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Preparation of low molecular weight aliphatic alcohols by direct hydration of olefins on zeolites
0031.-6458/79/0901-0194507.50/0
Petrol. Chem. U.S.S.R. Vol. 19, pp. 194-197. © Pergamon Press Ltd. 1980. Printed in Poland.
PREPARATION OF LOW MOLECULAR WEIGHT ALIPHATIC ALCOHOLS BY DIRECT HYDRATION OF OLEFINS ON ZEOLITES* A. M TSYBULEVSKII, L. A. NOV[KOVA, V. A. KOYl)RAT'VEV, L. N. TOLKACIIEVA, YE. S. MOI~TIKOV, YE. M. BRESHCHE~KO and X~. M. M1]qACHEV All-Union Scientific Resea.rch t~nd Design Institute for the Treatment of Gt~s N. D. Zelinskii Institute of Organic Chemistry, U.S.S.R. Academy of Sciences
PRODUCTIOn" Of alcohols b y h y d r a t i o n of olefins is one t)f the most i m p o r t a n t trends in m o d e r n petrochemical industry. E x i s t i n g processes of h y d r a t i o n are characterized b y complex technology, involve corrosion of a p p a r a t u s a n d a considerable p r o p o r t i o n of waste w a t e r a n d harmful discharge. Processes have recently been proposed [ 1---2] w i t h o u t these shortcomings, using zeolites as catalysts. F u r t h e r m o r e , zeolites m a k e it possible to control a c t i v i t y and selec.t i v i t y b y ion exchange and a l u m i n i u m removal. This p a p e r describes some of the special features of olefial k y d r a t i o n on zeolites of different structures a n d chemical composition. EXPERIMENTAL
S y n t h e t i c zeolites w i t h Ca, R E E (rare e a r t h elements), Cr and Ni cations were used as catalysts. D e a l u m i n a t i o n of zeolite (DALNZ samples) was carried out by t r e a t m e n t with a 2N solution of HC1 a t 80 ° H y d r a t i o n of ethylene, p r o p y l e n e a n d isobutylene was carried out in a continuous a p p a r a t u s [3] at a space velocity for olefins of 500-3000 hr -~, a pressure of 5-16 MPa, a molar ratio of w a t e r : oleFm of I-9 : I and a temperature of 200-350 °. With heterogeneous catalysts h y d r a t i o n is n o r m a l l y accompanied b y a concurrent reaction of oligomerization of olefms. Therefbre, in a d d i t i o n to deternlining olefin conversion, process selectixqty was evaluated. Kinetics of h y d r a t i o n of p r o p y l e n e were e x a m i n e d in a continuous apparatus ill a 25 cm s reactor with a s t a t i o n a r y catalyst layer. At increased pressures and considerable dilutions pcocess rate is described by the e q u a t i o n [4]:
'/~' :=k(a-:,') d/
The stability of catalyst operation was studied u n d e r the ~bllowing colt* Neftekhimiy~ 19, No. 5, 771-774, 1979. 194
Low molecular weight a!iphatic alcohols
195
ditions: 14 MPa, 275 °, space v e l o c i t y for p r o p y l e n e 1800 hr -1, ethylene, 2500 hr -1, w a t e r : olefin ratio being 2.5 : 1. RESULTS
Results of determining c a t a l y s t a c t i v i t y a n d selectivity in h y d r a t i o n of ethylene, p r o p y l e n e a n d isobutylene are shown in Table 1. During the interaction of e t h y l e n e w i t h w a t e r on a c a t a l y s t containing Ca, R E E a n d Cr cations ( C a R E E CrZ) a t the same time a considerable a m o u n t of sec-butyl alcohol is f o r m e d p r e s u m a b l y via the stage of dimerization of ethylene. Zeolite samples w i t h Ca, R E E , Ni (Ca, R E E NiZ) cations do n o t h a v e a bifunctional action a n d the process is c o m p l e t e d a t the stage of dimerization. C a t a l y s t s based on zeolites of H f o r m containing Cr +3 (CrNZ), as regards indices, a p p r o x i m a t e to p h o s p h a t e catalysts used in industry. T h e a d d i t i o n of Ni +~ cations w i t h Cr +a to zeolite of H form increases cat a l y s t a c t i v i t y in the c o n c u r r e n t reaction of oligomerization a n d accordingly, reduces its a c t i v i t y a n d selectivity in the m a i n reaction. D e a l u m i n a t i o n of zeolite of H f o r m s o m e w h a t increases a c t i v i t y , b u t reduces selectivity b y 4 - 1 0 % . T h e high selectivity of CrNZ catalysts should be noted; practically n o oligomer f o r m a t i o n is observed on these catalysts in the pressure a n d temp e r a t u r e range studied. TABLE
1. R E S U L T S
OF
TESTING ZEOLITE
CATALYST SAMPLES
IN
OLEFIN
]~II)RATION
(SPACE VELOCITY FOR OLEFINS 2 0 0 0 h r -1
Olefm :
Catalyst sample
T, °C
Pressure, MPa
Ethylene
CaNZ CaREENiZ CaREECrZ CrNZ CrNLNZ CrNDALZ
350 350 350 300 300 300
I0 7.5 9 12 12 12
1:3 1:6 1:4 1:1 1:1 1:1
Propylone
CaREECrZ CrNZ CrNiNZ Cr~TI)ALZ
260 285 285 285
9 10 10 10
1:6
11.0
1:4
17.8 18.2 20-8
CaNZ CaREENiZ CaREECrZ CrNZ CrNiNZ CrNDALZ
270 250 200 250 25O 250
I0 10 7 10 10 10
Initial olefin
Butylene
Olefin 1 conversion, Selectivity, ~o % mole/mole : water,
1 : 4
1:4 1:8
3"0 1-0 5.3 9.6 9-2 9.8
1:8
7'6 8.1 11.5
1 : 6
18.0
1 : 6
18.2 21.2
1 : 10
1:6
I
100 99 99 100 87 90 100 100 97 95 100 100 100 100 95 96
T h e effect o f pressure a n d t e m p e r a t u r e on process indices was skown,using p r o p y l e n e h y d r a t i o n o n a CrNZ sample (Fig. 1). An increase in conversion
A, M. TSYBULEVSKII et el.
196
~tog (Ill-x)] ~ 10 2
..-k ¢ §
ra
7/.7
I0
I2 14 IG Pressure )HPa
Jd
L/
FIe. 1
1.
18
0
5
I0 15 20 Contacf f/me, sec FIe. 2
Fie. 1. Dependence of propylene conversion on temperature and pressure. Catalyst CrNZ; T, °C; 1-- 240; 2-- 240; 3, 3'-- 265; 1-3--experimentai results; 3' --thermodynamic results. Fie. 2. Dependence of log ( l /1-- x) -- contact time during propylene hydration on a CrNZ catalyst. T, °C; 1--483; 2--513; 3--538 and 4--553. w i t h a n increase in pressure m a y p r o b a b l y be explained b y a n increase in diffusion in zeolites. On all k n o w n catalysts a n increase in pressure n o r m a l l y reduces selectivity considerably as a result of a higher rate of oligomerization. The possibility of achieving on a CrNZ c a t a l y s t a conversion of propylene to
mole % 25
l
? 0
#0 3#O 830 Duratlbn of operatlbn of the catalyst,hr
FIG. 3. Stability of the operation of a CrNZ catalyst over a period of time: 1--hydra. tion of propyleno; 2"hydration of ethylene.
Low molecular weight aliphatie alcohols
197
alcohol at 265 ° and 15 MPa, the conversion being close to equilibrium without a reduction of selectivity, is therefore of undoubted interest. Carrying out the process at different space velocities and water : olefin ratios suggests t h a t hydration of propylene on Crl~Z is a first order reaction. The dependence of log ( I / l - - x ) on contact time is shown in Fig. 2. Activation energy was about 58.8 kJ/mole on all zeolite catalysts studied. According to Mace and Bonila [5] the activation energy of hydration of propylene on a tungsten silicate catalyst is 126 kJ/mole. Hydration on zeolite probably takes place in the intra-dii~sion range. This is confirmed, in particular, b y an increase in activation energy from 54.6 to 71.4 kJ/mole on increasing the pressure of the process from 9 to 14 MPa (Table 2). T~SLE 2. APPARENTACTIVATIONENERGYAND I~J~E-~.~PONENTIAL]FACTORIN PROPY~LENE HYDRATION ON Z E O ~ CATALYSTS
Catalysts
~NiNZ
Prossul~,
MPa 9 14
Activation energy, kJ/mole 54.6 71.4
Proexpo nent
suro~ MPa
Activa. tion energy, k J/mole
9 14
42.8 73"8
Pros -
Catalysts
3.5 × 108 CrNDALZ 1.4 × 1051
P~. exponent
i
l . 2 × 10 ~ 10 ~
H
3.0 ×
Results in Fig. 3 demonstrate the high stability of CrNZ catalysts during hydration of both ethylene and propylene. After 380 hr operation catalyst activity decreased by 1.5-5% and oxidizing recovery of the catalyst with air a t 500-550 ° resulted in complete reduction of the initial activity. Results suggest t h a t it is promising and advisable to develop a hydration process for olefins using catalysts based on zeolites. A study of hydration of C2-C~ olefins on zeolites with Ca, Ni, Cr and R E E cations therefore indicates t h a t more satisfactory results are obtained using a chromo-exchange form of N-zeolite. Ethylene conversion on a CrNZ catalyst was 9 . 6 ~ , propylene conversion, 17.8°/o with 100~/o selectivity. The activity of zeolite catalysts (CrNZ) increases considerably on increasing pressure. The stable operation of the CrNZ catalyst continued for 380 hr. REFERENCES
1. U.S.A. Patent 3784614, 1974 2, Patent of the German Democratic Republic 113344, 1974 3. K h .
M. M I N A C H E V ,
Y e . S. M O R T I K O V ,
A. A. MASLOBOYEV,
I. F. K O N O N O V
and L. N. TOLK&CHEVA, Neftekhimiya 16, 16, 1976 4. G. M. PANCHENKOV and V. P. LEBEDEV, Khimieheskaya kinetika i kataliz (Chemical Kinetics and Catalysts). Izd. MGU, 1961 5. C. V. MACE and C. F. BONILA, Chem. Engng. Progr. 50, 385, 1954
Petrol. Chem. U.S.S.R. Vol. 19, pp. 194-197. © Pergamon Press Ltd. 1980. Printed in Poland.
PREPARATION OF LOW MOLECULAR WEIGHT ALIPHATIC ALCOHOLS BY DIRECT HYDRATION OF OLEFINS ON ZEOLITES* A. M TSYBULEVSKII, L. A. NOV[KOVA, V. A. KOYl)RAT'VEV, L. N. TOLKACIIEVA, YE. S. MOI~TIKOV, YE. M. BRESHCHE~KO and X~. M. M1]qACHEV All-Union Scientific Resea.rch t~nd Design Institute for the Treatment of Gt~s N. D. Zelinskii Institute of Organic Chemistry, U.S.S.R. Academy of Sciences
PRODUCTIOn" Of alcohols b y h y d r a t i o n of olefins is one t)f the most i m p o r t a n t trends in m o d e r n petrochemical industry. E x i s t i n g processes of h y d r a t i o n are characterized b y complex technology, involve corrosion of a p p a r a t u s a n d a considerable p r o p o r t i o n of waste w a t e r a n d harmful discharge. Processes have recently been proposed [ 1---2] w i t h o u t these shortcomings, using zeolites as catalysts. F u r t h e r m o r e , zeolites m a k e it possible to control a c t i v i t y and selec.t i v i t y b y ion exchange and a l u m i n i u m removal. This p a p e r describes some of the special features of olefial k y d r a t i o n on zeolites of different structures a n d chemical composition. EXPERIMENTAL
S y n t h e t i c zeolites w i t h Ca, R E E (rare e a r t h elements), Cr and Ni cations were used as catalysts. D e a l u m i n a t i o n of zeolite (DALNZ samples) was carried out by t r e a t m e n t with a 2N solution of HC1 a t 80 ° H y d r a t i o n of ethylene, p r o p y l e n e a n d isobutylene was carried out in a continuous a p p a r a t u s [3] at a space velocity for olefins of 500-3000 hr -~, a pressure of 5-16 MPa, a molar ratio of w a t e r : oleFm of I-9 : I and a temperature of 200-350 °. With heterogeneous catalysts h y d r a t i o n is n o r m a l l y accompanied b y a concurrent reaction of oligomerization of olefms. Therefbre, in a d d i t i o n to deternlining olefin conversion, process selectixqty was evaluated. Kinetics of h y d r a t i o n of p r o p y l e n e were e x a m i n e d in a continuous apparatus ill a 25 cm s reactor with a s t a t i o n a r y catalyst layer. At increased pressures and considerable dilutions pcocess rate is described by the e q u a t i o n [4]:
'/~' :=k(a-:,') d/
The stability of catalyst operation was studied u n d e r the ~bllowing colt* Neftekhimiy~ 19, No. 5, 771-774, 1979. 194
Low molecular weight a!iphatic alcohols
195
ditions: 14 MPa, 275 °, space v e l o c i t y for p r o p y l e n e 1800 hr -1, ethylene, 2500 hr -1, w a t e r : olefin ratio being 2.5 : 1. RESULTS
Results of determining c a t a l y s t a c t i v i t y a n d selectivity in h y d r a t i o n of ethylene, p r o p y l e n e a n d isobutylene are shown in Table 1. During the interaction of e t h y l e n e w i t h w a t e r on a c a t a l y s t containing Ca, R E E a n d Cr cations ( C a R E E CrZ) a t the same time a considerable a m o u n t of sec-butyl alcohol is f o r m e d p r e s u m a b l y via the stage of dimerization of ethylene. Zeolite samples w i t h Ca, R E E , Ni (Ca, R E E NiZ) cations do n o t h a v e a bifunctional action a n d the process is c o m p l e t e d a t the stage of dimerization. C a t a l y s t s based on zeolites of H f o r m containing Cr +3 (CrNZ), as regards indices, a p p r o x i m a t e to p h o s p h a t e catalysts used in industry. T h e a d d i t i o n of Ni +~ cations w i t h Cr +a to zeolite of H form increases cat a l y s t a c t i v i t y in the c o n c u r r e n t reaction of oligomerization a n d accordingly, reduces its a c t i v i t y a n d selectivity in the m a i n reaction. D e a l u m i n a t i o n of zeolite of H f o r m s o m e w h a t increases a c t i v i t y , b u t reduces selectivity b y 4 - 1 0 % . T h e high selectivity of CrNZ catalysts should be noted; practically n o oligomer f o r m a t i o n is observed on these catalysts in the pressure a n d temp e r a t u r e range studied. TABLE
1. R E S U L T S
OF
TESTING ZEOLITE
CATALYST SAMPLES
IN
OLEFIN
]~II)RATION
(SPACE VELOCITY FOR OLEFINS 2 0 0 0 h r -1
Olefm :
Catalyst sample
T, °C
Pressure, MPa
Ethylene
CaNZ CaREENiZ CaREECrZ CrNZ CrNLNZ CrNDALZ
350 350 350 300 300 300
I0 7.5 9 12 12 12
1:3 1:6 1:4 1:1 1:1 1:1
Propylone
CaREECrZ CrNZ CrNiNZ Cr~TI)ALZ
260 285 285 285
9 10 10 10
1:6
11.0
1:4
17.8 18.2 20-8
CaNZ CaREENiZ CaREECrZ CrNZ CrNiNZ CrNDALZ
270 250 200 250 25O 250
I0 10 7 10 10 10
Initial olefin
Butylene
Olefin 1 conversion, Selectivity, ~o % mole/mole : water,
1 : 4
1:4 1:8
3"0 1-0 5.3 9.6 9-2 9.8
1:8
7'6 8.1 11.5
1 : 6
18.0
1 : 6
18.2 21.2
1 : 10
1:6
I
100 99 99 100 87 90 100 100 97 95 100 100 100 100 95 96
T h e effect o f pressure a n d t e m p e r a t u r e on process indices was skown,using p r o p y l e n e h y d r a t i o n o n a CrNZ sample (Fig. 1). An increase in conversion
A, M. TSYBULEVSKII et el.
196
~tog (Ill-x)] ~ 10 2
..-k ¢ §
ra
7/.7
I0
I2 14 IG Pressure )HPa
Jd
L/
FIe. 1
1.
18
0
5
I0 15 20 Contacf f/me, sec FIe. 2
Fie. 1. Dependence of propylene conversion on temperature and pressure. Catalyst CrNZ; T, °C; 1-- 240; 2-- 240; 3, 3'-- 265; 1-3--experimentai results; 3' --thermodynamic results. Fie. 2. Dependence of log ( l /1-- x) -- contact time during propylene hydration on a CrNZ catalyst. T, °C; 1--483; 2--513; 3--538 and 4--553. w i t h a n increase in pressure m a y p r o b a b l y be explained b y a n increase in diffusion in zeolites. On all k n o w n catalysts a n increase in pressure n o r m a l l y reduces selectivity considerably as a result of a higher rate of oligomerization. The possibility of achieving on a CrNZ c a t a l y s t a conversion of propylene to
mole % 25
l
? 0
#0 3#O 830 Duratlbn of operatlbn of the catalyst,hr
FIG. 3. Stability of the operation of a CrNZ catalyst over a period of time: 1--hydra. tion of propyleno; 2"hydration of ethylene.
Low molecular weight aliphatie alcohols
197
alcohol at 265 ° and 15 MPa, the conversion being close to equilibrium without a reduction of selectivity, is therefore of undoubted interest. Carrying out the process at different space velocities and water : olefin ratios suggests t h a t hydration of propylene on Crl~Z is a first order reaction. The dependence of log ( I / l - - x ) on contact time is shown in Fig. 2. Activation energy was about 58.8 kJ/mole on all zeolite catalysts studied. According to Mace and Bonila [5] the activation energy of hydration of propylene on a tungsten silicate catalyst is 126 kJ/mole. Hydration on zeolite probably takes place in the intra-dii~sion range. This is confirmed, in particular, b y an increase in activation energy from 54.6 to 71.4 kJ/mole on increasing the pressure of the process from 9 to 14 MPa (Table 2). T~SLE 2. APPARENTACTIVATIONENERGYAND I~J~E-~.~PONENTIAL]FACTORIN PROPY~LENE HYDRATION ON Z E O ~ CATALYSTS
Catalysts
~NiNZ
Prossul~,
MPa 9 14
Activation energy, kJ/mole 54.6 71.4
Proexpo nent
suro~ MPa
Activa. tion energy, k J/mole
9 14
42.8 73"8
Pros -
Catalysts
3.5 × 108 CrNDALZ 1.4 × 1051
P~. exponent
i
l . 2 × 10 ~ 10 ~
H
3.0 ×
Results in Fig. 3 demonstrate the high stability of CrNZ catalysts during hydration of both ethylene and propylene. After 380 hr operation catalyst activity decreased by 1.5-5% and oxidizing recovery of the catalyst with air a t 500-550 ° resulted in complete reduction of the initial activity. Results suggest t h a t it is promising and advisable to develop a hydration process for olefins using catalysts based on zeolites. A study of hydration of C2-C~ olefins on zeolites with Ca, Ni, Cr and R E E cations therefore indicates t h a t more satisfactory results are obtained using a chromo-exchange form of N-zeolite. Ethylene conversion on a CrNZ catalyst was 9 . 6 ~ , propylene conversion, 17.8°/o with 100~/o selectivity. The activity of zeolite catalysts (CrNZ) increases considerably on increasing pressure. The stable operation of the CrNZ catalyst continued for 380 hr. REFERENCES
1. U.S.A. Patent 3784614, 1974 2, Patent of the German Democratic Republic 113344, 1974 3. K h .
M. M I N A C H E V ,
Y e . S. M O R T I K O V ,
A. A. MASLOBOYEV,
I. F. K O N O N O V
and L. N. TOLK&CHEVA, Neftekhimiya 16, 16, 1976 4. G. M. PANCHENKOV and V. P. LEBEDEV, Khimieheskaya kinetika i kataliz (Chemical Kinetics and Catalysts). Izd. MGU, 1961 5. C. V. MACE and C. F. BONILA, Chem. Engng. Progr. 50, 385, 1954