Industrial flue gas desulfurization device and desulfurization method by water glass method

Abstract

The present invention discloses an industrial flue gas water glass method desulfurization apparatus and a desulfurization method, and relates to the technical field of flue gas desulfurization, the industrial flue gas water glass method desulfurization apparatus comprises: a desulfurization tower used for reacting sulfur dioxide in industrial flue gas with a 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 white carbon black, sodium sulfite and sodium sulfate slurry; the reaction tank is used for reacting the sodium sulfite and sodium sulfate slurry with the calcium hydrogen sulfite solution to generate gypsum, sodium sulfite and sodium hydrogen sulfite slurry; the gypsum separator is used for separating gypsum and sodium sulfite slurry; and the sodium sulfite separator is used for separating the sodium sulfite slurry to form sodium sulfite crystals. The sodium silicate solution reacts with sulfur dioxide in industrial flue gas, so that the sulfur dioxide is absorbed, a byproduct sodium sulfite crystal can be produced while the sulfur dioxide is efficiently treated, and compared with the prior art, the industrial flue gas desulfurization cost is greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of flue gas desulfurization, and particularly to an industrial flue gas desilicate method desulfurization device and a desulfurization method. Background Art

[0002] Coal-fired industrial flue gas usually contains a certain concentration of sulfur dioxide, and desulfurization treatment must be carried out before the flue gas is discharged to meet the environmental protection emission requirements. In the prior art, most industrial flue gas desulfurization adopts limestone-gypsum wet desulfurization. Limestone-gypsum uses limestone obtained from open-pit mines, which is ground and mixed with water for desulfurization, and the product is gypsum. However, the current industrial application of desulfurized gypsum has reached saturation, and the excess gypsum can only be used as landfill materials or backfilled into the excavated limestone pits, resulting in waste of resources and indirectly increasing the cost of industrial flue gas desulfurization treatment.

[0003] In view of this, how to provide a device that can reduce the cost of industrial flue gas desulfurization treatment is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0004] The purpose of the present invention is to provide an industrial flue gas desilicate method desulfurization device and a desulfurization method to solve the problems existing in the prior art.

[0005] To achieve the above purpose, the present invention provides an industrial flue gas desilicate method desulfurization device, including:

[0006] A desulfurization tower, which is connected to the industrial flue gas pipeline and is used to react sulfur dioxide in the industrial flue gas with a water glass solution to form silica white, desulfurized flue gas, sodium sulfite, and sodium sulfate slurry;

[0007] A silica white separator, which is connected to the desulfurization tower through a desulfurization liquid discharge pump and is used to separate the silica white, sodium sulfite, and sodium sulfate slurry;

[0008] A reaction tank, which is connected to the silica white separator and is used to react the sodium sulfite and sodium sulfate slurry with a calcium bisulfite solution to generate gypsum, sodium sulfite, and sodium bisulfite slurry;

[0009] A gypsum separator, which is connected to the reaction tank through a mother liquor slurry pump and is used to separate gypsum and sodium sulfite slurry;

[0010] A sodium sulfite separator, which is used to separate the sodium sulfite slurry to form sodium sulfite crystals.

[0011] Further, it further includes:

[0012] A water glass dissolving tank, which is used to dissolve water glass to form a water glass solution, and the water glass dissolving tank is connected to the bottom of the desulfurization tower through a dissolving pump.

[0013] Further, it further includes:

[0014] A desulfurization circulating pump, whose input end is communicated with the bottom of the desulfurization tower, and the output end is communicated with the top of the desulfurization tower. The desulfurization circulating pump is used for circulating and pumping the sodium silicate solution in the desulfurization tower.

[0015] Furthermore, it further includes:

[0016] A sodium sulfite solution evaporator, which is communicated with the gypsum separator and is used for evaporating the sodium sulfite slurry to form a concentrated sodium sulfite solution;

[0017] A sodium sulfite solution cooling tank, which is communicated with the sodium sulfite solution evaporator and is used for cooling the concentrated sodium sulfite solution;

[0018] A sodium sulfite separator, which is communicated with the cooling tank through a sodium sulfite slurry pump and is used for separating the cooled concentrated sodium sulfite solution into sodium sulfite crystals and sodium sulfite separation liquid. The sodium sulfite separation liquid is transported to the sodium sulfite solution evaporator.

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

[0020] The present invention also provides an industrial flue gas desulfurization method by sodium silicate, which uses the industrial flue gas desulfurization device by sodium silicate and includes the following steps:

[0021] S1: The industrial flue gas after being washed and dedusted enters the desulfurization tower through the industrial flue gas pipeline, and reacts with the sodium silicate solution transported by the desulfurization circulating pump in the desulfurization tower to form silica white, desulfurized flue gas, sodium sulfite and sodium sulfate slurry. The desulfurized flue gas is discharged from the desulfurization tower;

[0022] S2: The silica white, sodium sulfite and sodium sulfate slurry are transported to the silica white separator by the desulfurized liquid discharge pump. The silica white separator separates the silica white, sodium sulfite and sodium sulfate slurry, and the silica white is stored after being washed and dried;

[0023] S3: The sodium sulfite and sodium sulfate slurry are transported to the reaction tank and react with the calcium bisulfite solution to generate gypsum, sodium sulfite and sodium bisulfite slurry;

[0024] S4: The sodium sulfite and sodium bisulfite slurry are transported to the gypsum separator by the mother liquor slurry pump to separate the gypsum and sodium sulfite slurry, and the gypsum is stored;

[0025] S5: The sodium sulfite slurry is transported to the sodium sulfite solution evaporator to evaporate the sodium sulfite slurry to form a concentrated sodium sulfite solution and evaporation water. The evaporation water is used for washing silica white or dissolving sodium silicate;

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

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

[0028] Furthermore, the concentration of the sodium silicate solution is 15 - 25%, the pH value is 7 - 9, and the temperature is 40 - 60 °C.

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

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

[0031] Furthermore, after the silica white is washed and dried, its specific surface area reaches 200 m 2 / g or more, and the DBP oil absorption value reaches 2.50 ml / g or more.

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

[0033] The present invention utilizes the reaction of a sodium silicate solution with sulfur dioxide in industrial flue gas to achieve the absorption of sulfur dioxide. While efficiently treating sulfur dioxide, it can also by - produce sodium sulfite crystals. Compared with the prior art, the cost of industrial flue gas desulfurization is greatly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0035] Figure 1 It is a schematic structural diagram of the present invention;

[0036] Among them, 1. Industrial flue gas pipeline; 2. Desulfurization tower; 3. Desulfurization circulation pump; 4. Desulfurized liquid discharge pump; 5. Sodium silicate dissolution tank; 6. Dissolution pump; 7. Silica white 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; 15. Sodium sulfite separator. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

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

[0039] An industrial flue gas sodium silicate desulfurization device provided by an embodiment of the present invention includes:

[0040] A desulfurization tower 2, which is connected to an industrial flue gas pipeline 1 and is used to react sulfur dioxide in the industrial flue gas with a sodium silicate solution to form silica white, desulfurized flue gas, sodium sulfite, and sodium sulfate slurry; multiple layers of sieve plates with automatically adjustable opening sizes are arranged in the desulfurization tower 2.

[0041] A silica white separator 7, which is connected to the desulfurization tower 2 through a desulfurization liquid discharge pump 4 and is used to separate the silica white, sodium sulfite, and sodium sulfate slurry.

[0042] A reaction tank 8, which is connected to the silica white separator 7 and is used to react the sodium sulfite and sodium sulfate slurry with a calcium bisulfite solution to generate gypsum, sodium sulfite, and sodium bisulfite slurry.

[0043] A gypsum separator 10, which is connected to the reaction tank 8 through a mother liquor slurry pump 9 and is used to separate gypsum and sodium sulfite slurry.

[0044] A sodium sulfite separator 15, which is used to separate the sodium sulfite slurry to form sodium sulfite crystals.

[0045] In this embodiment, it further includes:

[0046] A sodium silicate dissolution tank 5, which is used to dissolve sodium silicate to form a sodium silicate solution, and the sodium silicate dissolution tank 5 is connected to the bottom of the desulfurization tower 2 through a dissolution pump 6.

[0047] In this embodiment, it further includes:

[0048] A desulfurization circulation pump 3, whose input end is connected to the bottom of the desulfurization tower 2 and whose output end is connected to the top of the desulfurization tower 2. The desulfurization circulation pump 3 is used to circulate and pump the sodium silicate solution in the desulfurization tower 2.

[0049] In this embodiment, it further includes:

[0050] A sodium sulfite solution evaporator 11, which is connected to the gypsum separator and is used to evaporate the sodium sulfite slurry to form a 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 through the sodium sulfite slurry pump 14 and 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 transported to the sodium sulfite solution evaporator 11.

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

[0054] The embodiment of the present invention also provides an industrial flue gas sodium silicate desulfurization method, which is applied to an industrial flue gas sodium silicate desulfurization device and includes the following steps:

[0055] S1: The industrial flue gas after being washed and dedusted enters the desulfurization tower 2 through the industrial flue gas pipeline 1 and reacts with the sodium silicate solution transported by the desulfurization circulating pump 3 in the desulfurization tower 2 to form a slurry of silica white, 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 silica white, sodium sulfite and sodium sulfate is transported to the silica white separator 7 through the desulfurization liquid discharge pump 4. The silica white separator 7 separates the slurry of silica white, sodium sulfite and sodium sulfate, and the silica white is stored after being washed and dried.

[0057] S3: The slurry of sodium sulfite and sodium sulfate is transported to the reaction tank 8, and the sodium sulfate in the slurry reacts with the calcium bisulfite solution to generate sodium bisulfite and gypsum, thereby forming a slurry of gypsum, sodium sulfite and sodium bisulfite.

[0058] S4: The slurry of sodium sulfite and sodium bisulfite is transported to the gypsum separator 10 through the mother liquor slurry pump 9 to separate the gypsum and sodium sulfite slurry, and the gypsum is stored.

[0059] S5: The sodium sulfite slurry is transported to the sodium sulfite solution evaporator 11 to evaporate the sodium sulfite slurry to form a concentrated sodium sulfite solution and evaporation water. The evaporation water is used to wash the silica white or dissolve the sodium silicate.

[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 through the sodium sulfite slurry pump 14 and 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 stored after being dried.

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

[0063] Further, in step S1, an organic dispersant is added into the desulfurization tower 2, and the dosage is 0.2 - 0.4 kg / m 3 .

[0064] Further, the temperature of the sodium sulfite solution cooling tank 12 is 10 - 30°C.

[0065] Further, after the white carbon black is washed and dried with water, the specific surface area reaches 200 m 2 / g or more, and the DBP oil absorption value reaches 2.50 ml / g or more.

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

[0067]

[0068] The reaction equations in the desulfurization tower 2 are as follows:

[0069] SO2 + H2O → H2SO3

[0070] Na2SiO3 + H2SO3 → Na2SO3 + H2SiO3

[0071] H2SiO3 → H2O + SiO2↓ (white carbon black)

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

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

[0074] The following uses the above embodiments to carry out desulfurization treatment on the flue gas of the coal-fired furnace after dust removal

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

[0076]

[0077] After detection, after using the above embodiments to remove dust from the flue gas of the coal-fired furnace, the sulfur dioxide content meets the emission requirements.

[0078] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention.

[0079] The embodiments described above are only for describing the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. An industrial flue gas water glass desulfurization device, characterized in that: include: A desulfurization tower (2) is connected to the industrial flue gas pipeline (1) and is used to react sulfur dioxide in the industrial flue gas with a water glass solution to form white carbon black, desulfurized flue gas, sodium sulfite and sodium sulfate slurry; A white carbon black separator (7), connected to the desulfurization tower (2) via a desulfurization liquid discharge pump (4), for separating white carbon black, sodium sulfite and sodium sulfate slurry; A reaction tank (8) is connected to the white carbon black separator (7) and is used to react the sodium sulfite and sodium sulfate slurry with the calcium bisulfite solution to generate gypsum, sodium sulfite and sodium bisulfite slurry; A gypsum separator (10) is connected to the reaction tank (8) via a mother liquor slurry pump (9) and is used to separate gypsum and sodium sulfite slurry; The sodium sulfite separator (15) is used to separate the sodium sulfite slurry into sodium sulfite crystals.

2. The industrial flue gas water glass desulfurization device according to claim 1 is characterized in that: Also includes: 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) via a dissolving pump (6).

3. The industrial flue gas water glass desulfurization device according to claim 2 is characterized in that: Also includes: A desulfurization circulation pump (3) has an input end connected to the bottom of the desulfurization tower (2) and an output end connected to the top of the desulfurization tower (2). The desulfurization circulation pump (3) is used to circulate and pump the water glass solution in the desulfurization tower (2).

4. The industrial flue gas water glass desulfurization device according to claim 3 is characterized in that: Also includes: a sodium sulfite solution evaporator (11), which is in communication with the gypsum separator and is used for evaporating the sodium sulfite slurry to form a concentrated sodium sulfite solution; a sodium sulfite solution cooling tank (12), which is in communication with the sodium sulfite solution evaporator (11) and is used to cool the concentrated sodium sulfite solution; The sodium sulfite separator (15) is connected to the cooling tank via a sodium sulfite slurry pump (14) and is used to separate the cooled concentrated sodium sulfite solution into sodium sulfite crystals and sodium sulfite separated liquid, and the sodium sulfite separated liquid is transported to the sodium sulfite solution evaporator (11).

5. The industrial flue gas water glass desulfurization device according to claim 4 is characterized in that: The sodium sulfite solution cooling tank (12) has a water cooling system (13).

6. A method for desulfurization of industrial flue gas by water glass method, characterized in that: The industrial flue gas water glass desulfurization device according to claim 5 comprises the following steps: S1: The industrial flue gas after water washing and dust removal enters the desulfurization tower (2) through the industrial flue gas pipeline (1), and reacts with the water glass solution transported by the desulfurization circulation pump (3) in the desulfurization tower (2) to form white carbon black, desulfurized flue gas, sodium sulfite and sodium sulfate slurry, and the desulfurized flue gas is discharged from the desulfurization tower (2); S2: The white carbon, sodium sulfite and sodium sulfate slurry are transported to the white carbon separator (7) through the desulfurization liquid discharge pump (4). The white carbon separator (7) separates the white carbon, sodium sulfite and sodium sulfate slurry. The white carbon is washed, dried and stored; S3: sodium sulfite and sodium sulfate slurry are transported to a reaction tank (8) to react with a calcium bisulfite solution to generate gypsum, sodium sulfite and sodium bisulfite slurry; S4: The sodium sulfite and sodium bisulfite slurries are transported to a gypsum separator (10) via a mother liquor slurry pump (9) to separate the gypsum from the sodium sulfite slurry and store the gypsum; S5: The sodium sulfite slurry is transported to a sodium sulfite solution evaporator (11), where the sodium sulfite slurry is evaporated to form a concentrated sodium sulfite solution and evaporated water, and the evaporated water is used to wash white carbon black or dissolve water glass; S6: The concentrated sodium sulfite solution enters the sodium sulfite solution cooling tank (12) and is cooled by the water cooling system (13); S7: The cooled concentrated sodium sulfite is transported to a sodium sulfite separator (15) by a sodium sulfite slurry pump (14) to be separated into sodium sulfite crystals and a sodium sulfite separated liquid. The sodium sulfite separated liquid is transported to a sodium sulfite solution cooling tank (12), and the sodium sulfite crystals are dried and stored.

7. The method for desulfurization of industrial flue gas by water glass method according to claim 6, characterized in that: The concentration of the water glass solution is 15-25%, the pH value is 7-9, and the temperature is 40-60°C.

8. The method for desulfurization of industrial flue gas by water glass method according to claim 6, characterized in that: In step S1, an organic dispersant is added into the desulfurization tower (2) in an amount of 0.2-0.4 kg / m 3 .

9. The method for desulfurization of industrial flue gas by water glass method according to claim 6, characterized in that: The temperature of the sodium sulfite solution cooling tank (12) is 10-30°C.

10. The method for desulfurization of industrial flue gas by water glass method according to claim 6, characterized in that: After washing and drying, the white carbon black has a specific surface area of ​​200 m 2 / g or more, and the DBP oil absorption value is above 2.50ml / g.

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