METHOD FOR PREPARING VINYL ACETATE Russian patent published in 2004 - IPC

FIELD: organic chemistry, chemical technology. SUBSTANCE: invention relates to vapor-phase method for preparing vinyl acetate from ethylene, acetic acid and oxygen-containing gas. Method involves the following stages: addition of ethylene, acetic acid and oxygen-containing gas into reactor, interaction of ethylene, acetic acid and oxygen-containing gas in the presence of acetoxylation catalyst to obtain technological flow and drawing off this technological flow from reactor as product flow in maintenance of oxygen concentration in product flow near threshold value determined by its inflammability limit value. Product flow is recovered into reactor by contour comprising one or some technological stages, among them separating device wherein liquid components of this product including vinyl acetate, water and/or unreacted acetic acid are removed. Also, the oxygen concentration is controlled at one or some stages of recovery contour and reactor is stopped when the oxygen concentration on any of controlled stages exceeds the threshold value determined by inflammability limit value for oxygen in product flow. Preferable threshold value is assigned 10 vol. % of oxygen or less and at stage between reactor and separating device the threshold value is 4.0 vol. %. Invention provides possibility for regulation of oxygen conversion rate into reactor and improvement of technological indices of process. EFFECT: improved preparing method. 13 cl, 4 tbl, 2 dwg, 2 ex