Industrial flue gas desulfurization device and method using water glass

Abstract

The application discloses an industrial flue gas water glass desulfurization device and method, and relates to the technical field of flue gas desulfurization. The device comprises a desulfurization tower, a white carbon black separator, a reaction tank, a gypsum separator and a sodium sulfite separator. The desulfurization tower is used for reacting sulfur dioxide in industrial flue gas with water glass solution to form white carbon black, desulfurized flue gas, sodium sulfite and sodium sulfate slurry. The white carbon black separator is used for separating the white carbon black, sodium sulfite and sodium sulfate slurry. The reaction tank is used for reacting the sodium sulfite and sodium sulfate slurry with calcium bisulfite solution to generate gypsum, sodium sulfite and sodium bisulfite slurry. The gypsum separator is used for separating the gypsum and sodium sulfite slurry. The sodium sulfite separator is used for separating the sodium sulfite slurry to form sodium sulfite crystals. The water glass solution is used for reacting with sulfur dioxide in industrial flue gas to realize absorption of sulfur dioxide. The method can efficiently treat sulfur dioxide and by-product sodium sulfite crystals. Compared with the prior art, the industrial flue gas desulfurization cost is greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of flue gas desulfurization technology, and in particular to an industrial flue gas water glass desulfurization device and desulfurization method. Background Technology

[0002] Flue gas from coal-fired industries typically contains a certain concentration of sulfur dioxide, which must be desulfurized before emission to meet environmental emission standards. Currently, most industrial flue gas desulfurization technologies employ limestone-gypsum wet desulfurization. Limestone-gypsum is obtained from quarrying limestone, which is ground, diluted with water, and then used for desulfurization, producing gypsum. However, the industrial application of desulfurization gypsum is already saturated; excess gypsum is used as landfill material or to backfill excavated limestone pits, resulting in resource waste and indirectly increasing the cost of industrial flue gas desulfurization.

[0003] Therefore, how to provide a device that can reduce the cost of industrial flue gas desulfurization is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to provide an industrial flue gas desulfurization device and method using water glass to solve the problems existing in the prior art.

[0005] To achieve the above objectives, the present invention provides an industrial flue gas desulfurization device using water glass, comprising:

[0006] The desulfurization tower is connected to the industrial flue gas pipeline and is used to react sulfur dioxide in the industrial flue gas with water glass solution to form precipitated carbon black, desulfurized flue gas, sodium sulfite and sodium sulfate slurry.

[0007] The silica separator is connected to the desulfurization tower via a desulfurization liquid discharge pump and is used to separate silica, sodium sulfite and sodium sulfate slurry.

[0008] The reaction tank, connected to the silica separator, is used to react sodium sulfite and sodium sulfate slurry with calcium bisulfite solution to generate gypsum, sodium sulfite and sodium bisulfite slurry.

[0009] The gypsum separator is connected to the reaction tank via a mother liquor slurry pump and is used to separate gypsum and sodium sulfite slurry.

[0010] A sodium sulfite separator is used to separate sodium sulfite slurry into sodium sulfite crystals.

[0011] Furthermore, it also includes:

[0012] A water glass dissolving tank is used to dissolve water glass to form a water glass solution. The water glass dissolving tank is connected to the bottom of the desulfurization tower via a dissolving pump.

[0013] Furthermore, it also includes:

[0014] The desulfurization circulation pump has its input end connected to the bottom of the desulfurization tower and its output end connected to the top of the desulfurization tower. The desulfurization circulation pump is used to circulate and pump water glass solution within the desulfurization tower.

[0015] Furthermore, it also includes:

[0016] A sodium sulfite solution evaporator, connected to the gypsum separator, is used to evaporate sodium sulfite slurry to form a concentrated sodium sulfite solution;

[0017] A sodium sulfite solution cooling tank, connected to the sodium sulfite solution evaporator, is used to cool concentrated sodium sulfite solution;

[0018] The sodium sulfite separator is connected to the cooling tank via a sodium sulfite slurry pump. It is used to separate the cooled concentrated sodium sulfite solution into sodium sulfite crystals and sodium sulfite separation liquid. The sodium sulfite separation liquid is then transported to the sodium sulfite solution evaporator.

[0019] Furthermore, the sodium sulfite solution cooling tank has a water cooling system.

[0020] This invention also provides a method for desulfurizing industrial flue gas using water glass, which, when using the aforementioned industrial flue gas water glass desulfurization device, includes the following steps:

[0021] S1: The industrial flue gas after water washing and dust removal enters the desulfurization tower through the industrial flue gas pipeline. It reacts with the water glass solution transported by the desulfurization circulation pump in the desulfurization tower to form white carbon black, desulfurized flue gas, sodium sulfite and sodium sulfate slurry. The desulfurized flue gas is discharged from the desulfurization tower.

[0022] S2: The slurry of white carbon, sodium sulfite and sodium sulfate is transported to the white carbon black separator through the desulfurization liquid discharge pump. The white carbon black separator separates the white carbon black, sodium sulfite and sodium sulfate slurry. The white carbon black is then washed and dried before storage.

[0023] S3: Sodium sulfite and sodium sulfate slurry are transported to the reaction tank and reacted with calcium bisulfite solution to produce gypsum, sodium sulfite and sodium bisulfite slurry;

[0024] S4: Sodium sulfite and sodium bisulfite slurry are pumped to the gypsum separator via the mother liquor slurry pump to separate the gypsum and sodium sulfite slurry, and the gypsum is stored.

[0025] S5: Sodium sulfite slurry is transported to sodium sulfite solution evaporator to evaporate the sodium sulfite slurry into concentrated sodium sulfite solution and evaporated water. The evaporated water is used for washing silica or dissolving water glass.

[0026] S6: Concentrated sodium sulfite solution enters the sodium sulfite solution cooling tank and is cooled by a water cooling system;

[0027] S7: The cooled concentrated sodium sulfite is pumped to the sodium sulfite separator by the sodium sulfite slurry pump, where it is separated into sodium sulfite crystals and sodium sulfite separation liquid. The sodium sulfite separation liquid is then pumped to the sodium sulfite solution cooling tank, and the sodium sulfite crystals are dried and stored.

[0028] Furthermore, the concentration of the water glass solution is 15-25%, the pH value is 7-9, and the temperature is 40-60℃.

[0029] Furthermore, in step S1, an organic dispersant is added to the desulfurization tower at a dosage of 0.2-0.4 kg / m³. 3 .

[0030] Furthermore, the temperature of the sodium sulfite solution cooling tank is 10-30℃.

[0031] Furthermore, after being washed and dried, the silica has a specific surface area of ​​200 m². 2 / g or higher, and DBP oil absorption value reaches 2.50ml / g or higher.

[0032] The present invention discloses the following technical effects:

[0033] This invention utilizes a water glass solution to react with sulfur dioxide in industrial flue gas to achieve the absorption of sulfur dioxide. While efficiently treating sulfur dioxide, it can also produce sodium sulfite crystals as a byproduct. Compared with existing technologies, the cost of industrial flue gas desulfurization is greatly reduced. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the structure of the present invention;

[0036] The components include: 1. Industrial flue gas duct; 2. Desulfurization tower; 3. Desulfurization circulating pump; 4. Desulfurization liquid discharge pump; 5. Water glass dissolving tank; 6. Dissolving pump; 7. Silica separator; 8. Reaction tank; 9. Mother liquor slurry pump; 10. Gypsum separator; 11. Sodium sulfite solution evaporator; 12. Sodium sulfite solution cooling tank; 13. Water cooling system; 14. Sodium sulfite slurry pump; and 15. Sodium sulfite separator. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] This invention provides an industrial flue gas desulfurization device using water glass, comprising:

[0040] Desulfurization tower 2 is connected to industrial flue gas pipeline 1 and is used to react sulfur dioxide in industrial flue gas with water glass solution to form precipitated silica, desulfurized flue gas, sodium sulfite and sodium sulfate slurry; desulfurization tower 2 is equipped with multiple layers of sieve plates with automatically adjustable opening size;

[0041] The silica separator 7 is connected to the desulfurization tower 2 via the desulfurization liquid discharge pump 4, and is used to separate silica, sodium sulfite and sodium sulfate slurry.

[0042] The reaction tank 8 is connected to the silica separator 7 and is used to react sodium sulfite and sodium sulfate slurry with calcium bisulfite solution to produce gypsum, sodium sulfite and sodium bisulfite slurry.

[0043] The gypsum separator 10 is connected to the reaction tank 8 via the mother liquor slurry pump 9 and is used to separate gypsum and sodium sulfite slurry.

[0044] Sodium sulfite separator 15 is used to separate sodium sulfite slurry to form sodium sulfite crystals.

[0045] In this embodiment, it also includes:

[0046] The water glass dissolving tank 5 is used to dissolve water glass to form a water glass solution. The water glass dissolving tank 5 is connected to the bottom of the desulfurization tower 2 through the dissolving pump 6.

[0047] In this embodiment, it also includes:

[0048] The desulfurization circulation pump 3 has its input end connected to the bottom of the desulfurization tower 2 and its output end connected to the top of the desulfurization tower 2. The desulfurization circulation pump 3 is used to circulate and pump water glass solution within the desulfurization tower 2.

[0049] In this embodiment, it also includes:

[0050] Sodium sulfite solution evaporator 11 is connected to gypsum separator and is used to evaporate sodium sulfite slurry to form concentrated sodium sulfite solution;

[0051] The sodium sulfite solution cooling tank 12 is connected to the sodium sulfite solution evaporator 11 and is used to cool the concentrated sodium sulfite solution.

[0052] The sodium sulfite separator 15 is connected to the cooling tank via the sodium sulfite slurry pump 14. It is used to separate the cooled concentrated sodium sulfite solution into sodium sulfite crystals and sodium sulfite separation liquid. The sodium sulfite separation liquid is then transported to the sodium sulfite solution evaporator 11.

[0053] In this embodiment, the sodium sulfite solution cooling tank 12 has a water cooling system 13.

[0054] This invention also provides a method for desulfurizing industrial flue gas using water glass, employing an industrial flue gas water glass desulfurization device, and including the following steps:

[0055] S1: The industrial flue gas after water washing and dust removal enters the desulfurization tower 2 through the industrial flue gas pipeline 1. It reacts with the water glass solution transported by the desulfurization circulation pump 3 in the desulfurization tower 2 to form a slurry of white carbon black, desulfurized flue gas, sodium sulfite and sodium sulfate (a small amount of sodium sulfite is oxidized by oxygen in the flue gas to form sodium sulfate). The desulfurized flue gas is discharged from the desulfurization tower 2.

[0056] S2: The slurry of white carbon, sodium sulfite and sodium sulfate is transported to the white carbon black separator 7 through the desulfurization liquid discharge pump 4. The white carbon black separator 7 separates the white carbon black, sodium sulfite and sodium sulfate slurry. The white carbon black is then washed and dried before being stored.

[0057] S3: Sodium sulfite and sodium sulfate slurry are transported to reaction tank 8. Sodium sulfate in the slurry reacts with calcium bisulfite solution to generate sodium bisulfite and gypsum, thus forming gypsum, sodium sulfite and sodium bisulfite slurry.

[0058] S4: Sodium sulfite and sodium bisulfite slurry are transported to gypsum separator 10 via mother liquor slurry pump 9 to separate gypsum and sodium sulfite slurry, and gypsum is stored.

[0059] S5: Sodium sulfite slurry is conveyed to sodium sulfite solution evaporator 11, where the sodium sulfite slurry is evaporated to form concentrated sodium sulfite solution and evaporated water. The evaporated water is used to wash silica or dissolve water glass.

[0060] S6: The concentrated sodium sulfite solution enters the sodium sulfite solution cooling tank 12 and is cooled by the water cooling system 13;

[0061] S7: The cooled concentrated sodium sulfite is transported to the sodium sulfite separator 15 by the sodium sulfite slurry pump 14, where it is separated into sodium sulfite crystals and sodium sulfite separation liquid. The sodium sulfite separation liquid is transported to the sodium sulfite solution cooling tank 12, and the sodium sulfite crystals are dried and stored.

[0062] Furthermore, the concentration of the water glass solution is 15-25%, the pH value is 7-9, and the temperature is 40-60℃.

[0063] Furthermore, in step S1, an organic dispersant is added to the desulfurization tower 2 at a dosage of 0.2-0.4 kg / m³. 3 .

[0064] Furthermore, the temperature of the sodium sulfite solution cooling tank 12 is 10-30℃.

[0065] Furthermore, after being washed and dried, the specific surface area of ​​silica reaches 200 m². 2 / g or higher, and DBP oil absorption value reaches 2.50ml / g or higher.

[0066] The solubility of sodium sulfite and sodium bisulfite in water is as follows:

[0067]

[0068] The reaction equation inside desulfurization tower 2 is as follows:

[0069] SO2 + H2O → H2SO3

[0070] Na₂SiO₃ + H₂SO₃ → Na₂SO₃ + H₂SiO₃

[0071] H₂SiO₃→H₂O+SiO₂↓(Silica)

[0072] The reaction equation in reaction tank 8 is as follows: Na2SO3 (small amount) + O2 (oxygen dissolved in water in flue gas) → Na2SO4 (small amount):

[0073] Na₂SO₄ + Ca(HSO₃)₂ + 2H₂O → NaHSO₃ + CaSO₄·2H₂O↓ (gypsum)

[0074] The following application of the above embodiments is used for desulfurization treatment of flue gas from coal-fired boilers after dust removal.

[0075] The flue gas parameters of the coal-fired boiler are as follows:

[0076]

[0077] Testing showed that after dust removal from the flue gas of the coal-fired boiler using the above-described embodiments, the sulfur dioxide content met the emission requirements.

[0078] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0079] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for desulfurization of industrial flue gases by means of water glass, characterized in that, Industrial flue gas water glass method desulfurization device, industrial flue gas water glass method desulfurization device, comprising: Desulfurization tower (2), communicate with industrial flue gas pipeline (1), for the industrial flue gas in the sulfur dioxide and water glass solution reaction forms white carbon black, desulfurization flue gas, sodium sulfite and sodium sulfate slurry; White carbon black separator (7), through the desulfurization liquid discharge pump (4) and the desulfurization tower (2) are communicated, for the white carbon black, sodium sulfite and sodium sulfate slurry separation; Reaction tank (8), with the white carbon black separator (7) are communicated, for sodium sulfite and sodium sulfate slurry and calcium bisulfite solution reaction, generate gypsum, sodium sulfite and sodium bisulfite slurry; Gypsum separator (10), through the mother liquor slurry pump (9) and the reaction tank (8) are communicated, for the gypsum and sodium sulfite slurry separation; Sodium sulfite separator (15), for the sodium sulfite slurry separation forms sodium sulfite crystallization; Water glass dissolving tank (5), for dissolving water glass forms water glass solution, the water glass dissolving tank (5) through dissolving pump (6) and the bottom of the desulfurization tower (2) are communicated; Desulfurization circulating pump (3), its input end and the bottom of the desulfurization tower (2) are communicated, the output end and the top of the desulfurization tower (2) are communicated, the desulfurization circulating pump (3) is used for circulating pumping water glass solution in the desulfurization tower (2); Sodium sulfite solution evaporator (11), with the gypsum separator (10) are communicated, for the sodium sulfite slurry evaporation forms concentrated sodium sulfite solution; Sodium sulfite solution cooling tank (12), with the sodium sulfite solution evaporator (11) are communicated, for cooling concentrated sodium sulfite solution;The sodium sulfite solution cooling tank (12) has water cooling system (13); Sodium sulfite separator (15), through sodium sulfite slurry pump (14) and the cooling tank are communicated, for the cooled concentrated sodium sulfite solution separation is sodium sulfite crystallization and sodium sulfite separation liquid, the sodium sulfite separation liquid is transported to the sodium sulfite solution evaporator (11); Including the following steps: S1: after the water washing dust removal industrial flue gas through industrial flue gas pipeline (1) enters the desulfurization tower (2), with the desulfurization circulating pump (3) water glass solution in the desulfurization tower (2) reaction forms white carbon black, desulfurization flue gas, sodium sulfite and sodium sulfate slurry, desulfurization flue gas from the desulfurization tower (2) is discharged; S2: white black carbon, sodium sulfite and sodium sulfate slurry through the desulfurization liquid discharge pump (4) is transported to white carbon black separator (7), white carbon black separator (7) will white carbon black, sodium sulfite and sodium sulfate slurry separation, white carbon black is stored after water washing and drying; S3: sodium sulfite and sodium sulfate slurry is transported to reaction tank (8), and calcium bisulfite solution reaction, generate gypsum, sodium sulfite and sodium bisulfite slurry; S4: sodium sulfite and sodium bisulfite slurry through mother liquor slurry pump (9) is transported to gypsum separator (10), the gypsum and sodium sulfite slurry separation, gypsum storage; S5: sodium sulfite slurry is transported to sodium sulfite solution evaporator (11), and sodium sulfite slurry evaporation forms concentrated sodium sulfite solution and evaporation water, and the evaporation water is used for water washing white carbon black or dissolving water glass; S6: The concentrated sodium sulfite solution enters a sodium sulfite solution cooling tank (12) and is cooled by a water cooling system (13); S7: The cooled concentrated sodium sulfite solution is transported by a sodium sulfite slurry pump (14) to a sodium sulfite separator (15) to separate into sodium sulfite crystals and sodium sulfite separation liquid, the sodium sulfite separation liquid is transported to the sodium sulfite solution cooling tank (12), and the sodium sulfite crystals are dried and stored; The concentration of the water glass solution is 15-25%, the PH value is 7-9, and the temperature is 40-60℃; In step S1, an organic dispersant is added to the desulfurization tower (2) in an amount of 0.2-0.4 kg / m 3 ; The temperature of the sodium sulfite solution cooling tank (12) is 10-30℃; The white carbon black has a specific surface area of 200 m 2 / g or more and a DBP oil absorption value of 2.50 ml / g or more.

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