Process for manufacturing aminoundecanoic acid and aminodecanoic acid
Process for producing aminocarboxylic acid of formula (I): NH 3 —CH 2 —(CH 2 ) n —COOH (I) including: (i) reacting the unsaturated carboxylic acid of formula (II): CH═CH—(CH 2 ) n-1 —COOH (II) with hydrogen bromide to form the ω-bromoalkanoic acid of formula (iii): Br—CH 2 —(CH 2 ) n —COOH (III); (ii) reacting the ω-bromoalkanoic acid obtained with ammonia in aqueous solution to form a reaction mixture; (iii) separating the reaction mixture of the aminocarboxylic acid of formula (I) and an aqueous solution rich in ammonium bromide; (iv) bringing the aqueous solution rich in ammonium bromide into contact with sodium hydroxide to form ammonia and an aqueous solution rich in sodium bromide; (v) purifying the aqueous solution rich in sodium bromide; (vi) bringing the purified aqueous solution rich in sodium bromide into contact with chlorine to form bromine and an aqueous solution rich in sodium chloride; (vii) reacting the bromine with hydrogen to form hydrogen bromide; and (viii) recycling the hydrogen bromide to step (i).
1. A process for producing an aminocarboxylic acid of formula (I) below:
NH 2 —CH 2 —(CH 2 ) n —COOH (I)
in which n is an integer from 7 to 12, comprising the following steps:
(i) reacting the unsaturated carboxylic acid of formula (II) below:
CH 2 ═CH—(CH 2 ) n-1 —COOH (II)
with hydrogen bromide (HBr) to form the ω-bromoalkanoic acid of formula (III) below:
Br—CH 2 —(CH 2 ) n —COOH (III)
(ii) reacting the ω-bromoalkanoic acid of formula (III) obtained with ammonia in aqueous solution to form a reaction mixture comprising the aminocarboxylic acid of formula (I) and ammonium bromide;
(iii) separating, from the reaction mixture obtained in step (ii), the aminocarboxylic acid of formula (I) and an aqueous solution containing ammonium bromide;
(iv) bringing the aqueous solution containing ammonium bromide obtained into contact with sodium hydroxide to form ammonia and an aqueous solution containing sodium bromide;
(v) purifying the aqueous solution containing sodium bromide obtained in order to eliminate the organic impurities;
(vi) bringing the purified aqueous solution containing sodium bromide obtained into contact with chlorine to form bromine and an aqueous solution containing sodium chloride;
(vii) reacting the bromine obtained with hydrogen to form hydrogen bromide; and
(viii) recycling the hydrogen bromide obtained to step (i).
2. The process according to claim 1 , in which additional bromides are added to the solution containing ammonium bromide or sodium bromide of step (iv) or (v).
3. The process according to claim 1 , in which additional bromine is added to the bromine obtained in step (vi).
4. The process according to claim 1 , in which step (v) of purifying the aqueous solution containing sodium bromide reduces the measured Total Organic Carbon (TOC) by a factor of more than 5.
5. The process according to claim 1 , in which step (vi) is performed with a purified aqueous solution containing sodium bromide having less than 2% of measured TOC.
6. The process according to claim 1 , in which step (v) is carried out by acidification of the aqueous solution containing sodium bromide resulting from step (iv) followed by a decantation of the oily phase formed.
7. The process according to claim 6 , in which the aqueous solution containing sodium bromide resulting from step (iv) is acidified by addition of an acid to a pH of between 3 and 5.
8. The process according to claim 6 , in which step (v) comprises a subsequent step (va) in which the oily phase formed in step (v) is subjected to an extraction operation to obtain an aqueous solution enriched in sodium bromide, which is sent back to step (iv) or (vi).
9. The process according to claim 1 , in which step (v) is carried out by neutralization of the aqueous solution containing sodium bromide followed by a liquid/liquid extraction.
10. The process according to claim 9 , in which the aqueous solution containing sodium bromide is neutralized in step (v) to a pH between 3 and 10.
11. The process according to claim 1 , in which step (v) is carried out by adsorption on an adsorbent material; a silica or an alumina or a mixture thereof; or an organic material.
12. The process according to claim 1 , in which step (v) is carried out by membrane separation to form a permeate enriched in sodium bromide and depleted in organic impurities and a concentrate depleted in sodium bromide and enriched in organic impurities.
13. The process according to claim 12 , in which step (v) is carried out by means of one or more nanofiltration membranes.
14. The process according to claim 12 , in which step (v) comprises a subsequent step (va′) in which the concentrate depleted in sodium bromide and enriched in organic impurities which is obtained in step (v) is subjected to a step of diafiltration in order to recover an aqueous solution enriched in sodium bromide and depleted in organic impurities, which solution is then mixed with the permeate resulting from step (v).
15. The process according to claim 12 , in which step (v) comprises a subsequent step (vb) in which the permeate enriched in sodium bromide and depleted in organic impurities which is obtained in step (v) is subjected to a second step of membrane separation.
16. The process according to claim 14 in which step (v) comprises a subsequent step (vb′) in which the permeate enriched in sodium bromide and depleted in organic impurities which is obtained in step (v) and the aqueous solution enriched in sodium bromide and depleted in organic impurities resulting from step (va′) are subjected to a second step of membrane separation.