| 摘要 |
<p>Process for vinyl acetate prepn. comprises reacting ethylene, acetic acid and molecular oxygen in the gas phase at temps. of 120-250 deg.C pref. 150-200 deg.C, and pressures of 1-10 atm., with a Pt- or Au-contg. supported catalyst, the reaction being carried out continuously in the presence of 5-60 vol. % CO2 in the circulation gas. The CO2 is employed as a carrier gas to facilitate the use of a continuous process, so that unconverted ethylene and oxygen can be easily recycled to the process. Excess CO2 is easily removed from the residual gases by washing with aqs. carbonate soln., so that the concn. of CO2 in the recycle gas does not rise above 60 vol. %, pref. being 20-60 vol. %.</p> |
