| abstract |
The invention relates to an hydrolysis vessel (200) used during amidification step of acetone cyanohydrin (ACH), in the industrial process for production of a methyl methacrylate (MMA) or methacrylic acid (MAA). The hydrolysis vessel (200) is used for hydrolyzing acetone cyanohydrine with sulfuric acid to produce a mixture comprising α-sulfatoisobutyramide (SIBAM). It comprises at least one cooling system (212; 244) on its internal annular periphery area and it is divided into at least two stages, preferably three, along its vertical wall, each stage (S1 to S3) comprising a ACH feeding inlet (201, 202, 203). Such vessel allows controlling both homogeneity and temperature of the mixture, and thus obtaining a high yield for the hydrolyzing reaction in very safe conditions. |