METHOD FOR PRODUCING AMINOUNDECANOIC ACID AND AMINODECANOIC ACID

The invention mainly concerns a method for producing aminocarboxylic acid having the following formula (I): NH3-CH2-(CH2)n-COOH (I) in which n is an integer from 7 to 12, comprising the following steps: (i) reacting the unsaturated carboxylic acid having the following formula (II): CH=CH-(CH2)n-1-COOH (II), with hydrogen bromide (HBr) in order to form the ω-bromoalcanoic acid having the following formula (III): Br-CH2-(CH2)n-COOH (III); (ii) reacting the resulting ω-bromoalcanoic acid having formula (III) with ammonia in aqueous solution in order to form a reaction mixture comprising aminocarboxylic acid having formula (I) and ammonium bromide; (iii) separating, from the reaction mixture, the aminocarboxylic acid having formula (I) and an aqueous solution rich in ammonium bromide; (iv) bringing the resulting aqueous solution rich in ammonium bromide into contact with sodium hydroxide in order to form ammonia and an aqueous solution rich in sodium bromide; (v) purifying the resulting aqueous solution rich in sodium bromide in order to remove the organic impurities; (vi) bringing the resulting purified aqueous solution rich in sodium bromide into contact with chlorine in order to form bromine and an aqueous solution rich in sodium chloride; (vii) reacting the resulting bromine with hydrogen in order to form hydrogen bromide and (viii) recycling the resulting hydrogen bromide to step (i). The invention also concerns a method for producing polyamides or copolyamides from said aminocarboxylic acid. L'invention concerne principalement un procédé de production d'acide aminocarboxylique de formule (I) suivante : NH3-CH2-(CH2)n-COOH (I) dans laquelle n est un entier de 7 à 12 comprenant les étapes suivantes : (i) réaction de l'acide carboxylique insaturé de formule (II) suivante : CH=CH-(CH2)n-1-COOH (II) avec du bromure d'hydrogène (HBr) pour former l'acide ω-bromoalcanoïque de formule (III) suivante : Br-CH2-(CH2)n-COOH (III); (ii) réaction de l'acide ω-bromoalcanoïque de formule (III) obtenu avec l'ammoniac en solution aqueuse pour former un mélange réactionnel comprenant l'acide aminocarboxylique de formule (I) et du bromure d'ammonium; (iii) séparation du mélange réactionnel de l'acide aminocarboxylique de formule (I) et d'une solution aqueuse riche en bromure d'ammonium; (iv) mise en contact de la solution aqueuse riche en bromure d'ammonium obtenue avec de la soude pour former de l'ammoniac et une solution aqueuse riche en bromure de sodium; (v) purification