Process for separating reaction mixtures and recycling quaternary salts and bases
AssigneeBayer Aktiengesellschaft
InventorsPeter Fischer, Sven Michael Hansen, Claus-Peter Reisinger
Life of this patent
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Abstract
A process for the removal and recovery of quaternary salt (A) and base (D) from a reaction mixture is disclosed. The reaction mixture resulting from oxidative direct carbonylation contains in addition to (A) and (D), at least one hydroxyaromatic compound (B) and at least one reaction product (C) and optionally a solvent, and the process entails a) adding acid to the reaction mixture to cause conversion of (D) into a hydroxyaromatic compound (B2) b) separating the reaction mixture into b1.) that contains (C) and optionally (B) and/or (B2) and b2.) that contains (A) and optionally (B) and/or (B2), and c) reacting b1.) with a base (E) to re-form (D).
Claims9
A process for the removal and recovery of quaternary salt (A) and base (D) from a reaction mixture that contains in addition to (A) and (D), at least one hydroxyaromatic compound (B) and at least one reaction product (C) and optionally a solvent, comprising
- a) adding acid to the reaction mixture to cause conversion of (D) into a hydroxyaromatic compound (B2)
- b) separating the reaction mixture into
- b1.) that contains (C) and optionally (B) and/or (B2) and
- b2.) that contains (A) and optionally (B) and/or (B2), and
- c) reacting b1.) with a base (E) to re-form (D)
- where (A) conforms to
- (Qn+)m(Ym−)n, and
- (D) conforms to
- (Wl+)k[(−O)kAr′]l,
- wherein n, m, k and I independently one of the others represent integers,
- Ar′ represents an aromatic group,
- Qn+ denotes a hexaalkylguanidinium ion or XRr+)n, wherein X denotes an atom selected from group consisting of group Va and group VIa of the Periodic Table of the elements, r is an integer of 1 to 4, n is an integer of 1 to 10, and R independently represent C1-C18-alkyl, C1-C18-cycloalkyl, C7-C18-aralkyl or C6-C18-aryl with the proviso that a pair of substituents radicals may be replaced by a ring system, Ym− is at least one member selected from the group consisting of halides, nitrate, sulfate, hydrogen sulfate, carbonate, hydrogen carbonate, phosphate, hydrogen phosphate, dihydrogen phosphate, tetrafluoroborate, perchlorate, carboxylates and hexafluorophosphates and m is an integer of 1 to 3, Wl+ is at least one member selected from the group consisting of alkali metal, alkaline earth metal, rare earth metal, transition metal and quaternary cations Qn+, (B) and (B2) independently correspond to the formula Ar(OH)p, wherein Ar represents a aromatic group and p is an integer from 1 to 4, (E) is one or more hydroxide of a member selected from the group consisting of alkaline earth metal, alkali metal, ammonium and Qn+ and wherein acid is at least one member selected from the group consisting of hydrobromic acid, hydrochloric acid, carbon dioxide, phosphoric acid, dihydrogen phosphate, nitric acid, formic acid, acetic acid, oxalic acid, hydrogen sulfate and sulfuric acid.
Dependencies are inferred from the claim text.