PROCESS FOR PREPARATION OF METHACRYLIC ACID AND METHACRYLIC ACID ESTERS

摘要

The invention relates to a process for preparation of at least one of methacrylic acid and a methacrylic acid ester, comprising the process stepsgas phase oxidation of at least one C4 compound, quenching of the reaction phase, separation and purification of the obtained methacrylic acid and optionally esterification, wherein the C4 compound is a methacrolein comprising mixture, originating from at least two different methacrolein sources, a first methacrolein source being a feed stream obtained by the heterogeneously catalysed gas phase oxidation of isobutylene or tert-butyl alcohol or isobutylaldehyde or a mixture of two or more thereof, a second methacrolein source being a feed stream obtained by the reaction of propionaldehyde with a C1 extending agent, preferably formaldehyde, and where said methacrolein can be obtained either completely from the first methacrolein source, or completely from the second methacrolein source or from any mixture of both.

主权项

1: A process for preparing at least one of methacrylic acid and a methacrylic acid ester, the process comprising:
a1) oxidizing a C4 compound in a gas phase to obtain a reaction phase comprising methacrylic acid; a2) quenching the reaction phase to obtain a crude aqueous phase comprising methacrylic acid; a3) separating at least a part of the methacrylic acid from the aqueous phase comprising methacrylic acid to obtain at least one crude methacrylic acid-comprising phase; a4) separating and optionally purifying at least a part of the methacrylic acid from the crude methacrylic acid-comprising phase obtained in a3) via a thermal separation process; a5) optionally esterifying at least a part of the methacrylic acid obtained in a4); wherein the C4 compound oxidised in a1) originates from a mixture of at least two different methacrolein comprising feed streams, and the mixture comprises 1 to 99 percent by weight of a first methacrolein comprising feed stream obtained by a heterogeneously catalysed gas phase oxidation of isobutylene or tert-butyl alcohol or isobutylaldehyde or a mixture of two or more thereof, and 99 to 1 percent by weight of a second methacrolein comprising feed stream obtained by reacting propionaldehyde with a C1 extending agent.