阅读说明：本技术 一种气流床煤气化闪蒸不凝气净化系统及其方法 (Entrained flow bed coal gasification flash evaporation non-condensable gas purification system and method thereof ) 是由 吉烘樟 裴剑 杨腾飞 王福强 邓金泉 郝占全 郑永志 王小波 于 2019-10-28 设计创作，主要内容包括：本发明属气流床煤气化技术领域,为改善环境,净化处理气流床煤气化生产运行过程中不凝性气体,防止环境污染,提供一种气流床煤气化闪蒸不凝气吸收净化系统及其方法。真空闪蒸分离罐与吸收装置之间通过真空泵连接；真空闪蒸分离罐底部连沉降槽,顶部连真空泵；真空泵另一端连吸收装置；吸收装置为吸收罐底连接沉降槽,下部侧壁安液位计,顶部设脱盐水进水口、片碱加入口和不凝气进气口,上部侧壁设不凝气排气口；不凝气进气口与真空泵出口通过进气管连接,进气管的管口插入吸收罐中液面下,不凝气进气口处的进气管上设不凝气排放阀,进气管向外延伸设放空管线,进气管与放空管线之间设不凝气放空阀。达到祛除厂区周边异味的效果。(The invention belongs to the technical field of entrained flow coal gasification, and provides an entrained flow coal gasification flash non-condensable gas absorption and purification system and a method thereof in order to improve the environment, purify the non-condensable gas in the operation process of entrained flow coal gasification production and prevent environmental pollution. The vacuum flash separation tank is connected with the absorption device through a vacuum pump; the bottom of the vacuum flash separation tank is connected with a settling tank, and the top of the vacuum flash separation tank is connected with a vacuum pump; the other end of the vacuum pump is connected with an absorption device; the absorption device is characterized in that the bottom of the absorption tank is connected with a settling tank, the side wall of the lower part is provided with a liquid level meter, the top of the absorption tank is provided with a desalted water inlet, a caustic soda flake feeding port and a non-condensable gas inlet, and the side wall of the upper part is provided with a non-condensable gas exhaust port; the non-condensable gas air inlet passes through the intake-tube connection with the vacuum pump export, and under the mouth of pipe of intake pipe inserted the liquid level in the absorption tank, establish the non-condensable gas blow-down valve in the intake pipe of non-condensable gas intake port department, the air-out pipeline is established in the outside extension of intake pipe, establishes the non-condensable gas blow-down valve between intake pipe and the air-out pipeline. The effect of removing the peculiar smell around the factory is achieved.)

1. An entrained flow coal gasification flash evaporation non-condensable gas absorption and purification system, wherein a vacuum flash separation tank (1) is connected with an absorption device (2) through a vacuum pump (3); the method is characterized in that: the bottom of the vacuum flash separation tank (1) is connected with a settling tank (4), and the top of the vacuum flash separation tank is connected with a vacuum pump (3); the other end of the vacuum pump is connected with an absorption device (2);

the absorption device (2) is a non-condensable gas absorption device, the bottom of an absorption tank (2.1) is connected with a settling tank (4), a liquid level meter (2.2) is installed on the side wall of the lower part of the absorption tank (2.1), the top of the absorption tank (2.1) is provided with a desalted water inlet (2.3), a caustic soda flake feeding port (2.4) and a non-condensable gas inlet (2.5), and the side wall of the upper part of the absorption tank (2.1) is provided with a non-condensable gas exhaust port (2.6); noncondensable gas air inlet (2.5) export with vacuum pump (3) and are connected through intake pipe (5), and under the mouth of pipe of intake pipe (5) inserted the liquid level in the absorption tank, set up noncondensable gas blow-down valve (2.7) on intake pipe (5) of noncondensable gas air inlet (2.5) department, intake pipe (5) outwards extend and set up the evacuation pipeline, set up noncondensable gas blow-down valve (2.8) between intake pipe (5) and the evacuation pipeline.

2. The method for purifying the coal gasification flash evaporation non-condensable gas by using the entrained flow coal gasification flash evaporation non-condensable gas purification system as claimed in claim 1, is characterized in that: the method comprises the following steps:

(1) opening a non-condensable gas emptying valve on a pipeline of the non-condensable gas inlet absorption tank, emptying the non-condensable gas, and closing a non-condensable gas discharge valve;

(2) opening an alkali feeding port on the absorption tank; opening a waste liquid discharge port to discharge the waste liquid completely;

(3) adding caustic soda flakes NaOH into a caustic soda flake adding port, wherein the adding amount of the caustic soda flakes is 4kg each time, and closing the caustic soda flake adding port;

(4) opening desalted water, flushing the interior of the absorption tank and the liquid level meter, then closing a waste liquid discharge port, and filling desalted water until the liquid level reaches 75% of the total amount of the liquid level meter, wherein the total water amount is about 1m³(ii) a The pH value of the absorption liquid is 13; opening a non-condensable gas discharge valve, allowing the non-condensable gas to enter the absorption tank from the outlet of the vacuum pump below the liquid level, and reacting and absorbing the acid gas and the alkali liquor;

(5) and after the non-condensable gas is absorbed, opening a non-condensable gas emptying valve, closing a non-condensable gas discharge valve, feeding the absorbed non-condensable gas into an emptying pipeline, and emptying the non-condensable gas.

3. The method for purifying the coal gasification flash condensed gas by using the entrained flow coal gasification flash condensed gas purification system according to claim 2, wherein: and replacing caustic soda flakes in the absorption tank once a week, and draining and cleaning the absorption tank.

Technical Field

The invention belongs to the technical field of entrained flow coal gasification, and particularly relates to an entrained flow coal gasification flash evaporation non-condensable gas purification system and a method thereof.

Background

In the operation process of the entrained flow coal gasification production, grey water is needed to chill and wash the crude coal gas, reduce the temperature of the coal gas and wash away dust carried in the coal gas, and a black (grey) water flash evaporation system is arranged for carrying out heat recovery and treatment and recycling on part of grey (black) water. In the black water flash evaporation treatment, a large amount of flash steam is generated, and most of the flash steam becomes flash evaporation condensate after being condensed and returns to the system. Wherein a part of non-condensable gas is still contained, and the main component is H₂S、NH₃、CO₂CO and CH₄And the like. The part of gas is directly discharged in design, and environmental pollution can be caused to a certain extent.

Disclosure of Invention

The invention provides an entrained flow bed coal gasification flash evaporation non-condensable gas absorption and purification system and a method thereof in order to improve the environment and combine the production operation experience to purify the non-condensable gas in the entrained flow bed coal gasification production operation process and prevent the environmental pollution.

The invention is realized by the following technical scheme: an entrained flow coal gasification flash evaporation non-condensable gas absorption purification system, wherein a vacuum flash evaporation separation tank is connected with an absorption device through a vacuum pump; the bottom of the vacuum flash separation tank is connected with a settling tank, and the top of the vacuum flash separation tank is connected with a vacuum pump; the other end of the vacuum pump is connected with an absorption device;

the absorption device is a non-condensable gas absorption device, the bottom of the absorption tank is connected with a settling tank, a liquid level meter is arranged on the side wall of the lower part of the absorption tank, the top of the absorption tank is provided with a desalted water inlet, a flake caustic soda feeding port and a non-condensable gas inlet, and the side wall of the upper part of the absorption tank is provided with a non-condensable gas exhaust port; the non-condensable gas air inlet passes through intake-tube connection with the vacuum pump export, and under the mouth of pipe of intake pipe inserted the liquid level in the absorption tank, set up non-condensable gas blow-down valve in the intake pipe of non-condensable gas air inlet department, the intake pipe outwards extends and sets up the blow-down pipeline, sets up non-condensable gas blow-down valve between intake pipe and the blow-down pipeline.

The method for purifying the coal gasification flash evaporation non-condensable gas by using the entrained flow bed coal gasification flash evaporation non-condensable gas purification system comprises the following steps:

(1) opening a non-condensable gas emptying valve on a pipeline of the non-condensable gas inlet absorption tank, emptying the non-condensable gas, and closing a non-condensable gas discharge valve;

(2) opening an alkali feeding port on the absorption tank; opening a waste liquid discharge port to discharge the waste liquid completely;

(3) adding caustic soda flakes NaOH into a caustic soda flake adding port, wherein the adding amount of the caustic soda flakes is 4kg each time, and closing the caustic soda flake adding port;

(4) slowly opening desalted water, flushing the interior of the absorption tank and the liquid level meter, then closing a waste liquid discharge port, and filling desalted water until the liquid level reaches 75% of the total amount of the liquid level meter, wherein the total water amount is about 1m³(ii) a The pH value of the absorption liquid is 13; opening a non-condensable gas discharge valve, allowing the non-condensable gas to enter the absorption tank from the outlet of the vacuum pump below the liquid level, and reacting and absorbing the acid gas and the alkali liquor;

(5) and after the non-condensable gas is absorbed, opening a non-condensable gas emptying valve, closing a non-condensable gas discharge valve, feeding the absorbed non-condensable gas into an emptying pipeline, and emptying the non-condensable gas.

And replacing caustic soda flakes in the absorption tank once a week, and draining and cleaning the absorption tank.

The inlet of the absorption device is arranged at the outlet of the vacuum pump, the non-condensable gas discharge valve is closed, the non-condensable gas is introduced into the absorption device, and the non-condensable gas is discharged after being absorbed and closed. And an emptying pipeline is arranged on the air inlet pipeline and is used for leading the non-condensable gas out of the absorption device when the absorbent flake caustic soda is added.

Due to the fact that the quantity of the non-condensable gas is relatively small, the absorbent flake caustic soda and the waste liquid discharge are periodically added and discharged, the flake caustic soda addition and the waste liquid discharge are non-continuous processes, and the absorption of the non-condensable gas is continuously carried out. By comparing the data before and after the system is added, the total sulfur absorption rate in the non-condensable gas can be more than 90%, and the effect of removing the peculiar smell around the plant area is achieved.

Drawings

Fig. 1 is a schematic structural diagram of the system of the present invention.

In the figure: 1-vacuum flash separation tank; 2-an absorption device; 2.1-an absorption tank; 2.2-liquid level meter; 2.3-a desalted water inlet; 2.4-tablet alkali inlet; 2.5-noncondensable gas inlet; 2.6-noncondensable gas exhaust port; 2.7-noncondensable gas discharge valve; 2.8 non-condensable gas blow-down valve; 3-a vacuum pump; 4-a settling tank; 5-air inlet pipe.

Detailed Description

As shown in figure 1, in an entrained flow coal gasification flash non-condensable gas absorption and purification system, a vacuum flash separation tank 1 is connected with an absorption device 2 through a vacuum pump 3; the bottom of the vacuum flash separation tank 1 is connected with a settling tank 4, and the top of the vacuum flash separation tank is connected with a vacuum pump 3; the other end of the vacuum pump is connected with the absorption device 2;

the absorption device 2 is a noncondensable gas absorption device, the bottom of an absorption tank 2.1 is connected with a settling tank 4, a liquid level meter 2.2 is arranged on the side wall of the lower part of the absorption tank 2.1, the top of the absorption tank 2.1 is provided with a desalted water inlet 2.3, a caustic soda flake feeding port 2.4 and a noncondensable gas inlet 2.5, and the side wall of the upper part of the absorption tank 2.1 is provided with a noncondensable gas exhaust port 2.6; noncondensable gas air inlet 2.5 exports through intake pipe 5 with vacuum pump 3 and is connected, and under the mouth of pipe of intake pipe 5 inserted the liquid level in the absorption tank, set up noncondensable gas blow-off valve 2.7 on the intake pipe 5 of noncondensable gas air inlet 2.5 department, intake pipe 5 outwards extends and sets up the blow-down pipeline, sets up noncondensable gas blow-off valve 2.8 between intake pipe 5 and the blow-down pipeline.

The method for purifying the coal gasification flash evaporation non-condensable gas by using the entrained flow bed coal gasification flash evaporation non-condensable gas purification system comprises the following steps:

(1) opening a non-condensable gas emptying valve on a pipeline of the non-condensable gas inlet absorption tank, emptying the non-condensable gas, and closing a non-condensable gas discharge valve;

(2) opening an alkali feeding port on the absorption tank; opening a waste liquid discharge port to discharge the waste liquid completely;

(3) adding caustic soda flakes NaOH into a caustic soda flake adding port, wherein the adding amount of the caustic soda flakes is 4kg each time, and closing the caustic soda flake adding port;

(4) opening desalted water, flushing the interior of the absorption tank and the liquid level meter, then closing a waste liquid discharge port, and filling desalted water until the liquid level reaches 75% of the total amount of the liquid level meter, wherein the total water amount is about 1m³(ii) a The pH value of the absorption liquid is 13; opening a non-condensable gas discharge valve, allowing the non-condensable gas to enter the absorption tank from the outlet of the vacuum pump below the liquid level, and reacting and absorbing the acid gas and the alkali liquor;

(5) and after the non-condensable gas is absorbed, opening a non-condensable gas emptying valve, closing a non-condensable gas discharge valve, feeding the absorbed non-condensable gas into an emptying pipeline, and emptying the non-condensable gas.

Alkali is added into the absorption tank and liquid is drained. The caustic soda flakes are replaced once a week, and the absorption tank is drained and cleaned.

As shown in figure 1, the non-condensable gas is introduced into an absorption tank at the outlet of a vacuum pump, and NaOH solution and H in the non-condensable gas in the absorption tank₂S、CO₂After the chemical reaction is carried out and the gas is absorbed, the non-condensable gas enters an original emptying pipeline from an absorption tank outlet for emptying.

During normal working process, after alkali is added into the absorption tank, non-condensable gas enters the absorption tank from the outlet of the vacuum pump to be below the liquid level, and acid gas and alkali liquor still enter the emptying pipeline from the outlet after reaction and absorption.

By comparing the data before and after the addition of the invention, the total sulfur absorption rate in the non-condensable gas can be more than 90 percent, and the effect of removing the peculiar smell around the plant area is achieved.

Taking a flash gas sample from the top of the vacuum flash tank for analysis results: the total sulfur content in the flash steam is 4000ppm, the part of gas is a source for generating peculiar smell, and after the chemical absorption is carried out by the device, the total sulfur content of the absorbed non-condensable gas can be reduced to 200ppm as can be seen by sampling and analyzing at a 2.6 non-condensable gas exhaust port.

In the noncondensable gas absorption device, NaOH is always kept excessive, namely liquid in the device is always alkaline, so that the following chemical reactions can occur in the device: h₂S+2NaOH=Na₂S+2H₂O。

The reacted solution is periodically discharged to a settling tank, the settling tank is an open device, the normal temperature of the settling tank is 70 ℃, and the sodium sulfide solution can be quickly oxidized by air to generate sodium thiosulfate in the environment, so that the effect of removing peculiar smell is achieved.