Methanol catalytic synthesis system utilizing carbon dioxide in dry quenching recycle gas

Abstract

The utility model provides a methanol catalytic synthesis system utilizing carbon dioxide in dry quenching circulating gas, which is characterized in that an inlet of a desulfurizing tower of a dry quenching circulating gas decarburization system is used for introducing the dry quenching circulating gas, and a purified gas outlet of the desulfurizing tower is connected with a gas inlet of a decarburization absorption tower; an absorption liquid outlet of the decarburization absorption tower is communicated with an absorption liquid inlet of the desorption tower, an absorption liquid outlet of the desorption tower is communicated with an absorption liquid inlet of the decarburization absorption tower, a flue gas outlet of the desorption tower is communicated with an inlet of the CO2 separation device through the flue gas cooler, and a CO2 gas outlet of the CO2 separation device is communicated with an inlet of the catalytic reactor through the compression device; a hydrogen outlet of the coke oven gas hydrogen production system is communicated with an inlet of the catalytic reactor through the compression system, and methanol is synthesized from carbon dioxide generated by a dry quenching production unit in a coking plant and hydrogen generated by a coke oven gas unit in the catalytic reactor, so that effective utilization of resources is realized.

Description

Technical Field

[0001] The utility model belongs to the technical field of dry coke quenching process, and particularly relates to a methanol catalytic synthesis system utilizing carbon dioxide in dry coke quenching circulating gas. Background Art

[0002] In the CDQ production process, the red coke is cooled to below 200℃. The CDQ circulating gas needs to be blown in from the bottom of the CDQ furnace. After heat exchange with the red coke, it flows through the dust collector, CDQ waste heat boiler, circulating fan and feed water preheater in sequence and re-enters the CDQ furnace for circulation. Before entering the CDQ furnace, the flue gas temperature of the recycled CDQ circulating gas is generally 110-130℃, and the mass concentration of SO2 is 1000-3000mg / m 3 The mass concentration of particulate matter is about 1000 mg / m 3 The volume of CO2 accounts for about 12%-18%; the above gas components have a certain influence on the coke burnout rate. For example, CO2 has a direct effect on the coke burnout rate when the temperature is higher than 730℃, and it is easy to cause carbon dissolution reaction in the CDQ furnace, which seriously affects the coke production. Therefore, it is necessary to extract the CO2 in the CDQ circulating gas to reduce the concentration of CO2 in the CDQ circulating gas, thereby reducing the coke burnout rate and achieving the purpose of increasing the coke production. However, there is no effective CO2 extraction technology at present, resulting in a large amount of burnout.

[0003] On the other hand, in the coking industry, low-temperature carbonization is a thermal process that decomposes low-rank coal into coal tar, coke oven gas, and semi-coke at 500-650°C, isolated from air or with a small amount of air. It has become the main trend of the development of the coal chemical industry chain today because of its simple process, mild conditions, high product added value, low investment and cost. The coke oven gas obtained by low-temperature carbonization is generally used as a raw material for hydrogen production, and hydrogen is an important chemical raw material and a very clean fuel. It is widely used in chemical and other industries. Due to the good combustion performance of hydrogen, the current hydrogen energy application technology is developing faster and faster. A process that can produce methanol by reacting hydrogen with CO2 is widely used, which can realize the resource utilization of coke oven gas. Utility Model Content

[0004] In order to solve the problems existing in the prior art, the utility model provides a methanol catalytic synthesis system using carbon dioxide in dry quenching circulating gas, which can achieve effective extraction of CO2 in the dry quenching circulating gas, thereby reducing the coke burnout rate, and using the extracted carbon dioxide and hydrogen prepared from coke oven gas to prepare methanol, thereby achieving resource utilization of a large amount of coke oven gas and dry quenching circulating gas in the existing coking industry and avoiding waste of resources.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical scheme: a methanol catalytic synthesis system utilizing carbon dioxide in dry quenching circulating gas, comprising a dry quenching circulating gas decarbonization system, a coke oven gas hydrogen production system and a methanol catalytic synthesis system, wherein the methanol catalytic synthesis system comprises a catalytic reactor and a gas-liquid separation device, the dry quenching circulating gas decarbonization system comprises a desulfurization tower, a decarbonization absorption tower, a desorption tower and a CO2 separation device, the inlet of the desulfurization tower is used to introduce the dry quenching circulating gas, the purified gas outlet of the desulfurization tower is connected to the gas inlet of the decarbonization absorption tower, the absorption liquid inlet of the decarbonization absorption tower is connected to the absorption liquid inlet of the desorption tower, the flue gas outlet of the desorption tower is connected to the inlet of the CO2 separation device through a flue gas cooler, the CO2 gas outlet of the CO2 separation device is connected to the inlet of the catalytic reactor through a compression device, the hydrogen outlet of the coke oven gas hydrogen production system is connected to the inlet of the catalytic reactor through a compression system, the outlet of the catalytic reactor is connected to the inlet of the gas-liquid separation device, and the outlet of the gas-liquid separation device is connected to a downstream product preparation device.

[0006] Furthermore, the desulfurization tower is made of corrosion-resistant materials and is used to implement wet desulfurization technology or dry desulfurization technology to desulfurize the dry quenching circulating gas; the gas inlet of the desulfurization tower is located at the lower part of the desulfurization tower, the purified gas outlet of the desulfurization tower is located at the upper part of the desulfurization tower, the desulfurization liquid inlet is located at the upper part of the desulfurization tower, and the desulfurization liquid outlet is located at the lower part of the desulfurization tower.

[0007] Furthermore, the decarbonization absorption tower adopts chemical absorption method for decarbonization, and adopts organic amine absorption liquid, and the organic amine absorption liquid includes one or more of monoethanolamine, diethanolamine and N-methyldiethanolamine.

[0008] Furthermore, a decarbonization absorber tower purified gas outlet is opened at the top of the decarbonization absorber tower, the decarbonization absorber tower purified gas outlet is connected to the dry quenching furnace circulating gas inlet pipeline, the decarbonization absorber tower gas inlet is located at the lower part of the decarbonization absorber tower, the decarbonization absorber tower absorption liquid inlet is located at the upper part of the decarbonization absorber tower, and the decarbonization absorber tower absorption liquid outlet is located at the lower part of the decarbonization absorber tower.

[0009] Furthermore, a carbon absorbent preheating system is arranged between the decarbonization absorption tower and the desorption tower, and the carbon absorbent preheating system includes a rich liquid pump, a lean liquid pump, a lean-rich liquid heat exchanger and a lean liquid cooler. The absorption liquid outlet of the decarbonization absorption tower is connected to the cold side inlet of the lean-rich liquid heat exchanger through the rich liquid pump, the cold side outlet of the lean-rich liquid heat exchanger is connected to the absorption liquid inlet of the desorption tower, the absorption liquid outlet of the desorption tower is connected to the hot side inlet of the lean-rich liquid heat exchanger through the lean liquid pump, and the hot side outlet of the lean-rich liquid heat exchanger is connected to the absorption liquid inlet of the decarbonization absorption tower through the lean liquid cooler.

[0010] Furthermore, the lean-rich liquid heat exchanger adopts a shell and tube heat exchanger or a plate heat exchanger, and the hot fluid medium in the lean-rich liquid heat exchanger is the CO2 lean liquid regenerated in the desorption tower. After the CO2 lean liquid exchanges heat with the CO2 rich liquid, the CO2 lean liquid is transported to the lean liquid cooler for cooling treatment, and then is sent to the decarbonization absorption tower through the absorption liquid inlet of the decarbonization absorption tower for recycling.

[0011] Furthermore, a reboiler is provided at the bottom of the desorption tower, and the reboiler is used to heat the CO2 rich liquid entering the desorption tower.

[0012] Furthermore, a condensate outlet is provided at the bottom of the CO2 separation device, and the condensate outlet is connected to the condensate reflux port of the desorption tower.

[0013] Furthermore, the coke oven gas hydrogen production system includes a gas pretreatment tower, a pressure swing adsorption tower, a deoxygenation tower and a dehumidification tower. The pretreated coke oven gas is delivered to the inlet of the gas pretreatment tower through a coke oven gas delivery fan and a primary gas compressor. The outlet of the gas pretreatment tower is connected to the inlet of the pressure swing adsorption tower through a secondary gas compressor, the outlet of the pressure swing adsorption tower is connected to the inlet of the deoxygenation tower, the outlet of the deoxygenation tower is connected to the inlet of the dehumidification tower, and the outlet of the dehumidification tower is connected to the inlet of the catalytic reactor.

[0014] Furthermore, the pressure swing adsorption tower adopts a three-group tower structure.

[0015] Compared with the prior art, the utility model has at least the following beneficial effects:

[0016] The utility model provides a methanol catalytic synthesis system using carbon dioxide in the dry quenching circulating gas. A desulfurization tower and a decarbonization absorption tower are used to remove SO2 and CO2 in the dry quenching circulating gas respectively; a desorption tower is used to desorb the rich liquid that absorbs carbon dioxide, and a mixture of carbon dioxide gas and water vapor is released from the top of the desorption tower. The mixture is separated from carbon dioxide in a CO2 separation device; secondly, hydrogen is separated from the coke oven gas after passing through a coke oven gas hydrogen production system. After being compressed respectively, the carbon dioxide and hydrogen enter a catalytic reactor for catalytic reaction to synthesize methanol. The utility model removes the carbon dioxide contained in the dry quenching circulating gas, which, on the one hand, reduces the carbon melting reaction between carbon dioxide and carbon in the dry quenching furnace, and on the other hand, the removed carbon dioxide can be further utilized as a resource; there is a large amount of coke oven gas in the coking plant, and separating hydrogen from the coke oven gas has the advantages of convenience, simplicity, and low cost. The carbon dioxide produced by the dry quenching production unit and the hydrogen produced by the coke oven gas unit in the comprehensive coking plant are synthesized into methanol, which realizes the effective utilization of resources, increases the energy available to the enterprise, and creates considerable benefits for the development of the enterprise.

[0017] A lean liquid cooler is set at the lean liquid inlet of the decarbonization absorption tower to reduce the temperature of the carbon absorbent after releasing CO2, that is, the CO2 lean liquid, which can improve the absorption efficiency of the CO2 lean liquid; the absorption liquid outlet of the decarbonization absorption tower is connected to the lean-rich liquid heat exchanger to increase the temperature of the carbon absorbent after absorbing CO2, that is, the CO2 rich liquid, which can increase the desorption rate of the CO2 rich liquid in the desorption tower. The comprehensive effect realizes the efficient recovery and utilization of the CO2 absorbed in the carbon absorbent and avoids waste of resources.

[0018] Furthermore, a lean liquid cooler is provided at the lean liquid inlet of the decarbonization absorption tower to reduce the temperature of the carbon absorbent after the CO2 is released, i.e., the CO2 lean liquid, which can improve the absorption efficiency of the CO2 lean liquid; the absorption liquid outlet of the decarbonization absorption tower is connected to the lean-rich liquid heat exchanger to increase the temperature of the carbon absorbent after the CO2 is absorbed, i.e., the CO2 rich liquid, which can increase the desorption rate of the CO2 rich liquid in the desorption tower. The comprehensive effect realizes the efficient recovery and utilization of the CO2 absorbed in the carbon absorbent, and avoids the waste of resources.

[0019] Furthermore, an organic amine absorption liquid is used as a carbon absorbent in the decarbonization absorption tower, and decarbonization is carried out by chemical absorption, thereby ensuring a high carbon dioxide capture efficiency and avoiding the generation of solid or liquid pollutants; at the same time, it is convenient to recycle the CO2 absorbed in the carbon absorbent.

[0020] Furthermore, in the coke oven gas hydrogen production system, the coke oven gas passes through the pressure swing adsorption tower, deoxidation tower, and dehumidification tower system in sequence, among which the pressure swing adsorption tower adopts a three-group tower structure to ensure the adsorption efficiency of the coke oven gas. The deoxidation tower and dehumidification tower are equipped to effectively remove oxygen and moisture from the gas, ensuring the efficient completion of the downstream catalytic methanol synthesis process. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The utility model is a schematic diagram of a methanol catalytic synthesis system using carbon dioxide in dry coke quenching circulating gas.

[0022] Among them, 1 conveying fan, 2 desulfurization tower, 201 desulfurization tower gas inlet, 202 desulfurization tower purified gas outlet, 203 desulfurization liquid inlet, 204 desulfurization liquid outlet, 3 decarbonization absorption tower, 31 decarbonization absorption tower gas inlet, 32 decarbonization absorption tower purified gas outlet, 33 decarbonization absorption tower absorption liquid inlet, 34 decarbonization absorption tower absorption liquid outlet, 4 rich liquid pump, 5 lean liquid pump, 6 lean and rich liquid heat exchanger, 7 lean liquid cooler, 8 desorption tower, 81 desorption tower absorption liquid outlet, 82 desorption tower flue gas outlet, 83 desorption tower absorption liquid inlet, 84 condensate reflux port, 9 flue gas cooler, 10CO2 separation Separation device, 101CO2 gas outlet, 11 compressor, 12 water cooler, 13 coke oven gas conveying fan, 141 primary gas compressor, 142 secondary gas compressor, 15 gas pretreatment tower, 151 gas pretreatment tower gas inlet, 152 gas pretreatment tower gas outlet, 16 pressure swing adsorption tower, 161 pressure swing adsorption tower inlet, 162 pressure swing adsorption tower outlet, 17 deoxygenation tower, 171 deoxygenation tower inlet, 172 deoxygenation tower outlet, 18 dehumidification tower, 181 dehumidification tower inlet, 182 dehumidification tower outlet, 19 delivery pump, 20 catalytic reactor, 21 gas-liquid separation device. DETAILED DESCRIPTION

[0023] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0024] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0025] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0026] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In the present utility model, unless otherwise clearly stipulated and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0028] The embodiments of the present utility model are described in detail below with reference to the accompanying drawings.

[0029] As attached Figure 1 As shown, the utility model provides a methanol catalytic synthesis system using carbon dioxide in dry quenching circulating gas, including a dry quenching circulating gas decarbonization system, a coke oven gas hydrogen production system and a methanol catalytic synthesis system, wherein:

[0030] The dry coke quenching circulating gas decarbonization system comprises a conveying fan 1, a desulfurization tower 2, a decarbonization absorption tower 3, a rich liquid pump 4, a lean liquid pump 5, a lean and rich liquid heat exchanger 6, a lean liquid cooler 7, a desorption tower 8, a flue gas cooler 9, and a CO2 separation device 10. The dry coke quenching circulating gas passes through the conveying fan 1, the outlet of the conveying fan 1 is connected to the gas inlet 201 of the desulfurization tower, the purified gas outlet 202 of the desulfurization tower is connected to the gas inlet 31 of the decarbonization absorption tower, and the purified gas outlet 32 ​​of the decarbonization absorption tower is connected to the dry quenching furnace circulating gas inlet pipeline; the hot side inlet of the lean and rich liquid heat exchanger 6 is connected to the outlet of the lean liquid pump 5, and the hot side of the lean and rich liquid heat exchanger 6 is connected to the outlet of the lean liquid pump 5. The outlet is connected to the inlet of the lean liquid cooler 7, the outlet of the lean liquid cooler 7 is connected to the absorption liquid inlet 33 of the decarbonization absorber, the cold side inlet of the lean-rich liquid heat exchanger 6 is connected to the absorption liquid outlet 34 of the decarbonization absorber, the cold side outlet of the lean-rich liquid heat exchanger 6 is connected to the absorption liquid inlet 83 of the desorption tower, the inlet of the lean liquid pump 5 is connected to the absorption liquid outlet 81 of the desorption tower, the flue gas outlet 82 of the desorption tower is connected to the inlet of the flue gas cooler 9, the outlet of the flue gas cooler 9 is connected to the inlet of the CO2 separation device 10, and the CO2 gas outlet 101 of the CO2 separation device 10 is connected to the inlet of the four-stage compression system to obtain liquid carbon dioxide.

[0031] The four-stage compression system includes four groups of compressors 11 and water coolers 12 .

[0032] The coke oven gas hydrogen production system includes a coke oven gas delivery fan 13, a primary gas compressor 141, a secondary gas compressor 142, a gas pretreatment tower 15, a gas pretreatment tower gas inlet 151, a gas pretreatment tower gas outlet 152, a pressure swing adsorption tower 16, a deoxidation tower 17, a deoxidation tower inlet 171, a deoxidation tower outlet 172, a dehumidification tower 18, a dehumidification tower inlet 181, a dehumidification tower outlet 182, and a delivery pump 19.

[0033] The outlet of the coke oven gas delivery fan 13 is connected to the inlet of the first-stage gas compressor 141, and the outlet of the first-stage gas compressor 141 is connected to the gas inlet 151 of the gas pretreatment tower; the gas outlet 152 of the gas pretreatment tower is connected to the inlet of the second-stage gas compressor 142, and the outlet of the second-stage gas compressor 142 is connected to the inlet 161 of the pressure swing adsorption tower; the outlet 162 of the pressure swing adsorption tower is connected to the inlet 171 of the deoxygenation tower, the outlet 172 of the deoxygenation tower is connected to the inlet 181 of the dehumidification tower, and the outlet 182 of the dehumidification tower is connected to the inlet of the compressor 11 to obtain liquid hydrogen.

[0034] The methanol catalytic synthesis system includes a catalytic reactor 20 and a gas-liquid separation device 21. After compression, liquid carbon dioxide and liquid hydrogen are respectively transported by a delivery pump 19 into the catalytic reactor 20 for reaction. The outlet of the catalytic reactor 20 is connected to the inlet of the gas-liquid separation device 21, and the outlet of the gas-liquid separation device 21 is connected to a downstream product manufacturing device.

[0035] In one embodiment of the utility model, the desulfurization tower 2 is made of corrosion-resistant material and is used to implement wet desulfurization technology or dry desulfurization technology to carry out desulfurization treatment of dry quenching circulating gas; the desulfurization tower gas inlet 201 is arranged at the bottom of one side of the tower body of the desulfurization tower 2, and the desulfurization tower purified gas outlet 202 is arranged at the top of the tower body of the desulfurization tower 2; a desulfurization liquid inlet 23 is arranged at the upper end of the other side of the tower body of the desulfurization tower 2, which is used to inject desulfurization liquid into the interior of the desulfurization tower 2; a desulfurization liquid outlet 24 is arranged at the bottom of the other side of the tower body of the desulfurization tower 2, which is used to discharge the desulfurization liquid after desulfurization treatment.

[0036] In one embodiment of the utility model, the decarbonization absorption tower 3 is used to realize decarbonization by chemical absorption, which has the advantages of good absorption effect and easy regeneration, and can remove hydrogen sulfide at the same time; preferably, the chemical absorption method adopts the alcohol amine method, that is, an organic amine absorption liquid is used as a carbon absorbent; wherein the organic amine absorption liquid adopts one or more of monoethanolamine, diethanolamine and N-methyldiethanolamine;

[0037] In one embodiment of the utility model, in the decarbonization absorption tower 3, the CO2 in the dry quenching circulating gas is absorbed by using a carbon absorbent, and the carbon absorbent contacts the dry quenching circulating gas and reacts chemically with the CO2 therein, thereby achieving the capture and removal of the CO2 in the dry quenching circulating gas; the gas inlet 31 of the decarbonization absorption tower is arranged at the bottom of one side of the tower body of the decarbonization absorption tower 3, and the purified gas outlet 32 ​​of the decarbonization absorption tower is arranged at the top of the tower body of the decarbonization absorption tower 3.

[0038] It should be noted that when the desulfurization liquid flows down from the top of the tower body of the desulfurization tower 2 or the carbon absorbent flows down from the top of the tower body of the decarbonization absorption tower 3, a smooth liquid film can be formed, and the smooth liquid film can be broken under the action of gravity to form droplets. When the dry quenching circulating gas that needs to be desulfurized or decarbonized enters from the bottom of the tower body of the desulfurization tower 2 or the decarbonization absorption tower 3, the dry quenching circulating gas can be in reverse contact with the droplet-shaped desulfurization liquid or carbon absorbent. At this time, the droplet-shaped desulfurization liquid or carbon absorbent can be wrapped and carried by the dry quenching circulating gas, thereby realizing the absorption and removal of SO2 or CO2.

[0039] In one embodiment of the utility model, the absorption liquid outlet 34 of the decarbonization absorption tower is connected to the inlet of the rich liquid pump 4, and the outlet of the rich liquid pump 4 is connected to the cold side inlet of the lean-rich liquid heat exchanger 6; the cold side outlet of the lean-rich liquid heat exchanger 6 is connected to the absorption liquid inlet 83 of the desorption tower, the absorption liquid outlet 81 of the desorption tower is connected to the inlet of the lean liquid pump 5, the outlet of the lean liquid pump 5 is connected to the hot side inlet of the lean-rich liquid heat exchanger 6, the hot side outlet of the lean-rich liquid heat exchanger 6 is connected to the inlet of the lean liquid cooler 7, and the outlet of the lean liquid cooler 7 is connected to the absorption liquid inlet 33 of the decarbonization absorption tower.

[0040] In one embodiment of the utility model, the decarbonization absorption tower absorption liquid outlet 34 is arranged at the bottom of the other side of the tower body of the decarbonization absorption tower 3, which is used to discharge the carbon absorbent after absorbing CO2, that is, CO2 rich liquid, and pump the CO2 rich liquid to the lean-rich liquid heat exchanger 6 through the rich liquid pump 4; the decarbonization absorption tower absorption liquid inlet 33 is arranged at the upper end of the tower body of the decarbonization absorption tower 3 on the other side, and the absorption liquid inlet of the decarbonization absorption tower 3 is used to re-enter the carbon absorbent after releasing CO2, that is, CO2 lean liquid, into the decarbonization absorption tower 3 to realize the recycling of the carbon absorbent; the decarbonization absorption tower absorption liquid inlet 33 can also inject new carbon absorbent into the interior of the decarbonization absorption tower 3.

[0041] In one embodiment of the utility model, the rich liquid pump 4 is used to pump the CO2 rich liquid to the lean and rich liquid heat exchanger 6 to preheat the CO2 rich liquid, and the preheated CO2 rich liquid is sent to the desorption tower 8 through a pipeline; the desorption tower 8 is used to heat and decompose the preheated CO2 rich liquid to release the CO2 in the rich liquid, that is, to obtain the carbon absorbent and CO2 gas after the CO2 is released; wherein, the carbon absorbent after the CO2 is released is the CO2 lean liquid; and a reboiler 85 is also provided at the bottom of the desorption tower 8, and the reboiler 85 is used to heat the CO2 rich liquid entering the desorption tower 8; a desorption tower flue gas outlet 82 is provided at the top of the desorption tower 8, and the desorption tower flue gas outlet 82 is used for CO2 gas discharge.

[0042] In one embodiment of the utility model, the desorption tower 8 desorbs CO2 in the absorption liquid by steam stripping, and the reboiler 85 is used to heat the circulating liquid at the bottom of the desorption tower.

[0043] In one embodiment of the utility model, the lean liquid pump 5 pumps the CO2 lean liquid discharged from the desorption tower 8 to the lean-rich liquid heat exchanger 6, and performs heat exchange with the CO2 rich liquid in the lean-rich liquid heat exchanger 6 to achieve preheating of the CO2 rich liquid;

[0044] In one embodiment of the utility model, the lean-rich liquid heat exchanger 6 adopts a shell and tube heat exchanger or a plate heat exchanger, and the hot fluid medium in the lean-rich liquid heat exchanger 6 is the CO2 lean liquid regenerated from the desorption tower 8; on the other hand, the CO2 lean liquid is transported to the lean liquid cooler 7 for cooling treatment after heat exchange with the CO2 rich liquid, and then is sent to the decarbonization absorption tower 3 through the decarbonization absorption tower absorption liquid inlet 33 for recycling.

[0045] In one embodiment of the utility model, the inlet of the flue gas cooler 9 is connected to the flue gas outlet of the desorption tower 8, the outlet of the flue gas cooler 9 is connected to the air inlet of the CO2 separation device 10, and the condensate outlet of the CO2 separation device 10 is connected to the desorption tower 8; wherein, due to the heating and decomposition in the desorption tower 8 to obtain carbon absorbent-rich droplets in the CO2 gas, the CO2 gas is discharged from the flue gas outlet of the desorption tower 8 and transported to the CO2 separation device 10 after being cooled by the flue gas cooler 9; and the CO2 separation device 10 can separate the CO2 in the CO2 gas from the carbon absorbent droplets to obtain pure CO2 gas and condensate of the carbon absorbent; wherein, the pure CO2 gas is discharged from the top of the CO2 separation device 10, and the condensate of the carbon absorbent flows from the bottom of the CO2 separation device 10 to the desorption tower 8.

[0046] For the CO2 content in the circulating gas of 12% to 18%, the chemical absorption method using organic amine solvents as absorbents can efficiently remove CO2 from the circulating gas. Studies have shown that 1 mole of absorbent can absorb up to 1 mole of CO2. After purification in the decarbonization absorber, the CO2 content in the circulating gas can be reduced to 1% after the absorbent is circulated and absorbed. In the desorption tower, the organic amine solvent is desorbed, and the desorption efficiency is 50% to 55%. The desorbed absorbent is transported by the lean liquid pump, mixed with the newly added absorbent in the decarbonization absorber, and then circulated to absorb CO2. After absorbing CO2, it is transported at the bottom of the decarbonization absorber by the rich liquid pump and desorbed again in the desorption tower.

[0047] In one embodiment of the utility model, the outlet of the coke oven gas delivery fan 13 is connected to the inlet of the first-stage gas compressor 141, and the outlet of the first-stage gas compressor 141 is connected to the gas inlet 151 of the gas pretreatment tower; the gas outlet 152 of the gas pretreatment tower is connected to the inlet of the second-stage gas compressor 142, and the outlet of the second-stage gas compressor 142 is connected to the pressure swing adsorption tower inlet 161; the pressure swing adsorption tower outlet 162 is connected to the deoxidation tower inlet 171, the deoxidation tower outlet 172 is connected to the dehumidification tower inlet 181, and the dehumidification tower outlet 182 is connected to the inlet of the compressor 11; wherein, the gas pretreatment tower 15 mainly removes most of the hydrocarbon substances, naphthalene, sulfur and other substances in the coal gas; in the deoxidation tower 17, the hydrogen and oxygen in the mixed gas react to generate water through the palladium catalyst bed; the dehumidification tower 18 separates and removes condensed free moisture through a cooler and a gas-liquid separator.

[0048] After compression, liquid carbon dioxide and liquid hydrogen are transported by pump 19 to enter catalytic reactor 20 for reaction. The outlet of catalytic reactor 20 is connected to the inlet of gas-liquid separation device 21, and the outlet of gas-liquid separation device 21 is connected to downstream products.

[0049] The above shows and describes the basic principles and main features of the utility model and the advantages of the utility model. For those skilled in the art, it is obvious that the utility model is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic features of the utility model. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the utility model is defined by the attached claims rather than the above description, and it is intended to include all changes within the meaning and scope of the equivalent elements of the claims. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0050] In addition, it should be understood that although this specification is described in accordance with the implementation methods, not every implementation method contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should take the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of ​​the utility model, and cannot be used to limit the protection scope of the utility model. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the utility model shall fall within the protection scope of the claims of the utility model.

Claims

1. A methanol catalytic synthesis system using carbon dioxide in dry quenching circulating gas, characterized in that: The invention comprises a dry coke quenching circulating gas decarbonization system, a coke oven gas hydrogen production system and a methanol catalytic synthesis system, wherein the methanol catalytic synthesis system comprises a catalytic reactor (20) and a gas-liquid separation device (21), and the dry coke quenching circulating gas decarbonization system comprises a desulfurization tower (2), a decarbonization absorption tower (3), a desorption tower (8), and a CO2 separation device (10). The inlet of the desulfurization tower (2) is used to introduce the dry coke quenching circulating gas, the purified gas outlet (202) of the desulfurization tower is connected to the gas inlet (31) of the decarbonization absorption tower, the absorption liquid outlet (34) of the decarbonization absorption tower is connected to the absorption liquid inlet (83) of the desorption tower, and the absorption liquid outlet (34) of the decarbonization absorption tower is connected to the absorption liquid inlet (83) of the desorption tower. The liquid collection outlet (81) is connected to the absorption liquid inlet (33) of the decarbonization absorption tower, the desorption tower flue gas outlet (82) is connected to the inlet of the CO2 separation device (10) through the flue gas cooler (9), the CO2 gas outlet (101) of the CO2 separation device (10) is connected to the inlet of the catalytic reactor (20) through the compression device, the hydrogen outlet of the coke oven gas hydrogen production system is connected to the inlet of the catalytic reactor (20) through the compression system, the outlet of the catalytic reactor (20) is connected to the inlet of the gas-liquid separation device (21), and the outlet of the gas-liquid separation device (21) is connected to the downstream product preparation device.

2. A methanol catalytic synthesis system using carbon dioxide in dry quenching circulating gas according to claim 1, characterized in that: The desulfurization tower (2) is made of corrosion-resistant materials and is used to implement wet desulfurization technology or dry desulfurization technology to carry out desulfurization treatment of dry quenching circulating gas; the desulfurization tower gas inlet (201) is located at the lower part of the desulfurization tower (2), the desulfurization tower purified gas outlet (202) is located at the upper part of the desulfurization tower (2), the desulfurization liquid inlet (203) is located at the upper part of the desulfurization tower (2), and the desulfurization liquid outlet (204) is located at the lower part of the desulfurization tower (2).

3. The methanol catalytic synthesis system using carbon dioxide in the CDQ circulating gas according to claim 1, characterized in that: The decarbonization absorption tower (3) adopts chemical absorption method for decarbonization.

4. A methanol catalytic synthesis system using carbon dioxide in dry quenching circulating gas according to claim 1, characterized in that: The decarbonization absorption tower (3) has a decarbonization absorption tower purified gas outlet (32) at the top, the decarbonization absorption tower purified gas outlet (32) is connected to the dry quenching furnace circulating gas inlet pipeline, the decarbonization absorption tower gas inlet (31) is located at the lower part of the decarbonization absorption tower (3), the decarbonization absorption tower absorption liquid inlet (33) is located at the upper part of the decarbonization absorption tower (3), and the decarbonization absorption tower absorption liquid outlet (34) is located at the lower part of the decarbonization absorption tower (3).

5. The methanol catalytic synthesis system using carbon dioxide in the CDQ circulating gas according to claim 1, characterized in that: A carbon absorbent preheating system is provided between the decarbonization absorption tower (3) and the desorption tower (8), and the carbon absorbent preheating system comprises a rich liquid pump (4), a lean liquid pump (5), a lean-rich liquid heat exchanger (6) and a lean liquid cooler (7); the decarbonization absorption tower absorption liquid outlet (34) is connected to the cold side inlet of the lean-rich liquid heat exchanger (6) through the rich liquid pump (4); the cold side outlet of the lean-rich liquid heat exchanger (6) is connected to the desorption tower absorption liquid inlet (83); the desorption tower absorption liquid outlet (81) is connected to the hot side inlet of the lean-rich liquid heat exchanger (6) through the lean liquid pump (5); and the hot side outlet of the lean-rich liquid heat exchanger (6) is connected to the decarbonization absorption tower absorption liquid inlet (33) through the lean liquid cooler (7).

6. A methanol catalytic synthesis system using carbon dioxide in dry quenching circulating gas according to claim 5, characterized in that: The lean-rich liquid heat exchanger (6) is a shell-and-tube heat exchanger or a plate heat exchanger, and the hot fluid medium in the lean-rich liquid heat exchanger (6) is the CO2 lean liquid regenerated in the desorption tower (8).

7. The methanol catalytic synthesis system using carbon dioxide in the CDQ circulating gas according to claim 1, characterized in that: A reboiler (85) is provided at the bottom of the desorption tower (8), and the reboiler (85) is used to heat the CO2-rich liquid entering the desorption tower (8).

8. The methanol catalytic synthesis system using carbon dioxide in the CDQ circulating gas according to claim 1, characterized in that: A condensate outlet is provided at the bottom of the CO2 separation device (10), and the condensate outlet is connected to the condensate reflux port of the desorption tower (8).

9. The methanol catalytic synthesis system using carbon dioxide in the CDQ circulating gas according to claim 1, characterized in that: The coke oven gas hydrogen production system comprises a gas pretreatment tower (15), a pressure swing adsorption tower (16), a deoxidation tower (17) and a dehumidification tower (18). The pretreated coke oven gas is delivered to the inlet of the gas pretreatment tower (15) through a coke oven gas delivery fan and a primary gas compressor. The outlet of the gas pretreatment tower (15) is connected to the inlet of the pressure swing adsorption tower (16) through a secondary gas compressor (142). The outlet of the pressure swing adsorption tower (16) is connected to the inlet of the deoxidation tower (17). The outlet of the deoxidation tower (17) is connected to the inlet of the dehumidification tower (18). The outlet of the dehumidification tower (18) is connected to the inlet of the catalytic reactor (20).

10. A methanol catalytic synthesis system using carbon dioxide in coke dry quenching cycle gas according to claim 9, characterized in that: The pressure swing adsorption tower (16) adopts a three-group tower structure.

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