JPS61204024A - Removing apparatus for hydrogen sulfide contained in gas - Google Patents

Abstract

PURPOSE:To increase the gas-liquid contact efficiency with a gas contg. oxygen, to make a tank for collecting the sulfur particles small-sized or to omit it by providing a rotary atomizer to the lower part of a regeneration tower. CONSTITUTION:An absorbing liquid consisting of an alkali aq. soln. contg. hydroquinone wherein H2S is absorbed in an absorption tower 1 is sent to a regeneration tower 2 with a pump 7', and a gas contg. air or oxygen fed form a compressor 19 is sent therein as the fine foams with a rotary atomizer 17' of a lower part of the regeneration tower 2 and brought into contact with the absorbing liquid. The produced sulfur particles are floated. Immediately these are scraped with a conveyor 12 and passed through a chute to recover them with a filter 16. On the other hand, the oxidation treating liquid existing just under the floated sulfur particles is collected in a tank 4 through a conduit 22 and recirculated to the absorption tower 1 with a pump 7.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to an apparatus for removing hydrogen sulfide from gas, and more specifically, it relates to an apparatus for removing hydrogen sulfide from gas, and more specifically, for adding and dissolving hydroquinone (or quinone) to
The present invention relates to an apparatus for removing hydrogen sulfide from gas, in which the gas is cleaned using an aqueous alkaline solution as an absorption liquid, hydrogen sulfide is absorbed, and the absorption liquid is brought into contact with air in a regeneration tower to be oxidized and regenerated for circulation.

(Prior art) Conventionally, hydrogen sulfide present in the gas to be purified is absorbed using an alkaline aqueous solution of quinones, hydroquinones, or metal salts thereof, which have been made water-solubilized by introducing an oxidizing group, and the absorbed liquid after hydrogen sulfide absorption is A wet gas purification method in which Lm oxide yellow is precipitated, separated, and the absorption liquid is circulated again is known as the Takahax method and other similar processes. (Tokuko Sho 39-101
5, Japanese Patent Publication No. 53-1284, etc.) The process used in this method uses sodium 1,4-naphthoquinone-2-sulfonate as a catalyst,
An absorption liquid containing hydroquinone and dissolved sodium hydroxide, sodium carbonate, sodium bicarbonate, etc. as a potassium source flows down from the top of the absorption tower and is brought into gas-liquid contact with a gas containing hydrogen sulfide introduced from the bottom of the tower. After absorbing the hydrogen sulfide contained therein, the liquid is introduced into the bottom of a regeneration tower having a porous gas dispersion cylinder, etc., and at the same time compressed air is forced into the bottom of the tower to remove the oxygen dissolved in the liquid and the action of the catalyst. This method oxidizes the hydrogen sulfide absorbed by the absorber to precipitate sulfur, regenerates the liquid, and recirculates it to the absorption tower.

Furthermore, since a bubble column (having a dispersion branch or a dispersion tube) was normally used to regenerate the absorption liquid, the residence time of the absorption liquid in the regeneration tower was long, resulting in a large-sized device, and the amount of air used was also disadvantageous. (This is due to the poor utilization rate.) Furthermore, the pressure loss in the dispersion branches and dispersion pipes was large, and air pushing power was required.

On the other hand, a separate tank was required due to the enlargement of the sulfur particles produced and the need for flotation.

(Problems to be Solved by the Invention) The present invention has been made in view of the above circumstances, and aims to improve the gas-liquid contact efficiency and to make it possible to downsize or omit the tank for collecting sulfur particles. The present invention aims to provide an apparatus for removing hydrogen sulfide from gas.

(Means for Solving the Problems) That is, the present invention: (1) An absorption tower that absorbs hydrogen sulfide in gas by using an aqueous alkali solution containing hydroquinone as an absorption liquid, and regenerates the absorption liquid. An apparatus for removing hydrogen sulfide from a gas comprising a regeneration tower, characterized in that the regeneration tower is equipped with a rotary atomizer at the bottom; In an apparatus for removing hydrogen sulfide from gas, the apparatus includes an absorption tower that absorbs hydrogen sulfide in gas using an alkaline aqueous solution as an absorption liquid, and a regeneration tower that regenerates the absorption liquid, in which the regeneration tower has a rotary atomizer at the bottom, This is an apparatus for removing hydrogen sulfide from gas, characterized in that it is equipped with a conveyor at the top.

Hereinafter, the conventional method will be explained with reference to FIG. 2, and an embodiment of the apparatus of the present invention will be explained with reference to FIG. 1.

In FIG. 2, a gas containing hydrogen sulfide to be purified is introduced into the absorption tower 1 through a conduit 15, and is brought into countercurrent contact with an oxidation treatment liquid, which will be described later, which is sprayed through a spray pipe 15 at the top of the tower. In the absorption tower 1, hydrogen sulfide reacts with, for example, sodium carbonate to produce sodium hydrogen sulfide.

H2B+ Na2CO3-+ NaH8+ NaHCo
, 3 The absorption liquid flowing out from the absorption tower 1 is collected in the tank 5 through the conduit 6, during which time the quinone dissolved in the absorption liquid and the sodium hydrogen sulfide partially react as shown in the following equation.

In other words, quinone reacts with sodium hydrogen sulfide to form sulfur, and quinone becomes hydroquinone.

The absorption liquid is then fed from the bottom of the regeneration tower 2 via the conduit 21 by the pump 7' and is brought into co-current contact with the air or oxygen-containing gas fed from the compressor 19 to remove the remaining sodium hydrogen sulfide as follows: At the same time as the oxidation of the catalyst, oxidative regeneration of the catalyst takes place.

NaH8+NaHCO3+-02-+ Na2C○,+
The H20+S thus sufficiently regenerated oxidation treatment liquid is collected in the tank 4 through the conduit 22 and circulated by the pump 7 through the conduit 18 to the absorption tower 1 again. The oxidation treatment liquid is led to the tank 4, but sulfur floats to the surface of the tank 4, becomes thick, is removed by the conveyor 12, and is passed through the filter 1.
Collected at 6.

However, according to this method, sulfur does not float sufficiently in the tank 4, and a large amount of sulfur settles in the lower part of the tank 4, which often causes clogging of the conduit 18.

In contrast, the embodiment of the present invention, as shown in FIG.
The process until the absorption liquid is sent to the bottom of the regeneration tower 2 through the conduit 21 is the same as the conventional method shown in FIG. 2, so a description thereof will be omitted.

The air or oxygen-containing gas fed from the compressor 19 is turned into fine bubbles by the rotary atomizer 17' at the bottom of the regeneration tower 2, and is repeatedly reacted with the absorption liquid sent from the bottom of the tower to pass the regeneration tower 2 to the top. It flows.

OOH At this time, sulfur particles generated by the reaction are surrounded by the small bubbles, and there is almost no sulfur floating inside. If the bubbles are not microscopic, they will enlarge due to their own charge, and some will rise and surface with the bubbles.
Some of it is suspended in the liquid, and if there is no flow of liquid, it will settle at the bottom, as in the case of tank 4 in FIG.

This caused clogging of the packing in the absorption tower 1 and clogging of the air diffuser pipe 17 of the regeneration tower 2.

The sulfur particles thus floated on the liquid surface of the regeneration tower 2 along with air bubbles are immediately scraped off by the conveyor 12, passed through a chute, and collected by the filter 16. On the other hand, the oxidized liquid existing immediately below the floating sulfur particles is collected in the tank 4 through the conduit 22 and circulated to the absorption tower 1 again by the pump 7. Here, tank 4 is a conventional tank (as shown in Figure 2).
There is no need for the capacity of the tank 4, and the capacity within which the bonder 7 can be operated is sufficient.

The present invention has discovered that a rotary atomizer with high gas-liquid contact efficiency is excellent in treating the absorption liquid without using a conventional bubble column for oxidation regeneration of the absorption liquid with air or oxygen-containing gas.

Figure 5 shows a regeneration tower using a conventional bubble column B and a rotary atomizer A of the present invention when air (2 m'/h) is brought into contact with an alkaline aqueous solution (40 t) that has produced hydrosulfide containing hydroquinone. It is a graph showing the state of decrease in hydrosulfide ions over time when using. There is clearly a significant difference between the two.

It is clear that Figure 3 is a diffusion-limited reaction related to the rate of supplying oxygen into the liquid film. Therefore, if a regeneration method is adopted that increases the oxygen concentration and increases the contact efficiency between the absorbing liquid and oxygen, the regeneration reaction will occur. It is possible to proceed quickly.

In the present invention, in order to efficiently advance the above-mentioned diffusion-limited reaction, the dispersion diameter of the air or oxygen-containing gas supplied by a rotary atomizer installed at the bottom of the reactor is reduced to increase the gas-liquid surface area and increase the contact efficiency. It uses a regeneration tower.

As shown in FIG. 4, the rotary atomizer rotates a cup-shaped rotating body 2 in liquid at high speed, and continuously feeds air 5 into the cup to cause gas to overflow from the lower end of the cup. The overflowing gas forms a gas layer on the surface of the rotating body due to the centrifugal force effect based on the difference in specific gravity between the gas and the liquid. Since there is a relative velocity between this gas layer and the liquid around the entire rotation,
During this time, the gas layer is torn off by Wi-rubbing, forming fine bubbles and dispersing them in the liquid.

A drive device 5 is required to rotate the rotating body at high speed, but because there are no protrusions on the rotating body and the atmosphere around the rotating body is close to gas, its power consumption is lower than that of ordinary stirring blades. It has the advantage of being extremely rare.

In addition, the fluid that comes into contact with the shaft seal 4 is only gas, and even if the liquid contains solid matter such as sulfur particles, the liquid will not come into contact with the shaft seal, so there is a concern that the shaft seal may be damaged due to solid matter being mixed in. Since there are no pores like in a perforated plate or a porous dispersion cylinder, traps such as hole clogging can be completely avoided.

In other words, in the conventional method, the sulfur generated by oxidation and regeneration using a gas-liquid contact device such as an aeration pipe circulates in the water string at a constant concentration, except for what is separated by the conveyor, and this causes clogging. Ta. However, in the present invention, the above-mentioned troubles are solved because the rotary atomizer takes into consideration the high gas-liquid contact, the high floating ability of the sulfur produced by oxidation and regeneration, and the effective separation by the conveyor, and the rotary atomizer has high reliability and long-term operation. became possible.

[Brief explanation of drawings]

Fig. 1 is a system diagram showing one embodiment of the present invention, Fig. 2 is a system diagram showing a conventional embodiment, Fig. 3 is a diagram showing changes over time of hydrosulfide ions in an alkaline aqueous solution, and Fig. 4 is a diagram showing the present invention. 1 is a schematic diagram of a rotary atomizer used in the invention. Sub-agents 1) Meifuku agent Ryo Hagiwara - Up to Figure 1! L/ Figure 2

Claims (2)

[Claims] (1) In an apparatus for removing hydrogen sulfide from a gas, the regeneration tower is comprised of an absorption tower that absorbs hydrogen sulfide from a gas using an aqueous alkali solution containing hydroquinone as an absorption liquid, and a regeneration tower that regenerates the absorption liquid. A device for removing hydrogen sulfide from gas, characterized in that it is equipped with a rotary atomizer at the bottom. (2) In an apparatus for removing hydrogen sulfide from a gas, the regeneration tower is comprised of an absorption tower that absorbs hydrogen sulfide in the gas using an aqueous alkaline solution containing hydroquinone as an absorption liquid, and a regeneration tower that regenerates the absorption liquid. A device for removing hydrogen sulfide from gas, characterized by comprising a rotary atomizer at the bottom and a conveyor at the top.