Kinetics of tetrachloromethane fluorination by hydrogen fluoride in the presence of antimony pentachloride

Article abstract of DOI:10.1016/S0022-1139(02)00241-5

Contradictory information concerning the kinetics of tetrachloromethane fluorination by anhydrous hydrogen fluoride in the presence of antimony pentachloride has been explained. The present studies were performed using a stainless steel autoclave. The exchange of the first chlorine atom was carried out in the temperature range of 35-95°C, with the molar ratio of HF/CCl₄ varied within the range of 1.2-1.7 and at a constant molar ratio of SbCl₅/Cl₂ equal to 1.9. The degree of conversion of CCl₄ to CCl₃F and the reaction rate constant as a function of temperature fit to an Arrhenius straight line. The Arrhenius constants (pre-exponential factor) and the activation energy were determined. Studies concerning the exchange of the second chlorine atom, i.e. the conversion of CCl₃F to CCl₂F₂ have been performed. The results of kinetic investigations were created in the same way. Based on these results it was found that the Arrhenius equation is fulfilled also in the second stage of the fluorination. The same slope of the straight lines confirms that the fluorination stages proceed according to the same mechanism with the same activation energy but with different pre-exponential factors. Several kinetic problems associated with the performance of the reactor can be solved on the basis of the equations derived. However, knowledge of CCl₄ conversion as a function of time, temperature, catalyst concentration and the type of the reaction is required for this purpose. Such calculations enable the selection of the optimal process parameters.

Full text of DOI:10.1016/S0022-1139(02)00241-5

Journal of Fluorine Chemistry 119 (2003) 89±95
Kinetics of tetrachloromethane ¯uorination by hydrogen
¯uoride in the presence of antimony pentachloride
Egbert Meissner, Eugeniusz Milchert*
Department of Organic Technology, Technical University of Szczecin, PL 70-310 Szczecin, Poland
Received 27 February 2002; received in revised form 23 July 2002; accepted 24 September 2002
Abstract
Contradictory information concerning the kinetics of tetrachloromethane ¯uorination by anhydrous hydrogen ¯uoride in the presence of
antimony pentachloride has been explained. The present studies were performed using a stainless steel autoclave. The exchange of the ®rst
chlorine atom was carried out in the temperature range of 35±95 8C, with the molar ratio of HF/CCl4 varied within the range of 1.2±1.7 and at a
constant molar ratio of SbCl5/Cl2 equal to 1.9. The degree of conversion of CCl4 to CCl3F and the reaction rate constant as a function of
temperature ®t to an Arrhenius straight line. The Arrhenius constants (pre-exponential factor) and the activation energy were determined.
Studies concerning the exchange of the second chlorine atom, i.e. the conversion of CCl3F to CCl2F2 have been performed. The results of
kinetic investigations were created in the same way. Based on these results it was found that the Arrhenius equation is ful®lled also in the
second stage of the ¯uorination. The same slope of the straight lines con®rms that the ¯uorination stages proceed according to the same
mechanism with the same activation energy but with different pre-exponential factors.
Several kinetic problems associated with the performance of the reactor can be solved on the basis of the equations derived. However,
knowledge of CCl4 conversion as a function of time, temperature, catalyst concentration and the type of the reaction is required for this
purpose. Such calculations enable the selection of the optimal process parameters.
# 2002 Elsevier Science B.V. All rights reserved.
Keywords: Kinetics; Fluorination; Chloro¯uorocarbons
1. Introduction
There is also consistency in the opinions that the reaction
of antimony(V) chloro¯uoride with CCl4 proceeds accord-
ing to the following way
The ¯uorination of tetrachloromethane by anhydrous
hydrogen ¯uoride in the presence of antimony pentachloride
was the principal reaction in the synthesis of chloro¯uor-
ocarbons (CFCs): CCl3F (CFC-11) and CCl2F2 (CFC-12)
which were utilized previously as refrigerants.
The ¯uorine±chlorine exchange reaction is of considerable
practical importance in the synthesis of hydrochloro¯uoro-
carbons (HCFC) and completely safe hydro¯uorocarbons
(HFC), e.g. CF3CH2F (HFC-134a). The latter compound
[1,2] is most often used as a replacement for CFC-11 and -12.
Literature reports concerning the way in which SbCl5
participates in ¯uorine exchange between HF and CCl4
provide no intrinsic discrepancy [1±4]. There is convincing
evidence, con®rming that antimony(V) chloro¯uorides with
a general formula of SbCl5ÀnFn can be used as ¯uorinating
agents. They are formed in the following reaction
SbCl4ÀnFn‡1 ‡ CCl4 ! SbCl5ÀnFn ‡ CCl3F
SbCl4ÀnFn‡1 ‡ CCl3F ! SbCl5ÀnFn ‡ CCl2F2
SbCl4ÀnFn‡1 ‡ CCl2F2 ! SbCl5ÀnFn ‡ CClF3
SbCl4ÀnFn‡1 ‡ CClF3 ! SbCl5ÀnFn ‡ CF4
(2)
(3)
(4)
(5)
Antimony ¯uorides were the subject of many studies
performed by Kolditz and coworkers [4±7]. Although their
objective has been focused mainly on the analytical pro-
blems, they shed some light on the process of ¯uorine
exchange between HF and SbCl5. The results con®rm
that the exchange of ¯uorine with the ®rst and second
chlorine atoms in SbCl5 proceeds readily even at low
temperatures (from À70to À40 8C). Complete exchange
of the third atom occurs with a suf®cient excess of HF
in the temperature range from À40to 20 8C, whereas the
fourth atom is exchanged in the temperature range from
À25 to 0 8C. However, the exchange of the last chlorine
atom for ¯uorine does not proceed by this route. The use
of even a considerable excess of HF (HF/SbCl5 ꢀ20mol),
SbCl5 ‡ nHF ! SbCl5ÀnFn ‡ nHCl
where n ˆ 1 to 4.
(1)
* Corresponding author. Tel.: ‡48-91-449-4185; fax ‡48-91-449-4365.
E-mail address: milch@mailbox.tuniv.szczecin.pl (E. Milchert).
0022-1139/02/$ ± see front matter # 2002 Elsevier Science B.V. All rights reserved.
PII: S 002 2 - 1 1 3 9 ( 02 ) 00 2 4 1 - 5

90
E. Meissner, E. Milchert / Journal of Fluorine Chemistry 119 (2003) 89±95
with annealing carried out for more than 2 h at temperature
of 85 8C and distillation of HF, does not lead to the
formation SbF5 but to formation of SbClF4ÁHF. Further
distillation of SbClF4ÁHF causes its decomposition with
the evolution of chlorine, and simultaneous reduction of
Sb(V) to Sb(III).
Different values of the activation energy obtained by both
authors suggest that a change of the reaction mechanism take
places with change in temperature.
The reaction between antimony(V) chloro¯uorides and
CCl4 was also presented as (7).
SbCl2F3 ‡ 3CCl4 ! 3CCl3F ‡ SbCl5
(7)
However, the authors have restricted their discussion only
to a comparison of the kinetic curves of the reactions (6) and
(7). On the basis of the form of Eq. (7) they have assumed
that SbCl2F3 is three times more active than SbCl4F during
the exchange of ¯uorine. In accordance with this assumption
they compared the kinetic curves for solutions with the
initial composition: 1 mol SbCl4F ‡ nCCl4 and 1/3 mol
SbCl2F3 ‡ nCCl4.
2. The kinetic model
To our knowledge no paper has been published on the
kinetics of ¯uorine exchange between SbCl5 and HF in the
existing literature. Simakov and Korobochko [8] have
reported that the HF absorption is accompanied by the
chemical reaction, the role of which can be given by the
kinetic equation
However, the authors did not take into account that the
exchange abilities of SbCl4F and SbCl2F3 equalize with
increase in reaction temperature. By recalculation of the
number of moles of CCl3F formed in the reactions (6) and
(7) on 1 mol of SbCl5ÀnFn instead of 1/n mol, the initial rates
of both reaction are the same at 26 8C. The kinetic curve for
the reaction (7) is characteristic for a system of irreversible
consecutive reactions with the rate constants being identical
or very close to each other. Thus, it can be assumed that
SbCl2F3 participates in the three consecutive steps of reac-
tions (2), by exchanging consecutively with CCl4 by one
¯uoride atom according to
2
R ˆ k‰SbCl5Š ‰HFŠ
(1)
where [SbCl5]2 and [HF] are molar concentrations, k the
observed rate constant of reaction, estimated at room tem-
perature as k ˆ 1  103 dm6 molÀ2 sÀ1
.
From this value it can be concluded that it describes the
rate of exchange of the ®rst chlorine atom in SbCl5. How-
ever, one cannot evaluate whether further stages of
exchange in (1) for n ˆ 2; 3; 4 will proceed with the same
reaction rate. When the less advantageous variant is
assumed and in the reaction (1), only SbCl4F (n ˆ 1) is
formed, SbCl5 is regenerated in the reactions (2)±(5) and is
almost instantaneously ¯uorinated to SbCl4F. Thus, as long
as HF is present in the reaction, the principal process of
CCl4 ¯uorination proceeds at a constant concentration of
¯uorinating agent.
SbCl2F3 ‡ CCl4 ! CCl3F ‡ SbCl3F2
SbCl3F2 ‡ CCl4 ! CCl3F ‡ SbCl4F
SbCl4F ‡ CCl4 ! CCl3F ‡ SbCl5
SbCl2F3 ‡ 3CCl4 ! 3CCl3F ‡ SbCl5
(8)
(9)
(6)
(7)
The authors of the papers related to the kinetic aspect
[4,9,10] are in agreement that at temperature higher than 20±
26 8C the reaction is (Eq. (6)) irreversible
Assuming, that the above scheme describes the real reaction
mechanism and the rate constants of the reactions (6), (8)
and (9) are identical, then for a signi®cant excess of CCl4,
the kinetic equations are linear
SbCl4F ‡ CCl4 ! CCl3F ‡ SbCl5
(6)
Kolditz and Schultz [7] believed that the effect of tem-
perature can be attributed to the deactivation of SbCl4F. This
compound forms a stable complexes (SbCl4F)nÁSbCl5 at low
temperatures in which all ¯uorine atoms are involved in
bridge bonds, thereby they cannot participate in the
exchange reaction with CCl4.
The papers discussing the kinetic equation of the reaction
lead to contradictory conclusions. The results of studies
performed by Chekmarev et al. [9], indicate that the rate of
Eq. (6) reaction at the temperature range between 20and
50 8C can be described by the kinetic equation
9
d‰SbCl2F3Š
>
>
ˆ Àkef‰SbCl2F3Š
>
>
>
dt
>
=
d‰SbCl3F2Š
(4)
ˆ kef‰SbCl2F3Š À ‰SbCl3F2Š
ˆ kef‰SbCl3F2Š À ‰SbCl4FŠ
>
dt
>
>
>
>
d‰SbCl4FŠ
>
;
dt
where [SbClxFx] is the molar concentration of component, t-
reaction time, kef the effective rate constant of reaction
determined as: kef ˆ kb, where k the rate constants of
reactions (6), (8), (9), b the initial concentration of CCl4.
The rate of (6) reaction can be given by the equation
r ˆ k‰SbCl4FŠ ‰CCl4Š
(2)
2
Kolditz and Schultz [7] claimed that at a temperature range
between 0and 26 8C the following equation is more appro-
priate
d‰SbCl4FŠ
ˆ Àkef‰SbCl4FŠ
(5)
dt
Denoting by X and Y the yields of reactions (6) and (7)
respectively, and determining them as the ratio of the mole
r ˆ k‰SbCl4FŠ‰CCl4Š
(3)

E. Meissner, E. Milchert / Journal of Fluorine Chemistry 119 (2003) 89±95
91
Fig. 1. The yield of CCl3F in reaction (6) (^) and (7) (&) as a function of the reaction time.
number of CCl3F to the initial mole number of SbCl5ÀnFn,
where a is initial concentration of HF, b the initial concen-
tration of CCl4, x the concentration of CCl3F after time t.
The average reaction rate constants for particular tem-
peratures from the range under investigation are summarized
in Table 1. Due to the excess of hydrogen ¯uoride it can be
expected that under the conditions investigated, the rate of
conversion of CCl4 to CCl3F is dependent only on the CCl4
concentration and the initial concentration of SbCl5, i.e. the
kinetic equation is ful®lled
respectively for n ˆ 1 and 3, then we can obtain
ef t
X ˆ 1 À eÀk
(6)
By the solution of the equation system (4) and for a short
reaction time, it can be demonstrated that the relationship
Y ˆ fꢁt† is approximately linear
Y ˆ keft
(7)
The results of work performed by Kolditz and Schultz [7] are
consistent with this derived equation. The experimental
results of Kolditz are presented in Fig. 1 together with
the values calculated on the basis of Eqs. (6) and (7) for
r ˆ kcSbX‰CCl4Š
This equation is valid when the total amount of SbCl5 will be
transformed into the active form, i.e. when SbCl5 ˆ 0.
Taking into consideration the rate of reaction given by
(10)
kef ˆ 0:194 hÀ1
.
The proposed kinetic scheme indicates that in each ele-
mentary reaction one chlorine atom undergoes exchange,
according to reaction (2). The rate of the ®rst stage of
reaction describes the kinetic equation
Àd‰CCl4Š
r ˆ
(11)
dt
after the integration of Eqs. (10) and (11) we can obtain
rn ˆ k‰SbCl5ÀnFnŠ‰CCl4Š
with the reaction rate constant k independent of n.
(8)
SbXt
a ˆ 1 À eÀkc
(12)
Our studies reported here permit the explanation of
literature reports concerning the kinetics and mechanism
of this complex process.
Table 1
The kinetic constants of reaction in CCl4 fluorination to CCl3F
Number
Temperature (8C)
Kinetic constant of reaction
k  104 (dm3 molÀ1 sÀ1
)
3. Results and discussion
a
.33
1
00
13
2
0.69a
3.1. The exchange reaction of fluorine between
antimony(V) chlorofluorides and CCl4 (reaction (2))
3
26
1.67 Æ 0.39a
4.22 Æ 0.39
4.47 Æ 0.46
8.51 Æ 0.71
15.3 Æ 2.2
27.0 Æ 3.5
34.3 Æ 4.9
Æ 5.6
4
35
5
45
55
The kinetic constant of reaction was calculated with the
assumption, that the reaction is second order and proceeds in
the liquid phase, thus
6
7
65
8
75
85
9
1095
36.4
2:303
bꢁa À x†
aꢁb À x†
k ˆ
log
(9)
a Based on literature data.
tꢁa À b†

92
E. Meissner, E. Milchert / Journal of Fluorine Chemistry 119 (2003) 89±95
where a is the degree of CCl4 conversion. This equation can
be written in a more convenient form for testing as
of particular components was calculated from the equation
Mi
Vi ˆ
(15)
Àln ꢁ1 À a† ˆ kcSbXt
(13)
di
where Mi is the molecular weigh of component i, di the
density of component i (HF, CCl4, CCl3F, SbCl5, SbClF4).
The numbers of moles of the respective reagents were
calculated with the following assumptions:
Because of the uncertainly in the rate constant shown in
Eq. (9), testing of Eq. (13) separately for individual mea-
surements will give a wide scatter of results and it would not
be possible to show unequivocally that Eq. (13) correctly
describes the kinetics of transformation of CCl4 to CCl3F.
For this reason it was veri®ed that
ꢂ the reaction between SbCl5 and HF proceeds instanta-
neously and the total amount of SbCl5 is transformed to
SbClF4;
ꢂ the reaction rate constants calculated on the basis of
Eq. (13) comply with the Arrhenius equation;
ꢂ the values of the constants determined from this equation
(pre-exponential factor and the activation energy) are
consistent with the literature data.
ꢂ introduction of Cl2 and formation of HCl occur in the
gaseous phase;
ꢂ the pressure in the reactor is so high that the remaining
components, i.e. HF, CCl4, CCl3F and SbClF4 are in the
liquid phase.
The calculation were carried out in the following way:
From the mass balance calculation the catalyst concen-
trations cSbX are
ꢂ the concentration of cSbX catalyst was evaluated;
ꢂ for each measuring point (a, t) the value of reaction rate
constant, k, was calculated from Eq. (13);
ꢂ at each temperature after several reaction times, the value
of the constant, k, was averaged and the standard deviation
was calculated.
1
cSbX
ˆ
(16)
0:968 ‡ 1:891ꢁm=a† À 0:19
cSbX is the catalyst concentration (mol dmÀ3), m the mass of
mixture of CCl4, SbCl5, Cl2 (g); a the degree of CCl4
conversion.
These magnitudes are summarized in Table 1 and they were
compared with literature data [7]. In order to determine the
catalyst concentration, the volume of the liquid phase was
calculated. It was assumed that the volume is an additive
function
The catalyst concentrations in the particular tests calcu-
lated from Eq. (16) vary from 0.8 to 0.9 mol dmÀ3. Taking
into account simpli®cations, the average value of
cSbX ˆ 0:85 mol dmÀ3 was assumed.
X
Based on the results summarized in Table 1, Fig. 2, line 1
was plotted as
v ˆ
niVi
(14)
i
ꢀ ꢁ
1
where ni is the number of mole component i of the liquid
phase, Vi molar volume of component i. The molar volume
ln k ˆ f
(17)
T
Fig. 2. Verification of the Arrhenius equation for the reaction CCl4 ! CCl3F (1) and CCl3F ! CCl2F2 (2) (~), (&) the result of our studies; (*) data from
work of Kolditz and Schultz.

E. Meissner, E. Milchert / Journal of Fluorine Chemistry 119 (2003) 89±95
93
k85 C ˆ 1:39 Æ 0:26  10À4 dm3 molÀ1 sÀ1
ꢃ
This chart convincingly validates the assumed mechanism of
CCl4 ¯uorination. Most of the data points form a straight line
according to Arrhenius equation
k75 C ˆ 1:20 Æ 0:41  10À4 dm3 molÀ1 sÀ1
ꢃ
The results are presented in Fig. 2 (line 2). From this ®gure
results that the Arrhenius equation is also ful®lled for reaction
(3) (stage 2). The same slope of the straight line may indicate
that both stages of CCl4 ¯uorination proceed according to the
E
ln k ˆ ln k0 À
(18)
RT
These results are consistent with those obtained by Kol-
ditz et al. (Fig. 2, long line 1) [7]. The constants of the
Arrhenius equation determined from the graph are: pre-
exponential factor k0 ˆ 2:08  104 dm3 molÀ1 sÀ1, and
same mechanism with the activation energy E ˆ 46 kJ molÀ1
.
The pre-exponential factor of reaction (3) is signi®cantly
smaller and amounts to k0 ˆ 8:01  10À12 dm3 molÀ1 sÀ1
.
the activation energy E ˆ 46 kJ molÀ1
.
As a result of the rapid reaction of SbCl5 with HF, a
mixture of SbCl5ÀnFn (1 ꢄ n ꢄ 4) is formed, the composi-
tion of which is dependent on both temperature and the
amount of HF. In previous work [7,11] it has been concluded
that SbCl4F and SbCl2F3 play a signi®cant role in the
replacement of chlorine in CCl4 and consecutive chloro-
¯uorocarbons. Our studies reveal that the rate of replace-
ment of the ®rst chlorine atom in CCl4 does not depend on
the value of n in SbCl5ÀnFn. At signi®cantly high tempera-
ture, this compound is SbClF4. Thus the course of ¯uorina-
tion can be presented as follows:
3.2. Exchange reaction of fluorine between antimony(V)
chlorofluorides and CCl3F (reaction (3))
The second stage of CCl4 ¯uorination (reaction (3)) is
practically not recognised. It is known from the literature
[3,7] that the exchange of the second ¯uorine atom proceeds
with signi®cantly more dif®culty than the ®rst. From the
literature also, the only reaction product of CCl4 with
SbCl4F (reaction (2)) at atmospheric pressure and tempera-
ture below the boiling point of CCl4 (76.6 8C) is CCl3F. It
was found that a small amount of CCl2F2 occurs at tem-
perature 77 8C after several hours of the reaction [7].
The results of the kinetic studies of CCl3F ¯uorination
were created similarly to the results of the ®rst stage
(¯uorination of CCl4). The following parameters were cal-
culated: the catalyst concentration (cSbX ˆ 0:9 mol dmÀ3),
the reaction rate constant, assuming that the second stage
proceeds in excess of hydrogen ¯uoride according to the
same mechanism as the ®rst. Thereby, the rate of R-3
reaction can be described by the kinetic equation
CCl4 ‡ SbClF4 ! CCl3F ‡ SbCl2F3
CCl3F ‡ SbClF4 ! CCl2F2 ‡ SbCl2F3
SbCl2F3 ‡ HF ! SbClF4 ‡ HCl
(10)
(11)
(12)
Reaction (12) proceeds so rapidly that the total amount of
SbCl5 introduced occurs in the active form as SbClF4, i.e.
‰SbClF4Š ˆ ‰SbCl5Š ˆ cSbX
(20)
0
The rates reactions (10) and (11) which determine the ®rst
and the second stage of CCl4 ¯uorination can be described
by the following kinetic equations:
r ˆ kcSbX‰CCl3FŠ
(19)
rI ˆ kIcsbx‰CCl4Š
rII ˆ kIIcSbX‰CCl4Š
(21)
(22)
The results of calculations of the reaction rate constants
and the degrees of conversions are summarized in Table 2.
After the calculation of the averages, the following values
of the rate constants were obtained:
The reaction rate constants ful®ll the Arrhenius equation
k ˆ k0 eÀE=RT
The activation energies of both reactions are the same and
the pre-exponential factors are given by, respectively
(23)
k95 C ˆ 2:49 Æ 0:73  10À4 dm3 molÀ1 sÀ1
ꢃ
Table 2
Rate constants and degree of CCl3F conversion to CCl2F2
k0I ˆ 2:08  104 dm3 molÀ1 sÀ1
k0II ˆ 8:00  102 dm3 molÀ1 sÀ1
Temperature
Reaction
Degree of
conversion (%) (dm3 molÀ1 sÀ1
)
Rate constant k  104
(8C)
time (min)
Based on Eqs. (20)±(23) any kinetic problem associated
the operation of the reactor for the synthesis may be solved.
In the case of a closed batch reactor, a fundamental kinetic
75
13
16
19
11.8
13.4
13.5
1.79
1.40
1.41
approach leads to the solution of the system of equations
85
95
.1
1010 1.97
9
13
16
19
10.0
10.9
10.6
1.66
0.83
1.09
d‰CCl4Š
>
>
ˆ ÀkcSbX‰CCl4Š
>
>
>
dt
>
=
d‰CCl3FŠ
1011.3
13
16
2.22
(24)
ˆ kcSbX‰CCl4Š À kIIcSbX‰CCl3FŠ
ˆ kIIcSbX‰CCl3FŠ
>
dt
13.7
15.2
16.1
2.03
1.91
1.81
>
>
>
>
d‰CCl2F2Š
>
;
19
dt

94
E. Meissner, E. Milchert / Journal of Fluorine Chemistry 119 (2003) 89±95
Fig. 3. The degree of CCl4 conversion as a function of the time: aI, degree of CCl4 conversion to CCl3F; aII, degree of CCl4 conversion to CCl2F2; a, total
conversion.
The solution of system (24) for the isothermal process can be
presented in the analytical form
mixture of CCl4 or CCl3F with the catalyst SbCl5 and dichlor-
ine. The molar ratio of SbCl5/Cl2 was constant. After weigh-
ing, the autoclave was cooled to ca. À10 8C, anhydrous
hydrogen ¯uoride was introduced, and its amount determined
by weighing. The autoclaves were placed in a shaker and were
then submerged in oil bath. After a de®ned time the autoclaves
were taken out, cooled in a water bath with ice and were
unloaded. The gaseous content of the reactor was discharged
to a polyethylene tank under the water surface using a needle
valve. Above the tank was placed a polyethylene absorber,
which was sprinkled by cooled water. When the ¯ow of gases
was terminated while the needle valve was kept open, water
was sucked into the autoclave. The autoclave was opened, the
content was discharged to re¯ux from the absorber and the
concentration of the FÀ ion was determined potentiometricly.
Measurements were performed with ion-selective electrode in
OP-108 apparatus (Radelkis). Cl2 concentration was deter-
mined by iodometric titration. CCl4 and CFCs were deter-
mined by gas chromatography. The mass balance of the FÀ ion
and organic raw material was performed.
kI
SbXt
aI ˆ
ꢁeÀk c À eÀkc
II SbXt
†
(25)
kI À kII
kII
kI
SbXt
II SbXt
eÀk c
aII ˆ 1 ‡
eÀkc
À
(26)
(27)
kI À kII
kI À kII
a ˆ 1 À eÀkÁ
SbXt
where a is the total conversion of CCl4; aI, aII the conversion
of CCl4 to CCl3F and CCl2F2, respectively.
The results of calculation for the conditions: temperature
95 8C, catalyst concentration 0.6 mol dmÀ3 (the closed, batch
reactor) are presented in Fig. 3. Such the calculations for
various catalyst concentrations, different types of the reactor,
enable the optimal selection of the process parameters.
4. Experimental
4.1. Raw materials
4.3. Gas chromatography conditions
Hydrogen ¯uoride from a steel cylinder, purity 99.9 wt.%,
was the product of Lubon Chemical Works, Poland. Tetra-
chloromethane, purity 99.9 wt.%, after distillation was
obtained from Anwil, Poland. Antimony pentachloride,
purity ꢅ99 wt.%, from Fluka. Dichlorine from a steel
cylinder, purity 99.9 wt.% was the product ``Rokita'' Che-
mical Works, Poland. Chloro¯uorocarbons, CCl3F, CCl2F2;
purity 99.8 wt.% were obtained in Department of Organic
Technology, Technical University of Szczecin.
A Chrom 5 apparatus equipped with 2:5 m  4 mm steel
column packed with Porapak Q (80±100 mesh) was
employed. The apparatus was equipped with a ¯ame ioniza-
tion detector (FID) with N2 ¯ow rate 20cm 3 minÀ1 (carrier
gas), air ¯ow rate 300 cm3 minÀ1
, H2 ¯ow rate
30cm 3 minÀ1. The temperature were: thermostat 170 8C,
detector and sample injector 250 8C.
4.4. General procedure for the synthesis
4.2. Apparatus andprocedure
Experiments were carried out at a temperature range
between 35 and 95 8C with variation of the temperature
in 10 8C intervals, at a molar ratio of HF/CCl4 varied over a
All studies have been performed in a 7 cm3 stainless steel
autoclave which was charged by means of a syringe with a

E. Meissner, E. Milchert / Journal of Fluorine Chemistry 119 (2003) 89±95
95
[2] S. Brunet, R. Requieme, E. Colnay, J. Barrault, M. Blanchard, Appl.
Catal. B Environ. 5 (1995) 305±317.
range of 1.7À1.2. The composition of raw material was as
follows: CCl4, 82 wt.%; SbCl5, 16 wt.%; Cl2, 2 wt.%. The
degree of conversion of CCl4 to CCl3F was calculated using
the following de®nition
[3] S. Brunet, C. Batiot, J. Barrault, M. Blanchard, J.M. Coustard, J.
Fluorine Chem. 63 (1993) 227±232.
[4] L. Kolditz, H Daunicht, Z. Anorg. Allg. Chem. 302 (1959) 230±
233.
n0HF À nHF
CCI4
[5] L. Kolditz, Z. Anorg. Allg. Chem. 289 (1957) 128±133.
[6] L. Kolditz, W. von Lieth, Z. Anorg. Allg. Chem. 310(1961) 236±
242.
a ˆ
 100%
(28)
0
n
where n0HF and nHF the number of moles of hydrogen ¯uoride
[7] L. Kolditz, S. Schultz, J. Fluorine Chem. 5 (1975) 141±150.
[8] B.V. Simakov, N.A. Korobochko, Teor. Osn. Chim. Techn. 3 (1980)
117±140, CA v.91, 63317h (1979).
before and after the reaction, n0CCI : the number of moles of
CCl4 before the reaction.
4
[9] P.M. Chekmarev, B.V. Simakov, A.G. Oshuev, Raboty po, termodi-
nam. i kinetike chim. procesov 62 (1974) 99±102, CA v.83, 198336u
(1975).
References
[10] B.V. Siriakov, N.A. Kazakevicz, Modelirovane. i Upr. Chim.-Techn.
Procesami, Chimija, Moskva, 1981, pp. 42±48.
[11] S. Brunet, C. Batiot, P. Moriceau, N. Thybaud, J. Mol. Cat. A 142
(1999) 183±186.
[1] S. Brunet, C. Batiot, J. Barrault, M. Blanchard, J. Fluorine Chem. 59
(1992) 33±39.