CN116287521A - Hydrogen-rich petrochemical tail gas coupling furnace top gas recovery method and shaft furnace loop process system - Google Patents

Abstract

The invention belongs to the technical field of metallurgical industry, and specifically discloses a hydrogen-rich petrochemical tail gas coupled furnace top gas recycling method and a shaft furnace loop process system. The method comprises the following steps: performing dedusting and purification treatment on the hot gas discharged from the upper part of the shaft furnace to obtain clean gas; separating loop circulating gas containing H2 _and CO and high-concentration _CO2 mixed gas from the clean gas; The gas is mixed with hydrogen-rich petrochemical tail gas, and the hydrogen-rich petrochemical tail gas is preheated to form a mixed gas; after the mixed gas is heated to a preset temperature range, it is passed into a shaft furnace for reduction to produce sponge iron. The method of the present invention adopts petrochemical tail gas as the supplementary raw material gas of the shaft furnace process system, integrates the petrochemical tail gas containing hydrogen, carbon and other energy media with the iron and steel smelting process, realizes the "turning waste into treasure" of waste gas energy, and couples the high-temperature removal of top gas Technology, to realize the utilization of waste heat of loop gas, without gas reforming or preparation system, and simplify the configuration, land occupation and investment cost of the gas treatment system.

Description

Hydrogen-rich petrochemical tail gas coupling furnace top gas recovery method and shaft furnace loop process system

technical field

The invention relates to the field of metallurgical industry, in particular to a hydrogen-rich petrochemical tail gas coupling furnace top gas recycling method and a shaft furnace loop process system.

Background technique

Compared with the traditional blast furnace ironmaking process, changing the energy structure, abandoning coking coal resources with high carbon content, and using fossil fuels with less carbon and more hydrogen as the reducing agent are the main technical characteristics of the gas-based shaft furnace direct return process, and it is also the realization of The application of short-process iron and steel production can effectively reduce carbon emissions and realize an important direction of greening and high efficiency.

At present, the gas-based shaft furnace devices and process technology routes in operation and production in the world mainly use the method of external reforming of natural gas or self-reforming in the furnace to produce _H2 and CO as effective reducing gas for shaft furnace production. , the gas source supply and preparation process are more complicated. In addition, the carbon oxides, such as CO ₂ , produced by shaft furnace top gas are generally pre-washed and cooled to room temperature, and then treated by conventional pressure swing adsorption devices or wet decarbonization devices to separate CO ₂ . Sensible heat is wasted or can only be partially utilized, so that the circulating gas can be upgraded and reused.

Petrochemical tail gas is the waste gas produced in the production process of petroleum and chemical industry. For the safety of production, the simple method of petroleum refining and chemical plants is to directly vent and ignite the gas, which not only causes waste of gas rich in hydrogen and carbon elements, but also It will cause a certain degree of pollution to the environment, and the effective utilization of waste energy has not been realized.

Contents of the invention

In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a hydrogen-rich petrochemical tail gas coupling furnace top gas recycling method and a shaft furnace loop process system for solving the problem of hydrogen-rich petrochemical tail gas and furnace top gas in the prior art. Issues such as not being effectively utilized.

In order to achieve the above purpose and other related purposes, the present invention provides a hydrogen-rich petrochemical tail gas coupled furnace top gas recycling method comprising the following steps:

Dedust and purify the hot coal gas discharged from the upper part of the shaft furnace to obtain clean coal gas; separate the loop circulating gas containing H2 _and CO and the high-concentration _CO2 mixed gas from the clean coal gas; combine the loop circulating gas with hydrogen-rich The petrochemical tail gas is blended, and the hydrogen-rich petrochemical tail gas is preheated to form a mixed gas; after the mixed gas is heated to a preset temperature range, it is passed into a shaft furnace for reduction to produce sponge iron.

Further, the hot gas discharged from the upper part of the shaft furnace is sent to the gas dust removal equipment for dust removal and purification treatment.

Further, the gas dedusting equipment is selected from hot cyclone dedusting devices and/or high temperature dry bagging devices; preferably, the gas dedusting equipment includes hot cyclone dedusting devices and high temperature dry bagging devices arranged in sequence.

Furthermore, the temperature of the clean gas after dust removal and purification treatment is 300°C-550°C, and the dust content of the clean gas is <8mg/Nm ³ .

Further, the clean gas is sent to the high-temperature gas decarbonization equipment, and the loop cycle gas containing _H2 and CO and the high-concentration _CO2 mixed gas are separated.

Further, the high-temperature gas decarbonization equipment is a carbon dioxide removal device. When in use, the carbon dioxide removal device is in a high-temperature operating condition, so that there is no need to pre-cool and cool the clean gas at the entrance of the high-temperature gas decarbonization equipment.

Further, the temperature of the inlet gas of the high-temperature gas decarbonization equipment is ≤600°C.

Further, the loop gas containing _H2 and CO and the high-concentration _CO2 mixture separated from the carbon dioxide removal device under high-temperature operating conditions, the gas temperature of the two streams is 300 ° C to 600 ° C.

Further, the volume percentage of non-carbon dioxide gas in the high-concentration CO ₂ mixed gas is less than 10%.

Further, the high-concentration CO ₂ mixed gas is used as supplementary fuel gas for heating the mixed gas.

Further, 80% or more of the loop circulating gas is mixed with hydrogen-rich petrochemical tail gas to form a mixed gas, and the rest of the loop circulating gas is used as fuel gas to heat the mixed gas; preferably, 85% to 90% of the loop circulation Gas is mixed with hydrogen-rich petrochemical tail gas to form mixed gas, and the rest of the loop gas is used as fuel gas to heat the mixed gas.

Further, the temperature of the mixed coal gas formed after mixing the loop recycle gas and the hydrogen-rich petrochemical tail gas is 300-600°C.

Further, the temperature of the hydrogen-enriched petrochemical tail gas is 20-40°C, and includes the following chemical components in volume percentage: H ₂ 75-95%, CH ₄ <6.0%, C2+ alkanes <5.0%, CO ₂ <3.0% , N ₂ <4.0%.

Further, when blending, the supplementary amount of the hydrogen-rich petrochemical tail gas is 30-60% of the volume flow rate of the loop cycle gas containing H ₂ and CO.

Further, the mixed gas is heated by a heating furnace, and the heating furnace is preferably a tubular heating furnace.

Furthermore, after the mixed gas is heated to 820-1050° C., it is passed into a shaft furnace for reduction to produce sponge iron.

The present invention also provides a shaft furnace loop process system, which includes gas dedusting equipment, high-temperature gas decarburization equipment, gas mixer, and heating furnace connected in sequence through gas pipes. The upper part is connected, and the high-temperature gas decarbonization equipment is provided with a loop circulating gas outlet and a high-concentration CO ₂ mixed gas outlet, and the loop circulating gas outlet is connected to the gas mixer and the heating furnace respectively through gas pipes, and the high-temperature The coal gas decarbonization equipment is also connected to the heating furnace through a gas pipe, the gas mixer is provided with a hydrogen-rich petrochemical tail gas inlet, and the gas outlet of the heating furnace is connected to the middle of the shaft furnace through a gas pipe.

Further, the gas dedusting equipment is selected from hot cyclone dedusting devices and/or high temperature dry bagging devices; preferably, the gas dedusting equipment includes hot cyclone dedusting devices and high temperature dry bagging devices arranged in sequence.

Further, the high-temperature gas decarbonization equipment is a carbon dioxide removal device.

Further, the heating furnace is a tubular heating furnace.

As mentioned above, the hydrogen-rich petrochemical tail gas coupling furnace top gas recovery method and the shaft furnace loop process system of the present invention have the following beneficial effects:

1. The method provided by the present invention uses the smelting tail gas produced in the petrochemical field as the supplementary raw material gas of the shaft furnace process system, and integrates and applies the hydrogen-rich petrochemical tail gas containing hydrogen, carbon and other energy media with the iron and steel smelting process, realizing waste gas resources The "turning waste into treasure" not only reduces the environmental pollution caused by simple combustion and emission treatment, but also enriches the ways of effective utilization of waste energy.

2. The method provided by the present invention adopts hydrogen-rich petrochemical tail gas as a supplementary gas source and couples the high-temperature removal technology of the top gas without cooling to realize the effective utilization of the residual heat of the top gas in the whole process system of the shaft furnace. Combustion treatment of tail gas "turns waste into treasure", realizes the effective combination of chemical waste gas and metallurgical process, simplifies the process gas preparation system, shortens the process layout, land occupation and investment cost, and the process's operating energy consumption and carbon emissions are more comparable Advantage.

3. The shaft furnace circuit process system provided by the present invention, combined with the hydrogen-rich petrochemical tail gas coupled with the high-temperature removal technology of the shaft furnace top gas without cooling down, realizes the effective utilization of the residual heat of the shaft furnace circuit gas without supplementing the raw material gas reforming or preparation system, Simplifies the configuration, land occupation and investment cost of the gas treatment system.

Description of drawings

Fig. 1 shows a schematic flow diagram of a hydrogen-rich petrochemical tail gas coupling furnace top gas recovery method in an embodiment of the present invention, and a schematic layout diagram of a shaft furnace loop process system.

Explanation of reference signs:

Shaft furnace 1, hot cyclone dedusting device 2, high temperature dry bagging device 3, high temperature gas decarbonization equipment 4, gas mixer 5, heating furnace 6, hot gas P0, clean gas P1, loop circulating gas P2, high concentration CO ₂ mixed gas P3, hydrogen-rich petrochemical tail gas P4, sponge iron F.

Detailed ways

Embodiments of the present invention are described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes, and various modifications or changes can be made to the details in this specification based on different viewpoints and applications without departing from the spirit of the present invention.

It should be noted that the diagrams provided in this embodiment are only schematically illustrating the basic idea of the present invention, and only the components related to the present invention are shown in the diagrams rather than the number, shape and shape of the components in actual implementation. Dimensional drawing, the type, quantity and proportion of each component can be changed arbitrarily during actual implementation, and the component layout type may also be more complicated. The structures, proportions, sizes, etc. shown in the drawings attached to this specification are only used to match the content disclosed in the specification for the understanding and reading of those who are familiar with this technology, and are not used to limit the conditions for the implementation of the present invention , so it has no technical substantive meaning, and any modification of structure, change of proportional relationship or adjustment of size shall still fall within the scope of the disclosure of the present invention without affecting the functions and objectives of the present invention. The technical content must be within the scope covered. At the same time, terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description and are not used to limit this specification. The practicable scope of the invention and the change or adjustment of its relative relationship shall also be regarded as the practicable scope of the present invention without any substantial change in the technical content.

As shown in Figure 1, an embodiment of the present application provides a hydrogen-rich petrochemical tail gas coupled furnace top gas recycling method, including the following steps:

Perform dedusting and purification treatment on the hot gas P0 discharged from the upper part of the shaft furnace 1 to obtain the clean gas P1; separate the loop cycle gas P2 containing H2 _and CO and the high-concentration _CO2 mixed gas from the clean gas P1; The circulating gas P2 is mixed with the hydrogen-rich petrochemical tail gas P4, and the hydrogen-rich petrochemical tail gas P4 is preheated to form a mixed gas; after the mixed gas is heated to a preset temperature range, it is passed into the shaft furnace 1 for reduction to produce sponge iron F.

In some embodiments, the hot gas P0 discharged from the upper part of the shaft furnace 1 is sent to the gas dust removal equipment for dust removal and purification treatment. Wherein, the gas dust removal equipment is selected from hot cyclone dust removal device 2 and/or high temperature dry bag bag device 3; preferably, the gas dust removal equipment includes hot cyclone dust removal device 2 and high temperature dry bag bag device 3 arranged in sequence.

In some embodiments, the temperature of the clean coal gas P1 after dust removal and purification treatment is 300°C-550°C, and the dust content of the clean coal gas P1 is <8 mg/Nm ³ .

In some embodiments, the clean gas P1 is sent to the high-temperature gas decarbonization device 4 to separate the loop gas P2 containing H ₂ and CO and the mixed gas with high concentration of CO ₂ . Wherein, the high-temperature gas decarbonization equipment 4 is a carbon dioxide removal device. When in use, the carbon dioxide removal device is in a high-temperature operating condition, so that there is no need to pre-cool and cool the clean gas P1 at the entrance of the high-temperature gas decarbonization device 4 .

Further, in some embodiments, the temperature of the inlet gas of the high-temperature gas decarbonization equipment 4 is ≤600°C; the loop cycle gas P2 containing _H2 and CO separated from the carbon dioxide removal device in high-temperature operating conditions is separated from the High-concentration CO ₂ mixed gas, the gas temperature of the two streams is 300°C to 600°C. Wherein, the volume percentage of non-carbon dioxide gas in the high-concentration CO ₂ mixed gas is less than 10%.

In some embodiments, the high-concentration CO ₂ mixed gas can be used as a supplementary fuel gas for heating the mixed gas.

The carbon dioxide removal device in the embodiment of the present application may use a CO ₂ adsorbent to absorb carbon dioxide in the mixed gas to achieve carbon dioxide removal. Among them, the _CO2 adsorbent is preferably a fine-grained high-temperature solid adsorbent, which can adsorb _CO2 at a relatively high temperature (600 ° C), and can be specifically selected from magnesium oxides, calcium oxides, At least one of magnesium-calcium composites, lithium/zirconium silicates and composites/modifications thereof, such as magnesium oxide, calcium oxide, magnesium oxide-calcium oxide composites, lithium zirconate Li ₂ ZrO ₃ , Lithium silicate Li ₄ SiO ₄ , lithium zirconate-lithium silicate composite, etc., but not limited thereto; the particle size distribution range is generally controlled within 0.15 mm to 1.0 mm. The specific structural configuration and other technical parameters of the carbon dioxide removal device are not particularly limited in the embodiment of the present application, and common or existing equipment in the field can be used.

In some embodiments, 80% or more of the loop circulating gas P2 is blended with the hydrogen-rich petrochemical tail gas P4 to form a mixed gas, and the rest of the loop circulating gas P2 is used as fuel gas for heating the mixed gas; preferably, 85 %-90% of the loop circulating gas P2 is blended with the hydrogen-rich petrochemical tail gas P4 to form a mixed gas, and the rest of the loop circulating gas P2 is used as fuel gas for heating the mixed gas.

Further, in some embodiments, the temperature of the mixed gas formed after blending the loop recycle gas P2 and the hydrogen-rich petrochemical tail gas P4 is 300-600°C.

In some embodiments, the temperature of the hydrogen-enriched petrochemical tail gas P4 is 20-40°C, and includes the following chemical components in volume percentage: H ₂ 75-95%, CH ₄ <6.0%, C2+ alkanes <5.0%, CO ₂ <3.0%, N ₂ <4.0%.

In some embodiments, when blending, the supplementary amount of the hydrogen-rich petrochemical tail gas P4 is 30-60% of the volume flow rate of the loop cycle gas P2 containing H ₂ and CO.

In some embodiments, the mixed gas is heated by a heating furnace 6, and the heating furnace 6 is preferably a tubular heating furnace.

In some embodiments, the mixed gas is heated to 820-1050° C., and then passed into the shaft furnace 1 for reduction to produce sponge iron F.

The method provided in the above examples uses the smelting tail gas produced in the petrochemical field as the supplementary raw material gas for the shaft furnace process system, and integrates and applies the hydrogen-rich petrochemical tail gas containing hydrogen, carbon and other energy media with the iron and steel smelting process, realizing the utilization of waste gas resources. "Turning waste into treasure" not only reduces the environmental pollution caused by simple combustion and emission treatment, but also enriches the ways of effective utilization of waste energy.

At the same time, the method provided in the above examples uses hydrogen-rich petrochemical tail gas as a supplementary gas source and couples the high-temperature removal technology of the top gas without cooling to realize the effective utilization of the waste heat of the top gas in the whole process system of the shaft furnace. The tail gas of simple combustion treatment "turns waste into treasure", realizes the effective combination of chemical waste gas and metallurgical process, simplifies the process gas preparation system, shortens the process layout, land occupation and investment cost, and the operation energy consumption and carbon emission of the process are more efficient Comparative Advantage.

As shown in FIG. 1 , an embodiment of the present application also provides a shaft furnace loop process system, including gas dust removal equipment, high-temperature gas decarbonization equipment 4, gas mixer 5, and heating furnace 6 connected in sequence through gas pipes. The gas intake end of the gas dedusting equipment is connected to the upper part of the shaft furnace 1 through a gas pipe, and the high-temperature gas decarburization device 4 is provided with a loop circulation gas P2 outlet and a high-concentration _CO2 mixed gas outlet, and the loop circulation gas P2 outlet passes through the gas pipe respectively It is connected with the gas mixer 5 and the heating furnace 6, and the high-temperature gas decarburization equipment 4 is also connected with the heating furnace 6 through a gas pipe. The gas mixer 5 is provided with a hydrogen-rich petrochemical tail gas P4 inlet, so The gas outlet end of the heating furnace 6 is connected to the middle part of the shaft furnace 1 through a gas pipe.

In some embodiments, the gas dedusting equipment is selected from a hot cyclone dust removal device 2 and/or a high temperature dry bagging device 3; preferably, the gas dedusting equipment includes a hot cyclone dust removal device 2 and a high temperature dry method Bag device 3.

In some embodiments, the high-temperature gas decarbonization equipment 4 is a carbon dioxide removal device.

In some embodiments, the heating furnace 6 is a tubular heating furnace.

The shaft furnace circuit process system provided in the above embodiments, combined with the hydrogen-rich petrochemical tail gas coupled with the high-temperature removal technology of the shaft furnace top gas without cooling, realizes the effective utilization of the waste heat of the shaft furnace circuit gas without supplementing the raw material gas reforming or preparation system, simplifying The configuration, land occupation and investment costs of the gas treatment system are determined.

As shown in Figure 1, another embodiment of the present application provides a hydrogen-rich petrochemical tail gas coupling furnace top gas recycling method, including the following steps:

1) The hot gas P0 discharged from the upper part of the direct reduction shaft furnace 1 first enters the hot cyclone dust removal device 2, and then enters the dry bag system for secondary dust removal treatment. The clean gas P1 after dust removal enters the high-temperature high-temperature gas decarbonization equipment 4, Separate the loop cycle gas P2 containing _H2 and CO and high-concentration _CO2 mixed gas, the loop cycle gas P2 containing _H2 and CO output from the high-temperature high-temperature gas decarbonization equipment 4 and the pretreated hydrogen-rich petrochemical tail gas P4 is blended to form a mixed gas with a preheating temperature of about 300°C, and then it is further passed into the heating furnace 6, and after being heated to about 860°C, it is passed into the shaft furnace 1 for reduction to produce sponge iron F.

2) In the above step 1), after hot cyclone dust removal, dry bagging system is used to install the clean gas P1 after secondary dust removal, the temperature is 325°C, and the dust content of clean gas P1 is 5mg/Nm ³ .

3) The high-temperature high-temperature gas decarbonization equipment 4 in the above step ₁ ) is a device suitable for removing CO ₂ at high temperature. The gas temperature at the inlet of the decarbonization equipment is 325° C. The adsorption material is a composite of magnesium and calcium, and the adsorption material is in the shape of solid fine particles, and the particle size distribution is 0.5mm-1.0mm, accounting for 60%.

4) In the above step 1), the temperature of the loop circulation gas P2 containing _H2 and CO and the high-concentration _CO2 mixture separated by the high-temperature high-temperature gas decarbonization equipment 4 is about 320° C.;

5) In the above step 1), the high-concentration _CO2 mixed gas discharged from the high-temperature gas decarbonization equipment 4 has a non- _CO2 content of 9.2% (volume percentage) in the airflow, and is used as supplementary fuel gas for the heating system.

6) In the above step 1), the circulating gas P2 containing _H2 and CO discharged from the high-temperature gas decarbonization equipment 4 is mixed with the supplementary hydrogen-rich petrochemical tail gas P4, and the petrochemical The exhaust gas is preheated to form a mixed gas with a preheating temperature of about 300°C, and another part of the 12% (volume percentage) circulating gas circuit circulating gas P2 is extracted from the pipeline and used as fuel gas for the heating system.

7) In the above step 6), the supplemented hydrogen-rich petrochemical tail gas P4 has a temperature range of 40°C, and its main chemical components are: H ₂ content 87.4%, CO content 2.5%, CH ₄ content 4.96%, C _n The content of H _m (n≥2) is 1.58%, the content of CO ₂ is 1.0%, and the content of N ₂ is 3.60%.

8) In the above step 6), the supplemental hydrogen-rich petrochemical tail gas P4 flow rate is 52% of the loop cycle gas P2 flow rate containing _H2 and CO.

As shown in Figure 1, another embodiment of the present application provides a hydrogen-rich petrochemical tail gas coupling furnace top gas recycling method, including the following steps:

1) The hot gas P0 discharged from the upper part of the direct reduction shaft furnace 1 first enters the hot cyclone dust removal device 2, and then enters the dry bag system for secondary dust removal treatment. The clean gas P1 after dust removal enters the high-temperature high-temperature gas decarbonization equipment 4, Separating the loop cycle gas P2 containing _H2 and CO and high-concentration _CO2 mixture, the loop cycle gas P2 containing _H2 and CO output from the high-temperature high-temperature gas decarbonization equipment 4 and the pretreated hydrogen-rich petrochemical tail gas P4 Blending is carried out to form a mixed gas with a preheating temperature of about 342°C, which is further passed into the heating furnace 6, and after being heated to about 910°C, it is passed into the shaft furnace 1 for reduction to produce sponge iron F.

2) In the above step 1), after the hot cyclone dust removal, the dry bagging system is used to install the clean gas P1 after secondary dust removal, the temperature is 360°C, and the dust content of the clean gas P1 is 3mg/Nm ³ .

3) The high-temperature high-temperature gas decarbonization equipment 4 in the above step 1) is a device suitable for removing CO ₂ in a high- _temperature state. The inlet gas temperature of the decarbonization equipment is 360° C. The adsorption material is a lithium-zirconium silicate compound, the adsorption material is in the form of solid fine particles, and the particle size distribution is 0.5mm-1.0mm, accounting for 70%.

4) In the above step 1), the temperature of the loop gas P2 containing _H2 and CO and the high-concentration _CO2 mixture separated by the high-temperature gas decarbonization equipment 4 reaches about 349°C.

5) In the above step 1), the high-concentration _CO2 mixed gas discharged from the high-temperature gas decarbonization equipment 4 has a non- _CO2 content of 7.8% (volume percentage) in the airflow, and is used as supplementary fuel gas for the heating system.

6) In the above step 1), 90% (volume percent) of the loop gas P2 containing _H2 and CO discharged from the high-temperature gas decarbonization equipment 4 is mixed with the supplementary hydrogen-rich petrochemical tail gas P4, and the petrochemical tail gas Perform preheating to form a mixed gas with a preheating temperature of about 342°C, and another part of 10% (volume percentage) circulating gas circuit circulating gas P2 is extracted from the pipeline and used as fuel gas for the heating system.

7) In the above step 6), the supplemental hydrogen-rich petrochemical tail gas P4 has a temperature range of 38° C., and its main chemical components are: H ₂ content 88.34%, CH ₄ content 6.62%, C _n H _m (n≥ 2) Content 0.68%, CO ₂ content 1.14%, N ₂ content 2.05%.

8) In the above step 6), the supplementary hydrogen-rich petrochemical tail gas P4 flow rate is 55% of the loop cycle gas P2 flow rate containing _H2 and CO.

As shown in Figure 1, another embodiment of the present application provides a hydrogen-rich petrochemical tail gas-coupling furnace top gas recycling method, including the following steps:

1) The hot gas P0 discharged from the upper part of the direct reduction shaft furnace 1 first enters the hot cyclone dust removal device 2, and then enters the dry bag system for secondary dust removal treatment. The clean gas P1 after dust removal enters the high-temperature high-temperature gas decarbonization equipment 4, Separating the loop cycle gas P2 containing _H2 and CO and high-concentration _CO2 mixture, the loop cycle gas P2 containing _H2 and CO output from the high-temperature high-temperature gas decarbonization equipment 4 and the pretreated hydrogen-rich petrochemical tail gas P4 Blending is carried out to form a mixed gas with a preheating temperature of about 395°C, which is further passed into the heating furnace 6, and after being heated to about 950°C, it is passed into the shaft furnace 1 for reduction to produce sponge iron F.

2) In the above step 1), after the hot cyclone dust removal, the dry bagging system is used to install the clean gas P1 after secondary dust removal, the temperature is 450°C, and the dust content of the clean gas P1 is 5mg/Nm ³ .

3) The high-temperature high-temperature gas decarbonization equipment 4 in the above step 1) is a device suitable for removing CO ₂ at high _temperature . The gas temperature at the inlet of the decarbonization equipment is 450° C. The material is a lithium-zirconium silicate compound, and the adsorption material is in the form of solid fine particles, with a particle size distribution of 0.5 mm to 1.0 mm, accounting for 74%.

4) In the above step 1), the temperature of the loop gas P2 containing _H2 and CO and high-concentration _CO2 mixture separated by the decarbonization equipment high-temperature gas decarbonization equipment 4 reaches about 435°C.

5) In the above step 1), the high-concentration _CO2 mixed gas discharged from the high-temperature gas decarbonization equipment 4, the non- _CO2 content in the airflow is 8.0% (volume percentage), is used as supplementary fuel gas for the heating system.

6) In the above step 1), 85% (volume percentage) of the circulating gas P2 containing _H2 and CO discharged from the high-temperature gas decarbonization equipment 4 is mixed with the supplementary hydrogen-rich petrochemical tail gas P4, and the petrochemical tail gas Carry out preheating to form a mixed gas with a preheating temperature of about 395°C, and another part of 15% (volume percentage) circulating gas circuit circulating gas P2 is extracted from the pipeline and used as fuel gas for the heating system.

7) In the above step 6), the supplemented hydrogen-rich petrochemical tail gas P4 has a temperature range of 35° C., and its main chemical components are: H ₂ content 90.6%, CO content 2.6%, CH ₄ content 3.87%, C _n The _Hm content is 1.15%, the _CO2 content is 0.11%, and the _N2 content is 1.67%.

8) In the above step 6), the supplementary hydrogen-rich petrochemical tail gas P4 flow rate is 43% of the loop cycle gas P2 flow rate containing _H2 and CO.

The above-mentioned embodiments only illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Anyone skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical ideas disclosed in the present invention should still be covered by the claims of the present invention.

Claims (10)

1. A method for recycling hydrogen-rich petrochemical tail gas coupled top gas is characterized by comprising the following steps: performing dust removal and purification treatment on hot gas discharged from the upper part of the shaft furnace to obtain clean gas; separation of H-containing gas from clean gas ₂ And loop recycle gas of CO and high concentration CO ₂ A mixed gas; mixing the loop circulating gas with the hydrogen-rich petrochemical tail gas, and preheating the hydrogen-rich petrochemical tail gas to form mixed gas; and heating the mixed gas to a preset temperature range, and introducing the mixed gas into a shaft furnace for reduction to produce sponge iron.

2. The method for recycling hydrogen-rich petrochemical tail gas coupled top gas according to claim 1, wherein the method comprises the following steps: feeding hot gas discharged from the upper part of the shaft furnace into gas dust removal equipment for dust removal and purification treatment;

and/or the temperature of the clean gas after dust removal and purification treatment is 300-550 ℃, and the dust content of the clean gas is less than 8mg/Nm ³ 。

3. The method for recycling hydrogen-rich petrochemical tail gas coupled top gas according to claim 2, wherein: the gas dust removing equipment is selected from a hot cyclone dust removing device and/or a high-temperature dry cloth bag device.

4. The method for recycling hydrogen-rich petrochemical tail gas coupled top gas according to claim 1, wherein the method comprises the following steps: feeding the clean gas into high-temperature gas decarbonization equipment, and separating H-containing gas ₂ And loop recycle gas of CO and high concentration CO ₂ And (3) mixing gas.

5. The method for recycling hydrogen-rich petrochemical tail gas coupled top gas according to claim 4, wherein: the high-temperature gas decarburization device is a carbon dioxide removal device, and when the high-temperature gas decarburization device is used, the carbon dioxide removal device is in a high-temperature operation condition;

and/or the temperature of the inlet gas of the high-temperature gas decarburization device is less than or equal to 600 ℃;

and/or H-containing components separated by a carbon dioxide removal device operating at high temperatures ₂ And loop recycle gas of CO and high concentration CO ₂ The temperature of the gas of the two gas flows is 300-600 ℃.

6. The method for recycling hydrogen-rich petrochemical tail gas coupled top gas according to claim 1, wherein the method comprises the following steps: the high concentration CO ₂ The volume percentage of non-carbon dioxide gas in the mixed gas is less than 10 percent;

and/or, subjecting the high concentration CO ₂ The mixed gas is used as supplementary fuel gas for heating the mixed gas.

7. The method for recycling hydrogen-rich petrochemical tail gas coupled top gas according to claim 1, wherein the method comprises the following steps: mixing 80% or more of the loop circulating gas with the hydrogen-rich petrochemical tail gas to form mixed gas, and using the rest of the loop circulating gas as fuel gas for heating the mixed gas;

and/or mixing the loop circulating gas and the hydrogen-rich petrochemical tail gas to form mixed gas with the temperature of 300-600 ℃;

and/or the temperature of the hydrogen-rich petrochemical tail gas is 20-40 DEG CAt the temperature of the mixture, comprises the following chemical components in percentage by volume: h ₂ 75～95％，CH ₄ Less than 6.0%, C2+ alkane less than 5.0%, CO ₂ ＜3.0％，N ₂ ＜4.0％；

And/or, when blending, the supplementing amount of the hydrogen-rich petrochemical tail gas contains H ₂ And 30 to 60 percent of the loop recycle gas volume flow of CO.

8. The method for recycling hydrogen-rich petrochemical tail gas coupled top gas according to claim 1, wherein the method comprises the following steps: heating the mixed gas by a heating furnace;

and/or, heating the mixed gas to 820-1050 ℃, and introducing the mixed gas into a shaft furnace for reduction to produce sponge iron.

9. A shaft furnace loop flow system, characterized by: comprises a gas dust removing device, a high-temperature gas decarbonization device, a gas mixer and a heating furnace which are sequentially connected through a gas pipe, wherein the gas inlet end of the gas dust removing device is connected with the upper part of a shaft furnace through the gas pipe, and the high-temperature gas decarbonization device is provided with a loop circulating gas outlet and high-concentration CO ₂ The mixed gas outlet is connected with the gas mixer and the heating furnace respectively through gas pipes, the high-temperature gas decarburization equipment is connected with the heating furnace through gas pipes, the gas mixer is provided with a hydrogen-rich petrochemical tail gas inlet, and the gas outlet end of the heating furnace is connected with the middle part of the shaft furnace through gas pipes.

10. The shaft furnace loop flow system of claim 9, wherein: the gas dust removing equipment is selected from a hot cyclone dust removing device and/or a high-temperature dry cloth bag device;

and/or the high-temperature gas decarburization device is a carbon dioxide removal device;

and/or the heating furnace is a tubular heating furnace.

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