KR20030006120A - Absorbing method of hydrogen sulfide in coke oven gas - Google Patents

Abstract

PURPOSE: Provided is a method for absorbing hydrogen sulfide contained in coke oven gas, wherein a predetermined amount of surfactant is added to a liquid adsorbent, ammonia liquor, to maintain surface tension of the absorbent, thereby increasing vapor-liquid contact efficiency and hydrogen sulfide absorptivity of the liquid absorbent. CONSTITUTION: The method comprises the steps of (a) supplying liquid absorbent into a hydrogen sulfide absorption tower(10) after mixing 0.1¬3 to 0.5¬3 of surfactant with 10 m¬3 of ammonia liquid and adjusting vapor-liquid ratio between coke oven gas(70) and the liquid absorbent in a range of 1.5 to 1.7, (b) circulating the liquid absorbent in the hydrogen sulfide absorption tower(10) while maintaining a vapor-liquid contact time to 5-10 minutes at the top of the hydrogen sulfide absorption tower(10), (c) regenerating ammonia and the surfactant using a regeneration tower after transferring the liquid absorbent drawn from a lower portion of the hydrogen sulfide absorption tower to the regeneration tower, and (d) collecting liquid sulfide from acid gas discharged from an upper portion of the hydrogen sulfide absorption tower(10) by a desulfurization process.

Description

Absorption method of hydrogen sulfide in coke oven gas}

The present invention relates to a hydrogen sulfide absorption method capable of improving the absorption rate of hydrogen sulfide in the coke oven gas. More specifically, the present invention can improve the absorption rate of hydrogen sulfide by adding a certain amount of surfactant in the absorbent liquid, maintaining the surface tension of the absorbent liquid as a constant value to improve the gas-liquid contact efficiency in the filling in the hydrogen sulfide absorption tower. It relates to a method of absorbing hydrogen sulfide.

The hydrogen sulfide contained in the coke oven gas is absorbed by the absorbing liquid in the hydrogen sulfide absorption tower, and then hydrogen sulfide is separated in a conventional distillation column and transferred to the Klaus desulfurization process to convert a portion of the hydrogen sulfide into sulfur dioxide, and the ratio of hydrogen sulfide and sulfur dioxide in the gas. Is recovered to 2: 1 by converting the liquid sulfur into a high temperature catalytic reactor. In this step, as shown schematically in FIG. 1, in the case where the coke oven gas 70 passes through the hydrogen sulfide absorption tower 10, ordination as an absorption liquid for absorbing hydrogen sulfide is referred to the hydrogen sulfide absorption tower 10. Connected to the lower portion of the hydrogen sulfide absorption tower 10 in order to circulate to the Joan water tank 20 for recovering the ordination liquid absorbed therefrom, the joan water tank 20 is connected to the joan water tank to receive the water vapor (30) Hydrogen sulfide collection solution manufacturing tower 40 to react with the), a non-hydrogen water tank (50) for collecting the agricultural water discharged from the hydrogen sulfide collection solution manufacturing tower 40, the non-hydrogen tank 50 is again It is connected to the upper portion of the hydrogen sulfide absorption tower 10 to continuously circulate the ordination, and also in the upper portion of the hydrogen sulfide collection solution can be transferred to the Klaus desulfurization process part of the circulated ordination. It is rock configuration.

At this time, in the hydrogen sulfide absorption tower 10, ordination (wastewater containing a large amount of ammonia gas) is used as an absorption liquid, but ammonia in the ordination is a highly volatile substance, and when ammonia is volatilized into a gas, the ordination as a liquid and gas In a film in which mass transfer between hydrogen sulfides in the coke oven gas 70 is formed, ammonia in the ordination may not be uniformly distributed on the surface of the coating, resulting in a small gas-liquid contact area, and a decrease in the gas-liquid contact area immediately occurs. This leads to a problem of lowering the absorption rate of hydrogen sulfide in 70).

The volatility of the ammonia gas in the ordination depends on the latent heat of the ordination and the coke oven gas 70, and the hydrogen sulfide absorption rate can be continuously maintained by lowering the temperature of the ordination as the absorption liquid and the temperature of the coke oven gas 70 as much as possible. However, in order to maintain the temperature of the ordination and the coke oven gas 70 as an absorbent liquid at a low temperature, it is not economical to install an additional cooling device and continuously operate it, and it is expensive to maintain, and a cooling device The breakdown of Hb directly causes the hydrogen sulfide absorption rate to drop.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for absorbing hydrogen sulfide in coke oven gas, which can increase the gas-liquid contact area between ordination and coke oven gas by increasing a surface tension of the ordination by adding a surfactant to the ordination, thereby increasing the absorption rate of hydrogen sulfide. will be.

1 is a process diagram schematically showing a process for absorbing hydrogen sulfide in a conventional coke oven gas.

2 is a process diagram schematically showing a process for absorbing hydrogen sulfide in the coke oven gas according to the present invention.

※ Explanation of code for main part of drawing

10: hydrogen sulfide absorption tower 20: Joan water tank

30: water vapor 40: hydrogen sulfide collection solution manufacturing tower

50: non-depleted water tank 60: surfactant tank

70: coke oven gas

In the method for absorbing hydrogen sulfide in coke oven gas according to the present invention, in absorbing hydrogen sulfide in coke oven gas by contact between ordination and coke oven gas, (1) 0.1 to 0.5m 3 of surfactant per 10m 3 of ordination as an absorbent liquid Surfactant supply step of supplying to the hydrogen sulfide absorption tower by mixing to adjust the liquid ratio between the coke oven gas and the absorption liquid to 1.5 to 1.7; (2) a gas-liquid contact step of circulating the absorbent liquid so that the water-absorbed liquid is maintained at the top of the hydrogen sulfide absorption tower for 5 to 10 minutes; (3) regenerating the absorbing liquid containing hydrogen sulfide and the surfactant flowing out from the hydrogen sulfide absorption tower to the regeneration tower to regenerate the ammonia and the surfactant in the absorption liquid; And (4) a sulfur collection step of removing liquid ammonia and surfactant in the absorbent liquid to produce liquid sulfur through a desulfurization process of acid gas flowing out of the regeneration tower.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As schematically shown in Fig. 2, the method for absorbing hydrogen sulfide in the coke oven gas according to the present invention is a mass transfer between hydrogen sulfide in the coke oven gas 70 as a liquid and volatilization of ammonia in the ordination as an absorbent liquid. In the film to be formed, ammonia in the ordination is not uniformly distributed on the surface of the film, so that the gas-liquid contact area becomes small, and the gas-liquid contact area decreases, thereby reducing the absorption of hydrogen sulfide in the coke oven gas 70. A surfactant is added to increase the surface tension of the absorbent liquid and to increase the gas-liquid contact area between the ordination and the coke oven gas 70 to increase the absorption rate of hydrogen sulfide.

Referring to FIG. 2 again, in passing the coke oven gas 70 through the hydrogen sulfide absorption tower 10, the ordination as an absorption liquid for trapping hydrogen sulfide is circulated based on the hydrogen sulfide absorption tower 10. Connected to the lower portion of the hydrogen sulfide absorption tower (10) is connected to the joan water tank (20) for recovering the ordination water is discharged therefrom, the joan water tank (20) is supplied with the joan water to react with the steam (30) Hydrogen sulphide collection solution manufacturing tower 40, consisting of a non-hydrogen water tank (50) for collecting the farming water discharged from the hydrogen sulfide collection solution manufacturing tower 40, the agricultural water tank (50) is the hydrogen sulfide absorption tower ( It is connected to the upper part of 10) to continuously circulate the ordination, and also in the upper portion of the hydrogen sulfide collection solution is configured to transfer a portion of the circulated ordination to the Klaus desulfurization process In the hydrogen sulfide absorption process, the surfactant tank 60 and the hydrogen sulfide absorption tower 10 are further connected between the non-hydrogen sulfide tank 50 to release the surfactant from the surfactant tank 60 to release the non-hydrophobic tank 50 It is configured to further add a surfactant to the ordination supplied to the hydrogen sulfide absorption tower (10) from.

The ammonia in the ordinal water, which is originally an absorbent liquid, tends to be volatilized, and the volatilization of the ammonia becomes higher as the temperature of the absorbent liquid increases. In order to lower the volatility of the ammonia in the absorbent liquid, it is necessary to lower the temperature of the absorbent liquid and the temperature of the coke oven gas 70, but this requires a separate cooling device, which is a problem such as economic burden and difficulty in maintenance. In the present invention, by simply including a surfactant in the ordination to supply the ordination containing the surfactant to the hydrogen sulfide absorption tower 10 to increase the gas-liquid contact area between the ordination and the coke oven gas 70 to increase the absorption rate of hydrogen sulfide It is characterized by one point.

The surfactant added to the absorbent liquid may include all common surfactants including a hydrophilic portion and a hydrophobic portion in one molecule, preferably a mixture of polyoxyethylene and sorbitan monolaurate (trade name; Tween 20 20)) can be used.

The amount of the surfactant added to the absorbent liquid is preferably an amount of 0.1 to 0.5 m 3 of the surfactant per 10 m 3 of ordination which is the absorbent liquid. In this concentration range, the surfactant forms a film on the surface of the ammonia molecule in the ordination to prevent volatilization of ammonia, thereby promoting the reaction between the ammonia in the ordination and hydrogen sulfide in the coke oven gas 70 to improve the hydrogen sulfide absorption rate. When the amount of the surfactant is less than 0.1 m 3, there may be a problem that the appropriate film formation is not made, so that the effect of inhibiting ammonia volatilization is less, on the contrary, when the amount of the surfactant exceeds 0.5 m 3, hydrogen sulfide in the coke oven gas 70 and There may be a problem that the chemical reaction between ammonia in the ordination does not occur sufficiently.

The liquid ratio between the coke oven gas 70 and the absorbent liquid is preferably adjusted to 1.5 to 1.7. This makes it possible to minimize the amount of the absorbing liquid used while absorbing hydrogen sulfide in the coke oven gas 70 and to reduce the operating cost by reducing the flow rate of circulating water. If the liquid ratio is less than 1.5, there may be a problem that the absorption rate of the hydrogen sulfide is too low, on the contrary, if it exceeds 1.7, there is a disadvantage in that the operating cost is increased by excessively using the absorption liquid without improving the absorption rate of hydrogen sulfide. It is only.

The ordination, which is the absorbent liquid, is preferably circulated in the absorbent liquid such that the gas-liquid contact time is maintained at the top of the hydrogen sulfide absorption tower 10 for 5 to 10 minutes. This is because the absorption rate of hydrogen sulfide can be increased by selectively absorbing only hydrogen sulfide among carbon dioxide and hydrogen sulfide contained in the coke oven gas 70. Most of the coke oven gas 70 containing a high concentration of hydrogen sulfide is absorbed by ammonia in the ordinal water in the hydrogen sulfide absorption tower 10, but the coke oven gas 70 flows from the bottom to the top of the coke oven gas 70. The content of hydrogen sulfide in the water is reduced, making it difficult to selectively absorb hydrogen sulfide to carbon dioxide. Accordingly, by recirculating the ordination in the upper portion of the hydrogen sulfide absorption tower 10, the instantaneous chemical reaction between hydrogen sulfide and ammonia occurs, so that the hydrogen sulfide absorption rate is increased. Because it can increase.

In the hydrogen sulfide absorption tower 10, if the gas-liquid contact time becomes too long for more than 10 minutes, the reaction with carbon dioxide occurs before hydrogen sulfide, and the absorption rate of hydrogen sulfide is lowered. If the hydrogen sulfide becomes too short for less than 5 minutes, ammonia and coke in ordination Hydrogen sulfide in the oven gas 70 may be insufficient to cause a sufficient chemical reaction, there is also a problem that the absorption rate of hydrogen sulfide is lowered.

Subsequently, the surfactant added to the absorption liquid in feeding the absorption liquid containing hydrogen sulfide and surfactant flowing out from the hydrogen sulfide absorption tower 10 to the regeneration tower to regenerate the ammonia and the surfactant in the absorption liquid is in the temperature range of the regeneration tower. In the coke oven gas 70 may be recycled to absorb hydrogen sulfide in the coke oven gas 70.

Hereinafter, preferred embodiments and comparative examples of the present invention will be described.

The following examples are intended to illustrate the invention and should not be understood as limiting the scope of the invention.

Example 1

While maintaining the liquid ratio, the amount of surfactant, liquid ratio, and gas-liquid contact time were measured as shown in Table 1, and hydrogen sulfide absorption rate and carbon dioxide absorption rate were measured, and the results are also shown in Table 1 below.

Amount of Surfactant (㎥ / Ordination 10㎥) Liquid Gas-liquid contact time (minutes) Hydrogen sulfide absorption rate (%) CO2 absorption rate (%) 0 1.5 5 84 35 0.1 1.5 5 91 28 0.3 1.5 5 95 24 0.5 1.5 7 93 25 1.0 1.5 7 82 26

As the amount of surfactant in the ordination is changed, the hydrogen sulfide absorption rate is changing. If the amount of the surfactant is too large, it can be seen that the hydrogen sulfide absorption rate is lowered than when the surfactant is not added. In the range of 0.1 to 0.5 ㎥ of surfactant amount of hydrogen sulfide absorption rate was more than 90%, especially in the case of 0.3 ㎥ hydrogen sulfide absorption rate shows the maximum value, it was confirmed that the carbon dioxide absorption rate shows the minimum value.

Example 2

While keeping the amount of surfactant relatively constant, the amount of surfactant, liquid ratio, gas-liquid contact time was measured as shown in Table 2, hydrogen sulfide absorption rate and carbon dioxide absorption rate was also shown in Table 2 below.

Amount of Surfactant (㎥ / Ordination 10㎥) Liquid Gas-liquid contact time (minutes) Hydrogen sulfide absorption rate (%) CO2 absorption rate (%) 0.1 1.0 5 86 39 0.1 1.5 5 93 30 0.3 1.7 5 96 22 0.5 2.0 7 89 40

When a certain surfactant is added, the hydrogen sulfide absorption rate increases as the liquid ratio increases, and the absorption rate of carbon dioxide decreases. In the range of the liquid ratio of 1.5 to 1.7, the hydrogen sulfide absorption rate is 90% or more, and the absorption rate for carbon dioxide is also markedly lower than other conditions.

Example 3

While maintaining a relatively constant liquid ratio, the amount of surfactant, liquid ratio, gas-liquid contact time was measured as shown in Table 3, hydrogen sulfide absorption rate and carbon dioxide absorption rate was also shown in Table 3 below.

Amount of Surfactant (㎥ / Ordination 10㎥) Liquid Gas-liquid contact time (minutes) Hydrogen sulfide absorption rate (%) CO2 absorption rate (%) 0.1 1.5 One 84 45 0.3 1.5 3 86 39 0.3 1.5 5 92 33 0.5 1.7 7 93 25 0.5 1.7 10 94 22 0.5 1.7 15 89 44

As the gas-liquid contact time increases, the hydrogen sulfide absorption rate increases (from 86% to 92%), but the carbon dioxide absorption rate decreases. Particularly, when the liquid ratio is 1.7 and the gas-liquid contact time is 10 minutes, the hydrogen sulfide absorption rate shows the maximum value and the carbon dioxide absorption rate shows the minimum value.

As a result of the synthesis of the above embodiments, according to the present invention, the surfactant per 10 m 3 of the ordinal liquid absorbed according to the present invention is mixed in an amount of 0.1 to 0.5 m 3, and the liquid ratio between the coke oven gas 70 and the absorbed liquid is adjusted to 1.5 to 1.7. It can be seen that water sulfide, which is an absorbent liquid, can effectively absorb hydrogen sulfide by circulating the absorbent liquid so that the gas-liquid contact time is maintained at the top of the hydrogen sulfide absorption tower 10 at 5 to 10 minutes.

Therefore, according to this invention, it is effective to provide the method which can collect | recover hydrogen sulfide effectively by adding surfactant and adjusting an absorption condition suitably.

Although the present invention has been described in detail only with respect to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the technical scope of the present invention, and such modifications and modifications are within the scope of the appended claims.

Claims (1)

In absorbing hydrogen sulfide in coke oven gas by contact between ordination and coke oven gas, (1) a surfactant supplying step of supplying a hydrogen sulfide absorption tower by controlling a liquid ratio between coke oven gas and an absorption liquid to 1.5 to 1.7 by mixing a surfactant per 10 m 3 of ordination, which is an absorption liquid, in an amount of 0.1 to 0.5 m 3; (2) a gas-liquid contact step of circulating the absorbent liquid so that the water-absorbed liquid is maintained at the top of the hydrogen sulfide absorption tower for 5 to 10 minutes; (3) regenerating the absorbing liquid containing hydrogen sulfide and the surfactant flowing out from the hydrogen sulfide absorption tower to the regeneration tower to regenerate the ammonia and the surfactant in the absorption liquid; And (4) a sulfur collection step of removing liquid ammonia and surfactant in the absorbent liquid to produce liquid sulfur through a desulfurization process of the acid gas flowing out of the regeneration tower; Method for absorbing hydrogen sulfide in coke oven gas, characterized in that made.