PROCESSES FOR REGENERATION OF ORGANOCATIONS

Abstract

The present disclosure concerns processes for regenerating organocations from perchlorate-rich waste products, more specifically transformation of water-insoluble organocation-perchlorate salt, originating from perchlorate-removal water treatment processes, into a water-soluble perchlorate salt for reusing same.

Claims

1. A process for recovering a water-soluble organocation salt from a substantially water-insoluble organocation-perchlorate, the process comprising: (a) contacting said substantially water-insoluble organocation-perchlorate with a first solution containing a first salt dissolved in an organic solvent, the first salt consisting of a metal cation and a balancing anion, under conditions permitting precipitation of metal-perchlorate salt and formation of a second salt dissolved in said organic solvent, the second salt consisting of the organocation and the balancing anion; (b) separating the metal-perchlorate salt from the organic solvent in which the second salt is dissolved; and (c) separating the organic solvent from the second salt to obtain said second salt, said second salt being a water-soluble organocation salt.

2. The process of claim 1, wherein the separating in step (c) is carried out by evaporation of the organic solvent.

3. (canceled)

4. The process of claim 2, wherein step (c) further includes condensing vapors of the organic solvent formed during evaporation or distillation to obtain a condensate of organic solvent.

5. (canceled)

6. The process of claim 1, wherein said separating in step (b) is carried out by sedimentation, decantation, filtration, flotation or a combination thereof.

7. The process of claim 1, wherein metal-perchlorate salt separated in step (b) is further treated to remove the organic solvent from the metal-perchlorate salt.

8. The process of claim 7, wherein the organic solvent is removed from the metal-perchlorate salt by evaporating.

9. The process of claim 8, wherein the organic solvent removed from the metal-perchlorate salt is reintroduced into the process in step (a).

10. The process of claim 1, wherein said substantially water-insoluble organocation-perchlorate salt is introduced into step (a) in the form of an aqueous slurry.

11. The process of claim 1, wherein the molar ratio between the water-insoluble organocation salt and the first salt is in a range between 1:1 and 1:10.

12. The process of claim 1, wherein said organocation has is an organocation of formula (I): ##STR00004## wherein R is a (C.sub.3-C.sub.18)alkyl; R.sub.1 and R.sub.2 are each independently selected from H and (C.sub.1-C.sub.6)alkyl; and R.sub.3 is one or more substituents, each independently selected from H, (C.sub.1-C.sub.6)alkyl, (C.sub.1-C.sub.6)alkoxy, NHCO(C.sub.1-C.sub.6)alkyl, OH, and NH.sub.2.

13. The process of claim 12, wherein R.sub.1 and R.sub.2 are each independently selected from H and methyl.

14. The process of claim 12, wherein R.sub.3 is one or more substituent, each independently selected from H, methyl, ethyl and propyl.

15. The process of claim 12, wherein R.sub.1 and R.sub.2 are both H, and R.sub.3 is a methyl.

16. (canceled)

17. The process of claim 12, wherein R is a (C.sub.6-C.sub.18)alkyl.

18. (canceled)

19. The process of claim 12, wherein organocation is benzalkonium in which R is a (C.sub.3-C.sub.18)alkyl.

20. (canceled)

21. The process of claim 1, wherein said metal is selected from sodium, potassium, calcium and magnesium.

22. (canceled)

23. The process of claim 1, wherein the balancing anion is selected from hydroxyl, carboxyl, halogen, and oxyanion.

24. (canceled)

25. The process of claim 1, wherein said organic solvent is selected from ethanol, isopropanol, acetone, methanol, and mixtures thereof.

26. (canceled)

27. A process for obtaining water-soluble benzalkonium-hydroxide from substantially water-insoluble benzalkonium-perchlorate, the process comprising: (a) contacting an aqueous slurry of benzalkonium-perchlorate with a first solution containing potassium hydroxide dissolved in an organic solvent, under conditions permitting precipitation of potassium-perchlorate salt and formation of benzalkonium-hydroxide dissolved in said organic solvent; (b) separating the precipitated potassium-perchlorate from the organic solvent in which the benzalkonium-hydroxide is dissolve; and (c) separating the organic solvent from the benzalkonium-hydroxide to obtain a water-soluble benzalkonium-hydroxide, benzalkonium having the following formula (I): ##STR00005## wherein R is a (C.sub.3-C.sub.18)alkyl; R.sub.1 and R.sub.2 are each independently selected from H and (C.sub.1-C.sub.6)alkyl; and R.sub.3 is one or more substituents, each independently selected from H, (C.sub.1-C.sub.6)alkyl, (C.sub.1-C.sub.6)alkoxy, NHCO(C.sub.1-C.sub.6)alkyl, OH, and NH.sub.2.

28. The process of claim 27, wherein R1 and R2 are each methyl, R3 is H, and R is a (C3-C18)alkyl.

29. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0074] In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

[0075] FIG. 1 is a block diagram of a process according to an embodiment of this disclosure.

[0076] FIG. 2 is a block diagram of process according to another embodiment of this disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

[0077] The following description exemplifies how processes of this disclosure may be used to recover a water-soluble form of benzalkonium (BNZ) from water insoluble benzalkonium-perchlorate (BNZ-ClO.sub.4) complex. The recovery process is based on the different in solubility of BNZ-ClO.sub.4 complex exhibits in water compared to ethanol (Table 1).

TABLE-US-00001 TABLE 1 ClO.sub.4 equilibrium concentration and solubility in different solvents Complex/ ClO.sub.4 equilibrium Solubility precipitant Matrix conc. [mM] product [Ks] BNZ-ClO.sub.4 Salt water 0.81 6.56 10.sup.7 BNZ-ClO.sub.4 Deionized water 0.20 4.04 10.sup.8 BNZ-ClO.sub.4 Ethanol 231 5.35 10.sup.2 KClO.sub.4 Ethanol 0.27 7.36 10.sup.8

[0078] As clearly evident from Table 1, BNZ-ClO.sub.4 solubility product is larger in six orders of magnitude in ethanol compared to the solubility product in deionized water, and five orders of magnitude larger than the solubility in salt water.

[0079] Thus, BNZ-ClO.sub.4 complex that is a product of water treatment for perchlorate removal by precipitation of BNZ-ClO.sub.4 can be treated by dissolving the complex in ethanol, precipitation ClO.sub.4 in the ethanol and then evaporating of the ethanol.

[0080] An exemplary schematic diagram of a process according to this disclosure is shown in FIG. 1. Into reaction vessel 106, a slurry of organocation-perchlorate salt (e.g. BNZ-ClO.sub.4) and a solution of a first salt (e.g. KOH dissolved in ethanol) are fed via feeding lines 102 and 104, respectively. The organocation-perchlorate salt and first salt are brought into contact in reaction vessel 106, permitting formation of organic solvent (e.g. ethanol) soluble second salt (e.g. BNZ-OH), and precipitation of metal-perchlorate (e.g. KClO.sub.4) in solid form due to its negligible dissolution in ethanol. A stream 108 of second salt dissolved in the organic solvent (e.g. BNZ-OH ethanolic solution) mixed with the solid metal-perchlorate (e.g. KClO.sub.4) is fed into a separation unit 110, from which a stream 112 of the solution of the second salt (e.g. BNZ-OH ethanolic solution) is fed into a distillation column 116, separating the solution of the second salt into solvent (e.g. ethanol) 120 and water soluble second salt (which may be in the form of a solid or an aqueous slurry). The second salt (e.g. BNZ-OH) can then be utilized to treat waste water contaminated with perchlorate ions.

[0081] From separator 110, a stream 114 of metal-perchlorate in solvent (e.g. KClO.sub.4 in ethanol) slurry is transferred into drier 122, in which the solvent and the metal-perchlorate streams (124 and 126, respectively) are separated, to result in metal-perchlorate and solvent products.

[0082] FIG. 2 shows another variation of the process of this disclosure, in which, for the sake of brevity, functionally similar elements to those of FIG. 1 were given like numbers, however shifted by 100. For example, reactor 206 in FIG. 2 has the same functionality as reactor 106 in FIG. 1.

[0083] In FIG. 2, the organic solvent vapor stream 220 from the distillation unit 216 is passed through condenser 232 to obtain organic solvent condensate. Similarly, organic solvent vapors stream 224 from drier 222 is passed through condenser 230. The condensate streams are unified into feed line 234, which feeds organic solvent into mixer 203, to which a feed of first salt 236 is also fed. A solution of the first salt in the solvent (e.g. KOH in ethanol) is formed in mixer 203, and then fed as feed stream 204 into reactor 206. In this manner, the organic solvent may be recycled in the process.

[0084] An example of a process according to the present disclosure includes first mixing a slurry of water-insoluble organocation-perchlorate salt BNZ-ClO.sub.4 with an organic solvent, such as ethanol, to dissolve the BNZ-ClO.sub.4 in the ethanol. The low solubility of KClO.sub.4 in ethanol (i.e. Ks=7.3510.sup.8) allows to separate most of the BNZ from the ClO.sub.4 by adding KOH (as the first salt) and precipitating the ClO.sub.4 as KClO.sub.4 (which is ethanol insoluble). After the precipitation of the KClO.sub.4 and separation of the BNZ-OH (being the second salt) solution in ethanol, the ethanol is evaporated and BNZ-OH is recovered, and can be re-used for treating high perchlorate concentration in fresh water brackish water or even brine (e.g. as described in WO 2014/128702).

[0085] Results of recovery of BNZ-OH from BNZ-KCLO4 by treating with KOH in ethanol are shown in Tables 2-1 to 2-3.

TABLE-US-00002 TABLE 2-1 Step 1: Dissolving BNZ-ClO.sub.4 in ethanol BNZ ClO.sub.4 BNZ-ClO.sub.4 in in in in complex complex ethanol complex ethanol recovery (%) Test (g) (mg) (mg) (mg) (mg) BNZ ClO.sub.4 1 0.57 269.8 257.6 57.2 29.9 95.5 51.0 2 1.35 490.4 381.4 104.0 19.8 77.8 19.0 3 0.55 310.0 293.2 65.7 27.2 94.6 41.3

[0086] As seen from Table 2-1, most of the BNZ is dissolved in the ethanol, with most of the tests showing BNZ recovery >90%. This precipitation was clearly evident as white precipitate that settled at the bottom of the tube after few minutes, in contrast to the BNZ-ClO.sub.4 complex that floated in the source solution (due to the different densities of these solids0.94 g/cm.sup.3 and 2.2 g/cm.sup.3 for BNZ-ClO.sub.4 complex and KClO.sub.4, respectively).

[0087] The recovery of the ClO.sub.4 was lower, as once the BNZ-ClO.sub.4 complex is dissolved in the ethanol, some ClO.sub.4 precipitates as KClO.sub.4 in the presence of potassium ions that was attributed to drag out from the source solution (i.e. BNZ-ClO.sub.4 slurry) that had K/ClO.sub.4 ratio >50.

[0088] After dissolving the BNZ-ClO.sub.4 in the ethanol, the ethanol contains BNZ, ClO.sub.4 and any drag out from the source solution. At this point the goal is to remove as much ClO.sub.4 from the ethanol in order to BNZ which is substantially ClO.sub.4-free. This is carried out by utilizing potassium ions, in order to precipitate KClO.sub.4 out of the ethanol, as shown in Table 2-2.

TABLE-US-00003 TABLE 2-2 step 2: Dosing KOH to the ethanol solution BNZ (mg) ClO.sub.4 KOH/ClO.sub.4 Before After Before After Ethanol molar KOH KOH KOH KOH Recovery (%) Test (ml) ratio addition addition addition addition BNZ ClO.sub.4 1 5 0.86 128.8 137.4 28.6 16.6 106.6 58.1 0 5 2.01 190.7 182.6 9.9 8.5 95.7 85.8 3 8.8 1.15 252.1 250.1 23.4 3.0 99.2 12.8

[0089] As seen from Table 2-2, the addition of KOH reduced the perchlorate concentration from >20 mg/l to <10 mg/l. During this stage no significant loss of BNZ was found as the BNZ recovery was >95%.

[0090] The last stage in the BNZ recovery process was evaporation of the ethanol and measurement of the BNZ that was left in the sample. No significant losses of BNZ during evaporation were found, as the recovery of BNZ was 95%, as seen from Table 2-3. Recovery that is >100% is attributed to experiment limitation.

TABLE-US-00004 TABLE 2-3 step 3: ethanol evaporation Ethanol BNZ in BNZ recovery after BNZ Test (ml) ethanol (mg) evaporation (mg) recovery (%) 1 3 82.4 94.2 114.3 2 3 109.5 114.4 104.4 3 0.4 11.4 10.8 95.0

[0091] The BNZ recovery percentage for each step of the process staged the recovery percentage was >92.9% , and the overall (steps 1+2+3) recovery was 94.4% (19.9%). This results implies that it is possible to recover the BNZ with efficiency that is close to 100%.