Abstract: A process and a production plant for producing methacrolein from formaldehyde and propionaldehyde in the presence of a homogeneous catalyst mixture which is based at least on an acid and a base can be used. A catalyst mixture commonly used for this synthesis has an organic acid and a secondary amine. The presence of the homogeneous catalyst mixture in the reaction mixture is an essential prerequisite for achieving a high yield. The process realizes better water management, thus making it possible not only to reduce the total catalyst amount required but also to reduce undesired catalyst byproducts more efficiently than before.

Abstract: Methacrolein is prepared in a continuous process by a Mannich condensation reaction of formaldehyde with propanal. A methacrolein polymerization inhibitor is introduced during the production process and a part thereof is recycled back into the reactor where the Mannich condensation reaction is carried out.

Abstract: A novel process can be used for preparing methacrylates, such as methacrylic acid and/or alkyl methacrylates, especially MMA. The process allows for prolonging of the catalyst service life and an increase in efficiency of the methacrylate preparation based on C2 or C4 raw materials, especially when proceeding from isobutylene or tort-butanol or ethylene as raw material. The process allows for performance for longer periods without disruption, with constant or even increased activities and selectivities. This gives rise to the possibility of performing such processes in a very simple, economically viable, and environmentally benign manner. In addition, it has been possible to minimize known safety risks that emanate from the methacrolein intermediate.

Abstract: A process and a preparation plant prepares methacrolein from formaldehyde and propionaldehyde, in presence of water and a homogeneous catalyst based at least on an acid and a base. A reaction mixture is introduced into a methacrolein workup plant and separated in a first distillation column, into a first distillation mixture in a gas phase at the top and a second distillation mixture in a liquid phase at the bottom. The first distillation mixture is condensed and, in a first phase separator, the organic phase and the aqueous phase of the condensate are separated from one another. The aqueous phase is introduced into a second distillation column, that is not part of the methacrolein workup plant, and is separated into a third distillation mixture in a gas phase at the top and a fourth distillation mixture at the bottom. The third distillation mixture is introduced into the methacrolein workup plant.

Abstract: A process and a preparation plant can prepare methacrolein from formaldehyde and propionaldehyde in the presence of a homogeneous catalyst mixture based at least on an acid and a base. For a good workup of the reaction mixture leaving the reactor, with a good energy balance and where the process has simplified apparatus implementation, the liquid reaction mixture under pressure is expanded in an expansion vessel and separated into a first expansion mixture in a gas phase and a second expansion mixture in a liquid phase. The first expansion mixture is condensed in a first condenser and the second expansion mixture is introduced into a first distillation column and separated therein, into a first distillation mixture in a gas phase at the top and a second distillation mixture in a liquid phase at the bottom. The first distillation mixture is condensed in the first condenser.

Abstract: A process and a preparation plant prepares methacrolein from formaldehyde and propionaldehyde, in presence of water and a homogeneous catalyst based at least on an acid and a base. A reaction mixture is introduced into a methacrolein workup plant and separated in a first distillation column, into a first distillation mixture in a gas phase at the top and a second distillation mixture in a liquid phase at the bottom. The first distillation mixture is condensed and, in a first phase separator, the organic phase and the aqueous phase of the condensate are separated from one another. The aqueous phase is introduced into a second distillation column, that is not part of the methacrolein workup plant, and is separated into a third distillation mixture in a gas phase at the top and a fourth distillation mixture at the bottom. The third distillation mixture is introduced into the methacrolein workup plant.

Abstract: A process and a preparation plant can prepare methacrolein from formaldehyde and propionaldehyde in the presence of a homogeneous catalyst mixture based at least on an acid and a base. For a good workup of the reaction mixture leaving the reactor, with a good energy balance and where the process has simplified apparatus implementation, the liquid reaction mixture under pressure is expanded in an expansion vessel and separated into a first expansion mixture in a gas phase and a second expansion mixture in a liquid phase. The first expansion mixture is condensed in a first condenser and the second expansion mixture is introduced into a first distillation column and separated therein, into a first distillation mixture in a gas phase at the top and a second distillation mixture in a liquid phase at the bottom. The first distillation mixture is condensed in the first condenser.

Abstract: Methacrolein is prepared in a continuous process by a Mannich condensation reaction of formaldehyde with propanal. A methacrolein polymerization inhibitor is introduced during the production process and a part thereof is recycled back into the reactor where the Mannich condensation reaction is carried out.

Abstract: The present invention relates to a process for producing methyl methacrylate, comprising the following steps: A) producing methacrolein and B) reacting the methacrolein obtained in step A) in an oxidative esterification reaction to give methyl methacrylate, characterized in that the two steps A) and B) take place in a liquid phase at a pressure of from 2 to 100 bar, and step B) is carried out in the presence of a heterogeneous noble-metal-containing catalyst comprising metals and/or comprising metal oxides.

Abstract: The present invention relates to a process for producing methyl methacrylate, comprising the following steps: A) producing methacrolein and B) reacting the methacrolein obtained in step A) in an oxidative esterification reaction to give methyl methacrylate, characterized in that the two steps A) and B) take place in a liquid phase at a pressure of from 2 to 100 bar, and step B) is carried out in the presence of a heterogeneous noble-metal-containing catalyst comprising metals and/or comprising metal oxides.

Abstract: The present invention relates to a process for producing methyl methacrylate, comprising the following steps: A) producing methacrolein and B) reacting the methacrolein obtained in step A) in an oxidative esterification reaction to give methyl methacrylate, characterized in that the two steps A) and B) take place in a liquid phase at a pressure of from 2 to 100 bar, and step B) is carried out in the presence of a heterogeneous noble-metal-containing catalyst comprising metals and/or comprising metal oxides.

Abstract: The present invention relates to a process for producing methyl methacrylate, comprising the following steps: A) producing methacrolein and B) reacting the methacrolein obtained in step A) in an oxidative esterification reaction to give methyl methacrylate, characterized in that the two steps A) and B) take place in a liquid phase at a pressure of from 2 to 100 bar, and step B) is carried out in the presence of a heterogeneous noble-metal-containing catalyst comprising metals and/or comprising metal oxides.

Abstract: The present invention relates to a process for producing methyl methacrylate, comprising the following steps: A) producing methacrolein and B) reacting the methacrolein obtained in step A) in an oxidative esterification reaction to give methyl methacrylate, characterized in that the two steps A) and B) take place in a liquid phase at a pressure of from 2 to 100 bar, and step B) is carried out in the presence of a heterogeneous noble-metal-containing catalyst comprising metals and/or comprising metal oxides.

Abstract: The present invention relates to an optimized process for preparing methacrylic acid, wherein methacrolein is prepared in a first stage from propionaldehyde and formaldehyde by means of a Mannich reaction and oxidized in a second stage to methacrylic acid. More particularly, the present invention relates to the reduction in the amounts of catalyst to be used in the first stage, especially to the reduction in the amounts of acid to be used here, by virtue of the additional installation of recycling streams suitable for the purpose.

Abstract: The present invention relates to an optimized process for the preparation of methacrolein. Methacrolein is used in chemical synthesis particularly as an intermediate for the preparation of methacrylic acid, methyl methacrylate or even active ingredients, fragrances or flavorings. In particular the present invention relates to the optimization of the process parameters by which, inter alia, a reduction of the content of harmful dimeric methacrolein in the end product may be achieved.

Abstract: The present invention relates to a catalytic continuous process for producing methyl methacrylate, said process comprising the step of reacting methacrolein with oxygen and methanol in the presence of a heterogeneous noble-metal-containing catalyst in an oxidative esterification reaction to give methyl methacrylate, characterized in that the stationary concentration of the starting material methacrolein is equal to or less than 12% by weight based on the total weight of the reaction mixture in the reactor, and the ratio F between the total liquid volume within the reactor expressed in liters divided by the total weight of catalyst in the reactor expressed in kilograms is equal to or less than 4.

Abstract: The present invention relates to a process for producing methyl methacrylate, comprising the following steps: A) producing methacrolein and B) reacting the methacrolein obtained in step A) in an oxidative esterification reaction to give methyl methacrylate, characterized in that the two steps A) and B) take place in a liquid phase at a pressure of from 2 to 100 bar, and step B) is carried out in the presence of a heterogeneous noble-metal-containing catalyst comprising metals and/or comprising metal oxides.

Abstract: The present invention relates to a process for producing methyl methacrylate, comprising the following steps: A) producing methacrolein and B) reacting the methacrolein obtained in step A) in an oxidative esterification reaction to give methyl methacrylate, characterized in that the two steps A) and B) take place in a liquid phase at a pressure of from 2 to 100 bar, and step B) is carried out in the presence of a heterogeneous noble-metal-containing catalyst comprising metals and/or comprising metal oxides.

Abstract: The present invention relates to the oxidative combustion of amine-containing wastewaters, especially in a process for preparing methacrolein. Methacrolein is used in chemical synthesis particularly as an intermediate for preparation of methacrylic acid, methyl methacrylate, or else of active ingredients, odorants or flavorings. More particularly, the present invention relates to an oxidative combustion of the amine-containing wastewaters with only low nitrogen oxide formation.

Abstract: The present invention relates to an optimized process for preparing methacrylic acid, wherein methacrolein is prepared in a first stage from propionaldehyde and formaldehyde by means of a Mannich reaction and oxidized in a second stage to methacrylic acid. More particularly, the present invention relates to the reduction in the amounts of catalyst to be used in the first stage, especially to the reduction in the amounts of acid to be used here, by virtue of the additional installation of recycling streams suitable for the purpose.