.
OF FOSSIL FUEL
Homogeneous Pyrolysis of Anisole
V. V. Platonov, V. A. Proskuryakov, S. V. Ryl’tsova, and Yu. N. Popova
St. Petersburg State Technological Institute, St. Petersburg, Russia
Tolstoy State Pedagogical University, Tula, Russia
Received December 21, 2000
Abstract-Homogeneous pyrolysis of anisole in argon (1 : 25 volume ratio) at 7503900oC and contact time
of 1.534.5 s was studied. The conversion and group composition of the tar and component composition of
the gaseous pyrolysis products, phenols, and hydrocarbons were determined; asphaltenes and neutral oxygen-
containing compounds were characterized. The kinetic parameters of formation of methane, hydrogen, and
carbon monoxide and dioxide were calculated; mechanisms of their formation are proposed.
Intensifying high-rate pyrolysis of mineral oils
and raising the yield of tars of prescribed qualitative
and quantitative composition require detailed informa-
tion on high-temperature conversion of the primary
Since the primary tar and even its separate fractions
are complex multicomponent mixtures of compounds
of various classes, studying their high-temperature
conversion is rather difficult. Therefore, analysis of
the pyrolysis of groups of similar compounds and
especially of individual components making the most
pronounced contribution to the composition of liquid
products is the best way to attack the problem.
Based on the latter approach, we can determine
the mechanism and main pathways of the occurring
reactions, together with their order and activation en-
ergies. The kinetic equations obtained in this case
can be used to simulate the behavior of separate frac-
tions of primary tars and the resulting tar as a whole
in the course of pyrolysis.
Pyrolysis of individual compounds has been
studied extensively , but in some cases data
on the composition of secondary products are lacking
. Moreover, owing to different apparatus and ex-
perimental procedures used in these works, their re-
sults are difficult to compare.
The goal of this work was to study the homoge-
neous pyrolysis of anisole, to determine the composi-
tion of phenols, hydrocarbons, asphaltenes, and ox-
ygen-containing compounds (NOCs), and to evaluate
the kinetic parameters of formation of separate com-
ponents of the gaseous pyrolysis products.
Pyrolysis of anisole was performed in a setup de-
scribed in ; the tar composition was analyzed by
the procedure described elsewhere .
The material balance of anisole pyrolysis, the group
composition of liquid products, and the component
composition of the gaseous pyrolysis products are
given in Table 1. As seen, anisole decomposes to
a significant extent at the temperatures and contact
times used in the experiments.
Gases and tar are the main pyrolysis products at
7503800oC, whereas at 8503900oC the yield of pyro-
graphite increases simultaneously with the yield of
the gaseous pyrolysis products. For example, at a con-
tact time of 1.5 s and 800oC the yield of gaseous
pyrolysis products, tar, and pyrographite is 20.00,
52.00, and 18.80 wt %, whereas at 900oC it is 37.50,
24.90, and 32.80 wt %, respectively, based on anisole.
The yield of crude benzene, containing up to 90%
benzene, is the highest at 800oC and contact time of
1.5 s (9.20 wt % based on anisole); under more severe
conditions, the yield of benzene decreases.
The results of group analysis (Table 1) show that
up to 850oC (1.5 s) phenols are the main component
of the tar; their content varies from 63.50 wt %
(750oC) to 29.50 wt % (850oC) at contact times of
4.5 and 1.5 s, respectively. Raising the temperature
and contact time further strongly decreases the con-
tent of phenols. At 850oC and 3.0 s their content is
5.40 wt %, and at 900oC and 3.0 s the content of
phenols in the tar decreases to 1.5 wt %. This is prob-
ably due to the degradation of phenols and to a certain
change in the direction of pyrolysis reactions.