JP4745428B2 - Sugar production method - Google Patents

Description

  The present invention relates to a sugar production method in which a lime milk (lime milk) used for cleaning a sugar solution (raw juice) exuded from beet is produced from a baked product of shells and strawberries in a sugar production method of a beet sugar factory. It is about the method.

  Sugar juice (raw juice) exuded from sliced beet contains a lot of impurities such as protein and reducing sugar in addition to sugar, and in the sugar production method conventionally used in beet sugar factories to remove these Employs a carbonation saturation method in which lime milk is added to raw juice and then carbon dioxide is blown (JP 2003-116600, JP 2002-223800).

Carbonic acid saturation method means that water-soluble protein, which is an impurity, is first precipitated by increasing the pH by adding lime milk, and then adding lime milk to a highly alkaline state. At this time, reducing sugar is decomposed to lactic acid, and finally Calcium lactate is generated, but when carbon dioxide is blown in this state, calcium carbonate is generated by reaction with slaked lime in lime milk, and the precipitated protein and calcium lactate are combined with this calcium carbonate as a lime cake outside the system. Is discharged.

  As another method for removing impurities in the sugar solution, the magnesia method using magnesium oxide, which is found in the field of purified sugar, is known. It is not used in sugar factories, and the carbonation method using lime milk is the mainstream.

JP2003-116600, JP2002-223800

The lime milk used here is made from raw limestone that has been calcined in the kiln, but in recent years it has been difficult to supply high-quality limestone as a raw material for lime milk from specific production areas due to resource depletion. It is becoming increasingly necessary to procure from each production area.

In addition, the quality of limestone in each production area is different in calcium carbonate content, there is a variation in the yield of quick lime after firing, and the limestone contains a relatively large amount of iron, aluminum, silicic acid, etc. Therefore, there are difficulties such as generation of a large amount of clinker during firing.

On the other hand, the majority of scallops and oysters are supplied by aquaculture, and the shipping volume is also increasing. In addition, the shells themselves are industrial waste and are being recycled in China. Ten thousand tons of scallop shells are dumped in the sea.

Therefore, as a result of studying shells such as scallops and oyster shells or natural products such as corals as the raw material of lime milk, the present inventors have found that these shells and weathered corals are mainly composed of calcium carbonate, In particular, the content of scallop shells was higher than that of limestone, and despite the fact that it was a natural product, it was clarified that the content of calcium carbonate was small and stable.

Shells and corals were found to have lower iron, aluminum, and silicic acid contents than limestone.

  Based on these findings, the present invention provides a sugar production method in which lime milk is added to raw juice and carbon dioxide is blown to precipitate impurities to purify the raw juice. The method of using the lime milk manufactured from the above baked product is proposed.

  The shells used in this invention are not limited to the type, seawater, or freshwater, and can be used if the calcium carbonate content is high, but scallops, oysters, etc. are calcium carbonate content of limestone It is a value that exceeds (approximately 95%), and most of it is occupied by aquaculture. Therefore, scallops and oysters are preferred raw materials in terms of the stable supply of lime cake raw materials.

  In addition, scallop shells have lower iron, aluminum, and silicic acid content and higher calcium carbonate content than limestone, so the purity of calcined lime after firing is high, and the clinker due to the unit cost of energy and the influence of metal during firing. There are also advantages such as a reduction in generation and a reduction in the amount of lime cake.

On the other hand, with regard to soot, any one can be used, but weathered soot, in which calcium carbonate is the majority, is a preferred raw material.

  In this invention, shellfish, lime milk produced by pulverizing one or more baked products of salmon, pre-lime treatment of raw juice, carbonation after main lime treatment, According to the study by the inventors of the present invention, the raw juice treated in this way has increased sugar purity, reduced reducing sugar, and the degree of coloring compared to that processed using lime milk derived from limestone. I couldn't see the fading.

  In short, in the present invention, in the step of removing impurities in raw juice, by using lime milk produced by baking shells and weathered coral, a stable supply of lime milk raw material can be achieved. It is expected that a cleaning effect similar to that of lime milk of raw limestone used is obtained, and that the generation amount of lime cake is reduced with the reduction of clinker generation.

Carbonate after treatment when lime-treated with lime milk prepared by pulverizing a calcined product of conventional limestone in Example 3 and lime-treated with lime milk produced by pulverizing a calcined product of scallop shell of the present application Figure showing the transition of pH corresponding to the amount of carbon dioxide consumed by saturation

  Lime milk produced by pulverizing shells such as scallops and oyster shells and fired coral fired products in a sugar-making method that purifies raw juice by adding lime milk to raw juice and then blowing carbon dioxide to settle impurities. Sugar making method using

Example 1
Calcium carbonate content of shellfish

  Scallops and oyster shells are selected as the shells, the shells are washed with water, dried and crushed, and moisture is measured as a sample for firing.

  400g of crushed shells are put into a muffle furnace, the loss on drying is measured by treatment at 550 ° C for 6 hours, and then calcined again at 900 ° C for 18 hours to measure the loss on ignition.

The organic matter is a value obtained by subtracting moisture from the loss on drying, and the ignition residue is a value obtained by subtracting the loss on ignition from the sample.

  The value obtained by subtracting the loss on drying from the loss on ignition was regarded as the amount of carbon dioxide produced by the decomposition of calcium carbonate, and the calcium carbonate content was calculated from this molar concentration. The results are shown in Table 1.

  As shown in Table 1, the calcium carbonate content was over 95%, suggesting that there was no problem even with either or in combination.

Example 2 Sugar Production Method The sugar production method according to the present invention will be described. First, scallops, oysters, or weathered rice cakes are washed with water to remove salts and deposits, and fired at a predetermined furnace temperature.

Next, in order to produce lime milk by a soothing reaction, the fired product is crushed and poured into warm water.

  After heating the raw juice to 47 ° C. in advance, the pH is adjusted to 11 with the lime milk, and the protein in the solution is precipitated by the isoelectric point effect.

Next, after heating to 58 ° C., the lime milk is added until the solid content in the raw juice reaches 14% by weight in terms of quick lime.

  After charging, hold for 10 minutes and heat again to 88 ° C to convert the reducing sugar in raw juice to calcium lactate.

Next, the carbonic acid gas is used to reduce the pH of the raw juice to 11 and carbonic acid saturation is performed, and calcium carbonate produced by neutralizing slaked lime takes in impurities such as protein and calcium lactate.

  The insoluble material obtained by this operation is called lime cake and is removed by solid-liquid separation.

In order to reduce the calcium concentration of the sugar solution after removal, after heating to 87 ° C, the second carbonic acid saturation is performed again by reducing the pH to 9 with carbon dioxide, and the calcium ions in the solution are precipitated and removed as calcium carbonate. .

  By the two carbonation saturations, impurities in the raw juice are removed as a lime cake, and the raw juice is cleaned.

  Raw juice when scallop shells are used for purification does not show an inferiority compared to that derived from limestone in terms of increased sugar purity, reduced reducing sugar, and degree of coloring.

  In addition, since scallop shells have a low content of iron, aluminum and silicic acid and a high content of calcium carbonate compared to limestone, the purity of quick lime after firing is high.

  For this reason, it contributes to the reduction of clinker generation and the amount of lime cake due to the unit cost of energy and the influence of metal during firing.

Example 3
Cleaning test of raw juice A comparative cleaning test of raw juice is carried out using a fired product from a conventional raw limestone and a fired product from scallop shells.

  Each calcined product is poured into warm water of 50 ° C. or more (quick lime concentration: 15 to 20% by weight) to produce lime milk (slaked lime concentration: 20 to 26% by weight) by a dehydration reaction, and the raw juice with the lime milk Pre-lime treatment and main lime treatment are performed.

  The pre-lime treatment is an operation in which lime milk is added to the raw juice in a stepwise manner to adjust the pH to 11, and the protein is precipitated, and the main lime treatment is 14% by weight in terms of quick lime with respect to the solid content in the sugar solution. Of lime milk and changing the reducing sugar to calcium lactate.

After the main lime treatment, carbonic acid saturation is performed to reduce the pH to 11 with carbon dioxide gas, and impurities such as protein precipitated in the pre-lime treatment and calcium lactate produced by the main lime treatment along with calcium carbonate generated by this neutralization reaction are lime. Collect as a cake.

  After discharging out of the system as a lime cake, the pH is adjusted to 9 again by carbonation in order to lower the calcium concentration in the liquid, and the precipitated calcium carbonate is discharged out of the system as a lime cake.

  Table 2 shows the physical properties of the cleaning liquid cleaned by the above operation.

  As shown in Table 2, the baked product derived from the scallop shell, which is a comparative control, is an alternative to the burned product derived from limestone because there is no significant difference in the Pty., RS, and color values that are the basis for the cleaning effect. It was confirmed that it was effective as a product.

  In addition, as shown in FIG. 1, the pH transition corresponding to the amount of carbon dioxide consumed by carbonation after pre-lime treatment has the same tendency, and the difference in slaked lime in lime milk produced with different baked products Is not seen.

  Therefore, it was confirmed that the lime milk produced by baking shells is very effective as a substitute because it has the same cleaning effect and properties as the existing limestone.

  In short, according to the present invention, the stability of the quality is excellent, the stable securing is sufficiently possible, and the shells and weathered corals such as scallops and oysters, which are mostly discharged as industrial waste, are made of limestone. A sugar production method used as an alternative can be provided.

Claims (1)

In the sugar making method of purifying raw juice by adding lime milk to raw juice exuded from sliced beet and then sinking impurities by blowing carbon dioxide, one or more baked products of scallop shell, oyster shell A method for producing sugar, characterized by using lime milk produced by pulverizing

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