CN218932192U - Device for purifying reducing gas by using blast furnace or converter gas and returning reducing gas to blast furnace for reducing carbon emission - Google Patents
Device for purifying reducing gas by using blast furnace or converter gas and returning reducing gas to blast furnace for reducing carbon emission Download PDFInfo
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- CN218932192U CN218932192U CN202222994701.4U CN202222994701U CN218932192U CN 218932192 U CN218932192 U CN 218932192U CN 202222994701 U CN202222994701 U CN 202222994701U CN 218932192 U CN218932192 U CN 218932192U
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Abstract
The patent discloses a device for purifying reducing gas by using blast furnace or converter gas and returning the reducing gas to blast furnace carbon for emission reduction. The device comprises: the inlet of the pretreatment device is connected with the outlet of the gas mainly comprising blast furnace gas and/or converter gas; the pressure swing adsorption purification CO device is characterized in that an inlet of the pressure swing adsorption purification CO device is connected with an outlet of the pretreatment device, and an outlet of the pressure swing adsorption purification CO device is connected with a reducing gas inlet of the blast furnace device. The reducing gas obtained by the method returns to the blast furnace to smelt metals, is favorable for reducing carbon emission, and has the advantages of simple process flow and less equipment investment.
Description
Technical Field
The patent relates to a method for reducing CO by purifying reducing gas from blast furnace or converter gas and returning the reducing gas to the blast furnace to participate in metallurgy 2 An emission device belongs to the technical field of metallurgy.
Background
In the metallurgical industry, a great amount of coke oven gas (coking), blast furnace gas (ironmaking) and converter gas (steelmaking), referred to as "three gases" are produced. Blast furnace gas, converter gas and tail gas with gas components similar to those of blast furnace gas and converter gas are also generated in the smelting process of other ferrous metals and nonferrous metals, and the smelting process of other ferrous metals and nonferrous metals is similar to that of steel. The blast furnace and the subsequent tail gas treatment process of the steel smelting process are represented in the patent, and the treatment method and the treatment device of the process are also suitable for similar smelting processes of other ferrous metals and nonferrous metals.
In the steel mill "three gases", the blast furnace gas has the largest discharge amount although the effective gas content is the lowest. The blast furnace gas comprises the following main components: CO, CO 2 ，N 2 ，H 2 ，CH 4 And the like, wherein the content of CO is about 25 percent, CO 2 And N 2 The content of (2) is 15%, 55%, H 2 、CH 4 Is very small. The heat value of the blast furnace gas is low and is only 3300-3800 kJ/Nm3. Due to CO in blast furnace gas 2 ，N 2 The combustion-supporting type blast furnace gas combustion furnace is not involved in combustion to generate heat, can not support combustion, and on the contrary, absorbs a large amount of heat generated in the combustion process, so that the theoretical combustion temperature of the blast furnace gas is lower, and is only about 1300 ℃. The blast furnace gas is unstable in combustion at normal temperature, and the blast furnace gas cannot be used as fuel alone in general industrial furnaces, and needs to be mixed with high-heat-value gas such as coke oven gas or converter gas, but the fluctuation of heat value of the blast furnace gas mixed with the coke oven gas or the converter gas is large, so that higher requirements are put on a combustion device, and the quality of products is affected to different degrees. Because most enterprises have surplus blast furnace gas and lack high heat value gas, the blast furnace gas is scattered to different degrees, which not only pollutes the environment, but also wastes energy.
How to effectively utilize the blast furnace gas with low heat value, high impurity content, huge yield, difficult purification and serious environmental pollution is a difficult problem to be solved at home and abroad. Blast furnace gas is commonly used for combustion heat release or power generation at present, but has low heat value, high incombustible component content, poor combustion efficiency and utilization rate, wastes a large amount of valuable reducing gas CO which can be used for reaction, and generates much lower benefits when the combustion heat supply or power generation is used for heat supply or power generation than the reaction as the reducing gas CO after the treatment.
The specific targets of carbon peak and carbon neutralization are put forward in China, the strategy of carbon emission reduction is high, and the metal smelting industry is a large household of carbon emission and has huge requirements. This puts higher demands on the metal smelting process, especially the steel smelting process.
Taking blast furnace gas as an example, most of steel plants currently use blast furnace gas for combustion, after combustion or heating or power generation, and combustible components in the blast furnace gas are mostly CO, and the CO is changed into CO after combustion 2 This increases carbon emissions. In addition, it has been proposed to purify the blast furnace gas to produce useful components as organic chemical products (such as ethylene glycol and natural gas), but most of the organic chemical products are hydrocarbon compounds, and the hydrogen-carbon ratio is generally high, but the hydrogen component in the blast furnace gas is very small. To meet the hydrogen-carbon ratio requirement, or to produce hydrogen by CO conversion, CO is produced 2 Also increasing a portion of the carbon emissions; or the hydrogen is found from outside, but the availability of an external hydrogen source is costly. And for the existing steel plant personnel, the manufacturing of organic chemical products is a huge challenge in the aspects of a knowledge system, a management system, a safety system and the like, and a huge barrier exists between two different industries of metallurgy and chemical industry, so that the application route of blast furnace gas is hindered to advance towards the direction.
Compared with the prior art, the method for utilizing the returned blast furnace to smelt the metal has the advantages that fewer treatment devices are added, so that the carbon emission is reduced, the main useful reducing component CO in the blast furnace gas and the converter gas is utilized, and the low-order use mode of taking the CO as fuel is avoided.
Disclosure of Invention
The purpose of this patent is to provide a simple technological process, with little equipment investment and little power consumption, the gas mainly composed of the reducing components is prepared by the purification of blast furnace gas or converter gas, and they are returned to the blast furnace for metal smelting, thus not only reducing the carbon emission, but also realizing the high value utilization of blast furnace gas or converter gas with less investment.
In order to achieve the above purpose, the inventor provides a method for blast furnace coal or converter gas through dust removal, impurity removal, dehydrogenation and deoxidation, organic sulfur conversion, desulfurization, carbon dioxide removal and pressure swing adsorption to separate CO through a great deal of field investigation and years of engineering design experience, and the obtained reducing gas is injected into a blast furnace for metal smelting through a spray gun at a certain position at a certain angle and a certain speed.
The process not only simplifies the process flow, but also reduces the equipment investment and the overall energy consumption, reduces the carbon emission and realizes the high-value utilization of blast furnace gas or converter gas under the condition of smaller investment through the integral material and energy matching.
The technical proposal is as follows:
the method for reducing emission of the carbon of the blast furnace by purifying the reducing gas by the blast furnace or the converter gas comprises the following steps:
step 1, the coal gas passes through a pretreatment flow;
step 2, purifying CO gas (the volume fraction of the obtained CO is more than or equal to 50%) from the gas by a pressure swing adsorption method; and step 3, returning the obtained gas mainly containing CO as reducing gas to a blast furnace to participate in the metallurgical reaction process.
The gas mainly comprises: one or two of blast furnace gas and converter gas.
In one embodiment, the gas may further contain a small amount (volume fraction is less than or equal to 30%) of coke oven gas, other tail gas or a mixture of one or more of purge gases.
In one embodiment, the volume fraction of CO obtained in the step of pressure swing adsorption CO purification in the step 2 is more than or equal to 60%.
In one embodiment, the CO volume fraction obtained in the step of pressure swing adsorption CO purification in the step 2 is more than or equal to 70%.
In one embodiment, the CO volume fraction obtained in the step of pressure swing adsorption CO purification in the step 2 is more than or equal to 80%.
In one embodiment, the volume fraction of CO obtained in the step of pressure swing adsorption CO purification in the step 2 is more than or equal to 90%.
In one embodiment, the CO volume fraction obtained in the step of pressure swing adsorption CO purification in the step 2 is more than or equal to 99%.
In one embodiment, part of the gas mainly containing CO after purification obtained in the step 2 is supplied outside, and part of the gas is returned to the blast furnace as reducing gas to participate in the metallurgical reaction process through the step 3.
In one embodiment, the step 1 pretreatment includes: dehydrating and desulfurizing; the impurity removal pretreatment further comprises: dust removal, phosphorus removal, arsenic removal, deoxidation, organic sulfur conversion and CO removal 2 Or to remove CH 4 One or a combination of steps.
In one embodiment, the step 1 pretreatment comprises CO removal 2 In the step 2, the volume fraction of CO obtained in the step of pressure swing adsorption CO purification is more than or equal to 70%.
In one embodiment, the step 1 pretreatment comprises CO removal 2 In the step 2, the volume fraction of CO obtained in the step of pressure swing adsorption CO purification is more than or equal to 80%.
In one embodiment, the step 1 pretreatment comprises CO removal 2 In the step 2, the volume fraction of CO obtained in the step of pressure swing adsorption CO purification is more than or equal to 90%.
In one embodiment, the step 1 pretreatment comprises CO removal 2 In the step 2, the volume fraction of CO obtained in the step of pressure swing adsorption CO purification is more than or equal to 99%.
In one embodiment, the step 1 pretreatment includes: desulfurization and CO removal 2 Removing CO 2 Carried out synchronously with desulphurisation or CO removal 2 After the desulphurisation step.
In one embodiment, the step 1 CO removal 2 The steps are absorption or pressure swing adsorption.
In one embodimentIn the formula, the step 1 CO removal 2 When the absorption method is adopted in the step, CO is removed 2 And adding a temperature swing adsorption unit to remove water and heavy components and a fine desulfurization unit contained in some gases in sequence.
In one embodiment, the step 1 CO removal 2 When the adsorption method is adopted in the step, CO is removed 2 The step is positioned downstream of the temperature swing adsorption water removal and heavies removal step.
In one embodiment, the step 1 CO removal 2 When the adsorption method is adopted in the step, CO is removed 2 The step is located downstream of the desulfurization step.
In one embodiment, the step 1 pretreatment further comprises: CH removal 4 Step of removing CH 4 Is removed by a catalytic combustion method.
In one embodiment, the step 1 pretreatment divides CH 4 The step is located on the downstream side of the desulfurization step.
In one embodiment, the step 1 pretreatment divides CH 4 The steps are located at CO removal 2 Upstream of the step.
In one embodiment, the step 1 pretreatment further comprises: and a deoxidizing step, wherein the deoxidizing is carried out by a catalytic reaction method.
In one embodiment, the step 1 pre-treatment deoxygenation step is located to remove CH 4 Downstream of the step.
In one embodiment, the step 1 pre-treatment deoxygenation step is located at the CO removal 2 Upstream of the step.
In one embodiment, the step 1 organosulfur conversion step is performed by a catalytic hydrogenation reaction process or a catalytic hydrolysis reaction process.
In one embodiment, the step 1 organosulfur conversion step is located upstream of the desulfurization step.
In one embodiment, H in the step 1 gas 2 When the volume fraction of the gas is more than or equal to 5 percent, the pressure swing adsorption method is adopted for the other gas separated from the CO gas purified by the pressure swing adsorption method in the step 2Separating H with purity more than or equal to 80% by using the method 2 The H obtained 2 The mixture is pressurized to a pressure sufficient to mix with the CO gas returned to the blast furnace and then mixed with the CO gas, and the mixed gas is returned to the blast furnace as a reducing gas to participate in metallurgical reaction. The H obtained 2 As reducing gas, the gas returns to the blast furnace to participate in the metallurgical reaction process and/or external supply.
In one embodiment, H in the incoming gas 2 When the volume fraction of (2) is more than or equal to 8%.
In one embodiment, H in the incoming gas 2 When the volume fraction of (2) is more than or equal to 10%.
In one embodiment, the separation of H is performed by pressure swing adsorption 2 The purity of the product is more than or equal to 90 percent.
In one embodiment, the separation of H is performed by pressure swing adsorption 2 The purity of the product is more than or equal to 95 percent.
In one embodiment, the separation of H is performed by pressure swing adsorption 2 The purity of the product is more than or equal to 99 percent.
In one embodiment, the separation of H is performed by pressure swing adsorption 2 The purity of the product is more than or equal to 99.9 percent.
In one embodiment, the adjusting of the amount of metal oxide in the metal ore charged into the blast furnace in step 3: total amount of coke and fuel injection: under the condition of meeting the requirement of metal reduction degree, the proportion relation of the total amount of oxygen in air or oxygen-enriched air uses the minimum consumption of coke and jet fuel of unit metal, so that the total amount of CO leaving the blast furnace is more than or equal to the total amount of CO entering the blast furnace, the difference between the total amount of CO leaving the blast furnace and the total amount of CO entering the blast furnace is minimum, and the concentration of CO formed by the total amount of CO entering the blast furnace in the blast furnace can meet the concentration of reducing atmosphere required to be maintained by blast furnace smelting.
In one embodiment, the adjusting of the amount of metal oxide in the metal ore charged into the blast furnace in step 3: total amount of coke and fuel injection: the ratio of the total amount of air or oxygen of the oxygen-enriched air is used for ensuring that the total amount of CO leaving the blast furnace is equal to the total amount of CO entering the blast furnace by using the minimum consumption amount of coke and jet fuel of unit metal under the condition of meeting the requirement of metal reduction degree, and the concentration of CO formed by the total amount of CO entering the blast furnace in the blast furnace can meet the concentration of the reducing atmosphere required to be maintained by blast furnace smelting.
In one embodiment, the adjusting of the amount of metal oxide in the metal ore charged into the blast furnace in step 3: total amount of coke and coal injection: the ratio of the total amount of oxygen in air or oxygen-enriched air is such that the total amount of CO leaving the blast furnace is equal to or greater than the total amount of CO entering the blast furnace, the difference between the total amount of CO leaving the blast furnace and the total amount of CO entering the blast furnace is minimized, and the concentration of CO formed in the blast furnace and the H in the furnace by the total amount of CO entering the blast furnace are such that the minimum consumption of coke per metal and jet fuel under the condition of meeting the requirement of metal reduction degree 2 The concentration of the reducing atmosphere required to be maintained in the blast furnace smelting can be satisfied by the combined action of the concentrations.
In one embodiment, the adjusting of the amount of metal oxide in the metal ore charged into the blast furnace in step 3: total amount of coke and coal injection: the ratio of the total amount of oxygen in air or oxygen-enriched air is such that the total amount of CO leaving the blast furnace is equal to the total amount of CO entering the blast furnace, and the concentration of CO formed in the blast furnace and H in the furnace are such that the total amount of CO entering the blast furnace 2 The concentration of the reducing atmosphere required to be maintained in the blast furnace smelting can be satisfied by the combined action of the concentrations.
In one embodiment, the gas comprising mainly CO in step 3 is pressurized and then heated to a temperature of < 630 ℃ and sent to a blast furnace.
In one embodiment, the gas mainly containing CO in the step 3 is pressurized and then heated to the temperature of less than or equal to 620 ℃ and sent to a blast furnace.
In one embodiment, the gas mainly containing CO in the step 3 is pressurized and then heated to the temperature of less than or equal to 610 ℃ and sent to a blast furnace.
In one embodiment, the gas mainly containing CO in the step 3 is pressurized and then heated to the temperature of less than or equal to 600 ℃ and sent to a blast furnace.
In one embodiment, the gas mainly containing CO in the step 3 is returned to the blast furnace as reducing gas and is sprayed by a distributing pipe, a ring pipe surrounding the blast furnace and spray guns uniformly distributed on the blast furnace in a ring shape, the blast furnace is vertically provided with m groups of spray guns, wherein, 10 is more than or equal to 1, each group is composed of n spray guns uniformly distributed on the horizontal surrounding blast furnace with vertical height being close to each other, 240 is more than or equal to 2, the spray guns are positioned above an air inlet and a coal injection port, the vertical distance from the center of the highest spray gun is 0.5m to 15m, the horizontal inclination angle of the spray gun is-60 degrees to +15 degrees, the height difference between the spray guns in the vertical direction is 0m to 5m, the arc length between the spray guns in the same height in the horizontal direction is 0.5m to 2.5m, the inclination angle of the spray guns in the blast furnace and the area of spray gun outlet are adjustable, the area of the outlet of the spray gun and the horizontal inclination angle of the spray gun in different groups are adjusted, the inclination angle of each spray gun can be different, the gas flow rate can be different, the gas speed of the sprayed spray gun can reach 100-400 m/s, the blasting kinetic energy can reach 10-400 kJ/s, the spray gun is aligned to the reflow zone, the incident gas flow meets the reflow zone in the middle part of the radial direction of the blast furnace, the incident gas and the formed rotary diffusion movement can influence the reflow zone, the reflow zone can be loosened, the burden near the reflow zone can be fluidized, part of burden can be circularly moved, the gas in the blast furnace above the sprayed gas is uniform along the circumferential direction of the blast furnace, the gas flow in the middle part and the center of the radial direction of the blast furnace is relatively average, and the unit area flow rate is larger, while the radial edge position has a smaller air flow per unit area.
In one embodiment, the gas mainly containing CO in step 3 is additionally injected into a spray gun of the blast furnace, the gas is a small amount of air or oxygen-enriched air or oxygen, the gas is not mixed before being injected into the spray gun, the gas mainly containing CO is a combustible gas, the gas is excessive relative to the injected oxygen element, and after being mixed in the blast furnace after being injected into the spray gun, part of the gas mainly containing CO is combusted.
In one embodiment, the step 3 is that a large high-quality semicoke part is used for replacing coke in a blast furnace to be filled into the blast furnace, the mixing mass ratio of semicoke and coke is less than or equal to 70 percent;
in one embodiment, the step 3 is that a large high-quality semicoke part is used for replacing coke in a blast furnace to be filled into the blast furnace, the mixing mass ratio of semicoke and coke is less than or equal to 60 percent;
in one embodiment, the step 3 is that a large high-quality semicoke part is used for replacing coke in a blast furnace to be filled into the blast furnace, the mixing mass ratio of semicoke and coke is less than or equal to 50 percent;
in one embodiment, the step 3 is that a large high-quality semicoke part is used for replacing coke in a blast furnace to be filled into the blast furnace, the mixing mass ratio of semicoke and coke is less than or equal to 40 percent;
In one embodiment, the step 3 is that a large high-quality semicoke part is used for replacing coke in a blast furnace to be filled into the blast furnace, the mixing mass ratio of semicoke and coke is less than or equal to 30 percent;
in one embodiment, the main indexes of the massive high-quality semicoke used in the blast furnace in the step 3 are as follows: particle size not less than 25mm, ash content A d Less than or equal to 8 percent, volatile component V daf Less than or equal to 10 percent, fixed carbon FC d More than or equal to 80 percent, the total content W (K+Na) of sodium and potassium is less than 0.3 percent, the content of SiO in ash 2 +Al 2 O 3 )/(CaO+Fe 2 O 3 +MgO) is more than or equal to 2, the ash fusion softening temperature St is more than 1150 ℃, the Ha grindability index HGI is less than or equal to 50, the strength CSR after reaction is more than or equal to 40%, the reactivity CRI is less than or equal to 70%, and the thermal stability TS +6 > 80%, total sulfur content S t,d Less than or equal to 0.7 percent, and the falling strength SS is more than 60 percent.
In one embodiment, the main indexes of the massive high-quality semicoke used in the blast furnace in the step 3 are as follows: particle size not less than 40mm, ash content A d Less than or equal to 6 percent, volatile component V daf Less than or equal to 7 percent, fixed carbon FC d More than or equal to 85 percent, the total content W (K+Na) of sodium and potassium is less than 0.2 percent, the content of SiO in ash 2 +Al 2 O 3 )/(CaO+Fe 2 O 3 +MgO) is more than or equal to 4, ash fusion softening temperature St is more than 1250 ℃, ha grindability index HGI is less than or equal to 45, strength CSR after reaction is more than or equal to 45%, reactivity CRI is less than or equal to 60%, and thermal stability TS +6 > 85%, total sulfur content S t,d Less than or equal to 0.5 percent, and the falling strength SS is more than 65 percent.
In one embodiment, the main indexes of the massive high-quality semicoke used in the blast furnace in the step 3 are as follows: particle size not less than 50mm, ash content A d Less than or equal to 5 percent, volatile component V daf Less than or equal to 5 percent, fixed carbon FC d More than or equal to 90 percent, the total content W (K+Na) of sodium and potassium is less than 0.12 percent, the content of SiO in ash 2 +Al 2 O 3 )/(CaO+Fe 2 O 3 +MgO) is more than or equal to 6, the ash fusion softening temperature St is more than 1350 ℃, the Ha grindability index HGI is less than or equal to 40, the strength CSR after reaction is more than or equal to 50%, the reactivity CRI is less than or equal to 50%, and the thermal stability TS +6 > 90%, total sulfur content S t,d Less than or equal to 0.3 percent, and the falling strength SS is more than 70 percent.
For ash A d Less than or equal to 12 percent, the total weight W (K+Na) of sodium and potassium is less than 1.2 percent, the strength CSR after reaction is more than or equal to 30 percent, the reactivity CRI is less than or equal to 80 percent, and the thermal stability TS +6 The semicoke with the mass concentration of more than 70 percent is sprayed by adopting a common hydrochloric acid solution with the mass concentration of 35 to 38 percent on the market, then the temperature is raised to 70 ℃ and more by steam with the mass concentration of more than or equal to 100 ℃ to volatilize hydrochloric acid, the gas flow is maintained for more than 1h, the temperature is gradually reduced to 40 ℃ and less to condense the hydrochloric acid, and then the reaction product is stood for more than 2 h. And then the semicoke is purged by steam with the temperature of more than or equal to 200 ℃ (at the temperature of less than or equal to 550 ℃ and further at the temperature of less than or equal to 350 ℃) so that the semicoke is heated to 200 ℃ and above (at the temperature of less than or equal to 350 ℃ and further at the temperature of less than or equal to 280 ℃) for more than 2 hours. After purging, the semicoke is kept stand and cooled to normal temperature. Increasing the amount of hydrochloric acid and increasing the duration of the treatment step is beneficial in increasing the magnitude of the indicator.
The device for purifying reducing gas by using blast furnace or converter gas and returning the reducing gas to blast furnace carbon for reducing emission comprises:
the inlet of the impurity removal pretreatment device is connected with the outlet of the gas mainly comprising blast furnace gas and/or converter gas;
the inlet of the pressure swing adsorption CO purifying device is connected with the pretreatment device, and the outlet of the pressure swing adsorption CO purifying device is connected with the reducing gas inlet of the blast furnace device.
In one embodiment, the inlet of the blast furnace gas and/or the converter gas is also connected with an inlet of coke oven gas, other tail gas or purge gas.
In one embodiment, the pretreatment device comprises: a dehydration device and a desulfurization device; the impurity removal pretreatment device further comprises: dust collector, dephosphorizer, arsenic remover, deoxidizer, organic sulfur converter and CO remover 2 Devices or devices for removing CH 4 One or a combination of several of the devices.
In one embodiment, the pretreatment device comprises CO removal 2 And (3) a device.
In one embodiment, the pretreatment device removes CO 2 The device is an absorption method for removing CO 2 CO removal by apparatus or adsorption 2 And (3) a device.
In one embodiment, the pretreatment device removes CO 2 The device is an absorption method for removing CO 2 CO removal during installation 2 The outlet of the device is connected with a temperature swing adsorption dewatering and heavy component device, and the outlet of the temperature swing adsorption dewatering and heavy component device is connected with a fine desulfurization device.
In one embodiment, the pretreatment device removes CO 2 The device is to remove CO by adsorption 2 CO removal during installation 2 The device is positioned at the downstream side of the temperature swing adsorption water removal and recombination device.
In one embodiment, the pretreatment device removes CO 2 The device is to remove CO by adsorption 2 CO removal during installation 2 The device is positioned on the downstream side of the desulfurization device.
In one embodiment, the pretreatment device comprises a desulfurization device and a CO removal device 2 Device for removing CO 2 The device is integrated with a desulfurization device or removes CO 2 The device is positioned at the downstream side of the desulfurization device.
In one embodiment, the deoxidizing device in the pretreatment device is a catalytic reaction deoxidizing device.
In one embodiment, the deoxidizing device in the pretreatment device is positioned for removing CH 4 Downstream of the device.
In one embodiment, the deoxidizing device in the pretreatment device is positioned in the CO removal device 2 Upstream of the device.
In one embodiment, the pretreatment device is used for removing CH 4 The device is to burn off CH by catalysis 4 And (3) a device.
In one embodiment, the pretreatment device is used for removing CH 4 The device is positioned on the downstream side of the desulfurization device.
In one embodiment, the pretreatment device is used for removing CH 4 The device is positioned for CO removal 2 Upstream of the device.
In one embodiment, the organic sulfur conversion device in the pretreatment device is a catalytic hydrogenation reaction device or a catalytic hydrolysis reaction device.
In one embodiment, the organic sulfur conversion device in the pretreatment device is positioned at the upstream side of the desulfurization device.
In one embodiment, the other outlet of the pressure swing adsorption purification CO device is connected with pressure swing adsorption purification H 2 The inlet of the device is connected.
In one embodiment, the pressure swing adsorption purification of H 2 One of the outlets of the device is connected with the reducing gas inlet of the blast furnace device.
In one embodiment, the reducing gas inlet of the blast furnace device is connected with a distribution pipe, the distribution pipe is connected with a ring pipe surrounding the blast furnace, and the ring pipe is connected with more than or equal to 2 spray guns which are horizontally and annularly and uniformly distributed on the blast furnace.
In one embodiment, the spray gun is positioned above the horizontal height of the air inlet and the spray fuel outlet of the air or the oxygen-enriched air, the vertical center distance from the highest nozzle of the two nozzles is 0.5 m-15 m, and the angle between the spray gun and the horizontal plane is as follows: -60 to +15°.
In one embodiment, the lance is located between 2m and 10m from the vertical center of the air inlet for air or oxygen enriched air and the highest nozzle in the jet fuel port.
In one embodiment, the spray gun is 4 m-8 m from the vertical center of the highest nozzle in the air or oxygen-enriched air inlet and the spray fuel port.
In one embodiment, the angle of the spray gun with respect to the horizontal is: -45 to +0°.
In one embodiment, the angle of the spray gun with respect to the horizontal is: -30 to +0°.
In one embodiment, the angle of the spray gun with respect to the horizontal is: -20 to +0°.
In one embodiment, the angle of the spray gun with respect to the horizontal is: -15 to +0°.
In one embodiment, the angle of the spray gun with respect to the horizontal is: -55 DEG to-5 deg.
In one embodiment, the spray guns are divided into m groups in the vertical direction of the blast furnace, wherein m is more than or equal to 10 and more than or equal to 1.
In one embodiment, the spray guns are divided into m groups in the vertical direction of the blast furnace, wherein m is more than or equal to 5 and more than or equal to 1.
In one embodiment, the spray guns are divided into m groups in the vertical direction of the blast furnace, wherein 3 is more than or equal to m is more than or equal to 1.
In one embodiment, each group of spray guns consists of n spray guns with vertical heights close to each other and uniformly distributed around the blast furnace, wherein n is more than or equal to 240 and more than or equal to 2.
In one embodiment, each group of spray guns consists of n spray guns with vertical heights close to each other and uniformly distributed around the blast furnace, wherein n is more than or equal to 120 and more than or equal to 2.
In one embodiment, each group of spray guns consists of n spray guns with vertical heights close to each other and uniformly distributed around the blast furnace, wherein n is more than or equal to 60 and more than or equal to 2.
In one embodiment, the height difference of each group of spray guns is 0 m-5 m.
In one embodiment, the height difference of each group of spray guns is 0.2 m-3 m.
In one embodiment, the height difference of each group of spray guns is 0.5 m-2 m.
In one embodiment, the angle of inclination of the lance is adjustable.
In one embodiment, the inclination angle of the spray guns of the different sets to the horizontal may be different.
In one embodiment, the spray guns within each set may be inclined at different angles to the horizontal.
In one embodiment, the arc length between the same height lances within each set is 0.5m to 2.5m.
In one embodiment, the arc length between the spray guns of the same height in each group is 1 m-1.6 m.
In one embodiment, the groups of lances of different heights may be arranged vertically just above like a "rectangle".
In one embodiment, the groups of lances of different heights may be staggered laterally over each other like a "triangle".
In one embodiment, the area of the spray gun outlet can be adjusted, and the flow rate of the spray gas and the speed of the spray gas are adjusted by adjusting the area of the spray gun outlet.
In one embodiment, the gas flows of the different groups of lances may be different and the velocity of the injected gas may be different.
In one embodiment, the gas flow rates of the lances in each set may be different and the velocity of the injected gas may be different.
In one embodiment, the gas velocity of the spray gun is 100m/s to 500m/s.
In one embodiment, the gas velocity of the spray gun is 200m/s to 400m/s.
In one embodiment, the gas velocity of the spray gun is 200m/s to 350m/s.
In one embodiment, the gas velocity of the spray gun is 250m/s to 350m/s.
In one embodiment, the gas velocity of the spray gun is 250m/s to 300m/s.
In one embodiment, the blast energy of the gas sprayed out of the spray gun is 10kJ/s to 500kJ/s.
In one embodiment, the blast energy of the gas sprayed out of the spray gun is 10kJ/s to 400kJ/s.
In one embodiment, the blast energy of the gas sprayed out of the spray gun is 20kJ/s to 400kJ/s.
In one embodiment, the blast energy of the gas sprayed out of the spray gun is 20kJ/s to 300kJ/s.
In one embodiment, the blast energy of the gas sprayed out of the spray gun is 30kJ/s to 300kJ/s.
In one embodiment, the blast energy of the gas sprayed out of the spray gun is 30kJ/s to 200kJ/s.
In one embodiment, the blast energy of the gas sprayed out of the spray gun is 40kJ/s to 200kJ/s.
In one embodiment, the blast energy of the gas sprayed out of the spray gun is 40kJ/s to 300kJ/s.
In one embodiment, the blast energy of the gas sprayed out of the spray gun is 40kJ/s to 400kJ/s.
In one embodiment, the blast energy of the gas sprayed out of the spray gun is 40kJ/s to 500kJ/s.
Further, the pretreatment device also comprises CH removal 4 A device or/and a dehydrogenation and deoxygenation device; CH removal 4 The device is positioned at the downstream side of the desulfurization device; the deoxidizing device is used for removing CH 4 Downstream of the device. I.e. when containing CH 4 When in installation, CH is removed 4 The device is arranged at the downstream side of the desulfurization device, and the desulfurization device and the CO removal device 2 When the device is separated, CH is removed 4 The device is arranged at the downstream side of the desulfurization device and is used for removing CO 2 An upstream side of the device; desulfurizing device and CO removal device 2 When the device is separated, the deoxidizing device is in CO removal 2 On the upstream side of the apparatus, if it also contains a unit other than CH 4 Device, deoxidizing device is used for removing CH 4 Downstream of the device. For different combinations, it is obvious that the pressure swing adsorption apparatus is connected to the pretreatment unitThe tail (i.e. after the end of the last unit of the pretreatment device) is placed.
The names of the pressure swing adsorption devices in this patent and other functional names such as pressure swing adsorption purification CO device, pressure swing adsorption decarbonization device, etc. are all for clearly describing the patent, and the structure is not limited mainly.
The beneficial effects are that:
the technological thought of this patent is: purifying a gas of a reducing component CO with a certain concentration from blast furnace gas and converter gas, returning the obtained gas to a blast furnace for metal smelting, taking blast furnace ironmaking as an example, wherein other metal oxides are smelted into metal, and the blast furnace is subjected to various reaction processes of formulas (1) - (8), wherein the total reaction equation in the main blast furnace ironmaking process is changed from the original formula (9) into the formulas (10) and (11), namely, CO is generated in the smelting process of coke (the main component of the coke is carbon (C) and possibly injected fuel, such as common coal injection, wherein the coke refers to carbon element) which is originally introduced into the blast furnace 2 And CO, and the content of CO in the obtained blast furnace gas is higher than that of CO 2 . The patent changes the materials into coke (the main component is carbon (C)) and possibly injected fuel such as common coal injection into the blast furnace, and CO is generated in the smelting process 2 And CO, the general reaction equation in the main process is formula (10). The increase of CO in the furnace from coal and coke in the furnace = out of CO in the furnace from CO + out of CO + lost, ideally when CO is not supplied externally, the loss of CO in the purification process is negligible (loss of CO is minimized by optimization of the process) when balance in the furnace is stable, the increase of CO in the furnace is zero, and all CO out of the furnace is purified out as CO in the furnace, i.e. in the furnace CO = out of the furnace CO, i.e. CO in the furnace from coal and coke is zero. Finally, a new balance is achieved in the process of various reaction in the blast furnace, wherein the total amount of CO entering the blast furnace is equal to the total amount of CO leaving the blast furnace, namely, the CO entering and exiting the blast furnace are mutually counteracted, namely, the total reaction equation in the main process is changed into a formula (11). Namely, the original smelting process comprises the following steps: CO production by coke reduction of iron 2 And CO. Becomes into The smelting process of the patent comprises the following steps: coke reduced iron only produces CO 2 . I.e., the coke reaction is more complete during the overall reaction. In the prior art, blast furnace gas is taken as an example, most of the steel plants currently use the blast furnace gas for combustion, heat supply or power generation is carried out after the combustion, combustible components in the blast furnace gas are mostly CO, and the CO is changed into CO after the combustion 2 This increases carbon emissions. In the process, the gas of reducing component CO with a certain concentration is purified from blast furnace gas and converter gas, the obtained gas is returned to the blast furnace, and CO can reduce iron ore to produce pig iron and generate CO 2 However, CO is generated by the reaction of coke and coal in the blast furnace, and finally, the CO in the blast furnace is dynamically balanced, namely, the CO is continuously consumed and generated. That is, the coke (the main component of which is carbon (C) and possibly injected fuel, such as commonly used coal injection) required for smelting iron per unit mass in the patent is reduced, that is, CO is finally produced 2 And will be less, thereby reducing "carbon emissions". The separated reducing gas returned to the blast furnace can also be partially used as carrier gas in the furnace returning process, such as pulverized coal-carrying furnace returning and fuel-carrying furnace returning.
Since the reducing atmosphere is required to be maintained in the blast furnace smelting process, a CO component is present in the produced blast furnace gas, which in this patent corresponds to the circulation of CO between the blast furnace and the blast furnace gas purification and treatment apparatus in this patent, and the CO circulates like an intermediate medium to maintain the reducing atmosphere of the blast furnace. The blast furnace gas obtained is suitable for direct return to the blast furnace, because it causes CO 2 And N 2 The components and other minor components accumulate in the blast furnace, more and more, especially CO 2 And N 2 The contents of the components are originally high, and finally, the component balance and the mass balance of the inlet and the outlet of the whole system cannot be maintained, so that the blast furnace cannot work; but CO can be generated after the CO returns to the blast furnace and participates in the process of reducing iron 2 ，CO 2 Can be separated and separated from the blast furnace system so as to maintain the component balance and the mass balance of the inlet and the outlet of the whole blast furnace system, and all the gas mainly containing CO separated in the patent can be used as reducing gas to returnReturning to the blast furnace. So in order to maintain the component balance and the mass balance of the inlet and the outlet of the whole system, the catalyst is used for CO 2 And N 2 The components and other minor components need to be discharged, so that blast furnace gas is separated to separate most of CO 2 And N 2 Discharging other trace components, and introducing the separated gas mainly containing CO into a blast furnace, wherein the CO is involved in various reaction processes of metal smelting in the blast furnace to generate CO 2 ，CO 2 In the subsequent CO purification treatment process, the CO is separated and discharged, so that the CO cannot accumulate in a system between the blast furnace and the gas purification and treatment device, the balance of CO in the system is maintained, and the balance of carbon element (C) in the system is also maintained; the coke can generate CO through various reactions, namely, the dynamic balance of CO is maintained, so that the concentration of CO in the blast furnace is maintained, namely, the reducing atmosphere in the blast furnace is maintained, and the smelting of metals is facilitated. The gas of the reducing component CO with a certain concentration is purified, and the obtained reducing component is returned to the blast furnace to participate in the metal smelting process after being treated. The method changes the charging mode of the blast furnace, increases the charging process of CO as a reducing component entering the blast furnace, and changes the original metal ore (metal oxide), coke (or coal injection and the like), air (or oxygen-enriched air) and auxiliary materials into the metal ore (useful component is metal oxide), coke (or coal injection and the like), air (or oxygen-enriched air) and CO and auxiliary materials with certain concentration as the reducing component. The amount of metal ore (metal oxide) charged into the blast furnace was adjusted: total amount of coke and coal injection: the proportional relation (mass ratio or mole ratio) of the air (or oxygen-enriched air, i.e. the total amount of oxygen) to the amount of the oxygen in the air (or oxygen-enriched air) enables the blast furnace system to reach balance (1 t iron is produced, 0.15 to 1.2t coke is produced or the consumption of carbon elements in coal injection is 100 to 1000NM 3 The amount of oxygen contained in air or oxygen-enriched air), under the condition of meeting the requirement of metal reduction degree, using the minimum consumption of coke and jet fuel of unit metal, so that the total amount of CO leaving the blast furnace is more than or equal to the total amount of CO entering the blast furnace, and the difference between the total amount of CO leaving the blast furnace and the total amount of CO entering the blast furnace is minimized as much as possible; and the concentration of CO formed in the blast furnace and the others in the furnace are the same as the total amount of CO entering and exiting the blast furnaceThe primary gas (e.g. H) 2 ) The concentration of the reducing atmosphere required to be maintained in the blast furnace smelting can be satisfied by the combined action of the concentrations. The total amount of CO entering and exiting the blast furnace indirectly adjusts the concentration of CO in the blast furnace to meet the concentration of the reducing atmosphere required to be maintained in blast furnace smelting, and is also equivalent to adjusting the concentration of CO in blast furnace gas leaving the blast furnace, which is related to the furnace type and process of blast furnace smelting, the furnace type of the existing blast furnace is different, the smelting process is different, sources of raw materials such as ore, coke and coal are different, the production place is different, and the difference of oxygen content in air and oxygen-enriched air can lead to the difference of the concentration of the reducing atmosphere required to be maintained in blast furnace smelting, namely the difference of the required concentration of CO and hydrogen. The separation efficiency is also important, and the patent has high separation efficiency.
When H in the incoming gas 2 The volume fraction of (2) is more than or equal to 5 percent (further, H) 2 The volume fraction of (2) is more than or equal to 8 percent, and further, H 2 More than or equal to 10 percent by volume) in order to better utilize H therein 2 Can be H 2 Separated, and the other gas (mainly containing N) obtained in the separation process of purifying CO gas by pressure swing adsorption 2 And H 2 ) Continuously adopting a pressure swing adsorption method to separate H with purity more than or equal to 80 percent 2 (further, H 2 The purity of (C) is more than or equal to 90 percent, and further, H 2 The purity of (3) is more than or equal to 95 percent, and further, H 2 The purity of (C) is more than or equal to 99 percent, and further, H 2 Purity of 99.9% or more) of the obtained H 2 The mixture is pressurized to a pressure sufficient to mix with the CO gas returned to the blast furnace and then mixed with the CO gas, and the mixed gas is returned to the blast furnace as a reducing gas to participate in metallurgical reaction. The H obtained 2 The gas can be partially or completely used as reducing gas to be returned to the blast furnace to participate in the metallurgical reaction process, or can be partially or completely supplied externally.
Formulas (1) to (8) are reaction equations of main processes in the blast furnace ironmaking process, formula (9) is a total reaction equation of the main processes in the blast furnace ironmaking process at present, and formula (10) is a total reaction equation of the main processes in the blast furnace ironmaking process in the patent. Here, the reaction process of some unimportant and the reaction process of auxiliary materials in the blast furnace are not considered, such as the reaction process of lime stone and dolomite of flux in the blast furnace is not considered.
The reaction equation of the main process of blast furnace ironmaking is as follows:
Fe 2 O 3 +3CO＝2Fe+3CO 2 (1)
Fe 3 O 4 +4CO＝3Fe+4CO 2 (2)
2Fe 2 O 3 +3C＝4Fe+3CO 2 (3)
Fe 3 O 4 +2C＝3Fe+2CO 2 (4)
C+O 2 ＝CO 2 (5)
C+CO 2 ＝2CO (6)
Fe 2 O 3 +3C＝2Fe+3CO (7)
Fe 3 O 4 +4C＝3Fe+4CO (8)
the total reaction equation of the primary blast furnace ironmaking process is as follows:
Fe m O n +C→Fe+CO 2 +CO (9)
the total reaction equation of the main process of blast furnace ironmaking of the patent:
Fe m O n +C+CO→Fe+CO 2 +CO (10)
finally, the total reaction equation of the main process of blast furnace ironmaking of the patent is simplified as follows:
Fe m O n +C→Fe+CO 2 (11)
the carbon emission reduction in China has been raised strategically, and has a mandatory requirement for reducing carbon emission for each industry for China, and how to realize the carbon emission reduction in the iron and steel industry and the metallurgical industry. The metallurgical industry is similar to the steel industry, which is exemplified herein. The carbon emission ratio in the steel industry in China reaches 18.92% nationwide, the carbon emission of the blast furnace is about 73.6% of that of the steel plant, and the carbon emission of the converter is about 10% of that of the steel plant. Blast furnace gas and converter gas are large households in which carbon is discharged, particularly blast furnace gas, has huge gas quantity, accounts for more than 70% of three gases discharged by steel plants, is more critical for carbon emission reduction, and is converted into gasThe furnace gas contains a large amount of CO, the content of which exceeds that of CO 2 How to treat the CO contained in a large amount becomes a key.
The flow direction of gas in the blast furnace is from bottom to top, the temperature in the blast furnace is gradually reduced from the high temperature area at the lower part, the conventional blast furnace is generally divided into three parts in height from the temperature angle, namely, a lower high temperature area, a middle temperature area and an upper low temperature area, wherein the temperature gradient of the lower area is large, the heat exchange is strong, the temperature gradient of the middle area is small, the heat exchange is slow, and the temperature gradient of the upper area is large. The zone below the zone of reflow is generally considered to be a high temperature zone, where the iron ore and some of the slag are in a molten state, being molten iron and liquid slag-iron. The upper part of the soft melting zone is a medium temperature zone, and the iron ore is solid.
In the existing blast furnace, the porosity of the coke is generally larger than that of the iron ore, so that the air permeability of the coke is also higher than that of the iron ore. In a blast furnace in which iron ore and coke are alternately charged into the blast furnace from above, the average thickness of the iron ore layer and the average thickness of the coke layer are not the same, and it is generally desired that the ratio of the average thickness of the iron ore layer to the average thickness of the coke layer is greater, i.e., less coke is consumed by iron per smelting unit. The reason is that high-quality coals with strong cohesiveness such as coking coals, fat coals and the like are needed for producing coke, but the reserves and the yields of the high-quality coals such as coking coals, fat coals and the like in China are not large, and the proportions of the reserves and the yields of the high-quality coals such as coking coals, fat coals and the like in the world are not high, namely, the high-quality coals such as coking coals, fat coals and the like are relatively scarce resources, and the coke produced by the high-quality coals such as coking coals, fat coals and the like is also scarce resources, but the reserves and the yields of the high-quality coals such as coking coals, fat coals and the like in China are smaller, and the scarcity is more marked. Accordingly, modern blast furnaces have been strived to reduce the amount of coke used, and to reduce the amount of coke consumed per 1 ton of iron produced, i.e., to reduce the coke ratio.
Coke has four roles in blast furnaces: 1. the fuel, the combustion generates heat for metallurgical needs. 2. Reducing agent to produce reducing gas CO to reduce ore and react directly with iron ore to produce iron and CO 2 . 3. Carburizing agent for providing carbon element for pig iron carburization, and the carbon element in the coke in the blast furnace is from the reflow zoneThe molten iron dropped in the drop zone is brought into contact with the coke to further infiltrate carbon element into the iron. 4. The skeleton function ensures the air permeability and liquid permeability of the material column in the blast furnace, and the coke has enough strength, which is not replaced by any other solid fuel.
The conventional reflow zone in the blast furnace is generally divided into different forms such as V-shaped form, inverted V-shaped form, W-shaped form and M-shaped form, and the form of the reflow zone has close relation with the air supply system of the lower air or the oxygen-enriched air. The blast furnace in China is advocated to be large-sized at present, and the soft melting belt is generally inverted V-shaped. The ratio of the gas quantity passing through the upper coke window of the inverted V-shaped soft smelting belt is larger, namely the central gas flow is developed, and the ratio of the gas quantity passing through the lower part is smaller. The air flow rate per unit area of the center and edge positions of the common inverted V-shaped soft smelting belt along the radial direction of the blast furnace is larger, and the air flow rate per unit area of the middle position is smaller, which is not the most reasonable radial air flow distribution of the blast furnace.
Because of the existence of the reflow zone, the iron ore and part of slag begin to soften and melt under the action of temperature, the melted iron ore and slag become liquid, the viscosity of the liquid is high, the surface tension is high, the fluidity is poor, the pores among solid furnace charges are blocked, the gas is more difficult to pass through, and the air permeability is poor. In the reflow zone, the volume of the furnace burden is continuously reduced from solid state to softening, and then to slush and complete melting, the porosity is gradually reduced, the air permeability of the solid material layer is obviously reduced, and the air resistance is rapidly increased. After the iron ore is melted, the gas mainly moves in a coke interlayer like a louver, and the coke layer plays a role of a breathable framework in a blast furnace. Experience shows that many problems in the blast furnace are caused by poor air permeability or uneven air permeability, the reflow zone is the place with the largest air resistance in the blast furnace, if the pressure difference of the reflow zone is too large, the furnace burden descending process is difficult to realize, the blast furnace cannot run smoothly, and practice shows that the unsmooth furnace burden descending is often the cause of poor running condition of the blast furnace, so that frequent material collapse, material suspension and furnace cooling are caused. The heat transfer between the solid furnace charges is relatively difficult because the solid furnace charges at the upper part in the blast furnace are in point contact type heat conduction, the contact area is not large, the proportion of the heat transfer between the solid furnace charges in the total heat transfer process is small, even the heat conduction effect is negligible, the main heat transfer in the blast furnace is gas-solid convection heat transfer, and the heat transfer is also influenced when the air permeability is poor. I.e. the temperature difference at the two sides of the soft melting belt is larger. If the quality of iron ore, auxiliary materials and the like entering the blast furnace is poor, the soft melting belt becomes thick, the air permeability is poor, and the distribution of air flow in the blast furnace is affected, so that the yield of the whole blast furnace, the quality of products and the production input are affected. Sometimes, the blast furnace is operated under high pressure in order to allow smooth permeation of gas, smooth operation of the blast furnace, and even to increase the pressure of the blast furnace.
In general, the gas resistance distribution in a blast furnace is such that the gas resistance of the reflow zone is about 70% -80% as a whole, the gas resistance of the drip zone below the reflow zone is about 10% -20% as a whole, and the gas resistance of the solid layer of the block zone above the reflow zone is about 5% -10% as a whole.
In the reflow zone, iron ore and part of slag just start to melt, are in a softened and molten state, and the iron ore and the slag just start to become liquid, and the liquid has high viscosity, high surface tension and poor fluidity, and blocks the pores between solid furnace charges, so that the ventilation and liquid penetration resistance is the greatest.
In the area of the reflow zone and below, the iron ore and part of the slag are in a molten state and are molten into molten iron and liquid slag-iron liquid, and the liquid has high viscosity, high surface tension and poor fluidity, so that the pores among the solid furnace charges are blocked. The chemical reaction at the lower part of the blast furnace generates a lot of coal gas, a lot of coal gas needs to pass through liquid molten iron and liquid slag molten iron to generate bubbles, the bubbles are not easy to polymerize, the bubbles are not easy to escape, foam is easy to form, and the phenomenon of flooding can be formed when the gas quantity is large, so that slag and furnace burden are difficult to descend, difficult to run, suspend and collapse, and unstable operation and even shutdown of the blast furnace are caused.
In the drip zone below the reflow zone, the temperature is rapidly increased due to a large amount of heat released by the combustion reaction of the fuel and air at the lower part of the blast furnace, the temperature gradient is large, the temperature is rapidly increased as the temperature is sufficiently high, the viscosity of molten iron and liquid slag-iron liquid is rapidly reduced, and the fluidity is improved, so that the ventilation resistance and the liquid penetration resistance are both reduced.
That is, the most critical and most resistant part for ventilation and liquid penetration in the blast furnace is the reflow zone, followed by the drip zone below the reflow zone; the solid material layer part of the block-shaped belt above the reflow belt has less influence, and only needs to ensure that the gas distribution is 'reasonable' along the radial direction of the blast furnace and uniform along the circumferential direction of the blast furnace. In a blast furnace, the air permeability is critical, the importance of the air permeability is higher than that of liquid permeability, the air permeability affects the liquid permeability, the air permeability is poor, the liquid holdup at the lower part of the blast furnace is excessive, even the liquid is flooded, and the air permeability is most easy to occur in a reflow zone.
In the reflow zone, the coke mainly acts as a ventilated skeleton and carburizes the pig iron just at the beginning. While at the drip zone portion below the reflow zone, the coke acts primarily as a fuel and reductant, as well as a gas permeable framework, and more fully contacts the carburization of the coke with the liquid iron. The coke plays a role of a breathable framework and is mainly embodied in the soft melting belt, is embodied in the dripping belt below the soft melting belt, and is embodied in the solid material layer of the block belt above the soft melting belt.
The number and total sectional area of coke layers in the reflow zone have great influence on the resistance and distribution of gas flow, and modern blast furnaces tend to be large in size, and the reflow zone is generally inverted V-shaped for the gas flow distribution and the intensity of blast furnace smelting. In order to obtain smaller gas passing resistance and better gas distribution, the height of the reflow belt is required to be higher, the inner side of the reflow belt contains more coke interlayers, and the cross-sectional area for the gas to pass is larger. However, the higher height of the reflow zone means that less iron ore is needed in the direction of and near the axial center line of the blast furnace and most of the iron ore is charged as coke, which causes no metal smelting near the axial center line and reduces the smelting strength of the blast furnace; the higher height of the reflow zone means that the size of the furnace burden on the reflow zone in the axial center line direction of the blast furnace is shorter, the temperature gradient is large, the reaction is insufficient, heat similar to a pipeline and a leakage channel of unreacted useful gas are easy to form, the useful gas such as CO cannot perform sufficient reduction reaction, the smelting intensity of the blast furnace is reduced, the utilization rate of the useful gas such as CO is reduced, and the utilization rate of energy is also reduced; also, in order to achieve a # -shaped reflow zone, and better gas flow resistance and gas distribution, a better ore quality, proper ore particle size, and sifting out of powdered raw materials is required.
The temperature of the furnace wall of the blast furnace in the existing blast furnace is low, part of the blast furnace is a water-cooled wall surface, when the blast kinetic energy is smaller, the air flow at the edge of the blast furnace is larger, the heat dissipation capacity to the furnace wall is large, the gas energy utilization is poor, and the waste heat energy and the coke ratio are high; when the blast kinetic energy is larger, the central air flow of the blast furnace is larger, which also causes the gas flow to be abnormal and the furnace condition to be worsened. Therefore, the operation window is small, the operation is not easy to be stable, and the operation of the blast furnace is easy to be unstable and even stopped due to small errors of various reasons. The larger the blast furnace volume, the larger the required blast kinetic energy, the larger the required gas wind speed, and the larger the required gas flow rate.
In the scheme of the patent, the purified gas mainly containing CO is divided into a plurality of strands through a distribution pipe and then is sprayed by a spray gun to enter a blast furnace, the spray gun is annularly and uniformly distributed on the blast furnace in a surrounding manner, the distribution pipe is connected with a ring pipe for connecting the spray guns with the same height, the spray gun is positioned above the air (or oxygen-enriched air) inlet and the coal injection port, the center distance (more than or equal to 0.5m and less than or equal to 15 m) from the height of the highest nozzle of the two nozzles is further (more than or equal to 2m and less than or equal to 10 m), and the angle between the spray gun and the horizontal plane is further (more than or equal to 4m and less than or equal to 8 m: -60 ° - +15°, further: -45 ° - +0°, further: -30 ° - +0°, further: -20 ° - +0°, further: -15 ° - +0°, further: -15 deg. -5 deg.. The blast furnace is vertically distributed with m groups of spray guns (10.gtoreq.1, further 5.gtoreq.1, further 3.gtoreq.n.gtoreq.1), each group is composed of n spray guns (240.gtoreq.n.2, further 120.gtoreq.n.gtoreq.2, further 60.gtoreq.n.gtoreq.2) which are vertically close and evenly distributed around the blast furnace. Typically, the height difference of each group of lances is 0m to 5m (further 0.2m to 3m, further 0.5m to 2 m), the angle of the lances in each group may be different, and the inclination angle of the lances in the blast furnace is adjustable after the blast furnace is started, and the arc length between the lances at the same height is 0.5m to 2.5m (further 1m to 1.6 m). The groups of spray guns with different heights can be vertically arranged just above the spray guns like a rectangle, and can also be staggered above the spray guns like a triangle. The angle between each group of spray guns and the horizontal plane can be different, the flow rate of the sprayed gas can be different, and the speed of the sprayed gas can be different; the inclination, gas flow, gas velocity of the lances within a group may also be different. The areas of the spray gun outlets of different groups and the angles of the spray guns and the horizontal plane are adjusted, so that the incidence angles, incidence speeds and incidence gas amounts of the gas sprayed by the spray guns of different groups are controlled. After the gas is finally sprayed, the gas is uniformly distributed in the circumferential direction of the blast furnace and the gas flows in the middle and the center of the radial direction of the blast furnace are relatively average, the flow rate per unit area is larger, and the gas flow rate per unit area at the radial edge position is smaller, so that the most reasonable radial gas flow distribution of the blast furnace is satisfied. The gas spraying speeds of the spray guns are different, mainly the height positions of the spray guns of each group are different, and the distances from the spray guns to the reflow zone are different, so the gas spraying speeds of the spray guns of different groups are different, and the gas spraying speed range of the spray guns of different groups is larger. The gun sprays of different groups can be arranged at the same vertical height, the gun sprays of different groups are staggered, the incidence angles, incidence speeds and incidence gas amounts of the gun sprays of different groups are generally different, namely, the gun sprays at different positions in the blast furnace, the gun sprays at different positions of the soft melting belt, and the gas amounts of the gun sprays at different positions are different, so that the gun spray gun is practical for small blast furnaces.
The gas mainly containing CO after purification enters the blast furnace through the spray gun at a certain position at a certain angle and at a certain speed, the area of the outlet of the spray gun is adjusted, so that the speed of the gas mainly containing CO after purification sprayed out of the spray gun reaches 100-500 m/s (further 200-400 m/s, further 250-300 m/s), the blast kinetic energy reaches 10-500 kJ/s (further 20-350 m/s, further 30-200 kJ/s), and the speed of the incident gas is large enough, so that the incident gas can drive the furnace burden before the spray gun to perform rotary diffusion motion in a certain range, the gas sprayed into the blast furnace has a certain downward inclination angle, the incident gas can be aligned with a soft zone by adjusting the incident position and the speed of the incident gas, and the incident angle is controlled so that the incident gas meets the soft zone at the middle part of the radial direction of the blast furnace, the incident gas and the formed rotary diffusion motion zone can influence the soft zone, and even the soft zone can become the rotary motion of the furnace burden, and the soft zone can become the rotary motion of the furnace burden. Thus, the air permeability of the part of the reflow zone affected by the incident air is greatly increased, and the high-temperature gas at the lower part of the blast furnace can more easily pass through the reflow zone. And allows the relatively low temperature incident gas to convect with the high temperature reflow zone while also mixing with the gas penetrating up from below the reflow zone. Through the convection heat exchange and the mixed heat exchange processes, the incident low-temperature gas mainly containing CO is heated to high temperature, the temperature is rapidly increased, and the reduction reaction of reducing gases such as CO and the like and metals, namely, the metallurgical process is facilitated. Although hydrogen is also reducing gas, compared with CO, the molecular weight of the hydrogen is small, the weight is light, the kinetic energy is small, the impact force is weak, higher wind speed is required to reach certain kinetic energy, and the higher the wind speed is, the higher the kinetic energy loss speed is, so that the hydrogen is difficult to independently finish the aim of the process of loosening part of the soft melting zone and increasing the ventilation property of the part of the soft melting zone by injecting the hydrogen into the blast furnace. Because the hydrogen quantity is small, the density is small, the diffusion capability is strong, the hydrogen can rapidly escape to the furnace top after entering the blast furnace, the hydrogen can also flow from the nozzle below the reflow zone, and the influence on the ventilation resistance of the reflow zone is small, so the hydrogen can also be used as carrier gas, such as coal powder carrying return furnace and fuel carrying return furnace.
Iron ore fed into the blast furnace from the top is reduced from Fe in the downward process 2 O 3 (hematite) or Fe 3 O 4 (magnetite) gradually becomes FeO and becomes FeO 1/2 Part becomes Fe. In this patent, when the iron ore reaches the reflow zone, the reduction degree of the iron reaches 80% or more, or even 90% or more, that is, a considerable amount of iron has been reduced, and the remainder is mostly floating bodies. The blast furnace above the reflow zone is equivalent to a shaft furnace for directly reducing iron, and the method is equivalent to superposing a shaft furnace and a blast furnace to form a furnaceNew blast furnace. Under the condition of the traditional blast furnace, the reduction degree of the iron at the middle and upper parts of the blast furnace can only reach about 50 percent, and is difficult to reach 60 percent or more. The reduction degree of iron is improved, more spongy iron is reduced, the melting temperature of the spongy iron is reduced after carburization, the spongy iron is easier to melt, and compared with slag molten iron, the molten iron has lower viscosity, better fluidity and higher molten iron density, and the molten iron which rapidly drops under the action of gravity reduces the blocking possibility of a soft melting belt, thereby being beneficial to increasing the ventilation and liquid permeability of the soft melting belt. Similarly, the effect of ventilation and liquid permeation on the drip tape is greater. The reduction degree of iron is improved, the thickness of the soft melting belt is reduced, the ventilation property of the soft melting belt is increased, the heat below the soft melting belt is transferred to the soft melting belt, the temperature of a blast furnace above the soft melting belt is improved, and the time for furnace burden to pass through the soft melting belt is shortened.
If an inert gas such as nitrogen or CO incapable of reducing iron is used 2 Injecting into the blast furnace as described above affects the reflow zone, but inert gas does not participate in the reduction reaction, wasting heat, reducing reaction efficiency, reducing thermal and metallurgical efficiency.
The dripping zone below the reflow zone is subjected to combustion reaction at the lower part of the blast furnace and has high temperature, wherein the reaction is carried out according to formulas (3) to (5) to generate CO 2 And then reacts with C, namely the formula (6), and the final reaction is the formulas (7) and (8). I.e. the final reaction to form CO, so the product of the reaction in the lower part of the blast furnace is CO and essentially free of CO 2 . Compared with the spraying position of the main CO-containing gas in the patent, if the conventional spraying position is adopted at the spraying position below the soft melting zone at the lower part of the blast furnace and at the position close to the air spraying position, the sprayed CO does not participate in the reaction at the lower part of the blast furnace, but the sprayed gas can flow upwards and needs to pass through the drip zone and the soft melting zone, so that the difficulty of ventilation and liquid permeation of the soft melting zone and the drip zone is increased, the liquid holdup of the soft melting zone and the drip zone is increased, the possibility of flooding is increased, the burden is difficult to descend easily, the possibility of difficult running, suspension and material collapse of the blast furnace is increased, and the stable operation of the blast furnace is not facilitated. And the distance between the lower parts of the blast furnaces The injected gas mainly containing CO is easy to flow and mix with air and burns preferentially to coke, fuel and air, and the gas is easy to mix and burn, so that the burning position is closer to the outlet position of the spray gun, namely, the position closer to the outer wall surface of the blast furnace, the wall surface airflow is increased, and the wall surface heat dissipation is increased. The combustion position is close to the spray gun, so that the temperature of the spray gun is easily overhigh, the spray gun is easy to damage, the production of the whole blast furnace is influenced after the spray gun is damaged, and the blast furnace is required to be shut down for maintenance. And causes insufficient combustion at the center position in the radial direction of the blast furnace, and uneven distribution of combustion in the radial direction of the blast furnace. This in turn will lead to an enlarged area, enlarged volume, and increased height of the dead coke accumulation in the center of the furnace, which changes in shape will affect the shape of the belt and increase in height, which will reduce the production of the furnace and increase the height of the belt. The air-permeable liquid-permeable device has the advantages that ventilation and liquid-permeable effects of the reflow zone and the drip zone are more difficult, air flow distribution and temperature distribution at the lower part of the blast furnace are uneven, air flow at the edge of the radial direction of the blast furnace is developed, air flow distribution below the reflow zone can also influence air flow distribution above the reflow zone, the air flow at the edge of the radial direction of the blast furnace is developed, and even side flow and pipeline travel of the air flow are caused. The heat dissipation capacity through the outer wall surface of the blast furnace is increased, the energy utilization is poor, the furnace condition is deteriorated, the smelting of metal is not facilitated, and the stable operation of the blast furnace is not facilitated. And coke and coal at the lower part of the blast furnace are burnt with air vigorously, the temperature is higher, CO is sprayed into a nozzle at the lower part, the CO can be cracked to generate carbon, the generated carbon is blown away upwards by air flow and is easy to adhere to a soft melting zone, a gas passage is blocked, the air permeability is reduced, and the furnace condition is deteriorated.
The ignition point of CO gas is about 630 ℃, the explosion limit range of CO is 12.5% -74.2%, the explosion interval of CO is very wide, when the temperature of incident gas is more than or equal to 630 ℃ (the concentration of CO in the incident gas is different, so that the ignition point temperature of the incident gas is different), once the gas leaks into the air, the risk of combustion and explosion exists (the three elements of combustion are met, oxygen in the air and high-temperature ignition above the ignition point and combustible gas CO) exist. Therefore, when the gas mainly containing CO in the patent does not have enough safety measures, the temperature before incidence is less than 630 ℃, the temperature after incidence enters the blast furnace is basically higher than the temperature, and the blast furnace has enough safety measures, but if the gas before incidence has enough safety measures, the temperature can not be limited (namely, the incidence temperature is more than or equal to normal temperature, the incidence temperature is less than 2400 ℃, the incidence temperature is more than 1600 ℃, the incidence temperature is more than 1300 ℃, the incidence temperature is more than 1000 ℃, and the incidence temperature is more than 630 ℃). Thus, the combustion and explosion risks caused by gas leakage before the gas enters the blast furnace are reduced, and the intrinsic safety is enhanced. However, the temperature of the injected gas is lower than the temperature of the local burden and gas, and although the process of reducing iron by CO is an exothermic reaction as a whole, the heat released is not enough to complement the whole temperature difference, and if the temperature difference cannot be complemented, the temperature of the local burden and gas is lowered, which is unfavorable for the reduction reaction of iron, namely, the reduction degree of iron is lowered. In this patent, the heat that the gas of spouting produced through the reduction reaction process of CO and iron and with the heat transfer of high temperature soft zone and with the high temperature gas heat transfer of permeating the back soft zone of loosening, the gas of spouting is fast to be raised temperature, and the gas after the temperature rise continues to flow upwards. As a large amount of CO gas is injected, the CO content in the gas is higher, and the CO in the gas continuously reacts with the reduced iron to release heat, so that the temperature of furnace burden and the gas in the bed layer are increased. Compared with the existing blast furnace, the average temperature of furnace burden and gas in the middle upper part of the blast furnace or the part of the bed above the reflow zone in the patent is higher than the average temperature of the local position of the existing blast furnace, and the higher temperature is more favorable for the reaction of reducing iron, i.e. the reduction degree of the iron in the middle upper part of the blast furnace or the part above the reflow zone can be improved.
Due to H 2 The process of reducing iron is a strong endothermic reaction, or low in CO content and nitrogen or CO 2 High content of nitrogen and CO 2 The exothermic heat of reaction is not participated, but the heat is needed for heating them to the local furnace temperature, and the heat released by the CO reduced iron is insufficient to make up the gap, and is insufficient for preventing the temperature of the furnace burden and the gas from being reduced, and is insufficient for enabling the furnace burden and the gas on the furnace burden and the gas to reach the local temperature of the same conventional blast furnace. When spraying H into gas 2 Excessive content, or CO contentLower and other reasons may result in excessive gas temperature reduction in the charge after gas injection, and additional gas injection may be added to the lance with little air (or oxygen enriched air or oxygen) injected, the two gases not being mixed prior to injection into the lance. In the blast furnace, the two gases are quickly mixed after being sprayed out of the spray gun, and as the local temperature in the blast furnace far exceeds the ignition temperature, the gases are quickly ignited to release heat so that the furnace burden and the gases on the blast furnace are quickly heated, the total amount of sprayed air (or oxygen-enriched air or oxygen) is insufficient for full combustion, the sprayed gas mainly containing CO is partially combusted, and the furnace burden and the gases on the blast furnace are heated at least to the local temperature of the same conventional blast furnace by adjusting the amount of the air (or the oxygen-enriched air or the oxygen). The ratio of CO and hydrogen in the injected gas is determined by the mole ratio of CO and hydrogen in the feed gas and the amount of CO and hydrogen supplied. And the molar ratio of the amount of oxygen in the air (or oxygen-enriched air or oxygen) to the amount of injected reducing gas is 50% or less (40% or less, 30% or less, 20% or less, 10% or less). The temperature of the incident air (or oxygen-enriched air or oxygen) is more than or equal to normal temperature, and is more than 2400 ℃ (more than 1600 ℃, more than 1300 ℃, more than 1000 ℃ and more than 630 ℃). CO/(CO+H) is required 2 ) The molar ratio of (a) is more than or equal to 54 percent (more than or equal to 67 percent, more than or equal to 77 percent, more than or equal to 84 percent), H 2 /(CO+H 2 ) The molar ratio of (2) is less than or equal to 46 percent (more than or equal to 33 percent, more than or equal to 23 percent, more than or equal to 16 percent), otherwise, the heat released by CO is insufficient to compensate the heat absorption of hydrogen, and the heat absorption and the heat release are different due to different raw material conditions, different temperatures and different reduction degrees.
The conventional blast furnace is generally provided with a reverse V-shaped soft melting zone, and the reverse V-shaped soft melting zone is developed in the central gas flow in the radial direction of the blast furnace; from the standpoint of the radial distribution of the blast furnace, it is desirable that the gas flow in the central and middle portions of the radial direction of the blast furnace be relatively uniform and that the gas flow in the blast furnace pass mainly therethrough, and that the heat dissipation to the furnace wall be large due to the large gas flow at the furnace edge due to the low furnace wall temperature be low. The purification back main CO-containing gas that sprays in to the blast furnace in this patent mainly concentrates in the position in the middle part of blast furnace radial direction after going into the stove to also meet in radial middle part position and reflow zone, the loose reflow zone is favorable to the gas below the reflow zone to see through from this position, makes the gas flow increase of radial middle part position, and traditional Λ type reflow zone radial center unit area gas flow is big in the blast furnace, and radial middle part unit area gas flow is minimum, and radial edge unit area gas flow is less. The final result is that the air flow in the radial middle part and the center of the blast furnace in the patent is relatively average and has larger flow in unit area, and the air flow in the unit area of the radial edge position is smaller, namely the most proper radial air flow distribution of the blast furnace is satisfied, and the air flow distribution has higher metal smelting intensity of the blast furnace, lower coke ratio and fuel consumption ratio, higher energy utilization rate, higher gas utilization rate in the blast furnace and higher reducing gas utilization rate in the blast furnace.
In general, in this patent, the gas distribution in the upper middle part of the blast furnace is improved and the temperature distribution in the upper middle part of the blast furnace is also improved by adjusting the area of the spray gun outlets of different groups and the angle of the spray gun with the horizontal plane, thereby controlling the incidence angle, incidence speed and incidence gas amount of the gas sprayed by the spray guns of different groups. The gas mainly containing CO and heated to high temperature forms good gas flow distribution on the upper part of the reflow zone, and metal reduction reaction is carried out on the middle upper part of the blast furnace.
The blast furnace sprays CO-containing gas to participate in the reduction reaction, if the quantity of the sprayed CO is too large, the quantity of unreacted CO is increased, and the content of CO in the blast furnace gas is increased due to the unreacted CO, so that the waste of useful components CO is caused, the utilization rate of CO in the blast furnace is reduced, and the carbon emission reduction is also not facilitated. However, in the patent, as the subsequent multi-step blast furnace gas treatment device is provided, useful components such as CO and the like in the blast furnace gas are separated and purified to obtain gas mainly containing CO, and the obtained gas is returned to the blast furnace for recycling, thereby solving the problems that the content of CO in the blast furnace gas is increased, the CO and the like are generated in the process of the patent Waste of the components. Because the content of CO in the blast furnace gas rises, which means that the partial pressure of CO in the blast furnace gas rises, the total pressure drop required by the separation of the blast furnace gas is low (the pressure of the blast furnace gas from the blast furnace is generally more than or equal to), the pressure difference required for boosting becomes small, the energy required for boosting is reduced, namely the compression work of a compressor can be reduced, and even boosting is not required. This demonstrates that the CO-containing reducing gas, which is purified from the injected blast furnace gas, is involved in the metallurgical process between the blast furnace and the subsequent blast furnace gas treatment process, which is coupled and integral. When the blast furnace sprays H into the gas 2 Excessive amount causes H in blast furnace gas 2 The content is too high to waste, and the same is true.
When the amount of iron ore entering the blast furnace is fixed, the gas mainly containing CO after purification is injected into the blast furnace above the reflow zone, and then the gas flows upward, and the metal reduction reaction, i.e., the reaction processes of formulas (1) and (2), is performed in the middle upper portion of the blast furnace, the amount of reduced iron ore is increased relative to the existing blast furnace, i.e., the amount of reduced metal required in the lower portion of the blast furnace below the reflow zone, i.e., the reaction processes of formulas (3) to (8). It means that the amount of coke and coal injection required is reduced (coal injection is the most commonly used, so is often used to refer to the process of injecting fuel, and also can be injecting heavy oil, semi-coke, upgraded coal, semicoke, natural gas and other fuels), namely in this patent, the total amount of coke and injected fuel required for smelting iron per unit mass in the blast furnace is reduced, the amount of gas generated in the lower part of the blast furnace is reduced, the amount of gas passing through the lower reflow zone and the drip zone of the blast furnace is also reduced, the difficulty of ventilation and liquid permeation of the reflow zone and the drip zone is reduced, the liquid holdup of the reflow zone and the drip zone is reduced, and the possibility of flooding is reduced. The reduction of the quantity of the coal gas can lead the furnace burden to be easy to descend, reduce the possibility of difficult running, suspension and material collapse of the blast furnace and lead the blast furnace to stably run. The total amount of coke and injected fuel in the blast furnace is reduced, the height of the reflow zone is reduced due to the reduction of the amount of gas generated at the lower part of the blast furnace, the reflow zone of the blast furnace is moved downwards, the melting zone is narrowed, the air permeability is better, and the maximum pressure difference is reduced. This means that more ore can be charged in and near the axial centerline of the blast furnace, thereby enhancing the smelting of metal near the axial centerline, improving the smelting strength of the blast furnace, and increasing the yield; the height reduction of the reflow zone means that the size of the furnace burden on the reflow zone in the axial center line direction of the blast furnace is prolonged, the temperature gradient is reduced, the reaction is more complete, the possibility of forming a leakage channel similar to a pipeline for heat and unreacted useful gas is reduced, the diffusion of CO and hydrogen in the blast furnace into ore pores is facilitated, the reduction iron reaction of the useful gas such as CO is more complete, the smelting intensity of the blast furnace is improved, the utilization rate of the useful gas such as CO is improved, and the utilization rate of energy is also improved.
In the patent, as the gas mainly containing CO is injected, compared with a common blast furnace, the content of CO in the blast furnace is high, and the partial pressure of CO in a gas phase is increased, so that the gasification of alkali metal is blocked, the alkali metal has the positive catalytic function of carbon dissolution loss reaction, and the enrichment of the alkali metal gas at the coke is an important factor for reducing the coke strength and catalyzing the carbon dissolution loss reaction (namely formula (6)) of the coke; the content of CO is increased, then the CO 2 The content is reduced, so that the dissolution loss reaction rate of carbon is reduced; finally, the erosion to the structure of the coke is reduced, and the structural strength of the coke is protected.
The total amount of coke and injected fuel in the blast furnace is reduced, the amount of gas generated at the lower part of the blast furnace is reduced, the released heat is reduced, the heat taken away by the gas is reduced, the temperature at the upper part of the blast furnace is reduced, a soft melting zone is moved downwards, the oxygen enrichment rate of air injected into the blast furnace or the temperature of the air is increased, the oxygen enrichment rate of the air is increased from 3% in general to more than or equal to 5%, more than or equal to 8%, more than or equal to 13%, more than or equal to 20% or even more than or equal to 30%, and the heat taken away by unit gas is increased. The oxygen enrichment rate is improved, the nitrogen content of the inert gas is reduced, and the air permeability of a material column in the blast furnace is improved. As described above, the incident gas is made to impact the reflow zone, so that the reflow zone affected by the incident gas becomes loose and the air permeability is greatly increased, so that the high-temperature gas at the lower part of the blast furnace can more easily pass through the reflow zone, heat is brought to the block zone above the reflow zone, heat below the reflow zone is reduced, the temperature below the reflow zone is reduced, and the influence on the service life of the blast furnace body due to the overhigh temperature below the reflow zone is avoided.
The reaction of CO reducing iron is exothermic reaction, so that heat can be supplemented to the middle and upper parts of the blast furnace, the problem of 'upper cooling and lower heating' easily occurring in the blast furnace is solved, and particularly, when hydrogen is introduced into the blast furnace or the hydrogen content in the blast furnace is higher, the process of reducing iron by hydrogen is strong endothermic reaction, and the 'upper cooling and lower heating' problem of the blast furnace is more easily caused. The hydrogen density is small, the diffusion capacity is strong, the hydrogen rapidly escapes to the furnace top after entering the blast furnace, the single hydrogen can not well stay in the furnace to complete the reduction reaction, a small amount of hydrogen is mixed with CO, the hydrogen and the CO are mutually matched, the heat absorption and the heat release are complementary, the reduction speed and the reduction depth of iron can be improved, the reduction reaction of iron can be completed better and faster, and meanwhile, the problem that the temperature of the upper furnace burden in the blast furnace is reduced due to strong heat absorption of the hydrogen reduction iron reaction is solved.
The scarcity of high-quality coking coals such as coking coals, fat coals and the like in the world causes the same scarcity of coke, the price of the coke rises year by year, the price of the coke is high, the profit of iron and steel enterprises and metallurgical enterprises is very thin, even the coke is often lost, and the situation is more serious in China. Because various advantages of blast furnace are brought to the scheme in this patent, especially reduced the ventilative degree of difficulty that permeates liquid of reflow zone and drip area, reduced the liquid holdup of reflow zone and drip area, reduced the possibility of flooding. The furnace burden is easy to descend, the possibility of difficult running, suspending and disintegrating of the blast furnace is reduced, and the blast furnace can run more stably. In this patent, it is considered to use a high quality semicoke portion instead of coke to reduce the amount of scarce coke used and at the same time also to ensure stable operation of the blast furnace. Semicoke is not rare, the price of semicoke is generally about 1/3-1/2 of that of coke, and the use of semicoke instead of coke can bring great economic benefit to steel plants. Semicoke is generally obtained by dry distillation of coal with weak caking property or non-caking property at 600-700 ℃, and compared with coke, the semicoke is mainly characterized by high volatile and strong reactivity; the most important difference is the difference in semicoke strength, especially the difference in strength after the reaction, which makes it impossible to replace the coke for blast furnace ironmaking.
In the patent, large high-quality semicoke with granularity more than or equal to 25mm (more than or equal to 40mm and more than or equal to 50 mm) is selected and mixed with coke normally used by a common blast furnace, and the mixture and iron ore are layered and loaded into the blast furnace from the top of the blast furnace. Although superior semicoke has been selected, its strength has been required to be as great as possible, but its strength is still lower than that of coke. In the middle-upper part of the blast furnace, the main functions of the coke and the semicoke are reducing agents, and the reducing agents and the CO are as follows 2 CO is generated by the reaction, and is shown as a formula (6), and the reducing gas CO is used for reducing ore to generate iron and CO 2 . This dissolution loss reaction of carbon can erode the structure of the coke, which can reduce the structural strength of the coke. Although the reactivity of the semicoke selected is lower than that of the general semicoke, the reactivity of the added semicoke is still far higher than that of the coke, so that CO 2 The reaction with semicoke is preferential, and the reaction with the coke is less likely to occur, so that the coke is protected, the structure of the coke is protected by reducing the dissolution loss reaction of the carbon, and the structural strength of the reacted coke is also protected. The strength of the coke after the reaction is the key point of the skeleton action of the coke, which is the key for ensuring the air permeability and liquid permeability of a material column in a blast furnace, and the skeleton action is not replaced by any other solid fuel. Since in this patent the reducing gas containing a large amount of CO is sprayed on the reflow zone, the bulk zone above the reflow zone has a high CO content, whereas the CO 2 The content is low, so that the dissolution reaction of carbon at the middle upper part of the blast furnace above the reflow zone is not serious to the erosion of semicoke and coke, the structural integrity, the structural strength and the strength after the reaction are ensured. The strength of the coke is reduced slightly along with the condition that the temperature of the furnace burden moves downwards more, and the strength of the semicoke is reduced more, the selected large semicoke is eroded by the dissolution reaction of carbon to generate powder, the small powder is filled in the gaps of the nearby furnace burden, the reactivity of the small powder is higher, and the structure of the coke can be better protected. The soft melting belt is the place with the highest ventilation difficulty of the blast furnace and the place with the highest gas resistance, the gas resistance of the soft melting belt is about 70 to 80 percent, which indicates that the ventilation capacity of the soft melting belt is the blast furnaceThe key of stable operation is the whole blast furnace 'neck' place. After the charge enters the reflow zone, the temperature is higher, and although the dissolution reaction of the carbon occurs faster, the dissolution reaction of the carbon is sufficiently resistant to erosion of the large quality semicoke by the dissolution reaction of the carbon in the time of passing through the reflow zone due to the large size of the large quality semicoke. And the carbocoal and more small powder generated under the erosion of the carbocoal are subjected to carbon dissolution loss reaction preferentially to directly perform reduction reaction with the contacted molten iron material, and the carbocoal and the small powder are subjected to carburization preferentially to iron, so that the carbocoal is further protected. Since in this patent the iron ore reaches the zone of reflow, the degree of reduction of the iron reaches more than 80%, even more than 90%, and the remaining unreduced iron oxide has a lower proportion, less can directly undergo reduction reaction with carbon element, because of the good contact of liquid slag iron liquid with coke and semicoke, the reaction of the reduced iron is that the iron oxide directly reacts with carbon, and the reduction reaction of the drip zone iron at the zone of reflow and below is mainly that of this reaction. Due to the improvement of the reduction degree of iron, the ratio of the remaining unreduced ferric oxide is lower, less ferric oxide can directly carry out carbon melting loss reaction with carbon element, and the reverse reaction rate of the carbon melting loss reaction is increased, so that the structural integrity of coke and semicoke is maintained, namely the framework effect of the coke and semicoke is maintained, and the ventilation capability of a soft melting zone can be better maintained. The method is similar to the method in the dripping zone, the reduction degree of iron is improved, the melting loss reaction of carbon is reduced, the structural integrity of coke and semicoke is maintained, namely the skeleton effect of the coke and semicoke is maintained, and the ventilation and liquid permeability of the dripping zone can be better maintained. After the furnace burden enters the drip belt, more sponge iron is reduced due to the improvement of the reduction degree of iron, the melting temperature of the sponge iron is reduced after carburization, and the sponge iron is easier to melt, so that compared with slag iron liquid, the viscosity of the molten iron is much lower, the viscosity becomes lower along with the further downward movement of the furnace burden, the fluidity is better, the molten iron density is higher, the molten iron which rapidly drops under the action of gravity is reduced, the blocking possibility of the drip belt is reduced, and the ventilation and liquid permeability of the drip belt are increased. Also, because the reactivity of the semicoke is far higher than that of the coke, the semicoke reacts preferentially to the coke, and the semicoke is preferentially used as a reducing agent to the coke The reduced iron is used as fuel to supply heat for the metallurgical process and is used as carburizing agent to carburize the raw iron, thus protecting the structure of the coke, maintaining the structural strength of the coke after reaction and maintaining the skeleton effect of the coke. The semicoke only partially plays a role of a skeleton, the reaction speed is faster and faster along with the downward movement of the semicoke, the semicoke further reacts, the strength of the semicoke after the reaction is rapidly reduced, so that the semicoke cannot play a role of the skeleton later, and only plays a role of a reducing agent, fuel and a carburizing agent until the whole semicoke is completely reacted. However, the temperature is already high, exceeds 1400 ℃ and even exceeds 1500 ℃, and the melting loss reaction rate of carbon is rapidly increased. Since the reduction degree of the upper iron in the blast furnace is increased, the unreduced iron is reduced at this time, and the melting temperature is lowered; and the higher the temperature is, the lower the viscosity is, the better fluidity is, the molten iron density is higher, the molten iron which rapidly drops under the action of gravity enables the liquid retention to be low, the possibility of blocking the drip belt is reduced, and the ventilation and liquid permeability of the drip belt are improved. The whole air resistance of the drip belt below the reflow belt accounts for about 10-20%, is not the place with the largest air permeability difficulty of the blast furnace, is not the place with the largest air resistance, is not the place with the whole neck of the blast furnace, has complete protected coke structure, still can play the role of a framework, and is enough to ensure the air permeability and the liquid permeability of a material column in the lower part of the blast furnace. In combination with the various advantages mentioned in the scheme in the patent mentioned in the foregoing, the ventilation property of the soft melting belt and the dripping belt can be increased, the difficulty of ventilation and liquid permeation of the soft melting belt and the dripping belt can be reduced, the liquid holdup of the soft melting belt and the dripping belt can be reduced, the possibility of flooding can be reduced, and the stable operation of the blast furnace can be maintained. Therefore, in the patent, semicoke plays roles of reducing agent, fuel and carburizing agent in the blast furnace and plays a part of framework role; therefore, the high-quality semicoke can be partially replaced by coke in the blast furnace, and the blast furnace can still stably run after being mixed with the coke and then loaded into the blast furnace from the top of the blast furnace. In this patent, the coke alone corresponds to the difficulty of moving the "neck" from the reflow zone down into the drip zone where the coke and semicoke together bear the "neck". The mixing mass ratio of semicoke to coke can be reduced to 70%, the ratio of coke can be further reduced to 60%, the ratio of semicoke to coke can be further reduced to 50%, the ratio of semicoke to coke can be further reduced to 40%, and the ratio of coke to coke can be further reduced to 30%.
The high-quality semicoke adopted herein means semicoke which has the advantages of low ash content, low volatile content, high fixed carbon content, low alkalinity and high cold strength and high strength after reaction. The main indexes of semicoke are as follows: particle size not less than 25mm (further not less than 40mm, further not less than 50 mm), ash content A d Less than or equal to 8 percent (more than or equal to 6 percent and more than or equal to 5 percent), and volatile component V daf Less than or equal to 10 percent (more than or equal to 7 percent and more than or equal to 5 percent), and fixed carbon FC d More than or equal to 80 percent (more than or equal to 85 percent, more than or equal to 90 percent), the total amount W (K+Na) of sodium and potassium is less than 0.3 percent (more than 0.2 percent, more than 0.12 percent), and the content of SiO in semicoke ash 2 +Al 2 O 3 )/(CaO+Fe 2 O 3 +MgO) is not less than 2 (further not less than 4, further not less than 6), ash fusion softening temperature St is more than 1150 ℃ (further more than 1250 ℃, further more than 1350 ℃), hash grindability index HGI is not more than 50 (further not less than 45, further not more than 40), strength after reaction CSR is not less than 40% (further not less than 45, further not less than 50%), reactivity CRI is not less than 70% (further not less than 60%, further not more than 50%), thermal stability TS +6 More than 80% (more than 85%, more than or equal to 90%) of total sulfur S t,d Not more than 0.7% (further not more than 0.5%, further not more than 0.3%), and the falling strength SS > 60% (further > 65%, further > 70%). The better the index of the semicoke is, the higher the semicoke ratio is, the mixing ratio of the semicoke and the coke can be charged into the blast furnace. The ash fusion softening temperature St is not easily too high, too high is not suitable for entering the blast furnace, st < 1700 ℃ (further < 1600 ℃ and further < 1500 ℃), but usually this is rarely the case. The Hash grindability index HGI > 13 (further > 20, still further > 25). The granularity is less than or equal to 300mm (less than or equal to 100mm, and further less than or equal to 80 mm). In semicoke ash (SiO) 2 +Al 2 O 3 )/(CaO+Fe 2 O 3 +MgO) < 30 (further < 20, further < 9).
For insufficient alkalinity and ashThe semicoke which is not low enough and has some indexes not reaching standards can be sprayed by adopting common commercial hydrochloric acid solution with the mass concentration of 35-38 percent, then the steam with the mass concentration of more than or equal to 100 ℃ (less than or equal to 550 ℃, further less than or equal to 350 ℃ and further less than or equal to 200 ℃) is used for heating the semicoke to lead the temperature to be 70 ℃ and more so as to volatilize hydrochloric acid, the gas flow is kept at the gas temperature for more than 1h, then the temperature is gradually reduced to 40 ℃ and less (more than or equal to normal temperature) so as to lead the hydrochloric acid to be condensed, and then the semicoke is kept for more than or equal to 2h (less than or equal to 72h, further less than or equal to 48h and further less than or equal to 24 h). And then the semicoke is purged by steam with the temperature of more than or equal to 200 ℃ (less than or equal to 550 ℃ and further less than or equal to 350 ℃) so that the semicoke is heated to 200 ℃ and above (the temperature of less than or equal to 350 ℃ and further less than or equal to 280 ℃) for more than 2 hours (the time of less than or equal to 72 hours, further less than or equal to 48 hours and further less than or equal to 24 hours). After purging, the semicoke is cooled to normal temperature by standing, and at the moment, the semicoke is dried and various impurities after spraying hydrochloric acid are also blown away. And then detecting the ash mass proportion and the alkalinity of the semicoke and other indexes to see whether the semicoke meets the requirements. Various indexes of the semicoke after the treatment are generally improved to different degrees, and when ash A d Less than or equal to 12 percent, the total weight W (K+Na) of sodium and potassium is less than 1.2 percent, the strength CSR after reaction is more than or equal to 30 percent, the reactivity CRI is less than or equal to 80 percent, and the thermal stability TS +6 At > 70%, these criteria can generally be met by the above minimum requirements after the above treatment. When the existing index and the required index have large differences, the differences of the indexes can be reduced by increasing the amount of hydrochloric acid or increasing the duration of the treatment step. The standing cooling time is influenced by the intensified ventilation cooling condition, the cooling time is required to be at normal temperature, the time is required to be less than or equal to 72 hours (further less than or equal to 48 hours and further less than or equal to 24 hours), and the standing cooling time can be shortened through the intensified ventilation cooling condition. The total mass ratio of the hydrochloric acid solution and the semicoke is less than or equal to 25 percent (more than or equal to 20 percent, more than or equal to 15 percent, more than or equal to 12 percent, more than or equal to 10 percent, more than or equal to 8 percent and more than or equal to 5 percent).
As described above, in the present patent, the total amount of coke and injected fuel required for smelting iron per unit mass is reduced, the amount of coke charged into the blast furnace is reduced, the amount of iron ore charged into the blast furnace is increased, and the reaction of the injected reducing gas such as CO with reduced iron proceeds further in the upper middle portion of the blast furnaceFully improves the smelting strength of the blast furnace, improves the efficiency of the blast furnace, saves the amount of coke and fuel required by smelting metal, and reduces the coke ratio and the fuel consumption ratio. By adjusting the position, the spraying direction and the spraying amount of the sprayed gas, the gas flow in the radial middle part and the center of the blast furnace is uniform, the gas flow in unit area is larger, the gas flow in unit area at the radial edge position is smaller, and the radial gas flow of the blast furnace is more reasonable due to the distribution. At the same time, the total amount of coke and injected fuel in the blast furnace is reduced, the amount of gas generated at the lower part of the blast furnace is reduced, the height of a reflow zone is reduced, and the leakage passage of heat and unreacted useful gas similar to a pipeline is formed at the center of the radial direction of the blast furnace. The air flow distribution improves the metal smelting intensity of the blast furnace, improves the energy utilization rate, and improves the gas utilization rate in the blast furnace, namely improves the efficiency of the blast furnace. The efficiency of a blast furnace is typically determined by the CO in the blast furnace gas 2 /(CO+CO 2 ) Is calculated by the concentration ratio of (c). The efficiency of modern large blast furnaces is typically about 45%, while the efficiency of the blast furnace is typically about 50% or more (further 70%, further 80%, further 90%, even close to 100%) after the injected reducing gas is subtracted from the present patent and the injected CO is subtracted from the present patent. In this patent, the smelting intensity of the blast furnace can be increased by more than 5%, some can be increased by more than 10%, even some can be increased by more than 20%.
The common utilization method of blast furnace gas and converter gas in factories is used as fuel or power generation (the power generation is also to burn and release heat firstly), and the heat energy released by combustion is utilized (namely CO is burned to CO) 2 But this is an inefficient way of use and CO is emitted after combustion 2 . CO is a reducing component and can be used as a chemical production raw material or metal smelting, and the utilization mode is an efficient and high-added value utilization mode. The heat required can be provided by combusting natural gas, and the natural gas is mainly methane, has low C/H and provides CO generated by combustion of unit heat 2 The amount is small, namely, carbon emission reduction can be realized.
It has been proposed to use blast furnace gas The converter gas is purified to obtain useful components as organic chemical products (such as ethylene glycol, natural gas and the like), but the method is not practically implemented, and the main reason is that for the personnel in the existing steel works, the manufacturing of the organic chemical products is a great challenge in the aspects of knowledge system, management system, safety system and the like, and the great barriers exist between two different industries of metallurgy and chemical industry to make the application mode difficult to implement. And most of organic chemical products are hydrocarbon, and the hydrogen-carbon ratio is generally high, but the hydrogen components in blast furnace gas and converter gas are very small. To meet the hydrogen-carbon ratio requirement, or to shift the CO component of the gas to produce hydrogen, but this produces CO 2 And also increases a part of carbon emission, which is unfavorable for carbon emission reduction. Or the hydrogen is found from outside, but the external hydrogen source is not readily available, and an additional device kit (such as natural gas steam reforming hydrogen production) is likely to be added. Carbon emission is generated in most cases in the hydrogen production process, and the carbon emission reduction is also unfavorable.
Compared with the prior art, the patent has substantial characteristics and remarkable progress: the useful reducing component CO in the blast furnace gas or the converter gas is utilized with high efficiency and high added value, and the reducing property is utilized to return to the blast furnace for carrying out the metal smelting reaction, thereby fully utilizing the value. And reduces the carbon emission in the metal smelting process of the blast furnace. The carbon emission reduction method belongs to the metal smelting industry with small investment and quick effect, optimizes the process flow and reduces the equipment investment and the whole energy consumption. Nitrogen meeting industry nitrogen standards can also be obtained if process optimization is required (GB 3864-2008 and its updated versions).
Drawings
FIG. 1 is a flow chart of a process for reducing carbon emissions by purifying reducing gas from blast furnace gas or converter gas and returning the reducing gas to the blast furnace to participate in metallurgy;
FIG. 2 is a cross-sectional view of the blast furnace of FIG. 1;
FIG. 3 is a cross-sectional view of the blast furnace of FIG. 2;
FIG. 4 is a process flow diagram of the blast furnace gas purification reducing gas return blast furnace participation metallurgy carbon emission reduction method in example 1;
FIG. 5 is a process flow diagram of the blast furnace gas purification reducing gas return blast furnace participation metallurgy carbon emission reduction method in example 1;
FIG. 6 is a process flow diagram of the blast furnace gas purification reducing gas return blast furnace participation metallurgy carbon emission reduction method in example 2;
FIG. 7 is a process flow diagram of the blast furnace gas purification reducing gas return blast furnace participation metallurgy carbon emission reduction method in example 3;
FIG. 8 is a process flow diagram of the method for reducing carbon emissions in a blast furnace to participate in metallurgy by returning reducing gas for the purification of a blast furnace gas in example 4;
FIG. 9 is a process flow diagram of the blast furnace gas purification reducing gas return blast furnace participation metallurgy carbon emission reduction method in example 6;
FIG. 10 is a block diagram of a blast furnace gas purification reducing gas return blast furnace participation metallurgical carbon emission reduction device;
FIG. 11 is CO, H 2 ，N 2 Adsorption isotherms (25 ℃) on the novel CO adsorbent;
Detailed Description
The production method for producing natural gas mainly uses blast furnace gas and converter gas as raw materials or main raw materials, wherein the main raw materials account for the majority of components, such as 70%, 80% and 90% by volume, and the gas may also contain one or two or more of coke oven gas, other tail gas or purge gas.
The gas composition of the gas mainly comprises: n (N) 2 、H 2 、CO、CO 2 、O 2 、CH 4 、H 2 S, COS, etc., in some typical blast furnace gas compositions include, in percent by volume: n (N) 2 40～65％、H 2 0.5～5％、O 2 0.2～5％、CO 2 10～30％、CO 10～30％、CH 4 0.1～2.0％、H 2 S 5～1000mg、COS 0.1～1000mg。
The raw materials such as coal gas and the like can also be subjected to corresponding pretreatment processes such as dust removal, impurity removal and the like by a conventional method before entering the process and the equipment in the patent; these pretreatment are not particularly limited, and a certain gas treatment apparatus for dehydration, dust removal, impurity removal, etc. are already existing in the iron and steel plant, and these apparatuses can be regarded as an accessory apparatus of a blast furnace or a converter.
A method for reducing carbon emission by returning the purified reducing gas of blast furnace gas or converter gas to a blast furnace for metallurgy comprises the following steps:
step 1, the coal gas passes through a pretreatment flow;
Step 2, purifying CO gas (the volume fraction of the obtained CO is more than or equal to 50 percent, and the volume fraction of the obtained CO is more than or equal to 60 percent) by using the gas through a pressure swing adsorption method; ,
and step 3, returning the obtained gas mainly containing CO to the blast furnace as reducing gas.
The gas mainly comprises: one or two of blast furnace gas and converter gas.
In one embodiment, the gas may further contain a small amount (volume fraction is less than or equal to 30%) of coke oven gas, other tail gas or a mixture of one or more of purge gases.
Before purifying CO by the pressure swing adsorption separation method in step 2, the CO is further subjected to pretreatment, wherein the pretreatment comprises: dedusting, dephosphorizing, arsenic removing, dehydrating, deoxidizing, desulfurizing and CO removing 2 Or remove CH 4 One or a combination of steps. The content of harmful impurities in the purified gas is controlled to be less than or equal to 1.15ppm of sulfide and NH 3 ≤200ppm，O 2 ≤0.4％，H 2 O≤100ppm，Cl + Less than or equal to 0.03ppm, less than or equal to 0.1ppm of arsenide, less than or equal to 1mg/Nm of tar and dust 3 Naphthalene not more than 1mg/Nm 3 . Further, the content of harmful impurities is controlled to be less than or equal to 0.1ppm of sulfide and Cl + ≤0.01ppm，O 2 ≤0.2％。
Further said pre-treatment comprises: desulfurization and CO removal 2 Removing CO 2 Carried out synchronously with desulphurisation or CO removal 2 After the desulphurisation step. This is because the blast furnace gas and/or the converter gas contains a trace amount of sulfur, which adversely affects the subsequent adsorbent, particularly the adsorbent for purifying CO Even deactivated and shortened in service life, so that the waste water is removed first. And the blast furnace gas and/or the converter gas of the incoming materials can have higher starting temperature, which is beneficial to the reaction speed and the desulfurization effect of the desulfurizing agent adopting metal oxides.
The sulfur or various impurities containing sulfur may be removed by adsorption, membrane separation, solid desulfurizing agent containing iron or manganese or zinc or copper or nickel or calcium or tin oxide or hydroxide of a complex metal oxide formed therebetween, low-temperature methanol washing, propylene carbonate, N-methylpyrrolidone, polyethylene glycol dimethyl ether, polyethylene glycol methylpropyl ether, tributyl phosphate, hot potassium alkali, activated hot potassium alkali, MEA, DEA, MDEA, DIPA, propylene carbonate+DIPA, propylene carbonate+glycol amine, sulfolane, sulfolane+DIPA, sulfolane+MDEA, methanol+secondary amine, alkanolamine solution, MEA with an active agent DEA method, MDEA method, ammonia water washing method, caustic soda method, ADA method (stratford method), tannin extract method, LO-CAT method, sulferox method, sulfinit method, konox method, bio-SR method, naphthoquinone method (Takahax method), metal phthalocyanine method (PDS method), G-V (modified arsenic alkali method), arsenic alkali method, MSQ method, sulfolin method, EDTA method, wet oxidation method, alkali liquor absorption method, limestone-gypsum method, ammonia method, magnesium method, ammonium phosphate fertilizer method, organic acid sodium-gypsum method, lime-magnesium method, calcium method, dry circulating fluidized bed method, zinc oxide method, urea method, complexation absorption method, charged dry absorber spraying method, plasma method, electron beam method, double alkali method, sulfide alkali method, and combinations thereof. Wherein the removed sulfur is sent to a sulfur recovery system, and the sulfur in the gas is removed to 0.01-0.1 ppm after the raw gas is desulfurized. When the absorption method is adopted, if the absorbent has the absorption capacity for both sulfur and carbon dioxide, the sulfur and carbon dioxide can be removed simultaneously, and when the absorption method is adopted, it is preferable to further arrange a one-step fine desulfurization (for example, desulfurization by a solid desulfurizing agent) for achieving a better desulfurization effect. Desulfurization is carried out at 0.2-10 MPa, 20-700 ℃, in some embodiments (0.2-3 MPa, 20-400 ℃, such as 400-280 ℃ for some solid metal oxide desulfurizing agents, 20-100 ℃ for absorbing liquid). By absorption method To achieve CO removal 2 The desulfurization is carried out synchronously, and the fine desulfurization by adopting a solid desulfurizing agent is preferably carried out after dehydration and heavy component removal.
When the content of organic sulfur in the feed gas containing sulfur is too high, the organic sulfur can be converted into H through catalytic hydrogenation reaction or catalytic hydrolysis reaction 2 S, desulfurization is carried out again, SO that the sulfur content of the treated gas can meet the requirement, and when the feed gas contains sulfur mainly as SO 2 And the content is too high, SO can be caused by catalytic hydrogenation reaction 2 Conversion to H 2 S, desulfurization is carried out again, so that the sulfur content of the treated gas can meet the requirement. The catalyst for the catalytic hydrogenation reaction may be any catalyst commonly used in the art, or may contain iron and/or copper and/or cobalt and/or manganese and/or molybdenum and/or zinc and/or aluminum and/or nickel and/or titanium and/or zirconium and/or tungsten and/or cerium metals and/or their oxides and/or their sulfides and/or their soluble salts and/or complex metal oxides formed between them as an active component, and one or more of titanium, zirconium, manganese, iron, nickel, cobalt, copper, molybdenum, tungsten, zinc, cobalt, cerium metals and/or their oxides, and silicon, rare earth, alkali metals, alkaline earth metals, transition metal oxides and/or their sulfides as an auxiliary agent. The carrier is active carbon, alumina, silica, magnesia, titanium oxide, silica gel, molecular sieve, honeycomb ceramics, monazite, honeycomb metal, metal plate, corrugated filler, corrugated plate, fiber (cloth) material and structure, braided fabric, metal foam, ceramic foam, graphite-based foam and the like. The catalyst for catalytic hydrolysis reaction comprises magnesium and/or lanthanum and/or barium and/or aluminum and/or titanium and/or zirconium and/or cerium and/or potassium and/or calcium and/or cobalt and/or molybdenum and/or iron and/or copper and/or manganese and/or zinc and/or nickel and/or tungsten metal and/or oxides thereof and/or sulfides thereof and/or composite metal oxides formed between them as active components, and one or more of titanium, zirconium, nickel, cobalt, molybdenum, cobalt, cerium metal and/or oxides thereof and silicon, rare earth, alkali metal, alkaline earth metal, oxides of transition metal and/or sulfides thereof as auxiliary agents. Load carrier The body is activated carbon, alumina, silica, magnesia, titanium oxide, silica gel, molecular sieve, honeycomb ceramics, monazite, honeycomb metal, metal plate, corrugated filler, corrugated plate, fiber (cloth) material and structure, braided fabric, metal foam, ceramic foam, graphite-based foam and the like. The temperature and pressure ranges of the organosulfur conversion process are referenced to the desulfurization process.
If standard-meeting industrial nitrogen is required, dehydrogenation and deoxygenation and CH removal are required 4 . If no standard-meeting industrial nitrogen is needed, CH can not be removed 4 The resulting nitrogen gas contains a slight excess of CH 4 Further, the first impurity removal pretreatment further includes: CH removal 4 The catalytic oxidation method can be adopted, so that the purity of the obtained nitrogen meets the industrial nitrogen standard (GB 3864-2008 and updated version thereof), and the removal is carried out firstly, namely CH removal is carried out after the desulfurization step due to the higher temperature required by the reaction 4 If desulfurization and decarbonation are separated, CH will be removed 4 The device is arranged after desulfurization and before decarbonation, which is beneficial to saving energy and heat exchange equipment and reducing equipment investment and operation cost. In one embodiment, CH is removed 4 The catalyst is mainly prevented from losing activity by carrying out catalytic combustion reaction of methane at a certain temperature (150-1000 ℃, for example 200-350 ℃) and a certain pressure (0.1-10 MPa, for example 0.2-2 MPa) to remove methane. The catalyst used may be any catalyst commonly used in the art, or may be a metal and/or oxides thereof and/or soluble salts thereof and/or complex metal oxides formed therebetween containing iron and/or copper and/or cobalt and/or manganese and/or molybdenum and/or zinc and/or aluminum and/or nickel and/or chromium and/or bismuth and/or magnesium and/or titanium and/or barium and/or ruthenium and/or zirconium and/or cerium and/or lanthanide and/or platinum and/or palladium and/or gold and/or rhodium and/or calcium as the active component. Metals of titanium, zirconium, manganese, iron, nickel, cobalt, copper, molybdenum, tungsten, zinc, cobalt, cerium, aluminum, chromium, bismuth, magnesium, titanium, barium, ruthenium, zirconium, cerium, lanthanum, platinum, palladium, gold, rhodium, calcium and/or oxides thereof and/or soluble salts thereof and/or composite metal oxides formed therebetween, silicon, rare earth, alkali metal, ruthenium, zirconium, cerium, lanthanum, platinum, palladium, gold, rhodium, calcium, One or more of alkaline earth metal and transition metal oxides are auxiliary agents. The carrier is active carbon, alumina, silica, magnesia, titanium oxide, silica gel, molecular sieve, honeycomb ceramics, monazite, honeycomb metal, metal plate, corrugated filler, corrugated plate, fiber (cloth) material and structure, braided fabric, metal foam, ceramic foam, graphite-based foam and the like. CH removal 4 CH in the post-feed gas 4 The content of (2) is less than or equal to 0.5 percent, and further CH 4 ≤0.1％。
And then if the oxygen content in the blast furnace gas and/or the converter gas is high (about>0.1%, further>0.04% of typical gases, all above this value) can adversely affect, even deactivate, shorten the useful life of the adsorbent for purifying CO, requiring advanced deoxygenation to separate CO from nitrogen prior to entry into the pressure swing adsorption separation apparatus 2 The concentration of (2) is less than or equal to 0.4 percent, and is more less than or equal to 0.2 percent; so that the pre-treatment process of removing impurities is preceded by deoxidation (dehydrogenation is carried out at the same time of deoxidation, but the main purpose of removing hydrogen is not to be taken, but H is removed) 2 Resulting in higher purity of the nitrogen in the subsequent step), this deoxygenation may also be referred to as dehydrodeoxygenation.
Thus, if dehydrogenation deoxygenation is provided after desulfurization, if desulfurization and CO removal 2 The steps are separated, and dehydrogenation and deoxidation are arranged after desulfurization to remove CO 2 Previously, if there is a divide by CH 4 Setting the dehydrogenation and deoxidation to CH removal 4 After that, CO is removed 2 Before. Therefore, the method achieves the aim in one step, has the advantages of protecting the adsorbent and the catalyst in the subsequent steps, reducing the waste of CO, reducing the impurity removal step of impurities generated after catalytic dehydrogenation and deoxidation, shortening the flow, reducing the investment and the operation cost, simultaneously meeting the reaction temperature of the catalytic dehydrogenation and deoxidation due to higher temperature of the gas in front, avoiding the investment and the operation cost required by heat exchange equipment caused by the fact that the gas is placed at the back and needs to be heated, simultaneously meeting the step-by-step principle of the reaction temperature, reducing the investment and the operation cost of the heat exchange equipment, and being beneficial to increasing the purity of nitrogen in dehydrogenation and deoxidation, and obtaining the industrial nitrogen meeting the standard. Of course if the oxygen content in the feed gas is low (less than or equal to 0.1)In% by weight), the pretreatment process may not be performed with dehydrogenation deoxidation, so that the adsorbent is not deactivated rapidly, but the service life of the adsorbent is still shortened. The dehydrogenation and deoxidation step is added before the carbon dioxide removal step, so that the concentration of CO in the gas is low, the selectivity of catalytic oxidative dehydrogenation is improved, the reaction of CO and oxygen is reduced, the waste of CO is reduced, the reaction conditions are not severe, and the selection of a catalyst is facilitated. Removing H by adopting catalytic oxidation method 2 And take off O 2 The temperature of (2) is more than or equal to 100 ℃.
The dehydrogenation and deoxygenation may be accomplished by simultaneously removing H from the blast furnace gas with a selective dehydrogenation catalyst at a pressure of 0.1 to 10MPa (in some embodiments, 0.2 to 3 MPa) and a temperature of 50 to 1000 ℃ (in some embodiments, 80 to 250 ℃) 2 And O 2 . The catalyst can be a catalyst commonly used in the field, and can also use metals containing palladium and/or platinum and/or cobalt and/or manganese and/or copper and/or oxides and/or sulfides thereof as active components, and one or more of metals of sodium, potassium, magnesium, titanium, zirconium, vanadium, manganese, iron, nickel, cobalt, copper, molybdenum, tungsten, lanthanum, zinc, silver, palladium, cobalt or cerium and/or oxides and/or sulfides thereof and/or complexes formed by the metals can be used as auxiliary agents. The carrier is active carbon, alumina, silica, magnesia, titanium oxide, silica gel, molecular sieve, honeycomb ceramics, monazite, honeycomb metal, metal plate, corrugated filler, corrugated plate, fiber (cloth) material and structure, braided fabric, metal foam, ceramic foam, graphite-based foam and the like. And as an option due to O contained in the incoming gas 2 Is low in content and can not be subjected to O removal 2 So that O is before entering the pressure swing adsorption separation CO and nitrogen device 2 The concentration of the catalyst is less than or equal to 0.4 percent, so that the quick deactivation of the adsorbent and the catalyst is not caused, but the service life of the adsorbent is shortened, and the running cost is increased. When H in gas 2 And O 2 The ratio of (2) is greater than 2:1, namely, the hydrogen is excessive (hydrogen is excessive in general), and when the industrial nitrogen meeting the standard is needed, the oxygen can not be only deoxidized, but also the dehydrogenation and the deoxidation are needed at the same time, and then the oxygen or the air can be supplemented to lead the H in the coal gas 2 And O 2 Is about a ratio ofAnd (3) carrying out dehydrogenation and deoxidation at a ratio of 2:1. When dehydrogenation is not required, only deoxygenation may be performed. Only deoxygenation may be performed when standard industrial nitrogen is not required.
CO 2 Can influence the separation effect of the step of separating CO and nitrogen by pressure swing adsorption, due to CO 2 The adsorbent used in the CO and nitrogen separation step has a certain adsorption capacity, resulting in CO 2 And CO, CO 2 Has low separation coefficient with nitrogen and CO 2 The existence of (2) can lead to incomplete separation of CO and nitrogen, and can not obtain high-purity CO and nitrogen, so that the separated CO and nitrogen gas contains relatively more CO 2 Therefore, the CO is removed first 2 CO removal 2 The step (2) requires the removal of CO prior to the CO and nitrogen separation step 2 The method is characterized in that CO and nitrogen can be thoroughly separated in the CO and nitrogen separation step, high-purity CO and nitrogen are respectively obtained, meanwhile, the sequencing is in accordance with the progressive principle of adsorption capacity and the principle of adsorbing low-content components as much as possible and reducing desorption energy consumption, and the losses of adsorption pressure, intermediate-stage pressurization step and desorption step are reduced. CO removal from gas 2 Pressure swing adsorption, absorption, and combinations thereof may be employed. Wherein the absorption method comprises the following steps: washing with water, low-temperature methanol, propylene carbonate, N-methylpyrrolidone, polyethylene glycol dimethyl ether, polyethylene glycol methyl propyl ether, catacarb (catalytic hot alkali), hot potassium alkali, activated hot potassium alkali, modified hot alkali, hot carbonate, amino acid salt, ammonia water washing, urine (alkali) method, G-V (modified arsenic alkali), MEA, DEA, MDEA, DIPA, TEA, sulfolane, sulfolane+DIPA, sulfolane+MDEA, methanol+secondary amine, alkanolamine solution, active agent-added MEA, MDEA, DEA, and the like, and decarbonizing CO in raw gas 2 Removing CO to 0.01-0.8 Vol 2 Is carried out under the conditions of 0.2-20 MPa and 20-150 ℃, and in some embodiments (0.2-3 MPa and 20-80 ℃), the removed carbon dioxide can be sold as a carbon dioxide product or used as raw gas in other processes or is discharged or sent to a carbon capturing and carbon sealing unit after reaching the discharging standard. When usingWhen the absorption method is used as a separation unit for decarbonization, a trace amount of absorption liquid is usually carried out in the gas, and a temperature swing adsorption separation unit is required to be added after the unit to remove water and components such as components contained in some gases. Removing moisture, components and the like by a temperature swing adsorption method; the adsorbent is molecular sieve, active carbon, alumina, silica gel or their composite bed, and the removed tail gas containing great amount of carbon dioxide may enter the residual pressure recovering device to recover energy when the pressure is greater than 0.15 MPa. When the concentration requirement of CO to be purified is not high (the volume fraction of CO is more than or equal to 50 percent, the number of the further steps is more than or equal to 60 percent), the one-step method can also be adopted to directly purify CO, and simultaneously remove nitrogen and CO 2 CO only 2 The separation efficiency of (C) is low, the purity of CO is relatively low (about 70% or less is common, and the rest main components are CO 2 )。
After the pretreatment of impurity removal, CO is purified from the gas by a pressure swing adsorption separation method, which mainly separates CO and N 2 . CO and nitrogen are usually separated by pressure swing adsorption separation, and catalysts commonly used in the field can be used, and copper-loaded or silver-loaded adsorbents or metal-organic framework adsorbents (MOFs, ZIFs), metal-organic polyhedra (MOPs) and covalent organic framework adsorbents can also be used. The carrier can be activated carbon, alumina, silica gel, molecular sieve, honeycomb ceramics, monazite, honeycomb metal, metal plate, corrugated filler, corrugated plate, fiber (cloth) material and structure, braid, metal foam, ceramic foam, graphite-based foam, etc. CO is purified by a pressure swing adsorption separation method, the adsorption pressure of pressure swing adsorption is about 0.02-10 MPa (0.2-1.8 MPa in some embodiments), the operation temperature is 0-150 ℃ (20-80 ℃ in some embodiments), and the volume fraction of industrial grade nitrogen is 99.2% through pressure swing adsorption, so that the CO can be directly used as a product or sold. When CO and nitrogen are separated by adopting a pressure swing adsorption separation method, a temperature swing adsorption method is required to be added in front of a pressure swing adsorption unit, and water and heavy components are separated and removed, because the water and the heavy components can influence the effect of the subsequent pressure swing adsorption step, can have adverse effects on the adsorbent, can reduce the separation capacity of the pressure swing adsorption of the adsorbent, and even can cause ineligibility on the adsorbent Reverse damage, which causes deterioration of the adsorbent, even deactivation thereof, shortens its service life, and especially causes more serious damage to the adsorbent for separation of CO and nitrogen, which rapidly causes deterioration of the adsorbent, deactivation thereof, and non-use thereof. When the pressure swing adsorption device is connected in series, the temperature swing adsorption separation unit is added in front of the separation unit of the first pressure swing adsorption method, CO and nitrogen are separated by the pressure swing adsorption separation method, so that nitrogen which does not meet the industrial standard is obtained, when the pressure of the nitrogen is higher than 0.15MPa, the nitrogen can enter the residual pressure recovery system to recover the pressure energy carried by the nitrogen, and when the pressure swing adsorption method is adopted, the pressure swing adsorption device can be added with the energy recovery device, and the pressure energy wasted in the pressure swing adsorption process is recovered simultaneously when the pressure swing adsorption separation process is completed.
In the above processes, for example, CO purification by pressure swing adsorption and CO removal by pressure swing adsorption 2 And the like, a temperature swing adsorption separation unit can be added in front of the pressure swing adsorption unit to separate and remove water and components and the like contained in some gases. When more than one set of pressure swing adsorption units are used in series, a temperature swing adsorption separation unit is added in front of the separation unit of the first set of pressure swing adsorption process.
In this patent, the adsorbent used in the adsorption process may be any type of adsorbent having an adsorption effect, and may be molecular sieves, activated carbon, carbon molecular sieves, activated alumina, carbon fibers, etc., and their mixed packing and layered packing.
FIG. 1 shows a better process flow, wherein coal gas such as blast furnace gas is subjected to catalytic deoxidation, organic sulfur hydrolysis to convert inorganic sulfur, temperature swing adsorption to remove water and heavy components, desulfurization and CO removal in sequence 2 And purifying CO by a pressure swing adsorption method, and sending the purified CO into a blast furnace as reducing gas.
The correspondingly provided blast furnace gas or converter gas purifying reducing gas is returned to the blast furnace to participate in the metallurgical carbon emission reduction device, as shown in fig. 10, and comprises:
the pretreatment device is used for pretreating the gas raw material gas and comprises a deoxidizing device, an organic sulfur hydrolysis conversion device and a temperature swing adsorption removal device which are connected in sequenceWater and heavy component device, desulfurizing device and CO removing device 2 And (3) a device.
The pressure swing adsorption CO purifying device is connected with the gas outlet of the pretreatment device and purifies CO from the gas system.
The outlet of the pressure swing adsorption CO purifying device is connected with the reducing gas inlet of the blast furnace through a compressor.
In this patent, the blast furnace can be newly built, also can be to current blast furnace system transformation. When the existing blast furnace system is modified, spray guns are evenly arranged on the blast furnace around the blast furnace in a horizontal mode at the position, above the blast furnace air inlet and the coal injection port, of a vertical distance of 0.5 m-15 m from the center of the highest nozzle of the blast furnace air inlet and the coal injection port, the spray guns are connected with a ring pipe, the ring pipe is connected with a distribution pipe, and the distribution pipe is connected with a reducing gas inlet. The blast furnace is provided with m groups of spray guns in the vertical direction, wherein m is more than or equal to 1, each group is formed by uniformly distributing n spray guns which are horizontally encircling the blast furnace and are close to each other in vertical height, n is more than or equal to 2, the horizontal inclination angle of each spray gun is-60 degrees to +15 degrees, the height difference between the spray guns in the vertical direction is 0 m-5 m, the arc length between the spray guns in the same height in the horizontal direction is 0.5 m-2.5 m, the inclination angle of each spray gun and the area of the outlet of each spray gun in the blast furnace can be adjusted, the inclination angle of each spray gun can be different by adjusting the areas of the outlets of the spray guns in different positions and the horizontal inclination angle of each spray gun in different positions, the gas flow rate can be different, the inclination angle of the spray guns in the groups, the gas flow rate and the gas speed of each spray gun can be different, the gas speed of each spray gun can reach 200 m/s-350 m/s, the blast kinetic energy reaches 10 kJ/s-500 kJ/s, the incident air flow meets the reflow zone in the middle part in the radial direction of the blast furnace, the air flow can be adjusted by the reflow zone, the air flow can form the swirl zone and the swirl zone can be more uniformly along the radial direction of the air flow rate of the blast furnace, and the air flow rate can be more influenced by the average in the radial direction and the peripheral direction of the air flow rate of the furnace, and the air flow rate can be more than the peripheral to the flow zone of the furnace and the peripheral to the flow zone can be more than the peripheral to the air flow and the peripheral to the flow zone. I.e. the most rational radial blast furnace gas flow distribution that meets the expectations.
The blast furnace is filled with large-sized high-quality semicoke partially instead of coke from the top of the blast furnace, semicoke and coke are mixed in layers, the mixing mass ratio of semicoke and coke is less than or equal to 70%; the main indexes of semicoke are as follows: particle size not less than 25mm, ash content A d Less than or equal to 8 percent, volatile component V daf Less than or equal to 10 percent, fixed carbon FC d More than or equal to 80 percent, the total content W (K+Na) of sodium and potassium is less than 0.3 percent, the content of SiO in ash 2 +Al 2 O 3 )/(CaO+Fe 2 O 3 +MgO) is more than or equal to 2, the ash fusion softening temperature St is more than 1250 ℃, the Ha grindability index HGI is less than or equal to 50, the strength CSR after reaction is more than or equal to 40%, the reactivity CRI is less than or equal to 70%, and the thermal stability TS +6 > 80%, total sulfur content S t,d Less than or equal to 0.7 percent, and the falling strength SS is more than 60 percent.
For semicoke with insufficient alkalinity, insufficient ash content and some indexes which are not up to standard, commercial common hydrochloric acid solution with the mass concentration of 35-38% can be adopted for spraying, then steam with the mass concentration of more than or equal to 100 ℃ is used for heating the semicoke to 70 ℃ or more so as to volatilize hydrochloric acid, gas flow is kept for more than 1h, then the temperature is gradually reduced to 40 ℃ or less so as to condense hydrochloric acid, and then standing is carried out for more than 2 h. And then the semicoke is purged by steam with the temperature of more than or equal to 200 ℃ (at the temperature of less than or equal to 550 ℃ and further at the temperature of less than or equal to 350 ℃) so that the semicoke is heated to 200 ℃ and above (at the temperature of less than or equal to 350 ℃ and further at the temperature of less than or equal to 280 ℃) for more than 2 hours. After purging, the semicoke is cooled to normal temperature by standing, and at the moment, the semicoke is dried and various impurities after spraying hydrochloric acid are also blown away. And then detecting the ash mass proportion and the alkalinity of the semicoke and other indexes to see whether the semicoke meets the requirements. Various indexes of the semicoke after the treatment are generally improved to different degrees, and when ash A d Less than or equal to 12 percent, the total weight W (K+Na) of sodium and potassium is less than 1.2 percent, the strength CSR after reaction is more than or equal to 30 percent, the reactivity CRI is less than or equal to 80 percent, and the thermal stability TS +6 At > 70%, these several criteria can generally be met by the above criteria after the above treatment. When the existing index and the required index have large differences, the differences of the indexes can be reduced by increasing the amount of hydrochloric acid or increasing the duration of the treatment step.
The patent provides a preparation method of a supported metal organic framework CO adsorbent, which comprises the following steps:
(1) The molar ratio was set to 100:1 to 1:100, 0.06-0.1 mmol of bivalent copper compound and cerium nitrate hexahydrate are dissolved in 15-20 mL of deionized water to obtain a mixed solution of the bivalent copper compound and the cerium nitrate;
(2) Dissolving 0.3-0.5 mmol of melamine and 0.5-0.8 mmol of m-phthalaldehyde in a mixed solution of ethanol and dimethyl sulfoxide with the volume ratio of 10:1-1:10, and adding a commercially available 13X type molecular sieve into the mixed solution, wherein the molar ratio of the 13X type molecular sieve to a divalent copper compound-cerium nitrate is 1:40-50;
(3) Mixing and stirring the solutions in the steps (1) and (2) at room temperature for 5-8 min, heating for 10-30 min by using 100-200W microwaves, adding 0.01-1 mmol of N, N-Dimethylformamide and Methanol (DMF), heating to 130-180 ℃ at a heating rate of 3-5 ℃/min, preserving heat for 4-6 h, cooling to room temperature at a cooling rate of 2-5 ℃/min to generate precipitate, centrifuging and filtering; washing the obtained crystals with absolute ethyl alcohol;
(4) Adding Cu (NO) of 0.1-0.2 mmol/L into the obtained crystal 3 ) 2 3.0mL of ethanol solution, irradiating for 1-2 h by using 80-100W ultrasonic, immersing for 10-12 h in dark place, centrifugally separating and filtering; washing the obtained crystal with absolute ethyl alcohol for 3 times, irradiating with 100-150W ultraviolet lamp for 10-13 h, centrifuging, washing with absolute ethyl alcohol, and drying at 100-110 ℃ for 1-2 h to obtain powder;
(5) Dissolving CuCl and rare earth powder with the molar ratio of 10:1-2:0.25-0.5 and the molar weight of 1 mmol/0.1-0.2 mmol/0.025-0.05 mmol respectively in 30-40 mL of 0.4-0.5 mol/L nitric acid solution, adding 0.225-0.3 g of powder obtained in the step (4), irradiating for 20-30 min by using 100-150W ultrasonic waves, stirring for 2-3H at room temperature, evaporating the solvent by using a rotary evaporator, putting into a vacuum drying box, drying for 10-12H, and then drying at 200-220 ℃ under H 2 Activating for 4-5 h under the atmosphere to obtain the powder material.
(6) Weighing a certain amount of the powder material obtained in the step (5), methyl cellulose and citric acid aqueous solution (the mass ratio of the addition of the three is 0.5:0.3-0.4:0.1-0.2), placing the mixture into a kneader, stirring uniformly, placing the mixture into a centrifugal shot blasting machine for forming, and drying the formed product at 200-250 ℃ to obtain round particles with the diameter of about 2-3 mm, namely the formed product of the supported covalent organic framework CO adsorbent.
The preparation thought of the adsorbent is as follows: the covalent organic framework material is prepared from Cu and rare earth elements (cerium), and the rare earth elements (cerium) play a role in stabilizing the structure and simultaneously play roles in resisting sulfur and oxidation. Because the method for preparing the covalent organic bone material is not mature and has certain defects, the patent adopts the method of adding the commercial 13X type molecular sieve to fill the defects, increases the adsorption quantity and loads Cu on the covalent organic framework + The CO adsorption capacity and CO adsorption selectivity of the adsorbent can be improved.
Wherein in step (1), the divalent copper compound is selected from the group consisting of copper nitrate trihydrate, copper sulfate pentahydrate, copper chloride dihydrate and copper acetate tetrahydrate, preferably copper nitrate trihydrate.
In the step (5), the rare earth powder is one or more of scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium or gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium.
This patent is further illustrated below in conjunction with specific examples, which may be carried out by methods conventional in the art, unless otherwise indicated.
Example 1
In the existing blast furnace, the blast furnace gas from the blast furnace is desulfurized and then is directly combusted as fuel to supply heat for the combustion of other devices. The existing blast furnace system is modified, the reducing gas in the blast furnace gas is recovered and purified, and the reducing gas mainly containing CO is returned to the blast furnace to participate in metal smelting, so that carbon emission is reduced. The treated blast furnace gas feed (320 ℃ and 0.3 MPa) is subjected to cooling, dedusting and impurity removal by the existing blast furnace gas treatment device, and then enters a deoxidizing device to remove trace oxygen (250 ℃ and 0.3 MPa) in the blast furnace gas, and is converted into inorganic sulfur (250 ℃ and 0.3 MPa) by organic sulfur hydrolysis. Then pressurizing the gas to 0.5MPa (shown in figure 4), cooling to 38 ℃, introducing into a temperature swing adsorption device (0.5 MPa,38 ℃) to remove trace moisture and components contained in the gas, and introducing the gas into a degassing device The sulfur device adopts a temperature swing adsorption method to carry out coarse desulfurization and a fine desulfurization device composed of active carbon, manganese oxide and zinc oxide to carry out fine desulfurization, then gas enters a pressure swing adsorption decarburization device (0.5 MPa,38 ℃) to remove carbon dioxide, and the removed carbon dioxide is sent to a desulfurization tail gas treatment process device and a carbon capture subsequent treatment device after reaching the standard after being treated (CO with the purity of more than or equal to 90% is obtained in the decarburization process) 2 I.e. the carbon capture process is completed simultaneously, the captured CO 2 Is conveyed to a carbon sealing device through a pipeline to be injected into the ground for sealing. The gas component now contains mainly CO and nitrogen. The partial gas is sent into a pressure swing adsorption CO and nitrogen separation device (two-stage method, the low concentration CO recovered in the latter stage is mixed with the CO recovered in the first stage) for CO and nitrogen separation, and the gas containing a large amount of nitrogen separated from the top of the tower is treated to reach the emission standard after the pressure energy contained in the gas is recovered by a residual pressure recovery device under the conditions that the adsorption pressure is 0.5MPa and the operation temperature is 38 ℃. And then pressurizing the obtained CO with the volume composition of more than or equal to 99 percent to more than or equal to 2MPa, heating to 610 ℃ and delivering the CO to a blast furnace, spraying the CO into the blast furnace in a mode shown in figure 2, and carrying out various reactions on the reducing gas CO in the blast furnace, so that the reducing atmosphere in the blast furnace is maintained, and the reducing gas CO participates in the reaction of the reduced iron of the blast furnace. And (3) a hot blast stove system for heating the reducing gas is modified, wherein 30 spray guns, distribution pipes and annular pipes are newly added on the blast furnace. The horizontal dip angle of the spray gun is-5 degrees, the speed of the gas spraying spray gun is 250m/s, the spray gun is higher than the center of the air nozzle by 4m, the incident gas is aligned to the reflow zone, the incident gas meets the reflow zone in the middle of the radial direction of the blast furnace, and the air sprayed from the lower part of the blast furnace is changed into oxygen enriched with 3% of oxygen enriched rate.
Example 1 compared to the existing blast furnace: the amount of coke required for the original production of 1 ton of iron is reduced from 0.52 ton to 0.39 ton. The coke consumed per unit weight of iron produced is reduced by 25.6%, i.e. the CO produced finally 2 Emissions were also reduced by 25.6%. The produced blast furnace gas amount was increased by 22.16% as compared with the existing blast furnace, but the blast furnace gas amount after the gas amount of the return gas obtained by purification was reduced by 10.84% as compared with comparative example 1, and it can be seen from Table 3 that CO was contained in the blast furnace gas 2 Is of (1)The degree increases, as does the concentration of CO. The blast furnace gas from the blast furnace does not need to be pressurized from 0.3MPa to 0.5MPa, namely, after long-time stable operation, the concentration of each component in the blast furnace gas is regulated to be basically stable, and the blast furnace gas keeps the original 0.3MPa (shown in figure 5) to participate in the subsequent operation, so that a compressor is not needed to pressurize the blast furnace gas in practice, the energy is saved, and the investment is also saved. That is, in the above example 1, the area of 0.5MPa was all 0.3MPa.
Under the process and reaction flow of the embodiment, not only is the gas mainly containing CO obtained by purifying the blast furnace gas finished, but also the gas is returned to the blast furnace for metal smelting, so that the carbon emission is reduced, the amount of coke required for smelting metal is saved, and the high-value utilization of the blast furnace gas under the condition of low investment is realized. The carbon capture process is completed again in the carbon dioxide removal step, which also reduces "carbon emissions". In the embodiment, the steps are simplified, the flow is shortened, and the cost is saved.
Example 1 the specific process flow is detailed in fig. 5, and the gas composition during each step is shown in table 1.
TABLE 1
Example 2
In the existing blast furnace, the blast furnace gas from the blast furnace is desulfurized and then is used as fuel for combustion power generation. The existing blast furnace system is modified, the reducing gas in the blast furnace gas is recovered and purified, and the reducing gas mainly containing CO is returned to the blast furnace to participate in metal smelting, so that carbon emission is reduced. The treated blast furnace gas is treated by the existing blast furnace gas treatment device, the treated blast furnace gas feed (300 ℃ and 0.4 MPa) is subjected to dust removal and impurity removal, is subjected to organic sulfur hydrolysis and conversion into inorganic sulfur (300 ℃ and 0.4 MPa), is subjected to desulfurization by a desulfurizing agent consisting of manganese oxide and ZnO at 300 ℃ and 0.4MPa, is subjected to methane catalytic combustion reaction at 290 ℃ and 0.4MPa along with the reduction of the temperature, and is subjected to further reduction of the temperature to 220 ℃ and the pressure after trace methane is removedAnd (3) carrying out catalytic reaction under the condition of keeping the pressure of the gas constant at 0.4MPa, and removing trace hydrogen and oxygen in the blast furnace gas. Then the gas is cooled to 32 ℃, enters a temperature swing adsorption device (0.4 MPa,32 ℃) to remove trace moisture, heavy components and other components contained in the gas, then enters a pressure swing adsorption decarbonization device (0.4 MPa,32 ℃) to remove carbon dioxide, and the removed carbon dioxide is sent to a device for desulfurization tail gas treatment process and a device for carbon capture subsequent treatment after reaching the standard after being treated (the purity of CO is more than or equal to 90% is obtained in the decarbonization process) 2 I.e. the carbon capture process is completed simultaneously, the captured CO 2 Is conveyed to a carbon sealing device through a pipeline to be injected into the ground for sealing. The gas component now contains mainly CO and nitrogen. The partial gas is sent into a pressure swing adsorption CO and nitrogen separation device (two-stage method, CO recovered in the latter stage is returned to the inlet of the first stage after pressurization) for CO and nitrogen separation, and the partial industrial grade nitrogen with the volume composition of more than or equal to 99.2% is extracted under the conditions that the adsorption pressure is 0.4MPa and the operation temperature is 32 ℃ and is sent to a nitrogen recovery system as a product. And then pressurizing the obtained CO with the volume composition of more than or equal to 90 percent to more than or equal to 1MPa, heating to 610 ℃ and delivering the CO to a blast furnace, spraying the CO into the blast furnace in a mode shown in figure 3, and carrying out various reactions on the reducing gas CO in the blast furnace, so that the reducing atmosphere in the blast furnace is maintained, and the reducing gas CO participates in the reaction of the reduced iron of the blast furnace. Meanwhile, about 30% of high-quality semicoke is used for partially replacing coke, and large high-quality semicoke with granularity more than or equal to 40mm is mixed with about 70% of coke and then is filled into a blast furnace, so that the blast furnace can still stably run finally. 28 spray guns, distributing pipes and circular pipes are newly added on the modified blast furnace, and a hot blast stove system for heating reducing gas is provided. The horizontal dip angle of the spray gun is-8 degrees, the speed of the gas spraying spray gun is 275m/s, the spray gun is 5m higher than the center of the air nozzle, the incident gas is aligned to the reflow zone, the incident gas meets the reflow zone in the middle of the radial direction of the blast furnace, and the air sprayed from the lower part of the blast furnace is changed into oxygen enriched with 5% of oxygen enriched rate.
Example 2 compared to the existing blast furnace: the original production of 1 ton of iron needs 0.54 ton of coke to be reduced to 0.30 ton of coke and 0.13 ton of high-quality semicoke. The coke consumed per unit weight of iron produced is reduced by 44.4%, i.e. the CO produced finally 2 Emissions were also reduced by 25.2%. The produced blast furnace gas amount was increased by 24.51% as compared with the existing blast furnace, but the blast furnace gas amount was reduced by 9.65% as compared with comparative example 1 after the gas amount of the return gas obtained by purification was subtracted, and it can be seen from Table 4 that CO was contained in the blast furnace gas 2 Is increased.
Under the process and reaction flow of the embodiment, not only is the gas mainly containing CO obtained by purifying the blast furnace gas returned to the blast furnace for metal smelting, but also semicoke with low price and wide sources is used for replacing part of coke, thereby greatly saving the amount of coke required for smelting metal. Thus, not only the carbon emission is reduced, but also the high-value utilization of the blast furnace gas is realized under the condition of smaller investment. The carbon capture process is completed in the carbon dioxide removal step, which also reduces "carbon emissions" while recovering technical grade nitrogen. In the embodiment, the steps are simplified, the flow is shortened, and the cost is saved.
Example 2 the specific process flow is detailed in fig. 6.
Example 3
In the existing blast furnace, the blast furnace gas from the blast furnace is desulfurized and then is directly combusted as fuel to supply heat to the outside of the plant. The existing blast furnace system is modified, the reducing gas in the blast furnace gas is recovered and purified, and the reducing gas mainly containing CO is returned to the blast furnace to participate in metal smelting, so that carbon emission is reduced. The treated blast furnace gas feed (320 ℃ C., 0.2 MPa.) is dedusted and decontaminated by the existing blast furnace gas treatment device, and trace oxygen (250 ℃ C., 0.2 MPa) in the blast furnace gas is removed by the deoxidizing device, and then is converted into inorganic sulfur (250 ℃ C., 0.2 MPa) by organic sulfur hydrolysis. Then pressurizing the gas to 0.4MPa, cooling to 38 ℃, entering a temperature swing adsorption device (0.4 MPa,38 ℃) to remove trace moisture, components and the like contained in the gas, then entering a desulfurization device to perform coarse desulfurization by adopting a temperature swing adsorption method, and then entering a pressure swing adsorption CO purifying device to perform fine desulfurization by adopting a fine desulfurization device consisting of active carbon, manganese oxide and zinc oxide, wherein the CO purifying device is used for purifying a large amount of nitrogen and CO separated from the top of the tower under the conditions that the adsorption pressure is 0.4MPa and the operation temperature is 38 DEG C 2 The mixed gas of (2) is returned through the residual pressure recovery device And after the contained pressure energy is received, the air is discharged after the pressure energy reaches the discharge standard after being processed. Purifying and separating CO with concentration of about 70% at the bottom of the tower to obtain reducing gas, and purifying the reducing gas (CO concentration of about 70%, and the rest is mainly CO) 2 ) The mixture is pressurized to be more than or equal to 0.2MPa and then heated to 600 ℃ to be sent to a blast furnace, and is sprayed into the blast furnace in a mode shown in figure 3 (3 groups of spray guns are distributed in the vertical direction, and 2 groups are drawn in figure 3), and reducing gas CO undergoes various reactions in the blast furnace, so that the reducing atmosphere in the blast furnace is maintained, and the reducing gas CO participates in the reaction of the reduced iron of the blast furnace. Because the concentration of CO in the purified gas is lower, the content of inert gas is higher, the energy consumption for heating to the local temperature in the blast furnace is higher, and the cold furnace at the upper part of the blast furnace is easy to cause, another gas, namely oxygen, is introduced into the spray gun, and the addition amount of the oxygen is about 20 percent of that of the purified gas. The purified gas and oxygen are mixed and combusted in the blast furnace to release heat after being sprayed out of the spray gun, and the released heat is used for compensating the difference of insufficient heat of the sprayed gas with the temperature lower than the local temperature.
The gas recovered and purified in fig. 3 is sprayed into the blast furnace by spray guns, and the angles of 3 groups of spray guns and the horizontal plane are respectively as follows: 0 DEG, -10 DEG, -20 deg. The area of the spray gun outlet is adjusted to ensure that the speeds of 3 groups of gases sprayed out of the spray gun respectively reach 275m/s,250m/s and 225m/s from high to low. The positions of the spray guns are adjusted, and the distances of 3 groups of spray guns which are higher than the center of the air nozzle are 5m,6m and 7m respectively. The incident gas is directed at the reflow zone such that the incident gas flow meets the reflow zone in the middle of the furnace radial direction. The number of spray guns in each group on the blast furnace is 32. And simultaneously, the oxygen enrichment rate of the oxygen enriched air sprayed from the lower part of the blast furnace is improved from about 3% to about 10%.
Example 3 compared to the existing blast furnace: the production of 1 ton of iron from the original production needs 0.4 ton of coke and 0.15 ton of coal, and the production is reduced to the production needs 0.34 ton of coke and 0.15 ton of coal. The production unit weight of iron consumed coke is reduced by 15%, namely the final CO 2 The emission is also reduced by 10.4%.
Under the process and reaction flow of the embodiment, not only is the gas mainly containing CO obtained by purifying the blast furnace gas finished, but also the gas is returned to the blast furnace for metal smelting, so that the carbon emission is reduced, the amount of coke required for smelting metal is saved, and the high-value utilization of the blast furnace gas under the condition of low investment is realized. In the embodiment, the steps are simplified, the flow is shortened, and the cost is saved.
Example 3 the specific process flow is detailed in fig. 7.
Example 4
The method comprises the steps of firstly removing dust and impurities from the incoming materials (0.2 MPa,300 ℃) of converter gas, then converting sulfur in the gas into hydrogen sulfide (0.2 MPa,300 ℃) which is easy to remove through catalytic hydrogenation conversion, pressurizing the treated gas to 0.4MPa, cooling to 40 ℃, and then entering a carbon dioxide absorption tower, wherein the carbon dioxide absorption tower adopts a DEA absorption method, simultaneously removing most of sulfur contained in the gas, decompressing and regenerating a saturated DEA solution to release carbon dioxide, and taking most of activated and regenerated DEA solution as semi-lean solution to go to the absorption tower to remove carbon dioxide; and heating and regenerating the rest DEA solution in a thermal regeneration tower to release the sulfur and the rest small carbon dioxide, and then activating and regenerating the rest DEA solution, and finally completely activating and regenerating the DEA solution into a lean solution. The removed carbon dioxide after treatment reaches the standard is sent to a desulfurization tail gas treatment device and a device for carbon capture subsequent treatment (CO with purity more than or equal to 90% is obtained in the decarburization process) 2 I.e. the carbon capture process is completed simultaneously, the captured CO 2 Is conveyed to a carbon sealing device through a pipeline to be injected into the ground for sealing. The gas after carbon dioxide removal is sent into a temperature swing adsorption device, temperature swing adsorption separation is carried out under the conditions that the adsorption pressure is 0.2MPa and the operation temperature is 40 ℃, then water and other heavy components are removed, and then the gas is subjected to fine desulfurization by a fine desulfurization adsorption tower consisting of activated carbon, a molecular sieve, aluminum oxide, a special desulfurizing agent of metal oxide and the like, wherein the gas component mainly contains CO and nitrogen.
Delivering the partial gas into a pressure swing adsorption CO and nitrogen separation device for CO and nitrogen separation, separating CO and nitrogen by a pressure swing adsorption separation method under the conditions of similar adsorption pressure (0.2 MPa) and adsorption temperature (40 ℃), recovering the pressure energy contained in the gas by a residual pressure recovery device from the gas containing a large amount of nitrogen separated from the top of the tower, treating the gas, reaching the discharge standard, and then placingEmpty. Purifying the obtained reducing gas (CO concentration is more than or equal to 90%, and the rest is mainly N) 2 ) Pressurizing to more than or equal to 4MPa, heating to 610 ℃ and delivering to a blast furnace, spraying into the blast furnace in a mode shown in figure 2, and carrying out various reactions on reducing gas CO in the blast furnace to maintain the reducing atmosphere in the blast furnace and participate in the reaction of reducing iron in the blast furnace. And (3) modifying a hot blast stove system with 22 newly added spray guns, distribution pipes and annular pipes for heating reducing gas. The horizontal dip angle of the spray gun is 0 degrees, the speed of the gas spraying spray gun is 250m/s, the spray gun is 4.5m higher than the center of the air nozzle, the incident gas is aligned to the reflow zone, the incident gas meets the reflow zone at the middle part of the radial direction of the blast furnace, and the oxygen enrichment rate of oxygen enriched air sprayed from the lower part of the blast furnace is improved from 3% to 5%.
Since the converter gas yield is relatively low compared with the blast furnace gas, the amount of reducing gas to be purified is relatively low, so that the amount of reducing gas to be injected into the blast furnace is relatively low. The final injected gas blast furnace is compared to the prior art that did not inject gas: the production of 1 ton of iron from the original production needs 0.38 ton of coke and 0.18 ton of coal, and the production is reduced to the production needs 0.38 ton of coke and 0.1 ton of coal. The coal consumed per unit weight of iron produced is reduced by 44.4%, i.e. the CO produced finally 2 The emission is also reduced by 11.9%.
Under the process and reaction flow of the embodiment, CO-containing gas is obtained by purifying converter gas and returned to a blast furnace for metal smelting, so that the carbon emission is reduced, the amount of coal required for smelting metal is saved, and the high-value utilization of the converter gas under the condition of smaller investment is realized. And meanwhile, the carbon trapping process is completed in the carbon dioxide removal step, so that the carbon emission is reduced. In the embodiment, the steps are simplified, the flow is shortened, the cost is saved, and the residual pressure recovery system is used for recovering the pressure energy contained in the exhausted gas.
Example 4 the specific process flow is detailed in fig. 8.
Example 5
The main differences between example 5 and example 2 are: purifying the obtained CO with a volume composition of more than or equal to 80% in a pressure swing adsorption CO and nitrogen separation device (the main components of the rest) To be N 2 ) Pressurizing to more than or equal to 0.1MPa, heating to 630 ℃ and delivering to a blast furnace. And simultaneously, the air injected from the lower part of the blast furnace is changed into oxygen-enriched air with the oxygen enrichment rate of about 2 percent. The concentration of CO fed to the blast furnace, purified in this example and the previous examples, is different in order to minimize the overall process energy consumption. This is related to the component concentration of the blast furnace gas, and also to the type and process of the blast furnace smelting, and the different types of furnaces, different smelting processes, different sources of raw materials such as ore, coke and coal, and different oxygen contents of air and oxygen-enriched air of the existing blast furnace can lead to different CO concentrations with proper CO concentrations, so that the energy consumption of the whole process can be minimized.
Example 6
The main differences between example 6 and example 1 are: the compositions of the blast furnace gas supplies are different, and H in the blast furnace gas supplies in the embodiment 2 The content is relatively large, so in the process of pressure swing adsorption and CO purification, after the gas containing a large amount of nitrogen and hydrogen separated from the tower top is recycled by a pressure swing adsorption and hydrogen purification device, the tail gas mainly containing a large amount of nitrogen obtained from the tower bottom is discharged after being treated to reach the discharge standard, and the hydrogen separated from the tower top is used as reducing gas to be sent to a blast furnace (the hydrogen can also be used as finished hydrogen for output, and the hydrogen can also be used by other devices). CO gas with the concentration of more than or equal to 99% obtained in the process of purifying CO through pressure swing adsorption is externally supplied to other devices, CO gas with the gas content of 10% is taken as reducing gas, is mixed with hydrogen, is pressurized to more than or equal to 0.4MPa and is heated to 620 ℃ to be sent to a blast furnace, CO and hydrogen are sprayed into the blast furnace in a mode shown in figure 2 and are taken as reducing gas to undergo various reactions in the blast furnace, so that the reducing atmosphere in the blast furnace is maintained, and the reducing gas participates in the reaction of reduced iron of the blast furnace. In addition, when external demands exist, the hydrogen can be completely or partially output and partially returned to the blast furnace.
Example 6 the specific process flow is shown in detail in fig. 9 and the gas composition of the blast furnace gas of the blast furnace is shown in table 2.
TABLE 2
| Composition% | N 2 | H 2 | O 2 | CO 2 | CO | CH 4 |
| Blast furnace gas | 42.21 | 10.17 | 0.56 | 22.34 | 24.03 | 0.69 |
Example 7
The preparation method of the supported covalent organic framework CO adsorbent comprises the following steps:
(1) Copper nitrate trihydrate and cerium nitrate hexahydrate with the molar ratio of 19:1 and the total amount of 0.6mmol are dissolved in 15mL of deionized water together to obtain blue clear copper nitrate-cerium nitrate mixed solution;
(2) Dissolving 0.3mmol of melamine and 0.5mmol of m-phthalaldehyde in a mixed solution of ethanol and dimethyl sulfoxide (8 mL) in a volume ratio of 1:1, and adding a commercially available 13X type molecular sieve into the mixed solution, wherein the molar ratio of the 13X type molecular sieve to copper nitrate-cerium nitrate is 1:50;
(3) Mixing and stirring the solutions obtained in the steps (1) and (2) at room temperature for 5min, performing ultrasonic treatment at 150W for 20min, adding 0.1mmol of N, N-Dimethylformamide and Methanol (DMF), heating to 150 ℃ at a heating rate of 3-5 ℃/min, preserving heat for 5h, cooling to room temperature at a cooling rate of 2 ℃/min, generating precipitate, performing centrifugal separation, and filtering; washing the obtained crystal with absolute ethyl alcohol for 3 times;
(4) The obtained crystals were added with 0.1mmol/L Cu (NO 3 ) 2 3.0mL of ethanol solution, irradiating with 80W ultrasonic wave for 1h, soaking in dark for 12h, centrifuging, and filtering; washing the obtained crystal with absolute ethyl alcohol for 3 times, irradiating with 100W ultraviolet lamp for 10-13 h, centrifuging, washing with absolute ethyl alcohol, and drying at 110 ℃ for 1h to obtain powder;
(5) Dissolving CuCl and rare earth powder (mixture of yttrium, lanthanum and cerium in mass ratio of 1:1:2) with molar ratio of 10:1:0.25 and molar amount of 1mmol/0.1mmol/0.025mmol respectively in 30mL of 0.4mol/L hydrochloric acid solution, adding 0.225g of the powder obtained in the step (4), irradiating with 100W ultrasound for 20min, stirring at room temperature for 2H, evaporating the solvent with a rotary evaporator, placing into a vacuum drying oven, drying for 12H, and then heating at 220 ℃ in H 2 Activating for 5h under the atmosphere to obtain the powder material.
(6) Weighing a certain amount of the powder material obtained in the step (5), methyl cellulose and 5% citric acid aqueous solution (the mass ratio of the added water to the water is 10:0.3:0.2), placing the powder material, the methyl cellulose and the citric acid aqueous solution in a kneader, uniformly stirring, placing the mixture in a centrifugal shot blasting machine for forming, and drying the formed product at 200 ℃ to obtain round particles with the diameter of about 2mm, namely the formed product of the supported covalent organic framework CO adsorbent.
Comparative example 7-1
The solution in step (1) was copper nitrate alone, without cerium nitrate, and the solution in step (5) was free of rare earth powder (yttrium, lanthanum, cerium) in the same manner as in example 7.
Comparative example 7-2
In the step (2), the 13X type molecular sieve was not contained, and the procedure of example 7 was followed.
Comparative examples 7 to 3
Commercial CO adsorbent type NA was used.
Comparative examples 7 to 4
Commercial CO adsorbent type PU-1 was used.
Results: the adsorption capacity of each adsorbent for carbon monoxide was measured by using a physical chemisorber ASAP 2020, the temperature was 25 ℃, the adsorption capacity for carbon monoxide was 96mL/g when the conditions of use were 25℃and the pressure was 0.1MPa (as shown in FIG. 11), the adsorption capacities of comparative examples 7-1 to 7-2 were 82mL/g and 89mL/g, respectively, whereas the adsorption capacities of conventional commercially available adsorbents were 20 to 55mL/g, the commercially available adsorbent No. 1 was a copper-loaded activated carbon NA type CO adsorbent, the adsorption capacities were 30mL/g, and the adsorption capacities of comparative examples 7-4 were 55mL/g, respectively, based on the PU-1 type CO adsorbent of the copper-loaded NaY type molecular sieve. The present patent provides a significant improvement in the attachment capacity over the existing commercial adsorbents, as shown in table 5. As can be seen from table 5, the novel CO adsorbent provided in this patent has a higher CO adsorption capacity.
When sulfur compounds were accumulated to 0.2% by weight of the adsorbent, the adsorption capacity of example 7 was reduced by 3%, the adsorption capacity of comparative example 7-1 was reduced by 22%, and the adsorption capacities of comparative example 7-2 were respectively reduced by 5%, indicating that the adsorbent of example 7 has good sulfur resistance.
TABLE 5
| 25℃，0.1MPa | Example 7 | Comparative example 7-1 | Comparative example 7-2 | Comparative examples 7 to 3 | Comparative examples 7 to 4 |
| CO adsorption quantity (mL/g) | 96 | 82 | 89 | 30 | 55 |
Claims (8)
1. The device for purifying reducing gas by using blast furnace or converter gas and returning the reducing gas to blast furnace carbon for reducing emission is characterized by comprising the following components:
the inlet of the pretreatment device is connected with the outlet of the gas mainly comprising blast furnace gas and/or converter gas;
the pressure swing adsorption purification CO device is characterized in that an inlet of the pressure swing adsorption purification CO device is connected with an outlet of the pretreatment device, and an outlet of the pressure swing adsorption purification CO device is connected with a reducing gas inlet of the blast furnace device.
2. The device for reducing carbon emission of the blast furnace or converter gas purification reducing gas return blast furnace according to claim 1, wherein the reducing gas inlet of the blast furnace is connected with a circular pipe surrounding the blast furnace through a distribution pipe, the circular pipe is connected with spray guns uniformly distributed on the blast furnace in a circular shape, the blast furnace is vertically distributed with m groups of spray guns, wherein, 10 is more than or equal to 1, each group is composed of n spray guns which are vertically close and uniformly distributed around the blast furnace, 240 is more than or equal to 2, the spray guns are positioned above an air inlet and a coal injection port, the vertical distance from the center of the highest spray nozzle of the two spray guns is 0.5 m-15 m, the horizontal inclination angle of the spray guns is-60 degrees to +15 degrees, the height difference between the spray guns in the vertical direction is 0 m-5 m, the arc length between the spray guns in the horizontal direction is 0.5 m-2.5 m, the inclination angle of the spray guns and the area of the spray gun outlet are adjustable, and the gas velocity of the spray guns reaches 100 m/s-500 kJ/s.
3. The device for reducing carbon emission of blast furnace or converter gas by purifying reducing gas and returning the reducing gas to the blast furnace according to claim 1, wherein the device mainly comprises an inlet port for coke oven gas, other tail gas or purge gas which is possibly connected to the inlet of the blast furnace gas and/or converter gas.
4. The apparatus for reducing carbon emissions by returning reducing gas from blast furnace or converter gas purification as set forth in claim 1, wherein said pretreatment apparatus comprises: a dehydration device, a desulfurization device and/or an impurity removal pretreatment device; the impurity removal pretreatment device further comprises: dust collector, dephosphorizer, arsenic remover, deoxidizer, organic sulfur converter and CO remover 2 Devices or devices for removing CH 4 One or a combination of several of the devices.
5. The device for reducing carbon emission of blast furnace or converter gas by purifying reducing gas and returning it to blast furnace according to claim 1, wherein another outlet of said pressure swing adsorption purifying CO device is connected with pressure swing adsorption purifying H 2 Inlet connection of the device, pressure swing adsorption purification of H 2 One of the outlets of the device is connected with the gas inlet of the blast furnace device.
6. The device for reducing carbon emission of blast furnace or converter gas by purifying reducing gas and returning it to blast furnace according to claim 4, wherein said pretreatment device further comprises a desulfurizing device and a CO removing device 2 Device for removing CO 2 The device is integrated with a desulfurization device or removes CO 2 The device is positioned at the downstream side of the desulfurization device; CO removal in pretreatment device 2 The device is an absorption method for removing CO 2 CO removal by apparatus or adsorption 2 A device; CO removal in pretreatment device 2 The device is an absorption method for removing CO 2 CO removal during installation 2 The outlet of the device is connected with a temperature swing adsorption dewatering and heavy component device, and the outlet of the temperature swing adsorption dewatering and heavy component device is connected with a fine desulfurization device; CO removal in pretreatment device 2 The device is to remove CO by adsorption 2 CO removal during installation 2 The device is positioned at the temperature swing adsorption and removal deviceDownstream side of water and recombination device, CO removal 2 The device is positioned on the downstream side of the desulfurization device.
7. The apparatus for reducing carbon emissions by returning reducing gas purified from blast furnace or converter gas to blast furnace according to claim 4, wherein: the pretreatment device also comprises: CH removal 4 Means or/and deoxygenation means; the deoxidizing device is a catalytic reaction deoxidizing device, and the deoxidizing device is positioned for removing CH 4 On the downstream side of the apparatus, at the CO removal site 2 An upstream side of the device; CH removal 4 The device is to burn off CH by catalysis 4 Device for removing CH 4 The device is positioned at the downstream side of the desulfurization device and is positioned for CO removal 2 Upstream of the device.
8. The device for reducing carbon emission of blast furnace or converter gas by purifying reducing gas and returning it to blast furnace according to claim 4, wherein said pretreatment device is a catalytic hydrogenation reaction device or a catalytic hydrolysis reaction device, and the organic sulfur conversion device is located at upstream side of desulfurization device.
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|---|---|---|---|---|
| CN115679024A (en) * | 2022-11-10 | 2023-02-03 | 苏州盖沃净化科技有限公司 | Method and device for carbon emission reduction of blast furnace or converter gas by purifying reducing gas and returning to blast furnace |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115679024A (en) * | 2022-11-10 | 2023-02-03 | 苏州盖沃净化科技有限公司 | Method and device for carbon emission reduction of blast furnace or converter gas by purifying reducing gas and returning to blast furnace |
| CN115679024B (en) * | 2022-11-10 | 2024-04-19 | 苏州盖沃净化科技有限公司 | Method and device for reducing emission of carbon returned to blast furnace by purifying reducing gas from blast furnace or converter gas |
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