JPS5823798A - Purification of starch sugar containing liquid - 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 method for purification.

Sugar products such as glucose, high fructose sugar, and starch syrup (hereinafter collectively referred to as starch sugar) manufactured from starch are used as sweeteners or nutritional supplements for soft drinks, juices, bread, confectionery, candies, etc. It is widely used for medical and other purposes. These starch sugars contain impurities such as inorganic salts, pigments, proteins, amino acids, and organic acids caused by the starch used as a raw material and the enzymes and additives used in the saccharification and isomerization processes. Purification is carried out using resin.

In conventional purification methods, a starch-sugar-containing liquid is sequentially passed through a bed of strongly acidic cation exchange resin, a bed of weakly or moderately basic anion exchange resin, and a hot bed of strongly acidic cation exchange resin and strongly basic anion exchange resin. The liquid was then purified. At this time, the starch sugar-containing liquid is passed in a downward flow, and the regenerant is also passed in a downward flow for the strongly acidic cation exchange resin bed and the weak or medium basic anion exchange resin bed. I was worried.

However, in this method, the amount of regenerating agent used is large, the processing capacity of the starch sugar-containing solution is low, e.g. It has disadvantages such as the exchange resin may float, resulting in insufficient purification, the quality of the processing liquid is poor, and the stability against coloring is particularly poor (the degree of coloring increases during storage). , the improvements were highly anticipated.

Several methods have been proposed to improve these shortcomings of conventional purification methods, such as the use of strongly acidic cation exchange resin beds and weak or moderately basic anion exchange resin beds in conventional purification methods. A countercurrent regeneration method has been proposed in which a starch-sugar-containing solution is passed in a downward flow and a regenerant is passed in an upward flow. However, since the starch-sugar-containing solution is passed in a downward flow, the ion exchange resin may float during the flow, resulting in insufficient purification, or the regenerant may be passed in an upward flow. The problem is that the ion-exchange resin bed is loosened and disturbed, resulting in insufficient regeneration.Perhaps for this reason, the quality of the treated solution is hardly improved compared to conventional methods. , the stability against coloring is also poor.

In addition, the glucose-containing liquid for isomerized sugar is sequentially flowed upward into a strongly acidic cation exchange resin bed, a weak or medium basic anion exchange resin bed, a strongly acidic cation exchange resin bed, and a strong basic anion exchange resin bed. A countercurrent regeneration method has been proposed in which the liquid is passed through the regenerating agent in a downward direction (Japanese Patent Application Laid-Open No. 136-1983).
536), Although this method improves the amount of regenerant used, the purification processing capacity, the floating of the ion exchange resin during the passage of the glucose-containing liquid, and the disturbance of the ion exchange resin during the passage of the regenerant, The major drawback is that the treated glucose-containing liquid has a high pI4 and therefore very poor stability against coloring. Although this method can be used to purify glucose-containing liquids that undergo subsequent isomerization after being purified with an ion exchange resin, it can be used to purify other starch sugars, such as glucose other than high-fructose isomerized sugar, high-fructose isomerized sugar, and starch syrup. It is impossible to apply it to purification such as

The present inventor has conducted extensive studies to solve the above-mentioned drawbacks of conventional purification methods for starch-sugar-containing liquids and purification methods proposed as improvements thereto, and has found that, in conventional purification methods, strong acid oxidation These drawbacks are overcome by passing the starch sugar-containing liquid in an upward flow and the regenerant in a downward flow through the ion exchange resin bed and the weak or medium basic anion exchange resin bed. In particular, it has been found that the stability against coloring of the treatment liquid is significantly improved, and the present invention has been completed.

That is, the present invention provides a solution containing starch sugar in a strongly acidic cation exchange resin bed, a weak or medium basic anion exchange resin bed, and a mixed bed of a strongly acidic cation exchange resin and a strongly basic anion exchange resin. In the sequential purification method, a starch sugar-containing solution is passed in an upward flow through a strongly acidic cation exchange resin bed and a weak or medium basic anion exchange resin bed, and a regenerant is passed in a downward flow. This is a method for purifying starch-sugar-containing liquids.

The starch-sugar-containing liquid to be treated in the present invention is grapes produced from starches such as corn, starch, potato starch, cane starch, and tapioca starch.

It is an aqueous solution containing sugar, starch syrup, isomerized sugar produced by isomerizing glucose, norbit produced by reducing glucose, and the concentration is usually 20 to 70% by weight.
is within the range of

Such a starch sugar-containing liquid can be prepared using an ion exchange tower (hereinafter abbreviated as "tower") filled with a strongly acidic cation exchange resin, or an ion exchange tower (hereinafter referred to as "tower") filled with a weak or medium basic anion exchange resin.
(hereinafter abbreviated as A tower), and an ion exchange tower (hereinafter abbreviated as MB tower) filled with a mixture of a strongly acidic cation exchange resin and a strong basic anion exchange resin. However, the first feature of the present invention is that the starch-sugar-containing liquid is passed in an upward flow from the bottom of the column to the top of the column in the column A and the column A.

The starch sugar-containing liquid is passed through after regenerating the cation exchange resins in the K tower and MB tower with hydrochloric acid, and the anion exchange resins in the A tower and MB tower with caustic soda. The second feature is that the regenerant is passed through the A-column in the opposite direction to the passage of the starch-sugar-containing liquid, that is, in a downward flow from the top of the column to the bottom of the column.

However, as for the MB tower, the starch-sugar-containing liquid is passed in a downward flow according to a conventional method, and the regeneration is also carried out according to a conventional method.

An example of an ion exchange column used in the column A and column A of the present invention will be explained using the drawings.

FIG. 1a shows the state when the starch sugar-containing liquid is passed through.

The starch sugar-containing liquid enters the ion exchange tower as the starch sugar-containing liquid 9, passes through a strainer 3, is adsorbed by an ion exchange resin 5, and passes through an inert resin layer 6 such as styrofoam and a strainer 8. Through the starch sugar-containing liquid outlet l
Exit/exit the ion exchange tower from O. In order to fully exhibit the effects of the present invention, it is preferable that 20 or more ion exchange resins form a fixed bed in the upper part of the ion exchange column when the starch sugar-containing liquid is passed through the column. The rate at which a fixed bed is formed at the top of the ion exchange tower depends on the specific gravity, viscosity, and
It is affected by the specific gravity of the ion exchange resin, the proportion of free space in the ion exchange tower, etc., but usually,
The flow rate of the starch sugar-containing liquid is 2 m/hr to 50 m/hr based on the empty cylinder.
m/hr, preferably 5 m/hr to 25 m/hr
It may be within the range of hr. By setting the flow rate within the above range, a stable fixed bed is formed at the top of the ion exchange tower even if the free board inside the ion exchange tower is large, so backwashing of the resin can be performed inside the tower. This also eliminates the need for a special backwash tower. If the flow rate of the starch sugar-containing liquid is made larger than the above range, the pressure loss will become too large, and if it is made smaller than the above range, the fixed bed may not be sufficiently formed or the starch sugar containing liquid may cause uneven flow. , it becomes impossible to perform sufficient purification.

Figure 1 shows the state when the regenerant is flowing. The regenerant enters the ion exchange tower through the regenerant port 11 at the top of the tower and exits the ion exchange tower through the regenerant outlet 12 at the bottom of the tower. The ion exchange resin forms a fixed bed at the bottom of the column, thus allowing stable regeneration. In the case of K tower, the regeneration level of pure hydrochloric acid is 50~
100 gr// - resin, regenerant concentration 5-10%, regenerant flow rate 2-20 rn/hr, for A column, regeneration level pure caustic soda 35-80 gr/l - resin, regenerant concentration 2-6 rn/hr. It is preferable to carry out the regeneration at a regenerant flow rate of 2 to 20 m/hr.

FIG. 2a shows another example of the state when the starch-sugar-containing liquid is passed through. The ion exchange column is partitioned into two upper and lower chambers by a strainer support plate 13 and a strainer 14. The upper chamber is filled with ion exchange resin 5 without free boards, and the lower chamber is filled with ion exchange resin 5 without free boards. The chamber is filled with ion exchange resin 5' with sufficient free board.

The starch sugar-containing liquid enters the ion exchange tower from 17, passes through the strainer 3, undergoes adsorption treatment by the ion exchange resin 5' in the lower chamber, and passes through the strainer 14 to the ion exchange resin 5 in the upper chamber. After being subjected to adsorption treatment by 18, it passes through an inert resin 6 and a strainer 8 and exits from the ion exchange column 18. Since the ion exchange resin 5 in the upper chamber forms a fixed bed, extremely stable liquid flow is possible. The entire amount of the ion exchange resin 5' in the lower chamber may form a fluidized bed. The mole ratio of the ion exchange resins in the upper and lower chambers is usually in the range of 1:5 to 5:1. The flow rate of the starch sugar-containing liquid is 2 m/hr to 50 rn based on the empty cylinder.
/hr range, preferably from 3 m/hr to 25
m/hr range.

Figure 2 shows the state when the regenerant is flowing. The regenerant enters the ion exchange column from the top 19 and exits the ion exchange column from the bottom 20. Since the ion exchange resin forms a fixed bed in both the upper and lower chambers, extremely stable regeneration is possible. , the conditions for reproduction are the same as in the case of FIG. The nozzle 16 is normally closed, but when it is opened, the bottom 17
Alternatively, by introducing water from the tower top 19 and removing water from the tower top 18 or tower bottom 20, the ion exchange resin can be piped 15 from the lower chamber to the upper chamber or from the upper chamber to the lower chamber. and can be transferred through valve 16. In this way, it is possible to carry out backwashing of the ion exchange resin in the upper chamber or in the lower chamber, without requiring a special backwashing tower.

In the present invention, both the ion exchange towers shown in FIGS. 1 and 2 can be used as the ion tower and the A tower, but in the case of a ion exchange tower filled with a strongly acidic cation exchange resin having a relatively large specific gravity, It is preferable to use the ion exchange column shown in Figure 2 for the A column, which is filled with a weak to medium basic anion exchange resin that has relatively low specific gravity and large swelling and contraction. It is.

The effects of the present invention can be exerted regardless of whether the anion exchange resin filled in Tower A is a weakly basic resin or a medium basic resin, or a mixed resin thereof.

As the anion exchange resin for the A column and the strongly basic anion exchange resin for the MB column, it is preferable to use macroporous resins that are resistant to organic contamination.

The strongly acidic cation exchange resin of the K tower and the MB tower may be either a gel type resin or a macroporous type resin.

The amount of resin for each group is determined by the amount of starch sugar-containing liquid to be treated in one cycle, the content of cations and anions in the starch sugar-containing liquid to be treated, the degree of coloring, etc. The amount of resin in the K tower and the A tower is the amount of resin necessary to remove the total amount of cations and anions contained in the starch sugar-containing liquid to be treated in one cycle. The resin has the role of removing cations and anions leaking from the tower, and the amount of resin is usually 0.2 to 2 times that of the K tower and A tower, respectively, for the strong acidic cation exchange resin and the strong basic anion exchange resin. , preferably the amount of resin has 03 to 07 times the capacity.

According to the method of the present invention, the starch-sugar-containing liquid is passed in an upward flow to form a fixed bed at the top of the ion exchange column, which is different from the conventional method in which the liquid is passed in a downward flow. There is essentially no problem with the ion exchange resin floating during the flow, and since the regenerant is passed through the liquid in a downward flow, very stable regeneration is possible and there is no Since it is a flow regeneration method, the amount of regenerating agent used is reduced and the amount of starch-sugar-containing liquid processed per cycle is increased. At the same time, the quality of the treated starch-sugar-containing liquid is improved, and in particular, its stability against coloring is significantly improved.

This cannot be expected from conventional purification methods or purification methods proposed as improvements thereto.

The degree of coloration of the starch sugar-containing liquid is determined by the absorbance at the wavelength 42 Q nm and 7201 m of the liquid phase IQ cm using a spectrophotometer after diluting the sample with pure water and adjusting the starch sugar concentration to 0.3 gr/ml. It is determined as the difference in absorbance at both wavelengths, but the starch sugar-containing liquid purified by the conventional purification method or the purification method proposed as an improvement thereof has a coloration of 0.01 to 0.05 immediately after purification. By leaving it at 30℃ for 1 month, the temperature will be 0.07~01.
In contrast, in the starch-sugar-containing liquid purified by the method of the present invention, the degree of coloration was about -001 immediately after purification, but even after being left at 30°C for one month, the degree of coloration decreased to 0.02 to 0. .0
3, and is very stable against coloring.

The reason why the stability against coloring improves in this way is not clear, but considering that proteins or amino acids are said to be the cause of coloring, the method of the present invention can improve the stability of starch-sugar-containing liquids. Since the upward flowing liquid and the downward flowing liquid of the regenerant can be carried out in a very stable state,
This is presumed to be because the removal rate of proteins or amino acids is significantly improved.

Next, the present invention will be further explained with reference to Examples.

Example A saccharification solution produced using corn starch as a raw material, a liquefaction enzyme, and 7 saccharification enzymes was treated with activated carbon to obtain the raw sugar solution shown in Table 1.

Next, strongly acidic cation exchange resin Revachit 5100WS
(Bayer registered trademark) 250me-filled tower,
Weakly basic anion exchange resin Revatit hlP62WS5
A tower filled with 00ml of strongly acidic cation exchange resin Revatit SP I 12 W8100m/and strong basic anion exchange resin Revatit~fP600W8280ml
The raw sugar solution was sequentially passed through the MB tower filled with 5/hr at 5/hr for purification. Liquid was passed through the K column and A column in an upward flow, and liquid was passed in a downward flow in the MB column.

Prior to passing the raw sugar solution, the K tower was filled with 245 m of 6-dihydrochloric acid aqueous solution.
/ at 500 me/hr, and tower A was regenerated by passing 535 ml of 4% caustic soda aqueous solution at 1000 ml/hr in a downward flow. After separating the cation exchange resin and anion exchange resin in the MB tower, the anion exchange resin was treated with 535 ml of 4% caustic soda aqueous solution at 10,100 O/hr, and the cation exchange resin was treated with 130 ml of 6% hydrochloric acid aqueous solution! 300
The solution was passed through at a rate of ml/hr and regenerated.

The purification process of the raw sugar solution was terminated when the electrical conductivity of the treated liquid at the outlet of the MB tower exceeded 2 μv/cm, and the next cycle of regeneration was started.

In this way, the regeneration and purification treatments were repeated 4 times for 9 times.

Table 1 shows the amount of saccharified solution processed and the analysis results of the treated solution in cycles 2 to 4. In order to examine the stability of the treatment liquid against coloring, the degree of coloration was measured after the treatment liquid was left in a constant temperature bath at 30° C. for one month. The results are also shown in Table 1.

In the table, Example 1 uses the ion exchange tower shown in Figure 1 for both the K tower and the A tower3, and Example 2 uses the ion exchange tower shown in Figure 2 as the K tower, and the case where A This is a case where the ion exchange column shown in FIG. 1 is used as the column.

In Comparative Example 1, the purification treatment was carried out in the same manner as in Example 1, except that the saccharified liquid was passed through the K tower and the A tower in a downward flow, and the results are shown in Table 1.

In Comparative Example 2, the saccharified liquid was passed through the K tower and the A tower in a downward flow,
The results are shown in which the purification treatment was carried out in the same manner as in Example 1, except that the regenerant was passed in an upward flow.

Comparative Example 3 is a strongly acidic cation exchange resin Rebatit S 1
00W8 250m/(Kl tower), Weakly basic anion exchange resin Revatit MP62WS 500rr+1
! (AI tower), strongly acidic cation exchange resin Revatit 5P
112WS 1ooml! (K2 tower) and the strong basic anion exchange resin MP600WS 2somJ (A2 tower) were subjected to purification treatment by sequentially passing the saccharified solution in an upward flow. Regeneration from K2 Tower to Kll Behenries 6
% hydrochloric acid aqueous solution at 500 me/hr,
From the A2 tower to the Al tower, 4 samples of caustic nodal aqueous solution 8 are added in series.
The test was carried out by passing 40rr+j' of I O at 00ml/hr in a downward flow.

As can be seen from the results in Table 1, Examples 1 and 2 have a higher processing rate per cycle than Comparative Example 1, which is a conventional purification method, and Comparative Examples 2 and 3, which are proposed as improvements. Both the quantity and the quality of the processing liquid are excellent, and in particular, the stability against coloring of the processing liquid has been greatly improved.

[Brief explanation of drawings]

The drawings illustrate examples of ion exchange columns that may be utilized to carry out the present invention. Figures 1a and 2a show the state when the starch-sugar-containing solution is being passed through, and Figures 1 and 2 show the state when the regenerant is being passed through. show. Symbols in the drawings indicate the following: 1: Tower 2.7.13 Ni strainer-support plate 3.8
．． 14 Ny strainer 4: Free board (free space) 5.5': Ion exchange resin 6: Inert resin 9: Starch sugar-containing liquid inlet 10: Starch sugar-containing liquid outlet 11: Regenerant population 12: Regenerant outlet 15: Resin transfer piping 16: Valp 17: Starch sugar-containing liquid and resin transfer water inlet 18: Starch sugar-containing liquid and resin transfer water outlet 19: Regenerant and resin transfer water inlet 20: Regenerant and resin transfer water inlet Shi・Kakano＼ Mutsukura 31, 5 τc? J$6 out of 1 f th (+2.) j! I12

Claims (1)

[Claims] The starch sugar-containing liquid is sequentially passed through a strongly acidic cation exchange resin bed, a weakly or medium basic anion exchange resin bed, and a mixed bed of a strongly acidic cation exchange resin and a strongly basic anion exchange resin. The purification method is characterized by passing a starch sugar-containing liquid through a strongly acidic cation exchange resin bed and a weak or medium basic anion exchange resin bed in an upward flow, and passing the regenerant in a downward flow. A method for purifying starch sugar-containing liquids.