JPS6169740A - Production of glycol aldehyde - Google Patents

Abstract

PURPOSE:To improve the selectivity and purity in the production of the titled compound useful as pharmaceuticals, agricultural chemicals, textile treating agent, etc. economically, without using complicate process, by selecting specific catalyst and reaction condition in the vapor-phase catalyst dehydrogenation of ethylene glycol. CONSTITUTION:The objective compound is produced by contacting ethylene glycol with steam in vapor phase at 180-400 deg.C, preferably 250-300 deg.C using a copper-based catalyst or copper-zinc oxide catalyst, preferably copper-zinc oxide catalyst having a specific surface area of 0.01-500m<2>/g, preferably 0.1-300m<2>/g. The above copper-zinc oxide catalyst is composed of 0.1-50pts., especially 0.7-2pts. of zinc oxide per 1pt. of copper (in terms of copper oxide). The amount of water supplied to the catalyst-packed reactor as a mixture with the raw material is preferably 1-30mol per 1mol of the raw material.

Description

DETAILED DESCRIPTION OF THE INVENTION Background of the Invention; A. Technical Field The present invention comprises: 1. Gas-phase catalytic dehydrogenation of brene glycol,
: J. Concerning a method for producing glycolaldehyde.

More particularly, the present invention relates to a catalytic process for the production of glycolaldehyde, which is characterized by the catalyst used and the reaction conditions.

Glycolaldehyde is an α-amino acid, medical mulberry, pesticide,
It is a compound useful as a raw material for photographic chemicals or special polymers, and as a fiber treatment agent, odorant, deodorant, etc.

Prior art and its problems The following technology is known as a method for producing glycolaldehyde from ethylene glycol.

(1) A method of contacting ethylene glycol with hydrogen and water vapor to a copper-chromium catalyst at 300 to 400''C (USSR Patent No. 168,281 (1965)).

(2) A method in which ethylene glycol is brought into contact with a copper-zinc alloy (brass) at 220 to 370°C under a reduced pressure of 10 to 45 mmHg (Masato Nomura, Yoshito Fujiwara, Kindai University Faculty of Engineering Research Report No. 15).

In method (1) above, it is necessary to add hydrogen gas during the reaction, and there are several steps. ! ! Not only is it sloppy;
Low selectivity of glycolaldehyde and high IiI! There is a problem that 1q of glycolaldehyde is not produced.

On the other hand, in method (2) above, the reaction system is heated for 10 to 45 seconds!
It is necessary to maintain a vacuum with a high IQ, and the liquid hourly space velocity (
L HSV ) has to be extremely small at 0.01/hr, resulting in extremely low production efficiency.
.

J: In order to efficiently produce high-purity glycolaldehyde, none of the known techniques can be called industrially sufficient 4f technology.

Glycolaldehyde is a highly reactive aldehyde, and glycolaldehyde is easily further dehydrogenated to form glyoxal, and is also easily decomposed into r-M carbon, formaldehyde, and formic acid under reaction conditions. Glycolaldehyde also tends to react with excess ethylene glycol to form 2-methylol-1,3-dioxolane.

In other words, an object of the present invention is to suppress the above-mentioned sequential reactions or side reactions to efficiently produce highly purified glycolaldehyde.

SUMMARY OF THE INVENTION The present invention seeks to solve the aforementioned problems of the prior art with catalysts and reaction conditions.

That is, when producing glycolaldehyde by gas phase catalytic dehydrogenation of ethylene glycol according to the present invention, the specific surface area is 0.01 to 500.
Tdz! Ethylene glycol is added to a copper-based or copper-zinc oxide-based catalyst with water vapor in the gas phase at 180 to 400°C.
It is characterized by the fact that it is brought into contact with the

According to the present invention, glycolaldehyde is produced with high selectivity even under high LH8V, and as a result, highly pure glycolaldehyde can be efficiently produced.

Detailed Description of the Invention Catalyst The catalyst that can be used in the present invention has a specific surface area of 0.0.
1 to 500 go/g, preferably 0.1 to 300 m/9
, especially preferred t:1. ．． ．． 1 to 200 m/g, preferably a copper-based or copper-zinc oxide-based catalyst.

Here, "copper-based or copper-zinc oxide-based catalyst" means:
Refers to catalysts containing copper or copper and zinc oxide as main catalyst components, and also includes catalysts containing co-catalysts or carriers.
It's Riruchino.

In addition to being composed of specific catalyst components, the catalyst according to the present invention has a specific surface area of o, oi ~ 500 m/U. If it exceeds 500 TIl/y, side reactions are likely to occur and the selectivity of glycolaldehyde will be low, and the life of the catalyst will be shortened due to sinking etc., so Ikf will not be high.

These catalysts can be prepared by the conventionally known IJ method. For example, a method may be mentioned in which copper oxide or a copper oxide-zinc oxide mixture is reduced with hydrogen at 150 to 300°C. Copper oxide can be produced, for example, by heating metal steel in the form of powder, fibers, threads, or mesh in the presence of oxygen, or by firing a copper salt such as copper nitrate or copper sulfate. The copper oxide-zinc oxide mixture can be prepared, for example, by heating a copper-zinc alloy in the presence of oxygen, in the form of powder, fibers or threads, or in the form of a mesh, copper nitrate,
It can be produced by a method such as firing a mixture of a copper salt such as copper sulfate and a zinc salt such as zinc nitrate or zinc sulfate.

In the case of a copper-zinc oxide catalyst, its composition is equivalent to copper oxide 1
0.1 to 5 parts by weight of zinc oxide
0 parts, preferably 0.5 to 10 parts, particularly preferably 0.
The ratio corresponds to 7 to 2 parts.

These catalysts may contain less than 1 part of a transition metal compound such as chromium, manganese, iron, cobalt, nickel, etc. in terms of oxide per 1 part of copper oxide, but if glycolaldehyde is selected, In some cases, it is preferable not to include it because the I scale'1 may decrease.

Further, these catalysts may be supported on a 1U body such as pumice, activated carbon, graphite, llr sulfur 1, asbestos, silica, alumina, silica/lumina, or the like.

Reactor ¥1 The present invention C can efficiently produce glycolaldehyde by continuously passing a mixed gas of ethylene glycol/water through a reactor filled with the above catalyst.

The ratio of ethylene glycol to water is usually 0.1 to 100 mol, preferably 0.5 to 50 mol, particularly preferably 1 to 10 mol, of water per 1 mol of ethylene glycol.
That's about it. If the amount of water is less than 0.1 mol, the conversion rate of ethylene glycol and the selectivity of glycolaldehyde will decrease, which is not preferable. When water exceeds 100 moles,
The space-time yield deteriorates and economic efficiency decreases.

6 temperature is usually 180 to 400°C, preferably 2
00-350'C, particularly preferably 250-300'C
It is about 1. If the temperature is lower than 180°C, the conversion rate of ethylene glycol will be low, and if it exceeds 400°C, the selectivity of glycolaldehyde will decrease, both of which are not preferred.

L HSV Ha is usually about 0.05 to 10/hour, preferably 0.1 to 5/hour.

The reaction pressure may be normal pressure, reduced pressure, or increased pressure. Normal pressure is preferably used because of the economic efficiency of the reactor and ease of operation.

In addition to ethylene glycol and water vapor, an inert gas such as nitrogen or argon may be added as the atmospheric gas, but the inclusion of a large amount (10% by volume or more) of oxygen will reduce the selectivity of glycolaldehyde. It must be avoided because it can cause

EXPERIMENTAL EXAMPLES In the following experimental examples, the products were analyzed using gas chromatography and high performance liquid chromatography. In addition, the conversion rate of ethylene glycol (abbreviated as conversion rate) and the selectivity of glycolaldehyde (abbreviated as selectivity) were calculated based on the following equations.

Average diameter 2 mm, composition CIJO 50% by weight, ZnO
A catalyst precursor (rN211j, manufactured by JGC Chemical Co., Ltd.) having a specific surface area of 45% and a specific surface area of 31/J was packed into a reaction tower made of slanless steel with an inner diameter of 15IrIIR in an apparent volume equivalent to 20d.

This packed tower produces steam at -f 200°C.
O,5/h1°, then air at 200°C, G H
It was run for 3 hours at 3V300/hr. 200 steam again
℃, L HS V 0 , 5/hr for 1 hour, hydrogen was passed at 300° C. and GH3V 200/hr for 4 hours to obtain a copper-zinc oxide catalyst.

While maintaining this reaction tower at 280° C., a mixture of ethylene glycol, water, 1:4 (molar ratio) was gasified in a preheater, and passed through the reactor at 1H3V=2/hr.

After 4 hours, the conversion rate of ethylene glycol was 21% and the selectivity of glycolaldehyde was 91%.

Example 2 1fEl? of NaOH in a 1 liter beaker? Dissolve Cu (NO3)2 in 200 g of water, add ±16 g of diatomaceous solution, and heat to 40'C with stirring.
A solution of 31-12048.3rJ dissolved in 200 ml of water was added dropwise over 1 hour.

After aging at 40°C for 30 minutes, the pH was adjusted to 8.5 and filtered. The filtered solid was washed with water until the liquid became neutral, and then dried at 110° C. for 10 hours. This solid is made into a cocoon with a diameter of 2,
After molding into a cylindrical shape with a height of 2 m, it was fired at 380° C. for 3 hours to obtain a catalyst precursor.

This catalyst precursor was treated in the same manner as in Example 1 to obtain a supported copper-based catalyst.

Using this catalyst, ethylene glycol was reacted under the same conditions as in Example 1. The conversion rate of ethylene glycol was 20%, and the selectivity of glycolaldehyde was 88%.

119 Cu038 weight~%, Cr20337iUI%, MnO2
Catalyst precursor containing 2% by weight (rN20 manufactured by JGC Chemical Co., Ltd.
2DJ) was subjected to the same treatment as in Example 1, and then subjected to an ethylene glycol reaction under the same conditions as in Example 1.

The conversion rate of ethylene glycol was 28%, and the selectivity of glycolaldehyde was 79%.

L Kogoyu CCuO37fJ%, Cr20345ff11%, Mn
Catalyst precursor rN manufactured by Nikki Chemical Co., Ltd. containing 4% by weight of O2
Example 3 was repeated using 201J).

The conversion rate of ethylene glycol was 33%, and the selectivity of glycolaldehyde was 40%.

Comparative Example 2 Example 1 was repeated without adding water during the reaction of ethylene glycol.

The conversion of ethylene glycol was 9% and the conversion of glycolaldehyde was 67%.

Claims (1)

[Claims] When producing glycolaldehyde by gas phase catalytic dehydrogenation of ethylene glycol, the specific surface area is from 0.01 to
500m^2/g of copper-based or copper-zinc oxide-based catalyst with ethylene glycol in the gas phase with water vapor at 180~
A method for producing glycolaldehyde, which comprises contacting at a temperature of 400°C.