JP2004339118A - Method for producing monohydroxyacetone - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for efficiently producing monohydroxyacetone by vapor phase dehydrogenation of 1,2-propanediol in the presence of a catalyst carrying a small amount of copper thereon. <P>SOLUTION: This method for producing monohydroxyacetone comprises carrying out the vapor phase dehydrogenation of 1,2-propanediol in the presence of a copper oxide-silica catalyst having ≤0.10 mol×kg<SP>-1</SP>in ammonia elimination level determined by the temperature-rising ammonia elimination method. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing monohydroxyacetone.
[0002]
[Prior art]
Monohydroxyacetone is a compound useful as a raw material / intermediate of pharmaceuticals and agricultural chemicals. As a conventional technique for producing monohydroxyacetone, there is a technique for producing monohydroxyacetone from 1,2-propanediol by a gas-phase dehydrogenation reaction using a copper oxide-silica catalyst (for example, Patent Document 1). reference). However, in the case of this production method, the supported amount in terms of metallic copper with respect to silica is as large as 12% by weight, and copper is expensive, which is not economically advantageous.
[Patent Document 1]
JP-A-50-5311
[Problems to be solved by the invention]
Therefore, it is an issue to develop an effective catalyst with a small amount of supported copper. The present inventors have conducted intensive studies on this point, and found that the use of a copper oxide-silica catalyst having an ammonia desorption amount of 0.10 mol · kg ⁻¹ or less by an ammonia temperature-programmed desorption method, The present inventors have found that monohydroxyacetone can be obtained while suppressing the copper content much more than in the technique and maintaining sufficient productivity, and reached the present invention.
[0004]
[Means for Solving the Problems]
That is, in the present invention, when 1,2-propanediol is subjected to a gas phase dehydrogenation reaction in the presence of a catalyst to produce monohydroxyacetone, the amount of ammonia desorbed by the ammonia temperature-programmed desorption method as a catalyst is 0.10 mol The present invention relates to a method for producing monohydroxyacetone, wherein a copper oxide-silica catalyst having a weight of not more than kg ^-1 is used.
[0005]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described specifically.
[0006]
The catalyst used in the present invention uses copper oxide as an active ingredient and silica as a carrier. This catalyst can use copper nitrate, sulfate, carbonate temperature, acetate, chloride, oxide, and / or hydroxide as a raw material compound of copper oxide, and can be prepared by a conventional preparation method, for example, coprecipitation. It is prepared by a method, an impregnation method or a kneading method. A catalyst in which copper oxide prepared by an impregnation method is supported on a carrier is preferred. In a catalyst in which copper oxide is supported on a carrier, the amount of copper oxide supported is not particularly limited, but is usually 0.1 to 25% by weight, preferably 3 to 7% by weight based on the carrier. In addition, an alkali metal or an alkali metal may be contained as a cocatalyst, and the amount is usually 0.001 to 1% by weight, preferably 0.01 to 0.5%, based on the carrier. The catalyst is used in the reaction after being shaped into a desired shape such as a powder, a column, a sphere, and a granule. When a carrier is used, the carrier may be preliminarily formed into the desired shape, and a catalyst may be prepared using the formed carrier by an impregnation method to obtain a shaped catalyst.
[0007]
The catalyst used in the present invention has an ammonia desorption amount of 0.10 mol · kg ⁻¹ or less by the ammonia temperature-programmed desorption method, and preferably has an ammonia desorption amount of 0.10 mol in a temperature range of 100 to 350 ° C. ^{-It is not} more than kg ^-1 .
[0008]
The ammonia temperature-programmed desorption method (Temperature-Programmed-Desorption-method) is a method in which ammonia, which is a base, is adsorbed on a solid sample and the sample layer is heated to observe the desorption spectrum. This is an excellent method that can quickly and accurately measure the solid acid amount and strength in an environment close to the reaction conditions of many solid catalysts. The ammonia thermal desorption method is described in various scientific documents. (Example: Catal. Sureys Jpn., 1, 215 (1997))
[0009]
The amount of ammonia desorbed by the ammonia temperature-programmed desorption method of the catalyst used in the present invention is measured by a method recommended by the Catalysis Society of Japan Catalysis Committee (published by the Catalysis Society of Japan in August 1998; The catalyst was used for the measurement according to the reference manual for reference catalysts.
[0010]
The reaction of the present invention can be carried out in a fixed bed reactor or a fluidized bed reactor. When the gas-phase dehydrogenation reaction of the present invention is carried out using a fixed-bed reactor, for example, a reaction tube is filled with a catalyst, and the catalyst-filled portion of the reaction tube is usually set at 200 to 450 ° C., preferably 240 to 450 ° C. Raise the temperature to 300 ° C. Then, a gas phase dehydrogenation reaction is performed by supplying 1,2-propanediol to the catalyst-filled portion of the reaction tube, if desired, with a diluent. Liquid space velocity of 1,2-propanediol <hereinafter referred to as LHSV. > Is usually 0.01 to 8.0 g / (ml catalyst · hr), preferably 0.1 to 2.0 g / (ml catalyst · hr). Further, the reaction may be carried out using an inert gas such as nitrogen, helium, or steam as a diluent, and a preferred diluent is nitrogen. When a diluent is used, its amount is usually 0.1 to 50 mol, preferably 0.5 to 10 mol, per 1 mol of 1,2-propanediol. Also, the space velocity of the mixed gas consisting of a diluent and 1,2-propanediol (hereinafter. Referred SV) is usually 50～5000Hr ^-1, preferably 100～1000Hr ^-1. The reaction can be carried out under normal pressure, reduced pressure or increased pressure. By performing such a reaction, monohydroxyacetone is generated.
[0011]
After completion of the reaction, the reaction gas flowing out of the reactor is cooled and / or passed through a suitable solvent to obtain an aggregate and / or a solution containing monohydroxyacetone. Monohydroxyacetone can be isolated from the obtained condensate or collected liquid by combining unit operations such as concentration, extraction, and distillation.
[0012]
【Example】
Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited to Examples.
The conversion, yield and selectivity in the following examples were calculated according to the following definitions.
[0013]
Conversion rate (%) = reacted 1,2-propanediol (mol) × 100 / supplied 1,2-propanediol (mol)
[0014]
Yield (%) = monohydroxyacetone (mol) generated by the reaction × 100 / supplied 1,2-propanediol (mol)
[0015]
Selectivity (%) = monohydroxyacetone (mol) generated by the reaction × 100 / reacted 1,2-propanediol (mol)
[0016]
Example 1
The catalyst-prepared silica powder (having an amount of ammonia desorbed by the ammonia thermal desorption method of substantially 0) was extruded (columnar, 1.7 mm in diameter, 5 to 20 mm in length) on a silica carrier, A solution of 1.9 g of copper and 44.0 g of 28% aqueous ammonia was impregnated into 18.7 g of the above silica carrier, dried at 120 ° C. for 3 hours, and then calcined at 600 ° C. for 3 hours in an air stream. Thus, a catalyst in which copper oxide was supported on silica (content of copper oxide in the catalyst: 6% by weight) was obtained.
[0017]
Measurement of the amount of ammonia desorbed About 0.1 g of the catalyst sample thus obtained was heated from room temperature to 500 ° C. under vacuum (10 ° C./min), degassed at 500 ° C. for 1 hour, and degassed at 100 ° C. It was brought into contact with ammonia at 13.3 kPa for 30 minutes and degassed for 30 minutes. Thereafter, the sample bed is heated from 100 ° C. to 350 ° C. at a rate of 10 ° C./min under a total pressure of 13.3 kPa in a helium stream (50 ml / min), and the amount of desorbed ammonia is measured by a quadrupole mass. Detected by analyzer. (M / Z = 16, NH2 +). Finally, a known concentration of ammonium / helium was allowed to flow, and the ion intensity of the mass spectrometer was corrected and quantified.
(Measurement device: fully automatic thermal desorption spectrometer TPD-1-AT Nippon Bell Co., Ltd.)
The amount of ammonia released from the catalyst at 100 ° C. to 350 ° C. was 0.07 mol · kg ⁻¹ .
[0018]
Production of Monohydroxyacetone 8.0 ml of the above catalyst was charged into a heat-resistant tempered glass reaction tube having an inner diameter of 18 mm, and the catalyst-filled portion of the reaction tube was heated to 270 ° C. 1,67-propanediol was supplied at 0.067 g / min and nitrogen was supplied at 19.8 ml / min. The reaction product gas flowing out of the reaction tube was passed through 100 ml of ion-exchanged water for 15 minutes to dissolve the soluble components in the reaction product gas in methanol. The obtained solution was analyzed by gas chromatography. As a result, the conversion of 1,2 propanediol was 86.9%, the yield of monohydroxyacetone was 76.5%, and the selectivity for monohydroxyacetone was 88.0%.
[0019]
Comparative Example 1
1.9 g of copper carbonate is dissolved in 44.0 g of 28% aqueous ammonia, and the resulting solution is impregnated into spherical silica (having an ammonia desorption amount of substantially zero by the ammonia thermal desorption method). , Dried at 120 ° C for 3 hours, and then fired at 600 ° C for 6 hours in an air stream. In this way, a catalyst in which oxidized steel was supported on alumina (the content of copper oxide in the catalyst: 6% by weight) was obtained.
When this catalyst was measured by the above-mentioned ammonia thermal desorption method, the amount of desorbed ammonia from 100 ° C to 350 ° C was 0.12 mol · kg ^-1 .
Monohydroxyacetone was produced in the same manner as in Example 1 except that this catalyst was used. As a result, the conversion of 1,2-propanediol was 85.6%, the yield of monohydroxyacetone was 70.5%, and the selectivity for monohydroxyacetone was 82.3%.

Claims (1)

When 1,2-propanediol is subjected to a gas phase dehydrogenation reaction in the presence of a catalyst to produce monohydroxyacetone, the amount of ammonia desorbed by the ammonia temperature-programmed desorption method as a catalyst is 0.10 mol · kg ⁻¹ or less. A method for producing monohydroxyacetone, comprising using a copper oxide-silica catalyst as described above.