RU2010861C1 - Process for producing diffusion juice from sugar beet - Google Patents

Abstract

FIELD: sugar industry. SUBSTANCE: new process for producing diffusion juice from sugar beet included steps of comminuting sugar beet tubers to chip size, scalding chips prior to extraction with the use of catholyte and live saturated steam and extracting sugar from beet chips. Extractant taken in amount of 20 to 30 % by mass of sugar beet was added with either sulfate or chloride of polyvalent metals taken in amount of 0.01 to 0.03 % by mass of sugar beet and electrical activation was conducted in diaphragm electrolyzer cathode chamber until catholyte pH value reached point within 5.0 to 5.5 and redox potential fell within range of -800 to -1,000 mV. Entire mass of beet chips was simultaneously scalded by live saturated steam having temperature between 80 and 82 C at pressure of 45 to 47 kPa and taken in amount of 10 to 15 % by mass of sugar beet and heated catholyte. EFFECT: higher yield of end product. 1 dwg

Description

 The invention relates to methods for producing diffusion juice from sugar beets and can be used in conditions of sugar beet production.

 A known method of producing diffusion juice with a low colloid content in the extraction of sugar beets, comprising adding alkaline earth or other multivalent metals, preferably calcium or strontium, to the extractant with ions of alkaline earth or other multivalent metals, in the form of soluble or sparingly soluble inorganic or organic salts in an amount of not less than 0.001 kg per 100 kg of beet [1].

 The disadvantage of this method is the need for preliminary acidification of the extraction liquid with the help of chemical reagents (for example, acids, alumina sulfate, etc.) to a pH of 5.0-6.5, and then a slight alkalization with alkaline earth metal ions, which requires a significant consumption chemicals in the preparation of the extractant, as well as the low quality of diffusion juice and significant loss of sugar during extraction due to the activity of microorganisms.

A known method of producing diffusion juice, comprising adding to the beet chips, a magnesium compound, mainly MgO or 4 MgCO ₃ ^. Mg (OH) ₂ ^. 4H ₂ O in an amount of 0.08 g Mg ²⁺ per 100 g of chips, followed by its extraction with water acidified to pH 5.8-6.2 [2].

 To implement this method, a large consumption of an expensive reagent is required - magnesium, which for a plant with a daily productivity of 3.0 thousand tons of beet processing will be 240 tons per day. In addition, due to the vital activity of hydrophilic and thermophilic microorganisms, large sugar losses occur in the diffusion apparatus and receive diffusion juice of low quality and a significant content of colloidal substances and high molecular weight compounds.

The closest technical solution to the proposed method for producing a raw juice from sugar cane comprising crushing the latter into chips, the chips before extraction scalding saturated steam with a temperature of 101 ^C and a pressure of 0105 MPa for 20 seconds and extraction of sugar chip [3].

 Despite the achievement of denaturation of the protoplasm of beet cells in the known method, there are the following significant disadvantages: the completeness of sugar extraction from beets is not ensured; there is a transition of a large number of non-sugars, which reduces the benign quality of diffusion juice; in addition to scalding, additional antiseptic processing of beet chips is not performed, which worsens the microbiological situation in the apparatus and leads to an increase in sugar losses during extraction; scalding with steam of high potentials leads to some deterioration in the physical and mechanical properties of beet chips (a decrease in the elastic modulus), which complicates the conditions for sugar extraction and affects the quality indicators of the obtained diffusion juice.

 The aim of the invention is to improve the physico-mechanical properties of beet chips, increase the benign quality of diffusion juice and reduce sugar loss during extraction.

To achieve this, in the proposed method for producing diffusion juice from sugar beet, which involves crushing it into chips, scalding the chips with steam and extracting the chips with an extractant, a portion of the extractant is selected in an amount of 20-30% by weight of the beets and a polyvalent metal sulfate or chloride is added to it. in an amount of 0.01-0.03% by weight of beets, then this amount of extractant is electroactivated in the cathode chamber of the diaphragm electrolyzer until the catholyte pH is 5.0-5.5 and the redox potential is from -800 to -1100 mV, heated to 78-80 ^{° C} and fed to scalding cossettes, wherein the scalding chip extractant and steam is carried out simultaneously, using a sharp saturated steam at 80-82 ^{° C} and 45-47 kPa pressure in an amount of 10-15% by weight of beet.

 The drawing shows a flow chart.

 The method is as follows.

Extractant (barometric water) in an amount of 20-30% by weight of beets is mixed with a salt of sulfate or chloride of a polyvalent metal in an amount of 0.01-0.03% by weight of beets in a collection of feed water 1. The following salts can be used: aluminum sulfate, ferrous sulfate, magnesium sulfate, copper sulfate, calcium chloride. The saline solution is sent to the cathode chamber of the diaphragm electrolyzer 2. The latter is a container divided by a membrane impervious to molecules (for example, tarpaulin) into two chambers: the main one is the cathode one and the auxiliary one is the anode one. The auxiliary chamber has a capacity of one third of the capacity of the main, or working chamber, is filled with a similar saline solution and serves to close the electrical contact between the electrodes and the oxygen that is released at the anode. After electrochemical activation, the catholyte leaving the cathode chamber of the electrolytic cell with pH parameters of 5.0-5.5 and Eh - (800-1100) mV is selected, and the anolyte can be sent for reuse or for technological needs of a sugar factory (for example, to soften the nutritional water of boiler units or disinfection of technological equipment). The effluent from the cathode chamber the catholyte electrolysis with a temperature of 18-20 ^{° C} is heated to 78-80 ^{° C} in preheater 3 and then fed to a hydrator cossettes in hydrator 4. catholyte nozzles sprayed uniformly over the entire area. Simultaneously in the hydrator in particulate form is fed with live steam and a temperature of 80-82 ^{° C} and 45-47 kPa pressure in an amount of 10-15% by weight of beet. The last bactericidal treatment scalded for 20 s, the beet chips are sent to a diffusion apparatus 5 for extraction.

 Chip treatment with a part of the extractant - 20-30% by weight of beets and 10-15% by weight of beets of steam is necessary and sufficient to wet the surface and fill the pore volume. Impregnation of chips with a liquid with active adsorption, bactericidal and coagulating properties, as well as increased selectivity for dissolving and extracting sugar, allows creating conditions for increasing the molecular diffusion coefficient, intensifying the extraction process and thereby increasing the quality of diffusion juice, and reducing sugar loss in a coma and in a diffusion apparatus .

 Adding sulfates or chlorides of salts of polyvalent metals to the extractant is easy to conduct an electric current in the process of electrochemical activation (ECA) by increasing the electrical conductivity of aqueous salt solutions compared to the electrical conductivity of water. In addition, these salts favorably affect the technological parameters of diffusion juice - its good quality and sedimentation-filtration characteristics.

 Low salt concentrations (0.01-0.03% by weight of beets) significantly affect the kinetics of the interaction of the substances present in the catholyte solution, causing the phenomenon of preservation for several hours after ECA of the increased dissolving and extracting ability of catholyte, as well as its adsorption, bactericidal and coagulating properties. Such characteristics cannot be achieved through the use of chemicals or electrocoagulation. As a result of ECA of weakly concentrated solutions, the ions and molecules present in it, due to their mobility, acquire increased potential energy and catalytic activity. Such concentrations of salts in the extractant solution provide, as a result of ECA for 5-20 min, the achievement of the specified values of the redox potential, which leads to increased activity of catholyte. Exceeding the indicated concentrations leads to a decrease in the mobility of water molecules and ions of metals and impurities present, which contributes, on the one hand, to a decrease in the reactivity of catholyte and does not ensure the achievement of the required values of Eh = - (800-1100) mV, and therefore high technological parameters diffusion juice, on the other hand, requires a longer electrochemical effect, which affects the energy consumption in the preparation of the extractant.

-> H₂ + 2 OH^-
В свою очередь, при взаимодействии ионов металлов с растворенным водородом образуются высокоактивные гидриды. Например,
Са + Н₂ -> СаН₂
Гидроксид-ион может существовать в воде как в свободном виде, тогда при соединении с ионами металлов образуются гидроксиды, такие как Са(ОН)₂, Сu(OH)₂, Fe(OH)₂, Fe(OH)₃, Al(ОН)₃, так и в виде гидратированных частиц состава Н₃О₂ ^-, Н₅О₃ ^-, Н₇О₅ ^-, Н₉О₇ ^- с различной реакционной способностью.The most significant changes in the physicochemical properties of the extractant occur in the cathode chamber of the diaphragm electrolyzer during ECA. The catholyte resulting from ECA consists of a large group of complex chemical compounds. The preparation of catholyte is accompanied by various electrochemical reactions, among which the main one is the decomposition of water:
2 H ₂ O + 2

-> H ₂ + 2 OH ^-
In turn, the interaction of metal ions with dissolved hydrogen produces highly active hydrides. For instance,
Ca + H ₂ -> CaH ₂
The hydroxide ion can exist in water as in a free form, then when combined with metal ions, hydroxides are formed, such as Ca (OH) ₂ , Cu (OH) ₂ , Fe (OH) ₂ , Fe (OH) ₃ , Al (OH ) ₃ , and in the form of hydrated particles of the composition Н ₃ О ₂ ^- , Н ₅ О ₃ ^- , Н ₇ О ₅ ^- , Н ₉ О ₇ ^- with different reactivity.

Н⁺ + ОН^-) происходит образование свободного радикала:
H⁺ +

-> H^o. В результате дальнейшей рекомбинации возникает ряд высокоактивных продуктов:
H^o + H^o -> H₂ H₂O₂ + OH^- HO₂ ^o + H₂O
H^o + H₂O -> OH^- + H₂ H₂O₂

H⁺ + HO₂ ^-
OH^o + OH^o -> H₂O₂
Все эти соединения придают католиту многие положительные свойства катализатора окислительно-восстановительных процессов каталитических реакций, усиливающего в процессе экстрагирования селективность и скорость извлечения сахарозы.During the transition of an electron from a cathode to a hydroxonium ion, which is present in water due to its partial dissociation (Н ₂ 0

Н ⁺ + ОН ^- ) the formation of a free radical occurs:
H ^{+ +}

-> H ^o . As a result of further recombination, a number of highly active products arise:
H ^o + H ^o -> H ₂ H ₂ O ₂ + OH ^- HO ₂ ^o + H ₂ O
H ^o + H ₂ O -> OH ^- + H ₂ H ₂ O ₂

H ⁺⁺ HO ₂ ^-
OH ^o + OH ^o -> H ₂ O ₂
All these compounds give the catholyte many of the positive properties of the catalyst of redox processes of catalytic reactions, which enhances the selectivity and rate of sucrose extraction during the extraction process.

Simultaneously with the formation of hydroxides, heavy metal impurity ions precipitate and the concentrations of Ca ²⁺ and Mg ²⁺ ions change as a result of the formation of insoluble carbonate and hydroxyl compounds, which reduce the total hardness of water and increase the coagulating ability and bactericidal properties of catholyte and therefore reduce losses sugar upon extraction. The latter circumstance is explained by the fact that insoluble compounds based on calcium and magnesium, as well as polyvalent metal hydroxides that have a positive charge, are rapidly deposited on its surface during extraction with the interaction with a negatively charged tissue of beet chips. All this helps to reduce the solids content in diffusion juice. Other things being equal, the extraction process (temperature, pH, duration, etc.) is used. The use of catholyte allows one to obtain diffusion juice of higher quality (due to the fact that D _b = (CX / CB) · 100%). In addition, during ECA, electrolysis gases (hydrogen, oxygen, chlorine, etc.) are formed in the cathode chamber of the diaphragm electrolyzer, which contribute, on the one hand, to a decrease in the kinematic viscosity of the solution and, consequently, to an increase in the molecular diffusion coefficient and acceleration of subsequent extraction, and on the other hand, giving the solution disinfectant properties. Thus, the catholyte formed as a result of ECA has bactericidal properties and helps to reduce sugar losses in the diffusion apparatus by suppressing the activity of beet microorganisms, as well as by fixing the complex of non-sugars and VCP directly on the surface of the cell skeleton to reduce sugar losses in bagasse.

And finally, during ECA in the diaphragm electrolyzer there is a directed change in the physicochemical properties of the extractant directed to the processing (scalding) of beet chips and physico-mechanical properties of the chips treated with this extractant. So, in the course of ECA, over time, pH and Eh increase. With a shift in pH from the initial value, the sorption of the mono- and divalent anions lCl ^- , SO ₄ ^2- l on hydrocomplexes, which is ion-exchange in nature and enhances the coagulating properties of catholyte, also changes.

 Thus, ECA in the cathode chamber of a diaphragm electrolyzer gives the catholytes of saline solutions special properties that are unattainable for the electrocoagulation method, which contribute to the inefficient implementation of the extraction process.

 Achieving the catholyte parameters pH 5.0-5.5 and Eh - (800-1100) mV ensures extraction in the optimal technological mode.

Heating catholyte from 18-20 ^C to 78-80 ^{° C} provides: a) for scalding chip implementation denaturation protoplasm beet tissue; b) heating the chips to the optimum temperature.

With the same purpose, simultaneously with the catholyte in an amount of 20-30% by weight of beet chips fed under layer and an acute saturated steam in an amount of 10-15% by weight of beet with a temperature ^of 80-82 C and a pressure of 45-47 kPa. The scalding of chips is carried out in a separate apparatus, the scalder, in which the chips pass through a drip-steam mixture. This provides not only rapid scalding and heating of the chips to the required extraction temperature, but also bactericidal treatment of the external surface of the chips with giving it elastic properties and the ability to adsorb substances of the protein-pectin complex, ash and total nitrogen, i.e. a large number of non-sugars, easily skipping through sucrose cell membranes.

 Thus, the presence of all these characteristics to obtain diffusion juice from sugar beet allows the extraction process to be carried out with a high speed and lowest sugar loss and to obtain diffusion juice of high quality and the ability to further purify and beet pulp with a low sugar content and a large amount of pectin substances, which determines its high feed value.

PRI me R 1. Into water in an amount of 1 liter is injected 50 mg (0.01% to wt. St.) aluminum sulfate. The resulting solution with a pH of 4.76 is poured into the cathode chamber of the diaphragm electrolyzer. The anode chamber is filled with a similar solution, after which an ECA is performed at a current strength of 4.5 A, voltage of 11 V for 5.5 min until the pH of catholyte reaches 5.0 and Eh = -800 mV. Next, thus prepared extractant preheated to 78 ° ^C. A portion of 500 g of chips evenly placed on the perforated bottom-sealed container hydrator. An extractant (catholyte) in an amount of 100 g (20% by weight of beets) is sprayed from the nozzle in the upper part of the scalder tank. Simultaneously with the catholyte through a nozzle at the bottom of the bottom hydrator steam is supplied at a temperature ^of 80 C and a pressure of 45 kPa in an amount of 50 g (10% of the beet mass) for 20 seconds. The prepared chips were placed in a thermostated beaker for extraction at ⁷⁰ ° C for 60 min, with a ratio of solid and liquid phases of 1.0: 1.5. At the end of the process, the diffusion juice is drained and the pH, content of sucrose (CX) and dry matter (CB) are determined in it. Sugar content was determined in beet pulp. The indicators of cell juice amounted to:
pH 5.35
CX = 15.65%
SV = 18.3% and benign cell juice DB = 85.74%
Indicators of the obtained diffusion juice: pH, units 5.85 sucrose content,% 9.12 dry matter content,% 10.4 benignity,% 87.69 purification effect on diffusion,% 15.8
The sugar content in beet pulp,% 0.29
PRI me R 2. Into the water (extractant) in an amount of 1 l injected 100 mg (0.02% by weight of beets) of iron (II) sulfate. For the resulting solution with a pH of 4.85, ECA is performed at a current strength of 5.0 A, a voltage of 12 V for 8 min until the pH of catholyte reaches 5.3 and the redox potential is Eh = -860 mV. The catholyte is drained and heated to 79 ° ^C. A portion of 500 g of chips are placed evenly on the perforated bottom hydrator. Simultaneously, the top and bottom of the chip sprayed catholyte is heated to a temperature of 79 ^{° C} in an amount of 125 g (25% beet mass) and live steam with a temperature of 81 ^C and a pressure of 46 kPa in an amount of 60 g (12% beet weight) for 20 s, after which scalded chips are placed in a thermostatically controlled glass for extraction under the same conditions as those given in example 1. The indicators of diffusion juice were: pH, units 5.90 Sucrose content,% 9.15 Dry matter content,% 10.4 Benignity,% 87.98 Cleaning effect on diffusion,% 18.2 Sugar loss in pulp,% 0.30
Example 3. 150 mg (0.03% by weight of beets) of copper sulfate are introduced into water (extractant) in an amount of 1 liter and a solution with a pH of 5.26 is sent to the cathode chamber of a diaphragm electrolyzer for conducting ECA with the following parameters : current in the circuit 4.0 A, voltage 11 V, time 5 min until the pH of the catholyte reaches 5.5 and Eh = -960 mV. The resulting catholyte is heated to 80 ° ^C. The capacitance-hydrator placed 50 g of chips. 150 g (30% by weight of beets) of catholyte are sprayed from the nozzle in the upper part of the scalder. Simultaneously with the catholyte through a nozzle in the bottom layer under the hydrator chips fed with live steam temperature of 82 ^{° C} and 47 kPa pressure. Processed and scalded shavings in a thermostatically controlled glass are subjected to extraction according to the conditions according to example 1. In this case, the following technological parameters of diffusion juice were obtained: pH, units 6.05 Sucrose content,% 9.05 Solids content,% 10.3 Benignity,% 87.86 Cleaning effect on diffusion,% 17.0 Loss of sugar in pulp,% 0.30
PRI me R 4. Into the water (extractant) in an amount of 1 l enter 75 mg (0.015% by weight of beets) of magnesium sulfate. This solution with a pH of 5.12 is subjected to ECA in the cathode chamber of a diaphragm electrolyzer for 10 min at a current strength of 6.5 A and a voltage of 12 V until the pH of catholyte reaches 5.5 and Eh = -1100 mV. Prepared extractant preheated to 80 ° ^C. A portion of 500 g of chips evenly placed on a perforated bottom hydrator and sprayed therefrom a warmed to catholyte in an amount of 100 g was simultaneously through the lower tube hydrator chip under layer is fed with live steam temperature of 80 ^{° C} and a pressure of 45 kPa in an amount of 50 g for 20 s. The chips thus treated are placed in a thermostatically controlled beaker, where extraction is carried out under the conditions according to Example 1. The diffusion juice parameters were: pH, units 6.00 Sucrose content,% 8.98 Dry matter content,% 10.2 Benignity,% 88.03 Cleaning effect on diffusion,% 18.9 Sugar loss in pulp,% 0.29
PRI me R 5. Into the water (extractant) in an amount of 1 l enter 50 mg (0.01% by weight of beets) calcium chloride. The resulting solution with a pH of 4.98 is passed through the cathode chamber of the diaphragm electrolyzer with the following ECA parameters: current strength 5.0 A, voltage 14 V, time 11 min until the pH of catholyte reaches 5.45 and Eh = -1030 mV. The catholyte is drained and heated to 78 ^about C.

Cossettes in an amount of 500 g was placed in a hydrator, which simultaneously sprayed catholyte of 100 g (20% by weight beet) and 75 g of steam with a temperature of 82 ^{° C} for 20 seconds. Chips prepared in the scalder are sent to a thermostatically controlled beaker for extraction according to the conditions of Example 1. Technological parameters of diffusion juice: pH, units 5.90 Sucrose content,% 9.04 Dry matter content,% 10.3 Benignity,% 87.78 Cleaning effect on diffusion,% 16.5 Sugar loss in pulp,% 0.28
The above examples show that the proposed method for preparing beet chips for extraction allows to obtain diffusion juice of high quality and minimal loss of sugar in the pulp. Laboratory tests of the proposed method for ECA of the solutions of the above salts to achieve a catholyte pH of 5.0-5.5 and Eh = - (800-1100) mV and scalding with heated catholyte in a mixture with n arom at a temperature of 80 + 2 ^о С give similar results , and therefore are not given further.

 Such technological indicators are obtained due to the fact that the chips scalded with steam and catholyte become not only plasmolyzed, but also disinfected, acquire, in addition to coagulating properties, an active adsorption ability, which ensures the fixation of a large complex of non-sugar beets and extractant impurities on the surface of the cell skeleton, giving the chip rigidity and elasticity . The proposed method allows the extraction process under the conditions of "sterility" without the additional use of chemicals. The latter circumstance is especially important when working with sluggish, frostbitten or rotten beets. The adsorption activity of catholyte-treated chips far exceeds the ability to adsorb non-sugars in chips scalded with saturated steam.

 Thus, the use of electrochemically prepared catholyte of a weakly concentrated solution of a sulfate or chloride of a salt of polyvalent metals in a mixture with saturated steam for scalding beet chips can significantly intensify the process of sugar extraction and obtain diffusion juice with high technological parameters. (56) 1. Patent GDR N 104555, cl. C 13 D 1/08, 1974.

 2. USSR author's certificate N 217492, cl. C 13 D 1/08, 1984.

 3. Sugar industry N 11, 1983, p. 21-23.

Claims (1)

METHOD FOR PRODUCING DIFFUSION JUICE FROM SUGAR BEET, which involves grinding it into chips, scalding the chips with steam and extracting the chips with an extractant, characterized in that part of the extractant is taken in an amount of 20-30% by weight of the beets and salt is added - sulfate or chloride metal amount of 0.01 - 0.03% by weight of beets, then this amount of extractant is electroactivated in the cathode chamber of the diaphragm electrolyzer until the pH of the catholyte reaches 5.0 - 5.5 and the redox potential from - 800 to - 1100 mV, heated to 78 - 80 ^o C and direction They are scalded for beet chips, while scalding the chips with extractant and steam is carried out simultaneously, moreover, they use sharp saturated steam with a temperature of 80 - 82 ^o С and a pressure of 45 - 47 kPa in an amount of 10 - 15% by weight of beets.

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