Integrated desulfurization and decarbonization treatment system and process for blast furnace gas

Abstract

The invention discloses an integrated desulfurization and decarbonization treatment system and process for blast furnace gas, and belongs to the technical field of blast furnace gas purification. The integrated desulfurization and decarburization treatment system for the blast furnace gas comprises a pre-dewatering and drying unit, a pressure swing adsorption unit, a desulfurization and purification unit, a CO2 collection unit and a purified gas collection unit. The pressure swing adsorption unit is filled with desulfurization and decarbonization adsorbents in a layered manner, and the blast furnace gas is synchronously desulfurized and decarbonized in the pressure swing adsorption process. And after adsorption saturation, mixed gas of sulfur-containing gas and CO2 is conveyed to a desulfurization purification unit through depressurization desorption, and after the sulfur-containing gas is removed, high-concentration CO2 product gas and low-sulfur and low-carbon purified coal gas are finally obtained. The method effectively simplifies the process flow, avoids sulfur element deposition, prolongs the service life of the adsorbent, reduces the energy consumption of sulfur-containing gas separation, and is suitable for the development of new carbon and pollution reduction technologies in the iron and steel industry.

Description

Technical Field

[0001] The present invention belongs to the technical field of blast furnace gas purification, and more particularly relates to an integrated desulfurization and decarbonization treatment system and process for blast furnace gas. Background Art

[0002] my country's steel production mainly adopts the blast furnace-converter long process. The blast furnace gas volume is large and the carbon emission ratio is high. Its main components are CO2 (15-20%), CO (28-33%), H2 (1-4%), N2 (40-50%) and sulfide (total sulfur content 150-350 mg / m 3 , primarily carbonyl sulfide (COS). Sulfides can easily cause equipment corrosion and air pollution, while high CO2 concentrations restrict the calorific value of coal gas. Therefore, simultaneous desulfurization and decarbonization are key to achieving clean blast furnace gas and its resourceful utilization. Fine desulfurization of blast furnace gas is a crucial step in shifting the industry from end-of-pipe treatment to source control.

[0003] However, existing technologies usually adopt a solvent absorption method of "decarbonization first and then desulfurization", in which CO2 is absorbed by amine liquid and then desulfurized by adsorbent. However, sulfides in coal gas (such as COS) are not removed during the decarbonization stage, resulting in the subsequent poisoning and failure of the amine liquid. The decarbonizer needs to be frequently replaced, the operating cost increases significantly, and the coal gas cannot be utilized as a resource. There is also a method of desulfurization and decarbonization through wet spraying. This process relies on a hydrolysis tower to convert organic sulfur into H2S, which is then treated through multi-stage water washing towers and absorption towers. Although this process can simultaneously desulfurize and decarbonize, it produces a large amount of sulfur-containing wastewater, which requires supporting wastewater treatment facilities and has high equipment investment costs.

[0004] In summary, it is difficult for existing technologies to balance desulfurization and decarbonization efficiency, operating costs and environmental friendliness. There is an urgent need to develop an integrated, low-energy consumption and secondary pollution-free blast furnace gas purification process. Summary of the Invention

[0005] The purpose of the present invention is to provide an integrated desulfurization and decarbonization treatment system and process for blast furnace gas, so as to solve the problems existing in the above-mentioned prior art and realize integrated, low-energy-consumption and efficient purification of blast furnace gas without secondary pollution.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] One of the technical solutions of the present invention is to provide an integrated desulfurization and decarbonization treatment system for blast furnace gas, comprising: a pre-dehydration and drying unit, a pressure swing adsorption unit, a desulfurization and purification unit, a CO2 collection unit and a purified gas collection unit;

[0008] The pre-dehydration drying unit, pressure swing adsorption unit, desulfurization purification unit and CO2 collection unit are connected in sequence; the blast furnace gas inlet and the desorption gas outlet of the pressure swing adsorption unit are arranged on the same side, which is the top or bottom, and are respectively connected to the pre-dehydration drying unit and the desulfurization purification unit; the purified gas outlet is arranged on the side opposite to the blast furnace gas inlet and the desorption gas outlet, and is connected to the purified gas collection unit;

[0009] The pressure swing adsorption unit is divided into p levels, each level independently contains n adsorption towers, where p is 1 to 3, 2≤n≤30; the adsorption tower is divided into two parts, the upper part is filled with decarbonization adsorbent, and the lower part is filled with desulfurization adsorbent; the filling volume ratio of the decarbonization adsorbent and the desulfurization adsorbent is independently 1:2 to 10.

[0010] Furthermore, the pre-dehydration and drying unit includes more than one dehydration device connected in series; the dehydration device includes a heat exchange condenser and / or a temperature swing adsorption dehydration device.

[0011] Preferably, the decarbonization adsorbent includes at least one of modified activated carbon, silica gel, 13X zeolite, MOFs and corresponding amino functionalized materials (such as TEPA, DEPA, DPA, DETA, etc.); the desulfurization adsorbent includes at least one of modified activated carbon, modified molecular sieve and silica gel; the specific surface area of ​​the decarbonization adsorbent and the desulfurization adsorbent are independently 800 to 2000 m 2 / g, and the pore size is independent of 0.3 to 2 mm.

[0012] Furthermore, the desulfurization adsorbent can also be subjected to hydrophilic modification treatment. Since the blast furnace gas enters the bottom of the adsorption tower and passes through the desulfurization adsorbent and the decarbonization adsorbent in sequence, the hydrophilic modification treatment of the desulfurization adsorbent can absorb part of the moisture in the blast furnace gas and prevent the upper decarbonization adsorbent from absorbing water and causing performance degradation.

[0013] Preferably, the pressure swing adsorption units at each stage are connected in series, and the adsorption towers in the pressure swing adsorption units at each stage are connected in parallel.

[0014] Preferably, the desulfurization purification unit comprises m desulfurization towers, wherein 2≤m≤5; the diameter ratio of the adsorption tower and the desulfurization tower is 1:0.5-1, and the height ratio is 1:0.2-1.

[0015] The second technical solution of the present invention is to provide a method for integrated desulfurization and decarbonization of blast furnace gas. The method is implemented by the above-mentioned integrated desulfurization and decarbonization system for blast furnace gas, and comprises the following steps:

[0016] The blast furnace gas treated by the pre-dehydration and drying unit is alternately adsorbed and desorbed in the pressure swing adsorption unit. After adsorption, the purified gas is obtained and passed into the purified gas collection unit for collection. After desorption, a mixture of sulfur-containing gas and CO2 is obtained, which is passed into the desulfurization purification unit for desulfurization, and the obtained CO2 product gas is passed into the CO2 collection unit for collection.

[0017] The core of the integrated desulfurization and decarbonization treatment method for blast furnace gas described in the present invention is: simultaneous desulfurization and decarbonization in the pressure swing adsorption unit, and the mixed gas (sulfur-containing gas + CO2) in the desorption stage is uniformly transported to the back-end desulfurization and purification unit for centralized treatment; the pressure swing adsorption process of the pressure swing adsorption unit includes continuous adsorption and desorption stages;

[0018] Specifically, during the adsorption stage, blast furnace gas at a pressure of 100-800 kPa and a temperature of 20-120°C enters the bottom of the adsorption tower. The desulfurization adsorbent preferentially physically adsorbs sulfur-containing gases such as H2S and CO2, while the decarbonization adsorbent layer selectively adsorbs CO2. Purified gas (CO2 ≤ 2 vol%, H2S ≤ 20 ppm) is discharged from the top. During the desorption stage, the pressure is reduced to 10-80 kPa, and a mixture of sulfur-containing gases (H2S concentration ≥ 300 ppm) and CO2 is discharged from the desorbed gas outlet at the bottom.

[0019] Preferably, the adsorption parameters of each adsorption tower in the pressure swing adsorption unit are independently set as follows: pressure 100-800 kPa, temperature 20-120 ° C, adsorbent volume space velocity 150-300 h -1 .

[0020] Furthermore, when the CO2 or sulfur-containing gas concentration in the adsorption tower outlet gas reaches 5% of the inlet gas concentration, it is considered to be adsorption saturation, and desorption operation is then performed.

[0021] Preferably, the desorption parameters of each adsorption tower in the pressure swing adsorption unit are independently set as follows: pressure 10-80 kPa, temperature 20-120° C., and time 1-30 min.

[0022] Preferably, the desulfurization adopts wet desulfurization, dry catalytic oxidation desulfurization or membrane separation desulfurization.

[0023] Preferably, the desulfurization parameters of each desulfurization tower in the desulfurization purification unit are independently set as follows: temperature 25-65°C, pressure 10-200 kPa, gas processing space velocity 800-3000 h -1 .

[0024] Furthermore, after the desulfurization, the removal rate of H2S is ≥99%, and the purity of the remaining CO2 product gas is ≥90%, which can be directly utilized as a resource, such as urea synthesis or oil recovery.

[0025] Preferably, the volume concentration of CO2 in the mixture of sulfur-containing gas and CO2 is ≥15%; the H2S content in the purified coal gas is ≤10ppm, and the CO2 content is ≤2vol%.

[0026] This integrated system uses layered loading of a physical adsorption desulfurizer and a highly selective decarbonizer to simultaneously remove sulfur-containing gases and CO2 from blast furnace gas within a pressure swing adsorption unit, and then centrally desulfurizes the desorbed mixed gas. This system is suitable for the clean and resourceful utilization of blast furnace gas in the steel industry, simplifying the traditional step-by-step desulfurization and decarbonization process and reducing equipment investment and operating costs.

[0027] Compared with the existing blast furnace gas treatment method, the present invention removes sulfur before decarbonization, effectively avoiding the problem of frequent replacement of decarbonization adsorbents. At the same time, the required equipment and treatment process of the present invention are simple, and no treatment waste liquid and waste gas are generated, thereby realizing the cleanliness and resource utilization of blast furnace gas.

[0028] The present invention discloses the following technical effects:

[0029] The present invention provides an integrated desulfurization and decarbonization treatment system and process for blast furnace gas, which eliminates the front-end desulfurization device, simultaneously adsorbs sulfur and carbon components and transfers them to the back-end for centralized treatment, effectively reducing equipment investment costs; the adsorbent life is extended to more than 24 months; the CO2 purity in the final mixed desorbed gas is ≥90%, which can be directly used for urea synthesis or oil displacement, and the sulfur recovery rate is ≥98%, realizing the resource utilization of gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the integrated desulfurization and decarbonization process of blast furnace gas according to the present invention. DETAILED DESCRIPTION

[0031] The schematic diagram of the integrated desulfurization and decarbonization process of blast furnace gas according to the present invention is as follows: Figure 1 shown.

[0032] The present invention provides an integrated desulfurization and decarbonization treatment system for blast furnace gas, comprising: a pre-dehydration and drying unit, a pressure swing adsorption unit, a desulfurization and purification unit, a CO2 collection unit, and a purified gas collection unit;

[0033] The pre-dehydration drying unit, pressure swing adsorption unit, desulfurization purification unit and CO2 collection unit are connected in sequence; the blast furnace gas inlet and the desorption gas outlet of the pressure swing adsorption unit are arranged on the same side, which is the top or bottom, and are respectively connected to the pre-dehydration drying unit and the desulfurization purification unit; the purified gas outlet is arranged on the side opposite to the blast furnace gas inlet and the desorption gas outlet, and is connected to the purified gas collection unit;

[0034] The pressure swing adsorption unit is divided into p levels, each level independently contains n adsorption towers, where p is 1 to 3, 2≤n≤30; the adsorption tower is divided into two parts, the upper part is filled with decarbonization adsorbent, and the lower part is filled with desulfurization adsorbent; the filling volume ratio of the decarbonization adsorbent to the desulfurization adsorbent is 1:2 to 10.

[0035] In the present invention, the pre-dehydration and drying unit includes more than one dehydration device connected in series; the dehydration device includes a heat exchange condenser and / or a temperature swing adsorption dehydration device.

[0036] In the present invention, the number of adsorption towers in each stage of the pressure swing adsorption unit is preferably 2 to 12, specifically 2, 3, 4, 6, 8 or 12.

[0037] In the present invention, the loading volume ratio of the decarbonization adsorbent and the desulfurization adsorbent is preferably independently 1:2 to 10, specifically 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10.

[0038] In the present invention, the pressure swing adsorption unit is also equipped with supporting equipment for operation, such as pipes and valves connecting the equipment, and equipment for pressure, flow and temperature detection, such as pressure detectors, flow detection equipment, temperature detection equipment, etc.; further, in order to detect whether the carbon and sulfur content in the purified gas meets the standards, gas analysis and detection equipment can be configured simultaneously, and then connected to the central control to realize automatic control of each equipment in the pressure swing adsorption unit.

[0039] In the present invention, the decarbonization adsorbent includes at least one of modified activated carbon, silica gel, 13X zeolite, MOFs and corresponding amino functionalized materials (such as TEPA, DEPA, DPA, DETA, etc.); the desulfurization adsorbent includes at least one of modified activated carbon, modified molecular sieve and silica gel; the specific surface area of ​​the decarbonization adsorbent and the desulfurization adsorbent are independently 800 to 2000 m 2 / g, and the pore size is 0.3-2mm. The decarbonization adsorbent and desulfurization adsorbent are preferably spherical bulk adsorbents, and honeycomb-shaped adsorbents can also be used.

[0040] In the present invention, the desulfurization adsorbent can also be subjected to hydrophilic modification treatment. Since the blast furnace gas enters the bottom of the adsorption tower and passes through the desulfurization adsorbent and the decarbonization adsorbent in sequence, the hydrophilic modification treatment of the desulfurization adsorbent can absorb part of the moisture in the blast furnace gas and prevent the upper decarbonization adsorbent from absorbing water and causing performance degradation.

[0041] In the present invention, the pressure swing adsorption units at each stage are connected in series, and the adsorption towers in the pressure swing adsorption units at each stage are connected in parallel.

[0042] In the present invention, the desulfurization purification unit comprises m desulfurization towers, wherein 2≤m≤5.

[0043] In the present invention, the sulfur removal tower of the desulfurization purification unit is filled with sulfur removal reagents, such as common sulfur removal reagents such as iron oxide, zinc oxide, activated carbon, etc., and the form can be spherical, cylindrical, sheet or other shaped bulk catalysts, or plate-type, honeycomb-type and other shaped catalysts.

[0044] Wherein, an air pump is provided on the connecting pipeline between the desulfurization purification unit and the pressure swing adsorption unit.

[0045] Wherein, a pressure reducing valve group is provided between the pressure swing adsorption unit and the gas collecting unit.

[0046] In the present invention, the pressure reducing valve group provided between the pressure swing adsorption unit and the coal gas collecting unit reduces the pressure of the desulfurized and decarbonized coal gas, so that the gas flows smoothly into the coal gas collecting unit.

[0047] In the present invention, the diameter ratio of the adsorption tower and the desulfurization tower is preferably 1:0.5-1, specifically 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9 or 1:1, and the height ratio is preferably 1:0.2-1, specifically 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9 or 1:1.

[0048] The present invention also provides a method for integrated desulfurization and decarbonization of blast furnace gas. The method is implemented by the above-mentioned integrated desulfurization and decarbonization system for blast furnace gas, and comprises the following steps:

[0049] The blast furnace gas treated by the pre-dehydration and drying unit is alternately adsorbed and desorbed in the pressure swing adsorption unit. After adsorption, the purified gas is obtained and passed into the purified gas collection unit for collection. After desorption, a mixture of sulfur-containing gas and CO2 is obtained, which is passed into the desulfurization purification unit for desulfurization, and the obtained CO2 product gas is passed into the CO2 collection unit for collection.

[0050] In the present invention, the adsorption parameters of each adsorption tower in the pressure swing adsorption unit are independently set as follows: pressure 0.1-0.8 MPa, specifically 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa or 0.8 MPa, temperature 20-100 ° C, specifically 20 ° C, 25 ° C, 30 ° C, 35 ° C, 40 ° C, 45 ° C or 50 ° C, adsorbent volume space velocity 150-300 h -1 , specifically 150h -1 , 160h-1 , 180h -1 , 200h -1 , 220h -1 , 240h -1 , 260h -1 , 280h -1 or 300h -1 .

[0051] In the present invention, when the CO2 or sulfur-containing gas concentration in the adsorption tower outlet gas reaches 5% of the inlet gas concentration, it is considered as adsorption saturation, and the desorption operation is then performed.

[0052] In the present invention, the desorption parameters of each adsorption tower in the pressure swing adsorption unit are independently set as follows: pressure 10-80 kPa, temperature 20-120° C., and time 1-30 min.

[0053] In the present invention, the desulfurization adopts wet desulfurization, dry catalytic oxidation desulfurization or membrane separation desulfurization.

[0054] In the present invention, the desulfurization parameters of each desulfurization tower in the desulfurization purification unit are independently set as follows: temperature 25-65°C, specifically 30°C, 45°C or 60°C, pressure 10-200kPa, specifically 20kPa, 40kPa, 60kPa or 80kPa, gas treatment space velocity 800-3000h -1 , specifically 1000h -1 , 1500h -1 , 2000h -1 , 2500h -1 or 3000h -1 .

[0055] In the present invention, after the desulfurization, the removal rate of H2S is ≥99%, and the purity of the remaining CO2 product gas is ≥90%, which can be directly utilized as a resource, such as urea synthesis or oil recovery.

[0056] In the present invention, the volume concentration of CO2 in the mixture of sulfur-containing gas and CO2 is ≥15%; the H2S content in the purified coal gas is ≤10ppm, and the CO2 content is ≤2vol%.

[0057] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0058] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value within any stated value or stated range, and each smaller range between any other stated value or intermediate value within the stated range, is also encompassed within the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0059] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0060] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be illustrative only.

[0061] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0062] It should be pointed out that the matters not described in detail in the present invention are conventional operating means in this field and are not the focus of the present invention.

[0063] Unless otherwise specified, the raw materials used in the following examples of the present invention are all commercially available products, and the sources of the commercially available products do not affect the technical effects of the present invention.

[0064] Example 1

[0065] This embodiment adopts the blast furnace gas integrated desulfurization and decarbonization process provided by the present invention to purify the blast furnace gas. The blast furnace gas desulfurization and decarbonization device is composed of a pre-dehydration drying unit, a pressure swing adsorption unit, a desulfurization purification unit, a CO2 collection unit and a purified gas collection unit. Figure 1 Connect as shown.

[0066] The pre-dehydration and drying unit consists of two temperature-swing adsorption towers, which are filled with silica gel adsorbent (SG-01 purchased from Qingdao Zhongneng Silicon Chemical Co., Ltd.);

[0067] The pressure swing adsorption process in the pressure swing adsorption unit is configured as a single-stage pressure swing adsorption, and is equipped with four adsorption towers, which are connected in parallel;

[0068] The filling height ratio of the desulfurization adsorbent to the decarbonization adsorbent in the pressure swing adsorption unit is 1:8;

[0069] The desulfurization adsorbent and the decarbonization adsorbent are modified activated carbon adsorbent (ZR-T2 purchased from Zhuoran Environmental Protection Technology (Dalian) Co., Ltd.) and 13X molecular sieve (CO-1 purchased from Luoyang Jianlong Micro-Nano New Materials Co., Ltd.);

[0070] The desulfurization purification unit has two desulfurization towers; the desulfurizer in the desulfurization tower is iron oxide, and the filling volume of the desulfurizer is 400L;

[0071] An air pump is provided on the connecting pipeline between the desulfurization purification unit and the pressure swing adsorption unit; a pressure reducing valve group is provided between the pressure swing adsorption unit and the purified coal gas collection unit;

[0072] The diameter ratio of the adsorption tower and the desulfurization tower is 1:0.5, and the height ratio is 1:1.

[0073] The specific process is as follows:

[0074] The blast furnace gas is passed into the pre-dehydration drying unit at a space velocity of 300 h -1 The blast furnace gas treated by the pre-dehydration and drying unit is alternately adsorbed and desorbed in the pressure swing adsorption unit. Desorption is performed after each adsorption to saturation. The purified gas obtained after adsorption is passed into the purified gas collection unit for collection. After desorption, a mixed gas of sulfur-containing gas and CO2 is obtained, which is passed into the desulfurization purification unit for desulfurization, and the obtained CO2 product gas is passed into the CO2 collection unit for collection.

[0075] The adsorbent volume space velocity during the adsorption process is 250h -1 , the operating temperature is 40°C, and the operating pressure is 0.3MPa; after 8 minutes, the desorption process begins; during the desorption process, the operating temperature is kept unchanged and the operating pressure is 80kPa.

[0076] The desulfurization operation temperature is 50°C, the operation pressure is 200kPa, and the gas treatment space velocity is 1000h -1 .

[0077] According to the on-line gas chromatograph detection and analysis, the H2S removal rate in the desulfurized gas is 99%, and the purity of the CO2 product gas is >95%; the H2S content in the purified coal gas is <5ppm, and the CO2 content is 2.5%.

[0078] Example 2

[0079] This embodiment adopts the blast furnace gas integrated desulfurization and decarbonization process provided by the present invention to purify the blast furnace gas. The blast furnace gas desulfurization and decarbonization device consists of a pre-dehydration drying unit, a pressure swing adsorption unit, a desulfurization purification unit, a CO2 collection unit and a purified gas collection unit. Figure 1 Connect as shown.

[0080] The pre-dehydration and drying unit is composed of two temperature swing adsorption towers, which are filled with activated alumina adsorbent (AL-200 of Shandong Lubei Chemical Co., Ltd.);

[0081] The pressure swing adsorption process in the pressure swing adsorption unit is configured as a two-stage pressure swing adsorption process, with four adsorption towers configured in each stage. The two stages of pressure swing adsorption are connected in series, and the adsorption towers in the same stage of the pressure swing adsorption unit are connected in parallel.

[0082] The filling height ratio of the desulfurization adsorbent to the decarbonization adsorbent in the pressure swing adsorption unit is 1:8;

[0083] The desulfurization adsorbent and the decarbonization adsorbent are modified activated carbon adsorbent (ZR-T2 purchased from Zhuoran Environmental Protection Technology (Dalian) Co., Ltd.) and 13X molecular sieve (CO-1 purchased from Luoyang Jianlong Micro-Nano New Materials Co., Ltd.);

[0084] The desulfurization purification unit has four desulfurization towers; the desulfurization agent in the desulfurization tower is iron oxide, and the filling volume of the desulfurization agent is 400L;

[0085] An air pump is provided on the connecting pipeline between the desulfurization purification unit and the pressure swing adsorption unit; a pressure reducing valve group is provided between the pressure swing adsorption unit and the purified coal gas collection unit;

[0086] The diameter ratio of the adsorption tower and the desulfurization tower is 1:1, and the height ratio is 1:0.5.

[0087] The specific process is as follows:

[0088] The blast furnace gas is passed into the pre-dehydration drying unit at a space velocity of 300 h -1 The blast furnace gas treated by the pre-dehydration and drying unit is alternately adsorbed and desorbed in the pressure swing adsorption unit. Desorption is performed after each adsorption to saturation. The purified gas obtained after adsorption is passed into the purified gas collection unit for collection. After desorption, a mixed gas of sulfur-containing gas and CO2 is obtained, which is passed into the desulfurization purification unit for desulfurization, and the obtained CO2 product gas is passed into the CO2 collection unit for collection.

[0089] The adsorbent volume space velocity during the adsorption process is 250h -1, the operating temperature is 40°C, the operating pressure is 0.3MPa; after 10 minutes, the desorption process begins; during the desorption process, the operating temperature is kept unchanged and the operating pressure is 50kPa.

[0090] The desulfurization operation temperature is 50°C, the operation pressure is 200kPa, and the gas treatment space velocity is 1000h -1 .

[0091] According to the on-line gas chromatograph detection and analysis, the H2S removal rate in the desulfurized gas is 99%, and the purity of the CO2 product gas is 99%; the H2S content in the purified coal gas is <5ppm, and the CO2 content is 1%.

[0092] Example 3

[0093] This embodiment adopts the blast furnace gas integrated desulfurization and decarbonization process provided by the present invention to purify the blast furnace gas. The blast furnace gas desulfurization and decarbonization device consists of a pre-dehydration drying unit, a pressure swing adsorption unit, a desulfurization purification unit, a CO2 collection unit and a purified gas collection unit. Figure 1 Connect as shown.

[0094] The pre-dehydration and drying unit is composed of two parallel temperature swing adsorption towers, which are filled with silica gel adsorbent (SG-01 purchased from Qingdao Zhongneng Silicon Chemical Co., Ltd.);

[0095] The pressure swing adsorption process in the pressure swing adsorption unit is configured as a single-stage pressure swing adsorption, and is equipped with four adsorption towers, which are connected in parallel;

[0096] The filling height ratio of the desulfurization adsorbent to the decarbonization adsorbent in the pressure swing adsorption unit is 1:6;

[0097] The desulfurization adsorbent and decarbonization adsorbent are modified activated carbon adsorbent (desulfurization and denitrification activated carbon, purchased from Henan Yiheng Environmental Protection Technology Co., Ltd.) and 13X molecular sieve (CO-1 purchased from Luoyang Jianlong Micro-Nano New Materials Co., Ltd.);

[0098] The desulfurization purification unit has two desulfurization towers; the desulfurizer in the desulfurization tower is iron oxide, and the filling volume of the desulfurizer is 400L;

[0099] An air pump is provided on the connecting pipeline between the desulfurization purification unit and the pressure swing adsorption unit; a pressure reducing valve group is provided between the pressure swing adsorption unit and the purified coal gas collection unit;

[0100] The diameter ratio of the adsorption tower and the desulfurization tower is 1:0.8, and the height ratio is 1:0.6.

[0101] The specific process is as follows:

[0102] The blast furnace gas is passed into the pre-dehydration drying unit at a space velocity of 300 h -1 The blast furnace gas treated by the pre-dehydration and drying unit is alternately adsorbed and desorbed in the pressure swing adsorption unit. Desorption is performed after each adsorption to saturation. The purified gas obtained after adsorption is passed into the purified gas collection unit for collection. After desorption, a mixed gas of sulfur-containing gas and CO2 is obtained, which is passed into the desulfurization purification unit for desulfurization, and the obtained CO2 product gas is passed into the CO2 collection unit for collection.

[0103] The adsorbent volume space velocity during the adsorption process is 250h -1 , the operating temperature is 40°C, the operating pressure is 0.3MPa; after 10 minutes, the desorption process begins; during the desorption process, the operating temperature is kept unchanged and the operating pressure is 60kPa.

[0104] The desulfurization operation temperature is 50°C, the operation pressure is 200kPa, and the gas treatment space velocity is 1000h -1 .

[0105] According to the on-line gas chromatograph test and analysis, the H2S removal rate in the desulfurized gas is 99%, and the purity of the CO2 product gas is 98%; the H2S content in the purified coal gas is <5ppm, and the CO2 content is 3%.

[0106] Example 4

[0107] This embodiment adopts the blast furnace gas integrated desulfurization and decarbonization process provided by the present invention to purify the blast furnace gas. The blast furnace gas desulfurization and decarbonization device consists of a pre-dehydration drying unit, a pressure swing adsorption unit, a desulfurization purification unit, a CO2 collection unit and a purified gas collection unit. Figure 1 Connect as shown.

[0108] The pre-dehydration and drying unit is composed of two parallel temperature swing adsorption towers, which are filled with activated alumina (AL-200 of Shandong Lubei Chemical Co., Ltd.);

[0109] The pressure swing adsorption process in the pressure swing adsorption unit is configured as a single-stage pressure swing adsorption, and is equipped with four adsorption towers, which are connected in parallel;

[0110] The adsorption tower adopts an upper and lower layered structure, with the lower part filled with modified activated carbon (ZR-T2 purchased from Zhuoran Environmental Protection Technology (Dalian) Co., Ltd.) as a desulfurization adsorbent, and the upper part filled with MOFs amine functionalized material (MOF-66D purchased from Nanjing Xianfeng Nanomaterial Technology Co., Ltd.) as a decarbonization adsorbent, with a filling height ratio of 1:4;

[0111] The desulfurization purification unit has three desulfurization towers, and the desulfurizer filled in the tower is iron oxide (FeOx-G3 of China National Bluestar Group Co., Ltd.), and the desulfurizer filling volume is 500L;

[0112] A pressure reducing valve group is provided between the pressure swing adsorption unit and the purified coal gas collecting unit, and an air pump is provided between the pressure swing adsorption unit and the desulfurization purification unit.

[0113] The diameter ratio of the adsorption tower and the desulfurization tower is 1:0.5, and the height ratio is 1:1.

[0114] The adsorption process conditions are as follows:

[0115] The blast furnace gas is passed into the pre-dehydration drying unit at a space velocity of 300 h -1 The blast furnace gas treated by the pre-dehydration and drying unit is alternately adsorbed and desorbed in the pressure swing adsorption unit. Desorption is performed after each adsorption to saturation. The purified gas obtained after adsorption is passed into the purified gas collection unit for collection. After desorption, a mixed gas of sulfur-containing gas and CO2 is obtained, which is passed into the desulfurization purification unit for desulfurization, and the obtained CO2 product gas is passed into the CO2 collection unit for collection.

[0116] The adsorbent volume space velocity during the adsorption process is 200h -1 , the operating temperature is 30°C, the operating pressure is 0.3MPa; after 12 minutes, the desorption process begins; during the desorption process, the operating temperature is kept constant, the operating pressure is 60kPa, and the desorption time is 10 minutes;

[0117] The desulfurization operation temperature is 45°C, the operating pressure is 120kPa, and the gas processing space velocity is 1500h -1 .

[0118] According to the on-line gas chromatograph, the H2S removal rate in the desulfurized gas is 99.1%; the purity of the CO2 product gas is 96.2%; the H2S content in the purified coal gas is <5ppm, and the CO2 content is 1.8%.

[0119] Example 5

[0120] This embodiment adopts the blast furnace gas integrated desulfurization and decarbonization process provided by the present invention to purify the blast furnace gas. The blast furnace gas desulfurization and decarbonization device consists of a pre-dehydration drying unit, a pressure swing adsorption unit, a desulfurization purification unit, a CO2 collection unit and a purified gas collection unit. Figure 1 Connect as shown.

[0121] The pre-dehydration and drying unit is composed of two parallel temperature swing adsorption towers, which are filled with activated alumina adsorbent (ZNO-AA purchased from Shandong Zenuo Electronic Materials Co., Ltd.);

[0122] The pressure swing adsorption process in the pressure swing adsorption unit is configured as a single-stage pressure swing adsorption, and is equipped with six adsorption towers, which are connected in parallel;

[0123] The filling height ratio of the desulfurization adsorbent to the decarbonization adsorbent in the pressure swing adsorption unit is 1:5;

[0124] The desulfurization adsorbent and the decarbonization adsorbent are modified molecular sieve adsorbent (DS-H2S purchased from Nanjing Deshuo Company) and 13X molecular sieve (CO-1 purchased from Luoyang Jianlong Micro-Nano New Materials Co., Ltd.);

[0125] The desulfurization purification unit has four desulfurization towers; the desulfurizer in the desulfurization tower is a honeycomb zinc oxide adsorbent (Zhejiang Tiantai, TT-Zn-HX), and the filling volume of the desulfurizer is 600L;

[0126] An air pump is provided on the connecting pipeline between the desulfurization purification unit and the pressure swing adsorption unit; a pressure reducing valve group is provided between the pressure swing adsorption unit and the purified coal gas collection unit;

[0127] The diameter ratio of the adsorption tower and the desulfurization tower is 1:0.8, and the height ratio is 1:0.6.

[0128] The specific process is as follows:

[0129] The blast furnace gas is passed into the pre-dehydration drying unit at a space velocity of 300 h -1 The speed is 2.4m / s. The blast furnace gas treated by the pre-dehydration drying unit is alternately adsorbed and desorbed in the pressure swing adsorption unit. Desorption is performed after each adsorption to saturation. The purified gas obtained after adsorption is passed into the purified gas collection unit for collection. After desorption, a mixed gas of sulfur-containing gas and CO2 is obtained, which is passed into the desulfurization purification unit for desulfurization, and the obtained CO2 product gas is passed into the CO2 collection unit for collection.

[0130] The adsorbent volume space velocity during the adsorption process is 300 h -1 , the operating temperature is 45℃, the operating pressure is 0.35MPa; after 8min, the desorption process begins;

[0131] During the desorption process, the operating temperature was raised to 100°C, the operating pressure was 50 kPa, and the desorption time was 12 min;

[0132] The desulfurization operation temperature is 60°C, the operation pressure is 80kPa, and the gas treatment space velocity is 2500h -1 .

[0133] According to the detection and analysis by online gas chromatograph, the removal rate of H2S in the gas after desulfurization is 98.6%, and the purity of the remaining CO2 product gas is 94.8%; the volume concentration of CO2 in the mixed gas of sulfur-containing gas and CO2 is ≥15%; the H2S content in the purified coal gas is 6ppm, and the CO2 content is 2.0%.

[0134] Example 6

[0135] This embodiment adopts the blast furnace gas integrated desulfurization and decarbonization process provided by the present invention to purify the blast furnace gas. The blast furnace gas desulfurization and decarbonization device consists of a pre-dehydration drying unit, a pressure swing adsorption unit, a desulfurization purification unit, a CO2 collection unit and a purified gas collection unit. Figure 1 Connect as shown.

[0136] The pre-dehydration and drying unit is composed of two parallel temperature swing adsorption towers, which are filled with silica gel adsorbent (SG-01 from Qingdao Zhongneng Silicon Chemical Co., Ltd.);

[0137] The pressure swing adsorption process in the pressure swing adsorption unit is configured as a single-stage pressure swing adsorption, and is equipped with four adsorption towers, which are connected in parallel;

[0138] The filling height ratio of the desulfurization adsorbent to the decarbonization adsorbent in the pressure swing adsorption unit is 1:4;

[0139] The desulfurization adsorbent and the decarbonization adsorbent are modified activated carbon adsorbent (ZR-T2 purchased from Zhuoran Environmental Protection Technology (Dalian) Co., Ltd.) and MOF amino functionalized material UiO-66-NH2 (MOF-66N purchased from Nanjing Xianfeng Nanomaterial Technology Co., Ltd.);

[0140] The desulfurization purification unit has two membrane desulfurization devices, and the membrane material used is polyamide hollow fiber composite membrane (H2S-Select purchased from Tianjin Motian Membrane Technology Co., Ltd.); the effective membrane area of ​​a single membrane module is 35m 2 ;

[0141] An air pump is provided on the connecting pipeline between the desulfurization purification unit and the pressure swing adsorption unit; a pressure reducing valve group is provided between the pressure swing adsorption unit and the purified coal gas collection unit;

[0142] The diameter ratio of the adsorption tower and the desulfurization tower is 1:0.7, and the height ratio is 1:0.4.

[0143] The specific process is as follows:

[0144] The blast furnace gas is passed into the pre-dehydration drying unit at a space velocity of 300 h -1The speed is 2.2m / s. The blast furnace gas treated by the pre-dehydration drying unit is alternately adsorbed and desorbed in the pressure swing adsorption unit. Desorption is performed after each adsorption to saturation. The purified gas obtained after adsorption is passed into the purified gas collection unit for collection. After desorption, a mixed gas of sulfur-containing gas and CO2 is obtained, which is passed into the desulfurization purification unit for desulfurization, and the obtained CO2 product gas is passed into the CO2 collection unit for collection.

[0145] The adsorbent volume space velocity during the adsorption process is 250h -1 , the operating temperature is 40℃, the operating pressure is 0.3MPa; after 10min, the desorption process begins;

[0146] During the desorption process, the operating temperature was kept constant, the operating pressure was 60 kPa, and the desorption time was 10 min;

[0147] The desulfurization operation temperature is 35°C, the operation pressure is 100kPa, and the gas treatment space velocity is 2000h -1 .

[0148] According to the detection and analysis by online gas chromatograph, the removal rate of H2S in the gas after desulfurization is 97.2%, and the purity of the remaining CO2 product gas is 95.5%; the volume concentration of CO2 in the mixed gas of sulfur-containing gas and CO2 is ≥15%; the H2S content in the purified coal gas is 7ppm, and the CO2 content is 2.2%.

[0149] Comparative Example 1

[0150] This comparative example adopts the structure of the integrated blast furnace gas treatment device of the present invention, but sets the desulfurization purification unit before the pressure swing adsorption unit, that is, after the blast furnace gas is treated by the pre-dehydration and drying unit, the gas first enters the desulfurization purification unit and then enters the pressure swing adsorption unit for CO2 removal. Figure 1 The pre-dehydration and drying unit is two temperature-swing adsorption towers connected in series, and the towers are filled with silica gel adsorbent (SG-01 purchased from Qingdao Zhongneng Silicon Chemical Co., Ltd.);

[0151] The desulfurization purification unit has two wet desulfurization towers. The desulfurization liquid sprayed in the tower is 2wt% NaOH alkali solution, and the liquid-to-gas ratio of desulfurization liquid to gas is 6L / m 3 ;

[0152] The pressure swing adsorption unit is a single-stage configuration, provided with four adsorption towers, which are connected in parallel;

[0153] The adsorption tower in the pressure swing adsorption unit adopts an upper and lower layered structure, with the upper part filled with 13X molecular sieve decarbonization adsorbent (CO-1 purchased from Luoyang Jianlong Micro-Nano New Materials Co., Ltd.) and the lower part filled with modified activated carbon desulfurization adsorbent (ZR-T2 purchased from Zhuoran Environmental Protection Technology (Dalian) Co., Ltd.), with a filling height ratio of 6:1;

[0154] A buffer tank and an air pump are provided between the desulfurization purification unit and the pressure swing adsorption unit to maintain a stable airflow in the system; a pressure reducing valve group is provided between the pressure swing adsorption unit and the purified coal gas collection unit;

[0155] The diameter ratio of the adsorption tower to the desulfurization tower is 1:0.8, and the height ratio is 1:0.6.

[0156] The specific process is as follows:

[0157] The blast furnace gas is passed into the pre-dehydration drying unit at a space velocity of 300 h -1 After being dehumidified by the pre-dehydration drying unit, the coal gas first enters the desulfurization purification unit, and after being treated with spray-type wet desulfurization, it enters the pressure swing adsorption unit for alternating adsorption and desorption operations;

[0158] During the adsorption process, the adsorbent volume space velocity was 250h -1 , the operating temperature is 40℃, the operating pressure is 0.3MPa; the adsorption time is 10min;

[0159] During the desorption process, the operating temperature was kept constant, the operating pressure was reduced to 60 kPa, and the desorption time was 10 minutes.

[0160] The operating temperature of the desulfurization purification unit is 50°C, the operating pressure is 120kPa, and the gas treatment space velocity is 1000h-1.

[0161] After detection and analysis by online gas chromatography, the H2S removal rate in the desulfurized gas was 96.5%; the purity of the CO2 product gas was 89.2%; the H2S content in the purified coal gas was 9.7ppm, and the CO2 content was 2.5vol%; the decarbonization adsorbent showed a significant decrease in adsorption capacity after 8 months of operation and needed to be replaced in advance.

[0162] Comparative Example 2

[0163] This comparative example is similar to the main structure of the integrated blast furnace gas treatment system described in the present invention, but there is no desulfurization purification unit in the process flow, that is, the blast furnace gas directly enters the pressure swing adsorption unit after dehydration, and the blast furnace gas is simultaneously desulfurized and decarbonized in the unit.

[0164] The pre-dehydration and drying unit is composed of two temperature swing adsorption towers connected in series, and the towers are filled with silica gel adsorbent (SG-01 purchased from Qingdao Zhongneng Silicon Chemical Co., Ltd.);

[0165] The pressure swing adsorption unit is a single-stage configuration, provided with four adsorption towers, which are connected in parallel;

[0166] The adsorption tower in the pressure swing adsorption unit adopts an upper and lower layered structure, with the lower part filled with a desulfurization adsorbent (modified activated carbon, ZR-T2 purchased from Zhuoran Environmental Protection Technology (Dalian) Co., Ltd.) and the upper part filled with a decarbonization adsorbent (13X molecular sieve, CO-1 purchased from Luoyang Jianlong Micro-Nano New Materials Co., Ltd.), with a filling height ratio of 1:6;

[0167] There is no desulfurization and purification unit in the system, and all sulfur-containing components are directly processed during the pressure swing adsorption process;

[0168] The connection method of the adsorption tower, the CO2 collection unit, and the purified coal gas collection unit is consistent with that in the embodiment, and an air pump and a pressure reducing valve are provided in the system.

[0169] The process operating parameters are as follows:

[0170] The adsorbent volume space velocity during the adsorption process is 250h -1 , the operating temperature is 40℃, the operating pressure is 0.3MPa, and the adsorption time is 10min;

[0171] During the desorption process, the operating pressure dropped to 60 kPa, the desorption time was 10 min, and the temperature remained unchanged.

[0172] Due to the lack of desulfurization and purification units, the desorbed gas is no longer post-treated and is directly sent to the CO2 collection unit or discharged.

[0173] Tests conducted using an online gas chromatograph and a portable H2S analyzer showed that the H2S removal rate was 87.6%, significantly lower than the desulfurization efficiency of ≥99% in the embodiment. The CO2 product gas purity was 86.0%, lower than the level of >94% in the embodiment. The H2S content in the purified coal gas was 32 ppm and the CO2 content was 3.2 vol%, which did not meet downstream utilization requirements.

[0174] Less than 4 months after the adsorption operation, the decarbonization adsorbent began to show adsorption capacity decay and the CO2 breakthrough curve was advanced. Analysis showed that the upstream sulfur component caused the molecular sieve to become poisoned and fail.

[0175] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0176] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An integrated desulfurization and decarbonization treatment system for blast furnace gas, characterized in that: include: Pre-dehydration and drying unit, pressure swing adsorption unit, desulfurization and purification unit, CO2 collection unit and purified coal gas collection unit; The pre-dehydration and drying unit, pressure swing adsorption unit, desulfurization and purification unit and CO2 collection unit are connected in sequence; the blast furnace gas inlet and the desorption gas outlet of the pressure swing adsorption unit are arranged on the same side, and are respectively connected to the pre-dehydration and drying unit and the desulfurization and purification unit; the purified gas outlet is arranged on the side opposite to the blast furnace gas inlet and the desorption gas outlet, and is connected to the purified gas collection unit; The pressure swing adsorption unit is divided into p levels, each level independently contains n adsorption towers, where p is 1 to 3, 2≤n≤30; the adsorption tower is divided into two parts, the upper part is filled with decarbonization adsorbent, and the lower part is filled with desulfurization adsorbent; the filling volume ratio of the decarbonization adsorbent and the desulfurization adsorbent is independently 1:2 to 10.

2. The integrated desulfurization and decarbonization treatment system for blast furnace gas according to claim 1, characterized in that: The decarbonization adsorbent comprises at least one of modified activated carbon, silica gel, 13X zeolite, MOFs and corresponding amino-functionalized materials; and / or, the desulfurization adsorbent comprises at least one of modified activated carbon, modified molecular sieve and silica gel; and / or, the specific surface area of ​​the decarbonization adsorbent and the desulfurization adsorbent are independently 800 to 2000 m 2 / g, and the pore size is independent of 0.3 to 2 mm.

3. The integrated desulfurization and decarbonization treatment system for blast furnace gas according to claim 1, characterized in that: The pressure swing adsorption units at each stage are connected in series, and the adsorption towers in the pressure swing adsorption units at each stage are connected in parallel.

4. The integrated desulfurization and decarbonization treatment system for blast furnace gas according to claim 1, characterized in that: The desulfurization purification unit comprises m desulfurization towers, wherein 2≤m≤5; and / or the diameter ratio of the adsorption tower and the desulfurization tower is 1:0.5-1, and the height ratio is 1:0.2-1.

5. A method for integrated desulfurization and decarbonization of blast furnace gas, characterized in that: The integrated desulfurization and decarbonization treatment method for blast furnace gas is implemented by the integrated desulfurization and decarbonization treatment system for blast furnace gas according to any one of claims 1 to 4, comprising the following steps: The blast furnace gas treated by the pre-dehydration and drying unit is alternately adsorbed and desorbed in the pressure swing adsorption unit. After adsorption, the purified gas is obtained and passed into the purified gas collection unit for collection. After desorption, a mixture of sulfur-containing gas and CO2 is obtained, which is passed into the desulfurization purification unit for desulfurization, and the obtained CO2 product gas is passed into the CO2 collection unit for collection.

6. The integrated desulfurization and decarbonization method for blast furnace gas according to claim 5, characterized in that: The parameters for adsorption in each adsorption tower of the pressure swing adsorption unit are independently set as follows: pressure 0.1-0.8 MPa, temperature 20-100°C, adsorbent volume space velocity 150-300 h -1 .

7. The integrated desulfurization and decarbonization treatment method for blast furnace gas according to claim 5, characterized in that: Desorption is performed after each adsorption to saturation; the desorption parameters of each adsorption tower in the pressure swing adsorption unit are independently set as: pressure 10-80kPa, temperature 20-120°C, time 1-30min.

8. The integrated desulfurization and decarbonization method for blast furnace gas according to claim 5, characterized in that: The desulfurization adopts wet desulfurization, dry catalytic oxidation desulfurization or membrane separation desulfurization.

9. The integrated desulfurization and decarbonization method for blast furnace gas according to claim 5, characterized in that: The desulfurization parameters of each desulfurization tower in the desulfurization purification unit are independently set as follows: temperature 25-65°C, pressure 10-200kPa, gas processing space velocity 800-3000h -1 .

10. The integrated desulfurization and decarbonization method for blast furnace gas according to claim 5, characterized in that: The volume concentration of CO2 in the mixture of sulfur-containing gas and CO2 is ≥15%; and / or the H2S content in the purified coal gas is ≤10ppm, and the CO2 content is ≤2vol%.

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