Hydrogen sulfide purification system

Abstract

The utility model belongs to the technical field of gas purification, and particularly relates to a hydrogen sulfide purification system. The hydrogen sulfide purification system comprises multiple stages of pre-absorption towers connected in series and multiple stages of absorption towers connected with the multiple stages of pre-absorption towers, and a gas outlet of the last stage of pre-absorption tower of the multiple stages of pre-absorption towers is connected with a gas inlet of the first stage of absorption tower of the multiple stages of absorption towers through a pipeline. A valve is arranged on the pipeline; and booster pumps are arranged in front of the gas inlet and the liquid inlet of the first pre-absorption tower. The hydrogen sulfide purification system disclosed by the utility model consists of the multi-stage pre-absorption tower and the multi-stage absorption tower which are connected in series, and is low in equipment investment, simple to operate and good in purification effect.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the gas purification technical field, concretely relates to a hydrogen sulfide purification system. BACKGROUND

[0002] There are many methods for purifying hydrogen sulfide gas at present, the Chinese patent for invention with publication number CN108392948A discloses a hydrogen sulfide purification process and device, 99.5% hydrogen sulfide product is obtained by adopting alumina, silica gel, zeolite, activated carbon and different molecular sieves to adsorb gas phase impurities to 6-stage pressure swing adsorption of methanol washing acid gas, the Chinese patent for invention with publication number CN105731496A discloses a method for producing sodium bicarbonate from acid gas and purifying hydrogen sulfide, sodium sulfide and sodium bicarbonate are generated by absorbing hydrogen sulfide in acid gas with sodium carbonate as solution, then the sodium sulfide is decomposed by flash evaporation to obtain hydrogen sulfide with purity greater than 99%, the Chinese patent for invention with publication number CN102153053A discloses a method for preparing by-product hydrogen sulfide of carbon disulfide by purifying methane method, hydrogen sulfide and carbon disulfide are obtained by further compression cooling and rectification after desulfurization and distillation of the mixture.

[0003] But it is found in actual research that when the above-mentioned means is used to extract and purify target product, not only the purification process is complex and the investment cost is large, but also the purity of the extracted product is not ideal. INVENTION CONTENTS

[0004] In view of the defects of the prior art, the utility model provides a hydrogen sulfide purification system.

[0005] Specifically, the utility model is realized by the following technology:

[0006] A hydrogen sulfide purification system comprises:

[0007] The last-stage preabsorption tower of the multistage preabsorption tower and the first-stage absorption tower of the multistage absorption tower are connected by a pipeline, and a valve is arranged on the pipeline; a booster pump is arranged in front of the gas inlet and liquid inlet of the first preabsorption tower.

[0008] The liquid level of the absorption tower included in the multistage absorption tower is higher than the liquid level of the preabsorption tower included in the multistage preabsorption tower.

[0009] The multistage preabsorption tower comprises a first preabsorption tower, a second preabsorption tower and a third preabsorption tower; and the multistage absorption tower comprises a first absorption tower and a second absorption tower.

[0010] The hydrogen sulfide purification system described above includes a liquid inlet, a gas inlet, a liquid outlet, and a gas outlet in each of the first pre-absorption tower, the second pre-absorption tower, the third pre-absorption tower, the first absorption tower, and the second absorption tower; wherein the liquid inlet, the gas inlet, and the liquid outlet are located at the bottom of each device, and the gas outlet is located at the top of each device.

[0011] The inlet of the first pre-absorption tower is connected to the carbonization tail gas supply device via a pipeline; the outlet of the first pre-absorption tower is connected to the inlet of the second pre-absorption tower via a pipeline; the outlet of the second pre-absorption tower is connected to the inlet of the third pre-absorption tower via a pipeline; the outlet of the third pre-absorption tower is connected to the inlet of the first absorption tower via a pipeline; the outlet of the first absorption tower is connected to the inlet of the second absorption tower via a pipeline; the outlet of the second absorption tower is connected to the hydrogen sulfide treatment system via a pipeline; the liquid inlets of the first, second, and third pre-absorption towers, the first absorption tower, and the second absorption tower are connected to the yellow water supply equipment via pipelines, and the liquid outlets are connected to the material storage equipment via pipelines; valves are installed on each connecting pipeline.

[0012] In the aforementioned hydrogen sulfide purification system, a gas distributor is installed above the inlet of the first absorption tower and the second absorption tower.

[0013] In the aforementioned hydrogen sulfide purification system, the bottom of the first absorption tower and the second absorption tower are provided with steam inlets, which are connected to a steam supply device.

[0014] In the aforementioned hydrogen sulfide purification system, the top of the multi-stage pre-absorption tower and the multi-stage absorption tower are provided with another gas outlet, which is connected to the hydrogen sulfide treatment system through a pipeline.

[0015] In the aforementioned hydrogen sulfide purification system, a pre-buffer tank, a booster pump, and a flow meter are sequentially installed on the pipeline along the material flow direction before the air inlet and liquid inlet of the first pre-absorption tower.

[0016] In the aforementioned hydrogen sulfide purification system, the booster pump is a plunger-type booster pump.

[0017] On the other hand, this utility model provides a method for purifying hydrogen sulfide, which employs the aforementioned hydrogen sulfide purification system, comprising:

[0018] (1) Yellow water is pumped into the multi-stage pre-absorption tower and the multi-stage absorption tower; wherein the liquid level of the multi-stage absorption tower is higher than the liquid level of the multi-stage pre-absorption tower;

[0019] (2) Close the valve between the outlet of the last stage pre-absorption tower and the inlet of the first stage absorption tower;

[0020] (3) Carbonized tail gas is introduced into the multi-stage pre-absorption tower. The pressure of the carbonized tail gas is controlled by a booster pump. When the last stage pre-absorption tower is saturated with pre-carbonization, the valve is slowly opened. When the last stage pre-absorption tower reaches the end of pre-carbonization, high-purity hydrogen sulfide gas is discharged.

[0021] In the above-mentioned hydrogen sulfide purification method, the rate of introduction of the carbonized tail gas is 30-40 L / min, and the pressure is 0.1-0.3 MPa.

[0022] The technical solution of this utility model has the following beneficial effects:

[0023] (1) The hydrogen sulfide purification system of this utility model consists of a multi-stage pre-absorption tower and a multi-stage absorption tower connected in series. It has low equipment investment, simple operation and good purification effect.

[0024] (2) The hydrogen sulfide purification system of this utility model overcomes the defect that the yellow water cannot reach the carbonization pre-end point due to the solubility and impurity carbon dioxide in the pre-carbonization of the carbonized tail gas before it enters the multi-stage absorption tower, thus greatly improving the purification effect of hydrogen sulfide. Attached Figure Description

[0025] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention.

[0026] Figure 1 This is a schematic diagram of the hydrogen sulfide purification system used in one implementation method;

[0027] Figure 2 This is a schematic diagram of the hydrogen sulfide purification system used in another implementation method. Detailed Implementation

[0028] To fully understand the purpose, features, and effects of this utility model, the following detailed embodiments are provided. Except as described below, the process methods of this utility model employ conventional methods or apparatus in the art. Unless otherwise stated, the terms and expressions used below have the meanings commonly understood by those skilled in the art.

[0029] The terms “first,” “second,” etc., used herein do not indicate any order or importance, but are used to distinguish one element from another. The terms “the,” “the,” “an,” and “a” do not indicate a limitation of quantity, but rather indicate the presence of at least one of the mentioned objects. The terms “preferred,” “more preferred,” etc., refer to embodiments of the present invention that, in certain circumstances, provide certain beneficial effects. However, other embodiments may also be preferred in the same or other circumstances. Furthermore, the description of one or more embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of the present invention.

[0030] To further promote diversified product development, cultivate new economic growth points, and enhance the company's market competitiveness, the applicant intends to use carbonized acid gas (hydrogen sulfide) as one of the main raw materials to produce the downstream product sodium hydrosulfide, thereby reducing costs and improving economic efficiency.

[0031] During the research and development process, the applicant discovered that one of the key factors for success is the need for high-purity hydrogen sulfide gas as a reaction feedstock. However, in traditional carbonization processes, the purity of the acid gas produced is relatively low, containing 15-20% CO2, which can severely impact the production cost and quality of downstream sulfur-based products.

[0032] Based on the production principle of barium carbonate (BaS + CO2 + H2O → BaCO3↓ + H2S↑), this invention pressurizes the relatively high-concentration acidic gas at the tail end of carbonation and then introduces it into a designated series purification and absorption device. The hydrogen sulfide is purified using a multi-stage absorption process with yellow water, which overcomes the defect that the absorption of hydrogen sulfide by yellow water cannot reach the carbonation pre-end point due to solubility and impurity carbon dioxide, and greatly improves the purification effect of hydrogen sulfide.

[0033] Specifically, the present invention provides a hydrogen sulfide purification system comprising: a multi-stage pre-absorption tower connected in series and a multi-stage absorption tower connected to the multi-stage pre-absorption tower; the outlet of the last stage pre-absorption tower of the multi-stage pre-absorption tower is connected to the inlet of the first stage absorption tower of the multi-stage absorption tower via a pipeline, and a valve is provided on the pipeline; a booster pump is provided before the inlet and liquid inlet of the first pre-absorption tower.

[0034] This invention overcomes the defect that the absorption of hydrogen sulfide by yellow water cannot reach the pre-carbonization endpoint due to the solubility and impurities of carbon dioxide, by setting up a booster pump to pre-carbonize the carbonized tail gas under a certain pressure before it enters the multi-stage absorption tower, thus greatly improving the purification effect of hydrogen sulfide.

[0035] More preferably, the booster pump used in this invention is a plunger-type booster pump, which can be purchased from Jinan Simingte Technology Co., Ltd. The plunger-type booster pump has a maximum air volume of 108 L / min and a rated pressure adjustable within the range of 0.4-1 MPa.

[0036] In some preferred embodiments, the liquid level of the absorption tower included in the multi-stage absorption tower is higher than the liquid level of the pre-absorption tower included in the multi-stage pre-absorption tower.

[0037] Setting the liquid level in the absorption tower higher than that in the pre-absorption tower can effectively increase the gas-liquid contact area and reaction time in the absorption tower, which is beneficial to improving the absorption effect of the small amount of carbon dioxide contained in hydrogen sulfide and achieving the expected purification.

[0038] The number of pre-absorption towers connected in series in the multi-stage pre-absorption tower is three or more; the number of absorption towers connected in series in the multi-stage absorption tower is two or more.

[0039] In some preferred embodiments, such as Figure 1 As shown, the hydrogen sulfide purification system 10 of this utility model includes a first pre-absorption tower 1, a second pre-absorption tower 2, a third pre-absorption tower 3, a first absorption tower 4, and a second absorption tower 5 connected in series.

[0040] The first pre-absorption tower 1, the second pre-absorption tower 2, the third pre-absorption tower 3, the first absorption tower 4, and the second absorption tower 5 each include a liquid inlet, an air inlet, a liquid outlet, and an air outlet; wherein the liquid inlet, the air inlet, and the liquid outlet are located below each device, and the air outlet is located at the top of each device.

[0041] The inlet of the first pre-absorption tower 1 is connected to the carbonization tail gas supply device 6 via a pipeline; the outlet of the first pre-absorption tower 1 is connected to the inlet of the second pre-absorption tower 2 via a pipeline; the outlet of the second pre-absorption tower 2 is connected to the inlet of the third pre-absorption tower 3 via a pipeline; the outlet of the third pre-absorption tower 3 is connected to the inlet of the first absorption tower 4 via a pipeline; the outlet of the first absorption tower 4 is connected to the inlet of the second absorption tower 5 via a pipeline; the outlet of the second absorption tower 5 is connected to the hydrogen sulfide treatment system 7 via a pipeline; the liquid inlets of the first pre-absorption tower 1, the second pre-absorption tower 2, the third pre-absorption tower 3, the first absorption tower 4, and the second absorption tower 5 are connected to the yellow water supply device 8 via pipelines, and the liquid outlets are connected to the material storage device 9 via pipelines; and valves are installed on each connecting pipeline.

[0042] In some preferred embodiments, the pre-absorption tower is a separatory tank with dimensions of Φ0.8m*2m, V 容积 =1m 3 .

[0043] The volume of yellow water in the pre-absorption tower is based on the overflow pipe scale.

[0044] In some preferred embodiments, the absorption tower is made of Φ219*4mm stainless steel pipe and has a total height of 5m.

[0045] In some preferred embodiments, a gas distributor is provided above the air inlet of the first absorption tower 4 and the second absorption tower 5, thereby promoting uniform gas distribution and promoting gas-liquid contact reaction.

[0046] In some preferred embodiments, to prevent yellow water crystallization and blockage due to low temperature and to ensure the smooth progress of the experiment, the present invention provides steam inlets at the bottom of the first absorption tower 4 and the second absorption tower 5. The steam inlets are connected to a steam supply device (not shown).

[0047] In some preferred embodiments, such as Figure 2 As shown, the top of the multi-stage pre-absorption tower and the multi-stage absorption tower is provided with another gas outlet, which is connected to the hydrogen sulfide treatment system 7 through a pipeline.

[0048] This invention provides an additional outlet to facilitate the venting of hydrogen sulfide gas from the tower during equipment malfunctions or maintenance.

[0049] In some preferred embodiments, a pre-buffer tank (not shown), a booster pump (not coded), and a flow meter (not shown) are sequentially installed on the pipeline along the material flow direction before the air inlet and liquid inlet of the first pre-absorption tower.

[0050] This invention overcomes gas flow fluctuations by incorporating a pre-buffer tank and a flow meter, ensuring that the carbonized tail gas enters the pre-absorption tower at a stable rate. During experiments, the inventors discovered that after secondary, tertiary, and quaternary absorption, H2S-containing tail gas released both H2S and CO2 simultaneously, with the highest H2S concentration only reaching 66.44%, indicating incomplete CO2 absorption. BaS content testing of the yellow water revealed that under low-pressure conditions, when CO2 and H2S gases coexist, the yellow water struggles to saturate with H2S, exhibiting weak selective absorption and a slow reaction rate. Analysis led the inventors to conclude that system pressure significantly impacts the gas-liquid absorption reaction; excessively low test pressure reduces gas solubility, preventing the yellow water from reaching saturation for H2S absorption and thus failing to reach the carbonization pre-end point.

[0051] In some alternative implementations, the yellow water inlet pipe and the H2S air inlet pipe use the same pipe, which simplifies the equipment and reduces investment costs.

[0052] On the other hand, this utility model also provides a method for purifying hydrogen sulfide, which uses the above-mentioned hydrogen sulfide purification system, including:

[0053] (1) Yellow water is pumped into the multi-stage pre-absorption tower and the multi-stage absorption tower; wherein the liquid level of the multi-stage absorption tower is higher than the liquid level of the multi-stage pre-absorption tower;

[0054] (2) Close the valve between the outlet of the last stage pre-absorption tower and the inlet of the first stage absorption tower;

[0055] (3) Carbonized tail gas is introduced into the multi-stage pre-absorption tower. The pressure of the carbonized tail gas is controlled by a booster pump. When the last stage pre-absorption tower is saturated with pre-carbonization, the valve is slowly opened. When the last stage pre-absorption tower reaches the end of pre-carbonization, high-purity hydrogen sulfide gas is discharged.

[0056] After pre-carbonization saturation, the solution enters a multi-stage absorption tower for absorption. At this time, the barium sulfide solution in the multi-stage absorption tower only absorbs carbon dioxide and no longer absorbs hydrogen sulfide, creating conditions for obtaining high-purity hydrogen sulfide in a short time and improving experimental efficiency.

[0057] In some preferred embodiments, before using the hydrogen sulfide purification system of this invention, the booster pump needs to be tested for air tightness to ensure normal operation and that the instruments are sensitive and reliable.

[0058] In some preferred embodiments, the carbonized exhaust gas is introduced at a rate of 30-40 L / min and at a pressure of 0.1-0.3 MPa.

[0059] In a preferred embodiment, the hydrogen sulfide purification system of this invention includes a first pre-absorption tower 1, a second pre-absorption tower 2, a third pre-absorption tower 3, a first absorption tower 4, and a second absorption tower 5 connected in series. The first absorption tower 4 and the second absorption tower 5 are Φ219 pipes with a total height of 5m and a liquid level of 4m. The total liquid level of the first pre-absorption tower 1, the second pre-absorption tower 2, the third pre-absorption tower 3, the first absorption tower 4, and the second absorption tower 5 is approximately 12.5m.

[0060] The method of this invention purifies carbonized tail gas, reducing the dry basis hydrogen sulfide concentration to ≥99.5%, and the average carbon dioxide concentration after absorption remains stable at ≤0.1%. The sodium hydrosulfide product obtained using the purified hydrogen sulfide as raw material has sodium carbonate content far below national standards, demonstrating the feasibility of the purification process of this invention.

[0061] The present invention is further illustrated below by way of embodiments, but these embodiments do not limit the present invention to the scope of the embodiments described. Experimental methods in the following embodiments, unless otherwise specified, are performed according to conventional methods and conditions.

[0062] use Figure 1 The hydrogen sulfide purification system shown purifies carbonized tail gas. In this system, a pre-buffer tank, a booster pump, and a flow meter are sequentially installed on the pipeline along the material flow direction before the air inlet and liquid inlet of the first pre-absorption tower.

[0063] (1) Before use, the H2S booster pump should be tested for air tightness to ensure normal operation and that the instruments are sensitive and reliable.

[0064] (2) Connect the booster pump to the test process to ensure that it meets the process design requirements.

[0065] (3) Check that all preparations, such as the smooth operation of the process, safety and environmental protection, and operability, are in place.

[0066] (4) The yellow water inlet pipe and the H2S inlet pipe use the same pipe, and yellow water is pumped into the first pre-absorption tower, the second pre-absorption tower, the third pre-absorption tower, the first absorption tower, and the second absorption tower, respectively. The concentration of the yellow water is 120-130 g / L; the volume of yellow water in the first, second, and third pre-absorption towers is 0.7 m³. 3 The liquid level is 0.8m; the volume of yellow water in the first absorber and the second absorber is 0.17m³. 3 The liquid level is 4.5m.

[0067] (5) Start the booster pump to deliver carbonized tail gas at a rate of 30-40 L / min. Detect the composition of the carbonized tail gas multiple times. The test data is shown in Table 1. Pay attention to adjusting and observing the pump outlet pressure. Close the valve between the third pre-absorption tower and the first absorption tower so that the carbonized tail gas enters the first pre-absorption tower, the second pre-absorption tower, and the third pre-absorption tower in sequence.

[0068] Table 1 Carbonized exhaust gas detection data

[0069]

[0070] (6) As time progresses, the system pressure slowly rises, and the yellow water pre-carbonization in the first, second, and third pre-absorption towers is saturated in sequence. After the pre-carbonization in the third pre-absorption tower reaches its endpoint, the H2S valve between the third pre-absorption tower and the first absorption tower is slowly opened to allow gas to enter the first and second absorption towers. The carbonization changes in the first and second absorption towers are continuously monitored. When the pre-carbonization in the second absorption tower reaches its endpoint, high-purity hydrogen sulfide gas is discharged. After multiple sampling analyses, the average CO2 concentration in the high-purity hydrogen sulfide gas is 0.0179%.

[0071] This utility model has been disclosed above with preferred embodiments. However, those skilled in the art should understand that these embodiments are only for illustrating this utility model and should not be construed as limiting its scope. It should be noted that all equivalent variations and substitutions to these embodiments should be considered to be covered within the scope of the claims of this utility model. Therefore, the scope of protection of this utility model should be determined by the scope defined in the claims.

Claims

1. A hydrogen sulfide purification system, characterized in that, include: A multi-stage pre-absorption tower connected in series and a multi-stage absorption tower connected to the multi-stage pre-absorption tower, wherein the outlet of the last stage of the multi-stage pre-absorption tower is connected to the inlet of the first stage of the multi-stage absorption tower via a pipeline, and a valve is provided on the pipeline; a booster pump is provided before the inlet and liquid inlet of the first pre-absorption tower.

2. The hydrogen sulfide purification system according to claim 1, characterized in that, The liquid level of the absorption tower included in the multi-stage absorption tower is higher than the liquid level of the pre-absorption tower included in the multi-stage pre-absorption tower.

3. The hydrogen sulfide purification system according to claim 1, characterized in that, The multi-stage pre-absorption tower includes a first pre-absorption tower, a second pre-absorption tower, and a third pre-absorption tower; the multi-stage absorption tower includes a first absorption tower and a second absorption tower.

4. The hydrogen sulfide purification system according to claim 3, characterized in that, The first pre-absorption tower, the second pre-absorption tower, the third pre-absorption tower, the first absorption tower, and the second absorption tower all include a liquid inlet, a gas inlet, a liquid outlet, and a gas outlet; wherein, the liquid inlet, the gas inlet, and the liquid outlet are located at the bottom of each device, and the gas outlet is located at the top of each device; The inlet of the first pre-absorption tower is connected to the carbonization tail gas supply device via a pipeline; the outlet of the first pre-absorption tower is connected to the inlet of the second pre-absorption tower via a pipeline; the outlet of the second pre-absorption tower is connected to the inlet of the third pre-absorption tower via a pipeline; the outlet of the third pre-absorption tower is connected to the inlet of the first absorption tower via a pipeline; the outlet of the first absorption tower is connected to the inlet of the second absorption tower via a pipeline; the outlet of the second absorption tower is connected to the hydrogen sulfide treatment system via a pipeline; the liquid inlets of the first, second, and third pre-absorption towers, the first absorption tower, and the second absorption tower are connected to the yellow water supply equipment via pipelines, and the liquid outlets are connected to the material storage equipment via pipelines; valves are installed on each connecting pipeline.

5. The hydrogen sulfide purification system according to claim 4, characterized in that, Gas distributors are installed above the air inlets of the first and second absorption towers.

6. The hydrogen sulfide purification system according to claim 4, characterized in that, The bottom of the first absorption tower and the second absorption tower are provided with steam inlets, which are connected to steam supply equipment.

7. The hydrogen sulfide purification system according to claim 3, characterized in that, The top of the multi-stage pre-absorption tower and the multi-stage absorption tower are provided with another gas outlet, which is connected to the hydrogen sulfide treatment system through a pipeline.

8. The hydrogen sulfide purification system according to claim 3, characterized in that, A pre-buffer tank, a booster pump, and a flow meter are sequentially installed on the pipeline along the material flow direction before the air inlet and liquid inlet of the first pre-absorption tower.

9. The hydrogen sulfide purification system according to claim 8, characterized in that, The booster pump is a plunger-type booster pump.

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