Abstract: The present disclosure relates to a method for producing vinyl acetate, comprising a vinyl acetate synthesis process, a vinyl acetate refining process and a separation process of vinyl acetate and ethyl acetate, including an acetic acid evaporator, an oxygen mixer, a vinyl acetate synthesis reactor, a first gas separating tower, a second gas separating tower, a recovered gas compressor, a water washing tower, an absorption tower and a desorption tower, a recycling gas compressor; the vinyl acetate refining process comprising an acetic acid tower, a crude VAC tower, and a fine VAC tower, a rectifying tower, an ethyl acetate tower, a water phase receiving tank, an extracting and rectifying tower and an ethyl acetate phase separator.

Abstract: The present disclosure relates to a method for producing vinyl acetate, comprising a vinyl acetate synthesis process, a vinyl acetate refining process and a separation process of vinyl acetate and ethyl acetate, including an acetic acid evaporator, an oxygen mixer, a vinyl acetate synthesis reactor, a first gas separating tower, a second gas separating tower, a recovered gas compressor, a water washing tower, an absorption tower and a desorption tower, a recycling gas compressor; the vinyl acetate refining process comprising an acetic acid tower, a crude VAC tower, and a fine VAC tower, a rectifying tower, an ethyl acetate tower, a water phase receiving tank, an extracting and rectifying tower and an ethyl acetate phase separator.

Abstract: The present invention provides a method, which can be operated continuously and has a wide scope of application, for destructing part of fines in slurry in a crystallizer to obtain large crystals having high purity and large crystal size, characterized in that first and second filters are installed in the crystallizer, a part of slurry containing only fines of size smaller than the fines cut size is drawn from the crystallizer, through the first filter in the crystallizer to a fines destruction loop for destructing the fines and then to the crystallizer through the second filter in the crystallizer by using a circulating pump. The two filters are switched over at regular interval and washed with each other's effluent to ensure the cintinuous operation of the above process.The present invention also provides a method for preparing crystalline bisphenol A/phenol adduct and bisphenol A with high purity and large crystal size.

Abstract: High purity and ultrapure bisphenol A is prepared in a novel process.

Abstract: A process for producing high-quality polycarbonate grade bisphenol A directly by removing phenol from the adduct crystal of bisphenol A with phenol via a gas-solid reaction at low temperature comprises directly feeding the adduct crystal into a vacuum or pneumatic dephenolizing device under vacuum a inert gas stream, controlling the temperature of the adduct crystal below its melting point, decomposing the adduct crystal into gas phase and solid phase, removing the gas phase phenol and condensing phenol for recovery, well leaving the rest being the desirable bisphenol A. The process possesses easy operation, short procedure, low energy consumption, and high purity and good color of bisphenol A obtained. Bisphenol A produced according to the process of the invention may be used as the raw material for producing polycarbonates for optical use.