Patent ID: 8686195

Claim:
A process for synthesizing acrolein comprising in a first step, dehydrating a glycerol charge resulting from the methanolysis of plant oils or of animal fats resulting in acrolein according to the reaction CH 2 OHâ€”CHOHâ€”CH 2 OHâ†’CH 2 â•CHâ€”CHO+2H 2 O, then, in a second step, after having subjected the effluent resulting from the first step to cooling, in carrying out in a first zone, washing with water and condensation of gaseous effluent resulting from the first step, separating, in a second fractionation zone, firstly a light aldehydes-rich stream, secondly a water-rich stream and thirdly an acrolein stream, and then, in a third step, reacting acetaldehyde contained in the light aldehydes-rich stream preceding with formaldehyde so as to obtain an acrolein-rich second stream by aldol condensation reaction according to the following reaction: CH 3 â€”CHO+CH 2 Oâ†’CH 2 â•CHO+H 2 O, and recycling this acrolein-rich second stream to the preceding step 2.