Solid composition for sugar purification

Abstract

Solid composition for removing colored impurities in sugar liquid or syrup and method of using the same, wherein the solid composition comprises at least a quaternary ammonium compound and a phosphorus compound.

Description

[0001] This application is a divisional application of the following application: Application date: May 23, 2017; Application number: 201780032571.5; Invention title: "Solid composition for sugar purification".

[0002] This application claims priority to PCT International Patent Application No. PCT / CN2016 / 083428, filed on May 26, 2016, the entire contents of which are incorporated herein by reference for all purposes. Technical Field

[0003] This invention relates to a solid composition for sugar purification. The solid composition can remove colored impurities from sugar solutions or syrups. The solid composition comprises a quaternary ammonium compound and a phosphorus compound. Background Technology

[0004] Refined sugar is typically obtained by purifying raw sugar or sugar juice. For example, raw sugar can be obtained from sugar juice through purification, evaporation into a concentrated syrup, and crystallization. The crystallized product can then be dissolved in water to obtain a sugar solution. Subsequently, the sugar solution can be further purified and processed to obtain refined sugar with acceptable purity standards. Alternatively, syrup obtained from sugar juice can undergo a purification process without the crystallization step of raw sugar.

[0005] The whiteness of refined sugar is an important standard for sugar quality. One objective of sugar solution or syrup purification is to reduce colored impurities, resulting in a purified sugar product with the desired whiteness. Various methods for reducing colored impurities during sugar purification are known in the art. One known method is phosphate treatment, which aims to produce calcium phosphate flocs using phosphorus compounds and lime, followed by a flocculation step by adding a polymer as a flocculant. An important modification to this phosphate treatment is the application of a color precipitant, such as certain quaternary ammonium compounds. Quaternary ammonium compounds, being cationic, can improve the precipitation of anionic, high-molecular-weight colored impurities, which can be more easily removed as flotation scum.

[0006] Conventionally, quaternary ammonium compounds and phosphorus compounds are added to sugar mixtures in separate streams. For example, U.S. Patent No. 3,698,951 discloses a method for removing colored impurities from sugar solutions by adding a quaternary ammonium compound followed by phosphoric acid. The separate addition of reagents is laborious and this method also requires high carpex costs, energy, and maintenance costs. Typically, the quaternary ammonium compound is diluted in water before being added to the sugar solution or syrup. However, quaternary ammonium compound solutions tend to have relatively high viscosity, which affects the efficiency of addition and can sometimes cause equipment blockage. To address this issue, a high dilution factor is required to achieve a sufficiently low viscosity for the quaternary ammonium compound solution. This wastes water and incurs additional costs. Summary of the Invention

[0007] It has been found that the above problems can be solved by the present invention.

[0008] In a first aspect of the invention, a solid composition is provided, particularly a solid composition for removing colored impurities from sugar solutions or syrups, comprising at least a quaternary ammonium compound and a phosphorus compound; wherein the weight ratio of the quaternary ammonium compound to the phosphorus compound is in the range of 1:1 to 1:5.

[0009] Preferably, the weight ratio of the quaternary ammonium compound to the phosphate compound is in the range of 1:1 to 1:3.

[0010] In particular, this quaternary ammonium compound has the following general formula: [N + (R1)(R2)(R3)(R4)] y X - (I) in: R1, R2, R3, and R4 can be the same or different, representing saturated or unsaturated, straight-chain or branched aliphatic groups or aromatic groups having 1 to 30 carbon atoms. X is an anion; y is the valence of X.

[0011] Preferably, the quaternary ammonium compound has the following general formula: [N + (R5)2(R6)(R7)] y X - (II) in: R5 is an alkyl or hydroxyalkyl group containing 8 to 22 carbon atoms; R6 is an alkyl or hydroxyalkyl group containing 1 to 4 carbon atoms; R7 is either R5 or R6; X is an anion; y is the valence of X.

[0012] This quaternary ammonium compound can have the following general formula: [N + ((CH2) n -T-R8) m (R9) 4-m ] y X - (III) in: R8 is independently selected from C1-C 24 Alkyl or hydroxyalkyl; R9 is independently selected from C1-C4 alkyl or hydroxyalkyl; T is –C(=O)–O–, –O–C(=O)–, –NR 10 –C(=O)– or –(C=O)–NR 10 –, where R 10 It is hydrogen, C1-C6 alkyl, or C1-C6 hydroxyalkyl; n is an integer from 0 to 5; m is selected from 1, 2, and 3; X is an anion; y is the valence of X.

[0013] This quaternary ammonium compound can have the following general formula: [N + (R 11 (R) 12 (R) 13 (CH2) z -Ph)] y X - (V) in: R 11 and R 12 They can be the same or different, representing straight-chain or branched alkyl or hydroxyalkyl chains having 1 to 24 carbon atoms; R 13 It is a straight-chain or branched alkyl or hydroxyalkyl group having 1 to 8 carbon atoms; z = 0 or an integer from 1 to 3; Ph represents phenyl; X is an anion; y is the valence of X.

[0014] Preferably, the quaternary ammonium compound is selected from the group consisting of: C 14 -C 18 Alkyl dimethyl ammonium compounds, distearate dimethyl ammonium compounds, dipalmitoyl dimethyl ammonium compounds, dihexadecyl dimethyl ammonium compounds, dioctadecyl dimethyl ammonium compounds, dioleyl dimethyl ammonium compounds, dihydrogenated rapeseed alkyl dimethyl ammonium compounds, and mixtures thereof.

[0015] Preferably, the phosphorus compound is phosphoric acid.

[0016] In a second aspect of the invention, a method is provided for reducing colored impurities in a sugar solution or syrup by adding a quaternary ammonium compound and a phosphorus compound to the sugar solution or syrup; wherein the weight ratio of the quaternary ammonium compound to the phosphorus compound is in the range of 1:1 to 1:5.

[0017] In particular, a method for reducing colored impurities in sugar solutions or syrups is provided, the method comprising the following steps: (1) Providing an aqueous solution or dispersion of a solid composition according to a first aspect of the invention; and (2) Add the aqueous solution or dispersion to the sugar solution or syrup.

[0018] Preferably, the method further includes the following steps: (a) Adding lime-based compounds and flocculants to the sugar solution or syrup to form flocculent precipitates of these colored impurities; (b) Separate the flocculent precipitate from the sugar solution or syrup.

[0019] Preferably, the flocculant is polyacrylamide.

[0020] Preferably, the quaternary ammonium compound is present in an amount from 100 to 500 ppm based on the weight of the solid sugar in the sugar solution or syrup.

[0021] In a third aspect of the invention, the use of a solid composition according to the first aspect of the invention is provided for reducing colored impurities in sugar solutions or syrups.

[0022] In a fourth aspect of the invention, a method for preparing a solid composition comprising a quaternary ammonium compound and a phosphorus compound is provided; wherein the method includes the step of mixing the quaternary ammonium compound with the phosphorus compound in a weight ratio of 1:1 to 1:5. Detailed Implementation

[0023] Throughout this description, including the claims, the terms “comprising one” or “comprising a” shall be understood to be synonymous with the term “comprising at least one” unless otherwise specified, and “among” shall be understood to include the limit.

[0024] It should be noted that when specifying any concentration, weight ratio, or amount range, any specific upper limit concentration, weight ratio, or amount can be associated with any specific lower limit concentration, weight ratio, or amount.

[0025] As used herein, the term "alkyl" means a saturated hydrocarbon group that may be straight-chain, branched, or cyclic, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, n-hexyl, or cyclohexyl.

[0026] As used herein, the term "hydroxyalkyl" means an alkyl group that is replaced by a hydroxyl group, such as hydroxymethyl, hydroxyethyl, hydroxypropyl, and hydroxydecyl.

[0027] As used herein, the term "aryl" means a monovalent unsaturated hydrocarbon group containing one or more six-membered carbon rings, wherein the degree of unsaturation may be represented by three conjugated double bonds, which may be substituted at one or more carbons of the ring with hydroxyl, alkyl, alkenyl, halogen, haloalkyl or amino groups, such as phenoxy, phenyl, methylphenyl, dimethylphenyl, trimethylphenyl, chlorophenyl, trichloromethylphenyl, aminophenyl.

[0028] As used herein, the term "aralkyl" means an alkyl group substituted with one or more aryl groups, such as phenylmethyl, phenylethyl, triphenylmethyl.

[0029] This invention provides a solid composition, particularly a solid composition for reducing colored impurities in sugar solutions or syrups, comprising at least a quaternary ammonium compound and a phosphorus compound; wherein the weight ratio of the quaternary ammonium compound to the phosphorus compound is in the range of 1:1 to 1:5. Colored impurities in sugar solutions or syrups particularly include plant pigments, melanin, caramel, and alkaline degradation products of fructose. This solid composition exhibits good storage stability and provides excellent decolorization efficiency.

[0030] As used herein, the term "solid composition" means a composition in solid form such as powder, granules, agglomerates, flakes, pellets, granules, tablets, bricks, ointments, blocks (such as molded blocks), unit doses, or another solid form known to those skilled in the art. The term "solid" means the state of the composition under the intended conditions of storage and use. Generally, it is expected that the composition will remain in solid form at ambient temperature (approximately 25ºC). When referring to an ointment, it means that the solid composition will not flow imperceptibly and will substantially retain its shape under moderate stress or pressure or simply gravity, such as, for example, the shape of the mold when removed from a mold, or the shape of the article formed when extruded from an extruder.

[0031] As used herein, the term "quaternary ammonium compound" (also known as "quaternary ammonium salt") means a compound containing at least one quaternized nitrogen atom, wherein the nitrogen atom is attached to four organic groups. The quaternary ammonium salt may contain one or more quaternized nitrogen atoms. Preferably, the quaternary ammonium salt contains only one quaternized nitrogen atom.

[0032] As used herein, the term "sugar solution or syrup" refers to any liquid or syrup containing sugar or molten raw sugar. Typically, this sugar is derived from plant sources such as sugarcane, sugar beets, and corn. "Raw sugar" refers to sugar that has undergone minimal processing and contains both soluble and insoluble impurities. This raw sugar can be obtained from sugar juice through purification, evaporation into a concentrated syrup, and crystallization. The crystallized product can then be dissolved in water to obtain a sugar solution, also known as a "molten liquid." Alternatively, the syrup obtained from sugar juice can be used as a raw material in sugar refining processes.

[0033] According to the present invention, the quaternary ammonium salt may have the following general formula: [N + (R1)(R2)(R3)(R4)] y X - (I) in: R1, R2, R3, and R4 can be the same or different, representing saturated or unsaturated, straight or branched aliphatic groups or aromatic groups (such as aryl or aralkyl) having 1 to 30 carbon atoms. X is an anion, such as a halide ion like Cl or Br, sulfate, alkyl sulfate, nitrate or acetate, preferably, X is a chloride ion or methyl sulfate ion; y is the valence of X.

[0034] Aliphatic groups, as defined in general formula (I), may contain heteroatoms such as oxygen, nitrogen, sulfur, and halogens. Optionally, the aliphatic group contains at least an ester or amide functional group.

[0035] Advantageously, the quaternary ammonium salt is an alkyl quaternary ammonium salt having the following general formula: [N + (R5)2(R6)(R7)] y X - (II) in: R5 is an alkyl or hydroxyalkyl group containing 8 to 22 carbon atoms, such as C8H. 17 C 10 H 21 C 12 H 25 C 14 H 29 C 16 H 33 C 18 H 37 Preferably, R5 contains 12 to 20 carbon atoms; R6 is an alkyl or hydroxyalkyl group containing 1 to 4 carbon atoms, such as methyl, ethyl and propyl, preferably methyl; R7 is either R5 or R6; X is an anion, such as a halide ion like Cl or Br, sulfate, alkyl sulfate, nitrate or acetate, preferably, X is a chloride ion or methyl sulfate ion; y is the valence of X.

[0036] In particular, the quaternary ammonium salt according to general formula (II) is a dialkyldimethyl quaternary ammonium salt. Examples of quaternary ammonium salts having general formula (II) include C 14 -C 18 Alkyl dimethyl ammonium compounds (such as DHT21 sold by Solvay Company), ditallow alkyl dimethyl ammonium compounds, distearate dimethyl ammonium compounds, dipalmitoyl dimethyl ammonium compounds, dihexadecyl dimethyl ammonium compounds, dioctadecyl dimethyl ammonium compounds, dioleoyl dimethyl ammonium compounds, and dihydrogenated rapeseed alkyl dimethyl ammonium compounds.

[0037] Advantageously, the quaternary ammonium salt has the following general formula: [N + ((CH2) n -T-R8) m (R9) 4-m ] y X - (III) in: R8 is independently selected from C1-C 24 Alkyl or hydroxyalkyl; R9 is independently selected from C1-C4 alkyl or hydroxyalkyl; T is –C(=O)–O–, –O–C(=O)–, –NR 10 –C(=O)– or –(C=O)–NR 10 –, where R 10 It is hydrogen, C1-C6 alkyl, or C1-C6 hydroxyalkyl; n is an integer from 0 to 5; m is selected from 1, 2, and 3; X is an anion, such as a halide ion like Cl or Br, sulfate, alkyl sulfate, nitrate or acetate, preferably, X is a chloride ion or methyl sulfate ion; y is the valence of X.

[0038] Preferably, m is 2, as defined in general formula (III). Therefore, the quaternary ammonium salt can have the following general formula: [N + ((CH2) n -T-R8)2(R9)2] y X - (IV) R8, R9, T, n, X and y are as defined in general formula (III).

[0039] Examples of quaternary ammonium salts having general formula (III) include: TET: Di(tallowylcarboxyethyl)hydroxyethylmethylmethylammonium sulfate, TEO: Di(oleoylcarboxyethyl)hydroxyethylmethylmethylammonium sulfate, TES: Distearate-hydroxyethylmethyl methyl ammonium sulfate TEHT: Di(hydrogenated tallow-carboxyethyl)hydroxyethylmethylmethylammonium sulfate, TEP: Di(palmitoylcarboxyethyl)hydroxyethylmethylmethylammonium sulfate DEEDMAC: Dimethylbis[2-[(1-oxooctadecyl)oxy]ethyl]ammonium chloride.

[0040] Advantageously, the quaternary ammonium salt has the following general formula: [N + (R 11 (R) 12 (R) 13 (CH2) z -Ph)] y X - (V) in: R 11 and R 12 They may be the same or different, representing straight-chain or branched alkyl or hydroxyalkyl groups having 1 to 24 carbon atoms, preferably 8 to 24 carbon atoms; R 13 It is a straight-chain or branched alkyl or hydroxyalkyl group having 1 to 8 carbon atoms, preferably 1 to 3 carbon atoms; z = 0 or an integer from 1 to 3, preferably z = 1; Ph represents a phenyl group, which may have at least one substituent selected from the group consisting of halides, nitrites, and sulfates at any available position; X is an anion, such as a halide ion like Cl or Br, sulfate, alkyl sulfate, nitrate or acetate, preferably, X is a chloride ion or methyl sulfate ion; y is the valence of X.

[0041] Examples of quaternary ammonium salts having the general formula (V) include distearylmethylbenzylammonium compounds, ditaurylmethylbenzylammonium compounds, dipalmitylmethylbenzyl compounds, dihexadecylmethylbenzylammonium compounds, and dioctadecylmethylbenzylammonium compounds.

[0042] It should be understood that the solid composition may include a single quaternary ammonium salt or a mixture of more than one quaternary ammonium salt.

[0043] According to the present invention, the phosphorus compound may be phosphoric acid or a phosphate compound. Suitable phosphate compounds include, but are not limited to, tripolyphosphate, pyrophosphate, hexametaphosphate, trisodium phosphate, sodium dihydrogen phosphate, calcium dihydrogen phosphate, ammonium dihydrogen phosphate, disodium hydrogen phosphate, diammonium hydrogen phosphate, or any water-soluble phosphate contemplated not to substantially lower the pH of the syrup or sugar solution within the scope of the present invention. Preferably, the phosphorus compound is phosphoric acid.

[0044] The solid composition may further contain water and organic solvents such as ethanol and isopropanol.

[0045] The solid composition may further comprise a polycationic polymer. Suitable polycationic polymers include copolymers of diallyl dimethyl ammonium chloride (DADMAC) and acrylamide, copolymers of DADMAC and sodium acrylate, copolymers of DADMAC, acrylamide and sodium acrylate, and copolymers of dimethylamine-epimyl chloride.

[0046] The solid composition may also contain an oxidizing agent that can be used in sugar purification. Suitable oxidizing agents include hydrogen peroxide and hypochlorite.

[0047] According to the present invention, the weight ratio of the quaternary ammonium salt to the phosphorus compound contained in the solid composition is in the range of 1:1 to 1:5 (including: 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.8, 1:2, 1:2.2, 1:2.4, 1:2.6, 1:2.8, 1:3, 1:4, 1:5, etc., and all values ​​and sub-ranges between said values, as expressly stated). Preferably, the weight ratio is in the range of 1:1 to 1:3, more preferably in the range of 1:1.2 to 1:3. In the context of the present invention, this weight ratio is calculated based on the weight of the active ingredient.

[0048] This solid composition can be prepared by blending the quaternary ammonium salt component with the phosphorus compound component using any mixing method well known to those skilled in the art. Therefore, the present invention also provides a method for preparing a solid composition comprising a quaternary ammonium compound and a phosphorus compound; wherein the method includes the step of mixing the quaternary ammonium compound with the phosphorus compound in a weight ratio in the range of 1:1 to 1:5. Typically, the quaternary ammonium salt is melted by heating it to a temperature above its melting point (e.g., about 65ºC), and then the phosphorus compound is added to the quaternary ammonium salt under stirring, preferably under heating. The mixture can then be cooled to ambient temperature to solidify the composition.

[0049] In another aspect, the present invention provides a method for reducing colored impurities in a sugar solution or syrup by adding a quaternary ammonium compound and a phosphorus compound to the sugar solution or syrup; wherein the weight ratio of the quaternary ammonium compound to the phosphorus compound is in the range of 1:1 to 1:5. The quaternary ammonium compound and the phosphorus compound can be added simultaneously to the sugar solution or syrup or premixed and added as a blend.

[0050] The present invention also provides a method for reducing colored impurities in sugar solutions or syrups by using the solid composition described herein. In particular, the method includes the following steps: (1) Providing an aqueous solution or dispersion of the solid composition; and (2) Add the solution or dispersion to the sugar solution or syrup.

[0051] The solid composition can be dissolved or dispersed in water, optionally using an organic solvent. Preferably, the concentration of the quaternary ammonium salt in such a solution or dispersion is from 5 wt% to 30 wt%, more preferably from 10 wt% to 20 wt%.

[0052] A solution or dispersion containing quaternary ammonium salts and phosphorus compounds can be added to the sugar solution or syrup in the reaction vessel using a metering pump and a stirring device, so that the quaternary ammonium salt comes into contact with the colored impurities. In particular, the reaction is carried out at a temperature of 70ºC-90ºC, preferably 80ºC-85ºC. The precipitate formed in this reaction is initially very finely dispersed and almost invisible to the naked eye; however, its presence can be revealed by measuring the optical properties of the liquid, for example, by measuring the optical density at 420 nm using a spectrophotometer. According to an exemplary embodiment of the invention, such fine precipitates can be removed by filtration using a filter medium with sufficiently small porosity.

[0053] One advantage of this invention is that it allows for the convenient addition of quaternary ammonium salts and phosphorus compounds to sugar solutions or syrups in a single stream, saving time and costs. Furthermore, at the same quaternary ammonium salt concentration, the viscosity of the diluted aqueous solution of this solid composition is lower than that of a solution containing only quaternary ammonium salts. This is particularly advantageous because the lower viscosity of the diluted aqueous solution allows for rapid and thorough mixing of the quaternary ammonium salt with the sugar solution or syrup, which can improve the efficiency of the reaction between the quaternary ammonium salt and colored impurities. Moreover, the melting point of this solid composition is lower than that of the quaternary ammonium salt solid; therefore, when melting colored precipitates, energy can be saved by using this solid composition due to the lower temperature and shorter heating time required.

[0054] The effective dosage of the solid composition can be readily determined by those skilled in the art. Generally, the dosage of the solid composition ranges from about 200 ppm to about 2000 ppm, based on the weight of the solid sugar in the sugar solution or syrup. Preferably, the dosage of the solid composition ranges from about 400 ppm to about 1000 ppm, based on the weight of the solid sugar in the sugar solution or syrup.

[0055] According to the present invention, the method may further include the following steps: (a) Adding lime-based compounds and flocculants to the sugar solution or syrup to form flocculent precipitates of these colored impurities; (b) Separate the flocculent precipitate from the sugar solution or syrup.

[0056] In particular, the flocculent precipitate is calcium phosphate.

[0057] As used herein, the term "lime-based compound" refers to a calcium-containing compound that can be used to neutralize the acidity of a solution and to form a precipitate of phosphorus compounds in sugar solutions or syrups, specifically in the form of insoluble calcium phosphate. Suitable lime-based compounds include, but are not limited to, calcium hydroxide, as a slurry with water (lime milk) and lime succinate. This lime-based compound can be added to the sugar solution or syrup in sufficient quantity to raise the pH of the solution or syrup to between 6 and 8, preferably between 6.8 and 7.2.

[0058] Flocculants can be added to sugar solutions or syrups to increase the size of precipitate scum, which contains mostly calcium phosphate flocculants and other colored impurities that precipitate by binding with quaternary ammonium salts.

[0059] Preferably, the flocculant is an anionic polyelectrolyte, such as polyacrylate or polyacrylamide, with polyacrylamide being more preferred. Based on the weight of the solid sugar in the sugar solution or syrup, it may contain an amount of about 5 ppm to about 30 ppm of polyacrylamide. Preferably, based on the weight of the solid sugar in the sugar solution or syrup, polyacrylamide is present in an amount of about 10 ppm to about 25 ppm.

[0060] The polyacrylamide used in this invention preferably has an average molecular weight from 12,000,000 to 30,000,000 Daltons. More preferably, the polyacrylamide has an average molecular weight of 22,000,000 Daltons.

[0061] Following flocculation, the flocculent precipitate containing colored impurities, which may be in the form of floating scum, can be removed from the sugar solution or syrup by physical separation methods, including flotation (such as air flotation) and filtration. A preferred separation method for this invention is air flotation, in which an additional micro-aeration step precedes the addition of the flocculant. Micro-aeration can be performed to produce aerated sugar solution or syrup. This step can be carried out in a reaction tank equipped with a stirring device or using an air compressor. The air-captured scum floating in the sugar solution or syrup can then be removed from the liquid surface by a skimming device (e.g., a scraper).

[0062] Overall, by using the method of the present invention, the color value of sugar products can be reduced to 15-100 ICUMSA units, more typically 20-50 ICUMSA units.

[0063] The invention will now be described with reference to many specific examples, which should not be considered as limiting the scope of the claimed invention.

[0064] If any patent, patent application, or disclosure incorporated herein by reference conflicts with the description of this application to the extent that it may lead to ambiguity in terminology, then this description shall take precedence.

[0065] Example Material Dialkyl quaternary ammonium salt: DHT21; C 14 -C 18 Alkyl dimethyl ammonium chloride (CAS No. 68002-59-5); from Solvay. Monoalkyl quaternary ammonium salt: Octadecyltrimethylammonium chloride (CAS No. 112-03-8); from Solvay. Benzyl quaternary ammonium salt: diC 14 -C 18 Alkylmethylbenzylammonium chloride (CAS No. 61789-73-9); from Solvay. Phosphoric acid: 85 wt% Decolorization performance test Sample preparation Solid blends were prepared by mixing DHT21 (from Solvay) with phosphoric acid, wherein the weight ratio of DHT21 to phosphoric acid in such samples is shown in Table 1 below. These solid blends were melted at 60ºC and subsequently diluted in hot water to obtain a solution with a DHT21 concentration of 10 wt% (active). Raw sugar obtained from sugarcane juice through simple lime treatment was dissolved in hot water to obtain a sugar solution with a Brix value of 60-65. This sugar solution has a sugar value of 500-1500 ICUMSA units.

[0066] Phosphating treatment The sugar solution was heated to 80ºC-85ºC, and then a dilute solution of the blend was added to the sugar solution and stirred for 15 minutes. The dosage of the quaternary ammonium salt was 300 ppm based on the weight of the solid sugar in the sugar solution. Then, lime succinate was added to the mixture with stirring to bring the pH of the mixture to 6.9-7.0.

[0067] flotation The sugar solution was then transferred to a separatory funnel, and PAM solution (0.1 wt%) was added (the dosage of PAM is 15 ppm-20 ppm based on the solid sugar content). The sugar solution was shaken, and the separatory funnel was immersed in a boiling water bath for 10 minutes. The precipitate containing colored impurities floated to the top of the sugar solution. 40 ml of the clear sugar solution was collected from the bottom of the funnel for colorimetric testing.

[0068] Color value test The collected sugar solution was diluted in water (to a final sugar concentration of 35-40 Brix degrees). The pH of the solution was adjusted to 7.0 using diluted HCl or NaOH solution. Subsequently, the solution was filtered through filter paper (0.45 µm pore size) and the absorbance at 420 nm was detected using a UV / Vis spectrometer.

[0069] Calculate the color value (COL) using the following formula: COL (ICUSMA or IU420) = x 10 5 in: A420 represents the absorbance of the sugar solution at a wavelength of 420 nm. B represents the Brix content of the sugar solution at 25ºC (the Brix content of the sugar solution is measured using an Abbe refractometer, and the unit is 1000 ppm). o Bx); L is the length of the absorption cell; ρ is the density of the sugar solution.

[0070] The decolorization rate is calculated using the following formula: Decolorization rate = (COL) 原液 – COL 浮选 ) / COL 原液 * 100% The decolorization rate results are shown in Table 1 below: Table 1 sample DHT21 / H3PO4 (w / w) Decolorization rate (%) Example 1 1 : 1 51.8 Example 2 1 : 1.5 55.1 Example 3 1 : 2 54.8 Example 4 1 : 3 55.3 Comparison Example 1 1 : 0.5 44.5 Comparison Example 2 1 : 0.8 45.7 Another set of experiments was conducted using the method described above, the difference being that DHT21 in the solid blend was replaced by a benzyl quaternary ammonium salt, i.e., diC 14 -C 18 Alkylmethyl benzyl ammonium chloride (obtained from Solvay) is used as a substitute.

[0071] Table 2 sample <![CDATA[Benzyl quaternary ammonium salt / H3PO4 (w / w)]]> Decolorization rate (%) Example 5 1 : 1 57.6 Example 6 1 : 1.5 58.9 Example 7 1 : 2 59.2 Example 8 1 : 3 59.5 Comparison Example 3 1 : 0.5 50.1 Comparison Example 4 1 : 0.8 52.7 As shown in Tables 1 and 2, the decolorization efficiency of the solid composition is affected by the weight ratio of the quaternary ammonium salt to the phosphorus compound. When this weight ratio is not less than 1:1, the solid composition is more effective in reducing colored impurities.

[0072] Stability test A solid blend containing DHT21 and phosphoric acid was prepared as described above. The solid blend was incubated in an oven at 54ºC for 4 weeks. The contents of DHT21 and phosphoric acid were titrated before and after incubation. Phosphoric acid was titrated using NaOH, with phenolphthalein as a color indicator. The procedure for this titration is well known to those skilled in the art. DHT21 was titrated according to the method described in Chinese National Standard GB / T 5174-2004. The results are shown in Table 3 below: Table 3 DHT21 content (%) <![CDATA[Content of H3PO4 (%)]]> 0 weeks 49.5 35.7 4 weeks 49.9 36.1 The results showed that the solid composition according to the invention could maintain the stability of its components after incubation at 50ºC for up to 4 weeks. A slight decrease in DHT21 content was observed, which should be due to the evaporation of the organic solvent.

[0073] Viscosity test Solid DHT21 or a solid blend of DHT21 and phosphoric acid was dissolved in water, with various DHT21 concentrations shown in Table 4 below. The viscosity of the solution was then measured using a Brookfield LVT viscometer at a shear rate of 100 rpm (rotor #S2). Measurements were taken at ambient temperature, 40ºC, and 60ºC. The unit of viscosity is cP·s. The results are shown in Table 4 below: Table 4 The results showed that the solution containing both quaternary ammonium salt and phosphoric acid exhibited significantly lower viscosity compared to the solution containing only quaternary ammonium salt (while keeping the quaternary ammonium salt content the same).

[0074] Decolorization performance test of different quaternary ammonium salt compounds Prepare solid blends according to the procedure described above and the formulations in Table 5 below. Use dialkyl quaternary ammonium salts (DHT21) or monoalkyl quaternary ammonium salts (FENTACARE). ®1831 70). The decolorization performance was evaluated as described above. The results are shown in Table 5 below: Table 5 sample formula Decolorization rate (%) Example 9 <![CDATA[Dialkyl quaternary ammonium salt / H3PO4, 1:1 (w / w)]]> 51.8 Example 10 <![CDATA[Dialkyl quaternary ammonium salt / H3PO4, 1:2 (w / w)]]> 54.8 Comparison Example 5 <![CDATA[Monalkyl quaternary ammonium salt / H3PO4, 1:1 (w / w)]]> 45.8 Comparison Example 6 <![CDATA[Monalkyl quaternary ammonium salt / H3PO4, 1:2 (w / w)]]> 52.6 The results showed that dialkyl quaternary ammonium salts produced higher decolorization efficiency when formulated with phosphoric acid in solid blends compared to monoalkyl quaternary ammonium salts.

[0075] Flotation rate test Solid blends were prepared according to the procedure described above and the formulations in Table 6 below. Dialkyl quaternary ammonium salts (DHT21) or monoalkyl quaternary ammonium salts were used. The weight ratio of the quaternary ammonium salt compound to phosphoric acid in the solid blends was 1:1 (w / w).

[0076] These solid blends were melted at 60ºC and subsequently diluted in hot water to obtain a solution with a quaternary ammonium salt concentration of 10 wt% (active). Raw sugar obtained from sugarcane juice through simple lime treatment was dissolved in hot water to obtain a sugar solution with a Brix degree of 60-65. This sugar solution has a sugar value of 500-1500 ICUMSA units.

[0077] The sugar solution was subjected to phosphate treatment as described above. Subsequently, the sugar solution was transferred to a separatory funnel and a PAM solution (0.1 wt%) was added (the dosage of PAM was 15 ppm–20 ppm based on the solid sugar content). The sugar solution was agitated and the separatory funnel was immersed in a boiling water bath for 10 minutes. A precipitate containing colored impurities floated to the top of the sugar solution. After immersing the separatory funnel in the boiling water bath, the flotation rate was measured at different time points. To determine the flotation rate, the results were estimated by visual inspection, and the flotation rate was expressed by dividing the amount of flocculent precipitate floating to the top surface of the sugar solution by the total amount of flocculent precipitate present in the sugar solution. The results are shown in Table 6 below.

[0078] Table 6 Ideally, the flocculent precipitate containing colored impurities should float rapidly and separate from the clarified sugar solution as soon as it appears. This is particularly important in industrial-scale sugar purification processes, as faster flotation rates can lead to higher process efficiency. Results showed that dialkyl quaternary ammonium salts, when formulated in solid blends, produced faster flotation efficiencies compared to monoalkyl quaternary ammonium salts.

Claims

1. A solid composition comprising at least a quaternary ammonium compound and a phosphorus compound; wherein, The weight ratio of the quaternary ammonium compound to the phosphorus compound is in the range of 1:1 to 1:

5.

2. The solid composition according to claim 1, wherein, The weight ratio of the quaternary ammonium compound to the phosphate compound is in the range of 1:1 to 1:

3.

3. The solid composition according to claim 1 or 2, wherein, This quaternary ammonium compound has the following general formula: [N + (R1)(R2)(R3)(R4)] y X - (I) in: R1, R2, R3, and R4 can be the same or different, representing saturated or unsaturated, straight-chain or branched aliphatic groups or aromatic groups having 1 to 30 carbon atoms. X is an anion; y is the valence of X.

4. The solid composition according to any one of claims 1 to 3, wherein, This quaternary ammonium compound has the following general formula: [N + (R5)2(R6)(R7)] y X - (II) in: R5 is an alkyl or hydroxyalkyl group containing 8 to 22 carbon atoms; R6 is an alkyl or hydroxyalkyl group containing 1 to 4 carbon atoms; R7 is either R5 or R6; X is an anion; y is the valence of X.

5. The solid composition according to any one of claims 1 to 3, wherein, This quaternary ammonium compound has the following general formula: [N + ((CH2) n -T-R8) m (R9) 4-m ] y X - (III) in: R8 is independently selected from C1-C 24 Alkyl or hydroxyalkyl; R9 is independently selected from C1-C4 alkyl or hydroxyalkyl; T is –C(=O)–O–, –O–C(=O)–, –NR 10 –C(=O)– or –(C=O)–NR 10 –, where R 10 It is hydrogen, C1-C6 alkyl, or C1-C6 hydroxyalkyl; n is an integer from 0 to 5; m is selected from 1, 2, and 3; X is an anion; y is the valence of X.

6. The solid composition according to any one of claims 1 to 3, wherein, This quaternary ammonium compound has the following general formula: [N + (R 11 )(R 12 )(R 13 )((CH2) z -Ph)] y X - (V) in: R 11 and R 12 They can be the same or different, representing straight-chain or branched alkyl or hydroxyalkyl chains having 1 to 24 carbon atoms; R 13 It is a straight-chain or branched alkyl or hydroxyalkyl group having 1 to 8 carbon atoms; z = 0 or an integer from 1 to 3; Ph represents phenyl; X is an anion; y is the valence of X.

7. The solid composition according to any one of claims 1 to 4, wherein, This quaternary ammonium compound is selected from the group consisting of the following: C 14 -C 18 Alkyl dimethylammonium compounds, distearate dimethylammonium compounds, dipalmitoyl dimethylammonium compounds, dihexadecyl dimethylammonium compounds, dioctadecyl dimethylammonium compounds, dioleyl dimethylammonium compounds, dihydrogenated rapeseed alkyl dimethylammonium compounds, and mixtures thereof.

8. The solid composition according to any one of claims 1 to 7, wherein, The phosphorus compound is phosphoric acid.

9. A method for reducing colored impurities in a sugar solution or syrup by adding a quaternary ammonium compound and a phosphorus compound to the sugar solution or syrup; wherein, The weight ratio of the quaternary ammonium compound to the phosphorus compound is in the range of 1:1 to 1:

5.

10. A method for reducing colored impurities in sugar solutions or syrups, the method comprising the steps of: (1) Providing an aqueous solution or dispersion of the solid composition according to any one of claims 1 to 8; as well as (2) Add the aqueous solution or dispersion to the sugar solution or syrup.

11. The method according to claim 9 or 10, wherein, The method further includes the following steps: (a) Adding lime-based compounds and flocculants to the sugar solution or syrup to form flocculent precipitates of these colored impurities; (b) Separate the flocculent precipitate from the sugar solution or syrup.

12. The method according to claim 10 or 11, wherein, The flocculant is polyacrylamide.

13. The method according to any one of claims 9 to 12, wherein, The quaternary ammonium compound is present in amounts ranging from 100 ppm to 500 ppm, depending on the weight of the solid sugar in the sugar solution or syrup.

14. Use of the solid composition according to any one of claims 1 to 8 for reducing colored impurities in sugar solutions or syrups.

15. A method for preparing a solid composition comprising a quaternary ammonium compound and a phosphorus compound; wherein, The method includes the step of mixing the quaternary ammonium compound with the phosphorus compound in a weight ratio of 1:1 to 1:5.

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