A method for preparing porous effervescent sodium percarbonate particles for use as a disinfectant

Abstract

The application provides a preparation method of porous effervescent percarbonate used as a disinfectant, which comprises the following steps: (S1) preparation of an alkali solution, wherein the alkali solution comprises a mother liquor, soda ash, sodium chloride and a stabilizer; (S2) preparation of a hydrogen peroxide aqueous solution, wherein disodium ethylenediaminetetraacetate and magnesium sulfate are added into the hydrogen peroxide mother liquor; (S3) introduction of the prepared alkali solution and hydrogen peroxide aqueous solution into a reaction kettle for reaction, wherein the flow rate of the introduced alkali solution is 1600 kg / h-2500 kg / h, the flow rate of the introduced hydrogen peroxide aqueous solution is 600 kg / h-1000 kg / h, the reaction temperature is 15-30 DEG C, and the reaction time is 30 min-50 min; and (S4) after the reaction is completed, the crystallization product is separated from the reaction solution by a centrifugal machine, the water content of the crystallization product is 16%-22%, and the finished product is obtained after drying. The application controls the flow rates of the alkali solution and the hydrogen peroxide, and the sodium percarbonate intermediate with a water content of 16%-22% is prepared through rapid reaction, and the sodium percarbonate finished product with a loose porous structure is obtained after drying. The method of the application does not have a tablet pressing process, the equipment investment is small, and the energy consumption is lower.

Description

Technical Field

[0001] This invention relates to the preparation of porous effervescent sodium percarbonate granules for use as a disinfectant and bactericide, belonging to the technical field of inorganic salt peroxide-type daily chemical disinfectants and bactericides. Background Technology

[0002] Sodium percarbonate is a white crystalline or crystalline powder at room temperature, with the molecular formula 2Na₂CO₃·3H₂O₂, containing approximately 25% H₂O₂, commonly known as solid hydrogen peroxide. Because its structure contains hydrogen peroxide molecules, it possesses strong oxidizing properties and decomposes upon contact with moisture, releasing reactive oxygen species. Therefore, it is suitable for use in daily chemical detergents, textiles, medical applications, papermaking, electroplating, and other fields. When used as a disinfectant, its disinfection and sterilization principle is that the strong oxidizing reactive oxygen species released by the decomposition of sodium percarbonate inactivate microbial proteins, causing microbial death, thereby achieving the purpose of sterilization and disinfection.

[0003] Currently, commonly used disinfectant effervescent tablets on the market mainly contain sodium percarbonate. They are typically prepared using a wet process, with the main steps including: crystallization of sodium carbonate with hydrogen peroxide, drying of the sodium percarbonate intermediate, coating according to specific needs, and compression into effervescent tablets. In this sodium percarbonate effervescent tablet process, the intermediate prepared by the reaction of soda ash and hydrogen peroxide usually has a water content of 8%–14%, resulting in a relatively dense sodium percarbonate particle structure. Therefore, disintegrants and binders need to be added during the tableting stage to promote the rapid release of active oxygen, exhibiting a boiling-like oxygen-emission mode. However, the addition of disintegrants and binders not only increases production costs, but these types of percarbonate effervescent tablets are also environmentally unfriendly during use. Summary of the Invention

[0004] To address the shortcomings of the aforementioned percarbonate effervescent tablet production process and achieve energy-saving and emission-reducing production, this application provides a process for preparing porous effervescent sodium percarbonate. This process involves increasing the flow rate of alkaline solution and hydrogen peroxide in the reaction vessel to achieve a rapid reaction, producing an intermediate with a water content of 18%–20%. After drying, a loose, porous effervescent sodium percarbonate with low bulk density is obtained, and this structure also exhibits a boiling-like oxygen-evolving mode. This invention features a simple process, produces porous effervescent sodium percarbonate that meets standards, and also achieves the same visual effect as effervescent tablets.

[0005] This application discloses a method for preparing porous effervescent sodium percarbonate for use as a disinfectant, comprising the following steps: (S1) Preparation of the alkali solution, which includes a mother liquor, soda ash, sodium chloride, and a stabilizer; the mother liquor includes 8%–10% soda ash, 17%–22% sodium chloride, and 0.5%–1.5% hydrogen peroxide, with the remainder being water; the stabilizer is selected from one or more of polyethylene glycol, magnesium sulfonate, diethylenetriaminepentaacetate, sodium hexametaphosphate, and sodium metasilicate pentahydrate; (S2) Preparation of the hydrogen peroxide solution, by adding disodium ethylenediaminetetraacetate and magnesium sulfate to the hydrogen peroxide mother liquor; (S3) Introducing the prepared alkali solution and hydrogen peroxide solution from (S1) and (S2) into a reaction vessel for reaction, wherein the flow rate of the alkali solution is 1600 kg / h–2500 kg / h, and the flow rate of the hydrogen peroxide solution is 600 kg / h–1000 kg / h. kg / h, reaction temperature is 15℃~30℃, reaction time is 30min~50min; (S4) After the reaction is completed, the crystallized product in the reactor is separated from the reaction liquid by centrifuge. The water content of the crystallized product is 16%~22%. After drying, the finished product is obtained. The bulk density of the finished product is 540 g / L~650 g / L, and the effective active oxygen content is ≥12.5%.

[0006] Furthermore, the alkaline solution is prepared in a double-cone mixing vessel. First, the mother liquor is introduced, and then soda ash, sodium chloride, and a stabilizer are added. The soda ash is light anhydrous sodium carbonate.

[0007] Furthermore, the amount of stabilizer added is 0.2% to 1.5% of the amount of soda ash in the alkaline solution.

[0008] Furthermore, the concentration of the hydrogen peroxide mother liquor is 27.5% to 35%.

[0009] Furthermore, the mass ratio of the components in the hydrogen peroxide aqueous solution in (S2) is 70-90:2-6:1, where hydrogen peroxide: disodium ethylenediaminetetraacetate: magnesium sulfate.

[0010] Furthermore, in step (S3), the flow rate of the alkaline solution introduced is 1200 kg / h to 1400 kg / h, the flow rate of the hydrogen peroxide aqueous solution introduced is 800 kg / h to 900 kg / h, the reaction temperature is 20℃ to 25℃, the reaction time is 40 min, and the water content of the crystalline product is 18% to 20%.

[0011] Furthermore, the reaction solution is centrifuged and then recycled.

[0012] The above technical solution has the following advantages or beneficial effects: (1) It simplifies the preparation process of effervescent sodium percarbonate, eliminating the need for disintegrants and binders, making the process more energy-efficient, and the additive-free product more environmentally friendly and safe. (2) By improving the synthesis process of sodium percarbonate, a wet product with a water content as high as 18% to 20% can be obtained. (3) The low bulk density porous structure sodium percarbonate prepared by this invention has a visual effect of releasing active oxygen similar to that of sodium percarbonate effervescent tablets. Detailed Implementation

[0013] Example 1

[0014] 500 kg of mother liquor was introduced into a double-cone mixing vessel. The mother liquor consisted of 8% soda ash, 18.5% sodium chloride, 0.85% hydrogen peroxide, and the remainder was water. Then, 168 kg of light anhydrous sodium carbonate, 56 kg of sodium chloride, and 2.5 kg of sodium metasilicate pentahydrate were added to the double-cone mixing vessel to prepare an alkaline solution. 409 kg of a 27.5% hydrogen peroxide aqueous solution was introduced into a hydrogen peroxide tank, along with 2.5 kg of disodium ethylenediaminetetraacetate and 1.4 kg of magnesium sulfate, and stirred until homogeneous. The prepared alkaline solution and hydrogen peroxide aqueous solution were then introduced into a reaction vessel for reaction. The flow rate of the alkaline solution was 1400 kg / h, and the flow rate of the hydrogen peroxide aqueous solution was 900 kg / h. The reaction temperature was maintained between 20℃ and 25℃, and the reaction process took 40 min. After the reaction, the crystallized product in the reactor was separated from the mother liquor by a centrifuge. The filtrate was recycled back into the mother liquor tank to obtain 304 kg of wet sodium percarbonate with a water content of 18.8%. The wet sodium percarbonate was dried in a fluidized bed at 90°C for 30 minutes to obtain the finished product. The finished product had a bulk density of 580 g / L, an effective active oxygen content of 12.7%, a thermal stability of 72%, and a moisture stability of 59%.

[0015] Example 2

[0016] 750 kg of mother liquor was introduced into a double-cone mixing vessel. The mother liquor consisted of 8% soda ash, 22% sodium chloride, 1.5% hydrogen peroxide, and the remainder was water. Then, 250 kg of light anhydrous sodium carbonate, 83.3 kg of sodium chloride, and 3.8 kg of sodium metasilicate pentahydrate were added to the double-cone mixing vessel to prepare an alkaline solution. 606 kg of a 27.5% hydrogen peroxide aqueous solution was introduced into a hydrogen peroxide tank, along with 3.8 kg of disodium ethylenediaminetetraacetate and 2.1 kg of magnesium sulfate, and stirred until homogeneous. The alkaline solution and hydrogen peroxide were then introduced into a reaction vessel for reaction. The flow rate of the alkaline solution was 1400 kg / h, and the flow rate of the hydrogen peroxide was 900 kg / h. The reaction temperature was maintained between 20 and 25 °C, and the reaction process took 40 minutes. After the reaction, the crystallized product in the reaction vessel was separated from the mother liquor by centrifuge. The filtrate was recycled back into the mother liquor tank, yielding 452 kg of wet sodium percarbonate with a water content of 19.2%. The dried product has a bulk density of 620 g / L, an effective active oxygen content of 12.9%, a thermal stability of 82%, and a moisture stability of 60%.

[0017] Example 3

[0018] 900 kg of mother liquor was introduced into a double-cone mixing vessel. The mother liquor consisted of 10% soda ash, 17% sodium chloride, 0.5% hydrogen peroxide, and the remainder was water. Then, 300 kg of light anhydrous sodium carbonate, 100 kg of sodium chloride, and 4.5 kg of sodium metasilicate pentahydrate were added to the double-cone mixing vessel to prepare an alkaline solution. 571.4 kg of a 35% hydrogen peroxide aqueous solution was introduced into a hydrogen peroxide tank, along with 4.5 kg of disodium ethylenediaminetetraacetate and 2.5 kg of magnesium sulfate, and stirred until homogeneous. The alkaline solution and hydrogen peroxide were then introduced into a reaction vessel for reaction. The flow rate of the alkaline solution was 1200 kg / h, and the flow rate of the hydrogen peroxide was 800 kg / h. The reaction temperature was maintained between 20 and 25 °C, and the reaction process took 40 minutes. After the reaction, the crystallized product in the reaction vessel was separated from the mother liquor by centrifuge. The filtrate was recycled back into the mother liquor tank, yielding 543 kg of wet sodium percarbonate with a water content of 18.7%. The dried product has a bulk density of 650 g / L, an effective active oxygen content of 12.7%, a thermal stability of 80%, and a moisture stability of 61%.

[0019] Example 4

[0020] 1000 kg of mother liquor was introduced into a double-cone mixing vessel. The mother liquor consisted of 9% soda ash, 19.2% sodium chloride, 0.8% hydrogen peroxide, and the remainder was water. Then, 333.3 kg of light anhydrous sodium carbonate, 111.1 kg of sodium chloride, and 5.0 kg of sodium metasilicate pentahydrate were added to the double-cone mixing vessel to prepare an alkaline solution. 634.9 kg of a 35% hydrogen peroxide aqueous solution was introduced into a hydrogen peroxide tank, along with 5.0 kg of disodium ethylenediaminetetraacetate and 2.8 kg of magnesium sulfate, and stirred until homogeneous. The alkaline solution and hydrogen peroxide were then introduced into a reaction vessel for reaction. The flow rate of the alkaline solution was 1300 kg / h, and the flow rate of the hydrogen peroxide was 800 kg / h. The reaction temperature was maintained between 20 and 25 °C, and the reaction process took 40 minutes. After the reaction, the crystallized product in the reactor was separated from the mother liquor by a centrifuge. The filtrate was recycled back into the mother liquor tank to obtain 604 kg of wet sodium percarbonate with a water content of 19.5%. The wet product was dried to obtain the finished product with a bulk density of 540 g / L, an effective active oxygen content of 12.5%, a thermal stability of 76%, and a moisture stability of 65%.

[0021] Although embodiments of this application have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting this application. Various changes and modifications may be made to this application without departing from the spirit and scope thereof, and all such changes and modifications fall within the scope of the claims of this application.

Claims

1. A method for preparing porous effervescent sodium percarbonate for use as a disinfectant, comprising reacting an alkaline solution with an aqueous hydrogen peroxide solution, characterized in that... The process includes the following steps: (S1) Preparation of the alkali solution, which includes a mother liquor, soda ash, sodium chloride, and a stabilizer; the mother liquor includes 8%–10% soda ash, 17%–22% sodium chloride, and 0.5%–1.5% hydrogen peroxide, with the remainder being water; the soda ash is light anhydrous sodium carbonate; the stabilizer is selected from one or more of polyethylene glycol, magnesium sulfonate, diethylenetriamine pentaacetate, sodium hexametaphosphate, and sodium metasilicate pentahydrate, and the amount of stabilizer added is 0.2%–1.5% of the soda ash content in the alkali solution; (S2) Preparation of hydrogen peroxide aqueous solution: Add disodium ethylenediaminetetraacetate and magnesium sulfate to the hydrogen peroxide mother liquor. The concentration of the hydrogen peroxide mother liquor is 27.5% to 35%. The mass ratio of the components of the hydrogen peroxide aqueous solution is 70 to 90: 2 to 6:

1. (S3) The alkaline solution and hydrogen peroxide aqueous solution prepared in (S1) and (S2) are introduced into the reaction vessel for reaction. The flow rate of alkaline solution is 1200 kg / h to 1400 kg / h, the flow rate of hydrogen peroxide aqueous solution is 800 kg / h to 900 kg / h, the reaction temperature is 20℃ to 25℃, and the reaction time is 40 min. (S4) After the reaction is completed, the crystallized product in the reactor is separated from the reaction liquid by centrifuge. The water content of the crystallized product is 18% to 20%. After drying, the finished product is obtained. The bulk density of the finished product is 540 g / L to 650 g / L, and the effective active oxygen content is ≥12.5%.

2. The method for preparing porous effervescent sodium percarbonate as a disinfectant according to claim 1, characterized in that... The alkaline solution is prepared in a double-cone mixing vessel, first by introducing the mother liquor, and then by adding soda ash, sodium chloride and stabilizer.

3. The method for preparing porous effervescent sodium percarbonate as a disinfectant according to claim 1, characterized in that... The stabilizer is sodium metasilicate pentahydrate.

4. The method for preparing porous effervescent sodium percarbonate as a disinfectant according to claim 1, characterized in that... The reaction solution is centrifuged and then recycled.