A CO2 capture and utilization device suitable for blast furnace gas

Abstract

The present invention proposes a CO2 capture and utilization device suitable for blast furnace gas, characterized by comprising a bag filter, a hydrolysis tower, a two-stage desulfurization device, and a CO2 adsorption removal device, arranged sequentially along the gas processing direction. The bag filter is used to reduce the concentration of inlet particulate matter, the hydrolysis tower is used to hydrolyze organic sulfur in the blast furnace gas into CO2 and H2S, the two-stage desulfurization device is used to reduce the concentration of acidic gases, and the CO2 adsorption removal device comprises an adsorption bed, a cooling bed, and a desorption regeneration bed, arranged sequentially along the gas processing direction. The adsorption bed is used to adsorb CO2 from the CO2-containing gas. The adsorbent in the adsorption bed that has reacted with CO2 is transported to the cooling bed to react with CO2 again. The adsorbent in the cooling bed that has reached adsorption saturation is transported to the desorption regeneration bed, where the CO2 is desorbed by heating. This device can reduce capture energy consumption and achieve efficient adsorption and capture of CO2 in blast furnace gas.

Description

Technical field

[0001] The present invention relates to the technical field of CO2 emission treatment, and in particular to a CO2 capture and utilization device suitable for blast furnace gas. [Background Technology]

[0002] In recent years, the greenhouse effect caused by excessive CO2 emissions has garnered widespread international attention. Coal-fired power plants are the primary source of carbon emissions in my country, necessitating the development of appropriate carbon capture technologies. Among the numerous carbon capture technologies, solid adsorption CO2 removal has become a research hotspot due to its compatibility with coal-fired power plants, corrosion resistance, and lack of secondary pollution. Conventional processes use chemical absorption to adsorb CO2, resulting in high energy consumption and difficulty controlling the capture rate below 2.5 GJ / t CO2. Therefore, a CO2 capture and utilization device suitable for blast furnace gas is proposed. [Summary of the invention]

[0003] The purpose of the present invention is to solve the problems in the prior art and to propose a CO2 capture and utilization device suitable for blast furnace gas, which can reduce capture energy consumption and achieve efficient adsorption and capture of CO2 in blast furnace gas.

[0004] To achieve the above-mentioned objectives, the present invention proposes a CO2 capture and utilization device suitable for blast furnace gas, comprising a bag dust collector, a hydrolysis tower, a two-stage desulfurization device, and a CO2 adsorption and removal device arranged in sequence along the gas treatment direction, wherein the bag dust collector is used to reduce the inlet particulate matter concentration, the hydrolysis tower is used to hydrolyze the organic sulfur in the blast furnace gas into CO2 and H2S, the two-stage desulfurization device is used to reduce the acid gas concentration, and the CO2 adsorption and removal device comprises an adsorption bed, a cooling bed, and a decomposition and regeneration bed arranged in sequence along the gas treatment direction, the adsorption bed is used to adsorb CO2 in CO2-containing gas, the adsorbent in the adsorption bed that reacts with CO2 is transported to the cooling bed to react with CO2 again, and the adsorbent saturated with adsorption in the cooling bed is transported to the decomposition and regeneration bed to decompose CO2 by heating.

[0005] Preferably, the adsorption bed is provided with a first adsorbent addition port and a first adsorbent output port, the cooling bed is provided with a second adsorbent feeding port, a first adsorbent input port and a second adsorbent output port, the first adsorbent output port is connected to the adsorbent inlet of the cooling bed through a first riser, and the adsorbent after the reaction in the adsorption bed is transported to the cooling bed through the first riser, the desorption regeneration bed is provided with a second adsorbent input port, the second adsorbent output port is connected to the second adsorbent input port of the desorption regeneration bed through a second riser, and the adsorbent saturated with adsorption in the cooling bed is transported to the desorption regeneration bed through the second riser.

[0006] Preferably, the adsorption bed is a bubbling bed, and a plurality of adsorbent bed layers are arranged in the bed body of the adsorption bed, and the CO2-containing gas is adsorbed through the adsorbent bed layers.

[0007] Preferably, the adsorption bed is further provided with a multi-layer air distribution plate and a multi-stage heat exchanger, and the adsorption process of the adsorption bed is cooled by the multi-stage heat exchanger to control the reaction temperature.

[0008] Preferably, a water-cooled wall is provided in the cooling bed for controlling the reaction temperature.

[0009] Preferably, a cyclone separator is provided in the cooling bed for coarse and fine separation of the adsorbent. A portion of the large particle adsorbent cooled in the cooling bed is returned to the adsorption bed, and the adsorption-saturated small particle adsorbent is transported to the analytical regeneration bed through the second riser.

[0010] Preferably, the two-stage desulfurization device includes a coarse desulfurization tower and a fine desulfurization tower sequentially arranged along the gas processing direction, the coarse desulfurization adopts limestone-gypsum wet desulfurization, and the fine desulfurization adopts alkali solution spray desulfurization.

[0011] Beneficial effects of the present invention: The present invention achieves the adsorption and capture of more than 95% of CO2 in blast furnace gas through the two-stage adsorption reaction of the CO2 adsorption removal device, and can control the capture energy consumption within 1.5GJ / t CO2, solving the technical bottleneck of high energy consumption of traditional processes (chemical absorption method).

[0012] The features and advantages of the present invention will be described in detail through embodiments with reference to the accompanying drawings.

Brief Description of the Drawings

[0013] Figure 1 This is a structural schematic diagram of a CO2 capture and utilization device suitable for blast furnace gas according to the present invention;

[0014] Figure 2 It is a schematic structural diagram of the adsorption bed in the present invention;

[0015] Figure 3 It is a schematic structural diagram of the cooling bed in the present invention;

[0016] Figure 4 It is a structural diagram of the analytical regeneration bed in the present invention. [Specific implementation method]

[0017] See Figures 1 to 4The present invention discloses a CO2 capture and utilization device suitable for blast furnace gas, comprising a bag filter 1, a hydrolysis tower 2, a two-stage desulfurization device 3, and a CO2 adsorption removal device 4, which are sequentially arranged along the gas processing direction. The bag filter 1 is used to reduce the concentration of inlet particulate matter, and the hydrolysis tower 2 is used to hydrolyze organic sulfur in the blast furnace gas into CO2 and H2S. The reaction is carried out at a relatively low temperature (<200°C) and a relatively low pressure (<30kPa), with a conversion rate of >99%. The two-stage desulfurization device 3 is used to reduce the concentration of acidic gases, and the CO2 adsorption removal device 4 comprises an adsorption bed 41, a cooling bed 42, and a desorption regeneration bed 43, which are sequentially arranged along the gas processing direction. The adsorption bed 41 is used to adsorb CO2 in the CO2-containing gas. The adsorbent in the adsorption bed 41 that has reacted with CO2 is transported to the cooling bed 42 to react with CO2 again. The adsorbent in the cooling bed 42 that has been saturated with adsorption is transported to the desorption regeneration bed 43 to desorb the CO2 by heating.

[0018] Furthermore, the adsorption bed 41 is provided with a first adsorbent addition port 411 and a first adsorbent output port 412, and the cooling bed 42 is provided with a second adsorbent feeding port 421, a first adsorbent input port 422, and a second adsorbent output port 423. The first adsorbent output port 412 is connected to the adsorbent inlet 422 of the cooling bed 42 through a first riser 413, and the adsorbent after the reaction in the adsorption bed 41 is transported to the cooling bed 42 through the first riser 413. The desorption regeneration bed 43 is provided with a second adsorbent input port 431, and the second adsorbent output port 423 is connected to the second adsorbent input port 431 of the desorption regeneration bed 43 through a second riser 424. The adsorbent saturated with adsorption in the cooling bed 42 is transported to the desorption regeneration bed 43 through the second riser 424.

[0019] Furthermore, the adsorption bed 41 is a bubbling bed, and a plurality of adsorbent bed layers are arranged in the bed body of the adsorption bed 41, and the CO2-containing gas is adsorbed through the adsorbent bed layers.

[0020] Furthermore, the adsorption bed 41 is further provided with a multi-layer air distribution plate and a multi-stage heat exchanger, and the adsorption process of the adsorption bed 41 is cooled by the multi-stage heat exchanger to control the reaction temperature.

[0021] Furthermore, a water-cooled wall is provided in the cooling bed 42 for controlling the reaction temperature.

[0022] Furthermore, a cyclone separator is provided in the cooling bed 42 for coarse and fine separation of the adsorbent. A portion of the large-particle adsorbent cooled in the cooling bed 42 is returned to the adsorption bed 41 , and the saturated small-particle adsorbent is transported to the desorption regeneration bed 43 through the second riser 424 .

[0023] Furthermore, the two-stage desulfurization device 3 includes a coarse desulfurization tower 31 and a fine desulfurization tower 32 sequentially arranged along the gas processing direction. The coarse desulfurization adopts limestone-gypsum wet desulfurization, and the fine desulfurization adopts alkali solution spray desulfurization.

[0024] The adsorption bed operates as follows: CO2-containing gas enters the lower end of the bed, is purified by adsorption in the adsorbent (primary purification), and is discharged from the upper end to the cooling bed for secondary purification. The bed is equipped with an adsorbent feed port, and multiple layers of air distribution plates and a multi-stage heat exchanger are installed within the bed to ensure uniform distribution of air and control the reaction temperature within the optimal range. The abraded and crushed adsorbent particles are transported to the cooling bed via a riser.

[0025] The working principle of the cooling bed: air is inlet at the lower end and outlet at the upper end, an adsorbent feeding port is set, an air distribution plate and a heat exchanger (water-cooled wall) are set in the bed body, and a cyclone separator is set to perform coarse and fine separation. A part of the cooled adsorbent particles can continue to return to the adsorption bed to adsorb CO2 (large particles), and the small particles saturated with adsorption can further enter the regeneration bed through the riser.

[0026] The working principle of the regeneration bed: CO2 is decomposed by heating.

[0027] Working process of the present invention: bag filter 1, hydrolysis tower 2, two-stage desulfurization device 3 as the pretreatment system of CO2 adsorption removal device 4, to ensure that the inlet particulate matter concentration is less than 5mg / m 3 , the concentration of acidic gases such as SO2 and H2S is less than 1ppm. Several layers of adsorbent are arranged in the bed body of the adsorption bed 41 (the adsorbent particle size ranges from 1 to 20mm), and the CO2-containing coal gas is adsorbed through the adsorbent bed. The adsorption process is an exothermic reaction, and the reaction temperature is controlled within a suitable range by cooling through a heat exchanger. During the reaction, the adsorbent particles wear at a faster rate. When the particle size drops to a certain range, it will be transported to the cooling bed 42 through the first riser. The bed is provided with an additional second adsorbent feeding port, which reacts with CO2 in the bed body in the form of a fluidized bed, and passes through the water in the bed. The cold wall controls the reaction temperature, and through a two-stage adsorption reaction, over 95% of the CO₂ in blast furnace gas is adsorbed and captured. Finally, the saturated adsorbent particles are transported via a second riser to the desorption regeneration bed 43, where the CO₂ is desorbed by heating. The desorbed CO₂ can be used for top-blown converter steelmaking, as a replacement for argon in converter bottom blowing, as a shielding gas in continuous casting processes, for pulverized coal transportation in blast furnace ironmaking, and for CO₂ injection refining processes such as LF and AOD. It can also partially replace nitrogen for pipeline purging and can be used for mineralizing steel slag. Blast furnace gas naturally contains over 20% CO. Removing the CO₂ increases the CO concentration and calorific value of the gas.

[0028] The above embodiments are intended to illustrate the present invention, not to limit the present invention. Any solution that is a simple transformation of the present invention falls within the protection scope of the present invention.

Claims

1. A CO2 capture and utilization device suitable for blast furnace gas, characterized by: The invention comprises a bag filter (1), a hydrolysis tower (2), a two-stage desulfurization device (3), and a CO2 adsorption removal device (4) which are sequentially arranged along the coal gas processing direction, wherein the bag filter (1) is used to reduce the concentration of inlet particulate matter, the hydrolysis tower (2) is used to hydrolyze organic sulfur in blast furnace coal gas into CO2 and H2S, the two-stage desulfurization device (3) is used to reduce the concentration of acidic gas, and the CO2 adsorption removal device (4) comprises an adsorption bed (41), a cooling bed (42), and a desorption regeneration bed (43) which are sequentially arranged along the coal gas processing direction, the adsorption bed (41) is used to adsorb CO2 in the CO2-containing coal gas, the adsorbent in the adsorption bed (41) that has reacted with CO2 is transported to the cooling bed (42) to react with CO2 again, and the adsorbent in the cooling bed (42) that has been saturated with adsorption is transported to the desorption regeneration bed (43) to desorb CO2 by heating; The adsorption bed (41) is provided with a first adsorbent addition port (411) and a first adsorbent output port (412); the cooling bed (42) is provided with a second adsorbent addition port (421), a first adsorbent input port (422), and a second adsorbent output port (423); the first adsorbent output port (412) is connected to the first adsorbent inlet (422) of the cooling bed (42) via a first riser (413); the adsorbent after the reaction in the adsorption bed (41) is transported to the cooling bed (42) via the first riser (413); the desorption regeneration bed (43) is provided with a second adsorbent input port (431); the second adsorbent output port (423) is connected to the second adsorbent input port (431) of the desorption regeneration bed (43) via a second riser (424); the adsorbent saturated in the cooling bed (42) is transported to the desorption regeneration bed (43) via the second riser (424); The adsorption bed (41) is further provided with a multi-layer air distribution plate and a multi-stage heat exchanger, and the adsorption process of the adsorption bed (41) is cooled by the multi-stage heat exchanger to control the reaction temperature; the cooling bed (42) is provided with a cyclone separator for coarse and fine separation of the adsorbent, and a portion of the large-particle adsorbent in the cooling bed (42) is returned to the adsorption bed (41) after cooling, and the adsorption-saturated small-particle adsorbent is transported to the analytical regeneration bed (43) through the second riser (424).

2. The CO2 capture and utilization device for blast furnace gas according to claim 1, characterized in that: The adsorption bed (41) is a bubbling bed, and a plurality of adsorbent bed layers are arranged in the bed body of the adsorption bed (41), and the CO2-containing gas is adsorbed through the adsorbent bed layers.

3. The CO2 capture and utilization device for blast furnace gas according to claim 1, characterized in that: The cooling bed (42) is provided with a water-cooled wall for controlling the reaction temperature.

4. The CO2 capture and utilization device for blast furnace gas according to claim 1, characterized in that: The two-stage desulfurization device (3) comprises a coarse desulfurization tower (31) and a fine desulfurization tower (32) arranged in sequence along the coal gas processing direction. The coarse desulfurization adopts limestone-gypsum wet desulfurization, and the fine desulfurization adopts alkali solution spray desulfurization.

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