Patent ID: 11939288
Assignee: RÖHM GMBH
Field: Organic fine chemistry (Chemistry)
Classification: CPC C  Y | IPC C

Claim 0:
1. A process for producing alkyl methacrylates, the process comprising:
producing methacrolein in a first reaction stage in a reactor I, and
oxidatively esterifying the methacrolein with an alcohol in a second reaction stage in a reactor II in the presence of an oxygen-containing gas, to form reaction water in a liquid phase and to afford an alkyl methacrylate,
wherein a workup of a reaction mixture from the reactor II to afford the alkyl methacrylate comprises at least one distillation and at least one extraction;
wherein an aqueous phase containing the alcohol and an alkali metal and/or alkaline earth metal salt of a Brønsted acid from the at least one extraction is treated in at least one second distillation in a column II to form, in a bottom of the column II, a process water stream containing the reaction water and the alkali metal and/or the alkaline earth metal salt of a Brønsted acid, wherein in the process water stream a content of the alcohol and the alkyl methacrylate is less than 5% by weight based on a total process water stream, and
wherein the process water stream from the bottom of the column II is partially discharged from the process and sent for disposal and partially recycled into the workup of the reaction mixture from the reactor II.