Synthesis of Sec-butyl Acetate from Mixed C4 using the catalyst of Phosphotungstic Acid

In order to make full use of the resources of mixed C4,the esterification of acetic acid with the C4 mixture (which were composed of 1-butene,n-butane and isobutane) was studied by using phosphotungstic acid as the catalyst.The effect of various factors,such as reaction time,reaction temperature,reaction pressure,the amount of catalysts and the effect of the molar ratio of 1-butene to acetic acid,on the yield of sec-butyl acetate were carefully investigated.The experimental results show that the optimum reaction conditions were:reaction time 7 h,reaction temperature 170 ℃,reaction pressure 5.3 MPa,w(catalyst)=22.9%(nelative to the mass of acid) and n(1-butene)∶n(acetic acid)=3.5∶1;under the above conditions,the conversion of acetic acid reached 91.4%,and the selectivity of sec-butyl acetate was 90%.