JPH058177B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a process for producing unsaturated carboxylic acids and/or ethesurs by reacting formaldehyde or acetaldehyde with saturated carboxylic acids in the gas phase at elevated temperatures in the presence of catalysts. U.S. Pat. No. 3,701,798 describes formaldehyde with the general formula RCH ₂ X or XCH ₂ R ¹ CH ₂ R ¹ is a carbon-carbon bond or a divalent saturated aliphatic hydrocarbon group having 1 ^to 20 carbon atoms ^; is an alkyl group). ] on a catalyst consisting essentially of an inorganic oxide of one or more rare earth metals of the lanthanide series impregnated on a silica gel, alumina or diatomaceous earth support at a temperature of 300 to 525 °C. General formula including passing: _CH2 :C(R)(X) or _CH2 :C(X) ^R1C
(X): A method for preparing an α,β-unsaturated compound having CH ₂ where R, R ¹ and X are as defined above is described. U.S. Pat. No. 4,324,908 describes a vapor mixture of a saturated monocarboxylic acid or its ester and formaldehyde or a formaldehyde derivative using the empirical formula, A _a PO _x (where A is Fe, Ni, Co, Mn, Cu, Ag or a mixture thereof). , a is from 0.2 to 3.0, and x is determined by the nature and oxidation state of the other elements) into a reaction zone at a temperature of about 200 to 450°C. A method for producing saturated carboxylic acids and esters is described. U.S. Pat. No. 4,324,908 further teaches that the catalyst can be used unsupported, but with suitable supports, such as silica, alumina, mixtures of silica and alumina,
The preferred use of amorphous silica-alumina, crystalline aluminosilicates, titania, natural clays, etc. is disclosed. In the background of the invention, U.S. Patent No.
It is disclosed that type X or type Y zeolites with cesium, rubidium or potassium cations found in US Pat. No. 4,115,424 are examples of other catalysts found to be useful for this reaction. However _, in _fact , U.S. _Pat . and its use in the alkylation of toluene to styrene and ethylbenzene, but not in the production of unsaturated carboxylic acids and esters. It has now been discovered that high-silica synthetic crystalline aluminosilicates catalyze the reaction of formaldehyde or acetaldehyde with saturated carboxylic esters or anhydrides to form unsaturated carboxylic acids and/or esters. High silica crystalline aluminosilicates, i.e. crystalline aluminosilicates with a silica to alumina molar ratio greater than 10:1, not only have a higher silica to alumina molar ratio, but they are also more acidic;
It is distinguished from the X and Y zeolites used in the process of US Pat. No. 4,115,424 in that it has higher mechanical and thermal stability. Therefore, the present invention provides unsaturated carboxylic acids and/or
A method for producing the ester, wherein the saturated carboxylic acid derivative is an ester or anhydride, and the catalyst is 0.9±0.2M _2/o O: Al ₂ O ₃ : YSiO ₂ :zH ₂ O [wherein M is oxidation of molar ratios of H ⁺ and/or transition metal and/or rare earth metal cations with valence n, Y is an integer greater than 10, and z is an integer ranging from 0 to 40. The method includes a synthetic crystalline aluminosilicate having a composition related to the present invention. In the present invention, metal cations selected from the group consisting of chromium, vanadium, praseodymium, and lanthanum are used as transition metal and/or rare earth metal cations. The aldehyde reactant is formaldehyde or acetaldehyde, preferably formaldehyde. Formaldehyde can be derived from any commercially available source of formaldehyde, such as aqueous, alcoholic or polymeric formaldehyde. Suitable formaldehyde sources include formalin, methylal and trioxane. Similarly, acetaldehyde can be derived from any suitable commercially available source of acetaldehyde. Saturated carboxylic _acid esters suitably have ^the formula: R ¹ CH ₂ X or XCH ₂ R ² CH ² is a valent aliphatic hydrocarbon group, and X is a functional group having the formula: -COOR ³ (wherein R ³ is a hydrocarbon group or a substituted hydrocarbon group). Suitable carboxylic esters include methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl butyrate, methyl hexanoate, ethyl heptanoate and dimethyl adipate. Particularly preferred reactants are formaldehyde and methyl acetate, which yield methyl acrylate and/or acrylic acid, and acetaldehyde and methyl acetate, which yield methyl methacrylate and/or methacrylic acid. The saturated carboxylic acid anhydride may suitably have the formula R ⁴ CH ₂ CO.O.CH ₂ R ⁵ , where R ⁴ and R ⁵ are independently hydrogen or an alkyl group. A suitable alkyl group is C ₁
~ _C6 alkyl group. Examples of suitable carboxylic anhydrides include acetic anhydride, propionic anhydride, and mixed anhydrides thereof. The reaction of formaldehyde with acetic anhydride produces products containing acrylic acid. The molar ratio of acid derivative to aldehyde is not critical, but a range of 1:1 to 25:1 is suitable. However, the optimum ratio can be easily determined by one skilled in the art depending on the reaction conditions and the nature of the reactants. Regarding the crystalline aluminosilicate having the above composition, Y is preferably in the range of 15 to 100. Various synthetic crystalline aluminosilicates conforming to the above formula may be suitably used. Examples of preferred types of crystalline aluminosilicates are provided by The Structure Commission of the International Zeolite Association.
1978 by International Zeolite Association
Mayer et al. (WMMeier and
The Atlas of Zeolite Structure Types by DHOlson
Zeolite Structure Types) is indicated as MFI zeolite. These are generally ()
Silica (SiO ₂ ) source, () Alumina source (Al ₂ O ₃ ),
() Mineralizing agent selected from oxides and salts of alkali and alkaline earth metals (X _2/b O, where b is
), organic bases such as () as described below
(B), and () water and/or alcohol (ROH) in the following molar ratio: _SiO2 : _Al2O3 , greater than ₁₂ :1, preferably from 15:1 to 100:1 _SiO2 : _{X2 /b} O=1000:1~50:1 _SiO2 :B=50:1~1:20, and _SiO2 : _H2
O or ROH, from a gel containing less than 1:10 from 80 to 220 °C, preferably from 120 to 175
Produced by crystallization at a temperature in the range of °C for a period of not less than 0.5 hours. The term organic base used is the reaction: -log ₁₀ K for B + H ₂ OBH ⁺ +OH ^- (where K = [BH ⁺ ] [OH ^- ]/
[B] means an appropriate organic substance in which the value (B) is less than 7. Suitable organic bases include: ^{( ) Formula: R 1 R 2 R 3 R 4 N +} or hydrogen and X ^- is an organic or inorganic anion). Preferably ^R1 , ^R2 , ^R3 , and ^R4 are alkyl groups containing 1 to 5 carbon atoms. Preferably X ^- is a halide or hydroxide ion. Suitable tetraalkylammonium salts include tetraethylammonium hydroxide and tetrapropylammonium hydroxide. Alternatively, precursors of tetraalkylammonium compounds can be used. Formula (): R ¹ R ² R ³ N or R ¹ R ² N (CH ₂ ) _x NR ³ R ⁴ (where x is an integer in the range of 1 to 20) or R ¹ R ² N (CH ₂ ) _y N(CH ₂ ) ₂ NR ³ R ⁴ , where y and z are integers ranging from 1 to 20. Suitable amines include C1 _{- C9} primary monoalkylamines such as n-ethylamine, n-propylamine, and n-butylamine. () Mono-, di- and tri-alkanolamines, such as monoethanolamine, diethanolamine and triethanolamine, or their precursors in the form of alkylene oxides and ammonia. Suitable silica sources include, for example, sodium silicate, silica hydrogel, silica gel, silica sol, and silicic acid. A preferred silica source is an aqueous colloidal dispersion of silica particles. A suitable commercially available silica source is LUDOX ^* colloidal silica manufactured by DuPont. Suitable alumina sources include, for example, sodium aluminate, aluminum sulfate, and alumina. A preferred alumina source is sodium aluminate made by dissolving finely divided alumina in excess sodium hydroxide solution. Preferred mineralizing agents are alkali and alkaline earth metal hydroxides and halides, such as lithium hydroxide, sodium hydroxide, potassium hydroxide, potassium bromide and calcium bromide. A preferred mineralizing agent is sodium hydroxide. The silica, alumina, alkali or alkaline earth metal feedstocks can be provided by one or more initial reactants and then mixed in any suitable order. For example, sodium silicate is a source of both sodium and silica, and aluminosilicate is a source of both alumina and silica. Thus, the alumina source and the silica source can be supplied in whole or in part by the aluminosilicate, which can be crystalline or amorphous. Certain MFI-type zeolites and their preparation using organic bases are described, for example, in U.S. Pat.
No. 3702886, No. 3709979, No. 4205053, No.
4166099, 4139600 and 4151189; UK Patent Nos. 1365318 and 1567948, and European Patent Application Nos. 2899 and 2900. Alternatively, organic bases are described in Applicant's European Patent Application No. 30811, US Pat. No. 4,199,556 and UK Application No. 2018232A. or ferrierite as described in UK Patent No. 1436524, European Patent Application Publication No. 57049
Theta-1, described in U.S. Patent No. 4,209,498, FU-1, described in U.S. Patent No.
nu-1 described in No. 1559367, U.S. Patent No.
ZSM-5/ZSM-11 described in US Patent No. 4229424, ZSM-35, ZSM described in US Patent No. 4146584
Other crystalline aluminosilicates such as -23 and zeolite beta can be used. In addition, dealuminated Hojiasite can also be used. The crystalline aluminosilicates produced will almost certainly contain ions other than hydrogen and transition metal ions, such as alkali metal and/or alkaline earth metal ions, organic nitrogen ions and ammonium ions, and/or their pores. Contains organic chlorine precipitated in and on the surface. In order to obtain a catalyst with the desired composition, it is necessary in the present invention to replace the exchangeable cations with hydrogen ions or metal cations selected from the group consisting of chromium, vanadium, praseodymium, lanthanum. This can be accomplished using conventional ion exchange techniques. Additionally, calcination of the crystalline aluminosilicate after exchange is desirable and, in fact, necessary prior to exchange of crystalline aluminosilicates derived from some organochlorines. Calcination is 400~
This can be carried out by heating at a temperature in the range of 600° C. for at least 0.5 hours, suitably in a stream of air. The temperature at which the acid derivative is reacted with the aldehyde may suitably range from 300 to 525°C, preferably from 350 to 500°C, although higher and lower temperatures can be used if desired. The pressure is not critical, but is suitably consistent with maintaining the reactants in the gas phase. The process can be operated batchwise or continuously, preferably continuously. The residence time for continuous operation is preferably short, for example less than 20 seconds. Instead of using formaldehyde in certain variants of the invention, the formaldehyde precursor can be supplied in the form of methanol and oxygen-containing gas if the catalyst also contains an oxidizing component or an oxidizing/dehydrogenating component. The methanol used can be any suitable commercially available methanol, although purer or impure grades can be used if desired. The oxygen-containing gas may suitably be air, but if desired an oxygen-rich gas, such as molecular oxygen or molecular oxygen/air mixtures, or an oxygen-poor, such as air/inert gas mixture, may be used. In the present invention, silver or chromium is used as the oxidizing component or oxidizing/dehydrogenating component of the catalyst. The element can be exchanged using exchangeable cations associated with the synthetic crystalline aluminosilicate using conventional methods, or alternatively can be impregnated into the synthetic crystalline aluminosilicate using known methods, or Can be replaced and impregnated. Examples of suitable catalysts are crystalline aluminosilicates in which at least some of the H ⁺ , transition metal or rare earth metal cations have been exchanged, for example by silver or chromium cations. Alternatively, the catalyst may comprise a mixture of the synthetic crystalline aluminosilicate and an oxidation or oxidation/dehydrogenation catalyst comprising the element unsupported or supported on an inert support. Suitable such oxidation or oxidation/dehydrogenation catalysts are described by Ernest
Propylene and Its Industrial Derivatives, edited by EGHancock, published by Earnest Benn Limited, London and Tonbridge.
Industrial Derivatives, 1973, (p. 391) in Chapter 10 entitled "Catalyst Types Associated with the Oxidation of Propylene to Acrylic Acid." Furthermore, as an alternative, synthetic crystalline aluminosilicates, in whole or in part, whose cations are H ⁺ and/or transition metal and/or rare earth metal cations,
For example, it can be mixed with synthetic crystalline aluminosilicates exchanged with silver and/or chromium cations. In this modification, the high temperature used is appropriately 250 to 450.
℃, preferably in the range of 300-400℃. The invention will now be illustrated with reference to the following examples. Examples include X-MFI (NH ₃ ) zeolite and
Mention MOR zeolite. X-MFI ( _NH3 )
The zeolite is a MFI type zeolite crystallized from a gel containing ammonium ions as described in EP-A-30811, where X is a cation, e.g. H. X-MOR zeolite is a mordenite type zeolite with X cations. X-MFI
Both (NH ₃ ) type and X-MOR zeolites
having a silica to alumina molar ratio greater than 10:1. Example 1 A sample of X-MFI (NH ₃ ) zeolite in the hydrogen form was loaded into a quartz U-tube reaction in the form of pellets. 10-20 ml of zeolite was used. U tube reactor at 390℃
A feed consisting of a 3:1 molar ratio of methyl acetate and formaldehyde was passed over the zeolite with a contact time of 4 seconds (NTP). The feed flow across the zeolite was supported by a slow flow of nitrogen. removing the products of the reaction from the gas phase using a methanol stripper;
GC of the effluent from the stripper to determine product yield
Determined by analysis. Example 2 X-MFI (NH ₃ ) zeolite to Pr-MFI
(NH ₃ ) instead of zeolite, lowering the temperature to 350℃,
The procedure of Example 1 was repeated except that the contact time was increased to 8 seconds (NTP). Example 3 Raise the temperature to 400℃ and contact time for 4 seconds (NTP)
The procedure of Example 2 was repeated except that the temperature was lowered to . Example 4 The procedure of Example 2 was repeated except that the temperature was increased to 425°C. Example 5 The procedure of Example 3 was repeated except that the contact time was increased to 8 seconds (NTP). Example 6 H-MFI (NH ₃ ) zeolite to V-MFI (NH ₃ )
The procedure of Example 1 was repeated except that zeolite was substituted. Example 7 H-MFI (NH ₃ ) zeolite to Cr-MFI
Example 1 except that (NH ₃ )zeolite was used instead
The procedure was repeated. Example 8 The procedure of Example 1 was repeated except that the H-MFI ( _NH3 ) zeolite was replaced with La-MOR zeolite and the temperature was increased to 425<0>C. Example 9 H-MFI (NH ₃ ) zeolite to H-MFI (NH ₃ )
The procedure of Example 1 was repeated except that a steam treated sample of zeolite was substituted. After one hour of operation for Examples 1-9, the results in terms of percent yield (moles) relative to formaldehyde fed are shown in the table. Example 10 12.5 g of zeolite MFI (NH ₃ ) in hydrogen form was placed in a quartz U-tube reactor and heated to 390° C. in a bath of molten tin. A mixture of acetic anhydride and formaldehyde (3:2 mol) was passed over the catalyst at a rate of 23 ml per hour. The reaction product was analyzed by capillary GC after 1 hour of operation and was shown to have a 6.5 mole percent yield of acrylic acid based on the formaldehyde feed. Example 11 12.5 ml of molybdenum-loaded hydrogen MFI zeolite was mixed with 5 ml of 5% silver loaded on Davison 57 silica. The catalyst was then placed in a stream of air for 18 hours.
Activated at 500℃. At the end of this time, a 2:1 molar mixture of methyl acetate and methanol was passed in the gas phase over the catalyst at 390 DEG C. with a stream of dry air. A sample of the product stream was analyzed after 1 hour and was shown to contain methyl acrylate. The molar yield of methyl acrylate based on the methanol fed was 7.25%. Example 12 This time, silver-exchanged MFI type zeolite was used as a catalyst (12.5
The test conditions were as in Example 11, except that the test conditions were as follows:
It was exactly the same as the description. Both methyl acrylate and acrylic acid were detected as products. After one hour of operation, the molar yield of methyl acrylate based on the methanol fed was 4.5%. Example 13 Example 12 was repeated except that a reaction temperature of 420°C was used in this example. After 1 hour of operation, the molar yield of the above methyl acrylate was 57%. Example 14 The procedure of Example 11 was followed, but in this example a chromium-exchanged MFI zeolite was used. After 1 hour of operation, the molar yield of methyl acrylate was 0.9%.

[Table] * Not detected in test

Claims (1)

[Scope of Claims] 1. A method for producing an unsaturated carboxylic acid and/or its ester by reacting an aldehyde including formaldehyde or acetaldehyde with a saturated carboxylic acid derivative at high temperature in the gas phase in the presence of a catalyst. If the saturated carboxylic acid derivative is an ester or anhydride and the catalyst is 0.9±
0.2M _2/o O: Al ₂ O ₃ : YSiO ₂ :zH ₂ O [wherein M is H ⁺ and/or a cation selected from the group consisting of chromium, vanadium, praseodymium, and lanthanum having a valence n And Y
is an integer greater than 10, and z is an integer ranging from 0 to 40. 2. The method according to claim 1, wherein the aldehyde is formaldehyde. 3 ^The acid derivative has ^the formula: R ¹ CH ₂ X or XCH ₂ R ² CH ₂ is a hydrocarbon group, and X is a functional group having the formula -COOR ³ (wherein R ³ is a hydrocarbon group or a substituted hydrocarbon group).
or the method described in paragraph 2. 4. The method according to any one of claims 1 to 3, wherein methyl acrylate and/or acrylic acid are produced by reacting formaldehyde and methyl acetate. 5. The method according to any one of claims 1 to 3, wherein methyl methacrylate and/or methacrylic acid are produced by reacting acetaldehyde and methyl acetate. 6 Claims in which the acid derivative is a saturated carboxylic acid anhydride of the formula: R ⁴ CH ₂ CO.O.COCH ₂ R ⁵ , where R ⁴ and R ⁵ are independently hydrogen or an alkyl group. The method according to item 1 or 2. 7. The method of claim 6, wherein formaldehyde and acetic anhydride are reacted to produce a product containing acrylic acid. 8. The method according to any one of claims 1 to 7, wherein the synthetic crystalline aluminosilicate is an MFI type zeolite. 9 Unsaturated carboxylic acids and/or their Method of producing esters.