| abstract |
1358520 Aromatic acids K J A CRAMPTON (Institut Francais Du Petrole Des Carburants Et Lubrifiants) 5 June 1972 26097/72 Heading C2C A process for producing a polycarboxylic aromatic acid comprises reacting an aromatic organic compound having at least two oxidizable aliphatic side chains with an oxygen containing gas in the presence of an oxidation catalyst and an inert reaction diluent in a primary oxidation zone, while maintaining a liquid phase in said oxidation zone, and obtaining at least 90% conversion therein, passing the reaction offgases from said oxidation zone to a distillation zone prior to any appreciable condensation of the off-gases, recycling at least a portion of the bottoms of the distillation zone to said oxidation zone, said bottoms containing 1 to 10% by weight of water; conducting the overhead vapour from the distillation zone to a condensation zone, separating effluent from the condensation zone into a liquid stream and a vapour stream containing non-condensable gas, and introducing non-condensable gas, during at least a portion of the period during which oxygen is being substantially completely consumed, into the oxidation zone in an amount sufficient to cause a decrease in the temperature of the oxidation zone of about 5‹ C. |