Thermal conversion vessel used in a process for amidification of acetone cyanohydrin
View Patent ↗The invention relates to a thermal conversion 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 thermal conversion vessel ( 200 ) is used for converting an hydrolysis mixture of α-hydroxyisobutyramide (HIBAM), α-sulfatoisobutyramide (SIBAM), 2-methacrylamide (MACRYDE) and methacrylique acid (MAA), into a mixture of 2-methacrylamide (MACRYDE). at least one compartment (C 1 , C 2 , C 3 , . . . Ci) comprising an inner wall ( 206 a, 206 b, . . . 206 i ) separating said compartment into two communicating parts (C 1 a , C 1 b ) by a passage provided between the bottom of said vessel and said inner wall, said compartment having a space above said inner wall, for separating gas phase from liquid phase during thermal conversion, said compartment being connected to an outlet valve ( 204 a, 204 b, . . . 204 i ). Such vessel allows obtaining a high yield thermal conversion in very safe conditions.
1. A thermal conversion vessel ( 200 ) for converting an hydrolysis mixture of α-hydroxyisobutyramide (HIBAM), α-sulfatoisobutyramide (SIBAM), 2-methacrylamide (MACRYDE) and methacrylic acid (MAA), into a mixture comprising 2-methacrylamide (MACRYDE), wherein said vessel comprises:
at least three compartments (C 1 , C 2 , C 3 , . . . Ci) comprising an inner wall ( 206 a , 206 b , . . . 206 i ) separating said compartments into at least three communicating parts (C 1 a , C 1 b , C 1 c , . . . Ci) by a passage provided between the bottom of the vessel and said inner wall,
said compartments having a space above said inner wall, for separating a gas phase from a liquid phase during thermal conversion,
said compartments being connected to an outlet valve ( 204 a , 204 b , . . . 204 i ) at the bottom of said compartments, and
wherein said vessel further comprises an opening ( 203 ) for feeding with said hydrolysis mixture, said opening ( 203 ) being at the top of the vessel.
2. The thermal conversion vessel according to claim 1 wherein said vessel comprises at least three compartments (C 1 , C 2 , C 3 , . . . Ci) separated from each other by an overflow wall ( 205 a , 205 b , . . . , 205 i ), over which the hydrolysis mixture to be converted flows to pass from one compartment to the other, each compartment being connected to an outlet valve ( 204 a , 204 b , . . . 204 i ).
3. The thermal conversion vessel of claim 2 , wherein the height (h) of either overflow walls ( 205 a , 205 b , . . . , 205 i ) or inner walls ( 206 a , 206 b , . . . 206 i ) is between ⅔ and ¾ of the height (H) of said vessel.
4. The thermal conversion vessel of claim 1 , wherein the inner wall ( 206 a , 206 b , . . . 206 i ) is fixed to the side wall of the vessel.
5. The thermal conversion vessel of claim 1 , wherein the vessel does not contain any agitator element.
6. The thermal conversion vessel according to claim 2 , wherein the overall number of overflow and inner walls is comprised between 3 and 32.
7. The thermal conversion vessel according to claim 1 , wherein said vessel has a cylindrical shape.
8. The thermal conversion vessel according to claim 1 , wherein said vessel comprises a manhole ( 201 a , 201 b ) at, at least, one end.
9. The thermal conversion vessel according to claim 2 , wherein said vessel's side walls comprise flanges ( 220 ) regularly spaced on which are fixed the overflow walls and inner walls.
10. The thermal conversion vessel according to claim 2 , wherein said vessel and its overflow walls and inner walls are made of alloy chosen at least amongst: nickel based or tantalum alloys.
11. The thermal conversion vessel according to claim 1 , wherein said vessel further comprises a vent ( 209 ) and a bursting disk ( 208 ).
12. The thermal conversion vessel according to claim 1 , wherein said vessel further comprises at least two temperature sensors ( 207 a , 207 b , . . . , 207 i ) and at least one pressure sensor ( 211 ).
13. The thermal conversion vessel according to claim 1 , connected upstream to a heating means ( 132 ).