NZ250754A - Method for regenerating acid cation exchange resin using sodium hydroxide and sulphuric or hydrochloric acid - Google Patents
Method for regenerating acid cation exchange resin using sodium hydroxide and sulphuric or hydrochloric acidInfo
- Publication number
- NZ250754A NZ250754A NZ250754A NZ25075494A NZ250754A NZ 250754 A NZ250754 A NZ 250754A NZ 250754 A NZ250754 A NZ 250754A NZ 25075494 A NZ25075494 A NZ 25075494A NZ 250754 A NZ250754 A NZ 250754A
- Authority
- NZ
- New Zealand
- Prior art keywords
- resin
- exchange resin
- cation exchange
- strong acid
- acid cation
- Prior art date
Links
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 title claims description 90
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 title claims description 78
- 239000003729 cation exchange resin Substances 0.000 title claims description 60
- NWUYHJFMYQTDRP-UHFFFAOYSA-N 1,2-bis(ethenyl)benzene;1-ethenyl-2-ethylbenzene;styrene Chemical compound C=CC1=CC=CC=C1.CCC1=CC=CC=C1C=C.C=CC1=CC=CC=C1C=C NWUYHJFMYQTDRP-UHFFFAOYSA-N 0.000 title claims description 59
- 239000002253 acid Substances 0.000 title claims description 57
- 238000000034 method Methods 0.000 title claims description 44
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 title claims description 28
- 230000001172 regenerating effect Effects 0.000 title claims description 17
- 239000001117 sulphuric acid Substances 0.000 title 1
- 235000011149 sulphuric acid Nutrition 0.000 title 1
- 239000011347 resin Substances 0.000 claims description 76
- 229920005989 resin Polymers 0.000 claims description 76
- 239000003957 anion exchange resin Substances 0.000 claims description 21
- 238000011069 regeneration method Methods 0.000 claims description 14
- 230000008929 regeneration Effects 0.000 claims description 13
- 239000011734 sodium Substances 0.000 claims description 6
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims 1
- 239000003795 chemical substances by application Substances 0.000 claims 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 claims 1
- 229910052708 sodium Inorganic materials 0.000 claims 1
- 239000000243 solution Substances 0.000 description 29
- 229910052791 calcium Inorganic materials 0.000 description 20
- 239000011575 calcium Substances 0.000 description 20
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical group [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 19
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 18
- 238000006243 chemical reaction Methods 0.000 description 13
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 description 12
- 150000002500 ions Chemical class 0.000 description 12
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 8
- 238000000151 deposition Methods 0.000 description 6
- 239000012492 regenerant Substances 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 5
- 238000011033 desalting Methods 0.000 description 5
- 239000002244 precipitate Substances 0.000 description 5
- 230000008021 deposition Effects 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 150000003839 salts Chemical class 0.000 description 4
- 239000011780 sodium chloride Substances 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- 239000003112 inhibitor Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 230000035484 reaction time Effects 0.000 description 3
- -1 Ca2+ and Mg2+ Chemical class 0.000 description 2
- 239000005862 Whey Substances 0.000 description 2
- 102000007544 Whey Proteins Human genes 0.000 description 2
- 108010046377 Whey Proteins Proteins 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- RSWGJHLUYNHPMX-UHFFFAOYSA-N Abietic-Saeure Natural products C12CCC(C(C)C)=CC2=CCC2C1(C)CCCC2(C)C(O)=O RSWGJHLUYNHPMX-UHFFFAOYSA-N 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- ABLZXFCXXLZCGV-UHFFFAOYSA-N Phosphorous acid Chemical class OP(O)=O ABLZXFCXXLZCGV-UHFFFAOYSA-N 0.000 description 1
- KHPCPRHQVVSZAH-HUOMCSJISA-N Rosin Natural products O(C/C=C/c1ccccc1)[C@H]1[C@H](O)[C@@H](O)[C@@H](O)[C@@H](CO)O1 KHPCPRHQVVSZAH-HUOMCSJISA-N 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 238000005349 anion exchange Methods 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 238000011001 backwashing Methods 0.000 description 1
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- 238000005341 cation exchange Methods 0.000 description 1
- 229940023913 cation exchange resins Drugs 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000000994 depressogenic effect Effects 0.000 description 1
- 235000013305 food Nutrition 0.000 description 1
- 238000005342 ion exchange Methods 0.000 description 1
- 239000008267 milk Substances 0.000 description 1
- 210000004080 milk Anatomy 0.000 description 1
- 235000013336 milk Nutrition 0.000 description 1
- 235000021317 phosphate Nutrition 0.000 description 1
- 150000003013 phosphoric acid derivatives Chemical class 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 235000002020 sage Nutrition 0.000 description 1
- 238000007790 scraping Methods 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- KHPCPRHQVVSZAH-UHFFFAOYSA-N trans-cinnamyl beta-D-glucopyranoside Natural products OC1C(O)C(O)C(CO)OC1OCC=CC1=CC=CC=C1 KHPCPRHQVVSZAH-UHFFFAOYSA-N 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Landscapes
- Treatment Of Water By Ion Exchange (AREA)
Description
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Priority Datc(u): . .3*..\<7lv>.
Complete C- T '
Cb?s: .
Publication Date: ...!???
P.O. Journal, No: ..J3SP.
NEW ZEALAND PATENTS ACT. 1953
No.:
Dale:
COMPLETE SPECIFICATION
PATENT OFFICE
? 6 JAN «
■ C.EiVE;-
METHOD FOR REGENERATING STRONG ACID CATION EXCHANGE RESIN
A~!We, SNOW BRAND MILK PRODUCTS CO., LTD., a Japanese company, of 6-1-1, Naebocho, Higashi-ku, Sapporo-shi, Hakkaido, Japan hereby declare the invention for which«*t" / we pray that a patent may be granted to jane/us, and the method by which it is to be performed, to be particularly described in and by the following statement: -
(followed by page la)
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METHOD FOR REGENERATING STRONG ACID CATION EXCHANGE RESIN The present invention relates to a method for efficiently regenerating strong acid cation exchange resin. 5 More particularly, it relates to a method for regenerating strong acid cation exchange resin without depositing calcium sulfate and the like.
As a regenerant of strong acid cation exchange resin, hydrochloric acid or sulfuric acid is used, and particu-10 larly cheap sulfuric acid is industrially used in general. However, in the case of regeneration of the resin which has treated by desalting an aqueous solution containing a great quantity of Ca2+ or Mg2+ there is a problem that, if the resin is regenerated with sulfuric 15 acid, eluted Ca2+ or Mg2+ is reacted with S042- to produce and deposit a slightly soluble sulfate (CaSO^ or MgSO^) on the resin layer, and finally it becomes impossible to pass sulfuric acid through the resin. To resolve the problem, there is a method that sulfuric acid 20 is kept at low concentration at the beginning of the regeneration, and then the concentration is increased stepwise. In the method, a solution of sulfuric acid having concentration of 1-2% is made to flow through the resin at high flow rate to partially remove Ca2+ or Mg2+, 25 the concentration of sulfuric acid is increased in proportion to the removed amount and finally the regeneration is conducted in concentration from 4 to 5%, so that
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the regeneration efficiency becomes low because a large quantity of sulfuric acid is required.
For the above reasons, the disadvantage is that the cost of the regenerant is not so much lowered even if 5 cheap sulfuric acid is used. Further, it is not negligible that, since Ca2+ and the like are not so much removed with sulfuric acid, a large quantity of Ca2+ is accumulated on the strong acidic cation exchange resin by the partially repeated regeneration and the desired ion 10 exchange reaction is inhibited. For the reasons, hitherto, various methods for regenerating cation exchange resin has been studied, for example, the resin is efficiently regenerated by passing hydrochloric acid through the resin to partially remove Ca2+ or Mg2+ and treating 15 with a 4% solution of sulfuric acid (referred to Japanese Unexamined Patent Publication number 52-74587). However, equipment having resistance to corrosion from hydrochloric acid is required and care must be taken in handling a mixture of two kinds of acids.
Moreover, a method for regenerating resin is known,
in which a NaCl solution is passed through resin to exchange Ca2+ or Mg2+ for Na+ and then the resin is treated with a 5-6% solution of sulfuric acid. In addition, in Japanese Patent Publication number 58-35741, it 25 is described that cation exchange resin of a countercur-rent mode is regenerated by adding an inhibitor of deposition of calcium sulfate such as polymeric phosphates,
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phosphonates, low molecular polymers and the like to an intermediate part of the resin layer to control the deposition of calcium sulfate. However, in these methods, since the inhibitor of deposition of calcium sul-5 fate, IlaCl and sulfuric acid are used as regenerants, the cost of these regenerants is increased. Further, effluent of NaCl, the inhibitor and the like is produced so that the cost for treating the effluent is increased.
To resolve the above-mentioned problems of conven-10 tional methods for regenerating cation exchange resin,
the present invention aims to provide a method for regenerating strong acid cation exchange resin by using hydrochloric acid or sulfuric acid, wherein the resin is regenerated by using a sodium hydroxide solution or the 15 effluent containing sodium hydroxide which is obtained after anion exchange resin has been regenerated with a sodium hydroxide solution, and the regeneration efficiency is enhanced without increasing of the cost of regenerants and the cost for treatment of effluent. 2 0 The present invention resides in a method for regen erating strong acid cation exchange resin characterized in that it comprises reacting the resin with a sodium hydroxide solution, and treating the resin with sulfuric acid or hydrochloric acid to regenerate the resin. As 25 the sodium hydroxide solution, it is possible to use the effluent obtained after anion exchange resin has been regenerated with a sodium hydroxide solution.
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Fig. 1 is a graph showing tho relation of exchange capacity, number of cycles and amount of adsorbed calcium for the regeneration of strong acid cation exchange resin in example 2. A indicates exchange capacity of resin by 5 a column method using effluent and sulfuric acid, and ▲ indicates adsorbed amount of calcium, o indicates exchange capacity of resin by a conventional method using sulfuric acid, and • indicates adsorbed amount of calcium.
In the method for regenerating strong acid cation exchange resin, generally, the resin adsorbing univalent ions such as Na+ and K+ is easily regenerated more than the resin adsorbing bivalent ions such as Ca2+ and Mg2+, and the tendency is more enhanced in strong acid cation 15 exchange resin in comparison with other acid cation exchange resins. Accordingly, exhausted strong acid cation exchange resin to which Ca2+ or Mg2+ is adsorbed is substituted by a Na form, then the resin is regenerated with hydrochloric acid or sulfuric acid, and the 20 regeneration efficiency is remarkably enhanced. Particularly, when the resin is regenerated with sulfuric acid, it is possible to pass sulfuric acid of high concentration through the resin from the beginning because the deposition of calcium sulfate and the like is depressed. 25 A Had solution is generally used for changing the resin into a Na form, but in the present invention, a sodium hydroxide solution is used. Especially, noticing the
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effluent containing a large quantity of Ha+ which is discharged when anion exchange resin is regenerated with a sodium hydroxide solution, it is most preferred to use the effluent from the cost. The sodium hydroxide solu-5 tion is reacted with the strong acid cation exchange resin to change an exchange group of a polyvalent form into a Na form, firstly. In such a replacement reaction, the concentration and amount of Na+, the reaction temperature and the reaction time significantly influence the 10 reaction efficiency.
When the Na+ concentration in the sodium hydroxide solution is high, the substitution becomes effective. For the reason, when the effluent obtained by regeneration of anion exchange resin is used, a sodium hydroxide 15 solution having high concentration as possibly as one can is ideally used for regenerating anion exchange resin. However, when the concentration of sodium hydroxide is too high, the anion exchange resin deteriorates to shorten the resin life, so that it is desired to generally use 20 NaOH/T.-R of 60-300 g at 3-9% by weight.
As a method for reacting strong acid cation exchange resin with a sodium hydroxide solution or such effluent obtained by regeneration of anion exchange resin, there is a column method or a batch method in which the 25 solution is mixed in a column for a certain hours. In the former method, the operation is simple and effective to react a large quantity of the sodium hydroxide solu-
250754
tion with the cation exchange resin at a short time.
However, since OH" and the like are found in quantities in the effluent, and calcium hydroxide is apt to deposit during the reaction of the effluent with the strong acid 5 cation exchange resin, there is a problem that it becomes difficult to pass the liquor through the resin. Further,
in the batch method, since a large quantity of the sodium hydroxide solution is reacted with the resin at a time, a large column is required, while, even if precipitates are 10 produced, it is possible to easily remove them by upflow washing. Moreover, when scales of slightly soluble salts are formed on the surface of the strong acid cation exchange resin, the scales can be removed by scraping with stirring, so that polyvalent ions easily forming the 15 scales are efficiently removed. Accordingly, in either case, it is necessary to judge by the amount of the sodium hydroxide solution, the ion composition or the like. For example, in the anion exchange resin by which food, particularly whey has been desalted, the effluent 9 9
contains S04 , CC>2 and Oil", so that these anions easily react with a large quantity of Ca2+ desorbed on the strong acid cation exchange resin. For this reason,
it is effective to use the batch method. The reaction time of the column method differs from that of the batch 25 method. As a standard, the former is SV=1-5 L/(L-R x hr)
and the latter is about 20-60 minutes at a reaction temperature of 60°C. (SV is the abbreviation for solution volume which is a volume of liquid passed through one liter of resin in one hour).
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In the strong acid cation exchange resin, generally, since the selectivity coefficient of Ca2 + or Mg2 + is two to three tines as high as that of Na+, a solution containing a large quantity of tla+ having high concentration 5 is required for the entire replacement of a Ca or Mg form by a Na form. One of the factors for minimizing the difference of the selectivity coefficient is reaction temperatures. The more the reaction temperature is elevated, the more the replacement efficiency is in-10 creased. Considering the reactivity and the resistance properties of the apparatus, the reaction temperature is 40-100°C, preferably 50-80°C. Since the reaction temperatures are closely related to the reaction times, when the one side of conditions are difficult to control, it 15 is possible to obtain the most suitable reaction conditions by control of the other side of conditions.
As described above, after most of active groups of the strong acid cation exchange resin are replaced by a Na form, pure water is passed through the resin, and then 20 a solution of hydrochloric acid or sulfuric acid is passed at SV=3-7 L/(L-R x hr) through the column to regenerate the resin. The concentration of the solution of sulfuric acid is preferably 5-12% by weight, while the concentration of the solution of hydrochloric acid is 25 preferably 2-9% by weight. It is able to decrease the amount of the regenerant 30% in comparison with common methods.
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To clarify the norits of the present invention, the following illustrates the present invention by examples and comparative examples (conventional examples) in detail.
Example 1
In this example, anion exchange resin was regenerated with sodium hydroxide, the effluent was reacted with strong acid cation exchange resin by a batch method, and 10 the strong acid cation exchange resin was regenerated with sulfuric acid.
Strong acid cation exchange resin (Duolight C-20, a registered trademark of Rome and liars Co. Ltd., U.S.A.) was repeatedly used for desalting until the content of 15 calcium adsorbed on the resin becomes 24g/L-R. One liter of the resin, and one liter of strong base anion exchange resin (Amberlight IRA-410, a registered trademark of Rome and Hars Co. Ltd., in U.S.A.), which was used for desalting of whey, were charged into columns having an inner 20 diameter of 6 cm, respectively. 1.4 liters of six per-cents of a NaOH solution were passed through the anion exchange resin at SV=5.0 L/(L-R x hr) and the resin was washed with three liters of pure water. Then, the effluent was collected from the beginning of the liquid pas-25 sage to 10-33 minutes and mixed. 1.4 liters of the effluent were warmed to 80°C and poured into the column having one liter of the strong acid cation exchange resin
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CD n to react for 4 5 minutes with stirring every 15 minutes. Then, pure water was passed into the column from the bottom at a flow rate that the resin layer was lifted to expand the linear volume by about 50%, and suspended 5 materials in the resin layer were thoroughly removed. 1.7 liters of 6% sulfuric acid was continued to pass through the column at SV=4.0 L/(L-R x hr) and the resin was washed with three liters of pure water. Such exchange capacity of cation exchange resin was 1.00 eq/L-R 10 and adsorbed amount of calcium was 12.5 g/L-R. After the reprocessed effluent was poured into the column of the cation exchange resin as described above, the column was warmed to maintain the reaction temperature at 60°C. Exchange capacity of the cation exchange resin was 1.09 15 eq/L-R and adsorbed amount of calcium was 10.8 g/L-R. Example 2
In this example, anion exchange resin was regenerated with sodium hydroxide, the effluent was reacted with strong acid cation exchange resin by a column method, and 2 0 the strong acid cation exchange resin was regenerated with sulfuric acid.
(1) Anion exchange resin was regenerated by the same conditions as described in example 1 to obtain effluent. A total amount of 1.76 liters of the effluent was heated 25 at 60°C and passed through strong acid cation exchange resin at SV=6.0 L/(L-R x hr). The resin was washed with 3.0 liters of pure water, 1.7 liters of 6% sulfuric acid
9
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were passed at SV = 4.0 L/(t,-r x hr) , and the resin was washed with 3.0 liters of pure water. Hxchange capacity of the resin and adsorbed amount of calcium were determined. The former was 0.9 7 eq/L-R and the latter was 5 13.0 g/L-R. However, precipitates were produced in the layer of the strong acid cation exchange resin at the passage of the effluent. The precipitates remained after the regenerating treatment with sulfuric acid and they could be removed by only back washing. From the result, 10 it shows that the column method is not effective to the reaction of the cation exchange resin with the effluent when the precipitates were produced.
However, when no precipitates were produced, the column method was effective as shown in the following. 15 (2) One liter of strong acid cation exchange resin
(Diaion SK-1B, a registered trademark of Mitsubishi Kasei Co. Ltd.) and one liter of middle base anion exchange resin (Amberlight IRA-60E, a registered trademark of Rome and Hars Co. Ltd. in U.S.A.) were thoroughly regenerated 20 with 6% hydrochloric acid, and 6% sodium hydroxide solution, respectively, and each resin was charged into columns having an inner diameter of 4 cm. Each water having an ion concentration of 230 mg/L of Na+, 32 mg/L of Ca2+, 5.2 mg/L of Mg2+ and 400 mg/L of Cl~ was passed 25 through strong acid cation exchange resin and then anion exchange resin to desalt from the water. After the desalting, one liter of a 6% NaOH solution was passed
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d through the anion exchange rosin at SV=4.0 L/(L-R x hr) and the resin was washed with three liters of pure water. Then, effluent which passed through the anion exchange resin column from the beginning of the liquid passage to 5 25 minutes was warmed at 70°C and passed through the strong acid cation exchange resin from the bottom of the anion exchange resin column. After the effluent, which remained in the strong acid exchange resin column, was removed with one liter of pure water, 1.7 liters of 6% 10 sulfuric acid was passed through the column at SV=5.0
L/(t,-r x hr), and the resin was washed with three liters of pure water. Then, exchange capacity of the resin and adsorbed amount of calcium were determined. The former was 1.2 eq/L-R and the latter was 5.1 g/L-R. Further, 15 the desalting and regeneration of the resin were repeated by the same method, and there is no change in exchange capacity of the resin and adsorbed amount of calcium. On the other hand, after the effluent was reacted with strong acid cation exchange resin by a batch method and 20 the resin was treated with sulfuric acid, exchange capacity of the resin was 1.12 eq/L-R and adsorbed amount of calcium was 6.4 g/L-R. Further, when the resin was regenerated with only sulfuric acid, exchange capacity of the resin was 0.98 eq/L-R and adsorbed amount of calcium 2 5 was 7.8 g/L-R. It shows that the exchange capacity of the resin was slowly decreased by repeated application and the adsorbed amount of calcium was increased (as
11
shown in Fig. 1).
Example 3
In this example, anion exchange resin was regenerated with sodium hydroxide, the effluent was reacted with 5 strong acid cation exchange resin by a batch method, and the strong acid cation exchange resin was regenerated with hydrochloric acid.
(1) Anion exchange resin was regenerated by the same conditions as described in example 1 to obtain effluent. 10 1.4 liters of the effluent was warmed to 80 °C and passed through a column in which one liter of strong acid cation exchange resin was charged, to react for 4 5 minutes with air stirring every 15 minutes. Then, pure water was passed into the column from the bottom at a flow rate 15 that the resin layer was lifted to expand the linear volume by about 50%, and suspended materials in the resin layer were thoroughly removed. 1.8 liters of 4% hydrochloric acid was continued to pass through the column at SV=5.0 L/(T,-R x hr) and the resin was washed with three 20 liters of pure water. Such exchange capacity of strong acid cation exchange resin was 1.28 eq/L-R and adsorbed amount of calcium was 10.5 g/L-R.
On the other hand, when the strong acid cation exchange resin was regenerated with 4% hydrochloric acid by 25 using the same method as described above except that effluent was not used, exchange capacity was 1.10 eq/L-R and adsorbed amount of calcium was 13.4 g/L-R.
1 2
The result shows that, when the strong acid cation exchange resin adsorbing slightly exchangeable ions (having increased selectivity) is regenerated, even if a regenerant which does not form slightly soluble salts is 5 used, by using effluent of anion exchange resin, regeneration efficiency of the resin is increased about 16%. Example 4
In this example, the strong acid cation exchange resin was reacted with sodium hydroxide by a batch method 10 and the resin was treated with sulfuric acid.
One liter of the same strong acid cation exchange resin as described in example 1 was charged into a column under the same conditions. 1.4 liters of 6% sodium hydroxide solution were warmed to 8 0 °C and poured into 15 the column to react for 45 minutes with air stirring every 15 minutes. Then, pure water was passed into the column from the bottom at a flow rate that the resin layer was lifted to expand the linear volume by about 50%, and suspended materials in the resin layer were 20 thoroughly removed. 1.7 liters of 6% sulfuric acid was continued to pass through the column at SV=4.0 L/(I»-R x hr) and the resin was washed with three liters of pure water. Such exchange capacity of strong acid cation exchange resin was 1.10 eq/L-R and adsorbed amount of 25 calcium was 11.3 g/L-R.
Comparative example 1
In this comparative example, concentration of sulfur-
1 3
ic acid is increased stepwise.
One liter of the same strong acid cation exchange resin as described in example 1 was charged into a column having an inner diameter of 6 cm under the same condi-5 tions. Two liters of one % sulfuric acid was passed through the resin at SV=10 x hr), 1.5 liters of two % sulfuric acid was passed through the resin at 5V=1 0 L/(L-R x hr) and 1.2 liters of four % of sulfuric acid was passed through the resin at SV=5L/(Tj-R x hr) to 10 regenerate the resin. Then, the resin was washed with three liters of pure water, and exchange capacity of the resin was 0.73 eq/T,-R and adsorbed amount of calcium was 1 7.2 g/t.-R.
Comparative example 2 15 In this comparative example, a NaCl solution was used to exchange Ca2+ and Mg2+, and a sulfuric acid was used to regenerate resin.
One liter of the same strong acid cation exchange resin as described in example 1 was charged into a column 20 under the same conditions. After 1.5 liters of a solution of four % NaCl was passed through the resin, the resin was washed with two liters of pure water and two liters of five % sulfuric acid was passed through the resin at SV=7 L/(L-R x hr) to regenerate the resin. 25 Then, the resin was washed with three liters of pure water and exchange capacity of the resin and adsorbed amount of calcium were determined. Exchange capacity of
1 4
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the resin was 1.0 5 eq/T.-R and adsorbed amount of calcium was 10.3 u/T.-R. Further, five sulfuric acid was passed through the resin at SV=5 t,/(t.-P. x hr) under the same conditions, calcium sulfate v/as deposited and it becomes 5 impossible to pass the liquid in the course of regenerating .
According to the regeneration method of strong acid cation exchange resin of the present invention, polyvalent ions can be more efficiently removed than that 10 conventional methods are used, and the lowering of ion exchange capacity based on adsorption and accumulation of the polyvalent ions can be significantly controlled. Moreover, even if sulfuric acid of high concentration is used, the strong acid cation exchange resin can be effi-15 ciently regenerated without depositing slightly soluble salts such as calcium sulfate, and the amount of regenerant and the amount of effluent can be decreased.
The method of the present invention is particularly effective to regenerate the strong acid cation exchange 20 resin having adsorbed ions, otherwise the ions will be adsorbed to form slightly soluble salts with the regenerant. Further, the strong acid cation exchange resin having adsorbed slightly exchangeable ions can be regenerated by the method of the present invention.
1 5
WHAT/tfWE CLAIM IS
Claims (6)
1. A method for regenerating strong acid cation exchange resin characterized in that it comprises reacting the strong acid cation exchange resin with a sodium 5 hydroxide solution, and regenerating the resin with sulfuric acid or hydrochloric acid.
2. A method as claimed in claim 1, wherein effluent is used as the sodium hydroxide solution, the effluent being obtained by regeneration of anion exchange resin 10 with a sodium hydroxide solution.
3. A method as claimed in claim 1 or 2, wherein the strong acid cation exchange resin is reacted with the sodium hydroxide solution at temperatures of 40° to 100°C. 15
4. A method as claimed in claim 1, 2, or 3, wherein the strong acid cation exchange resin is reacted with the sodium hydroxide solution by a column method or a batch method.
5. A method for regenerating strong acid cation exchange resin 2o as claimed in claim 1 when performed substantially as herein described with reference to any example thereof.
6. A regenerated strong acid cation exchange resin when produced by the method as claimed in any one of claims 1 to 5. DATED THIS SSVti Cfcj of (vbcemte A. J. PARK & SON 25 AGENTS FOR THE APPLICANTS 1 6
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24221793A JP3216027B2 (en) | 1993-09-03 | 1993-09-03 | Method for regenerating strongly acidic cation exchange resin |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| NZ250754A true NZ250754A (en) | 1995-03-28 |
Family
ID=17085988
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| NZ250754A NZ250754A (en) | 1993-09-03 | 1994-01-26 | Method for regenerating acid cation exchange resin using sodium hydroxide and sulphuric or hydrochloric acid |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JP3216027B2 (en) |
| AU (1) | AU655132B1 (en) |
| NZ (1) | NZ250754A (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR102439190B1 (en) * | 2020-07-23 | 2022-09-02 | 한국전력공사 | Apparatus and method for recovering acids from mixed waste acid |
| CN113024696B (en) * | 2021-03-10 | 2022-12-02 | 上海核工程研究设计院有限公司 | Method for preparing strong-acid sodium type resin |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5753245A (en) * | 1980-09-18 | 1982-03-30 | Shigeru Chiaki | Method and apparatus for automatically regenerating ion exchange resin for preparing pure water |
| JP3348109B2 (en) * | 1992-01-02 | 2002-11-20 | コノコ・インコーポレーテッド | Monitor and control system for selective regeneration of alkanolamines from cation exchange resins with sodium hydroxide |
-
1993
- 1993-09-03 JP JP24221793A patent/JP3216027B2/en not_active Expired - Fee Related
-
1994
- 1994-01-26 NZ NZ250754A patent/NZ250754A/en unknown
- 1994-01-28 AU AU54763/94A patent/AU655132B1/en not_active Ceased
Also Published As
| Publication number | Publication date |
|---|---|
| JP3216027B2 (en) | 2001-10-09 |
| JPH0768187A (en) | 1995-03-14 |
| AU655132B1 (en) | 1994-12-01 |
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