Device for treating gas containing H2S and CO2

Abstract

The present invention belongs to the field of gas separation, and particularly relates to a device for stepwise treating a gas containing H2S and CO2. The device comprises a gas source introducing mechanism, a pre-absorption tower, a deep absorption tower and an optional deep separation tower which are connected in sequence; a throttling structure is arranged between the gas source introducing mechanism and the pre-absorption tower, and a throttling structure is arranged between the pre-absorption tower and the deep absorption tower; the deep absorption tower is sequentially provided with a gas distributor, a hollow liquid-reducing sprayer, a liquid receiving pipe, a flow guiding plate, a demister and a gas discharge pipe from bottom to top. The device of the present invention is not only applicable to the on-site of oil and gas fields containing H2S and CO2 gas, but also applicable to the high-efficiency purification treatment of H2S and CO2 gas generated by experimental simulation devices. The technical solution of the present invention can reduce the environmental pollution caused by H2S and reduce the impact of the release of CO2 gas on the environment and climate change.

Description

Technical Field

[0001] The present invention belongs to the field of gas separation, and particularly relates to a device for step-by-step treatment of gases containing H2S and CO2. Background Art

[0002] In oil and gas field production, H2S and CO2 often accompany the production of oil and gas. H2S is toxic, and direct emission will pollute the environment. H2S and CO2 will also corrode devices and equipment. When the concentration of H2S in the environment reaches 10 ppm, the eyes and respiratory tract will start to be irritated to a certain extent. When the concentration rises to 20 - 300 ppm, it will cause dizziness, headache, temporary loss of smell and swelling. When the concentration rises to 300 - 500 ppm, short-term exposure will also pose a life threat and require timely treatment. According to the requirements of GB31573 - 2015 (Discharge Standard of Pollutants for Inorganic Chemical Industry), the emission limit of H2S in the atmosphere is 10 mg / m 3 . Therefore, it is necessary to effectively treat the produced gas containing H2S and CO2 to meet the requirements of emission and corrosion control.

[0003] And after carrying out simulated H2S and CO2 corrosion experiments in the laboratory using devices such as high-temperature and high-pressure autoclaves, atmospheric pressure closed devices and corrosion loops, the gas after the experiment also needs to be purified to meet the emission requirements.

[0004] Due to the toxicity of H2S, currently, more attention is paid to H2S removal technology at home and abroad, and relatively few technical reports on the simultaneous removal of H2S and CO2 are available. Desulfurization technologies are mainly divided into dry desulfurization and wet desulfurization. Dry desulfurization usually uses granular or powdered desulfurizers to adsorb, absorb or oxidize H2S, but dry desulfurizers have difficulties in regeneration and require relatively high reaction temperatures. Wet desulfurization is to use a solvent with the property of absorbing H2S to absorb or absorb and oxidize H2S. In fact, after CO2 reacts with the alkaline substances in the desulfurizer, it will affect the acidity and alkalinity of the system and consume the components of the desulfurization solution. Therefore, higher requirements are imposed on the absorption performance of the treatment solution for gases containing H2S and CO2.

[0005] CN205659554U discloses a novel hydrogen sulfide tail gas purification and treatment device, which treats H2S tail gas through two series-connected storage tanks. Multiple layers of baffles with openings are alternately arranged inside the storage tanks to extend the circulation time of the tail gas in the storage tanks and improve the H2S purification and treatment efficiency; a spray port is arranged at the top of the storage tank. However, this device is only applicable to the treatment of hydrogen sulfide tail gas and does not mention the specific composition of the treatment solvent.

[0006] CN106381182B discloses a liquid absorbent for removing hydrogen sulfide and its application. The absorbent consists of the following components by mass percentage: 30 - 50% of a mixture of hexahydrotriazine compounds and pyridine compounds, 10 - 20% of acetonitrile, and the balance is water. This hydrogen sulfide absorbent can rapidly and efficiently absorb hydrogen sulfide in the produced gas in the wellbore. The product is stable and water-soluble, and has a good effect on wellbores with a low content of hydrogen sulfide gas, reducing the corrosion of the wellbore string by hydrogen sulfide and protecting on-site employees from hydrogen sulfide poisoning. However, hexahydrotriazine compounds are mainly applicable to the case of relatively low-concentration H2S (such as below 300 ppm), and their effect is not good at higher H2S contents. In addition, the pH value of general oil and gas field produced water is 5 - 7, the pH value of hexahydrotriazine compounds (1% aqueous solution) is 9.5 - 11.5, and pyridine compounds are also alkaline. Adding such alkaline absorbents directly into the wellbore will cause the pH value of the produced water to increase and change the properties of the produced water; for produced water with a high salinity or a high content of scaling ions such as calcium and magnesium, it will significantly increase the scaling tendency of the produced water, form a scale layer in the wellbore, block the wellbore in severe cases, and pitting corrosion is likely to occur on the metal surface under the scale layer.

[0007] CN109381981A discloses a novel desulfurizer and a process for oxidative removal of hydrogen sulfide. The desulfurizer includes an iron-based ionic liquid and a co-solvent, and preferably also includes an antifoaming agent. The weight ratio of the iron-based ionic liquid, co-solvent, and antifoaming agent is 200:(1 - 80):(1 - 60). The iron-based ionic liquid is an organic amine-type iron-based ionic liquid, such as triethylamine hydrochloride iron-based ionic liquid Et3NHFeCl4. The co-solvent is selected from any one or more of N,N-dimethylacetamide, N,N-dimethylformamide, tributyl phosphate, N-methylpyrrolidone, and propylene carbonate. The antifoaming agent is selected from any one or several of tributyl phosphate, silicone antifoaming agent, polyether antifoaming agent, and polyether compounded with silicone antifoaming agent. The iron-based ionic liquid oxidizes H2S to sulfur. However, this desulfurization process is actually a complex iron desulfurization process, which is not suitable for the treatment of gases with a high content of H2S. And during the treatment process, when the complex iron solution reacts with H2S, the resulting rich liquid has a high viscosity, reducing the gas-liquid mass transfer efficiency and limiting the conversion rate of hydrogen sulfide. Another prominent problem of this process is the sulfur blockage problem in the device, which affects the production efficiency and is prone to cause safety problems. Summary of the Invention

[0008] The object of the present invention is to provide a device for treating gases containing H2S and CO2 in order to overcome the problem of low efficiency in treating gases containing H2S and CO2 existing in the prior art.

[0009] To achieve the above object, the present invention provides a device for treating a gas containing H2S and CO2, which device includes a gas source introducing mechanism, a pre-absorption tower, a deep absorption tower and an optional deep separation tower connected in sequence;

[0010] A throttling structure is provided between the gas source introducing mechanism and the pre-absorption tower, and a throttling structure is provided between the pre-absorption tower and the deep absorption tower;

[0011] The deep absorption tower is sequentially provided with a gas distributor, a hollow liquid reduction sprayer, a liquid receiving pipe, a deflector, a mist eliminator and a gas discharge pipe from bottom to top;

[0012] The deep absorption tower is further provided with a first hollow pipe, the bottom inlet of the first hollow pipe is located in the space between the hollow liquid reduction sprayer and the gas distributor, and the top outlet of the first hollow pipe is located in the space between the hollow liquid reduction sprayer and the mist eliminator, so that the reacted gas can contact the mist eliminator through the first hollow pipe to separate the liquid reduction agent;

[0013] One end of the deflector is connected to the top of the first hollow pipe, and the other end is connected to the liquid receiving pipe, so that the liquid reduction agent separated by the mist eliminator flows into the liquid receiving pipe along the deflector, and the liquid receiving pipe is communicated with the hollow liquid reduction sprayer to make the separated liquid reduction agent flow back into the hollow liquid reduction sprayer.

[0014] By the above technical solution, the present invention has the following beneficial effects:

[0015] The prior art mainly achieves the purpose of removing H2S by combining a desulfurization agent with a treatment device, mainly for desulfurization treatment of natural gas containing H2S or tail gas containing H2S. There are problems such as low treatment effect, and it is difficult for the H2S concentration in the treated gas to meet the emission limit requirement of 10 mg / m 3 , and there are also problems such as foaming and corrosion. In addition, these devices and methods are not for treating gases containing H2S and CO2. When the gas contains both H2S and CO2, the reaction of CO2 with the alkaline substances in the desulfurization agent will affect the acidity and alkalinity of the system and consume the components of the desulfurization liquid. Therefore, the difficulty of desulfurization and decarbonization is increased.

[0016] In a preferred embodiment, the organic amine in the reducing agent of the present invention can react with hydrogen sulfide and carbon dioxide to form a bound amine (R3NH + ); the inorganic base in the present invention has two functions. One is that it can directly react with hydrogen sulfide and carbon dioxide; the other is that it can convert the bound amine (R3NH +) It is converted into free amine, and the free amine can react with hydrogen sulfide and carbon dioxide again to achieve the purpose of activation and recycling. The promoter of the present invention can further promote the reaction of organic amine and inorganic base with hydrogen sulfide and carbon dioxide, and increase the elimination effect of the elimination liquid. Combined with the device for treating the gas containing H2S and CO2 of the present invention, the concentrations of H2S and CO2 are gradually reduced. The eliminator of the present invention has a certain corrosion inhibition effect on the device. The device and method of the present invention have a wide application range and high treatment efficiency.

[0017] The device and method for gradually treating the gas containing H2S and CO2 provided by the present invention are not only applicable to the on-site oil and gas fields containing H2S and CO2 gas, but also applicable to the efficient purification treatment of the gas containing H2S and CO2 generated by the experimental simulation device. The technical solution of the present invention can reduce the environmental pollution caused by H2S and the impact of the release of CO2 gas on the environment and climate change; the content of H2S in the treated gas is less than 10mg / m 3 to meet the requirements, and solve the problems of low efficiency, foaming and corrosion in the treatment of the gas containing H2S and CO2. Brief Description of the Drawings

[0018] Figure 1 is a schematic structural diagram of the device for treating the gas containing H2S and CO2 in a specific embodiment of the present invention;

[0019] Figure 2 is a schematic structural diagram of the deep absorption tower of the present invention;

[0020] Figure 3 is a schematic structural diagram of the guide vane and the second hollow tube of the present invention;

[0021] Figure 4 is a schematic structural diagram of the gas source area when the device of the present invention is used for experimental simulation.

[0022] Description of the Reference Numerals

[0023] 1 Gas source introduction mechanism 2 Pre-absorption tower

[0024] 3 Deep absorption tower 4 Deep separation tower

[0025] 5 Elimination liquid storage tank 6-1 One-way pressure reducing valve

[0026] 7-1 Large-diameter gas pipeline 8-1 Small-diameter gas pipeline

[0027] 2-1 Gas distribution structure 2-2 Elimination liquid spray pipe

[0028] 31 H2S concentration measuring instrument 3-1 Gas distributor

[0029] 3-2 Hollow Reduction Liquid Sprayer 3-21 Porous Nozzle

[0030] 3-3 Liquid Receiving Pipe 3-4 First Hollow Pipe

[0031] 3-5 Deflector 3-6 Mist Catcher

[0032] 3-7 Gas Discharge Pipe 41 Flame Arrestor

[0033] 42 Burner 43 Drain Pipe

[0034] 4-1 Guide Vane 4-2 Second Hollow Pipe

[0035] 4-3 Support Plate 4-4 Inclined Plate

[0036] 4-5 Flow Restrictor 4-6 Porous Mist Catching Plate

[0037] 51 Acid Liquid Storage Tank 52 Alkali Liquid Storage Tank

[0038] 53 Reduction Liquid Circulation Pump 5-1 Stirrer

[0039] 5-2 pH Meter 9 Isolation Room

[0040] 9-1 First Air Inlet Pipe 9-2 First Check Valve

[0041] 9-3 First Air Pump 9-1-1 Second Air Inlet Pipe

[0042] 9-2-1 Second Check Valve 9-3-1 Second Air Pump

[0043] 6-2 One-way Pressure Reducing Valve 7-2 Large-diameter Gas Pipeline

[0044] 8-2 Small-diameter Gas Pipeline Detailed Embodiment

[0045] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0046] In the present invention, "I, II, III, IV, V, VI, VII, VIII" are only used to distinguish the products obtained in different steps and do not play a limiting role.

[0047] In the present invention, unless otherwise specified, orientation terms such as "upper, lower, bottom, top" generally refer to the upper, lower, bottom, and top shown in the reference drawings; "inner, outer" refer to the inner and outer of the contour of each device itself.

[0048] In the present invention, the pressure mentioned all refers to gauge pressure.

[0049] The present invention provides a device for treating a gas containing H2S and CO2, which device includes a gas source introducing mechanism 1, a pre-absorption tower 2, a deep absorption tower 3, and an optional deep separation tower 4 connected in sequence;

[0050] A throttling structure is provided between the gas source introducing mechanism 1 and the pre-absorption tower 2, and a throttling structure is provided between the pre-absorption tower 2 and the deep absorption tower 3;

[0051] The deep absorption tower 3 is provided with a gas distributor 3-1, a hollow liquid reducing sprayer 3-2, a liquid receiving pipe 3-3, a deflector 3-5, a mist eliminator 3-6, and a gas discharge pipe 3-7 from bottom to top in sequence;

[0052] The deep absorption tower 3 is further provided with a first hollow pipe 3-4. The bottom inlet of the first hollow pipe 3-4 is located in the space between the hollow liquid reducing sprayer 3-2 and the gas distributor 3-1, and the top outlet of the first hollow pipe 3-4 is located in the space between the hollow liquid reducing sprayer 3-2 and the mist eliminator 3-6, so that the reacted gas can contact the mist eliminator 3-6 through the first hollow pipe 3-4 to separate the reducing liquid;

[0053] One end of the deflector 3-5 is connected to the top of the first hollow pipe 3-4, and the other end is connected to the liquid receiving pipe 3-3, so that the reducing liquid separated by the mist eliminator 3-6 flows into the liquid receiving pipe 3-3 along the deflector 3-5, and the liquid receiving pipe 3-3 is communicated with the hollow liquid reducing sprayer 3-2 to make the separated reducing liquid flow back into the hollow liquid reducing sprayer 3-2.

[0054] According to the present invention, preferably, the hollow liquid reducing sprayer 3-2 is provided with a porous nozzle 3-21. The porous nozzles 3-21 are uniformly distributed along the radial and axial directions of the hollow liquid reducing sprayer 3-2 so that the reducing liquid is uniformly distributed in all directions in the deep absorption tower 3.

[0055] According to the present invention, preferably, the mist eliminator 3-6 has a porous structure, and the mist eliminator 3-6 can be a porous mesh structure made of a foam metal or non-metal material.

[0056] According to the present invention, the number of the deep absorption towers 3 in the device can be adjusted as needed. When there are multiple deep absorption towers 3, the deep absorption towers 3 can be connected in series or in parallel. Preferably, there are 3 deep absorption towers 3 in the device, which are connected in parallel.

[0057] According to the present invention, preferably, the throttling structure between the gas source introducing mechanism 1 and the pre-absorption tower 2 includes a first large-diameter gas pipeline 7-1, a first small-diameter gas pipeline 8, and a first one-way pressure reducing valve 6 provided on the first large-diameter gas pipeline 7. The inner diameter ratio of the first large-diameter gas pipeline 7-1 to the first small-diameter gas pipeline 8-1 is 1.1-3:1. The gas enters the pre-absorption tower 2 in sequence through the large-diameter gas pipeline 7-1 and the small-diameter gas pipeline 8-1 from the gas source introducing mechanism 1.

[0058] According to the present invention, preferably, the throttling structure between the pre-absorption tower 2 and the deep absorption tower 3 includes a second large-diameter gas pipeline 7-2, a second small-diameter gas pipeline 8-2, and a second one-way pressure reducing valve 6-2 provided on the second large-diameter gas pipeline 7-2. The inner diameter ratio of the second large-diameter gas pipeline 7-2 to the second small-diameter gas pipeline 8-2 is 1.1-3:1. The gas discharged from the pre-absorption tower 2 enters the deep absorption tower 3 in sequence through the second large-diameter gas pipeline 7-2 and the second small-diameter gas pipeline 8-2, and first passes through the gas distributor 3-1 to make the gas flow upward evenly.

[0059] According to the present invention, preferably, a throttling structure can also be provided between the deep absorption tower 3 and the deep separation tower 4. The throttling structure between the deep absorption tower 3 and the deep separation tower 4 is composed of a gas discharge pipe 3-7 and a small-diameter gas pipeline, and the ratio of the gas discharge pipe 3-7 to the small-diameter gas pipeline is 1.1-3:1.

[0060] According to the present invention, preferably, a gas distribution structure 2-1 and a reducing liquid spray pipe 2-2 are provided in the pre-absorption tower 2. In order to make the gas fully contact with the reducing liquid, more preferably, the reducing liquid spray pipe 2-2 is located above the gas distribution structure 2-1. Further preferably, the radial and axial uniformly distributed apertures of the reducing liquid spray pipe 2-2 are small holes with a diameter of 0.1-0.15 mm, so that the reducing liquid is sprayed out evenly to contact the gas, in order to reduce the contents of H2S and CO2 in the gas.

[0061] According to the present invention, preferably, 2 - 6 liquid reduction spray pipes are arranged in the pre - absorption tower 2, and the included angle between two adjacent liquid reduction spray pipes is 60 - 180 degrees. When 2 liquid reduction spray pipes are arranged in the pre - absorption tower 2, the included angle between the 2 liquid reduction spray pipes is 180 degrees, and it is arranged parallel to the gas distribution structure 2 - 1. In order to further increase the contact probability between the gas and the liquid reduction solution, the number of liquid reduction spray pipes can be increased. Further preferably, 3 liquid reduction spray pipes are arranged in the pre - absorption tower 2, and the included angle between two adjacent liquid reduction spray pipes is 120 degrees, as Figure 2 shown.

[0062] According to the present invention, preferably, a flow - guiding vane 4 - 1, a second hollow tube 4 - 2, a support plate 4 - 3, an inclined plate 4 - 4, a flow restrictor 4 - 5, and a porous mist - catching plate 4 - 6 are arranged in the deep - separation tower 4. The gas discharged from the deep - absorption tower 3 enters the deep - separation tower 4 through the gas discharge pipe 3 - 7, so that the gas is subjected to cyclone separation under the action of the flow - guiding vane 4 - 1, and then passes through the second hollow tube 4 - 2 and then through the gap between the inclined plate 4 - 4 and the flow restrictor 4 - 5, and then discharges from the deep - separation tower 4 upward through the porous mist - catching plate 4 - 6.

[0063] The support plate 4 - 3 divides the deep - separation tower 4 into an upper space and a lower space. The second hollow tube 4 - 2 is vertically fixed at the center of the deep - separation tower 4. The bottom inlet and the top inlet of the second hollow tube 4 - 2 are respectively located in the lower space and the upper space. The flow - guiding vane 4 - 1 is located in the lower space and is connected to the inner wall of the deep - separation tower 4 and the outer wall of the second hollow tube 4 - 2, so that part of the liquid reduction solution in the gas entering the lower space of the deep - separation tower 4 is separated and enters the upper space of the deep - separation tower 4 through the second hollow tube (4 - 2);

[0064] The porous mist - catching plate 4 - 6 is arranged in the upper space of the deep - separation tower 4. The flow restrictor 4 - 5 is fixed on the porous mist - catching plate 4 - 6. The inclined plate 4 - 4 is arranged parallel to the flow restrictor 4 - 5, so that the gas entering the upper space from the second hollow tube 4 - 2 can only pass through the gap between the inclined plate 4 - 4 and the flow restrictor 4 - 5 and then contact the porous mist - catching plate 4 - 6 to further separate the liquid reduction solution.

[0065] According to the present invention, preferably, the vertical distance between the inclined plate 4 - 4 and the flow restrictor 4 - 5 is 1 - 5 cm.

[0066] According to the present invention, preferably, the inclination angle of the flow - guiding vane 4 - 1 with respect to the vertical direction is 30 - 60 degrees. The gas forms a downward - rotating flow in the deep - separation tower 4 under the action of the flow - guiding vane 4 - 1. The liquid droplets are thrown to the side wall and fall under the action of gravity, achieving the purpose of gas - liquid separation. The separated liquid gathers at the bottom of the deep - separation tower 4, and the separated gas enters the upper space through the hollow tube 4 - 2.

[0067] According to the present invention, preferably, the choke 4-5 is a conical choke. The center of the choke 4-5 is fixed on the porous mist-catching plate 4-6 and the edge extends towards the side wall of the deep separation tower 4. One end of the inclined plate 4-4 is fixed on the side wall of the deep separation tower 4 and the other end extends towards the porous mist-catching plate 4-6, so that the inclined plate 4-4 is arranged opposite to the conical surface of the conical choke.

[0068] According to the present invention, preferably, the device further includes a flame arrester 41, a burner 42 and an exhaust pipe 43 which are connected in sequence. The flame arrester 41 is connected to the top of the deep separation tower 4 so that the separated gas enters the burner 42 for combustion and then is discharged through the exhaust pipe 43.

[0069] According to the present invention, preferably, the device further includes an H2S concentration measuring instrument 31 arranged on the gas discharge pipe 3-7 for measuring the H2S concentration in the gas discharged from the gas discharge pipe 3-7;

[0070] The gas discharge pipe 3-7 is communicated with the deep separation tower 4 and the exhaust pipe 43 through pipelines, so that the gas meeting the discharge requirements is directly discharged through the exhaust pipe 43, and the gas not meeting the discharge requirements enters the deep separation tower 4.

[0071] The gas discharged from the gas discharge pipe 3-7 is measured by the H2S concentration measuring instrument 31. When the H2S concentration in the gas is less than 10 mg / m 3 , the gas is directly discharged through the exhaust pipe 43; when the H2S concentration in the gas is greater than 10 mg / m 3 , the gas enters the deep separation tower 4. After the gas in the deep separation tower 4 is separated from the abatement liquid, the obtained gas enters the exhaust pipe 43 through the flame arrester 41 and is discharged after combustion by the burner 42.

[0072] According to the present invention, preferably, the device further includes an abatement liquid storage tank 5 and an acid liquid storage tank 51, an alkali liquid storage tank 52 and an abatement liquid circulation pump 53 communicated therewith. The abatement liquid circulation pump 53 is communicated with the pre-absorption tower 2 and the deep absorption tower 3 through pipelines for supplying the abatement liquid in the abatement liquid storage tank 5 to the abatement liquid spray pipe 2-2 and the hollow abatement liquid sprayer 3-2. The abatement liquid storage tank 5 is communicated with the bottoms of the pre-absorption tower 2, the deep absorption tower 3 and the deep separation tower 4 through pipelines so as to collect the abatement liquid recovered by the pre-absorption tower 2, the deep absorption tower 3 and the deep separation tower 4. The acid liquid storage tank 51 is used for storing acid liquid, and the alkali liquid storage tank 52 is used for storing alkali liquid. The acid liquid and the alkali liquid are used to adjust the pH value of the abatement liquid in the abatement liquid storage tank 5. The acid liquid is hydrochloric acid solution and / or acetic acid solution. The alkali liquid is at least one of sodium hydroxide solution, potassium hydroxide solution, cesium carbonate solution, ethanolamine solution and formamide solution. The acid liquid is an aqueous solution and / or an alcohol solution of an acid, and the alkali liquid is an aqueous solution and / or an alcohol solution of an alkali.

[0073] According to the present invention, preferably, a pH meter 5-2 and a stirrer 5-1 are provided in the depletion liquid storage tank 5. The pH meter 5-2 is used to detect the pH value of the depletion liquid in the depletion liquid storage tank 5, and then the pH value of the depletion liquid in the depletion liquid storage tank 5 is adjusted to 7-11 by using acid liquid and alkali liquid. The stirrer 5-1 is used to make the components of the depletion liquid in the depletion liquid storage tank 5 evenly distributed.

[0074] According to the present invention, the device can also connect the gas discharge pipe 3-7 to the inlet of the deep absorption tower 3 by adding pipelines to circulate the gas in the deep absorption tower 3 to reduce the concentration of H2S until the concentration of H2S is lower than the emission standard, and then directly discharge it or enter the deep separation tower 4. According to the requirements in Table 3 of GB 31573-2015 (Emission Standard of Pollutants for Inorganic Chemical Industry), the emission limit of H2S in the atmosphere is 10 mg / m 3 。

[0075] In the present invention, the pipelines and equipment in the device are all made of materials resistant to H2S and CO2 corrosion.

[0076] During the simulation experiment in the laboratory, gases containing H2S and CO2 will also be generated, which may be the tail gas during the experiment or the gas accidentally leaked during the experiment. Therefore, the device of the present invention is also applicable to the treatment of gases containing H2S and CO2 generated during the experimental simulation process. When used for the experimental simulation experiment, the experimental simulation device can be used as the gas source introduction mechanism 1. It is necessary to add an isolation room 9 around the gas source introduction mechanism 1. The large-diameter gas pipeline 7 passes through the middle of the top of the isolation room 9. It is also necessary to drill holes in the top of the isolation room 9 to make the first air inlet pipe 9-1 pass through, and install a first one-way valve 9-2 and a first air pump 9-3 on the first air inlet pipe 9-1. Drill holes in the bottom of the isolation room 9 to make the second air inlet pipe 9-1-1 pass through, and install a second one-way valve 9-2-1 and a second air pump 9-3-1 on the second air inlet pipe 9-1-1. When gas is generated, the gas can directly enter the device of the present invention through the large-diameter gas pipeline 7. When gas leakage occurs, the first air inlet pipe 9-1, the first one-way valve 9-2 and the first air pump 9-3 can be opened to allow external gas to enter the isolation room 9 through the first air inlet pipe 9-1 to dilute the gas in the isolation room 9, and the second air inlet pipe 9-1-1, the second one-way valve 9-2-1 and the second air pump 9-3-1 can be opened to allow the gas in the isolation room 9 to enter the device of the present invention through the second air inlet pipe 9-1-1. After entering the device of the present invention, the removal of H2S and CO2 can be carried out according to the method of the present invention.

[0077] According to the present invention, preferably, the gas containing H2S and CO2 is removed of H2S and CO2 in the device according to the following method, and the method includes the following steps:

[0078] A: The gas containing H2S and CO2 to be processed is throttled to obtain Gas I, and the flow rate of Gas I is 0.1 - 1.5 m / s;

[0079] B: Gas I is pre-absorbed with a reducing liquid to obtain Gas II after pre-absorption. Gas II after pre-absorption is then throttled to obtain Gas III, and the flow rate of Gas III is 0.05 - 1 m / s;

[0080] C: Gas III is further deeply absorbed with the reducing liquid to obtain Gas IV after deep absorption. Gas IV after deep absorption is separated by mist catching to obtain Gas V and Liquid I, and Liquid I is reused as the reducing liquid.

[0081] According to the present invention, preferably, when the H2S concentration in Gas V is less than 10 mg / m 3 , Gas V is directly discharged.

[0082] According to the present invention, preferably, when the H2S concentration in Gas V is greater than 10 mg / m 3 , the method further includes step D: Gas V is subjected to cyclone separation to obtain Gas VI and Liquid II. Gas VI is collided to obtain Gas VII and Liquid III. Gas VII is separated by mist catching to obtain Gas VIII and Liquid IV, and Gas VIII is combusted by a burner (42) and then discharged; Liquid II, Liquid III, and Liquid IV are reused as the reducing liquid.

[0083] According to the present invention, preferably, the reducing liquid in step A and step B is the same or different. The reducing liquid includes organic amine, inorganic base, and promoter, and the weight ratio of the organic amine, inorganic base, and promoter is 1:0.1 - 40:0.03 - 0.3, preferably 1:1 - 30:0.1 - 0.2, more preferably 1:20 - 30:0.15 - 0.2. The organic amine includes alkanolamine and / or polyamine. The inorganic base includes inorganic bases containing alkali metal and / or alkaline earth metal. The promoter includes at least one of imide, amide, nitrogen-containing six-membered heterocyclic compound, nitrogen-containing condensed heterocyclic compound, sulfoxide with C2 - C5, sulfone with C3 - C5, and nitrile with C2 - C5.

[0084] According to the present invention, preferably, the alkanolamine includes ethanolamine and / or triethanolamine citrate.

[0085] According to the present invention, preferably, the polyamine includes diethylenetriamine and / or triethylenetetramine.

[0086] According to the present invention, preferably, the organic amine is selected from a combination of one of triethanolamine citrate, diethylenetriamine, and triethylenetetramine and ethanolamine; more preferably, the weight ratio of one of triethanolamine citrate, diethylenetriamine, and triethylenetetramine to ethanolamine is 1:4 - 5.

[0087] According to the present invention, preferably, the inorganic base includes at least one of NaOH, Na2CO3, KOH, NaHCO3, K2CO3, Ca(OH)2, and Cs2CO3.

[0088] According to the present invention, preferably, the imide includes N-hydroxyphthalimide.

[0089] According to the present invention, preferably, the amide includes at least one of N,N-dimethylacetamide, N,N-dimethylformamide, and formamide.

[0090] According to the present invention, preferably, the nitrogen-containing six-membered heterocyclic compound includes pyridine.

[0091] According to the present invention, preferably, the nitrogen-containing condensed heterocyclic compound includes quinoline.

[0092] According to the present invention, preferably, the C2-C5 sulfoxide includes dimethyl sulfoxide.

[0093] According to the present invention, preferably, the C3-C5 sulfone includes sulfolane.

[0094] According to the present invention, preferably, the C2-C5 nitrile includes acetonitrile.

[0095] According to the present invention, preferably, the etching solution further includes an antifoaming agent and a solvent, the antifoaming agent is a silicone antifoaming agent, and the solvent includes water or a C1-C5 alcohol.

[0096] According to the present invention, preferably, the weight ratio of the organic amine, the antifoaming agent, and the solvent is 1:0.003-0.1:0.1-30, preferably 1:0.03-0.08:1-25.

[0097] According to the present invention, preferably, the silicone antifoaming agent includes at least one of polydimethylsiloxane antifoaming agents, ethylene glycol siloxane antifoaming agents, and polyether-modified silicone antifoaming agents.

[0098] According to the present invention, preferably, the C1-C5 alcohol includes at least one of C1-C5 monohydric alcohols, C1-C5 dihydric alcohols, and C1-C5 polyhydric alcohols, the C1-C5 monohydric alcohol includes at least one of ethanol, methanol, and isopropanol, the C1-C5 dihydric alcohol includes ethylene glycol, and the C1-C5 polyhydric alcohol includes glycerol.

[0099] According to the present invention, preferably, the pH value of the etching solution is 7-11.

[0100] According to the present invention, preferably, in the gas containing H2S and CO2, the content of H2S is 0.00001 - 15% by volume, and the content of CO2 is 0 - 99% by volume. Preferably, the content of H2S is 0.1 - 15% by volume, and the content of CO2 is 5 - 20% by volume. Other gases in the gas containing H2S and CO2 may be nitrogen, methane, etc.

[0101] According to the present invention, preferably, the temperature of the gas containing H2S and CO2 is 20 - 80 °C, and the pressure is 0.1 - 8 MPa.

[0102] According to the present invention, preferably, the dosage of the abatement liquid is 1 - 30 Nm 3 / h.

[0103] The following refers to Figure 1 and Figure 2 the schematic process flow diagram of the present invention for treating the gas containing H2S and CO2 as shown, and describes the working process of the device for treating the gas containing H2S and CO2.

[0104] The gas containing H2S and CO2 is introduced through the gas source introducing mechanism 1 and successively passes through the first large-diameter gas pipeline 7-1, the first one-way pressure reducing valve 6-1 and the first small-diameter gas pipeline 8-1 to reduce the temperature and pressure of the gas containing H2S and CO2 to obtain gas I. Gas I enters the pre-absorption tower 2, first passes through the horizontally arranged gas distribution structure 2-1 to evenly disperse the gas and make it flow upward, and then contacts the abatement liquid sprayed by the abatement liquid spraying pipe 2-2 to absorb H2S and CO2, obtaining the pre-absorbed gas II. Gas II then successively passes through the second large-diameter gas pipeline 7-2, the second one-way pressure reducing valve 6-2 and the second small-diameter gas pipeline 8-2 to further reduce the temperature and pressure of the gas containing H2S and CO2 to obtain gas III. Gas III enters the deep absorption tower 3, first passes through the horizontally arranged gas distributor 3-1 to evenly disperse the gas and make it flow upward, and then contacts the abatement liquid sprayed by the porous nozzle 3-21 to absorb H2S and CO2, obtaining the deeply absorbed gas IV. Gas IV passes through the first hollow tube 3-4 and then contacts the mist eliminator 3-6 to separate the liquid I in gas IV to obtain gas V. The liquid I intercepted by the mist eliminator 3-6 drips onto the deflector 3-5, and then converges into the liquid receiving pipe 3-3 and is recycled back to the hollow abatement liquid sprayer 3-2 as the abatement liquid for repeated use. Gas V is discharged from the deep absorption tower 3 through the gas discharge pipe 3-7, and then the H2S concentration in gas V is measured by the H2S concentration measuring instrument 31. When the H2S concentration in gas V is less than 10 mg / m 3 , gas V can be directly discharged through the exhaust pipe 43. When the H2S concentration in gas V is greater than 10 mg / m 3At this time, gas Ⅴ enters the deep separation tower 4, and under the action of the guide vane 4-1, a centrifugal force for cyclone separation is generated, separating the gas and liquid in gas Ⅴ to obtain gas Ⅵ and liquid Ⅱ. Gas Ⅵ enters the upper space of the deep separation tower 4 through the second hollow tube 4-2, and after colliding with the inclined plate 4-4 and the flow restrictor 4-5, gas Ⅶ and liquid Ⅲ are obtained. Gas Ⅶ ascends through the gap between the inclined plate 4-4 and the flow restrictor 4-5 to the porous mist eliminator 4-6, and under the action of the porous mist eliminator 4-6, gas Ⅷ and liquid Ⅳ are separated. Gas Ⅷ enters the drain pipe 43 through the flame arrester 41 and is discharged after being burned by the burner 42. Liquid Ⅱ, liquid Ⅲ, and liquid Ⅳ are recycled to the abatement liquid storage tank 5 through pipelines for reuse. The abatement liquid storage tank 5 is filled with abatement liquid, which is an alkaline liquid with a controlled pH value of 7 - 11. A pH meter 5-2 is provided on the abatement liquid storage tank 5 and is connected to the acid liquid storage tank 51 and the alkaline liquid storage tank 52. The pH meter 5-2 monitors the pH value of the abatement liquid in real time, and acid liquid or alkaline liquid is added to the abatement liquid storage tank 5 through an automatic adjustment device to adjust the pH value of the abatement liquid. A stirrer 5-1 is also provided on the abatement liquid storage tank 5 to ensure that the components in the abatement liquid in the abatement liquid storage tank 5 are evenly dispersed. The abatement liquid storage tank 5 provides abatement liquid to the abatement liquid spray pipe 2-2 and the hollow abatement liquid sprayer 3-2 through the abatement liquid circulation pump 53. The abatement liquid storage tank 5 is connected to the bottoms of the pre-absorption tower 2, the deep absorption tower 3, and the deep separation tower 4 through pipelines for recovering the abatement liquid.

[0105] The present invention will be described in detail below through embodiments, but the present invention is not limited to the following embodiments.

[0106] Example 1

[0107] Using the device as shown in Figure 1 and Figure 2 to process the gas containing H2S and CO2, the temperature of the gas containing H2S and CO2 is 80 °C, the pressure is 4 MPa, and the flow rate is 0.26 m / s. The steps are as follows:

[0108] Add abatement liquid to the abatement liquid storage tank 5, start the stirrer 5-1 to evenly disperse the abatement liquid, the pH meter 5-2 monitors the pH value of the abatement liquid in real time, and add acid liquid or alkaline liquid through the acid liquid storage tank 51 or the alkaline liquid storage tank 52 to control the pH value of the abatement liquid. Then, provide abatement liquid to the abatement liquid spray pipe 2-2 and the hollow abatement liquid sprayer 3-2 through the abatement liquid circulation pump 53. The composition and pH value of the abatement liquid are shown in Table 1. The consumption of the abatement liquid is 25 Nm 3 / h.

[0109] A: The gas containing H2S and CO2 to be processed in the gas source introduction mechanism 1 sequentially passes through the first large-diameter gas pipeline 7-1, the first one-way pressure reducing valve 6-1, and the first small-diameter gas pipeline 8-1 (the inner diameter ratio of the first large-diameter gas pipeline 7-1 to the first small-diameter gas pipeline 8-1 is 2:1) to reduce the temperature and pressure of the gas containing H2S and CO2 to obtain gas I. The contents of H2S and CO2 in the gas containing H2S and CO2 to be processed are shown in Table 2.

[0110] B: Gas I is sent into the pre-absorption tower 2 for pre-absorption with the reduction liquid, and the flow rate of gas I is 1.05 m / s. Gas I first passes through the horizontally arranged gas distribution structure 2-1 to make the gas evenly dispersed and flow upward, and then contacts the reduction liquid sprayed by the reduction liquid spray pipe 2-2 to absorb H2S and CO2, obtaining the pre-absorbed gas II. The pre-absorbed gas II then passes through the second large-diameter gas pipeline 7-2, the second one-way pressure reducing valve 6-2, and the second small-diameter gas pipeline 8-2 (the inner diameter of the second large-diameter gas pipeline 7-2 to the second small-diameter gas pipeline 8-2 is 3:1) to reduce the temperature and pressure of the gas containing H2S and CO2 to obtain gas III.

[0111] C: Gas III is sent into the deep absorption tower 3 for deep absorption, and the flow rate of gas III is 0.5 m / s. Gas III first passes through the horizontally arranged gas distributor 3-1 to make the gas evenly dispersed and flow upward, and then contacts the reduction liquid sprayed by the porous nozzle 3-21 to absorb H2S and CO2, obtaining the deeply absorbed gas IV. Gas IV passes through the first hollow tube 3-4 and then contacts the mist eliminator 3-6 to separate the liquid I in gas IV to obtain gas V. The liquid I drips on the deflector 3-5, and then is collected into the liquid receiving pipe 3-3 and recycled back to the hollow reduction liquid sprayer 3-2 as the reduction liquid for repeated use. After measuring by the H2S concentration measuring instrument 31, the concentration of H2S in gas V is 5 mg / m 3 , reaching the emission standard and can be discharged through the exhaust pipe 43.

[0112] Example 1-1

[0113] The gas containing H2S and CO2 is processed according to the method of Example 1, except that the dosage of the reduction liquid is 30 Nm 3 / h, and the contents of H2S and CO2 in the gas containing H2S and CO2 to be processed are shown in Table 2. The concentration of H2S in gas V is shown in Table 2.

[0114] Example 2-11

[0115] The gas containing H2S and CO2 is processed according to the method of Example 1, except that the composition of the abatement liquid and the contents of H2S and CO2 in the gas containing H2S and CO2 to be processed are different. The composition of the abatement liquid is shown in Table 1, and the contents of H2S and CO2 in the gas containing H2S and CO2 to be processed are shown in Table 2.

[0116] When the concentration of H2S in gas Ⅴ measured by the H2S concentration measuring instrument 31 is lower than 10 mg / m 3 , the emission standard is met and it can be discharged through the exhaust pipe 43. The concentration of H2S in gas Ⅴ is shown in Table 2.

[0117] When the concentration of H2S in gas Ⅴ measured by the H2S concentration measuring instrument 31 is higher than 10 mg / m 3 , gas Ⅴ is sent to the deep separation tower 4 for deep separation. After gas Ⅴ enters the deep separation tower 4, it undergoes cyclone separation under the action of the guide vane 4-1 to obtain gas Ⅵ and liquid Ⅱ. Gas Ⅵ collides with the inclined plate 4-4 and the flow restrictor 4-5 to obtain gas Ⅶ and liquid Ⅲ. Gas Ⅶ undergoes demisting separation to obtain gas Ⅷ and liquid Ⅳ. Gas Ⅷ passes through the flame arrester 41, is burned by the burner 42, and enters the exhaust pipe 43 for discharge; liquid Ⅱ, liquid Ⅲ, and liquid Ⅳ flow back to the abatement liquid storage tank 5 through the bottom of the deep separation tower 4 and are reused as the abatement liquid.

[0118] Example 12

[0119] The gas containing H2S and CO2 is processed according to the method of Example 1, except that pipelines with the same inner diameter are used to replace the first large-diameter gas pipeline 7-1, the first small-diameter gas pipeline 8-1, the second large-diameter gas pipeline 7-2, and the second small-diameter gas pipeline 8-2 respectively, and ordinary one-way valves are used to replace the first one-way pressure reducing valve 6-1 and the second one-way pressure reducing valve 6-2 respectively.

[0120] Table 1

[0121]

[0122]

[0123] Table 2

[0124]

[0125] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the technical concept scope of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A device for treating a gas containing H2S and CO2, characterized in that, The device includes a gas source introducing mechanism (1), a pre-absorption tower (2), a deep absorption tower (3), and a deep separation tower (4) connected in sequence; A throttling structure is provided between the gas source introducing mechanism (1) and the pre-absorption tower (2), and a throttling structure is provided between the pre-absorption tower (2) and the deep absorption tower (3); The deep absorption tower (3) is sequentially provided with a gas distributor (3-1), a hollow liquid reduction sprayer (3-2), a liquid receiving pipe (3-3), a deflector (3-5), a mist eliminator (3-6), and a gas discharge pipe (3-7) from bottom to top; The deep absorption tower (3) is further provided with a first hollow pipe (3-4). The bottom inlet of the first hollow pipe (3-4) is located in the space between the hollow liquid reduction sprayer (3-2) and the gas distributor (3-1), and the top outlet of the first hollow pipe (3-4) is located in the space between the hollow liquid reduction sprayer (3-2) and the mist eliminator (3-6), so that the reacted gas can contact the mist eliminator (3-6) through the first hollow pipe (3-4) to separate the liquid reduction; One end of the deflector (3-5) is connected to the top of the first hollow pipe (3-4), and the other end is connected to the liquid receiving pipe (3-3), so that the liquid reduction separated by the mist eliminator (3-6) flows into the liquid receiving pipe (3-3) along the deflector (3-5), and the liquid receiving pipe (3-3) is communicated with the hollow liquid reduction sprayer (3-2) to return the separated liquid reduction to the hollow liquid reduction sprayer (3-2); The device further includes an H2S concentration measuring instrument (31) provided on the gas discharge pipe (3-7) for measuring the H2S concentration in the gas discharged from the gas discharge pipe (3-7); The gas discharge pipe (3-7) is communicated with the deep separation tower (4) and the exhaust pipe (43) through a pipeline, so that the gas meeting the discharge requirements is directly discharged through the exhaust pipe (43), and the gas not meeting the discharge requirements enters the deep separation tower (4); A deflector vane (4-1), a second hollow pipe (4-2), a support plate (4-3), an inclined plate (4-4), a flow restrictor (4-5), and a porous mist eliminator plate (4-6) are provided in the deep separation tower (4); The support plate (4-3) divides the deep separation tower (4) into an upper space and a lower space. The second hollow pipe (4-2) is vertically fixed at the center of the deep separation tower (4) perpendicular to the support plate (4-3). The bottom inlet and the top inlet of the second hollow pipe (4-2) are respectively located in the lower space and the upper space. The deflector vane (4-1) is located in the lower space and is connected to the inner wall of the deep separation tower (4) and the outer wall of the second hollow pipe (4-2), so that part of the liquid reduction in the gas entering the lower space of the deep separation tower (4) is separated and enters the upper space of the deep separation tower (4) through the second hollow pipe (4); The porous mist-catching plate (4-6) is arranged in the upper space of the depth separation tower (4), the flow restrictor (4-5) is fixed on the porous mist-catching plate (4-6), the inclined plate (4-4) is arranged in parallel with the flow restrictor (4-5), so that the gas entering the upper space from the second hollow tube (4-2) can only pass through the gap between the inclined plate (4-4) and the flow restrictor (4-5) and then contact with the porous mist-catching plate (4-6) to further separate and reduce the liquid.

2. The device according to claim 1, wherein The throttling structure between the gas source introducing mechanism (1) and the pre-absorption tower (2) includes a first large-diameter gas pipeline (7-1), a first small-diameter gas pipeline (8-1), and a first one-way pressure reducing valve (6-1) arranged on the first large-diameter gas pipeline (7-1), and the inner diameter ratio of the first large-diameter gas pipeline (7-1) to the first small-diameter gas pipeline (8-1) is 1.1-3:1; And / or, the throttling structure between the pre-absorption tower (2) and the depth absorption tower (3) includes a second large-diameter gas pipeline (7-2), a second small-diameter gas pipeline (8-2), and a second one-way pressure reducing valve (6-2) arranged on the second large-diameter gas pipeline (7-2), and the inner diameter ratio of the second large-diameter gas pipeline (7-2) to the second small-diameter gas pipeline (8-2) is 1.1-3:

1.

3. The device according to claim 1 or 2, wherein, The hollow liquid-reducing sprayer (3-2) is provided with a porous spray head (3-21).

4. The device according to claim 1 or 2, wherein, A gas distribution structure (2-1) and a liquid-reducing spray pipe (2-2) are arranged in the pre-absorption tower (2).

5. The device according to claim 1 or 2, wherein, 1-6 liquid-reducing spray pipes are arranged in the pre-absorption tower (2), and the included angle between adjacent two liquid-reducing spray pipes is 60-180 degrees.

6. The apparatus according to claim 5, wherein, 3 liquid-reducing spray pipes are arranged in the pre-absorption tower (2), and the included angle between adjacent two liquid-reducing spray pipes is 120 degrees.

7. The device according to claim 1 or 2, wherein The vertical distance of the gap between the inclined plate (4-4) and the flow restrictor (4-5) is 1-5 cm; And / or, the inclination angle of the guide vane (4-1) with respect to the vertical direction is 30-60 degrees; And / or, the flow restrictor (4-5) is a conical flow restrictor.

8. The device according to claim 1 or 2, wherein The device further includes a flame arrester (41), a burner (42) and an exhaust pipe (43) connected in sequence. The flame arrester (41) is connected to the top of the depth separation tower (4) so that the separated gas enters the burner (42) for combustion and is discharged through the exhaust pipe (43).

9. The device according to claim 1 or 2, wherein The device further includes a liquid-reducing liquid storage tank (5) and an acid liquid storage tank (51), an alkali liquid storage tank (52) and a liquid-reducing liquid circulation pump (53) communicated with it. The liquid-reducing liquid circulation pump (53) is communicated with the pre-absorption tower (2) and the depth absorption tower (3) through pipelines to supply the liquid-reducing liquid in the liquid-reducing liquid storage tank (5) to the liquid-reducing spray pipe (2-2) and the hollow liquid-reducing sprayer (3-2). The liquid-reducing liquid storage tank (5) is communicated with the bottoms of the pre-absorption tower (2), the depth absorption tower (3) and the depth separation tower (4) through pipelines to collect the liquid-reducing liquid recovered by the pre-absorption tower (2), the depth absorption tower (3) and the depth separation tower (4).

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