Dehydrogenation of alkylene glycol ethers to ether detones and aldehydes

Abstract

A catalytic dehydrogenation of alkylene glycol ether to ether ketone or aldehyde is disclosed. The dehydrogenation is performed with copper chromite catalyst and at least 5 wt % of water based on alkylene glycol ether. It has been found that the selectively to formation of ether ketone or aldehyde increases with increasing the amount of water in the alkylene glycol ether.

Description

field of invention

[0001] The present invention relates to the preparation of ether ketone and ether aldehyde. In particular, the present invention relates to the catalytic dehydrogenation of alkylene glycol ethers to prepare ether ketones and ether aldehydes. Background of the invention

[0002] By dehydrogenation, primary alcohols can be converted to aldehydes and secondary alcohols can be converted to ketones. Similarly, glycol ethers can be converted to ether aldehydes or ether ketones. Catalytic dehydrogenation is more often used in industry because it has higher selectivity to aldehydes or ketones.

[0003] U.S. Pat. No. 3,462,495 teaches the dehydrogenation of glycol ethers with "calcium nickel phosphate" catalysts. The dehydrogenation was carried out by feeding a mixture of glycol ether and 1-25% water at 425°C, which resulted in a conversion of glycol ether of 55% and a selectivity of ether ketone of 72.5%.

[0004] U.S. Pat. No. 4,233,246 ...

Examples

Embodiment 1

[0021] The hydrogenation reaction is carried out in a stainless steel fixed bed reactor. A copper chromite catalyst (4.1 kg, Cu-0203-T, product of Engelhard Company) was charged into the reactor. The catalyst is activated with a mixture of hydrogen and nitrogen. To drive off moisture and air, the catalyst bed was heated to 150°C and maintained at this temperature for 5-8 hours under a nitrogen flow at a rate of 500 L / hr. Hydrogen is then added to the reactor. The reaction is exothermic so hydrogen addition is slow initially at a rate of 1.0-1.5% of the nitrogen flow rate. As the reaction continued, the concentration of hydrogen was gradually increased so as to control the temperature not to exceed 170°C. The hydrogen concentration reached 100% at the end of the reaction.

[0022] A mixture of 40% by weight water and 60% by weight propylene glycol methyl ether was fed into the reactor at a weight hourly space velocity (WHSV) of 1.1. The temperature of the reactor was maint...

Embodiment 2

[0024] Example 1 was repeated, but using a mixture of 20% by weight water and 80% by weight propylene glycol methyl ether. At this steady state, the conversion of propylene glycol methyl ether was 37.5%, and the selectivity to methoxyacetone was 85.4 mol%.

Embodiment 3

[0026] Example 1 was repeated, but using a mixture of 10% by weight water and 90% by weight propylene glycol methyl ether. At this steady state, the conversion of propylene glycol methyl ether was 34%, and the selectivity to methoxyacetone was 75.2 mol%.

field of invention

[0001] The present invention relates to the preparation of ether ketone and ether aldehyde. In particular, the present invention relates to the catalytic dehydrogenation of alkylene glycol ethers to prepare ether ketones and ether aldehydes. Background of the invention

[0002] By dehydrogenation, primary alcohols can be converted to aldehydes and secondary alcohols can be converted to ketones. Similarly, glycol ethers can be converted to ether aldehydes or ether ketones. Catalytic dehydrogenation is more often used in industry because it has higher selectivity to aldehydes or ketones.

[0003] U.S. Pat. No. 3,462,495 teaches the dehydrogenation of glycol ethers with "calcium nickel phosphate" catalysts. The dehydrogenation was carried out by feeding a mixture of glycol ether and 1-25% water at 425°C, which resulted in a conversion of glycol ether of 55% and a selectivity of ether ketone of 72.5%.

[0004] U.S. Pat. No. 4,233,246 ...

Examples

Embodiment 1

[0021] The hydrogenation reaction is carried out in a stainless steel fixed bed reactor. A copper chromite catalyst (4.1 kg, Cu-0203-T, product of Engelhard Company) was charged into the reactor. The catalyst is activated with a mixture of hydrogen and nitrogen. To drive off moisture and air, the catalyst bed was heated to 150°C and maintained at this temperature for 5-8 hours under a nitrogen flow at a rate of 500 L / hr. Hydrogen is then added to the reactor. The reaction is exothermic so hydrogen addition is slow initially at a rate of 1.0-1.5% of the nitrogen flow rate. As the reaction continued, the concentration of hydrogen was gradually increased so as to control the temperature not to exceed 170°C. The hydrogen concentration reached 100% at the end of the reaction.

[0022] A mixture of 40% by weight water and 60% by weight propylene glycol methyl ether was fed into the reactor at a weight hourly space velocity (WHSV) of 1.1. The temperature of the reactor was maint...

Embodiment 2

[0024] Example 1 was repeated, but using a mixture of 20% by weight water and 80% by weight propylene glycol methyl ether. At this steady state, the conversion of propylene glycol methyl ether was 37.5%, and the selectivity to methoxyacetone was 85.4 mol%.

Embodiment 3

[0026] Example 1 was repeated, but using a mixture of 10% by weight water and 90% by weight propylene glycol methyl ether. At this steady state, the conversion of propylene glycol methyl ether was 34%, and the selectivity to methoxyacetone was 75.2 mol%.