| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for producing high quality isophthalic acid through liquid phase oxidation reaction, by reducing generation amount of a byproduct having a specific structure causing problems when increasing recycling rate of mother liquor, and reducing generation amount of discoloring impurities, thereby stably conducting the liquid phase oxidation reaction. <P>SOLUTION: This method for producing isophthalic acid comprises oxidizing m-xylene in liquid phase by oxygen-containing gas in a reaction solvent containing lower aliphatic carboxylic acid in the presence of a catalyst containing a heavy metal and bromine, wherein a part of offgas obtained by removing condensable components from a gas extracted from an oxidation reactor is cyclically fed to the oxidation reactor continuously, and the reaction pressure is made larger than the pressure in case of not performing the cyclical feeding under the same conditions. <P>COPYRIGHT: (C)2013,JPO&INPIT |
