Blast furnace gas fine desulfurization integrated equipment and method

Abstract

The invention provides blast furnace gas fine desulfurization integrated equipment and a blast furnace gas fine desulfurization integrated method. The integrated equipment comprises a cloth bag dust removal device, a deoxidation unit tower, a hydrolysis unit tower, a power generation device and a dry desulfurization device, according to the method, firstly, blast furnace gas is subjected to bag dust removal, then passes through a deoxidation unit and then enters the carbonyl sulfide hydrolysis system, the hydrolyzed gas enters the residual pressure turbine power generation device and then enters the dry desulfurization system, the desulfurization system is provided with two towers, one tower is used, and the other tower is standby. And when the working desulfurization tower is saturated in adsorption, the standby tower is started, and meanwhile, the regeneration system is started to regenerate the desulfurizer saturated in adsorption. The method can protect the rear-end hydrolytic agent, does not generate solid waste and wastewater, and is safer, more environment-friendly and more economical.

Description

Technical Field

[0001] The present invention relates to the technical field of air pollution control, and in particular to an integrated device and method for fine desulfurization of blast furnace gas. Background Art

[0002] Blast furnace gas is one of the main fuels for the entire steel company and is often used as fuel for blast furnaces in power plants, hot blast furnaces in steel rolling mills, and heating furnaces in ironmaking plants. The SO2 content in the flue gas emitted by blast furnace gas does not meet the national ultra-clean emission requirements. The SO2 content in the flue gas emitted is usually greater than 50mg / m 3 , even up to 200mg / m 3 above.

[0003] The main components of blast furnace gas are CO, CO2, N2, and also contain a small amount of O2, COS, H2S, dust, etc. In order to meet the requirements of source control, COS, H2S and dust in blast furnace gas need to be removed. Patent CN110643395A uses bag dust removal and then enters the top of the hydrolysis tower to contact with the honeycomb carbonyl sulfide hydrolysis catalyst in the tower to convert organic sulfur into hydrogen sulfide. After the hydrolyzed hydrogen sulfide-containing blast furnace gas passes through a turbine to generate electricity, the sulfide is removed by countercurrent contact with alkaline solution in the absorption tower. After the purified blast furnace gas is separated by a demister from the top of the absorption tower, the gas enters the gas pipeline network. This method has small pressure loss and has little impact on TRT power generation, but the hydrolysis reaction temperature of this process is higher than 80°C. Hydrolysis tests under O2 conditions found that the hydrolyzing agent is easily sulfated, and the active components of the hydrolyzing agent generate sulfate, which reduces the hydrolysis efficiency and shortens the life of the hydrolyzing agent. In addition, the agent uses alkaline solution absorption method to remove hydrogen sulfide, which will produce a large amount of wastewater.

[0004] Therefore, at present, there are few cases of blast furnace gas source control. Blast furnace gas is mainly composed of CO, CO2, a small amount of H2, O2, and harmful components such as carbonyl sulfide COS and inorganic sulfur H2S. Source control requires that carbonyl sulfide COS be converted into inorganic sulfur H2S under the action of carbonyl sulfide hydrolyzing agent before desulfurization. Due to the oxygen content in the raw gas, the current carbonyl sulfide hydrolyzing agent is easily sulfated under oxygen-containing conditions, and the hydrolysis efficiency decreases, resulting in a shortened hydrolyzing agent life and incomplete carbonyl sulfide hydrolysis. In addition, carbonyl sulfide is converted into inorganic sulfur hydrogen sulfide after hydrolysis. Hydrogen sulfide is usually absorbed by alkali solution method. Since the raw gas contains a large amount of CO2, it consumes a lot of alkali and also produces a large amount of difficult-to-control desulfurization wastewater.

[0005] Therefore, in response to this situation, the present invention has developed an integrated device and method that can remove oxygen from blast furnace gas, protect the life of carbonyl sulfide hydrolyzing agent, adopt dry method to recycle and regenerate desulfurizing agent, solve the problems of wastewater and solid waste, and has excellent economic efficiency. Summary of the invention

[0006] The purpose of the present invention is to solve the shortcomings of the prior art and to propose an integrated device and method for fine desulfurization of blast furnace gas.

[0007] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: an integrated device for fine desulfurization of blast furnace gas, the integrated device comprising a bag dust removal device, a deoxidation unit tower, a hydrolysis unit tower, a power generation device and a dry desulfurization device; the dry desulfurization device comprises a desulfurization unit tower and a desulfurization standby unit tower.

[0008] A method for integrated equipment for fine desulfurization of blast furnace gas, the specific steps of the method are as follows: S1: Blast furnace gas passes through bag dust removal device; S2: The blast furnace gas after dust removal passes through the deoxidation unit tower and enters the hydrolysis unit tower; S3: The hydrolyzed coal gas enters the power generation device; S4: The coal gas treated in step S3 enters the dry desulfurization device, and the desulfurization standby unit tower is opened when the desulfurization unit tower is saturated with adsorption.

[0009] Preferably, in step S1, the bag dust removal device has an intelligent monitoring device and an automatic cleaning device.

[0010] Preferably, in step S2, a deoxidizer layer is provided in the deoxidizer unit tower; a deoxidizer discharge port and a deoxidizer feed port are provided at the bottom of the deoxidizer layer; and the deoxidizer in the deoxidizer layer adopts a sulfur-resistant deoxidation catalyst.

[0011] Preferably, the hydrolysis unit tower in step S2 comprises a hydrolysis reactor and a sonic soot blowing system; the hydrolysis unit tower adopts a carbonyl sulfide hydrolysis system.

[0012] Preferably, the desulfurization unit tower in step S2 includes a desulfurizer layer; a desulfurizer discharge port and a desulfurizer feed port are provided at the bottom of the desulfurizer layer; the desulfurizer in the desulfurizer layer is an iron-based desulfurizer; and the desulfurizer adsorbs hydrogen sulfide to generate Fe2S3.

[0013] Preferably, the power generation device uses a residual pressure turbine for power generation.

[0014] Preferably, in step S4, a desulfurization agent regeneration system is further provided in the dry desulfurization device; the desulfurization agent regeneration system is respectively connected to pipelines of the desulfurization standby unit towers which are opened after the desulfurization unit towers are saturated with adsorption.

[0015] Preferably, the desulfurizer regeneration system includes a high-speed pulping tank, an oxidation tank, a flotation tank, a deodorizing draft fan, an oxidation air compressor, a plate and frame filter and a molding device.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention protects the carbonyl sulfide hydrolyzing agent and ensures the efficiency of carbonyl sulfide hydrolysis by adopting the combined method of "deoxygenation + carbonyl sulfide hydrolysis + dry desulfurization + desulfurizing agent regeneration"; adopts the dry desulfurization process to achieve deep purification of blast furnace gas of steel enterprises before entering downstream users, thereby solving the problem of excessive flue gas emissions of downstream users of blast furnace gas in the industry; adopts a renewable and recyclable desulfurizing agent, thereby eliminating the problem of a large amount of wastewater caused by alkaline solution desulfurization, and through regeneration and circulation, avoids the generation of solid waste. The equipment and method have the advantages of economy, environmental protection, safety, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a process flow chart of blast furnace gas desulfurization according to the present invention; Figure 2 This is a flow chart of the desulfurizer regeneration process of the present invention. DETAILED DESCRIPTION

[0018] In order to provide a further understanding of the purpose, structure, features, and functions of the present invention, the following detailed description is given in conjunction with the embodiments.

[0019] Please refer to Figure 1 The present invention provides an integrated device for fine desulfurization of blast furnace gas, the integrated device comprising a bag dust removal device 1, a deoxidation unit tower 2, a hydrolysis unit tower 3, a power generation device 4 and a dry desulfurization device 5; the dry desulfurization device 5 comprises a desulfurization unit tower 51 and a desulfurization standby unit tower 52.

[0020] A method for integrated equipment for fine desulfurization of blast furnace gas, the specific steps of the method are as follows: S1: blast furnace gas passes through bag dust removal device 1; S2: The blast furnace gas after dust removal passes through the deoxidation unit tower 2 and enters the hydrolysis unit tower 3; S3: The hydrolyzed coal gas enters the power generation device 4; S4: The coal gas treated in step S3 enters the dry desulfurization device 5, and the desulfurization standby unit tower 52 is opened when the desulfurization unit tower 51 is saturated with adsorption.

[0021] The blast furnace gas after the bag dust removal device 1 first enters the deoxygenation unit tower 2. Under the action of the deoxygenation catalyst, the low concentration of oxygen in the raw gas reacts with CO or H2 to achieve the purpose of removing oxygen. The deoxygenated raw gas then enters from the top of the hydrolysis tower. The hydrolysis reactor 31 includes a hydrolysis catalyst. The raw gas and the hydrolysis catalyst are in contact in the tower. The carbonyl sulfide in the blast furnace gas converts organic sulfur into hydrogen sulfide under the action of the hydrolysis agent. At the same time, in order to prevent the hydrolysis catalyst in the hydrolysis reactor 31 from being blocked, a sonic soot blowing system 32 is added to perform regular blowing to prevent the hydrolysis catalyst pores from being blocked by fly ash and reducing the hydrolysis efficiency.

[0022] Preferably, in step S1, the bag dust removal device 1 has an intelligent monitoring device and an automatic cleaning device.

[0023] Preferably, in step S2, a deoxidizer layer 21 is provided in the deoxidizer unit tower 2; a deoxidizer discharge port 22 and a deoxidizer feed port 23 are provided at the bottom of the deoxidizer layer 21; and the deoxidizer in the deoxidizer layer 21 is a sulfur-resistant deoxidation catalyst.

[0024] Preferably, the hydrolysis unit tower 3 in step S2 includes a hydrolysis reactor 31 and a sonic soot blowing system 32; the hydrolysis unit tower 3 adopts a carbonyl sulfide hydrolysis system.

[0025] Compared with traditional hydrolysis methods, the carbonyl sulfide hydrolysis system may produce fewer by-products, reduce pollution to the environment, and meet the requirements of sustainable development; the sonic soot blowing system can effectively remove the sediment inside the reactor and maintain the efficient operation of the reactor. This system can reduce the adhesion of sediments through sonic vibration, thereby improving the hydrolysis efficiency.

[0026] Preferably, in step S2, the desulfurization unit tower 51 includes a desulfurizer layer 511; a desulfurizer discharge port 512 and a desulfurizer feed port 513 are provided at the bottom of the desulfurizer layer 511; the desulfurizer in the desulfurizer layer 511 is an iron-based desulfurizer; and the desulfurizer adsorbs hydrogen sulfide to generate Fe2S3.

[0027] Iron-based desulfurizers can effectively adsorb H2S and generate Fe2S3 through chemical reactions. This reaction is highly efficient and can remove hydrogen sulfide from the gas in a relatively short period of time. At the same time, iron-based desulfurizers are relatively cheap and easy to obtain, which reduces material costs. The generated Fe2S3 can be recycled or reused, further reducing operating costs. Using iron-based desulfurizers for desulfurization can effectively reduce harmful components in exhaust gas, meet environmental protection requirements, and reduce the impact on the environment.

[0028] Compared with some other desulfurizers, the reaction of iron-based desulfurizers is milder, which reduces the safety risk in operation and improves the safety of the overall system. Fe2S3 as a product is relatively easy to handle and can be subsequently treated by physical or chemical methods, reducing the pressure on subsequent treatment facilities.

[0029] Preferably, the power generation device 4 uses a residual pressure turbine for power generation.

[0030] The residual pressure turbine power generation device is a power generation device that uses industrial residual pressure energy (such as natural gas pipelines, steam pipelines, etc.). It converts the pressure energy of the fluid into mechanical energy, and then converts the mechanical energy into electrical energy through the generator.

[0031] The hydrolyzed blast furnace gas is introduced into the power generation device 4 and generates electricity through the residual pressure turbine. The fluid passes through the turbine. During this process, the pressure energy of the fluid is converted into mechanical energy, which makes the turbine rotate. The turbine is connected to the generator. The rotation of the turbine drives the generator to rotate, thereby generating electricity. After the fluid loses part of its pressure in the turbine, it is discharged at a lower pressure.

[0032] Preferably, in step S4, a desulfurization agent regeneration system 53 is further provided in the dry desulfurization device 5; the desulfurization agent regeneration system 53 is respectively connected with pipelines of the desulfurization standby unit tower 52 which is opened after the desulfurization unit tower 51 is adsorbed and saturated.

[0033] The temperature of the blast furnace gas after turbine power generation is reduced to 60-120°C, and the blast furnace gas enters the dry desulfurization device 5 and enters from the lower part of the desulfurization unit tower 51. The blast furnace gas containing hydrogen sulfide undergoes a chemical adsorption reaction with the desulfurizer in the desulfurization unit tower 51 to remove hydrogen sulfide, and the purified blast furnace gas enters the gas pipeline network.

[0034] Preferably, the desulfurizer regeneration system 53 includes a high-speed pulping tank, an oxidation tank, a flotation tank, a deodorizing draft fan, an oxidation air compressor, a plate and frame filter and a molding device.

[0035] When the desulfurizer is saturated with adsorption and cannot remove hydrogen sulfide, it becomes a waste desulfurizer. The waste desulfurizer Fe2S3 is crushed, pulped, oxidized and regenerated, filtered on a plate and frame, formed, and dried to obtain a new desulfurizer through the above production process.

[0036] The present invention has been described by the above-mentioned relevant embodiments, however, the above-mentioned embodiments are only examples for implementing the present invention. It must be pointed out that the disclosed embodiments do not limit the scope of the present invention. On the contrary, changes and modifications made without departing from the spirit and scope of the present invention are all within the scope of patent protection of the present invention.

Claims

1. An integrated blast furnace gas desulfurization device, characterized in that: The integrated equipment comprises a bag dust removal device (1), a deoxidation unit tower (2), a hydrolysis unit tower (3), a power generation device (4) and a dry desulfurization device (5); the dry desulfurization device (5) comprises a desulfurization unit tower (51) and a desulfurization standby unit tower (52).

2. A method for the integrated blast furnace gas desulfurization equipment as claimed in claim 1, characterized in that: The specific steps of the method are as follows: S1: Blast furnace gas passes through bag filter (1); S2: The blast furnace gas after dust removal passes through the deoxidation unit tower (2) and enters the hydrolysis unit tower (3); S3: The hydrolyzed coal gas enters the power generation device (4); S4: The coal gas treated in step S3 enters the dry desulfurization device (5), and when the desulfurization unit tower (51) is saturated with adsorption, the desulfurization standby unit tower (52) is started.

3. The method of the integrated equipment for blast furnace gas fine desulfurization according to claim 2, characterized in that: In step S1, the bag dust removal device (1) has an intelligent monitoring device and an automatic cleaning device.

4. The method of the integrated equipment for blast furnace gas fine desulfurization according to claim 2, characterized in that: In the step S2, a deoxidizer layer (21) is provided in the deoxidizer unit tower (2); a deoxidizer discharge port (22) and a deoxidizer feed port (23) are provided at the bottom of the deoxidizer layer (21); and the deoxidizer in the deoxidizer layer (21) adopts a sulfur-resistant deoxidation catalyst.

5. The method of the integrated equipment for blast furnace gas fine desulfurization according to claim 2, characterized in that: The hydrolysis unit tower (3) in step S2 comprises a hydrolysis reactor (31) and a sonic soot blowing system (32); the hydrolysis unit tower (3) adopts a carbonyl sulfide hydrolysis system.

6. The method of the integrated equipment for blast furnace gas fine desulfurization according to claim 1, characterized in that: In step S2, the desulfurization unit tower (51) comprises a desulfurization agent layer (511); a desulfurization agent discharge port (512) and a desulfurization agent feeding port (513) are provided at the bottom of the desulfurization agent layer (511); the desulfurization agent in the desulfurization agent layer (511) is an iron-based desulfurization agent; and the desulfurization agent generates Fe2S3 after adsorbing hydrogen sulfide.

7. The method of the integrated equipment for blast furnace gas fine desulfurization according to claim 1, characterized in that: The power generation device (4) uses a residual pressure turbine for power generation.

8. The method of the integrated equipment for blast furnace gas fine desulfurization as claimed in claim 1, characterized in that: In the step S4, a desulfurization agent regeneration system (53) is further provided in the dry desulfurization device (5); the desulfurization agent regeneration system (53) is respectively connected to the pipeline of the desulfurization standby unit tower (52) which is opened after the desulfurization unit tower (51) is adsorbed and saturated.

9. The method of the integrated equipment for blast furnace gas fine desulfurization as claimed in claim 6, characterized in that: The desulfurizing agent regeneration system (53) comprises a high-speed pulping tank, an oxidation tank, a flotation tank, a deodorizing induced draft fan, an oxidation air compressor, a plate and frame filter and a molding device.

Images