The present invention relates to the technical field of plasticizers, and discloses a
citric acid mixed ester production method, which comprises the steps of: an esterification process; a neutralizingand washing process; a steam stripping process; and a
filtration process. According to the
citric acid mixed ester production method, concentrated
sulfuric acid is adopted as a catalyst, the catalystactivity is high, the
reaction temperature is low, the
reaction speed is high, the catalyst cost is low, the esterification synthesis temperature is controlled within 145 DEG C, it is ensured that the color number of the produced mixed citrate product is within 45, the market use requirement is met, and by adjusting the added
butanol according to the market requirement, tetrabutyl citrate, dibutyl-octyl citrate, monobutyl dioctyl citrate and trioctyl citrate in different proportions can be obtained according to the
octanol proportion, it is ensured that the produced
citric acid mixed ester does not have the phenomena of
precipitation and oil seepage in the using process, meanwhile, the using requirements of production of different customers are met, an intermittent esterification processis adopted, the operation elasticity is high, the strain capacity is high, and market requirements can be met.