WO2007058221A1 - Process for dehydration of polyhydric alcohols - Google Patents

Abstract

The invention has been accomplished in view of the above circumstances and aims at providing a process for production of dehydrates by gas-phase dehydration which is excellent in yield and selectivity and economically advantageous in industrial practice and a catalyst for gas-phase dehydration to be used in the process. The invention also aims at providing, as preferable embodiments, an embodiment wherein acrolein can be obtained from glycerol through gas-phase dehydration with high selectivity, particularly, an embodiment wherein acrolein can be produced in high yield even when a high-concentration glycerol solution is used to thereby obtain a high-concentration acrolein solution directly, and an embodiment wherein the catalyst little deteriorates even after the lapse of time. The invention further aims at providing a novel catalyst suitable for producing acrolein from glycerol not originating from petroleum and a process for producing acrolein efficiently from such glycerol. The invention relates to a process for the production of dehydrates by gas-phase dehydration of a compound having three or more hydroxyl groups which comprises the step of bringing the compound into contact with a gas-phase dehydration catalyst containing at least one Group 6 element.

Description

 Polyhydric alcohol dehydration method

 Technical field

 [0001] The present invention relates to a method for producing a dehydration product using a compound having three or more hydroxyl groups as a raw material, and a catalyst for gas phase dehydration. More specifically, the present invention relates to a method for producing a dehydrated product suitable for producing acrolein or an acrolein aqueous solution by contacting glycerol with a catalyst in the gas phase to dehydrate, and a gas phase dehydrating catalyst used therefor. In the present invention, when producing acrolein or an aqueous solution of acrolein, since glycerin as a raw material can be derived from vegetable oil, which is a renewable resource, acrolein as a raw material for important chemical substances such as acrylic acid and methionine is used. A method for efficiently producing from renewable resources can be provided.

 The present invention also relates to a catalyst for producing acrolein and a method for producing acrolein using the same, and is suitable for a method for producing acrolein using glycerin not derived from petroleum as a raw material. More specifically, the present invention relates to an acrolein production catalyst suitable for producing acrolein or an acrolein aqueous solution by dehydrating glycerin using a catalyst, and an acrolein production method using the same. In the present invention, when acrolein or acrolein aqueous solution is produced, since the raw material glycerin can be derived from vegetable oil, which is a renewable resource, acrolein, which is a raw material for important chemical substances such as acrylic acid and methionine, can be regenerated. Resource power An efficient manufacturing method can be provided.

 Background art

[0003] A method for producing a dehydrated product using a compound having three or more hydroxyl groups as a raw material is useful as a method for producing industrial raw materials such as glycerin-acrolein, and various methods have been studied. Thus, the production of acrolein by dehydration of glycerin has the following advantages. In other words, acrolein is usually produced by propylene gas-phase acid, but the raw material propylene is a fossil resource, and there are concerns about future resource depletion and increased carbon dioxide in the atmosphere. is there. On the other hand, when acrolein is produced by dehydration of glycerin, glycerin used as a raw material can be obtained from vegetable oil. It can be obtained as biodiesel fuel by transesterification of vegetable oil or as a by-product in the production of sarcophagus. Therefore, in a method that can use glycerin as a raw material, it can be regenerated because glycerin is derived from plants, and the carbon source that is worried about resource depletion is diacid carbon in the atmosphere. Therefore, it does not contribute to the increase of carbon dioxide in the atmosphere!

[0004] As a conventional method for producing a dehydrated product, for example, the following method is disclosed as a method for producing glycerin acrolein.

 That is, a method for producing glycerin acrolein using an acidic substance as a catalyst has been disclosed (for example, Non-Patent Document 1; “Industrial Science”, 1934, 37th (Suppl, binding), p. See 538;). This discloses a method in which glycerin is dripped onto a fixed bed catalyst maintained at 340 ° C to 650 ° C. Examples of the catalyst include iron phosphate, activated clay, KHSO K S

 4 2

Note that a mixture of O can be used and yields of up to 51% are obtained when using iron phosphate.

Four

 It is listed. In addition, it is stated that the Schering 'Karlbaum patent, which is introduced as the prior art, describes that phosphates such as lithium phosphate and copper phosphate are effective. However, the yields obtained with these catalysts were not sufficient for industrial production.

[0005] It is disclosed that acrolein can be obtained by dehydrating glycerin using benzenesulfonic acid as a catalyst and phthalic anhydride as a dehydrating agent (for example, Non-Patent Document 2; "Chemische Berichte" (Germany), 1950, 83rd pp. 287-291.) However, it was not an industrially practical technique because the amount of phthalic anhydride used was greater than the obtained acrolein.

 In addition, as a method for producing acrolein using a raw material not derived from petroleum, a method using a dehydration reaction of glycerin has been proposed. For example, for the production of acrolein using a catalyst in which phosphoric acid is supported on a catalyst carrier, HPO, HPO, HPO or PO

3 4 3 4 2 7 2 5 By using a catalyst supported on a carrier and dehydrating at 250-325 ° C in an organic solvent with a high boiling point, 72.3% of glycerol must be obtained as acrolein. (For example, see Patent Document 1; US Pat. No. 2,585,520.) ₀ It is described that acrolein was obtained in a relatively high yield in this dehydration reaction. However, Therefore, in this method, accumulation of tar in the reaction liquid is inevitable, and waste liquid in which tar and catalyst are mixed is generated. In addition, there was room for improvement in terms of yield. Thus, no catalyst suitable for the dehydration reaction of polyhydric alcohol has been found, and it has not been an effective and stable catalyst capable of efficiently producing acrolein.

It is disclosed that acrolein is produced from glycerin in gas chromatography, that is, acrolein is produced by gas-phase dehydration (for example, Non-Patent Document 3; Koichi ISHIKAWA et al., “Analysis Chemistry (English: BUNSEKI K AGAKU) ”, 1983, 32 卷, No. 10, pp.E321-E325.) However, it is not a technology that has special conditions and a small amount of acrolein and that has a possibility of industrial implementation. In addition, it has also been disclosed that glycerin and acrolein are produced by using proton type ZSM-5 as a catalyst in biomass pyrolysis (for example, Non-Patent Document 4; Lee H. Dao et al., “Reactions of Model Compounds of Biomass- Pyrolysis Oils over Z SM- 5 Zeolite Catalysts) —American 'Chemical' Society, Symposium Series (USA), 1988, P. 376 (Pyrolysis Oils Biomass) ゝ pp. 328—341 reference

. The yield of acrolein is not clearly shown, and many by-products such as carbon, id-mouthed carbon and tar are shown to be produced, which is not an industrially advantageous technique.

Furthermore, it has been disclosed that acrolein can also be obtained in supercritical water (for example, Non-Patent Document 5; “Preblind'Ob'Paper's American'Chemical'Society 1, Tyhi, Chillon '"). “Fuenore” Chemistry (Preprints of Papers-American Chemical Society, Division of Fuel Chemistry;) (USA), 1985, No. 30, No. 3, pp. 78-87, Non-Patent Document 6; "Energy from Biomass and Wastes;" (USA), 1987, No. 10, p. 865-877, and Non-Patent Document 7; "Fuel", (United Kingdom), 1987, 66, No. 10, pp. 13 64–1371 etc.). However, the method of using supercritical water is an industrial practice. 言 It is difficult to say that it is economically advantageous.

[0007] A method for producing acrolein or an aqueous solution of acrolein by reacting a glycerin Z water mixture with a solid catalyst in a liquid phase or a gas phase at a temperature of 180 ° C or higher has been disclosed (for example, , Patent Document 2: Japanese Patent Laid-Open No. 6-211724.) _{0 In} this, dehydration was carried out at 300 ° C in the gas phase using a catalyst prepared by mixing a-A1 O with a phosphoric acid solution.

twenty three

 In other words, it was described that acrolein was obtained at a yield of up to 75% when the acrolein concentration was 10% by weight. However, it has been described that the use of a high concentration glycerin aqueous solution significantly reduces both the selectivity of the reaction and the life of the catalyst. Therefore, the low concentration acrolein aqueous solution cannot be used effectively. There was room for ingenuity to make it a simple manufacturing method. In addition, there are many by-products such as hydroxyacetone, and it is difficult to say that the yield of acrolein is sufficient. In addition, a -A1 O

 A catalyst was prepared by mixing 23 with a phosphoric acid solution. However, when phosphorus was included, stability against changes with time decreased, and the performance of the solid catalyst was likely to deteriorate. The stability of the catalyst against aging is an important factor in terms of economic productivity, and if this is impaired, it will be detrimental to the economics of industrial production. Thus, simply specifying that the reaction is brought into contact with a solid catalyst is not an advantage in terms of characteristics such as yield, selectivity, and stability over time.

[0008] By the way, an acid catalyst is effective for the dehydration reaction of a conventional alcohol. For example, a book such as Tabe et al. Describes that various solid acid bases are effective, and that a solid acid is particularly excellent. In addition, acid-tungsten is also listed as one of the effective solid acids (for example, Non-Patent Document 8; Kozo Tanabe et al., “NEWSOLID ACIDS AND AND BASICS”). BASES) (ISBN 0-444-988000-9) ”1989, Chapter 7“ DEHYDRATION ”, pp. 260-272, (KODANSHA, ELSEVIE R).) O Others In addition, a report using a catalyst containing tungsten (W) has already been made. For example, a technology for producing ethylene and ether from ethanoluca using a catalyst consisting of acid tungsten and acid titanium. (E.g., Patent Document 3; United Kingdom) (Refer to the specification of Patent No. 650475.) ₀ Also for the dehydration reaction of polyhydric alcohols having multiple hydroxyl groups, 1, 4 butanediol to THF (tetrahydrofuran) ) Is shown (for example, see Patent Document 4; Chinese Patent No. 1272495;). However, even in the above-mentioned patent documents where the description up to the dehydration reaction of the dihydric alcohol is not included in the books of Tabe et al. And the dehydration reaction of the trihydric alcohol is not described, what is obtained is olefin or ether. Yes, it is different from the reaction that produces acrolein. It is also a product of a single-stage dehydration reaction. In other words, these reactions were completely different in the reaction form from the method for producing a dehydration product using a compound having 3 or more hydroxyl groups as a raw material, such as a dehydration reaction that produces glycerin acrolein. .

 [0009] Among the methods for producing a dehydrated product using a compound having three or more hydroxyl groups as a raw material, the method for producing acrolein using glycerin as a raw material is particularly useful as a method for producing an industrial raw material. The production of acrolein by dehydration of glycerin has the following advantages. In other words, acrolein is usually produced by the gas phase oxidation of propylene, but the raw material propylene is a fossil resource, and there are concerns about future resource depletion and increased carbon dioxide in the atmosphere. is there. On the other hand, when acrolein is produced by dehydration of glycerin, the glycerin used as a raw material can be obtained from vegetable oil, and it can also be used as a biodiesel fuel by transesterification of plant oil and as a by-product in the production of sarcophagus. Obtainable. Therefore, in the method in which glycerin can be used as a raw material, it can be regenerated because glycerin is derived from a plant, and the carbon source for which there is no concern about resource depletion is that it is carbon dioxide in the atmosphere. Therefore, it has the advantage that it does not contribute to the increase of carbon dioxide in the atmosphere.

[0010] As a method for producing acrolein, a method in which propylene is vapor-phase oxidized using a catalyst is generally used, and this method is generally adopted industrially (for example, Patent Document 5; (See JP-A-8-3093 and Patent Document 6; JP-A-8-40969.) However, the method of vapor phase oxidation of propylene as described in the above document is based on the use of propylene derived from petroleum.

 2 In order to suppress global warming due to the increase, there is a demand for a process for producing acrolein using raw materials that do not depend on fossil resources.

[0011] In addition, a method for producing acrolein with an acid catalyst in supercritical water has been studied (for example, For example, see Non-Patent Document 7; Fuel 66 卷 1987, pages 1364 to 1371. ). However, no catalyst suitable for polyhydric alcohol dehydration has been found, and an effective and stable catalyst capable of efficiently producing acrolein has not yet been reported.

In addition, glycerol is used in the presence of a strong acid solid catalyst having a Hammett acidity H of -9 to -18.

 0

Techniques for producing acrolein by vapor phase dehydration are disclosed (for example, Patent Document 7; International Application WO2006Z087083 and Patent Document 8; International Application WO2006Z 087084;).

International application WO2006Z087083 describes extending the life of the catalyst by introducing oxygen during the reaction, and international application WO2006Z087084 shows that the catalyst has an H function that indicates acid strength. Is described. In addition, the examples include tongue

0

Dusten-zircoua catalyst is described, and H = — 14.5 is described. However

 0

However, these technologies are optimal in various respects such as the H function and catalyst morphology.

 0

There was room for improvement to make it more industrially efficient, especially by improving the selectivity of acrolein. In addition, international application WO2006

/ 087083 and international application WO2006 / 087084i, all of which have been filed on January 6, 2006. Both international publication dates are the basic applications of the present application (Japanese Patent Application No. 2005-330481, Japanese Patent Application No. 2006-000004, and Japanese Patent Application No. 2006-244504), which is later than August 24, 2006. Patent Document 1: US Patent No. 2558520

Patent Document 2: Japanese Patent Laid-Open No. 6-211724

Patent Document 3: Specification of British Patent No. 650475

Patent Document 4: Chinese Patent No. 1272495

Patent Document 5: JP-A-8-3093

Patent Document 6: Japanese Patent Laid-Open No. 8-40969

Patent Document 7: International Publication No. 06Z087083 Pamphlet

Patent Document 8: International Publication No. 06Z087084 Pamphlet

Non-Patent Document 1: “Industrial Chemistry”, 1934, 37th (Suppl, binding), p. 538 Non-patent Document 2: “Chemische Berichte” (Germany), 1950, 83 卷, pp. 287-291

Non-Patent Document 3: Koichi ISHIKAWA et al., “Analytical Chemistry (BUN SEKI KAGAKU)”, 1983, No. 32, No. 10, pp. E321—E325

Non-Patent Document 4: Lee H. Dao et al., “Reactions' Ob 'Model Compound' Ob 'Biomass Pyrolysis Inenoles' Over ~ ~ ZSM-5 Zeolite Catalysts (Reactions of Model and ompounas of Biomass- PyrolysisOiis over ZSM-5 z-eolite Catalysts) —American Chemical Society Symposium Series (USA), 1988, No. 376 (Pyrolysis Oils Biomass), pp. 328—341

Non-Patent Document 5: "Preprints of Papers-American Chemical Society, Division of FudChemistry" (USA), 1985, 30th, No. 3, pp. 78—87

Non-Patent Document 6: “Energy from Biomass and Waste” (USA), 1987, No. 10, p. 865—877

Non-Patent Document 7: “Fuel” (UK), 1987, 66th, No. 10, PP. 136 4-1371

Non-Patent Document 8: Kozo Tanabe et al., `` NEW SOLID ACIDS AND BASES (ISBN 0-444-988000-9) '', Chapter 7, `` Dehide '' "DEHYDRATION" ", pp.260-272, (KODANSHA, ELSEVIER)

Disclosure of the invention

Problems to be solved by the invention

The present invention has been made in view of the above situation, and is a catalyst used for producing a dehydrated product by a dehydration reaction (particularly, a gas phase dehydration reaction), which is excellent in yield and selectivity. It is an object of the present invention to provide a method for producing a dehydration product that is economically advantageous in practical implementation and a catalyst (particularly, a gas phase dehydration catalyst) used therefor. Another object of the present invention is to acrolein using glycerin, which is a raw material not derived from petroleum. Another object of the present invention is to provide a catalyst suitable for the production of a novel acrolein that can be obtained, and a method for efficiently producing acrolein. Another object of the present invention is to provide a form in which glycerin acrolein can be obtained with high selectivity by gas phase dehydration reaction. In this case, even when a high-concentration glycerin solution is used, acrolein can be obtained in a high yield, whereby a high-concentration acrolein solution can be obtained directly. Another object is to provide a form with little deterioration. Means for solving the problem

 [0014] As a result of searching for a catalyst for obtaining a dehydrated product and various methods for producing the dehydrated product, the present inventors, for example, when acrolein is obtained by glycerin force dehydration reaction, the raw material is contacted with the catalyst. Focusing on the fact that the gas phase dehydration reaction to be carried out is advantageous in terms of resources and the environment, if a catalyst using a group 6 element is essential, the desired dehydration product can be obtained with high selectivity. I found it advantageous. It was also found that such a catalyst has high stability over time, and it is difficult for the catalyst activity to decrease even in a reaction using a high-concentration glycerin solution. Thus, the inventors have arrived at the present invention by conceiving that the above-mentioned problems can be solved by specifying the essential elements contained in the catalyst in the gas phase dehydration reaction.

 [0015] In the method for producing glycerin acrolein, a solid acid can be used for the gas-phase dehydration reaction of glycerin. In this case, phosphoric acid or phosphoric acid compound, potassium sulfate, potassium hydrogen sulfate, activated clay is used alone or A catalyst supported on a carrier can be used as a catalyst. In addition, as described above, Japanese Patent Application Laid-Open No. 6-211724 discloses that when 40% by weight or less of a dariserine aqueous solution is used as a raw material, the acid strength is no and the Met acidity function is +2 or less. A known solid substance having acidity is shown. However, these catalysts cannot be said to have sufficient selectivity, and higher selectivity has been desired. As a result of studying various solid substances in a wide range for the gas-phase dehydration reaction of dariserine, the present inventors have highly selected a catalyst containing a Group 6 element. In addition, it has been found out that it has high selectivity, has both high selectivity and high activity, and is excellent in stability over time.

[0016] As described above, an acid catalyst is effective for the conventional alcohol dehydration reaction. Although a report using a catalyst containing stainless (w) has already been made, the reaction form is completely different from the method for producing a dehydrated product using a compound having 3 or more hydroxyl groups as a raw material of the present invention. . That is, in a method for producing a dehydration product using a compound having three or more hydroxyl groups as a raw material, for example, a dehydration reaction for producing glycerin acrolein is performed by dehydrating two molecules of water from one molecule of glycerin and olefin and carbohydrate. In the above dehydration reaction, only olefin and ether are formed, no carbo- yl is formed, and the functional group of the product is completely different. In addition, due to this, the influence of the sequential reaction is also completely different. For example, acrolein obtained by dehydrating glycerin is a highly reactive substance, and so many reactions are known. For example, Japanese Patent Laid-Open No. 4 266884 describes a method of obtaining acrolein glycerin acetal by reacting glycerin as a raw material of the present application with acrolein as a product. In addition to acetal candy, various reactions such as Michael addition and Diels-Alder reaction may occur. For example, there is a reaction that reacts with water to produce 3-hydroxypropanal. A catalyst suitable for production needs to have low activity with respect to these sequential reactions, and an excellent catalyst cannot be obtained simply by having a high dewatering reaction capability. As for the dehydration reaction itself, glycerin has a terminal OH and a central OH, and the product differs depending on which OH is desorbed first. The reaction that produces the same product when either OH group is eliminated, such as dehydration of ethyl alcohol or 1,4 butanediol, which has only one OH group, is the reaction Factors affecting selectivity are likely to be different.

As described above, the method for producing a dehydrated product by vapor-phase dehydration using a compound having 3 or more hydroxyl groups that can generate acrolein as a raw material is a regioselectivity of a reaction that is not limited to simple dehydration power. Suitable catalysts are difficult to predict because sequential reactions have a major impact.

The present invention has been made by finding that at least one group 6 element exhibits particularly excellent selectivity and activity for the elimination of a compound having three or more hydroxyl groups such as glycerin, and is simultaneously deteriorated with time. However, it was achieved by seeing little things. As mentioned above, the stability of the catalyst against aging is an important factor in the economic aspect of industrial production, The present invention also has a remarkable effect in this respect.

 In addition, as a result of intensive studies to solve the above-mentioned problems, the present inventor studied the production of acrolein using glycerin that can be easily obtained from naturally derived oils and fats as a raw material. The inventors have found that acrolein can be obtained more efficiently by the method for producing acrolein in which glycerin is reacted in the presence of a heteropolyacid catalyst, and the present invention has been completed.

 That is, the present invention is a method for producing a dehydrated product by dehydrating a compound having 3 or more hydroxyl groups, wherein the production method is contacted with a catalyst containing at least one group 6 element. It is a manufacturing method of the dehydration product including a process.

 The present invention is also a method for producing a dehydrated product by dehydrating a compound having 3 or more hydroxyl groups, wherein the production method comprises reacting glycerin in the presence of a heteropolyacid catalyst to produce acrolein. It is also a method for producing a dehydrated product.

 Furthermore, this invention is also a catalyst used for the manufacturing method of the said dehydration product.

[0018] Preferred embodiments of all of the present invention described above include the following embodiments.

 A method for producing a dehydrated product by dehydrating a compound having three or more hydroxyl groups, wherein the production method comprises a step of contacting with a catalyst containing at least one group 6 element Preferred to be the way.

 The method for producing a dehydrated product is preferably a method for producing a dehydrated product, which is a method for producing acrolein by dehydrating glycerin.

 The catalyst is preferably a method for producing a dehydrated product in which the Group 6 element is at least one element selected from the group consisting of tungsten, chromium, and molybdenum.

 The catalyst is preferably a method for producing a dehydrated product in which the Group 6 element is tungsten.

 The heteropolyacid catalyst is preferably a method for producing a dehydrated product having a Keggin structure.

The heteropolyacid catalyst is preferably a method for producing a dehydrated product in which the hetero elements are phosphorus and Z or silicon. The heteropolyacid catalyst is preferably a method for producing a dehydration product in which the coordination elements are tungsten and z or molybdenum.

The catalyst is preferably a method for producing a dehydrated product supported on an inorganic carrier.

The inorganic carrier is preferably a method for producing a dehydrated product having at least one element selected from the group consisting of silicon, aluminum, titanium, and zirconium.

The inorganic carrier is preferably a method for producing a dehydrated product mainly composed of silicon oxide.

The inorganic carrier is preferably a method for producing a dehydrated product having binary pores. In addition, the manufacturing method of this invention is not restricted to said embodiment illustrated above. The technical significance of the above embodiment is as described later.

The present invention is described in detail below.

A method for producing a dehydrated product by dehydrating a compound having three or more hydroxyl groups, wherein the production method comprises a step of contacting with a catalyst containing at least one group 6 element Hereinafter, this method is also referred to as a method for producing a dehydrated product using a catalyst containing at least one group 6 element.

Further, it is a method for producing a dehydrated product by dehydrating a compound having three or more hydroxyl groups, wherein the production method comprises dehydration by reacting glycerin in the presence of a heteropolyacid catalyst to produce acrolein. Hereinafter, the production method of the product is also referred to as acrolein production method.

In the present specification, the method for producing acrolein and the method for producing a dehydrated product using a catalyst containing at least one group 6 element are also collectively referred to as a method for producing a dehydrated product. In the present specification, the production method of the present invention or the production method of a dehydrated product refers to the production method of acrolein and the at least one group 6 element unless otherwise specified. It also means a process for producing a dehydrated product using the catalyst it contains. Therefore, the catalyst used in the method for producing a dehydrated product is, in other words, used in the method for producing a dehydrated product using a catalyst containing at least one group 6 element. And the catalyst used in the above-described method for producing acrolein.

More specifically, the method for producing a dehydrated product using a catalyst containing at least one group 6 element is a method for producing a dehydrated product by vapor-phase dehydration of a compound having 3 or more hydroxyl groups. A method for producing a dehydrated product comprising a step of contacting with a gas phase dehydration catalyst containing at least one group 6 element.

The catalyst in the present invention (particularly preferably, a gas phase dehydration catalyst) contains at least one group 6 element. In such a gas phase dehydration catalyst, the Group 6 element is preferably at least one element selected from the group consisting of tungsten (W), chromium (Cr) and molybdenum (Mo) forces. The vapor phase dehydration catalyst is more preferably in a form in which the Group 6 element is tungsten (W). Gas phase dehydration catalysts using W are, for example, P O /

 twenty five

Compared to catalysts such as Al 2 O, the rate of by-products such as hydroxyacetone is reduced.

twenty three

Therefore, the selectivity over time can be improved and the stability over time can be improved. The content of the Group 6 element is preferably 1 or more, more preferably 20 or more, and still more preferably 60, out of all 1000 atoms excluding oxygen and hydrogen from the catalyst constituents including the support. More than one. When the content of the group 6 element is less than the above range, the catalyst activity may be insufficient, or the decrease in activity over time may be large, which is preferable. The upper limit of the content of the Group 6 element is not particularly limited, but even if it contains 80% or more of the catalyst weight, no effect can be expected. In addition, elements other than Group 6 elements are not particularly limited, but vanadium increases by-products and decreases the acrolein yield, so that the amount of vanadium atoms exceeds the number of tungsten atoms. Saddle is not preferred.

The catalyst having the Group 6 element only needs to contain at least one group 6 element, and its form is not specified. For example, an amorphous compound, a single oxide, or a complex oxide may be used. included. The source of addition of elements in Group 6 is not specified, but inorganic salts such as nitrates, sulfates, hydrochlorides, phosphates and carbonates, and organic acid salts such as oxalates, citrates and tartrates, Complex salts or acid compounds can be used. Heteropolyacids such as phosphotungstic acid can also be suitably used. Of these, heteropolyacids are particularly preferred. [0021] The gas phase dehydration catalyst may be one in which a Group 6 element is supported on an inorganic carrier. By using a supported catalyst, the active substance can be used effectively and the shape of the catalyst can be easily provided. The shape of the catalyst may be an indefinite shape such as a crushed product, but preferably a spherical shape, ring shape, cylindrical shape, saddle shape, half ring shape or the like generally used for a gas phase reaction is preferably used.

 It is preferable that the inorganic carrier includes at least one element selected from the group consisting of zirconium, aluminum, and silicon, such oxides, hydrated oxides, nitrides, carbides, and the like. Available. Further, it is particularly preferable to contain zirconium. For example, as such an inorganic carrier, industrially used oxides such as zirconium, alumina and silica, and powders and molding carriers made of complex oxides or mixtures thereof can be used. In addition, these precursors such as hydroxides, hydrated oxides and salts can be used.

[0022] The method for preparing the catalyst in which the Group 6 element is supported on the inorganic carrier is not particularly limited, and it is only necessary that the active substance containing the Group 6 element is finally present on the inorganic carrier. Common catalyst preparation methods are used. For example, for convenience, an inorganic carrier powder and a compound having at least one group 6 element are mixed in a liquid medium, then the liquid medium is removed and dried, and the resulting solid is pulverized to an appropriate particle size. Can be done. As the liquid medium, a non-aqueous solvent capable of suitably using a hydrophilic solvent such as water or ethanol can be used, and in particular, a substance capable of dissolving the Group 6 element compound to be used is preferable. It is also preferable to use a dehydrated solvent from which dissolved water has been removed. For example, a catalyst obtained by calcining a heteropolyacid dissolved in absolute ethanol on a hydroxide-zircol powder gives favorable results. The firing conditions are preferably performed in an inert gas atmosphere, for example, in a nitrogen atmosphere. In addition, a mixture of a Group 6 element solution and an inorganic oxide powder is formed into a kneaded product by extrusion, or formed into a slurry and then coated on the surface of another formed carrier. Catalyst preparation methods can be used. In addition, it is supported by impregnating a solution containing at least one group 6 element using a composition carrier made of an inorganic oxide containing one or more of zirconium, aluminum, and silicon as a constituent element. Also good. In addition, a salt solution containing any one of zirconium, aluminum, and silicon may be used. Even if it is a method of adding at least one group 6 element, precipitating by neutralization method, etc., then drying and firing, the form in which group 6 element finally exists on the surface of these inorganic oxides If the method becomes! /, The method of deviation can also be used.

[0023] The gas phase dehydration catalyst is represented by an H function when the acid strength is measured by Hammett titration.

 0

 And 8 · 2≤H ≤ + 6. 8 are preferred.

 0

 The Hammett acidity function is preferably measured using, for example, the no-met indicator method. When measuring using the Hammett indicator method, for example, keep the catalyst dehydrated by heating in dry benzene, and in turn add +6, 8, -3.0, -8.2, The highest acid strength was measured, and then the dehydrated catalyst was added to dry benzene to which each indicator was added, and titration was performed with an n-butylamine'benzene solution with a known concentration until the color disappeared. It is also preferable to measure the amount.

 Hammett's acidity function is defined by the degree of discoloration of an indicator using a specific indicator group of neutral base (B) and the tendency of an oxide to transfer protons to these indicators. is there. If the dissociation constant of the acid form BH + of the indicator is K,

 BH +

 The degree function H is defined by the following equation.

 o

 h = K (C / C)

 O BH + BH + B

 H = logh

 O 0

 Where h is the acidity of the oxide and C / C is the indicator conjugate acid BH + and its co-

0 BH + B

 Concentration ratio of B )

[0024] The method for producing a dehydrated product of the present invention is a method for producing a dehydrated product by dehydrating a compound having 3 or more hydroxyl groups. The compound having 3 or more hydroxyl groups as a raw material for production may be a compound such as a polyhydric alcohol having at least 3 hydroxyl groups in one molecule. In the present invention, a compound having 3 hydroxyl groups is used. It is preferable to use some glycerin. In the dehydration reaction using glycerin as a raw material, acrolein is obtained as a dehydrated product. In this case, as described above, glycerin is reproducible because it is derived from a plant, and its carbon source that is free from fear of resource depletion is essentially dioxygen carbon in the atmosphere. This has the advantage of not contributing to the increase of carbon dioxide. Therefore, the method for producing the dehydrated product described above is based on vapor phase dehydration of glycerin. Thus, a method for producing acrolein is preferred.

 [0025] In the method for producing a dehydrated product of the present invention, the reaction pressure is not particularly specified but is preferably 1 atm or less. The temperature in the gas phase dehydration is preferably 200 to 500 ° C. If the temperature is lower than 200 ° C, the reaction rate may extremely decrease, and if it exceeds 500 ° C, the degradation of dariselin or the sequential reaction of the generated acrolein may increase, leading to a decrease in selectivity. There is. More preferably, it is 200-450 degreeC. In addition, the lower limit of the reaction temperature is also limited by the vapor pressure of glycerin, and it is preferable that all of the supplied glycerin be at or above the temperature at which it can exist in a gaseous state. I like it. Also, the feed rate of the raw material gas to the catalyst is preferably about 100 to 5000 Zhr as the space velocity. If it is less than lOOZhr, the yield may decrease due to the sequential reaction, and if it exceeds 5000 Zhr, the reaction does not proceed sufficiently. The conversion rate may be reduced. As a method for subjecting the catalyst to a gas phase dehydration reaction, for example, a catalyst layer can be formed by filling a catalyst in a reaction tube.

 For example, in the case of a gas phase dehydration reaction of glycerin, it is preferable to conduct a glycerin-containing gas obtained by vaporizing glycerin and Z or a glycerin solution through a catalyst layer of 200 ° C force and 600 ° C. As the glycerin solution to be used, an aqueous solution can be suitably used. In addition, an organic solvent may be used as long as it is a substance that dissolves dalyserin and does not inhibit the reaction. Therefore, a glycerin solution in which glycerin is dissolved in an organic solvent can also be used. The concentration of the glycerin solution is not particularly limited, and may be 100% by mass of glycerin. However, for the purpose of adjusting the gas concentration and the space velocity with respect to the catalyst, the concentration of the organic substance that is gaseous at the reaction temperature and inactive to the reaction. Dilute with an inert gas such as CO or nitrogen.

 2

 Good.

[0026] When an inert gas is used in the dehydration reaction (particularly preferably, the gas phase dehydration reaction) in the method for producing the dehydrated product, acrolein is accompanied by the inert gas because the boiling point of acrolein is low. As a result, the recovery rate of acrolein due to the reaction gas power may be reduced, so that condensable substances and acrolein can be used simultaneously with inert condensable substances such as water (inert condensable substances). It is preferable to carry out by a method of separating after collecting. On the other hand, when a large amount of inert condensable substance was used, the concentration of acrolein obtained decreased and was recovered. Since the amount of inert condensable substances increases and processing costs increase, a method using a combination of inert gas and inert condensable substance is preferred.

 [0027] In the above method for producing a dehydrated product, the ratio of glycerin to an inert condensable substance such as water is preferably 0 to 12 mol of inert condensable substance with respect to 1 mol of glycerin, for example. . That is, the glycerin concentration is preferably 7.7 to: LOOmol%. More preferably, the glycerin concentration is 23 to: LOOmol%, and still more preferably the glycerin concentration is 31 to: LOOmol%. In the present invention, acrolein can be obtained in a high yield even when such a high-concentration glycerin solution is used, and thus a high-concentration acrolein solution can be obtained directly.

 [0028] The reaction product gas can be cooled and condensed to be acrolein or an acrolein solution, used as a raw material for producing acrylic acid or methionine, and acrolein obtained by condensation can be used. Acrylic acid can be obtained by vaporizing again and mixing with a suitable amount of air or water vapor using a known method of gas phase oxidation to oxidize. Also, omitting the condensation step, for example, tandem, which is currently used in the production of acrylic acid by propylene two-stage gas phase acid, is directly acrylic acid using a method using a single reactor. Can also be obtained. That is, the two-stage gas phase acid is a reaction site that mainly generates acrolein by oxidizing propylene and a reaction site force that generates acrylic acid by oxidizing the generated acrolein. By installing the catalyst of the present application at the site where it is fed and converting the raw material into propylene power and glycerin, the acrylic acid produced from the glycerin power is fed to the reaction site where acrylic acid is obtained to produce acrylic acid directly. You can also do it.

 The above-described production method is an example of a method for producing a dehydrated product, and can be applied to other methods for producing a dehydrated product.

[0029] The present invention is also a gas phase dehydration catalyst used in the method for producing the dehydrated product.

 That is, the catalyst of the present invention is preferably applied to a gas phase dehydration reaction for dehydrating a compound having 3 or more hydroxyl groups in the gas phase to obtain a dehydrated product.

The preferred form of the catalyst for vapor phase dehydration of the present invention is as described above, and is suitably applied to a method for producing acrolein by vapor phase dehydration of glycerin. As catalyst form The group 6 element is preferably at least one element selected from the group consisting of tungsten, chromium, and molybdenum, and more preferably the group 6 element is tungsten. In addition, it is preferable that the Group 6 element is supported on an inorganic carrier. Further, the inorganic carrier preferably has at least one element selected from the group consisting of zirconium, aluminum, and silicon. Better ,.

 The catalyst for vapor phase dehydration of the present invention is useful for the production of industrial dehydration products, and is useful in terms of activity, selectivity, and productivity. It is something that can be done.

 Of the conversion rate and selectivity, in industrial production, it is preferable that both the conversion rate and the selectivity are high, but it is more important that the selectivity is high. The reason is that the selectivity is largely related to the quality of the product. If the conversion rate is low but the selectivity is high, the final yield can be improved by recovering and reusing unreacted raw materials. It is also the power that can bring the selection rate close.

[0030] The present invention is also a method for producing acrolein in which glycerin is reacted in the presence of a heteropolyacid catalyst.

 Incidentally, it is a method for producing a dehydrated product by dehydrating a compound having 3 or more hydroxyl groups, wherein the production method comprises dehydration in which acrolein is produced by reacting glycerin in the presence of a heteropolyacid catalyst. In other words, the method for producing a product is a method for producing acrolein in which the glycerin is reacted in the presence of a heteropolyacid catalyst.

 Employing the following first and second means is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited thereto. As a first means, a catalyst having a heteropolyacid and a catalyst carrier is used.

[0031] Further, in this means, the catalyst support that the heteropolyacid preferably contains at least one of silicon, phosphorus, tungsten, and molybdenum is at least silica, alumina, titanium, and zircoure. Although it is desirable to contain any of the acids, it is not limited to these.

[0032] Further, in this means, it is also desirable that glycerin is used for producing glycerin acrolein which is desired to be subjected to the reaction as glycerin water having a water content of 95% by weight or less. [0033] A second means is a method for producing acrolein in which glycerin is reacted in the presence of a catalyst having a heteropolyacid and a catalyst carrier.

 The catalyst for producing acrolein according to the present embodiment (hereinafter also simply referred to as “catalyst”) preferably has a heteropolyacid and a catalyst carrier. By using this catalyst, the raw material glycerin can be dehydrated to produce acrolein. Here, the dehydration reaction of glycerin is a reaction in which glycerin is converted to acrolein, and the raw material (glycerin or glycerin water) is vaporized into gaseous form, and this gaseous raw material is brought into gas phase contact with the catalyst to be reacted. This is preferred. The present invention provides a further excellent effect by using a catalyst having a heteropolyacid and a catalyst carrier as in the first means, but is not limited to a form having a catalyst carrier, and a single catalyst A sufficiently high effect can be obtained even if it is used.

 [0035] The heteropolyacid as the catalyst raw material refers to an inorganic oxygen acid in which two or more oxygen acids are condensed, and is not limited to the following, but specific examples include dodecatandustric acid, Dodecamolybdophosphoric acid and dodecatan dust key acid are applicable. As a compound containing a heteropoly acid as a catalyst raw material, commercially available compounds can be used, and a reagent represented by the chemical formula of H PW O, H PMo O, H SiW O is used to form a catalyst.

3 12 40 3 12 40 4 12 40

 The raw material can be used as a catalyst by adhering and supporting the raw material on a catalyst carrier. On the other hand, SiO, Al 2 O, TiO, or ZrO can be used as the catalyst carrier. These are usually

 2 2 3 2 2

 It is preferable to use it as a shape such as a sphere, a column, a ring, or a bowl, and it may be used by impregnating an already formed carrier or applying it to the surface. In addition, when the catalyst support is silica, for example, silica having binary pores described in JP-A-2004-250387 can be suitably used. The catalyst carrier having binary pores will be described later.

 [0036] The content of the heteropolyacid contained in the catalyst is preferably 50% by weight or less of the total catalyst in order to maintain good catalytic activity. More preferably, it is in the range of 35% by weight or less of the total catalyst. Examples of the components such as metal oxides suitably used for the catalyst support include, but are not limited to, oxides such as silicon, aluminum, titanium, and zirconium.

[0037] The reaction apparatus used in the production of acrolein is not particularly limited. The reaction temperature in the process for producing acrolein using this catalyst is preferably in the temperature range of 150 ° C or higher and 450 ° C or lower. To improve the conversion rate of the raw material glycerin, a temperature of 150 ° C or higher is a preferred by-product This is because 450 ° C. or lower is preferable in order to suppress the formation of the product and improve the selectivity of acrolein as the target product. The reaction temperature in the above acrolein production method means the reaction temperature in the dehydration reaction step of producing acrolein by dehydrating glycerin.

 Therefore, in the method for producing acrolein, the reaction temperature in the dehydration reaction step is 15%.

It is one of the preferred embodiments of the present invention that the temperature is 0 ° C to 400 ° C.

 In the method for producing acrolein, by performing the dehydration reaction step in the above temperature range, the selectivity for acrolein can be further improved, and the production of by-products can be further suppressed.

 More preferably, the temperature range is from 200 ° C to 400 ° C. Specifically, for example, the catalytic reaction may be performed by vaporizing the raw material into a gaseous state, and circulating this gas through a reactor filled with the catalyst and controlled at the above reaction temperature!ヽ. There is no particular limitation on the gas flow rate when the gas is circulated through the reactor. In the method for producing a dehydrated product of the present invention, the reaction pressure is not particularly specified, but the reaction is an increase in the number of moles. preferable.

 The reaction temperature is preferably 220 ° C or higher. More preferably, it is 245 ° C or higher, and further preferably 275 ° C or higher. The reaction temperature is preferably 500 ° C. or lower. More preferably, it is 450 ° C or less, more preferably 400 ° C or less.

[0038] The relationship between the reaction temperature and the catalyst weight Z raw material flow rate ratio is as follows. The reaction weight is low when the catalyst weight is higher. The larger the Z raw material flow rate ratio, the higher the reaction temperature, the higher the catalyst weight. A smaller Z raw material flow ratio is preferred. In order to improve the selectivity of the target product, it is preferable to increase the ratio of catalyst weight Z raw material flow rate at a low temperature.

[0039] Further, the supply rate of the raw material gas to the catalyst is preferably about 100 to 5000 Zhr as the space velocity. If it is less than lOOZhr, the yield may decrease due to the sequential reaction, and if it is 5000 Zhr or more, the reaction is sufficient. There is a possibility that the conversion does not proceed and the conversion rate decreases. As a method for subjecting the catalyst to a gas phase dehydration reaction, for example, a catalyst layer can be formed by filling a catalyst in a reaction tube. The glycerin solution used is water-soluble A liquid can be used suitably. In addition, an organic solvent may be used if it is a substance that dissolves glycerin and does not inhibit the reaction. Therefore, a glycerin solution in which glycerin is dissolved in an organic solvent can also be used. The concentration of the glycerin solution is not particularly limited, and may be 100% by mass of glycerin. However, in order to adjust the gas concentration and the space velocity with respect to the catalyst, Condensable substance, CO

 2 Dilute with an inert gas such as nitrogen.

 [0040] When an inert gas is used in the above gas phase dehydration reaction, the boiling point of acrolein is low, so acrolein is discharged along with the inert gas, and the recovery rate of acrolein with a reactive gas force is increased. Therefore, it is preferable to use a method in which an insoluble condensable substance such as water (inert condensable substance) is simultaneously collected and separated after simultaneously collecting the condensable substance and acrolein. On the other hand, when a large amount of inert condensable material is used, the concentration of acrolein obtained decreases, and the amount of recovered inactive condensable material increases, resulting in increased processing costs. A method using a condensable substance in combination is preferable.

 [0041] The raw material glycerin may contain an inert condensable substance such as water of 0 to 95% by weight, or a solvent that does not participate in the reaction. The concentration of the raw material glycerin is preferably 5 to: L00 wt%. More preferably, it is 10 to 80% by weight. In the present invention, acrolein can be obtained in high yield even when such a high-concentration glycerin solution is used, whereby a high-concentration acrolein solution can be obtained directly.

[0042] The reaction product gas can be cooled and condensed to be acrolein or an acrolein solution, used as a raw material for producing acrylic acid or methionine, and acrolein obtained by condensation can be used. Acrylic acid can be obtained by vaporizing again and mixing with an appropriate amount of air or water vapor and oxidizing using a known method using gas phase acid. Also, omitting the condensation process, for example, currently used in the production of acrylic acid with propylene two-stage gas-phase acid V, is tandem or directly using a method using a single reactor. Acrylic acid can also be obtained. That is, the two-stage gas-phase acid has a reaction site that mainly generates acrolein by oxidizing propylene and a reaction site that generates acrylic acid by oxidizing the generated acrolein. By installing the catalyst of the present application at the site where acidification occurs, the raw material is converted into propylene power and glycerin, so that acrolein that also generates glycerin power Acrylic acid can also be produced directly by feeding it to the reaction site to obtain acrylic acid by acidification. In this case, air or oxygen, which is the oxidant necessary for the oxidation reaction, may be supplied from the first-stage dewatering reaction inlet force, or supplied to the second-stage oxidation reaction inlet!

 The acrolein production method described above is an example of a dehydrated product production method, and can be applied to other dehydrated product production methods.

 [0043] The reason why heteropolyacid is effective in the above production method is that the acid strength is stronger than the general solid acid catalyst S ίθ · Α1Ο, which contributes to the activity of the polyhydric alcohol.

2 2 3

One possible reason. Solids represented by SO ² "/ ZrO called super strong acids

 4 2

 In this case, the activity is high, but the acid strength of the product is too strong to cause side reactions. As a result, it is considered that a heteropolyacid having an appropriate acid strength works effectively. In addition, the heteropolyacid is thermally stable, so that even when the reaction is carried out for a long time by the above production method, the catalytic activity is not lost, and the reaction is carried out with a high conversion rate and selectivity. Is considered possible.

 [0044] Examples of the heteropolyacid catalyst include the following general formulas (1) to (4);

(1) Keggin structure; HX ^{n +} M ^{m +} O,

 80—12m—n 12 40

Or HX ^{n +} M ^{m +} O

 78—11m— n 11 39

(2) B-type Silverton structure; HX ⁴⁺ M ^{m +} O

 80-12m 12 42

(3) Dawson structure; HX ⁵⁺ M ^{m +} O

 114—18m 2 18 62

(4) Anderson structure; HX ^{n +} M ^{m +} O

 48-6m-n 6 24

 What has the structure represented by these is suitable.

 Regarding the (1) Keggin structure, a structure with 12 coordinate elements is sometimes referred to as A-type. In the above general formulas (1) to (4), X represents a hetero element and is not particularly limited as long as it is an element capable of forming a heteropolyacid. For example, phosphorus, silicon, germanium, arsenic, trimethyl, manganese , Nickel, tellurium, iodine, connold, aluminum, and chromium. M represents a coordination element and is not particularly limited as long as it is an element capable of forming heteropolyacid as a coordination element, and examples thereof include molybdenum, tungsten, niobium, and vanadium. O represents an oxygen atom.

When the heteropolyacid has an A-type Keggin structure, the hetero element is phosphorus, silicon, gel Manium and arsenic are preferred. In the case of having the above-mentioned heteropolyacid strength type silverton structure, the hetero element is preferably cerium or thorium. When the heteropolyacid has a Keggin structure, the hetero element is preferably phosphorus, arsenic, or germanium. When the heteropolyacid has a Dawson structure, the hetero element is preferably phosphorus or arsenic. When the heteropolyacid has an Anderson structure, it is preferable that the hetero element is tellurium, iodine, connort, aluminum, or chromium.

 [0045] It is one of the preferred embodiments of the present invention that the heteropolyacid catalyst has a Keggin structure. Since the heteropolyacid catalyst has a Keggin structure, thermal stability is increased.

 Furthermore, it is suitable for the production of acrolein. The heteropolyacid catalyst having a Keggin structure preferably has a structure represented by the above general formula (1).

[0046] In one embodiment of the present invention, the heteropolyacid catalyst includes hetero elements such as phosphorus and Z or silicon.

 When the heteropolyacid catalyst has the above form, the yield and selectivity of acrolein can be improved.

[0047] It is one of the preferred embodiments of the present invention that the heteropolyacid catalyst contains at least one group 6 element.

 The method for producing acrolein having the above embodiment is, in other words, a method for producing a dehydrated product by dehydrating a compound having 3 or more hydroxyl groups, wherein the production method comprises converting glycerol to a heteropolyacid catalyst. A method for producing a dehydrated product in which acrolein is produced by reacting in the presence, wherein the heteropolyacid catalyst is a method for producing a dehydrated product containing at least one group 6 element.

Further, the production method of acrolein having the embodiment is, in other words, a method of producing a dehydrated product by dehydrating a compound having 3 or more hydroxyl groups, and the production method includes at least one kind of 6 The catalyst is a heteropolyacid catalyst, the compound having three or more hydroxyl groups is glycerin, and the dehydration product is acrolein. It is a manufacturing method. In the method for producing acrolein having the above embodiment, the group 6 element is preferably contained as a coordination element of heteropolyacid.

[0048] In the above-described heteropolyacid catalyst, the coordination element is tungsten and Z or molybdenum, which is one of the preferred embodiments of the present invention.

 When the heteropolyacid catalyst has the above form, the yield and selectivity of acrolein can be improved. More preferably, the coordination element is tungsten.

[0049] It is also a preferred embodiment of the present invention that the heteropolyacid catalyst is a heteropolyacid supported on an inorganic carrier.

 When the heteropolyacid catalyst becomes a supported catalyst, the active substance can be used effectively, and the shape of the catalyst can be easily imparted. Therefore, the selectivity of acrolein can be further improved. When the heteropolyacid is supported on an inorganic carrier, the supported amount of the catalyst component is preferably 1 to 50% by weight. More preferably, it is 5 to 30% by weight.

 The shape of the catalyst may be an irregular shape such as a crushed product, but preferably a shape such as a sphere, a ring, a column, a saddle or a half ring generally used for gas phase reactions is preferably used.

[0050] It is also a preferred embodiment of the present invention that the inorganic carrier has at least one element selected from the group consisting of silicon, aluminum, titanium, and zirconium force.

 When the inorganic carrier has the above-mentioned form, the active ingredient heteropolyacid is uniformly highly dispersed, which makes it more suitable for the production of acrolein and improves the yield and selectivity of acrolein. Is possible. The inorganic carrier has at least one element selected from the group consisting of zirconium, aluminum and silicon, or these oxides, hydrated oxides, nitrides, carbides and the like can be used. In particular, it is preferable to contain silicon. For example, as such an inorganic carrier, industrially used powders such as silica, alumina, titer, and zirconium oxide, and composite powders and mixtures of these oxides and mixtures are used. be able to. These precursors such as hydroxides, hydrates and salts can also be used.

[0051] One of the preferred embodiments of the present invention is that the inorganic carrier contains silicon oxide as a main component. It is.

 When the inorganic carrier has the above-described form, the dispersibility is further improved, so that the inorganic carrier is more suitable for the production of acrolein and the acrolein yield and selectivity can be improved.

 The phrase “silicon oxide as a main component” means that the weight ratio occupied by silicon oxide in the inorganic carrier is at least 50% by weight or more. The weight ratio is preferably 80% by weight or more. More preferably, it is 90 weight% or more, More preferably, it is 95 weight% or more.

 [0052] The inorganic carrier is one prepared using tetraethoxysilane as a raw material, and is also one preferred embodiment of the present invention. By using tetraethoxysilane, which is substantially free of sodium element, as the raw material for the inorganic carrier, the selectivity and yield of the dehydrated product in the above production method can be further improved. The inorganic carrier preferably includes a portion prepared using tetraethoxysilane as a raw material. The inorganic carrier preferably has a weight ratio of 50% by weight or more occupied by a portion prepared using tetraethoxysilane in 100% by weight of the inorganic carrier. The weight ratio is more preferably 80% by weight or more. More preferably, it is 90% by weight or more, and particularly preferably 95% by weight or more.

[0053] It is also one of the preferred embodiments of the present invention that the inorganic carrier has a specific surface area of 30 to 1500 m ² / g. By using the inorganic carrier having the specific surface area, the selectivity and yield of the dehydrated product in the production method can be further improved. In the case where the inorganic carrier does not have binary pores described later, the specific surface area is preferably 50 to: L000m ² / g. More preferably, it is 100 to 800 m ² Zg. The specific surface area is more preferably 200 to 700 m ² / g. Particularly preferred is 250 to 600 m ² Zg. Most preferably, it is 300 to 500 m ² Zg.

 [0054] One of the preferred embodiments of the present invention is that the inorganic carrier has binary pores.

The binary pore is an inorganic porous material having both macropores having a pore size in the micrometer region and nanopores having a pore size in the nanometer region. The inorganic carrier having binary pores as described above is a macropore having excellent mass transporting ability, and In addition, it has both nanopores with a high specific surface area, has sufficient mechanical strength, and has little pressure loss. Therefore, it is suitable as a catalyst support used in the above production method, and further, acrolein selectivity and yield are obtained. The rate can be improved.

The macropores preferably have a pore diameter of 0.5 to 200 m. More preferably, 1 to: LOO / z m. The nanopore is preferably 1 to 50 nm, and preferably has a structure in which the through holes are entangled in a three-dimensional network. The macropores can be measured by mercury porosimetry or direct observation with an electron microscope. The nanopores can be confirmed by mercury porosimetry or nitrogen adsorption.

The inorganic carrier having binary pores is preferably in the form of particles having an average particle diameter of 5 to 10 mm. The pore volume of the inorganic carrier is preferably 0.3 to 4 cm ³ per lg of carrier. In consideration of the ease of production, it is preferably 1 to ³ cm ³ .

The method for producing the inorganic carrier having the binary pores is not particularly limited. For example, it is preferable to produce the inorganic carrier by the methods described in JP-A-2005-281012 and JP-A-2005-162504.

Therefore, it is one of the preferred embodiments of the present invention that the inorganic carrier having the binary pores includes a structure having through holes entangled in a three-dimensional network.

In addition, the inorganic carrier having the above-mentioned binary pores is an inorganic carrier having binary pores indispensable for macropores and nanopores. It is one of the preferred embodiments of the present invention that the pore diameter is 0.5 to 200 / ζ πι and the pore diameter of the nanopore is 1 to 50 nm.

One of the preferred embodiments of the present invention is that the inorganic carrier having the above-mentioned binary pores has a specific surface area of 300 to L000m ² Zg.

By using an inorganic carrier having binary pores having the above specific surface area, the selectivity and yield of the dehydrated product in the above production method can be further improved.

The specific surface area of the inorganic carrier having binary pores is preferably 400 to 900 m ² Zg, more preferably 500 to 850 m ² / g. More preferably, it is 550 to 800 m ² / g. Particularly preferred is 650 to 800 m ² Zg. [0055] The present invention is also a heteropolyacid catalyst used in the above production method. That is, the heteropolyacid catalyst of the present invention is applied to a gas phase dehydration reaction for dehydrating glycerol in the gas phase to obtain acrolein. A preferred form of the heteropolyacid catalyst is as described in the above production method. The heteropolyacid catalyst of the present invention is useful from the viewpoint of activity, selectivity, and productivity in the production of industrial dehydration products, and its operational effects can be sufficiently enhanced by the above preferred embodiments. Is.

 [0056] The method for producing the dehydrated product and the method for producing acrolein are common in the means and effects of dehydrating a compound having 3 or more hydroxyl groups to obtain the desired dehydrated product with high selectivity. To do. Therefore, preferred embodiments and reaction conditions in the acrolein production method are preferred embodiments for the dehydration product production method, and can be appropriately applied to the dehydration product production method. Conversely, preferred embodiments, reaction conditions, and the like in the method for producing the dehydrated product are also preferred embodiments for the method for producing acrolein, and can be appropriately applied to the method for producing acrolein. .

 [0057] When a dehydrated product is produced using the catalyst of the present invention (particularly preferably, a gas phase dehydration catalyst), the activity (conversion rate, yield) is higher than when a conventional acidic oxide catalyst is used. It exhibits excellent characteristics in both selectivity and suppresses the decrease in activity and selectivity over time, which is economically advantageous in industrial implementation. Moreover, it is economically advantageous in industrial implementation in that acrolein can be obtained without being derived from petroleum. In particular, glycerin can also be obtained with high selectivity by gas phase dehydration reaction. In this case, even when a high-concentration glycerin solution is used, acrolein can be obtained in a high yield, whereby a high-concentration acrolein solution can be obtained directly, and further, there is little deterioration of the catalyst over time. The form can be provided.

Moreover, a catalyst suitable for acrolein production can be provided, and acrolein can be obtained using V and raw materials not derived from petroleum. Compared to the case of using a conventional catalyst, it shows excellent characteristics in both activity (conversion rate, yield) and selectivity, and suppresses the decrease in activity and selectivity over time, making it economical in industrial implementation. Is advantageous. In particular, gas phase dehydration By the reaction, glycerin can also obtain acrolein with high selectivity. In this case, even when a high-concentration glycerin solution is used, acrolein can be obtained in a high yield, whereby a high-concentration acrolein solution can be obtained directly, and the catalyst deterioration over time can be reduced. Less form can be provided. Further, acrylic acid can be produced by reacting acrolein obtained by the production method of the present invention with an acid reaction. The present invention is also a method for producing acrylic acid by an industrially advantageous method starting from glycerin.

 [0058] In the method for producing acrolein, it is one of preferred embodiments of the present invention that the selectivity of acrolein is 60 mol% or more.

The acrolein selectivity is preferably 65 mol% or more. More preferably, it is 70 mol% or more, still more preferably 75 mol% or more, particularly preferably 80 mol% or more, and most preferably 85 mol% or more. The selectivity is high Rukoto of Akurorein production method of the above-mentioned Akurorein is still becomes good industrially more efficient, and the selectivity of Akurorein is 60 mole _^0/0 above, i.e., the Akurorein It means that the yield (mole) is 60 mol% or more with respect to the amount (mole) of glycerin converted in the above production method.

 The acrolein selectivity is preferably obtained, for example, as follows.

 Selectivity (mol%) = {Yield of acrolein obtained after reaction (mol) Z [Amount of glycerin subjected to reaction (mol) Amount of glycerin remaining after reaction (mol)]} X 100

 It is preferable to measure the amount of acrolein and the amount of glycerin using a gas chromatography analyzer, for example, using a Shimadzu GC-8A, TC-WAX capillary column, can do.

[0059] The method for producing the Akurorein, it Akurorein yield is 40 mol _^0/0 above is one preferred embodiment of the present invention.

The yield of acrolein is preferably 70 mol% or more. More preferably, it is 74% or more, more preferably 77% by mole or more, particularly preferably 80% or more, most preferably 83% by mole or more, and most preferably 85% or more. More than mol% It is.

Note that to be the yield strength 0 mole _^0/0 or more Akurorein, i.e., the yield of Akurorein

(Mole) force It means 40 mol% or more with respect to glycerin (mol) subjected to the above production method.

The yield of acrolein is preferably determined, for example, as follows.

Yield of acrolein (mol%) = {Yield of acrolein (mol) Amount of glycerin subjected to Z reaction (mol)} x ioo

Of the conversion rate and selectivity, in industrial production, it is preferable that both the conversion rate and the selectivity are high, but it is more important that the selectivity is high. The reason is that the selectivity is largely related to the quality of the product. If the conversion rate is low but the selectivity is high, the final yield can be improved by recovering and reusing unreacted raw materials. It is also the power that can bring the selection rate close. In the acrolein production method described above, the ability to recover and reuse unreacted glycerin means that the conversion of glycerin to a byproduct that is not acrolein requires that glycerin be recovered and reused. Means you can no longer do. In other words, in the above acrolein production method, the amount of glycerin transferred to a by-product that is not acrolein is an amount of waste of glycerin. Therefore, from the viewpoint of reducing costs by reducing the amount of wasted glycerin, it is preferable to reduce as much as possible the amount of glycerin transferred to a byproduct that is not acrolein.

Therefore, in the method for producing acrolein, it is one of the preferred embodiments of the present invention that the yield of by-products produced by glycerin force is 55 mol% or less.

The yield of by-products produced by converting the glycerin power is preferably 45 mol% or less. More preferably, it is 35 mol% or less, more preferably 25 mol% or less, particularly preferably 20 mol% or less, and most preferably 15 to 10 mol%.

In addition, the by-product generated by the conversion of the glycerin force is, in other words, a compound formed by the conversion of glycerin, and is a compound that is not acrolein.

The yield of the by-product produced by the above glycerin force conversion is preferably obtained, for example, as follows.

Yield of by-product produced by glycerin conversion (mol%) = [{Dariy remaining after reaction Amount of serine (mole) -acrolein yield (mole)} Amount of glycerin used for Z reaction (mole)] χ ιοο

Also, acrylic acid can be produced by reacting acrolein obtained by the above acrolein production method with an acid reaction. That is, the present invention is also a method for producing acrylic acid comprising a step of acidifying acrolein obtained by the above production method and converting it to acrylic acid.

The invention's effect

When producing a dehydrated product using the catalyst of the present invention (particularly preferably, a catalyst for gas phase dehydration), activity (conversion rate, yield) and selectivity are compared with the case of using a conventional acidic oxide catalyst. Both exhibit excellent properties and suppress the decrease in activity and selectivity over time, which is economically advantageous in industrial implementation. Moreover, it is economically advantageous in industrial implementation in that acrolein can be obtained without being derived from petroleum. In particular, glycerin can also be obtained with high selectivity by gas phase dehydration reaction. In this case, even when a high-concentration glycerin solution is used, acrolein can be obtained in a high yield, whereby a high-concentration acrolein solution can be obtained directly, and further, there is little deterioration of the catalyst over time. The form can be provided.

Moreover, a catalyst suitable for acrolein production can be provided, and acrolein can be obtained using V and raw materials not derived from petroleum. Compared to the case of using a conventional catalyst, it shows excellent characteristics in both activity (conversion rate, yield) and selectivity, and suppresses the decrease in activity and selectivity over time, making it economical in industrial implementation. Is advantageous. In particular, glycerin can also be obtained with high selectivity by gas phase dehydration reaction. In this case, even when a high-concentration glycerin solution is used, acrolein can be obtained in a high yield, whereby a high-concentration acrolein solution can be obtained directly, and the catalyst deterioration over time can be reduced. Less form can be provided. Further, acrylic acid can be produced by reacting acrolein obtained by the production method of the present invention with an acid reaction. The present invention is also a method for producing acrylic acid by an industrially advantageous method starting from glycerin.

BEST MODE FOR CARRYING OUT THE INVENTION [0062] Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, “part” means “part by weight” and “%” means “mass%”.

 [0063] (Preparation of catalyst A)

Tungstate ammonium of 1.6 mass _^0/0 to eggplant type flask 150 cc - © beam lOOcc the Karoe here 10g of Mizusani匕zirconate - Le (ZrO (OH)) powder were added 50-60 ° Stir for 4 hours at C

 2

 Then, water was removed with a rotary evaporator using a water bath at 60 to 80 ° C. The obtained powder was dried at 110 ° C in air for 1 hour and then calcined at 900 ° C for 4 hours. After being lightly crushed, it was adjusted to 20 to 40 mesh using a sieve.

 (Measurement of Hammett acidity)

 The catalyst dehydrated by heating was kept in dry benzene, the Hammett indicators of +6.8, -3.0, -8.2 were added in order, the maximum acid strength was measured, and then each indicator was added. The dehydrated catalyst was added to dry benzene, and titration was performed with an n-butylamine benzene solution with a known concentration until the color disappeared, and the acid amount in each acid strength range was also measured.

 The finished catalyst A has a Hammett acidity of −8.2 <H and −3, and 0.099m per lg of catalyst.

 0

 mol, −3 <Η <+ 6 · 8, and 0.227 mmol per hornworm medium.

 o

 For the following catalysts, the Hammett acidity was measured by the same method.

 [0064] (Preparation of catalyst B)

the eggplant type flask lOOcc 2. 1 mass _^0/0 H PW O solution 25cc were added, 10 g here

 3 12 40

 The α-alumina powder was added and kneaded, dried in air at 110 ° C for 1 hour, and further dried in vacuum at 150 ° C for 4 hours. After lightly crushing, it was adjusted to 20-40 mesh (mesh) using a sieve.

 The finished catalyst B has a Hammett acidity of −8.2 <H and −3 and 0.008 m per lg of catalyst.

 0

 mol, −3 <Η <+ 6 · 8 and 0.173 mmol per hornworm medium.

 o

 [0065] (Preparation of catalyst C)

Ka卩E the α- alumina powder 19g to form type flask LOOcc, after over晚攪拌here 3 mass _^0/0 phosphoric acid aqueous solution 33ml to example mosquitoes卩of rotary evaporation using a water bath of 60-80 ° C Water was removed with a rater. The powder obtained was dried in 120 ° C air for 24 hours and lightly crushed. Aligned to 20-40 mesh using a sieve.

 The resulting catalyst C has a Met acidity of −8.2 <H and −3 and a catalyst of 0.007 m per lg.

 0

 mol, −3 <Η <+ 6 · 8, and 0.13 O / mmol of hornworm medium.

 o

 [0066] (Preparation of catalyst D)

the eggplant type flask lOOcc 3. 1 mass _^0/0 of ammonium sulfate - © beam ((NH) SO) solution 25

 4 2 4 cc was added, 10 g of zirconyl hydroxide powder was added thereto, and the mixture was stirred at 50 to 60 ° C. for 4 hours, and then water was removed with a rotary evaporator using a 60 to 80 ° C. water bath. The obtained powder was dried at 110 ° C in air for 1 hour and then calcined at 600 ° C for 4 hours. After being lightly crushed, it was aligned to 20 to 40 mesh using a sieve.

 The resulting catalyst D has a Hammett acidity of 0.2982 mmol per lg catalyst with H <-8.2,

 0

 -8. 0 <057mmol per lg of catalyst with 2 <H <-3, lg per catalyst with 3 <H <+6.8

 0 0

 It was 0.128 mmol.

[0067] (Preparation of catalyst E)

4. eggplant type flask LOOcc 0 mass _^0/0 Ka卩E boric acid aqueous solution 50 cc, here 10g water oxidation zirconate - After stirring for 4 hours Le powder mosquitoes卩in Ete 50-60 ° C, 60 Water was removed on a rotary evaporator using a water bath at -80 ° C. The obtained powder was dried at 110 ° C in air for 1 hour and then calcined at 700 ° C for 4 hours. After being lightly crushed, it was aligned to 20 to 40 mesh using a sieve.

 The resulting catalyst E has a Hammett acidity of −8.2 <H <−3, and is 0.09 per lg of catalyst.

 0

 mmol, 1 <3 <で <+ 6 · 8 and 0 · 117 mmol.

 o

 [0068] (Preparation of catalysts F and G)

 Nb O · ηΗ 0 (CBMM, “HY-340” product name)

2 5 2

 Was calcined at 600 ° C. to obtain catalyst G.

 The finished catalyst F has a Hammett acidity of H <−8.2 and 0.0224 mmol per lg of catalyst,

 0

 -8. 0.15 mmol per lg of catalyst with 2 <H <-3, lg per catalyst with lg of 3 <H <+6.8

 0 0

 It was 0.1112 mmol.

 Further, the Hammett acidity of catalyst G is -8.2 <H <-3, and 0.022 mmol per lg of catalyst,-

0

3 <H <+6.8, and the amount was 0.050 mmol per lg of insect medium. [0069] (Preparation of catalyst H)

 H-type ZSM—5 (SiO /) obtained from Nankai University Catalyst Research Laboratory (Tianjin Z China)

 2

Al 2 O = 38) was designated as catalyst H.

 twenty three

 [0070] (Preparation of catalyst I)

4. H PW O in eggplant-shaped flask LOOcc 3 mass _^0/0 absolute ethanol solution 5 containing

 3 12 40

 Add Occ, add 10 g of zirconium hydroxide (ZrO (OH)) and stir for 4 hours at room temperature.

 2

 After stirring, ethanol was removed with a rotary evaporator using a 30-35 ° C water bath. The obtained powder was dried overnight at 110 ° C in vacuum, and then calcined at 650 ° C with nitrogen flow for 4 hours. After being lightly crushed, it was aligned to 20 to 40 mesh using a sieve. When the obtained catalyst was measured using a thermobalance, the exothermic peak observed in the unfired catalyst precursor was absent, and the exothermic peak was observed from room temperature to 800 ° C.

[0071] Example 1

A quartz reaction tube with an inner diameter of 10.4 mm was installed in an electrothermal annular furnace with a total length of 400 mm installed vertically and controlled at 315 ° C. Nitrogen was circulated at a standard state of 8.5 mlZ, and 0.63 ml of catalyst A was charged in the isothermal part obtained by measuring the temperature distribution in the reaction tube. Both ends of the catalyst layer were filled with 5 mm quartz wool and the top was filled with 30 mm quartz sand. A 36 mass% glycerin aqueous solution was introduced from the upper part of the reaction tube at a rate of 0.58 gZ time (hr). As a result of collecting the generated gas for 8 to 10 hours after starting the introduction of glycerin and analyzing it by gas chromatography, the conversion of glycerin was 100 mol% and the yield of acrolein was 63 mol%. The production of hydroxyacetone was only 3 mol%. Introduced in the catalyst (catalyst A) to 36 mass _^0/0 of glycerin aqueous solution introduction rate 2. 9GZ time (hr), the collected by a gas chromatograph product gas between 10:00 to 8 hours after the start of the reaction As a result of the analysis, the conversion rate of glycerin was 50 mol% and the selectivity for acrolein was 75 mol%. Even when the supply amount (space velocity) of the reaction raw material was increased, acrolein was produced with higher selectivity.

[0072] Comparative Example 1

The reaction was performed in the same manner as in Example 1 except that the catalyst C was used as the catalyst. As a result of collecting gas produced for 8 hours and 10 hours after starting the introduction of glycerin and analyzing by gas chromatography, the conversion of glycerin was 70 mol%, the yield of acrolein was 41 mol%, and the selectivity Was 59 mol%. The product gas collected 3 to 5 hours after the start of glycerin introduction and analyzed by gas chromatography showed that the conversion rate of glycerin was 88 mol%, the yield of acrolein was 51 mol%, and the selectivity Was 58 mol%, and both the activity and selectivity decreased with time. Further, 14 mol% of hydroxyacetone was produced.

 [0073] Example 2, Comparative Examples 2 to 6

 The reaction was conducted in the same manner as in Example 1 except that Catalyst B and Catalysts D and F to H were used as catalysts, and the produced gas was collected for 8 to 10 hours after the introduction of glycerin and analyzed by gas chromatography. . Since the yield of catalyst E was too low, the reaction was stopped in 4 hours, and the product gas was collected for 3 to 4 hours and analyzed by gas chromatography. The result was ¾kl.

 [0074] [Table 1]

 [0075] Example 3

A quartz reaction tube with an inner diameter of 10.4 mm was installed in an electrothermal annular furnace with a total length of 400 mm installed vertically and controlled at 350 ° C. Nitrogen was circulated in a standard state at a rate of 30.8 mlZ, and 2.1 ml of catalyst A was charged into the isothermal part obtained by measuring the temperature distribution in the reaction tube. Both ends of the catalyst layer were filled with 5 mm quartz wool and the top was filled with 30 mm quartz sand. From the upper part of the reaction tube, 100% by mass of glycerin was introduced at a rate of 0.70 gZ time (hr) and nitrogen at 28 mlZmin. As a result of collecting the generated gas for 8 hours to 10 hours after starting the introduction of glycerin and analyzing it by gas chromatography, the conversion of glycerin was 100 mol% and the yield of acrolein was 63 mol%. When 100% by weight glycerin is used, Acrolein was obtained with the same yield.

 [0076] Example 4

 The reaction was conducted in the same manner as in Example 1 except that Catalyst I was used as a catalyst and a 36 mass% glycerin aqueous solution was used as a raw material at an introduction rate of 2.9 g Z time (hr). As a result of collecting and analyzing the generated gas for 4 to 5 hours after the start of glycerin introduction, the conversion rate of glycerin was 100 mol% and the selectivity of acrolein was 70 mol%. As a result of collecting and analyzing the product gas 8 to 10 hours after the start of glycerin introduction, the conversion rate of glycerin was 70 mol% and the selectivity of acrolein was 72 mol%. By using heteropolyacid as a catalyst precursor, both selectivity and lifetime were improved.

[0077] The results of the above examples and comparative examples are summarized as follows.

 For example, when a raw material gas having a composition of 9 mol of water relative to 1 mol of glycerin is contacted with a catalyst having phosphoric acid supported on an alumina support (Comparative Example 1), the initial conversion is 88 mol% and the initial selectivity is 59 mol%. The initial yield was 51 mol%. After 10 hours, the conversion rate was 70 mol%, the selectivity was 59 mol%, and the yield was 41 mol%, and the conversion rate decreased. In contrast, a catalyst having a tungsten composition, which is zircoure and a group 6 element, showed a conversion rate of 100 mol%, a selectivity of 63 mol%, and a yield of 63 mol% even after 10 hours, indicating that the activity and the selection were high. It showed excellent characteristics in terms of sex, and there was no decrease in activity or selectivity over time. H P

 Three

Even in the catalyst in which W 2 O is supported on an alumina carrier, the conversion rate is as low as 28%.

12 40

 The selectivity after time was 70 mol%, and the selectivity with time was not decreased. Other acid oxides, SO / ZrO, B 2 O 3 / ZrO, Nb 2 O, H-type ZSM-5 (SiO 2 / Al

 4 2 2 3 2 2 4 2 2

The performance after 10 hours of aging when using O = 38) is SO / ZrO with a conversion rate of 100 mol%,

3 4 2

 Selectivity 34mol%, B O conversion to 100mol%, selectivity 10mol%, to NbO

 In 2 3 2 4, the conversion rate is 100 mol% and the selectivity is 38 mol%. In ZSM-5, the conversion rate is 25 mol% and the selectivity is 53 mol%, and the selectivity of the catalyst containing the Group 6 element is high. It has been shown.

 [0078] Thus, from the examples and comparative examples, the solid acid catalyst (P O ZA1 O, SO / ZrO, B

 2 5 2 3 4 2 2

O / ZrO, NbO, ZSM-5)

3 2 2 5

Although it is not advantageous for characteristics such as selectivity, a compound having a group 6 element as in the present invention. It is clear that contact with a gas phase dehydration catalyst composed of a product is excellent in yield and selectivity, and is economically advantageous in industrial implementation.

[0079] (Test using heteropolyacid catalyst)

 The fixed bed atmospheric pressure gas flow reactor used in the examples and comparative examples is mainly composed of a reactor having an inner diameter of 18 mm and a total length of 300 mm. The reactor has a reaction gas collection vessel with a carrier gas inlet and a raw material inlet at the upper end and a gas outlet at the lower end. In order to heat and vaporize the raw material in advance, the reactor has a vaporization layer between the raw material inlet and the reaction layer. The crude reaction liquid collected in a collection container at 78 ° C was measured with gas chromatography (Shimadzu GC-8A, TC—WAX Kiri-Kiri Ichiram), and after calibration curve correction, The yield and the remaining amount of raw materials were determined, and the conversion rate (%; molar basis) and the selectivity (%; molar basis) were determined from these values. The conversion rate is (the amount of raw material minus the remaining amount of raw material) the amount of Z raw material, and the selectivity is the target product yield Z (the amount of raw material equal to the remaining amount of raw material). The average value for the first 5 hours. A conversion of 100% means that the catalytic activity did not decrease during the reaction for 5 hours.

[0080] (Example 5)

 (Catalyst preparation)

Dodecatungstokeic acid (H SiW 2 O, purity 99.0% or more) to 14 g of support consisting mainly of silica (Fujishirishi CARiACT Q-6 specific surface area 466 m ² Zg) 6. 100 ml of Og

 4 12 40

 After impregnation from an aqueous solution, the catalyst was dried in a dryer at 110 ° C. to obtain a catalyst (Q6-SiW-30) having a dodecatan dust caustic acid loading of 30% by weight. Similarly, a catalyst (Q6—PW

3 12 40

 — 30) Similarly, dodecamolybdophosphoric acid (H PMo O purity 99.0% or more)

 3 12 40,

 The catalyst (Q6-PMo-30) supported on the silica gel was obtained.

[0081] (Example 6)

 (Dehydration reaction)

0.3 g of the Q6-SiW-30 catalyst prepared in Example 5 was charged into a fixed bed gas phase flow reactor. Nitrogen gas was flowed at a flow rate of 11.8 lZh as the upper force carrier gas of a fixed bed atmospheric pressure gas flow reactor with a catalyst layer. Along with this nitrogen gas, glycerin (Wako Jun 10% by weight aqueous solution 1. 67mlZh was vaporized in the vaporization layer and supplied. The reaction was performed at 325 ° C. In addition to Q6—SiW-30, the catalyst was Q6—PW-30 and Q6—PMo-30. Table 2 shows the glycerin conversion, acrolein selectivity, and hydroxyacetone selectivity for different catalysts.

[Table 2]

The reaction was carried out in the same manner as in Example 6 except that the charge amount of the Q6-SiW-30 catalyst prepared in Example 5 was 0.3 g and the reaction temperature was changed. The reaction temperature is 225 except 325 ° C. C, 250. C, 275. C, 300. C, and 350. C. Table 3 shows the glycerin conversion, acrolein selectivity and hydroxyacetone selectivity depending on the reaction temperature.

[Table 3]

Reaction temperature Catalytic weight, 'lyserine acrolein salt'

 (° C) ω Conversion (%) Selectivity (%) Selectivity (%) Yield (¾) Byproduct yield (¾)

Q6-Si -30 225 0.3 88.9 79.3 5.9 70.5 18.4

 Q6-SiW-30 250 0.3 90.3 81.7 7.1 73.8 16.5

 Q6-Si -30 275 0.3 91.6 82.6 7.7 75.7 15.9

 Q6-SiW-30 300 0.3 91.5 82.2 8.6 75.2 16.3

 Q6-Si -30 325 0.3 100 70.7 6.7 70.7 29.3

Q6-SiW-30 350 0.3 100 65.4 4.0 65.4 34.6

The Q6—SiW-30 catalyst prepared in Example 5 above was packed into a fixed bed gas phase flow reactor. The upper force of the fixed bed atmospheric pressure gas flow reactor with the catalyst layer Nitrogen gas was flowed at a flow rate of 1.8 lZh as the carrier gas. Along with this nitrogen gas, glycerin (manufactured by Wako Pure Chemical Co., Ltd., 10% by weight) 1.67 ml Zh was vaporized in the vaporization layer and supplied. The reaction was performed at 275 ° C. The catalyst loading was 0.6 g and 0.9 g in addition to 0.3 g. Table 4 shows the glycerin conversion, acrolein selectivity, and hydroxyacetone selectivity according to the difference in catalyst loading.

[Table 4]

(Example 9)

CARIACT Q-3 (specific surface area of 733m ² Zg) manufactured by Fujishiriya as the catalyst support silica Except that it was used, the same procedure as in Example 6 was carried out with 30% by weight of dodecatan dust key acid.

These results are shown in Table 5.

[Table 5]

Room) ¾00810

Was carried out in the same manner as in Example 6 with 30% by weight of dodecatan dust key acid. These results are shown in Table 6.

[Table 6]

[Example 11]

 (Catalyst preparation)

Silica having a binary pore structure (B6; specific surface area 780 m ² Zg) 14 g of dodecantastoketic acid (H SiW 2 O, purity 99.0% or more) 6. Og was impregnated from 100 ml of aqueous solution

 4 12 40

 Thereafter, the catalyst was dried in a dryer at 110 ° C. to obtain a catalyst (B6—SiW-30) having a dodecatan dust key acid loading ratio of 30% by weight.

[0092] (Example 12)

 (Dehydration reaction)

 The reaction was carried out in the same manner as in Example 6 except that the amount of B6-SiW-30 catalyst prepared in Example 11 was changed to 0.3 g and the reaction temperature was changed. In addition to 325 ° C, the reaction temperatures were 225 ° C, 250 ° C, 275 ° C and 300 ° C. Table 7 shows the glycerin conversion, acrolein selectivity, and hydroxyacetone selectivity for different reaction temperatures.

[0093] [Table 7]

^^ ¾, room))

The same operation was performed to obtain B3—SiW-30.

Using the obtained catalyst, a test was conducted in accordance with Example 12 under the reaction conditions as shown in Table 8 below.

These results are shown in Table 8 below.

[Table 8]

(Example 14)

Example 1 with the exception of using silica (B10) having a dual pore structure with a specific surface area of 698 m ² Zg In the same manner as in No. 2, the reaction was carried out with 30% by weight of dodecatan dust caustic acid (BIO—SiW-30). The macropores and mesopores of the catalyst (BIO—SiW-30) used in Example 14 were 2 / zm in macropores and 10 nm in mesopores. These results are shown in Table 9 below.

[Table 9]

(Example 15)

The test was conducted in accordance with Example 6 except that the reaction conditions were changed as shown in Table 10 below.

S¾S0091 [0100] (Example 16)

 The test was performed according to Example 6 except that the reaction conditions were changed as shown in Table 11 below. These results are shown in Table 11 below.

[0101] [Table 11]

(Example 17)

The test was conducted according to Example 6 except that the reaction conditions were changed as shown in Table 12 below.

[Example 18]

 The test was performed according to Example 12 except that the reaction conditions were changed as shown in Table 13 below. These results are shown in Table 13 below.

[0105] [Table 13]

(Example 19)

Tested according to Example 12 except that the reaction conditions were changed as shown in Table 14 below.

[Example 20]

 The test was performed according to Example 12 except that the reaction conditions were changed as shown in Table 15 below. These results are shown in Table 15 below.

[0109] [Table 15]

(Example 21)

Tested according to Example 12 except that the reaction conditions were changed as shown in Table 16 below.

SSI [0112] In Tables 2 to 16 above, the catalyst is represented by the following method.

 Catalyst = (Type of support) (Element symbol of heteroelement · Element symbol of coordination element) (Catalyst loading (wt%))

 Furthermore, “Na-Free” is added after the indication of the catalyst to those using tetraethoxysilane (TEOS) which does not contain sodium instead of water glass containing a large amount of sodium as silicon. However, it does not mean that it is completely free of sodium because of the contamination of containers and other reagents.

Q3 means a CARiACT Q-3 (specific surface area of 733 m ² Zg) carrier manufactured by Fujishirishia. Q6 means a carrier (Fujishirishi CARiACT Q-6 specific surface area 466 m ² / g). Q10 means a CARiACT Q10 (specific surface area 310 m ² Zg) carrier manufactured by Fujishirishia.

B3 means a silica (specific surface area 548 m ² Zg) support having binary pores. B6 means a silica (specific surface area 780 m ² Zg) support having binary pores. B10 means a silica (specific surface area 698 m ² / g) support having binary pores. According to the above notation method, for example, B6-SiW-30 means a catalyst prepared as in Example 7 above.

[0113] (Comparative Example 7)

 (Dehydration reaction)

 Examples of commercially available oxide catalyst samples include acid aluminum (DC2282: manufactured by Diacatalyst) (referred to as Al 2 O in the table below), silica alumina (N632HN; manufactured by JGC Chemical Co., Ltd.) (

 twenty three

 In the following Table 17, it is expressed as SiO 2 -Al 2 O. ), Silica (CariacteQ—6: Fujishishishia

 2 2 3

 (In the table below, it is expressed as SiO.), Titanium oxide (Wako Pure Chemicals: special grade) (below

 2

 In the table, it is written as TiO. ) And RSC100 from Daiichi Rare Element Chemical Industry (below

 2

 In the table, expressed as ZrO. The reaction was conducted according to Example 6 except that the catalyst was changed to

 2

 went. Table 17 shows the glycerin conversion, acrolein selectivity, and hydroxyacetone selectivity for different catalysts.

[0114] [Table 17] § [] 0115

The catalyst mounted is the same as the catalyst described in Comparative Example 7. These results are shown in Table 18.

[Table 18]

[0117] (Comparative Example 9)

 (Catalyst preparation)

To 10 g of a carrier composed mainly of silica gel (specific surface area 350 m ² / g), phosphoric acid (H 3 PO, purity

 3 4

85%) 2. 1 g of lg was impregnated with 70 ml of aqueous solution, and then dried at 110 ° C. in a dryer to obtain a catalyst (PSiO) having a phosphoric acid loading of 15 wt%. Similarly, a catalyst (PAIO) in which phosphoric acid was supported on alumina (specific surface area 200 m ² Zg) and the phosphoric acid loading rate was 15% by weight was obtained. Similarly, a catalyst (BAIO) in which boric acid was supported on alumina (specific surface area 200 m ² Zg) and boric acid was supported was 15% by weight was obtained.

[0118] (Comparative Example 10)

 (Dehydration reaction)

 A fixed bed gas phase flow reactor was charged with 0.3 g of the PSiO catalyst prepared in Comparative Example 9 described above. The reaction was carried out according to Example 6 except for the catalyst used. The reaction was performed at 325 ° C. Thereafter, the reaction temperature was changed to 325 ° C and 350 ° C to carry out the reaction. When the catalyst was changed to PAIO and BAIO, the reaction temperature was 300 ° C. Table 19 shows the glycerin conversion, acrolein selectivity, and hydroxyacetone selectivity according to differences in catalyst and reaction temperature.

[0119] [Table 19]

As a result, even when a heteropolyacid catalyst was used, the target product acrolein was more than when various solid acid catalysts not containing a group 6 element described in Comparative Examples 78 and 10 were used. It can be seen that the inn selectivity is high.

This application is based on Japanese Patent Application No. 2005-330481 “Dehydration Method of Polyhydric Alcohol” filed on November 15, 2005, Japanese Patent Application No. 2006 — 000004 filed on January 4, 2006. "Acrolein production catalyst and acrolein production method using the same", and Japanese Patent Application No. 2006-244504 filed on September 8, 2006 "Acrolein production catalyst and acrolein production using the same Claims priority based on “method”. The contents of that application are incorporated herein by reference in their entirety.

Claims

The scope of the claims

 [I] A method for producing a dehydrated product by dehydrating a compound having 3 or more hydroxyl groups, the production method comprising a step of contacting with a catalyst containing at least one group 6 element A method for producing a dehydrated product.

2. The method for producing a dehydrated product according to claim 1, wherein the method for producing the dehydrated product is a method for producing acrolein by dehydrating glycerin.

[3] In the catalyst, the Group 6 element is at least one element selected from the group consisting of tungsten, chromium, and molybdenum.

 The method for producing a dehydrated product according to claim 1 or 2, wherein:

[4] In the catalyst, the group 6 element is tungsten.

 The method for producing a dehydrated product according to claim 3, wherein:

[5] A method for producing a dehydrated product by dehydrating a compound having 3 or more hydroxyl groups, which comprises reacting glycerin in the presence of a heteropolyacid catalyst to produce acrolein. A method for producing a dehydrated product.

[6] The heteropolyacid catalyst has a Keggin structure.

 The method for producing a dehydrated product according to claim 5, wherein:

[7] In the heteropolyacid catalyst, the heteroelement is phosphorus and Z or silicon.

 The method for producing a dehydrated product according to claim 5 or 6, wherein:

[8] The method for producing a dehydrated product according to any one of [5] to [7], wherein in the heteropolyacid catalyst, a coordination element is tungsten and Z or molybdenum.

[9] The catalyst is supported on an inorganic carrier.

 A method for producing a dehydrated product according to any one of claims 1 to 8.

[10] The inorganic carrier has at least one element selected from the group consisting of silicon, aluminum, titanium, and zirconium.

 The method for producing a dehydrated product according to claim 9.

 [II] The inorganic carrier is mainly composed of silicon oxide.

 The method for producing a dehydrated product according to claim 9 or 10, wherein:

[12] The inorganic carrier has binary pores The method for producing a dehydrated product according to any one of claims 9 to 11, wherein: It is used for the manufacturing method of the dehydration product in any one of Claims 1-12. The catalyst characterized by the above-mentioned.