Efficient food production pipeline acid detergent and preparation method thereof

Abstract

The invention discloses a high-efficiency acidic detergent for food production pipelines and a preparation method thereof, the preparation method comprises preparation of an acidic detergent, and the high-efficiency acidic detergent for production pipelines is prepared from modified nano silicon dioxide, a slow-release corrosion inhibitor, a self-repairing antibacterial microcapsule and a composite acid solution, wherein the composite acid liquor comprises sulfuric acid, nitric acid, citric acid and oligophosphoric acid, and supercritical carbon dioxide auxiliary treatment is carried out on the composite acid liquor after the composite acid liquor is prepared, the invention relates to the technical field of surface modification, the composite acid liquor is added into the acid detergent, and the sulfuric acid, the nitric acid, the citric acid and the oligophosphoric acid in the composite acid liquor are matched with one another, so that the surface modification effect is improved. Sulfuric acid, nitric acid and citric acid can effectively dissolve calcium and magnesium salt scales, nitric acid can also dissolve organic residues, oligophosphoric acid is chelated with calcium and magnesium ions to enhance the dissolving and dispersing capacity on the calcium and magnesium salt scales by virtue of a special structure, and lipophilic groups of oligophosphoric acid permeate grease to reduce the adhesive force and improve the grease removal effect.

Description

Technical Field

[0001] The invention relates to the technical field of surface modification, in particular to a high-efficiency acidic detergent for food production pipelines and a preparation method thereof. Background Art

[0002] With the increasing diversification of food production scenarios, the piping systems of different food production companies show significant differences in materials, structures and dirt types. In dairy production pipelines, since the milk, yogurt and other materials transported are rich in protein and fat, a layer of sticky organic dirt easily forms on the inner wall of the pipeline. This dirt is not only difficult to clean, but also produces odor under the action of microorganisms, affecting the flavor and quality of dairy products. The pipelines of meat processing companies face the challenges of complex dirt such as blood, grease and animal tissue debris. If these dirt are not removed in time and thoroughly, they will quickly breed a large number of bacteria, leading to food safety hazards. Traditional acidic detergents are generally Detergents that rely on a single inorganic acid, such as sulfuric acid, have obvious limitations when dealing with mixed scale. They are not capable of removing organic residues and grease-based scale other than calcium and magnesium salt scale, resulting in a reduction of more than 30% in overall decontamination efficiency and a prolongation of cleaning time by more than 30%. Furthermore, the corrosion inhibitors in traditional detergents are unevenly adsorbed, resulting in large fluctuations in the thickness of the protective film formed on the pipe surface, unstable corrosion inhibition effects, and ineffective corrosion inhibitor loss accounting for 40% under non-cleaning conditions. Furthermore, their disinfecting ingredients decompose quickly, leading to a high risk of residual microorganisms, making it difficult to achieve long-term protection and sustained antibacterial properties. Therefore, we propose a highly efficient acidic detergent for food production pipelines and a preparation method thereof. Summary of the Invention

[0003] The object of the present invention is to provide a high-efficiency food production pipeline acid detergent and a preparation method thereof.

[0004] To achieve the above objectives, the present invention provides the following technical solutions: a method for preparing an efficient acidic detergent for food production pipelines, comprising preparing the acidic detergent, wherein the materials for preparing the efficient acidic detergent for food production pipelines include modified nano-silica, a slow-release corrosion inhibitor, a self-repairing antibacterial microcapsule, and a composite acid solution, wherein the composite acid solution includes sulfuric acid, nitric acid, citric acid, and oligophosphoric acid. After the composite acid solution is prepared, it is subjected to supercritical carbon dioxide-assisted treatment. The specific operating steps of the method for preparing the efficient acidic detergent for food production pipelines are as follows: Step 1: Pre-treating raw materials to prepare nano-silica, slow-release corrosion inhibitors and self-repairing antibacterial microcapsules; Step 2: preparing the composite acid solution, adding deionized water into the microchannel reactor and turning on the cold water circulation device, and then adding sulfuric acid, nitric acid, citric acid and oligophosphoric acid in sequence to prepare the composite acid solution for use; Step 3: adding a slow-release corrosion inhibitor and a pH-responsive corrosion inhibitor to the composite acid solution, stirring, and sequentially adding peracetic acid, HEDP stabilizer, and sodium dodecyl diphenyl ether disulfonate, stirring and mixing, and then adding self-repairing antibacterial microcapsules and lactic acid, and mixing evenly to obtain a crude acid detergent for standby use; Step 4: Transfer the crude acid detergent to a supercritical carbon dioxide reactor and stir and mix. After the components are evenly dispersed, transfer the mixture to an emulsification tank, add fumed silica, and start an emulsifier to perform an emulsification operation. After emulsification, use a negative pressure filling machine to fill the packaging barrel with nitrogen to replace the oxygen. After packaging, the finished acid detergent is obtained. Step 5: After the acidic detergent is used, calcium hydroxide powder is added thereto, and the calcium sulfate crystals are separated after stirring the reaction. The residue in the waste liquid is adsorbed using ion exchange resin. After the treatment is completed, the quality is tested and the qualified ones are discharged.

[0005] As a further embodiment of the present invention: in the step 1, the surface of 50nm-70nm nano-silica is modified, and a silane coupling agent containing an amino group is grafted on its surface. The nano-silica is placed in a three-necked flask, anhydrous toluene is added, and ultrasonic dispersion is carried out for 30 minutes. Then, the silane coupling agent accounting for 3%-5% of the mass of the nano-silica is added dropwise, and the mixture is stirred and refluxed at 80°C-90°C for 4h-6h. After the reaction is completed, the mixture is centrifuged, washed, and dried to obtain the surface-modified nano-silica.

[0006] As a further embodiment of the present invention, in step 1, surface-modified nano-silica and mesoporous silica nanoparticles are dispersed in anhydrous ethanol, ultrasonically treated for 30 minutes to form a uniform suspension, HEDP is added thereto, and the mass ratio of HEDP to surface-modified nano-silica and mesoporous silica nanoparticles is 1:2:8-10, and the mixture is stirred for 6 hours to 8 hours to obtain a mixed solution, and the ethanol in the mixed solution is removed by evaporation to obtain HEDP-loaded mesoporous silica nanoparticles, dimethylaminoethyl methacrylate and n-butyl acrylate are mixed and dissolved in anhydrous ethanol at a molar ratio of 3:1 to prepare a solution with a mass concentration of 10%, and Mesoporous silica nanoparticles loaded with HEDP are dispersed in the solution, and azobisisobutyronitrile accounting for 1% of the total mass of the polymer monomer is added to the solution as an initiator. The reaction system is placed in a constant temperature water bath, the reaction temperature is controlled at 65°C, and stirring is continued at a stirring speed of 200r / min for 9 hours. A polymer molecular brush that responds to both pH and temperature is modified at the orifice. After the reaction is completed, the product is centrifuged at a speed of 5000r / min for 10min-15min. After separation, it is washed with anhydrous ethanol 3-4 times to remove unreacted monomers and initiators. After washing, it is transferred to a vacuum drying oven at 45°C and dried for 12h to obtain a finished slow-release corrosion inhibitor.

[0007] As a further scheme of the present invention: in the step one, self-repairing antibacterial microcapsules containing lysozyme and ε-polylysine are prepared, chitosan is dissolved in 1% acetic acid solution to prepare a chitosan solution with a mass concentration of 2%-3%, sodium alginate is dissolved in deionized water to prepare a sodium alginate solution with a mass concentration of 1.5%-2.5%, lysozyme and ε-polylysine are dissolved in deionized water at a mass ratio of 1:3-1:4, and stirred to form a mixed solution, and the mixed solution is added dropwise to the sodium alginate solution by a solution dropwise addition method. After the dropwise addition is completed, the mixture is stirred at a stirring speed of 180r / min-200r / min to prepare a colostrum, and the colostrum is slowly added dropwise to the chitosan solution. The self-assembly reaction is carried out at a stirring speed of 250r / min-280r / min for 30min-60min to prepare self-repairing antibacterial microcapsules.

[0008] As a further scheme of the present invention: in the step 2, deionized water accounting for 60% of the total mass is added to the microchannel reactor, the cold water circulation system is turned on, the water temperature is maintained at 20±2°C, the temperature monitoring equipment is started at the same time, the reaction temperature is recorded in real time, and sulfuric acid with a concentration of 18% is injected into the reactor at a flow rate of 10L / min. At the same time, the stirring device is turned on and the stirring speed is adjusted to 500r / min-600r / min. After all the sulfuric acid is injected and mixed evenly, nitric acid with a concentration of 6% is injected at a flow rate of 8L / min and stirred for 10min. The nitric acid is fully mixed with the reaction solution. After the nitric acid is added and stirred for 10min, 2.5% food-grade citric acid is added. Stirring is maintained during the addition process to quickly and evenly disperse the citric acid in the reaction solution. Oligophosphoric acid accounting for 1%-2% by mass is added. After the addition is completed, stirring is continued for 10min-15min to fully mix all the acid solutions. The pH value of the reaction solution is detected using a pH detector. The pH value is 1.2±0.1, which meets the composite requirement, thereby obtaining a composite acid solution.

[0009] As a further solution of the present invention: in the step three, 1% and 0.35% of the finished slow-release corrosion inhibitor and the pH-responsive corrosion inhibitor are added to the composite acid solution respectively, the stirring device is turned on, the stirring speed is adjusted to 200 r / min, and the stirring is continued for 10 minutes to uniformly disperse the slow-release corrosion inhibitor in the composite acid solution. After the dispersion is completed, 5%-6% of peracetic acid, 0.8% of HEDP stabilizer and 0.2% of sodium dodecyl diphenyl ether disulfonate accounting for the total mass of the reaction solution are added in sequence. During the addition process, the stirring speed is adjusted to 150 r / min, and the reaction temperature is maintained at 25°C-30°C. After the addition is completed, stirring is continued for 15 minutes. After the components are fully mixed, 0.08% of the self-repairing antibacterial microcapsules and 1.5% of lactic acid accounting for the total mass of the reaction solution are added, and the mixture is stirred evenly to obtain a crude acid detergent.

[0010] As a further solution of the present invention: in the step 4, the crude acidic detergent is transferred to a supercritical carbon dioxide reactor, the pressure in the reactor is adjusted to 8MPa-10MPa, and the temperature is set at 35°C-40°C. The stirring device is turned on, and the mixture is stirred for 30min-60min under the set temperature and pressure conditions, and the stirring speed is 100r / min-200r / min. After the reaction is completed, the pressure in the reactor is reduced to normal pressure, the treated acid solution is taken out and transferred to an emulsification tank, and 2.5% of the total mass of the detergent is accurately weighed using an electronic scale. Slowly add fumed silica to the emulsification tank, turn on the emulsifier, adjust the speed to 3000r / min-3500r / min, and continue stirring for 20 minutes to evenly disperse the fumed silica in the detergent. Control the viscosity of the detergent within the range of 200mPa・s-400mPa・s. After dispersion, fill it through a negative pressure filling machine, adjust the vacuum degree of the negative pressure filling machine to -0.08MPa, use nitrogen to replace the oxygen in the packaging barrel, and control the packaging temperature between 30℃-35℃ during the packaging process. After packaging, store it for future use.

[0011] As a further solution of the present invention: in the step 5, after the acidic detergent is used, calcium hydroxide powder is added to the waste liquid, and the added amount is calculated according to a molar ratio of 1:1 with the acidic substance in the waste liquid. The stirring device is turned on to continuously stir the waste liquid at a stirring speed of 100r / min-150r / min, and the pH value of the waste liquid is monitored in real time using a pH detector. When the pH value is between 6.5 and 7.5, the addition of calcium hydroxide powder is stopped, and the stirring is stopped. The waste liquid is allowed to settle for 2h-3h. After the calcium sulfate crystals are fully precipitated, the supernatant of the waste liquid is taken out and slowly passed through an ion exchange column filled with D001 ion exchange resin. The neutralized waste liquid is directly discharged after passing the test, and the metal ions adsorbed by the ion exchange column are collected.

[0012] A high-efficiency acidic detergent for food production pipelines, the formula of the high-efficiency acidic detergent for food production pipelines comprising a composite acid solution, corrosion inhibitors and antibacterial agents, additives and auxiliary materials, wherein the formulas of the composite acid solution are sulfuric acid, nitric acid, citric acid, oligophosphoric acid and deionized water, respectively, and their mass proportions in the acidic detergent are 18%, 6%, 2.5%, 2% and 60%, respectively; wherein the corrosion inhibitors and antibacterial agents and additives comprise a slow-release corrosion inhibitor, a pH-responsive corrosion inhibitor, peracetic acid, HEDP stabilizer, sodium dodecyl diphenyl ether disulfonate, self-healing antibacterial microcapsules and lactic acid, and their mass proportions in the acidic detergent are 1%, 0.35%, 5.07%, 0.8%, 0.2%, 0.08% and 1.5%, respectively; wherein the auxiliary material comprises fumed silica, and its mass proportion in the acidic detergent is 2.5%.

[0013] By adopting the above technical solution, compared with the prior art, the beneficial effects of the present invention are: 1. The present invention adds a composite acid solution to an acidic detergent. Sulfuric acid, nitric acid, citric acid and oligophosphoric acid in the composite acid solution cooperate with each other. Sulfuric acid, nitric acid and citric acid can effectively dissolve calcium and magnesium salt scale, and nitric acid can also dissolve organic residues. Oligophosphoric acid, with its special structure, can chelate with calcium and magnesium ions to enhance the dissolution and dispersion ability of calcium and magnesium salt scale. On the other hand, its lipophilic groups penetrate grease to reduce adhesion and improve grease removal effect. In actual cleaning, this composite acid system greatly improves the removal rate of calcium and magnesium salt scale and significantly shortens the dissolution time of organic stains. It can effectively cope with dairy products and meat processing. The complex mixed dirt in the pipeline solves the problem of traditional detergents' insufficient ability to remove organic residues and grease-based dirt, significantly shortening the cleaning time. By adding HEDP loaded on mesoporous silica nanoparticles and modifying polymer molecular brushes that are dual-responsive to pH and temperature, the polymer molecular brushes open their pores and slowly release HEDP during cleaning, forming a more uniform and dense protective film on the pipeline surface. This significantly reduces the corrosion rate and greatly improves the utilization rate of the corrosion inhibitor. This solves the problems of uneven adsorption, unstable corrosion inhibition effect, and high ineffective loss of traditional corrosion inhibitors, achieving long-term protection. 2. The present invention adds self-repairing antibacterial microcapsules containing lysozyme and ε-polylysine. When microorganisms erode the pipeline surface, the wall material degrades and releases the two components. Lysozyme destroys the cell walls of microorganisms, and ε-polylysine inhibits their growth and reproduction. The degradation products of the microcapsules participate in repairing the corrosion-inhibiting protective film, thereby enhancing the protective effect. This solves the problems of rapid decomposition of disinfectant ingredients and high risk of microbial residues in traditional detergents, and achieves a sustained antibacterial effect. By introducing supercritical carbon dioxide auxiliary technology during the preparation process, the composite acid solution and functional ingredients are treated at a specific temperature and pressure, promoting uniform dispersion of the ingredients and improving mixing uniformity. At the same time, the decomposition rate of easily decomposable ingredients such as peracetic acid is reduced, thereby enhancing detergent stability, reducing performance differences between batches, and improving product quality stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a flow chart for preparing an acidic detergent according to an embodiment of the present invention; Figure 2 This is a graph showing the acidic detergent detection data in an embodiment of the present invention; Figure 3 This is a test data diagram of detergent A in an embodiment of the present invention; Figure 4 This is a graph showing the detection data of detergent B in an embodiment of the present invention; Figure 5 This is a comparison chart of acidic detergent test data in an embodiment of the present invention. DETAILED DESCRIPTION

[0015] The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0016] In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0017] Please see the attached Figure 1 -Attached Figure 5 The present invention provides a method for preparing a high-efficiency acidic detergent for food production pipelines, including preparing the acidic detergent. The materials for preparing the high-efficiency acidic detergent for food production pipelines include modified nano-silica, a slow-release corrosion inhibitor, a self-repairing antibacterial microcapsule, and a composite acid solution, wherein the composite acid solution includes sulfuric acid, nitric acid, citric acid, and oligophosphoric acid. After the composite acid solution is prepared, it is subjected to supercritical carbon dioxide-assisted treatment. The specific operating steps of the method for preparing the high-efficiency acidic detergent for food production pipelines are as follows: Step 1: Pre-treating raw materials to prepare nano-silica, slow-release corrosion inhibitors and self-repairing antibacterial microcapsules; Step 2: preparing the composite acid solution, adding deionized water into the microchannel reactor and turning on the cold water circulation device, and then adding sulfuric acid, nitric acid, citric acid and oligophosphoric acid in sequence to prepare the composite acid solution for use; Step 3: adding a slow-release corrosion inhibitor and a pH-responsive corrosion inhibitor to the composite acid solution, stirring, and sequentially adding peracetic acid, HEDP stabilizer, and sodium dodecyl diphenyl ether disulfonate, stirring and mixing, and then adding self-repairing antibacterial microcapsules and lactic acid, and mixing evenly to obtain a crude acid detergent for standby use; Step 4: Transfer the crude acid detergent to a supercritical carbon dioxide reactor and stir and mix. After the components are evenly dispersed, transfer the mixture to an emulsification tank, add fumed silica, and start an emulsifier to perform an emulsification operation. After emulsification, use a negative pressure filling machine to fill the packaging barrel with nitrogen to replace the oxygen. After packaging, the finished acid detergent is obtained. Step 5: After the acidic detergent is used, calcium hydroxide powder is added thereto, and the calcium sulfate crystals are separated after stirring the reaction. The residue in the waste liquid is adsorbed using ion exchange resin. After the treatment is completed, the quality is tested and the qualified ones are discharged.

[0018] In one embodiment of the present invention, in step 1, surface modification of 50 nm-70 nm nano-silica is performed, and a silane coupling agent containing an amino group is grafted onto its surface. The nano-silica is placed in a three-necked flask, anhydrous toluene is added, and ultrasonic dispersion is performed for 30 minutes. Then, a silane coupling agent accounting for 3%-5% of the mass of the nano-silica is added dropwise, and the mixture is stirred and refluxed at 80° C.-90° C. for 4 h-6 h. After the reaction is completed, the mixture is centrifuged, washed, and dried to obtain surface-modified nano-silica.

[0019] In one embodiment of the present invention, in step 1, surface-modified nano-silica and mesoporous silica nanoparticles are dispersed in anhydrous ethanol, ultrasonically treated for 30 minutes to form a uniform suspension, HEDP is added thereto, and the mass ratio of HEDP to surface-modified nano-silica and mesoporous silica nanoparticles is 1:2:8-10. The mixture is stirred for 6 hours to 8 hours to obtain a mixed solution, and the ethanol in the mixed solution is removed by evaporation to obtain HEDP-loaded mesoporous silica nanoparticles. Dimethylaminoethyl methacrylate and n-butyl acrylate are mixed and dissolved in anhydrous ethanol at a molar ratio of 3:1 to prepare a solution with a mass concentration of 10%. Mesoporous silica nanoparticles loaded with HEDP are dispersed in the solution, and azobisisobutyronitrile accounting for 1% of the total mass of the polymer monomer is added to the solution as an initiator. The reaction system is placed in a constant temperature water bath, the reaction temperature is controlled at 65°C, and stirring is continued at a stirring speed of 200r / min for 9 hours. A polymer molecular brush that responds to both pH and temperature is modified at the orifice. After the reaction is completed, the product is centrifuged at a speed of 5000r / min for 10min-15min. After separation, it is washed with anhydrous ethanol 3-4 times to remove unreacted monomers and initiators. After washing, it is transferred to a vacuum drying oven at 45°C and dried for 12h to obtain a finished slow-release corrosion inhibitor.

[0020] In one embodiment of the present invention: in step 1, self-repairing antibacterial microcapsules containing lysozyme and ε-polylysine are prepared, chitosan is dissolved in 1% acetic acid solution to prepare a chitosan solution with a mass concentration of 2%-3%, sodium alginate is dissolved in deionized water to prepare a sodium alginate solution with a mass concentration of 1.5%-2.5%, lysozyme and ε-polylysine are dissolved in deionized water at a mass ratio of 1:3-1:4, and stirred to form a mixed solution, and the mixed solution is added dropwise to the sodium alginate solution by a solution dropwise addition method, and after the dropwise addition is completed, the mixture is stirred at a stirring speed of 180r / min-200r / min to prepare a colostrum, and the colostrum is slowly added dropwise to the chitosan solution, and a self-assembly reaction is carried out at a stirring speed of 250r / min-280r / min for 30min-60min to prepare self-repairing antibacterial microcapsules.

[0021] In one embodiment of the present invention: in step 2, deionized water accounting for 60% of the total mass is added to the microchannel reactor, the cold water circulation system is turned on, the water temperature is maintained at 20±2°C, the temperature monitoring equipment is started at the same time, the reaction temperature is recorded in real time, and sulfuric acid with a concentration of 18% is injected into the reactor at a flow rate of 10L / min. At the same time, the stirring device is turned on and the stirring speed is adjusted to 500r / min-600r / min. After all the sulfuric acid is injected and mixed evenly, nitric acid with a concentration of 6% is injected at a flow rate of 8L / min and stirred for 10min. The nitric acid is fully mixed with the reaction solution. After the nitric acid is added and stirred for 10min, 2.5% food-grade citric acid is added. Stirring is maintained during the addition process to quickly and evenly disperse the citric acid in the reaction solution. Oligophosphoric acid accounting for 1%-2% by mass is added. After the addition is completed, stirring is continued for 10min-15min to fully mix all the acid solutions. The pH value of the reaction solution is detected using a pH detector. The pH value is 1.2±0.1, which meets the composite requirement, and a composite acid solution is obtained.

[0022] In one embodiment of the present invention: in step three, 1% and 0.35% of the finished slow-release corrosion inhibitor and the pH-responsive corrosion inhibitor are added to the composite acid solution respectively, the stirring device is turned on, the stirring speed is adjusted to 200r / min, and the stirring is continued for 10min to uniformly disperse the slow-release corrosion inhibitor in the composite acid solution. After the dispersion is completed, 5%-6% of peracetic acid, 0.8% of HEDP stabilizer and 0.2% of sodium dodecyl diphenyl ether disulfonate accounting for the total mass of the reaction solution are added in sequence. During the addition process, the stirring speed is adjusted to 150r / min, and the reaction temperature is maintained at 25°C-30°C. After the addition is completed, stirring is continued for 15min. After the components are fully mixed, 0.08% of the self-repairing antibacterial microcapsules and 1.5% of lactic acid accounting for the total mass of the reaction solution are added, and the mixture is stirred evenly to obtain a crude acid detergent.

[0023] In one embodiment of the present invention: in step 4, the crude acidic detergent is transferred to a supercritical carbon dioxide reactor, the pressure in the reactor is adjusted to 8MPa-10MPa, and the temperature is set at 35°C-40°C. The stirring device is turned on and stirred for 30min-60min under the set temperature and pressure conditions, and the stirring speed is 100r / min-200r / min. After the reaction is completed, the pressure in the reactor is reduced to normal pressure, the treated acid solution is taken out and transferred to an emulsification tank, and 2.5% of the total mass of the detergent is accurately weighed using an electronic scale. Slowly add fumed silica to the emulsification tank, turn on the emulsifier, adjust the speed to 3000r / min-3500r / min, and continue stirring for 20 minutes to evenly disperse the fumed silica in the detergent. Control the viscosity of the detergent within the range of 200mPa・s-400mPa・s. After dispersion, fill it through a negative pressure filling machine, adjust the vacuum degree of the negative pressure filling machine to -0.08MPa, use nitrogen to replace the oxygen in the packaging barrel, and control the packaging temperature between 30℃-35℃ during the packaging process. After packaging, store it for future use.

[0024] In one embodiment of the present invention: in step five, after the acidic detergent is used, calcium hydroxide powder is added to the waste liquid, and the added amount is calculated according to a molar ratio of 1:1 with the acidic substance in the waste liquid. The stirring device is turned on to continuously stir the waste liquid at a stirring speed of 100r / min-150r / min, and the pH value of the waste liquid is monitored in real time using a pH detector. When the pH value is between 6.5 and 7.5, the addition of calcium hydroxide powder is stopped, and the stirring is stopped. The waste liquid is allowed to stand and settle for 2h-3h. After the calcium sulfate crystals are fully precipitated, the supernatant of the waste liquid is taken out and slowly passed through an ion exchange column containing D001 type ion exchange resin. The neutralized waste liquid is directly discharged after passing the test, and the metal ions adsorbed by the ion exchange column are collected.

[0025] A high-efficiency acidic detergent for food production pipelines, the formula of the high-efficiency acidic detergent for food production pipelines includes a composite acid solution, corrosion inhibitors and antibacterial agents, additives and auxiliary materials, wherein the formulas of the composite acid solution are sulfuric acid, nitric acid, citric acid, oligophosphoric acid and deionized water, respectively, and their mass proportions in the acidic detergent are 18%, 6%, 2.5%, 2% and 60%, respectively; wherein the corrosion inhibitors and antibacterial agents and additives include a slow-release corrosion inhibitor, a pH-responsive corrosion inhibitor, peracetic acid, HEDP stabilizer, sodium dodecyl diphenyl ether disulfonate, self-healing antibacterial microcapsules and lactic acid, and their mass proportions in the acidic detergent are 1%, 0.35%, 5.07%, 0.8%, 0.2%, 0.08% and 1.5%, respectively; wherein the auxiliary material includes fumed silica, and its mass proportion in the acidic detergent is 2.5%.

[0026] In one embodiment of the present invention: In step 2, if the pH value does not meet the requirements, the amount of acid added can be appropriately adjusted, and the mixing uniformity of the reaction liquid can be detected using a conductivity detector to ensure that the mixing uniformity is >98%. At the same time, the time of the entire reaction process is recorded to ensure that the reaction time is ≤15 minutes. If the quantitative indicators are not met, the reasons need to be analyzed and corresponding measures need to be taken, including extending the stirring time, adjusting the order of acid addition, etc.

[0027] In one embodiment of the present invention: in step 5, the purity of the separated calcium sulfate crystals is detected by XRD detection method to ensure that the purity is ≥90%, and the residual amount of heavy metals in the waste liquid is detected by AAS detection method to ensure that the heavy metal residue is <0.1ppm. If the test result does not meet the quantitative index, the neutralization treatment and metal ion recovery process need to be optimized and adjusted.

[0028] In one embodiment of the present invention, in step 5, the main acidic substances in the waste liquid after the use of the acidic detergent come from sulfuric acid, nitric acid, citric acid and oligophosphoric acid in the composite acid solution. Taking sulfuric acid as an example, the chemical equation for the neutralization reaction with calcium hydroxide is:

[0029] The chemical equation for the reaction of nitric acid and calcium hydroxide is:

[0030] The chemical equation for the reaction of citric acid and calcium hydroxide is:

[0031] The chemical equation for the reaction of oligophosphoric acid and calcium hydroxide is:

[0032] Among them, the degree of polymerization of oligophosphate It is not fixed, and its general formula is The reactions are all acid-base neutralization reactions, generating corresponding calcium salt precipitation and water. The specific reaction equation will vary depending on the actual degree of polymerization of oligophosphoric acid.

[0033] Example 10 g of 50 nm nano-silica was placed in a three-necked flask, 100 mL of anhydrous toluene was added, and ultrasonic dispersion was performed for 30 min. 0.3 g of an amino-containing silane coupling agent was added dropwise, and the mixture was stirred and refluxed at 80°C for 6 h. After the reaction, the surface-modified nano-silica was obtained by centrifugation, washing, and drying. 2 g of surface-modified nano-silica and 8 g of mesoporous silica nanoparticles were dispersed in 100 mL of anhydrous ethanol, ultrasonically treated for 30 min, 1 g of HEDP was added, stirred and reacted for 8 h, and the ethanol was evaporated to obtain mesoporous silica nanoparticles loaded with HEDP. Dimethylaminoethyl methacrylate and n-butyl acrylate were mixed in a molar ratio of 3:1 and dissolved in anhydrous ethanol to prepare a 10% solution, in which the mesoporous silica nanoparticles loaded with HEDP were dispersed, 0.1 g of azobisisobutyronitrile was added, and the mixture was reacted at 65° C. and a stirring speed of 200 r / min for 9 h. The product was centrifuged at 5000 r / min for 15 min, washed four times with anhydrous ethanol, and dried in a vacuum drying oven at 45° C. for 12 h to obtain a slow-release corrosion inhibitor. 2 g of chitosan was dissolved in 100 mL of 1% acetic acid solution to prepare a 2% chitosan solution, 1.5 g of sodium alginate was dissolved in 100 mL of deionized water to prepare a 1.5% sodium alginate solution, lysozyme and ε-polylysine were dissolved in deionized water at a mass ratio of 1:3 to prepare a mixed solution, the mixed solution was added dropwise to the sodium alginate solution, and after the addition was complete, the mixture was stirred at 180 r / min to prepare a colostrum, which was slowly added dropwise to the chitosan solution. The self-assembly reaction was carried out at a stirring speed of 250 r / min for 60 minutes to prepare self-repairing antibacterial microcapsules; 600g of deionized water was added to the microchannel reactor, the cold water circulation system was turned on, the water temperature was maintained at 20±2°C, 180g of 18% sulfuric acid was injected at a flow rate of 10L / min, the stirring speed was 500r / min, and after the sulfuric acid was added and mixed evenly, 60g of 6% nitric acid was injected at a flow rate of 8L / min, stirred for 10min, 25g of food-grade citric acid was added, and then 20g of oligophosphoric acid was added. The stirring was continued for 15min, and the pH was tested with a pH detector. The pH was 1.2, and the conductivity detector tested the mixing uniformity to be 99%. The reaction time was 12min to prepare a composite acid solution. 10g of slow-release corrosion inhibitor and 3.5g of A pH-responsive corrosion inhibitor was stirred at 200 r / min for 10 min, 50.7 g of peracetic acid, 8 g of HEDP stabilizer, and 2 g of sodium dodecyl diphenyl ether disulfonate were added in sequence, the mixture was stirred at 150 r / min, the temperature was controlled at 25° C., and the mixture was stirred for 15 min. 0.8 g of self-repairing antibacterial microcapsules and 15 g of lactic acid were added and stirred evenly to obtain a crude acidic detergent. The crude acidic detergent was transferred to a supercritical carbon dioxide reactor, stirred and mixed at 35° C. and 8 MPa for 60 min, and then transferred to an emulsification tank, 25 g of fumed silica was added, and the mixture was stirred at 3000 r / min for 20 min. The viscosity was controlled at 200-400 mPa·s to obtain a finished acidic detergent.

[0034] Comparative Example 1 An acidic detergent purchased on the market was selected and labeled as detergent A. Its composition is as follows: Acid composition: nitric acid (40%), sulfuric acid (10%), and the rest is deionized water. This formula utilizes the strong oxidizing and acidic properties of nitric acid to effectively dissolve some metal oxides and some dirt. Sulfuric acid helps to enhance the overall acidity and improve the solubility of stubborn inorganic salt scale. Auxiliary ingredients: About 0.5% of conventional corrosion inhibitors are added to inhibit acid corrosion on metal pipes to a certain extent. It contains 0.2% of non-ionic surfactants, which can reduce the surface tension of the solution, enhance the wetting and penetration of the detergent on dirt, and achieve better cleaning results. This detergent does not contain special ingredients such as self-healing antibacterial microcapsules.

[0035] Comparative Example 2 Select an acidic detergent purchased on the market and label it as detergent B. Its composition is as follows: Acid: Phosphoric acid (25%) and citric acid (8%), using deionized water as the solvent. Phosphoric acid has a good complexing ability for metal ions and can effectively remove metal salt scales such as calcium and magnesium. It is also relatively weak in corrosiveness to equipment. Citric acid has a chelating effect and can form stable chelates with metal ions, helping to remove rust stains and other dirt. It is relatively safe and meets the requirements for food equipment cleaning. Other ingredients: Contains 0.8% organic amine corrosion inhibitor, which can form a protective film on the metal surface to reduce acid corrosion on the equipment; 0.3% anionic surfactant is added to improve the detergent's emulsification and dispersion ability on grease and oil dirt; the disinfection ingredient is mainly sodium hypochlorite, which is used to kill microorganisms on the surface of the equipment, but does not contain the advanced corrosion inhibition and antibacterial system of the present invention, such as self-repairing antibacterial microcapsules and slow-release corrosion inhibitors that respond to both pH and temperature.

[0036] The acidic detergents prepared in the examples and the acidic detergents A and B of comparative examples 1 and 2 were tested; Materials: Food-grade stainless steel pipe specimens (50 mm diameter, 20 cm length, 3 per group), simulated dirt (a mixture of 30% calcium and magnesium salt scale, 25% milk fat, 25% protein, and 20% meat scraps), pH test paper, conductivity meter, electrochemical workstation, microbial incubator, sterile cotton swabs, and culture medium. Equipment: constant temperature water bath cleaning tank, ultrasonic cleaning machine, electronic balance, drying oven; Simulated fouling preparation and pipeline pretreatment, Apply the simulated dirt evenly on the inner wall of the pipe with a thickness of about 0.5mm and let it stand for 24 hours to solidify.

[0037] Rinse the pipe surface with distilled water to remove loose dirt and then dry it for later use; Cleaning test, Detergent preparation: Dilute the example, detergent A, and detergent B at a ratio of 1:150 (commercially available detergents A and B are diluted according to the concentrations recommended in the product instructions).

[0038] Cleaning operation: The pipe specimens were immersed in a constant temperature water bath containing 200 mL of the corresponding detergent, set at 40°C, and cleaned for 30 minutes. During this period, ultrasonic assisted cleaning was performed for 5 minutes every 10 minutes, and the power of the ultrasonic equipment was set to 100W. Performance testing, Decontamination efficiency test: After cleaning, take out the pipe, rinse it with distilled water and dry it. Weigh the pipe mass with an electronic balance and calculate the amount of dirt residue.

[0039] Decontamination efficiency (%) = [(initial dirt mass - residual dirt mass) / initial dirt mass] × 100%.

[0040] Corrosion inhibition performance test: The corrosion rate of the pipeline specimen was measured using an electrochemical workstation. The test conditions were room temperature, polarization scanning under open circuit potential, and a scanning rate of 1 mV / s.

[0041] Antibacterial effect detection: After cleaning, wipe the inner wall of the pipe with a sterile cotton swab, place the cotton swab in 10 mL of sterile saline and shake to mix.

[0042] Take 1 mL of the dilution and spread it on the nutrient agar medium. After incubation at 37°C for 24 hours, count the total number of colonies and calculate the inhibition rate. The detection inhibition rate includes the inhibition rate of Escherichia coli and Staphylococcus aureus.

[0043] Inhibition rate (%) = [(number of colonies in the control group - number of colonies in the experimental group) / number of colonies in the control group] × 100%.

[0044] The test results of the acidic detergent prepared in this embodiment are shown in the attached Figure 2 As shown, the test results of the acid detergent of Comparative Example 1 are shown in the attached Figure 3 As shown, the test results of the acid detergent of Comparative Example 2 are shown in the attached Figure 4 The final comparison data is shown in the attached Figure 5 shown.

[0045] According to the above tests and the final comparative data, the acidic detergents of the embodiments of the present invention have significantly better comprehensive performance than commercially available products in the cleaning of food production pipelines, especially in the removal of complex dirt, long-term corrosion inhibition, and continuous antibacterial performance. They can effectively solve the limitations of traditional detergents and have high industrial application value.

[0046] Although the present invention is disclosed above with reference to preferred embodiments, this is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modifications, equivalent variations, and modifications made to the above embodiments in accordance with the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for preparing an efficient acidic detergent for food production pipelines, comprising preparing the acidic detergent, characterized in that: The materials for preparing the high-efficiency acidic detergent for food production pipelines include modified nano-silica, a slow-release corrosion inhibitor, self-repairing antibacterial microcapsules, and a composite acid solution, wherein the composite acid solution includes sulfuric acid, nitric acid, citric acid, and oligophosphoric acid. After the composite acid solution is prepared, it is subjected to supercritical carbon dioxide-assisted treatment. The specific operating steps of the method for preparing the high-efficiency acidic detergent for food production pipelines are as follows: Step 1: Pre-treating raw materials to prepare nano-silica, slow-release corrosion inhibitors and self-repairing antibacterial microcapsules; Step 2: preparing the composite acid solution, adding deionized water into the microchannel reactor and turning on the cold water circulation device, and then adding sulfuric acid, nitric acid, citric acid and oligophosphoric acid in sequence to prepare the composite acid solution for use; Step 3: adding a slow-release corrosion inhibitor and a pH-responsive corrosion inhibitor to the composite acid solution, stirring, and sequentially adding peracetic acid, HEDP stabilizer, and sodium dodecyl diphenyl ether disulfonate, stirring and mixing, and then adding self-repairing antibacterial microcapsules and lactic acid, and mixing evenly to obtain a crude acid detergent for standby use; Step 4: Transfer the crude acid detergent to a supercritical carbon dioxide reactor and stir and mix. After the components are evenly dispersed, transfer the mixture to an emulsification tank, add fumed silica, and start an emulsifier to perform an emulsification operation. After emulsification, use a negative pressure filling machine to fill the packaging barrel with nitrogen to replace the oxygen. After packaging, the finished acid detergent is obtained. Step 5: After the acidic detergent is used, calcium hydroxide powder is added thereto, and the calcium sulfate crystals are separated after stirring the reaction. The residue in the waste liquid is adsorbed using ion exchange resin. After the treatment is completed, the quality is tested and the qualified ones are discharged.

2. The method for preparing a high-efficiency acidic detergent for food production pipelines according to claim 1, characterized in that: In the step 1, 50nm-70nm nano-silica is surface-modified, and a silane coupling agent containing an amino group is grafted onto the surface of the nano-silica. The nano-silica is placed in a three-necked flask, anhydrous toluene is added, and ultrasonic dispersion is performed for 30 minutes. Then, the silane coupling agent accounting for 3%-5% of the mass of the nano-silica is added dropwise, and the mixture is stirred and refluxed at 80°C-90°C for 4h-6h. After the reaction is completed, the mixture is centrifuged, washed, and dried to obtain the surface-modified nano-silica.

3. The method for preparing a high-efficiency acidic detergent for food production pipelines according to claim 2, characterized in that: In the step 1, surface-modified nano-silica and mesoporous silica nanoparticles are dispersed in anhydrous ethanol and ultrasonically treated for 30 minutes to form a uniform suspension, HEDP is added thereto, and the mass ratio of HEDP to surface-modified nano-silica and mesoporous silica nanoparticles is 1:2:8-10. The mixture is stirred and reacted for 6 hours to 8 hours to obtain a mixed solution, and the ethanol in the mixed solution is removed by evaporation to obtain HEDP-loaded mesoporous silica nanoparticles. Dimethylaminoethyl methacrylate and n-butyl acrylate are mixed and dissolved in anhydrous ethanol at a molar ratio of 3:1 to prepare a solution with a mass concentration of 10%, and HEDP-loaded Mesoporous silica nanoparticles are dispersed in the solution, and azobisisobutyronitrile accounting for 1% of the total mass of the polymer monomer is added to the solution as an initiator. The reaction system is placed in a constant temperature water bath, the reaction temperature is controlled at 65°C, and stirring is continued at a stirring speed of 200r / min for 9 hours. A polymer molecular brush that responds to both pH and temperature is modified at the pore mouth. After the reaction is completed, the product is centrifuged at a speed of 5000r / min for 10min-15min. After separation, it is washed with anhydrous ethanol 3-4 times to remove unreacted monomers and initiators. After washing, it is transferred to a vacuum drying oven at 45°C and dried for 12h to obtain a finished slow-release corrosion inhibitor.

4. The method for preparing a high-efficiency acidic detergent for food production pipelines according to claim 3, characterized in that: In the step 1, self-repairing antibacterial microcapsules containing lysozyme and ε-polylysine are prepared, chitosan is dissolved in 1% acetic acid solution to prepare a chitosan solution with a mass concentration of 2%-3%, sodium alginate is dissolved in deionized water to prepare a sodium alginate solution with a mass concentration of 1.5%-2.5%, lysozyme and ε-polylysine are dissolved in deionized water at a mass ratio of 1:3-1:4, and stirred to prepare a mixed solution, and the mixed solution is added dropwise to the sodium alginate solution by using a solution dropwise addition method, and after the dropwise addition is completed, the mixture is stirred at a stirring speed of 180r / min-200r / min to prepare a colostrum, and the colostrum is slowly added dropwise to the chitosan solution, and a self-assembly reaction is carried out at a stirring speed of 250r / min-280r / min for 30min-60min to prepare the self-repairing antibacterial microcapsules.

5. The method for preparing a high-efficiency acidic detergent for food production pipelines according to claim 4, characterized in that: In the step 2, deionized water accounting for 60% of the total mass is added to the microchannel reactor, the cold water circulation system is turned on, the water temperature is maintained at 20±2°C, the temperature monitoring equipment is started at the same time, the reaction temperature is recorded in real time, and sulfuric acid with a concentration of 18% is injected into the reactor at a flow rate of 10L / min. At the same time, the stirring device is turned on and the stirring speed is adjusted to 500r / min-600r / min. After all the sulfuric acid is injected and mixed evenly, nitric acid with a concentration of 6% is injected at a flow rate of 8L / min and stirred for 10min. The nitric acid and the reaction solution are fully mixed. After the nitric acid is added and stirred for 10min, 2.5% food-grade citric acid is added. Stirring is maintained during the addition process to quickly and evenly disperse the citric acid in the reaction solution. Oligophosphoric acid accounting for 1%-2% by mass is added. After the addition is completed, stirring is continued for 10min-15min to fully mix all the acid solutions. The pH value of the reaction solution is detected using a pH detector. pH=1.2±0.1 meets the requirements, and a composite acid solution is obtained.

6. The method for preparing a high-efficiency acidic detergent for food production pipelines according to claim 5, characterized in that: In the step three, 1% and 0.35% of the finished slow-release corrosion inhibitor and the pH-responsive corrosion inhibitor, respectively, are added to the composite acid solution, the stirring device is turned on, the stirring speed is adjusted to 200 r / min, and the stirring is continued for 10 minutes to uniformly disperse the slow-release corrosion inhibitor in the composite acid solution. After the dispersion is completed, 5%-6% of peracetic acid, 0.8% of HEDP stabilizer and 0.2% of sodium dodecyl diphenyl ether disulfonate, accounting for the total mass of the reaction solution, are added in sequence. During the addition process, the stirring speed is adjusted to 150 r / min, and the reaction temperature is maintained at 25°C-30°C. After the addition is completed, stirring is continued for 15 minutes. After the components are fully mixed, 0.08% of the self-repairing antibacterial microcapsules and 1.5% of lactic acid, accounting for the total mass of the reaction solution, are added, and the mixture is stirred evenly to obtain a crude acid detergent.

7. The method for preparing a high-efficiency acidic detergent for food production pipelines according to claim 6, characterized in that: In the step 4, the crude acidic detergent is transferred to a supercritical carbon dioxide reactor, the pressure in the reactor is adjusted to 8MPa-10MPa, and the temperature is set at 35°C-40°C. The stirring device is turned on and stirred for 30min-60min under the set temperature and pressure conditions. The stirring speed is 100r / min-200r / min. After the reaction is completed, the pressure in the reactor is reduced to normal pressure, the treated acid solution is taken out and transferred to an emulsification tank, and an electronic scale is used to accurately weigh 2.5% of the total mass of the detergent. , slowly add it to the emulsification tank, turn on the emulsifier, adjust the speed to 3000r / min-3500r / min, continue stirring for 20min, evenly disperse the fumed silica in the detergent, and control the viscosity of the detergent within the range of 200mPa・s-400mPa・s. After the dispersion is completed, it is filled through a negative pressure filling machine, and the vacuum degree of the negative pressure filling machine is adjusted to -0.08MPa. Nitrogen is used to replace the oxygen in the packaging barrel. The packaging temperature is controlled between 30℃-35℃ during the packaging process. After the packaging is completed, it is stored for future use.

8. The method for preparing a high-efficiency acidic detergent for food production pipelines according to claim 7, characterized in that: In the step 5, after the acidic detergent is used, calcium hydroxide powder is added to the waste liquid, and the added amount is calculated according to a molar ratio of 1:1 with the acidic substance in the waste liquid. The stirring device is turned on to continuously stir the waste liquid at a stirring speed of 100r / min-150r / min, and the pH value of the waste liquid is monitored in real time using a pH detector. When the pH value is between 6.5 and 7.5, the addition of calcium hydroxide powder is stopped, and the stirring is stopped. The waste liquid is allowed to stand and settle for 2h-3h. After the calcium sulfate crystals are fully precipitated, the supernatant of the waste liquid is taken out and slowly passed through an ion exchange column equipped with D001 ion exchange resin. The neutralized waste liquid is directly discharged after passing the test, and the metal ions adsorbed by the ion exchange column are collected.

9. A high-efficiency acidic detergent for food production pipelines suitable for the preparation method of the high-efficiency acidic detergent for food production pipelines according to any one of claims 1 to 8, characterized in that: The formula of the high-efficiency acid detergent for food production pipelines includes a composite acid solution, corrosion inhibitors and antibacterial agents, additives and auxiliary materials, wherein the formula of the composite acid solution is sulfuric acid, nitric acid, citric acid, oligophosphoric acid and deionized water, and their mass proportions in the acid detergent are 18%, 6%, 2.5%, 2% and 60%, respectively; wherein the corrosion inhibitors and antibacterial agents and additives include slow-release corrosion inhibitors, pH-responsive corrosion inhibitors, peracetic acid, HEDP stabilizers, sodium dodecyl diphenyl ether disulfonate, self-healing antibacterial microcapsules and lactic acid, and their mass proportions in the acid detergent are 1%, 0.35%, 5.07%, 0.8%, 0.2%, 0.08% and 1.5%, respectively; wherein the auxiliary material includes fumed silica, and its mass proportion in the acid detergent is 2.5%.

Images