Macrokinetics of the vinyl acetate synthesis on the catalyst of super-high specific surface area activated carbon supported Zn(Ac)_2

The macrokinetics of vinyl acetate synthesis from acetylene and acetic acid on the Zn(Ac)_2/super-high specific surface area activated carbon (s_(BET)=2713m~(2)/g) catalyst has been studied under conditions approaching those of industrial operation, and compared with Zn(Ac)_2/Japaniese coco-shell carbon (s_(BET)=1384m~2/g) catalyst. The macrokinetics equations are υ_1=28.22p~(1.00)_(C_2H_2)p~(-0.62)_(VAc) and υ_2=25.03p~(1.01)_(C_2H_2)p~(-0.52)_(VAc) for two kinds of catalysts, respectively. The average apparent activation energy are 52.49(kJ·mol~(-1)) and 53.87(kJ·mol~(-1)) for the catalysts at temperature range of 160℃~175℃, respectively. The results indicated that the reaction order to (acetylene) was one, and the reaction order to vinyl acetate was negative. The activation energy was less than real activation energy 87.80(kJ·mol~(-1)), which indicated that the synthesis reaction was seriously affected by diffusion. The catalytic activity increased with the increment of the specific surface area of the catalysts support. At the same time, the catalytic activity was less affected by increasing in specific surface area of support at high temperature range of 185℃~195℃.