The invention discloses a method for producing a
terephthalic acid through the oxidation of p-
xylene by using air based on a gas-liquid-
solid heterogeneous reaction separation
synchronizing reactor, which comprises the following steps that: p-
xylene is added into the gas-liquid-
solid heterogeneous reaction separation
synchronizing reactor, wherein the reactor comprises a reaction
tower and at least two constant-temperature
subsidence towers communicated with the bottom of the reaction
tower, a gaseous phase area, an oxidation area and a gas outlet are arranged in the reaction
tower; in the process of reaction, the oxidation area and the constant-temperature
subsidence tower are filled with p-
xylene, air is continuously fed from bottom of the oxidation area so as to contact and react with the p-xylene, and generated
terephthalic acid solids enter the constant-temperature
subsidence tower by
settling, and meanwhile, the p-xylene in the constant-temperature subsidence tower enters the oxidation area through an outer
circulatory system, so that the reaction is running continuously, the p-xylene continues to be settled in the constant-temperature subsidence tower until the constant-temperature subsidence tower is filled, then the reaction tower is switched to be communicated with the other constant-temperature subsidence tower filled with p-xylene, in such an alternate way,
continuous production is achieved. According to the method, a
terephthalic acid can be continuously produced at high conversion rate and high yield, so that the production efficiency is improved, and the production cost is reduced.