Abstract: A process for purifying a diaryl carbonate, comprises introducing an aqueous stream to a diaryl carbonate stream that comprises a metal contaminant, wherein the aqueous stream reacts with the metal contaminant to form a precipitate; wherein introducing the aqueous stream to the diaryl carbonate stream results in introducing 100 to 10,000 ppm water based on the total composition of the diaryl carbonate stream and the aqueous stream; removing the precipitate via one or both of a separation column and a filter to result in a purified diaryl carbonate.

Abstract: In an embodiment, a method of producing a carbonate comprises reacting carbon monoxide and chlorine in a phosgene reactor in the presence of a catalyst to produce a first product comprising phosgene; wherein carbon tetrachloride is present in the first product in an amount of 0 to 10 ppm by volume based on the total volume of phosgene; and reacting a monohydroxy compound with the phosgene to produce the carbonate; wherein the phosgene reactor comprises a tube, a shell, and a space located between the tube and the shell; wherein the tube comprises one or more of a mini-tube section and a second tube section; a first concentric tube concentrically located in the shell; a twisted tube; an internal scaffold; and an external scaffold.

Abstract: In an embodiment, a method of producing carbonate can comprise: reacting a feed comprising carbon monoxide and chlorine in a tube of a reactor to produce a product composition comprising phosgene, wherein the tube has a particulate catalyst contained therein, wherein a thermally conductive material separate from the tube contacts at least a portion of the particulate catalyst, and wherein carbon tetrachloride is present in the product composition in an amount of 0 to 10 ppm by volume based on the volume of the phosgene; and reacting a monohydroxy compound with the phosgene to produce the carbonate.

Abstract: In an embodiment, a method of producing a carbonate comprises reacting carbon monoxide and chlorine in a phosgene reactor in the presence of a catalyst to produce a first product comprising phosgene; wherein carbon tetrachloride is present in the first product in an amount of 0 to 10 ppm by volume based on the total volume of phosgene; and reacting a monohydroxy compound with the phosgene to produce the carbonate; wherein the phosgene reactor comprises a tube, a shell, and a space located between the tube and the shell; wherein the tube comprises one or more of a mini-tube section and a second tube section; a first concentric tube concentrically located in the shell; a twisted tube; an internal scaffold; and an external scaffold.

Abstract: In an embodiment, a method of producing carbonate can comprise: reacting a feed comprising carbon monoxide and chlorine in a tube of a reactor to produce a product composition comprising phosgene, wherein the tube has a particulate catalyst contained therein, wherein a thermally conductive material separate from the tube contacts at least a portion of the particulate catalyst, and wherein carbon tetrachloride is present in the product composition in an amount of 0 to 10 ppm by volume based on the volume of the phosgene; and reacting a monohydroxy compound with the phosgene to produce the carbonate.

Abstract: In an embodiment, a process for preparing an alkyl aryl carbonate and a diaryl carbonate, comprising: reacting a dialkyl carbonate and an aromatic hydroxy compound in a production column to form the alkyl aryl carbonate and the diaryl carbonate; directing a bottom stream of the production column to a reboiler, wherein the bottom stream comprises the alkyl aryl carbonate and the diaryl carbonate; heating the bottom stream in the reboiler with heat from an overhead stream of the production column to result in a heated bottom stream; directing a first portion of the heated bottom stream back into the production column, wherein the first portion comprises an aromatic hydroxy compound; and collecting the diaryl carbonate and the alkyl aryl carbonate from a second portion of the heated bottom stream.

Abstract: A method for producing polycarbonate by melt polymerization can comprise: (a) adding acetone, diaryl carbonate, and dihydroxy compound to the melt polymerization unit, wherein the acetone is added to the melt polymerization unit as a mixture with the diaryl carbonate and/or the dihydroxy compound; (b) adding a catalyst to the melt polymerization unit, optionally without separating out acetone prior to the addition of the catalyst; and (c) operating the melt polymerization unit under conditions so that the diaryl carbonate(s) and dihydroxy compound(s); dihydroxy compound reacts with the diaryl carbonate to produce polycarbonate with a desired specification, and a phenol by-product.

Abstract: A method for producing a polycarbonate comprising: reacting a diaryl carbonate with a dihydroxy compound to form a polycarbonate, wherein the polycarbonate comprises: less than or equal to 1000 ppb of molybdenum; less than or equal to 33 ppb of vanadium; less than or equal to 33 ppb of chromium; less than or equal to 375 ppb of niobium; less than or equal to 33 ppb of nickel; less than or equal to 10 ppb of zirconium; and less or equal to 10 ppb iron.

Abstract: A process for purifying a diaryl carbonate, comprises introducing an aqueous stream to a diaryl carbonate stream that comprises a metal contaminant, wherein the aqueous stream reacts with the metal contaminant to form a precipitate; wherein introducing the aqueous stream to the diaryl carbonate stream results in introducing 100 to 10,000 ppm water based on the total composition of the diaryl carbonate stream and the aqueous stream; removing the precipitate via one or both of a separation column and a filter to result in a purified diaryl carbonate.

Abstract: A method for producing a polycarbonate comprising: reacting a diaryl carbonate with a dihydroxy compound to form a polycarbonate, wherein the polycarbonate comprises: less than or equal to 1000 ppb of molybdenum; less than or equal to 33 ppb of vanadium; less than or equal to 33 ppb of chromium; less than or equal to 375 ppb of niobium; less than or equal to 33 ppb of nickel; less than or equal to 10 ppb of zirconium; and less or equal to 10 ppb iron.

Abstract: A method for producing polycarbonate by melt polymerization can comprise: (a) adding acetone, diaryl carbonate, and dihydroxy compound to the melt polymerization unit, wherein the acetone is added to the melt polymerization unit as a mixture with the diaryl carbonate and/or the dihydroxy compound; (b) adding a catalyst to the melt polymerization unit, optionally without separating out acetone prior to the addition of the catalyst; and (c) operating the melt polymerization unit under conditions so that the diaryl carbonate(s) and dihydroxy compound(s); dihydroxy compound reacts with the diaryl carbonate to produce polycarbonate with a desired specification, and a phenol by-product.

Abstract: In an embodiment, a process for preparing an alkyl aryl carbonate and a diaryl carbonate, comprising: reacting a dialkyl carbonate and an aromatic hydroxy compound in a production column 200, 300 to form the alkyl aryl carbonate and the diaryl carbonate; directing a bottom stream of the production column to a reboiler 205, 305, wherein the bottom stream comprises the alkyl aryl carbonate and the diaryl carbonate; heating the bottom stream in the reboiler 205, 305 with heat from an overhead stream of the production column 200, 300 to result in a heated bottom stream; directing a first portion of the heated bottom stream back into the production column 200, 300, wherein the first portion comprises phenol; and collecting the diaryl carbonate and the alkyl aryl carbonate from a second portion of the heated bottom stream.