Abstract: The invention relates to a process for obtaining isobutene from an isobutene containing C4-hydrocarbon mixture (1) in a plant comprising an etherification unit (3), a first distillation unit (5), an ether cleavage unit (10) and a second distillation unit (12), the process comprising: (a) contacting the C4-hydrocarbon mixture (1) with a primary alcohol (2) and reacting the mixture with the primary alcohol in the presence of an acidic catalyst to form the corresponding alkyl tert-butyl ether in the etherification unit (3); (b) distilling the reaction mixture (4) from the etherification unit (3) in the first distillation unit (5), a C4-hydrocarbon raffinate being withdrawn as the overhead product (6), and the alkyl tert-butyl ether being withdrawn as the bottom product (7); (c) vaporizing the bottom product from the first distillation unit (5) in an evaporator (8) obtaining a vapor stream (9); (d) reacting the vapor stream (9) of step (c) in the presence of an acidic catalyst obtaining isobutene and the primary

Abstract: The invention relates to a process for starting up a plant for removing isobutene from an isobutene-containing C4-hydrocarbon mixture, the plant comprising an etherification unit containing moist acidic ion exchange resin, a first distillation unit, an ether cleavage unit, and a second distillation unit. The invention further relates to a process for shutting down the plant from a stationary operation mode.

Abstract: The invention relates to a process for obtaining isobutene from an isobutene containing C4-hydrocarbon mixture (1) in a plant comprising an etherification unit (3), a first distillation unit (5), an ether cleavage unit (8) and a second distillation unit (10), the process comprising: (a) contacting the C4-hydrocarbon mixture (1) with a primary alcohol (2) and reacting the mixture with the primary alcohol in the presence of an acidic catalyst to form the corresponding alkyl tert-butyl ether as an intermediate product and diisobutene as a by-product in the etherification unit (3); (b) distilling the reaction mixture (4) from the etherification unit (3) in the first distillation unit (5), a C4-hydrocarbon raffinate being withdrawn as the overhead product (6), the alkyl tert-butyl ether and diisobutene being withdrawn as the liquid or vaporous bottom product (7), and vaporizing the bottom product (7) if it is withdrawn as a liquid; (c) reacting the vaporous bottom product (7) in the presence of an acidic catalyst

Abstract: A process for the purification of isobutene from a C4 stream with at least 1-butene, 2-butene, isobutane and isobutene includes isomerizing 1-butene from a stream of material which is concentrated in isobutane and isobutene obtained from the C4 stream into 2-butene, using a catalyst in an isomerization reactor; supplying a product stream from the isomerization reactor to a rectification column; and providing a stream of material which is concentrated in isobutene. A processing facility is utilized for the purification of isobutene from the C4 stream.

Abstract: A process for the purification of isobutene from a C4 stream with at least 1-butene, 2-butene, isobutane and isobutene includes isomerizing 1-butene from a stream of material which is concentrated in isobutane and isobutene obtained from the C4 stream into 2-butene, using a catalyst in an isomerization reactor; supplying a product stream from the isomerization reactor to a rectification column; and providing a stream of material which is concentrated in isobutene. A processing facility is utilized for the purification of isobutene from the C4 stream.

Abstract: A process for the purification of isobutene from a C4 stream with at least 1-butene, 2-butene, isobutane and isobutene includes isomerizing 1-butene from a stream of material which is concentrated in isobutane and isobutene obtained from the C4 stream into 2-butene, using a catalyst in an isomerization reactor; supplying a product stream from the isomerization reactor to a rectification column; and providing a stream of material which is concentrated in isobutene. A processing facility is utilized for the purification of isobutene from the C4 stream.

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 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.