Device for separating trace carbon disulfide from hydrogen sulfide and preparation method of carbon disulfide adsorption catalyst

Abstract

The invention belongs to the field of chemical technology innovation, and relates to a device and a method for separating trace carbon disulfide from hydrogen sulfide. A mixed gas of hydrogen sulfide and carbon disulfide enters an adsorption tower device, the carbon disulfide is decomposed into carbon simple substances and sulfur simple substances at the temperature of 175 + / -5 DEG C, then the carbon simple substances and the sulfur simple substances are attached to a porous filler, the hydrogen sulfide gas is not affected and enters a rear-end reaction unit to participate in a reaction, the method does not need participation of a catalyst, the removal rate of the carbon disulfide can reach 99% or above, and the method is suitable for industrial production. The loss rate of hydrogen sulfide is lower than 1%, and meanwhile, the content of carbon disulfide in high-purity hydrogen sulfide gas produced at the rear end is lower than 0.005%.

Description

Technical Field

[0001] This invention belongs to the field of chemical technology innovation and relates to an apparatus and method for separating trace amounts of carbon disulfide from hydrogen sulfide. Background Technology

[0002] Hydrogen sulfide (H2S) is a colorless, highly toxic acidic gas with a typical rotten egg odor. In industry, hydrogen sulfide is an important chemical raw material, and its conversion and utilization have significant value in chemical engineering and materials science. Examples include the synthesis of different series of thiols, its use as a raw material for dimethyl sulfoxide (DMSO), its role as a metal precipitant, and its application in the preparation of optoelectronic materials. Industrial synthesis of hydrogen sulfide primarily employs the hydrogen-sulfur process and the methane-sulfur process. The methane-sulfur process produces carbon disulfide as a byproduct. Although multi-stage distillation columns can remove most of the carbon disulfide, trace amounts remain, affecting the purity of the hydrogen sulfide. This invention patent utilizes an adsorption separation device to separate trace amounts of carbon disulfide from hydrogen sulfide at a specific temperature. Compared to the commonly used industrial carbon disulfide hydrolysis method, this method has a simpler reaction principle, requires no catalyst, and allows for continuous production. Therefore, it represents a reasonable separation device and method. Summary of the Invention

[0003] The purpose of this invention is to address the existing technical challenges by developing a new trace carbon disulfide separation device, which includes a heating unit, an adsorption separation unit, and a regeneration unit.

[0004] The entire device is made of 316L material and can withstand pressure from atmospheric pressure to 8MPa; the adsorption separation device consists of two sets, A and B, with one in use and one on standby.

[0005] The heating unit includes a heat insulation plate and a heating system; the heating system can be one of heat transfer oil, electric heating or gas heating, to achieve temperature control of 30~650℃.

[0006] The adsorption separation unit includes an air inlet, an adsorption separation zone, a support filter, and an air outlet; the raw material gas passes through from bottom to top, and carbon disulfide decomposes into elemental carbon (C) and elemental sulfur (S) at high temperature; support filters are installed at both the upper and lower ends of the adsorption separation zone, and a structured packing is installed between the two support filters. The structured packing is either 904 stainless steel or foamed silicon carbide, and the pore size of the foamed silicon carbide ranges from 5 nm to 200 nm.

[0007] In the adsorption separation unit, three-way valves are installed at the front end of the gas inlet and the rear end of the gas outlet of the separation tower. One end of the three-way valve is connected to the raw material gas pipeline, and the other end is connected to the compressed air pipeline. When the raw material gas is subjected to carbon disulfide adsorption separation, the valve at the front end of the gas inlet is switched to the raw material gas inlet pipeline, and the valve at the rear end of the gas outlet is switched to the hydrogen sulfide buffer tank. The high-purity hydrogen sulfide collected then enters the subsequent reactor to participate in the reaction.

[0008] In the adsorption separation unit, the feed rate of the raw gas is 5~500 kg / h, the purity of the hydrogen sulfide obtained at the outlet is 99.5%~99.9%, and the decomposition temperature of carbon disulfide is 175±5℃.

[0009] In the regeneration unit, the separation efficiency of the device is monitored in real time through online chromatography. High-purity hydrogen sulfide gas in the downstream hydrogen sulfide buffer tank is sampled and analyzed online periodically. When the carbon disulfide content exceeds 0.005%, the feed gas from set A is shut off and feed gas from set B is switched on. At the same time, the compressed air feed pipeline at the inlet of set A is opened, and the heating system is heated to ≥550℃. At high temperature, elemental carbon (C) and elemental sulfur (S) are converted into carbon dioxide (CO2) and sulfur dioxide gas (SO2). Meanwhile, by switching the three-way valve at the outlet to the tail gas absorption pipeline, the by-products are effectively utilized.

[0010] In the regeneration unit, the regeneration temperature is 550~650℃ and the regeneration time is 0.5~24 h.

[0011] The beneficial technical effects of this invention are as follows: trace amounts of carbon disulfide in hydrogen sulfide can be removed using only a simple adsorption separation tower without the need for a catalyst. The device regeneration process is simple, and the exhaust gas generated during regeneration can be incorporated into the exhaust gas treatment device, thus avoiding environmental pollution and enabling multiple uses of resources. This adsorption separation device and method is simple in principle and can operate for a long time, improving the purity of hydrogen sulfide while also facilitating the subsequent product purification process. Attached Figure Description

[0012] Figure 1 This is a simplified internal structure diagram of the adsorption tower device in this invention. Wherein, 1. Gas inlet, 2. Gas outlet, 3. Adsorption separation zone, 4. Supporting filter, 5. Heat insulation plate, 6. Heating system. Detailed Implementation

[0013] The present invention will be further illustrated below through embodiments. It should be noted that the given embodiments should not be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made to the present invention by those skilled in the art based on the content of the present invention should still fall within the scope of protection of the present invention. Example 1 A device for separating trace amounts of carbon disulfide from hydrogen sulfide, with the structure as follows: Figure 1 As shown, the separation device includes a heating unit, an adsorption separation unit, and a regeneration unit. The entire device is made of 316L material and can withstand pressure from atmospheric pressure to 8MPa; the adsorption separation device consists of two sets, A and B, with one in use and one on standby.

[0014] The heating unit includes a heat insulation plate 5 and a heating system 6; the heating system 6 can be one of heat transfer oil, electric heating or gas heating, to achieve temperature control of 30~650℃.

[0015] The adsorption separation unit includes an air inlet 1, an adsorption separation zone 3, a support filter 4, and an air outlet 2; the raw material gas passes through from bottom to top, and carbon disulfide decomposes into elemental carbon (C) and elemental sulfur (S) at high temperature; the adsorption separation zone 3 is equipped with support filters 4 at both the upper and lower ends, and a regular porous packing material with a pore size of 100~200 mm is installed between the two support filters. The porous packing material is foamed silicon carbide.

[0016] The implementation process of the device for separating trace amounts of carbon disulfide from hydrogen sulfide is as follows: Mixed feed gas feeding stage: Three-way valves are installed at the front end of the gas inlet 1 and the rear end of the gas outlet 2 of the separation tower. One end of the three-way valve is connected to the mixed feed gas pipeline and the other end is connected to the compressed air pipeline. When the mixed feed gas is subjected to carbon disulfide adsorption and separation, the valve at the front end of the gas inlet 1 is switched to the mixed feed gas inlet pipeline, and the valve at the rear end of the gas outlet 2 is switched to the hydrogen sulfide buffer tank. The high-purity hydrogen sulfide collected then enters the subsequent reactor to participate in the reaction. Adsorption separation stage: After being metered by a flow meter, the mixed raw material gas enters the adsorption separation unit of the adsorption tower through a three-way valve. The mixed raw material gas passes through the adsorption separation zone 3, which is filled with porous packing, from bottom to top. Under the set pressure and temperature, carbon disulfide begins to be adsorbed and decomposed into carbon elemental (C) and sulfur elemental (S). High-purity hydrogen sulfide gas is collected and enters the downstream hydrogen sulfide buffer tank. Unit regeneration stage: In order to monitor the separation efficiency of the unit in a timely manner, the high-purity hydrogen sulfide in the downstream hydrogen sulfide buffer tank is sampled and analyzed online regularly. When the carbon disulfide content exceeds 0.005%, the feed gas of set A is shut off and set B is used instead. At the same time, the compressed air feed pipeline at the inlet 1 of set A is switched through a three-way valve. The heating system is heated to ≥550℃. At high temperature, elemental carbon (C) and elemental sulfur (S) are converted into carbon dioxide (CO2) and sulfur dioxide gas (SO2). At the same time, the three-way valve at outlet 2 is switched to the tail gas absorption pipeline to realize the effective utilization of by-products.

[0017] Example 2 The apparatus for separating trace amounts of carbon disulfide from hydrogen sulfide in Example 1 was used. The adsorption separation zone 3 was filled with Pall rings made of 904 stainless steel. The heating system 6 controlled the reaction temperature at 170°C. The feed rate of the mixed raw material gas was 400 kg / h, and the carbon disulfide content was 1.0%. After 2 h, the hydrogen sulfide gas in the downstream hydrogen sulfide buffer tank was subjected to chromatographic analysis. The tested and calculated hydrogen sulfide content was 99.67%, and the carbon disulfide content was 0.0025%.

[0018] Example 3 The apparatus for separating trace amounts of carbon disulfide from hydrogen sulfide as described in Example 1 was used. The adsorption separation zone 3 was filled with a compound of 904 stainless steel Pall rings and foamed silicon carbide. The heating system 6 controlled the reaction temperature at 180°C, and the feed rate of the mixed raw material gas was 400 kg / h, with a carbon disulfide content of 1.0%. After 2 hours, the hydrogen sulfide gas in the downstream hydrogen sulfide buffer tank was subjected to chromatographic analysis. The tested and calculated hydrogen sulfide content was 99.78%, and the carbon disulfide content was 0.0015%.

[0019] Example 4 The apparatus for separating trace amounts of carbon disulfide from hydrogen sulfide as described in Example 1 was used. The adsorption separation zone 3 was filled with DN25 ceramic. The heating system 6 controlled the reaction temperature at 180°C. The feed rate of the mixed raw material gas was 400 kg / h, in which the carbon disulfide content was 0.83%. After 2 h, the hydrogen sulfide gas in the downstream hydrogen sulfide buffer tank was subjected to chromatographic analysis. The tested and calculated hydrogen sulfide content was 95.88%, and the carbon disulfide content was 0.2513%.

[0020] Example 5 The apparatus for separating trace amounts of carbon disulfide from hydrogen sulfide as described in Example 1 was used. The adsorption separation zone 3 was filled with 316L Pall rings. The heating system 6 controlled the reaction temperature at 180°C. The feed rate of the mixed raw material gas was 400 kg / h, and the carbon disulfide content was 0.95%. After 2 hours, the hydrogen sulfide gas in the downstream hydrogen sulfide buffer tank was analyzed by chromatography. The tested and calculated hydrogen sulfide content was 92.79%, and the carbon disulfide content was 0.3328%.

[0021] Example 6 Using the apparatus for separating trace amounts of carbon disulfide from hydrogen sulfide as described in Example 1, when the carbon disulfide content in the downstream hydrogen sulfide buffer tank was 0.0053%, the heating system 6 controlled the reaction temperature at 600°C, the compressed air feed rate was 80 kg / h, and after 18 h of reaction, the gas in the tail gas pipeline was sampled and analyzed. The tested and calculated sulfur dioxide content was 1.32%, and the carbon dioxide content was 0.981%.

Claims

1. A separation system for separating carbon disulfide from hydrogen sulfide, characterized in that, include: An adsorption separation unit comprising at least two adsorption towers that can be switched on and operated. A heating unit is used to provide and maintain the required operating temperature for the adsorption tower; A regeneration unit is used to regenerate a saturated adsorption tower.

2. The separation system according to claim 1, characterized in that, The adsorption tower is made of 316L stainless steel and is designed to withstand pressures from atmospheric pressure to 8 MPa.

3. The separation system according to claim 1 or 2, characterized in that, The heating unit includes a heat insulation structure and a heating system, which can be any one of a heat transfer oil system, an electric heating system, or a gas heating system, and can achieve temperature control within the range of 30°C to 650°C.

4. The separation system according to claim 1, characterized in that, Each of the adsorption towers is provided with an air inlet, an air outlet, and an adsorption separation zone located between the two; the two ends of the adsorption separation zone are provided with supporting filter screens, and the space between the two supporting filter screens is filled with regular porous packing material.

5. The separation system according to claim 4, characterized in that, The structured filler is either 904 stainless steel or foamed silicon carbide, and the pore size of the foamed silicon carbide ranges from 5 nm to 200 nm.

6. The separation system according to claim 1, characterized in that, The regeneration unit includes a gas path switching device, which is located at the inlet and outlet of the adsorption tower. The gas path switching device can switch the gas source of the adsorption tower between the raw material gas pipeline and the oxygen-containing gas pipeline, and direct the gas outlet to the product gas collection pipeline or the tail gas treatment pipeline.

7. A method for separating carbon disulfide from hydrogen sulfide using the separation system described in any one of claims 1-6, characterized in that, Includes the following steps: Mixed feed gas feeding stage: Three-way valves are installed at the front end of the gas inlet and the rear end of the gas outlet of the separation tower. One end of the three-way valve is connected to the mixed feed gas pipeline and the other end is connected to the compressed air pipeline. When the mixed feed gas is subjected to carbon disulfide adsorption and separation, the valve at the front end of the gas inlet is switched to the mixed feed gas inlet pipeline and the valve at the rear end of the gas outlet is switched to the hydrogen sulfide buffer tank. The high-purity hydrogen sulfide collected then enters the subsequent reactor to participate in the reaction. Adsorption separation step: Hydrogen sulfide feed gas containing carbon disulfide is introduced into the adsorption separation zone of an adsorption tower. At an operating temperature of 175±5℃, carbon disulfide is thermally decomposed into elemental carbon and elemental sulfur, which are retained in the adsorption separation zone, thereby obtaining hydrogen sulfide gas with improved purity. Regeneration step: When the separation efficiency of the adsorption separation zone drops to a set threshold, the feed gas is stopped, and oxygen-containing gas is introduced into the adsorption tower. The regeneration operation is carried out at a temperature of ≥550℃, so that the retained carbon and sulfur are converted into gaseous oxides and discharged.

8. The method according to claim 7, characterized in that, In the adsorption separation step, the feed rate of the raw gas is 5 kg / h to 500 kg / h, the operating pressure of the adsorption separation zone is atmospheric pressure to 8 MPa, and the purity of the obtained hydrogen sulfide gas is 99.5% to 99.9%.

9. The method according to claim 7, characterized in that, The regeneration temperature in the regeneration step is 550°C to 650°C, and the regeneration time is 0.5 hours to 24 hours; the oxygen-containing substance is compressed air.

10. The method according to claim 7, characterized in that, In the adsorption separation step, the flow direction of the raw gas in the adsorption separation zone is from bottom to top. The criterion for determining the decrease in separation efficiency is: the volume content of carbon disulfide in the hydrogen sulfide gas collected from the outlet of the adsorption tower exceeds 0.005%.

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