Integrated device for preparing hydrogen sulfide through self-circulation drainage catalytic reduction

Abstract

The invention relates to an integrated device for preparing hydrogen sulfide through self-circulation drainage catalytic reduction. The integrated device comprises a catalytic reduction section (1), a Venturi jet device and a product gas backflow unit (7), the catalytic reduction section (1) is provided with an SO2 reduction catalyst packing layer, raw material gas is sprayed into the device through a raw material gas inlet at a high speed at a subsonic flow speed, sulfide product gas obtained by catalytic reduction conversion of SO2 is partially refluxed by negative pressure generated under high-speed jet flow and flows out through an outlet (4) of the venturi type jet device, and the tail gas of the venturi type jet device is discharged through an outlet (5) of the venturi type jet device. And the mixed gas is fully mixed with raw material gas and then drained to the bottom of the catalytic reduction section (1), and high-concentration hydrogen sulfide product gas is prepared through efficient reduction conversion of SO2 under the action of a catalyst based on the reverse disproportionation reaction principle of sulfur. Compared with the prior art, operation energy consumption can be reduced, economic and environmental benefits are improved, and the method has good application and popularization prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of environmental protection, and in particular relates to an integrated device for preparing hydrogen sulfide by self-circulating drainage catalytic reduction. Background Art

[0002] The sulfidation method is a commonly used method for treating heavy metals in waste acid. The main measure is to add sodium sulfide, hydrogen sulfide, ferrous sulfide and other reagents to the acidic arsenic-containing waste liquid. However, the addition of sodium sulfide and ferrous sulfide will introduce a large amount of sodium ions and ferrous ions into the solution, affecting the quality of the recovered acid and arsenic slag. In the non-ferrous industry, the use of flue gas sulfur dioxide reduction to produce H2S to treat heavy metals in waste acid can directly remove arsenic with hydrogen sulfide, which can avoid the introduction of other cations and is conducive to the recovery of acid. How to safely and economically produce H2S for the removal of heavy metals in waste acid in the smelting industry has become a hot topic of research. Therefore, if a new device can be designed to rationally utilize sulfur dioxide and natural gas to produce hydrogen sulfide, it will have good application prospects.

[0003] Invention Publication No. CN103626134B discloses a hydrogen sulfide generator for hydrogen sulfide production. The hydrogen sulfide generator in the invention uses sodium sulfide as a raw material to produce hydrogen sulfide. Invention Publication No. CN212102450U discloses a microbial hydrogen sulfide generator for waste acid sulfidation precipitation. The hydrogen sulfide generator in the invention uses a microbial sulfate reduction method to produce hydrogen sulfide, but the above two devices cannot be heated, have no self-circulation system and no matching jet device. Invention Publication No. CN110479026B discloses a method and system for in-situ preparation of hydrogen sulfide for treating arsenic-containing wastewater. The hydrogen sulfide production system in the invention uses an activated carbon bed to absorb sulfur dioxide and then heats and washes to collect the generated hydrogen sulfide, but the invention does not have a self-circulation system and a matching jet device, so there are problems such as low conversion efficiency and unstable operation. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide an integrated device for preparing hydrogen sulfide by self-circulating drainage catalytic reduction. The device has a simple structure, does not produce waste liquid, has high hydrogen sulfide preparation efficiency, and operates stably and reliably.

[0005] The object of the present invention can be achieved by the following technical scheme: an integrated device for preparing hydrogen sulfide by self-circulating drainage catalytic reduction, comprising a catalytic reduction section, a Venturi-type injection device and a product gas reflux unit; the catalytic reduction section is provided with a SO2 reduction catalyst packing layer, the product gas reflux unit is arranged in the packing layer, the bottom of which is connected to the Venturi-type injection device, the top passes through the catalytic reduction section, and a sulfide product gas reflux port is arranged, the side of the Venturi-type injection reflux device is connected to the raw gas inlet, and the bottom is provided with a Venturi-type injection device outlet, the raw gas is injected into the device at a subsonic flow rate through the raw gas inlet, the negative pressure generated under the high-speed jet partially refluxes the sulfide product gas converted by the catalytic reduction of SO2, and flows out through the outlet of the Venturi-type injection device, and then is fully mixed with the raw gas and then guided to the bottom of the catalytic reduction section, based on the reverse disproportionation reaction principle of sulfur and under the action of the catalyst, SO2 is efficiently reduced and converted to prepare a high-concentration hydrogen sulfide product gas, which can then be used for the subsequent waste acid heavy metal removal purification process.

[0006] Furthermore, the SO2 reduction catalyst loaded in the catalytic layer of the catalytic reduction section is commercial active γ-alumina, and a catalytic material modified by hydrothermal, impregnation and other methods. The modified components used include active metals such as Ti / Zr, Co / Mo or Ni / Mo. The filling amount of the filler layer is determined according to the air velocity ratio, and the air velocity ratio is 200-1500h -1 .

[0007] Furthermore, the Venturi-type jet reflux device is composed of a nozzle, a throat and a diffuser.

[0008] The nozzle diameter of the Venturi injection device is 9-15mm, and the gas flow rate of the nozzle is 200-300m / s, reaching the subsonic level; the throat diameter at the nozzle is 15-20mm, and the gas flow rate of the throat is 70-100m / s.

[0009] Furthermore, the Venturi-type injection device has a detachable sealing clamp fixing module, which can be easily removed and pulled out during maintenance to replace the nozzle; at the same time, the nozzle can be kept fixed during operation and kept on a concentric axis with the center of the throat, so that the Venturi effect is optimized.

[0010] Furthermore, the Venturi-type injection device comprises a secondary Venturi-type injection device and a primary Venturi-type injection device arranged up and down;

[0011] The raw gas inlet includes a primary raw gas inlet and a secondary raw gas inlet. The secondary venturi-type injection device is connected to the primary raw gas inlet. The primary venturi-type injection device is connected to the secondary raw gas inlet. The top of the secondary venturi-type injection device is connected to the product gas reflux unit. The bottom of the primary venturi-type injection device is connected to the outlet of the venturi-type injection device.

[0012] Furthermore, the pressure drop generated by the product gas reflux unit under the jet action of the Venturi-type injection device is 1000-2500 Pa.

[0013] Furthermore, the product gas reflux unit guides the reduction product sulfide gas to the bottom of the catalytic reduction section through self-circulation with a reflux ratio of 1:10 to 1:3, that is, 10 to 33% of the reduction product mixed gas is refluxed, and the refluxed sulfide gas induces the newly input raw gas to undergo an efficient catalytic reduction reaction under the action of the catalyst.

[0014] Furthermore, the raw gas is a mixed gas of sulfur dioxide and methane gas.

[0015] Furthermore, the catalytic reduction section has 4 to 6 filler layers, and the catalytic reduction reaction temperature is 500 to 700°C.

[0016] Furthermore, the main body material of the catalytic reduction section, the Venturi injection device and the product gas reflow unit is 304H or 310S stainless steel.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0018] 1) The present invention adopts an integrated device, whose outer shell is a sealed shell, a product outlet is arranged on the top, a raw gas inlet is arranged on the bottom, a catalyst layer is arranged in the middle of the shell, the top of the catalyst layer is a product gas and reflux zone, the bottom of the catalyst layer is a raw gas and reflux gas mixing zone, and a Venturi-type jet reflux device is arranged at the bottom of the catalyst layer. By controlling the speed of the raw gas introduced into the raw gas inlet and combining the Venturi-type jet reflux device, a strong negative pressure is formed, and the top product gas part is returned through the product gas reflux unit, and after mixing with the raw gas, it is ejected from the outlet of the bottom Venturi-type jet device, forming a self-induced internal circulation process with good sealing performance, negative pressure production, prevention of hydrogen sulfide leakage, and higher safety.

[0019] 2) The device of the present invention is conducive to reducing heat loss through the internal circulation process, thereby reducing energy consumption during the operation process, and the catalyst bed has good stability and can operate continuously, which is conducive to practical industrial applications.

[0020] 3) The overall structure is simple, compact, economical and practical. The hydrogen sulfide product gas is more conducive to its activation of the reaction materials through the internal circulation process, thereby increasing the preparation efficiency of the hydrogen sulfide product gas. The operation is stable and reliable, and has good application prospects. The self-circulation drainage method promotes the efficient reduction and conversion of sulfur dioxide, and the conversion efficiency of SO2 can reach more than 97%, reducing the operating energy consumption (the existing technology is generally 10kW / Kg-H2S, and this application can be reduced to less than 1kW / Kg-H2S), and the operation is stable and reliable (can continue to operate for more than 2000 hours), improving economic and environmental benefits, and has good application and promotion prospects.

[0021] 4) The device of the present invention is used to prepare hydrogen sulfide, which has a simple method, is easy to operate and implement, has a low production cost, and is suitable for large-scale production in enterprises. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the main reaction device structure of the present invention;

[0023] Description of the markings in the figure:

[0024] 1—catalytic reduction section, 2—primary raw gas inlet, 3—secondary raw gas inlet, 4—venturi injection device outlet, 5—primary venturi injection device, 6—secondary venturi injection device, 7—product gas reflux unit, 8—sulfide product gas reflux port, 9—hydrogen sulfide product gas outlet. DETAILED DESCRIPTION

[0025] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0026] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0027] In conjunction with the accompanying drawings, some embodiments of the present invention are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0028] In the following embodiments, if there is no special description of raw materials or processing technology, it means that they are all conventional commercially available raw materials or conventional processing technologies in the field. If there is no special description of functional components or structures, it means that they are all conventional components or conventional structures used in the field to achieve corresponding functions.

[0029] like Figure 1As shown, an integrated device for preparing hydrogen sulfide by self-circulation drainage catalytic reduction includes a shell, a catalytic reduction section 1, a venturi-type injection device and a product gas reflux unit 7. The catalytic reduction section 1 is located in the middle position inside the shell, the top of the catalytic layer is the product gas and reflux zone, the bottom of the catalytic layer is the raw gas and reflux gas mixing zone, the catalytic reduction section 1 is provided with a SO2 reduction catalyst packing layer, the product gas reflux unit 7 is arranged in the middle of the packing layer of the catalytic reduction section 1, and passes through the packing layer, the bottom of which is connected to the venturi-type injection device, the top passes through the catalytic reduction section 1 to connect to the hydrogen sulfide product gas outlet 9, and a sulfide product gas reflux port 8 is provided at the top of the product gas reflux unit 7.

[0030] The SO2 reduction catalyst loaded in the catalytic layer of the catalytic reduction section (1) is commercial active γ-alumina, or a catalytic material modified by hydrothermal, impregnation or other methods. The modified components used include active metals such as Ti / Zr, Co / Mo or Ni / Mo. The filling amount of the filler layer is determined according to the air velocity ratio, and the air velocity ratio is 200-1500h -1 The catalytic reduction section 1 has 4 to 6 packing layers, and the catalytic reduction reaction temperature is 500 to 700°C.

[0031] The venturi-type injection reflux device includes a primary venturi-type injection device 5 and a secondary venturi-type injection device 6, and both of the two venturi-type injection devices are composed of a throat and a diffuser. Among them, the secondary venturi-type injection device 6 is connected to the primary raw gas inlet 2, the primary venturi-type injection device 5 is connected to the secondary raw gas inlet 3, the secondary venturi-type injection device 6 is located above the primary venturi-type injection device 5, the top of the secondary venturi-type injection device 6 is connected to the product gas reflux unit 7, the bottom of the primary venturi-type injection device 5 is connected to the venturi-type injection device outlet 4, the nozzle diameter of the venturi-type injection device is 9-15mm, and the gas flow rate of the nozzle is 200-300m / s, reaching the subsonic level; the throat diameter at the nozzle is 15-20mm, and the gas flow rate of the throat is 70-100m / s. The Venturi-type injection device has a detachable sealing clamp fixing module, which can be easily disassembled and pulled out during maintenance to replace the nozzle; at the same time, the nozzle can be kept fixed during operation and kept on a concentric axis with the center of the throat, so that the Venturi effect is optimized.

[0032] The raw gas is a mixed gas of sulfur dioxide and methane gas. The mixed gas of sulfur dioxide, methane and the like is sprayed into the reaction device at a subsonic flow rate through the primary raw gas inlet 2 and the secondary raw gas inlet 3. The negative pressure (pressure drop is generally 1000-2500Pa) generated under the high-speed jet can partially reflux the sulfide product gas converted by catalytic reduction of SO2 (that is, the top of the catalyst layer is the product gas and part of the product gas in the reflux zone is returned through the product gas reflux unit 7 under the action of negative pressure). The reflux ratio is 1:10-1:3, and it flows out through the outlet 4 of the Venturi injection device, and then is fully mixed with the raw gas and then guided to the bottom of the packing layer of the catalytic reduction section 1. Based on the reverse disproportionation reaction principle of sulfur and under the action of the catalyst, SO2 is efficiently reduced and converted to prepare a high-concentration hydrogen sulfide product gas, which can then be used for the subsequent waste acid heavy metal removal purification process.

[0033] Compared with the prior art, the present invention can promote the efficient reduction and conversion of sulfur dioxide by means of self-circulation drainage, reduce operating energy consumption, improve economic and environmental benefits, and has good application and promotion prospects. The following is a detailed description through specific embodiments. The reduction catalyst used in the following embodiments is a commercial activated alumina ball modified by impregnation of cobalt molybdenum sulfide, wherein the activated alumina comes from Henan Jiezhiyuan Water Purification Material Co., Ltd., model: JZY-HXYHL01, cobalt disulfide and molybdenum disulfide are dissolved in deionized water to prepare a solution with a concentration of 5%, and the molar ratio of Co and Mo is controlled to be 1:1, and mixed to obtain a mixed solution, and then the mixed solution is impregnated on the commercial activated alumina ball for 12 hours according to the equal volume impregnation method, dried at 100°C for 1 hour, and then placed at 550°C for calcination for 2 hours to obtain a reduction catalyst.

[0034] Embodiment 1:

[0035] The reliability test of the device adopts the self-circulating drainage method to produce hydrogen sulfide, in which the nozzle diameter of the Venturi jet reflux device is 9mm, and the gas flow rate of the nozzle is about 280m / s. The throat diameter of the lower part of the nozzle of the Venturi jet reflux device is 18mm, and the gas flow rate of the throat is about 80m / s. The reduction catalyst used is a commercial activated alumina ball modified by impregnation of cobalt molybdenum sulfide, with a diameter of 3mm. The temperature of the reduction zone is 600℃. After operation, the hydrogen sulfide reflux volume is 10% of the output, the ratio of imported sulfur dioxide to methane is 4:3, and the total gas volume is about 65m 3 / h. The concentration of hydrogen sulfide produced was detected at the outlet and was 45 vol%.

[0036] Embodiment 2:

[0037] A self-circulating drainage integrated device is used to produce hydrogen sulfide. The designed hydrogen sulfide output is 10 kg / h. The catalytic pre-reduction catalyst uses a cobalt-molybdenum modified commercial activated alumina catalyst (diameter 5 mm). The total space velocity is about 510 h -1 The ratio of imported SO2 to CH4 is 4:3, and the total gas volume is about 68m 3 / h. The operating temperature of the reduction bed is set to 650°C. The nozzle diameter of the Venturi jet reflux device is 9mm, and the gas flow rate of the nozzle is about 300m / s. The throat diameter of the lower part of the nozzle of the Venturi jet reflux device is 17mm, and the gas flow rate of the throat is about 83m / s. The outlet hydrogen sulfide concentration was detected to be 53vol%.

[0038] Embodiment 3:

[0039] A self-circulating drainage integrated device is used to produce hydrogen sulfide. The designed hydrogen sulfide output is 25 kg / h. The catalytic pre-reduction catalyst uses a nickel-molybdenum modified commercial activated alumina catalyst (diameter 4 mm). The total space velocity is 600 h -1 , where the ratio of imported SO2 to CH4 is 4:3. The operating temperature of the reduction bed is set to 680℃. The nozzle diameter of the Venturi jet reflux device is 9mm, and the gas flow rate of the nozzle is about 300m / s. The throat diameter of the lower part of the nozzle of the Venturi jet reflux device is 17mm, and the gas flow rate of the throat is about 83m / s. It was detected that the outlet hydrogen sulfide concentration was 55vol%, and it was operated for a long time for 2000h, the conversion efficiency loss of SO2 was within 3%, and the operating energy consumption of hydrogen sulfide preparation was basically maintained at 0.9~1.0kW / Kg-H2S.

[0040] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. An integrated device for preparing hydrogen sulfide by self-circulating drainage catalytic reduction, characterized in that: The invention comprises a catalytic reduction section (1), a venturi-type injection device and a product gas reflux unit (7); the catalytic reduction section (1) is provided with a SO2 reduction catalyst packing layer, the product gas reflux unit (7) is arranged in the packing layer, the bottom of the product gas reflux unit (7) is connected to the venturi-type injection device, the top of the product gas reflux unit (7) is connected to the venturi-type injection device, and the sulfide product gas reflux port (8) is arranged; the side of the venturi-type injection reflux device is connected to the raw gas inlet, and the bottom of the venturi-type injection device is provided with a venturi-type injection device outlet (4); the raw gas is injected into the device at a subsonic flow rate through the raw gas inlet, and the negative pressure generated by the high-speed jet causes the sulfide product gas converted by catalytic reduction of SO2 to partially reflux, and flows out through the venturi-type injection device outlet (4), and then is fully mixed with the raw gas and then led to the bottom of the catalytic reduction section (1); based on the principle of reverse disproportionation reaction of sulfur and under the action of the catalyst, SO2 is efficiently reduced and converted to prepare a high-concentration hydrogen sulfide product gas.

2. The integrated device for preparing hydrogen sulfide by self-circulating drainage catalytic reduction according to claim 1, characterized in that: The SO2 reduction catalyst filled in the catalytic layer of the catalytic reduction section (1) is commercial active γ-alumina, or a catalytic material modified by hydrothermal or impregnation methods. The modified components used include Ti / Zr, Co / Mo or Ni / Mo. The filling amount of the filler layer is determined according to the air velocity ratio, and the air velocity ratio is 200-1500h -1 .

3. The integrated device for preparing hydrogen sulfide by self-circulating drainage catalytic reduction according to claim 1, characterized in that: The Venturi type jet reflux device is composed of a nozzle, a throat and a diffuser. The nozzle diameter of the Venturi injection device is 9-15mm, and the gas flow rate of the nozzle is 200-300m / s, reaching the subsonic level; the throat diameter at the nozzle is 15-20mm, and the gas flow rate of the throat is 70-100m / s.

4. The integrated device for preparing hydrogen sulfide by self-circulation drainage catalytic reduction according to claim 1, characterized in that: The venturi-type injection device has a detachable sealing clamp ring fixing module, which keeps the nozzle fixed and kept on a concentric axis with the center of the throat.

5. An integrated device for preparing hydrogen sulfide by self-circulating drainage catalytic reduction according to claim 1, 3 or 4, characterized in that: The Venturi-type injection device comprises a secondary Venturi-type injection device (6) and a primary Venturi-type injection device (5) arranged up and down; The raw gas inlet includes a primary raw gas inlet (2) and a secondary raw gas inlet (3); the secondary venturi-type injection device (6) is connected to the primary raw gas inlet (2); the primary venturi-type injection device (5) is connected to the secondary raw gas inlet (3); the top of the secondary venturi-type injection device (6) is connected to the product gas reflux unit (7); and the bottom of the primary venturi-type injection device (5) is connected to the venturi-type injection device outlet (4).

6. The integrated device for preparing hydrogen sulfide by self-circulating drainage catalytic reduction according to claim 1, characterized in that: The pressure drop generated by the product gas reflow unit (7) under the jet action of the Venturi-type injection device is 1000-2500 Pa.

7. The integrated device for preparing hydrogen sulfide by self-circulating drainage catalytic reduction according to claim 1, characterized in that: The product gas reflux unit (7) guides the reduction product sulfide gas to the bottom of the catalytic reduction section (1) through self-circulation at a reflux ratio of 1:10 to 1:3, that is, 10 to 33% of the reduction product mixed gas is refluxed, and the refluxed sulfide gas induces the newly input raw gas to undergo an efficient catalytic reduction reaction under the action of the catalyst.

8. The integrated device for preparing hydrogen sulfide by self-circulating drainage catalytic reduction according to claim 1, characterized in that: The raw material gas is a mixed gas of sulfur dioxide and methane gas.

9. The integrated device for preparing hydrogen sulfide by self-circulating drainage catalytic reduction according to claim 1, characterized in that: The catalytic reduction section (1) has 4 to 6 filler layers, and its catalytic reduction reaction temperature is 500 to 700°C.

10. The integrated device for preparing hydrogen sulfide by self-circulating drainage catalytic reduction according to claim 1, characterized in that: The main body material of the catalytic reduction section (1), the Venturi-type injection device and the product gas reflow unit (7) is 304H or 310S stainless steel.

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