JPS59173100A - Recovery of saccharose - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for the purification of sugar, and more particularly to an improved process for recovering sucrose from an aqueous solution.

In the usual purification of beet juice and recovery of the saccharose contained in the juice, milk of lime is added to the diffused juice from the beets and then precipitated from the solution by carbon dioxide gas. Physical and chemical changes by adding milk of lime and carbon dioxide gas, and subsequent standing or filtration of the precipitated calcium carbonate, remove 20-40% of the impurities present in the juice. This purification step is known as the first carbonation step. The amounts of carbon dioxide and lime used are selected to achieve optimal removal of color and other impurities, and optimal filtration performance of the produced sludge. The normal alkalinity range for this process reservoir is 0.065 to 0.1404 C.
It is aO. Following the first carbonation step is a second carbonation step. The purpose of the second carbonation is to minimize the amount of dissolved calcium (lime salts) remaining in the diesel. This is done by reducing the scale that adheres to the device and by removing calcium ions that contribute to the formation of sugar compacts.

A number of processes for sugar refining are known that use lime and, in addition to lime, magnesium oxide or magnesium carbonate. Some of these processes use first and second carbonation steps. Such processes include:

a) Prelime addition with carbonation b) Prelime addition without carbonation C) Defueco (
Defeco) - Carbonation d) Separation of pre-lime addition sludge 5- e) Separation of pre-carbonation sludge f) Recycling of spent lime from the first carbonation step g) Intermediate lime addition h) Main lime addition i) Main Carbonation j) Supercarbonation before main lime addition k) Second supercarbonation which is supercarbonation and subsequent re-alkalization with magnesium oxide l) Second carbonation to optimum alkalinity and subsequent new The ability of the refining process to recover white sugar from the magnesium carbonate-added beets prepared in the process depends on the extent of process losses.

These include losses of pulp in the diffusion operation, losses in the lime channel, conversion in the process, uncontrolled leakage, and loss of sugar contained in the molasses produced by the process. The biggest loss is in the saccharose in the sugar concentration,
The amount of sugar contained in the molasses depends largely on the efficiency of removing impurities by carbonation.

Several processes have been developed and employed to facilitate the recovery of sucrose from beets. The most common process for selective recovery of sucrose from molasses is the Steffens process, which uses lime at low temperatures to precipitate the saccharose. A similar method employs all barium hydroxide to precipitate saccharose. It is also possible to separate saccharose using ion exchange columns using chromatographic methods.

Another major technique is to modify the gies composition by ion exchange.

One approach is the Quentin process, in which cations are selectively exchanged for magnesium. Another approach is to partially or completely remove all ionic impurities to reduce or eliminate molasses formation.

Another method of recovering sucrose from beet molasses is to concentrate the molasses to a very highly dry material and then mix it with a solvent. As a result, the saccharose precipitates out, while almost all impurities remain in solution. Although this method has been practiced continuously since the 1920s, it has not reached commercial implementation. Also, this method has not been applied to substances other than molasses.

A two-phase solvent extraction system was also devised for total sucrose recovery. For example, in one known process, sugar juice is contacted countercurrently with an immiscible solvent consisting of two mutually insoluble phases. Addition of acid is necessary to control the pH between 3 and 1.5, thereby accelerating the conversion of sucrose and reducing the amount of sucrose recovered. This process has also not been commercially implemented.

The juice extracted from sugar cane also needs to be processed by one or a combination of processes for the production of white sugar or raw sugar. The usual refining agents used are lime or magnesia and the treatment step is named defecation. Other processes employed include treatment with sulfurous acid, treatment with phosphoric acid, and treatment with carbon dioxide gas. Processes using flocculants or foaming agents to remove colored substances are also employed.

All of the methods employed in the refining process in the sugarcane industry are chemically mild methods. This is necessary for economic and quality reasons, as the harsh chemical conditions required for beet sugar production lead to the destruction of invert sugar and the formation of large amounts of colored substances in the cane sugar refining process. Invert sugars in the process are advantageous because they reduce the solubility of saccharose in the final density, and colored substances are detrimental because they reduce the overall quality of the sugar produced. However, mild conditions cannot remove sufficient amounts of impurities, and the improvement is generally 0.5-2 purity. Recovery of sucrose from sugarcane juice is thus limited. Removal of impurities in sugarcane sugar processing -9= By comparison, the amount of impurities removed in beet processing is also smaller. However, the ability to crystallize the raw saccharose to obtain low purity molasses in cane sugar processing completely compensates for the low impurity removal.

The method of the invention preferably involves rapidly adding the solution and rapidly dispersing it in the acid to ensure rapid maximum growth of large saccharose crystals and facilitate their selective recovery. , a pre-prepared solution of sucrose (approximately 55-95 B
r1x) consisting of contacting f with a selected aliphatic carboxylic acid having an average carbon chain length of about 2 to 6. The weight ratio of water to acid in the solution is about 0.02 to 0.2:1. The solution also usually contains non-carbohydrate solids and the solids to acid weight ratio is about 01 to 1:1. The sucrose precipitate is then separated by p-filtration, centrifugation, etc., and recovered in purified form. The solution containing the carboxylic acid from which the saccharose has been removed is recycled and optionally removed from the carboxylic acid.

10- The basic principle of the invention is the precipitation of sucrose by solvent change. Sucrose and the non-carbohydrates present in sugar-containing juices have different solubilities in different solvents. In normal aqueous systems, all impurities have high solubility, as does sucrose. Aliphatic carboxylic acids with an average carbon chain of about 2 to 6, saccharose has a very low solubility in it, and all the impurities normally associated with sugar-containing plant juices are present in such acids. It has excellent properties for this purpose in that it has high solubility. In contrast, saccharose is highly soluble in formic acid. Precipitation of impurities along with saccharose results in low recovery of saccharose in subsequent steps in the purification process.
Undesirable.

The solvent change is accomplished in the giesse, which is first concentrated to a cylindrical solids content. The solvent system consists of pure or highly diluted acid, recycled solvent stream, or mixtures thereof. Such acids include acetic acid, propionic acid, butyric acid, except when the solution is molasses or derivatized molasses.
Pentanoic acid, hexanoic acid or mixtures thereof are preferred. Note that even if acetic acid is present in the molasses, other aliphatic carboxylic acids are also present. If the average carbon chain length of the mixture is about 2 to 6, then the selected acid is
It should also be understood that there may be mixtures containing aliphatic carboxylic acids having a total carbon chain length of more than 2 and less than 2. Thus, formic acid can only be present in the form of a mixture with other aliphatic carboxylic acids such that the average sucrose solubility of the acid mixture is acceptably low.

The purity of the saccharose produced by contacting the acid with a solution can be promoted by pretreatment, such as is commonly employed for sugar production. Crystallization of saccharose by selective acid solvent precipitation is significantly improved compared to aqueous systems and approaches equilibrium in less than 2 hours at room temperature under many laboratory conditions.

In the case of sugar juice purified by conventional methods, the juice is concentrated to a high solids content of 55 to 96 grams, as described above. The concentrated aqueous solution is then introduced into a solution containing, for example, acetic acid or recycled acetic acid, where the sucrose is precipitated in high yield and purity. The slurry of crystals and solution has a very low viscosity, and the crystals are separated by rotary, −
It is recovered by conventional filtration means such as vacuum filters. The mother liquor resulting from the separation process contains a small amount of dissolved sucrose, and the sucrose concentration is a function of water content, amount of impurities, and acetic acid concentration.

The weight ratio of water to the selected carboxylic acid in the contact zone is typically 0.02 to 0.2:1, and the weight ratio of non-carbohydrate to the selected acid is typically 0.1 to 1. The ratio is 0:1.

The selected acids must be recovered for the most economical operation of the sugar refining process.

Care must be taken in the case of acetic acid, since dehydration of acetic acid by boiling tends to result in substantial losses of acetic acid due to decomposition, and the process must therefore contain sufficient water to minimize such losses. shall be operated under conditions that ensure that Other means may be employed, such as recovery by solvent extraction using liquid carbon dioxide or other solvents in which the carboxylic acid has a high solubility.

By adding an aqueous sucrose-containing solution to a selected acid and then rapidly dispersing it in the acid, substantially better control of rapid and large saccharose crystal growth is obtained.
, slow diffusion of saccharose-containing solutions into acids or addition of acids to aqueous solutions leads to local supersaturation, resulting in the formation of small sucrose crystals, making recovery of sucrose completely difficult.

Substantial economic advantages are achieved when conventional solution purification is not carried out before the contacting step for several reasons.

First, the costs of conventional purification are removed from the economics of sugar production. Second, non-carbohydrate production for sale will increase to 50%. Third, only low levels of saccharose remain in the resulting molasses, so extraction is substantially reduced.

A substantial reduction in energy requirements is possible if sucrose is sold as produced or dissolved and sold as a liquid. If regular granular sucrose is desired, it is an intermediate and by-product of the sugar refining process, due to the high purity of the sugar and the consequent ability to revert to the low purity syrup of the processed plant produced for the solvent precipitation step. is not needed in its raw form, so energy requirements are reduced.

The process can be applied to the beet sugar industry with various variations depending on the desired sugar quality and desired impurity production. An example of such a possibility is given below, 1 variant 1 normal untreated beet sugar diffused north is concentrated to 55-96 Brix while adjusting the pH. The juice is then fed to a selected carboxylic acid contacting zone where sucrose is precipitated from solution. The saccharose is separated and recovered by filtration or other solid separation means. The separated sugar contains suspended solids and colloidal materials in the diffusion gel.

Variant 2 Ordinary beet sugar juice is treated by preliming technology to remove suspended solids and proteinaceous substances and to clarify and stabilize the juice.

Gies then under controlled conditions 55-95
It is concentrated to Brix and then fed to a selected carboxylic acid contacting zone where the sucrose is separated from the mother liquor. In this case, careful control of the conditions in the solvent precipitation can produce high purity saccharose for direct sale. The sucrose is separated from the mother liquor by filtration or other means and the remaining acetic acid is removed by drying, solvent extraction or other means.

Variant 3 Beet sugar diffusion juice is first purified by conventional means and then concentrated to 55-95% (Br1x) solids content. The resulting juice is fed to a selected carboxylic acid contacting zone where the sucrose is separated from the mother liquor. In this case, by careful control of the conditions of solvent precipitation, high purity sucrose for sale can be produced. Sucrose is separated from the mother liquor by filtration or other solid-liquid separation techniques, and residual acetic acid can be removed by air drying, solvent extraction, or other means.

Variant 4 The sugar factory may be operated in a conventional manner up to the secondary operation of raw materials. In this case, the raw material bread film
lmass) is condensed into tractable rix,
It is then fed to a selected carboxylic acid contacting zone where sucrose is precipitated from the mother liquor. The precipitated sucrose is returned to the high melter in the usual manner, where it is used in the conventional manner to produce white sugar.

Modification Example 5 In the production of sugarcane sugar, Modification Example 1゜2.3.4
At optional step 17- of a similar process shown in Figure 1, the juice is concentrated to 55-96 Brix and fed to a selected carboxylic acid contacting step where the saccharose precipitates out of solution and is recovered for sale or further processing. be done.

Variant 6 Crude cane sugar is dissolved in water to produce a solution of 55-96 Br1x, which is then fed to a selected carboxylic acid contacting zone where it is separated from the mother liquor as described above.

Variation 7 The effluent containing sucrose, such as that involved in sugarcane processing operations, is
The selected cals mentioned above are fed to the acid contact zone from which saccharose is precipitated.

Variant 8 The sucrose is contacted with a selected carboxylic acid to remove available saccharose.

The following examples further demonstrate the features of the invention.

18- Example 1 Diffusion gel (solid content 13.87%, purity 86.7%)
Sample 1700dl about 30°Br1x milk of lime 35
The pH was adjusted to 10.3 at 150°C.

The separated sludge was removed by filtration and the p-liquid was carbonated in the usual manner at 35°C to PF (7,6).

The liquid was heated to 90°C and stirred to remove calcium carbonate.

Sample 745 of treated gies obtained as described above.
(Water in the gies sample was evaporated under air flow in a 2t filter flask with a 1'i air outlet. The water bath provided p-heat. The residual syrup
After reaching 9.0% solids by weight, the frusto was removed from the water bath, disconnected from the air supply, and 127-g glacial acetic acid was added to the hot syrup. Saccharose precipitated immediately. The entire solution was allowed to cool to room temperature, and the product was collected by suction filtration. The filter cake was treated with 30 rnl of glacial acetic acid three times.
It was washed four times with 25-g of acetone and dried at 80°C for 1 hour. The yield is sucrose 81 with a pol of 97.99S.
．． It was 7f. Yield based on sucrose corrected for product purity was 89.3%. Therefore, the method of the present invention was found to be effective and practical in rapidly providing whole saccharose from sugar refining lines.

Example 2 Production of Saccharose from Dilute Gyce The equipment employed in this example was the same as that used in Example 1. Dilute G-su (solid content 88.8%, purity 8
8.8%) 677,:l' was placed in a 2-t filter flask, and all water was removed until the solid content of the syrup was 89.9% by weight. To ice acetic acid 110++ff1
When added to hot syrup, saccharose precipitated immediately. All washing and drying were carried out in the same manner as in Example 1.

A satsukalosufu 1.399 of 97.7°S pol was obtained. The yield based on sucrose corrected for product purity was 88.6% by weight.

Example 3 Recovery of saccharose from concentrated juice Concentrated juice (solid content 67.72 t, purity 87.4 t) 2
05, Or was placed in the evaporator described in Example 1 and water was removed in the usual manner. Solid content is 91.0% by weight
When reached, acetic acid (170d) was added to the whole hot syrup to immediately precipitate the sucrose. When the product was completely isolated using a method similar to Example 1, it was found that 98.0°S pol
112.614i of sucrose was obtained. The yield based on sucrose corrected for product purity was 90.9% by weight.

Example 4 Purification of raw sugar from sugarcane Sample 100 of raw sugarcane sugar (96.3° S pot ), Of 25. Mixed with C1' water, solid content is 8
Water was evaporated until reaching 8.5% by weight. Glacial acetic acid 12
5 ml - In addition to the hot slurry of crystals and syrup, sucrose precipitated out in the usual form.

97.2°S pol sugar 88.63f'? Obtained. The yield corrected for product purity was 89.4% by weight.

=21-Example 5 Carbonated beet juice (solid content 55.0%, purity 87
．． Samples 25Q and QQ5' of
and crystallization was allowed to proceed at 25°C.

After an initial introduction period of 0.5 hours, saccharose precipitated out as small crystals. The crystals were isolated, washed and dried to yield sugar 83.22F of 97.6°S pal (p
recovery rate corrected to ol 67.9%).

Example 6 massecuite (solid content 96.0%, purity 89.0%)
6%) Heated in a 100.20fi hot water bath to about 100°
C. and 129.0 Of glacial acetic acid. Saccharose precipitated quickly. After cooling, the product is collected, washed and 9
Sugar 77.53f of 9.4°S pol was obtained (pot
recovery rate ss, 2%).

22- Example 7 Geese from beets (solid content 65.4t, purity 90.
8%) was placed in a 200.13 ton flask and evaporated to 88.4% solids under a stream of air. 253.44 tft of n-propionic acid was heated to about 100°C, immediately added to a heat source girth, and stirred. Within 45 seconds the sucrose began to crystallize. After cooling, filtering, and washing four times with 150 g of methanol, the product was dried in an oven. The yield is 109. Or (99,, OoS p
ol ) (recovery rate corrected to pol 91.7
%).

Example 8 Recovery of sucrose from concentrated juice using n-butyric acid 141.84 rk samples of concentrated juice (solid content 67.4%, purity 90.5%) were treated in the same manner as in Example 7. 1
n-butyric acid z93 at 00°C. oorft = immediately added to the heat source juice (90.0% solids). After cooling, filtration, washing and drying, the sucrose yield was 79.56 f,p
ol was 95.6°S (recovery rate corrected to pol 91.9%).

In Example 8 above, formic acid was used instead of n-butyric acid. However, saccharose was not precipitated. Formic acid kept the sucrose in solution form.

Example 9 Recovery of sucrose from concentrated juice using mixed acid Concentrated juice (solid content 68.06≠, purity 90.0%) 2
00.001t - heated in a water bath and evaporated under a stream of air to reduce the weight to 150.414 (solids content 136.12r). Then 120.1Of acetic acid and 14
Contacted with a 1000C mixture with 4.16r of n-propionic acid (15.00? less of the acid mixture was discarded before contact). The acid was immediately added to the sugar solution and stirred. The resulting mixture was cooled to room temperature. The precipitated mixture was collected by filtration, washed with 75-n-propionic acid, then methanol, and dried. The dry product was 105.4Of, 86.0% yield (99
,0°S pol ).

In Examples 1 to 9, beet sugar raw material (diffusion) juice, dilute juice, concentrated juice, or crude cane sugar solution was about 5
When concentrated to 5 to 96 Brix and then contacted with a selected aliphatic carboxylic acid of 2 to 6 carbon chain length, such as acetic acid, propionic acid, butyric acid or mixtures thereof, saccharose immediately precipitates in high yield; It is clearly stated that it can be easily recovered by filtration, centrifugation, etc.

Variations 1 to above, concentrated to about 55-96 Brlx
Gies and other solutions containing sucrose, such as those described in Section 7, can be prepared with acetic acid, propionic acid, butyric acid, pentanoic acid, hexanoic acid or a mixture of aliphatic carboxylic acids with an average carbon chain length of about 2 to 6; Parallel experiments have shown that it precipitates readily upon contact at concentrations sufficient to provide a water to carboxylic acid weight ratio of 0.02 to 0.2:1. After precipitation and recovery of the saccharose, the selected carboxylic acid solution can itself be recycled, or the carboxylic acid can be recovered for reuse.

Applicant's agent: Patent attorney Suzue Takehiko 26- 1.Display of the incident Patent application No. 58-252380 2. Name of the invention How to recover sucrose 3. Person who makes corrections Relationship to the case Patent applicant Union Sugar Kampf 9 Knees 4. Agent March 27, 1982 6. Subject of correction Specification 7 Contents of the amendment As shown in the attached sheet Engraving of the statement (no changes to the contents)

Claims (9)

[Claims] (1) An aqueous sucrose-containing solution derived from plant seeds is mixed with aliphatic carbon having an average carbon chain length of 2 to 6. 1. A method for total recovery of sucrose from an aqueous solution derived from plants, which comprises contacting with a sufficient amount of saccharose to selectively precipitate saccharose, and separating and recovering the precipitated saccharose. (2) The method according to claim 1, wherein the contacting is carried out before the formation of molasses. (3) The contacting is carried out after the formation of molasses, and when acetic acid is present in the acid, it is in the form of a mixture with other aliphatic carboxylic acids. Method. (4) The method of claim 1, wherein the solution is a juice selected from the group consisting of sugar beet juice, sugar cane juice, and mixtures thereof. (5) The method according to claim 3, wherein the acetic acid is glacial acetic acid. (6) said juice is about 55 ml before contacting said solution with acid;
Claim 4 concentrated to ~96% solids by weight
The method described in section. 7. The method of claim 6, wherein during the contacting of the solution with the acid, the weight ratio of water to acid in the solution is from 0.02 to 0.2:1. 8. The method of claim 7, wherein during contacting the solution with the acid, the weight ratio of non-carbohydrate solids in the solution to the acid is about 0.1 to 1:1. 9. The method of claim 7, wherein said solution is untreated diffusion gel concentrated to about 55-96 BriX. α@ The solution is subjected to pre-liming and/or pre-defecation to remove suspended solids and proteinaceous materials and to clarify the gies, and then to about 55-96 Br1x. 8. The method of claim 7, which is a concentrated diffusion gas. 0]) The method of claim 7, wherein the diffusion gas is a diffusion gas produced in a conventional manner and then concentrated to about 55-96 Brix. 12. The method of claim 11, wherein: (b) the solution is concentrated to about 96 Brix before contacting with the acid. α] The solution is initially formed by dissolving a raw sugar selected from the group consisting of cane sugar, beet sugar, and mixtures thereof in a sufficient amount of water to provide a sugar concentration of about 55 to 96 Brix. The method according to claim 1. a → The solution is an aqueous saccharose-containing solution from a sugarcane processing operation p, and the solution is about 55-96 Bri
3. The method of claim 2, wherein the method is concentrated to x. 0υ The method according to claim 2, wherein the saccharose-poor common liquid after the precipitation, separation, and recovery is treated to recover all of the acid. C1→ The contacting involves rapidly adding the saccharose-containing solution to the acid, rapidly dispersing it in the acid, and forming a large,
3. The method of claim 2, which is carried out by promoting rapid saccharose crystal growth.