JPH01319490A - Method for recovering unreacted sucrose in reaction mixture of sugar-fatty acid ester synthesizing reaction as powdery form - Google Patents

Abstract

PURPOSE:To remove a reaction solvent and efficiently recover an unreacted saccharide without using any solvent for purification by subjecting a reaction mixture to specific treatment to form precipitates, removing the precipitates, bringing a residual liquid into contact with a reverse osmosis membrane and spray-drying an unpermeated portion. CONSTITUTION:First, a reaction mixture from reaction for synthesizing sucrose ester of a fatty acid (hereinafter referred to as SE), containing the objective SE, an unreacted sucrose, an unreacted fatty acid methyl ester, a catalyst, soap, a fatty acid and a volatile matter is adjusted at a pH within the neutral region and are added with water, a neutral salt and sugar to precipitate the SE. The after removing the precipitates a residual liquid is brought into contact with a reverse osmosis membrane (preferably a crosslinked polyamide type, etc., with a fractioning molecular weight of 130-200). Finally an unpermeated portion is spray-dried to recover the unreacted sucrose as a powder. A temperature of the liquid to be treated with the reverse osmosis membrane is preferably 40-60 deg.C and a pH thereof is preferably 6.2-8.2.

Description

[Detailed description of the invention] [Industrial application field]

The present invention purifies unreacted sugars in a sucrose fatty acid ester synthesis reaction mixture by a solvent method without using an organic solvent for purification.
It relates to a method of separating the residual reaction solvent and recovering it industrially in a powder state.

[Conventional technology]

(Background) Currently, sucrose fatty acid esters (
(hereinafter also abbreviated as <(S E ))) is industrially
! i and a C8-C22 higher fatty acid methyl ester are reacted in a solvent (dimethylformamide, dimethyl sulfoxide, etc.) under an appropriate catalyst (solvent method: Tokko Sho 3)
5-13102) or by making sucrose into a molten mixture with fatty acid soap in the presence of water without using a solvent, and then reacting it with higher fatty acid methyl ester in the presence of a catalyst (Mizunu method: Japanese Patent Publication No. 1973- No. 14485). However, in both of these two synthetic methods, in addition to the target SE, the reaction mixture contains unreacted minuta, unreacted fatty acid methyl ester, residual catalyst, soap, M
Contains impurities such as fatty acids, volatile matter, etc. Among these impurities, impurities whose content exceeds the specified amount must be removed before becoming a product, but this involves using a large amount of organic solvent. In particular, among the impurities mentioned above, the removal of residual solvent (volatile matter) associated with the latter solvent method has recently been regulated '1.
) is becoming increasingly strict, so this is extremely important. Note: According to the US FDA standards, the amount of residual mesityl sulfoxide allowed during SE is 2 pp+m or less (Fe
d, Register, 51(214), 40160-
1). Furthermore, another important problem in the industrial production of SH is the problem of recovering unreacted sugar. That is, as is well known,
The reaction rate of sucrose during SE synthesis is low1, for example, it does not reach 50% even in the dimethylformamide method (Sugar Ester Story (1984), published by the applicant company) 35
(see page), wood industry cannot exist without recovery of unreacted sucrose. Therefore, large amounts of organic solvents have conventionally been used for the dual purpose of removing residual reaction solvent from crude SE and recovering unreacted sugars, but the heavy use of such solvents has hindered the industrial production of SH. , resulting in significant disadvantages such as: ■ Risk of explosion or fire. ■ Explosion-proofing of electrical equipment in preparation for ■ above. ■ Seal the manufacturing equipment in preparation for the above ■. [Co., Ltd.] The entire building has a fire-resistant structure in preparation for ■ above. ■ Increase in fixed costs due to ■, ■, and ■ above. ■ Increased cost due to solvent wastage. ■ Negative effects due to residual solvent remaining in product SE. ■ An increase in fixed costs due to an increase in the number of shifts required to prevent negative health effects on employees. Under these circumstances, there has been a pressing need in the industry to develop a technology that eliminates the need for the use of organic solvents during SE purification and sugar recovery. (Problems with the prior art) Therefore, SE purification and sugar recovery methods that do not use organic solvents have been studied, and representative methods include: (1) SE precipitation method using an acidic aqueous solution (British Patent No. 80
9,815 (1959)) (2) A method of precipitation of SE using a general neutral salt aqueous solution (Japanese Patent Publication No. 42-8850) is known. However, when an aqueous solution of hydrochloric acid is added to the reaction mixture as in method (1), SE is immediately precipitated, but unreacted sucrose is easily decomposed and converted into glucose and fructose, and even at low temperatures ( Decomposition cannot be avoided even if the reaction is carried out at a temperature of 0 to 5°C, making it difficult to recover and reuse unreacted sugar.6 As is well known, the reaction rate of sucrose during SE synthesis is low, e.g. , even in the case of the dimethylformamide method, 50
% (see page 35 of Sugar Ester Materials 35 (1984) published by the applicant's company), wood industry cannot exist without recovery of unreacted sucrose. Furthermore, even if an aqueous solution of a neutral salt such as common salt or Glauber's salt is added to the reaction mixture as in method (2), SE will immediately precipitate. In this case, unreacted sugar does not decompose, but the monoester, which is a useful component in SE, is dissolved in the aqueous phase, which not only causes a large loss, but also high According to the more recent Japanese Patent Application Laid-Open No. 51-29417, a mixed solution of water and a "purified solvent" (especially referred to as such to distinguish it from a reaction solvent) is a light-weight solution. The property of phase separation into a liquid layer (upper layer) and a positive liquid layer (lower layer) is utilized.In other words, in general, the positive liquid layer (
Since the lower layer contains a lot of water, unreacted hydrophilic sugars, catalyst-derived salts, etc. are dissolved in this positive liquid layer (lower layer). On the other hand, since the light liquid layer (upper layer) contains a large amount of purified solvent, substances with low polarity such as SE, fatty acids, and unreacted fatty acid methyl esters are dissolved in this light liquid layer. However, reaction solvents such as dimethyl sulfoxide dissolve in the lower positive liquid layer, but unfortunately they also dissolve in the upper light liquid layer, so it is impossible to completely separate the reaction solvent using this method alone. It is. Moreover, not only trace amounts of reaction solvent but also unreacted sugars are removed.
For recovery purposes, very large amounts of purified solvent are required. (Principle of the Invention) As described above, in order to make purification of crude SE using water and recovery of unreacted sugar industrially possible, it is necessary to completely remove the reaction solvent and the purification solvent, and to reduce the loss of sugar and product SH. The major premise is to develop a purification method that does not produce. Purification of the reaction mixture based on this principle basically utilizes the solubility difference between SE and unreacted sucrose in water, so it is inevitable that a large amount of unreacted sugar will migrate to the water side. Without the purification and recovery of dissolved sugar, the wood industry cannot exist both economically and socially.Therefore, an important objective of the invention is how to effectively recover the sugar that has migrated to the water side during purification. be.

[Problem to be solved by the invention]

Therefore, the problem to be solved by the present invention is to industrially remove the reaction solvent without using a purification solvent, and to
The objective is to develop a means to recover unreacted sugars in the reaction mixture. (Concept of the Invention) Therefore, the inventor of the present invention aimed to (a) not only minimize the amount of SE dissolved in the aqueous phase side, but also set the amount to zero if possible to precipitate the entire amount of SE; (c) separating the remaining reaction solvent from the SE by dissolving it outside the aqueous phase; and (d) separating the above precipitate from the separated injection solution (or supernatant). As a result of many salting-out experiments aimed at solving the three points of efficiently recovering unreacted sugar, we found that when sucrose and neutral salts are dissolved in an aqueous solution of the reaction mixture, an appropriate pH 1 temperature is reached. , under the combination of neutral salt and sucrose concentrations and water amounts, not only almost the entire amount of SE precipitates, but surprisingly, not only is the reaction solvent dissolved in the aqueous phase in addition to the unreacted sugar. I discovered a convenient phenomenon. Therefore. Taking advantage of this phenomenon, after dissolving the precipitated SE in water again,
By repeating the precipitation operation with a neutral salt and sucrose aqueous solution, the remaining volatiles (residual reaction solvent) can be completely transferred into the aqueous phase while virtually preventing loss of SE; It has become clear that unreacted sugars in the SE reaction mixture can be efficiently recovered in a purified state by contacting the residual liquid after removing the above precipitate with an appropriate reverse osmosis membrane. (Summary) The present invention is based on the above findings, and its gist is that, in addition to the target sucrose fatty acid ester, unreacted sugar, unreacted fatty acid methyl ester, and a catalyst. The sucrose fatty acid ester synthesis reaction mixture containing soap, fatty acids, and volatile components was adjusted to a neutral pH, wood, neutral salt, and sucrose were added, and after separating the precipitate, the remaining liquid was subjected to reverse osmosis. The present invention relates to a method for recovering unreacted 4 in a sucrose fatty acid ester synthesis reaction mixture in the form of powder, which comprises contacting with a membrane and spray-drying an impermeable part. The various elements constituting one invention will be explained below. (Left below) (Solvent method SE synthesis reaction mixture) In the synthesis of SH by the solvent method, 1. Usually, a reaction solvent such as dimethyl is added to a mixture of sealing sugar and fatty acid methyl ester in an amount several times the total amount of these. A reaction rate of 90% or more can be easily achieved by adding and dissolving sulfoxide and maintaining it at 80 to 80°C for several hours under reduced pressure around 20 to 30 Tarr in the presence of an alkaline catalyst such as potassium carbonate (K2C03). An SE reaction mixture is produced (based on fatty acid methyl ester). Next, in order to eliminate the activity of the alkaline catalyst in the SE reaction mixture, an equivalent amount of an organic acid such as lactic acid or acetic acid or a mineral acid such as hydrochloric acid or sulfuric acid is added to the SE reaction composition. This neutralization converts the catalyst into a potassium salt, such as potassium lactate, depending on the type of acid used for neutralization. Finally, the reaction solvent (for example, dimethyl sulfoxide) is distilled off under vacuum, resulting in an AI'1 product (reaction mixture after neutralization and distillation) approximately having the following composition range. SE-15,
0-92% unreacted sugar -1,0-80
% unreacted fatty acid methyl ester = 0.5-1O% neutral salt derived from potassium carbonate = 0.05-7% soap
=1.0-10% fatty acids
=0.5-10% volatile content (residual reaction solvent)=
5.0 to 30% At this time, the ester distribution of SH is monoester 10 to 75% (diester or more is 90 to 25%
). The fatty acid roots mainly contained in each of fatty acid methyl ester, soap, and fatty acid are saturated and CI6
They have a common carbon number of ~022. (Addition of water) Next, water was added to the above reaction mixture, water: reaction mixture = 5 = 1 to 40: I (weight ratio)... (1
) More preferably, the ratio is as follows. Water: Reaction mixture = 20: l (weight ratio) (
2) Add to the ratio of the formula and adjust the pH to 6.2 to 8.2.
Preferably p) is 17.5. In this case, the water addition ratio is outside the above range. For example, if the ratio of water to reaction mixture is less than 5, the resulting aqueous solution will have a high viscosity, making subsequent operations substantially difficult. Conversely, if an excess of water is added to the extent that the ratio of water to reaction mixture becomes 4ONi, the viscosity decreases and subsequent operations become easier, and the desired reaction solvent is Although removal is carried out suitably, on the other hand, a large amount of energy cost is required to remove water when recovering unreacted sugars, etc., resulting in a loss of economic efficiency. Furthermore, the pH of the aqueous solution is preferably adjusted between pH 6.2 and 8.2 in order to avoid decomposition of the target SE, under hydrogen ion concentrations of pH 8.2 or higher. There is a risk that SE may be quantitatively decomposed by alkali, and even in a weakly acidic range of pH 6.2 or lower, there is a risk of acid decomposition if exposed to high temperatures of, for example, 80° C. or higher. (Salting out) The aqueous solution of the SE reaction mixture whose pH has been adjusted as described above is maintained at a temperature of 50 to 80° C., and a neutral salt and sucrose are further added thereto. In this case, it is preferable that the neutral salt to be added first satisfies the following formula (3). = 0.015 to 0.12 (weight ratio)...
・(3) Here, total amount of bases = amount of neutral salts to be added + amount of bases formed from the catalyst (4) Total amount of w4 = amount of bases to be added Amount of unreacted spears since the beginning of 10...
(5) Next, the amount of sucrose to be added is preferably determined by the following formula (8). = 0.025 to 0.20 (!rr amount ratio)...
(6) Furthermore, in addition to the above two formulas, it is preferable that the weight ratio of one total ring member to the total II amount also satisfies the following formula (7). The present inventors heated an aqueous solution containing SE precipitate obtained by adding a neutral salt and sucrose to 50 to 80°C so as to satisfy all three of the above formulas (3), (8) and (7). When the temperature is raised, approximately the entire amount of SE will precipitate, even if the composition of the volatile components (residual reaction solvent) contained in the 5Eff reaction mixture varies greatly from 5.0 to 30.0%. I found out what to do. This phenomenon is both unique and of important value in relation to one purpose of the invention. The attached FIG. 1 is a ternary graph showing this phenomenon in more detail. In this figure. Weight of SE dissolved in the aqueous phase = Y [g] Weight of precipitated SH = X [g] SE dissolved in the aqueous phase relative to the total SE (X + Y) [g] If weight ratio = φ [%], φ is defined by the following formula (8). φ= −X 100 ($) (8)X+
Y Here, the following conditions: (blank space below) Temperature: 280°C, pH: -7.5, Water: Reaction mixture = 7.4: 1 (Urani ratio) Fatty acid residue = Stearic acid Composition of the reaction mixture SE = 29% unreacted loquat
= 35% Unreacted fatty acid methyl ester = 2% Salt derived from catalyst = 1% Ishichichi = 3% Fatty acid = 1% Volatile matter (residual reaction solvent) = 29% Ester distribution in SE: monoester 273% or more diester =27%, how the value of φ changes is shown by triangular coordinates. Here, the total salt is the amount defined by formula (4), and the total sugar is the amount defined by formula (5), respectively, and they are expressed as water amount + total base amount + total amount = 100%. The shaded part in Figure 1 is the formula (3) discovered by the present inventors.
), equation (6), and equation (7) at the same time. By determining the dissolved amounts of neutral salt and sucrose that fall within this shaded area, it is possible to substantially precipitate φ=0, that is, approximately the entire amount of SE, and at the same time remove volatiles from the aqueous phase. (
(residual reaction melt). Unreacted sucrose, by-product salts from the catalyst, and added neutral salts can be dissolved and completely separated from the precipitated SE component. (Reverse osmosis) Next, sucrose separated as an aqueous phase from the SE synthesis reaction mixture through the above steps, by-product salts from the catalyst (K2 CO3), neutral salts added for salting out, and volatile components. Selectively separate only sucrose from a mixed aqueous solution containing 1
Recovery is an important condition for achieving the purpose of the invention. However, the inventors have found that the use of reverse osmosis is particularly effective for this purpose. If a reverse osmosis membrane with a molecular weight cutoff in the range of 130 to 200 is selected, unreacted sugars (molecules 1342) and SE (molecules m60
0 or more) are expected to be separated without any problem. On the other hand, if the molecular weight cutoff of the membrane is smaller than 130-200,
By-product salts from the catalyst 1 For example, potassium lactate (molecule 141
28), added neutral salts and volatile substances, such as dimethyl sulfoxide (molecular weight: 78), will pass through the micropores of the reverse osmosis membrane without any problem. Based on this assumption, many experiments were conducted. As a result, sucrose that has undergone the salting-out process in the previous stage, by-product salts from the catalyst, neutral salts and volatile matter added during salting-out, and sometimes a small to trace amount of S
The aqueous solution containing E has a molecular weight cutoff of 1 at a temperature of 40 to 60°C.
When brought into contact with a reverse osmosis membrane of around 50 to 200 membranes under a higher pressure than during ultrafiltration as a driving source, the by-product salts from the catalyst, the added neutral salts, and the volatile components are , it was found that it easily passes through the micropores of reverse osmosis membranes along with water. This reverse osmosis operation removes impure seawater.
ffl aqueous solution (optionally containing a small amount of SE) is water,
It is separated from low-molecular-weight substances such as by-product salts from the catalyst, neutral salts added during salting out, and volatile components, and becomes a concentrated aqueous solution of raw sugar. By dissolving the obtained crude sugar aqueous solution in fresh water again and subjecting it to the same reverse osmosis treatment again (or several times), a sucrose aqueous solution with higher purity can be obtained. In the above, the temperature of the aqueous solution to be treated that is supplied to the reverse osmosis membrane is important in order to expect good results.If the temperature drops below 40℃, the treatment capacity will drop significantly, so it is not practical. It is better to choose a temperature of 40℃ or higher; however, if it exceeds 60℃, there will be concerns about the heat resistance of the reverse osmosis membrane.
In addition, since the micelle structure of SE may also change, it is wise to perform the treatment at a temperature below the upper limit temperature. In addition,
The pH of the above aqueous solution is also important in practice, and pH 8.2 to
A range of 8.2 is preferable because there is little risk of affecting the quality of sucrose. (Reverse Osmosis Membrane) Many industrial reverse osmosis membranes, which have been advanced in recent years, are being sold by various companies. Among these commercially available reverse osmosis membranes, durability,
A cross-linked polynamide-based reverse osmosis membrane is an example of a membrane having excellent heat resistance, acid resistance, alkali resistance, bacterium resistance, and abrasion resistance. This membrane, for example, the reverse osmosis membrane manufactured by Toshi Engineering Co., Ltd. and Hanuri Co., Ltd. (trade name (S11-200)), etc., has a molecular weight cutoff of around 200, as described above, and is well suited to the purpose of the present invention. In the case of a reverse osmosis membrane with a fraction molecular weight of around 200, the solute concentration in the supplied aqueous solution is approximately 8 to 20% as an upper limit.
, Desirably, by suppressing the upper limit of the solute concentration to about 8 to 15%, industrial processing ability can be achieved. If the solute concentration exceeds 15%, it becomes difficult for water, by-product salts from the catalyst, and volatile matter to pass through the micropores of the reverse osmosis membrane, making it necessary to increase the driving pressure accordingly. , as a result, the membrane surface has to be widened, and also,
It is extremely uneconomical as it requires a large amount of power. On the other hand, if the solute concentration is about 8 to 15%, industrial separation of sucrose is fully possible.
In the case of an aqueous solution with a composition of 1, the separation rate of sucrose is at pH 7.
, 5. At a temperature of 50°C and a driving pressure of 58.0 kg/cm'G, the reverse osmosis membrane <<5IJ-200>) with an effective area of u8rn' per unit reaches 7.3 kg/sugar hour, which is similar to that of other companies. Almost the same results were obtained for Flight 8. In all cases, a small amount of dissolved SE was also recovered in good yield along with sucrose. In the above reverse osmosis treatment, by one repetition of reverse osmosis membrane treatment,
A sucrose-containing aqueous solution from which by-product salts from the catalyst, added neutral salts, and volatile components have been sufficiently removed contains 15 to 20%
It is possible to maintain a certain sugar concentration. Obtaining an aqueous sugar solution with a concentration of 20% or more is not only technically difficult, but also less economical. (Spray drying) Through the above reverse osmosis treatment, unreacted sucrose and sucrose added during salting out can be recovered in the form of a substantially pure aqueous solution, and this sucrose solution itself can be used for various purposes. However, it cannot be used in the SE synthesis reaction because it is known that the presence of a trace amount of water has a negative effect on the woodworking transesterification reaction in the solvent method SE synthesis process (LLOID 0
3IPOW at at,. Journal of the American Oil Chemists Society (JAOCS) Vol. 34, p. 185), anhydrous conditions of 0.05% or less are adopted as actual working conditions (see p. 44 of the above publications). )),Therefore,
Even if it is possible to recover a highly purified sucrose solution, unless industrial dehydration and drying are successful, the recovery of sucrose will ultimately be meaningless. By the way, chemically pure SiH sugar melts at 188°C, but this melting point is significantly lowered by the presence of small amounts of impurities. In addition, a concentrated sucrose aqueous solution becomes a viscous syrup,
Because it has the property of caramelizing when heated, if a concentrated sucrose aqueous solution is vacuum dried using a regular stirring type vacuum dryer, dehydration and drying become difficult as the V4 concentration increases, so it is unavoidable to dry it at high temperatures for a long time. Another drying method is the so-called flash dryer, in which the slurry is continuously heated, fed into a vacuum chamber, and discharged. Even when using water, the large latent heat (500
Kcal/Kg・water), it is difficult to dehydrate and dry the sugar sufficiently. Even if these difficulties could be overcome, the sucrose after being dehydrated and dried under vacuum After taking it out of the dryer, it needs to be cooled by blowing cold air to below its melting point, and then pulverized. To summarize the series of steps to produce powdered sucrose, the steps are: ■ Dehydration and drying under vacuum, ■ Removal of sucrose from a vacuum dryer, ■ Cooling and solidification of the removed sucrose,
■ Since it requires multiple steps such as crushing the solidified sucrose, it is economically undesirable, and especially in the crushing step (■), there is a risk of dust explosion. However, as a result of research, the present inventor found that a spray drying method is particularly suitable as an industrial dehydration and drying method that does not deteriorate the quality of sucrose from a sucrose solution obtained by reverse osmosis. That is, by continuously supplying an aqueous sucrose solution to a spray drying tower via a pump and dispersing and atomizing the aqueous sucrose solution supplied via a nozzle or a rotating disk, preferably the latter, the evaporation surface of water is Since the scale can be made extremely large, dehydration and drying can be completed within a few seconds after spraying. The temperature of the sucrose aqueous solution supplied to the spray drying tower is usually 4
When dispersing using a 0-rotation disc with a good temperature within the range of 0°C to 80°C, when the diameter of the disc is 5 to 10 cmφ,
15.00Orpm ~24. A rotational speed of OOOrpm is appropriate. The blown air should have more than the amount of heat required to evaporate the moisture in the slurry, so naturally a large amount of air is required when the air temperature is low. The air temperature can be selected between 10°C and 100°C, but preferably between 60°C and 80°C to avoid deterioration of the sucrose. The humidity in the blown air is also important along with the air temperature, but it is generally economical to select the value of absolute humidity. Factors such as the capacity, tower diameter, and height of the spray drying tower should be determined based on the above spray conditions, if the zero conditions are appropriate.
Powdered sucrose with a moisture content of 5% or less is continuously taken out from the bottom of the spray drying tower. As explained above, by organically combining the three steps of salting out, reverse osmosis and spray drying. Unreacted Si in the SE reaction mixture! It becomes possible to industrially recover monosaccharide.

[Effect]

Unreacted sugar, unreacted fatty acid methyl ester. Add acid to the sucrose fatty acid ester producing reaction mixture containing the catalyst, fatty acid and volatile matter (residual reaction solvent) to adjust the pH to a neutral range, then add water, neutral salt and sucrose to the appropriate temperature. When salted out at a certain temperature, sucrose fatty acid ester,
Unreacted fatty acid methyl ester, copper, and fatty acids are precipitated, and volatile components (residual reaction solvent) are transferred to the aqueous phase, making it possible to remove residual volatile components without using any organic solvent. . In particular, by operating so as to satisfy the conditions of formulas (3), (6), and (7), the residual solvent can be removed with virtually no loss of SE. Next, after subjecting the aqueous phase to reverse osmosis treatment, the residual liquid is spray-dried to selectively separate unreacted sucrose from the by-product salt from the catalyst, neutral salt for salting out, and volatiles. Unreacted sucrose can be recovered in a reusable powder form. (Margin below)

【Example】

Hereinafter, the embodiments and effects of the invention will be explained with reference to Examples, but the examples are of course for illustrative purposes only and are not intended to limit or limit the idea of the invention. Example 1 After the reaction solvent was distilled off from the solvent method SE reaction mixture represented by the composition shown in Table 2 below, the residual liquid was neutralized with lactic acid. 1.000 kg of water was added to 100 kg of the dried material to dissolve it. (Space below) Table 2 Zero ester distribution: Monoester 70L3 target diester or more 30%. To this aqueous solution, 2.5 kg of ShoiB and 97.6 kg of 50% potassium lactate were added, heated to 75°C, and the precipitated cake was filtered off and dried at 80°C under vacuum to determine the composition of the solid. Upon investigation, the results were as shown in Table 3 below. Note that the moisture content in the cake was 45%. (Margins below) Table 3 In addition, SEi in the filtrate filtered from the cake was analyzed using gel filtration chromatography (GPC) method (cited above, 63).
When measured on page 1, the presence of SE was not observed at all, and 85% of the reaction solvent dimethyl sulfoxide was removed. Water was added to 1,180 kg of the filtrate thus obtained (an aqueous solution containing sucrose, salt, and volatile components from which SE had been removed) to prepare a liquid having the composition shown in Table 4 below. (Margins below) Table 4 This aqueous solution (p) 17.4) was heated to 50 to 52.5°C, and a reverse osmosis membrane ((trade name (1:5U-200) )) (mentioned above) (diameter: 4 inches x length: 1 meter, +!! overload: 8 g) under the following conditions. Discharge rate of aqueous solution permeating through the membrane = 3.9 to 2.2 min/min @ring speed around the reverse osmosis membrane = 19.2 to 20.9 min/min
Supply time = approximately 550 minutes The concentrated liquid that did not pass through the membrane contained approximately the entire amount of sucrose that was originally weighed, and 4 of the initial amount of by-product salt from the catalyst.
6.0% and volatiles contained 52.0X of the original amount, respectively. On the other hand, as shown in Table 5 below, the aqueous solution containing by-product salts from the catalyst and volatile matter that has passed through the membrane contains almost no sugar, and the by-product salts from the catalyst and the added neutral m are the initial amount. 54.0
% and volatile content of 48.0% of the initial amount. Table 5゛1) Derived from catalyst 2) Dimethyl sulfoxide (reaction solvent) Hazards , 900 kg was added, and sucrose was separated by supplying it to a reverse osmosis membrane under the same conditions as in the example, and the results shown in Table 6 below were obtained. Table 6 (blank below) Back groove J1 Nyu 1,015.2k of the concentrated liquid described in Example 1 and Table 5 above
2,200 kg of wood was newly added to g (solute concentration 1006%), and the liquid was supplied to the reverse osmosis membrane under the same conditions as for turning, to separate sucrose. The results were as shown in Table 7 below. Table 7 1) Derived from catalyst 2) Dimethyl sulfoxide (reaction solvent) (blank below) Example 4 Spray 10.4 kg of concentrated unreacted sugar aqueous solution (10% solute concentration) obtained in Example 3 above. It was supplied to a drying tower and subjected to spray drying under the following conditions. Diameter of spray drying tower 2. Omφ Vertical tube length: 1.5m Nm'' Air flow rate: 350- Hour rotation disk diameter: 10cmφ Rotation a: 22.OQOrpm Inlet air temperature = 80℃. ?3 Condensate supply rate: 1.7 kg7' hour drying is The sucrose obtained from the bottom of the spray drying tower is a white powder that does not contain reducing substances such as glucose.
It had good fluidity with a moisture content of 2.70% and a bulk ratio of g10.41. For reference, the obtained analytical results are shown in Table 8 below. Table-8

【Effect of the invention】

As explained above, the present invention provides a means for industrially removing a reaction solvent and industrially recovering unreacted sugars in a reaction mixture without using a purification solvent. Bringing technological innovation to woodworking.

[Brief explanation of the drawing]

The t51 diagram is a ternary graph showing the relationship between each change in water, total sugar, and total salt and SEi dissolved in the aqueous phase. Patent applicant Dai-Kogyo Seiyaku Co., Ltd. Figure 1 Total salt ('1.) To 7

Claims (1)

[Scope of Claims] 1. A sucrose fatty acid ester synthesis reaction mixture containing, in addition to the target sucrose fatty acid ester, unreacted sugar, unreacted fatty acid methyl ester, catalyst, soap, fatty acid, and volatile matter, is A sucrose fatty acid ester characterized by adjusting the pH of the region, adding water, a neutral salt, and sucrose, separating the precipitate, and then contacting the residual liquid with a reverse osmosis membrane and spray-drying the impermeable part. A method for recovering unreacted sugar in a synthesis reaction mixture as a powder. 2. The method according to claim 1, wherein the reaction mixture is adjusted to a pH in the range of 6.2 to 8.2. 3. The method according to claim 1, wherein the reaction mixture after pH adjustment is heated to 50 to 80C. 4 To the reaction mixture after pH adjustment, water: reaction mixture = 5:
2. A method according to claim 1, wherein water is added in a weight ratio of 1 to 40:1. 5. Claim 1, wherein a neutral salt and sucrose are added to the reaction mixture after pH adjustment according to the following relational expression:
Method described. Total salt amount/water amount + total salt amount + total sugar amount = 0.015 to 0
．． 12 and total sugar amount/water amount + total salt amount + total sugar amount = 0.025 to 0
．． 20 and total amount of salt/total amount of sugar = 0.4 to 0.6, where, total amount of salt: amount of neutral salt to be added + amount of salt produced by neutralization of catalyst Total amount of sugar: amount of shoto to be added Amount of sugar + amount of unreacted sugar from the beginning 6 The acid used to adjust the pH of the reaction mixture is any acid selected from the group consisting of lactic acid, acetic acid, hydrochloric acid and sulfuric acid, according to claim 1 or 2. Method. 7 The composition of the reaction mixture is: Sucrose fatty acid ester = 15.0-92.0% Unreacted sucrose = 1.0-80.0% Unreacted fatty acid methyl ester = 0.5-10.0% Catalyst = 0.05 to 7.0% Soap = 1.0 to 10.0% Fatty acid = 0.5 to 10.0% Volatile content (residual reaction solvent) = 5.0 to 30.0% The method described in 1. 8 The fatty acid radical mainly contained in each of the fatty acid methyl ester, soap, and fatty acid in the reaction mixture has a carbon number of 16.
3. The method of claim 1 or 2, having ~22 common saturated fatty acid roots. 9. The method according to claim 1 or 2, wherein the volatile component (residual reaction solvent) in the reaction mixture is dimethyl sulfoxide or dimethyl formamide. 10 The neutral salt added to the reaction mixture is common salt, mirabilite,
6. The method according to claim 1, wherein the salt is selected from the group consisting of potassium lactate and potassium acetate. 11. The method according to claim 1, wherein the reverse osmosis membrane has a molecular weight cutoff of 150 to 200. 12. The method of claim 1, wherein the reverse osmosis is carried out within a temperature range of 40-60<0>C. 13. The method according to claim 1, wherein the pH of the feed liquid to the reverse osmosis membrane is 6.2 to 8.2. 14. The method according to any one of claims 1 or 11 to 13, wherein the reverse osmosis membrane is made of crosslinked polyamide plastic. 15. The method according to claim 1 or 13, wherein the sucrose concentration of the feed solution to the reverse osmosis membrane is 20% or less. 16. The method according to claim 1, wherein the sucrose concentration in the reverse osmosis membrane impermeable part is 20% or less. 17. The method according to claim 1, wherein the humidity and temperature during spray drying are: absolute humidity = 0.008 to 0.05 (kg.water/kg.dry air) temperature = 10 to 100°C.