1070-4272/02/7505-0771$27.00C2002 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 75, No. 5, 2002, pp. 771!776. Translated from Zhurnal Prikladnoi Khimii, Vol. 75, No. 5,
2002, pp. 789!794.
Original Russian Text Copyright + 2002 by Dmitriev, Trukshin, Smykalov.
AND INDUSTRIAL ORGANIC CHEMISTRY
A Study of Trichloroethylene Hydrofluorination
Using a Kinetic Model
A. V. Dmitriev, I. G. Trukshin, and P. Yu. Smykalov
Prikladnaya Khimiya Russian Scientific Center, St. Petersburg, Russia
Received January 17, 2002
Abstract-The kinetic features of catalytic hydrofluorination of trichloroethylene and 2-chloro-1,1,1-trifluo-
roethane on chromium fluoride/magnesium fluoride catalyst were studied. The effect of pressure and addition
of various components of the reaction mixture at the reactor inlet was studied using the developed model.
The procedure of production of 1,1,1,2-tetrafluoro-
ethane by gas-phase catalytic hydrofluorination of
trichloroethylene is well known in the world practice
and is commercially used by various companies.
There are many patents related to this procedure of
tetrafluoroethane production  and to the catalyst
production [4, 5]. In gas-phase fluorination processes,
chromium(III) compounds in the form of fluorides and
oxofluorides are mainly used.
At the same time, there are no published data on
the kinetics and mechanism of hydrofluorination of
trichloroethylene, which are necessary to design the
The goal of this work was to study experimentally
this process on the chromium fluoride/magnesium
fluoride catalyst and, based on the developed kinetic
model, to study the effect of pressure and addition of
various components of the reaction mixture (hydrogen
chloride, 1,1-difluoroethylene, 1,1,1-trifluoroethane,
and pentafluoroethane) at the reactor inlet.
The study was carried out on a continuous installa-
tion consisting of a nickel reactor with electrical heat-
ing, units for dosing the initial reagents, and a system
for collection and analysis of the synthesis products.
The total capacity of the reactor was 1000 cm
inner diameter was 36 mm. The reactor temperature
was monitored by a multizone thermocouple. Hydro-
gen fluoride and 2-chloro-1,1,1-trifluoroethane were
Reported at the Third International Conference [Chemistry,
Technology, and Application of Fluorine Compounds,]
St. Petersburg, June 639, 2001.
fed into the reactor through nickel capillaries. The
flow rate of these reagents was set using the calibrat-
ing plot of the flow rate vs. the pressure in the service
vessels, which, in turn, was produced by their tempera-
ture control. Trichloroethylene was fed into the reactor
with a dosing pump. The flows of the initial reagents
were mixed and fed into a coil-type evaporator
equipped with electrical heating, and then into the
reactor. After washing with water, neutralization,
and drying, the reaction mixture was collected in
a glass condenser cooled with a mixture of dry ice and
The reaction mixture was analyzed on a Tsvet-
500M chromatograph equipped with a heat conductiv-
ity detector. The 2-m chromatographic column was
packed with ASK silica gel impregnated with liquid
The products were identified by gas chromatogra-
phy3mass spectrometry on a Hewlett3Packard device
equipped with an Al
/KCl capillary column (l =
To determine the kinetic parameters, the experi-
ments were performed in the reactor with a fluidized
bed of the chromium fluoride/magnesium fluoride
The initial 2-chloro-1,1,1-trifluoroethane and tri-
chloroethylene were purified by fractional distillation.
When developing the kinetic model, the following
assumptions were made: the process is kinetically
controlled; the catalyst activity is constant in time;
This catalyst (chromium fluoride applied to magnesium fluor-
ide) is produced by the pilot plant of the Prikladnaya Khimiya
Russian Scientific Center and is used in various hydrofluori-