A device for vacuumizing an octanol rectification system

Abstract

The utility model discloses a kind of octanol rectification system vacuumizing device, including liquid ring vacuum pump, steam-water separator and water-oil separator, the air inlet of liquid ring vacuum pump is connected octanol rectification system tail gas, with by-product polycarboxylic alcohol as working fluid, after inhaling octanol rectification system process gas, process gas and polycarboxylic alcohol are sent to steam-water separator, process gas is separated from polycarboxylic alcohol in steam-water separator, polycarboxylic alcohol enters water-oil separator from steam-water separator bottom, polycarboxylic alcohol is recycled to polycarboxylic alcohol tank after separation, and water phase is discharged to octanol device water stripping system.The utility model's octanol rectification system vacuumizing device, using liquid ring vacuum pump replaces steam ejector, more environmental protection and energy saving;While using device by-product polycarboxylic alcohol as working fluid, polycarboxylic alcohol and water are separated after vacuumizing and realize self-circulation, and do not affect the quality of polycarboxylic alcohol.

Description

Technical Field

[0001] This utility model belongs to the field of octanol synthesis technology, specifically relating to a device for evacuating the octanol distillation system in an octanol apparatus. Background Technology

[0002] The octanol process is a method for producing isooctanol using propylene, carbon monoxide, and hydrogen as raw materials. The octanol unit uses two carbonyl synthesis reactors connected in series. Under appropriate temperature and pressure (85-110℃, 1.8-1.95MPa), the reaction, catalyzed by a rhodium catalyst, produces n-butyraldehyde and isobutyraldehyde. The n-butyraldehyde undergoes condensation and hydrogenation reactions to obtain crude octanol. The crude octanol is then subjected to an octanol distillation system to remove light and heavy components, yielding the final octanol product. Due to the high boiling point of octanol (around 185℃), the distillation system operates under negative pressure.

[0003] The conventional method for creating negative pressure in a distillation system is using an ejector, employing 1.3 MPa steam to evacuate the system to negative pressure. After the oil-containing process gas is drawn in, it mixes with the condensate obtained from steam cooling, generating a large amount of wastewater. Furthermore, the operation of the steam ejector is significantly affected by the steam pressure; fluctuations in the steam pipeline network directly impact the pressure of the distillation system, potentially affecting the quality of the octanol product in severe cases. Summary of the Invention

[0004] The purpose of this invention is to provide a device for vacuuming the octanol distillation system in an octanol unit, which can improve the stability of the octanol distillation system, reduce the consumption of steam and water in the unit, reduce wastewater, and achieve the goal of reducing energy consumption and clean production.

[0005] To achieve the above-mentioned objectives, the technical solution adopted by this utility model is as follows: An apparatus for vacuuming an octanol distillation system is characterized by comprising a liquid ring vacuum pump, a vapor-liquid separator, and a water-oil separator. The inlet of the liquid ring vacuum pump is connected to the tail gas of the octanol distillation system. Using a byproduct polyol as the working fluid, the process gas from the octanol distillation system is drawn in, and the process gas and polyol are sent to the vapor-liquid separator. In the vapor-liquid separator, the process gas and polyol are separated. The polyol enters the water-oil separator from the bottom of the vapor-liquid separator. After separation, the polyol is recovered into a polyol tank, and the aqueous phase is discharged to the water stripping system of the octanol unit.

[0006] Furthermore, a process gas inlet pressure gauge is installed at the inlet of the liquid ring vacuum pump to monitor the inlet process gas pressure.

[0007] The working fluid of the liquid ring vacuum pump in the device is a polyol produced as a byproduct of the octanol unit, which is separated by a gas-liquid separator and then self-circulated. A working fluid heat exchanger is installed before the liquid ring vacuum pump, and the polyol enters the chamber of the liquid ring vacuum pump after being heated by the working fluid heat exchanger.

[0008] Furthermore, the flow rate of the by-product polyol is controlled by a polyol flow meter and a polyol flow regulating valve. During daily operation, the polyol maintains a certain inlet and outlet flow rate to prevent water entrained by the process gas from accumulating in the system.

[0009] Furthermore, the top gas phase outlet of the gas-water separator is connected to the tail gas treatment unit, sending the separated process gas to the tail gas treatment unit. The bottom liquid phase outlet is connected to the water-oil separator via the gas-water separator level regulating valve.

[0010] Furthermore, a process gas circulation pipeline is provided at the top gas phase outlet of the gas-water separator and connected to the inlet of the liquid ring vacuum pump. A reflux regulating valve is provided on the process gas circulation pipeline to adjust the load of the liquid ring vacuum pump.

[0011] Furthermore, a working fluid circulation pipeline is provided at the middle liquid phase outlet below the liquid level of the gas-water separator, which is connected to the working fluid heat exchanger inlet of the liquid ring vacuum pump, so that part of the separated polyols are returned to the liquid ring vacuum pump from the upper liquid phase.

[0012] Furthermore, the steam-water separator is equipped with a pressure gauge and a safety valve to monitor the pressure and prevent system overpressure. The steam-water separator also includes a level gauge, which, in conjunction with a level regulating valve, controls the stability of the steam-water separator level.

[0013] Furthermore, the water-oil separator is internally equipped with baffles to divide it into an oil phase zone and an aqueous phase zone, which promotes the chromatography and separation of water and oil. The aqueous phase zone includes a water leg.

[0014] Furthermore, the oil phase zone of the water-oil separator is equipped with a water-oil separator level gauge, a multicarbon alcohol transfer pump, and a water-oil separator level regulating valve to control the stability of the water-oil separator level; the water phase zone is equipped with a water leg level gauge, and a water leg level regulating valve is installed at the bottom of the water leg to maintain the water level of the water leg and the stable operation of the downstream water stripping system.

[0015] Beneficial Effects: The vacuum pumping device for the octanol distillation system of this invention uses a liquid ring vacuum pump instead of a steam ejector, which is more environmentally friendly and energy-efficient than a steam ejector. The device also changes the working fluid of the vacuum pump from water to polyols produced as a byproduct of the process, eliminating the generation of additional wastewater during operation. The liquid ring vacuum pump can be used in a standby configuration, making the equipment more stable and easier to maintain compared to the original single-device operation with an ejector. During operation, the process gas and working fluid are mixed in the liquid ring vacuum pump. The process gas and polyols are separated in the gas-water separator. Some water entrained in the process gas remains in the polyol working fluid and is finally separated in the water-oil separator. The aqueous phase is discharged to the water stripping system via a water leg, while the oil phase is sent to the polyol storage tank. The polyols and water are separated and self-circulated, ultimately not affecting the quality of the polyols. Attached Figure Description

[0016] Figure 1 This invention relates to a vacuum device for an octanol distillation system. 1-Process gas inlet pressure gauge; 2-Liquid ring vacuum pump; 3-Steam-water separator; 4-Steam-water separator pressure gauge; 5-Steam-water separator safety valve; 6-Steam-water separator level gauge; 7-Steam-water separator level regulating valve; 8-Reflux regulating valve; 9-Multi-carbon alcohol flow meter; 10-Multi-carbon alcohol flow regulating valve; 11-Working fluid heat exchanger; 12-Working fluid thermometer; 13-Working fluid pressure gauge; 14-Water-oil separator; 15-Water-oil separator level gauge; 16-Multi-carbon alcohol transfer pump; 17-Water-oil separator level regulating valve; 18-Water leg level gauge; 19-Water leg level regulating valve. Detailed Implementation

[0017] The specific embodiments of this utility model will be described in detail below. However, it should be noted that the scope of protection of this utility model is not limited by these specific embodiments, but is determined by the claims.

[0018] like Figure 1As shown, the vacuum device for the octanol distillation system of this invention uses an electrically powered liquid ring vacuum pump 2 instead of the commonly used steam ejector for vacuuming. The liquid ring vacuum pump 2 is connected to the tail gas of the octanol distillation system and draws in the process gas of the octanol distillation system to generate a vacuum. A pressure gauge 1 is installed before the process gas inlet of the liquid ring vacuum pump 2 to monitor the inlet pressure. The working fluid of the liquid ring vacuum pump 2 is a polyol, provided by the octanol distillation system. Valves are installed at the inlet and outlet of the process gas and working fluid of the liquid ring vacuum pump 2 for equipment isolation. The polyol by-product of the octanol unit is regulated by a flow meter 9 and a flow regulating valve 10 on the feed line. After the fresh polyol working fluid is mixed with the circulating working fluid, it is cooled to 45°C through a heat exchanger 11 and finally enters the chamber of the liquid ring vacuum pump 2. A thermometer 12 and a pressure gauge 13 are installed at the outlet of the heat exchanger 11. Through the work done by the liquid ring vacuum pump 2, the process gas and polyol working fluid of the octanol distillation system are sent to the gas-liquid separator 3 for separation. In the gas-water separator 3, the process gas and polyol are separated. The process gas is sent to the tail gas treatment unit through the top outlet of the gas-water separator 3. The gas-water separator 3 is equipped with a pressure gauge 4 and a level gauge 6, and also has a safety valve 5 to prevent overpressure. The top outlet of the gas-water separator 3 is connected to a return pipeline to the inlet of the liquid ring vacuum pump 2. A regulating valve 8 is installed on the return pipeline to regulate the outlet delivery pressure. After the polyol working fluid is separated, part of it returns to the liquid ring vacuum pump 2 through the working fluid circulation pipeline in the middle of the gas-water separator 3, and part of it is sent to the aqueous phase zone of the water-oil separator 14 through the bottom of the gas-water separator 3. In the water-oil separator 14, the polyol and water separate into layers. The density of the polyol is less than that of the aqueous phase, so it floats on top of the aqueous phase. As polyols accumulate, the liquid level rises and eventually overflows the internal baffle of the water-oil separator 14, entering the oil phase zone on the other side of the baffle, and is then sent to the polyol tank by the transfer pump 16; the aqueous phase is discharged to the octanol unit water stripping system through the bottom of the water leg of the water-oil separator via the liquid level regulating valve 19.

Claims

1. A device for evacuating a vacuum in an octanol distillation system, characterized in that, The system includes a liquid ring vacuum pump (2), a vapor-water separator (3), and a water-oil separator (14). The inlet of the liquid ring vacuum pump (2) is connected to the tail gas of the octanol distillation system. Using the polyol produced by the unit as the working liquid, the process gas from the octanol distillation system is drawn in and the process gas and polyol are sent to the vapor-water separator (3). In the vapor-water separator (3), the process gas and polyol are separated. The polyol enters the water-oil separator (14) from the bottom of the vapor-water separator (3). After separation, the polyol is recovered into the polyol tank, and the aqueous phase is discharged to the octanol unit water stripping system.

2. The apparatus for evacuating the octanol distillation system according to claim 1, characterized in that, The liquid ring vacuum pump (2) is equipped with a process gas inlet pressure gauge (1) at its inlet.

3. The apparatus for vacuuming the octanol distillation system according to claim 1, characterized in that, A working fluid heat exchanger (11) is installed in front of the liquid ring vacuum pump (2). After the polyol is heated by the working fluid heat exchanger (11), it enters the cavity of the liquid ring vacuum pump (2).

4. The apparatus for evacuating the octanol distillation system according to claim 1, characterized in that, The by-product polyol is controlled by a polyol flow meter (9) and a polyol flow regulating valve (10).

5. The apparatus for evacuating the octanol distillation system according to claim 1, characterized in that, The top gas phase outlet of the gas-water separator (3) is connected to the tail gas treatment unit, and the separated process gas is sent to the tail gas treatment unit; the bottom liquid phase outlet is connected to the water-oil separator (14) through the gas-water separator level regulating valve (7).

6. The apparatus for evacuating the octanol distillation system according to claim 1, characterized in that, The gas phase outlet at the top of the gas-water separator (3) is provided with a process gas circulation pipeline, which is connected to the inlet of the liquid ring vacuum pump (2). A reflux regulating valve (8) is provided on the process gas circulation pipeline.

7. The apparatus for evacuating the octanol distillation system according to claim 1, characterized in that, The working fluid circulation pipeline is provided at the middle liquid phase outlet below the liquid level of the steam-water separator (3) and connected to the inlet of the working fluid heat exchanger (11) of the liquid ring vacuum pump (2).

8. The apparatus for evacuating the octanol distillation system according to claim 1, characterized in that, The steam-water separator (3) is equipped with a steam-water separator pressure gauge (4), a steam-water separator level gauge (6), a steam-water separator level regulating valve (7), and a steam-water separator safety valve (5).

9. The apparatus for evacuating the octanol distillation system according to claim 1, characterized in that, The water-oil separator (14) is equipped with a baffle to divide it into an oil phase zone and a water phase zone; the water phase zone includes a water leg.

10. The apparatus for evacuating the octanol distillation system according to claim 9, characterized in that, The oil phase zone of the water-oil separator (14) is equipped with a water-oil separator level gauge (15), a multi-carbon alcohol transfer pump (16), and a water-oil separator level regulating valve (17); the water phase zone is equipped with a water leg level gauge (18), and a water leg level regulating valve (19) is installed at the bottom.

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