JP5162123B2 - Method for producing acrolein by glycerin dehydration - Google Patents

Description

  The present invention relates to a catalyst for dehydration reaction of glycerin, and more particularly to a catalyst capable of producing acrolein while suppressing the production of coke when producing acrolein by dehydration reaction of glycerin.

Biodiesel produced from vegetable oil is attracting attention not only as a substitute for fossil fuels but also because it emits less carbon dioxide, and demand is expected to increase. When this biodiesel is produced, glycerin is produced as a by-product, so it is necessary to make effective use of it. One embodiment of the use of glycerin includes the use of glycerin as a raw material for acrolein.

It has long been known to use a solid acid catalyst when producing acrolein from glycerin by a dehydration reaction. For example, a method of producing acrolein by dehydrating glycerin using HZSM-5 which is MFI type zeolite as a solid acid catalyst having an acid strength function H ₀ of +2 or less under liquid phase conditions (see Patent Document 1), as a solid acid catalyst is _{H 0} the phase conditions in the range of _-10 <H 0 <-16, using a mixture of HZSM-5 and aerosil, a method for producing acrolein by dehydration of glycerin (Patent Document 2 reference ) Is disclosed.

Also disclosed is a method for producing acrolein by dehydrating glycerin using a catalyst composed of 20% by mass of bentonite and 80% by mass of HZSM-5 under gas phase conditions. Although HZSM-5 constituting this catalyst is described as H type, it is specified that 0.52% by mass of Na ₂ O is contained (see Non-Patent Document 1).

Although what is disclosed in Patent Document 1 is not described in detail with respect to HZSM-5, which is a catalyst used, HZSM-5 has a H ₀ value of −8.0 or less and has such a H ₀ value. It is described that the catalyst is not suitable for the production of acrolein from glycerin by gas phase dehydration, and the initial yield of acrolein is only 45%, which is quite inactive after only 4 hours of operation. It is described that it has become.

  In addition, it describes that the catalyst life is extremely short when the reaction temperature is 340 ° C. or higher, and suggests that the catalyst after the reaction is black at the reaction temperature of 380 ° C., that is, catalyst deterioration due to coke is remarkable. A description is made.

  In Patent Document 2, HZSM-5 (Zeocat PZ) manufactured by Chemie Uetikon is used as a catalyst to carry out the gas phase dehydration reaction of glycerin. Recognized and catalyst degradation has occurred.

Further, in Non-Patent Document 1, although there is a description suggesting that it has been converted to the proton type as HZSM-5, the HZSM-5 used has Na ₂ O of 0.55% by mass, When recalculated to L / T value, Na used in the zeolite synthesis stage contains L / T = 0.4, and the acrolein yield is very low.

Japanese Patent Application Laid-Open No. 06-217724 International Publication WO2006-070883 Specification Le H. Dao, Reaction of Models Compounds of Biomass-Pyrolysis Oils over ZSM-5 Zeolite Catalysts, American Chemical Society, 1988, 376, p. 328-341

  As described above, when crystalline metallosilicate is used as a catalyst in the reaction for synthesizing acrolein from glycerin, the most serious problem is that the yield of acrolein decreases with time, that is, the activity of the catalyst deteriorates.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the ratio of T atom in the crystalline metallosilicate and the counter cation species (referred to as L atoms) contained during the synthesis of the crystalline metallosilicate is L / T. <At least one atom selected from an alkali metal atom, an alkaline earth metal atom, and a rare earth metal atom (referred to as M atom) using a crystalline metallosilicate converted to a proton type until 0.3 It has been found that the use of a catalyst with the addition of can reduce the amount of coke without lowering the yield of acrolein, lower the combustion temperature of coke, and solve the above problems.

  If a catalyst in which at least one atom selected from an alkali metal atom, an alkaline earth metal atom and a rare earth metal atom is added to a crystalline metallosilicate converted to a proton type until L / T <0.3 is used, Without reducing the acrolein yield, the amount of coke can be reduced, the combustion temperature of coke can be lowered, and activation degradation can be suppressed.

  Further, in the above catalyst, it is more effective to add M atoms so that the ratio of T atom, L atom and M atom in the crystalline metallosilicate is in the range of 0 <(L + M) / T <1.0. is there.

  By using a crystalline metallosilicate containing M atoms as a catalyst as in the present invention, the amount of coke is reduced without reducing the yield of acrolein when producing acrolein by vapor phase dehydration reaction of glycerin. In addition, the combustion temperature of the coke can be lowered, and the activity deterioration can be suppressed.

  Further, if the catalyst of the present invention is used, acrolein can be produced in a high yield without depending on the concentration of the raw material glycerin and the activity deterioration can be suppressed, so that the production efficiency is greatly improved. That is, since the concentration of the raw material can be increased, enormous energy loss due to evaporation and liquefaction of the added water can be reduced, and acrolein can be produced very advantageously economically. Due to the effects described above, it is expected that an industrial production method for producing acrolein by glycerin dehydration reaction can be more easily established.

  The reason why the crystalline metallosilicate containing M atoms as in the present invention is effective as a catalyst for the reaction of synthesizing acrolein from glycerin can be estimated as follows. The strength, position, and distribution of the active sites of the catalyst may affect the amount of coke produced and the degree of coking (the coke combustion temperature shifts to higher temperatures as coking progresses), and is particularly strong. When there are many active points, coking is remarkably promoted, and there is a possibility that the deterioration of the activity proceeds rapidly. By adding M atoms as in the present invention, it is presumed that coking can be suppressed and activity deterioration can be suppressed without reducing the acrolein yield by appropriately adjusting the strength and distribution of active sites. .

  The present invention will be described below based on embodiments.

(catalyst)
The catalyst of the present invention is useful in a method for producing acrolein by gas-phase dehydration reaction of glycerin. A crystalline metallosilicate subjected to a specific treatment is converted from an alkali metal atom, an alkaline earth metal atom and a rare earth metal atom. What added the at least 1 atom (it is set as M atom) selected is used as a catalyst.

  The above-mentioned crystalline metallosilicate is expressed as L / T <0.3 when the ratio of the counter cation species (referred to as L atom) contained in the synthesis and the T atom in the crystalline metallosilicate is expressed in L / T. , Preferably L / T <0.2, more preferably L / T <0.1, even more preferably L / T <0.05, even more preferably L / T <0.01, most preferably this L atom. Is a crystalline metallosilicate that has been replaced with protons, that is, converted to protonic form until L / T becomes 0 (below the detection limit). The L atom is added as an alkali raw material in the raw material solution or raw material aqueous slurry during the synthesis of the crystalline metallosilicate, and is usually contained after the synthesis and is an ion-exchangeable cation species existing outside the crystal lattice. Examples of the L atom include Li, Na, Rb, Cs, Mg, Ca, Sr, Ba, Sc, Y, and La.

  Examples of the method for synthesizing the crystalline metallosilicate include known synthesis methods. For example, it can be synthesized by a hydrothermal synthesis method, a dry gel conversion method, a solid phase crystallization method, or the like.

  Specifically, for example, a method for producing ZSM-5 is described as follows: hydrothermal synthesis method described in US Pat. No. 3,702,886, dry gel conversion method described in JP-A 2000-344515, JP-A 2001-058817. Examples thereof include ZSM-5 synthesized by a solid phase crystallization method described in the publicity specification.

  In order to convert the crystalline metallosilicate into a proton type, usually, an alkali raw material added during the synthesis of the crystalline metallosilicate, that is, L atoms are removed by ion exchange with ammonium ions, and heat treatment is performed at a high temperature. Can be converted to proton type.

  In order to prepare a crystalline metallosilicate converted to a proton type until L / T <0.3, the ion exchange and heat treatment steps may be performed once or repeatedly. good.

  In the crystalline metallosilicate, the ratio of Si and T atoms is preferably 10 <Si / T <3000, more preferably 10 <Si / T <1500, and even more preferably 10 <Si / T <800. Most preferably, 10 <Si / T <400.

  In the crystalline metallosilicate, a crystalline aluminosilicate in which the T atom is an Al atom (generally also referred to as zeolite), and another metal atom is introduced into the crystal lattice instead of the Al atom as the T atom of the crystalline aluminosilicate. A compound. Specific examples of other metal atoms include B, Fe, Ga, P, Sc, Ti, V, Cr, Zn, Ge, As, Y, Zr, In, Sn, Sb, La and the like. It may be used alone or in combination of two or more. From the viewpoint of catalytic activity and ease of catalyst production, a crystalline metallosilicate in which the T atom is selected from Al, B, In, Fe, Ga, Co, Ni and Zn is preferable. Certain crystalline aluminosilicates are particularly suitable.

  As the crystal structure of the above-mentioned crystalline metallosilicate, the metallosilicate of the crystal structure classified by the structure committee of the International Zeolite Society, “ZEOLITES, Vol-12, No. 5, 1992” and “HANDBOOK OF” A metallosilicate having a structure described in “MOLECULAR SIEVES, R. Szostak, VAN NOST RAND REINHOLD publication” can be given, and the crystal structure is not particularly limited. Among these, those having a crystal structure of any of MFI, MEL, BEA, and MWW are preferable from the viewpoint that acrolein can be produced with high yield, and crystalline metallosilicates having an MFI crystal structure are particularly preferable. Is preferred.

  In the catalyst of the present invention, any form of the crystalline metallosilicate may be used, for example, a spherical shape, a columnar shape, a ring shape, or a bowl shape, and the size is equivalent to a diameter, and is usually about 0.1 mm to 10 mm. Good to have.

  The catalyst according to the present invention is obtained by adding at least one atom (referred to as M atom) selected from an alkali metal atom, an alkaline earth metal atom, and a rare earth metal atom to the crystalline metallosilicate. In the present invention, by adding at least one atom selected from M atoms to a crystalline metallosilicate, coking can be performed without reducing the acrolein yield when producing acrolein by vapor phase dehydration reaction of glycerin. It is possible to suppress the activity deterioration.

  Examples of the alkali metal atom include Li, Na, K, Rb, and Cs, and examples of the alkaline earth metal atom include Be, Mg, Ca, Sr, and Ba. Examples of the rare earth metal atom include Sc, Y, La, Ce, Pr, Nd, Sm, Gd, Dy, and Ho. These may be used alone or in combination of two or more. May be. In the present invention, among these M atoms, Li, Na, K, Rb, Cs, Ca, Sr, Ba, Y, La, and Ce are preferable, and Na, K, Rb are not limited thereto. , Cs, Ba, Y are particularly preferred.

  The content of M atoms in the crystalline metallosilicate must be considered together with the amount of L atoms originally contained in the crystalline metallosilicate. Preferably, the ratio of T atoms, L atoms, and M atoms is 0 < (L + M) / T <1.0, more preferably 0 <(L + M) / T <0.8, and most preferably 0 <(L + M) / T <0.5.

  The method for adding the M atom to the crystalline metallosilicate is not particularly limited, and is performed by a generally used catalyst preparation method. For example, a method of supporting by a kneading method, an impregnation method, an ion exchange method or the like can be mentioned. The raw material compound containing M atom for adding M atom is appropriately selected from various compounds having physical properties required for these catalyst preparation methods, such as water solubility. For example, these chlorides, fluorides, bromides, iodides, sulfides, nitrides, hydroxides, oxides, nitrates, sulfates, carbonates, phosphates, and other inorganic salts, alkoxides, acetates, propions Examples thereof include organic salts such as acid salts, among which nitrates and carbonates are preferred.

  The M atom contained in the crystalline metallosilicate by the above method is generally in the form of an ion or oxide, and even in this state, it has a coking suppressing effect and can suppress the deterioration of activity. Accordingly, M atoms in an ion or oxide state may be used after being heat-treated under an air stream, that is, after firing.

  For example, a crystalline metallosilicate containing M atoms can be treated in a range of room temperature to 600 ° C. under an air stream, and the temperature range needs to be limited to a range in which the crystalline structure of the crystalline metallosilicate is not destroyed. There is. When the crystal structure of the crystalline metallosilicate is destroyed, T atoms are desorbed out of the lattice (so-called dealumination in which Al atoms are desorbed out of the lattice in the case of crystalline aluminosilicate where T atoms are Al atoms) In some cases, the yield of acrolein is greatly reduced.

(Acrolein production method)
Next, a method for producing acrolein using the catalyst of the present embodiment will be described. The production method of acrolein in this embodiment is a gas phase dehydration reaction in which a reaction raw material gas containing glycerin and a catalyst are brought into contact in a reactor arbitrarily selected from a fixed bed reactor, a moving bed reactor, a fluidized bed reactor and the like. To produce acrolein.

The raw material glycerin may be a purified product, a crude product, or an aqueous solution.
The reaction raw material gas may be a gas composed only of glycerin, and may contain a gas inert to the glycerin dehydration reaction in order to adjust the glycerin concentration in the reaction raw material gas. Examples of the inert gas include water vapor, nitrogen gas, and air. Particularly, when water vapor is added, advantageous effects are seen with respect to the life of the catalyst and the yield of acrolein.

  The concentration of glycerin in the reaction raw material gas may be 0.1 to 100 mol%, preferably 1 mol% or more. In order to produce acrolein economically and efficiently, it is 10 mol% or more. Is more preferable.

  The flow rate of the reactive gas is preferably 100 to 10,000 hr-1 in terms of the reactive gas flow rate (GHSV) per unit catalyst volume. Preferably, it is 5000 hr-1 or less, and 3000 hr-1 or less is more preferable in order to produce acrolein economically and with high efficiency.

  The reaction temperature may be 200 to 500 ° C, preferably 250 to 450 ° C, and more preferably 300 to 400 ° C.

  The reaction pressure is not particularly limited as long as glycerin is not condensed. Usually, it is good in it being 0.001-1 MPa, Preferably, it is 0.01-0.5 MPa or less.

  Acrolein can be produced by the above method. The produced acrolein can be used as a raw material for the production of acrolein derivatives such as acrylic acid, 1,3-propanediol, allyl alcohol, polyacrylic acid, polyacrylate, methionine, etc., using known techniques. is there. Therefore, it is naturally possible to incorporate the acrolein production method described above into the acrolein derivative production method.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, the scope of the present invention is not limited only to these Examples. The glycerin conversion rate, acrolein yield, and SV (space velocity) are values calculated by the following formula.

Glycerin conversion rate = (1− (number of moles of glycerin in the collected effluent) / (number of moles of glycerin introduced into the reactor in 30 minutes)) × 100
Yield of acrolein = ((number of moles of acrolein in the collected effluent) / (number of moles of glycerin introduced into the reactor in 30 minutes)) × 100
SV (space velocity) = (gas supply amount converted under standard conditions, L / hr) / (catalyst amount, L).

(Manufacture of catalyst)
(Catalyst preparation comparative example 1)
An H-type Al-MFI catalyst (metallosilicate molded body in which T atoms are Al) was produced by performing the following supporting step, crystallization step, and ion exchange step.

(Supporting process)
1.40 g of NaOH and 0.47 g of NaAlO ₂ were sequentially dissolved in 15.00 g of distilled water, and 10.15 g of 40 mass% tetra-n-propylammonium hydroxide aqueous solution was added to distilled water. Then, distilled water was further added to this solution to prepare an impregnating solution having a total amount of 30 ml.

  Next, silica beads (“CARTIACT Q50” manufactured by Fuji Silysia Chemical Co., Ltd., 10 to 20 mesh, average pore diameter of 50 nm) are used as the silica compact, and 30 g of silica beads dried at 120 ° C. for 1 day are used as the impregnating solution. Impregnated for hours. The silica beads are then dried on an evaporating dish placed on a 100 ° C. hot water bath, and further dried at 80 ° C. under a nitrogen stream for 7 hours to obtain Na and Al crystallizing agents necessary for crystallization. To obtain a crystalline methanosilicate precursor.

(Crystallization process)
The precursor obtained in the loading step is placed in the hollow part of a tetrafluoroethylene jacketed crucible having a volume of 100 ml, 1.00 g of distilled water is placed in the bottom of the crucible, and this crucible is placed in an electric furnace at 180 ° C. for 8 hours. Let stand for hours.

(Ion exchange process)
The solid after the crystallization step was immersed in 300 g of a 1 mol / L aqueous ammonium nitrate solution at 60 ° C. and stirred for 1 hour, and then the supernatant was discarded. This operation was repeated several times. Thereafter, the solid was washed with water.

(Baking process)
The solid after the ion exchange step was fired at 550 ° C. for 5 hours in an air stream.

  After the firing step, an ion exchange step was performed again, and further a firing step was performed to obtain an H-type Al-MFI (T atom is Al) catalyst having a Si / Al ratio of 100 mol / mol used in this example. As a result of measuring the amount of Na contained in the obtained catalyst by fluorescent X-ray analysis (XRF), it was 0.003 mass% or less (Na / Al <0.01 mol / mol) in Na2O.

  On the extracted catalyst after completion of the reaction, 8.5% by weight of coke was precipitated. The combustion temperature of the coke was 530 ° C.

(Catalyst preparation comparative example 2)
Al-MFI (T atom is Al) catalyst in which a part of Na is replaced by proton in the same preparation method as in Catalyst Preparation Comparative Example 1 except that the number of times of ion exchange and firing is reduced once. Got. By reducing the ion exchange step and the firing step, a part of Na charged in the supporting step remained on the catalyst. The amount of Na ₂ O contained in the obtained catalyst was 0.43% by mass (Na / Al ratio = 0.6 mol / mol).

(Catalyst Preparation Example 1)
A Li-containing solution was prepared by dissolving 0.11 g of LiNO ₃ in 27.98 g of distilled water.
40.0 g of H-type Al-MFI prepared in the same manner as in Catalyst Preparation Comparative Example 1 was weighed into an eggplant-shaped flask, and the above Li solution was added to this while shaking and mixing sufficiently to impregnate uniformly. Was added and impregnated for 3 hours.

  Then, it is dried while stirring on an evaporating dish placed on a 90 ° C. hot water bath, then further dried at 120 ° C. for 9 hours in an air stream in a baking furnace, and finally baked at 550 ° C. for 5 hours. As a result, a Li-containing catalyst containing 0.24 mol / mol of Li in a Li / Al ratio was obtained.

(Catalyst Preparation Example 2)
A Na-containing solution was prepared by dissolving 0.02 g of Na ₂ CO ₃ in 27.99 g of distilled water.
A Na-containing catalyst containing Na in an Na / Al ratio of 0.06 mol / mol was obtained in the same manner as in Catalyst Preparation Example 1, except that the above solution was used as the impregnation solution.

(Catalyst Preparation Example 3)
A Na-containing solution was prepared by dissolving 0.21 g of Na ₂ CO ₃ in 27.92 g of distilled water.
A Na-containing catalyst containing Na in an Na / Al ratio of 0.60 mol / mol was obtained in the same manner as in Catalyst Preparation Example 1, except that the above solution was used as the impregnation solution.

(Catalyst Preparation Example 4)
A K-containing solution was prepared by dissolving 0.029 g of K ₂ CO ₃ in 27.99 g of distilled water.
A K-containing catalyst containing K in a K / Al ratio of 0.06 mol / mol was obtained in the same manner as in Catalyst Preparation Example 1, except that the above solution was used as the impregnation solution.

(Catalyst Preparation Example 5)
0.049 g of Rb ₂ CO ₃ was dissolved in 27.97 g of distilled water to prepare an Rb-containing solution. An Rb-containing catalyst containing Rb in an Rb / Al ratio of 0.07 mol / mol was obtained in the same manner as in Catalyst Preparation Example 1, except that the above solution was used as the impregnation solution.

(Catalyst Preparation Example 6)
A Cs-containing solution was prepared by dissolving 0.041 g of Cs ₂ CO ₃ in 27.96 g of distilled water. A Cs-containing catalyst containing Cs at a Cs / Al ratio of 0.04 mol / mol was obtained in the same manner as in Catalyst Preparation Example 1, except that the above solution was used as the impregnation solution.

(Catalyst Preparation Example 7)
0.462 g of Cs ₂ CO ₃ was dissolved in 27.72 g of distilled water to prepare a Cs-containing solution. A Cs-containing catalyst containing Cs at a Cs / Al ratio of 0.43 mol / mol was obtained in the same manner as in Catalyst Preparation Example 1, except that the above solution was used as the impregnation solution.

(Catalyst Preparation Example 8)
A Cs-containing solution was prepared by dissolving 0.660 g of Cs ₂ CO ₃ in 27.34 g of distilled water. A Cs-containing catalyst containing Cs at a Cs / Al ratio of 0.61 mol / mol was obtained in the same manner as in Catalyst Preparation Example 1, except that the above solution was used as the impregnation solution.

(Catalyst Preparation Example 9)
A Y-containing solution was prepared by dissolving 0.063 g of Y ₂ (CO ₃ ) ₃ in 27.97 g of distilled water. A Y-containing catalyst containing Y at 0.05 mol / mol in a Y / Al ratio was obtained in the same manner as in Catalyst Preparation Example 1, except that the above solution was used as the impregnation solution.

(Catalyst Preparation Example 10)
A Ba-containing solution was prepared by dissolving 0.205 g Ba (NO ₃ ) ₂ in 27.92 g distilled water. A Ba-containing catalyst containing Ba in a Ba / Al ratio of 0.12 mol / mol was obtained in the same manner as in Catalyst Preparation Example 1, except that the above solution was used as the impregnation solution.

(Catalyst preparation comparative example 3)
A metallosilicate in which the T atom is Ga in the same preparation method as in Catalyst Preparation Comparative Example 1, except that 1.74 g of Ga (NO ₃ ) ₃ .9H ₂ O was used instead of NaAlO _{2 in} the supporting step. An H-type Ga-MFI (T atom is Ga) catalyst having a Si / Ga ratio of 100 mol / mol was obtained as a compact. The amount of Na contained in the catalyst contained in the obtained catalyst was measured by fluorescent X-ray analysis (XRF), and as a result, was 0.003% by mass or less (Na / Al <0.01 mol / mol) in Na ₂ O. Met.

  On the extracted catalyst after completion of the reaction, 8.7% by weight of coke was precipitated. The combustion temperature of the coke was 537 ° C.

(Catalyst Preparation Example 11)
A Na-containing solution was prepared by dissolving 0.02 g of Na ₂ CO ₃ in 27.99 g of distilled water.
40.0 g of H-type Ga-MFI prepared by the same method as in Catalyst Preparation Comparative Example 3 was weighed into an eggplant-type flask, and the above Na solution was added to this while shaking and mixing sufficiently to impregnate uniformly. Was added and impregnated for 3 hours. Then, it is dried while stirring on an evaporating dish placed on a 90 ° C. hot water bath, then further dried at 120 ° C. for 9 hours in an air stream in a baking furnace, and finally baked at 550 ° C. for 5 hours. Thus, a Na-containing catalyst containing Na at a Na / Ga ratio of 0.06 mol / mol was obtained.

(Production example of acrolein using catalyst)
Using the catalysts produced in the catalyst preparation comparative examples and examples described above, glycerin was dehydrated and acrolein was produced according to the atmospheric pressure fixed-bed flow reaction format shown in the following method.

15 ml of catalyst was filled in a stainless steel reaction tube (inner diameter 10 mm, length 500 mm), and this fixed bed reactor was immersed in a salt bath at 360 ° C. Thereafter, nitrogen was introduced into the reactor at 62 ml / min. Then, the reaction gas (reaction gas composition: glycerin 27 mol%, water 34 mol%, nitrogen 39 mol%) consisting of a vaporized gas of 80 mass% glycerin aqueous solution and nitrogen is circulated at a flow rate of 650 hr ^−1. It was. After flowing the reaction gas through the reactor, 0.5 to 1 hour, 2.5 to 3 hours, and further 4.5 to 5.0 hours, the effluent gas for 30 minutes was cooled and absorbed into acetonitrile. I collected it.

  A part of the absorbed liquid was taken, and qualitative and quantitative analysis of the effluent was performed by gas chromatography (GC). As a result of qualitative analysis by GC, by-products such as 1-hydroxyacetone were detected together with glycerin and acrolein. Moreover, the glycerol conversion rate and the acrolein yield were computed from the quantitative analysis result.

  After the reaction, nitrogen was introduced into the reactor at 62 ml / min. The catalyst was extracted after flowing for 30 minutes at a flow rate of, and coke adhered to the catalyst was measured by thermogravimetric-differential thermal analysis (TG-DTA). Thermal analysis was performed at 10 ° C./min. The coke deposited on the catalyst was burned and removed, the weight loss during that period was taken as the amount of coke accumulated, and the temperature at the top of the exothermic peak was taken as the coke combustion temperature.

(Reaction result)
Tables 1 and 2 summarize the reaction results and coke analysis results. Regarding the description in the table, glycerin is abbreviated as GLY, and acrolein is abbreviated as ACR. The elapsed reaction time is indicated by the time after the end of collection.

  From Tables 1 and 2, in the crystalline metallosilicate added with M atoms as in the present invention, the amount of coke produced is suppressed, and the activity degradation over time is not observed.

  Moreover, it can be seen that the combustion temperature of coke can be lowered and the progress of coking is suppressed. This may facilitate the regeneration process by combustion removal.

  From Comparative Example 2 and Example 3, even if the Na content is the same, if a large amount of Na as the L atom contained in the production of the crystalline metallosilicate is contained, the acrolein yield is greatly reduced. You can see that

  From the results in Table 3, it can be seen that the effects of the present invention are not affected by the type of T atom of the crystalline metallosilicate.

  According to the present invention, it is converted to a proton type until the ratio of the counter cation species (L atom) contained in the synthesis of the crystalline metallosilicate and the T atom in the crystalline metallosilicate is L / T <0.3. Gas phase dehydration of glycerin by using at least one atom selected from an alkali metal atom, an alkaline earth metal atom and a rare earth metal atom (M atom) as a catalyst. When producing acrolein by reaction, coking can be suppressed and activity deterioration can be suppressed without reducing the acrolein yield.

  Further, when the catalyst of the present invention is used, even when a high concentration of glycerin is used as a raw material, it can be produced without reducing the yield of acrolein, and the deterioration of activity can be suppressed. Can be expected to improve greatly.

  In addition, since the combustion temperature of coke is lowered, the temperature required for regenerating (burning and removing) a deteriorated catalyst is reduced, the temperature difference between the dehydration reaction and regeneration is small, and the temperature rises and falls in the regeneration process. Is expected to be reduced or unnecessary, and the catalyst regeneration step may be easily performed.

Claims (5)

In the dehydration reaction for producing acrolein from glycerin, the ratio (molar ratio) of the counter cation species (referred to as L atoms) contained during the synthesis of the crystalline metallosilicate and the T atom in the crystalline metallosilicate is L / T <0. A catalyst prepared by adding at least one atom selected from an alkali metal atom, an alkaline earth metal atom and a rare earth metal atom (referred to as M atom) to a crystalline metallosilicate converted to a proton type until it becomes 3 A method for producing acrolein,
The T atom is selected from Al, B, In, Fe, Ga, Co, Ni and Zn;
The catalyst has a ratio (molar ratio) of T atom to L atom and M atom in the crystalline metallosilicate of 0 <(L + M) / T <1.0,
In the crystalline metallosilicate of the catalyst, the ratio (molar ratio) between Si and T atoms is 10 <Si / T <3000 . M atoms of the catalyst, Li, Na, K, Rb , Cs, Ca, Sr, Ba, Y, La, acrolein placing serial to claim 1, characterized in that at least one selected from Ce Production method. The method for producing acrolein according to claim 1 or 2, wherein the crystalline metallosilicate has a crystal structure of MFI. An acrolein derivative selected from acrylic acid, 1,3-propanediol, allyl alcohol, polyacrylic acid, polyacrylate and methionine is produced from acrolein obtained by the production method according to claim 1. A method for producing an acrolein derivative. The catalyst for acrolein manufacture used with the manufacturing method in any one of Claims 1-3 .