Abstract:
The invention relates to a method for obtaining 3-aminomethyl-3,5,5-trimethyl cyclohexylamine (isophorone diamine, IPDA) with a cis/trans isomer ratio of at least 73/27 by fractional distillation. Said method comprises the following steps: a) preparation of IPDA with a cis/trans isomer ratio /=73/27 and iv) an IPDA fraction with a cis/trans isomer ratio
Abstract:
The invention relates to a method for producing a flow of aliphatic hydrocarbons which comprise from 5 to 12 carbon atoms per molecule and whose content in linear a- olefins is increased with respect to a feeding flow of aliphatic hydrocarbons comprising from 5 to 12 carbon atoms per molecule and containing linear a- olefins, internal linear olefins and dienes. The inventive method consists in bringing the feeding flow to a first distillation area D1 comprising at least 5 theoretical separation stages, wherein linear a-olefins are partially or totally separated in the form of a steam flux component which also contains dienes and on whose lower end a fluid flow partially or totally depleted of the linear a-olefins is obtainable, in introducing said fluid flow from the lower end of the first distillation area D1 into an isomerisation unit which is provided with an isomerisation catalyst in which the internal linear olefins are partially or totally isomerised into linear a- olefins and the thus formed linear a- olefins are separated in the form of the steam flux component mounting to the first distillation area D1 and entering a selective hydrogenation unit in which at least one part of dienes are selectively hydrogenated into olefins in a low-isomerisation selective hydrogenation catalyst and the thus obtainable steam flux is extracted, totally or partially condensed and removed in the form of a product flow whose content in linear a- olefins is increased with respect to the feeding stream.
Abstract:
Disclosed is a method for hydrating hydrocarbon compounds selected among the group comprising alkynes, dienes, alkenynes, and polyenes (hydrocarbons I). According to the inventive method, a gas stream containing hydrogen and a hydrocarbon I is directed through a hydration zone containing a hydration catalyst. The beginning of the hydration zone is located at a point whose geodetic height is lower than that of the end of the hydration zone.
Abstract:
The invention relates to a continuous method for separating a C4 cut (C4) by means of extractive distillation using a selective solvent (LM) in an extractive distillation column (EDK). A separating wall (TW), forming a first partial region (A), a second partial region (B) and a lower common column region (C), is arranged in the longitudinal direction of the extractive distillation column (EDK). According to said method, a head flow (C4H10) comprising butane is separated from the first partial region (A), a head flow (C4H8) comprising butene is separated from the second partial region (B), and a flow (C4H6) comprising the hydrocarbons from the C4 cut is separated from the lower common column region (C), said hydrocarbons dissolving more easily in the selective solvent (LM) than the butane and the butene.
Abstract:
In a continuous process for fractionating a C4 fraction (C4) by extractive distillation using a selective solvent (LM) in an extractive distillation column (EDK), it is proposed that a dividing wall (TW) is installed in the longitudinal direction in the extractive distillation column (EDK) to form a first region (A), a second region (B) and a lower combined column region (C) and a top stream (C4H10) comprising the butanes is taken off from the first region (A), a top stream (C4H8) comprising the butenes is taken off from the second region (B) and a stream (C4H6) comprising the hydrocarbons from the C4 fraction which are more soluble in the selective solvent (LM) than are the butanes and the butenes is taken off from the lower combined column region (C).
Abstract:
Pure isophorone-diamine (IPDA) with a cis/trans isomer ratio (CTR) of at least 73/27 is obtained by (a) making crude IPDA with a CTR below 73/27, (b) purifying and separating into fractions with CTR of at least 73/27 (b1) and below 63/37 (b2), (c) isomerizing (b2) in presence of hydrogen, ammonia and catalyst to give IPDA with a CTR of 63/37-66/34 which is recycled to stage (a). A method (M1) for the production of substantially pure 3-aminomethyl-3,5,5-trimethyl cyclohexylamine (isophorone-diamine; IPDA) with a cis/trans isomer ratio (CTR) of at least 73/27 involves: (a) preparation of crude IPDA with a CTR of less than 73/27, (b) purification and separation to give fractions (b1) with a CTR of at least 73/27 and (b2) with a CTR of less than 63/27 and (c) isomerization of (b2) in presence of hydrogen, ammonia and a hydrogenation catalyst to give IPDA with a CTR of 63/37-66/34 which is then recycled to stage (a). An Independent claim is also included for a method (M2) for the production of IPDA with a CTR in the range 63/37 to 66/34 by reacting IPDA with any CTR value with hydrogen and ammonia in presence of a hydrogenation catalyst.
Abstract:
Pure isophorone-diamine (IPDA) with a cis/trans isomer ratio (CTR) of at least 73/27 is obtained by (a) making crude IPDA with a CTR below 73/27, (b) purifying and separating into fractions with CTR of at least 73/27 (b1) and below 63/37 (b2), (c) isomerizing (b2) in presence of hydrogen, ammonia and catalyst to give IPDA with a CTR of 63/37-66/34 which is recycled to stage (a). A method (M1) for the production of substantially pure 3-aminomethyl-3,5,5-trimethyl cyclohexylamine (isophorone-diamine; IPDA) with a cis/trans isomer ratio (CTR) of at least 73/27 involves: (a) preparation of crude IPDA with a CTR of less than 73/27, (b) purification and separation to give fractions (b1) with a CTR of at least 73/27 and (b2) with a CTR of less than 63/27 and (c) isomerization of (b2) in presence of hydrogen, ammonia and a hydrogenation catalyst to give IPDA with a CTR of 63/37-66/34 which is then recycled to stage (a). An Independent claim is also included for a method (M2) for the production of IPDA with a CTR in the range 63/37 to 66/34 by reacting IPDA with any CTR value with hydrogen and ammonia in presence of a hydrogenation catalyst.
Abstract:
In a process for the work-up of a C4 fraction, comprising the process steps Extractive distillation (I), Selective hydrogenation over a heterogeneous catalyst (II), a crude 1,3-butadiene stream being obtained following process steps (I) and (II) and Distillation of the crude 1,3-butadiene stream for isolating pure 1,3-butadiene (III), the process steps I and II are carried out in a single column or in thermally coupled columns and the process step III is carried out in a second column.
Abstract:
A process is proposed for obtaining a stream of aliphatic hydrocarbons comprising from 5 to 12 carbon atoms per molecule, with an increased proportion of linear alpha-olefins compared to a feed stream of aliphatic hydrocarbons comprising from 5 to 12 carbon atoms per molecule, with a content of linear alpha-olefins, linear internal olefins and dienes, wherein the feed stream is fed to a first distillation zone D 1 having at least 5 theoretical plates, in which the linear alpha-olefins are removed partly or fully as a component of a vapor stream which additionally also comprises the dienes, and at whose lower end a liquid stream is obtained which has been depleted partly or fully of linear alpha-olefins, the liquid stream from the lower end of the first distillation zone D 1 is introduced into a isomerization unit which is equipped with an isomerization catalyst over which the linear internal olefins are isomerized partly or fully to linear alpha-olefins, and the linear alpha-olefins formed in this way are removed as a component of a vapor stream ascending into the first distillation zone D 1, the vapor stream ascending out of the first distillation zone D 1 enters a selective hydrogenation unit in which at least a portion of the dienes are hydrogenated selectively to olefins over a low-isomerization selective hydrogenation catalyst to obtain a vapor stream which is drawn off, condensed fully or partly and drawn off as a product stream with an increased proportion of linear alpha-olefins compared to the feed stream.