A methanol-to-aromatics carbon-containing tail gas cyclone jet capture and reforming process

Abstract

This application discloses a cyclone jet collection and reforming process for carbon-containing tail gas from methanol-to-aromatics production, relating to the fields of coal chemical and environmental protection technologies. The process includes: feeding carbon-containing, dust-laden tail gas from methanol-to-aromatics production at a temperature of 80-300℃ tangentially into the cyclone jet scrubbing core tube of a cyclone jet scrubbing tower via a gas supply device; extracting washing water from the washing water storage tank at the bottom of the cyclone jet scrubbing tower using a washing water pump, pressurizing it, and injecting it into the cyclone jet scrubbing core tube; and using a combination of cyclone jet scrubbing and spray scrubbing for cooling and dust removal, controlling the temperature of the carbon-containing tail gas to ≤50℃ and the dust content to ≤10mg / m³. 3 By integrating technologies such as cyclone spray water washing and cooling, multi-stage cyclone jet absorption, pressure difference flash evaporation regeneration, and nickel-based catalytic reforming, a high-efficiency and low-consumption methanol-to-aromatics carbon-containing tail gas treatment system was constructed. It achieved the technical goals of carbon capture efficiency ≥95%, CO₂ desorption rate ≥85%, and conversion efficiency ≥95%, providing a brand-new solution for carbon reduction and resource utilization of carbon-containing tail gas.

Description

Technical Field

[0001] This application relates to the fields of coal chemical and environmental protection technology, specifically to a methanol-to-aromatics carbon-containing tail gas cyclone jet capture and reforming process. Background Technology

[0002] Methanol-to-aromatics (MTO) is an important process in the coal chemical industry. During aromatics production, it generates a large amount of carbon-containing tail gas, rich in carbon dioxide, methane, and small amounts of dust. Direct emission of this gas would not only cause a severe greenhouse effect but also waste carbon resources, contradicting current "dual-carbon" goals and the development needs of resource recycling. Therefore, the efficient capture and resource conversion of carbon-containing tail gas from MTO has become a critical issue that the industry urgently needs to address.

[0003] Chinese patent application 201611010621.3 proposes an integrated oxygen-enriched combustion carbon dioxide capture system suitable for peak-valley load operation in power grids. Its core principle is carbon capture through pressure swing adsorption (PSA) technology. PSA relies on the selective adsorption and desorption of carbon dioxide by the adsorbent, requiring frequent pressure switching, resulting in extremely high system energy consumption. Furthermore, this system targets oxygen-enriched combustion exhaust gases, where the CO2 concentration is typically >80%. However, methanol-to-aromatics (MTO) carbon-containing exhaust gases not only have lower CO2 concentrations but also contain impurities such as dust and aromatic derivatives. Directly applying PSA would lead to rapid adsorbent poisoning and failure, and the high temperature of the exhaust gases would further reduce adsorption efficiency. Therefore, this technology suffers from excessive energy consumption, poor applicability, and high maintenance costs when treating MTO carbon-containing exhaust gases, failing to meet the actual needs of the MTO process.

[0004] Chinese patent application 202210985775.3 discloses an absorption device and a carbon dioxide capture system, which improves carbon capture capacity by using multi-stage packing in series combined with interlayer heat exchange. Its core is absorption through gas-liquid contact in traditional packed towers. However, the gas-liquid mass transfer efficiency of packed towers is limited by the specific surface area of ​​the packing and the uniformity of liquid distribution; even with multi-stage series connection, the carbon capture efficiency is difficult to exceed 90%. In contrast, the swirling jet core tube used in this application forms a strong swirling field through tangential feeding, atomizing the amine absorbent liquid into micron-sized droplets under high-speed jetting. The gas-liquid contact area is significantly increased compared to traditional packed towers. Combined with pretreatment by the packing absorption module, higher carbon capture efficiency can be achieved. Simultaneously, the centrifugal force of the swirling field enhances gas-liquid mixing, reduces short-circuiting of the absorbent liquid, and significantly improves absorption uniformity and stability, solving the defects of low mass transfer efficiency and easy clogging in traditional packed structures.

[0005] Chinese patent application 202111543863.X discloses a staged regeneration tower and carbon dioxide capture system, which improves desorption efficiency through multi-stage packed regeneration units. However, its regeneration process relies on counter-current gas-liquid contact within the packed layer, and the desorption rate is limited by the heat transfer efficiency between steam and absorbent, resulting in a CO2 desorption rate typically below 80% and high regeneration energy consumption. The cyclone flash regeneration technology in this application, driven by pressure difference, creates a strong vortex within the cyclone flash core tube, using centrifugal force to accelerate the generation and detachment of CO2 bubbles, significantly improving the desorption rate. Simultaneously, the cyclone field enhances heat and mass transfer between the rich liquid and steam, and combined with staged heat exchange for energy recovery, further reduces regeneration energy consumption compared to traditional staged regeneration towers. It also avoids problems such as amine degradation and equipment scaling during packed regeneration, significantly improving the system's economy and stability.

[0006] Currently, carbon capture technologies for carbon-containing tail gases mainly include absorption, adsorption, and membrane separation, among which amine-based absorbents are widely used due to their high absorption efficiency. However, existing processes have the following shortcomings: First, the tail gas temperature is high and the dust content is large, which can lead to absorbent degradation and equipment blockage if the gas directly enters the absorption system, affecting absorption efficiency and system stability. Second, the gas-liquid mass transfer efficiency of traditional absorption equipment is limited, making it difficult to achieve deep carbon dioxide capture, with capture efficiencies often below 90%. Third, the absorbent regeneration process consumes a lot of energy, and the carbon dioxide desorption rate is insufficient during flash evaporation or heating desorption. Furthermore, the energy recovery design for recycling the regenerated absorbent is unreasonable, further increasing process energy consumption. Fourth, the resource utilization pathway for captured carbon dioxide is limited, mainly relying on storage, and it has not been effectively converted into high-value-added products such as syngas, resulting in limited economic benefits.

[0007] Furthermore, in existing methane reforming technologies, the catalytic conversion efficiency of carbon dioxide and methane is often affected by reaction temperature, catalyst activity, and feedstock ratio, making it difficult to stably generate high-quality syngas with an H2 / CO ratio of 1, thus restricting subsequent chemical utilization. Therefore, developing an integrated process that combines efficient cooling and dust removal, enhanced mass transfer and absorption, low-energy regeneration, and highly selective conversion is of great significance for improving the treatment efficiency and resource value of carbonaceous tail gas from methanol-to-aromatics production. Summary of the Invention

[0008] The purpose of this application is to provide a methanol-to-aromatics carbon-containing tail gas cyclone jet capture and reforming process to solve the above problems and overcome the defects of the prior art, as detailed below.

[0009] To achieve the above objectives, this application provides the following technical solution:

[0010] This application provides a methanol-to-aromatics carbon-containing tail gas cyclone jet capture and reforming process, including the following steps:

[0011] S1. Water Washing and Cooling Unit: The methanol-to-aromatics tail gas containing dust and carbon at a temperature of 80-300℃ is tangentially fed into the cyclone spray core tube of the cyclone spray water washing tower via a gas supply device. Washing water is extracted from the washing water storage tank at the bottom of the cyclone spray water washing tower by a water pump, pressurized, and then injected into the cyclone spray core tube. Cooling and dust removal are achieved using a combination of cyclone and spray water washing methods, controlling the temperature of the carbon-containing tail gas to ≤50℃ and the dust content to ≤10mg / m³. 3 After being washed and cooled, the carbon-containing tail gas from the methanol-to-aromatics process continues to move upwards and leaves the cyclone spray water washing tower after passing through the first gas-liquid separation module.

[0012] S2, Cyclone Absorption Unit: The carbon-containing tail gas after water washing enters the cyclone jet absorption tower and passes through the packing absorption module and the cyclone jet core tube in sequence. It is subjected to multi-stage cyclone enhanced absorption using amine-based absorbent liquid. The decarbonized tail gas after absorption continues to move upward and leaves the cyclone jet absorption tower after passing through the second gas-liquid separation module.

[0013] S3, Flash Regeneration Unit: After being discharged from the cyclone jet absorption tower, the low-temperature rich liquid is heated to 120-140℃ in stages through the lean-rich liquid heat exchanger and the steam heat exchanger. Then, it is input into the cyclone flash core tube of the cyclone flash regeneration tower with a pressure difference of 0.6-1.2MPa. Carbon dioxide in the absorbent is separated by the action of cyclone flash evaporation. The high-temperature lean liquid with the same flow rate as the low-temperature rich liquid is pumped out by the lean liquid pump and passes through the lean-rich liquid heat exchanger and the first water cooler in sequence. After being cooled to 40℃, it enters the cyclone jet absorption tower.

[0014] S4, Methane Reforming Unit: After the regenerated carbon dioxide is cooled to 80°C by the second water cooler, it enters the gas-liquid separator to separate the cooled condensate. The condensate is returned to the cyclone flash regeneration tower by the action of the condensate pump. The deliquescent carbon dioxide is mixed with supplementary methane at a molar ratio of 1:1 and heated to 800-900°C by an electric heater before entering the fixed-bed reactor filled with nickel-based catalyst. Syngas is formed under the action of catalytic reforming.

[0015] In some embodiments of this application, the cylindrical section of the swirl spray core tube has a diameter of 150-500 mm, each core tube has 200-1500 small holes with a diameter of 1.5 mm, the water washing spray rate is 0.5-1 m / s, and a single tube can handle a gas flow rate of 200-2500 m³ / s. 3 / h, the pressure drop of the cyclone spray water washing tower is 1-5kPa.

[0016] In some embodiments of this application, the pressure drop of the cyclone spray scrubbing tower is 1-5 kPa.

[0017] In some embodiments of this application, the cylindrical section of the swirling jet core tube has a diameter of 150-500 mm, each core tube has 600-3000 small holes with a diameter of 1.2 mm, the amine absorbent jetting rate is 1-3 m / s, and a single tube can handle a gas flow rate of 200-2500 m³ / s. 3 / h.

[0018] In some embodiments of this application, the pressure drop of the cyclone jet absorber is 3-20 kPa, the carbon capture efficiency is above 95%, and the liquid content of the outlet gas is ≤50 mg / L.

[0019] In some embodiments of this application, the diameter of the cylindrical section of the cyclone flash core tube is 50-100 mm, the liquid inlet rate is 3-7 m / s, and the rich liquid flow rate that a single tube can handle is 20-100 m³ / s. 3 / h.

[0020] In some embodiments of this application, the catalyst in the fixed-bed reactor is a nickel-based catalyst, the bed porosity is 35-65%, and the reforming conversion efficiency is ≥95%.

[0021] In some embodiments of this application, the syngas composition at the outlet of the fixed-bed reactor is H2 and CO in a molar ratio of 1:1, and the temperature is 800-900°C.

[0022] The beneficial effects are:

[0023] By integrating technologies such as swirling spray water washing and cooling, multi-stage swirling jet absorption, pressure difference flash evaporation regeneration, and nickel-based catalytic reforming, a high-efficiency and low-consumption methanol-to-aromatics carbon-containing tail gas treatment system has been constructed. It has achieved the technical goals of carbon capture efficiency ≥95%, CO2 desorption rate ≥85%, and conversion efficiency ≥95%, providing a brand-new solution for carbon reduction and resource utilization of carbon-containing tail gas. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a diagram of the methanol-to-aromatics carbon-containing tail gas cyclone jet capture and reforming process of this application;

[0026] Figure 2 This application Figure 1 A schematic diagram of the swirl spray water scrubbing tower structure;

[0027] Figure 3 This application Figure 1 A schematic diagram of the swirling jet absorption tower structure;

[0028] Figure 4 This application Figure 1 A schematic diagram of the cyclone flash regeneration tower structure;

[0029] Figure 5 This is a schematic diagram showing the variation of carbon dioxide absorption efficiency of various absorbents under different liquid flow rates.

[0030] The reference numerals in the attached drawings are explained as follows: 1. Air supply device; 2. Cyclone spray scrubbing tower; 201. First shell; 202. Cyclone spray core tube; 203. Washing water storage tank; 204. First gas-liquid separation module; 205. First tray; 206. First downcomer; 207. First air inlet; 208. Air outlet; 209. Washing water outlet; 210. Washing water inlet; 211. Drain outlet; 212. Water replenishment outlet; 3. Washing water pump; 4. Cyclone jet absorption tower; 401. Second shell; 402. Cyclone jet core tube; 403. Packed absorption module; 404. Absorbent liquid storage tank; 405. Second gas-liquid separation module; 406. Second downcomer; 407. Second tray; 408. Second air inlet; 409. Absorbent liquid circulation outlet; 410. Absorbent liquid. 411. Circulation inlet; 412. Vent; 413. Low-temperature lean liquid inlet; 414. Low-temperature rich liquid outlet; 415. Make-up port; 5. Absorbent circulation pump; 6. Rich liquid pump; 7. Lean / rich liquid heat exchanger; 8. Steam heat exchanger; 9. Cyclone flash regeneration tower; 901. Third shell; 902. Cyclone flash core tube; 903. Storage tank; 904. Third tray; 905. Third downcomer; 906. High-temperature rich liquid inlet; 907. Regeneration outlet; 908. High-temperature lean liquid outlet; 909. Condensate inlet; 910. Regeneration gas outlet; 10. Lean liquid pump; 11. First water cooler; 12. Regeneration pump; 13. Carbon dioxide fan; 14. Condensate pump; 15. Gas-liquid separator; 16. Electric heater; 17. Fixed bed reactor; 18. Second water cooler. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] This application's technical concept revolves around the efficient treatment and resource utilization of carbon-containing tail gas from methanol-to-aromatics production. Through an integrated multi-unit collaborative process, it achieves cooling and dust removal of the carbon-containing tail gas, efficient carbon capture, absorbent regeneration, and carbon dioxide resource conversion. The specific process is as follows:

[0033] First, the gas supply device 1 delivers dust- and carbon-containing exhaust gas at 80-300℃ tangentially into the cyclone spray core tube 202 inside the first housing 201 through the first air inlet 207. The water washing pump 3 draws water washing water from the water washing water storage tank 203, pressurizes it, and injects it into the cyclone spray core tube 202. The combination of cyclone and spraying achieves cooling and dust removal, controlling the exhaust gas temperature to ≤50℃ and the dust content to ≤10mg / m³. After treatment, the exhaust gas flows upward through the first gas-liquid separation module 204 to remove liquid, and is discharged through the air outlet 208 of the cyclone spray water washing tower 2. During the process, the first tower plate 205 and the first downcomer 206 of the cyclone spray water washing tower 2 assist in gas-liquid distribution. The water washing water can be discharged through the drain outlet 211 or replenished from the water inlet 212. The water washing water inlet 210 and the water washing water outlet 209 cooperate with the water washing water circulation.

[0034] After washing, the exhaust gas enters through the second inlet 408 on the second shell 401, and passes sequentially through the packed absorption module 403 and the cyclone jet core tube 402. The amine absorbent is drawn from the absorbent storage tank 404 through the absorbent circulation pump 5 from the absorbent circulation outlet 409, pressurized, and injected into the cyclone jet core tube 402 through the absorbent circulation inlet 410, where it is sprayed at a rate of 1-3 m / s to enhance gas-liquid mass transfer. The decarbonization exhaust gas is discharged from the exhaust port 411 after being deliquescent by the second gas-liquid separation module 405. The low-temperature rich liquid after CO2 absorption is discharged from the low-temperature rich liquid outlet 413. The second tray 407 and the second downcomer 406 of the cyclone jet absorption tower 4 ensure uniform gas-liquid contact. The absorbent can be replenished through the replenishment port 414, and regenerated lean liquid can be input through the low-temperature lean liquid inlet 412 to achieve a carbon capture efficiency of ≥95%.

[0035] The low-temperature rich liquid is transported by the rich liquid pump 6, first exchanged with the high-temperature lean liquid in the rich-lean liquid heat exchanger 7, and then heated to 120-140℃ by the steam heat exchanger 8. It is then injected into the cyclone flash evaporation core tube 902 in the third shell 901 with a pressure difference of 0.6-1.2MPa from the high-temperature rich liquid inlet 906. The CO2 desorption rate is ≥85% through cyclone flash evaporation. The separated high-temperature lean liquid is discharged from the high-temperature lean liquid outlet 908, transported to the rich-lean liquid heat exchanger 7 by the lean liquid pump 10 to recover heat, and then cooled to 40℃ by the first water cooler 11 before being returned to the cyclone jet absorption tower 4. The flashed CO2 is discharged from the regeneration gas outlet 910, and the condensate is returned to the storage tank 903 from the condensate inlet 909. The regenerated liquid can be discharged from the regeneration outlet 907 and transported by the regeneration pump 12. The third tray 904 and the third downcomer 905 assist in gas-liquid separation.

[0036] The regenerated CO2 is cooled to 80°C by the second water cooler 18 and then enters the gas-liquid separator 15 to separate condensate. The condensate is pumped back to the cyclone flash regeneration tower 9 by the condensate pump 14. The dehydrated CO2 is transported by the carbon dioxide fan 13 and mixed with supplementary methane at a 1:1 molar ratio. The mixture is then heated to 800-900°C by the electric heater 16 and enters the fixed-bed reactor 17, which is filled with nickel-based catalyst and has a bed porosity of 35-65%. Under catalytic reforming, CO2 and methane are converted into syngas with an H2 / CO ratio of 1, with a conversion efficiency of ≥95%, achieving high-value-added utilization of carbon resources.

[0037] See instruction manual attached Figures 1 to 5 As shown, in order to solve the above-mentioned technical problems, this application proposes a methanol-to-aromatics carbon-containing tail gas cyclone jet capture and reforming process, comprising:

[0038] S1. Water Washing and Cooling Unit: Methanol-to-aromatics tail gas containing dust and carbon at a temperature of 80-300℃ is tangentially fed into the cyclone spray core tube 202 of the cyclone spray water washing tower 2 via the gas supply device 1; washing water is extracted from the washing water storage tank 203 at the bottom of the cyclone spray water washing tower 2 by the water washing pump 3, pressurized, and injected into the cyclone spray core tube 202. Cooling and dust removal are achieved using a combination of cyclone and spray water washing methods, controlling the carbon-containing tail gas temperature to ≤50℃ and the dust content to ≤10mg / m³. 3 The carbon-containing tail gas from methanol-to-aromatics production, after being washed and cooled, continues to move upwards and exits the cyclone spray water washing tower 2 after passing through the first gas-liquid separation module 204.

[0039] S2, Cyclone Absorption Unit: The carbon-containing tail gas after being washed by the cyclone spray washing tower 2 enters the cyclone jet absorption tower 4, and passes sequentially through the packed absorption module 403 and the cyclone jet core tube 402. It is subjected to multi-stage cyclone enhanced absorption using amine-based absorbents such as MDEA and MEA. The multi-stage absorption is achieved by the packed absorption module 403 and the cyclone jet core tube 402. The decarbonized tail gas continues to move upward and leaves the cyclone jet absorption tower 4 after passing through the second gas-liquid separation module 405.

[0040] S3, Flash Regeneration Unit: The low-temperature rich liquid is discharged from the cyclone jet absorption tower 4 and then heated to 120-140℃ in stages by the lean-rich liquid heat exchanger 7 and the steam heat exchanger 8. It is then input into the cyclone flash core tube 902 of the cyclone flash regeneration tower 9 with a pressure difference of 0.6-1.2MPa. The regeneration efficiency of the cyclone flash regeneration tower 9 is ≥85%. Carbon dioxide in the absorbent is separated by the action of cyclone flash evaporation. The high-temperature lean liquid with the same flow rate as the low-temperature rich liquid is extracted by the lean liquid pump 10 and passes through the lean-rich liquid heat exchanger 7 and the first water cooler 11 in sequence. After being cooled to 40℃, it enters the cyclone jet absorption tower 4.

[0041] S4, Methane Reforming Unit: After regeneration, the carbon dioxide at a temperature of 100-120℃ is cooled to 80℃ by the second water cooler 18 and then enters the gas-liquid separator 15 to separate the cooled condensate. The condensate is returned to the cyclone flash regeneration tower 9 by the action of the condensate pump 14. The dehydrated carbon dioxide is mixed with the supplementary methane at a molar ratio of 1:1 and heated to 800-900℃ by the electric heater 16 before entering the fixed bed reactor 17 filled with nickel-based catalyst. Syngas is formed under the action of catalytic reforming.

[0042] In this embodiment, the cyclone spray washing tower 2 includes a first shell 201, a cyclone spray core tube 202 vertically installed inside the first shell 201, a washing water storage tank 203 located at the bottom of the first shell 201, a first gas-liquid separation module 204 located above the cyclone spray core tube 202, and a first tower plate 205 and a first downcomer 206 located between the cyclone spray core tube 202 and the washing water storage tank 203; the lower part of the side wall of the first shell 201 is provided with a first air inlet 207 that can be connected to the air supply device 1 for tangential feeding, the top is provided with an air outlet 208, the bottom is provided with a drain outlet 211, the middle part of the side wall is provided with a washing water inlet 210, the washing water inlet 210 is connected to the outlet of the washing water pump 3, the lower part is provided with a washing water outlet 209 that communicates with the washing water storage tank 203, and the top is provided with a water replenishment inlet 212; the cyclone spray core tube 202 vertically penetrates the first tower plate 205.

[0043] The first gas-liquid separation module 204 is a baffle-type separator, consisting of 3-5 layers of inclined baffles, used to separate water mist entrained in the exhaust gas, ensuring that the liquid content of the outlet gas is ≤50mg / m³.

[0044] The first tray 205 is a perforated tray. The first downcomers 206 are symmetrically arranged on both sides of the first tray 205 to guide the wash water back evenly to the wash water storage tank 203, preventing short-circuiting of the wash water. The cylindrical section of the swirl spray core tube 202 has a diameter of 150-500 mm, and each core tube has 200-1500 small holes with a diameter of 1.5 mm. The wash water spray rate is 0.5-1 m / s, and a single tube can handle a gas flow rate of 200-2500 m³ / s. 3 / h.

[0045] In this embodiment, the pressure drop of the cyclone spray water washing tower 2 is 1-5 kPa.

[0046] In this embodiment, the cyclone jet absorption tower 4 includes a second shell 401, a packing absorption module 403 and a cyclone jet core tube 402 disposed inside the second shell 401, an absorbent liquid storage tank 404 disposed at the bottom of the second shell 401, a second gas-liquid separation module 405 disposed above the cyclone jet core tube 402, and a second tower plate 407 and a second downcomer 406 located between the packing absorption module 403 and the absorbent liquid storage tank 404.

[0047] The lower part of the side wall of the second shell 401 is provided with a second air inlet 408 connected to the air outlet 208 of the cyclone spray water washing tower 2, and an exhaust hole 411 is provided at the top. The middle part of the side wall is provided with an absorbent circulation inlet 410 connected to the outlet of the first water cooler 11, and the lower part is provided with an absorbent circulation outlet 409 connected to the absorbent storage tank 404. The upper part of the side wall is provided with a low temperature lean liquid inlet 412, the lower part is provided with a low temperature rich liquid outlet 413, and the top is provided with a replenishment port 414.

[0048] The packed absorber module 403 uses structured packing to pretreat part of the CO2 in the exhaust gas and improve the efficiency of subsequent swirl jet absorption.

[0049] The swirl jet core tube 402 is vertically installed above the packing absorption module 403. The amine absorbent liquid is injected through the absorbent circulation inlet 410 and then jetted at a rate of 1-3 m / s to form micron-sized droplets. A single tube can handle a gas flow rate of 200-2500 m³ / s. 3 / h;

[0050] The second gas-liquid separation module 405 is a cyclone separator (cyclone blade angle 30°) used to separate amine liquid droplets entrained in the decarbonization tail gas, ensuring that the liquid content of the outlet gas is ≤50mg / l.

[0051] In this embodiment, the pressure drop of the cyclone jet absorber 4 is 3-20 kPa, the carbon capture efficiency is above 95%, and the liquid content of the outlet gas is ≤50 mg / L.

[0052] In this embodiment, the cyclone flash regeneration tower 9 includes a third shell 901, a cyclone flash core tube 902 vertically installed inside the third shell 901, a liquid storage tank 903 located at the bottom of the third shell 901, a third tower plate 904 located below the cyclone flash core tube 902, and a third downcomer 905.

[0053] The third housing 901 has a high-temperature rich liquid inlet 906 in the middle of its side wall, which is connected to the outlet of the steam heat exchanger 8 for tangential feeding; a regeneration gas outlet 910 at the top, which is connected to the second water cooler 18; a high-temperature lean liquid outlet 908 at the bottom, which is connected to the lean liquid pump 10; a condensate inlet 909 at the lower part of its side wall, which is connected to the condensate pump 14; and a regeneration outlet 907 at the bottom side, which is connected to the regeneration pump 12.

[0054] The cylindrical section of the 902 cyclone flash evaporator core tube has a diameter of 50-100mm, a liquid inlet rate of 3-7m / s, and a single tube can handle a rich liquid flow rate of 20-100m³ / s. 3 / h, the tube wall is smooth and non-porous, and the lower part of the core tube is equipped with a conical guide section (cone angle 60°). The high-temperature rich liquid enters the core tube tangentially from the high-temperature rich liquid inlet 906 at a speed of 3-7m / s, forming a strong swirling flow field (swirling speed 15-20m / s), which accelerates the release of CO2 bubbles.

[0055] The third tray 904 is a floating valve tray (50-80 floating valves / m²), used to evenly distribute the lean liquor after regeneration. The third downcomer 905 guides the lean liquor back to the storage tank 903 to ensure that the lean liquor is discharged evenly.

[0056] In this embodiment, the catalyst in the fixed-bed reactor 17 is a nickel-based catalyst, the bed porosity is 35-65%, and the reforming conversion efficiency is ≥95%.

[0057] In this embodiment, the syngas composition at the outlet of the fixed-bed reactor 17 is H2 and CO in a molar ratio of 1:1, and the temperature is 800-900℃.

[0058] Engineering examples of system and equipment selection based on the above methanol-to-aromatics carbon-containing tail gas cyclone jet capture and reforming process:

[0059] The carbon-containing tail gas flow rate of methanol-to-aromatics production is 10000 Nm³. 3 The atmosphere is heated at a temperature of 80℃ and a pressure of 0.15 MPaG per hour, with a carbon dioxide content of 15% and a dust content of 0.15 MPaG.

[0060] After being treated by the water washing and cooling unit, the temperature is reduced to 40℃, and the dust content at the outlet is reduced to 50mg / Nm³. 3 Within this range, the pressure drop is less than 2 kPa.

[0061] After being processed by the cyclone absorption unit, the carbon dioxide content was reduced from 15% to below 0.75%, the carbon dioxide capture efficiency was >95%, and the pressure drop was less than 10 kPa.

[0062] After passing through the flash regeneration unit, the rich amine solution is regenerated to produce >1200 Nm 3 / h of carbon dioxide, with a regeneration efficiency of >85%.

[0063] The regenerated CO2 enters the methane reforming unit, where it reacts with 1200 Nm³ of oxygen. 3 / h of methane and 600Nm 3 Nitrogen gas at a rate of / h is subjected to high-temperature catalytic reforming to produce 5400 Nm³. 3 Synthetic gas per hour is reformed.

[0064] See instruction manual attached Figure 5 As shown in the figure, the horizontal axis represents the absorbent flow rate, and the vertical axis represents the absorption efficiency. This graph shows that when the room temperature is 20℃, the inlet gas flow rate is stable at 20 L·min. -1 When the concentration of carbon dioxide in the gas to be treated is kept constant at 10000 mg / L, the liquid phase flow rate is controlled at 30 L·h by changing the inlet flow rate of the absorbent. -1 -100L·h -1 Between these, absorbents of 35% MDEA, 34% MDEA+1% MEA, 34% MDEA+1% DEA, 34% MDEA+1% PZ, 34% MDEA+1% AMP, and 3.3 mol / L MEA were selected to obtain the changes in the absorption efficiency of various absorbents for carbon dioxide under different liquid flow rates.

[0065] When the liquid phase absorbent is 35% MDEA, 34% MDEA+1% MEA, 34% MDEA+1% DEA, 34% MDEA+1% PZ, 34% MDEA+1% AMP, and 3.3 mol / L MEA, the absorption efficiencies of the solution for carbon dioxide are 68.56%-92.79%, 70.98%-96.58%, 64.12%-94.38%, 55.21%-94.55%, 54.43%-87.01%, and 94.56%-97.86%, respectively.

[0066] As can be seen from the figure, the general trends of MDEA and its mixed amine solutions with MEA, DEA, PZ, and AMP are very similar. With increasing liquid flow rate, the absorption efficiency of the six formulations for carbon dioxide shows an increasing trend. As the absorbent flow rate increases, the water pressure increases accordingly, which accelerates the jet velocity entering from the injection orifice, increases the total amount of absorbent entering the gas-liquid cyclone jet absorber, strengthens the jet breaking process, increases the contact area between carbon dioxide and the absorbent, and enhances the absorption effect. The absorption efficiency of the six solutions reaches a liquid phase flow rate of 100 L·h. -1 The average efficiency reached its maximum, with the 3.3 mol / L LMEA solution achieving an efficiency of 97.86%. However, the graph also shows that when the absorbent flow rate exceeds 70 L·h... -1 Subsequently, the increase in absorption efficiency for all six absorbents became less significant, indicating that the atomization and fragmentation process of the jet and airflow was already quite intense, and further increasing the absorbent flow rate would hardly yield any noticeable effect. After adding the activator, the 34% MDEA + 1% MEA combination showed relatively better results, but its overall absorption efficiency was lower than that of the 3.3 mol / L MDEA solution. This is because, when MDEA and MEA are mixed, MDEA, as the main absorber of carbon dioxide, has a slightly weaker absorption effect as a tertiary alkanolamine than the primary alkanolamine MEA.

[0067] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A methanol-to-aromatics carbon-containing tail gas cyclone jet capture and reforming process, characterized in that: include: S1. Water Washing and Cooling Unit: The methanol-to-aromatics tail gas containing dust and carbon at a temperature of 80-300℃ is tangentially fed into the cyclone spray core tube of the cyclone spray water washing tower via a gas supply device. Washing water is extracted from the washing water storage tank at the bottom of the cyclone spray water washing tower by a water pump, pressurized, and then injected into the cyclone spray core tube. Cooling and dust removal are achieved using a combination of cyclone and spray water washing methods, controlling the temperature of the carbon-containing tail gas to ≤50℃ and the dust content to ≤10mg / m³. 3 After being washed and cooled, the carbon-containing tail gas from the methanol-to-aromatics process continues to move upwards and leaves the cyclone spray water washing tower after passing through the first gas-liquid separation module. S2, Cyclone Absorption Unit: The carbon-containing tail gas after water washing enters the cyclone jet absorption tower and passes through the packing absorption module and the cyclone jet core tube in sequence. It is subjected to multi-stage cyclone enhanced absorption using amine-based absorbent liquid. The decarbonized tail gas after absorption continues to move upward and leaves the cyclone jet absorption tower after passing through the second gas-liquid separation module. S3, Flash Regeneration Unit: After being discharged from the cyclone jet absorption tower, the low-temperature rich liquid is heated to 120-140℃ in stages through the lean-rich liquid heat exchanger and the steam heat exchanger. Then, it is input into the cyclone flash core tube of the cyclone flash regeneration tower with a pressure difference of 0.6-1.2MPa. Carbon dioxide in the absorbent is separated by the action of cyclone flash evaporation. The high-temperature lean liquid with the same flow rate as the low-temperature rich liquid is pumped out by the lean liquid pump and passes through the lean-rich liquid heat exchanger and the first water cooler in sequence. After being cooled to 40℃, it enters the cyclone jet absorption tower. S4, Methane Reforming Unit: After the regenerated carbon dioxide is cooled to 80°C by the second water cooler, it enters the gas-liquid separator to separate the cooled condensate. The condensate is returned to the cyclone flash regeneration tower by the action of the condensate pump. The deliquified carbon dioxide is mixed with the supplementary methane at a molar ratio of 1:1, heated to 800-900°C by the electric heater, and then enters the fixed bed reactor filled with nickel-based catalyst to form syngas under the action of catalytic reforming. The cylindrical section of the swirl spray core tube has a diameter of 150-500 mm, and each core tube has 200-1500 small holes with a diameter of 1.5 mm. The water spray rate is 0.5-1 m / s, and a single tube can handle a gas flow rate of 200-2500 m³ / s. 3 / h, the pressure drop of the cyclone spray water washing tower is 1-5kPa; The cylindrical section of the swirling jet core tube has a diameter of 150-500 mm, and each core tube has 600-3000 small holes with a diameter of 1.2 mm. The amine absorbent injection rate is 1-3 m / s, and a single tube can handle a gas flow rate of 200-2500 m³ / s. 3 / h; The pressure drop of the cyclone jet absorber is 3-20 kPa, the carbon capture efficiency is over 95%, and the liquid content of the outlet gas is ≤50 mg / L.

2. The methanol-to-aromatics carbon-containing tail gas cyclone jet capture and reforming process according to claim 1, characterized in that: The cylindrical section of the cyclone flash core tube has a diameter of 50-100 mm, a liquid inlet rate of 3-7 m / s, and a single tube can handle a rich liquid flow rate of 20-100 m³ / s. 3 / h.

3. The methanol-to-aromatics carbon-containing tail gas cyclone jet capture and reforming process according to claim 1, characterized in that: In the fixed-bed reactor, the catalyst is a nickel-based catalyst, the bed porosity is 35-65%, and the reforming conversion efficiency is ≥95%.

4. The methanol-to-aromatics carbon-containing tail gas cyclone jet capture and reforming process according to claim 1, characterized in that: The syngas at the outlet of the fixed-bed reactor consists of H2 and CO in a molar ratio of 1:1, and the temperature is 800-900℃.

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