JP5162128B2 - Method for producing acrolein from glycerin - Google Patents

Description

  The present invention relates to a gas phase reaction method for producing acrolein from glycerin using a solid catalyst, which is excellent in acrolein productivity.

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.

  In the production of acrolein from glycerin by a dehydration reaction, it has long been known to use a solid acid catalyst.

  Disclosed is to produce acrolein by dehydrating a solid acid catalyst having an acid strength function H0 of +2 or less and a glycerol aqueous solution having a glycerol content of 10 to 40% by weight by catalytic gas phase reaction at 250 to 340 ° C. The glycerin supply amount per hour per 1 L of catalyst in the examples (hereinafter sometimes referred to as glycerin unit supply amount) is calculated as 80 to 160 g glycerin / hr / L-catalyst (see Patent Document 1). .

  Also disclosed is a method for producing acrolein by gas phase dehydration reaction of glycerin using a solid strong acid catalyst having an acid strength function H0 in the range of -9 to -18. In carrying out the catalytic gas phase reaction with the catalyst, it is described that the preferable reaction temperature is 250 ° C. to 350 ° C., and the glycerin unit supply amount in the examples is calculated as 230 g glycerin / hr / L-catalyst ( Reference 2).

  The level of supply of these glycerin units is still low when assuming industrial production, and if it is low, the productivity will be poor, and therefore there will be a problem that the reactor will be large, and the productivity will be increased. The inventor of the present application diligently studied the device.

  Acrolein is widely produced industrially by catalytic gas phase oxidation of propylene. For example, as a load of propylene per unit time per unit amount of propylene, the load of propylene under conditions of 90 to 160 NL / L-catalyst. A catalytic partial gas phase oxidation method is disclosed, and this condition corresponds to 360 to 658 g glycerin / hr / L-catalyst when converted to a glycerin unit supply amount (Patent Document 3).

Japanese Patent Laid-Open No. 06-211724 International Publication WO2006-070883 JP-T-2006-521317

  An object of this invention is to provide the method of manufacturing without impairing the yield of acrolein on practical glycerol load conditions in view of the said situation.

  As a result of intensive studies on the synthesis reaction of acrolein from glycerin, the present inventors have found that acrolein can be produced under practical load conditions, with a reaction temperature of 350 ° C. to 460 ° C. and a contact time of 0. It discovered that it could manufacture, without impairing the yield of acrolein in the range of 1 to 7.2 seconds.

That is, the following method was invented as means for solving the above-mentioned problems.
(1) In a catalytic gas phase dehydration reaction in which a gas containing glycerin is brought into contact with a solid acid catalyst to synthesize acrolein, the amount of glycerin converted per unit time per unit catalyst is 300 to 15000 g glycerin / hr / L-catalyst, and the reaction A process for producing acrolein, wherein the reaction is carried out at a temperature of 350 to 460 ° C.

  (2) The method for producing acrolein according to (1), wherein the contact time is 0.1 to 7.2 seconds.

  According to the present invention, in the production of acrolein by dehydration reaction of glycerin, when a gas phase reaction is performed at a reaction temperature of 350 to 460 ° C., it can be produced without impairing the yield of acrolein under practical high load conditions. .

  The production method of acrolein in the present embodiment is a gas phase dehydration reaction in which a raw material gas containing glycerin is brought into contact with a catalyst in a reactor arbitrarily selected from a fixed bed reactor, a moving bed reactor, a fluidized bed reactor and the like. Acrolein is produced.

  The solid acid catalyst may be any compound having solid acidity. (1) Crystalline metallosilicate, (2) Metal oxide, (3) Clay mineral, (4) Mineral acid with α-alumina, silica, oxidation (5) Metal salts of phosphoric acid and sulfuric acid and those supported on an inorganic carrier such as α-alumina, silica, zirconium oxide, titanium oxide, etc. .

  (1) As a crystalline metallosilicate, one or more elements selected from Al, B, Fe, Ga and the like are T atoms, and the crystal structure thereof is LTA, CHA, FER, MFI, MOR, There are BEA, MTW, etc. (2) As the metal oxide, in addition to single metal oxides such as Al2O3, TiO2, ZrO2, SnO2, V2O5, SiO2-Al2O3, SiO2-TiO2, TiO2-WO3, WO3-ZrO2 (3) Clay minerals include bentonite, kaolin, montmorillonite, etc. (4) As mineral acid is supported on an inorganic carrier, phosphoric acid and sulfuric acid are alumina, silica, zirconia, etc. (5) Metal salts of phosphoric acid and sulfuric acid include MgSO4, Al2 (SO4) 3, K2SO4 AlPO4, Zr3 (PO4) 4 and the like.

  Specifically, solid acids (such as zirconium oxide carrying phosphoric acid, sulfuric acid or tungsten oxide) disclosed in International Publications WO2006 / 087083 and WO2006 / 087084 can also be used.

  Among these, since they are exposed to an oxidizing or reducing atmosphere at a high temperature during dehydration or regeneration, a solid catalyst having good stability is preferable, and crystalline metallosilicates, metal oxides, clay minerals, and the like are preferable. As the crystalline metallosilicate, ZSM5 having a TFI of Al and an MFI structure is particularly suitable.

  The amount of glycerin supplied per unit catalyst per unit time means the amount of glycerin supplied per hour per 1 L of catalyst (glycerin unit supply amount), and the weight of glycerin per hour supplied onto the catalyst is the reaction of the catalyst. It is the value divided by the volume (L) in the vessel.

  The glycerin unit supply amount is 300 to 15000 g glycerin / hr / L-catalyst, preferably 400 to 12000 g glycerin / hr / L-catalyst, more preferably 500 to 10,000 g glycerin / hr / L-catalyst.

The contact time is a value obtained by dividing the catalyst volume by the gas flow rate per second.
The contact time is preferably 0.1 to 7.2 seconds, more preferably 0.2 to 7.0 seconds, and still more preferably 0.3 to 6.0 seconds.

  The glycerin unit supply amount, contact time, and temperature are correlated, and the following range is more preferable in consideration of performance. For example, when the reaction temperature is 350 ° C. or higher and lower than 380 ° C., the glycerin supply amount is 300 to 3000 g glycerin / hr / L-catalyst and the contact time is 0.1 to 7.2 seconds, similarly 380 ° C. or higher. Below 410 ° C, 300 to 7000 g glycerin / hr / L-catalyst is used for 0.1 to 7.2 seconds, and when 410 ° C or more and below 440 ° C, 700 to 10000 g glycerin / hr / L-catalyst is used at 0.1 to 3.5. 2 seconds, also from 440 ° C. to below 460 ° C., 0.1 to 2.0 seconds with 2000 to 15000 g glycerin / hr / L-catalyst. More preferably, when the reaction temperature is 350 ° C. or higher and lower than 380 ° C., 300 to 2000 g glycerin / hr / L-catalyst is used for 0.3 to 7.2 seconds, and when 380 ° C. or higher and lower than 410 ° C. is 600 to 4000 g glycerin / hr / L-catalyst. 0.3 to 6.0 seconds, also from 410 ° C. to less than 440 ° C., from 1000 to 7500 g glycerol / hr / L-catalyst for 0.1 to 2.5 seconds, and from 440 ° C. to less than 460 ° C. It is 0.1 to 1.0 second with 10000 g glycerin / hr / L-catalyst.

  The reaction temperature is preferably 350 to 460 ° C, more preferably 350 to 450 ° C. When the reaction temperature is low, unconverted glycerin increases and the yield of acrolein decreases, so not only the glycerol unit supply amount is substantially reduced, but also an apparatus for recovering unconverted glycerin. This increases the production cost of acrolein. On the other hand, if the reaction temperature is too high, the yield of acrolein is greatly reduced, which is not preferable.

  The glycerin concentration in the reaction raw material gas may be 0.1 to 100 mol%. However, particularly under conditions where the glycerin unit supply amount is large, the amount of dilution gas used is reduced, the pressure loss of the reaction system is reduced, and the generated acrolein is reduced. From an economic viewpoint such as collection efficiency, it is more preferably 1 mol% or more.

  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 reaction pressure is not particularly limited as long as glycerin is not condensed. Usually, it is good that it is 0.001 to 1 MPa, and preferably 0.01 to 0.5 MPa.

  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. Unless otherwise specified, “%” indicates “mass%” and “part” indicates “mass part”.

(Catalyst Preparation Example 1)
0.58 g of NaOH and 1.95 g of NaAlO2 were dissolved in 15.00 g of distilled water sequentially, and 10.15 g of 40% by mass tetra-n-prohilammonium 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, silica beads ("Caractect Q-50" manufactured by Fuji Silysia Chemical Ltd., 10 to 20 mesh, average pore diameter 50 nm) are used as the silica molded body, and impregnated with 30 g silica beads dried at 120 ° C for 1 day. The liquid was impregnated for 1 hour. Thereafter, the impregnated silica beads are dried on an evaporating dish placed on a 100 ° C. hot water bath, and further dried at 80 ° C. under a nitrogen stream for 5 hours to obtain Na and Al crystallization agents necessary for crystallization. Was supported on silica beads to obtain a crystalline methanosilicate precursor.

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

  The solid material that had undergone the crystallization step was immersed in 300 g of a 1 mol / L aqueous ammonium nitrate solution at 60 ° C. for 1 hour, and then the supernatant was discarded. This operation was repeated several times. Thereafter, the solid was washed with water.

  The solid after the ion exchange step was baked at 540 ° C. for 3.5 hours in an air stream. By this calcination, catalyst A which is H-type MFI was obtained.

(Catalyst preparation example 2)
A commercially available granular activated alumina ("ALUMINIUMOXIDE 90 Active acid (0.063-0.200 mm) (Activity Stage I)" manufactured by Merck & Co., production number 101078) is filled into a vinyl chloride tube having an inner diameter of 3 cm and a height of 5 mm. Then, pressure forming was carried out, and the resulting molded body was crushed and classified into 0.7 to 1.4 mm to obtain catalyst B.

(Catalyst Preparation Example 3)
350 g of ion-exchanged water and 40 g of SiO2 powder were mixed and stirred to prepare a mixed solution, and the mixed solution was heated to 80 ° C. Next, 7.1573 g of ZrO (NO 3) 2 .2H 2 O dissolved in a small amount of ion-exchanged water and 6.1507 g of 85 mass% orthophosphoric acid aqueous solution were added. Heating and stirring are continued until it becomes a paste at 80 ° C., and the obtained paste is dried at 100 ° C. and then fired in an air atmosphere at 600 ° C. for 5 hours, and the resulting solid is crushed. Then, catalyst C was obtained by classification to 0.7 to 1.4 mm.

Example 1
First, a stainless steel reaction tube (inner diameter 10 mm, length 500 mm) filled with 15 ml of catalyst was prepared as a fixed bed reactor, and this reactor was immersed in a salt bath at 360 ° C., and then an 80% by mass glycerin aqueous solution was vaporized. A reaction gas composed of a gas and nitrogen (reaction gas composition: glycerin 27 mol%, water 34 mol%, nitrogen 39 mol%) was circulated at a flow rate of 632 hr-1. The glycerin unit supply amount under these conditions is 701 g glycerin / hr / L-catalyst, and the contact time is 5.7 seconds. The effluent gas for 30 to 60 minutes and 150 to 180 minutes after flowing the reaction gas through the reactor was cooled and liquefied and collected (hereinafter referred to as “cooled liquefied product of the collected effluent gas”). Referred to as “spill”).

  Then, qualitative and quantitative analysis of the effluent was performed by gas chromatography (GC). As a result of qualitative analysis by GC, 1-hydroxyacetone was detected together with glycerin and acrolein. Moreover, the conversion rate and the acrolein yield were calculated from the quantitative analysis results. Here, the conversion rate is a value calculated by (1− (number of moles of glycerin in the collected effluent) / (number of moles of glycerin introduced into the reactor in 30 minutes)) × 100. The yield of acrolein is a value calculated by ((molar number of acrolein) / (molar number of glycerin introduced into the reactor in 30 minutes)) × 100. The results are shown in Table 1.

Example 2
In Example 1, it carried out like Example 1 except having changed the catalyst amount from 15 ml to 7.5 ml. At this time, the glycerin unit supply amount was 1400 g glycerin / hr / L-catalyst, and the contact time was 2.8 seconds. The results are shown in Table 1.

Example 3
In Example 1, it carried out like Example 1 except having changed salt bath temperature from 360 degreeC to 390 degreeC. The results are shown in Table 1.

Example 4
In Example 1, it carried out like Example 1 except having changed the salt bath temperature from 360 degreeC to 390 degreeC, and changing the catalyst amount from 15 ml to 4 ml. At this time, the supply amount of glycerol unit was 2625 g glycerol / hr / L-catalyst, and the contact time was 1.5 seconds. The results are shown in Table 1.

Example 5
In Example 1, it carried out like Example 1 except having changed the salt bath temperature from 360 degreeC to 420 degreeC, and changing the catalyst amount from 15 ml to 4 ml. At this time, the supply amount of glycerol unit was 2625 g glycerol / hr / L-catalyst, and the contact time was 1.5 seconds. The results are shown in Table 1.

Example 6
In Example 1, it carried out like Example 1 except having changed the salt bath temperature from 360 degreeC to 420 degreeC, and changing the catalyst amount from 15 ml to 2 ml. At this time, the glycerin unit supply amount was 5250 g glycerin / hr / L-catalyst, and the contact time was 0.76 seconds. The results are shown in Table 1.

Example 7
In Example 1, it carried out like Example 1 except having changed the salt bath temperature from 360 degreeC to 450 degreeC, and having changed the catalyst amount from 15 ml to 2 ml. At this time, the glycerin unit supply amount was 5250 g glycerin / hr / L-catalyst, and the contact time was 0.76 seconds. The results are shown in Table 1.

Example 8
In Example 1, it carried out like Example 1 except having changed the salt bath temperature from 360 degreeC to 450 degreeC, and changing the catalyst amount from 15 ml to 1 ml. At this time, the supply amount of glycerol unit was 10500 g glycerol / hr / L-catalyst, and the contact time was 0.38 seconds. The results are shown in Table 1.

Example 9
In Example 1, it carried out like Example 1 except having changed the catalyst A into the catalyst B. The results are shown in Table 1.

Example 10
In Example 1, it carried out like Example 1 except having changed the catalyst A into the catalyst C. The results are shown in Table 1.

Comparative Example 1
In Example 1, it carried out like Example 1 except having made salt bath temperature into 300 degreeC. The results are shown in Table 1.

Comparative Example 2
In Example 8, it carried out like Example 8 except having made salt bath temperature into 480 degreeC. The results are shown in Table 1.

Comparative Example 3
In Example 1, it carried out like Example 1 except having made the salt bath temperature into 390 degreeC and making the reaction gas composition 6.2 mol% of glycerol, 7.9 mol% of water, and 85.9 mol% of nitrogen. The results are shown in Table 1.

  As shown in Comparative Example 1, a rapid decrease in activity was observed at a reaction temperature of 300 ° C., and almost no acrolein was obtained at a reaction temperature of 480 ° C. in Comparative Example 2. Furthermore, in Comparative Example 3, it can be seen that the yield of acrolein is reduced even when the reaction temperature is increased while the glycerin unit supply amount is low. On the other hand, it can be seen that a good acrolein yield is exhibited under the reaction conditions of the present invention.

  By using the present invention, the reactor can be made compact, and acrolein can be produced from glycerin with high productivity.

Claims (7)

  In the catalytic gas phase dehydration reaction in which a gas containing glycerin is brought into contact with a solid acid catalyst to synthesize acrolein, the glycerin supply amount per unit catalyst is 300 to 15000 g glycerin / hr / L-catalyst, and the reaction temperature is 350 A process for producing acrolein, wherein the reaction is carried out at a temperature of ˜460 ° C. The method for producing acrolein according to claim 1, wherein the contact time is 0.1 to 7.2 seconds. The method for producing acrolein according to claim 1 or 2, wherein the reaction temperature is 350 ° C or higher and lower than 380 ° C, and the glycerin supply amount is 300 to 3000 g glycerin / hr / L-catalyst. The method for producing acrolein according to claim 1 or 2, wherein the reaction temperature is 380 ° C or higher and lower than 410 ° C, and the glycerin supply amount is 300 to 7000 g glycerin / hr / L-catalyst. The method for producing acrolein according to claim 1 or 2, wherein the reaction temperature is 410 ° C or higher and lower than 440 ° C, the glycerin supply amount is 700 to 10000 g glycerin / hr / L-catalyst, and the contact time is 0.1 to 3.5 seconds. . The method for producing acrolein according to claim 1 or 2, wherein the reaction temperature is 440 ° C or higher and lower than 460 ° C, the glycerin supply amount is 2000 to 15000 g glycerin / hr / L-catalyst, and the contact time is 0.1 to 2.0 seconds. . Solid acid catalyst with crystalline metallosilicate, metal oxide, clay mineral, mineral acid supported on inorganic support, phosphoric acid or sulfuric acid metal salt, or phosphoric acid or sulfuric acid metal salt supported on inorganic support The method for producing acrolein according to any one of claims 1 to 6.