RU2034646C1 - Sorption and filtrating material for purifying half-finished wine product, alcohol drinks and grape juices - Google Patents

Abstract

FIELD: wine and juice production. SUBSTANCE: proposed material represents hydrated zirconium phosphate having atomic ratio P/Zr 1.8-2.1 which contains 3-20 moles of water per one atom of zirconium. Said material has spheric granulation, size of granules being 0.1-2.5 mm. Proposed material may be used in hydrogen, salt or in hydrogen-salt ion-exchange form. EFFECT: stabilizes alcohol drinks and juices, prevents their cloudiness, purifies drinks and juices against heavy metals and radiotoxic nuclides. 2 cl, 3 tbl

Description

 The invention relates to the wine industry, in particular to a method for the sorption purification of wine materials, wines, cognac spirits, cognacs and grape juices from metal cations and radioactive nuclides on inorganic zirconium phosphate material.

 In winemaking, to improve the quality of grape processing products and the warranty period for their storage, one of the main problems is the stabilization of wines against metallic and crystalline opacities, which in the latter case constitute 70-80% of the total amount of opacities.

The main reason for the formation of turbidity in wines, wine materials, juices, cognac spirits and cognacs is the increased content of metals such as calcium (as well as iron, copper, etc.), which precipitates in the form of tartrate, mucate, oxalate, calcium tartrate malate. Therefore, in the wine industry, the maximum calcium content is regulated depending on the type of wine material. For example, the maximum permissible concentration of calcium is 80 mg / dm ³ for white table wines and champagne wine materials.

 To prevent the formation of calcium turbidity in practice, various methods and techniques are used to ensure that the calcium content is reduced to a level that ensures long-term stability of wines. The traditional method of stabilizing wines against crystalline opacities by cold treatment is effective for removing excess amounts of potassium, but it does not allow stabilizing wines against calcium opacities.

 In domestic and foreign winemaking practices, precipitation methods for processing wine materials are also used to stabilize them by binding calcium to insoluble compounds. However, in wine-making practice, more efficient sorption methods are used to remove excess calcium from wine materials.

 Known sorption methods for decalcification of wine materials using ion exchange resins, organic cation exchangers [1,2] In the first method [1], resins of the type Amberlite IR-120, Dowex-50, Duolite C-20, Zeocarb-225, are used to remove calcium ions in a column Allassion CS, which absorb calcium quite well from wine materials (up to 35-40% of the initial content). In the second method [2], organic cation exchanger is used predominantly in acidic ionic form to remove calcium, magnesium, and iron from wine, which is contacted with wine under static conditions with stirring. A common drawback of sorption methods based on the use of organic ion-exchange cation exchangers is the risk of toxic organic monomers (degradation products) entering wine materials from resins, which limits the possibility of their use in winemaking.

It is known that wine-making is used in practice for processing alcoholic beverages and wine materials with the aim of stabilizing inorganic sorbents such as silica gel or bentonite against turbidity, which are distinguished by high chemical resistance, sorption activity and low toxicity [3,4] According to the method [3] for processing beer and low alcohol drinks it is recommended to use porous silica gel containing 35-75 wt. water and having a specific surface area of 175-450 m ² / g, specific pore volume of 1.5-2.4 cm ³ / g in the form of particles with a size of 4-30 microns. Silica gel removes the colloidal component of organic origin from wine materials, mainly protein and protein-phenolic complexes. However, it is not effective in stabilizing wines against crystalline and metallic opacities, since it does not have the cation exchange ability in a slightly acidic environment, which is typical for wine materials.

 The effect of bentonite [4] during the stabilization of wine materials is similar to the action of organic cation exchangers, however, it is weaker due to the low ion-exchange ability to metal cations, which cause the formation of clouding of wines. The main disadvantage of this natural aluminosilicate sorbent is the very low exchange rate of cations, which does not allow it to be effectively used in the flow processing of wine materials in dynamics with high costs and speeds. In addition, a very significant swelling of bentonite in wines leads to a noticeable loss of wine material.

 The closest in technical essence and the achieved result is sorbent-filtering material for stabilizing wine materials cellulose acid phosphate [5] In the known invention, after preliminary mechanical filtration, the wine material is passed through a layer of cellulose phosphate at a rate of 3-4 ml / min, as a result of which the material is removed excessive amounts of calcium and iron ions. After the sorption operation, the material is sent for regeneration for reuse. The main disadvantage of the material is its low real dynamic exchange capacity for calcium, comprising 3.2-4.2 mg / g. In addition, due to the poor chemical resistance of the sorbent, degradation products of phosphate ions can enter the wine material during the filtration process. A significant limitation of this material in industrial applications in the dynamic sorption mode is also that it cannot be granulated: the material is used in the form of fibers, threads, cotton wool. In addition, when using cellulose phosphate, large losses of wine material occur due to the large swelling of the sorbent in contact with wine, reaching 3-4 times.

 The objective of the invention is the selection of such material for the purification of wine materials, alcoholic beverages and grape juices, which would improve their stability to metallic opacities during long-term storage.

This is achieved by using as a sorption-filtering material for the purification of wine materials, alcoholic beverages and grape juices granular hydrated zirconium phosphate in hydrogen, salt or hydrogen-salt ion exchange form, with an atomic ratio P / Zr equal to 1.8-2.1, containing 3-20 mol of H ₂ O per 1 zirconium atom, the granules having a predominantly spherical shape and a diameter of 01, -2.5 mm.

 It should be noted that zirconium phosphate-based ion-exchange material with an atomic ratio of P / Zr of 1.8-2.1, containing water in an amount of 0.8-2 mol per Zr atom, is known for the selective separation of cesium, strontium and uranyl ions from acidic solutions.

 However, the known material has poor kinetics of metabolism due to the low water content in the composition of the material. In addition, the known material has low mechanical crush strength of the granules. As a result of these shortcomings, the known material cannot be used for effective purification of wine materials in the dynamic mode: at high speeds of the medium being cleaned through the column, the working filter cycle will be low due to the early appearance of calcium leakage into the effluent and clogging of the column as a result of granule destruction.

 The inventive step of this technical solution is to propose a material containing a significantly larger number of moles of water, providing high porosity (25-50%), good kinetic characteristics and high strength properties.

 In accordance with the invention, the recommended range of atomic ratios P / Zr, equal to 1.8-2.1, characterizes the optimal concentration of ionogenic phosphate groups in the sorbent, which ensures maximum sorption ability of the material to metal ions. The upper value of the P / Zr ratio is limited by the chemical nature of zirconium phosphate and the technological capabilities of its production, the lower value by a noticeable decrease in the exchange capacity for metals. The range of declared water contents in zirconium phosphate is determined by the kinetic and strength properties of the ion-exchange material, which are important when it is used in the dynamic sorption mode. At water contents below 3 mol per 1 mol of zirconium, the porosity of the material decreases, which leads to a significant deterioration in its kinetic characteristics. As a result of this, when operating columns loaded with material in high-speed mode, the dynamic exchange capacity is significantly reduced. The upper limit of the water content in zirconium phosphate is due to technical difficulties in obtaining ion-exchange material in the form of mechanically strong granules.

 To ensure optimal hydrodynamics of the process in a sorption column, it is recommended to use zirconium phosphate in the form of spherical granules having a diameter of 0.1-2.5 mm. The upper value of the granule size is limited by the technological capabilities of the synthesis of the material with satisfactory strength properties, the lower value is the technical inconvenience associated with the operation of such a fine-grained material in the column mode (clogged drainage, increase in pressure drop).

The proposed material can be used in hydrogen form. Moreover, the range of pH values at which it can be used is in the range from 3.0 for tablespoons to 4.4 for dessert wine materials. When using zirconium phosphate in the H ⁺ form, a slight increase in the acidity of the wine material is observed due to the release of hydrogen ions from the sorbent as a result of the absorption of cations from the filtered wine material. Moreover, in real conditions, as our experiments show, a decrease in the pH of the medium does not exceed 0.1-0.3, depending on the missed volume, the type of wine material being processed and its chemical composition. This process is especially favorable for wine materials with a flat taste having high pH values of more than 3.6.

In the case of highly acidic wine materials, such as champagne, for which a decrease in pH is undesirable, it is recommended to use zirconium phosphate in a salt, partially neutral form. In this case, zirconium phosphate is transferred before use in a previously known manner from the H ⁺ form, for example, to the Na ⁺ or K ⁺ form. It is preferable to convert the material into sodium form, since the Na content in wine materials (usually 40 to 100 mg / dm ³ ) is significantly lower than potassium by about 10-20 times. In addition, with increased concentrations of potassium in wine materials, there is a danger of the formation of crystalline opacities based on potassium bitartrate. When converting zirconium phosphate to the sodium form, the amount of metal in the solid phase can be varied, taking into account the chemical composition, pH, and volume of wine material to be sorbed. The upper limit of the sodium content in the sorbent is limited by the possibility of it entering the effluent in appreciable quantities (as a result of displacement of sodium ions from the solid phase by absorbed ions, for example, calcium or magnesium), which negatively affects the organoleptic characteristics of the wine material; the lower limit is the insignificant effect of sodium introduced into the sorbent on the effect of lowering the pH value in the processed wine material.

 The material can be used in mixed salt form. This method of demetallization of wine materials is recommended for high concentrations of calcium and low concentrations of magnesium and sodium. In this case, it is preferable to use zirconium phosphate in the sodium-magnesium form, since magnesium (as opposed to calcium) released into the wine material during sorption processing does not form turbidity. It should be noted that when converting zirconium phosphate to the sodium-magnesium form, the total amount of these metals in the solid phase varies depending on the ratio of calcium and magnesium concentrations, pH, and macroelement composition of the initial wine material.

 The proposed sorption-filtering material is recommended to be obtained using sol-gel technology.

An example of obtaining material in the H ⁺ form. The material can be obtained, for example, as follows. A solution of zirconium chloride with an initial concentration of 1.0 mol / dm ^{3 was} poured into the cathode space of a two-chamber electrolyzer separated from the anode organic anion-exchange membrane MA-40. 0.2 mol / dm ³ hydrochloric acid solution was fed into the anode space. The following materials were used as electrode materials: platinum for the cathode and graphite for the anode. Electrolysis was carried out at a membrane current density of 360 A / m ² for 6 h until the atomic ratio of chlorine to zirconium in catholyte reached 0.64. The synthesized sol was dispersed dropwise into a concentrated ammonia solution using a glass capillary with an inner diameter of 0.16 mm, and after washing with deionized water, spherogels of zirconium hydroxide were treated, which were treated with 1 mol / dm ³ phosphoric acid solution for 20 h with periodic stirring (solid volume ratio) liquid 1 4). Pellets were washed by excess water phosphates and dried in air to a relative humidity of 30.2% estimated by weight loss on ignition at 1000 sample sample ^C. Obtained white glassy solid granules are of spherical form with diameter 0,40-1,0 mm composition Zr (HPO ₄ ) _2.01 ˙ 6.8 H ₂ O (aka P / Zr 2.01, H ₂ O / Zr 7.8) with a specific pore volume of 0.25 g / cm ³ and with a mechanical crushing strength of 13 MPa.

PRI me R s 1.2. Evaluation of the effectiveness of the material synthesized as described above was carried out under dynamic conditions on grape juice obtained from the 1990 Rkatsiteli grape variety. Grape juice had the following conditions: sugar content 14%, the concentration of titratable acids was 7.8 g / dm ³ , and the concentration of calcium 126 mg / dm ³ , iron 17.3 mg / dm ³ . In two glass columns with an inner diameter of 7.9 mm, 5.0 g of granular zirconium phosphate (H ⁺ form) and cellulose phosphate (for comparison) were loaded and 1.0 dm ^{3 of} grape juice was passed at a constant speed of 100 ml / h, selecting for analysis of the effluent fraction every hour.

The content of calcium and iron in the effluent was determined by atomic absorption method. Based on the results of the analysis of fractions, the average value of the final (after the column) metal concentration in the purified juice and the dynamic exchange capacity of the material were calculated. Then the fractions were combined and the processed juice after each column was sent for cold tests to assess stability. Cold tests were carried out at a temperature of -2 +3 ^о С for 3 days in accordance with the "Methodology for testing wine materials and wines for a tendency to cloudiness", approved by Glavvino Ministry of Food Industry of the USSR 11/17/67.

 The results of the experiments are given in table 1; the composition of the material in table.2.

 From the data presented it obviously follows that the proposed material is more effective than the known. The resulting grape juice is resistant to metallic clouding due to the increased sorption ability of the ion exchanger to calcium and iron (about two times). During sorption processing of grape juice with zirconium phosphate, a decrease in pH (in our case, from 3.3 in the initial to 3.12) and an increase in titratable acidity are observed, which, however, varies within the limits regulated by OST 18-142-73 "Grape wine materials processed. " Test tests showed that such processing does not have any effect on the transparency, color and bouquet of both this grape juice and all other wine materials given in the following examples. Colorimetric analyzes of the effluent confirmed the high chemical resistance of zirconium phosphate: in all processed wine materials there was no increase in phosphorus concentration (phosphoromolybdate method), and the zirconium concentration was below the detection limit of 10 μg / L (determination with arsenazo-3).

 PRI me R 3-11. In order to optimize the composition of the material, 9 samples of zirconium phosphate were synthesized according to the procedure according to example 1. Moreover, samples 3, 4, 6, 9, 10, 11 differed from sample 1 only in the degree of dehydration, and samples 6, 7 and 8 in volumetric ratio of the solid phase to liquid (T: G) when phosphating the gel spheres of zirconium hydroxide. Sample 5 was chemically modified with phosphates at T: W 1: 6, sample 7 at T: W 1: 2.5, and sample 8 at T: W 1: 2.0, due to which the concentration of phosphate groups changed (molar ratio P / Zr) in the sorbent.

Samples were tested in dynamic conditions (similar to examples 1-2) to determine the exchange capacity for calcium on table wine material for Riesling-Tamani wine of the 1989 vintage. 0.75 dm ^{3 of} wine was passed through a column with a sorbent in an amount of 5 cm ³ 20 column volumes per hour.

From the data of table 2 it follows that from the point of view of sorption ability, the most effective is a sorbent having a molar ratio P / Zr of 1.8-2.1 and H ₂ O / Zr 3-20.

 PRI me R 12. The use of zirconium phosphate in sodium form for the processing of cognac.

Received a sample of material with a chemical composition, as in example 6, but with a spherical granule size of 2.0-2.5 mm, for which the dispersion of the sol into ammonia was carried out through a larger capillary of 0.8 mm. When transferring to the salt form, 10 g of the sorbent was loaded into a column with an inner diameter of 10 mm, 100 ml of a 0.1 mol / dm ³ sodium chloride solution was passed and washed with distilled water from the electrolyte.

The material was used to clean ordinary cognac ("three stars") from calcium under dynamic conditions, as in example 1. Cognac was prepared from three-year-old cognac spirits with conditioning: volume fraction of ethyl alcohol 40% sugar content 1.5% calcium concentration 42 mg / dm ³ . After purification, the average concentration of calcium in cognac was 5.8 mg / dm ³ . Cold tests confirmed that no crystalline turbidity of calcium tartrate was found in the cognac sample that underwent sorption treatment.

PRI me R 13. The use of zirconium phosphate in mixed hydrogen-salt form for the processing of wine material. A sorbent sample was obtained by chemical composition as in example 4, but with a spherical granule size of 0.1-0.2 mm, for which the dispersion of the sol into ammonia was carried out through a capillary with an inner diameter of 0.2 mm. Translation into the H ⁺ -Na ⁺ -Mg ²⁺ form was carried out under static conditions by contacting 10 ml of the sorbent with 100 ml of a solution containing 1.25 g / dm ³ of magnesium chloride and 0.19 g / dm ³ of sodium chloride, with stirring. After two hours, the solution was neutralized by the gradual introduction of 0.01 mol / dm ³ sodium hydroxide solution to a pH value of 3.54. The sorbent was separated from the mother liquor, washed with water and dried in air to a certain humidity. Ultimately, a spherical granular material of the composition ZrNa _0.04 Mg _0.31 H _1.65 (PO ₄ ) _2.01 ˙ 2H ₂ O.

1.0 dm ^{3 of} wine material for Cabernet Tamani wine, harvest 1990, was passed through 50 ml of the sorbent in salt form at a speed of 30 column volumes per hour.

 The test results are shown in table.3.

 From the data of Table 5 it follows that the use of the proposed material not only stabilizes the wine material by removing excess calcium, iron and potassium, but also contributes to its deeper purification from trace elements of heavy metals (copper, chromium, cobalt). In addition to the demetallization of wine material, as can be seen from the table, the material also allows efficient extraction of cesium-137 radionuclide, which has a half-life of 30 years. Assessment of the effectiveness of the deactivation of wine material was carried out by measuring the gamma activity of the ashed sample residue before and after the column on a low-background germanium-lithium detector. It was found that a slight increase in the effluent concentrations of sodium and magnesium does not affect the quality and organoleptic characteristics of the wine material.

 Thus, the proposed sorption-filtering material for the purification of wine materials allows it to be used with high efficiency in winemaking technology to stabilize wines, juices, cognacs against crystalline (due to excess calcium and potassium) and metallic (due to excess iron and copper) turbidity. The material can be useful when cleaning from heavy metals and radiotoxic nuclides, not only grape juices and alcoholic drinks, but also soft drinks, alcohols.

Claims (2)

1. SORPTION-FILTERING MATERIAL FOR PURIFICATION OF WINE MATERIALS, ALCOHOLIC BEVERAGES AND GRAPE JUICES, containing phosphoric acid groups, characterized in that it is a granular hydrated zirconium phosphate in the hydrogen, saline or hydrogen-ion-exchanged P-ionic form with the ion-hydrogen exchange of 1.8 P 2.1, containing 3 to 20 mol of H ₂ O per 1 zirconium atom.  2. The material according to p. 1, characterized in that it has a spherical shape of the granules with a granule diameter of 0.1 to 2.5 mm

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