Method for extracting salts and temperature-regenerated extracting composition
A temperature-regenerated hydrophobic liquid composition includes an extracting molecule of a non-alkaline cationic species, a solvating molecule of a complimentary anionic species and a fluidizing agent. The extracting molecule of a non-alkaline cationic species is a macrocycle of which the ring is formed from 24-32 carbon atoms and has the following formula (I) or (II): wherein -n is an integer ranging from 5 to 8, -p is 1 or 2, -m is 3 or 4, -q and t, which may be identical or different, are 0, 1 or 2, —R is a tert-butyl, tert-octyl, O-methyl, O-ethyl, O-propyl, O-isopropyl, O-butyl, O-isobutyl, O-pentyl, O-hexyl, O-heptyl, O-octyl, or OCH 2 Phenyl group or a hydrogen atom, and—R′ and R″, which may be identical or different, are chosen from methyl, ethyl, propyl, isopropyl, butyl, isobutyl, heptyl and octyl groups or R′ and R″ together form a pyrrolidine, piperidine or morpholine ring.
1. A process for deionizing water by extraction in a liquid medium with thermal regeneration, applied to the extraction of at least one alkaline cationic species and of a complementary anionic species from a saline liquid aqueous solution, the saline liquid aqueous solution comprising:
a salt of the at least one alkaline cationic species, and
a salt of a cationic species of an alkaline earth metal, the process comprising the following steps:
a) mixing in a first reactor, at a first temperature, a liquid hydrophobic organic phase and the saline liquid aqueous solution, in order to subsequently obtain a treated liquid aqueous solution and a liquid hydrophobic organic phase charged with the at least one alkaline cationic species and the complementary anionic species,
the liquid hydrophobic organic phase comprising an extracting molecule of the at least one alkaline cationic species, a solvating molecule of the complementary anionic species;
b) separating the treated liquid aqueous solution and the liquid hydrophobic organic phase charged with the at least one alkaline cationic species and the complementary anionic species; and
c) mixing in a second reactor, the liquid hydrophobic organic phase, charged with the at least one alkaline cationic species and the complementary anionic species, with a regeneration liquid aqueous solution, in order to subsequently obtain a regenerated liquid hydrophobic organic phase and a regeneration liquid aqueous solution charged with the at least one alkaline cationic species and the complementary anionic species, the difference between the first and second temperatures varying from 30° C. to 150° C.;
wherein the extracting molecule of the at least one alkaline cationic species is a macrocycle, the cycle of which is formed from 16 to 24 atoms and functionalized with ester or ketone groups.
2. The process according to claim 1 , wherein the extracting molecule of the at least one alkaline cationic species is selected from the compounds of formulae (V) or (VI):
where
n is 4, 5 or 6
p is 1 or 2,
m is 2 or 3,
q and t, identical or different, are 0, 1 or 2,
R is a tert-butyl, tert-pentyl, tert-octyl group, or a hydrogen atom,
R′ is selected from the group constituted by methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, hexyl, heptyl and octyl groups, in order to make a ketone-type binding group, or R′ is selected from the group consisting of O-methyl, O-ethyl, O-propyl, O-isopropyl, O-butyl, O-isobutyl, O-pentyl, O-hexyl, O-heptyl, O-octyl, OCH 2 -Phenyl groups in order to make an ester-type binding group.
3. The process according to claim 1 , wherein the extracting molecule of the at least one alkaline cationic species is selected from the compounds of formula (V) with calixarene macrocycle, with p=1, and R, R′ and n as defined below:
R
R′
n
H
O-ethyl
4
H
O-isopropyl
4
H
O-tert-butyl
4
tert-butyl
O-ethyl
4
tert-butyl
O-isopropyl
4
tert-butyl
O-tert-butyl
4
tert-octyl
O-ethyl
4
tert-butyl
O-ethyl
5
tert-butyl
tert-butyl
4
tert-butyl
O-ethyl
6.
4. The process according to claim 1 , wherein the extracting molecule has a complexing constant Log K, in methanol at 25° C., of the at least one alkaline cationic species to be extracted, higher than 3 and less than 11.
5. The process according to claim 1 , wherein the at least one alkaline cationic species is selected from lithium, sodium, potassium, rubidium and cesium.
6. The process according to claim 1 , wherein the process consists in a selective extraction of alkaline salts with hydrophilic anions.
7. The process according to claim 1 , wherein the liquid hydrophobic organic phase comprises a fluidizing agent.
8. The process according to claim 7 , wherein the fluidizing agent is selected from the aromatic polar solvents derived from dichlorobenzenes, dichlorotoluenes, derivatives thereof and mixtures thereof.
9. The process according to claim 1 , wherein the solvating molecule of the complementary anionic species is a hydrophobic compound and, the pKa of which in water at 25° C. is at least 9, and is lower than the pKa of water at 25° C.
10. Process according to claim 1 , wherein the solvating molecule of the complementary anionic species is a molecule of formula:
in which R is R=n-C 7 H 15 , n-C 9 H 19 , n-C 11 H 23 or n-C 13 H 27 .