METHOD FOR PREDICTING PARTICLE SIZE DISTRIBUTION OF TEREPHTHALIC ACID REDUCING PROCESS AND METHOD FOR QUALITY MANAGEMENT OF TEREPHTHALIC ACID USING THE SAME

摘要

A method for predicting the PSD(Particle Size Distribution) in the reduction process of terephthalic acid, and a method for managing the quality of terephthalic acid by determining the PSD are provided to minimize the generation of inferior goods and to improve the stability of operation by predicting the PSD of terephthalic acid precisely and conveniently. A terephthalic acid is reduced by carrying out the oxidation and reduction reaction in a reactor for the preparation of terephthalic acid; and crystallizing the reduced terephthalic acid slurry in a first crystallization bath, a second crystallization bath and a third crystallization bath, wherein the PSD is predicted by determining the amount of terephthalic acid supplied to the reactor for reduction; and measuring the amount of terephthalic acid and the pressure difference among the reactor, the first crystallization bath, the second crystallization bath and the third crystallization bath so as to calculate the average particle size and PSD of terephthalic acid. The calculation is carried out by using the two mathematical formulas: (the average particle size of terephthalic acid) = -108.313 + 109.3422 x the amount of terephthalic acid + 1.5283 x the treated amount - 5.1907 x the difference between a reactor and a first crystallization bath - 0.1888 x the pressure of a first crystallization bath + 0.9794 x the pressure difference between a first crystallization bath and a second crystallization bath - 3.3551 x the pressure difference between a second crystallization bath and a third crystallization bath; and (the PSD of terephthalic acid) = -3.6829 - 5.906 x the amount of terephthalic acid + 0.0045 x the treated amount - 0.2874 x the pressure difference between a reactor and a first crystallization bath - 0.4918 x the pressure of a first crystallization bath + 0.7075 x the pressure difference between a first crystallization bath and a second crystallization bath - 0.3892 x the pressure difference between a second crystallization bath and a third crystallization bath.