With inreased critical discussions about potential toxicological effects of phthalates in the mid-nineties

esters of cyclohexane polycarboxylic acids are considered the most promising alternatives to phthalate as plasticizers. Hydrogenation of dibutyl phthalate (DBP) and diisobutyl phthalate (DIBP) using Ni as catalyst was studied by experiment. The products of hydrogenation were respectively dibutyl hexahydrophthalate and diisobutyl hexahydrophthalate. The appropriate reaction conditions for DBP hydrogenation were temperature 130℃

pressure 6.1 MPa and space velocity 1 h-1. The conversion and selectivity of reaction were 99.93% and 92.47% respectively. The appropriate reaction conditions for DIBP hydrogenation were temperature 100℃

pressure 6.1 MPa and space velocity 0.5 h-1. The conversion and selectivity of reaction were 99.70% and 90.42% respectively. Conversion and selectivity were chosen as reaction model parameters

and the synthesis and separation processes of dibutyl hexahydrophthalate and diisobutyl hexahydrophthalate was established by using Aspen Plus software. The purity of product was higher than 99%(mass). Process parameters have important guiding significance to commercialization of hydrogenation of DBP and DIBP.