Process for the continuous preparation of dialkyl carbonates
AssigneeBayer Aktiengesellschaft
InventorsPaul Wagner, Franz-Josef Mais, Hans-Josef Buysch, Reinhard Langer, Alexander Klausener
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Abstract
Di-(C.sub.1 -C.sub.4 -alkyl) carbonates can be prepared by catalysed counter-current reesterification of ethylene glycol carbonate or propylene glycol carbonate with a C.sub.1 -C.sub.4 -alcohol in a column, ethylene glycol carbonate or propylene glycol carbonate being introduced into the upper part of the column and a dialkyl carbonate-containing C.sub.1 -C.sub.4 -alcohol being introduced into the central or lower part of the column and pure alcohol being additionally introduced below the introduction of the dialkyl carbonate-containing alcohol.
Claims17
A process for the continuous preparation of dialkyl carbonate of the formula
- (R.sup.1 O).sub.2 CO,
- in which R.sup.1 signifies straight-chain or branched C.sub.1 -C.sub.4 -alkyl,
- by catalysed reesterification of ethylene glycol carbonate or propylene glycol carbonate with an alcohol of the formula
- R.sup.1 OH,
- in which R.sup.1 has the above meaning,
- wherein the reesterification is carried out in a column in counter-current in such a manner that ethylene glycol carbonate OF propylene glycol carbonate is introduced into the upper part of the column and a dialkyl carbonate-containing alcohol, whose dialkyl carbonate content is 0.2 to 30% by weight is introduced into the central or lower part of the column and pure alcohol is additionally introduced below the introduction of the dialkyl carbonate-containing alcohol.
Dependencies are inferred from the claim text.