Sodium bicarbonate production device and production method for producing sodium bicarbonate from solution containing sodium sulfate

Abstract

One embodiment of the present invention may comprise: a mixing reactor for mixing a solution, which contains sodium sulfate (Na2SO4), with ammonium bicarbonate (NH4HCO3) so as to prepare supersaturated sodium bicarbonate (NaHCO3); a crystallizer for cooling a mixture, which contains the sodium bicarbonate prepared in the mixing reactor, so as to crystallize the sodium bicarbonate; a precipitator for precipitating sodium bicarbonate in a solution containing the sodium bicarbonate obtained from the crystallizer; a solid-liquid separator for dehydrating the sodium bicarbonate precipitated in the precipitator; and a dryer for drying the sodium bicarbonate obtained from the solid-liquid separator.

Description

Sodium bicarbonate manufacturing apparatus and manufacturing method for producing sodium bicarbonate from a solution containing sodium sulfate

[0001] The present invention relates to a baking soda manufacturing apparatus and a manufacturing method for producing baking soda from a solution containing sodium sulfate.

[0002] Flue gas desulfurization refers to the removal of sulfur (S) components, particularly sulfur dioxide (SO2), from exhaust gases emitted from sources such as steel mills and thermal power plants. With industrial development, sulfur oxides (SO2) emitted from various factories, thermal power plants, and incinerators... x Harmful gases such as sodium sulfate cause severe air pollution and induce various diseases in the human body, including respiratory diseases, asthma, and lung cancer. Currently, desulfurizing agents used in steel mills include sodium bicarbonate (NaHCO3), activated carbon, and calcium hydroxide (Ca(OH)2). In particular, sodium bicarbonate is known to exhibit excellent adsorption efficiency when sprayed into high-temperature flue gas, as its specific surface area is maximized. During this process, waste sodium sulfate (Na2SO4) is generated as a byproduct of the desulfurization treatment.

[0003] Furthermore, with the recent expansion of electric vehicle adoption, the demand for lithium, a raw material for secondary batteries, is increasing. Since the main byproducts generated during lithium production include silica (SiO2) and sodium sulfate (Na2SO4), it is expected that the amount of sodium sulfate byproducts will also increase in line with the growing demand for lithium. Therefore, the development of technology to recycle sodium sulfate is an essential prerequisite for the widespread adoption of secondary batteries.

[0004] Currently, by-products are either dissolved in water and treated as wastewater or landfilled as is, which simultaneously causes treatment costs and secondary environmental problems, so there is a need for a method to recycle them.

[0005] One embodiment of the present invention may provide a baking soda manufacturing apparatus and a manufacturing method capable of producing baking soda by recycling sodium sulfate byproducts.

[0006] One embodiment of the present invention may provide a baking soda manufacturing apparatus and a manufacturing method capable of manufacturing baking soda using ammonium bicarbonate.

[0007] One embodiment of the present invention may provide a baking soda manufacturing apparatus and a manufacturing method capable of manufacturing baking soda with a large particle size (D50).

[0008] One embodiment of the present invention may provide a baking soda manufacturing apparatus and a manufacturing method capable of producing baking soda of high purity.

[0009] The problems of the present invention are not limited to those described above. A person skilled in the art to which the present invention pertains will have no difficulty understanding additional problems of the present invention from the overall contents of this specification.

[0010] A baking soda manufacturing apparatus according to one embodiment of the present invention may include: a mixing reactor that mixes a solution containing sodium sulfate (Na2SO4) with ammonium bicarbonate (NH4HCO3) to produce baking soda (NaHCO3) in a supersaturated state; a crystallizer that cools a mixture containing baking soda produced in the mixing reactor to crystallize the baking soda; a precipitator that precipitates baking soda from a solution containing baking soda obtained in the crystallizer; a solid-liquid separator that dehydrates the baking soda precipitated in the precipitator; and a dryer that dries the baking soda obtained in the solid-liquid separator.

[0011] The above-mentioned solid-liquid separator may include a washing device for washing the sodium bicarbonate after dehydration of the sodium bicarbonate.

[0012] It may further include a carbon dioxide supply unit that supplies carbon dioxide to the above-mentioned mixing reactor.

[0013] The above carbon dioxide supply device can supply carbon dioxide to the crystallizer.

[0014] The above carbon dioxide supply device can supply carbon dioxide to the above dryer.

[0015] It may further include a first pipe for transferring the filtrate obtained from the above-mentioned precipitator to at least one selected from the group consisting of the above-mentioned mixing reactor and the above-mentioned crystallizer.

[0016] It may further include a second pipe for dehydrating sodium bicarbonate in the solid-liquid separator and transferring the obtained filtrate to at least one selected from the group consisting of the mixing reactor and the crystallizer.

[0017] A method for producing sodium bicarbonate according to one embodiment of the present invention may include: a mixing step of producing sodium bicarbonate (NaHCO3) in a supersaturated state by mixing a solution containing sodium sulfate (Na2SO4) with ammonium bicarbonate (NH4HCO3); a crystallization step of crystallizing sodium bicarbonate by cooling the solution produced in the mixing step; a precipitation step of precipitating sodium bicarbonate from the solution obtained in the crystallization step; a solid-liquid separation step of dehydrating the sodium bicarbonate precipitated in the precipitation step; and a drying step of drying the sodium bicarbonate separated in the solid-liquid separation step.

[0018] The solid content concentration of the sodium bicarbonate included in the mixture containing the sodium bicarbonate prepared in the above mixing step may be 7 weight% or less.

[0019] In the above mixing step, the mixing temperature may be 40 to 120℃.

[0020] In the above mixing step, the molar ratio of ammonium bicarbonate to sodium sulfate may be 1:0.8 to 1:1.3.

[0021] In the crystallization step above, the crystallization reaction temperature may be 1 to 35°C lower than the mixing temperature of the mixing step above.

[0022] The above precipitation step may be a step of controlling the moisture content of the sodium bicarbonate obtained in the above crystallization step to 65 weight% or less.

[0023] The method may further include a step of transferring the filtrate obtained from the above sedimentation step to the above mixing step.

[0024] The method may further include a step of transferring the filtrate obtained from the above precipitation step to the above crystallization step.

[0025] The method may further include a step of transferring the liquid obtained from the above-mentioned solid-liquid separation step to the above-mentioned mixing step.

[0026] The method may further include a step of transferring the liquid obtained from the solid-liquid separation step to the crystallization step.

[0027] The method may further include a washing step for separating solids and liquids after washing the sodium bicarbonate obtained in the above solid-liquid separation step.

[0028] The above mixing step may further include a step of additionally supplying carbon dioxide.

[0029] The above crystallization step may further include a step of additionally supplying carbon dioxide.

[0030] The above drying step may further include a step of additionally supplying carbon dioxide.

[0031] A baking soda manufacturing apparatus and method, which is an embodiment of the present invention, can produce baking soda by recycling sodium sulfate byproducts.

[0032] A manufacturing apparatus and method, which is an embodiment of the present invention, can produce sodium bicarbonate by utilizing ammonium bicarbonate.

[0033] A manufacturing apparatus and method, which is an embodiment of the present invention, can produce a medium with a large particle size (D50).

[0034] A manufacturing apparatus and method, which is an embodiment of the present invention, can produce high-purity sodium bicarbonate.

[0035] FIG. 1 is a schematic diagram showing a sodium bicarbonate manufacturing apparatus system, which is an embodiment of the present invention.

[0036] FIG. 2 is a flowchart schematically illustrating a method for manufacturing sodium bicarbonate, which is an embodiment of the present invention.

[0037] Figure 3 is a graph showing the particle size (D50) of sodium bicarbonate produced without a crystallizer at each temperature.

[0038] Preferred embodiments of the present invention will be described below with reference to the attached drawings. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below.

[0039] In addition, embodiments of the present invention are provided to more fully explain the present invention to those with average knowledge in the relevant technical field.

[0040] In drawings, the shapes and sizes of elements may be exaggerated for clearer explanation.

[0041] In describing the embodiments of the present invention, if it is determined that a detailed description of known technology related to the present invention may unnecessarily obscure the essence of the present invention, such detailed description will be omitted. Furthermore, the terms described below are defined considering their functions in the present invention, and these may vary depending on the intentions or conventions of the user or operator. Therefore, such definitions should be based on the content throughout this specification. The terms used in the detailed description are merely for describing the embodiments of the present invention and should not be limited in any way. Unless explicitly stated otherwise, expressions in the singular form include the meaning of the plural form.

[0042] In this description, expressions such as “include” or “equipped” are intended to refer to certain characteristics, numbers, steps, actions, elements, parts or combinations thereof, and should not be interpreted to exclude the existence or possibility of one or more other characteristics, numbers, steps, actions, elements, parts or combinations thereof other than those described.

[0043] Unless otherwise specifically defined in the specification of the present invention, % units mean weight %.

[0044] In this specification, terms such as 'top', 'upper', 'upper surface', 'lower', 'lower surface', 'lower surface', and 'side surface' are based on the drawings and may actually vary depending on the direction in which the elements or components are arranged.

[0045] Additionally, throughout the specification, when it is said that one part is 'connected' to another part, this includes not only cases where they are 'directly connected,' but also cases where they are 'indirectly connected' with other elements in between.

[0046] The present invention will be described in detail below through each embodiment or example of the invention. It should be noted that each embodiment or example described in this specification is not limited to a single embodiment or example, but may also be combined with other embodiments or examples. Accordingly, the citation of claims in the patent claims is merely an example of an embodiment, and the technical concept of the present invention should not be interpreted as being limited only to a combination with the cited claims; rather, combinations with various claims are also included within the scope of the technical concept of the present invention.

[0047] Sodium bicarbonate manufacturing device

[0048] A baking soda manufacturing apparatus, which is an embodiment of the present invention, is a baking soda manufacturing apparatus for producing baking soda from a solution containing sodium sulfate (Na2SO4). Specifically, it relates to an apparatus for producing baking soda of high purity with a large particle size (D50) from waste containing sodium sulfate and ammonium bicarbonate.

[0049] FIG. 1 is a schematic diagram illustrating a system of a baking soda manufacturing apparatus according to one embodiment of the present invention. Referring to FIG. 1, a baking soda manufacturing apparatus according to one embodiment of the present invention may include: a mixing reactor (10) that mixes a solution containing sodium sulfate (Na2SO4) with ammonium bicarbonate (NH4HCO3) to produce baking soda (NaHCO3) in a supersaturated state; a crystallizer (20) that cools a mixture containing baking soda produced in the mixing reactor (10) to crystallize the baking soda; a precipitator (30) that precipitates baking soda from a solution containing baking soda obtained from the crystallizer (20); a solid-liquid separator that dehydrates the baking soda precipitated in the precipitator (30); and a dryer (50) that dries the baking soda obtained from the solid-liquid separator.

[0050] In the above mixing reactor (10), the solution containing sodium sulfate and ammonium bicarbonate are mixed, and sodium bicarbonate can be produced according to the reaction of formula (1) below.

[0051] [Equation (1)]

[0052] Na2SO4+ 2NH4HCO3→ 2NaHCO3+ (NH4)2SO4

[0053] When producing sodium bicarbonate according to the reaction of Equation (1), the reaction rate is faster compared to producing sodium bicarbonate using carbon dioxide and ammonia, and since ammonium bicarbonate is in a solid state, the composition of the solution can be manipulated much more easily. The sodium bicarbonate produced in the above-mentioned mixing reactor (10) may be in a supersaturated state, and the specific supersaturated state will be described later.

[0054] In one embodiment of the present invention, the sodium sulfate-containing solution used may be a sodium sulfate-containing material such as sodium sulfate-containing waste or natural minerals. For example, it may be produced by desulfurizing flue gas generated by combustion in thermal power plants, steel mills, incinerators, etc. using sodium sulfate. When manufacturing sodium sulfate using a sodium sulfate-containing material, impurities such as K, Ca, Fe, Cl, and Pb may be included in addition to sodium sulfate. When manufacturing a sodium sulfate solution, the sodium sulfate-containing material may be manufactured through a solid-liquid separation procedure in which solid impurities are separated by stirring.

[0055] The above ammonium bicarbonate (NH4HCO3) can be prepared by dissolving a solid ammonium bicarbonate in water or by dissolving carbon dioxide in ammonia water according to the reaction of the following formula (2).

[0056] [Equation (2)]

[0057] NH4OH + CO2 → NH4HCO3

[0058] The concentration of the ammonia solution used to prepare the ammonium bicarbonate solution may be 25 to 30 weight%. The solubility of ammonium bicarbonate is 21.6 g in 100 ml of water at 20°C. Therefore, when carbon dioxide is dissolved in this ammonia solution, ammonium bicarbonate salt is precipitated. Even if ammonium bicarbonate salt is precipitated, it is redissolved when mixed with a sodium sulfate-containing solution and can be used as a mixed solution of sodium sulfate and sodium bicarbonate.

[0059] One embodiment of the present invention may further include an ammonium bicarbonate manufacturing apparatus that produces ammonium bicarbonate by reacting ammonia water with carbon dioxide.

[0060] The carbon dioxide may be selected from the group consisting of pure carbon dioxide, FINEX OFF GAS (FOG), blast furnace gas (BFG), converter gas, coal power plant flue gas, incinerator flue gas, sintering furnace flue gas, glass melting flue gas, petrochemical process flue gas, pre-combustion flue gas, gasifier flue gas, and methane-hydrogen conversion process flue gas. In addition, the carbon dioxide may be concentrated by one or more methods from the group consisting of the wet amine method, PSA process, and membrane process.

[0061] Meanwhile, sodium bicarbonate produced solely by mixing a solution containing sodium sulfate with ammonium bicarbonate precipitates into small particles of 20 μm or less. The substances produced during the dissolution-precipitation process undergo coarsening through two mechanisms. The first is the formation of nuclei, and the second is a coarsening reaction in which the formed nuclei grow larger. Sodium bicarbonate precipitated solely by mixing a sodium sulfate solution and an ammonium bicarbonate solution does not undergo the coarsening process in which nuclei grow larger due to the rapid precipitation reaction.

[0062] Accordingly, one embodiment of the present invention may include a crystallizer (20) that cools a mixture containing sodium carbonate produced in the mixing reactor (10) to crystallize the sodium carbonate. The particle size (D50) of the sodium carbonate produced in the crystallizer (20) may be large particles of 40 μm or more.

[0063] Meanwhile, one embodiment of the present invention may include a precipitator (30) for precipitating sodium bicarbonate from a solution containing sodium bicarbonate obtained from the crystallizer (20). The precipitator (30) can deliver a sodium bicarbonate slurry by adjusting the moisture content of the sodium bicarbonate to be delivered to a solid-liquid separator to be described later.

[0064] One embodiment of the present invention may further include a first pipe (31) for transferring the liquid remaining after obtaining sodium bicarbonate in the precipitator (30) to at least one selected from the group consisting of the mixing reactor (10) and the crystallizer (20). The liquid transferred along the first pipe (31) is Na₂, which is the raw material for sodium bicarbonate. + and HCO3 - It contains ions, and a saturated solution can be prepared by controlling the amount of sodium sulfate solution and ammonium carbonate injected.

[0065] In addition, one embodiment of the present invention may include a solid-liquid separator (40) for dewatering the sodium bicarbonate precipitated in the precipitator (30). Sodium bicarbonate in a solid state can be obtained from the solid-liquid separator (40).

[0066] One embodiment of the present invention may further include a second pipe (41) for transferring the filtrate remaining after obtaining sodium bicarbonate in the solid-liquid separator (40) to at least one selected from the group consisting of the mixing reactor (10) and the crystallizer (20). The filtrate transferred along the second pipe (41) may be transferred to the mixing reactor (10) and / or the crystallizer (20). The circulating filtrate is Na₂, which is the raw material for sodium bicarbonate. + and HCO3 - It may contain ions, and Na of the mixing reactor (10) and the crystallizer (20) + and HCO3 - It can perform a buffering role that regulates ion concentration.

[0067] The second pipe (41) can be connected to the third pipe (42), and the third pipe (42) can discharge unused wastewater from the liquid remaining after obtaining sodium bicarbonate from the solid-liquid separator (40).

[0068] The above solid-liquid separator (40) may include a washing device (not shown) for washing the baking soda after dehydration. In addition, the washing device may wash the baking soda after dehydration as well as wash the baking soda during dehydration. The baking soda manufacturing device including the washing device may include two or more solid-liquid separators (40), and the baking soda that has passed through the washing device may be fed back into the solid-liquid separator (40).

[0069] One embodiment of the present invention may include a dryer (50) for drying the sodium bicarbonate obtained from the solid-liquid separator (40).

[0070] Additionally, one embodiment of the present invention may further include a carbon dioxide supply unit (60) that supplies carbon dioxide to the mixing reactor (10). The carbon dioxide supply unit (60) can capture carbon dioxide contained in exhaust gas generated in a predetermined industrial process with high purity, and the captured carbon dioxide can be supplied to the mixing reactor (10) to be used as a reactant for a sodium carbonate manufacturing reaction.

[0071] Additionally, the carbon dioxide supply unit (60) can supply carbon dioxide to the crystallizer (20). The carbon dioxide is HCO3 in the crystallizer (20). - It can serve the role of replenishing ions if they are insufficient.

[0072] The carbon dioxide supply unit (60) can supply carbon dioxide to the dryer (50). The carbon dioxide supplied to the dryer (50) can prevent the baking soda from being converted into sodium carbonate in the dryer (50).

[0073] Sodium bicarbonate manufacturing method

[0074] A method for producing baking soda, which is an embodiment of the present invention, is a method for producing baking soda from a solution containing sodium sulfate (Na2SO4). Specifically, it relates to a method for producing baking soda of high purity with a large particle size (D50) using waste containing sodium sulfate and ammonium bicarbonate.

[0075] This is a flowchart schematically illustrating a method for producing sodium bicarbonate, which is an embodiment of the present invention. Referring to FIG. 2, the method for producing sodium bicarbonate according to the present invention may include: a mixing step (S10) of producing sodium bicarbonate (NaHCO3) in a supersaturated state by mixing a solution containing sodium sulfate (Na2SO4) with ammonium bicarbonate (NH4HCO3); a crystallization step (S20) of crystallizing sodium bicarbonate by cooling the solution produced in the mixing step (S10); a precipitation step (S30) of precipitating sodium bicarbonate from the solution obtained in the crystallization step (S20); a solid-liquid separation step (S40) of dehydrating the sodium bicarbonate precipitated in the precipitation step (S30); and a drying step (S50) of drying the sodium bicarbonate separated in the solid-liquid separation step (S40).

[0076] In one embodiment of the present invention, the mixing step (S10) may be a step of producing supersaturated sodium bicarbonate (NaHCO3) by mixing a solution containing sodium sulfate (Na2SO4) with ammonium bicarbonate (NH4HCO3). The mixing reaction of the mixing step (S10) may be a reaction that produces sodium bicarbonate according to the reaction of formula (1) described above.

[0077] The sodium bicarbonate produced in the above mixing step (S10) may be in a supersaturated state, and specifically, the solid content concentration of the sodium bicarbonate included in the mixture containing the sodium bicarbonate produced in the above mixing step (S10) may be 7 weight% or less.

[0078] If the solid content concentration of the sodium bicarbonate produced in the above mixing step (S10) exceeds 7% by weight, the sodium bicarbonate is excessively precipitated in the mixing reaction of sodium sulfate and ammonium bicarbonate, and when the solution is transferred to the crystallization step (S20) described later, the coarsening efficiency may decrease, and the sodium bicarbonate produced thereafter may have a particle size (D50) of less than 40 μm, resulting in the production of small particle size sodium bicarbonate.

[0079] In addition, in the mixing step (S10), the mixing temperature may be 40 to 120°C, specifically 60 to 80°C. If the mixing temperature is less than 40°C, the solubility of sodium sulfate is not high, so Na in sodium sulfate + The recovery rate may be lowered, which may result in a lower final yield of sodium bicarbonate. On the other hand, if the temperature exceeds 120°C, the temperature condition of the subsequent crystallizer (20) cannot be satisfied, so a cooling process must be added, which may reduce the economic efficiency of the process.

[0080] In the above mixing step (S10), the reaction pressure may be 1 to 10 atm. If the reaction pressure is less than 1 atm, the solubility of the mixture may be lowered, and if the reaction pressure exceeds 10 atm, the energy required is high, which may reduce the economic efficiency of the sodium bicarbonate manufacturing process.

[0081] Although not specifically limited, for example, in the mixing step (S10), the molar ratio of ammonium bicarbonate to sodium sulfate may be 1:0.8 to 1:1.3.

[0082] In one embodiment of the present invention, the crystallization step (S20) may be a step of cooling the solution prepared in the mixing step (S10) to crystallize sodium carbonate.

[0083] In the crystallization step (S20), the crystallization reaction temperature may be 1 to 35°C lower than the mixing temperature of the mixing step (S10), specifically 10 to 30°C lower. If the difference between the crystallization reaction temperature and the mixing temperature of the mixing step (S10) is less than 1°C, the particle size control of the sodium carbonate may not be performed smoothly, and if it exceeds 35°C, it may be difficult to control the distribution of the particle size.

[0084] In one embodiment of the present invention, the precipitation step (S30) may be a step of precipitating sodium bicarbonate from the solution obtained in the crystallization step (S20). The precipitation step (S30) can control the moisture content of the sodium bicarbonate and can produce sodium bicarbonate of high purity.

[0085] The above precipitation step (S30) may be a step for controlling the moisture content of the sodium bicarbonate obtained in the above crystallization step (S20) to 65 weight% or less. If the moisture content of the sodium bicarbonate exceeds 65 weight%, the purity of the finally produced sodium bicarbonate may be lowered.

[0086] The method may further include a step of transferring the filtrate obtained in the above sedimentation step (S30) to the above mixing step (S10). The filtrate obtained in the above sedimentation step (S30) is Na + and HCO3 - It may contain ions and is transferred to the mixing step (S10) to prepare a saturated solution by adjusting the amount of sodium sulfate solution and ammonium carbonate injected.

[0087] Additionally, the method may further include a step of transferring the filtrate obtained in the precipitation step (S30) to the crystallization step (S20). The filtrate obtained in the precipitation step (S30) is Na + and HCO3 - It may contain ions and is transferred to the crystallization step (S20) to prepare a saturated solution by adjusting the amount of sodium sulfate solution and ammonium carbonate injected.

[0088] In one embodiment of the present invention, the solid-liquid separation step (S40) may be a step of dewatering the sodium bicarbonate precipitated in the precipitation step (S30).

[0089] Additionally, the method may further include a washing step (S41) for washing the sodium bicarbonate obtained in the solid-liquid separation step (S40) and then separating the solid and liquid. The washing step (S41) may wash the sodium bicarbonate obtained in the solid-liquid separation step (S40), and may wash the sodium bicarbonate during the solid-liquid separation step (S40).

[0090] In addition, a solid-liquid separation step (S40) can be further performed after the washing step (S41).

[0091] In the washing step (S41) above, although not specifically limited, for example, the weight of water used for washing may be three times or less the weight of the baking soda before drying. If the weight of water is three times or more, the baking soda, which is the final product, may also dissolve in water, and the yield may be lowered.

[0092] The method may further include a step of transferring the filtrate obtained in the solid-liquid separation step (S40) to the mixing step (S10). The filtrate obtained in the solid-liquid separation step (S40) is Na + and HCO3 - It may contain ions and is transferred to the mixing step (S10) so as to Na + and HCO3 - The concentration of ions can be controlled.

[0093] Additionally, the method may further include a step of transferring the filtrate obtained in the solid-liquid separation step (S40) to the crystallization step (S20). The filtrate obtained in the solid-liquid separation step (S40) is Na + and HCO3 - It may contain ions and is transferred to the crystallization step (S20) to Na + and HCO3 - The concentration of ions can be controlled.

[0094] In one embodiment of the present invention, the drying step (S50) may be a step of drying the sodium bicarbonate separated in the solid-liquid separation step (S40). The drying temperature is not particularly limited, but may be, for example, 50 to 80°C. If the drying temperature of the drying step (S50) is less than 50°C, drying may not proceed sufficiently, and if it exceeds 80°C, the sodium bicarbonate may be separated into soda ash.

[0095] In one embodiment of the present invention, the mixing step (S10) may further include a step of additionally supplying carbon dioxide. The carbon dioxide included in the mixing step (S10) may be used in a reaction to produce baking soda.

[0096] The crystallization step (S20) may further include a step of additionally supplying carbon dioxide. The carbon dioxide additionally supplied to the crystallization step (S20) is HCO3 in the crystallization step (S20). - It can serve the role of replenishing ions if they are insufficient.

[0097] The drying step (S50) may further include a step of additionally supplying carbon dioxide. The carbon dioxide supplied to the drying step (S50) can prevent the sodium bicarbonate from being converted into sodium carbonate.

[0098] Examples

[0099] The present invention will be described in detail below through examples. However, it should be noted that the examples described below are intended merely to illustrate and embody the present invention and are not intended to limit the scope of the present invention. This is because the scope of the present invention is determined by the matters described in the patent claims and matters reasonably inferred therefrom.

[0100] 1. Experimental Example 1 (Preparation of baking soda without a crystallizer)

[0101] 84g of sodium sulfate was added to 164g of water to prepare a 33% by weight sodium sulfate solution.

[0102] A mixed solution of sodium sulfate and ammonium bicarbonate was prepared by heating the prepared sodium sulfate solution to 40, 50, 60, and 70 ℃, respectively, and adding 30 wt% of ammonium bicarbonate solution to each.

[0103] After that, the precipitated sodium bicarbonate was dried, and the particle size (D50) was measured at each temperature and is shown in Fig. 3.

[0104] FIG. 3 is a graph showing the particle size (D50) of sodium bicarbonate produced without a crystallizer at each temperature. Referring to FIG. 3, it can be seen that even when the temperature is raised to 70°C, the particle size (D50) of the sodium bicarbonate does not exceed 20 μm. These results indicate that a crystallizer capable of increasing the particle size (D50) is required to increase the particle size (D50) to 40 μm or more.

[0105] 2. Experimental Example 2 (Sodium Bicarbonate Particle Size According to Amount of Ammonium Bicarbonate Added)

[0106] A 33% by weight sodium sulfate solution was prepared by adding 84g of sodium sulfate to 164g of water at 70℃.

[0107] A mixed solution of sodium sulfate and ammonium bicarbonate was prepared by adding ammonium bicarbonate to the prepared sodium sulfate solution in the proportions shown in Table 1 below.

[0108] The weight of the solid content of the sodium bicarbonate produced after filtering the prepared mixed solution was measured, and the particle size (D50) of the crystallized sodium bicarbonate was measured after introducing the mixed solution under the same conditions into a crystallizer operated at 40°C and is shown in Table 1 below.

[0109] Weight of ammonium bicarbonate input (g) Weight ratio of solid sodium bicarbonate produced in the mixing reactor (wt%) Weight of solid sodium bicarbonate produced in the crystallizer (d50) (㎛) Example 1 100 60 Example 2 15 350 Example 3 19 545 Example 4 23 741 Comparative Example 1 27 1026 Comparative Example 2 31 1322

[0110] Referring to Table 1 above, it can be confirmed that the sodium bicarbonate particle size (D50) of Examples 1 to 4, in which the weight ratio of sodium bicarbonate solids produced in the mixing reactor is 7% by weight or less, is 40㎛ or more.

[0111] On the other hand, it can be confirmed that the particle size (D50) of Comparative Examples 1 and 2, in which the weight ratio of the sodium bicarbonate solid content produced in the mixing reactor exceeds 7 wt%, is less than 40 μm.

[0112] 3. Experimental Example 3 (Sodium bicarbonate particle size according to crystallizer temperature (D50))

[0113] A 33% by weight sodium sulfate solution was prepared by adding 84g of sodium sulfate to 164g of water at 70℃.

[0114] 20 g of ammonium bicarbonate was added to the prepared sodium sulfate solution to prepare a mixed solution of sodium sulfate and ammonium bicarbonate.

[0115] The prepared sodium sulfate and ammonium bicarbonate mixed solution was injected into a crystallizer, and the operating temperature of the crystallizer was controlled to the temperature shown in Table 2 below. The weight and particle size (D50) of the sodium bicarbonate produced were measured and are shown in Table 2 below.

[0116] Crystallizer Temperature (°C) Difference between Mixing Temperature and Crystallization Temperature (°C) Weight of Medium Soy Sauce (g) Medium Soy Sauce Particle Size (D50) (g) Example 5 68 23.85 2 Example 6 60 10 18 51 Example 7 50 20 34 49 Example 8 40 30 48 48 Comparative Example 3 30 40 60 25 Comparative Example 4 700 Extraction X-

[0117] Referring to Table 2 above, it can be seen that the medium particle size (D50) of Examples 5 to 8, in which the difference between the mixing temperature and the crystallization temperature is 2 to 35°C, is 40 μm or more.

[0118] On the other hand, it can be confirmed that the particle size (D50) of Comparative Example 3, in which the difference between the mixing temperature and the crystallization temperature exceeds 35℃, is less than 40㎛.

[0119] Meanwhile, in Comparative Example 4, where the difference between the mixing temperature and the crystallization temperature is less than 2℃, it can be confirmed that no sodium bicarbonate was produced.

[0120] 4. Experimental Example 4 (Purity of sodium bicarbonate according to sodium bicarbonate washing)

[0121] A 33% by weight sodium sulfate solution was prepared by adding 84g of sodium sulfate to 164g of water at 70℃.

[0122] 22 g of ammonium bicarbonate was added to the prepared sodium sulfate solution to prepare a mixed solution of sodium sulfate and ammonium bicarbonate.

[0123] The prepared mixed solution of sodium sulfate and ammonium bicarbonate was injected into a crystallizer, and the operating temperature of the crystallizer was controlled to 40 ℃. The purity of the resulting sodium bicarbonate was measured according to the moisture content after dehydration as indicated in Table 3 below.

[0124] Afterwards, washing was performed using water three times the weight of the generated baking soda, and after washing, the process of dehydration and drying was carried out, and the purity of the baking soda was re-measured, which is shown in Table 3 below.

[0125] Moisture content (%) of extracted baking soda before washing Purity of baking soda according to moisture content before washing (weight %) Purity of baking soda after washing (weight %) Example 9 205≤99 Example 10 308≤99 Example 11 4012≤99 Example 12 5015≤99 Example 13 6018≤99 Comparative Example 5 702196

[0126] Referring to Table 3 above, it can be confirmed that when the sodium bicarbonate of Examples 9 to 13, in which the moisture content of the sodium bicarbonate before washing is 65% or less, is washed, the purity of the sodium bicarbonate is 99% by weight or more.

[0127] On the other hand, when the sodium bicarbonate of Comparative Example 5, in which the moisture content of the sodium bicarbonate before washing exceeds 65%, is washed, it can be confirmed that the purity of the sodium bicarbonate is less than 99% by weight.

[0128] Although embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and it will be obvious to those skilled in the art that various modifications and variations are possible within the scope of the technical concept of the present invention as described in the claims.

[0129] [Explanation of the symbol]

[0130] 10: Mixed reactor

[0131] 20: Crystallizer

[0132] 30: Sedimentation device

[0133] 31: 1st Pipeline

[0134] 40: High-value separator

[0135] 41: 2nd Piping

[0136] 42: Third Piping

[0137] 50: Dryer

[0138] 60: Carbon dioxide supplier

Claims

1. A mixing reactor for producing supersaturated sodium bicarbonate (NaHCO3) by mixing a solution containing sodium sulfate (Na2SO4) with ammonium bicarbonate (NH4HCO3); A crystallizer that cools a mixture containing sodium bicarbonate produced in the above-mentioned mixing reactor to crystallize the sodium bicarbonate; A precipitator for precipitating sodium bicarbonate from a solution containing sodium bicarbonate obtained from the crystallizer above; A solid-liquid separator for dewatering sodium bicarbonate precipitated in the above-mentioned precipitator; and A baking soda manufacturing apparatus comprising a dryer for drying baking soda obtained from the above-mentioned solid-liquid separator.

2. In Paragraph 1, The above-mentioned solid-liquid separator is a baking soda manufacturing device comprising a washing device for washing baking soda after dehydration of baking soda.

3. In Paragraph 1, A soda manufacturing apparatus further comprising a carbon dioxide supply unit that supplies carbon dioxide to the above-mentioned mixing reactor.

4. In Paragraph 3, The above carbon dioxide supply device supplies carbon dioxide to the crystallizer, a baking soda manufacturing device.

5. In Paragraph 3, The above carbon dioxide supply device supplies carbon dioxide to the above dryer, a baking soda manufacturing device.

6. In Paragraph 1, A baking soda manufacturing apparatus further comprising a first pipe for transferring the filtrate obtained from the above-mentioned precipitator to at least one selected from the group consisting of the above-mentioned mixing reactor and the above-mentioned crystallizer.

7. In Paragraph 1, A sodium bicarbonate manufacturing apparatus further comprising a second pipe for dehydrating sodium bicarbonate in the solid-liquid separator and transferring the obtained filtrate to at least one selected from the group consisting of the mixing reactor and the crystallizer.

8. A mixing step of preparing supersaturated sodium bicarbonate (NaHCO3) by mixing a solution containing sodium sulfate (Na2SO4) with ammonium bicarbonate (NH4HCO3); A crystallization step in which the solution prepared in the above mixing step is cooled to crystallize sodium bicarbonate; A precipitation step for precipitating sodium bicarbonate from the solution obtained in the crystallization step above; A solid-liquid separation step for dehydrating the sodium bicarbonate precipitated in the above precipitation step; and A method for manufacturing sodium bicarbonate comprising a drying step for drying sodium bicarbonate separated in the above solid-liquid separation step.

9. In Paragraph 8, A method for manufacturing sodium bicarbonate, wherein the solid content concentration of sodium bicarbonate included in a mixture containing sodium bicarbonate prepared in the above mixing step is 7% by weight or less.

10. In Paragraph 8, A method for manufacturing baking soda, wherein in the above mixing step, the mixing temperature is 40 to 120℃.

11. In Paragraph 8, A method for preparing sodium bicarbonate, wherein, in the above mixing step, the molar ratio of ammonium bicarbonate to sodium sulfate is 1:0.8 to 1:1.

3.

12. In Paragraph 8, A method for manufacturing sodium bicarbonate, wherein in the crystallization step, the crystallization reaction temperature is 1 to 35°C lower than the mixing temperature of the mixing step.

13. In Paragraph 8, A method for producing sodium bicarbonate, wherein the above-mentioned precipitation step is a step of controlling the moisture content of the sodium bicarbonate obtained in the above-mentioned crystallization step to 65 weight% or less.

14. In Paragraph 8, A method for manufacturing sodium bicarbonate, further comprising the step of transferring the filtrate obtained from the above-mentioned sedimentation step to the above-mentioned mixing step.

15. In Paragraph 8, A method for manufacturing sodium bicarbonate, further comprising the step of transferring the filtrate obtained from the above precipitation step to the above crystallization step.

16. In Paragraph 8, A method for manufacturing sodium bicarbonate, further comprising the step of transferring the liquid obtained in the solid-liquid separation step to the mixing step.

17. In Paragraph 8, A method for manufacturing sodium bicarbonate, further comprising the step of transferring the liquid obtained from the solid-liquid separation step to the crystallization step.

18. In Paragraph 8, A method for manufacturing sodium bicarbonate, further comprising a washing step of washing the sodium bicarbonate obtained in the solid-liquid separation step and then separating the solid and liquid.

19. In Paragraph 8, A method for manufacturing sodium bicarbonate, further comprising a step of additionally supplying carbon dioxide to the above mixing step.

20. In Paragraph 8, A method for manufacturing sodium bicarbonate, further comprising the step of additionally supplying carbon dioxide to the crystallization step.

21. In Paragraph 8, A method for manufacturing sodium bicarbonate, further comprising a step of additionally supplying carbon dioxide to the drying step.

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