阅读说明：本技术 一种丁醛分离装置及工艺 (Butyraldehyde separation device and technology ) 是由 李延顺 张德厚 魏传令 荆庆勇 田博 申国庆 于 2021-09-06 设计创作，主要内容包括：本发明属于精馏提纯领域,具体涉及一种丁醛分离装置及工艺。所述丁醛分离装置,包括丁醛异构物精馏塔和异丁醛精馏塔,其特征在于：所述丁醛异构物精馏塔的塔顶分别连接有冷却器和异丁醛精馏塔；冷却器的出料口通过丁醛异构物精馏塔回流罐连接到丁醛异构物精馏塔塔顶；混合丁醛在丁醛异构物精馏塔内精馏后,塔釜得到正丁醛产品,塔顶得到的混合丁醛气相,塔顶出料分为两路,一路经第一冷却器返回丁醛异构物精馏塔作为回流组分,另一路在底部进入异丁醛精馏塔作为异丁醛精馏塔的塔釜气相,异丁醛精馏塔塔顶获得异丁醛产品。该装置不仅能够实现正丁醛和异丁醛的有效分离,还能大大减少蒸汽的用量,降低分离成本,节能高效。(The invention belongs to the field of rectification and purification, and particularly relates to a butyraldehyde separation device and a butyraldehyde separation process. The butyraldehyde separation device comprises a butyraldehyde isomer rectifying tower and an isobutyraldehyde rectifying tower, and is characterized in that: the tower top of the butyraldehyde isomerate rectifying tower is respectively connected with a cooler and an isobutyraldehyde rectifying tower; a discharge port of the cooler is connected to the top of the butyraldehyde isomer rectifying tower through a butyraldehyde isomer rectifying tower reflux tank; after the mixed butyraldehyde is rectified in a butyraldehyde isomer rectifying tower, a normal butyraldehyde product is obtained at the tower bottom, a mixed butyraldehyde gas phase obtained at the tower top is divided into two paths, one path of mixed butyraldehyde gas phase is returned to the butyraldehyde isomer rectifying tower through a first cooler to be used as a reflux component, the other path of mixed butyraldehyde gas phase enters an isobutyraldehyde rectifying tower at the bottom to be used as a tower bottom gas phase of an isobutyraldehyde rectifying tower, and an isobutyraldehyde product is obtained at the tower top of the isobutyraldehyde rectifying tower. The device not only can realize the effective separation of n-butyraldehyde and isobutyraldehyde, but also can greatly reduce the steam consumption, reduce the separation cost, save energy and have high efficiency.)

1. The utility model provides a butyraldehyde separator, includes butyraldehyde isomer rectifying column and isobutyraldehyde rectifying column, its characterized in that: the tower top of the butyraldehyde isomerate rectifying tower is connected with a first cooler and an isobutyraldehyde rectifying tower respectively; the discharge port of the first cooler is connected to the top of the butyraldehyde isomer rectifying tower through a butyraldehyde isomer rectifying tower reflux tank.

2. A butyraldehyde separation apparatus according to claim 1, wherein: and condensing the gas phase at the top of the isobutyraldehyde rectifying tower through a second cooler and collecting the gas phase in a reflux tank of the isobutyraldehyde rectifying tower to obtain an isobutyraldehyde product.

3. A butyraldehyde separation apparatus according to claim 1, wherein: the liquid phase outlet of the reflux tank of the isobutyraldehyde rectifying tower is respectively connected with an isobutyraldehyde rectifying tower and an isobutyraldehyde storage tank, most of the liquid phase enters the isobutyraldehyde rectifying tower to reflux, and a small part of the liquid phase is extracted as an isobutyraldehyde product.

4. A butyraldehyde separation apparatus according to claim 1, wherein: the second cooler and the reflux tank of the isobutyraldehyde rectifying tower are both connected with the emptying deep cooler and are used for condensing the liquid phase component in the emptying component of the isobutyraldehyde rectifying tower.

5. A butyraldehyde separation apparatus according to claim 1, wherein: the emptying cryogenic cooler is connected with an emptying cryogenic separator, a gas-phase outlet of the emptying cryogenic separator is connected with a vacuum device, and a liquid-phase outlet of the emptying cryogenic separator is connected with a reflux tank of an isobutyraldehyde rectifying tower; and condensing the substances in the emptying cryogenic cooler, then feeding the condensed substances into an emptying cryogenic separator for gas-liquid separation, feeding the gas-phase components into a vacuum device, and feeding the liquid-phase components into a reflux tank of an isobutyraldehyde rectifying tower.

6. A butyraldehyde separation apparatus according to claim 1, wherein: the liquid phase outlet at the bottom of the isobutyraldehyde rectifying tower is connected with a butyraldehyde isomerate rectifying tower reflux tank or a butyraldehyde isomerate rectifying tower.

7. A butyraldehyde separation process is characterized in that: the method specifically comprises the following steps: the mixed butyraldehyde enters a butyraldehyde isomer rectifying tower for rectification, a normal butyraldehyde product is obtained at the tower bottom, one part of gas phase at the tower top is condensed by a first cooler and collected in a butyraldehyde isomer rectifying tower reflux tank and then returns to the butyraldehyde isomer rectifying tower, and the other part of gas phase enters an isobutyraldehyde rectifying tower at the bottom; and condensing the gas phase at the top of the isobutyraldehyde rectifying tower by a second cooler, collecting the gas phase in a reflux tank of the isobutyraldehyde rectifying tower, taking most of the gas phase as a reflux component of the isobutyraldehyde rectifying tower, and taking a small part of the gas phase as an isobutyraldehyde product to be extracted.

8. The butyraldehyde separation process of claim 7, wherein: and gas phases in the second cooler and the reflux tank of the isobutyraldehyde rectifying tower are sent to an emptying cryogenic cooler for condensation, the condensed gas phases enter an emptying cryogenic separator for gas-liquid separation, gas-phase components are sent to a vacuum device, and liquid-phase components are sent to the reflux tank of the isobutyraldehyde rectifying tower.

9. The butyraldehyde separation process of claim 7, wherein: and returning the liquid phase component at the bottom of the isobutyraldehyde rectifying tower to a return tank of the butyraldehyde isomerate rectifying tower or directly entering the butyraldehyde isomerate rectifying tower for feeding, and performing circular rectification.

10. The butyraldehyde separation process of claim 7, wherein: the operating pressure of the butyraldehyde isomer rectifying tower is 80-150Kpa, and the operating pressure of the isobutyraldehyde rectifying tower is 5-30 Kpa.

Technical Field

The invention belongs to the field of rectification and purification, and particularly relates to a butyraldehyde separation device and a butyraldehyde separation process.

Background

The information in this background section is only for enhancement of understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art that is already known to a person of ordinary skill in the art.

Isobutyraldehyde is an important organic chemical raw material, is colorless liquid at normal temperature, is combustible and volatile, and has strong pungent smell. Isobutyraldehyde derives many fine chemicals, such as: isobutyraldehyde, neopentyl glycol, methacrylic acid, isobutyrate, isobutyronitrile, and the like. The production of isobutyraldehyde generally adopts propylene and synthesis gas as raw materials in a butanol-octanol device, and rhodium/triphenylphosphine complex as a catalyst to generate mixed butyraldehyde in a oxo-synthesis reactor, wherein the main component of the mixed butyraldehyde is a mixture of normal-isobutyraldehyde and isobutyraldehyde with the mass ratio of 10: 1. The normal butyl aldehyde has a boiling point of 74 ℃ at normal pressure, the isobutyl aldehyde has a boiling point of 64 ℃ and is very difficult to separate.

The prior art discloses a method for separating and purifying n-butyraldehyde and iso-butyraldehyde, which comprises a butyraldehyde isomer tower, a butyraldehyde isomer rectifying tower and an iso-butyraldehyde rectifying tower, wherein mixed gas containing n-butyraldehyde and iso-butyraldehyde isomers enters the butyraldehyde isomer tower for separation, iso-butyraldehyde is discharged from the top of the butyraldehyde isomer tower and enters the butyraldehyde isomer rectifying tower for further separation and purification; and discharging the n-butyraldehyde from the bottom of the butyraldehyde isomeride tower, and feeding the n-butyraldehyde into an isobutyraldehyde rectifying tower for further separation and purification. The method has high product purity, but the process is complex and the process operation is difficult.

The prior art also discloses a method for separating n-butyraldehyde and iso-butyraldehyde, which comprises the steps of primarily separating n-butyraldehyde from iso-butyraldehyde in a double-tower continuous rectification mode, collecting n-butyraldehyde at a tower bottom, collecting a 3.5-4: 1 n-isobutyraldehyde mixture at a tower top, further separating in an iso-butyraldehyde rectification tower, collecting iso-butyraldehyde products at a side line of the iso-butyraldehyde rectification tower in a side line rectification mode, wherein the process is relatively simple, but a large amount of steam is consumed in the rectification process, the energy consumption of the whole process is high, and the separation cost is high.

Disclosure of Invention

In order to solve the defects of the prior art, the invention provides a butyraldehyde separation device and a butyraldehyde separation process, wherein the device can realize effective separation of n-butyraldehyde and isobutyraldehyde to obtain high-purity n-butyraldehyde and isobutyraldehyde products respectively, and can also greatly reduce the consumption of steam, reduce the separation cost, save energy and realize high efficiency.

In order to achieve the above object, a first aspect of the present invention provides a butyraldehyde separation device, comprising: butyraldehyde isomerate rectifying tower and isobutyraldehyde rectifying tower; the tower top of the butyraldehyde isomerate rectifying tower is connected with a first cooler and an isobutyraldehyde rectifying tower respectively; a discharge port of the first cooler is connected to the top of the butyraldehyde isomerate rectifying tower through a butyraldehyde isomerate rectifying tower reflux tank;

after the mixed butyraldehyde is rectified in a butyraldehyde isomer rectifying tower, a normal butyraldehyde product is obtained at the tower bottom, a mixed butyraldehyde gas phase obtained at the tower top is divided into two paths, one path is condensed by a first cooler and collected in a butyraldehyde isomer rectifying tower reflux tank, then returns to the butyraldehyde isomer rectifying tower to serve as a reflux component, the other path enters an isobutyraldehyde rectifying tower at the bottom to serve as a tower bottom gas phase of the isobutyraldehyde rectifying tower, and an isobutyraldehyde product is collected at the tower top of the isobutyraldehyde rectifying tower.

The second aspect of the invention provides a butyraldehyde separation process, which specifically comprises the following steps: the mixed butyraldehyde enters a butyraldehyde isomer rectifying tower for rectification, a normal butyraldehyde product is obtained at the tower bottom, one part of gas phase at the tower top is condensed and collected in a butyraldehyde isomer rectifying tower reflux tank through a butyraldehyde isomer rectifying tower top cooler and then returns to the butyraldehyde isomer rectifying tower, and the other part of gas phase enters an isobutyraldehyde rectifying tower at the bottom; condensing the gas phase at the top of the isobutyraldehyde rectifying tower by a cooler at the top of the isobutyraldehyde rectifying tower, collecting the gas phase in a reflux tank of the isobutyraldehyde rectifying tower, taking most of the gas phase as a reflux component of the isobutyraldehyde rectifying tower, and taking a small part of the gas phase as an isobutyraldehyde product;

one or more embodiments of the present invention have at least the following advantageous effects:

(1) according to the invention, a part of gas phase at the top of the butyraldehyde isomer rectifying tower is directly introduced into the isobutyraldehyde rectifying tower to be used as the rectifying gas phase at the bottom of the tower, so that a large amount of heating steam is prevented from being provided for the isobutyraldehyde rectifying tower, the energy is saved, the consumption is reduced, and the cost is reduced.

(2) The butyraldehyde separation device provided by the invention can respectively extract high-purity n-butyraldehyde and isobutyraldehyde, and the purity is more than 99.5%.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and together with the description serve to explain the invention and not to limit the invention.

Fig. 1 is a schematic view of a butyraldehyde separation device provided in example 1 of the present invention;

fig. 2 is a schematic view of a butyraldehyde separation device provided in example 2 of the present invention;

the system comprises a butyraldehyde isomer rectifying tower 1, a butyraldehyde isomer rectifying tower 2, a first cooler 3, a butyraldehyde isomer rectifying tower reflux tank 4, an isobutyraldehyde rectifying tower 5, a second cooler 6, an isobutyraldehyde rectifying tower reflux tank 7, a vent deep cooler 8, a vent cryogenic separator 9 and a vacuum device.

Detailed Description

It is to be understood that the following detailed description is exemplary and is intended to provide further explanation of the invention as claimed. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

As introduced in the background art, in the existing n-butyraldehyde and isobutyraldehyde separation process, a large amount of steam is consumed in the rectification process, the energy consumption of the whole process is high, and the separation cost is high.

In order to solve the above technical problems, a first aspect of the present invention provides a butyraldehyde separation device, including a butyraldehyde isomer rectifying column and an isobutyraldehyde rectifying column; the tower top of the butyraldehyde isomerate rectifying tower is connected with a first cooler and an isobutyraldehyde rectifying tower respectively; a discharge port of the first cooler is connected to the top of the butyraldehyde isomerate rectifying tower through a butyraldehyde isomerate rectifying tower reflux tank;

the 'butyraldehyde isomer rectifying tower' is a device for obtaining n-butyraldehyde at the tower bottom and obtaining mixed gas of the n-butyraldehyde and the isobutyraldehyde at the tower top when rectifying the mixed butyraldehyde;

the isobutyraldehyde rectifying tower is a device for obtaining isobutyraldehyde at the top of the tower and obtaining mixed liquid of n-butyraldehyde and isobutyraldehyde at the bottom of the tower when rectifying mixed gas of n-butyraldehyde and isobutyraldehyde.

After the mixed butyraldehyde is rectified in a butyraldehyde isomer rectifying tower, a normal butyraldehyde product is obtained at the tower bottom, a mixed butyraldehyde gas phase obtained at the tower top is divided into two paths, one path is condensed by a first cooler and collected in a butyraldehyde isomer rectifying tower reflux tank, then returns to the butyraldehyde isomer rectifying tower to serve as a reflux component, the other path enters an isobutyraldehyde rectifying tower at the bottom to serve as a tower bottom gas phase of the isobutyraldehyde rectifying tower, and an isobutyraldehyde product is collected at the tower top of the isobutyraldehyde rectifying tower.

The invention adopts a butyraldehyde isomerate rectifying tower with a cooler and an isobutyraldehyde rectifying tower connected to the top of the tower respectively, and carries out branch treatment on the gas phase at the top of the tower, because: firstly, cooling a gas phase at the top of a tower, refluxing the gas phase by a reflux tank of a butyraldehyde isomer rectifying tower, and then sending the gas phase into the butyraldehyde isomer rectifying tower to form reflux, so that a gas phase and a liquid phase are contacted on a tower tray in a counter-current manner, heat transfer and mass transfer are continuously carried out, and pure n-butyl aldehyde is obtained at a tower kettle; secondly, the gas phase obtained at the top of the tower is a mixed gas of n-butyraldehyde and isobutyraldehyde, and continuous rectification is needed to separate isobutyraldehyde from the mixed gas, so that part of the gas phase at the top of the tower enters an isobutyraldehyde rectifying tower to carry out secondary rectification treatment.

In the invention, part of the gas phase at the top of the tower is directly introduced into the isobutyraldehyde rectifying tower instead of refluxing to form a liquid phase first and then introducing, because:

if the gas phase at the top of the butyraldehyde isomerization rectifying tower is directly refluxed and introduced into the isobutyraldehyde rectifying tower, the steam load of the isobutyraldehyde rectifying tower is overlarge, a large amount of energy is consumed to provide steam, and thus, high energy cost is needed to realize the separation of n-butyraldehyde and isobutyraldehyde.

Further, condensing the gas phase at the top of the isobutyraldehyde rectifying tower through a second cooler and collecting the gas phase in a reflux tank of the isobutyraldehyde rectifying tower to obtain an isobutyraldehyde product.

Further, a liquid phase outlet of the reflux tank of the isobutyraldehyde rectifying tower is respectively connected with the isobutyraldehyde rectifying tower and the isobutyraldehyde storage tank, most of the liquid phase enters the isobutyraldehyde rectifying tower to reflux, and a small part of the liquid phase is extracted as an isobutyraldehyde product; among them, a part of the reflux is also caused to form a reflux in the isobutyraldehyde rectifying column, and the recovery of isobutyraldehyde from the column top is facilitated.

In order to avoid the loss of isobutyraldehyde for the further condensation of gaseous phase in second cooler and the isobutyraldehyde rectifying column reflux drum, in this device, second cooler and isobutyraldehyde rectifying column reflux drum all are connected with the unloading deep cooler for the gaseous phase to in second cooler and the isobutyraldehyde rectifying column reflux drum condenses, avoids the refrigerated condensation effect of second not enough.

Further, the emptying cryogenic cooler is connected with an emptying cryogenic separator, a gas-phase outlet of the emptying cryogenic separator is connected with a vacuum device, and a liquid-phase outlet of the emptying cryogenic separator is connected with a reflux tank of the isobutyraldehyde rectifying tower; condensing substances in the emptying cryogenic cooler, then feeding the condensed substances into an emptying cryogenic separator for gas-liquid separation, feeding gas-phase components into a vacuum device, and feeding liquid-phase components into a reflux tank of an isobutyraldehyde rectifying tower;

in order to continuously separate the mixed liquid, the liquid phase outlet at the bottom of the isobutyraldehyde rectifying tower is connected to a butyraldehyde isomer rectifying tower reflux tank or a butyraldehyde isomer rectifying tower for circular rectification.

The second aspect of the invention provides a butyraldehyde separation process, which specifically comprises the following steps: the mixed butyraldehyde enters a butyraldehyde isomer rectifying tower for rectification, a normal butyraldehyde product is obtained at the tower bottom, one part of gas phase at the tower top is condensed by a first cooler and collected in a butyraldehyde isomer rectifying tower reflux tank and then returns to the butyraldehyde isomer rectifying tower, and the other part of gas phase enters an isobutyraldehyde rectifying tower at the bottom; condensing the gas phase at the top of the isobutyraldehyde rectifying tower by a second cooler and collecting the gas phase in a reflux tank of the isobutyraldehyde rectifying tower, wherein most of the gas phase is used as a reflux component of the isobutyraldehyde rectifying tower, and a small part of the gas phase is used as an isobutyraldehyde product and is extracted;

further, gas phase in the second cooler and the reflux tank of the isobutyraldehyde rectifying tower is sent to an emptying cryogenic cooler for condensation, the condensed gas phase enters an emptying cryogenic separator for gas-liquid separation, gas phase components are sent to a vacuum device, and liquid phase components are sent to the reflux tank of the isobutyraldehyde rectifying tower;

further, the liquid phase component at the bottom of the isobutyraldehyde rectifying tower returns to a return tank of the butyraldehyde isomer rectifying tower or directly enters the butyraldehyde isomer rectifying tower for feeding, and the cyclic rectification is carried out.

Further, the operating pressure of the butyraldehyde isomer rectifying tower is 80-150Kpa, and the operating pressure of the isobutyraldehyde rectifying tower is 5-30 Kpa;

in order to make the technical solutions of the present invention more clearly understood by those skilled in the art, the technical solutions of the present invention will be described in detail below with reference to specific embodiments.

Example 1

The invention provides a butyraldehyde separation device which comprises a butyraldehyde isomer rectifying tower 1 and an isobutyraldehyde rectifying tower 4, wherein when mixed butyraldehyde is rectified in the butyraldehyde isomer rectifying tower 1, a normal butyraldehyde product is obtained at the tower bottom, gas-phase mixed butyraldehyde is obtained at the tower top, the tower top is respectively connected with a first cooler 2 and the isobutyraldehyde rectifying tower 4, so that the discharge at the tower top is divided into two paths, one path is condensed and collected in a butyraldehyde isomer rectifying tower reflux tank 3 through the first cooler 2, then the butyraldehyde isomer rectifying tower 1 is returned as a reflux component, and the other path enters the isobutyraldehyde rectifying tower 4 at the bottom to serve as the tower bottom gas phase of the isobutyraldehyde rectifying tower 4.

The top of the isobutyraldehyde rectifying tower 4 is sequentially connected with a second cooler 5 and an isobutyraldehyde rectifying tower reflux tank 6, gas phase at the top of the tower is condensed and collected in the isobutyraldehyde rectifying tower reflux tank 6, a liquid phase outlet of the isobutyraldehyde rectifying tower reflux tank 6 is respectively connected with the isobutyraldehyde rectifying tower 4 and an isobutyraldehyde storage tank, most of liquid phase enters the isobutyraldehyde rectifying tower 4 for reflux, and a small part of liquid phase is taken as an isobutyraldehyde product and is extracted to the isobutyraldehyde storage tank;

the second cooler 5 and the return tank 6 of the isobutyraldehyde rectifying tower are both connected with the emptying deep cooler 7 and are used for condensing the liquid phase component in the emptying component of the isobutyraldehyde rectifying tower 4; the emptying cryogenic cooler 7 is connected with an emptying cryogenic separator 8 for carrying out gas-liquid separation on condensed substances in the emptying cryogenic cooler, a gas-phase outlet of the emptying cryogenic separator 8 is connected with a vacuum device 9, and a liquid-phase outlet is connected with a reflux tank 6 of an isobutyraldehyde rectifying tower;

the liquid phase outlet at the bottom of the isobutyraldehyde rectifying tower is connected with a return tank 3 of the butyraldehyde isomerate rectifying tower.

Example 2

The invention provides a butyraldehyde separation device which comprises a butyraldehyde isomer rectifying tower 1 and an isobutyraldehyde rectifying tower 4, wherein when mixed butyraldehyde is rectified in the butyraldehyde isomer rectifying tower 1, a normal butyraldehyde product is obtained at the tower bottom, gas-phase mixed butyraldehyde is obtained at the tower top, the tower top is respectively connected with a first cooler 2 and the isobutyraldehyde rectifying tower 4, so that the discharge at the tower top is divided into two paths, one path is condensed and collected in a butyraldehyde isomer rectifying tower reflux tank 3 through the first cooler 2, then the butyraldehyde isomer rectifying tower 1 is returned as a reflux component, and the other path enters the isobutyraldehyde rectifying tower 4 at the bottom to serve as the tower bottom gas phase of the isobutyraldehyde rectifying tower 4.

The top of the isobutyraldehyde rectifying tower 4 is sequentially connected with a second cooler 5 and an isobutyraldehyde rectifying tower reflux tank 6, gas phase at the top of the tower is condensed and collected in the isobutyraldehyde rectifying tower reflux tank 6, a liquid phase outlet of the isobutyraldehyde rectifying tower reflux tank 6 is respectively connected with the isobutyraldehyde rectifying tower 4 and an isobutyraldehyde storage tank, most of liquid phase enters the isobutyraldehyde rectifying tower 4 for reflux, and a small part of liquid phase is taken as an isobutyraldehyde product and is extracted to the isobutyraldehyde storage tank;

the second cooler 5 and the return tank 6 of the isobutyraldehyde rectifying tower are both connected with the emptying deep cooler 7 and are used for condensing the liquid phase component in the emptying component of the isobutyraldehyde rectifying tower 4; the emptying cryogenic cooler 7 is connected with an emptying cryogenic separator 8 for carrying out gas-liquid separation on condensed substances in the emptying cryogenic cooler, a gas-phase outlet of the emptying cryogenic separator 8 is connected with a vacuum device 9, and a liquid-phase outlet is connected with a reflux tank 6 of an isobutyraldehyde rectifying tower;

the liquid phase outlet at the bottom of the isobutyraldehyde rectifying tower is connected with a butyraldehyde isomerate rectifying tower 1.

Example 3

The mixed butyraldehyde enters a butyraldehyde isomer rectifying tower 1 to be rectified, the operating pressure of the butyraldehyde isomer rectifying tower 1 is 80Kpa, a normal butyraldehyde product is obtained at the tower bottom, the mixed butyraldehyde gas phase obtained at the tower top is divided into two paths of discharged materials at the tower top, one path of the mixed butyraldehyde gas phase is condensed and collected in a butyraldehyde isomer rectifying tower reflux tank 3 through a first cooler 2, then the mixed butyraldehyde gas phase returns to the butyraldehyde isomer rectifying tower 1 to be used as a reflux component, and the other path of the mixed butyraldehyde gas phase enters an isobutyraldehyde rectifying tower 4 at the bottom to be used as a tower bottom gas phase of an isobutyraldehyde rectifying tower; the operating pressure of the isobutyraldehyde rectifying tower 4 is 5Kpa, the gas phase at the top of the isobutyraldehyde rectifying tower 4 is condensed by a second cooler 5 and collected in a reflux tank 6 of the isobutyraldehyde rectifying tower, then most of the gas phase is used as a reflux component of the isobutyraldehyde rectifying tower 4, and a small part of the gas phase is extracted as an isobutyraldehyde product; the second cooler 5 and the return tank 6 of the isobutyraldehyde rectifying tower are respectively connected with the emptying cryogenic cooler 7 and are used for condensing liquid phase components in the emptying components of the isobutyraldehyde rectifying tower, the condensed liquid phase components enter the emptying cryogenic separator 8 for gas-liquid separation, gas phase components enter the vacuum device 9, and the liquid phase components enter the return tank 6 of the isobutyraldehyde rectifying tower; and returning the liquid phase component at the bottom of the isobutyraldehyde rectifying tower to a return tank 3 of the butyraldehyde isomerate rectifying tower for circular rectification.

Example 4

The mixed butyraldehyde enters a butyraldehyde isomer rectifying tower 1 to be rectified, the operating pressure of the butyraldehyde isomer rectifying tower 1 is 150Kpa, a normal butyraldehyde product is obtained at the tower bottom, the mixed butyraldehyde gas phase obtained at the tower top is divided into two paths of discharged materials at the tower top, one path of the mixed butyraldehyde gas phase is condensed and collected in a butyraldehyde isomer rectifying tower reflux tank 3 through a first cooler 2, then the mixed butyraldehyde gas phase returns to the butyraldehyde isomer rectifying tower 1 to be used as a reflux component, and the other path of the mixed butyraldehyde gas phase enters an isobutyraldehyde rectifying tower 4 at the bottom to be used as a tower bottom gas phase of an isobutyraldehyde rectifying tower; the operating pressure of the isobutyraldehyde rectifying tower 4 is 30Kpa, the gas phase at the top of the isobutyraldehyde rectifying tower 4 is condensed by a second cooler 5 and collected in a reflux tank 6 of the isobutyraldehyde rectifying tower, then most of the gas phase is used as a reflux component of the isobutyraldehyde rectifying tower 4, and a small part of the gas phase is extracted as an isobutyraldehyde product; the second cooler 5 and the return tank 6 of the isobutyraldehyde rectifying tower are respectively connected with the emptying cryogenic cooler 7 and are used for condensing liquid phase components in the emptying components of the isobutyraldehyde rectifying tower, the condensed liquid phase components enter the emptying cryogenic separator 8 for gas-liquid separation, gas phase components enter the vacuum device 9, and the liquid phase components enter the return tank 6 of the isobutyraldehyde rectifying tower; feeding the liquid phase component at the bottom of the isobutyraldehyde rectifying tower into a butyraldehyde isomerate rectifying tower 1 for circular rectification.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.