Abstract: The present invention relates to a process for preparing C4-C15 lactams, in which a C1-C10-alkyl nitrite is reacted with a C4-C15-cycloalkane and is illuminated with a light-emitting diode during the reaction. This forms a C4-C15-cyclohexanone oxime which is then converted further to a C4-C15 lactam; the C1-C10 alcohol formed is recycled into the preparation of the C1-C10-alkyl nitrite.

Abstract: The present invention relates to a process for preparing C4-C15 lactams, in which a C1-C10-alkyl nitrite is reacted with a C4-C15-cycloalkane and is illuminated with a light-emitting diode during the reaction. This forms a C4-C15-cyclohexanone oxime which is then converted further to a C4-C15 lactam; the C1-C10 alcohol formed is recycled into the preparation of the C1-C10-alkyl nitrite.

Abstract: The invention relates to a process for continuously preparing di-C1-3-alkyl succinates by reacting succinic acid with an C1-3-alkanol in the presence of a fixed-bed heterogeneous acidic esterification catalyst in a tubular reactor at a temperature in the range of from 60 to 100° C., wherein a mixture, comprising succinic acid, C1-3-alkanol, mono-C1-3-alkyl succinate, di-C1-3-alkyl succinate and water, is formed in a mixing stage and fed to the entrance of the tubular reactor, and wherein 5 to 75% of the outlet flow rate of the tubular reactor are recycled directly to the mixing stage as a recycle stream, and the molar ratio of C1-3-alkanol to succinic acid added to the mixing zone, and not including the C1-3-alkanol and succinic acid at the recycle stream, being in the range of from 2.0 to 9.5.

Abstract: The invention relates to a process for continuously preparing di-C1-3-alkyl succinates by reacting succinic acid with an C1-3-alkanol in the presence of a fixed-bed heterogeneous acidic esterification catalyst in a tubular reactor at a temperature in the range of from 60 to 100° C., wherein a mixture, comprising succinic acid, C1-3-alkanol, mono-C1-3-alkyl succinate, di-C1-3-alkyl succinate and water, is formed in a mixing stage and fed to the entrance of the tubular reactor, and wherein 5 to 75% of the outlet flow rate of the tubular reactor are recycled directly to the mixing stage as a recycle stream, and the molar ratio of C1-3-alkanol to succinic acid added to the mixing zone, and not including the C1-3-alkanol and succinic acid at the recycle stream, being in the range of from 2.0 to 9.5.

Abstract: The invention relates to a process for preparing acrylic acid from formaldehyde and acetic acid, comprising (i) providing a gaseous stream S1 comprising formaldehyde, acetic acid and acrylic acid, where the molar ratio of acrylic acid to the sum total of formaldehyde and acetic acid in stream S1 is in the range from 0.005:1 to 0.3:1; (ii) contacting stream S1 with an aldol condensation catalyst in a reaction zone to obtain a gaseous stream S2 comprising acrylic acid.

Abstract: A process for preparing acrylic acid from formaldehyde and acetic acid, is performed by (i) providing a gaseous stream S1 comprising formaldehyde, acetic acid, oxygen and water, where the formaldehyde content of stream S1 is in the range from 8% to 18% by volume, based on the total volume of stream S1, the ratio of the volumes of acetic acid to formaldehyde is in the range from 0.6:1 to 1.1:1, and the molar ratio of oxygen to the total amount of organic carbon is in the range from 0.02:1 to 0.15:1; and (ii) contacting stream S1 with an aldol condensation catalyst in a reaction zone to obtain a gaseous stream S2 containing acrylic acid.

Abstract: The invention relates to a process for preparing acrylic acid from formaldehyde and acetic acid, comprising (i) providing a gaseous stream S1 comprising formaldehyde, acetic acid and acrylic acid, where the molar ratio of acrylic acid to the sum total of formaldehyde and acetic acid in stream S1 is in the range from 0.005:1 to 0.3:1; (ii) contacting stream S1 with an aldol condensation catalyst in a reaction zone to obtain a gaseous stream S2 comprising acrylic acid.

Abstract: An oxidic composition comprising vanadium, tungsten, phosphorus, oxygen and optionally tin, where the molar ratio of phosphorus to the sum total of vanadium, tungsten and any tin in the oxidic composition is in the range from 1.4:1 to 2.4:1.

Abstract: The invention relates to a process for preparing acrylic acid from formaldehyde and acetic acid, comprising (i) providing a gaseous stream S1 comprising formaldehyde, acetic acid, oxygen and water, where the formaldehyde content of stream S1 is in the range from 8% to 18% by volume, based on the total volume of stream S1, the ratio of the volumes of acetic acid to formaldehyde is in the range from 0.6:1 to 1.1:1, and the molar ratio of oxygen to the total amount of organic carbon is in the range from 0.02:1 to 0.15:1; (ii) contacting stream S1 with an aldol condensation catalyst in a reaction zone to obtain a gaseous stream S2 comprising acrylic acid.

Abstract: The present invention relates to a process for preparing acrylic acid from formaldehyde and acetic acid, comprising reacting formaldehyde and acetic acid via an aldol condensation in a reaction unit comprising n reaction zones arranged in series, each comprising an aldol condensation catalyst, where n is at least 2, and wherein at least one stream leaving a reaction zone, before being fed into the reaction zone immediately downstream, is mixed with a stream comprising formaldehyde and optionally comprising acetic acid. The present invention further relates to an apparatus for preparing acrylic acid from formaldehyde and acetic acid and to the use of this apparatus.

Abstract: The present invention relates to a process for preparing acrylic acid from formaldehyde and acetic acid, comprising reacting formaldehyde and acetic acid via an aldol condensation in a reaction unit comprising n reaction zones arranged in series, each comprising an aldol condensation catalyst, where n is at least 2, and wherein at least one stream leaving a reaction zone, before being fed into the reaction zone immediately downstream, is mixed with a stream comprising formaldehyde and optionally comprising acetic acid. The present invention further relates to an apparatus for preparing acrylic acid from formaldehyde and acetic acid and to the use of this apparatus.

Abstract: The invention relates to a process for continuously preparing di-C1-3-alkyl succinates by reacting succinic acid with an C1-3-alkanol in the presence of a fixed-bed heterogeneous acidic esterification catalyst in a tubular reactor at a temperature in the range of from 60 to 100° C., wherein a mixture, comprising succinic acid, C1-3-alkanol, mono-C1-3-alkyl succinate, di-C1-3-alkyl succinate and water, is formed in a mixing stage and fed to the entrance of the tubular reactor, and wherein 5 to 75% of the outlet flow rate of the tubular reactor are recycled directly to the mixing stage as a recycle stream, and the molar ratio of C1-3-alkanol to succinic acid added to the mixing zone, and not including the C1-3-alkanol and succinic acid at the recycle stream, being in the range of from 2.0 to 9.5.