AU600806B2

AU600806B2 - An improved process for demineralizing sugar solutions

Info

Publication number: AU600806B2
Application number: AU13514/88A
Authority: AU
Inventors: Upen J. Bharwada; Robert L. Labrie
Original assignee: Dow Chemical Co
Current assignee: Dow Chemical Co
Priority date: 1987-03-31
Filing date: 1988-03-23
Publication date: 1990-08-23
Anticipated expiration: 2008-03-23
Also published as: JP2575171B2; CA1321193C; DE3880196T2; EP0292662A3; AR244809A1; KR880011347A; EP0292662A2; AU1351488A; KR960000480B1; ES2039490T3; EP0292662B1; JPS63263099A; BR8801520A; DE3880196D1

Description

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AUSTRALIA

Patents Act 600f O 6 COMPLETE SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: r rrr

I

r r t APPLICANT'S REFERENCE: 35915-F N,me(s) of Applicant(s): The Dow Chemical Company Addrers(es) of Applicant(s): 2030 Dow Center, Abbott Road, Midland, Michigan 48640, UNITED STATES OF AMERICA.

Address for Service is: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Complete Specification for the invention entitled: AN IMPROVED PROCESS FOR DEMINERALIZING SUG',R SOLUTIONS Our Ref 87607 POF Code: 1037/1037 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): 6003q/1 1 DEMINERALIZING A SUGAR-CONTAINING SOLUTION 0 tsolutions, especially high fructose corn syrups, by contacting the solutions with specific ion exchange resins.

requires the removal of various impurities froved methe s o sr process stremoving ams. The main impurities in sugar are measued as suphated ash which frucontains cations and anions such as Ca w Nasp Ke, SO3, Cio S04ex resiand the like. For the production of a refined sugar-containing solution, it is necessary to remove these impurities. This is achieved by a demineralization process. It is standard puriactice i n the demineralization sulphooated ass to pass the sugar solution 20 first through a strongly acidic tion exchange resin aion exchanger in the hydroxide or free base form.

Once the ion exchange resins b ecome nearly exhausted, i demineralization irocess to pass the sugar solution in the hydrogen form, folowed by passage through a strongly basic anion exchanger and/or weakly basic Once the ion exchange resins become nearly exhausted, 35,915-F -iA Agent RICHARD G. WATERMAN Phillips, Ormonde Fitzpatrick General.Patent Counsel N41 le:ali/ntion or other -2it becomes necessary to regenerate their ion exchanging capacity. Prior to contacting the ion exchange resin with the regenerating agent, it is necessary to remove essentially all of the sugar solution from the resin bed. This is accomplished by passing effective quantities of water over the resin in order to "sweeten-off" the sugar solution within the resin bed.

The resulting effluent is known in the industry as sweet-water.

The "sweetening-off" water or "sweet-water" after having sweetened-off the sugar from the resin contains an amount of recoverable sugar. The sweeto -water is desirably recycled back as a dilution medium S1," 5 to other process steps high fructose corn syrup saccharification). Typically, there is substantially S more sweet-iater generated than can be utilized for dilution purposes. Also, the sweet-water composition limits the usefulness of the sweet-water as a dilution q source high fructoss sweet-water is not added back to the dextrose solution at the saccharification step). The excess sweet-water normally requires concentrating during some step in the refining process.

25 This is accomplished by removing a substantial portion of the water without removing any of the sugar Which i has been washed off of the resin. This is generally accomplished by evaporating off an amount of water which results in a desired dissolved solids content, 30 sugar content, in the unevaporated sweet-water.

The evaporation of the water is an expensive unit operation in the process for preparing refined sugars. Therefore, it is desirable to reduce the expense incurred during the evaporation operation of the process without detrimentally affecting the quality 35,915-F -2j I -3of sugar which is produced by the process. It is also desirable to increase the operating capacity of the resins for demineralizing a sugar-containing solution.

cThe invention is an improved process for demineralizing a sugar-containing solution. The improvement comprises using an ion exchange resin in bead form wherein the volume average diameter of the beads is from 400 to 700 pm and which resin exhibits a bead diameter distribution such that at least 80 volume j percent of the beads have diameters which fall within a .Ii! range of ±15 percent of the volume average diameter of Sthe resin used.

15 The resin of the improved process has a smaller volume average bead diameter and a narrower bead size distribution relative to conventional resins used for demineralizing sugar-containing solutions. The smaller mean diameter of the beads shortens the average diffusion distance traveled by exchanging components within the beads. Therefore, the operating capacity of the resin for demineralizIng a sugar-ocontaining solution is increased and the volume of water required to sweeten-off sugar from the resin is decreased.

However, beads with a mean diameter below 400 pm will create unacceptably high pressure drops within a resincontaining column and would therefore limit operating capacity. Since the resin used in this invention has a narrow bead size distribution, the volume percent of beads having a bead diameter less than 400 jim is insignificant and would not adversely affect the operating characteristics of the resin.

35,915-F -3r 4-4 In a preferred embodiment, the present invention relates to an improvement in the deminoealizing of high fructoe corn syrup solutions.

Macroporous ion exchange resins which are capable of removing ionic impurities from sugar- -containing solutions may be of the anion exchange variety or of the cation exchange variety or of the type resin which contains both anion exchange sites and cation exchange sites.

V Macroporous ion exchange resins which are available commercially may be employed, such as those which have been offered commercially under the tradenames DOWEX M

AMBERLITE

TM

DUOLITE'

M

and others.

The cation exchange resins are those capable of exchanging cations. This capability is provided by resins having functional pendant acid groups on the polymer chain, such as carboxylic and/or sulfonic groups. The anion exchange resins are those capable of exchanging anions. This capability is provided by I resins having functional pendant base groups on the i polymer chain, such as ammonium or amine groups.

Resins having both types of exchange groups are also I within the purview of the present invention.

Examples of macroporous strong-acid exchange I resins include the sulfonated styrene-divinylbenzene copolymers such as are offered commercially under the tradenames DOWEX' T 88, DOWEX T M MSC-1, DUOLITE T M C-280,

AMBERLITE

T M 200, and KASTEL'" C301.

35,915-F Acid resins of intermediate strength have also been reported, such as those containing functional phosphonic or arsonic groups.

Macroporous weak-acid resins include those having functional groups of, phenolic, phosphonous, or carboxylic types. Some common weak- -acid resins are those derived by crosslinking of acrylic, methacrylic or maleic acid groups by use of a crosslinking agent such as ethylene dimethacrylate or divinylbenzene. DUOLITE'I C-464 is a tradename applied to a resin having such functional carboxylic groups.

Among the macroporous strong-base resins are those which, notably, contain quaternary ammonium groups pendant from a poly(styrene-divinylbenzene) matrix. DOWEX'" MSA-1 and DUOLITE A-191 are tradenames of strong-base resins reported as having amine functionality derived from trimethylamine.

DOWEX

T M MSA-2 is a tradename of a macroporous strong- -base resin reported as having amine functionality derived from dimethylethanolamine.

Macroporous weak-base anion exchange resins 25 generally contain functional groups derived from i primary, secondary, or tertiary amines or mixtures of Sthese. Functional amine groups are derived from condensation resins of aliphatic polyamines with formaldehyde or with alkyl dihalides or with epichlorohydrin, such as those available under the tradenames DOWEX'" WGR and DOWEX"' WGR-2.

Other macroporous weak-base resins are prepared by reaction of an amine or polyamine with chloromethylated styrene-divinylbenzene copolymer 35,915-F LL_ I_ -6beads, such as DOWEX'" MWA-1, DOWEX

T

66, and DUOLITE" A-392S.

The above-described resins may be used as ion exchange resins in the demineralization of sugar- -containing solutions. Sugar solutions usually contain ionic impurities such as Na+, S03--, S04-, Cl- and the like. The removal of such impurities is essential to the preparation of marketable sugar products.

SExamples of sugar-containing solutions include aqueous solutions of cane and beet sugar, high fructose corn syrups, high fructose syrups derived froi inulin, tapioca and potato starches, maple sugar, palm sugar, sorghum derived sugar, and the like, the most preferred being solutions of high fructose corn syrup. The disclosed sugar solutions which may be effectively demineralized exhibit dissolved solids, sugar content, ranging from 20 percent to 60 percent.

SAn effective demineralization may be i accomplished by using a strongly acidic cation exchange resin in the hydrogen form, followed by an anion 2 exchange resin preferably in the hydroxide or free base form. The sugar solution to be demineralized may be contacted with the resin by any conventional means which results in intimate contact between the resin and the sugar solution. Such methods include batch vessels, packed columns, fluidized beds and the like.

The contacting may be of a batch, semi-continuous or continuous nature. Preferably the sugar solution and the resins are contacted continuously in an ion exchange column.

35,915-F -6- I I

L

I c -7- 1 The resins and the sugar solution are effectively contacted for a period of time sufficient to remove a substantial portion of the ionic impurities. The contact time is largely dependent on the type of vessel used to contact the resin and the sugar solution, the amount of resin used, the pH of the sugar solution, the temperature, the level of demineralization desired, and the like. The resin may be used until the ion exchange capacity of the resin becomes nearly exhausted as evidenced by an increase in the mineral content of the sugar solution after having been treated with the resin. At this time it becomes necessary to regenerate the ion exchange capacity of the resin in order to prepare it for reuse.

The regeneration of the demineralizing resins involves the steps of "sweetening-off" the sugar solution from the resin, backwashing the resin to 20 remove impurities, contacting the resin with an 2O appropriate regenerant solution in an amount effective to regenerate the ion exchange capacity, and then (4) rinsing the resin to remove any of the excess regenerant. The resin is then ready to be reused as a demineralizing resin and may be contacted with the sugar solution to be demineralized.

The step of "sweetening-off" the sugar solution from the resin involves the washing of the resin with water in order to remove essentially all of the sugar from the ion exchange resins. This i3 accomplished by contacting the ion exchange resin which has been sweetened-on with an amount of water effective to wash substantially all of the sugar solution from the ion exchange resin. The resin and water are contacted until essentially only water is coming off of the resin 35,915-F -7bed. The sweetening-off is considered complete when there is essentially no sugar in the effluent sweet- -water stream.

The sweet-water, which results from the sweetening-off of the sugar from the resin, contains an amount of sugar which may go to waste if not recovered within the system. It is desirable to recover this sugar in as economical a way as possible. Recovery of this sugar may be accomplished by tPecycling thfe sweet- -water stream back into the sugar-containing solution of the main process stream. Some of the sweet-water stream maay be needed for dilution purposes elsewhere in the main sugar process stream. However, most of T he swe-water volume is returned to the main sugar process stream as an unwanted dilution medium. This excess dilution water is removed in preparing the sugar solution for further processing increasing the dissolved solids level in preparation for crystallization and/or storage of the sugar solution).

The removal of the excess dilution water may be accomplished by evaporating off some of the water from the sugar-containing solution, This evaporation results in an effective increase in the level of dissolved solids present in the process streams.

It has been discovered that by using ion exchange resins which exhibit bead diameters which fall within a specific size distribution, the oper4 ting capacity of the resins for, demineralizing sugaircontaining solutions and the amount of water which must be used to sweeten-off the sugar solution from the cemineralizing resins may be appreciably decreased, also decreasing the amount of recycled dilution water which must be evaporated froi- 'Whe diluted main 35,f9 t~tr t 4 t t( K t ~t V' 4 -9process stream in order to achieve the desired dissolved solids level. By increasing operating capacity and reducing the amount of water which must be evaporated off, the production costs of the sugar refining process may be reduced.

The size distribution of the beads employed in this invention is such that at least about 80 volume percent, more preferably 85 volume percent, and most preferably at least about 90 volume percent of the beads exhibit a bead diameter which falls within a range of about ±15 percent preferably within a range of ±10 percent of the mean diameter of the ion exchange resins used. Mean diameter is determined by the 15 following sequential steps: 1) measuring the diameter of each bead in a population of beads, 2) calculating the volume percent of beads within the preset ranges of bead diameters to determine a bead diameter distribution (determined by dividing the volume of beads within a preset range of bead diameters by the total volume of beads in the population), and 3) calculating the mean from the bead diameter distribution obtained. The mean diameter which may be used ranges from 400 pm to 700 pm, and more preferably from 500 pm to 600 pm, and most preferably from 525 pm to 575 pm.

The following examples are intended to illustrate the invention. All parts and percentages are by weight unless otherwise indicated.

Example 1 3 700 mis of a macroporous strong acid cation exchange resin (available as DOWEX 88 from The Dow

L

I

35,915-F -9- 4, Chemical Company) which had been screened to the following bead size distribution 1 Bead Diameter Range (pm) Min. Max.

150 300 300 440 440 495 495 505 505 520 520 540 540 555 555 575 575 590 590 620 620 707 707 2500 AVERAGE DIAMETER VOLUME MEAN Volume Resin u- Invention Example 1 0.1 1.7 9.2 11.7 17.6 17.2 17.1 6.4 2.4 0.0 Volume Range 95.7 percent ±15 percent of mean, 1 Each of the bead size distributions in these exmaples are determined by a particle size analyzer sold commercial by the HIAC Division of Pacific Scientific Company as Model PC-320.

was loaded into a 2.54 cm I.D. glass column system consisting of two 61 cm, water jacketed sections, coupled together. A third unjacketed 61 cm long section is attached on top of the two 61 cm columns to 35,915-F

LL

-11- .44, 4 I+ 44 t4 It I I, I allow backwashing of the resin. The resin is in the sodium form.

The bed of resin is backwashed with deionized S water at room temperature at a flow rate sufficient to expand the bed by 50 percent of the settled height. This is done in order to remove any unwanted matter present in the bed and also to classify the beads by size. The backwashi.jg is continued for about 30 minutes.

The resin is then converted to the hydrogen form by pumping a minimum of 2 bed volumes of 2N hydrochlorio acid through the bed for a minimum of 15 1 hour contact time. After converting the resin to the hydrochloric acid form the resin is rinsed with flow of D.I. water until the effluent water exhibits a pH of at least After the backwashing As accomplished the top unjacketed 61 cm portion of the column is removed and the column is capped with a glass fritted flow distributor.

One liter of degassed D.I. water is pumped downflow while the jacketed columns are being heated to a temperature of about 50 0 C by circulating hot water through the column jackets.

One liter of refined 42 percent high fructose corn syrup (HFCS) exhibiting a dissolved solids sugar content, of 50 percent is passed downflow through the bed with a contact time of 60 minutes.

Next, 1 liter of refined 42 percent HFCS, containing 117 g of sodium chloride, is passed downflow through the bed over a period of time effective to exhaust the 35,915-F -11- -12resin to the sodium form, generally about 60 minutes.

The HFCS containing the sodium chloride is followed by 1 liter of refined 42 percent HFCS passed downflow through the reoiin bed for a period of 30 minutes. The resin bed is sweetened-off by passing degassed D.I.

water downflow at 2 bed volumes/hr. During the sweetening-off process, the flow out of the column is monitored and samples of the effluent are collected at recorded intervals in a fraction collector. Each sample is analyzed for refractive index by using an i Abbe Mark II refractometer and the D.S. content is I determined from industry standards based on the irefractive indices. The results are reported in i5 Table 1 under Example 1.

j 15 A plot of the D.S. concentrations versus the volume of water used to sweeten-off the sugar solution from the resin bed may be made and the areas under the curves integrated by known means. The integration results give a measure of the total amount of dissolved solids in the collected samples. From this value can be calculated the amount of water which must be removed from the total volume of liquid collected in i return the collected sample to the original D, 1 of the 42 percent HFCS. This value is then used for, comparison purposes to illustrate how much water must Sbe evaporated from the sweet-water when an ion exchange resin which does not exhibit a uniform size distribution is used.

The results are summarized in Table 3 under Example 1.

3S 915-F 12- -13- Comparative Example 1 The method of Example 1 was essentially repeated except that the strong acid cation exchange resin (available as DOWEX' 88 from The Dow Chemioal Company) used to demineralize the HFCS had the following bead size distribution: Bead Diameter Range 41im) Min.

150 250 297 3514 420 500 595 707 8141 1000 1190 2000 Max.

250 297 354 420 500 595 707 8141 1000 1190 2000 2500 Volume Example C-i DOWE X

T

88 0.0 0.0 0.1 6.1 14.0 28.4 36.2 11.7 0.0 0.0 AVERAGE DIAMETR VOLUME MBEAN 820 Volume Range 78.t3 percent ±15 percent cf mean.

35,915-F -14- The results are summarized in Tables 1 and 3 under Example C-1.

TABLE T Catic Rlesin 4411 4aa a Ill al a ala a a' a I a a' 1:1 4~ 4.1 Example 1 Volume of Sweet-Water Grams (ml) D.S. /,100 ml1 299 62.06 324 58.71 349 54*49 374 50.09 399 45.79 424 41.07 4110 36.36 467 33.04 488 30.0o4 508 27.28 528 24.50 548 21.62 568 '18.61 587 12.01 607 6.50 627 3.75 647 2.o6 667 1.15 Volume of Sweet-Water (ml) 274 299 324 349 374 399 4124 1467 488 508 528 548 568 587 607 627 647 667 Grams D.S. /100 m3 63.04 60.71 57.98 54.49 49.81 47.51 43.89 36.93 31 24.62 18.65 13.99 10.49 7.97 6.06 4.62 3.38 2 4 9 Comparative Exaimple C-1* $4 $1 Not an example of the invention.

3519 15-F -4 -14- I r i i TABLE I Cation Example 1 (Cont.) Resin Comoarative Examole C-1I Volume of Sweet-Wat'er (ml) 686 706 726 746 766 785 805 Grams D.S./100 ml 0.65 0.40 0.10 0.09 0.08 0.07 0.07 Volume of Sweet-Water (ml) 686 706 726 746 766 785 805 825 845 865 884 904 Grams D.S./100 ml 1.81 1.35 1 .00 0.70 0.50 0.30 0.15 0.10 0.09 0.08 0.07 0.07 Not an example of the invention.

Example 2 700 mls of a macroporous weak base anion exchange resin (available as DOWEX T 66, from The Dow Chemical Company) which had been screened to the following bead size distribution: 35,915-F

_J

I_ .L i- i I t -16- Bead Diameter Range (ln) Min.

250 297 325 350 400 420 450 475 500 540 595 707 Max.

297 325 350 400 420 450 475 500 540 595 707 2500 Volume Resin of Invention Example 2 0.0 0.0 0.0 2.7 3.7 12.5 13.3 14.6 24.0 24.1 5.1 0.0 AVERAGE DIAMETER VOLUME MEAN 510 Volume Range 88.5 percent ±15 percent of mean.

was loaded into a 2.54 cm I.D. glass column system consisting of two 61 cm long, water jacketed sections, coupled together. A third unjacketed 61 cm long section is attached on top of the two 61 cm columns to allow backwashing of the resin. The resin is used in the free base form.

The bed of resin is backwashed with D.I. water at room temperature at a flow rate sufficient to expand the bed by 50 percent of the settled height. This is done in order to remove any unwanted matter present in done in order to remove any unwanted matter present in 35,915-F -16r -17the bed and also to classify the beads by size. The backwashing is continued for about 30 minutes.

To insure complete conversion of the resin to the free base form, a minimum of 2 bed volumes of 1N sodium hydroxide is passed downflow through the resin for a period of about 60 minutes. After complete conversion, the resin is rinsed with a downward flow of r D.I. water until the effluent water exhibits a pH of at least 9.

After the backwashing is accomplished the top unjacketed 61 cm portion of the column is removed and the column is capped with a glass fritted flow I 15 distributor.

One liter of degassed D.I. water is pumped I downflow while the jacketed columns are being heated to a temperature of about 50 C by circulating hot water i 20 through the column jackets.

One liter of refined 42 percent HFCS exhibiting a D.S. of 50 percent is passed downflow through the bed Swith a contact time of 2.5 hours. The resin bed is sweetened-off by passing degassed D.I. water downflow at 2 bed volumes/hr. During the sweetening-off process, the flow out of the column is monitored and I samples of the effluent are collected at recorded intervals in a fraction collector. Each sample is Sanalyzed for refractive index using an Abbe Mark II refractometer and the D.S. content is determined by industry standards from the refractive indices. The results are reported in Table 2 under Example 2.

A plot of the D.S. concentrations versus the volume of water used to sweeten-off the sugar solution 35,915-F -17r -18from the resin bed may be made and the areas under the curves integrated by known means. The integration results give a measure of the total amount of dissolved solids in the collected samples. From this value can be calculated the amount of water which must be removed from the total volume of liquid collected in order to return the collected sample to the original D.S. level of the 42 percent HFCS. This value is then used for comparison purposes to illustrate how much water must be evaporated from the sweet-water when an ion exchange resin which does not exhibit a uniform size distribution is used.

The results are summarized in Table 3 under 15 15 Example 2.

Comparative Example 2 The method of Example 2 was essentially repeated except that the weak-base anion exchange resin S(available as DOWEX' TM 66 from The Dow Chemical Company) used to demineralize the HFCS had the following bead size distribution: e t, I te Ce 35,915-F -18-

L,

I. -19- Bead Diameter Range (Pm) Min. Max.

150 250 250 297 297 3514 3514 420 420 500 500 595 595 707 707 841 841 1000 1000 1190 1190 2000 2000 2500 AVERAGE DIAMETER VOLUME MEAN Volume Example C-2

DOWEX

T m 66 0.0 0 .4 5.9 10.5 16.9 24.3 22. 2 17.3 0.0 0.0 0.0 660 4 Volumpe Range 63.4 percent ±15 percent of mean.

The results are summarized in Tables 2 and 3 under Example C-2.

915-F'-9 TABLE II Anion Exchange Resin Example 2 Comparative Example C-2* Volume of Sweet-Water (ml) 230.3 260.0 279.8 299.6 3 19. 4~ 339.2 359.0 378.8 398.6 418.4 438.2 458.0 477.8 497.6 507.5 517.4 537.2 547.1 Grams D.S./100 ml 59.85 57.94 55.05 53. 10 50. 10 46 .77 43.28 39.74 36.20 33. 17 30.30 28.28 25.06 17. 15 13.69 11.10 7.25 5.99 Volume of Sweet-Water (ml 266.6 286.4 306.2 326,.0 345.8 ,365.6 385.4 405.2 425.0 444.8 464.6 484.4 504.2 524.0 543.8 563.3 583.4 603.2 Grams 0.S./laO ml 58.90 57.05 54.63 52.60 49.60 46.61 44.15 41 38.15 3~4-95 28.85 22.43 17.93 14.45 11.28 8.98 7.05 5.64 Not an example of the invention.

35,1915-F -0 I

I

-21- TABLE II (Cont.) Anion Exchange Resin Example 2 Volume of Sweet-Water Grams D.S./100 ml 557.0 4.72 576.8 3.10 596.6 1.84 606.5 1.14 626.3 0.95 636.2 0.51 656.0 0.16 675.8 0.10 696.6 0.16 774.8 0.00 Comparative Example C-2* Volume of Sweet-Water (ml 623.0 642.8 662.6 682.4 702.2 722.0 741.8 761.6 781.4 801.2 821.0 860.6 880.4 930.4 Grams D.S. /10O ml 4.47 3.33 2.34 1.91 1.42 1.09 0.80 0.70 0.50 0.50O 0.38 0.30 0.38 0.00 *Not an example of the invention.

35,9 15-F -21- I- rr~ -22- Table III Example Volume of Water (ml) Which Must be Removed to Return to Original D.S. Level 244 341 358 Percent Reduction C-1* 2 C-2* 485 Not an example of the present invention.

A comparison of the data indicates that when an ion exchange resin of claimed bead diameter size distribution is used, the amount of water which must be evaporated in order to return the sweet-water to a percent dissolved solids level is reduced by a measurable amount 28 percent) compared to the amount of water which must be evaporated from the sweet-water generated .com sweetening off the sugar solution from an ion exchange resin exhibiting a conventional 'size distribution. Therefore, the amount of water which needs to be evaporated within the sugar refining process is reduced.

35,915-F -22i I Sll_~-11 i -23- Example 3 Operating capacity data was obtained while demineralizing dextrose syrup in a full scale high fructose refining plant. In this plant the resins employed in Examples C-1 and C-2 were set up in sequence (175 cubic feet of each 4.96 cubic meters) and a parallel system employing the same volume of the same resins which had been screened to the following bead size distribution was set up: Bead Diameter Range (Jim) Min.

150 210 370 420 470 500 525 550 575 600 625 650 Max.

210 370 420 470 500 525 550 575 600 625 650 2500 Volume Cation Resin of Invention 0.0 1.6 3.7 10.2 12.7 17.0 18.5 18.6 11.8 5.9 0.0 0.0 AVERAGE DIAMETER VOLUME MEAN 523 pm Volume Range 88.8 percent ±15 percent of mean.

35,915-F -23- Bead Diameter Range (Pm) Min.

250 297 3514 380 400 420 460 480 500 525 595 Max.

297 354 380 400 42Q 460 480 500 525 550 595 2500 Volume Anion Resin of Invention 0.2 1 2.2 3.2 4.8 17.2 Th6.8 14.7 16.8 13.3 9.o2, 0.0 AVERAGE DIAMETER VOLUME MEAN 48$ pm Volume Range 92.8 percent ;L15 percent of mean, Operating capacities were measured as volumes of dextrose syrup demineralized per cycle with cycles alternating between conventional resins and resins of the invention. The resins wer~e regenerated back tio usablte f'orm each cycle. The results are shown in the following Table IV.

35,9154' i Table IV Average Cubic Meters Treated Per Cycle Test Period

A

Conventional Resin 466.1 449,9 430.9 415.2 Resin of Invention 517.8 504.8 488.6 470.0 %Increase in Operating Capacity 11 12 13 13 The resins employed in the present invention 1 show from 11 to 13 percent improvement in operating capacity over the conventional resins when operating as a two-bed unit process (cation resin followed by anion resin in a single pass).

35,915-F m

Claims

1. A process for demineralizing sugar- co'taining solution which comprises passing said solution through an ion exchange resin in bead form wherein the mean diameter of the beads is from 400 to 700 pm and which resin exhibits a bead diameter distribution such that at least 8C volume percent of the beads have diameters which fall within a range of ±15 percent of the mean diameter of the resin used.

2. The process of Claim 1 wherein the bead diameter distribution is such that at least 85 percent of the beads exhibit diameters which fall within a 1 range of ±15 percent of the mean diameter of the ion exchange resin.

3. The process of Claim 2 wherein the bead diameter distribution is such that at least 90 percent 1 of the beads exhibit diameters which fall within a range of ±15 percent of the mean diameter of the ion exchange resin.

4. The process of Claim 2 wherein the mean diameter of the ion exchange resins ranges from 500 pm to 600 pm, The process of any one of Claims 1 to 4 wherein the ion exchange resin is a macroporous 35,915-F -26- V f S -27- strongly acidic cation exchange resin, a macroporous weakly basic anion exchange resin, or a macroporous strongly basic anion exchange resin.

6. The process of Claim 5 wherein the ion exchange resin comprises a copolymer of styrene and divinylbenzene.

7. The process of Claim 6 wherein the sugar-containing solution is a solution comprising high fructose corn syrup. DATED: 23 March 1988 PHILLIPS ORMONDE FITZPATRICK Attorneys for: THE DOW CHEMICAL COMPANY i| 1 I i 35,915-F -27-