Process for preparing or recovering acetals or ketals by means of pervaporation
AssigneeDsm IP Assets B.V.
InventorThomas Clavey
Life of this patent
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Abstract
The process of the present invention comprises reacting an aldehyde or ketone with an alcohol in the presence of a solid acid, and removing water and methanol from the reaction product by pervaporation, characterized in that a membrane having a flux density for water of 0.04 to 2.8 kg/(hm2) is used to remove the water and another membrane having a flux density for methanol of 2.0 to 100 kg/(hm2) is used to remove the methanol.
Claims9
A process for the preparation of acetals or ketals which comprises:
- (i) reacting an aldehyde or ketone with an alcohol in the presence of a solid acid at a reaction temperature of between about −80° C. to about −45° C. to form a reaction product mixture, and
- (ii) removing water and methanol from the reaction product mixture by pervaporation, wherein
- step (ii) includes removing the water from the reaction product mixture by bringing the reaction product mixture into contact with a first membrane having a flux density for water of 0.04 to 2.8 kg/(hm2), and removing the methanol from the reaction product mixture by bringing the reaction product mixture into contact with a second membrane having a flux density for methanol of 2.0 to 100 kg/(hm2), and wherein
- step (ii) is practiced under a temperature condition of about 60° C. to about 150° C. and under pressure conditions of a pressure on a retentate side of the membrane of up to 16 bar and a pressure on a permeate side of the membrane of about 1 to 500 mbar.
A process for recovering acetals or ketals from a reaction product mixture obtained by reacting aldehydes or ketones with alcohols at a reaction temperature of between about −80° C. to about −45° C. in the presence of a solid acid, wherein the process comprises:
- (i) subjecting the reaction product mixture containing an acetal or ketal together with water and unreacted aldehyde or ketone and alcohol to treatment with a solid base followed by,
- (ii) conducting pervaporation to remove water and methanol from the reaction product, wherein
- step (ii) comprises removing water from the reaction product mixture by bringing the reaction product mixture into contact with a first membrane having a flux density for water of 0.04 to 2.8 kg/(hm2), and removing the methanol from the reaction product mixture by bringing the reaction product mixture into contact with a second membrane having a flux density for methanol of 2.0 to 100 kg/(hm2), and wherein
- step (ii) is practiced under a temperature condition of about 60° C. to about 150° C. and under pressure conditions of a pressure on a retentate side of the membrane of up to 16 bar and a pressure on a permeate side of the membrane of about 1 to 500 mbar.
Dependencies are inferred from the claim text.