Flue gas purification resource recycling system and method based on low-temperature flue gas adsorption regeneration

Abstract

The invention relates to the technical field of flue gas purification and discloses a flue gas purification resource recycling system and method based on low-temperature flue gas adsorption regeneration. The flue gas purification resource recycling system comprises a low-temperature flue gas adsorption regeneration system, an oxidation tower, a reactor and a purification system. The low-temperature flue gas adsorption and regeneration system comprises a cooling device, an adsorption device and a regeneration device which are arranged in sequence so as to generate regenerated gas containing nitrogen and sulfur; a water spraying device is arranged in the oxidation tower, so that nitrogen-containing and sulfur-containing regenerated gas discharged from the regeneration device is sprayed by the water spraying device after being oxidized by ozone in the oxidation tower to obtain acid liquor; the reactor is provided with an ammonia water inlet and is connected with the acid liquor outlet and the residual gas outlet of the oxidation tower so as to react to obtain an ammonium nitrate-sulfate solution. And the purification system is used for purifying the ammonium nitrate-sulfate solution discharged from the reactor to obtain an ammonium nitrate-sulfate finished product. The flue gas purification resource recycling system has the advantages that the process steps are simplified, and the production cost is low.

Description

Technical Field

[0001] The present invention relates to the field of flue gas purification technology, and in particular to a flue gas purification resource recycling system and a flue gas purification resource recycling method based on low-temperature flue gas adsorption regeneration. Background Art

[0002] Low-temperature pollutant integrated removal technology (COAP technology for short) is a comprehensive flue gas pollutant treatment technology. This technology is based on the principle of low-temperature adsorption of flue gas. After the flue gas to be purified is cooled to a low temperature in the sub-zero temperature range, it enters the low-temperature adsorption tower and is adsorbed and purified by adsorbent. NO in the flue gas x It can be deeply adsorbed and removed at low temperatures. The saturated adsorbent is regenerated to generate a large amount of nitrogen-sulfur regeneration gas. In the related art, in order to recycle and utilize resources, the nitrogen-sulfur regeneration gas is first separated from the sulfur-nitrogen gas, and then the sulfur-containing gas and the nitrogen-containing gas are separated and prepared into corresponding products through relevant processes. In the related art, it is necessary to separate the sulfur-nitrogen gas and prepare the corresponding products through multiple corresponding processes, which has the problems of high cost and complex process. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, the present invention proposes a flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration. The flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration has the advantages of simplified process steps and low production cost.

[0004] The present invention also proposes a flue gas purification resource recycling method based on low-temperature flue gas adsorption regeneration.

[0005] The flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration of the present invention comprises: a low-temperature flue gas adsorption regeneration system, an oxidation tower, a reactor and a purification system.

[0006] The low-temperature flue gas adsorption regeneration system comprises a cooling device, an adsorption device and a regeneration device, wherein the cooling device is used to cool the flue gas to low-temperature flue gas at a temperature below zero, the adsorption device is used to adsorb and purify the low-temperature flue gas into clean flue gas through an adsorbent, and the regeneration device is used to regenerate the adsorbent saturated with adsorption and generate nitrogen-sulfur regeneration gas; a water spray device is provided in the oxidation tower, the oxidation tower has a nitrogen-sulfur regeneration gas inlet, an ozone inlet for supplying ozone to the oxidation tower, an acid liquid outlet for discharging the acid liquid in the oxidation tower and a residual gas outlet for discharging the residual gas in the oxidation tower, and the nitrogen-sulfur regeneration gas inlet of the oxidation tower is connected to the nitrogen-sulfur regeneration gas inlet of the regeneration device. The regeneration gas outlet is connected, the nitrogen-sulfur regeneration gas discharged from the regeneration device is oxidized by ozone in the oxidation tower to become ozone oxidation regeneration gas, and the ozone oxidation regeneration gas is sprayed by the water spray device to obtain acid solution; the reactor has an ammonia water inlet for supplying ammonia water to the reactor, and the reactor is connected to the acid solution outlet and the residual gas outlet of the oxidation tower, the acid solution and the residual gas discharged from the oxidation tower enter the reactor and react with the ammonia water supplied to the reactor through the ammonia water inlet in the reactor to obtain nitric acid and sulfur ammonia solution; the purification system is connected to the reactor, and is used to purify the nitric acid and sulfur ammonia solution discharged from the reactor to obtain nitric acid and sulfur ammonia finished product.

[0007] Optionally, the oxidation tower also includes an acid liquid concentration pipeline, and the oxidation tower also has an acid liquid circulation inlet arranged at the upper part thereof, and the acid liquid outlet is arranged at the bottom of the oxidation tower, one end of the acid liquid concentration pipeline is connected to the acid liquid outlet, and the other end of the acid liquid concentration pipeline is connected to the acid liquid circulation inlet, and the acid liquid concentration pipeline is switchably connected to the reactor.

[0008] Optionally, the flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration also includes an ozone destructor, which is arranged between the residual gas outlet of the oxidation tower and the reactor to remove ozone in the residual gas discharged from the oxidation tower.

[0009] Optionally, the residual gas outlet is arranged at the top of the oxidation tower.

[0010] Optionally, the flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration further includes a gas distributor, which is arranged in the oxidation tower and is used to evenly disperse the regeneration gas in the oxidation tower.

[0011] Optionally, the flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration also includes an ammonium nitrate concentration pipeline, and the reactor also has an ammonium nitrate liquid outlet and an ammonium nitrate liquid circulation port, the ammonium nitrate concentration pipeline connects the ammonium nitrate liquid outlet and the ammonium nitrate liquid circulation port, and the ammonium nitrate liquid outlet can be switchably connected to the purification system and the ammonium nitrate liquid circulation port.

[0012] Optionally, the purification system includes a flash separator, a neutralization and washing tower, a stirring and mixing device, a flash tank and an evaporator, the gas phase outlet of the flash separator is connected to the gas phase inlet of the neutralization and washing tower through a pipeline, the liquid phase outlet of the flash separator is connected to the liquid phase inlet of the stirring and mixing device through a pipeline, the gas phase outlet of the neutralization and washing tower is connected to the gas phase inlet of the stirring and mixing device through a pipeline, the discharge port of the stirring and mixing device is connected to the feed port of the flash tank through a pipeline, the discharge port of the flash tank is connected to the feed port of the evaporator through a pipeline, the steam outlet of the neutralization and washing tower is connected to the steam inlet of the evaporator through a pipeline, and the discharge port of the evaporator is connected to a filter press device.

[0013] Optionally, the nitrogen-sulfur regeneration gas comprises the following components by volume: SO2 28-30%, NO x 4.8-5.2%, N242-44%, CO2 4-6%, H2O 19-21%;

[0014] Optionally, the ozone oxidation regeneration gas comprises the following components by volume: SO2: 30-32%, N2: 43-45%, CO2: 3-4%, H2O: 19-21%.

[0015] The flue gas purification resource recycling method based on low-temperature flue gas adsorption regeneration of the present invention comprises the following steps:

[0016] The flue gas is cooled to a low-temperature flue gas having a sub-zero temperature by a cooling device;

[0017] Passing low-temperature flue gas into an adsorption device to obtain clean flue gas and saturated adsorbent;

[0018] regenerating the adsorbent saturated with adsorption to obtain a regenerated adsorbent and a nitrogen-sulfur-containing regeneration gas;

[0019] The nitrogen-sulfur regeneration gas is ozonated in an oxidation tower and sprayed with water to obtain an acid solution;

[0020] Passing ammonia water, the acid solution in the oxidation tower and the residual gas into a reactor with ammonia water to react to obtain a nitric-sulfuric-ammonia solution;

[0021] The nitrate-ammonia-sulfuron solution is sequentially subjected to solid-liquid separation and drying to obtain a nitrate-ammonia-sulfuron product.

[0022] Optionally, the nitrogen-sulfur regeneration gas comprises the following components by volume: SO2 28-30%, NO x 4.8-5.2%, N242-44%, CO2 4-6%, H2O 19-21%.

[0023] Optionally, the ozone oxidation regeneration gas comprises the following components by volume: SO2: 30-32%, N2: 43-45%, CO2: 3-4%, H2O: 19-21%.

[0024] The beneficial effects of the present invention are:

[0025] (1) The flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration of the present invention can simultaneously pre-treat the nitrogen-containing gas and the sulfur-containing gas in the nitrogen-containing sulfur regeneration gas by passing the nitrogen-containing sulfur regeneration gas produced by the low-temperature flue gas adsorption regeneration system through an oxidation tower, a reactor and a purification system to obtain a nitric acid and sulfur ammonia product. x The generated NO2 can react with water to generate acid, and SO2 is also converted into SO3, which dissolves in water to generate acid. x The sulfur and nitrogen gases are separated from SO2 first and then treated separately, that is, there is no need to separate the sulfur and nitrogen gases. The acid solution is then reacted with the alkali solution (ammonia water) in the reactor so that it can react with the ammonia water and then pass through the purification system to generate nitrate-sulfur-ammonia products, which can be used to prepare nitrate-sulfur-ammonia fertilizers. This not only realizes the recycling of resources, but also simplifies the process steps and further reduces the cost of the entire process. In addition, the entire process converts the nitrogen-sulfur regeneration gas into non-polluting gas as much as possible, avoiding secondary pollution of the gas in the production of nitrate-sulfur-ammonia finished products.

[0026] Therefore, the flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration of the present invention has the advantages of simplified process steps and low production cost.

[0027] (2) By setting up an acid liquid concentration pipeline, the obtained acid liquid can be concentrated, and the obtained acid liquid can be circulated multiple times according to the output of nitrogen-sulfur regeneration gas to obtain a high-concentration acid liquid, which is beneficial to reduce the drying cost in the purification system. Therefore, it has the advantage of further reducing production costs.

[0028] (3) A gas distributor is provided in the oxidation tower to evenly disperse the regeneration gas in the oxidation tower. This helps to evenly classify the residual gas and ozone introduced into the oxidation tower, thereby improving the contact effectiveness between ozone and residual gas. This has the advantage of high treatment efficiency for nitrogen-sulfur regeneration gas.

[0029] (4) The ammonium nitrate concentration pipeline is provided to concentrate the obtained ammonium nitrate solution, and the obtained ammonium nitrate solution can be circulated multiple times according to the concentration of the ammonium nitrate solution to obtain a high-concentration ammonium nitrate solution, thereby reducing the drying cost in the purification system. Thus, the production cost is further reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of a flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration according to an embodiment of the present invention.

[0031] Figure 2 It is a flow chart of the process of a flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration according to an embodiment of the present invention.

[0032] Reference numerals:

[0033] Low-temperature flue gas adsorption regeneration system 1; cooling device 11; adsorption device 12; regeneration device 13;

[0034] Oxidation tower 2; ozone inlet 21; nitrogen-sulfur regeneration gas inlet 22; acid liquid outlet 23; residual gas outlet 24; acid liquid concentration pipeline 25; water spray device 26;

[0035] Reactor 3; ammonia water inlet 31; ammonium nitrate liquid outlet 32; ammonium nitrate liquid circulation port 33; ammonium nitrate concentration pipeline 34;

[0036] Purification system 4; flash separator 41; neutralization washing tower 42; stirring and mixing device 43; flash tank 44; evaporator 45;

[0037] Ozone destroyer5. DETAILED DESCRIPTION

[0038] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0039] Reference below Figure 1-Figure 2 The invention describes a flue gas purification resource recycling system and method based on low-temperature flue gas adsorption regeneration according to an embodiment of the invention.

[0040] The flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration according to the embodiment of the present invention comprises a low-temperature flue gas adsorption regeneration system 1 , an oxidation tower 2 , a reactor 3 and a purification system 4 .

[0041] The low-temperature flue gas adsorption regeneration system 1 includes a cooling device 11, an adsorption device 12 and a regeneration device 13. The cooling device 11 is used to cool the flue gas into low-temperature flue gas at a sub-zero temperature. The adsorption device 12 is used to purify the low-temperature flue gas into clean flue gas through low-temperature adsorption of an adsorbent. The regeneration device 13 is used to regenerate the adsorbent saturated with adsorption and generate nitrogen-sulfur regeneration gas.

[0042] A water spray device 26 is provided in the oxidation tower 2. The oxidation tower 2 has a nitrogen-sulfur regeneration gas inlet 22, an ozone inlet 21 for supplying ozone into the oxidation tower 2, an acid liquid outlet 23 for discharging the acid liquid in the oxidation tower 2, and a residual gas outlet 24 for discharging the residual gas in the oxidation tower 2. The nitrogen-sulfur regeneration gas inlet 22 of the oxidation tower 2 is connected to the nitrogen-sulfur regeneration gas outlet of the regeneration device 13. The nitrogen-sulfur regeneration gas discharged from the regeneration device 13 is oxidized by ozone in the oxidation tower 2 to become ozone oxidation regeneration gas. The ozone oxidation regeneration gas is sprayed by the water spray device 26 to obtain acid liquid.

[0043] The reactor 3 has an ammonia water inlet 31 for supplying ammonia water into the reactor 3. The reactor 3 is connected to the acid solution outlet 23 and the residual gas outlet 24 of the oxidation tower 2. The acid solution and the residual gas discharged from the oxidation tower 2 enter the reactor 3 and react with the ammonia water supplied into the reactor 3 through the ammonia water inlet 31 to obtain a nitric acid and sulfuric acid ammonia solution.

[0044] The purification system 4 is connected to the reactor 3 and is used for purifying the nitrate-ammonia-sulfuron solution discharged from the reactor 3 to obtain the nitrate-ammonia-sulfuron finished product.

[0045] The flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration in the embodiment of the present invention can simultaneously pre-treat the nitrogen-containing gas and the sulfur-containing gas in the nitrogen-containing sulfur regeneration gas by passing the nitrogen-containing sulfur regeneration gas produced by the low-temperature flue gas adsorption regeneration system 1 through the oxidation tower 2, the reactor 3 and the purification system 4 to obtain the nitric acid and sulfur ammonia finished product. x NO2 is generated, which dissolves in water to form acid. SO2 is also converted into SO3, which dissolves in water to form acid. x After the separation of sulfur and SO2, separate treatment is performed, that is, there is no need to separate sulfur and nitrogen gases. Then, the acid solution is reacted with alkali solution (ammonia water) in reactor 3, and the obtained acid solution reacts with ammonia water and then passes through purification system 4 to generate nitrate-sulfur-ammonia product, which can be used to prepare nitrate-sulfur-ammonia fertilizer, which not only realizes the recycling of resources, but also simplifies the process steps and further reduces the cost of the entire process. In addition, the whole process converts the nitrogen-sulfur regeneration gas into non-polluting gas as much as possible, avoiding secondary pollution of no gas in the production of nitrate-sulfur-ammonia finished products.

[0046] Therefore, the flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration according to the embodiment of the present invention has the advantages of simplified process steps and low production cost.

[0047] like Figure 1 The nitrogen-sulfur regeneration gas inlet 22 and the ozone inlet 21 are arranged at the bottom of the oxidation tower 2. The nitrogen-sulfur regeneration gas and ozone are introduced from the bottom of the oxidation tower 2, and water spray is sprayed from the top of the oxidation tower 2.

[0048] Furthermore, the oxidation tower 2 is made of glass fiber reinforced plastics, stainless steel or titanium steel.

[0049] Optionally, the water spray device 26 may be connected to process water so as to continuously and stably provide spray water.

[0050] like Figure 1 As shown, the oxidation tower 2 also includes an acid liquid concentration pipeline 25, and the oxidation tower 2 also has an acid liquid circulation inlet arranged at its upper part. The acid liquid outlet 23 is arranged at the bottom of the oxidation tower 2. One end of the acid liquid concentration pipeline 25 is connected to the acid liquid outlet 23, and the other end of the acid liquid concentration pipeline 25 is connected to the acid liquid circulation inlet. The acid liquid concentration pipeline 25 is switchably connected to the reactor 3.

[0051] The flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration in the embodiment of the present invention can concentrate the obtained acid solution by setting the acid solution concentration pipeline 25, and can circulate the obtained acid solution multiple times according to the output of nitrogen-sulfur regeneration gas to obtain high-concentration acid solution, thereby facilitating the reduction of the drying cost in the purification system 4. Thus, the production cost is further reduced.

[0052] like Figure 1 and Figure 2 As shown, the flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration also includes an ozone destroyer 5, which is arranged between the residual gas outlet 24 of the oxidation tower 2 and the reactor 3, and is used to remove ozone in the residual gas discharged from the oxidation tower 2.

[0053] The flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration of the embodiment of the present invention is provided with an ozone destroyer 5 between the residual gas outlet 24 of the oxidation tower 2 and the reactor 3. Furthermore, the emission of residual gas can be reduced (according to the reducibility of the gas in the nitrogen-sulfur regeneration gas, there is excess ozone and SO2 in the residual gas), and the excessive ozone can be further reduced or removed by introducing SO2, which can prevent ozone from entering the downstream reactor 3 and the purification system 4 and causing corrosion to the vessels therein. Therefore, the ozone destroyer 5 provided has the advantage of improving the service life of downstream equipment. In addition, it can also provide space for the reaction of SO2 and ozone in the residual gas, which is beneficial to improve the purity of ammonium nitrate and sulfate fertilizer.

[0054] Optionally, the residual gas outlet 24 is arranged at the top of the oxidation tower 2. Thus, it is convenient to discharge the residual gas therein.

[0055] The flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration also includes a gas distributor, which is arranged in the oxidation tower 2 and is used to evenly disperse the regeneration gas in the oxidation tower 2. This helps to evenly classify the residual gas and ozone introduced into the oxidation tower 2, thereby improving the contact effectiveness between ozone and residual gas. As a result, it has the advantage of high treatment efficiency for nitrogen-sulfur regeneration gas.

[0056] like Figure 1 and Figure 2 As shown, the flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration of an embodiment of the present invention also includes an ammonium nitrate concentration pipeline 34, and the reactor 3 also has an ammonium nitrate liquid outlet 32 ​​and an ammonium nitrate liquid circulation port 33. The ammonium nitrate concentration pipeline 34 connects the ammonium nitrate liquid outlet 32 ​​and the ammonium nitrate liquid circulation port 33, and the ammonium nitrate liquid outlet 32 ​​can be switchably connected to the purification system 4 and the ammonium nitrate liquid circulation port 33.

[0057] The flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration of the embodiment of the present invention can concentrate the obtained ammonium nitrate solution through the provided ammonium nitrate concentration pipeline 34, and can circulate the obtained ammonium nitrate solution multiple times according to the concentration of the ammonium nitrate solution to obtain an ammonium nitrate solution of suitable concentration, thereby facilitating the reduction of the drying cost in the purification system 4. Thus, the production cost is further reduced.

[0058] like Figure 1 and Figure 2 As shown, the purification system 4 includes a flash separator 41, a neutralization and washing tower 42, a stirring and mixing device 43, a flash tank 44 and an evaporator 45. The gas phase outlet of the flash separator 41 is connected to the gas phase inlet of the neutralization and washing tower 42 through a pipeline, the liquid phase outlet of the flash separator 41 is connected to the liquid phase inlet of the stirring and mixing device 43 through a pipeline, the gas phase outlet of the neutralization and washing tower 42 is connected to the gas phase inlet of the stirring and mixing device 43 through a pipeline, the discharge port of the stirring and mixing device 43 is connected to the feed port of the flash tank 44 through a pipeline, the discharge port of the flash tank 44 is connected to the feed port of the evaporator 45 through a pipeline, the steam outlet of the neutralization and washing tower 42 is connected to the steam inlet of the evaporator 45 through a pipeline, and the discharge port of the evaporator 45 is connected to a filter press device (not shown).

[0059] The flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration of the embodiment of the present invention is divided into a purification system 4 into a flash separator 41, a neutralization washing tower 42, a stirring and mixing device 43, a flash tank 44 and an evaporator 45.

[0060] Specifically, one end of the reflux pipe is connected to the pipeline between the gas phase outlet of the neutralization washing tower 42 and the gas phase inlet of the stirring and mixing device 43 through a three-way pipe fitting, and the other end of the reflux pipe is connected to the reflux inlet of the neutralization washing tower 42. The dilute ammonium nitrate solution discharged from the neutralization washing tower 42 is used as an absorption liquid and transported back to the neutralization washing tower 42 to repeatedly wash the ammonia-containing steam; and the liquid level at the bottom of the tower can also be maintained. The steam outlet of the neutralization washing tower 42 is connected to the steam inlet of the evaporator 45 through a pipeline. After the ammonia in the ammonia-containing steam is removed in the neutralization washing tower 42, process steam is obtained and passed into the evaporator 45 to be used as a heat source for evaporating the material.

[0061] Furthermore, the pipeline between the liquid phase outlet of the oxidation tower 2 and the liquid phase inlet of the reactor 3 is connected to a first pump body, the pipeline between the liquid phase outlet of the flash separator 41 and the liquid phase inlet of the stirring and mixing device 43 is connected to a second pump body, and the pipeline between the discharge port of the stirring and mixing device 43 and the feed port of the flash tank 44 is connected to a third pump body.

[0062] The nitrogen-sulfur regeneration gas includes the following components by volume: SO2 28-30%, NO x 4.8-5.2%, N2 42-44%, CO24-6%, H2O 19-21%. The flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration of the embodiment of the present invention is conducive to improving the adequacy of resource utilization by controlling the proportion of the components of the nitrogen-sulfur regeneration gas. The nitrate-sulfur-ammonia finished product produced by this gas ratio can be directly used as nitrate-sulfur-ammonia fertilizer without treatment, and no further treatment is required. Therefore, it has the advantage of improving the application benefits of the nitrate-sulfur-ammonia finished product.

[0063] The ozone oxidation regeneration gas includes the following components by volume: SO2: 30-32%, N2: 43-45%, CO2: 3-4%, H2O: 19-21%.

[0064] The flue gas purification resource recycling method based on low-temperature flue gas adsorption regeneration of the embodiment of the present invention is carried out by using the flue gas purification resource recycling system. The flue gas purification resource recycling method includes the following steps:

[0065] The flue gas is cooled to a low-temperature flue gas with a sub-zero temperature by a cooling device 11;

[0066] Passing low-temperature flue gas into the adsorption device 12 to obtain clean flue gas and saturated adsorbent;

[0067] regenerating the adsorbent saturated with adsorption to obtain a regenerated adsorbent and a nitrogen-sulfur-containing regeneration gas;

[0068] In the oxidation tower 2, the nitrogen-sulfur regeneration gas is ozonated and water sprayed to obtain acid solution;

[0069] The ammonia water, the acid solution in the oxidation tower 2 and the residual gas are introduced into the reactor 3 with the ammonia water to react, so as to obtain a nitric-sulfuric-ammonia solution;

[0070] The ammonium nitrate-sulfate solution is sequentially subjected to solid-liquid separation and drying to obtain the ammonium nitrate-sulfate product.

[0071] Therefore, the flue gas purification resource recycling method based on low-temperature flue gas adsorption regeneration according to the embodiment of the present invention has the advantages of simplified process steps and low production cost.

[0072] Specifically, the flue gas purification resource recycling method comprises the following steps:

[0073] S1, cooling the flue gas to low-temperature flue gas at a sub-zero temperature by means of a cooling device 11; passing the low-temperature flue gas into an adsorption device 12 to obtain clean flue gas and saturated adsorbent; regenerating the saturated adsorbent to obtain a regenerated adsorbent and nitrogen-sulfur-containing regeneration gas;

[0074] S2, the flue gas from the plant area is desulfurized and denitrified to generate regenerated gas, which is passed into the oxidation tower 2 for oxidation, and process water (circulating water in the plant area, for example, water obtained by solid-liquid separation) is sprayed from top to bottom, and the gas and liquid phases are in countercurrent mass transfer contact in the oxidation tower 2, and the process water reacts with the oxidized acid gas to generate acid solution;

[0075] S3, the acid solution in S2 is sent into the reactor 3, the gas discharged from the top of the oxidation tower 2 is treated by the ozone destroyer 5, and then sent into the reactor 3. Ammonia water is introduced into the reactor 3 to react with the acid solution in step S2 and the gas treated by the ozone destroyer 5, and the generated gas-liquid mixture is introduced into the flash separator 41;

[0076] S4, the ammonia-containing vapor after flash evaporation is passed into a neutralization washing tower 42 for washing, and a dilute ammonium nitrate solution is obtained after washing, which is passed into a stirring and mixing device 43; at the same time, the liquid after flash evaporation is passed into the stirring and mixing device 43 for reaction to generate a supersaturated solution of ammonium nitrate sulfate and a crystalline ammonium nitrate sulfate salt.

[0077] The liquid in the stirring and mixing device 43 is a mixed solution of ammonium nitrate and ammonium sulfate. The reaction equations involved are: 2NH3·H2O+H2SO4=(NH4)2SO4, NH3·H2O+HNO3=NH4NO3+H2O.

[0078] S5, the supersaturated solution of ammonium nitrate sulfate and the crystalline salt of ammonium nitrate sulfate are passed into the flash tank 44, the supersaturated solution of ammonium nitrate sulfate is converted into the crystalline salt of ammonium nitrate sulfate, and the water vapor is discharged at the same time, and then the crystalline salt of ammonium nitrate sulfate after the water vapor is discharged is passed into the evaporator 45 to remove moisture to obtain solid crystalline salt of ammonium nitrate sulfate, and finally transported to the filter press device for filter pressing to form an ammonium nitrate sulfate filter cake, and then dried to obtain the finished ammonium nitrate sulfate, i.e., ammonium nitrate sulfate fertilizer.

[0079] It should be noted that if Figure 2 As shown, the low-temperature flue gas adsorption regeneration system 1 (COAP system) in the embodiment of the present invention includes a cooling device 11, an adsorption device 12 and a regeneration device 13. The flue gas from the factory area passes through a spray cooling tower to form a cooled flue gas, which is passed into the adsorption regeneration system, the regenerated gas is discharged, and then passed into the oxidation tower 2.

[0080] Further, ozone is produced by an ozone generator.

[0081] Further, in step S2, the temperature in the reactor 3 is 160-180°C, the pressure is 2.5-3.5MPa, and the concentration of the added ammonia water is 22-27%. Optionally, the concentration of the ammonia water is 25%.

[0082] Furthermore, in step S3, the operating temperature of the flash separator 41 is 110-130°C.

[0083] Furthermore, in step S3, the reaction temperature in the stirring and mixing device 43 is 70-90°C, the reaction time is 30-100 min, the pressure is 1.5 MPa, and the stirring and mixing device 43 is equipped with a stirring paddle, and the stirring speed is 40-90 rpm.

[0084] Furthermore, in the reactor 3, the ratio of the amount of pure ammonia to the amount of pure nitric acid and pure sulfuric acid in the ammonia water is 3-4:2:1.

[0085] Furthermore, in the reactor 3, the residence time of the gas in the reactor 3, ie, the reaction time, is 5-20 min.

[0086] Furthermore, in step S3, the washing liquid of the neutralization washing tower 42 is nitric acid. The gas coming out of the flash separator 41 is ammonia-containing steam, which is introduced into the neutralization washing tower 42 to wash the ammonia in the steam. Ammonia water reacts with nitric acid to generate a low-concentration ammonium nitrate solution, which falls to the bottom of the neutralization washing tower 42. Since there is more nitric acid, the overall solution is acidic. Therefore, it helps to improve the purity of the nitric acid-ammonia product.

[0087] When the pH of the acid solution is 4-5, the acid solution can be introduced into the reactor 3.

[0088] Furthermore, the acid solution generated in step S1 is dilute nitric acid, nitrous acid, dilute sulfurous acid and dilute sulfuric acid.

[0089] Further, the gas pressure in the flash tank 44 is 0.1-0.3 MPa, and the temperature is 120-140° C. Optionally, the gas pressure in the flash tank 44 is 0.2 MPa, and the temperature is 130° C.

[0090] Optionally, the adsorption device 12 uses an adsorbent to perform low-temperature adsorption of flue gas. The adsorbent can be a granular or powdered adsorbent, or an adsorbent body made of powder or granular adsorbent, such as a sphere or cylinder formed by a powder or granular adsorbent through a binder. Of course, a protective shell can be further formed on the outside of the adsorbent body, such as a breathable film covering the outside of the adsorbent body to improve the strength of the adsorbent body. The adsorbent can be in the form of an adsorption unit, and the adsorption unit includes a breathable outer shell and an adsorbent filled inside the breathable outer shell. The diameter of the adsorbent particles is 1mm-10mm, and the diameter of the adsorbent is 10mm-100mm.

[0091] It should be noted that the basic principle of flue gas low-temperature adsorbent is to remove pollutant components from low-temperature flue gas through adsorption by adsorbent. In a low-temperature environment, usually below room temperature, preferably below zero degrees Celsius, and more preferably at a low temperature of -20°C to -5°C, nitrogen oxides in flue gas undergo low-temperature oxidation and adsorption on the surface of adsorbents such as activated carbon, oxidizing the difficult-to-adsorb nitric oxide gas into easily adsorbed nitrogen dioxide gas, which can achieve a hundreds-fold increase in adsorption capacity. In addition, the adsorption capacity of sulfur dioxide, carbon dioxide, and heavy metals is also multiplied in a low-temperature environment.

[0092] The inventor found through research that the lower the flue gas temperature, the more beneficial it is for adsorption purification. However, if the flue gas temperature is too low, the equipment structure will be complicated and the energy consumption will increase. For example, the cooling device, the adsorption device and the pipeline will be required to be provided with an insulation layer, and the sealing requirement will be high, which will increase the cost. In addition, the too low temperature condition will easily cause condensation water to appear in the adsorption device, causing the adsorbent to stick and clog, affecting the adsorption. Therefore, it is advantageous for the low-temperature flue gas temperature to be -20°C to -5°C. 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 the orientation or position relationship based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0093] 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 the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0094] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; 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, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0095] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0096] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0097] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration, characterized in that: include: A low-temperature flue gas adsorption regeneration system, the low-temperature flue gas adsorption regeneration system comprising a cooling device, an adsorption device and a regeneration device, the cooling device is used to cool the flue gas to low-temperature flue gas at a sub-zero temperature, the adsorption device is used to adsorb and purify the low-temperature flue gas into clean flue gas through an adsorbent, and the regeneration device is used to regenerate the adsorbent saturated with adsorption and generate nitrogen-sulfur regeneration gas; An oxidation tower, wherein a water spray device is provided in the oxidation tower, the oxidation tower has a nitrogen-sulfur regeneration gas inlet, an ozone inlet for supplying ozone into the oxidation tower, an acid liquid outlet for discharging acid liquid in the oxidation tower, and a residual gas outlet for discharging residual gas in the oxidation tower, the nitrogen-sulfur regeneration gas inlet of the oxidation tower is connected to the nitrogen-sulfur regeneration gas outlet of the regeneration device, the nitrogen-sulfur regeneration gas discharged from the regeneration device is oxidized by ozone in the oxidation tower to become ozone oxidized regeneration gas, and the ozone oxidized regeneration gas is sprayed by the water spray device to obtain acid liquid; A reactor, wherein the reactor has an ammonia inlet for supplying ammonia into the reactor, the reactor is connected to the acid outlet and the residual gas outlet of the oxidation tower, the acid and the residual gas discharged from the oxidation tower enter the reactor and react with the ammonia supplied into the reactor through the ammonia inlet in the reactor to obtain a nitric-sulfuric-ammonia solution; A purification system is connected to the reactor and is used for purifying the nitrate-ammonia-sulfuron solution discharged from the reactor to obtain a nitrate-ammonia-sulfuron finished product.

2. The flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration according to claim 1 is characterized in that: The oxidation tower also includes an acid liquid concentration pipeline, which also has an acid liquid circulation inlet arranged at its upper part, and the acid liquid outlet is arranged at the bottom of the oxidation tower. One end of the acid liquid concentration pipeline is connected to the acid liquid outlet, and the other end of the acid liquid concentration pipeline is connected to the acid liquid circulation inlet. The acid liquid concentration pipeline is switchably connected to the reactor.

3. The flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration according to claim 1 is characterized in that: It also includes an ozone destroyer, which is arranged between the residual gas outlet of the oxidation tower and the reactor and is used to remove ozone in the residual gas discharged from the oxidation tower.

4. The flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration according to claim 3 is characterized in that: The residual gas outlet is arranged at the top of the oxidation tower.

5. The flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration according to claim 1 is characterized in that: It also includes a gas distributor, which is arranged in the oxidation tower and is used to evenly disperse the regeneration gas in the oxidation tower.

6. The flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration according to claim 1 is characterized in that: It also includes an ammonium nitrate concentration pipeline, and the reactor also has an ammonium nitrate liquid outlet and an ammonium nitrate liquid circulation port. The ammonium nitrate concentration pipeline connects the ammonium nitrate liquid outlet and the ammonium nitrate liquid circulation port, and the ammonium nitrate liquid outlet can be switchably connected to the purification system and the ammonium nitrate liquid circulation port.

7. The flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration according to claim 1 is characterized in that: The purification system comprises a flash separator, a neutralization washing tower, a stirring and mixing device, a flash tank and an evaporator. The gas phase outlet of the flash separator is connected to the gas phase inlet of the neutralization washing tower through a pipeline, the liquid phase outlet of the flash separator is connected to the liquid phase inlet of the stirring and mixing device through a pipeline, the gas phase outlet of the neutralization washing tower is connected to the gas phase inlet of the stirring and mixing device through a pipeline, the discharge port of the stirring and mixing device is connected to the feed port of the flash tank through a pipeline, the discharge port of the flash tank is connected to the feed port of the evaporator through a pipeline, the steam outlet of the neutralization washing tower is connected to the steam inlet of the evaporator through a pipeline, and the discharge port of the evaporator is connected to a filter press device.

8. The flue gas purification resource recycling system based on low-temperature flue gas adsorption regeneration according to any one of claims 1 to 7, characterized in that: The nitrogen-sulfur regeneration gas includes the following components by volume: SO2 28-30%, NO x 4.8-5.2%, N2 42-44%, CO2 4-6%, H2O 19-21%; And / or, the ozone oxidation regeneration gas comprises the following components by volume: SO2: 30-32%, N2: 43-45%, CO2: 3-4%, H2O: 19-21%.

9. A flue gas purification resource recycling method based on low-temperature flue gas adsorption regeneration, characterized in that: The steps include: The flue gas is cooled to a low-temperature flue gas having a sub-zero temperature by a cooling device; Passing low-temperature flue gas into an adsorption device to obtain clean flue gas and saturated adsorbent; regenerating the adsorbent saturated with adsorption to obtain a regenerated adsorbent and a nitrogen-sulfur-containing regeneration gas; The nitrogen-sulfur regeneration gas is ozonated in an oxidation tower and sprayed with water to obtain an acid solution; Passing ammonia water, the acid solution in the oxidation tower and the residual gas into a reactor with ammonia water to react to obtain a nitric-sulfuric-ammonia solution; The nitrate-ammonia-sulfuron solution is sequentially subjected to solid-liquid separation and drying to obtain a nitrate-ammonia-sulfuron product.

10. The flue gas purification resource recycling method based on low-temperature flue gas adsorption regeneration according to claim 9 is characterized in that: The nitrogen-sulfur regeneration gas includes the following components by volume: SO2 28-30%, NO x 4.8-5.2%, N242-44%, CO2 4-6%, H2O 19-21%; And / or, the ozone oxidation regeneration gas comprises the following components by volume: SO2: 30-32%, N2: 43-45%, CO2: 3-4%, H2O: 19-21%.

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