nickel , manganese , and terephthalic acid in a liquid phase oxidation of p- xylene under a catalyst system containing bromine present

摘要

The present invention relates to a process for liquid phase oxidation of p- xylene to terephthalic acid using a molecular oxygen- such, the method of the present invention minimizes the loss of the solvent through the solvent to minimize the formation of incomplete combustion and oxidation products , such as 4-carboxy benzaldehyde (4-CBA). In this way , in the p- xylene is 120 to 250 range of temperature , and molecular oxygen source, a nickel (Ni) atoms source , manganese (Mn) atoms , and a source of bromine (Br) atoms containing a source of zirconium atoms , and is substantially does not contain a stoichiometric molar ratio of bromine atoms to manganese atoms is 1.5 or less , and the amount of the nickel atoms is oxidized in the presence of a catalyst composition less than 500 ppm, terephthalic acid , and 4-CBA contained bath containing the incomplete oxidation products ( crude) to form a reaction mixture .