CN209848633U - Methanol washing and recovering device in methanol synthesis flash evaporation gas - Google Patents

Abstract

The utility model discloses a methyl alcohol washing recovery unit in methyl alcohol synthesis flash distillation gas, remove fuel gas pipe network, thick methyl alcohol and remove methyl alcohol jar district and washing water pipe network, its characterized in that including flash tank, scrubbing tower, flash distillation gas: the flash tank comprises a gas-phase outlet arranged at the top end of the flash tank and a liquid-phase outlet arranged at the bottom end of the flash tank, the gas-phase outlet is connected with the flash gas-to-fuel gas pipe network, and the liquid-phase outlet is connected with the crude methanol-to-methanol tank region; the flash tank is connected with the washing tower through a pipeline, the top of the washing tower is connected with the flash gas-to-fuel gas pipe network through a pipeline, the bottom of the washing tower is connected with the crude methanol-removing tank area through a pipeline, and the washing water pipe network is connected with the washing tower through a pipeline; and a packing layer is arranged in the washing tower. This methyl alcohol washing recovery unit in methyl alcohol synthesis flash distillation gas, washing recovery effect is obvious, can retrieve the methyl alcohol of originally losing again, has reduced the loss of methyl alcohol and the waste of resource.

Description

Methanol washing recovery device in methanol synthesis flash gas

technical field

The utility model relates to the technical field of coal chemical industry, in particular to a washing and recovering device for methanol in methanol synthesis flash gas.

Background technique

The coal-to-methanol production process is complicated, and the main processes include gasification process, purification process, methanol synthesis process, rectification process, etc. Among them, the methanol synthesis process is to make the purified gas react under a certain temperature, pressure and catalyst to generate methanol. The gas is cooled, condensed, and gas-liquid separated to separate the liquid methanol, and the liquid methanol is flashed to obtain crude methanol products.

In the methanol synthesis process, the flash evaporation of crude methanol is an important process. Its purpose is to initially separate light components such as CO, H2, CO2 and DME dissolved in methanol through the principle of vacuum flash evaporation. Methanol flash vapor is the gas phase component discharged after crude methanol is flashed under reduced pressure, in which some methanol droplets will be entrained. How to reduce the entrainment of methanol, reduce the loss of methanol with gas phase components, and improve the gas-liquid separation efficiency and methanol yield is also an important issue in the methanol synthesis process.

At present, most of the new methanol synthesis processes have made significant progress in reducing the loss of methanol with the gas phase components, improving the gas-liquid separation efficiency and methanol recovery rate, including the methanol synthesis process of East China University of Science and Technology (hereinafter referred to as Huali), The methanol flash system of this process adopts a horizontal methanol flash tank to separate the H2, CO, CO2 and other gases dissolved in the crude methanol by flashing under reduced pressure, and the flashed gas is separated by a simple wire mesh demister The entrained methanol droplets are then directly fed into the fuel gas pipe network for use as fuel gas or discharged to the torch for combustion. However, due to the poor separation effect of the wire mesh demister, unnecessary waste of methanol is caused, which affects the recovery rate of methanol, so it cannot Thoroughly recycle the methanol in the flash gas.

Contents of the invention

In view of the above existing problems, the utility model aims to provide a methanol washing recovery device in the flash gas of methanol synthesis, including a flash tank, a washing tower, a gas pipeline network for defueling of the flash gas, a crude methanol tank area for methanol removal, and a washing water pipeline network.

In order to achieve the above object, the technical scheme adopted by the utility model is as follows: Methanol washing recovery device in methanol synthesis flash gas, including flash tank, scrubber, flash gas to fuel gas pipeline network, crude methanol to methanol tank area and washing water pipeline network , characterized in that: the flash tank includes a gas phase outlet at its top and a liquid phase outlet at its bottom, the gas phase outlet is connected to the flash gas defueling gas pipeline network, and the liquid phase outlet is connected to the The crude methanol is connected to the methanol tank area; the flash tank is connected to the scrubber through a pipeline, the top of the scrubber is connected to the flash gas defueling gas pipeline network through a pipeline, and the bottom of the scrubber is connected to the crude methanol through a pipeline. To connect to the methanol tank area, the washing water pipe network is connected to the washing tower through pipelines; a packing layer is arranged in the washing tower.

Preferably, a flash tank pressure regulating valve is provided between the gas phase outlet and the flash gas defueling gas pipeline network, and a flash tank liquid level regulating valve is provided between the liquid phase outlet and the crude methanol demethanol tank area .

Preferably, a washing water regulating valve is arranged between the washing water pipe network and the washing tower.

Preferably, a flash tank pressure regulating valve is arranged between the gas phase outlet and the washing tower.

Preferably, a filter and defoaming device is provided on the top of the packing layer.

The beneficial effects of the utility model are: compared with the prior art, the improvement of the utility model is that a washing tower is added at the gas phase outlet of the methanol flash tank, and a packing layer is set in the washing tower, and the packing layer Washing water is added to the tank, and the methanol discharged from the gas phase outlet of the flash tank is reversely contacted and absorbed by the packing layer, and then the flash gas at the outlet of the flash tank is washed, and the originally discharged methanol can be recovered, which saves energy.

The comparison between the design value and the measured average value of the methanol content in the flash vapor of the methanol flash system of Huali Synthesis Plant is as follows:

From the comparison of the above data, it can be seen that 6.21% of methanol is still lost in vain in the methanol flash system of the Huali Synthesis Unit, so it is necessary to transform the Huali Synthesis Flash System to recover methanol in the methanol flash vapor and reduce methanol loss .

The comparison of the methanol content in the exhaust gas before and after the installation of the methanol washing and recovery device in the methanol synthesis flash gas is as follows:

From the analysis data in the above table, after the methanol washing and recovery device in the methanol synthesis flash gas is implemented, the content of methanol in the direct exhaust gas is reduced from 6.21% to 0.05%, and the amount of methanol recovered after the transformation is:

330×(6.21%-0.05%)=20.33Nm ³ /h

20.33÷22.4×32＝29.04Kg/h

29.04×24=696.9Kg

That is, 696.9Kg of methanol can be recovered every day, and the recovery effect of washing is obvious, fully reaching the expected effect.

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of the utility model.

Fig. 2 is a schematic diagram of the filtration and defoaming device of the present invention.

Detailed ways

In order to enable those skilled in the art to better understand the technical solution of the utility model, the technical solution of the utility model will be further described below in conjunction with the drawings and embodiments.

With reference to the methanol washing recovery device in the methanol synthesis flash gas shown in accompanying drawing 1, comprise flash tank 1, washing tower 6, flash gas remove fuel gas pipe network 2, crude methanol remove methanol tank area 3 and wash water pipe network 8, described The flash tank 1 comprises a gas phase outlet 11 arranged at its top and a liquid phase outlet 12 arranged at the bottom, the gas phase outlet 11 is connected with the flash gas defueling gas pipeline network 2, and the liquid phase outlet 12 is connected with the crude Methanol is connected to the methanol tank area 3; the flash tank 1 is connected to the scrubber 6 through a pipeline, and the top of the scrubber 6 is connected to the flash gas fuel gas pipeline network 2 through a pipeline, and the bottom of the scrubber 6 Be connected with crude methanol to methanol tank area 3 through pipelines, and the washing water pipe network 8 is connected with the washing tower 6 through pipelines; packing layer 61 is arranged in the washing tower 6, and the washing water in the washing water pipe network 8 It is desalted water (0.5~0.6MPa, ≤40°C).

In order to facilitate regulation and control of the gas pressure in the flash tank 1 and the scrubber 6, a flash tank pressure regulating valve 4 is arranged between the gas phase outlet 11 and the flash gas defueling gas pipeline network 2, and the flash tank pressure regulation Valve 4 regulates the pressure in the balance flash tank 1 to ensure that the pressure in the flash tank 1 is maintained at a constant value. A flash tank liquid level regulating valve 5 is arranged between the liquid phase outlet 12 and the crude methanol-removing methanol tank area 3 to control the methanol droplets extracted in the flash tank 1 to enter the liquid in the crude methanol-removing methanol tank area 3. Drop volume.

In order to facilitate the control of the amount of washing water added, a washing water regulating valve 7 is provided between the washing water pipe network 8 and the washing tower 6, and the washing water is controlled and added according to the methanol content in the gas phase after washing in the packing layer 61.

For the convenience of controlling the flash pressure of the flash tank 1, a flash tank pressure regulating valve 4 is arranged between the gas phase outlet 11 and the washing tower 6, and the flash tank 1 is controlled by adjusting the flash tank pressure regulating valve 4. The pipeline enters the pressure of the flash gas in the scrubber 6 to ensure the flash evaporation effect of the light components in the methanol flash tank.

In order to avoid entrainment of liquid droplets in the gas after washing, the top of the packing layer 61 is provided with a filter defoaming device 62, through which the liquid droplets entrained in the gas phase are removed, so as to avoid bringing liquid droplets into the flash gas to remove the fuel gas pipe network 2.

The principle of the utility model is: a washing tower 6 is set to recycle the methanol that enters the flash gas defueling gas pipeline network 2 with the flash steam or is sent into the torch combustion chamber; The pipeline guides the methanol gas to the washing tower 6 for washing and recovery, and the washed methanol droplets flow from the bottom of the washing tower 6 into the crude methanol demethanol tank area 3 for subsequent processing.

The basic principles, main features and advantages of the present utility model have been shown and described above. Those skilled in the art should understand that the utility model is not limited by the above-mentioned embodiments. The above-mentioned embodiments and descriptions only illustrate the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model The new model also has various changes and improvements, and these changes and improvements all fall within the scope of the claimed utility model. The scope of protection required by the utility model is defined by the appended claims and their equivalents.

Claims (5)

1. Methanol washing recovery unit in methyl alcohol synthesis flash distillation gas, remove fuel gas pipe network (2), crude methyl alcohol and remove methyl alcohol jar district (3) and washing water pipe network (8) including flash tank (1), scrubbing tower (6), flash distillation gas, its characterized in that: the flash tank (1) comprises a gas phase outlet (11) arranged at the top end of the flash tank and a liquid phase outlet (12) arranged at the bottom end of the flash tank, the gas phase outlet (11) is connected with the flash evaporation gas-removing fuel gas pipe network (2), and the liquid phase outlet (12) is connected with the crude methanol-removing methanol tank area (3); the flash tank (1) is connected with the washing tower (6) through a pipeline, the top of the washing tower (6) is connected with the flash gas-to-fuel gas pipe network (2) through a pipeline, the bottom of the washing tower (6) is connected with the crude methanol-to-methanol tank area (3) through a pipeline, and the washing water pipe network (8) is connected with the washing tower (6) through a pipeline; a packing layer (61) is arranged in the washing tower (6).

2. The methanol washing and recovering device in methanol synthesis flash evaporation gas as claimed in claim 1, characterized in that: a flash tank pressure regulating valve (4) is arranged between the gas phase outlet (11) and the flash gas-removing fuel gas pipe network (2), and a flash tank liquid level regulating valve (5) is arranged between the liquid phase outlet (12) and the crude methanol-removing methanol tank area (3).

3. The methanol washing and recovering device in methanol synthesis flash evaporation gas as claimed in claim 2, characterized in that: a washing water adjusting valve (7) is arranged between the washing water pipe network (8) and the washing tower (6).

4. The methanol washing and recovering device in methanol synthesis flash evaporation gas as claimed in claim 3, characterized in that: a flash tank pressure regulating valve (4) is arranged between the gas phase outlet (11) and the washing tower (6).

5. The methanol washing and recovering device in methanol synthesis flash evaporation gas as claimed in claim 4, characterized in that: and a filtering and defoaming device (62) is arranged at the top of the packing layer (61).