CA1187098A - Methacrylic acid from isobutyric acid using a modified iron phosphate catalyst - Google Patents
Methacrylic acid from isobutyric acid using a modified iron phosphate catalystInfo
- Publication number
- CA1187098A CA1187098A CA000388440A CA388440A CA1187098A CA 1187098 A CA1187098 A CA 1187098A CA 000388440 A CA000388440 A CA 000388440A CA 388440 A CA388440 A CA 388440A CA 1187098 A CA1187098 A CA 1187098A
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- Prior art keywords
- catalyst
- iron phosphate
- acid
- phosphate catalyst
- modified iron
- Prior art date
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
- B01J27/14—Phosphorus; Compounds thereof
- B01J27/185—Phosphorus; Compounds thereof with iron group metals or platinum group metals
- B01J27/1853—Phosphorus; Compounds thereof with iron group metals or platinum group metals with iron, cobalt or nickel
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
- B01J27/14—Phosphorus; Compounds thereof
- B01J27/16—Phosphorus; Compounds thereof containing oxygen, i.e. acids, anhydrides and their derivates with N, S, B or halogens without carriers or on carriers based on C, Si, Al or Zr; also salts of Si, Al and Zr
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/347—Preparation of carboxylic acids or their salts, halides or anhydrides by reactions not involving formation of carboxyl groups
- C07C51/377—Preparation of carboxylic acids or their salts, halides or anhydrides by reactions not involving formation of carboxyl groups by splitting-off hydrogen or functional groups; by hydrogenolysis of functional groups
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- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Materials Engineering (AREA)
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- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Catalysts (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
Abstract
OXYDEHYDROGENATION CATALYST
ABSTRACT OF THE DISCLOSURE
Isobutyric acid is oxidatively dehydrogenated to methacrylic acid by contact with a heterogeneous cata-lyst in the presence of molecular oxygen. The catalyst is composed of calcined phosphates of iron containing aluminum or gallium as a modifier or dopant component.
ABSTRACT OF THE DISCLOSURE
Isobutyric acid is oxidatively dehydrogenated to methacrylic acid by contact with a heterogeneous cata-lyst in the presence of molecular oxygen. The catalyst is composed of calcined phosphates of iron containing aluminum or gallium as a modifier or dopant component.
Description
~87~
~ACKGROUND OF TH~ INVEWTION
Field of the Invention This invention relates to a process for the con version by oxydehydrogenation o~ isobutyric acid to methacrylic acid. The process applies as well to functional equivalents of isobutyric acid such as pro-pionic acid and methylisobutyrate.
Description of the Prior Art There is considerable prior art directed to the oxydehydrogenation of the lower saturated mono-carboxylic acids to prepare the correspondiny a, ~ unsaturated acids. The initial work reported in this area was that of thermally effecting the indicated oxydehydrogenation by the vapor phase reaction of the acid substrate with iodine and oxygen. This approach has not attracted much aktention as a potentially viable way for com~
mercially implementing the underlying reaction~ This is understandably so inasmuch as iodine is costly, exhibits extreme corrosive properties and poses con-siderable problems in realizing complete recovery ofthe comparatively large amounts thereof required in the process.
As the subsequent prior art picture amply points ~7~
up, the heterogeneous catalytic method for effecting the oxydehydrogenation reaction is viewed as being much more attractive from the standpoint of potential commercial applicability. In the main, the more recent relevant prior art activities have centered on the use of two types of catalyst compositions for this purpose.
One type includes generally the heteropoly-acids, typically representative of which is 12-molybdophosphoric acid optionally including vanadium and/or tungsten elements in a like structural arrangement. The other type catalyst includes those systems having in common a calcined iron phosphate matrix.
Iron phosphates sub~ected to calcination exist in a plurality of crystalline phases or species. While it is believed that the oxidation/reduction couple in-volved in the underlying reaction is attributable to the iron phosphate, which species is or are catalytically active has not been identified. There is, however, evidence that the presence of an additional metal com-ponent in the preparation serves to facilitate theormation of the catalytically active species~ For example, U.S. Patent 3,~48,959 nota~ly teaches that an alkali or alkaline earth metal as the additional metal component is effective for this purpose. The present invention accordingly represents a furtherance of this particulax aspect of the current state of the art.
SUMMA:RY_OF THE IN~TENTION
In accordance with this invention, a catalytic process is provided for effecting the oxidative de-hydrogenation of isobutyric acid to form methacrylicacid~ The process of this invention compris~s con-tacting a heterogeneous catalyst at a temperature from 300-550C. with a co-feed of said isobutyric acid ~8t7g~
substrate and diluted oxygen gas, characterized in that said catalyst is calcined iron phosphate containing the additional metal alumin~ as the modifier or dopant component. Other Group IIIa elements; ~oron, gallium and indium may serve as the modifier or dopant component.
In the broadest aspect of the invention the contemplated catalyst is defined by the gram-atom empirical formula FeM0 01 lPl 2x in which M represents aluminum, boron, gallium or indium and x represents the number of oxygen atoms bound to the other metals in their res-pective states of oxidation in the catalyst. It has been found that the aluminum modi~ied iron phosphate catalyst is active over long periods of time. Unlike the iron phosphate catalyst which loses activity over time, the aluminum modifi~d catalyst has been shown to retain activity in studies of 100 hour duration.
DESCRIPTION OF THE PREFERRED EMBODI~lENTS
There are a number of techniques applica~le ~or preparing the catalyst useful in the practice of this invention. Of these, the more facile methods involve preparing the integral composition prior to calcination.
This can be readily accomplished by employing the so-called slurry method or the precipitation method.
In the latter me-thod an aqueous solution of salts of the contemplated metals and phosphoric acid is first prepared and thereupon neutralized with an appropriate base in order to precipitate the mixed metal phosphates.
The precipitate is desirably carefully washed to remove all traces of water solubles and then dried prior to calcining. In the alternative, one can add ammonium phosphate to the solution of metal salts in order to precipitate directly the metal phosphates. As indicated, any water-soluble salt of iron or aluminum can be used.
~37~
However, because of the solubility characteristics of the nitrate salts, among other reasons ! such salts are preferred.
The so-called slurry method is even more convenient to carry out and ~or this reason represents the pre-ferred method herein~ In accordance with this pro cedure, the aqueous solution of the iron and aluminum salts together with the phosphoric acid is obtained~
The solution is heated continuously until the mass can be no longer stirred~ The residue is then frag-mented and again heated at a moderately elevated tem perature in the order of a~out 120C. until completely dried. Thereupon the dried composite is sized and calcined. Su~table calcination temperatures broadly range from 400-1000C. or more preferably from 400 to 850C.
In the manner of either of these techniques~ a supported catalyst can be prepared~ For example, in the slurry method colloidal silica or colloidal alumina or any other form thereof can be added prior to removing the water content. When colloidal alumina is used it may serve ~s well as an add~tional source o$ the aluminum cations which pro~ide the impro~ed activity and long catalyst life observed in the aluminum modified iron phosphate catalyst o~ the present ~nvention.
Supports such as alumina! Silica~ titania~ etc. !
can be added prior to removin~ the water content.
The support may also be soaked ~n a solution o~ the metal phosphate and allowed to dry. The soaking and dry-ing steps may be repeated until the desired number o~layers of dried metal phosphate are obtained~ Simil~rly, in the alternate method described, the precipitat-`on of the metal phosphates can be accomplished in the presence of suspended particulates of the intended support, In a typical commercial catalyst preparation a spray drying ~ 3'7~
technique is used in which the slurry i5 fed to a spray drier and the solid product is then tableted or extruded and then calcined.
The catalyst compositions of this invention can be employed in a fluidized bed reactor, stirred tank reactor, or fixed-bed type reactor Because of the convenience associated with the use of a fixed~bed reactor in a small scale operation, such a reactor will be exemplified herein. In the preferred mode of operation the feed to the reactor comprises a pre-heated gaseous mixture of the substrate, molecular oxygen, steam and inert diluent gas, A pre-heat temperature in the range of about 300 to 350C. is customarily observed. A broad range of applicable reaction temperatures is from 250-550C.
but more generally a temperature of from 350 to 450C.
provides for optimum processing.
The mole ratio of molecular oxygen to substrate is ~rom 0.2 to 1.5 and more preferably 0.5 to 1.0, While steam is not necessary for the purpose of effecting the reaction, the presence thereof in the feed improves the y~eld of the desired product~ An applicable mole ratio of water to the substrate in the feed IS from about 1 to 75. The optimum ratio is more in the order of about 10 ~o 30.
Another important parameter re$ides in the concen~
tration of the substrate in the feed. Expressed in terms of mole percents, the concentration of the contemplated su~strates ran~es broadly from 0.1-20. As is common in reactions of this type~ y~eld of the desired product 3Q is an inverse function of the concentration. From the standpoint of achieving a reasonable through~put combined with an acceptable yield, the concentration of the sub-strate in -the feed is from about 3-6 mole percent~ Con-centration is controlled by the amount of water and inert gas present in the feed stream. The preferred diluent ~7~g8 ~6--g~s is nitrogen although other gases such as carbon diox~de, helium, argon, and the like are suitable, Of coùrse if the desired concentration of substrate permits, air represents a suitable diluted oxidant.
Another applicable parameter is that of contact time.
Contact time is deined as the catalyst volume d~vided by the volume o gas feed per second at reaction tem-perature. The catalyst volume is the bulk volume occupied ~y the catalyst in the reactor. The term catalyst in this sense not only includes the modified iron phosphate itself but also the solid diluent or support if present.
Accordin~ly~ applicable contact times range fxom 0.05~50 seconds and more yenerally in the order o~ from 0.1~20 seconds. The reaction is carried out at atmospheric pressure.
~EX~MP-~E~l The purpose of this example is to ~llustrate the hereinabove described slurry method ~ox preparlng a cata-lyst useful in the pract~ce of this in~ention. Iron nitrate nona-hydrate in the amount of 122 gS alon~
with 11.33 g. of aluminu~ nitrate nona hydrate were dlssolved in 250 ml. of water~ Concentrated phosphoric ac~d in the amount of 42~4 g, was added with stirring to the solution of metal salts. The solution was then stirred and heated until the bulk of the water was evaporated~ The result~nt paste was further dried at 125C. until in condition to be fragmented whereupon the solid was broken into half-inch and smaller pieces and calcined for 16 hours in flowing air at 450C. The calcined material was crushed and screened to 12/20 mesh size before use. The gram~atom empirical formula of the calcined mixed phosphates of iron and aluminum follows: FeA1o,llPl.1x' ~8~
7~
~EXAMPLE 2 This example illùstrates the preparation of an aluminum modified iron phosphate catalyst having a higher ratio of phosphorus to aluminum than the catalyst of Example 1. Iron nitrate nona-hydrate in the amount of 610.0 grams along with 62.6 g. aluminum nitrate nona-hydra~e were dissolved in 1,2 liters of distilled watex, Concentrated phosphoric acid in the amount of 250 g.
was added~ The remaining procedure was followed as given in Example 1. The gram atom empirical formula of the calcined mixed phosphates of iron and aluminum follows; Fe~lo,l1P1~4 ~
This example illustrates the preparation of an alu~
minum modified iron phosphate catalyst of the gram atom empirical formula o FeAl~,05Pl.05Ox nona-hydrate in the amount of 128,6 g, along with 5.86 g. aluminum nitrate nona-hydrate were dissolved in 250 ml. distilled water, Concentrated phosphoric acid in the amount of 50.0 g. was added, The remaining pro-cedure as given in Example 1 was followed.
EX~MPLE` 4 This example illustrates the preparation of an aluminum modified iron phosphate catalyst of the gram atom empirical formula of FeAl0,llPl 1x has the same gram atom empirical formula as the catalyst of Example 1. This catalyst differs, however, from the catalyst of Example 1 in that the preparation avoids the use of additional water. The catalyst of Example 4 was prepared by mixing 610 g. of iron nitrate nona-hydrate and 56.65 g. aluminum nitrate nona-hydrate. This mixture was heated ~mtil melted and 212 grams of 85%
phosphorîc acid was then added with stirring. The remaining procedure as given in Example l ~as followed.
This example il]ustrates the preparation of a gallium modified iron phosphate catalyst having the gram atom empirical formula of Fe~aO llPl 1x~ Iron nitrate nona-hydrate in the amount of 71,0 g. along with 5.0 g.
gallium nitrate nona-hydrate was dissolved in lO0 ml.
water. Concentrated phosphoric acid in the amount of 24.8 g. was then added. The remaining procedure as giv~n in Example l was followed.
This example illustrates the preparation of a gallium modified iron phosphate catalyst having the gram atom empirical f~rmula of FeGaO llPl 44x~ Iron nitrate nona-hydrate in the amount of 71.0 g. along with 5.0 g gallium nitrate nona-hydra-te was dissolved in lO~ ml.
water and 29.3 g. concentrated phosphoric acid was then added. The remaining procedure as given in Example l was followed.
EXAMP~E 7 This example illustrates the preparation of an iron phosphate catalyst which is not modified ~y the addition of another metal. Iron nitrate nona-hydrate in the amount of 101 g. was dissolved in 200 ml. water, Con-centrated phosphoric acid in the amount of 29.1 g. was then added. The remaining procedure a~ given in Example l was followed. The gram atom empirical formula of the calcined iron phosphate ~ollows; FePOx.
- ~L87~98 .
g This exam~le illustrates the use o,~ the catalyst composition of the foregoing examples in effecting the oxidative dehydrogenation of isobutyric acid ~IBA~.
The reactor and -the general manner of conduct~ng the reaction was the same for each o~ the enumerated runs, The catalyst was diluted ~itn quartz chips (1 part by volume catalyst to 4 parts by volume quartz chips) and loaded into a conventional down flow tuhular reactor.
Tests were conducted at 400 to 425C. The procedure consisted of feeding a pre-heated mixture of iso~utyric acid, oxygen, nitrogen and steam through a stainless steel tube of 1~2" OD (3/8" ID) and approximately 18"
in length containing the test catalyst as a 15 cc ? packed bed maintained at the reaction temperature utilized in the particular run. The ratio of water to isobutyric acid in the feed was 20 to 1, the ratio of oxygen to isobutyric acid in the feed was 1 to 1 and contact time was on the order of 0.4 to 0,5 seconds. These ratios result in a feed mixture containing 4 mole % isobutyric acid, 78 mole % water, 4 mole % oxygen and 14 mole % of diluent nitrogen.
The pre-heater consisted o~ a length of stainless steel tube similar to the reactor but packed with glass beads~ The condensed organic product was collected and analyzed by gas chromatography. Gaseous products were analyzed separately by gas chromat~graphy.
Pertinent results observed for the individual runs are set forth in Table I presented hereinbelow. The results obtained in texms of selectivity and conversion axe likewise given in said table. Conversion represents the mole ratio of substrate consumed to that charged to the reactor. Selectivity to methacrylic acid (~
represents the mole ratio of methacrylic acid found in the effluent to that of IBA consumed in the reaction, .
:
The catalyst prepared as described in Example 1 and used as described in Example 8 to effec~ the oxydehydro~enation of isobutyric acid has ~een on-stream for 100 hour~
without showing signs of deactivation.
TABLE I
Temp. Hours IBA MAA
Catalyst O~ _ On Stream Conv. ~ Sel. %
Example 1 401 10 96 70 Example 1 406 30 98 69 10 Example 1 402 70 97 69 Example 1 399 100 37 68 F.xample 2 420 25 95 67 Example 2 420 45 97 70 Example 3 421 12 95 73 Example 3 399 30 94 75 Example 4 408 20 97 69 Example 4 409 40 98 70 Example 5 409 3 93 67 Example 5 416 24 8~ 69 20 Example 6 397 ~ 69 72 Example 7 413 4 99 60 Example 7 412 22 85 67 Example 7 411 42 62 53
~ACKGROUND OF TH~ INVEWTION
Field of the Invention This invention relates to a process for the con version by oxydehydrogenation o~ isobutyric acid to methacrylic acid. The process applies as well to functional equivalents of isobutyric acid such as pro-pionic acid and methylisobutyrate.
Description of the Prior Art There is considerable prior art directed to the oxydehydrogenation of the lower saturated mono-carboxylic acids to prepare the correspondiny a, ~ unsaturated acids. The initial work reported in this area was that of thermally effecting the indicated oxydehydrogenation by the vapor phase reaction of the acid substrate with iodine and oxygen. This approach has not attracted much aktention as a potentially viable way for com~
mercially implementing the underlying reaction~ This is understandably so inasmuch as iodine is costly, exhibits extreme corrosive properties and poses con-siderable problems in realizing complete recovery ofthe comparatively large amounts thereof required in the process.
As the subsequent prior art picture amply points ~7~
up, the heterogeneous catalytic method for effecting the oxydehydrogenation reaction is viewed as being much more attractive from the standpoint of potential commercial applicability. In the main, the more recent relevant prior art activities have centered on the use of two types of catalyst compositions for this purpose.
One type includes generally the heteropoly-acids, typically representative of which is 12-molybdophosphoric acid optionally including vanadium and/or tungsten elements in a like structural arrangement. The other type catalyst includes those systems having in common a calcined iron phosphate matrix.
Iron phosphates sub~ected to calcination exist in a plurality of crystalline phases or species. While it is believed that the oxidation/reduction couple in-volved in the underlying reaction is attributable to the iron phosphate, which species is or are catalytically active has not been identified. There is, however, evidence that the presence of an additional metal com-ponent in the preparation serves to facilitate theormation of the catalytically active species~ For example, U.S. Patent 3,~48,959 nota~ly teaches that an alkali or alkaline earth metal as the additional metal component is effective for this purpose. The present invention accordingly represents a furtherance of this particulax aspect of the current state of the art.
SUMMA:RY_OF THE IN~TENTION
In accordance with this invention, a catalytic process is provided for effecting the oxidative de-hydrogenation of isobutyric acid to form methacrylicacid~ The process of this invention compris~s con-tacting a heterogeneous catalyst at a temperature from 300-550C. with a co-feed of said isobutyric acid ~8t7g~
substrate and diluted oxygen gas, characterized in that said catalyst is calcined iron phosphate containing the additional metal alumin~ as the modifier or dopant component. Other Group IIIa elements; ~oron, gallium and indium may serve as the modifier or dopant component.
In the broadest aspect of the invention the contemplated catalyst is defined by the gram-atom empirical formula FeM0 01 lPl 2x in which M represents aluminum, boron, gallium or indium and x represents the number of oxygen atoms bound to the other metals in their res-pective states of oxidation in the catalyst. It has been found that the aluminum modi~ied iron phosphate catalyst is active over long periods of time. Unlike the iron phosphate catalyst which loses activity over time, the aluminum modifi~d catalyst has been shown to retain activity in studies of 100 hour duration.
DESCRIPTION OF THE PREFERRED EMBODI~lENTS
There are a number of techniques applica~le ~or preparing the catalyst useful in the practice of this invention. Of these, the more facile methods involve preparing the integral composition prior to calcination.
This can be readily accomplished by employing the so-called slurry method or the precipitation method.
In the latter me-thod an aqueous solution of salts of the contemplated metals and phosphoric acid is first prepared and thereupon neutralized with an appropriate base in order to precipitate the mixed metal phosphates.
The precipitate is desirably carefully washed to remove all traces of water solubles and then dried prior to calcining. In the alternative, one can add ammonium phosphate to the solution of metal salts in order to precipitate directly the metal phosphates. As indicated, any water-soluble salt of iron or aluminum can be used.
~37~
However, because of the solubility characteristics of the nitrate salts, among other reasons ! such salts are preferred.
The so-called slurry method is even more convenient to carry out and ~or this reason represents the pre-ferred method herein~ In accordance with this pro cedure, the aqueous solution of the iron and aluminum salts together with the phosphoric acid is obtained~
The solution is heated continuously until the mass can be no longer stirred~ The residue is then frag-mented and again heated at a moderately elevated tem perature in the order of a~out 120C. until completely dried. Thereupon the dried composite is sized and calcined. Su~table calcination temperatures broadly range from 400-1000C. or more preferably from 400 to 850C.
In the manner of either of these techniques~ a supported catalyst can be prepared~ For example, in the slurry method colloidal silica or colloidal alumina or any other form thereof can be added prior to removing the water content. When colloidal alumina is used it may serve ~s well as an add~tional source o$ the aluminum cations which pro~ide the impro~ed activity and long catalyst life observed in the aluminum modified iron phosphate catalyst o~ the present ~nvention.
Supports such as alumina! Silica~ titania~ etc. !
can be added prior to removin~ the water content.
The support may also be soaked ~n a solution o~ the metal phosphate and allowed to dry. The soaking and dry-ing steps may be repeated until the desired number o~layers of dried metal phosphate are obtained~ Simil~rly, in the alternate method described, the precipitat-`on of the metal phosphates can be accomplished in the presence of suspended particulates of the intended support, In a typical commercial catalyst preparation a spray drying ~ 3'7~
technique is used in which the slurry i5 fed to a spray drier and the solid product is then tableted or extruded and then calcined.
The catalyst compositions of this invention can be employed in a fluidized bed reactor, stirred tank reactor, or fixed-bed type reactor Because of the convenience associated with the use of a fixed~bed reactor in a small scale operation, such a reactor will be exemplified herein. In the preferred mode of operation the feed to the reactor comprises a pre-heated gaseous mixture of the substrate, molecular oxygen, steam and inert diluent gas, A pre-heat temperature in the range of about 300 to 350C. is customarily observed. A broad range of applicable reaction temperatures is from 250-550C.
but more generally a temperature of from 350 to 450C.
provides for optimum processing.
The mole ratio of molecular oxygen to substrate is ~rom 0.2 to 1.5 and more preferably 0.5 to 1.0, While steam is not necessary for the purpose of effecting the reaction, the presence thereof in the feed improves the y~eld of the desired product~ An applicable mole ratio of water to the substrate in the feed IS from about 1 to 75. The optimum ratio is more in the order of about 10 ~o 30.
Another important parameter re$ides in the concen~
tration of the substrate in the feed. Expressed in terms of mole percents, the concentration of the contemplated su~strates ran~es broadly from 0.1-20. As is common in reactions of this type~ y~eld of the desired product 3Q is an inverse function of the concentration. From the standpoint of achieving a reasonable through~put combined with an acceptable yield, the concentration of the sub-strate in -the feed is from about 3-6 mole percent~ Con-centration is controlled by the amount of water and inert gas present in the feed stream. The preferred diluent ~7~g8 ~6--g~s is nitrogen although other gases such as carbon diox~de, helium, argon, and the like are suitable, Of coùrse if the desired concentration of substrate permits, air represents a suitable diluted oxidant.
Another applicable parameter is that of contact time.
Contact time is deined as the catalyst volume d~vided by the volume o gas feed per second at reaction tem-perature. The catalyst volume is the bulk volume occupied ~y the catalyst in the reactor. The term catalyst in this sense not only includes the modified iron phosphate itself but also the solid diluent or support if present.
Accordin~ly~ applicable contact times range fxom 0.05~50 seconds and more yenerally in the order o~ from 0.1~20 seconds. The reaction is carried out at atmospheric pressure.
~EX~MP-~E~l The purpose of this example is to ~llustrate the hereinabove described slurry method ~ox preparlng a cata-lyst useful in the pract~ce of this in~ention. Iron nitrate nona-hydrate in the amount of 122 gS alon~
with 11.33 g. of aluminu~ nitrate nona hydrate were dlssolved in 250 ml. of water~ Concentrated phosphoric ac~d in the amount of 42~4 g, was added with stirring to the solution of metal salts. The solution was then stirred and heated until the bulk of the water was evaporated~ The result~nt paste was further dried at 125C. until in condition to be fragmented whereupon the solid was broken into half-inch and smaller pieces and calcined for 16 hours in flowing air at 450C. The calcined material was crushed and screened to 12/20 mesh size before use. The gram~atom empirical formula of the calcined mixed phosphates of iron and aluminum follows: FeA1o,llPl.1x' ~8~
7~
~EXAMPLE 2 This example illùstrates the preparation of an aluminum modified iron phosphate catalyst having a higher ratio of phosphorus to aluminum than the catalyst of Example 1. Iron nitrate nona-hydrate in the amount of 610.0 grams along with 62.6 g. aluminum nitrate nona-hydra~e were dissolved in 1,2 liters of distilled watex, Concentrated phosphoric acid in the amount of 250 g.
was added~ The remaining procedure was followed as given in Example 1. The gram atom empirical formula of the calcined mixed phosphates of iron and aluminum follows; Fe~lo,l1P1~4 ~
This example illustrates the preparation of an alu~
minum modified iron phosphate catalyst of the gram atom empirical formula o FeAl~,05Pl.05Ox nona-hydrate in the amount of 128,6 g, along with 5.86 g. aluminum nitrate nona-hydrate were dissolved in 250 ml. distilled water, Concentrated phosphoric acid in the amount of 50.0 g. was added, The remaining pro-cedure as given in Example 1 was followed.
EX~MPLE` 4 This example illustrates the preparation of an aluminum modified iron phosphate catalyst of the gram atom empirical formula of FeAl0,llPl 1x has the same gram atom empirical formula as the catalyst of Example 1. This catalyst differs, however, from the catalyst of Example 1 in that the preparation avoids the use of additional water. The catalyst of Example 4 was prepared by mixing 610 g. of iron nitrate nona-hydrate and 56.65 g. aluminum nitrate nona-hydrate. This mixture was heated ~mtil melted and 212 grams of 85%
phosphorîc acid was then added with stirring. The remaining procedure as given in Example l ~as followed.
This example il]ustrates the preparation of a gallium modified iron phosphate catalyst having the gram atom empirical formula of Fe~aO llPl 1x~ Iron nitrate nona-hydrate in the amount of 71,0 g. along with 5.0 g.
gallium nitrate nona-hydrate was dissolved in lO0 ml.
water. Concentrated phosphoric acid in the amount of 24.8 g. was then added. The remaining procedure as giv~n in Example l was followed.
This example illustrates the preparation of a gallium modified iron phosphate catalyst having the gram atom empirical f~rmula of FeGaO llPl 44x~ Iron nitrate nona-hydrate in the amount of 71.0 g. along with 5.0 g gallium nitrate nona-hydra-te was dissolved in lO~ ml.
water and 29.3 g. concentrated phosphoric acid was then added. The remaining procedure as given in Example l was followed.
EXAMP~E 7 This example illustrates the preparation of an iron phosphate catalyst which is not modified ~y the addition of another metal. Iron nitrate nona-hydrate in the amount of 101 g. was dissolved in 200 ml. water, Con-centrated phosphoric acid in the amount of 29.1 g. was then added. The remaining procedure a~ given in Example l was followed. The gram atom empirical formula of the calcined iron phosphate ~ollows; FePOx.
- ~L87~98 .
g This exam~le illustrates the use o,~ the catalyst composition of the foregoing examples in effecting the oxidative dehydrogenation of isobutyric acid ~IBA~.
The reactor and -the general manner of conduct~ng the reaction was the same for each o~ the enumerated runs, The catalyst was diluted ~itn quartz chips (1 part by volume catalyst to 4 parts by volume quartz chips) and loaded into a conventional down flow tuhular reactor.
Tests were conducted at 400 to 425C. The procedure consisted of feeding a pre-heated mixture of iso~utyric acid, oxygen, nitrogen and steam through a stainless steel tube of 1~2" OD (3/8" ID) and approximately 18"
in length containing the test catalyst as a 15 cc ? packed bed maintained at the reaction temperature utilized in the particular run. The ratio of water to isobutyric acid in the feed was 20 to 1, the ratio of oxygen to isobutyric acid in the feed was 1 to 1 and contact time was on the order of 0.4 to 0,5 seconds. These ratios result in a feed mixture containing 4 mole % isobutyric acid, 78 mole % water, 4 mole % oxygen and 14 mole % of diluent nitrogen.
The pre-heater consisted o~ a length of stainless steel tube similar to the reactor but packed with glass beads~ The condensed organic product was collected and analyzed by gas chromatography. Gaseous products were analyzed separately by gas chromat~graphy.
Pertinent results observed for the individual runs are set forth in Table I presented hereinbelow. The results obtained in texms of selectivity and conversion axe likewise given in said table. Conversion represents the mole ratio of substrate consumed to that charged to the reactor. Selectivity to methacrylic acid (~
represents the mole ratio of methacrylic acid found in the effluent to that of IBA consumed in the reaction, .
:
The catalyst prepared as described in Example 1 and used as described in Example 8 to effec~ the oxydehydro~enation of isobutyric acid has ~een on-stream for 100 hour~
without showing signs of deactivation.
TABLE I
Temp. Hours IBA MAA
Catalyst O~ _ On Stream Conv. ~ Sel. %
Example 1 401 10 96 70 Example 1 406 30 98 69 10 Example 1 402 70 97 69 Example 1 399 100 37 68 F.xample 2 420 25 95 67 Example 2 420 45 97 70 Example 3 421 12 95 73 Example 3 399 30 94 75 Example 4 408 20 97 69 Example 4 409 40 98 70 Example 5 409 3 93 67 Example 5 416 24 8~ 69 20 Example 6 397 ~ 69 72 Example 7 413 4 99 60 Example 7 412 22 85 67 Example 7 411 42 62 53
Claims (5)
1. A process for the catalytic conversion of isobutyric acid to methacrylic acid via an oxyde-hydrogenation reaction wherein an iron phosphate catalyst is contacted with a gaseous feed stream containing said acid substrate and oxygen at a temperature between about 300 and 550°C, said oxydehydrogenation reaction being affected in the presence of a modified iron phosphate catalyst having the gram-atom empirical formula FeM0.01-1P1-2Ox in which represents a metal selected from the group consisting of boron, aluminum, gallium, and indium and in which x represents the number of oxygen atoms bound to the other elements in their respective states of oxidation in the catalyst, the mole ratio of molecular oxygen to substrate being from 0.2 to 1.5, the concentration of substrate in the feed being from 0.1 to 20 mole per cent, and the contact time being 0.05 to 50 seconds.
2. A process according to claim 1 wherein M is aluminum.
3. A process according to claim 2 wherein the modified iron phosphate catalyst has the gramatom formula FeA10.05-0.11P1.0-1.5Ox.
4. A process according to claim 1 wherein M is gallium.
5. A process according to claim 4 wherein the modified iron phosphate catalyst has the gramatom formula FeGa0.11P1.1.5Ox.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US22307781A | 1981-01-07 | 1981-01-07 | |
| US223,077 | 1981-01-07 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1187098A true CA1187098A (en) | 1985-05-14 |
Family
ID=22834926
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000388440A Expired CA1187098A (en) | 1981-01-07 | 1981-10-21 | Methacrylic acid from isobutyric acid using a modified iron phosphate catalyst |
Country Status (18)
| Country | Link |
|---|---|
| JP (1) | JPS57134442A (en) |
| AT (1) | AT375632B (en) |
| AU (1) | AU527862B2 (en) |
| BR (1) | BR8107103A (en) |
| CA (1) | CA1187098A (en) |
| CH (1) | CH653667A5 (en) |
| DD (1) | DD201977A5 (en) |
| DE (1) | DE3151833C2 (en) |
| ES (1) | ES508512A0 (en) |
| FR (1) | FR2497795B1 (en) |
| GB (1) | GB2090589B (en) |
| IT (1) | IT1195291B (en) |
| MX (1) | MX160779A (en) |
| NL (1) | NL8104926A (en) |
| PL (2) | PL136178B1 (en) |
| RO (1) | RO83665B1 (en) |
| SE (1) | SE451583B (en) |
| ZA (1) | ZA817271B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2657792B1 (en) * | 1990-02-07 | 1992-05-15 | Norsolor Sa | CATALYTIC SYSTEM AND ITS APPLICATION TO THE OXIDE OF HYDROGENATION OF SATURATED CARBOXYLIC ACIDS. |
| JP4233685B2 (en) * | 1999-06-08 | 2009-03-04 | 花王株式会社 | Transesterification catalyst |
| FR2921361B1 (en) | 2007-09-20 | 2012-10-12 | Arkema France | PROCESS FOR PRODUCING ACROLEIN FROM GLYCEROL |
| EP2179981A1 (en) | 2008-10-24 | 2010-04-28 | Arkema France | Process for manufacturing acrolein from glycerol |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT995328B (en) * | 1973-08-13 | 1975-11-10 | Montedison Spa | PROCEDURE FOR THE PREPARATION OF UNSATURATED ALPHA BETA ACIDS BY CATALYTIC OXIDATION IN THE GASEOUS PHASE OF CORRESPONDING SATURATED ACIDS |
| US3855279A (en) * | 1973-10-26 | 1974-12-17 | Eastman Kodak Co | Catalytic process for the manufacture of unsaturated acids and esters |
| US4029695A (en) * | 1974-08-20 | 1977-06-14 | Eastman Kodak Company | Catalytic process for the manufacture of unsaturated acids and esters |
| US4298755A (en) * | 1980-02-25 | 1981-11-03 | Ashland Oil, Inc. | Catalytic oxydehydrogenation process |
-
1981
- 1981-10-20 GB GB8131616A patent/GB2090589B/en not_active Expired
- 1981-10-20 AU AU76647/81A patent/AU527862B2/en not_active Ceased
- 1981-10-21 CA CA000388440A patent/CA1187098A/en not_active Expired
- 1981-10-21 ZA ZA817271A patent/ZA817271B/en unknown
- 1981-10-29 AT AT0462081A patent/AT375632B/en not_active IP Right Cessation
- 1981-10-30 NL NL8104926A patent/NL8104926A/en not_active Application Discontinuation
- 1981-11-03 BR BR8107103A patent/BR8107103A/en unknown
- 1981-11-20 IT IT25207/81A patent/IT1195291B/en active
- 1981-12-15 SE SE8107516A patent/SE451583B/en not_active IP Right Cessation
- 1981-12-28 RO RO106138A patent/RO83665B1/en unknown
- 1981-12-29 DE DE3151833A patent/DE3151833C2/en not_active Expired
-
1982
- 1982-01-04 MX MX190740A patent/MX160779A/en unknown
- 1982-01-04 ES ES508512A patent/ES508512A0/en active Granted
- 1982-01-05 JP JP57000126A patent/JPS57134442A/en active Granted
- 1982-01-05 PL PL1982234604A patent/PL136178B1/en unknown
- 1982-01-05 CH CH37/82A patent/CH653667A5/en not_active IP Right Cessation
- 1982-01-05 PL PL2134604A patent/PL234604A1/xx unknown
- 1982-01-06 DD DD82236592A patent/DD201977A5/en not_active IP Right Cessation
- 1982-01-07 FR FR8200140A patent/FR2497795B1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| ZA817271B (en) | 1982-10-27 |
| CH653667A5 (en) | 1986-01-15 |
| RO83665A2 (en) | 1984-04-02 |
| AU527862B2 (en) | 1983-03-24 |
| IT8125207A0 (en) | 1981-11-20 |
| GB2090589B (en) | 1985-01-23 |
| ES8300669A1 (en) | 1982-11-01 |
| JPH0257527B2 (en) | 1990-12-05 |
| JPS57134442A (en) | 1982-08-19 |
| FR2497795A1 (en) | 1982-07-16 |
| SE8107516L (en) | 1982-07-08 |
| MX160779A (en) | 1990-05-16 |
| AT375632B (en) | 1984-08-27 |
| RO83665B1 (en) | 1984-04-30 |
| FR2497795B1 (en) | 1986-04-04 |
| DD201977A5 (en) | 1983-08-24 |
| DE3151833A1 (en) | 1982-07-22 |
| NL8104926A (en) | 1982-08-02 |
| PL136178B1 (en) | 1986-01-31 |
| GB2090589A (en) | 1982-07-14 |
| ES508512A0 (en) | 1982-11-01 |
| AU7664781A (en) | 1982-07-15 |
| ATA462081A (en) | 1984-01-15 |
| PL234604A1 (en) | 1982-09-13 |
| BR8107103A (en) | 1982-07-20 |
| IT1195291B (en) | 1988-10-12 |
| DE3151833C2 (en) | 1983-09-22 |
| SE451583B (en) | 1987-10-19 |
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