Fine desulfurization system for synergistically recovering COS in metallurgical gas and control method of fine desulfurization system

Abstract

The invention belongs to the technical field of industrial gas desulfurization, and relates to a fine desulfurization system for synergistically recovering COS in metallurgical gas and a control method of the fine desulfurization system. The fine desulfurization system comprises a pretreatment device, a H2S removal device and a COS adsorption device which are arranged in sequence; the pretreatment device is filled with a pretreatment agent for removing organic and inorganic impurities in the metallurgical gas, the H2S removal device is filled with a desulfurizer for converting H2S in the metallurgical gas into S, and the COS adsorption device is filled with an adsorbent for adsorbing COS in the metallurgical gas; one end of the regeneration device is connected to an outlet pipeline of the COS adsorption device, and the other end of the regeneration device is connected to the H2S removal device so as to regenerate a saturated desulfurizer and a saturated adsorbent. A regenerated tail gas outlet of the COS adsorption device is connected to the purification device, and the purification device is used for purifying COS in regenerated tail gas of the COS adsorption device to obtain high-purity 4N carbonyl sulfide. According to the method, COS in the metallurgical gas is recycled in a synergistic manner when the metallurgical gas is subjected to desulfurization treatment, H2S corrosion is reduced, and the resource utilization degree of the sulfur element is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial gas desulfurization, and relates to a fine desulfurization system for collaboratively recovering COS in metallurgical coal gas and a control method thereof. Background Art

[0002] Carbonyl sulfide, chemical formula COS, also known as carbon oxysulfide, carbon sulfide, is usually a colorless gas with the smell of rotten eggs. High-purity carbonyl sulfide is part of the key supporting materials for the country's future development of the two strategic emerging industries of "information technology" and "new energy". It is also part of the key raw materials in the fields of high-end general chip technology, 12-inch integrated circuit chip production process, high-performance semiconductor materials (semiconductor lighting materials) large-scale production technology, TFT-LCD flat panel display technology, silicon solar cells and thin-film solar cells. It is widely used in thin film growth, etching, epitaxial wafer vapor polishing, doping, cleaning, vapor deposition, diffusion and other processes; at the same time, it also has important applications in many other fields such as optoelectronics, compound semiconductors, hard alloy coating, solar photovoltaic cells, liquid crystal displays, optical fiber manufacturing, etc. It can be predicted that its demand will show rapid growth in the next few years. However, the production capacity of my country's largest carbonyl sulfide producer is only 70t / a, which cannot meet market demand and has a high dependence on imported carbonyl sulfide.

[0003] Metallurgical gas contains different contents of COS due to different smelting processes. For example, the COS content in blast furnace gas is about 100-200 mg / Nm 3 The COS content in coke oven gas is about 250 mg / Nm 3 . According to the ultra-low emission policy, metallurgical gas (especially blast furnace gas) should be desulfurized at the source, generally using hydrolysis + dry desulfurization, in which hydrolysis converts the organic sulfur (COS, CS2) in blast furnace gas into inorganic sulfur (H2S), and then transfers the H2S in the gas to the adsorption material through physical or chemical control methods. After the material is saturated with adsorption, the sulfide is transferred to the sintering, power generation and other units equipped with flue gas desulfurization for treatment through regeneration or analysis. This desulfurization process does not make resource utilization of sulfides in the gas. Hydrolysis generates a large amount of H2S, which causes corrosion of the gas pipeline. The temperature mismatch between the hydrolysis and dry desulfurization processes causes additional gas temperature rise and fall operations, and at the same time increases the processing capacity of sintering, power generation and other units equipped with flue gas desulfurization. Taking a 1780m 3 Taking the blast furnace as an example, the amount of blast furnace gas to be processed is about 350,000 Nm 3 / h, annual operation 8000h, COS content is about 100~200mg / Nm 3 Its annual COS output is about 280 to 560 tons. If the COS can be recycled as a resource, the recycled volume can provide a stable supply to the domestic electronic special gas market. Summary of the invention

[0004] In view of this, the present invention provides a fine desulfurization system and a control method for synergistically recovering COS in metallurgical gas, which synergistically recovers COS in the metallurgical gas when the metallurgical gas is desulfurized, and is used to solve the problems of H2S corrosion, failure to recycle sulfur elements, large energy medium consumption and excessively high operating costs when the existing desulfurization process is applied to the field of metallurgical gas desulfurization.

[0005] To achieve the above-mentioned object, in a first aspect, the present invention provides a fine desulfurization system for synergistically recovering COS in metallurgical gas, comprising a pretreatment device, a H2S removal device and a COS adsorption device arranged in sequence; the metallurgical gas to be treated is introduced into the pretreatment device, and the outlet of the COS adsorption device is connected to the metallurgical gas pipeline network;

[0006] The pretreatment device is filled with a pretreatment agent for removing organic and inorganic impurities in the metallurgical gas, the H2S removal device is filled with a desulfurization agent for converting H2S in the metallurgical gas into S, and the COS adsorption device is filled with an adsorbent for adsorbing COS in the metallurgical gas;

[0007] It also includes a regeneration device for providing regeneration gas, one end of which is connected to the outlet pipeline of the COS adsorption device, and the other end is respectively connected to the de-H2S device and the COS adsorption device to regenerate the saturated desulfurizer in the de-H2S device and the saturated adsorbent in the COS adsorption device.

[0008] Optionally, the regeneration tail gas outlet of the H2S removal device is connected to the inlet pipeline of the pretreatment device.

[0009] Optionally, a purification device is further included, wherein the regeneration tail gas outlet of the COS adsorption device is connected to the purification device, and the purification device purifies COS in the regeneration tail gas of the COS adsorption device to obtain high-purity 4N carbonyl sulfide; the tail gas outlet of the purification device is connected to the inlet pipeline of the pretreatment device

[0010] Optionally, the H2S removal device includes a first H2S removal device and a second H2S removal device, the first H2S removal device is arranged between the pretreatment device and the COS adsorption device, and the second H2S removal device is connected in parallel to both ends of the first H2S removal device.

[0011] Optionally, the COS adsorption device includes a first COS adsorption device and a second COS adsorption device, the first COS adsorption device is arranged downstream of the H2S removal device, and the second COS adsorption device is connected in parallel at both ends of the first COS adsorption device.

[0012] Optionally, the regeneration device includes a first induced draft fan, a second induced draft fan and a heating device, and the regeneration gas is introduced by the first induced draft fan or the second induced draft fan; one end of the first induced draft fan is connected to the outlet pipe of the COS adsorption device, and the other end is connected to the heating device, and the second induced draft fan is connected in parallel to both ends of the first induced draft fan; the heating device is respectively connected to the H2S removal device and the COS adsorption device.

[0013] Optionally, the heating devices are respectively connected to the first H 2 S removal device, the second H 2 S removal device, the first COS adsorption device and the second COS adsorption device.

[0014] Optionally, the pretreatment device is a reactor for gas-solid phase catalytic reaction.

[0015] Optionally, the catalytic component of the pretreatment agent is one or a combination of calcium hydroxide, sodium hydroxide, magnesium hydroxide, calcium oxide, sodium oxide, and magnesium oxide; the carrier of the pretreatment agent is one or a combination of activated carbon, metal oxides, and molecular sieves.

[0016] Optionally, the H2S removal device is a reactor for gas-solid phase catalytic reaction.

[0017] Optionally, the catalytic component of the desulfurizer is one or a combination of potassium hydroxide, sodium hydroxide, ferric hydroxide, magnesium oxide, aluminum oxide, and nickel oxide; the carrier of the desulfurizer is one or a combination of activated carbon, metal oxides, and molecular sieves.

[0018] Optionally, the COS adsorption device is a reactor for gas-solid phase catalytic reaction.

[0019] Optionally, the COS adsorption device is filled with an adsorbent, and the adsorbent is one or a combination of molecular sieves, metal oxides, and activated carbon.

[0020] Optionally, a control device is also included, which is connected to the inlet of the pretreatment device, between the H2S removal device and the COS adsorption device, the outlet of the COS adsorption device and the outlet of the purification device through pipelines. A detection device for detecting the sulfur content is provided on the connecting pipelines of the control device. The control device controls the fine desulfurization system in real time according to the sulfur content detection data.

[0021] Optionally, the detection device has a built-in alkaline washing device, which is a washing bottle filled with an alkaline solution with a mass fraction of 0.1% to 30%.

[0022] Optionally, the purification device adopts a cryogenic condensation process and / or a distillation process.

[0023] In a second aspect, the present invention provides a fine desulfurization control method for collaboratively recovering COS in metallurgical coal gas, which is applied to the aforementioned fine desulfurization system for collaboratively recovering COS in metallurgical coal gas, comprising:

[0024] When the H2S content at the outlet of the first H2S removal device is ≥20mg / Nm 3 When the first H2S removal device is offline and the second H2S removal device is activated, the regeneration gas is introduced into the first H2S removal device to regenerate the saturated desulfurization agent in the first H2S removal device;

[0025] When the COS content at the outlet of the first COS adsorption device is ≥20 mg / Nm 3 When the first COS adsorption device is offline, the second COS adsorption device is activated, and the regeneration gas is introduced into the first COS adsorption device to regenerate the saturated adsorbent in the first COS adsorption device;

[0026] Alternatively, when the H2S content at the outlet of the second H2S removal device is ≥20mg / Nm 3 When the second H2S removal device is offline and the first H2S removal device is activated, the regeneration gas is introduced into the second H2S removal device to regenerate the saturated desulfurizer in the second H2S removal device;

[0027] When the COS content at the outlet of the second COS adsorption device is ≥20 mg / Nm 3 When the second COS adsorption device is offline, the first COS adsorption device is activated, and the regeneration gas is introduced into the second COS adsorption device to regenerate the saturated adsorbent in the second COS adsorption device.

[0028] Optionally, the first induced draft fan and / or the second induced draft fan are controlled to increase the pressure of the regeneration gas by 5-10 kPa; and the heating device is controlled to make the temperature of the regeneration gas reach 200-500°C.

[0029] Optionally, the reaction temperature of the pretreatment device, the H2S removal device and the COS adsorption device is controlled within the range of 30°C to 300°C, and the air velocity during the desulfurization treatment of the pretreatment device, the H2S removal device and the COS adsorption device is controlled within the range of 0 to 1000 h -1 Within the range, the space velocity during the regeneration of the H2S removal device and the COS adsorption device is controlled at 0~500h -1 within the range.

[0030] Optionally, when the desulfurizer in the first H2S removal device or the second H2S removal device is saturated, an inert gas doped with CO is used as the regeneration gas passed into the regeneration device, or a metallurgical gas after fine desulfurization treated by a pretreatment device, a H2S removal device and a COS adsorption device is used as the regeneration gas passed into the regeneration device;

[0031] When the adsorbent in the first COS adsorption device or the second COS adsorption device is saturated, N2 or water vapor is used as the regeneration gas passed into the regeneration device, or the metallurgical gas after fine desulfurization treated by the pretreatment device, the H2S removal device and the COS adsorption device is used as the regeneration gas passed into the regeneration device.

[0032] The beneficial effects of the present invention are:

[0033] First, the fine desulfurization system and control method for synergistically recovering COS from metallurgical gas provided by the present invention effectively avoids the large amount of H2S produced by the conventional fine desulfurization hydrolysis process, thereby significantly reducing the corrosion problem of the gas pipeline and improving the safe operation performance of the blast furnace gas pipeline network. This not only extends the service life of the pipeline, but also reduces the maintenance cost and safety risks caused by corrosion.

[0034] Secondly, the present invention fully matches the metallurgical gas working conditions, and does not require additional heating or cooling operations for blast furnace gas, which greatly reduces the consumption of energy media and significantly reduces the overall operating cost. This optimization of energy consumption gives the process obvious advantages in terms of economy and practicality.

[0035] Furthermore, the present invention fully absorbs COS in metallurgical coal gas through an adsorbent, and purifies COS using a purification device to finally obtain high-purity 4N carbonyl sulfide, thereby realizing high-value utilization of sulfur resources. As an important raw material in the electronic specialty gas market, the stable supply of high-purity carbonyl sulfide helps meet the needs of related domestic industries and reduce dependence on imported products.

[0036] In addition, no three wastes are generated during the entire fine desulfurization process, which meets the national environmental protection requirements and embodies the concept of green chemistry. At the same time, the desulfurization export can stably meet the national ultra-low emission standards, which helps enterprises achieve environmental compliance and enhance their corporate image and market competitiveness.

[0037] In summary, the fine desulfurization system and control method for synergistically recovering COS in metallurgical gas provided by the present invention have significant advantages such as safe operation, resource utilization of sulfur element, low operating cost, and no generation of three wastes. It is not only suitable for the field of metallurgical gas desulfurization, but also provides a technical solution that can be used as a reference for other waste gas desulfurization and purification fields.

[0038] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0040] Figure 1 A schematic structural diagram of a fine desulfurization system for collaboratively recovering COS in metallurgical coal gas provided by the present invention.

[0041] Reference numerals:

[0042] 1-pretreatment device; 2-H2S removal device; 2.1-first H2S removal device; 2.2-second H2S removal device; 3-COS adsorption device; 3.1-first COS adsorption device; 3.2-second COS adsorption device; 4-regeneration device; 4.1-first induced draft fan; 4.2-second induced draft fan; 4.3-heating device; 5-detection device; 6-control device; 7-purification device. DETAILED DESCRIPTION

[0043] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0044] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0045] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0046] The COS content in metallurgical gas varies depending on the smelting process. The current desulfurization process mainly adopts hydrolysis plus dry desulfurization, but this method has some problems: COS hydrolysis to generate H2S will cause corrosion of the gas pipeline. Due to the difference in the temperature required for the hydrolysis and desulfurization processes, the gas to be treated needs to be heated and cooled, and the processing burden of the subsequent processing units will be increased. In addition, this desulfurization process does not make resource utilization of the sulfides in the gas, and often transfers them to units equipped with flue gas desulfurization systems such as sintering and power generation for treatment. Based on this, the present invention provides a fine desulfurization system and a control method for synergistically recovering COS in metallurgical gas, which synergistically recovers COS when desulfurizing the metallurgical gas to reduce H2S corrosion and improve the resource utilization of sulfur elements.

[0047] See also Figure 1 The present invention provides a fine desulfurization system for synergistically recovering COS in metallurgical coal gas, comprising a pretreatment device 1, a H2S removal device 2, a COS adsorption device 3, a regeneration device 4, a purification device 7, a detection device 5 and a control device 6.

[0048] The pretreatment device 1, the H2S removal device 2 and the COS adsorption device 3 are arranged in series along the flow direction of the metallurgical gas to be treated, the metallurgical gas to be treated is introduced into the pretreatment device 1, and the outlet of the COS adsorption device 3 is connected to the metallurgical gas pipeline network. The regeneration device 4 is used to provide regeneration gas, one end of which is connected to the outlet pipeline of the COS adsorption device 3, and the other end is connected to the H2S removal device 2 and the COS adsorption device 3 respectively, so as to regenerate the saturated desulfurizer in the H2S removal device 2 and the saturated adsorbent in the COS adsorption device 3.

[0049] Further, the H2S removal device 2 includes a first H2S removal device 2.1 and a second H2S removal device 2.2, the first H2S removal device 2.1 is arranged between the pretreatment device 1 and the COS adsorption device 3, and the second H2S removal device 2.2 is connected in parallel at both ends of the first H2S removal device 2.1. The COS adsorption device 3 includes a first COS adsorption device 3.1 and a second COS adsorption device 3.2, the first COS adsorption device 3.1 is arranged downstream of the H2S removal device 2, and the second COS adsorption device 3.2 is connected in parallel at both ends of the first COS adsorption device 3.1.

[0050] The regeneration device 4 includes a first induced draft fan 4.1, a second induced draft fan 4.2 and a heating device 4.3; one end of the first induced draft fan 4.1 is connected to the outlet pipe of the COS adsorption device 3, and the other end is connected to the heating device 4.3, and the second induced draft fan 4.2 is connected in parallel to both ends of the first induced draft fan 4.1; the heating device 4.3 is respectively connected to the H2S removal device 2 and the COS adsorption device 3. In this embodiment, the heating device 4.3 is respectively connected to the first H2S removal device 2.1, the second H2S removal device 2.2, the first COS adsorption device 3.1 and the second COS adsorption device 3.2.

[0051] Furthermore, the control device 6 is connected to the inlet of the pretreatment device 1, between the H2S removal device 2 and the COS adsorption device 3, the outlet of the COS adsorption device 3 and the outlet of the purification device 7 through pipelines. A detection device 5 for detecting the sulfur content is provided on the connecting pipelines of the control device 6. The control device 6 controls the fine desulfurization system in real time according to the sulfur content detection data.

[0052] Specifically, the pretreatment device 1 is used to remove organic and inorganic impurities in the metallurgical gas, such as chlorine, naphthalene, tar, etc., to protect the normal operation of the subsequent H2S removal device 2. The pretreatment device 1 can use a fixed bed, radial bed, fluidized bed, etc. reactor for gas-solid phase catalytic reaction, and its reaction temperature is controlled within the range of 30°C to 300°C, and the space velocity during desulfurization is controlled within the range of 0 to 1000h -1 Preferably, the air velocity during desulfurization of the pretreatment device 1 is 500h -1 ; Further, the pretreatment device 1 is filled with a pretreatment agent, the catalytic component of the pretreatment agent is one or a combination of calcium hydroxide, sodium hydroxide, magnesium hydroxide, calcium oxide, sodium oxide, and magnesium oxide; the carrier of the pretreatment agent is one or a combination of activated carbon, metal oxide, and molecular sieve.

[0053] The H2S removal device 2 is used to remove H2S from metallurgical coal gas, and oxidizes H2S to generate S through catalytic action and stores it in the pores of the desulfurizer. The H2S removal device 2 can use a fixed bed, radial bed, fluidized bed or other reactor for gas-solid phase catalytic reaction, and its reaction temperature is controlled within the range of 30℃~300℃, and the space velocity during desulfurization is controlled within the range of 0~1000h -1 Preferably, the space velocity during desulfurization of the H2S removal device 2 is 500h -1 Furthermore, the H2S removal device 2 is loaded with a desulfurizer, the catalytic component of the desulfurizer is one or a combination of potassium hydroxide, sodium hydroxide, iron hydroxide, magnesium oxide, aluminum oxide, and nickel oxide; the carrier of the desulfurizer is one or a combination of activated carbon, metal oxides, and molecular sieves.

[0054] The COS adsorption device 3 is used to adsorb organic sulfur (COS) in metallurgical coal gas, and desorbs COS through regeneration and passes it into the purification device 7 to obtain high-purity 4N carbonyl sulfide. The COS adsorption device 3 can use a fixed bed, radial bed, fluidized bed or other reactor for gas-solid phase reaction, and its reaction temperature is controlled within the range of 30°C to 300°C, and the space velocity during desulfurization is controlled within the range of 0 to 1000 h -1 Preferably, the space velocity during desulfurization of COS adsorption device 3 is 500h -1 Furthermore, the COS adsorption device 3 is filled with an adsorbent, which is one or a combination of molecular sieves, metal oxides, and activated carbon.

[0055] The regeneration device 4 is used to regenerate the saturated desulfurizer in the H2S removal device 2 and the saturated adsorbent in the COS adsorption device 3. The first induced draft fan 4.1 and the second induced draft fan 4.2 are used to increase the pressure of the regenerated gas by 5 to 10 kPa, and the heating device 4.3 is used to increase the temperature of the regenerated gas to 200°C to 500°C;

[0056] Furthermore, the regeneration gas introduced into the regeneration device 4 is metallurgical gas after fine desulfurization, inert gas doped with CO, N2, water vapor, etc.

[0057] When regenerating the desulfurizer in the H2S removal device 2, an inert gas doped with CO is selected as the regeneration gas. CO reacts with the S in the saturated desulfurizer to generate COS. The regenerated tail gas containing a small amount of COS is introduced into the inlet of the pretreatment device 1 and merged with the newly introduced metallurgical coal gas to be treated for pretreatment.

[0058] When regenerating the adsorbent in the COS adsorption device 3, metallurgical gas after fine desulfurization, N2, and water vapor are selected as the regeneration gas, and N2 is more preferably used. The regeneration process of the adsorbent mainly depends on the high temperature environment. The high-temperature regeneration gas after heating is introduced into the COS adsorption device 3, and the COS in the saturated adsorbent is desorbed at high temperature. The regeneration tail gas containing a large amount of COS is introduced into the purification device 7, and the purification device 7 purifies COS to obtain high-purity 4N carbonyl sulfide.

[0059] Furthermore, the regeneration temperature of the regeneration device 4 is controlled within the range of 200°C to 500°C, and the air velocity is controlled within the range of 0 to 500 h -1 Preferably, the air velocity of the regeneration device 4 is 100h -1 .

[0060] The purification device 7 is used to purify COS in the regenerated tail gas of the COS adsorption device to obtain high-purity 4N carbonyl sulfide. The purification device 7 can use a low-temperature condensation process and / or a distillation process. The tail gas generated by the purification operation is combined with the metallurgical coal gas to be treated before being introduced into the pretreatment device 1 for pretreatment.

[0061] The detection device 5 is used to detect the sulfur content in the gas of each process in real time, and the control device 5 controls the fine desulfurization system in real time according to the sulfur content detection data. The detection device 5 can select gas detection instruments such as gas chromatograph, detection tube, portable detector, etc., preferably using a gas chromatograph. Further, the air intake flow rate of the detection device 5 is controlled within the range of 20 to 50 mL / min. The detection device 5 has a built-in alkaline washing device to absorb the sulfur-containing components in the gas after detection by the sulfur content detection device. The alkaline washing device is a gas washing bottle, which is filled with an alkaline solution with a mass fraction of 0.1% to 30%, and the alkaline solution is one or more mixed solutions of NaOH, KOH, Na2CO3, and K2CO3.

[0062] Based on the above-mentioned fine desulfurization system for synergistically recovering COS in metallurgical gas, the present invention also proposes a control method for the fine desulfurization system for synergistically recovering COS in metallurgical gas. When the sulfur content detection data at the outlet of the H2S removal device 2 shows that the H2S content is ≥20mg / Nm 3 When the sulfur content at the outlet of COS adsorption device 3 is detected, the COS content is ≥20mg / Nm 3 When the COS adsorption device is switched to a spare COS adsorption device, the original COS adsorption device is regenerated, and the regenerated tail gas is passed into a purification device for COS purification to obtain high-purity 4N carbonyl sulfide.

[0063] In this embodiment, when the H2S content at the outlet of the first H2S removal device 2.1 (or the second H2S removal device 2.2) is ≥ 20 mg / Nm 3 When the first H2S removal device 2.1 (or the second H2S removal device 2.2) is offline and the second H2S removal device 2.2 (or the first H2S removal device 2.1) is activated, and the regeneration gas is introduced into the first H2S removal device 2.1 (or the second H2S removal device 2.2) to regenerate the saturated desulfurization agent in the first H2S removal device 2.1 (or the second H2S removal device 2.2). The space velocity during the regeneration of the first H2S removal device 2.1 or the second H2S removal device 2.2 is controlled at 0 to 500 h -1 within the range.

[0064] When the COS content at the outlet of the first COS adsorption device 3.1 (or the second COS adsorption device 3.2) is ≥ 20 mg / Nm 3When the first COS adsorption device 3.1 (or the second COS adsorption device 3.2) is offline and the second COS adsorption device 3.2 (or the first COS adsorption device 3.1) is activated, the regeneration gas is introduced into the first COS adsorption device 3.1 (or the second COS adsorption device 3.2) to regenerate the saturated adsorbent in the first COS adsorption device 3.1 (or the second COS adsorption device 3.2). The space velocity during the regeneration of the first COS adsorption device 3.1 or the second COS adsorption device 3.2 is controlled at 0 to 500 h -1 within the range.

[0065] When the desulfurizer in the first H2S removal device 2.1 or the second H2S removal device 2.2 is saturated, the regeneration gas introduced into the regeneration device 4 is the metallurgical gas after fine desulfurization or the inert gas doped with CO, and the metallurgical gas after fine desulfurization is drawn from the outlet pipe of the COS adsorption device 3; when the adsorbent in the first COS adsorption device 3.1 or the second COS adsorption device 3.2 is saturated, the regeneration gas introduced into the regeneration device 4 is the metallurgical gas after fine desulfurization, N2 or water vapor, and the metallurgical gas after fine desulfurization is drawn from the outlet pipe of the COS adsorption device 3.

[0066] Furthermore, the first induced draft fan 4.1 and / or the second induced draft fan 4.2 are controlled to increase the pressure of the regeneration gas by 5 to 10 kPa; the heating device 4.3 is controlled to make the temperature of the regeneration gas reach 200 to 500°C. The reaction temperature of the pretreatment device 1, the H2S removal device 2 and the COS adsorption device 3 is controlled within the range of 30°C to 300°C, and the air velocity during the desulfurization treatment of the pretreatment device 1, the H2S removal device 2 and the COS adsorption device 3 is controlled within the range of 0 to 1000 h / min. -1 Within the range, the space velocity during the regeneration of the H2S removal device 2 and the COS adsorption device 3 is controlled within the range of 0 to 500 h -1 within the range.

[0067] Based on the above-mentioned fine desulfurization system for collaboratively recovering COS in metallurgical gas and its control, the present invention provides the following embodiments:

[0068] Example 1

[0069] 1) The amount of blast furnace gas to be processed is 100,000 Nm 3 / h, the temperature range is 100℃~200℃, the pressure is 0.2MPa(g), and the sulfur content in blast furnace gas is H2S(30mg / Nm 3 )、COS(120mg / Nm 3 ).

[0070] 2) Pre-treatment device 1 filling 200m 3 Calcium oxide-molecular sieve catalyst, space velocity maintained at 500h -1After being treated in the pretreatment device 1, the blast furnace gas is introduced into the first H2S removal device 2.1.

[0071] 3) First H2S removal unit 2.1 filling 200m 3 Ferric hydroxide-activated carbon catalyst, space velocity maintained at 500h -1 After being treated by the first H2S removal device 2.1, the sulfur content of the blast furnace gas is H2S (3mg / Nm 3 )、COS(110mg / Nm 3 ), the H2S removal efficiency is 90%, and a small amount of COS can be removed at the same time, with an efficiency of 8.33%.

[0072] 4) The first COS adsorption device 3.1 uses 200m 3 Molecular sieve adsorbent, space velocity maintained at 500h -1 After being treated by the first COS adsorption device 3.1, the sulfur content of the blast furnace gas is H2S (3mg / Nm 3 )、COS(10mg / Nm 3 ), COS removal efficiency 90.91%.

[0073] 5) When the sulfur content detection data at the outlet of the first H2S removal device 2.1 shows that the H2S content is 20 mg / Nm 3 When the second H2S removal device 2.2 is switched, the first H2S removal device 2.1 is regenerated: 20,000 Nm 3 / h of fine desulfurized blast furnace gas pressurized to 5kPa, heated to 200℃ and then passed into the first H2S removal device 2.1 with saturated adsorption, and the air velocity was maintained at 100h -1 , CO in the blast furnace gas reacts with S generated by the desulfurization reaction in the first H2S removal device 2.1 to generate COS for regeneration, and the regenerated tail gas is combined with the blast furnace gas to be treated before entering the pretreatment device 1 for pretreatment, and then all the generated COS is adsorbed by the COS adsorption device 3 to avoid waste of sulfur resources.

[0074] 6) When the sulfur content detection data at the outlet of the first COS adsorption device 3.1 is 20 mg / Nm 3 When the second COS adsorption device 3.2 is switched, the first COS adsorption device 3.1 is regenerated: 20,000 Nm 3 / h of desulfurized blast furnace gas at 5 kPa, heated to 350°C and then introduced into the first COS adsorption device 3.1, which is saturated with adsorption, with the air velocity maintained at 100 h -1 The regenerated tail gas is introduced into the purification device 7, and COS is purified by a low-temperature condensation process to obtain high-purity 4N carbonyl sulfide. The tail gas produced by the purification device 7 is introduced into the pretreatment device 1 and merged with the blast furnace gas to be treated for pretreatment.

[0075] Example 2

[0076] 1) The amount of coke oven gas to be processed is 40,000 Nm 3 / h, the temperature range is 40℃~60℃, the pressure is 5kPa(g), and the sulfur content in the coke oven gas is H2S(50mg / Nm 3 )、COS(250mg / Nm 3 ).

[0077] 2) Pre-treatment device 1 is filled with 100m 3 Sodium hydroxide-activated carbon catalyst, space velocity maintained at 400h -1 After being treated in the pretreatment device 1, the coke oven gas is introduced into the first H2S removal device 2.1.

[0078] 3) First H2S removal unit 2.1 filling 100m 3 Nickel oxide-molecular sieve catalyst, space velocity maintained at 400h -1 The sulfur content of the coke oven gas after treatment by the first H2S removal device 2.1 is H2S (5mg / Nm 3 )、COS(250mg / Nm 3 ), H2S removal efficiency 90%.

[0079] 4) The first COS adsorption device 3.1 uses 200m 3 Activated carbon adsorbent, space velocity maintained at 200h -1 After being treated by COS adsorption device 3.1, the sulfur content of coke oven gas is H2S (5mg / Nm 3 )、COS(15mg / Nm 3 ), COS removal efficiency 94%.

[0080] 5) When the sulfur content detection data at the outlet of the first H2S removal device 2.1 shows that the H2S content is 20 mg / Nm 3 When the second H2S removal device 2.2 is switched, the first H2S removal device 2.1 is regenerated: 5000Nm 3 / h pressurized 10kPa purified coke oven gas, heated to 230℃ and then passed into the first H2S removal device 2.1 with saturated adsorption, and the air velocity was maintained at 50h -1 , CO in the coke oven gas reacts with S generated by the desulfurization reaction in the first H2S removal device 2.1 to generate COS for regeneration, and the regenerated tail gas is combined with the coke oven gas to be treated before entering the pretreatment device 1 for pretreatment, and then all the generated COS is adsorbed by the COS adsorption device 3 to avoid waste of sulfur resources.

[0081] 6) When the sulfur content detection data after the first COS adsorption device 3.1 is 20mg / Nm3 When the second COS adsorption device 3.2 is switched, the first COS adsorption device 3.1 is regenerated: 10,000 Nm 3 / h pressurized 10kPa purified coke oven gas, heated to 300℃ and then passed into the first COS adsorption device 3.1 for adsorption saturation, with the air velocity maintained at 50h -1 The regenerated tail gas is introduced into the purification device 7, and COS is purified by distillation process to obtain high-purity 4N carbonyl sulfide. The tail gas produced by the purification device 7 is introduced into the pretreatment device 1 and merged with the coke oven gas to be treated for pretreatment.

[0082] Example 3

[0083] 1) The amount of blast furnace gas to be processed is 500,000 Nm 3 / h, the temperature range is 40℃~80℃, the pressure is 10kPa(g), and the sulfur content in blast furnace gas is H2S(70mg / Nm 3 )、COS(100mg / Nm 3 ).

[0084] 2) Pre-treatment device 1 filling 500m 3 Calcium oxide-molecular sieve catalyst, space velocity maintained at 1000h -1 After being treated in the pretreatment device 1, the blast furnace gas is introduced into the first H2S removal device 2.1.

[0085] 3) First H2S removal unit 2.1 filling 1000m 3 Alumina-activated carbon catalyst, space velocity maintained at 500h -1 After being treated by the first H2S removal device 2.1, the sulfur content of the blast furnace gas is H2S (7mg / Nm 3 )、COS(100mg / Nm 3 ), H2S removal efficiency 90%.

[0086] 4) The first COS adsorption device 3.1 uses 1000m 3 Al2O3 adsorbent, space velocity maintained at 500h -1 After being treated by the first COS adsorption device 3.1, the sulfur content of the blast furnace gas is H2S (7mg / Nm 3 )、COS(10mg / Nm 3 ), COS removal efficiency 90%.

[0087] 5) When the sulfur content detection data at the outlet of the first H2S removal device 2.1 shows that the H2S content is 20 mg / Nm 3 When the second H2S removal device 2.2 is switched, the first H2S removal device 2.1 is regenerated: 50,000 Nm 3 / h pressurized 5kPa purified blast furnace gas, heated to 200℃ and then passed into the first H2S removal device 2.1 with saturated adsorption, and the air velocity was maintained at 50h -1 , CO in the blast furnace gas reacts with S generated by the desulfurization reaction to generate COS for regeneration, and the regenerated tail gas is combined with the blast furnace gas to be treated before entering the pretreatment device 1 for pretreatment, and then all the generated COS is adsorbed by the COS adsorption device 3 to avoid waste of sulfur resources.

[0088] 6) When the sulfur content detection data at the outlet of the first COS adsorption device 3.1 is 20 mg / Nm 3 When the second COS adsorption device 3.2 is switched, the first COS adsorption device 3.1 is regenerated: 50,000 Nm 3 / h pressurized with 10kPa N2, heated to 220℃ and then introduced into the first COS adsorption device 3.1 for adsorption saturation, and the air velocity was maintained at 50h -1 The regenerated tail gas is introduced into the purification device 7, and COS is purified by a low-temperature condensation process to obtain high-purity 4N carbonyl sulfide. The tail gas produced by the purification device 7 is introduced into the pretreatment device 1 and merged with the blast furnace gas to be treated for pretreatment.

[0089] In summary, it can be seen that the fine desulfurization system and control method for synergistically recovering COS in metallurgical gas provided by the present invention effectively avoids the corrosion of H2S produced in the conventional hydrolysis process to the gas pipeline, matches the metallurgical gas working conditions to reduce energy consumption, and realizes high-value utilization of sulfur resources through adsorption and purification. In addition, no three wastes are generated in the entire process, which meets the national environmental protection requirements, has multiple advantages such as safe operation, low cost, and environmental protection, and provides a technical solution that can be used as a reference for the field of desulfurization and purification of metallurgical gas and other waste gases.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A fine desulfurization system for collaboratively recovering COS from metallurgical coal gas, characterized by: The invention comprises a pretreatment device (1), a H2S removal device (2) and a COS adsorption device (3) which are arranged in sequence; the metallurgical gas to be treated is introduced into the pretreatment device (1), and the outlet of the COS adsorption device (3) is connected to the metallurgical gas pipeline network; The pretreatment device (1) is filled with a pretreatment agent for removing organic and inorganic impurities in the metallurgical gas, the H2S removal device is filled with a desulfurization agent for converting H2S in the metallurgical gas into S, and the COS adsorption device (3) is filled with an adsorbent for adsorbing COS in the metallurgical gas; It also includes a regeneration device (4), which is used to provide regeneration gas, one end of which is connected to the outlet pipeline of the COS adsorption device (3), and the other end is connected to the H2S removal device (2) and the COS adsorption device (3) respectively, so as to regenerate the saturated desulfurization agent in the H2S removal device (2) and the saturated adsorbent in the COS adsorption device (3).

2. The fine desulfurization system according to claim 1, characterized in that: The regeneration tail gas outlet of the H2S removal device (2) is connected to the inlet pipeline of the pretreatment device (1).

3. The fine desulfurization system according to claim 1, characterized in that: The invention also comprises a purification device (7), wherein the regeneration tail gas outlet of the COS adsorption device (3) is connected to the purification device (7), and the purification device (7) purifies COS in the regeneration tail gas of the COS adsorption device (3) to obtain high-purity 4N carbonyl sulfide; and the tail gas outlet of the purification device (7) is connected to the inlet pipe of the pretreatment device (1).

4. The fine desulfurization system according to claim 1, characterized in that: The H2S removal device (2) comprises a first H2S removal device (2.1) and a second H2S removal device (2.2), wherein the first H2S removal device (2.1) is arranged between the pretreatment device (1) and the COS adsorption device (3), and the second H2S removal device (2.2) is connected in parallel to both ends of the first H2S removal device (2.1).

5. The fine desulfurization system according to claim 4, characterized in that: The COS adsorption device (3) comprises a first COS adsorption device (3.1) and a second COS adsorption device (3.2), wherein the first COS adsorption device (3.1) is arranged downstream of the H2S removal device (2), and the second COS adsorption device (3.2) is connected in parallel to both ends of the first COS adsorption device (3.1).

6. The fine desulfurization system according to claim 5, characterized in that: The regeneration device (4) comprises a first induced draft fan (4.1), a second induced draft fan (4.2) and a heating device (4.3); the regeneration gas is introduced by the first induced draft fan (4.1) or the second induced draft fan (4.2); One end of the first induced draft fan (4.1) is connected to the outlet pipe of the COS adsorption device (3), and the other end is connected to the heating device (4.3); the second induced draft fan (4.2) is connected in parallel to both ends of the first induced draft fan (4.1); The heating device (4.3) is connected to the H2S removal device (2) and the COS adsorption device (3) respectively.

7. The fine desulfurization system according to claim 6, characterized in that: The heating device (4.3) is connected to the first H2S removal device (2.1), the second H2S removal device (2.2), the first COS adsorption device (3.1) and the second COS adsorption device (3.2), respectively.

8. The fine desulfurization system according to claim 1, characterized in that: The pretreatment device (1) is a reactor used for gas-solid phase catalytic reaction.

9. The fine desulfurization system according to claim 1, characterized in that: The catalytic component of the pretreatment agent (1) is one or a combination of calcium hydroxide, sodium hydroxide, magnesium hydroxide, calcium oxide, sodium oxide, and magnesium oxide; the carrier of the pretreatment agent (1) is one or a combination of activated carbon, metal oxide, and molecular sieve.

10. The fine desulfurization system according to claim 1, characterized in that: The H2S removal device (2) is a reactor used for gas-solid phase catalytic reaction.

11. The fine desulfurization system according to claim 1, characterized in that: The catalytic component of the desulfurizer is one or a combination of potassium hydroxide, sodium hydroxide, ferric hydroxide, magnesium oxide, aluminum oxide, and nickel oxide; the carrier of the desulfurizer is one or a combination of activated carbon, metal oxide, and molecular sieve.

12. The fine desulfurization system according to claim 1, characterized in that: The COS adsorption device (3) is a reactor used for gas-solid phase catalytic reaction.

13. The fine desulfurization system according to claim 1, characterized in that: The adsorbent is one or a combination of molecular sieves, metal oxides and activated carbon.

14. The fine desulfurization system according to claim 1, characterized in that: The system further comprises a control device (6), which is connected to the inlet of the pretreatment device (1), between the H2S removal device (2) and the COS adsorption device (3), the outlet of the COS adsorption device (3) and the outlet of the purification device (7) through pipelines. A detection device (5) for detecting the sulfur content is provided on the connecting pipelines of the control device (6). The control device (6) controls the fine desulfurization system in real time according to the sulfur content detection data.

15. The fine desulfurization system according to claim 14, characterized in that: The detection device (5) has an alkali washing device built in, and the alkali washing device is a washing bottle filled with an alkaline solution with a mass fraction of 0.1% to 30%.

16. The fine desulfurization system according to claim 3, characterized in that: The purification device (7) adopts a low-temperature condensation process and / or a distillation process.

17. A fine desulfurization control method for synergistic recovery of COS in metallurgical coal gas, applied to the fine desulfurization system for synergistic recovery of COS in metallurgical coal gas as claimed in any of the preceding claims, characterized in that: When the H2S content at the outlet of the first H2S removal device (2.1) is ≥ 20 mg / Nm 3 When the first H2S removal device (2.1) is offline and the second H2S removal device (2.2) is activated, the regeneration gas is introduced into the first H2S removal device (2.1) to regenerate the saturated desulfurizing agent in the first H2S removal device (2.1); When the COS content at the outlet of the first COS adsorption device (3.1) is ≥20 mg / Nm 3 When the first COS adsorption device (3.1) is offline and the second COS adsorption device (3.2) is activated, the regeneration gas is introduced into the first COS adsorption device (3.1) to regenerate the saturated adsorbent in the first COS adsorption device (3.1); Alternatively, when the H2S content at the outlet of the second H2S removal device (2.2) is ≥ 20 mg / Nm 3 When the second H2S removal device (2.2) is offline and the first H2S removal device (2.1) is activated, the regeneration gas is introduced into the second H2S removal device (2.2) to regenerate the saturated desulfurizing agent in the second H2S removal device (2.2); When the COS content at the outlet of the second COS adsorption device (3.2) is ≥ 20 mg / Nm 3 When the second COS adsorption device (3.2) is offline and the first COS adsorption device (3.1) is activated, the regeneration gas is introduced into the second COS adsorption device (3.2) to regenerate the saturated adsorbent in the second COS adsorption device (3.2).

18. The fine desulfurization control method according to claim 17, characterized in that: The first induced draft fan (4.1) and / or the second induced draft fan (4.2) are controlled to increase the pressure of the regeneration gas by 5 to 10 kPa; and the heating device (4.3) is controlled to increase the temperature of the regeneration gas to 200 to 500°C.

19. The fine desulfurization control method according to claim 17, characterized in that: The reaction temperature of the pretreatment device (1), the H2S removal device (2) and the COS adsorption device (3) is controlled within the range of 30°C to 300°C, and the space velocity during desulfurization treatment of the pretreatment device (1), the H2S removal device (2) and the COS adsorption device (3) is controlled within the range of 0 to 1000 h / s. -1 Within the range, the space velocity during the regeneration of the H2S removal device (2) and the COS adsorption device (3) is controlled to be 0 to 500 h -1 within the range.

20. The fine desulfurization control method according to claim 17, characterized in that: When the desulfurizing agent in the first H2S removal device (2.1) or the second H2S removal device (2.2) is saturated, an inert gas doped with CO is used as the regeneration gas introduced into the regeneration device (4), or a metallurgical gas subjected to fine desulfurization after being treated by the pretreatment device (1), the H2S removal device (2) and the COS adsorption device (3) is used as the regeneration gas introduced into the regeneration device (4); When the adsorbent in the first COS adsorption device (3.1) or the second COS adsorption device (3.2) is saturated, N2 or water vapor is used as the regeneration gas passed into the regeneration device (4), or the metallurgical gas after fine desulfurization treated by the pretreatment device (1), the H2S removal device (2) and the COS adsorption device (3) is used as the regeneration gas passed into the regeneration device (4).

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