Shell core ion exchange resins - Purolite

Table 7: Samoan two-bed deionization study31% greater through-put from shell-core SAC41% yearly savings in acid and waterLonger runs on the following standard SBA resin saving $35,000on NaOHSodium leakage slightly lower.4. Another commercial case study replaced a standard SAC resin in a parallel twobeddeionization train at Elekeiroz, a Brazilian chemical intermediates producer.Table 8: Brazilian chemical company73% saving of H 2 SO 4 (shell-core SAC)29% saving of NaOH (Std. SBA)5. Two-bed lactic acid deionization was studied in which the shell-core SAC resinbed (counter-flow acid regeneration) gave 45% longer throughput at lower regenerationlevels and half the rinse water consumption in commercial use.In fact, the shell-core SAC resin throughput capacity was affected little by the HClregeneration level used.Table 9: Lactic acid two-bed deionization study (capacity used, meq mL -1 )Regeneration Level, lbft -3 Std. Macro Resin Std. Gel Resin Shell-CoreResin8.8 (141 g/l)7.4 (118.5 g/l)5.6 (90 g/l)4.4 (70 g/l)0.640.610.580.520.760.690.660.470.780.800.760.762.3 Mixed-Bed DeionizationA mixed-bed study with a shell-core SAC resin component produced high qualitywater more abundantly in a Philadelphia lab study. No advantage in lower quality waterproduction was seen.9

0.067Water Quality(cond., μS cm -1 )Table 10: High quality water productionStd. Mixed-BedCapacity,(meq mL -1 )5010.20.10.150.660.580.540.38Mixed-Bed with S/CSAC Capacity,(meq mL -1 )0.330.590.450.440.402.4 Sugar ChromatographyA lab study was made of the commercial process of separating glucose and fructoseto produce High Fructose Corn Syrup using SAC resin in the calcium form. Acceptedindustry test methods were used. The first test was hot water rinse-out rate of resinsaturated with 50% dextrose. The second was actual column chromatographic separationefficiency of glucose and fructose in a mixed stream.In the former (Table 11) the time required to reach a specific low glucose level isless as the S/R ratio of the resin decreased indicating faster diffusion kinetics.In the latter (Table 12) the separation efficiency of the shell/core resin isuninfluenced by the uniformity of the resin’s bead size (higher UC = less uniform bead sizedistribution) and whether the beads are stratified by size or remain randomly mixed. Beadstratification is known to harm chromatographic performance but not in the case of shellcoreresins.Table 11: Glucose rinse-out rate (minutes to glucose level)Shell/Radius Ratio 10% 5% 3% 1%1.0 std.0.720.391258576136968414610595174150145Shell/RadiusRatio1.0 std.1.00.750.75Table 12: Glucose-Fructose separationMean Size Uniformity Separation Indexmicrons Coefficient mixed bed4571.1544571.5604331.1604331.560Separation Indexstratified bed5552606010

2.5 Weak Acid Resin (WAC) ExampleWAC resin in shell-core form was used in simulated hot brine softening withstandard co-flow regeneration.The regeneration level was able to be reduced substantially while maintaining ahigher operating capacity than standard WAC resin.Table 13: Hot brine softening (recycling) in lab simulated oil recovery(co-flow HCl regeneration)Regen. Level Capacity (kg ft -3 ) to 0.2 ppm hardness Heel, ppm, hardnesslb HCl ft -3 Std. Resin Shell-Core Resin Std. Shell-Core9 (144 g L -1 )6.8 (109 g L -1 )24 350 310.7 02.1 1.42.6 Strong-Base Anion Resin (SBA) ExampleAn aggressive synthetic water made by extracting humic soil containing high levelsof SiO 2 , colloidal SiO 2 , and fulvic acid foulant. This was deionized with parallel two-bedlab systems. One system contained shell-core SBA resin (patent pending) in the lagposition; the other a standard SBA resin.The shell-core SBA resin train produced consistently lower silica and fulvic acid leakagethan the parallel system of all standard resins. The fulvic acid foulant was regenerated moreeffectively with caustic regeneration using3 lb NaOH ft -3 (48 g L -1 ) regeneration levels.Table 14: Aggressive water deionizationResinStd. SBAShell-Core SBACapacity,(meqmL -1 )0.300.28Fulvic Acid Leakage(%)112SiO 2 Leakage(%)43Average Cycles: 2 – 5; Water Composition: SiO 2 =20.5 ppm, Colloidal SiO 2 = 2.3 ppmTOC as Fulvic Acid = 14.3 ppm2.7 Other CharacteristicsThere are a number of accepted accelerated lab tests that predict the stability of ionexchange resin beads. All were used to test the long term stability of shell-core (SAC)resin with an appropriate standard resin control. The results show consistently moreresistance by the shell-core resins, particularly as the S/R ratio decreases.No instance of significant instability of shell-core resins beads has been reported inseventeen years of commercial use.1. Shell-core resin decreases in reversible swelling 1 (acid to base cycling) asshell/radius ratio decreases.11

Table 15: Reversible swellingShell/Radius Ratio %Swelling1.0 std.70.6460.4612. Shell-core resin resists accelerated oxidation 1 using 6% H 2 O 2 and 1000 ppm Fe +3 ,as a catalyst. The loss in resin solids and dry weight are equated with ion exchange resindecrosslinking that occurs naturally in commercial use (Table 16).Table 16: Accelerated oxidationShell/RadiusRatio% Resin SolidsLost% Resin DryWeight Loss1.0 std.0.725.92.9713. Acid-base cycling stability 1 increases with lower S/R ratio Table 17.Table 17: Accelerated acid/base stabilityShell/Radius Ratio % Loss of Perfect Beads1.0 std.0 to 50.730 to 10.4004. Crush resistance 1 increases with lower S/R ratio (Table 18).Table 18: Crush resistanceShell/Radius Ratio Average Breakpoint,g/bead0.972930.792900.733220.603785. The size uniformity of copolymer beads increases (lower UC) with initial shellsulfonation to a point where the S/R ratio is about 0.5, after which the uniformity decreasesagain when proceeding onward towards full functionalization (S/R ratio = 1).12

Table 19: Bead size uniformityShell/Radius Ratio Uniformity Coefficient0.00 copolymer1.370.481.160.501.150.641.281.00 std. resin1.533. RESULTSThe theses proposed in the Introduction are substantiated individually with specificexamples, all commercially related. Generally, ion exchange resin made with deeplyfunctionalized shells and impervious cores is shown to operate more efficiently, particularlyin regeneration efficiency and subsequent effluent quality. This concept is broadened toinclude SAC, WAC, and SBA ion exchange resins and suggests it can be broadened furtherto all absorbents. Further, the resin beads have superior stability in normal ion exchangeresin cycling.AcknowledgementI must recognize all the organizations that are using these SST resins and tookthe effort to document the results herein.REFERENCES1. Fries William, Superior performance of ion-exchange resins with short, optimaldiffusion paths – SDP resins, Reactive Polymers, 19, 97-104 (1993).2. Fries William, Ion exchange resins, European Patent EP0361685, 01/19/19943. Downey Don, SST-60 Shallow Shell Strong Acid Cation Resins, Purolite.com.4. Heller Terence, Iron Removal with SST Ion Exchange Resins, Purolite.com.5. Boodoo Francis, Enhancing RO Permeate Recoveries with Cyclic Ion Exchange, IWCSan Antonio, TX, IWC 10-56.6. Downey Don, Use of Seawater to Regenerate PUROLITE R SST-80 Shallow ShellSAC Resin, IWC 11-06.7. Downey Don, Producing High-Purity Water with Shallow-Shell Resins, UltrapureWater, 18(6), 20, 22-24,26 (July/August 2001).8. Anon, Demineralization Cost Reduction News, Reported independently byDemineralization Cost Reduction News, Div. Indumark, New York, NY, February2009.9. Case History, SST-60 Shallow Shell Strong Acid Cation Resin.13