Continuous production of diaryl carbonates form dialkyl carbonates

PURPOSE: To prepare diaryl carbonates continuously by reacting dialkyl carbonates with phenols in the mass-coupled and energy-coupled combination of a counter column and a reactive column. CONSTITUTION: The reaction is carried out in the mass-coupled and energy- coupled combination of a counter column A and a reactive column B, in which an aromatic hydroxyl compound 1 removed in an at least partially liquid state from the column B and a mixture 2 consisting of 100 to 95 pts.wt. of dialkyl carbonate removed in a gaseous state and 0 to 5 pts.wt. of alcohol in the column A are reacted with each other in the presence of a transesterification catalyst, in a liquid phase, at the temperature of 100 to 300°C and the pressure of 0.05 to 20 bar. The head product 6 (gaseous mixture of alcohols and raw materials) in the column A and a still residue product (containing alkylaryl carbonates) 5 are feed to the column B and the reaction is carried out at the temperature of 100 to 300°C and from 0.05 to 5 bar, and the diaryl carbonate formed is removed from the tube 7. COPYRIGHT: (C)1994,JPO