Process for the continuous manufacture of aryl alkyl carbonate and/or diaryl carbonate using vapor recompression

A process for preparing an alkyl aryl carbonate and a diaryl carbonate comprises:

• reacting a dialkyl carbonate and an aromatic hydroxy compound in a production column to form the alkyl aryl carbonate and the diaryl carbonate;
• compressing an overhead stream in a compressor resulting in a heated overhead stream;
• directing a bottom stream of the production column and at least a portion of the heated overhead stream into a reboiler;
• heating the bottom stream in the reboiler with heat from the heated overhead stream, resulting in a cooled overhead stream;
• directing at least a portion of the cooled overhead stream back into the production column;
• directing a first portion of the heated bottom stream back into the production column, 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.

A process for preparing alkyl aryl carbonate and diaryl carbonate comprises:

• reacting a dialkyl carbonate and an aromatic hydroxy compound in a production column to form the alkyl aryl carbonate and the diaryl carbonate, wherein the production column has an overhead stream and a bottom stream;
• heating an external fluid III with heat from the overhead stream in a condenser;
• compressing the external fluid III in a compressor resulting in a heated external fluid III;
• heating the bottom stream with the heated external fluid III in the reboiler to result in a heated bottom stream and a cooled external fluid III;
• directing a first portion of the heated bottom stream back into the production column;
• collecting the diaryl carbonate and the alkyl aryl carbonate from a second portion of the heated bottom stream;
• and
• directing the cooled external fluid III back into the condenser such that the external fluid III flows in a closed loop.

A process for preparing alkyl aryl carbonate and diaryl carbonate comprises:

• reacting a dialkyl carbonate and an aromatic hydroxy compound in a production column to form the alkyl aryl carbonate and the diaryl carbonate, wherein the production column has an overhead stream and a bottom stream;
• heating an external fluid III with heat from the overhead stream in a condenser;
• compressing the external fluid III in a compressor resulting in a heated external fluid III;
• heating the bottom stream with the heated external fluid III in the reboiler to result in a heated bottom stream and a cooled external fluid III;
• directing a first portion of the heated bottom stream back into the production column;
• collecting the diaryl carbonate and the alkyl aryl carbonate from a second portion of the heated bottom stream;
• and
• directing the cooled external fluid III back into the condenser such that the external fluid III flows in a closed loop;
• wherein the diaryl carbonate comprises diphenyl carbonate;
• wherein the dialkyl carbonate comprises at least one of dimethyl carbonate, dipropyl carbonate, dibutyl carbonate, and diethyl carbonate;
• wherein the alkyl aryl carbonate comprises at least one of phenyl methyl carbonate, phenyl ethyl carbonate, propyl phenyl carbonate, and butyl phenyl carbonate;
• and
• wherein an aromatic hydroxy compound comprises phenol.