1070-4272/05/7803-0399+2005 Pleiades Publishing, Inc.
Russian Journal of Applied Chemistry, Vol. 78, No. 3, 2005, pp. 399! 403. Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 3,
2005, pp. 403! 407.
Original Russian Text Copyright + 2005 by Prikhod’ko, Komarova, Gorelova, Gorlova, Bondaletov.
OF SYSTEMS AND PROCESSES
Liquid!Vapor Phase Equilibria in Binary and Ternary
Subsystems Constituted by Pyrocondensate Components
from the Pyrolysis of Straight-Run Naphtha
S. I. Prikhod’ko, L. F. Komarova, O. M. Gorelova,
N. N. Gorlova, and V. G. Bondaletov
Polzunov Altai State Engineering University, Barnaul, Russia
Tomsk Polytechnic University, Tomsk, Russia
Received November 20, 2003; in final form, September 2004
Abstract-Liquid3vapor equilibrium in the binary subsystems of the ethylbenzene3o-xylene3a-methyl-
styrene3p-vinyltoluene3dicyclopentadiene3indene system was predicted using UNIFAC group model and
studied experimentally. To assess the reliability of parameters, the liquid3vapor equilibrium was studied
experimentally in the ternary systems and compared with the calculated data.
Petroleum polymeric resins (PPRs) are widely used
as a rosin substitute and in production of paintwork
materials, wooden fiberboards, adhesive solutions, and
anticorrosive coatings. Waste and side products of
petroleum-chemical production, and, first of all, liquid
products of hydrocarbon pyrolysis are the raw mate-
rials for PPR production .
Unsaturated reactive hydrocarbons are the resin-
forming components. Their content in the raw mate-
rial should be no less than 30%. In addition, it may
contain admixtures decreasing the quality of the poly-
mers synthesized, which makes necessary appropriate
pretreatment of the raw material.
The requirements to the raw material are deter-
mined by the properties of PPR formed, polymeriza-
tion conditions, and catalytic systems used, which
allows selection of the method of the raw material
preparation. As a rule, distillation is used to separate
Ethylene and propylene monomers are gaseous
products of the pyrolysis of hydrocarbon raw material,
in particular, straight-run naphtha. The residual (after
ethylene or propylene separation) pyrocondensate con-
tains a lot of components with unsaturated bonds,
namely, styrene, a- and b-methylstyrenes, vinyl-
toluenes, allylbenzene, dicyclopentadiene, indene, and
indan in a mixture with such solvents as toluene,
xylene, ethylbenzene, propylbenzene, and cumene.
High-molecular-weight resinous products can also be
present. This pyrocondensate can be used to prepare
PPRs (which are the components of varnishes and
paints) after removal of solvents, dicyclopentadiene
(DCPD), and tars.
Although DCPD is unsaturated hydrocarbon and
hence a resin-forming component, its presence in
the raw-material is undesirable. The point is that
powdered aluminum chloride used as a catalytic sys-
tem polymerizes DCPD to form insoluble in PPR
cross-linked polymers, which is inadmissible. High
content of DCPD favors formation of the intensely
colored polymerizate, which is also undesirable.
With regard to the above facts, the raw material
preparation includes distillation of highly resinous
liquid products of the pyrolysis of straight-run naphtha
with high content of oligomers and monomers.
To develop the process for distillation separation
of the pyrocondensate, we have analyzed the known
properties of substances comprising PPR [2, 3]. Many
components of the mixture to be separated have close
boiling point, which makes it impossible to solve the
task by the elementary distillation. The mixture con-
tains thermolabile components, capable of polymeriza-
tion, which requires addition of polymerization inhib-
itors and reduced pressure in the distillation column.
Preliminarily, we reduced the dimension of the ini-
tial concentration space by discrimination of certain
homologs, isomers, and components with low concen-
trations . To develop the process for separation
by distillation, the system ethylbenzene (EB)-o-xylene
(o-X)3styrene (S)3a-methylstyrene (a-MS)3p-vinyl-