Present invention relates to a process and an installation (100) for the preparation of hydrogen cyanide by the Andrussow process, and more precisely for improving the conditions of mixing the reactant gases before feeding the Andrussow type reactor (60), in order to improve safety, to avoid any risk of explosion and to produce HCN in safe and efficient manner. The installation is configured in such a manner that oxygen is pre-mixed with air with a ratio comprised between 20.95% and 32.5% by volume, preferably between 25% and 30.5% by volume; methane containing gas and ammonia are simultaneously added in the pre-mixture of oxygen-enriched air in such a manner that the volumic ratio of methane to ammonia is comprised between 1.35 and 1.02 depending on the content of oxygen into air; said obtained reactant gases mixture having a temperature comprised between 80 C. and 120 C., preferably between 95 C. and 115 C. for feeding the Andrussow type reactor (60).

Present invention relates to a process and an installation (100) for the preparation of hydrogen cyanide by the Andrussow process, and more precisely for improving the conditions of mixing the reactant gases before feeding the Andrussow type reactor (60), in order to improve safety, to avoid any risk of explosion and to produce HCN in safe and efficient manner. The installation is configured in such a manner that oxygen is pre-mixed with air with a ratio comprised between 20.95% and 32.5% by volume, preferably between 25% and 30.5% by volume; methane containing gas and ammonia are simultaneously added in the pre-mixture of oxygen-enriched air in such a manner that the volumic ratio of methane to ammonia is comprised between 1.35 and 1.02 depending on the content of oxygen into air; said obtained reactant gases mixture having a temperature comprised between 80 C. and 120 C., preferably between 95 C. and 115 C. for feeding the Andrussow type reactor (60).

The invention relates to methyl methacrylate characterized in that at least one portion of the carbons thereof is biologically sourced and, more specifically, in that it contains between 0.210.sup.10 and 1.210.sup.10 wt.-% of .sup.14C in relation to total carbon weight according to the ASTM D6866 standard. The preparation method uses acetone cyanohydrin as a raw material, the acetone cyanohydrin being obtained by condensing cyanohydric acid on acetone, and the methyl methacrylate is prepared using a process involving the addition of methanol. According to the invention, at least one from among the acetone, cyanohydric acid and methanol is obtained by a reaction or series of reactions involving the biomass.

The invention relates to methyl methacrylate characterized in that at least one portion of the carbons thereof is biologically sourced and, more specifically, in that it contains between 0.210.sup.10 and 1.210.sup.10 wt.-% of .sup.14C in relation to total carbon weight according to the ASTM D6866 standard. The preparation method uses acetone cyanohydrin as a raw material, the acetone cyanohydrin being obtained by condensing cyanohydric acid on acetone, and the methyl methacrylate is prepared using a process involving the addition of methanol. According to the invention, at least one from among the acetone, cyanohydric acid and methanol is obtained by a reaction or series of reactions involving the biomass.

The invention relates to methyl methacrylate characterized in that at least one portion of the carbons thereof is biologically sourced and, more specifically, in that it contains between 0.210.sup.10 and 1.210.sup.10 wt.-% of .sup.14C in relation to total carbon weight according to the ASTM D6866 standard. The preparation method uses acetone cyanohydrin as a raw material, the acetone cyanohydrin being obtained by condensing cyanohydric acid on acetone, and the methyl methacrylate is prepared using a process involving the addition of methanol. According to the invention, at least one from among the acetone, cyanohydric acid and methanol is obtained by a reaction or series of reactions involving the biomass.

Fouling of an MMA process is reduced by acidifying a stream comprising recycled components.

Fouling of an MMA process is reduced by acidifying a stream comprising recycled components.

Fouling of an MMA process is reduced by acidifying a stream comprising recycled components.

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 -hydroxyisobutyramide (HIBAM), -sulfatoisobutyramide (SIBAM), 2-methacrylamide (MACRYDE) and methacrylique acid (MAA), into a mixture of 2-methacrylamide (MACRYDE). It comprises: at least one compartment (C1, C2, C3, . . . Ci) comprising an inner wall (206a, 206b, 206i) separating said compartment into two communicating parts (C1a, C1b) 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 (204a, 204b, . . . 204i).

Such vessel allows obtaining a high yield thermal conversion in very safe conditions.

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 -hydroxyisobutyramide (HIBAM), -sulfatoisobutyramide (SIBAM), 2-methacrylamide (MACRYDE) and methacrylique acid (MAA), into a mixture of 2-methacrylamide (MACRYDE). It comprises: at least one compartment (C1, C2, C3, . . . Ci) comprising an inner wall (206a, 206b, 206i) separating said compartment into two communicating parts (C1a, C1b) 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 (204a, 204b, . . . 204i).

Such vessel allows obtaining a high yield thermal conversion in very safe conditions.