Built-in micro-interface oxidation system and method for preparing terephthalic acid from p-xylene

A built-in micro-interface oxidation system for preparing terephthalic acid from p-xylene, comprising:

• a first reactor, a rectifying tower and a second reactor which are sequentially connected, wherein a first outlet is disposed on a side wall of the first reactor, a first inlet is disposed on a side wall of the second reactor, a material inlet is disposed on a side wall of the rectifying tower, and a material outlet is disposed at a bottom of the rectifying tower;
• the first outlet is connected with the material inlet of the rectifying tower, and the first inlet is connected with the material outlet of the rectifying tower;
• a plurality of micro-interface units are arranged in the first reactor and the second reactor and used for dispersing and crushing air into bubbles;
• wherein the plurality of micro-interface units comprise a first micro-interface generator and a second micro-interface generator which are arranged up and down;
• the first micro-interface generator is connected with an air guide pipe, and a top end of the air guide pipe extends out of a liquid surface of the first reactor and is used for recovering air;
• a second inlet is further disposed on the side wall of the first reactor, and a tail end of the second inlet extends into the second micro-interface generator;
• and a structure of the micro-interface unit in the second reactor is the same as that in the first reactor;
• wherein the first micro-interface generator is fixed inside the first reactor and the second reactor by using wave-proof grids;
• wherein both interior tops of the first reactor and the second reactor are provided with filter screens.