Preparation of 4-phenylphthalonitrile by vapor-phase ammoxidation of 4-phenyl-o-xylene: Reaction kinetics

Article abstract of DOI:10.1134/S0965544112020028

The kinetic features of the process of 4-phenylphthalonitrile synthesis by vapor-phase ammoxidation of 4-phenyl-o-xylene in the temperature range of 633-713 K have been studied. It has been shown that 4-phenylphthalonitrile is produced consecutively via 4-phenyl-o-tolunitrile as an intermediate. The 4-phenyl-o-xylene and 4-phenyl-o-tolunitrile conversion rates have been found to follow a half-order rate law in these components and to be independent of the oxygen and ammonia concentration. The kinetic behavior of the formation and consumption of byproducts are also discussed, their buildup rate equations are given, and possible reaction mechanisms are proposed. It has been revealed that the formation of the byproduct 4-phenylphthalimide at high ammonia concentrations is due to hydrolysis of 4-phenylphthalonitrile, carbon dioxide is produced via oxidation of 4-phenyl-o-xylene and decarboxylation of 4-phenylphthalimide, and 4-phenylbenzonitrile is produced from 4-phenyl-o-tolunitrile and 4-phenylphthalimide. Additional routes of the formation of 4-phenylphthalimide and CO₂ from 4-phenyl-o-xylene appear at low ammonia concentrations. Pleiades Publishing, Ltd., 2012.

Full text of DOI:10.1134/S0965544112020028

ISSN 0965ꢀ5441, Petroleum Chemistry, 2012, Vol. 52, No. 2, pp. 105–112. © Pleiades Publishing, Ltd., 2012.
Original Russian Text © G.A. Bagirzade, 2012, published in Neftekhimiya, 2012, Vol. 52, No. 2, pp. 124–131.
Preparation of 4ꢀPhenylphthalonitrile by VaporꢀPhase
Ammoxidation of 4ꢀPhenylꢀoꢀxylene: Reaction Kinetics
G. A. Bagirzade
Nagiev Institute of Chemistry Problems, National Academy of Sciences of Azerbaijan, Baku, Azerbaijan
eꢀmail: itpcht@itpcht.ab.az
Received September 27, 2011
Abstract—The kinetic features of the process of 4ꢀphenylphthalonitrile synthesis by vaporꢀphase ammoxiꢀ
dation of 4ꢀphenylꢀ
that 4ꢀphenylphthalonitrile is produced consecutively via 4ꢀphenylꢀ
phenylꢀ ꢀxylene and 4ꢀphenylꢀ ꢀtolunitrile conversion rates have been found to follow a halfꢀorder rate law
oꢀxylene in the temperature range of 633–713 K have been studied. It has been shown
o
ꢀtolunitrile as an intermediate. The 4ꢀ
o
o
in these components and to be independent of the oxygen and ammonia concentration. The kinetic behavior
of the formation and consumption of byproducts are also discussed, their buildup rate equations are given,
and possible reaction mechanisms are proposed. It has been revealed that the formation of the byproduct 4ꢀ
phenylphthalimide at high ammonia concentrations is due to hydrolysis of 4ꢀphenylphthalonitrile, carbon
dioxide is produced via oxidation of 4ꢀphenylꢀ
phenylbenzonitrile is produced from 4ꢀphenylꢀ
o
ꢀxylene and decarboxylation of 4ꢀphenylphthalimide, and 4ꢀ
ꢀtolunitrile and 4ꢀphenylphthalimide. Additional routes of
o
the formation of 4ꢀphenylphthalimide and CO from 4ꢀphenylꢀ
o
ꢀxylene appear at low ammonia concentraꢀ
2
tions.
DOI: 10.1134/S0965544112020028
The vaporꢀphase catalytic ammoxidation of 4ꢀpheꢀ Regarding the ammoxidation of substituted
nylꢀ ꢀxylene can give with a yield of 80% 4ꢀpheꢀ it should be noted that the kinetic behavior of 4ꢀ
nylphthalonitrile, a feedstock for the synthesis of copꢀ bromoꢀ1,2ꢀdimethylbenzene on the (V–Sb–Bi–
per tetraphenyl tetrazoporphinate (copper tetrapheꢀ Zr/ ꢀAl O3 catalyst was studied in the temperature
nylphthalocyanine), which in turn is used for range of 633–693 K [7, 8].
оꢀxylene,
o
γ
2
manufacturing phthalocyanine pigments and turꢀ
quoise and yellow hue dyes [1]. The use of 4ꢀpheꢀ
nylphthalonitrile will make it possible to replace
highly chlorinated copper phthalocyanine, which is
manufactured through quite a sophisticated, environꢀ
mentally unfriendly process of chlorination of copper
phthalocyanine in an aluminum chloride–sodium
chloride melt [2].
The objective of this work was to investigate in
detail the kinetics of ammoxidation of 4ꢀphenylꢀ
xylene of a retrofitted, zirconiaꢀmodified catalyst of
the Lꢀ8 brand, i.e., the V–Sb–BiꢀZr/ ꢀAl O3 contact
catalyst, which under certain conditions can preclude
the formation of 4ꢀphenylphthalimide.
оꢀ
γ
2
EXPERIMENTAL
Studying the ammoxidation of
et al. [3] derived equations for the phthalonitrile,
ꢀtolunitrile, and phthalimide buildup rates. They
assumed that in the presence of the catalyst Lꢀ8 (V–
Sb–Bi/ ꢀAl O ), phthalonitrile is produced both from
ꢀxylene immediately and through
byproduct phthalimide is formed from
Earlier [4, 5], we studied the kinetics of ammoxidation
of ꢀxylene in the presence of the modified catalyst
Lꢀ8ꢀU (V–Sb–Bi–Zr/ ꢀAl O3) adopted for indusꢀ
trial application. In that works, we obtained rate equaꢀ
tions for phthalonitrile, ꢀtolunitrile, benzonitrile,
and phthalimide buildup. We showed that that phthaꢀ
lonitrile is produced from ꢀtolunitrile alone. Phthalꢀ
imide, the byproduct, is formed both directly from
oꢀxylene, Rizaev
Kinetic measurements were performed in a setup
with a vibrating fluidizedꢀbed, gradientless flow reacꢀ
o
3
tor of 20ꢀcm capacity made from 12Kh18N10T steel.
To prevent highꢀboilingꢀpoint products from condenꢀ
sation, part of the setup was thermostated at 500–
γ
2
3
о
о
ꢀtolunitrile. The
5
20 K. Prior to use, oxygen and nitrogen were purified
о
ꢀtolunitrile.
for removal of trace organic compounds and dried,
Ammonia was passed through an oil bath filter. 4ꢀPheꢀ
о
nylꢀ
nylphthalonitrile (PPN), 4ꢀphenylphthalimide (PPI),
ꢀphenylꢀ ꢀtolunitrile (PoTN), and 4ꢀphenylbenꢀ
оꢀxylene (PoX) was of the reagent grade. 4ꢀPheꢀ
γ
2
4
о
о
zonitrile (PBN) were isolated from the PoX ammoxiꢀ
dation product and purified by distillation.
о
о
ꢀ
PPN, PoTN, PPI, PBN, carbon dioxide, unreꢀ
xylene and through phthalonitrile. Specific features of acted PoX, oxygen and the diluent gas nitrogen were
the ammoxidation process of alkylaromatic hydrocarꢀ determined in the products by gas chromatography
bons including
оꢀxylene were also revealed [6]. according to the following scheme. The reaction gases
105

106
BAGIRZADE
Table 1. Dependence of the 4ꢀphenylꢀ
o
ꢀtolunitrile buildup and 4ꢀphenylꢀ
o
ꢀxylene conversion rates (mmol/(g h)) upon
τ
0
0
0
and
P
(713 K,
P
= 7.80–8.37 kPa,
P
= 33.20–61.91 kPa)
PoX
O2
NH3
Pi, kPa
WPoX
rPoX
0
PoX
τ
, s
P
, kPa
PoX
PoTN
exp
calc
exp
calc
1
.23
.91
.59
.27
.20
.13
.09
.27
.27
.27
.27
1.24
1.24
0.014
0.021
0.055
0.191
0.267
0.435
0.593
0.015
0.051
0.210
0.479
0.012
0.018
0.047
0.139
0.168
0.217
0.230
0.012
0.040
0.152
0.311
0.64
0.85
1.28
2.50
3.09
3.83
4.39
0.70
1.30
2.65
4.03
0.69
0.84
1.36
2.54
3.00
3.83
4.47
0.71
1.31
2.66
4.02
0.006
0.013
0.051
0.333
0.536
1.041
1.571
0.028
0.096
0.360
0.740
0.006
0.013
0.051
0.325
0.564
1.042
1.603
0.031
0.098
0.360
0.730
0
0
0
0
0
0
0
0
0
0
1.24
1.24
1.24
1.24
1.24
0.31
0.60
1.33
2.18
were successively passed through a 1,4ꢀdioxaneꢀfilled effects of reactor material, mass transfer processes,
trap for absorption of nitriles, PPI, and PoX and a sulꢀ and homogeneous steps on the observed rates Wi
.
furic acidꢀfilled trap for absorption of ammonia, Carꢀ
The kinetics was studied in the range of 633–
13 K, The contact time (0.09–1.87 s) was varied
depending on the catalyst sample mass, the space
velocity, and the gas pressure. The pressure PPoX was
changed by varying both the PoX concentration at the
bon dioxide was determined on an LKhMꢀ8MD chroꢀ
matograph with triethylene glycol butyrate supported
on INZꢀ600 (calcined diatomaceous earth) as the staꢀ
tionary phase. Separation of О2 and N2 was carried out
on the same chromatograph using a parallel column
packed with NaX. The concentration of ammonia at
the reactor outlet was determined by titration of unreꢀ
acted sulfuric acid from the second trap. The products
absorbed by 1,4ꢀdioxane were determined on a
7
τ
reactor outlet for
τ
= 0.27 s and the contact time
τ
at
0
P
PoX
= 1.24 kPa. The results obtained at 713 K are
presented in Table 1.
It was found that variation of oxygen pressure PO2 at
Chromeꢀ5 chromatograph equipped with an FID and PNH3 = 33.2 kPa had no effect on the observed PoX
a column of 1.2 m length. The column packing was conversion and product buildup rates. The variation of
Chromaton NꢀAW (0.2–0.25 mm) coated with a
mixed stationary phase of Apiezon L (21%) and PEG
an ammonium pressure PNH3 showed that neither PoX
conversion rate WPoX nor the PoTN buildup rate rPoTN
depends to a noticeable extent upon this parameter. A
similar behavior was observed at temperatures of 633,
4
0000 (0.5%) or with Polisorbꢀ1 (0.25–0.5 mm)
alone. The carrierꢀgas (nitrogen) flow rate was
80 mL/min. The sample injection temperature was
353 K, and the temperature programming rate was
20 K/min.
6
53, 673, and 693 K.
From these data, it follows that the observed
0
order of WPoX in
P
is less than unity. It is known
PoX
that fractional rate order can result from a certain
stepwise reaction mechanism or be due to approxiꢀ
mation of rational fractional equations [9]. In the
RESULTS AND DISCUSSION
The kinetic measurements per se were preceded by latter case, it is reasonable to assume that WPoTN is
experimental verification of the conditions for reactor described by a rate equation of the same type as
n
operation in the nongradient mode in terms of temꢀ WPoX with the same denominator Wi
= k P f(P1),
i i
perature and concentration and the absence of the where P1) is a temperatureꢀdependent function of
f
(
PETROLEUM CHEMISTRY Vol. 52
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2012

PREPARATION OF 4ꢀPHENYLPHTHALONITRILE
107
SPoTN
1
2
3
4
5
1.0
0
0
0
0
.8
.6
.4
.2
0
.2 0.4 0.6 0.8 1.0 1.2 PPoTN 0.5
0
( PPoX
Dependence of the 4ꢀphenylꢀ
tolunitrile plotted in the coordinates of Eq. (1) at different temperatures; (
o
ꢀtolunitrile formation selectivity on the partial pressures of 4ꢀphenylꢀ
o
ꢀxylene and 4ꢀphenylꢀ
oꢀ
1
) 633, ( ) 653, ( ) 673, ( ) 693, and (5
2
3
4
) 713 K.
partial pressures of the reaction components. The formation selectivity SPoTN on PPoX and PPoTN for the
choice of the type of the rate equation was made on parallel–consecutive scheme of the formation of 4ꢀ
the basis of analysis of the dependence of the PoTN phenylphthalonitrile.
3
CH3
CN
CN
CN
1
2
H C
C H
6 5
C
3
H
CH3
CH3
C H
6 5
6
5
n
W – W
k P
CN
1
PoTN
2
⎛
PoTN
⎞
⎠
SPoTN = ꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀ = a – ꢀꢀꢀ ꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀ
.
(1)
⎝
2
+ 1.5O + NH3
W
k
P
PoX
PoX
1
C H
6
5
CH3
(II)
The value of
n
was selected graphically. It was found
CN
+ 3H O,
that in Eq. (1) is close to 0.5 (see figure). From the
n
=
2
data in the figure, it is seen that the parallel route of
formation of PPN is not operative. An insignificant
C H
6
5
CN
deviation of SPoTN from unity at (PPoTN
/
PPoX) = 0 is due
Variation in PNH3 over a broader range showed
to the oxidation of PoX in CO , which was ignored in
2
(
Table 2) that the zero order in this component in the
this study, since the value of SCO2 did not exceed 0.094 entire region examined is observed for the overall PoX
n
PoX
conversion rate only. When
P is smaller that a cerꢀ
NH3
even at 713 K. An analysis of the WPoX
/P
ratio
showed that
f
(
Pi
)
≡
1
at any temperature. Conseꢀ
tain value denoted as (PNH3
)
min, the selectivity for
quently, the rates of the PoX and PoTN conversion
reaction are described by halfꢀorder equations in these
components:
PPI, PBN, and СО2 increases and the selectivity for
PPN and PoTN correspondingly decreases. A similar
behavior was observed at temperatures of 633, 653,
6
93, and 713 K.
Table 3 presents experimental data on the depenꢀ
CH3
+
1.5O + NH
2 3
dence of the buildup rates of PoX ammoxidation prodꢀ
ucts on the contact time at the following composiꢀ
tion of the reactant mixture corresponding to
C H
6
5
CH3
τ
(I)
P
>
CN
NH3
=
+
3H O,
2
(PNH3 : PoX, 1.24%; О – 7.80%, NH3, 61.91 mol %;
)
min
2
C H
6
5
CH3
and nitrogen, the rest. As the temperature increases,
PETROLEUM CHEMISTRY Vol. 52
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2012

1
08
Table 2. Dependence of the product buildup rates upon PNH3
Wtot
BAGIRZADE
= 673 K,
Pii, kPa
0
PoX
0
O2
(T
τ
= 0.27 s,
P
= 1.33 kPa,
O2
P
= 8.37 kPa)
,
PNH kPa
3,
mmol/(g h)
PoX
PoTN
PPN
PPI
H O
2
1
3
8
.24
.08
.29
1.69
1.69
1.69
1.70
1.72
1.71
1.70
1.69
0.61
0.61
0.61
0.61
0.60
0.61
0.61
0.61
0.216
0.234
0.249
0.262
0.277
0.273
0.270
0.274
0.21
0.30
0.36
0.38
0.42
0.42
0.42
0.41
0.116
0.068
0.035
0.020
–
4.14
4.98
5.58
5.85
6.14
6.16
6.16
6.18
3.56
3.54
3.54
3.52
3.56
3.53
3.52
3.49
1
1
3
4
5
4.89
8.81
2.10
5.38
8.67
–
–
–
Wi, mmol/(g h)
P
kPa
NH3
,
PoX
exp
PPN
PPI
PBN
CO2
calc
calc
exp
calc
exp
calc
exp
calc
exp
1
.24
.08
.29
0.51
0.55
0.59
0.62
0.66
0.65
0.64
0.65
0.54
0.60
0.64
0.64
0.63
0.65
0.66
0.65
0.50
0.70
0.85
0.91
0.99
0.99
0.98
0.96
0.51
0.71
0.85
0.92
1.01
1.00
0.99
1.00
0.276
0.161
0.082
0.047
–
0.283
0.156
0.075
0.045
–
0.013
0.013
–
0.013
0.013
–
0.394
0.260
0.165
0.125
0.075
0.075
0.075
0.075
0.372
0.244
0.153
0.122
0.074
0.075
0.075
0.075
3
8
1
4.89
8.81
2.10
5.38
8.67
–
–
1
3
4
5
–
–
–
–
–
–
–
–
–
–
–
–
–
–
the PBN and СО2 buildup rates increase and the PPI
buildup rate drops. At 693 K or a higher temperature,
PPI was not found among the products. The absence
of PPI from the products of the reaction at short conꢀ
CN
+
2H O
2
C6H5
CH
N
3
(III)
tact times (
directly from PoX at high ammonia concentrations. As
increases, the selectivity ( i is the ratio of the buildup
rate of the th compound Wi to the overall PoX conꢀ
τ) suggests that PPI cannot be produced
CO
CO
NH + NH
3
τ
S
C H
6
5
i
sumption rate Wtot) of conversion into PPI and PBN
increases at any of the temperatures examined. The
To reveal the PBN formation routes, were carried
dependence of the СО2 selectivity on
τ
is less proꢀ out experiments on the oxidation and ammoxidation
nounced. This implies that СО2 is produced immediꢀ of PPI at 693 K and
τ
= 1.23 s. In the absence of NH3
,
ately from PoX, unlike PPI and PBN which are
formed via the consecutive mechanism.
only CО2 and PBN were observed to have a molar ratio
of 2.3 in the products along with PPI and O . When
2
Special experiments showed that PPI is stable until NH3 is added, PPN appears in the products.
7
23 K under the ammoxidation conditions. However,
An increase in PNH3 from 4.2 to 18.3 kPa reduces the
an Н О admixture to О2 and NH3 leads to the converꢀ
sion of PPN into PPI and PBN. The gaseous products
were found to contain СО2. The degree of conversion
2
СО2 : PBN ratio from 1.6 to 1. The same СО2 : FBN
ratio was observed in the case of PPN hydrolysis.
Knowing of the aforementioned thermal stability of
(α) in this case is affected by both NH3 and Н О conꢀ
2
centrations. Evidently, the formation of PPI involves PPN, we may assume that the main PBN formation
the hydrolysis of PPN:
route is the decarboxylation of PPI:
PETROLEUM CHEMISTRY Vol. 52
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2012

PREPARATION OF 4ꢀPHENYLPHTHALONITRILE
109
Table 3. Dependence of the product buildup rates upon
a)
τ
Pi, kPa
Wtot
mmol/(g h)
,
τ
, s
PoX
PoTN
PPN
PPI
NH3
H O
2
633 K
673 K
713 K
1
1
1
0
0
0
0
0
0
0
.87
.55
.23
.91
.75
.59
.43
.27
.20
.13
0.35
0.40
0.46
0.54
0.58
0.63
0.69
0.74
0.79
0.82
0.212
0.266
0.351
0.468
0.558
0.656
0.774
0.926
0.988
1.063
0.196
0.223
0.250
0.269
0.272
0.275
0.245
0.192
0.159
0.119
0.676
0.626
0.552
0.447
0.371
0.282
0.204
0.112
0.083
0.049
0.117
0.090
0.056
0.030
0.016
0.007
0.004
–
60.05
60.15
60.31
60.53
60.69
60.88
61.07
61.31
61.40
61.51
5.30
4.96
4.44
3.73
3.21
2.63
2.03
1.28
1.01
0.67
–
–
1.87
1.55
1.23
0.91
0.75
0.59
0.43
0.27
0.20
0.13
0.41
0.49
0.60
0.78
0.90
1.08
1.32
1.65
1.77
2.02
0.037
0.052
0.074
0.128
0.187
0.245
0.353
0.546
0.679
0.813
0.041
0.056
0.077
0.121
0.158
0.187
0.220
0.254
0.241
0.211
1.03
1.00
0.98
0.90
0.82
0.74
0.62
0.41
0.29
0.19
0.035
0.031
0.023
0.014
0.008
0.004
–
59.56
59.60
59.64
59.77
59.91
60.04
60.26
60.66
60.91
61.13
6.96
6.84
6.67
6.25
5.81
5.39
4.67
3.40
2.63
1.92
–
–
–
1.23
0.91
0.59
0.27
0.20
0.13
0.09
0.64
0.85
1.28
2.50
3.09
3.83
4.39
0.014
0.021
0.055
0.191
0.267
0.435
0.593
0.012
0.018
0.047
0.139
0.168
0.217
0.230
0.942
0.955
0.932
0.770
0.684
0.494
0.354
–
–
–
–
–
–
–
59.68
59.67
59.73
60.01
60.16
60.51
60.79
7.10
7.08
6.86
5.86
5.33
4.19
3.22
b)
Wi, mmol/(g h)
PoX
PoTN
PPN
exp
PPI
CO2
τ
, s
exp
calc
exp
calc
calc
exp
calc
exp
calc
633 K
1.87
1.55
1.23
0.91
0.75
0.59
0.43
0.27
0.20
0.13
0.067
0.092
0.130
0.190
0.233
0.300
0.366
0.460
0.510
0.570
0.068
0.091
0.131
0.188
0.233
0.279
0.350
0.448
0.496
0.558
0.232
0.259
0.288
0.315
0.318
0.307
0.306
0.267
0.267
0.236
0.233
0.256
0.279
0.301
0.309
0.317
0.305
0.275
0.250
0.217
0.0400
0.0370
0.0290
0.0210
0.0140
0.0075
0.0060
–
0.0400
0.0360
0.0300
0.0190
0.0140
0.0074
0.0060
–
0.005
0.005
0.005
0.005
0.005
0.005
–
–
–
–
0.005
0.005
0.005
0.005
0.005
0.005
–
–
–
–
0.006
0.007
0.008
0.010
0.010
0.011
0.012
0.013
0.013
0.014
0.006
0.007
0.008
0.010
0.010
0.011
0.012
0.013
0.014
0.014
–
–
–
–
PETROLEUM CHEMISTRY Vol. 52
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110
BAGIRZADE
Table 3. (Contd.)
Wi, mmol/(g h)
PoX
PoTN
PPN
exp
PPI
CO2
τ
, s
exp
calc
exp
calc
calc
exp
calc
exp
calc
673 K
1.87
1.55
1.23
0.91
0.75
0.59
0.43
0.27
0.20
0.13
0.014
0.023
0.040
0.085
0.140
0.200
0.330
0.610
0.770
1.010
0.014
0.024
0.039
0.086
0.150
0.210
0.360
0.600
0.800
1.030
0.350
0.420
0.505
0.630
0.700
0.800
0.930
0.970
0.930
0.920
0.360
0.430
0.506
0.640
0.740
0.810
0.880
0.960
0.930
0.880
0.0120
0.0130
0.0120
0.0100
0.0067
0.0040
–
0.0138
0.0120
0.0120
0.0093
0.0066
0.0040
–
0.0150
0.0170
0.0170
0.0165
0.0160
0.0140
–
0.0168
0.0170
0.0170
0.0166
0.0160
0.0150
–
0.018
0.022
0.026
0.034
0.039
0.047
0.057
0.071
0.076
0.086
0.018
0.022
0.026
0.034
0.042
0.048
0.057
0.071
0.079
0.087
–
–
–
–
–
–
–
–
–
–
–
–
713 K
1.23
0.91
0.59
0.27
0.20
0.13
0.09
0.006
0.013
0.051
0.333
0.536
1.041
1.571
0.006
0.013
0.051
0.325
0.564
1.042
1.603
0.494
0.669
1.011
1.844
2.186
2.367
2.421
0.556
0.682
1.106
1.908
2.099
2.388
2.460
–
–
–
–
–
–
–
–
–
–
–
–
–
–
0.080
0.090
0.100
0.095
0.086
0.074
–
0.082
0.089
0.100
0.095
0.086
0.074
–
0.060
0.078
0.117
0.228
0.281
0.348
0.398
0.062
0.071
0.124
0.230
0.273
0.348
0.406
Reaction (V) is inhibited by PoX. Thus, the PBN
formation rates during the ammoxidation of PoTN
(τ = 0.75 s and PPoTN, PO2, and PNH3 are 1.52, 9.55,
CO
NH
CO
C H
6
5
and 53.03 kPa, respectively) at 653 and 673 K are 0.016
and 0.032 mmol/(g h), respectively. Introduction of
PoX to the reactant mixture up to PPoX = 3 kPa reduces
the rate of PBN buildup at these temperatures to 0.01
and 0.02 mmol/(g h). Therefore, the rate of reaction
CN
+ CO2
(IV)
.
=
C H
6
5
From the experimental data (Tables 2, 3), it follows (V) was described by the following equation:
that the rate of this reaction at τ ≤
by the zeroꢀorder equation
1
can be described
P
PoTN
W5
=
k ꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀ.
(3)
5
1
+ aP
PoX
W4
= k4
(2)
Variation in
; presumably, this below (PNH3
τ
in the range of NH3 partial pressures
(Table 4) showed that the formation
An additional PBN formation route seems to exist
at higher temperatures and longer
τ
)
min
is the oxidative degradation of PoTN:
of PPI occurs at any value of
α
for PoX, probably,
because of its formation directly from PoX in this case:
CN
+
1.5O2
CH3
C H
6
5
CH3
+ 3O + NH3
2
C H
6
5
CH3
CN
+ CO + H O
2
(VI)
=
.
(V)
2
CO
CO
=
C H
NH + 4H O.
2
6
5
C H
6
5
PETROLEUM CHEMISTRY Vol. 52
No. 2
2012

PREPARATION OF 4ꢀPHENYLPHTHALONITRILE
111
0
PoX
Table 4. Dependence of the product buildup rates upon
τ
in the region of PNH3
<
(PNH3
)
(633 K,
P
= 1.33 kPa,
min
0
O2
0
P
= 8.37 kPa,
P
= 3.98 kPa)
NH3
a)
Pi, kPa
Wtot
mmol/(g h)
,
τ
, s
PoX
PoTN
PPN
PPI
O2
NH3
H O
2
1.03
0.75
0.62
0.43
0.32
0.27
0.20
0.14
0.53
0.60
0.64
0.71
0.75
0.77
0.79
0.82
0.48
0.62
0.71
0.86
0.96
1.00
1.08
1.14
0.290
0.280
0.279
0.237
0.200
0.184
0.154
0.122
0.20
0.19
0.18
0.15
0.12
0.10
0.07
0.05
0.311
0.189
0.126
0.058
0.031
0.020
0.010
0.005
5.46
6.03
6.37
6.88
7.23
7.38
7.63
7.83
2.99
3.13
3.23
3.39
3.52
3.58
3.68
3.76
3.68
3.06
2.67
2.04
1.58
1.38
1.03
0.74
b)
Wi, mmol/(g h)
Wtot
mmol/(g h)
,
τ
, s
PoTN
PPN
PPI
CO2
exp
calc
exp
calc
exp
calc
exp
calc
1.03
0.75
0.62
0.43
0.32
0.27
0.20
0.14
0.53
0.60
0.64
0.71
0.75
0.77
0.79
0.82
0.18
0.24
0.29
0.36
0.41
0.44
0.49
0.54
0.17
0.24
0.28
0.36
0.42
0.45
0.50
0.54
0.124
0.160
0.180
0.220
0.240
0.240
0.220
0.210
0.122
0.160
0.190
0.210
0.220
0.220
0.220
0.200
0.193
0.161
0.130
0.087
0.063
0.048
0.032
0.024
0.208
0.165
0.140
0.093
0.060
0.048
0.030
0.023
0.033
0.038
0.040
0.044
0.046
0.048
0.049
0.050
0.030
0.035
0.038
0.042
0.045
0.046
0.048
0.050
From the data in Tables 3 and 4, it follows that the to follows the halfꢀorder rate law in PoX and the prodꢀ
selectivity for СО2 does not depend on ; this suggests uct distribution depends on the ratio between NH3 and
τ
a parallel route of its formation at a low NH3 concenꢀ
О concentrations as shown in Tables 2 and 4, the rates
of reactions (I), (VI), and (VIII) were described by the
following equations
2
tration as well. However, the CO selectivity substanꢀ
2
tially increases at PNH3
<
(PNH3
)
, thereby indicatꢀ
min
ing the presence of at least two СО2 formation routes:
0.5
k P
P
PoTN NH
3
1
W1
=
ꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀ ,
(5)
(6)
(7)
P
+ bP
O
2
NH
3
CH3
0.5
k P
bP β
O
2
1
PoTN
(VII), (VIII)
W6
=
ꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀ ꢀꢀ ,
C H
6
5
CH3
P
+ bP
O
2
NH
3
+
17.5O = 14CO + 7H O.
2 2 2
0
.5
k P
bP (1 – β)
O
2
1
PoTN
The rate of the reaction by one of these routes does
not depend on the concentration of NH3 and is
described by the following equation:
W8
=
ꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀ ꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀ ꢀ,
P
+ bP
O
2
NH
3
0
.5
W7
=
k7P
PoX
.
(4)
The rate of reaction (VIII) is dependent on the from its common intermediate with СО
NH3 concentration. Since Wtot W1 W6 W7 W8 ammonia concentrations. Taking into account the
does not depend on the NH3 concentration (Table 2) similarity of reactions (I) and (II), we expressed the
where
β
is the proportion of PoX converted into PPI
at low
2
=
+
+
+
PETROLEUM CHEMISTRY Vol. 52
No. 2
2012

112
BAGIRZADE
rate of the latter reaction by the same law as given by
Eq. (5):
Extrapolating Eq. (9) to all of the temperatures
examined and taking into account the stoichiometry
of reaction (III), we find the following rate equation
for the 4ꢀphenylphthalimide ammonolysis reaction:
0
.5
k P
P
PoTN NH
3
2
W2
=
ꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀ ,
+ bP
(8)
P
NH
O
2
3
P
PPI
W–3
=
k ꢀꢀꢀꢀꢀꢀꢀꢀ.
(10)
–3
The PPI buildup rate is equal to the difference of
the rates of reaction (III) in the forward and reverse
directions minus the rate of reaction (IV). It turned
out that the PPI hydrolysis rate obeys the following
equation:
P
H O
2
The constants of Eqs. (2)–(10) describing the conꢀ
version of PoX in accordance with the scheme given
below were selected by fitting on a Pentium IV perꢀ
sonal computer, minimizing the sum of the squared
(9) relative deviations of the calculated buildup rates from
the experimental rates for all of the products:
P
P
2
PPN H O
W3
=
k ꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀ.
3
P
NH
3
CH3
CH3
1
CN
2
CN
CN
CH3
C H
6
C H
6
C H
6
5
5
5
5
7
8
6
3
CO2
CN
CO
CO
4
NH
C H
C H
6
6
5
5
It was found that
k1 = 107 exp (–91319.8/RT);
k3 = 10–12.18 exp (149071.3/RT); k–3 = 10–3.57 exp(45863.5/RT);
k4 = 104.16 exp (–78447.8/RT); k5 = 1011.05 exp (–135050.8/RT);
= 10–9.88 exp (164046.05/RT); = 107.47 exp (–107987.36/RT);
k7 = 1012.17 exp (–169722.2/RT).
.42
k2 = 107.93 exp (–98439.9/RT);
a
b
The activation energy is given in J/mol. The value
is taken to be 0.37 at any temperature.
The values of the reaction rates given in Table 1
Society “Innovative Chemical Technologies and Biotechꢀ
nologies of Materials and Products” (RKhTU im.
D. I. Mendeleeva, Moscow, 2010), p. 197 [in Russian].
. R. G. Rizaev, V. E. Sheinin, G. A. Bagirzade, et al., in
Abstracts of Papers of the First Baku International Conꢀ
ference on Petroleum Chemistry (Baku, 1994), p. 34 [in
Russian].
. R. G. Rizaev, V. E. Sheinin, and F. D. Guseinov, in Proꢀ
ceedings of the Second AllꢀUnion Conference on Kinetics
of Catalytic Reactions “Kineticsꢀ2” (Institut Kataliza SO
AN SSSR, Novosibirsk, 1975), Vol. 1, p. 105 [in Rusꢀ
sian].
. R. G. Rizaev, V. E. Sheinin, and A. ogly Allakhkulu,
et al., Kinet. Katal. 26, 345 (1985).
. R. G. Rizaev, V. E. Sheinin, and A. ogly Allakhkulu,
et al., Kinet. Katal. 27, 339 (1986).
. R. G. Rizaev, E. A. Mamedov, V. E. Sheinin, et al.,
Neftekhimiya 26, 654 (1986).
. G. A. Bagirzade, Zh. Org. Khim. 80, 1360 (2010).
. G. A. Bagirzade, Zh. Org. Khim. 80, 1460 (2010).
of
β
2
were calculated with the use of the constants found.
The data in this table show that the maximum deviaꢀ
tions of the calculated from the experimental values of
WPoX and rPoTN are 7.2 and 9.7%, respectively.
Tables 2–4 present the values for the product buildup
rates and the PoX consumption rate calculated by
Eqs. (2)–(10) with the use of the constants found for
these equations. It is seen from these tables that the
maximum discrepancies between the experimental
and calculated values of Wi for PoTN, PPN, PPI, and
CO2 are 8.3, 11.2, 13.0, 10.7, and 9.1%, respectively.
The mechanism of the formation of the PoX
ammoxidation products consistent with the observed
kinetic features will be discussed in the forthcoming
paper.
3
4
5
6
7
8
9
REFERENCES
. S. L. Kiperman, Introduction to Kinetics of Heterogeꢀ
neous Catalytic Reactions (Nauka, Moscow, 1964) [in
Russian].
1
. G. A. Bagirzade, in Abstracts of Papers of II Internaꢀ
tional Conference of the Mendeleev Russian Chemical
PETROLEUM CHEMISTRY Vol. 52
No. 2
2012