Process for the manufacture of epichlorohydrin
View Patent ↗The invention relates to a process for the manufacture of epichlorohydrin (“ECH”) by catalytic oxidation of allyl chloride (“AC”) with an oxidant wherein the catalytic oxidation is performed in an aqueous reaction medium, wherein a water-soluble manganese complex is used as oxidation catalyst, followed by the isolation of epichlorohydrin.
1. A process for the manufacture of epichlorohydrin, comprising:
reacting allyl chloride with an oxidant in the presence of a catalyst in an aqueous reaction medium, wherein the catalyst comprises a water-soluble manganese complex and the molar ratio of allyl chloride to oxidant is from 1:0.1 to 1:1; and isolating an epichlorohydrin product, wherein the water-soluble manganese complex comprises a mononuclear manganese complex of the general formula (I):
[LMnX 3 ]Y (I)
or a binuclear manganese complex of the general formula (II):
[LMn (μ−X ) 3 MnL]Y 2 (II)
wherein Mn is a manganese; L or each L independently is a polydentate ligand; each X independently is a coordinating species: and each μ−X independently is a bridging coordinating species, selected from the group consisting of: RO − , Cl − , Br 31 , I − , F − , NCS − , N 3 − , I 3 − , NH 3 , NR 3 , RCOO − , RSO 3 − , RSO 4 − , OH − , O 2− , O 2 2− , HOO − , H 2 O , SH − , CN − , OCN − , and S4 2− and combinations thereof, wherein R is a C 1 -C 20 radical selected from the group consisting of alkyl, cycloalkyl, aryl, benzyl and combinations thereof, and Y is an oxidatively-stable counterion.
2. The process of claim 1 , wherein the epichlorohydrin product or a part of the epichlorohydrin product is isolated as an organic phase, wherein the organic phase comprises epichlorohydrin product or a mixture of allyl chloride and epichlorohydrin product.
3. The process of claim 1 , wherein each polydentate ligand is independently selected from acyclic compounds containing at least 7 atoms in the backbone or cyclic compounds containing at least 9 atoms in the ring, wherein each polydentate ligand having 3 nitrogen atoms with the nitrogen atoms separated by at least two carbon atoms.
4. The process of claim 1 , wherein a binuclear water-soluble manganese complex is used as the catalyst.
5. The process of claim 1 , wherein the catalyst is used in a molar ratio of the catalyst (Mn) to the allyl chloride from 1:10 to 1:10,000,000.
6. The process of claim 1 , wherein the aqueous reaction medium is a water phase.
7. The process of claim 1 , wherein the aqueous reaction medium further comprises a buffer system and a pH in the range of from 2.5 to 7.
8. The process of claim 1 , wherein the reaction is carried out at temperatures in the range from −5° C. and 30° C.
9. The process of claim 1 , wherein the oxidant is hydrogen peroxide.
10. The process of claim 9 , wherein the hydrogen peroxide is used as an aqueous solution in a concentration from 15% to 98%.
11. The process of claim 1 , wherein the allyl chloride and the oxidant are reacted at a molar ratio of the allyl chloride to the oxidant in the range from 1:0.2 to 0.8.
12. The process of claim 1 , wherein the oxidant is added to the aqueous reaction medium at a rate about equal to the reaction rate.
13. The process of claim 1 , wherein the reaction is performed in a batch process, in a continuous process or in a semi-continuous process.
14. The process of claim 1 , wherein the aqueous reaction medium comprises a 100% aqueous medium excluding any dissolved epoxide and ally chloride.
15. The process of claim 1 , wherein the wherein each L is independently a triazacyclononane or substituted triazacyclononane.
16. The process of claim 1 , wherein the manganese complex comprises the formula [Mn IV 2 (μ−O) 3 L 2 ]Y 2 , wherein L is a triazacyclononane or substituted triazacyclononane and the counterion Y is PF 6 − or CH 3 CO 2 − .
17. The process of claim 1 , wherein the catalyst comprises a mononuclear manganese complex of the general formula (I):
[LMnX 3 ]Y (I)
or a binuclear manganese complex of the general formula (II):
[LMn (μ−X ) 3 MnL]Y 2 (II)
wherein Mn is a manganese; L or each L independently is a polydentate ligand; each X independently is a coordinating species and each μ−X independently is a bridging coordinating species, selected from the group consisting of: RO − , Cl − , Br − , I − , F − , NCS − , N 3 − , I 3 − , NH 3 , NR 3 , RCOO − , RSO 3 31 , RSO 4 − , OH − , O 2 − , O 2 2− , HOO − , H 2 O , SH − , CN − , OCN − , and S 4 2− and combinations thereof, wherein R is a C 1 -C 20 radical selected from the group consisting of alkyl, cycloalkyl, aryl, benzyl and combinations thereof, and Y is an oxidatively-stable counterion;
wherein the aqueous reaction medium further comprises a buffer system with a pH range from 2.5 to 7; and
wherein the molar ratio of the terminal olefin to the hydrogen peroxide in the range of from 1:0.1 to 1.2:1.
18. The process of claim 1 , wherein Y is an oxidatively-stable counterion selected from the group consisting of RO − , Cl − , Br − , I − , F − , SO 4 2 − , RCOO − , PF 6 − , acetate, tosylate, triflate (CF 3 SO 3 − ) and a combination thereof.