KR101219258B1 - Method For The Hydrogenation Of Aldehydes And Apparatus Using The Same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrogenation method for producing alcohol and an apparatus for producing the same. More particularly, the aldehyde and hydrogen gas are first contacted with a high active catalyst in a reactor and then reacted with a low active catalyst to hydrogenate aldehyde. The present invention relates to a method for producing an alcohol and a device thereof.

According to the present invention, it is possible to improve the selectivity through the activity control to increase the efficiency of the hydrogenation reaction, there is an effect that can reduce the formation of by-products and obtain the desired alcohol in high yield.

Hydrogenation reaction, hydroformylation reaction, oxo reaction, continuous stirred reactor, high activity catalyst, nickel catalyst, low activity catalyst, copper catalyst, venturi-loop reactor, aldehyde, alcohol

Description

Hydrogenation method and apparatus for producing alcohol {Method For The Hydrogenation Of Aldehydes And Apparatus Using The Same}

The present invention relates to a method for producing an alcohol by hydrogenation of an aldehyde and a device thereof. More particularly, a product in which a liquid aldehyde and hydrogen gas are first contacted with a high active catalyst in a reactor and reacted, and then the temperature is increased by the heat of reaction. The present invention relates to a method for producing an alcohol, and a device thereof, characterized in that a hydrogenation reaction of an aldehyde is completed by contacting a low activity catalyst.

The method of reacting olefins with carbon monoxide and hydrogen in the presence of a catalyst to produce saturated aldehydes in which hydrogen and formyl group (-CHO) are added to a C = C bond is known as a hydroformylation reaction or an oxo reaction. have. Generally, the resulting aldehydes are then condensed and then hydrogenated to synthesize longer chain alcohols.

The production of octanol (2-ethylhexanol) from propylene using a rhodium-based catalyst is a representative example of hydroformylation.

Examples of the hydrogenation process include hydrogenation of aldehyde to alcohol, hydrogenation of ketone to secondary alcohol, hydrogenation of nitrite to primary amine, hydrogenation of aliphatic monocarboxylic acid to alkanol and aliphatic Hydrogenation of an alkyl ester of dicarboxylic acid to an aliphatic diol and the like.

The hydrogenation of aldehydes to produce the corresponding alcohols is already known and widely used on an industrial scale. For example, a process for producing n-butanol by massive hydrogenation of n-butyl aldehyde synthesized from propylene through an oxo process, n-butylaldehyde by aldol condensation of 2-ethyl-3-hydroxyhexane The method of preparing 2-ethylhexanol used as a plasticizer by reducing the 2-ethylhexanal obtained by obtaining an egg and dehydrating it corresponds.

The hydrogenation of aldehydes to produce the corresponding alcohols can be carried out by passing a vapor phase stream comprising aldehydes and a hydrogen containing gas over the catalyst. Typical hydrogenation conditions depend on the nature of the hydrogenation reaction and the activity of the chosen hydrogenation catalyst.

As a method of the hydrogenation reaction, it is common to use a continuous stirred tank reactor (CSTR) filled with a nickel-based or copper-based hydrogenation catalyst mainly inside the reactor, and the starting material aldehyde is evaporated to vaporize. There is a method of performing a hydrogenation reaction in the phase, a method of performing a hydrogenation reaction in the vapor phase by evaporating the aldehyde of the starting material and a method of performing the hydrogenation reaction in the liquid phase by introducing the starting material aldehyde into the reactor in a liquid state.

Since the hydrogenation reaction is exothermic, the temperature of the catalyst bed increases as it is closer to the outlet of the reactor than the inlet of the reactor.Increasing the temperature inside the reactor promotes side reactions to increase the concentration of light and ether components in the product and yield of alcohol. Decreases. In general, hydrogenation of aldehydes uses a single catalyst of nickel or copper. When using a highly active catalyst to reduce the volume of the reactor to increase the economics of the process, losses due to side reactions caused by increasing the reactor temperature will be increased. Can be.

In order to solve the problems of the prior art as described above, the present invention provides a method for producing an alcohol by hydrogenating the aldehyde, a method of hydrogenation of the aldehyde and the apparatus used therein to reduce the by-product formation of the side reaction and obtain the alcohol in high yield It aims to provide.

These and other objects of the present invention can be achieved by the present invention described below.

In order to achieve the above object, the present invention comprises the steps of contacting aldehyde and hydrogen with a high activity catalyst; And sequentially contacting the reacted reactants with the low activity catalyst to produce an alcohol.

In the hydrogenation method of the aldehyde, the hydrogenation of the aldehyde may be carried out in a trickle-bed reactor having a fixed-bed form of a single cylinder.

In the hydrogenation method of the aldehyde, the high activity catalyst in the hydrogenation reactor may be a nickel catalyst, the low activity catalyst may be a copper catalyst.

In the hydrogenation method of the aldehyde, the hydrogenation reactor can be maintained at a temperature of 50 ~ 300 ℃, pressure 2 ~ 100 bar.

In the hydrogenation method of the aldehyde, the molar ratio of the aldehyde and hydrogen may be 1: 1 to 10: 1.

The reactant injected into the reactor is a mixture formed by partially recycling (recycling) the aldehyde and the alcohol obtained by hydrogenation thereof, and the concentration of the aldehyde is between 1% and 50%.

The hydrogenation method of the aldehyde may further comprise the step of feeding the remaining reaction mixture back to the hydrogenation reactor after separating the alcohol from the reaction mixture.

The present invention also provides a hydrogenation reactor having a two-stage catalyst layer consisting of a high activity catalyst in contact with aldehyde and hydrogen, and a low activity catalyst in contact with the reaction mixture thereafter; And an aldehyde supply pipe and a hydrogen supply pipe respectively connected to the reactor. It provides a hydrogenation device of the aldehyde comprising a.

The height of the reactor is 0.2 to 20 m, the diameter is 0.05 to 5 m, and the diameter of the catalyst to be filled is between 0.5 mm and 5 mm.

In the hydrogenation apparatus of the aldehyde, the high active catalyst layer in the hydrogenation reactor may be a nickel catalyst, the low active catalyst layer may be a copper catalyst.

As described above, according to the present invention can improve the selectivity through the activity control to increase the efficiency of the hydrogenation reaction has the effect of reducing the formation of by-products and obtain the desired alcohol in high yield.

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention.

1 is a schematic process diagram showing a hydrogenation process of an aldehyde according to an embodiment of the present invention.

2 is a schematic process diagram showing a two stage catalyst bed of the present invention.

In FIG. 1, various standard items actually used in a factory, such as valves, temperature measuring devices, and pressure regulators, which are easily recognized by those skilled in the art, are omitted.

According to FIG. 1, aldehyde is injected into the reactor in a liquid state without vaporization, and hydrogen is introduced into the reactor through separate lines in a gaseous state. This type of reactor is called a trickle-bed reactor. In a trickle-bed reactor, the reaction occurs as gas and liquid flow co-down downwards between packed bed catalysts. At this time, in order to prevent a sudden temperature rise inside the reactor, aldehyde is mixed with the product alcohol and injected into the reactor.

In general, the hydrogenation of aldehyde uses a single catalyst of nickel or copper, but the present invention uses a two-layer catalyst consisting of a high active catalyst layer and a low active catalyst layer, for example, a two-layer catalyst 323 of nickel and copper. It is characterized by using.

In the present invention, the reaction rate is increased by using a high active catalyst layer, for example, a nickel catalyst layer 323a at the reactor inlet side having a high concentration of the reactant to be converted, and low activity at the reactor outlet side having a low concentration of the reactant to be converted. A side reaction is suppressed by using a catalyst layer, for example, a copper catalyst layer 323b.

The two-layer catalyst bed passes liquid gas of aldehyde and hydrogen gas in the fluidized bed into the fixed bed.

The present invention is preferably carried out by passing aldehyde and hydrogen gas through a catalyst layer consisting of two layers, a high active catalyst layer and a low active catalyst layer.

Aldehyde and hydrogen gas injected into the reactor pass through a two-layered catalyst bed to produce alcohol, the reaction product.

Catalysts that may be used in the high active catalyst layer include nickel, platinum, ruthenium, rhodium, and the like, preferably nickel, platinum.

In addition, the catalyst that can be used in the low activity catalyst layer includes copper, chromium, zinc, CuCr ₂ O ₄ and the like, preferably copper, CuCr ₂ O ₄ It may be.

In the hydrogenation reaction of aldehyde as in the present invention, in the case of using a catalyst layer composed of two layers of a high active catalyst layer and a low active catalyst layer in a reactor, a high active catalyst layer is used at the beginning of the reaction having a high concentration of the reactant to be converted. The reaction rate is increased, and later reactions with low concentrations of reactants to be converted have an effect of suppressing side reactions by using a low activity catalyst layer.

The aldehyde used as the starting material in the present invention preferably contains 1 to 20 carbons and at least one aldehyde group. Specific examples include formaldehyde, acetaldehyde, propionaldehyde, n-butylaldehyde, isobutylaldehyde, n-valealdehyde, iso-valealdehyde, n-hexaaldehyde, n-heptaaldehyde, n-octanal, 2-ethylhexane Egg, 2-ethylhexenal (ethylpropylacrolein), n-decanal, 2-ethylbutanal, propargylaldehyde, acrolein, glyoxal, crotonaldehyde, furfural, aldol, hexahydrobenzaldehyde, alpha-citronellal , Citral, chromal, trimethylacetaldehyde, diethylacetaldehyde, tetrahydrofurfural, phenylacetaldehyde, cinnamic aldehyde, hydrocinnamaldehyde and mixtures thereof, and preferably n-butylaldehyde, isobutylaldehyde, 2-ethylhexenal, isononylaldehyde, and the like.

The hydrogenation reaction is carried out at 50 to 300 ℃, 2 to 100 bar.

The invention is explained in more detail through the following examples. However, these embodiments are merely exemplary and do not limit the technical scope of the present invention.

[Example]

Example 1

Hydrogenation of butyraldehyde was carried out on a fixed bed reactor having an internal diameter of 50 mm and a length of 1200 mm.

A jacket was installed on the outer wall of the reactor to control the reaction temperature. After filling the alumina ball in the lower part of the reactor, 500cc of the catalyst was charged in the middle part. Ni catalyst was added to the 3/4 part from the inlet to the outlet. The remaining quarter was filled with a Cu / Zn mixed oxide catalyst.

The reactants introduced into the reactor were prepared with 80% butanol and 20% butyraldehyde composition.

The feed rate (LHSV) of the reactants was 2.8 and the pressure inside the reactor was 24 barg. The jacket was attached to the reactor outer wall to control the temperature of the reactor inlet through the temperature of the fruit flowing inside the jacket.

The temperature of the reactor inlet was 40 to 130 ℃, and as the reaction proceeds the temperature inside the reactor rose from 110 ℃ to 190 ℃.

Table 1 below describes the composition of the product according to the reaction temperature.

[Table 1]

C (BAL) T H ₂ / BAL Conversion Rate BuOH (%) Light (%) BE (%) 20 40 2 97.0 95.1 0 0 20 50 2 98.6 95.8 0 0 20 60 2 99.2 96.2 0 0 20 70 2 99.5 96.4 0 0.1 20 90 2 100.0 96.5 0 0.3 20 110 2 100.0 96.3 0.1 0.9 20 130 2 100.0 95.8 0.6 1.4

C (BAL): the concentration of butyraldehyde in the feed

T: Reactor temperature (° C) at the catalyst bed inlet

BuOH (%): concentration of butanol in the product

Light (%): Low light material composition (%) in the product-Low light material composition (%) in the feed

BE (%): Composition of butylether in the product (%)-Composition of butylether in the feed (%)

Comparative Example 1

Example 1 was carried out in the same manner as in Example 1, except that only 500 cc of the Ni catalyst was filled in the middle portion.

Table 2 shows the composition of the product according to the reaction temperature.

[Table 2]

C (BAL) T H ₂ / BAL Conversion Rate BuOH (%) Light (%) BE (%) 20 40 2 99.2 97.1 0.0 0.0 20 50 2 99.8 96.9 0.0 0.0 20 60 2 99.9 96.4 0.0 0.0 20 70 2 100.0 95.7 0.0 0.2 20 90 2 100.0 95.0 0.0 0.9 20 110 2 100.0 95.4 0.2 1.8 20 130 2 100.0 94.6 1.2 2.2

As shown in Tables 1 and 2, the hydrogenation method (Examples 1 and 1) of the present invention is more stable in butanol yield compared to the case of using only Ni catalysts (Comparative Examples 1 and 2), and side reactions are performed at high temperatures. It was confirmed that there is little effect of low boiling point material and butyl ether.

Although the present invention has been described in detail with reference to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the scope and spirit of the present invention, and such modifications and modifications fall within the scope of the appended claims. It is also natural.

1 is a schematic process chart showing a hydrogenation process of an aldehyde according to an embodiment of the present invention.

2 is a schematic process diagram showing a two stage catalyst bed in a hydrogenation reactor of the present invention.

<Explanation of symbols for the main parts of the drawings>

300: hydrogenation reaction unit 321: hydrogenation reactor

322: Aldehyde and Hydrogen Gas

323 catalyst layer

323a: high active catalyst layer 323b: low active catalyst layer

324 reactor outlet 325 aldehyde and hydrogen supply piping

326: reaction product discharge pipe

Claims (15)

From above, aldehyde and in a trickle-bed reactor, in which two stage catalysts of the high and low active catalysts are internally charged, and the reactor inlet temperature is adjusted to 40 to 130 ° C. through the reactor outer jacket. Contacting hydrogen to the high activity catalyst in a molar ratio of 1: 1 to 10: 1; And Sequentially contacting the contacted reaction mixture with the low activity catalyst; Hydrogenation of aldehydes to obtain alcohol from aldehydes. The method of claim 1, The high activity catalyst is characterized in that at least one catalyst selected from the group consisting of nickel, platinum, ruthenium, rhodium Hydrogenation of Aldehydes. The method of claim 1, The low activity catalyst is characterized in that at least one catalyst selected from the group consisting of copper, chromium, zinc, CuCr ₂ O ₄ Hydrogenation of Aldehydes. The method of claim 1, The high activity catalyst and low activity catalyst are characterized in that the stationary phase Hydrogenation of Aldehydes. The method of claim 1, Hydrogenation of the aldehyde is characterized in that it is carried out at 50 ~ 300 ℃, 2 ~ 100 bar Hydrogenation of Aldehydes. The method of claim 1, The aldehydes are formaldehyde, acetaldehyde, propionaldehyde, n-butylaldehyde, isobutylaldehyde, n-valealdehyde, iso-valealdehyde, n-hexaaldehyde, n-heptaaldehyde, n-octanal, 2-ethylhexane Egg, 2-ethylhexenal (ethylpropylacrolein), n-decanal, 2-ethylbutanal, propargylaldehyde, acrolein, glyoxal, crotonaldehyde, furfural, aldol, hexahydrobenzaldehyde, alpha-citronellal , Citral, chromal, trimethyl acetaldehyde, diethyl acetaldehyde, tetrahydrofurfural, phenyl acetaldehyde, cinnamic aldehyde, hydrocinnamaldehyde and mixtures thereof. Hydrogenation of Aldehydes. delete The method of claim 1, And separating the alcohol from the reaction mixture and feeding the remaining reaction mixture back to the hydrogenation reactor. Hydrogenation of Aldehydes. A two-stage catalyst layer consisting of a high activity catalyst, and a low activity catalyst from above, a trickle-bed reactor type hydrogenation reactor formed therein; And An aldehyde supply pipe and a hydrogen supply pipe connected to the reactor; / RTI &gt; The two-stage catalyst layer is arranged such that the aldehyde and hydrogen supplied to the hydrogenation reactor first react on the high active catalyst at the top and then on the low active catalyst at the bottom. Aldehyde hydrogenation device. The method of claim 9, The high active catalyst is disposed at the inlet side of the hydrogenation reactor, and the low active catalyst is disposed at the outlet side of the hydrogenation reactor. Aldehyde hydrogenation device. The method of claim 9, The high activity catalyst is characterized in that at least one catalyst selected from the group consisting of nickel, platinum, ruthenium, rhodium Aldehyde hydrogenation device. The method of claim 9, The low activity catalyst is characterized in that at least one catalyst selected from the group consisting of copper, chromium, zinc, CuCr ₂ O ₄ Aldehyde hydrogenation device. The method of claim 9, The high activity catalyst and low activity catalyst are characterized in that the stationary phase Aldehyde hydrogenation device. The method of claim 9, And a recirculation pipe for supplying the remaining reaction mixture back to the hydrogenation reactor after separating the alcohol from the reaction mixture of the hydrogenation reactor. Aldehyde hydrogenation device. The method of claim 9, The hydrogenation reactor is characterized in that the hydrogenation reactor is provided with a nozzle Aldehyde hydrogenation device.

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