RU2039831C1 - Process for producing sugar from molasses - Google Patents

Abstract

FIELD: sugar industry. SUBSTANCE: essence of this process resides in allowing diluted molasses to pass through cationite (Ca++), carrying out elution of fractions and thickening of fraction containing saccharose to obtain syrup, subjecting syrup to electrodialytic refinement at flow rate of about 0.0008 to 0.0016 m/s and temperature of about 70 to 80 C by allowing it to pass through electrolyzer working chamber filled with filtering material nonconducting electric current, drying refined saccharic fraction of molasses in high-frequency electromagnetic field at electric field intensity of 1200 to 1500 V/cm, vacuum of 95.8 to 98.8 kPa and temperature of 30 to 40 C to moisture content of about 1.5 to 2.5 briquetting resultant crystalline stock, drying thus treated briquettes in high-frequency field at temperature of about 50 to 70 C and residual humidity of 0.1 to 0.3 and finally cooling resulting stock. EFFECT: disclosed method allows producing high-quality end product from molasses, namely, soft yellow sugar containing microelements, aminoacids, vitamins, and other compounds promising for food industry. 2 tbl

Description

 The invention relates to the sugar industry, and the resulting product can be used in the food industry.

 In the sugar beet industry, large quantities of molasses are obtained as waste. The bulk of molasses consists of 50 sugar, 20 water and 30 so-called non-sugar, consisting of 20 organic and 10 minerals. All three components, i.e. sugar, nesugar organic and mineral are in such a ratio that they keep each other from crystallizing.

A known method of producing sugar from molasses, comprising passing it diluted with water to a solution through cation exchange resin in a Ca ⁺⁺ form, eluting fractions, thickening a fraction containing sucrose, until a syrup is obtained. Elution is carried out with decarbonized water. Separation is carried out at 50-99 ° ^C. The ion exchange resin is regenerated with concentrated insipidus part molasses or sugar-containing fraction.

This method of separating molasses by the method of lagging electrolyte, based on the difference in the adsorption strength of sucrose, organic and mineral sugar in cation exchange resin in a Ca ⁺⁺ form, containing both acidic and basic groups (polymer in the copolymer), allows to separate high molecular weight non-electrolyte from the electrolyte and obtain sugar part of high purity (about 90), suitable for crystallization.

 The disadvantage of this method is the instability of the parameters (purity, sucrose and non-sugar content) of the product fraction obtained by chromatography of molasses of equal composition and quality. This is due to the fact that with this method of separating molasses, a cation exchange resin (polymer in a copolymer) is used, which unequally adsorbs various electrolytes. With large differences in the composition of electrolytes for molasses of different benignity and physico-chemical properties obtained from beets grown under various agricultural conditions, produced by various methods and at different times, it is impossible to obtain a product with guaranteed properties.

 The technical problem that the invention solves is to increase the yield of sugar from molasses and to provide soft yellow sugars.

To solve this problem, according to the proposed method, which involves passing molasses molten solution diluted with water through cation exchange resin in a Ca ⁺⁺ form, eluting fractions, thickening the sucrose-containing fraction to obtain a syrup, this syrup is subjected to electrodialysis purification by passing at a rate of 0.0008-0 , 0016 m / s at a temperature of 70-80 ^о С through the working chamber of the electrodialyzer, filled with non-conductive filtering material, and the purified syrup is dried in a high-frequency electromagnetic field at a voltage electric field 1200-1500 V / cm, the negative pressure 95,68-98,8 kPa and a temperature of 30-40 ^{° C} to a moisture content of 1.5-2.5 and the resulting crystal crop was compressed into briquettes and then drying them in a high-frequency electromagnetic field when the electric field strength of 300-400 V / cm and a temperature of 60-70 ^C to a residual moisture content of 0.1-0.3 and cooled.

 A method of producing sugar is as follows.

Molasses is diluted with water to a solids content of 50 filtered and the diluted solution is passed through cation exchange resin in a Ca ⁺⁺ form, the molasses sugar and non-sugar fractions are eluted. Sugar molasses fraction was boiled under vacuum at 21.33 kPa negative pressure to a solids content of 60 was purified by electrodialysis, by passing it into a DC field with a velocity 0,0008-0,0016 m / s and a temperature of 70-80 ^{° C} through the working chamber an electrolytic cell of an electrodialyzer, filled with non-conductive filtering material: expanded clay or silica gel with a diameter of granules of 2-3 mm, or fired clay. An electrolytic cell is used, made in the form of a capacitance divided by cation-exchange membranes into three chambers: cathodic, middle and anodic. The electrodes are graphite, steel or platinum electrodes. A 0.1 N NaCl solution is pumped through the electrode chambers to prevent gas polarization of the electrodes at a speed of 0.03-0.05 m / s. A purified syrup containing sucrose 80-85 is passed through the middle (working) chamber at a speed of 0.0008-0.0016 m / s. Purification was performed at 70-80 ° ^C. The residence time of the solution in the layer of filter material is 1.5-2 hours. At the end of the operation cycle of the electrolysis cell defined by the number of impurities or retained their concentration in the filter solution, syrup supply is stopped, the voltage is removed and give water to the working chamber. In this case, the sediment is destroyed and removed from the intergranular space of the layer by a stream of water. Then the cycle repeats.

Cleaning through a non-conductive filtering material placed in a constant electric field, the sugar fraction of molasses with a high content of sucrose allows to achieve high electric field strengths and thereby remove a significant amount of electrolytes, colloidal and coloring substances from this molasses fraction. At the same time, it seems possible to increase the cleaning effect of the molasses product fraction by 65-70 and reduce the color by 70-90
Thus, as a result of electrodialysis purification of the molasses sugar fraction, a concentrated transparent light brown sugar-containing solution with a high sucrose content and non-sugar useful for humans is obtained.

Purified sugar molasses portion is dried in high-frequency electromagnetic field with a frequency of 2450 MHz at the electric field intensity of 1200-1500 V / cm, vacuum 95,8-98,8 kPa and a temperature of 30-40 ^{° C} to a moisture content of 1.5-2.5 Drying is performed on a microwave installation of continuous operation, which is a sealed cylindrical chamber, closed from the ends by covers. Inside is a conveyor belt made of radiolucent material. The purified molasses product fraction from the tank is pumped by the metering pump to the nozzle and applied as a dispersion to the conveyor belt. Microwave energy from the generator through the waveguide and the dielectric lens is supplied to the drying zone. The process temperature is controlled by a non-contact thermometer. After drying, the material is crushed by a crusher and its residues on the tape are removed with a brush. The lock system of the installation allows continuous removal of the dried material. The vacuum is created using a liquid ring pump with an ejector installation.

 Microwave heating refers to the category of processes with the so-called internal heat source, which is a microwave wave penetrating into the heating object. In this case, the energy of the electromagnetic field is dissipated, accompanied by the release of heat. With high-frequency heating, the temperature on the surface of the material due to heat loss is less than inside, and therefore the temperature and pressure gradients have the opposite direction, which dramatically accelerates the removal of moisture from the material.

 The specific dissipation power in a material depends on its electrophysical parameters, which, in turn, depend on humidity and other factors. As the material dries, the humidity decreases, while the dielectric loss factor decreases and, accordingly, the energy release decreases.

 Converting the energy of electromagnetic waves into thermal energy directly inside the product itself and the release of energy in the material in proportion to its mass fraction of moisture allows for a high heating rate, inertia-free process control, and high quality of the product.

 The resulting powder is light brown in color and can be used in the food industry.

To increase the moisture resistance of the resultant powder as a fine yellow soft sugar compressed into briquettes, for example, presses the disc at an optimum production of sugar refining 1.5-2.5 humidity and a temperature of 30-40 ^{° C,} which it has at the output of the microwave unit. When pressing, the sugar crystals and their debris are interlocked, which facilitates the further cementation of the crystals of pressed soft yellow sugar, which ends with the crystallization of additional sugar during the evaporation of the water that dissolved it.

 The use of high-frequency heating in the production of soft yellow sugars makes it possible to intensify thermal processes with high quality products.

PRI me R 1 (by a known method). Molasses having a purity of 59 is diluted with water to a dry solids content of 50 filtered and chromatographic separation of the resulting solution into sugar and non-sugar fractions is carried out according to a known method in an installation consisting of two columns of the same size connected in series with an ion exchanger working height of 6 m and an internal working diameter of 80 mm 30 l. KU-2-4 cation exchanger is placed in columns in a Ca ⁺⁺ form with a granule size of 0.3-0.4 mm, operating in a lagging electrolyte mode. The total amount of cation exchange resin is divided in such a way that 65 vol. of the total number, and in the second 35 vol.

2 l (which corresponds to the ratio of the liquid to the volume of the ion exchanger equal to 0.06) molasses, having a temperature of 90 ^about C and containing 50 wt. solids at 59th purity and color 58.3 units. PC. pumped into the first column. The flow rate of molasses is 3 cm / min. The moment when the solution level coincides with the level of cation exchanger, the molasses supply was stopped and the column is fed decarburization water (condensate) at ⁹⁰ ° C with the same transmission speed. As soon as sugar appears in the eluate of the first column, a second column is connected to it and hot condensate is continued to be supplied to the first column until sugar is detected in the eluate from the second column. After that, the second column is disconnected from the first and the sugarless part from the first column and sugars from the second column are eluted by feeding decarbonized water into them.

Sugar fraction from the second column was collected as long as the polarimeter does not show 0.45 ^C. The resulting eluate was then collected together with the non-sugar fraction coming from the first column. Upon completion of the elution fractions sugar process (second column sugar no more), the two columns were washed with warmed to 90 ^{° C} decarburized water.

 In the table. 1 shows the results of five cycles of separation of molasses for different chromatographic rates with one regeneration operation, and the molasses processing cycle includes a process from the moment the molasses solution is fed into the columns until the elution of sugar and non-sugars is complete.

The volume of the fraction containing sugar ranges from 5.46 to 5.85 L, the ratio of this fraction to the volume of cation exchange resin used is in the range 0.195-0.182. The sugar fraction contains 9.56-10.5 wt. solids, 7.97-9.06 sugar and 1.34-1.59 non-sugars. The cleaning effect averaged 76.4 bleaching effect 56.9
The achieved values of purity 83.4-86.8 and color 23.8-29.7 units. PC. do not provide soft yellow sugars of high quality.

PRI me R 2. Molasses diluted with water to a solids content of 50 and filtered through a layer of perlite washed on the base. A molasses solution with a sugar content of 29 non-sugars 20.5 with a purity of 59 and a color of 58.3 units. PC. subjected to chromatographic separation into sugar (food) and non-sugar (molasses) fractions by passing molasses through cation exchange resin with a molasses flow rate of 3 cm / min. Cation exchange resin is used in a Ca ⁺⁺ form.

The obtained sugar fraction of molasses with a solids content of 10.2 sugars 8.83 nesugar 1.37 with a purity of 86.6 and a color of 24 units. PC. boiled under vacuum at a vacuum of 21.33 kPa to a solids content of 65 and passed at 75 ^about With a speed of 0,00085 m / s through the working chamber of the electrolytic cell of the electrodialyzer made of fluoroplastic, size 15 x 20 x 1450 mm, pre-filled with expanded clay . A 0.1 N NaCl solution is pumped through the electrode chambers separated from the middle by MK-40, MA-40 membranes. The distance between the electrodes is 20 mm. A constant voltage is applied to the electrodes. At the end of the cycle time of 1.5 hours, the supply of product fraction is stopped, the current is switched off and washed with water cell middle chamber at ²⁵ ° C until a colorless solution at the outlet. Then the cycle is repeated, increasing the magnitude of the voltage supplied to the electrodes and subjecting the product to molasses, purified already in the previous cycle.

 In each cycle, the cleaning effect is determined by changing the purity of the solution and the effect of discoloration by the concentration of colored substances. In the course of the experiments, the electric field strength in the working chamber of the cell is controlled using platinum probes. The results of the experiments are shown in table. 2.

 As can be seen from the table. 2, after the third cleaning cycle, a cleaning effect of 66.3 and a bleaching effect of 87.9 were obtained. The overall cleaning effect obtained by chromatographic separation of molasses in a known manner and the electrodialysis of the sugar fraction in a layer of non-conductive filtering material was 93.3 and the bleaching effect was 95 , 5 These figures are considered sufficient in the production of high-quality soft yellow sugars.

Purified molasses weighing 1 kg, containing 65 wt. solids at 95th purity, color 2.7 units PC. having an initial temperature of 70 ^{° C,} using a pump-dispenser is applied as a dispersion onto the conveyor belt microwave installation type "Gigavak" and dried in a high-frequency electromagnetic field with a frequency of 2450 MHz at the electric field intensity of 1200-1500 V / cm, the vacuum 95, 8-98,8 kPa and a temperature of 30-40 ^{° C} to a moisture content of 1.5-2.5
Because the syrup supplied to the drying has a temperature of 70 ° ^C, and drying it performed at a lower temperature of 30-40 ^{° C,} it can be considered, ignoring the losses of microwave power (less than 5) due to radiation, convection, conduction and loss excluding power for heating molasses, that all microwave energy is spent on the phase transformation of evaporation.

 Removal of free moisture occurs in the form of intense vaporization of the sugar fraction at a boiling point corresponding to a vacuum in the drying chamber. After drying, the product is discharged through a lock device into the finished product container.

The resulting soft brown sugar in the form of fine powder with a moisture content of 1.5 compressed into briquettes, and then dried in a high-frequency electromagnetic field with a carrier frequency of 2450 MHz with the electric field strength of 300-400 V / cm and a temperature of 60-70 ^C to a residual humidity 0 1-0.3 and cool.

 In its presentation, the soft yellow sugar obtained from molasses contains, by weight. sucrose 95, invert sugar 0.2, macro- and micronutrients 1.5, nitrogenous substances 1.5, basazotous substances 1.7, water 0.1.

 This soft yellow sugar in terms of quality and storage meets the requirements of the food industry (bakery, soft drinks, confectionery, etc.).

 The proposed method allows to obtain soft yellow sugar of high quality from molasses, the physiological value of which is much higher, since in addition to sucrose it contains trace elements, amino acids, vitamins and other compounds of interest from a nutritional point of view.

Claims (1)

METHOD FOR PRODUCING SUGAR FROM MELASS, which involves passing its diluted with water solution through cation exchange resin in a Ca ++ form, eluting fractions, thickening a fraction containing sucrose to obtain a syrup, characterized in that this syrup is subjected to electrolysis purification by passing it at a rate of 0.0008 0. 0016 m / s at a temperature of 70 80 ^o C through the working chamber of the electrodialyzer, filled with non-conductive filtering material, and the purified syrup is dried in a high-frequency electromagnetic field at an electric field tricity field 1200 1500 V / cm, a discharge of 95.8 98.8 kPa at a temperature of 30 40 ^o C to a moisture content of 1.5 to 2.5% and the resulting crystalline mass is pressed into briquettes, followed by drying in a high-frequency electromagnetic field at an electric field field 300 400 V / cm and a temperature of 60 70 ^o C to a residual moisture content of 0.1 0.3% and cooling.

Images