Method for manufacturing diaryl carbonates from dialkyl carbonates

摘要

Preparing at least one diaryl carbonate, comprises: (a) reacting dialkyl carbonate(s) with aromatic hydroxyl compound(s) in a first reaction column; (b) feeding the sump product of the first reaction column containing at least one further reaction column; (c) separating the unreacted or dialkyl carbonate; (d) completely or partially feeding obtained aromatic hydroxyl compound(s) containing steam into at least one further process step comprising at least one distillation column; and (e) further processing the sump product containing diaryl carbonate from the reaction column(s). Preparing at least one diaryl carbonate from dialkyl carbonate and at least one aromatic hydroxyl compound, comprises: (a) reacting dialkyl carbonate(s) in the presence of at least one transesterification catalyst with aromatic hydroxyl compound(s) in a first reaction column containing at least one rectifying section in the upper part of the column and at least one reaction zone, which has at least two sections, below the rectification section; (b) feeding the sump product of the first reaction column containing at least one further reaction column having at least one rectification section in the upper part of the column and at least one reaction zone below the rectification section and further reacting; (c) completely or partially separating the unreacted or dialkyl carbonate formed during the reaction, in the reaction columns of steps (a) and/or (b); (d) completely or partially feeding obtained aromatic hydroxyl compound(s) containing steam, at the head of at least a reaction column from (b) optionally after condensation in at least one condenser, into at least one further process step comprising at least one distillation column, where the compound, whose boiling point is between the boiling point of dialkylcarbonate and alkylarylcarbonate, is formed during the manufacture of the diarylcarbonate are removed; and (e) further processing the sump product containing diarylcarbonate from the reaction column(s) of the step (b) to purification process by feeding into at least a distillation column, which contains at least a strengthening part in the upper part of the column and at least a stripping portion in the lower part of the column, where at least a reaction column(s) from the first or the other reaction column(s) is equipped with one or more intermediate condensers and the condensation heat from the condensers is directly or indirectly recycled into the process.