Abstract: A method of producing a purified ester-substituted phenol stream is provided. The method includes a first step of obtaining from a melt transesterification reaction a byproduct stream containing a residual ester-substituted diaryl carbonate, an ester-substituted phenol, a residual melt transesterification catalyst, and a catalyst degradation product. A second step includes treating the reaction byproduct stream to separate ester-substituted phenol and catalyst degradation product from residual ester-substituted diaryl carbonate and residual melt transesterification catalyst to create a light recycle stream containing ester-substituted phenol and catalyst degradation product and a heavy recycle stream containing residual ester-substituted diaryl carbonate and residual melt transesterification catalyst. A third step includes treating the light recycle stream to reduce catalyst degradation product concentration thereby producing a purified ester-substituted phenol stream.

Abstract: A method of producing a purified ester-substituted phenol stream is provided. The method includes a first step of obtaining from a melt transesterification reaction a byproduct stream containing a residual ester-substituted diaryl carbonate, an ester-substituted phenol, a residual melt transesterification catalyst, and a catalyst degradation product. A second step includes treating the reaction byproduct stream to separate ester-substituted phenol and catalyst degradation product from residual ester-substituted diaryl carbonate and residual melt transesterification catalyst to create a light recycle stream containing ester-substituted phenol and catalyst degradation product and a heavy recycle stream containing residual ester-substituted diaryl carbonate and residual melt transesterification catalyst. A third step includes treating the light recycle stream to reduce catalyst degradation product concentration thereby producing a purified ester-substituted phenol stream.

Abstract: An apparatus for preparing a dialkyl carbonate comprises means for reacting an alkanol, oxygen, carbon monoxide, and a catalyst to form a mixture comprising a dialkyl carbonate, an alkyl chloroformate, hydrochloric acid, water, carbon dioxide, and carbon monoxide; means for separating from the mixture a gaseous fraction comprising carbon monoxide and alkyl chloroformate; and means for removing alkyl chloroformate from the gaseous fraction.

Abstract: A method of preparing a dialkyl carbonate includes reacting an alkanol, oxygen, carbon monoxide, and a catalyst to form a mixture that includes a dialkyl carbonate and an alkyl chloroformate. The mixture is separated into a liquid fraction and a gaseous fraction, and alkyl chloroformate is removed from the gaseous fraction. Also described is an apparatus for carrying out the method. The method is particularly useful for preventing corrosion in a cold wash unit that removes further organic impurities from the gaseous fraction.

Abstract: An apparatus for preparing a dialkyl carbonate comprises means for reacting an alkanol, oxygen, carbon monoxide, and a catalyst to form a mixture comprising a dialkyl carbonate, an alkyl chloroformate, hydrochloric acid, water, carbon dioxide, and carbon monoxide; means for separating from the mixture a gaseous fraction comprising carbon monoxide and alkyl chloroformate; and means for removing alkyl chloroformate from the gaseous fraction.

Abstract: A method of preparing a dialkyl carbonate includes reacting an alkanol, oxygen, carbon monoxide, and a catalyst to form a mixture that includes a dialkyl carbonate and an alkyl chloroformate. The mixture is separated into a liquid fraction and a gaseous fraction, and alkyl chloroformate is removed from the gaseous fraction. Also described is an apparatus for carrying out the method. The method is particularly useful for preventing corrosion in a cold wash unit that removes further organic impurities from the gaseous fraction.