Device for improving purity of butyraldehyde

Abstract

The utility model discloses a device for improving the purity of butyraldehyde, which comprises a rectifying tower, a condenser, an isobutyraldehyde return tank and an n-butyraldehyde receiving tank, in the separation process of mixed butyraldehyde, n-butyraldehyde is extracted from a side extraction pipeline in the middle of the rectifying tower, heavy components such as heavy components and terpolymers are extracted from the bottom of the rectifying tower, and the purity of butyraldehyde is improved.

Description

Technical Field

[0001] This utility model belongs to the field of fine chemicals, specifically relating to a device for improving the purity of butyraldehyde. Background Technology

[0002] Isobutyraldehyde is a colorless, transparent liquid with a pungent odor; it gradually oxidizes in air to form isobutyric acid; it is slightly soluble in water and miscible with ethanol, benzene, chloroform, ether, toluene, acetone, and carbon disulfide.

[0003] Currently, the main gas phase at the top of the neopentyl glycol isobutyraldehyde recovery tower consists of water, trimethylamine, isobutyraldehyde, and methanol. Water and isobutyraldehyde are condensed by a condenser. Part of the condensed water and isobutyraldehyde is used as reflux, and the rest is returned to the condensation reactor. After the top of the isobutyraldehyde recovery tower is cooled by the condenser, the liquid phase contains isobutyraldehyde and water, and it is impossible to effectively separate isobutyraldehyde and water.

[0004] Currently, in traditional isomer tower processes, n-butyraldehyde is extracted from the bottom of the tower, resulting in a high content of heavy components and trimers in the system. Isobutyraldehyde is extracted from the upper tray at the top of the tower, which presents the problem of high moisture content in isobutyraldehyde. Summary of the Invention

[0005] The purpose of this invention is to provide a device for improving the purity of butyraldehyde, thereby increasing the purity of isobutyraldehyde and overcoming the shortcomings of existing technologies that cannot effectively separate isobutyraldehyde and water.

[0006] To achieve the above objectives, the technical solution of this utility model is as follows:

[0007] An apparatus for improving the purity of butyraldehyde includes: a distillation column, a condenser, an isobutyraldehyde reflux tank, and a n-butyraldehyde receiving tank;

[0008] The distillation column has a feed inlet on the side wall, a gas outlet at the top, a reboiler and a heavy component collection pipe at the bottom, and a side-stream collection pipe in the middle of the distillation column.

[0009] A condenser is provided with a material inlet, a waste gas outlet and an isobutyraldehyde outlet, wherein the material inlet is connected to the gas phase outlet of the distillation column via a pipeline;

[0010] An isobutyraldehyde reflux tank is provided with an isobutyraldehyde inlet and an isobutyraldehyde outlet. The isobutyraldehyde inlet is connected to the isobutyraldehyde outlet of the condenser through a pipeline, and the isobutyraldehyde outlet is connected to the feed inlet of the distillation column through a pipeline.

[0011] The n-butyraldehyde receiving tank is equipped with an inlet, a gas phase outlet, and a n-butyraldehyde outlet. The side-stream outlet pipe is connected to the inlet of the n-butyraldehyde receiving tank, and the gas phase outlet is connected to the distillation column via a pipe.

[0012] Preferably, the distillation column is a plate column, with feed inlets at the top, middle and bottom.

[0013] Preferably, both the side-line extraction pipeline and the isobutyraldehyde extraction pipeline are equipped with online analyzers.

[0014] After some light components are removed by a stabilization column, the mixed butyraldehyde enters a distillation column. In the distillation column, it is further refined by a reboiler at the bottom. Light components (small amounts of water, isobutyraldehyde, etc.) are condensed in a condenser at the top of the column and sent to an isobutyraldehyde reflux tank. A portion of the isobutyraldehyde is refluxed back into the distillation column through a pipeline to maintain gas-liquid balance and improve isobutyraldehyde purity; another portion is collected through a pipeline to obtain the isobutyraldehyde product. The remaining light components are discharged to the flare system from the condenser exhaust outlet through a pipeline. The mixed butyraldehyde feed flow rate is controlled between 20 and 70 t / h, with a positive-to-isobutyraldehyde ratio between 6 and 12, achieving good separation. The condenser temperature after cooling is controlled between 32 and 55°C, and the isobutyraldehyde reflux flow rate back into the distillation column is controlled between 150 and 180 t / h.

[0015] During the separation process, the pressure inside the distillation column is controlled at 40-60 kPa and the temperature is controlled at 100-108°C. The bottom temperature of the column is controlled by collecting the heavy components from the bottom of the distillation column. Furthermore, the light components inside the distillation column are discharged to the flare system through the tail gas discharge pipe at the constant gas outlet of the distillation column to control the pressure range of the distillation column.

[0016] n-Butyraldehyde enters the n-butyraldehyde receiving tank through a side-stream outlet pipe located in the middle of the distillation column. Qualified n-butyraldehyde product is then collected through the n-butyraldehyde outlet on the n-butyraldehyde receiving tank. The gas phase in the n-butyraldehyde receiving tank is returned to the distillation column through the gas phase outlet and pipeline.

[0017] The heavy components carried in the mixed butyraldehyde and the heavy components produced after heating in the distillation column, such as trimers, are collected through the heavy component collection pipeline at the bottom of the distillation column and sent to the cracking system or residual liquid tank.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0019] Using this invention, n-butyraldehyde is extracted from a side-stream pipeline, increasing its content to over 99.8% and reducing the isobutyraldehyde content to below 0.05%; and increasing the isobutyraldehyde content to over 99.9%, while reducing the n-butyraldehyde content to below 0.05%. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the device of this utility model. Detailed Implementation

[0021] See Figure 1 An apparatus for improving the purity of butyraldehyde includes: a distillation column, a condenser, an isobutyraldehyde reflux tank, and a n-butyraldehyde receiving tank;

[0022] The distillation column 1 has a feed inlet on its side wall, a gas outlet at the top of the column, a reboiler 5 and a heavy component collection pipe at the bottom of the column, and a side-stream collection pipe in the middle of the distillation column 1.

[0023] Condenser 3 is provided with a material inlet, a waste gas outlet and an isobutyraldehyde outlet. The material inlet is connected to the gas phase outlet of distillation column 1 through a pipeline.

[0024] Isobutyraldehyde reflux tank 4 is equipped with an isobutyraldehyde inlet and an isobutyraldehyde outlet. The isobutyraldehyde inlet is connected to the isobutyraldehyde outlet of the condenser 3 through a pipeline, and the isobutyraldehyde outlet is connected to the feed inlet of the distillation column 1 through a pipeline.

[0025] The butyraldehyde receiving tank 2 is equipped with an inlet, a gas phase outlet and a butyraldehyde extraction outlet. The side-stream extraction pipeline is connected to the inlet of the butyraldehyde receiving tank, and the gas phase extraction outlet is connected to the feed port of the distillation column 1 through a pipeline.

[0026] Preferably, the distillation column is a plate column, with feed inlets at the top, middle and bottom.

[0027] Preferably, both the side-line extraction pipeline and the isobutyraldehyde extraction pipeline are equipped with online analyzers.

[0028] In this embodiment, the mixed butyraldehyde, after having some light components removed by a stabilizing column, enters distillation column 1. In distillation column 1, the mixed butyraldehyde is further refined by a reboiler 5 located at the bottom of the column. The light components (small amounts of water, isobutyraldehyde, etc.) in the mixed butyraldehyde are condensed from the condenser 3 at the top of the column and then transported to the isobutyraldehyde reflux tank 4. A portion of the isobutyraldehyde is refluxed back into distillation column 1 through a pipeline to maintain the gas-liquid balance within the distillation column and improve the purity of the isobutyraldehyde; another portion is collected through a pipeline to obtain the isobutyraldehyde product, while the remaining light components are discharged to the flare system from the condenser exhaust outlet through a pipeline. The mixed butyraldehyde feed flow rate is controlled at 20–70 t / h, with a positive-to-isobutyraldehyde ratio between 6 and 12, achieving good separation results. The post-cooling temperature in the condenser is controlled at 32–55°C, and the isobutyraldehyde reflux flow rate back into the distillation column is controlled at 150–180 t / h.

[0029] During the separation process, the pressure inside distillation column 1 is controlled at 40-60 kPa and the temperature is controlled at 100-108°C. The bottom temperature of the column is controlled by collecting the heavy components from the bottom of distillation column 1. Furthermore, the light components inside the distillation column are discharged to the flare system through the tail gas discharge pipe at the constant gas outlet of distillation column 1 to control the pressure range of the distillation column.

[0030] n-Butyraldehyde enters n-butyraldehyde receiving tank 2 through a side-stream outlet pipe in the middle of the distillation column. Then, qualified n-butyraldehyde product is collected through the n-butyraldehyde outlet on the n-butyraldehyde receiving tank 2. The gas phase in the n-butyraldehyde receiving tank is returned to the distillation column 1 through the gas phase outlet and pipeline.

[0031] The heavy components carried in the mixed butyraldehyde and the heavy components produced after heating in the distillation column, such as trimers, are collected through the heavy component collection pipeline at the bottom of the distillation column and sent to the cracking system or residual liquid tank.

[0032] The obtained isobutyraldehyde content was 99.9286%, and the n-butyraldehyde content in isobutyraldehyde was 0.0259%; the n-butyraldehyde content was 99.8%, and the isobutyraldehyde content in n-butyraldehyde was 0.0265%.

[0033] Comparative Example

[0034] The difference from the embodiments of the present invention is that n-butyraldehyde is extracted from the bottom of the tower, and the obtained isobutyraldehyde content is 99.5%, and the n-butyraldehyde content in isobutyraldehyde is 0.2%; the n-butyraldehyde content is 99.6%, and the isobutyraldehyde content in n-butyraldehyde is 0.1%.

Claims

1. An apparatus for improving the purity of butyraldehyde, characterized in that it comprises: Distillation column, condenser, isobutyraldehyde reflux tank, n-butyraldehyde receiving tank; The distillation column has a feed inlet on the side wall, a gas outlet at the top, a reboiler and a heavy component collection pipe at the bottom, and a side-stream collection pipe in the middle of the distillation column. A condenser is provided with a material inlet, a waste gas outlet and an isobutyraldehyde outlet, wherein the material inlet is connected to the gas phase outlet of the distillation column via a pipeline; An isobutyraldehyde reflux tank is provided with an isobutyraldehyde inlet and an isobutyraldehyde outlet. The isobutyraldehyde inlet is connected to the isobutyraldehyde outlet of the condenser through a pipeline, and the isobutyraldehyde outlet is connected to the feed inlet of the distillation column through a pipeline. The n-butyraldehyde receiving tank is equipped with an inlet, a gas phase outlet, and a n-butyraldehyde outlet. The side-stream outlet pipe is connected to the inlet of the n-butyraldehyde receiving tank, and the gas phase outlet is connected to the feed inlet of the distillation column via a pipe.

2. The apparatus as claimed in claim 1, characterized in that, The distillation column is a plate column, with feed inlets at the top, middle and bottom.

3. The apparatus as claimed in claim 1, characterized in that, Both the side-line extraction pipeline and the isobutyraldehyde extraction pipeline are equipped with online analyzers.

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