JP2008266165A - Method for producing acrolein - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing acrolein by which uncollected gas left after collecting the acrolein from an acrolein-containing gas is effectively utilized. <P>SOLUTION: The method for producing the acrolein includes producing the acrolein-containing gas by bringing a glycerol-containing gas into contact with a catalyst for dehydrating the glycerol, collecting the acrolein in the acrolein-containing gas and simultaneously discharging the uncollected gas, and bringing the uncollected gas into contact with the catalyst for dehydrating the glycerol. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing acrolein.

  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. Therefore, the amount of by-product of glycerin, which is a by-product of biodiesel, is expected to increase, and effective utilization of glycerin is desired.

  Patent Document 1 discloses that acrolein can be produced by dehydrating glycerin. Acrolein has been known to be a raw material for acrolein derivatives such as acrylic acid, 1,3-propanediol, allyl alcohol, polyacrylic acid, polyacrylate, and methionine. Can be said to be an embodiment of effective utilization of glycerin.

By the way, the fact that acrolein-containing gas can be produced by vapor phase dehydration reaction of glycerin is disclosed in Patent Document 1, but in order to increase the concentration of acrolein, acrolein is collected from the acrolein-containing gas. Is required. On the other hand, it is necessary to treat the gas that has not been collected, but if the uncollected gas can be used effectively, not only the economic value of the method for producing acrolein from glycerin will be improved, but The economic value to use will also increase.
JP-A-6-217724

  In view of the above circumstances, an object of the present invention is to provide a method for producing acrolein that effectively utilizes an uncollected gas in which acrolein is collected from an acrolein-containing gas.

  The present invention includes a dehydration reaction step of producing an acrolein-containing gas by bringing a glycerin-containing gas into contact with a glycerol dehydration catalyst, an acrolein collection step of collecting acrolein in the acrolein-containing gas and discharging uncollected gas; A method for producing acrolein, wherein the uncollected gas is brought into contact with the glycerol dehydration catalyst. The contact of the uncollected gas with the glycerin dehydration catalyst may be performed by causing the glycerin-containing gas to contain the uncollected gas in the dehydration reaction step. Further, before the dehydration reaction step, the uncollected gas may be brought into contact with the glycerol dehydration catalyst.

  The method for producing acrolein according to the present invention can be used in an acrolein production process in the method for producing an acrolein derivative.

  According to the present invention, since the uncollected gas containing one or more compounds produced by the glycerol dehydration reaction is brought into contact with the glycerol dehydration catalyst, acrolein can be produced with high yield from the beginning of the glycerol dehydration reaction.

A method for producing acrolein according to the present invention will be described below based on an embodiment.
The method for producing acrolein according to the present embodiment includes a dehydration reaction step of producing an acrolein-containing gas by bringing a glycerin-containing gas into contact with a glycerin-dehydrating catalyst (hereinafter, “glycerol dehydrating catalyst” is simply referred to as “dehydrating catalyst”). And acrolein collecting step of collecting acrolein from the produced acrolein-containing gas. The present method is characterized in that uncollected gas that has not been collected in the acrolein collection step is discharged, and this uncollected gas is brought into contact with the catalyst for dehydration.

  First, it will be described that the uncollected gas, which is a feature of the present method, is brought into contact with the catalyst for dehydration, and then the dehydration reaction step and the acrolein collection step of the present method will be described for each step.

(Contact of uncollected gas)
When the uncollected gas is brought into contact with the dehydration catalyst as in this method, the following problems can be solved. The problem is that the yield of acrolein gradually increases with time from the beginning of the dehydration reaction of glycerin. If the dehydration reaction is continued, the increase in the acrolein yield is suppressed and the acrolein yield is stabilized. However, if the time until this stabilization is shortened or if the acrolein yield can be stabilized from the start of the dehydration reaction, acrolein can be produced with good yield from the beginning of the dehydration reaction. In order to produce acrolein with a good yield, in this method, an uncollected gas is brought into contact with a catalyst for dehydration.

  The uncollected gas contains acrolein that could not be collected. The uncollected gas may contain one or more by-products generated in the process of generating the acrolein-containing gas. Its by-products are mainly low in boiling point compared to acrolein such as acetaldehyde (boiling point: 21 ° C), propylene (boiling point: -48 ° C), ethylene (boiling point: -104 ° C), methane (boiling point: -162 ° C), etc. Boiling by-product.

  The catalyst for dehydration to be contacted with uncollected gas may be used for the glycerin dehydration reaction for the first time after preparation, or may be subjected to regeneration treatment described later. This is because any dehydration catalyst increases the yield of acrolein from the beginning of the dehydration reaction.

  In order to bring the uncollected gas into contact with the dehydration catalyst, the uncollected gas may be included in the glycerin-containing gas that is brought into contact with the dehydration catalyst in the dehydration reaction step. In this case, the uncollected gas may be included in the glycerin-containing gas until the increase in the acrolein yield is subsided. If the amount of uncollected gas in the glycerin-containing gas increases, the yield of acrolein stabilizes early, but the problem of reducing the collection efficiency of acrolein in the collection process and the problem of losing the pressure of dehydration reaction in the dehydration reaction process Therefore, it is preferable to set the amount of uncollected gas in the glycerin-containing gas in consideration of the entire production process of acrolein. Moreover, in order to adjust the glycerin concentration of the glycerin-containing gas in the dehydration reaction step, immediately after the start of operation of the acrolein production apparatus, nitrogen, air, or water vapor is used as a dilution gas for preparing the glycerin-containing gas, and the acrolein production apparatus As the operation is continued, it is possible to gradually increase the amount of uncollected gas in the dilution gas and finally use only the uncollected gas as the dilution gas. When using uncollected gas for dilution gas, the amount of uncollected gas is used so that the glycerin concentration falls within an appropriate range.

  When the uncollected gas is brought into contact with the dehydration catalyst by including the uncollected gas in the glycerin-containing gas as described above, the uncollected gas is sent again to the collection step. Therefore, since the acrolein contained in the uncollected gas after contact with the dehydration catalyst is collected in the collection step, the collection rate of the produced acrolein is increased.

  An uncollected gas may be brought into contact with the dehydration catalyst before the dehydration step. The temperature for performing the contact before the dehydration step is not particularly limited, but may be 100 to 500 ° C, preferably 150 ° C to 450 ° C, more preferably 200 ° C to 450 ° C, and still more preferably in the dehydration reaction step. This is the dehydration temperature of glycerin. The contact time should be appropriately set depending on the concentration of the organic compound contained in the uncollected gas and the amount of the dehydration catalyst to be contacted. Since the acrolein yield tends to increase gradually as the contact time elapses, the contact time can be set in a wide range. However, even if the contact time is too long, the acrolein yield does not rise above a certain level, and acrolein cannot be dehydrated in the reactor in which the contact is made, so the acrolein yield is improved and the reactor operating rate is increased. In consideration of the above, it is necessary to appropriately determine the longest contact time. Usually, the contact time can be set between 1 minute and 24 hours, and is preferably between 10 minutes and 12 hours.

(Dehydration reaction process)
The acrolein production reaction in the dehydration reaction step is a catalytic gas phase dehydration reaction of glycerin for causing an intramolecular dehydration reaction of glycerin. In this step, an acrolein-containing gas is produced from a glycerin-containing gas.

  The dehydration catalyst used in this step is for accelerating the intramolecular dehydration reaction of glycerin. The catalyst may be a solid acid catalyst, and its size is usually about 0.1 to 10 mm in diameter. The shape of the catalyst is not particularly limited, such as a spherical shape, a columnar shape, a ring shape, or a bowl shape.

Examples of the dehydration catalyst include Al, B, Ti, Cr, Fe, Co, Ni, Cu, Zn, Ga, In, P, Sc, V, Ge, As, Y, Zr, In, Sn, Sb, And a crystalline metallosilicate having a crystal structure such as LTA, CHA, FER, MFI, MOR, BEA, MTW, wherein one or more atoms selected from La, Si, B, Fe, Ga and the like are T atoms. Clay minerals such as bentonite, montmorillonite, and kaolinite; sulfate metal salts such as MgSO ₄ , Al ₂ (SO ₄ ) ₃ , K ₂ SO ₄ , Zr (SO ₄ ) ₂ ; AlPO ₄ , Al ₂ (HPO ₄ ) ₃ Phosphorus such as Al (H ₂ PO ₄ ) ₃ , Al ₄ (P ₂ O ₇ ) ₃ , AlHP ₂ O ₇ , Al ₂ (H ₂ P ₂ O ₇ ) ₃ , Al (H ₃ P ₂ O ₇ ) ₃ Aluminum phosphate, magnesium phosphate such as Zr (HPO ₄ ) ₂ , ZrP ₂ O ₇ , M Manganese phosphates such as nPO ₄ , Mn ₃ (PO ₄ ) ₂ , MnHPO ₄ , Mn (H ₂ PO ₄ ) ₂ , Na ₂ HPO ₄ , NaH ₂ PO ₄ , Na ₄ P ₂ O ₇ , Na ₂ H ₂ P ₂ O ₇ , K ₂ HPO ₄ , KH ₂ PO ₄ , K ₄ P ₂ O ₇ , K ₂ H ₂ P ₂ O ₇ , Cs ₂ HPO ₄ , CsH ₂ PO ₄ , Cs ₄ P ₂ O ₇ , Cs ₂ Metal phosphates such as alkali metal phosphates such as H ₂ P ₂ O _7, metal phosphates such as alkaline earth metal salts such as MgHPO ₄ , CaHPO ₄ , SrHPO ₄ and BaHPO ₄ ; metal phosphates having a crystal structure; metal sulfate Catalyst in which salt or metal phosphate is supported on α-alumina, silica, zirconium oxide, titanium oxide, etc .; Mineral acid such as phosphoric acid or sulfuric acid is supported on α-alumina, silica, zirconium oxide, titanium oxide, etc. Activated alumina; TiO ₂ , ZrO ₂ , SnO ₂ , V ₂ O ₅ , SiO ₂ —Al ₂ O ₃ , SiO ₂ —TiO ₂ , TiO ₂ —WO ₃ , TiO ₂ —ZrO _2, and other inorganic oxides or inorganic composite oxides. Other dehydration catalysts include zirconium oxide supporting phosphoric acid, sulfuric acid, or tungsten oxide, and solid acids disclosed in International Publication Nos. WO2006 / 087083 and WO2006 / 087084.

  Preferred examples of the dehydration catalyst exemplified above are crystalline metallosilicates with excellent acrolein yield, MFI type crystalline metallosilicates are preferred, and MFI type crystalline aluminosilicates are more preferred. Further, from the viewpoint of suppressing the amount of carbonaceous material produced, which is one of the causes for shortening the life of the dehydration catalyst, it is preferable to use a metal phosphate having a crystal structure as the dehydration catalyst.

  The catalyst for dehydration used in this step may be one that has been subjected to regeneration treatment to recover the reduced activity. Here, the regeneration treatment refers to the carbonaceous material deposited on the surface of the catalyst for dehydration in the intramolecular dehydration reaction of glycerin by contacting the oxidizing agent with carbon dioxide, carbon monoxide, or other carbon-containing compounds. This is a process of removing by oxidative decomposition (a process of burning and removing carbonaceous substances). As the oxidizing agent used in the regeneration treatment, one or two kinds of gas molecules capable of supplying an oxygen element to the carbonaceous material for oxidative decomposition of the carbonaceous material are usually used. Examples of gas molecules that can be used as the oxidizing agent include oxygen (oxygen in the air also corresponds to the oxidizing agent), ozone, nitric oxide, nitrogen dioxide, and dinitrogen monoxide. When using an oxidant in the regeneration process, an inert gas (nitrogen, carbon dioxide, argon, helium, water vapor, etc.) that does not participate in the oxidative decomposition of the carbonaceous material is arbitrarily selected in order to avoid sudden combustion heat generation of the carbonaceous material. A mixed gas of one or more selected gases and an oxidizing agent may be used.

  In order to carry out the catalytic gas phase dehydration reaction of glycerin, the glycerin-containing gas is circulated in a reactor arbitrarily selected from a fixed bed reactor, a moving bed reactor, a fluidized bed reactor, etc. with a catalyst for dehydration inside. And good.

  The glycerin used in the glycerin-containing gas may be either purified glycerin or crude glycerin. The glycerin concentration in the glycerin-containing gas is not particularly limited, but is preferably 0.1 to 100 mol%, and is preferably 10 mol% or more that can produce acrolein economically and highly efficiently. When adjustment of the glycerin concentration in the glycerin-containing gas is necessary, one or more gases selected from water vapor, nitrogen, air, and the like can be used as the concentration adjusting gas. In addition, when oxygen and / or water vapor is included in the glycerin-containing gas, it is preferable because the decrease in the activity of the dehydrating catalyst is suppressed and the acrolein yield is increased.

The amount of glycerin-containing gas in the reactor is preferably 100 to 10,000 hr ⁻¹ in terms of the glycerin-containing 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 for producing acrolein economically and with high efficiency. The temperature when the intramolecular dehydration reaction of glycerin proceeds is preferably 200 to 500 ° C, preferably 250 to 450 ° C, more preferably 300 to 400 ° C. And the pressure in a dehydration reaction will not be specifically limited if it is a pressure of the range which glycerin does not condense. Usually, it is good that it is 0.001 to 1 MPa, and preferably 0.01 to 0.5 MPa.

(Acrolein collection process)
In the acrolein collection step, acrolein is collected from the acrolein-containing gas produced in the dehydration reaction step, and uncollected gas is discharged. The acrolein-containing gas contains not only acrolein (boiling point: 53 ° C.) and unreacted glycerin (boiling point: 290 ° C.), but also acrolein by-products. This by-product is a low-boiling by-product having a lower boiling point than acrolein such as acetaldehyde (boiling point: 21 ° C.), propylene (boiling point: −48 ° C.), ethylene (boiling point: −104 ° C.), methane (boiling point: −162 ° C.), etc. Organisms: High-boiling by-products having a higher boiling point than acrolein such as phenol (boiling point: 182 ° C), 1-hydroxyacetone (boiling point: 146 ° C), water (boiling point: 100 ° C), allyl alcohol (boiling point: 97 ° C) Including. In this step, acrolein is collected by cooling the acrolein-containing gas. And the uncollected gas which was not collected is discharged | emitted, and part or all of this uncollected gas is used for the contact to the said dehydration catalyst.

  In order to collect acrolein from the acrolein-containing gas, for example, there is a method in which the acrolein is condensed and liquefied by cooling the acrolein-containing gas to a temperature lower than the boiling point of the acrolein that is the target of collection. In the condensate liquefaction, a multi-tube heat exchanger, a finned tube heat exchanger, an air-cooled heat exchanger, a double-tube heat exchanger, a coil heat exchanger that can separate high-boiling byproducts from the acrolein-containing gas, Known condensers such as a direct contact heat exchanger and a plate heat exchanger can be used.

  As another example of the method for collecting acrolein, there is a method in which acrolein is absorbed by the collection solvent by bringing acrolein-containing gas into contact with a collection solvent having acrolein solubility. Here, it is possible to use water as the collection solvent, but it is preferable to use an aqueous solution containing a water-soluble organic compound because the collection solvent of water alone has low acrolein solubility. . Examples of the water-soluble organic compound include glycerin, a high-boiling by-product generated by glycerol dehydration reaction such as 1-hydroxyacetone. The temperature of the collecting solvent is usually 0 to 40 ° C, preferably 1 to 30 ° C. The contact method between the acrolein-containing gas and the collection solvent includes cross-flow contact using bubble bell tray, uniflat tray, perforated plate tray, jet tray, bubble tray, venturi tray; turbo grid tray, dual flow tray , Ripple tray, kittel tray, gauze type, sheet type, grit type regular packing, and countercurrent contact using irregular packing.

  Each of the acrolein collection methods described above is a method utilizing the difference in boiling point between acrolein and another compound, and any other known collection method can be used as long as it is a method for collecting acrolein utilizing the difference in boiling point. It may be replaced.

Next, the method of this embodiment will be described with reference to the process flow diagram of FIG.
In FIG. 1, two reactors 100a and 100b for producing acrolein-containing gas from glycerin-containing gas (hereinafter, "reactor 100a and reactor 100b" are collectively referred to as "reactor 100"), Separation tower 200 for separating high-boiling by-products from acrolein-containing gas, collection tower 300 for collecting acrolein from acrolein-containing gas after high-boiling by-products are separated, and reactor 100 and the like The connected piping line 1a (hereinafter, “piping line” is simply referred to as “line”) and the like are arranged as follows.

  Lines are connected to the reactor 100 at both ends. One end of the reactor 100 is connected to a line 1a or 1b for supplying one or more of a glycerin-containing gas, an uncollected gas, and an oxidant-containing gas. A line 2a branched from the supply line 2 and a line 3a branched from the oxidant-containing gas supply line 3 are connected to the line 1b (from the line 2b branched from the line 2 and from the line 3 similarly to the line 1a). Branched line 3b is connected). The other end of one reactor 100 is connected to a line 4a or 4b serving as an acrolein-containing gas flow path from the reactor 100 to the separation tower 200. In the middle of the gas flow path lines 4a and 4b, the line 4a or 4b is not connected. A line 5a or 5b for discharging the collected gas and the oxidizing agent-containing gas is connected. Both ends of the lines 4 a and 4 b are connected to the line 4 which is a direct supply line of the acrolein-containing gas to the separation tower 200.

  A line 4 is connected to the separation tower 200, a line 6 for discharging high-boiling by-products in the production of acrolein-containing gas is connected to the bottom, and a line 7 for supplying the acrolein-containing gas to the collection tower 300. Connected to the top.

  One end of a line 7 is connected to the collection tower 300. A line 8 for discharging the collected acrolein is connected to the lower part of the collection tower 300, and a line 9 for discharging uncollected gas to the outside of the collection tower 300 is connected to the top. . At the tip of the line 9, a line 9c for discharging uncollected gas and a line 9a for supplying uncollected gas to the lines 1a and 1b are extended.

  In order to realize the invention according to this embodiment, although not shown, a control valve for controlling the amount of gas or liquid flowing through each line, a pump for flowing gas, etc. It will be provided as appropriate.

  Each configuration shown in FIG. 1 will be further described together with the configuration operation.

Reactor 100
The reactor 100 is filled with a dehydration catalyst and has a function of raising the internal temperature to an arbitrary temperature. The reactors 100a and 100b are installed in parallel between the line 1a or 1b and the line 4, and the reactor 100a or 100b has a glycerin-containing gas through the lines 1a, 1b, 2a, 2b, 3a, or 3b. Then, an uncollected gas, a mixed gas of glycerin-containing gas and uncollected gas, or an oxidant-containing gas for regenerating the catalyst for dehydration flows in. The glycerin-containing gas continuously flows into one of the reactors 100a and 100b in order to continuously produce the acrolein-containing gas. If an uncollected gas is allowed to flow into the reactor 100 at the same time when the glycerin-containing gas flows in, a mixed gas of the glycerin-containing gas and the uncollected gas will flow into the reactor 100. On the other hand, uncollected gas or oxidizing agent-containing gas flows into the reactor 100 where there is no inflow of glycerin-containing gas.

  When the glycerin-containing gas flows into the reactor 100, the inflowed glycerin-containing gas comes into contact with the dehydration catalyst to generate an acrolein-containing gas. The generated acrolein-containing gas flows into the separation tower 200 through the line 4a or 4b and the line 4.

  When the uncollected gas flows into the reactor 100 before the glycerol dehydration reaction, it flows out of the reactor 100 toward the line 5a or 5b. The inflow time is appropriately set.

  When the oxidant-containing gas flows into the reactor 100, the oxidant-containing gas flows out of the reactor 100 toward the line 5a or 5b after being used for the regeneration treatment of the dehydration catalyst. In order to increase the reduced acrolein yield, the oxidant-containing gas is allowed to flow into the reactor 100. Therefore, the inflow time of the oxidant-containing gas is set to a time required for regeneration of the dehydration catalyst. When an unused dehydration catalyst is built in the reactor 100, the oxidant-containing gas does not flow into the reactor 100.

  In addition, although the two reactors 100 are represented in FIG. 1, the installation number of the reactor 100 for implementing the manufacturing method of the acrolein of this invention may be 1 unit | set or 3 units | sets or more. The number of reactors 100 installed in the case of continuously producing acrolein needs to be able to continuously produce acrolein-containing gas. For this purpose, the required number of reactors 100 to be installed is determined in consideration of the time required for the pretreatment and regeneration treatment of the dehydration catalyst.

Separation tower 200
The separation tower 200 is for removing high-boiling by-products from the acrolein-containing gas. For example, the separation tower 200 may be capable of absorbing high-boiling by-products with a solvent such as water. In this case, the acrolein-containing gas flows into the solvent through the line 4, and high-boiling by-products are absorbed by the solvent while the acrolein-containing gas rises in the solvent. The acrolein-containing gas that has not been absorbed by the solvent flows into the collection tower 300 through the line 7. On the other hand, the high boiling point by-product separated from the acrolein-containing gas is periodically discharged through the line 6 together with the solvent.

  In order to carry out the method for producing acrolein according to the present invention, the separation tower 200 is not essential. Therefore, if it is not necessary to separate the high boiling point by-product from the acrolein-containing gas, the line 4 may be directly connected to the collection tower 300.

Collection tower 300
The collection tower 300 is for condensing and collecting acrolein containing acrolein-containing gas and discharging non-condensed gas as uncollected gas, and stores a collection solvent. The temperature of the collecting solvent is such that the lower the temperature of the collecting solvent is, the higher the collection efficiency of acrolein. Therefore, the temperature is preferably 40 ° C. or lower, preferably 30 ° C. or lower, below the boiling point of acrolein. On the other hand, for industrial reasons such as avoiding the high boiling point of cooling costs and avoiding blockage of piping due to condensation of the collecting solvent, the temperature of the collecting solvent is preferably 0 ° C. or higher, and preferably 1 ° C. or higher.

  The acrolein-containing gas flows into the collection solvent through the line 7, and the acrolein is absorbed by the collection solvent while the acrolein-containing gas rises in the collection solvent. Then, the collection solvent that has absorbed acrolein is discharged out of the collection tower 300 through the line 8. On the other hand, uncollected gas is discharged out of the collection tower 300 through the line 9. Part or all of the uncollected gas flows into the reactor 100 through the line 9a and the line 1a or 1b. In addition, when it is not necessary to supply uncollected gas to the reactor 100, uncollected gas is discharged through the line 9c.

  The method for producing acrolein according to the present embodiment is as described above. The produced acrolein is a raw material for producing acrolein derivatives such as acrylic acid, 1,3-propanediol, methionine, 3-methylpropionaldehyde, allyl alcohol, polyacrylic acid, polyacrylate and the like as already known. Can be used as Therefore, it is naturally possible to incorporate the acrolein production method described above into the acrolein derivative production method.

Experimental Example Next, the experimental example shows that when the acrolein production method according to the present invention is used, the acrolein yield at the beginning of the glycerol dehydration reaction is improved.

  As an experimental example, acrolein was produced from glycerin. The details of the dehydration catalyst used, the pretreatment method of the dehydration catalyst, and the production method of acrolein are as in Experimental Examples 1 to 5 and Comparative Experimental Examples 1 to 5 below.

(Dehydration catalyst)
MFI type aluminosilicate and activated alumina were produced as follows.

MFI type aluminosilicate:
0.58 g of NaOH and 1.95 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 the distilled water. Then, distilled water was added to this solution to prepare an impregnating solution having a total amount of 30 ml. Next, after drying a molded body of silica beads (“CARTIACT Q-50” manufactured by Fuji Silysia Chemical Co., Ltd., 10 to 20 mesh, average pore diameter of 50 nm) at 120 ° C. for 1 day, 30 g of this is added to the impregnation liquid. The silica bead compact was impregnated with the impregnating solution by dipping for a period of time. Thereafter, the silica beads were dried on an evaporating dish (drying temperature 100 ° C.), and further dried at 80 ° C. under a nitrogen stream for 5 hours to obtain a crystalline metallosilicate precursor. This precursor is placed in the hollow part of a 100 ml tetrafluoroethylene jacketed crucible storing 1.00 g of distilled water at the bottom, and this crucible is allowed to stand in an electric furnace at 180 ° C. for 8 hours. The body crystallized. This crystallized product was immersed in 300 g of a 1 mol / L ammonium nitrate aqueous solution at 60 ° C. for 1 hour, and after repeating the immersion operation, the crystallized product was washed with water. Thereafter, the crystallized product was calcined in an air stream at 540 ° C. for 3.5 hours to produce MFI type aluminosilicate (H-ZSM5).

Activated alumina:
Commercially available granular activated alumina (“ALUMINIUMOXIDE90 ACTIVE ACIDIC, 0.063-0.200MM, ACTIVITY STAGEI” manufactured by Merck, production number 101078) was calcined at 500 ° C. for 2 hours in an air atmosphere. The obtained fired product was filled into a vinyl chloride cylinder having an inner diameter of 3 cm and a height of 5 mm, and after pressure molding, crushed and classified, to obtain 0.7 to 1.4 mm of activated alumina.

(Pretreatment of dehydration catalyst)
A stainless steel reaction tube (inner diameter 10 mm, length 500 mm) filled with 15 ml of the above MFI type aluminosilicate or activated alumina was used as a fixed bed reactor. As preparation for pretreatment, nitrogen gas was circulated for 30 minutes at a flow rate of 61.5 ml / min in the fixed bed reactor immersed in a salt bath at 360 ° C. Subsequently, as a pretreatment, a pretreatment gas was circulated in the fixed bed reactor for 30 minutes. The pretreatment gas used here and the flow rate thereof are as follows.

Experimental example 1
Catalyst for dehydration: MFI type aluminosilicate Gas composition for pretreatment: 10.1 mol% acrolein, 63.4 mol% water, 26.5 mol% nitrogen
Pretreatment gas flow rate: 928 hr ⁻¹ (GHSV value)

Experimental example 2
Catalyst for dehydration: MFI type aluminosilicate Pretreatment gas composition: 21 mol% 1-hydroxyacetone, 48.2 mol% water, 30.8 mol% nitrogen
Pretreatment gas flow rate: 799 hr ⁻¹ (GHSV value)

Experimental example 3
Catalyst for dehydration: MFI type aluminosilicate Pretreatment gas composition: 21 mol% of 1-hydroxyacetone, water 48.2 mol%, nitrogen 24.3 mol%, oxygen 6.5 mol%
Pretreatment gas flow rate: 799 hr ⁻¹ (GHSV value)

Experimental Example 4
Catalyst for dehydration: activated alumina Gas composition for pretreatment: 10.1 mol% acrolein, 63.4 mol% water, 26.5 mol% nitrogen
Pretreatment gas flow rate: 928 hr ⁻¹ (GHSV value)

Experimental Example 5
Catalyst for dehydration: activated alumina Gas composition for pretreatment: 1-hydroxyacetone 21 mol%, water 48.2 mol%, nitrogen 30.8 mol%
Pretreatment gas flow rate: 799 hr ⁻¹ (GHSV value)

Comparative Experiment Example 1
Catalyst for dehydration: MFI type aluminosilicate No pretreatment gas distribution

Comparative Experiment Example 2
Catalyst for dehydration: MFI type aluminosilicate Pretreatment gas composition: 100 mol% nitrogen
Pretreatment gas flow rate: 61.5 ml / min

Comparative Experiment Example 3
Catalyst for dehydration: MFI type aluminosilicate Pretreatment gas composition: water 81.4 mol%, nitrogen 18.6 mol%
Gas flow for pretreatment: 1326 hr ⁻¹ (GHSV value)

Comparative Experiment Example 4
Dehydration catalyst: MFI type aluminosilicate Pretreatment gas composition: Air Pretreatment gas flow rate: 61.5 ml / min

Comparative Experiment Example 5
Catalyst for dehydration: Activated alumina No pretreatment gas distribution

(Manufacture of acrolein)
In a fixed bed reactor after pretreatment immersed in a salt bath at 360 ° C., a glycerin-containing gas in which a vaporized gas of 80 mass% glycerin aqueous solution and nitrogen are mixed (glycerin-containing gas composition: glycerin 27 mol%, water 34 mol%) , 39 mol% of nitrogen) was allowed to flow (GHSV: 632 hr ⁻¹ ) to convert glycerin in the glycerin-containing gas into acrolein.

  After flowing the glycerin-containing gas into the fixed bed reactor, the effluent gas was cooled and liquefied and collected for 0 to 30 minutes, 30 to 60 minutes, and 150 to 180 minutes (hereinafter referred to as “cooled liquefied and collected effluent gas”). Is called “spill”). And qualitative and quantitative analysis of the effluent was performed by gas chromatography (GC). As a result of analysis by GC, glycerin and 1-hydroxyacetone were detected and quantified together with acrolein. Using this analysis result value, the conversion rate of glycerin and the yield of acrolein were calculated. The conversion rate of glycerin and the yield of acrolein were calculated by the following formulas (1) and (2).

  Table 1 shows the results of the above experimental examples and comparative experimental examples.

  In Table 1, Experimental Example 1 using a pretreatment gas containing acrolein that will be present in the uncollected gas discharged in the acrolein collection step is a comparative experiment using a pretreatment gas not containing acrolein. It can be confirmed that the acrolein yield was high for 0 to 30 minutes as compared with Examples 1 to 3. Experimental Examples 2 and 3 using a pretreatment gas containing 1-hydroxyacetone by-produced in the production of acrolein are also compared to Comparative Experimental Examples 1 to 3 using a pretreatment gas not containing 1-hydroxyacetone. It can be confirmed that the acrolein yield was high for 0 to 30 minutes. Such a high yield of acrolein was the same in Experimental Examples 4 and 5.

  Apart from the above Experimental Examples 1 to 5 and Comparative Experimental Examples 1 to 5, acrolein was produced as in Experimental Example 6 below.

(Experimental example 6)
Acrolein was the same as Comparative Example 1 except that a gas having a composition of 0.5 mol% acrolein, 26.5 mol% glycerin, 34.3 mol% water, and 38.7 mol% nitrogen was used as the glycerin-containing gas in the production of acrolein. Manufactured.

  The results of Experimental Example 6 are shown in Table 2 together with Comparative Experimental Example 1.

  In Table 2, Experimental Example 6 using glycerin-containing gas containing acrolein as an uncollected gas component is 0 to 30 minutes acrolein compared to Comparative Experimental Example 1 using glycerin-containing gas not containing acrolein. It can be confirmed that the yield was high. The high acrolein yield of Experimental Example 6 in 0 to 30 minutes was not mainly due to the inclusion of acrolein in the glycerin-containing gas. This is because most of the acrolein in contact with the catalyst for dehydration at the beginning of the production of acrolein disappears, as shown in a reference experiment example described later.

  Moreover, in Table 2, it can confirm that the acrolein yield of Experimental Example 6 was higher than Comparative Experimental Example 1 at 30 to 60 minutes and 150 to 180 minutes. The high acrolein yield of Experimental Example 6 at 30 to 60 minutes and 150 to 180 minutes is mainly due to the inclusion of acrolein in the glycerin-containing gas (see Reference Experimental Examples below).

  Apart from the above Experimental Examples 1-6 and Comparative Experimental Examples 1-5, acrolein was produced as in Experimental Examples 7, 8 and 6 below.

(Experimental example 7)
The catalyst used for the production of acrolein as in Experimental Example 2 was calcined in an air stream at 500 ° C. for 2 hours to regenerate the catalyst. Acrolein was produced in the same manner as in Experimental Example 2, except that this regenerated catalyst was used.

(Experimental example 8)
The catalyst used for the production of acrolein in Comparative Experimental Example 1 was calcined in an air stream at 500 ° C. for 2 hours to regenerate the catalyst. Acrolein was produced in the same manner as in Experimental Example 2, except that this regenerated catalyst was used.

(Comparative Experimental Example 6)
The catalyst used for the production of acrolein as in Experimental Example 2 was calcined in an air stream at 500 ° C. for 2 hours to regenerate the catalyst. Acrolein was produced in the same manner as in Comparative Experimental Example 1, except that this regenerated catalyst was used.

  Table 3 shows the results of Experimental Example 7, Experimental Example 8, and Comparative Experimental Example 6.

  In comparison between Experimental Examples 7 and 8 and Comparative Experimental Example 6 in Table 3, Experimental Examples 7 and 8 in the case of using the pretreatment gas are compared with Comparative Experimental Example 6 in which the pretreatment gas is not used. It can be confirmed that the acrolein yield was high for 0 to 30 minutes. That is, whether or not the dehydration catalyst is regenerated does not affect the effect of the present invention.

Reference Experimental Example Next, a reference experimental example was performed to confirm the change of acrolein when contacting the dehydration catalyst.

In the reference experimental example, an acrolein-containing gas (a gas not containing glycerin) was brought into contact with the dehydration catalyst as follows. A stainless steel reaction tube (inner diameter 10 mm, length 500 mm) filled with 15 ml of MFI type aluminosilicate prepared in the same manner as in Experimental Example 1 was used as a fixed bed reactor. First, nitrogen gas was passed through the fixed bed reactor immersed in a salt bath at 360 ° C. at a flow rate of 61.5 ml / min for 30 minutes. Thereafter, an acrolein-containing gas (gas composition: acrolein 7.6 vol%, water 47.9 vol%, nitrogen 44.5 vol%) was circulated through the fixed bed reactor at GHSV 550 hr ⁻¹ .

  The effluents from 0 to 30 minutes, 30 to 60 minutes and 150 to 180 minutes after the acrolein-containing gas was circulated in the fixed bed reactor were qualitatively and quantitatively analyzed by GC. In the qualitative analysis, acrolein was detected. Further, the recovery rate of acrolein was calculated according to the following formula (3).

  The results of the reference experiment example are shown in Table 4 below.

  As shown in Table 4, the acrolein recovery rates for 30 to 60 minutes and 150 to 180 minutes are 100%, and it can be confirmed that the acrolein contacted with the catalyst for dehydration did not change at all. On the other hand, since the acrolein recovery rate for 0 to 30 minutes was 1.44%, most of the acrolein contacted with the catalyst for dehydration at the start of use had disappeared.

It is an acrolein manufacturing process figure which concerns on one Embodiment of this invention.

Explanation of symbols

100a, 100b reactor 200 separation tower 300 collector

Claims (4)

A dehydration reaction step of producing an acrolein-containing gas by contacting the glycerin-containing gas with a glycerol dehydration catalyst;
And acrolein collecting step of collecting acrolein in the acrolein-containing gas and discharging uncollected gas,
A method for producing acrolein, wherein the uncollected gas is brought into contact with the glycerol dehydration catalyst.   2. The method for producing acrolein according to claim 1, wherein in the dehydration reaction step, the uncollected gas is brought into contact with the glycerol dehydration catalyst by causing the glycerin-containing gas to contain the uncollected gas.   The method for producing acrolein according to claim 1 or 2, wherein an uncollected gas is brought into contact with the glycerol dehydration catalyst before the dehydration reaction step.   The manufacturing method of the acrolein derivative which has the process of manufacturing acrolein using the manufacturing method of the acrolein in any one of Claims 1-3.

Images