Title of Invention	AN IMPROVED PROCESS FOR THE PREPARATION OF ACETO NITRILE FROM ETHANAL OVER VANADIUM-ALUMINO-PHOSPHATE CATALYSTS VIA AMMOXIDATION
Abstract	This invention relates to an improved process for the preparation of acetonitrile from ethanol over vanadium-alumino-phosphate catalysts which comprises passing a feed consisting of ethanol, ammonia, water and air over a Vanadium alumino phosphate (VAPO) catalyst at a temperature in the range of 300-450°C and weight hourly space velocity of liquid products in the range of 0.25 to 1.0 per hour and recovering the acetonitrile by conventional methods.

Title of Invention

AN IMPROVED PROCESS FOR THE PREPARATION OF ACETO NITRILE FROM ETHANAL OVER VANADIUM-ALUMINO-PHOSPHATE CATALYSTS VIA AMMOXIDATION

Abstract

This invention relates to an improved process for the preparation of acetonitrile from ethanol over vanadium-alumino-phosphate catalysts which comprises passing a feed consisting of ethanol, ammonia, water and air over a Vanadium alumino phosphate (VAPO) catalyst at a temperature in the range of 300-450°C and weight hourly space velocity of liquid products in the range of 0.25 to 1.0 per hour and recovering the acetonitrile by conventional methods.

Full Text	This invention relates to an improved process for the preparation of acetonitrile from ethanol over vanadium-alumino-phosphate catalysts. Particularly, this invention relates to an improved process for the preparation of acetonitrile from ethanol over vanadium-alumino-phosphate catalysts via amoxidation. According to the process of the present invention ethanol is reacted with ammonia and air in the presence of crystalline, porous vanadium-alumino phosphates (VAPO) catalyst. The process of preparing the above catalyst has been described and claimed in our copending application number 1459/Del/95. In the presently known process, acetonitrile can be produced from amination of acetic acid followed by dehydration or dehydrogenation of ethylamine. The conventional catalysts have been amorphous in nature and not shape selective catalysts. These catalysts have been employed in mostly fixed bed reactors. The following patents have discussed the preparation of nitriles of present interest, e.g. Eur.Pat; Appl. EP 37173 (1981), US Patent 4876348 (1989), US Patent 4603 207 (1986), Eur. Pat 0037123AI (1981), Brit. Patent 77746 (1957), Ger. (East)DDPatent 241903 (1985), US Patent 3981879 (1976), US Patent 2839535 (1958), US Patent 2510605 (1950), US Patent 2981879 (1976). In these inventions the yield of nitrite may or may not be highly selective. Particularly high-boiling products, CO, C02 were formed, due to the amorphous nature of the catalysts. The high-boiling products create environmental and disposal problems. The main object of the present invention is to develop selective and particularly provide an improved process for the preparation of nitriles employing porous active catalytic materials. The other objective of the present invention is to provide a process for the preparation of nitriles wherein the formation of CO, C02 and high boiling products are minimized. Accordingly, the present invention provides >90% yield of acetonitrile from ethanol by ammoxidation in one step with very high selectivity over VAPO catalysts at a temperature in the range of 350-450oC and weight hourly space velocity in the range of 0.25 to 1.0 per hour. Accordingly, the present invention provides an improved process for the preparation of acetonitrile from ethanol over vanadium-alumino-phosphate catalysts which comprises passing a feed consisting of ethanol, ammonia, water and air over a Vanadium alumino phosphate (VAPO) catalyst at a temperature in o the range of 300-450*JO and weight hourly space velocity of liquid products in the range of 0.25 to 1.0 per hour and recovering the acetonitrile by conventional methods. The molar ratio of ethanol and ammonia may be in the range of 1:1 to 1:20. The feed ratio of air may be in the range of 30 to 100 cc/hour. The catalysts are prepared in general in the following way AI2(S04)3, H3P04 with or without NaCI, V205 and tetrapropyl ammonium bromide (TPA) used as a template mixed in distilled water in the pH range of 7 to 12.0. The slurry is mixed for at least 2 hours at room temperature with constant stirring and the pH is adjusted by aqueous ammonia. The slurry was put into an autoclave for autoclaving under autogeneous pressure in the tempera' ure range of 150 to 220° C for 24 hrs to 80 hrs till complete crystallization was achieved. The mixture was filtered and wash with distilled water.The solid catalyst was dried in oven at l70° C over night. The organic template was removed by the activation of the catalyst at 500-550° C for 5-15 hrs. Then the calcined material was modified by promoters like Sb203 or oxides of the elements active as promoters in the respective reactions. Basically in aluminophosphate molecular sieves the Al : P atomi- ratio is 1:1. We have substituted P partially by V as dipgused and claimed in the copending patent number : 1459/Del/95. Al also may be substituted partially by V with the corresponding variation in the atomic ratio. The above s a i reactions were carried out in a tubular,down-flow, pyiex reactor with 20 mm internal diameter. The reaction mixture was fed from top using syringe pump(Sage Instruments,USA). The product was cooled by using ice-cooled water and collected at -he bottom. The required number of ice-cooled traps were used to collect the total amount of products. The products were analysed by using SE-30 (5%) and OV-17 columns.The analysis was confirmed by mass spectra and GC-mass. The reaction of -=-hanol with ammonia in the presence of air (or oxygen) was carried out over VAPO(TPA-B), VAPO(TPA-C), VAPO(TPA-D). The temperature was varied from 250 to 420° C. The higest yield of acet :r. i t rile obtained was >83.0 wt% over VAPO(TPA) at 350° C ammoxidation in one step. The following examples are given to illustrate the process of the present invention,however, these should not be construed to limit the scope of invention. EXAMPLE - 1 0.78 gm of Ethanol, 1.0 gm of water per hour,0.228 gm ( 30 cc per min)of ammonia and 30.0 cc per min air over VAPO(TPA-B) at 350° C and 0.5 hr weight hourly space velocity of liquid feed. The ethanol to ammonia mole ratio was 1:5. The one step ammoxidation of ethanol was highly selective. No deactivation weis observed for more than 6 hrs time on stream. The template TPA (tetra propyl ammonium bromide) was removed before the rection. The yield of acetonitrile was 24.9 wt% based on ethanol at 62.3 wt% conversion of ethanol. EXAMPLE - 2 0.78 gm of Ethanol, 1.0 gm of water per hour,0.228 gm( 30 cc per min)of ammonia and 30.0 cc per min air over VAPO(TPA-C) at 350° C and 0.5 hr-1 weight hourly space velocity of liquid feed. The ethanol to ammonia mole ratio was 1:5. The one step ammoxidation of ethanol was highly selective. No deactivation was observed for more than 6 hrs time on stream. The template TPA (tetra propyl ammonium bromide) was removed before the rection. The yield of acetonitrile was 52.9 wt% based on ethanol at 54.0 wt% conversion of ethanol. EXAMPLE - 3 0.78 gm of Ethanol, 1.0 gm of water per hour,0.228 gm ( 30 cc per min)of ammonia and 30.0 cc per min air over VAPO(TPA-D) at 350° C and 0.5 hr weight hourly space velocity of liquid feed. The ethanol to ammonia mole ratio was 1:5. The one step ammoxidation of ethanol was highly selective. No deactivation was observed for more than 6 hrs time on stream. The template TPA (tetra propyl ammonium bromide) was removed before the rection. The yield of acetonitrile was 41.2 wt% based on ethanol at 43.0 wt% conversion of ethanol. Advantages of the invention : 1. The process of the present invention is one step process for the preparation of acetonitrile and ammoxidation of ethanol is highly selective. 2. Provides a process for the preparation of acetronitrile wherein the formation of CO, C02 and high boiling products are minimised . 3. Yield of acetonitrile is very high > 85 % . claim : 1. An improved process for the preparation of acetonitrile from ethanol over vanadium-alumino-phosphate catalysts which comprises passing a feed consisting of ethanol, ammonia, water and air over a Vanadium alumino o phosphate (VAPO) catalyst at a temperature in the range of 300-450\C and weight hourly space velocity of liquid products in the range of 0.25 to 1.0 per hour and recovering the acetonitrile by conventional methods. 2. An improved process as claimed in claim 1 wherein the molar ratio of ethanol and ammonia ranges from 1:1 to 1:20. 3. An improved process as claimed in claims 1-2 wherein the feed ratio of air ranges from 30 cc per minute to 100 cc per minute. 4. An improved process for the preparation of acetonitrile from ethanol over vanadium-alumino-phosphate catalysts substantially as herein described with reference to the examples.

Full Text

This invention relates to an improved process for the preparation of acetonitrile from ethanol over vanadium-alumino-phosphate catalysts. Particularly, this invention relates to an improved process for the preparation of acetonitrile from ethanol over vanadium-alumino-phosphate catalysts via amoxidation. According to the process of the present invention ethanol is reacted with ammonia and air in the presence of crystalline, porous vanadium-alumino phosphates (VAPO) catalyst. The process of preparing the above catalyst has been described and claimed in our copending application number 1459/Del/95.
In the presently known process, acetonitrile can be produced from amination of acetic acid followed by dehydration or dehydrogenation of ethylamine.
The conventional catalysts have been amorphous in nature and not shape
selective catalysts. These catalysts have been employed in mostly fixed bed
reactors. The following patents have discussed the preparation of nitriles of
present interest, e.g. Eur.Pat; Appl. EP 37173 (1981), US Patent 4876348
(1989), US Patent 4603 207 (1986), Eur. Pat 0037123AI (1981), Brit. Patent
77746 (1957), Ger. (East)DDPatent 241903 (1985), US Patent 3981879 (1976),
US Patent 2839535 (1958), US Patent 2510605 (1950), US Patent 2981879
(1976). In these inventions the yield of nitrite may
or may not be highly selective. Particularly high-boiling products, CO, C02 were formed, due to the amorphous nature of the catalysts. The high-boiling products create environmental and disposal problems.

The main object of the present invention is to develop selective and particularly provide an improved process for the preparation of nitriles employing porous active catalytic materials. The other objective of the present invention is to provide a process for the preparation of nitriles wherein the formation of CO, C02 and high boiling products are minimized.
Accordingly, the present invention provides >90% yield of acetonitrile from ethanol by ammoxidation in one step with very high selectivity over VAPO catalysts at a temperature in the range of 350-450oC and weight hourly space velocity in the range of 0.25 to 1.0 per hour.
Accordingly, the present invention provides an improved process for the preparation of acetonitrile from ethanol over vanadium-alumino-phosphate catalysts which comprises passing a feed consisting of ethanol, ammonia, water and air over a Vanadium alumino phosphate (VAPO) catalyst at a temperature in
o
the range of 300-450*JO and weight hourly space velocity of liquid products in the range of 0.25 to 1.0 per hour and recovering the acetonitrile by conventional methods.
The molar ratio of ethanol and ammonia may be in the range of 1:1 to 1:20. The feed ratio of air may be in the range of 30 to 100 cc/hour.
The catalysts are prepared in general in the following way AI2(S04)3, H3P04 with or without NaCI, V205 and tetrapropyl ammonium bromide (TPA) used as a template mixed in distilled water in the pH range of 7 to 12.0. The slurry is mixed for at least 2 hours at room temperature with constant
stirring and the pH is adjusted by aqueous ammonia. The slurry was put into an autoclave for autoclaving under autogeneous pressure in the tempera' ure range of 150 to 220° C for 24 hrs to 80 hrs till complete crystallization was achieved. The mixture was filtered and wash with distilled water.The solid catalyst was dried in oven at l70° C over night. The organic template was removed by the activation of the catalyst at 500-550° C for 5-15 hrs. Then the calcined material was modified by promoters like Sb203 or oxides of the elements active as promoters in the respective reactions. Basically in aluminophosphate molecular sieves the Al : P atomi- ratio is 1:1. We have substituted P partially by V as dipgused and claimed in the copending patent number : 1459/Del/95. Al also may be substituted partially by V with the corresponding variation in the atomic ratio.
The above s a i reactions were carried out in a tubular,down-flow, pyiex reactor with 20 mm internal diameter. The reaction mixture was fed from top using syringe pump(Sage Instruments,USA). The product was cooled by using ice-cooled water and collected at -he bottom. The required number of ice-cooled traps were used to collect the total amount of products. The products were analysed by using SE-30 (5%) and OV-17 columns.The analysis was confirmed by mass spectra and GC-mass.
The reaction of -=-hanol with ammonia in the presence of air (or oxygen) was carried out over VAPO(TPA-B), VAPO(TPA-C), VAPO(TPA-D). The temperature was varied from 250 to 420° C. The higest yield of acet :r. i t rile obtained was >83.0 wt% over VAPO(TPA) at 350° C ammoxidation in one step.
The following examples are given to illustrate the process of the present invention,however, these should not be construed to limit the scope of invention.
EXAMPLE - 1
0.78 gm of Ethanol, 1.0 gm of water per hour,0.228 gm ( 30 cc per min)of ammonia and 30.0 cc per min air over VAPO(TPA-B) at 350° C and 0.5 hr weight hourly space velocity of liquid feed. The ethanol to ammonia mole ratio was 1:5. The one step ammoxidation of ethanol was highly selective. No deactivation weis
observed for more than 6 hrs time on stream. The template TPA (tetra propyl ammonium bromide) was removed before the rection. The yield of acetonitrile was 24.9 wt% based on ethanol at 62.3 wt% conversion of ethanol.
EXAMPLE - 2
0.78 gm of Ethanol, 1.0 gm of water per hour,0.228 gm( 30 cc per min)of ammonia and 30.0 cc per min air over VAPO(TPA-C) at 350° C and 0.5 hr-1 weight hourly space velocity of liquid feed. The ethanol to ammonia mole ratio was 1:5. The one step ammoxidation of ethanol was highly selective. No deactivation was observed for more than 6 hrs time on stream. The template TPA (tetra propyl ammonium bromide) was removed before the rection. The yield of acetonitrile was 52.9 wt% based on ethanol at 54.0 wt% conversion of ethanol.
EXAMPLE - 3
0.78 gm of Ethanol, 1.0 gm of water per hour,0.228 gm ( 30
cc per min)of ammonia and 30.0 cc per min air over VAPO(TPA-D) at 350° C and 0.5 hr weight hourly space velocity of liquid feed. The ethanol to ammonia mole ratio was 1:5. The one step ammoxidation of ethanol was highly selective. No deactivation was observed for more than 6 hrs time on stream. The template TPA (tetra propyl ammonium bromide) was removed before the rection. The yield of acetonitrile was 41.2 wt% based on ethanol at 43.0 wt% conversion of ethanol.
Advantages of the invention :
1. The process of the present invention is one step process for the preparation of acetonitrile and ammoxidation of ethanol is highly selective.
2. Provides a process for the preparation of acetronitrile wherein the formation of CO, C02 and high boiling products are minimised .
3. Yield of acetonitrile is very high > 85 % .

claim :
1. An improved process for the preparation of acetonitrile from ethanol over
vanadium-alumino-phosphate catalysts which comprises passing a feed
consisting of ethanol, ammonia, water and air over a Vanadium alumino
o phosphate (VAPO) catalyst at a temperature in the range of 300-450\C
and weight hourly space velocity of liquid products in the range of 0.25 to
1.0 per hour and recovering the acetonitrile by conventional methods.
2. An improved process as claimed in claim 1 wherein the molar ratio of ethanol and ammonia ranges from 1:1 to 1:20.
3. An improved process as claimed in claims 1-2 wherein the feed ratio of air ranges from 30 cc per minute to 100 cc per minute.
4. An improved process for the preparation of acetonitrile from ethanol over vanadium-alumino-phosphate catalysts substantially as herein described with reference to the examples.

Documents:

« Previous Patent

Next Patent »

Patent Number

191169

Indian Patent Application Number

962/DEL/1995

PG Journal Number

39/2003

Publication Date

27-Sep-2003

Grant Date

12-Apr-2004

Date of Filing

25-May-1995

Name of Patentee

COUNICL OF SCIENTIFIC & INDUSTRIAL RESEARCH

Applicant Address

RAFI MARG, NEW DELHI 110 001,INDIA

Inventors:

#	Inventor's Name	Inventor's Address
1	ALLA VENKAT RAMA RAO	INDIAN INSTITUTE OF CHEMICAL TECHNOLOGY, HYDERABAD, INDIA
2	SURESH FARSINAVIS	INDIAN INSTITUTE OF CHEMICAL TECHNOLOGY, HYDERABAD, INDIA
3	MACHIRAJU SUBRAHMANYAM	INDIAN INSTITUTE OF CHEMICAL TECHNOLOGY, HYDERABAD, INDIA
4	REVUR RAMCHANDRA RAO	INDIAN INSTITUTE OF CHEMICAL TECHNOLOGY, HYDERABAD, INDIA
5	PANJA KANTA RAO	INDIAN INSTITUTE OF CHEMICAL TECHNOLOGY, HYDERABAD, INDIA
6	SHIVANAND JANARDAN KULKARNI	INDIAN INSTITUTE OF CHEMICAL TECHNOLOGY, HYDERABAD, INDIA

PCT International Classification Number

C07C 121/32

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA