Abstract: A process for recovering 1-hexene comprising: a) separating the mixture obtained from the ethylene trimerization reaction into a top fraction comprising ethylene and a bottom fraction, b) separating a portion of the bottom fraction obtained from step a) into a top fraction comprising 1-hexene and 1-butene and a bottom fraction, c) separating a portion of the fraction comprising 1-hexene and 1-butene obtained from step b) into a top fraction principally comprising 1-butene and into a bottom fraction principally comprising 1-hexene, and in said process: a portion of the bottom fraction obtained from step b) is returned to the reaction section and another portion of said bottom fraction obtained from step b) is used in a recirculation loop connecting the reaction section and the column of said step b), said recirculation loop being used to cool the reaction section and to reboil said column of step b).

Abstract: A process for recovering 1-hexene comprising: a) separating the mixture obtained from the ethylene trimerization reaction into a top fraction comprising ethylene and a bottom fraction, b) separating a portion of the bottom fraction obtained from step a) into a top fraction comprising 1-hexene and 1-butene and a bottom fraction, c) separating a portion of the fraction comprising 1-hexene and 1-butene obtained from step b) into a top fraction principally comprising 1-butene and into a bottom fraction principally comprising 1-hexene, and in said process: a portion of the bottom fraction obtained from step b) is returned to the reaction section and another portion of said bottom fraction obtained from step b) is used in a recirculation loop connecting the reaction section and the column of said step b), said recirculation loop being used to cool the reaction section and to reboil said column of step b).

Abstract: A process for producing high purity propylene comprises: a step for dimerizing ethylene to 1-butene; a step for hydroisomerizing 1-butene to 2-butenes; and a step for metathesis of 2-butenes by ethylene. Advantageously, the ethylene used to produce the 1-butene and ethylene for metathesis derive from a steam cracking unit. To increase propylene production, the process can use a steam cracking or FCC C4cut as an additional butene source.

Abstract: A process for producing high purity propylene comprises: a step for dimerizing ethylene to 1-butene; a step for hydroisomerizing 1-butene to 2-butenes; and a step for metathesis of 2-butenes by ethylene. Advantageously, the ethylene used to produce the 1-butene and ethylene for metathesis derive from a steam cracking unit. To increase propylene production, the process can use a steam cracking or FCC C4 cut as an additional butene source.

Abstract: Alkyl esters of fatty acids, and high purity glycerin, are produced using a process comprising a set of transesterification reactions between a vegetable or animal oil and an aliphatic monoalcohol employing a heterogeneous catalyst, for example based on zinc aluminate, the water content in the reaction medium being controlled to a value that is below a given limiting value.

Abstract: Alkyl esters of fatty acids, and high purity glycerin, are produced using a process comprising a set of transesterification reactions between a vegetable or animal oil and an aliphatic monoalcohol employing a heterogeneous catalyst, for example based on zinc aluminate, the water content in the reaction medium being controlled to a value that is below a given limiting value.

Abstract: A facility for converting an olefinic C4 cut to isobutene and propylene comprising, in succession: 1) a zone 1 for selective hydrogenation of olefins in the olefinic C4 cut with simultaneous isomerisation of butene-1 to butene-2, said zone comprising at least one device for introducing the olefinic C4 cut to be converted, at least one device for removing an effluent, and at least one device for introducing hydrogen, said zone also comprising at least one catalyst bed; 2) a separation zone, comprising at least one device for introducing the effluent from zone 1 directly connected to said at least one device for removing an effluent, at least one device for removing a first fraction comprising isobutene and butene-1, and at least one device for removing a second fraction comprising butene-2 and n-butane, wherein the second fraction comprises at most 1% by weight of isobutene and at most 1% by weight of butene-1; 3) a metathesis zone for metathesis of butene-2 with ethylene to produce propylene, wherein the m

Abstract: The present invention concerns a process for the conversion of an olefinic C4 cut to polyisobutene and to propylene by metathesis. The process comprises three successive steps: (1) selective hydrogenation of diolefins with simultaneous isomerisation of 1-butene to 2-butenes, (2) polymerisation of the isobutene, including optional prior extraction of the isobutene, (3) metathesis of 2-butene with ethylene. Part or all of the C4 cut may originate from the metathesis of an olefinic C5 cut with ethylene after hydroisomerisation of the C5 cut. Application to C4 and C5 steam cracking cuts.

Abstract: The present invention concerns a plant for the conversion of an olefinic C.sub.4 or C.sub.5 cut to an alkyl-tertiobutylether or alkyl-tertioamylether and to propylene, by metathesis. The plant comprises four successive stages: (1) selective hydrogenation of the diolefins with simultaneous isomerisation of the alpha olefins to internal olefins; (2) etherification of the isoolefins; (3) elimination of oxygen-containing impurities; (4) metathesis of internal olefins with ethylene. Application to C.sub.4 and C.sub.5 steam cracking units.

Abstract: The invention relates to a process for producing high purity isobutene from a hydrocarbon cut essentially comprising olefinic hydrocarbons containing 4 carbon atoms per molecule including isobutene, also butene-1 and butene-2 compounds in a ratio which substantially corresponds to the thermodynamic equilibrium. The process comprises passing the cut into a distillation zone (3) associated with a hydroisomerisation reaction zone, the bottom product of the distillation zone comprising butene-2 compounds being passed into a skeletal isomerisation zone (2) where the linear butenes are at least partially isomerised to isobutene, at least part of the principal effluent from the skeletal isomerisation zone being recycled upstream of the reactive distillation zone (3).

Abstract: The present invention concerns a process for the production of isobutene and propylene by metathesis of an olefinic C.sub.4 cut. The process comprises three successive steps: 1) selective hydrogenation of butadiene with isomerisation of butene-1 to butene-2; 2) separation by distillation to produce isobutene overhead, leaving a butene-2 bottom cut; 3) metathesis of the butene-2 cut with ethylene. The advantage of this process is that polymerisation quality propylene can be produced very selectively, in contrast to other processes such as dehydrogenation of propane or other cracking processes.

Abstract: The invention relates to a process for producing high purity isobutene from a hydrocarbon cut essentially comprising olefinic hydrocarbons containing 4 carbon atoms per molecule including isobutene, also butene-1 and butene-2 compounds in a ratio which substantially corresponds to the thermodynamic equilibrium.

Abstract: For the conversion of an olefinic C.sub.4 or C.sub.5 cut to an alkyl-tertiobutylether or alkyl-tertioamylether and to propylene, by metathesis, the process comprises four successive steps: (1) selective hydrogenation of the diolefins with simultaneous isomerisation of the alpha olefins to internal olefins; (2) etherification of the isoolefins; (3) elimination of oxygen-containing impurities; (4) metathesis of internal olefins with ethylene. The process has application, e.g., to C.sub.4 and C.sub.5 steam cracking cuts.

Abstract: The present invention concerns a process for the conversion of an olefinic C.sub.4 cut to polyisobutene and to propylene by metathesis. The process comprises three successive steps: (1) selective hydrogenation of diolefins with simultaneous isomerisation of 1-butene to 2-butenes, (2) polymerisation of the isobutene, including optional prior extraction of the isobutene, (3) metathesis of 2-butene with ethylene. Part or all of the C.sub.4 cut may originate from the metathesis of an olefinic C.sub.5 cut with ethylene after hydroisomerisation of the C.sub.5 cut. Application to C.sub.4 and C.sub.5 steam cracking cuts.

Abstract: The invention concerns a process for the separation of a mixture comprising ethylene, 1-butene, alpha-olefins containing at least 6 carbon atoms per molecule and possibly heavier hydrocarbon products, the ethylene content of the mixture being in the range 30% to 70% by weight, in which separation is effected in a distillation zone to obtain an overhead fraction comprising the major portion of the ethylene present in the mixture and between 0% and 100% by weight of the 1-butene present in the mixture, the process being characterized in that the zone is also supplied with supplemental 1-butene in an amount in the range 1 to 40 times the quantity (by weight) of 1-butene present in the mixture. In a preferred implementation of the process of the invention, the mixture originates form a homogenous liquid phase ethylene oligomerisation zone.