Method for dibutyl phthalate synthesis

Di-butyl phthalate ester was prepared by esterification of phthalic anhydride with normal butyl alcohol (n-butanol), in the presence of concentrated sulfuric acid as a catalyst at temperature range from 120°C to 150 °C. The synthesis had done at the laboratory and pilot plant scales. The synthesized dibutyl phthalate was tested and examined. The results show that; the specifications matched that of a standard material in terms of viscosity, density, refractive index, and other specifications. The reaction takes place in a liquid state with a moderate temperature between 120-150 °C, and at atmospheric pressure. As for the catalyst used in the reaction, the sulfuric acid is easily obtainable and is used in a small percentage that does not exceed 2% of the total volume of the materials involved in the reaction. Likewise, for sodium hydroxide, which is used to neutralize the acidity, it is also included in a percentage of no more than 2%, The esterification and purification processes in this research give 99.5% pure substance in laboratory and in large-scale unit with 92% product.