Verfahren zur Herstellung von Vinylacetat

摘要

Vinyl acetate is synthesized by the vapour phase reaction of acetylene and acetic acid in a fluidized catalytic reaction apparatus 1 wherein the reaction temperature is controlled by regulating the temperature of the starting material entering the reactor in response to the variation of the reaction temperature so as to maintain the reaction temperature substantially constant. In one method of operation, the starting material mixture 3, comprising acetylene gas from a blower and acetic acid vapour from an evaporator, is passed through a cooler or preheater 4 and a by-pass 5 in parallel and the proportion which passes through either path is regulated by valves 6 and 61 controlled in response to variations in the reaction temperature whereby the temperature of the starting material mixture entering the reactor is adjusted so as to maintain the reaction temperature substantially constant. In the apparatus shown, in which the reactor is large, two instruments 7 and 8 form a compound controlling system in which 7 measures the internal temperature (a) of the reactor 1 and will give a command to 8 corresponding to the variation of temperature whilst 8 will measure the temperature (b) and operate the valves 6 and 61 to make temperature (b) vary by an amount equal to the command given by 7. In a smaller apparatus, the instrument 7 can be used to control 6 and 61 directly. The catalyst may be powdered active carbon impregnated with zinc acetate and dried.ALSO: Vinyl acetate is synthesized by this vapour phase reaction of acetylene and acetic acid in fluidized catalytic reaction apparatus 1 wherein the reaction temperature is controlled by regulating the temperature of the starting material entering the reactor in response to the variation of the reaction temperature so as to maintain the reaction temperature substantially constant. In one method operation, the starting material mixture 3, comprising acetylene gas from a blower and acetic acid vapour from an evaporator, is passed through a cooler or preheater 4 and a bypass 5 in parallel and the proportion which passes through either path is regulated by valves 6 and 61 controlled in response to variations in the reaction temperature whereby the temperature of the starting material mixture entering the reactor is adjusted so as to maintain the reaction temperature substantially constant. In the apparatus shown, in which the reactor is large, two instruments 7 and 8 form a compound controlling system in which 7 measures the internal temperature (a) of the reactor 1 and will give a command to 8 corresponding to the variation of the temperature, whilst 8 will measure the temperature (b) and operate the valves 6 and 61 to make the temperature (b) vary by an amount equal to the command given by 7. In smaller apparatus, the instrument 7 can be used to control 6 and 61 directly. The catalyst may be powdered active carbon impregnated with zinc acetate and dried.