Butanol separation device

Abstract

The utility model belongs to the field of chemical industry, and relates to a butanol separation device, which comprises a butanol light component removal tower, a butanol vacuum tower and a butanol pressurization tower, the three towers are respectively provided with a corresponding reflux tank and a reboiler, the gas phase at the top of the butanol vacuum tower is a heat source of the butanol light component removal tower reboiler, and the gas phase at the top of the butanol pressurization tower is a heat source of the butanol vacuum tower reboiler. By optimizing the process, the butanol light component removal tower, the butanol vacuum tower and the butanol pressurizing tower realize triple-effect thermal coupling rectification, only the butanol pressurizing tower needs to be heated by steam, and the energy consumption is 65% lower than that of a conventional two-tower process.

Description

Technical Field

[0001] This utility model belongs to the field of chemical industry and relates to a butanol separation device. Background Technology

[0002] Butanol and octanol can be produced in the same unit using a carbonyl synthesis method, hence the common name butanol-octanol. Butanol and octanol are important raw materials for the synthesis of fine chemical products, mainly used in the production of plasticizers, solvents, dehydrating agents, defoamers, dispersants, flotation agents, petroleum additives, and synthetic fragrances. Downstream consumption of butanol mainly includes butyl acrylate, butyl acetate, and DBP. Downstream consumption of octanol mainly includes DOP, DOTP, and octyl acrylate.

[0003] The production of butanol and octanol has developed rapidly with the development of petrochemical, polyvinyl chloride materials industry and carbonyl synthesis technology. The main industrial production methods of butanol and octanol include acetaldehyde condensation, fermentation, Ziegler process and carbonyl synthesis, among which carbonyl synthesis is the most important butanol production technology today.

[0004] The process of propylene carbonyl synthesis to produce butanol and octanol is as follows: (1) Propylene hydroformylation reaction, crude aldehyde is purified to obtain n-butyraldehyde and isobutyraldehyde; (2) n-butyraldehyde and isobutyraldehyde are hydrogenated to obtain n-butanol and isobutanol; (3) n-butyraldehyde is condensed and hydrogenated to obtain butanol and octanol. Propylene carbonyl synthesis is further divided into high pressure method, medium pressure method and low pressure method.

[0005] Low-pressure butanol and octanol technology is a low-pressure carbonylation process that uses propylene and syngas (a mixture of hydrogen and carbon monoxide) to produce n- and isobutyraldehyde. For over 30 years, Davy Process Technology has jointly marketed and provided technology transfer and services for low-pressure butanol and octanol technology with Dow Chemical Company; to date, this technology has been transferred to 29 projects in 15 countries and regions across four continents. Low-pressure butanol and octanol technology is considered the world's leading transferable butanol and octanol technology, accounting for over 85% of global butanol and octanol production using propylene as a feedstock through technology transfer. Low-pressure butanol and octanol technology offers significant advantages in each reaction stage. Currently, one conventional process involves completely separating n-butyraldehyde and isobutyraldehyde in the butyraldehyde separation stage, followed by hydrogenation of n-butyraldehyde to n-butanol. The butanol separation process only requires the removal of light and heavy components to obtain the n-butanol product.

[0006] One common process currently involves completely separating n-butyraldehyde and isobutyraldehyde in the butyraldehyde separation stage, followed by hydrogenation of n-butyraldehyde to produce n-butanol. The butanol separation process only requires the removal of light and heavy components to obtain the n-butanol product. The separation of n-butanol primarily employs conventional distillation. Chinese patent CN115006862A describes an energy-saving, high-purity n-butanol extraction system. This system mainly consists of a preheater, a n-butanol light component removal tower, a n-butanol heavy component removal tower, and an n-isobutyraldehyde separation tower, arranged sequentially. Crude n-butanol feedstock enters the system via the preheater, where it exchanges heat with the n-butanol product obtained from the n-butanol heavy component removal tower. The n-butanol light component removal tower, n-butanol heavy component removal tower, and n-isobutyraldehyde separation tower are each connected to a reboiler for heat recovery. The top of the n-butanol heavy component removal tower is connected to the reboiler pipeline of the n-isobutyraldehyde separation tower. The extraction system uses a coupled distillation method with the top gas phase of the butanol deweighting tower as the heat source and the reboiler of the isobutyraldehyde separation tower as the heat source to achieve energy saving. However, since it is only a double-effect coupled distillation, the energy consumption is still relatively high.

[0007] Therefore, it is necessary to improve the technology of subsequent separation processes to save energy. Utility Model Content

[0008] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a butanol separation device that comprehensively optimizes the heat exchange network, changes the single-tower process of the butanol de-heavy tower to a dual-tower thermal coupling process, uses the top gas phase of the butanol vacuum tower as the heat source of the heat exchanger and reboiler of the butanol de-light tower, and uses the top gas phase of the butanol pressurization tower as the heat source of the reboiler of the butanol vacuum tower, thereby reducing energy consumption.

[0009] The technical solution adopted by this utility model to solve the technical problem is:

[0010] A butanol separation device includes a butanol light phase removal tower, a butanol vacuum distillation tower, and a butanol pressurization tower. The butanol light phase removal tower has a crude butanol feed inlet. The bottom outlet pipeline of the butanol light phase removal tower is connected to the inlet of the butanol vacuum distillation tower. The bottom outlet pipeline of the butanol vacuum distillation tower is connected to the inlet of the butanol pressurization tower. The bottom outlet pipeline of the butanol pressurization tower is connected to a heavy component tank. A heat exchanger / reboiler is installed at the bottom of the butanol light phase removal tower. A reflux tank is installed at the top of the butanol vacuum distillation tower. The top vapor phase outlet pipeline of the butanol vacuum distillation tower is connected to the inlet of the heat exchanger / reboiler. The outlet of the heat exchanger / reboiler is connected via a pipeline to... The butanol vacuum distillation tower reflux tank has an inlet. The outlet pipeline of the butanol vacuum distillation tower reflux tank is divided into two lines: one connects to the top reflux port of the butanol vacuum distillation tower, and the other serves as the butanol product collection pipeline. A butanol vacuum distillation tower reboiler is installed at the bottom of the butanol vacuum distillation tower, and a butanol pressurization tower reflux tank is installed at the top of the butanol pressurization tower. The top vapor phase collection pipeline of the butanol pressurization tower is connected to the inlet of the butanol vacuum distillation tower reboiler. The outlet of the butanol vacuum distillation tower reboiler is connected to the inlet of the butanol pressurization tower reflux tank via a pipeline. The outlet pipeline of the butanol pressurization tower reflux tank is divided into two lines: one connects to the top reflux port of the butanol pressurization tower, and the other serves as the butanol product collection pipeline.

[0011] Furthermore, the butanol light phase removal tower is equipped with a butanol light phase removal tower condenser and a butanol light phase removal tower reflux phase separator at the top. The gas phase exit pipeline at the top of the butanol light phase removal tower is connected to the inlet of the butanol light phase removal tower condenser. The outlet of the butanol light phase removal tower condenser is connected to the inlet of the butanol light phase removal tower reflux phase separator via a pipeline. The organic phase outlet of the butanol light phase removal tower reflux phase separator is divided into two paths via a pipeline. One path is connected to the top reflux port of the butanol light phase removal tower, and the other path serves as the light component exit pipeline.

[0012] Furthermore, the bottom of the butanol light removal tower reflux phase separation tank is provided with a wastewater outlet.

[0013] Furthermore, the internal components of both the butanol light removal tower and the butanol vacuum distillation tower are packed with packing material.

[0014] Furthermore, a butanol light-removal column steam reboiler is configured at the bottom of the butanol light-removal column.

[0015] Furthermore, a butanol light-removal tower reflux pump, a butanol vacuum tower reflux pump, and a butanol pressurization tower reflux pump are respectively installed on the outflow pipelines of the butanol light-removal tower reflux separation tank, the butanol vacuum tower reflux tank, and the butanol pressurization tower reflux tank.

[0016] Furthermore, a bottom pump for the butanol light removal tower, a bottom pump for the butanol vacuum tower, and a bottom pump for the butanol pressurization tower are respectively installed on the bottom outflow pipelines of the butanol light removal tower, the butanol vacuum tower, and the butanol pressurization tower.

[0017] Furthermore, a butanol pressurization column reboiler is configured at the bottom of the column.

[0018] The advantages and positive effects of this utility model are:

[0019] 1. The pressure of the butanol light removal tower was changed from the slightly positive pressure of the conventional process to the reduced pressure, which lowered the operating temperature of the entire tower. The internal components of the tower were replaced with packing instead of the trays of the conventional process, which greatly reduced the pressure drop of the entire tower and further reduced the bottom temperature of the tower. This provided the conditions for the top gas phase of the butanol reduced pressure tower to serve as a heat source for the reboiler of the butanol light removal tower, which reduced the steam energy consumption of the butanol light removal tower and even eliminated the need for an additional heat source.

[0020] 2. The butanol deweighting tower was changed from a conventional single-tower process to a dual-tower thermally coupled process. The pressure of the butanol vacuum tower was changed from a slightly positive pressure in the conventional process to a reduced pressure, which lowered the overall operating temperature of the tower. The use of packing instead of the trays in the conventional process greatly reduced the overall pressure drop of the tower and further reduced the bottom temperature. The gas phase at the top of the butanol pressurized tower provided the conditions for the butanol vacuum tower reboiler to serve as a heat source, so that the butanol vacuum tower no longer needed an additional heat source.

[0021] 3. By optimizing the process, the butanol light removal tower, butanol vacuum tower and butanol pressurization tower can achieve triple-effect thermal coupling distillation. Only the butanol pressurization tower needs steam heating, and the energy consumption is 65% lower than the conventional two-tower process.

[0022] 4. This device has low energy consumption, a reasonable design, and is easy to operate. Attached Figure Description

[0023] Figure 1 This is a structural diagram of the butanol separation device of this utility model.

[0024] The attached diagram is labeled as follows: 1-Butanol light-weight removal tower; 2-Butanol light-weight removal tower steam reboiler; 3-Butanol light-weight removal tower heat exchange reboiler; 4-Butanol light-weight removal tower condenser; 5-Butanol light-weight removal tower reflux phase separator; 6-Butanol light-weight removal tower reflux pump; 7-Butanol light-weight removal tower bottom pump; 8-Butanol vacuum distillation tower; 9-Butanol vacuum distillation tower reboiler; 10-Butanol vacuum distillation tower reflux tank; 11-Butanol vacuum distillation tower reflux pump; 12-Butanol vacuum distillation tower bottom pump; 13-Butanol pressurized tower; 14-Butanol pressurized tower reboiler; 15-Butanol pressurized tower reflux tank; 16-Butanol pressurized tower reflux pump; 17-Butanol pressurized tower bottom pump. Detailed Implementation

[0025] The present invention will be further described in detail below through specific embodiments. The following embodiments are only descriptive and not limiting, and should not be used to limit the protection scope of the present invention.

[0026] like Figure 1The butanol separation device shown includes a butanol light-removal tower 1, a butanol vacuum tower 8, and a butanol pressurization tower 13. All three towers are equipped with corresponding reflux tanks and reboilers. The internal components of the butanol light-removal tower 1 and the butanol vacuum tower 8 are all packed.

[0027] The crude butanol product from the butanol reaction system is fed to butanol removal tower 1 via the crude butanol feed inlet. Butanol removal tower 1 is equipped with two reboilers: one is a steam reboiler 2, using steam as the heat source, with its shell-side inlet connected to the steam ST pipeline and its shell-side outlet connected to the steam condensate RW pipeline; the other is a heat exchange reboiler 3, using the overhead vapor from butanol vacuum distillation tower 8 as its heat source. Butanol removal tower 1 is a vacuum distillation tower with a top pressure of -95 kPa. a-Atmospheric pressure, top temperature of the column is 40-90℃, and bottom temperature of the column is 70-120℃; the gas phase at the top of the butanol light component removal column 1 enters the butanol light component removal column condenser 4 for condensation, and the condensed liquid enters the butanol light component removal column reflux phase separator 5. The aqueous phase in the butanol light component removal column reflux phase separator 5 is discharged from the boundary area through the wastewater outlet, and the organic phase in the butanol light component removal column reflux phase separator 5 is transported by the butanol light component removal column reflux pump 6. Part of it is returned to the top of the butanol light component removal column 1 as reflux, and the other part is collected as light component.

[0028] The material at the bottom of the butanol light-removal tower 1 is pumped into the butanol vacuum tower 8 by the bottom pump 7. The butanol vacuum tower 8 is equipped with a butanol vacuum tower reboiler 9, using the gas phase from the top of the butanol pressurized tower 13 as the heat source for the reboiler. The butanol vacuum tower 8 is a vacuum tower with a top pressure of -60 kPa to atmospheric pressure and a top temperature of 85-135℃ and a bottom temperature of 90-140℃. The gas phase from the top of the butanol vacuum tower 8 enters the butanol light-removal tower heat exchange reboiler 3 for condensation. The condensed liquid enters the butanol vacuum tower reflux tank 10. The material in the butanol vacuum tower reflux tank 10 is pumped by the butanol vacuum tower reflux pump 11. Part of it is returned to the top of the butanol vacuum tower 8 as reflux, and the other part is collected as butanol product.

[0029] The material at the bottom of the butanol vacuum distillation column 8 is pumped into the butanol pressurization column 13 via the bottom pump 12. The butanol pressurization column 13 is equipped with a butanol pressurization column reboiler 14, using steam as the heat source. The shell-side inlet is connected to the steam ST pipeline, and the shell-side outlet is connected to the steam condensate RW pipeline. The butanol pressurization column 13 is a pressurization column with a top pressure of atmospheric pressure to 100 kPa, a top temperature of 105-145℃, and a bottom temperature of 125-155℃. The vapor phase at the top of the butanol pressurization column 13 enters the butanol vacuum distillation column reboiler 9 for condensation. The condensed liquid enters the butanol pressurization column reflux tank 15. The material in the reflux tank 15 is pumped by the butanol pressurization column reflux pump 16, with part returning as reflux to the top of the butanol pressurization column 13 and part being collected as butanol product. The heavy components at the bottom of the butanol pressurization column 13 are collected and pumped to the heavy components tank via the bottom pump 17.

[0030] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the concept of the utility model, and these all fall within the protection scope of the present utility model.

Claims

1. A butanol separation device, characterized in that, The system includes a butanol light-removal tower (1), a butanol vacuum distillation tower (8), and a butanol pressurization tower (13). The butanol light-removal tower (1) has a crude butanol feedstock inlet. The bottom outlet pipeline of the butanol light-removal tower (1) is connected to the inlet of the butanol vacuum distillation tower (8). The bottom outlet pipeline of the butanol vacuum distillation tower (8) is connected to the inlet of the butanol pressurization tower (13). The bottom outlet pipeline of the butanol pressurization tower (13) is connected to the heavy component tank. A butanol light-removal tower heat exchanger reboiler (3) is installed at the bottom of the butanol light-removal tower (1). A butanol vacuum distillation tower reflux tank (10) is installed at the top of the butanol vacuum distillation tower (8). The vapor phase outlet pipeline at the top of the butanol vacuum distillation tower (8) is connected to the inlet of the butanol light-removal tower heat exchanger reboiler (3). The outlet of the butanol light-removal tower heat exchanger reboiler (3) is connected to the butanol feedstock via a pipeline. The inlet of the vacuum distillation tower reflux tank (10) is connected to the outlet of the butanol vacuum distillation tower reflux tank (10), which is divided into two paths. One path is connected to the top reflux port of the butanol vacuum distillation tower (8), and the other path is used as the butanol product collection line. The bottom of the butanol vacuum distillation tower (8) is equipped with a butanol vacuum distillation tower reboiler (9), and the top of the butanol pressurization tower (13) is equipped with a butanol pressurization tower reflux tank (15). The top gas phase collection line of the butanol pressurization tower (13) is connected to the inlet of the butanol vacuum distillation tower reboiler (9). The outlet of the butanol vacuum distillation tower reboiler (9) is connected to the inlet of the butanol pressurization tower reflux tank (15) through a pipeline. The outlet of the butanol pressurization tower reflux tank (15) is divided into two paths. One path is connected to the top reflux port of the butanol pressurization tower (13), and the other path is used as the butanol product collection line.

2. The butanol separation apparatus according to claim 1, characterized in that, The butanol light phase removal tower (1) is equipped with a butanol light phase removal tower condenser (4) and a butanol light phase removal tower reflux separation tank (5) at the top. The gas phase exit pipeline at the top of the butanol light phase removal tower (1) is connected to the inlet of the butanol light phase removal tower condenser (4). The outlet of the butanol light phase removal tower condenser (4) is connected to the inlet of the butanol light phase removal tower reflux separation tank (5) through a pipeline. The organic phase outlet of the butanol light phase removal tower reflux separation tank (5) is divided into two paths through a pipeline. One path is connected to the top reflux port of the butanol light phase removal tower (1), and the other path is used as a light phase exit pipeline.

3. The butanol separation apparatus according to claim 2, characterized in that, The bottom of the butanol light removal tower reflux phase separation tank (5) is equipped with a wastewater outlet.

4. The butanol separation apparatus according to claim 1, characterized in that, The internal components of the butanol light removal tower (1) and the butanol vacuum tower (8) are all packed.

5. The butanol separation apparatus according to claim 1, characterized in that, The bottom of the butanol light removal column (1) is equipped with a butanol light removal column steam reboiler (2).

6. The butanol separation apparatus according to claim 2, characterized in that, A butanol light removal tower reflux pump (6), a butanol vacuum tower reflux pump (11), and a butanol pressure tower reflux pump (16) are respectively installed on the outflow pipelines of the butanol light removal tower reflux separation tank (5), the butanol vacuum tower reflux tank (10), and the butanol pressure tower reflux tank (15).

7. The butanol separation apparatus according to claim 1, characterized in that, A bottom pump (7) for the butanol light removal tower (1), a bottom pump (12) for the butanol vacuum tower (8), and a bottom pump (17) for the butanol pressurization tower (13) are respectively installed on the bottom outflow pipelines of the butanol light removal tower (1), the butanol vacuum tower (8), and the butanol pressurization tower (13).

8. The butanol separation apparatus according to claim 1, characterized in that, The butanol pressurization column (13) is equipped with a butanol pressurization column reboiler (14) at the bottom.

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