JP2001157599A - Process for producing refined sugar from sugar cane by ultrafiltration treatment including softening treatment by addition of sodium carbonate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To directly produce refined sugar at a cane producing district in high efficiency. SOLUTION: The sugar-producing process contains (1) a step to produce a crude juice comprising a squeezed juice obtained by squeezing sugar cane, an extracted juice obtained by extracting sugar cane or a sugar juice obtained by mixing the squeezed juice and the extracted juice, (2) a step to heat the crude juice, (3) a step to remove the insoluble matters from he crude juice by filtration, (4) a step to add sodium carbonate to the crude juice to effect the softening and the adjustment of pH, (5) an ultrafiltration step to remove the soluble polymeric materials and insoluble materials from the crude juice by ultrafiltration, (6) a step to concentrate the clear juice obtained by the above step and (7) a step to separate the concentrated liquid obtained by the above step into a sucrose fraction, a reducing sugar fraction and a non-sucrose fraction by chromatographic separation method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing sugar from sugar cane, which comprises addition of sodium carbonate and ultrafiltration.
More specifically, a method of producing purified sugar directly on cultivated land by effectively utilizing the energy of a sugarcane production plant and efficiently removing organic and inorganic non-sugar components contained in the sugarcane from the sugarcane cut at the sugarcane-producing area. It is about.

[0002]

2. Description of the Related Art <Conventional process for recovering sucrose from cane sugar> A conventional method of obtaining sucrose from cane sugar is to grow sugarcane in the tropics or subtropics and crush and compress the crude juice to obtain a simple physical juice. -Chemical treatment (adding lime milk) to remove impurities, concentrate the resulting clear liquid in a concentration can, place the concentrated syrup in a crystal can, and evaporate and crystallize sucrose crystals (crude sugar) stepwise ( Sucrose method) to produce sucrose crystals.

[0003] Since the crystals obtained in this process have low purity, the crude sugar is transported to the consuming area, dissolved, and the melt is subjected to physical and chemical treatments and purified to obtain sucrose (high-purity product) and sell it. are doing. On the other hand, there have been many attempts to obtain cultivated land white sugar (or cultivated land purified sugar) on arable land, and these have been put to practical use. Details of the crude sugar production method and the cultivated land white sugar production method are as follows.

(Method for producing crude sugar) A method in which a mixed juice is heated, lime milk is added to clean the mixture, and sucrose crystals are obtained from the resulting supernatant (clean juice). Although this process is simple, it has the following disadvantages: 1) Due to the sedimentation treatment, suspended solids and soluble polymer substances in the supernatant cannot be completely removed. 2) Since a certain residence time is required for the sedimentation treatment, the sucrose content changes into reducing sugar, and the sucrose recovery rate decreases. 3) Inorganic salts are precipitated as calcium salts due to the added lime, but calcium dissolved in the sugar solution is partially precipitated as a scale in the evaporation step. Therefore, it is necessary to remove calcium by a washing operation. Also, the purity is not good because it cannot be completely removed from the sugar solution.

[0005] (Cultivated land white sugar production method) [0005] In the case of producing white sugar in a crude sugar production site, there are the following methods. 1) Sulfurous acid method: The principle of cleaning is to evaporate the liquid obtained by hot lime treatment and add sulfurous acid gas and milk of lime at 40% to decolorize. In this method, sulfurous acid contained in the product cannot be used for canning. 2) Double carbonic acid method: The principle of cleaning is a method in which lime milk and carbon dioxide gas are reacted in two steps. It generates a large amount of mud, requires a large amount of energy for lime burning, and is not economical. 3) Cultivated land refined sugar: The principle of cleaning is to accept the crude sugar next to the crude sugar factory, re-dissolve and refine the sugar solution using carbonation-saturated or ion-exchange resin, and crystallize to obtain a product similar to purified sugar. .
The company has two facilities, a crude sugar factory and a refined sugar factory, and the capital investment is high.

<Conventional Softening Technique> Ca and Mg in sugarcane squeezed juice and extracted juice cause scaling during concentration, and at the same time, displace the exchange groups of the resin used in the chromatographic separation, thereby causing chromatographic separation. It is necessary to soften / remove in the previous process because the performance is reduced. Current,
As a means for the softening treatment, a strongly acidic cation exchange resin is used. However, since the resin needs to be regenerated, there are problems such as waste liquid treatment due to the use of a regenerant and chemical cost.

In the method disclosed in Japanese Patent Publication No. 7-67399, sodium carbonate is used in an amount of 1 to 3 times the total amount of Ca and Mg in the molasses separated from the crystallization step of recovering sucrose from cane molasses. 0.5-3wt% C to molasses
It is said that 90% removal is possible by adding a (OH) ₂ to adjust the pH to 9.0 to 10.0. In this prior patent, cane molasses obtained by disintegrating in a crystal can at a cane sugar production plant is used as a raw material, and about 1% of C is contained in molasses.
a, Mg ions are contained. Here, since the raw material is molasses, the content of Ca and Mg is large. Further, since sludge is contained in addition to Ca and Mg, all of the contained impurities cannot be completely removed by sodium carbonate alone, so calcium hydroxide is added as a promoting aid for sludge formation. However, addition of calcium hydroxide also increases residual calcium ions, so that if the amount is too large, there is no meaning as softening due to the addition of sodium carbonate.

[0008]

In a conventional lime cleaning process in a crude sugar factory, the pH can be adjusted by adding lime, and it is good as a sedimentation accelerator for insoluble suspended substances. Because of the use of the agent and the calcium saturated state in the fresh juice, remarkable scaling occurs in the concentration step, and in order to remove this, frequently use a chemical for scaling removal. Is in a situation. In addition, natural gravity sedimentation for removing aggregates after addition of lime requires a certain residence time (approximately 4 hours for both lime addition and sedimentation time). It is converted to sugar, causing a decrease in the recovery rate of sucrose.

Among the above-mentioned cultivated land white sugar production methods, the cultivated land purified sugar production method involves a double production step of crude sugar-purified sugar,
It costs a lot of money and energy for construction and manufacturing and is not economical. In addition, while a large amount of excess bagasse (fiber after sugar cane squeezing) that can be used as energy in the crude sugar production process is generated and discarded, the refined sugar production process involves contradictions that require energy from fossil fuels. .

The means for recovering sucrose in crude and refined sugar factories is by crystallization, and cannot recover sucrose accompanying non-sucrose in molasses. This limits the sucrose recovery rate.

[0011] Accordingly, an object of the present invention is to make it possible to produce purified sugar directly and efficiently in a sugarcane-producing area. In addition, the present invention incorporates a sodium carbonate addition step and an ultrafiltration treatment step (further, a chromatographic separation step), thereby improving sucrose recovery, producing by-products (mainly reducing sugars), and reducing chemicals. Plan.

[0012]

According to a first aspect of the present invention, there is provided a method for producing sugar from sugar cane, comprising the steps of adding sodium carbonate and ultrafiltration. Is the law. (1) A crude juice producing step of obtaining a squeezed juice obtained by squeezing a sugar cane, an extracted juice obtained by extracting a sugar cane, or a sugar juice obtained by mixing a squeezed juice and an extracted juice. (2) A heating step of heating the crude juice. (3) An insoluble substance removing step of removing insoluble substances in the crude juice by filtration. (4) A step of adding sodium carbonate to the crude juice to perform a softening treatment and pH adjustment. (5) An ultrafiltration step of removing a soluble polymer substance and an insoluble substance from the crude juice by ultrafiltration to obtain a clear liquid. (6) a concentration step of concentrating the clarified liquid. (7) A chromatographic separation step in which the concentrated liquid from the concentration step is chromatographed and separated into a sucrose fraction, a reducing sugar fraction and a non-sucrose fraction.

[0013] The invention according to claim 2 is that the sucrose fraction from the chromatographic separation step is sent to a concentration step, and the concentrated liquid is used as a liquid sugar product, or the concentrated liquid is crystallized to produce purified sugar. The sugar production method according to claim 1, further comprising a crystallization step for obtaining.

According to a third aspect of the present invention, there is provided a sugar solution sending / concentrating / crystallizing step in which the sucrose fraction from the above-mentioned chromatographic separation step is sent to a concentration step, and high-purity sugar crystals are obtained in a crystallization step. The sugar production method according to claim 1, further comprising:

The invention according to claim 4 is the sugar production method according to claim 3, further comprising a sugar recovery step of recovering sugar from molasses from the crystallization step in a chromatographic separation step.

A fifth aspect of the present invention is a method of recovering a sugar liquid from at least one of a sludge from an insoluble substance removing step, a sludge from a sodium carbonate adding step, and a concentrated liquid from an ultrafiltration treatment step. 2. The method of claim 1, further comprising the step of:
It is the sugar production method described.

The invention according to claim 6 is the sugar production method according to claim 5, further comprising a sugar solution sending step of sending the sugar solution collected from the sugar solution collecting step to an insoluble substance removing step.

The invention according to claim 7 is the sugar production method according to claim 1, wherein caustic soda can be used for pH adjustment in the sodium carbonate adding step.

The invention according to claim 8 is the sugar production method according to claim 1, wherein the pH is adjusted in the range of 6 to 8 in the sodium carbonate adding step.

<Outline of the Present Invention> The outline of the present invention is as follows. That is, the mainstream of the cleaning method in the production of sucrose and purified sugar from sugarcane is precipitation of aggregates by addition of lime milk and desalting and softening by an ion exchange resin. Here, the addition of lime milk increases the Ca concentration in the sugar juice, but this is replaced with a later-stage ion exchange resin, and this resin is regenerated according to use.

In the method of the present invention, addition of sodium carbonate and a UF membrane are used as a method for cleaning sugarcane pressed juice or extracted juice, or a sugar juice obtained by mixing them. Addition of sodium carbonate plays two roles of pH adjustment and softening of sugar juice, and addition of sodium carbonate causes calcium and magnesium in the sugar solution to precipitate as precipitates of calcium carbonate and magnesium carbonate. The UF membrane is removed together with other fine insoluble suspended substances and soluble polymer substances.

The crude juice consisting of cane squeezed juice, extracted juice, or a mixed sugar juice thereof is heated to about 105 ° C. in a heat exchanger. Next, fine fibrous substances and insoluble suspended substances from the sugar cane are filtered and removed with a gradient filter or a bag filter. The pH of the sugar juice at this point is pH 5-7.

The first purpose of adding sodium carbonate is to remove calcium and magnesium which hinder the separation performance in the subsequent chromatographic separation. The second purpose is that the production of reducing sugar is easily promoted because the crude juice is in the acidic region.
To 8 to reduce the production of reducing sugars.

The amount of sodium carbonate added is determined by the amount of Ca and M in the crude juice.
g is specified for the purpose of reducing the content of the resin to such an extent as not to impair the separation ability of the resin for chromatographic separation. In general, the concentration of Ca and Mg is N
It is desired that the concentration is less than 5% with respect to a and K concentrations. The amount of sodium carbonate added depends on the properties of the sugar solution. The second purpose of adding sodium carbonate is to add a necessary amount of sodium carbonate for the purpose of softening, and when the pH of the sugar solution does not reach pH 6 to 7, in order to suppress the generation of reducing sugar due to decomposition of sucrose.
H adjustment is performed simultaneously. At that time, caustic soda or the like can be used instead of sodium carbonate. The softened crude juice after the addition of sodium carbonate is passed through a UF membrane, and the carbonate, insoluble suspended substances, and soluble polymer substances are filtered and separated. The permeate is further concentrated in an evaporator and reduced from Bx13 to Bx50. Alternatively, it can be concentrated to about Bx70 to obtain a liquid sugar product. Bx
The sugar solution concentrated to 50 is applied to a fixed bed type, or preferably a continuous or simulated moving bed type chromatograph, to separate it into three components: a sucrose fraction, a reducing sugar fraction and a non-sucrose fraction. The sucrose fraction is crystallized in the crystallization step to obtain a purified sugar. By sending the molasses in the crystallization step to the chromatographic separation step, sucrose can be further recovered.

[0025]

According to the present invention, the following effects can be obtained. 1) By adding sodium carbonate to the crude juice that has undergone the squeezing step, calcium and magnesium, which cause scaling at the time of concentration, can be carbonated and settled and separated. The effect of reducing scaling by using sodium carbonate instead of lime cleaning is that, for example, washing the evaporator once a week can be reduced to once a month. Operational load can be reduced, and the amount of cleaning chemicals can be reduced.

2) The purpose of adding sodium carbonate is to soften the sugar juice and adjust the pH. As an example, Ca: 2 in the softening solution
0 ppm, Mg: 80 ppm, and the amount of sodium carbonate added when the Ca and Mg concentrations are 5% or less with respect to the Na and K concentrations in the sugar solution is as large as about 2800 ppm. Becomes pH 7 and pH
The role of the operation performed in two steps of adjustment and softening is performed in one step, and the operation is simplified. Regarding the role of pH adjustment, the pH of the sugar juice when pH adjustment is not performed is pH 5 to 6, and when concentration in the subsequent step is performed at this pH, the amount of reducing sugar generated increases. This is adjusted to pH by adding sodium carbonate.
By setting it to about 6 to 8, the production of reducing sugar is suppressed. Furthermore, Ca and Mg dissolved in the sugar solution not only cause a problem in the scaling in the concentration step, but also replace the exchange group of the resin for the chromatographic separation and reduce the separation ability. As a carbonate.

3) The method of adding sodium carbonate for pH adjustment and softening treatment has conventionally been considered to be remarkably colored and expensive. However, in the present invention, after adding sodium carbonate, an ultra-high-temperature solution for removing soluble high-molecular substances (gum, dextran, proteins, coloring substances, etc.) and fine insoluble suspended substances contained in the fresh juice is used. By employing a filtration membrane, components colored by the addition of sodium carbonate, soluble polymer substances, S. Minutes can be removed. As for the removal rate, the coloring component is 20 to 40.
%, Soluble polymer substance is 40 to 60%, and other S.P. S.
The minute is over 99%. These coloring components and soluble polymer substances cannot be removed by conventional lime cleaning.

4) The conventional settler has a long residence time and is large-scale in terms of equipment, whereas the ultrafiltration membrane has a short residence time and equipment.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment: See FIG.
FIG. 1 shows a first embodiment according to the first aspect of the present invention.

<Squeezing step to obtain crude juice by squeezing cane>
The whole amount of squeezed juice obtained by squeezing sugar cane with a squeezing machine, or the entire amount of extracted juice by the extraction method, or a mixed juice obtained by mixing the extracted juice and the extracted juice, that is, the crude juice is heated to 105 ° C. by using steam as a heat source. . Examples of the equipment for performing heating include a shell-and-tube type or plate type heat exchanger.

<Insoluble matter removal step of removing insoluble matter in crude juice by filtration> Next, in the crude juice, net fibrous material derived from sugar cane or other foreign matter (hereinafter referred to as "insoluble suspended material") Or "insoluble material"). Filtration is performed to remove these insoluble suspended substances. Means for removing these insoluble suspended substances include inclined screens. This inclined screen can remove insoluble substances of 50 μm or more, can be operated continuously, can continuously discharge clean juice and insoluble substances, and is easy to operate because there is no movable part. The screen of the inclined type screen is preferably a wedge wire type screen having an operating pressure of 1 kgf / cm ² G or more. In addition, in order to avoid the film processing load in the post-process, the inclined screen is divided into two stages and 50 μm in the first stage.
The second cut can be a 10 μm cut.
In addition, the particle size to be removed of insoluble suspended substances is determined by the membrane structure in the subsequent ultrafiltration treatment, but it is necessary to remove the insoluble suspended substances in this step as much as possible in the ultrafiltration treatment step. Can be raised and is economical.

<Sodium carbonate addition step of adding sodium carbonate to the filtrate to perform softening treatment> The calcium and magnesium concentrations in the crude juice differ depending on the existing and production areas, but sodium and potassium are inferior in chromatographic separation resin performance. The sedimentation is carried out by adding sodium carbonate so that the concentration becomes 5% or less. The pH after the addition depends on the concentrations of calcium and magnesium contained in the juice,
H is about 6-8. When the pH is 6 or less, the state is such that the production of reducing sugar is easily promoted. At this time, for the purpose of suppressing the generation of reducing sugar and increasing the recovery rate, adjustment to pH 6 to 8 with an alkali chemical such as caustic soda can be mentioned as a means. However, even if reducing sugars are generated, the reducing sugars can be recovered by the subsequent chromatographic treatment. Therefore, there is no problem to carry out the treatment at pH 7 or lower only for the purpose of softening.

<Ultrafiltration Step of Ultrafiltration of Softening Solution to Obtain Clarified Solution> In this ultrafiltration step, calcium and magnesium carbonates in the liquid after addition of sodium carbonate, fine insoluble suspension Remove suspended substances and soluble polymer substances. Cross-flow type continuous membrane filtration is appropriate as the filtration for removing these. Ultrafiltration (normally UF)
Membrane) is optimal. Considering the filtration ability and contamination by various bacteria, a membrane having a high temperature (80 ° C. or higher) specification is suitable. There are various types of film structures and film materials, but any material can be used as long as the above conditions are satisfied.

Regarding the concentration ratio when the membrane treatment is retarded, the higher the concentration ratio, the higher the sugar solution recovery rate in the membrane treatment can be. However, the membrane area increases, which is not economical.
Conversely, if the concentration ratio is set low, the equipment for the recovery step becomes large, and it is not economical. From this, about 30 ~
50 times is appropriate, and the concentration ratio is determined by the amount of insoluble suspended solids in the mixed juice. Regarding the concentration method, since the filtration capacity of the membrane varies depending on the concentration ratio, the membrane area can be reduced by dividing the concentration into several stages instead of performing the entire concentration in one stage. The determinant for dividing the membrane treatment into several stages is determined by the membrane treatment capacity at each concentration ratio. Further, as a means for increasing the recovery rate in the membrane treatment, a method based on water dilution can also be mentioned.

<Concentration step for concentrating the clarified liquid from the ultrafiltration treatment> Next, the softened saccharide liquid is mixed with, for example, Bx1
Concentrate from 5 to Bx50. This concentration step is performed according to a conventional technique. Examples of the concentrator include a calandria type and a plate heat exchange type. However, as for the enrichment apparatus for cans with a high Bx, a type capable of washing and removing the same is desirable because scaling to a heat exchanger can be considered.

<Chromatographic Separation Step for Chromatographic Separation of the Concentrate from the Concentration Step> The concentrate from the concentration step is chromatographed and separated and purified into a sucrose fraction, a reducing sugar fraction and a non-sucrose fraction. As a device used for chromatographic separation, a fixed-bed type device can be used, and preferably, continuous operation with a simulated moving-bed type device increases the resin usage and the separation efficiency.

"Second and Third Embodiments: See FIG. 1" FIG. 1 shows an embodiment of the invention according to the second and third aspects of the present invention. <Step of converting the concentrated liquid from the concentration step to a liquid sugar product> The concentrated liquid from the concentration step is further concentrated to about Bx72 to obtain a liquid sugar product.

[Third Embodiment: See FIG. 1] FIG. 1 shows a third embodiment of the invention according to the third aspect of the present invention. <Sucrose fraction from the above chromatographic separation step is sent to the concentration step, and the sugar liquid is sent, concentrated and crystallized for further crystallization>
Since the sucrose fraction from the chromatographic separation step is diluted at the time of the separation, it is sent to the concentration step for crystallization to obtain a highly purified purified sugar. In the concentration step, 5 to 6 double effect cans are effective, and 2 to 3 cans are used for concentrating the sugar solution after the ultrafiltration membrane treatment, and the remaining 2 to 3 cans are used to remove the sucrose fraction from the chromatographic separation step. Concentration. Sorting of cans to each concentrate depends on the operating conditions.

"Fourth Embodiment: See FIG. 1" FIG. 1 shows a fourth embodiment of the invention according to claim 4 of the present invention. In order to further recover the sugar contained in molasses from the crystallization step, separation and purification are performed in the chromatographic separation step,
Increase sucrose recovery.

[Fifth and Sixth Embodiments: See FIG. 1] FIG. 1 shows a fifth embodiment of the present invention according to claim 5 and a sixth embodiment of the present invention according to claim 6. Indicated. <Sugar liquid recovery step of recovering the sugar liquid from the sludge from the insoluble substance removal step, the sludge from the sodium carbonate addition step, and the concentrated concentrate (including carbonate) from the ultrafiltration processing step>
And <sugar liquid feeding step of sending the recovered sugar liquid to the insoluble substance removing step> In the sugar liquid collecting step, sludge (insoluble suspended substance) generated from the insoluble substance removing step, sludge from the sodium carbonate softening step, and The sugar solution is recovered from the concentrated solution generated from the ultrafiltration process. As a collection method,
Lime milk having a flocculant effect, a polymer flocculant and pis (sugar cane-derived braided fiber) as a filter aid are added, these flocculated solids are removed by filtration, and the filtrate is subjected to an insoluble matter removal step. Return to As the filter, a continuous filter such as a horizontal belt filter or a drum filter is preferable. Alternatively, the solid is concentrated and separated by the coagulation sedimentation tank, and the clarified liquid is returned to the previous step. In the sugar liquid collecting step, the concentrated liquid generated from the ultrafiltration processing step can be effectively used elsewhere (for example, feed for livestock, fertilizer for farmland, and the like). The condensed solid matter generated in the coagulation sedimentation tank can be burned together with bagasse.

[0041]

(Example 1) 50 parts of the heated crude juice after the pressing step
A liquid (Bx12, pH5, Ca: 150 ppm, Mg:
145 ppm, ss. (500 ppm) was raised to a temperature of 80 ° C., and a softening test was performed. 0.5% by volume of a 20% sodium carbonate solution to 100 parts by volume of crude juice (2% when sodium carbonate is softened with respect to Ca and Mg contained in crude juice)
Twice the equivalent amount of sodium carbonate) and add 3 with a stirrer.
Stirred for 0 minutes. The softened solution was filtered through an ultrafiltration membrane having a molecular weight cutoff of 30,000 to 50,000. The concentration of Ca and Mg in the filtrate is C
a: 9 ppm, Mg: 52 ppm, and a Ca removal rate of 9
4%, the Mg removal rate was 64%, and most of Ca and Mg were removed. The amount of sodium carbonate added was adjusted to the content of Ca, Mg
Juice p when 1-fold, 2-fold, 5-fold, and 10-fold
The concentrations of H and Ca and Mg after addition were examined. The results are shown in FIG.

As a conventional technique, there is a lime cleaning method in which the juice is heated and lime milk is added. For comparison, add lime and p
After the H adjustment, a test was performed in consideration of the pH adjustment and the softening treatment in a two-stage system in which the treatment was softened with sodium carbonate. The heated crude juice that passed through the squeezing process was coarsely filtered,
Liquid from which impurities have been removed (Bx14, pH5, Ca: 19
(0 ppm, Mg: 155 ppm). 15% lime milk per 100 parts of crude juice
H was added until the pH reached pH 6, pH 6.5, pH 7, and pH 8. PH change due to change in lime addition amount at that time, and C content in sugar juice at each pH after lime milk addition
The relationship between a and Mg concentration was examined. The results are shown in FIG.

Next, 50 parts by volume of the supernatant liquid of the lime-added crude juice were taken, and while maintaining the temperature at 80 ° C., the pH of the sugar juice was adjusted to 8%.
An appropriate amount of a 20% sodium carbonate solution was added so that
At this time, the pH due to the addition of sodium carbonate and the Ca, M
FIG. 4 shows the relationship between the decrease in g concentration.

From the above two results, the addition of lime increases the dissolved Ca concentration in the added liquid, but the dissolved Ca can be precipitated and separated by sodium carbonate added thereafter. However, for example, when the amount of added lime is about 500 ppm (pH 6),
After that, the dissolved Ca concentration in the sugar solution after adding sodium carbonate to pH 8 became 250 ppm, and it could not be sufficiently removed.
When only sodium carbonate is added without adding lime, the added amount is 3000 ppm.
The a concentration becomes as low as about 100 ppm, and the Ca concentration is suppressed to a level that does not inhibit the chromatographic separation.

In the present invention, the addition of sodium carbonate has two effects, namely, a softening treatment and a pH adjustment. The effect of the pH adjustment is to reduce the pH of the acidic (about pH 5) sugar solution to neutral (p).
H7 to 8) is characterized in that the production of reducing sugars due to heating of the sugar solution during concentration is suppressed. Cane squeezed juice is softened with an ion exchange resin (SK1B) and 10% -Na
The pH was adjusted with OH, the pH was not adjusted, and the pH was adjusted to 6, 7, and 8, respectively, and concentrated in a rotary evaporator for 2 to 3 hours while maintaining the temperature at 85 ° C. Were compared.
FIG. 5 shows a test result of examining the ratio of the amount of reducing sugar produced by pH.

(Embodiment 2) This is an example applied to a 5,000 TCD factory with an equipment processing capacity of the flow shown in FIG. To screen crude juice from the squeezing step, an inclined screen (0.7 W
It was removed from t% to 0.4 wt%.

200 m at a temperature of 85 to 90 ° C. and pH 5 to 6
^The pressure of the crude juice of ³ / Hr was increased to 0.7 MPa, and
A 198 m ³ / Hr permeate and a 7 m ³ / Hr concentrate were obtained with a 00 m ² spiral membrane (fraction molecular weight: 20,000 to 30,000). The resulting permeate was S.P. S. Concentration: 150 ppm,
The impurity concentration was 0.5 wt%.

The permeate was added with 50% sodium carbonate (0.7%).
5 m ³ / Hr, Ca concentration: 200 ppm, Mg
Concentration: 160 ppm, pH 5 to Ca concentration: 0 to 20 p
pm, Mg concentration: 0 to 60 ppm, Ca, M up to pH 8
g was removed.

The softened sugar solution was concentrated to Bx50 in the first three cans of a six-effect concentrate, and as a result, sucrose: 75.5%, reducing sugar: 7.4%, non-sugar content: 17.1
%Met. The heat transfer area of the first three cans at this time was 60
It became a 00m ^2. The heat exchanger was a plate type.

Diameter 330 filled with strongly acidic cationic resin
Chromatographic equipment with a rotary valve consisting of 30 columns of 0 mm x packing height of 2000 mm and having a rotation valve of 0.6 hours / time;
This sugar solution was supplied at 61.5 m ³ / Hr to a total resin amount of 515 m ³ , and eluent water was supplied at 615 m ³ / Hr, a sucrose solution fraction of 21.4 m ³ / Hr, a sucrose concentration of 24.5%, Purity 9
7.8%, reducing sugar solution fraction 162m ³ / Hr, reducing sugar concentration 1.5%, purity 42.9%, non-sugar liquid fraction: 19.5m
³ / Hr, a sucrose concentration of 0.1% and a reducing sugar concentration of 0% were obtained.

Depending on the product required next, it is possible to combine the desalting step with an ion exchange resin and the decolorizing step with activated carbon, but in this embodiment, the decolorizing step is not performed and the following treatment is performed. did.

The sugar cane solution (113 t / Hr) was further added to the above 6
Evaporation and concentration by the latter three cans
A sugar solution of x65 solution: 43.3 t / Hr and ICUMSA: 40 was obtained. The heat transfer area of the latter three cans at this time was 38
It became a 00m ^2.

This is subjected to sugar infusion by the standard sugar infusion method,
No. 1 molasses is supplied to ^two calandria type crystal cans having a crystal can capacity of 50 m ³ and a heat transfer area of 325 m ² , and the average flow rate is 13.5 m ³ / Hr.
, Two-stage crystal 7.81 t / Hr, purity 99.8
%, A three-stage crystal can, a capacity of 50 m ³ , and a heat transfer area of 325
supplies 2nd molasses at an average flow rate of 6.8 m ³ / Hr to calandria type crystallizer 2 cans of m ^2, final molasses 7.35t / H
r, Bx50 and purity 81.3% were obtained.

[0054]

As described above, according to the present invention, by incorporating the step of adding sodium carbonate and the step of ultrafiltration, it is possible to efficiently produce purified cultivated land directly in a sugarcane-producing area. Become. In addition, it is possible to suppress the generation of by-products (mainly reducing sugars), reduce the amount of chemicals, and improve the recovery rate of sucrose.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an embodiment of the present invention.

FIG. 2 is a graph showing experimental results.

FIG. 3 is a graph showing experimental results.

FIG. 4 is a graph showing experimental results.

FIG. 5 is a graph showing experimental results.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kenji Ouchi 2-17-15 Tsukushima, Chuo-ku, Tokyo Tsukishima Kikai Co., Ltd. (72) Inventor Minoru Sugiura 2-17-15 Tsukushima, Chuo-ku, Tokyo Tsukishima Machinery Co., Ltd. (72) Inventor Naoko Wada 2-17-15 Tsukuda, Chuo-ku, Tokyo Tsukishima Machinery Co., Ltd.

Claims (8)

[Claims] 1. A method for producing sugar from sugar cane, comprising the steps of adding sodium carbonate and ultrafiltration, comprising the following steps: (1) A crude juice producing step of obtaining a squeezed juice obtained by squeezing a sugar cane, an extracted juice obtained by extracting a sugar cane, or a sugar juice obtained by mixing a squeezed juice and an extracted juice. (2) A heating step of heating the crude juice. (3) An insoluble substance removing step of removing insoluble substances in the crude juice by filtration. (4) A step of adding sodium carbonate to the crude juice to perform a softening treatment and pH adjustment. (5) An ultrafiltration step of removing a soluble polymer substance and an insoluble substance from the crude juice by ultrafiltration to obtain a clear liquid. (6) a concentration step of concentrating the clarified liquid. (7) A chromatographic separation step in which the concentrated liquid from the concentration step is chromatographed and separated into a sucrose fraction, a reducing sugar fraction and a non-sucrose fraction. 2. The method according to claim 1, wherein the sucrose fraction from the chromatographic separation step is sent to a concentration step, and a part or all of the concentrated liquid is used as a liquid sugar product. 3. The method according to claim 1, further comprising a step of sending a sucrose fraction from the chromatographic separation step to a concentration step, and a step of sending, concentrating and crystallizing a sugar solution to obtain a high-purity purified sugar in the crystallization step. 2. The sugar production method according to 1. 4. The method for producing sugar according to claim 3, further comprising a sugar recovery step of sending molasses from the crystallization step to a chromatographic separation step and recovering a sugar content. 5. A method for recovering a sugar liquid from at least one of a sludge from an insoluble substance removing step, a sludge from a step of adding sodium carbonate, and a concentrated liquid from an ultrafiltration treatment step. 2. The sugar production method according to 1. 6. The sugar production method according to claim 5, further comprising a sugar solution sending step of sending the sugar solution recovered from the sugar solution collecting step to an insoluble substance removing step. 7. The method according to claim 1, wherein the pH is adjusted in the range of 6 to 8 in the sodium carbonate adding step. 8. The method according to claim 1, wherein in the sodium carbonate adding step, the pH is adjusted.
The method according to claim 1, wherein caustic soda can be used for the adjustment.