Purification of (meth)acrylic esters by membrane separation dehydration

A process for producing an alkyl (meth)acrylate or alkyl acrylate comprising a linear or branched alkyl chain comprising from 4 to 10 carbon atoms, by direct esterification of (meth)acrylic acid or acrylic acid with a linear or branched alcohol comprising from 4 to 10 carbon atoms in the presence of a catalyst, leading to the formation of a reaction mixture comprising an ester, unreacted acid and alcohol, light by-products and heavy by-products, which mixture is purified by separation to obtain purified alkyl (meth)acrylate or alkyl acrylate, said purification by separation comprising:

• i) a step of settling out the reaction mixture to produce an aqueous feed stream and an organic stream and ii) a step of treating the aqueous feed stream originating from settling out of the reaction mixture to membrane separation dehydration;
• wherein the feed stream treated by membrane separation comprises from 80 to 99% by weight of water, less than 2% by weight of (meth)acrylic ester or acrylic ester and from 1 to 20% by weight of alcohol,
• wherein said membrane consists of a hydrophobic polymeric membrane,
• wherein said step of membrane separation dehydration is dehydration by pervaporation or vapor permeation at a temperature ranging from 50 to 100° C. and without dephlegmation, and
• wherein a permeate is obtained having a lower water percentage by weight and a higher alcohol percentage by weight than that of the feed stream.