Abstract: A process for producing alkyl methacrylates, in particular methyl methacrylate (MMA), includes production of methacrolein (MAL) in a first reaction stage; direct oxidative esterification (DOE) of the methacrolein with an alcohol, preferably methanol, to afford an alkyl methacrylate in a second reaction stage; and workup of the alkyl methacrylate crude product from the second reaction stage. An optimized workup of the reactor output from the oxidative esterification of methacrolein involves minimizing the amount of employed water, the amount of employed acid, and/or the amount of aqueous waste streams, through an optimized recycling of the generated process water streams.

Abstract: A novel process can be used for a heterogeneously catalysed oxidation reaction, in the presence of a pulverulent noble metal-containing catalyst, where (meth)acrolein, an alkyl alcohol, in particular methanol, and an oxygen-containing gas are converted to an alkyl (meth)acrylate, in particular methyl (meth)acrylate. A corresponding reactor suitable for performing the reaction is also useful. The process allows for an effective retention of the particulate catalyst and the continuous discharge of fines fractions of the catalyst powder which are present, particularly in a fresh catalyst batch as a consequence of its preparation. Such fines fractions may also be produced by abrasion during the reaction. The process allows for effective recycling, recovery, and utilization of these discharged catalyst fractions.

Abstract: A new method can be used for producing suitable improved carrier materials as a base material for catalysts for carrying out a direct oxidative esterification. In general, the catalyst is used to convert aldehydes with alcohols in the presence of oxygenic gases directly to the corresponding ester, for example, where (meth)acrolein can be converted to methyl(meth)acrylate. The catalysts used are characterized in particular by high mechanical and chemical stability as well as by good catalytic performance even over very long periods of time. This applies in particular to an improvement of catalyst service life, activity and selectivity in comparison to other catalysts.

Abstract: A process can be used for producing hydroxyalkyl (meth)acrylate esters, in particular hydroxyethyl methacrylate (HEMA). The process involves a first reaction of (meth)acrolein with at least one polyhydric alcohol, in particular ethylene glycol, in the presence of a first catalyst C1, wherein a first reaction product containing a cyclic acetal is obtained. The process then involves a second reaction of the first reaction product with oxygen in the presence of a second catalyst C2, wherein a second reaction product containing at least one hydroxyalkyl (meth)acrylate ester is obtained. After the first reaction, water and optionally further components, in particular (meth)acrolein and/or the polyhydric alcohol, e.g. ethylene glycol, are at least partially removed from the first reaction product.

Abstract: A process produces methyl methacrylate by direct oxidative esterification of methacrolein. Methyl methacrylate is used in large amounts for producing polymers and copolymers with other polymerizable compounds. An optimized workup of the reactor discharge from the oxidative esterification of methacrolein allows for co-discharged fine catalyst particles to be very efficiently separated and optionally removed or recycled. In addition, this process can reduce the formation of byproducts in extended continuous operation compared to known variant. A reactor system contains stirrer configurations which allow virtually abrasion-free operation and thus a catalyst on-stream time of several years.

Abstract: A process for producing alkyl methacrylates, in particular methyl methacrylate (MMA), includes production of methacrolein (MAL) in a first reaction stage; direct oxidative esterification (DOE) of the methacrolein with an alcohol, preferably methanol, to afford an alkyl methacrylate in a second reaction stage: and workup of the alkyl methacrylate crude product from the second reaction stage. An optimized workup of the reactor output from the oxidative esterification of methacrolein involves minimizing the amount of employed water, the amount of employed acid, and/or the amount of aqueous waste streams, through an optimized recycling of the generated process water streams.

Abstract: A process for producing alkyl methacrylates, in particular methyl methacrylate (MMA), includes production of methacrolein (MAL) in a first reaction stage; direct oxidative esterification (DOE) of the methacrolein with an alcohol, preferably methanol, to afford an alkyl methacrylate in a second reaction stage; and workup of the alkyl methacrylate crude product from the second reaction stage. An optimized workup of the reactor output from the oxidative esterification of methacrolein involves minimizing the amount of employed water, the amount of employed acid, and/or the amount of aqueous waste streams, through an optimized recycling of the generated process water streams.

Abstract: A novel process can be used for a heterogeneously catalysed oxidation reaction, in the presence of a pulverulent noble metal-containing catalyst, where (meth)acrolein, an alkyl alcohol, in particular methanol, and an oxygen-containing gas are converted to an alkyl (meth)acrylate, in particular methyl (meth)acrylate. A corresponding reactor suitable for performing the reaction is also useful. The process allows for an effective retention of the particulate catalyst and the continuous discharge of fines fractions of the catalyst powder which are present, particularly in a fresh catalyst batch as a consequence of its preparation. Such fines fractions may also be produced by abrasion during the reaction. The process allows for effective recycling, recovery, and utilization of these discharged catalyst fractions.

Abstract: A process produces methyl methacrylate by direct oxidative esterification of methacrolein. Methyl methacrylate is used in large amounts for producing polymers and copolymers with other polymerizable compounds. An optimized workup of the reactor discharge from the oxidative esterification of methacrolein allows for co-discharged fine catalyst particles to be very efficiently separated and optionally removed or recycled. In addition, this process can reduce the formation of byproducts in extended continuous operation compared to known variant. A reactor system contains stirrer configurations which allow virtually abrasion-free operation and thus a catalyst on-stream time of several years.

Abstract: A process for producing alkyl methacrylates, in particular methyl methacrylate (MMA), includes production of methacrolein (MAL) in a first reaction stage; direct oxidative esterification (DOE) of the methacrolein with an alcohol, preferably methanol, to afford an alkyl methacrylate in a second reaction stage; and workup of the alkyl methacrylate crude product from the second reaction stage. An optimized workup of the reactor output from the oxidative esterification of methacrolein involves minimizing the amount of employed water, the amount of employed acid, and/or the amount of aqueous waste streams, through an optimized recycling of the generated process water streams.

Abstract: A novel process can be used for producing methacrylates such as methacrylic acid and/or alkyl methacrylates, in particular MMA. The process leads to an increased yield and increased efficiency compared to other C4-based production processes, in particular processes starting from isobutylene or tert-butanol as raw material. The process can be operated for longer periods without disruption and with the same or even increased activities and selectivities. The process can also be executed in a manner that is as simple, cost-effective, and environmentally friendly as possible.

Abstract: A novel process can be used for producing methacrylates such as methacrylic acid and/or alkyl methacrylates, in particular MMA. The process leads to an increased yield and increased efficiency compared to other C4-based production processes, in particular processes starting from isobutylene or tert-butanol as raw material. The process can be operated for longer periods without disruption and with the same or even increased activities and selectivities. The process can also be executed in a manner that is as simple, cost-effective, and environmentally friendly as possible.