Ammonium sulfate purification device and ammonium sulfate production system

Abstract

The utility model relates to an ammonium sulfate purification device and an ammonium sulfate production system. The ammonium sulfate purification device comprises an adsorption unit and a nanofiltration unit, the adsorption unit is used for carrying out adsorption treatment on a raw material solution containing ammonium sulfate to obtain an adsorption treatment solution; the nanofiltration unit is used for carrying out nanofiltration treatment on the adsorption treatment liquid to obtain a purified ammonium sulfate solution and a solution containing chloride ions and ammonium ions. According to the ammonium sulfate purification device disclosed by the embodiment of the utility model, the quality of an ammonium sulfate product produced by a boiler can be improved by carrying out purification treatment on the ammonium sulfate-containing raw material liquid discharged from the desulfurization tower.

Description

TECHNICAL FIELD

[0001] The utility model relates to the purification of ammonium sulfate, especially to a device for purifying the washing waste liquid containing ammonium sulfate discharged from a flue gas desulfurization tower. BACKGROUND

[0002] Ammonium sulfate is an inorganic substance with the chemical formula (NH4)2SO4, which is colorless crystal or white granule. High-purity ammonium sulfate can be used as a raw material for the production of a biological fermentation system to provide a nitrogen source required in the bacterial metabolic process.

[0003] The flue gas generated by boiler combustion contains sulfur dioxide, soluble inorganic salts (containing chlorine ions, etc.), and other components, which need to be purified to meet the emission standards before being discharged. Currently, the flue gas generated by boiler combustion can be purified by the following process: the flue gas is introduced into an electric bag composite dust collector, and after being treated by electric dust collection and bag filtration, the flue gas is then introduced into a desulfurization tower, and sequentially passes through the enrichment system, desulfurization system, and washing system of the desulfurization tower, and then is discharged into a chimney. If ammonia water solution is used as the washing liquid for the washing system, the ammonia water can react with sulfur dioxide in the flue gas to produce a washing waste liquid containing ammonium sulfate. The washing waste liquid is transported and discharged by a thickening circulating pump to obtain ammonium sulfate stock solution. By recycling the ammonium sulfate in the washing waste liquid, ammonium sulfate products can be obtained, thereby converting sulfur dioxide, which affects air quality, into economically valuable ammonium sulfate, thereby simultaneously achieving flue gas purification and ammonium sulfate production.

[0004] However, during the purification process in the desulfurization tower, various impurities (such as soluble inorganic salts containing chlorine ions) enter the washing waste liquid through the desulfurization system, so the washing waste liquid often has a dark color. If the impurities cannot be effectively removed during the extraction of ammonium sulfate, only a high-residue impurity ammonium sulfate product can be obtained, which reduces the economic value of the ammonium sulfate product. In addition, since the fermentation equipment and the subsequent process equipment and pipeline materials for extracting fermentation products are mainly made of 304 stainless steel, which can tolerate chlorine ion corrosion at a concentration of <150 ppm, if the ammonium sulfate product prepared by the flue gas generated by boiler combustion contains a high concentration of chlorine ions, it will have strong penetrating corrosion to the stainless steel. Moreover, ammonium sulfate with a high content of impurities cannot be used as a nitrogen source for the fermentation system. SUMMARY

[0005] To overcome at least one of the above-mentioned deficiencies of the prior art, in a first aspect, an embodiment of the present utility model provides a purification device for ammonium sulfate, comprising an adsorption unit and a nanofiltration unit; the adsorption unit is used for adsorbing a raw liquid containing ammonium sulfate to obtain an adsorption-treated liquid; the nanofiltration unit is used for nanofiltration treatment of the adsorption-treated liquid to obtain a purified ammonium sulfate solution and a solution containing chlorine ions and ammonium ions.

[0006] According to an embodiment of the present application, the ammonium sulfate purification device further comprises a storage unit for storing the purified ammonium sulfate solution.

[0007] According to an embodiment of the present application, the adsorption unit comprises an adsorbent and a stirring device.

[0008] According to an embodiment of the present application, the adsorption unit comprises an adsorption tank, and the adsorbent and the stirring device are arranged in the adsorption tank; and / or, the adsorbent is silicon carbide.

[0009] According to an embodiment of the present application, the nanofiltration unit comprises one or more than two layers of nanofiltration membranes; and / or, the storage unit comprises a storage tank.

[0010] According to an embodiment of the present application, the ammonium sulfate purification device further comprises a crystallization unit for performing crystallization treatment on the purified ammonium sulfate solution to separate ammonium sulfate solids.

[0011] According to an embodiment of the present application, the ammonium sulfate purification device further comprises a reverse osmosis unit for treating the solution containing chloride ions and ammonium ions through a reverse osmosis membrane to obtain clean water and concentrated solution containing ammonium chloride.

[0012] According to an embodiment of the present application, the ammonium sulfate purification device further comprises an alkalization unit for performing alkalization treatment on the concentrated solution containing ammonium chloride by an alkali solution to obtain ammonia gas.

[0013] According to an embodiment of the present application, the alkalization unit comprises an alkalization tank and an alkali solution storage tank, the alkalization tank is used for performing the alkalization treatment, and the alkali solution storage tank is used for providing the alkalization tank with alkali solution.

[0014] In the second aspect, an embodiment of the present application provides an ammonium sulfate production system, comprising a raw liquid providing device and the ammonium sulfate purification device, and the raw liquid providing device is used for providing the ammonium sulfate purification device with raw liquid containing ammonium sulfate.

[0015] According to an embodiment of the present application, the raw liquid providing device comprises a desulfurization tower.

[0016] The ammonium sulfate purification device of an embodiment of the present application can improve the quality of the self-produced ammonium sulfate product of the boiler by performing purification treatment on the raw liquid containing ammonium sulfate discharged from the desulfurization tower. BRIEF DESCRIPTION OF DRAWINGS

[0017] The drawings are only used for the purpose of illustrating specific embodiments and are not considered as limiting the present application.

[0018] in:

[0019] Figure 1 This is a schematic diagram of the ammonium sulfate purification device according to one embodiment of the present invention.

[0020] The annotations in the attached figures are explained as follows:

[0021] 10. Adsorption unit; 20. Nanofiltration unit; 30. Storage unit; 31. Fermentation tank; 40. Crystallization unit; 50. Reverse osmosis unit; 51. Water purification tank; 61. Alkaliization tank; 62. Alkali storage tank; 100. Desulfurization tower. Detailed Implementation

[0022] Typical embodiments embodying the features and advantages of this utility model will be described in detail in the following description. It should be understood that this utility model can have various variations in different embodiments, all of which do not depart from the scope of this utility model, and the description herein is for illustrative purposes only and not intended to limit this utility model.

[0023] Reference Figure 1 As shown, one embodiment of this utility model provides an ammonium sulfate purification device, including an adsorption unit 10 and a nanofiltration unit 20; the adsorption unit 10 is used to adsorb the raw material liquid containing ammonium sulfate to obtain an adsorption treatment liquid; the nanofiltration unit 20 is used to perform nanofiltration treatment on the adsorption treatment liquid to obtain a purified ammonium sulfate solution (purified liquid) and a solution containing chloride ions and ammonium ions (impurity liquid).

[0024] In one embodiment, the ammonium sulfate-containing feed liquid can be the washing waste liquid containing ammonium sulfate discharged from the desulfurization tower 100 after the boiler flue gas has been treated by the desulfurization tower 100.

[0025] In one embodiment, the adsorption unit 10 includes an adsorbent and a stirring device. The adsorption treatment with the adsorbent removes suspended solids and dust particles from the ammonium sulfate-containing raw material liquid, resulting in an adsorption-treated liquid containing ammonium sulfate. Furthermore, the adsorption treatment can be carried out under the stirring action of the stirring device.

[0026] In one embodiment, the adsorbent of the adsorption unit 10 is a conventional adsorbent, such as silicon carbide.

[0027] In one embodiment, the adsorption unit 10 includes an adsorption tank, in which an adsorbent and a stirring device are disposed, and the adsorption treatment of the ammonium sulfate-containing raw material liquid is carried out in the adsorption tank.

[0028] In one embodiment, the adsorption unit 10 discharges the adsorption treated solution into the nanofiltration unit 20 for nanofiltration treatment to remove chloride ions and obtain a purified ammonium sulfate solution intercepted by the nanofiltration membrane. Further, the adsorption treated solution can be delivered into the nanofiltration unit 20 by a delivery pump.

[0029] In one embodiment, the nanofiltration membrane filtration device is provided in the nanofiltration unit 20. Further, the nanofiltration unit 20 includes one, two or more layers of nanofiltration membranes, and the number of layers of nanofiltration membranes can be adjusted according to the impurity content (e.g. chloride ion concentration) in the adsorption treated solution.

[0030] In one embodiment, when the density of the adsorption treated solution intercepted by the nanofiltration membrane approaches the saturation density of the ammonium sulfate solution (the saturation density at room temperature is about 1.32 g / cm 3 ), the solution is discharged from the nanofiltration membrane filtration device to obtain a purified ammonium sulfate solution. In this way, both the pipe blockage caused by the too high density of the ammonium sulfate solution and the efficiency of the device operation are taken into account.

[0031] In one embodiment, the purification device further includes a storage unit 30 for storing the purified ammonium sulfate solution.

[0032] In one embodiment, the storage unit 30 includes a storage tank, and the purified ammonium sulfate solution can be delivered into the storage tank for storage. Further, the purified ammonium sulfate solution in the storage unit 30 can be directly applied, for example, delivered to a fermentation tank 31 in a fermentation workshop for application.

[0033] In one embodiment, the purification device of ammonium sulfate further includes a crystallization unit 40, and the purified ammonium sulfate solution can be subjected to crystallization treatment by the crystallization unit 40 to separate ammonium sulfate solids, which are applied in solid form. Further, the purified ammonium sulfate solution can be subjected to crystallization treatment by evaporation crystallization.

[0034] In one embodiment, the purification device of ammonium sulfate further includes a reverse osmosis unit 50 for purifying a solution containing chloride ions and ammonium ions by a reverse osmosis membrane to obtain purified water and a concentrated solution containing ammonium chloride.

[0035] In one embodiment, the reverse osmosis unit 50 includes a reverse osmosis membrane, and the solution containing chloride ions and ammonium ions can be subjected to desalination treatment and concentration treatment by the reverse osmosis membrane device to obtain purified water; the conductivity of the purified water is <20 μs / cm, and the water quality is good, basically reaching the level of pure water. Further, the purification device of ammonium sulfate further includes a purified water storage tank 51, and the purified water can be collected into the purified water storage tank 51, which can be delivered to a desulfurization tower 100 for repeated use by a pump in subsequent use, or can be used for boiler feed water.

[0036] In an embodiment, the purification device of ammonium sulfate further comprises an alkalization unit, and an alkali solution is arranged in the alkalization unit, so that the concentrated solution containing ammonium chloride is subjected to alkalization treatment to obtain ammonia gas and a hydrochloride.

[0037] In an embodiment, the alkali solution refers to a basic solution capable of reacting with NH4Cl, such as a NaOH solution. When the NaOH solution is used as the alkali solution, the reaction equation between the NaOH solution and the concentrated solution containing ammonium chloride is: NH4Cl+NaOH→NaCl+NH3↑+H2O.

[0038] In an embodiment, the alkalization unit comprises an alkalization tank 61 and an alkali solution storage tank 62. The alkali solution is arranged in the alkalization tank 61, so that the concentrated solution containing ammonium chloride is subjected to alkalization treatment in the alkalization tank 61. The alkali solution storage tank 62 is used to provide the alkali solution for the alkalization tank 61.

[0039] In an embodiment, the alkalization unit comprises a ventilation component (or a blowing component). Further, the ventilation component can be arranged in the alkalization tank 61, and the ventilation component can be, for example, a bubble blower. The ammonia gas volatilized from the alkalization unit can be sent into the desulfurization tower 100 for reuse through the ventilation component, and the chemical reaction in the alkalization unit can be promoted to proceed in a positive direction. Specifically, on the one hand, the liquid in the alkalization tank 61 can be blown by the ventilation component to increase the contact area between the liquid alkali and the ammonium chloride solution, and to accelerate the ion reaction rate in the alkalization tank 61. On the other hand, because ammonia gas is extremely volatile, and the temperature of the raw material solution containing ammonium sulfate from the desulfurization tower 100 is about 60°C, correspondingly, the temperature of the concentrated solution containing ammonium chloride is also relatively high, which exacerbates the volatilization of ammonia gas, promotes the discharge of the generated ammonia gas, and also promotes the ion reaction to proceed in a positive direction.

[0040] In an embodiment, the alkalization tank 61 of the alkalization unit can be connected with the desulfurization tower 100, so that the generated ammonia gas is sent into the desulfurization tower 100 as a source of liquid ammonia for washing liquid in the desulfurization tower.

[0041] In an embodiment, after the alkalization treatment, there is a solution containing sodium chloride and ammonia water remaining in the alkalization tank 61. The solution contains a large amount of sodium chloride and only a trace amount of ammonia water. When the pH value of the solution is detected to be between 7 and 8, the ammonia nitrogen is close to 0. At this time, the alkalization tank 61 is emptied, and the discharged liquid is subjected to simple sewage treatment, which can reach the environmental protection standard.

[0042] In an embodiment, the production system of ammonium sulfate provided by the utility model comprises a raw material solution providing device and the above-mentioned purification device of ammonium sulfate. The raw material solution providing device is used to provide the purification device of ammonium sulfate with a raw material solution containing ammonium sulfate.

[0043] In an embodiment, the raw material solution providing device comprises the desulfurization tower 100.

[0044] In one embodiment, the raw material liquid providing device comprises an electrostatic bag composite dust collector and a desulfurization tower 100, and the flue gas is treated by the electrostatic bag composite dust collector and then enters the desulfurization tower 100 for corresponding treatment.

[0045] The purification device of the ammonium sulfate can make the purified ammonium sulfate product reach the market value of the coking grade ammonium sulfate level, about 1200 yuan / ton, greatly improving the economic value of the product.

[0046] The purification device of the ammonium sulfate can make the purified ammonium sulfate product reach the market value of the coking grade ammonium sulfate level, about 1200 yuan / ton, greatly improving the economic value of the product.

[0047] The purification device of the ammonium sulfate can make the purified ammonium sulfate product reach the market value of the coking grade ammonium sulfate level, about 1200 yuan / ton, greatly improving the economic value of the product.

[0048] Unless specifically limited, the terms used in the present application are commonly understood by those skilled in the art.

[0049] The embodiments described in the present application are for illustrative purposes only and are not intended to limit the scope of protection of the present application. Those skilled in the art can make various other replacements, changes and improvements within the scope of the present application, and therefore the present application is not limited to the above embodiments, but is limited only by the claims.

Claims

1. A purification device for ammonium sulfate, characterized by comprising: The purification device for ammonium sulfate comprises: an adsorption unit for adsorbing a raw solution containing ammonium sulfate to obtain an adsorbed solution; and a nanofiltration unit for nanofiltrating the adsorbed solution to obtain a purified ammonium sulfate solution and a solution containing chloride ions and ammonium ions.

2. The apparatus for purifying ammonium sulfate according to claim 1, characterized by The adsorption unit comprises an adsorbent and a stirring device.

3. The apparatus for purifying ammonium sulfate according to claim 2, characterized by The adsorption unit comprises an adsorption tank, and the adsorbent and the stirring device are arranged in the adsorption tank; and / or The adsorbent is silicon carbide.

4. The apparatus for purifying ammonium sulfate according to claim 1, characterized by The nanofiltration unit comprises one or more than two nanofiltration membranes.

5. The apparatus for purifying ammonium sulfate according to claim 1, characterized by The purification device further comprises a crystallization unit for crystallizing the purified ammonium sulfate solution to separate ammonium sulfate solids; and / or The purification device further comprises a storage unit for storing the purified ammonium sulfate solution.

6. The apparatus for purifying ammonium sulfate according to claim 1, characterized by The purification device further comprises a reverse osmosis unit for treating the solution containing chloride ions and ammonium ions through a reverse osmosis membrane to obtain clean water and a concentrated solution containing ammonium chloride.

7. The apparatus for purifying ammonium sulfate according to claim 6, characterized by The purification device further comprises an alkalization unit for alkalizing the concentrated solution containing ammonium chloride through an alkali solution to obtain ammonia gas.

8. The apparatus for purifying ammonium sulfate according to claim 7, characterized by The alkalization unit comprises an alkalization tank for performing the alkalization treatment and an alkali solution storage tank for providing the alkali solution for the alkalization tank.

9. An ammonium sulfate production system characterized by comprising: The purification device for ammonium sulfate comprises:

10. The system for producing ammonium sulfate according to claim 9, characterized by, an adsorption unit for adsorbing a raw solution containing ammonium sulfate to obtain an adsorbed solution; and a nanofiltration unit for nanofiltrating the adsorbed solution to obtain a purified ammonium sulfate solution and a solution containing chloride ions and ammonium ions. The adsorption unit comprises an adsorbent and a stirring device. The adsorption unit comprises an adsorption tank, and the adsorbent and the stirring device are arranged in the adsorption tank; and / or The adsorbent is silicon carbide. The nanofiltration unit comprises one or more than two nanofiltration membranes. The purification device further comprises a crystallization unit for crystallizing the purified ammonium sulfate solution to separate ammonium sulfate solids; and / or The purification device further comprises a storage unit for storing the purified ammonium sulfate solution. The purification device further comprises a reverse osmosis unit for treating the solution containing chloride ions and ammonium ions through a reverse osmosis membrane to obtain clean water and a concentrated solution containing ammonium chloride. The purification device further comprises an alkalization unit for alkalizing the concentrated solution containing ammonium chloride through an alkali solution to obtain ammonia gas. The alkalization unit comprises an alkalization tank for performing the alkalization treatment and an alkali solution storage tank for providing the alkali solution for the alkalization tank. The purification device for ammonium sulfate comprises: an adsorption unit for adsorbing a raw solution containing ammonium sulfate to obtain an adsorbed solution; and a nanofiltration unit for nanofiltrating the adsorbed solution to obtain a purified ammonium sulfate solution and a solution containing chloride ions and ammonium ions. The adsorption unit comprises an adsorbent and a stirring device. The adsorption unit comprises an adsorption tank, and the adsorbent and the stirring device are arranged in the adsorption tank; and / or The adsorbent is silicon carbide. The nanofiltration unit comprises one or more than two nanofiltration membranes. The purification device further comprises a crystallization unit for crystallizing the purified ammonium sulfate solution to separate ammonium sulfate solids; and / or The purification device further comprises a storage unit for storing the purified ammonium sulfate solution. The purification device further comprises a reverse osmosis unit for treating the solution containing chloride ions and ammonium ions through a reverse osmosis membrane to obtain clean water and a concentrated solution containing ammonium chloride. The purification device further comprises an alkalization unit for alkalizing the concentrated solution containing ammonium chloride through an alkali solution to obtain ammonia gas. The alkalization unit comprises an alkalization tank for performing the alkalization treatment and an alkali solution storage tank for providing the alkali solution for the alkalization tank. The purification device for ammonium sulfate comprises: an adsorption unit for adsorbing a raw solution containing ammonium sulfate to obtain an adsorbed solution; and a nanofiltration unit for nanofiltrating the adsor

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