Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
264 words
A process for recovering heavy metal ions and organic bromine compounds from a mother liquor of a reaction mixture derived from liquid phase oxidation to a carboxylic acid of a substituted benzene oxidizable thereto by means of a molecular oxygen-containing gas in a lower aliphatic monocarboxylic acid in the presence of a heavy metal catalyst system and a bromine compound as a reaction promotor, which comprises the step of contacting said mother liquor comprising a lower aliphatic monocarboxylic acid, water in an amount less than 20% by weight and heavy metal ions, dissolved therein, of at least one member selected from the group consisting of vanadium, cobalt, chromium, manganese, nickel, copper, zinc, molybdenum and iron and halogen values in the form of bromine ions, non-dissociative bromine compounds and organic bromine compounds, with an anion exchange resin, at least 60% of the ion-exchange groups of said anion exchange resin being in the bromide state, thereby adsorbing said heavy metal ions and bromine ions on the anion exchange resin to remove the same from the mother liquor; and the steps of subjecting the resulting mother liquor to a distillation comprising a first step distillation to recover the lower aliphatic monocarboxylic acid and a second step distillation which is carried out so that the relationship between the vapor temperature and the distillation pressure satisfies the requirement represented by the following equation: ##EQU2## wherein p stands for the distillation pressure (mmHg absolute) and t stands for the vapor temperature (°C.), to recover the remaining non-dissociative and organic bromine compounds which had not been adsorbed in the preceding step.
Claim 2
Dependent Claim
264 words
A process for recovering heavy metal ions and organic bromine compounds from a mother liquor of a reaction mixture derived from liquid phase oxidation to a carboxylic acid of a substituted benzene oxidizable thereto by means of a molecular oxygen-containing gas in a lower aliphatic monocarboxylic acid in the presence of a heavy metal catalyst system and a bromine compound as a reaction promotor, which comprises the step of contacting said mother liquor comprising a lower aliphatic monocarboxylic acid, water in an amount less than 20% by weight and heavy metal ions, dissolved therein, of at least one member selected from the group consisting of vanadium, cobalt, chromium, manganese, nickel, copper, zinc, molybdenum and iron and halogen values in the form of bromine ions, non-dissociative bromine compounds and organic bromine compounds, with an anion exchange resin, at least 60% of the ion-exchange groups of said anion exchange resin being in the bromide state, thereby adsorbing said heavy metal ions and bromine ions on the anion exchange resin to remove the same from the mother liquor; and the steps of subjecting the resulting mother liquor to a distillation comprising a first step distillation to recover the lower aliphatic monocarboxylic acid and a second step distillation which is carried out so that the relationship between the vapor temperature and the distillation pressure satisfies the requirement represented by the following equation: ##EQU2## wherein p stands for the distillation pressure (mmHg absolute) and t stands for the vapor temperature (°C.), to recover the remaining non-dissociative and organic bromine compounds which had not been adsorbed in the preceding step.
Claim 3
Dependent Claim
48 words
A process according to claim 1, wherein said substituted benzene has 1 to 4 substituents selected from the group consisting of C 1 -C 3 alkyl, aldehyde and carboxyl, and when said substituted benzene has a carboxyl group, it further has at least one substituent other than carboxyl.
Claim 4
Dependent Claim
21 words
A process according to claim 1, wherein said substituted benzene is p-xylene and said lower aliphatic monocarboxylic acid is acetic acid.
Claim 5
Dependent Claim
28 words
A process according to claim 1, wherein said mother liquor of reaction mixture is contacted with said anion exchange resin at a temperature of 30° to 120° C.
Claim 6
Dependent Claim
28 words
A process according to claim 1, wherein said mother liquor of reaction mixture is contacted with said anion exchange resin at a temperature of 50° to 100° C.
Claim 7
Dependent Claim
26 words
A process according to claim 1, wherein said heavy metal ions are at least one ion selected from the group consisting of cobalt and manganese ions.
Claim 8
Dependent Claim
21 words
A process according to claim 1, wherein said second step distillation is carried out by using a rotary thin layer evaporator.