MXPA99001365A

MXPA99001365A - Propeno preparation and, if desired, 1-but

Info

Publication number: MXPA99001365A
Application number: MXPA/A/1999/001365A
Authority: MX
Inventors: Schwab Peter; Schulz Michael; Breitscheidel Boris; Oost Carsten; Schulz Ralf
Original assignee: Basf Aktiengesellschaft
Priority date: 1998-02-12
Filing date: 1999-02-09
Publication date: 2000-08-01

Abstract

Propene and, if desired, 1-butene are prepared by: a) the reaction of 1-butene and 2-butene to provide propene and 2-pentene in the presence of a metathesis catalyst comprising at least one metal compound of transition of groups VIb, VIIb to well VIII of the Periodic Table of the Elements, b) the subsequent separation of propene and 2-pentene formed, c) the subsequent reaction of 2-pentene with ethene to provide propene and 1-butene in the presence of a metathesis catalyst comprising at least one metal compound of the transition groups VIb, VIIb or VIII of the Periodic Table of the Elements, d) the subsequent separation of the propene and 1-butene formed, e) the discharge of at least a certain part of the 1-butene formed and / or the at least partial isomerization of the 1-butene formed to provide 2-butene in the presence of an isomerization catalyst and the subsequent return of the 1-butene not discharged and the 2-butene formed together with a part of the C4 fraction that did not react in step a) to step

Description

PREPARATION OF PROPEMO AND, IF DESIRED, 1-BUTANE. The present invention relates to a process for the preparation of propene and, if desired, i-butene by metathesis of olefins. The metathesis of olefins in its simplest form describes the metal-catalyzed, reversible rearrangement of alefins by dissociation and reformation of the C = C double bonds. For example, olefins of the formula R1-CH = CH-R2 and of the formula R3 -CH = CH-R4 react reversibly to form olefins of the formulas R1-CH = CH-R3 and R2-CH = CH ~ -R4. In the metathesis of acyclic alefins, a distinction is made between the self-synthesis in which an alefin is converted into a mixture of two alephinates having different molar masses and cross-metathesis at good ca-metis where two different alefins react. An example of auto-metathesis is the reaction of two prapene molecules to provide etena and 2-butene, as is done, for example, in the Phillips triolefin process, see Hydrocarbon Pracesing (volume 46). , November 1967, number ii, page 232"An example of metathesis cru.za.dai is the reaction of prapene and 1-butene to obtain etena and 2-pentene, If one of the reactants is etena, the reaction is usually known bed an etenolisis. The metathesis reactions are carried out in the presence of catalysts »Catalysts suitable for this purpose, in principle, homogeneous and heterogeneous compounds of transition metals, particularly those of the transition groups VI to VIII of the Periodic Table of the Elements, so bed homogeneous and heterogeneous systems of catalysts in dande these compounds are present »The document DE-A-19 40 433 presents the metathesis of 1-butena can 2-butene to form prapena and 2-pent.ena, using Re207 / A1203 bed catalyst. The formed 2-pentene reacts additionally with sadia hydride or potassium carbonate and etena to provide heptenas. The metathesis of β-butene and 2-butene to provide prapene and 2-pentene is mentioned in .L. Anderson, T.D. Brown, Hidracarban Processing, (Processing of Hydrocarbons), volume 35, agosta, 1978, number 8, pages 119-122, with a secondary reaction in the synthesis of isaalene. Document EP-A-0 304 515 presents a metathesis process for the reaction of α-butepo with 2-butene in order to provide propene and pentenes, which is carried out in a reactive distillation apparatus using Re207 / A1203 bed catalyst. US 3,526,676 presents the metathesis of 1-butene can 2 -butene to provide prapene and pentene. It is carried out in Mo03 and CaO in A1203.

The document US 3,785,957 presents a process for the production of fuel that has a high octane »In this process, an olefinic fuel is subjected to metathesis together with ethylene, the product is subjected to metathesis together with ethylene, the product is fractionated in a carriage of prapylene, a stream of butene, a stream of alefin CS or C5 - C6 and a fuel tank C6 + or C7 +. The C5 or C5-C6 alefin stream is metathesis with ethylene in a fixed bed catalyst WQ3 / S102 to provide propylene and butenes. The propylene obtained is subjected to metathesis to form ethylene and butenes and the alkylated cannabutane batteries. US 3,767,565 presents a process for increasing the octane of a fuel in proportion to a C5 fraction of a fuel reacted with ethylene in the presence of of a catalyst comprising W03 / SiO2 and HgQ to form ethylene, propylene, n-butenes and isabutenes the obtained prapilene is subjected to metathesis and the resulting n-butenes are alkylated with isobutane. The obtained prapylene is subjected to metathesis and the resulting n-butenes are alkylated with isobutane. EP-A-0 691 3/8 presents a process of metaphthesis of alefins in which C5 and ethylene reafins react in the presence of up catalyst to give mixed C4 olefins and propene. A) Yes, 2-methyl-1-2-butene reacts with ethene to provide isobutene and prapene. A mixture of 2-pentyne-2-methyl-1-butene reacts to provide a mixture of 1-butene, isabutepo and propene. In the aforementioned processes, prapene is prepared with the addition of at least equimolar amounts of etena. To achieve high propene selectivities, a large amount of ethene must be circulated. It is an object of the present invention to provide a process for preparing prapene and, if desired, 1-butene as an alloyed product in varying amounts employing C4 -efins or, for example, refined TT. We have found that this object is achieved by the propene preparation process and, if desired, i-butene mediates the reaction of β-butene and 2-butene to provide propene and 2-pendant in the presence of a catalyst. metathesis comprising the ore a compound of a transition metal of groups VIb, VI Ib to VIII of the Periodic Table of the Elements, b) the subsequent separation of the prapena and 2-pentene formed, c) the subsequent reaction of the 2 -pentene can etena to provide propene and i-butene in the presence of a metathesis catalyst comprising at least one metal compound of the transition groups VIb, VI Ib or biep VIII of the Periodic Table of the Elements, d) the subsequent separation of the formed yi-butene propene, e) the discharge of at least a certain part of the 1-butene formed and / or at least the partialisation of the 1-butene formed to provide 2-butene in the presence of a isomerization and The subsequent return of the non-discharged 1-butene and 2-butene forming tips with a part of the C4 fraction that did not react in step a) to step a) "The process of the present invention comprises metathesis raisins. In the first pass, l-butene and 2-butene react to provide propene? 2-pentene, In a second step, 2-pentene reacts with ethene to provide 1-butene and prapene. According to one embodiment of the present invention, 1-butene is at least partially bristled in the presence of an isomerization catalyst to provide 2-butene and the resulting mixture of 1-butepa and 2-butene is returned to the first step of reaction. A part of the 1-butene may be discharged before the isamerization or it may be carried by passing the isamerization reactor and combined with the outlet of the isamerization reactor. This, and also the regulation of the conversion into the isamerization catalyst, can be used to establish an optimum ratio between 1-butene and 2-butene-the entry of the first metathesis reactor in order to achieve a maximum yield of prapene. From this pharma, the requirements of raw materials in terms of etena and C4-alefins can be reduced by an amount of about 5 to 157. compared to single-stage ethanal processes as described, eg example bed in US Pat. No. 3,660,506 and in EP-A-0 273 817. According to one embodiment, the 1-butene formed in step c) is at least partially isomerized in the presence of an isomerization catalyst to provide 2-butene and the resulting mixture of 1-butene and 2-butene is returned to step a). According to an additional embodiment, at least a certain part of the 1-butene formed in step c) is discharged and the discharged isomer is returned to step a). The net reaction is therefore the reaction of 2-butene can etena to form two molecules of propene. According to one embodiment of the invention, the reaction of 2-pentene can ethene formally requires only equimolar amounts of starting materials in order to obtain the products in a high yield. Therefore, in contrast to the reverse trialefin process, the amount of ethene used may remain small. Both metathesis steps can be carried out with reactive distillation, as described below. In accordance with one embodiment of the invention, 1-butene and 2-buthene can be used in the reaction as pure substances. According to another embodiment of the invention, the butenes are used in pharmacy of a C4 stream originating, for example, from a disintegrating still, particularly a steam disintegrating still, or a refining process. This stream of C4 may comprise C4 ranges in addition to the butenes. According to one embodiment of the present invention, a current of C4 which is refined of refined I IX is used. The refined II here is a fraction comprising 1-butene, cis / trans-2-butene, little to no isobutene, and also n- butane and iso-butane. For example, the refined II can yield from 80 to 857. by weight of olefins and from 15 to 207. by weight of butans, for example, bed of 25 to 507. in weight of 1-butene, from 30 to 557. in 2-butene weight, and maximum coma 1-27. by weight of isabutene. According to the embodiment of the invention, the C4 stream used has a butene content of 20 to 100% by weight, preferably 50 to 907. by weight, particularly from 70 to 907 by weight. The ratio between 1-butene and 2-butene is from 10.1 to 1:10, preferably from 3si to 1.3, particularly 1.1. In accordance with one embodiment of the present invention, the C4 stream may contain small amounts of other hydrocarbons. According to one embodiment of the invention, the initial material used can be any carrier in dande i-butene and 2-butene are present. According to one embodiment of the invention, the initial material used can be any stream wherein 1-butene and 2-butene are present. In accordance with one embodiment of the invention, the butene can originate from the synthesis of the present invention itself and can be mixed with inductive. The C4 feed stream used is preferably prepurified before its use in the process of the present invention in order to remove any water footprint, oxygenated substances, sulfur-containing compounds or chlorides that may be present. The removal is preferably carried out by means of passing the feed carriage C4 in an absorber material, with for example aluminum oxide to molecular sieves, preferably NaX molecular sieve. The absorbent materials are preferably present in a bed of pratection. From the reaction of i-butene and 2-butene to form propene and 2-pentene, a small proportion of 3-hexene and ethene can be obtained as a by-product. In addition, small amounts of high-boiling point compounds may also be present. The small amounts of by-products which, according to one embodiment of the present invention, constitute from 1 to 30% by weight, preferably from 5 to 207% by weight, of the amount of 2-penthene formed, do not interfere in the subsequent reaction in such a way that, in accordance with one embodiment of the invention, no purification of the 2-enanti is required to remove these by-products before the subsequent reaction. In accordance with one embodiment of the present invention, Pentene is used in pure pharma in the secondary reaction. Thus, the term "2-pentene" also includes mixtures comprising only 2-pentene if also small amounts of hexen, particularly 3-hexenhene and others composed of high boiling point. Correspondingly, the term "butene", "i-butene", "2-butene-" also include a mixture comprising not only butene or butenes but also C4 alkanes, particularly butanes. Below are several embodiments of the invention with the help of the drawing, wherein Figure 1 schematically represents a processing mode of the invention.

Figure 2 schematically represents a further embodiment of the process of the invention. The abbreviations used in the figures have the following meanings. I-Bus I-butene 2-Bus 2-butene Bu 5 butanes E stenas Pr ". Propena 2-Pe: pentene 3-H; 3-hexene H. High boiling point compounds lys Refined 11 C4: C4 C5: __ alefines having 5 or more carbon atoms ROI: React (metathesis) R02: Reactor (methesis) R03? Reactor (isomerization) LiOl: Distillation column (preferably a column with dividing wall, lateral column in good arrangement of 2 colines) K201Í Distillation column (preferably a dividing wall column, side column a well arranged two-column) K301; Distillation column li Next, a preferred embodiment of the process of the invention is described, which comprises: a) the reaction of l-butene and 2-butene to provide prapene and 2-pentene in the presence of a metathesis catalyst comprising at least one compound of metal of the transition groups VIb, Vllb, or VIII of the Periodic Table of the Elements, b) the subsequent separation of the propene and the 2-pentene formed, c) the subsequent reaction of the 2-pentene with ethene to provide pentene and -butene in the presence of a metathesis catalyst comprising at least one metal compound of the transition groups VIb., Vllb to VIII of the Periodic Table of the Elements, d) the subsequent separation of propene and 1-butene formed, e) the at least partial isoerization of the l-butene formed to provide 2-butene in the presence of an isomerization catalyst and the subsequent return of l-butene and 2-butene formed together with a part of the fr action C4 that na reacted in step a) to step a). This embodiment is illustrated in Figure 1. In a first ROI reactor, 1-butene and 2-butene react in the presence of the metathesis catalyst of the present invention to provide propene and 2-pentene. For this purpose, a stream of reagent II is fed to the reactor. The reactor is followed by a distillation column K101, configured as a dividing wall column, side column or an array of 2 columns, in the upper part of which the prapene and ethene formed by-product bed removed. The refined II is removed without reacting in the to medium and a certain part of said product is returned to the feed stream of raffinate II. Some part of this product can also be downloaded. The 2-pentene and 3-hexene formed as by-products as well as high-boiling compounds are removed in the KiOi bottom. The fonts are then fed together with the atom added to the upstream reactor R02 which also contains a metathesis catalyst of the present invention. In this R02 reactant, the reaction of 2-pentene can etene to provide 1-butene and prapene takes place. The product of the reaction of the reactor R02 is fed to a distillation column K201, configured with or a dividing wall column, side column or 2-column arrangement, in the upper part of which the unreacted prapene and etena are removed. . A certain part of the 1-butene formed can be removed in the middle of the medium and at least a certain part of this product is preferably fed to the isomerization reactor R03. Unreacted 2-pentene and also, as by-products, 3-hexene and high-boiling compounds are obtained in the K201 facility. These san discharged or preferably returned to R02. The mixtures of prapene and by-product ethene removed in the upper part of iOl and K20i are fractionated in an additional distillation column K301, which is obtained in the upper part of K301 and this product is preferably returned to the reactor R02. In the R03 isomerization reactor, the l-butene is partially hydrolyzed to provide 2-butene in an isamerization catalyst, and the isamerization mixture is returned to the ROI reactor. The interrupted line in R03 indicates the possible discharge of l-butene. The propene obtained as K301 bottom, in addition to 1-bu ena discharged from K'201, the product of the desired reaction of the process of the present invention. KiOl and K201 are designed in such a way that a phase of low boiling point compounds particularly a C 2/3 phase comprising ethene and prapene is removed at the top of the column. C4 currents are removed. particularly butenas and butans phase bed of compounds of intermediate boiling point. As warehouses, C5 + hydrocarbons are discharged. Between raisins b) and c), the high-boiling product comprising 2-pentene and 3-hexene which has been separated can be subjected to distillation to separate 2-pentene and 3-hexene. The distillation can be carried out in any suitable device. The fraction containing 2-pentene is then fed to reactor R02. 3-Hexene can be discharged and, for example, fed to a dimerization process to provide a mixture of alefins The reactors RO1 ,, R02 and R03 can be any of several suitable reactors. They can be used for continuous operation or in batches. Thus, in accordance with one embodiment, they can be pressure vessels with, for example, glass pressure vessels, while in accordance with a further embodiment, they can be tuba reactors or reaction columns. Tuba reactors are preferred. According to one embodiment of the invention, the total conversion to ROI is from 20 to 90%, preferably from 50 to 80%. According to one embodiment of the invention, the total conversion in R02 is from 20 to 100%, preferably from 60 to 90%. The reaction in ROI is preferably carried out in the liquid phase here, pressure and temperature are selected in such a way that the reactants remain in the liquid phase.

According to one embodiment of the invention, ROI is from 0 to 150 ° C, preferably from 20 to 80 ° C. According to one embodiment of the invention, the pressure is from 1 to 200 bar, preferably from 5 to 30 bar. According to one embodiment of the invention, the pressure is from 1 to 200 bar, preferably from 5 to 30 bar. The reaction in R02 (ethenolysis) is carried out, according to one embodiment of the invention, at a temperature of from O to 150 ° C »preferably 20 a. 80QC, a pressure of ethane from 1 to 200 bar, preferably from 20 to 80 bar. In addition, ethene can be continuously injected in such a way that a constant pressure is maintained. The reactions in ROI and R02 can be carried out during the period from one second to 10 hours, preferably from 1 to 60 minutes. The distillation columns L101 and K201 are, according to one embodiment of the invention, columns that allow the separation of a hydrocarbon carrier in C2-C3 currents, C4 currents and C5 + currents. Columns can be designed as dividing wall columns, side columns as well as 2-column arrays. In accordance with one embodiment of the present invention,! < 301 is a column that allows the separation of ethene and propene. In accordance with one embodiment of the invention, the reactant R101 is combined with the distillation column K101 to form a reactive distillation apparatus. Here, the reaction is carried out directly in the distillation column. The catalyst is present in the reaction column in such a way that the distillation is carried out simultaneously with the reaction or immediately afterwards. A corresponding process is known under the name of "reactive distillation". According to one embodiment, the reactor R02 and the distillation column K201 combine to form a reactive distillation apparatus, wherein the reaction and the distillation are combined as in the reactive distillation described above. In accordance with one embodiment of the invention, both reactions occur in reactive distillation apparatus. Both reactions and equilibrium reactions in such a way that, according to one embodiment of the invention, the process products are removed as quickly as possible from the equilibrium to achieve the highest possible conversion. This is possible, particularly when using reactive distillation apparatus. A further embodiment of the process of the present invention is illustrated in Figure 2. Figure 2 shows a process for preparing prapene by means of. a) the reaction of 1-butene and 2-butene to provide propene and 2-pentene in the presence of a metathesis catalyst comprising at least one transition metal compound of groups VIb, VIIb or VIII of the Periodic Table of the Elementas, b) the subsequent separation of the propene and the 2-pentene formed and the unreacted butenes, c) the subsequent reaction of the 2-pentene ethene to provide propene and 1-butene in the presence of a metathesis catalyst comprising at least one compound of a metal of the transition groups VIb, Vllb, or VIII of the Periodic Table of the Elements, d) the subsequent transfer of the unreacted mixture to step b) to separate the prapene and the 1-butene formed, e) the discharge of at least a portion of the unreacted C4 fraction separated in step b)? or the at least partial isomerization of 1-butene present in this C4 fraction to provide 2-butene in the presence of an isamerization catalyst and subsequently the return of the mixture obtained in the step a). As for the reaction conditions, the one mentioned above in the relation to the illustrated table of Figure 1 is applied analogously. The mixture obtained from the second metathesis reactor R02 is returned directly to the KiOl distillation column. At least a certain portion of the intermediate boiling product comprising C4-alefins and butanes obtained from column K101 is discharged and / or at least partially converted into the isomerization reactor R03 wherein the l-butene is isdrylated in 2- buteno »The output of the isomerization reactor R03 is returned to step a), that is, the ROÍ metathesis reactor. In this variant of the process, the distillation column K201 can be eliminated.

All suitable metathesis catalysts can be used in ROI and R02 in the process of the present invention. According to one embodiment of the invention, the catalyst is a heteragenous catalyst, particularly a supported catalyst. According to one embodiment of the invention, the catalyst comprises at least one compound of a metal of the transition groups VIb, Vllb, or VIII of the Periodic Table of the Elements. The catalyst preferably comprises a ruthenium compound and / or a rhenium compound. Such catalysts are described, for example, in K.J. Ivin, I.C. Mol, Qlefin ietathesis and Metathesis Pal merization (metathesis of olefins and polymerization of metathesis), second edition, Academic Press, New York, 1996; G.W. Parshall, S.D. Ittel, Hsmageneous Catalysis, (homogeneous catalysis), 2nd edition, 1992, John Wiley & Sons, New York, Chichester, Brisbane, Toranta, Singapore, page 217 et seq .; RH. Grubbs ip Pragr. Inorg. Chem., S. Lippard (ed.), John Wiley & Sons, New York, 1978, Val. 24, 1-50; R.H. Grubbs ip Comprehensive Organomet Chem, G. Wilkinsan (ed.), Programan Press Ltd., New York, 1982, Val. 8, 499-551; D.S. Breslow, Prag. Polym, Sci. 1993, Val. 18, 1141-1195. In accordance with one embodiment of the invention, the metal compound is a metal oxide, partial oxide with additional organic radicals to either a carbonyl compound. In accordance with one embodiment of the invention, a homogeneous catalyst is employed. The catalyst here is at least one compound of a metal of the transition groups VIb, Vllb, to hien VIII of the Table Periodicity of the Elements. The use of rhenium or ruthenium in the metal compounds is preferred. The metal compound is preferably a rhenium oxide, in particular Re2D7. SUPPORT According to one embodiment of the invention, the catalysts of the present invention comprise a support. The fluids used here, in particular, inorganic supports such as A1203, particulate and μ-A1203, SiO2, Fe203, or mixtures thereof, such as, for example, SIO2 / A1203, B203 / SIO2 / A12D3 to either Fe203 / A1203. The metal oxide content in the support is, according to one embodiment of the present invention, from 1 to 20% by weight, preferably from 3 to JL57. by weight, particularly from 8 to 12% by weight, based on the total weight of the supported catalyst. The catalyst used is preferably Re207 in A1203, Si02 / A1203, Si02 / A12D3 / Fe203 or B203 / A1203. The proportion of metal oxide here is preferably 1 to 20% by weight, particularly 3 to 10% by weight. In accordance with one embodiment of the invention, MeRe03 is used instead of Re.207 or mixed with it. In accordance with the present invention, special preference is given to the use of Re207 in A1203. In accordance with one embodiment of the present invention, the catalysts are used in a freshly calcined drug and therefore require no further activation, for example, medium pair of alkylating agents. The deactivated catalysts can, according to the present invention, be regenerated by the combustion of carbon residues, for example, at a temperature of 550 ° C in a stream of air and with cooling in an argon atmosphere. The reactions of the present invention can be carried out in the presence of a solvent, for example, a hydrocarbon solvent. According to a preferred embodiment of the invention, the invention is carried out without additional added solvent. ISOHERIZATION CATALYST As an isomerization catalyst, it is possible to use all the catalytic converters and catalyze the isomerization of 1-butene to 2-butene »Suitable isamerization catalysts, in principle, all homogeneous to heterogeneous noble metal compounds in the presence of In the absence of hydrogen, bed is described, for example, in AJ Hubert, H. Rei Binger, Synthesis (synthesis) 1970, 1,405. For example, the isamerization can be carried out in accordance with that described in US 3,592,868 in Ru03 in a bed inorganic soup for example Si02, A12Q3 or Ti02 or mixed supports. US 4,684,760 and US 4,889,840 disclose mixed catalysts comprising magnesia oxide, zirconium oxide and an alkali metal oxide in an inorganic support. EP-A-0 129 899 and DE-A-34 27 979 describe suitable phosphoric acids and. compounds containing phosphate and also zeolites of the pentasilike type or zealites doped with transition metals. The zeolites of the ZSM type for example ZSM-22, ZSM-23, to ZSM-35, described in document US 5,177,281 are useful in terms of catalyst operating life and reaction conditions. Particularly active palladium catalysts, for example, in A1203 biscuit bed are described in US 3,531,545. The isomerization catalyst is preferably a homogeneous catalyst comprising a noble metal compound of the transition series of the Periodic Table of the You elementa that may be present in the form of metal to good r7">; an oxide or mixed oxide. In addition, compounds of a metal of the major group I or II of the mixture Periodic Table of the Elements are also considered, and may be present as oxide or mixed oxide. Preference is given to using metal from either metal oxide of transition groups VII to VIII of the Periodic Table of the Elements, which may be present in a support, as an isamerization catalyst in an inert gas atmosphere or in a Presence of hydrogen »Preferred alkali metal oxide and / or alkali metal oxide catalysts according to the present invention are preferably prepared by impregnating inorganic supports such as, for example, Si02, A1203, Zr02, Ti02 or mixtures thereof with alkali metal compounds and / or alkaline earth metal compounds, with subsequent drying and calcination to provide the corresponding oxides »A deactivated catalyst can be regenerated in a simple manner by combustion of the cache residues at higher temperatures at 350 ° C in a stream of air and by cooling in an inert gas atmosphere »The catalyst Particularly preferred polymerization employed is PdO on a support of A1203 to well Si02 in the presence of hydrogen, since the Pd content is 0.1 to 5% by weight, based on the total weight of the catalyst.

When the aforementioned catalysts are used, the C4 fraction with intermediate boiling point of the K201 column is converted by partial isomerization into a mixture of i-butene and 2-butenes and returned to the cross-metathesis in ROI to increase the yield of prapena »Alternatively, if the refined feed stream II has an appropriate purity, 1-butene can be obtained without further preparation. It can then be used, for example, to prepare polymers such as copolymers of LLDPE, HDPE copolymer, poly-i-butene, or to prepare butylene oxide. In the isamerization, in the metathesis reactions in ROI and R02, the conditions are selected in such a way that the reactants are present in the liquid phase. The temperature is therefore preferably from 0 to 200 ° C, particularly preferably from 50 to 150 ° C. The pressure is preferably from 2 to 200 bar. The isomerization is preferably completed after 1 second hour, preferably 5 minutes. It can be carried out continuously or in batches, and the reactors can, bed the metathesis reactors, be glass pressure vessels, tube reactors or distillation columns. Here also, the use of tube reactors is preferred. The invention also provides an apparatus for carrying the described process. An apparatus for carrying the process as illustrated in FIG. 1 comprises a metathesis reactor (ROI) for reacting 1-butene with 2-butene whose output leads to a distillation column (K101), which can be configured as a column bed. of dividing wall, to separate the phases C2 / 3 of low boiling point, C4 of intermediate point of boiling and C5 + of high boiling point, where the output of the compounds of lower boiling point leads to a column (K301 ) to separate ethene and prapene, the exit of the intermediate boiling compounds leads the reactor (ROI) to good discharge, and the output of high boiling point compounds leads to a reactor (R02) to react -penteno with etena whose output leads to the column (KiOl) or discharge, where the output of the column (D3) and a line feeding ethene lead to reactar (R2). An apparatus for carrying out the process as illustrated in FIG. 1 comprises a metathesis reactor (ROI) for reacting l-butene with 2-butene whose outlet leads to a distillation column (K101), which can be configured as a dividing wall column, a side column or as an arrangement of two columns, to separate the phases of low boiling point C2 / 3 compounds, intermediate boiling point C4 compounds and high boiling point C5 + compounds, where the low boiling compounds exit leads to a column (K301) to separate etena and prapena, the output of the intermediate boiling point composite leads to the reactor (ROI) or to the discharge and the output of the high boiling point compounds leads to up reactor (R02) to react 2- pentene with ethene whose outlet leads to a distillation column (201), which can be configured as a dividing wall column, a lateral column or a two-column arrangement, to separate phases of low-boiling C2 / 3 compounds , intermediate boiling point C4 compounds and high boiling point C5 + compounds, where the low-boiling compounds exit leads to the -column (K301), the output of the intertidal compounds The boiling medium leads to an isomerization reactor (R03) for the partial isomerization of l-butene to 2-butene and, if desired, in addition to the discharge, where the output of the isomerization reactor (R03) is the output of the intermediate boiling point compounds from (K101) leads to the reactor (ROI) and the output of the high-boiling points leads to the discharge, from the outlet of the column (K301) and a line Etena feed leads to the reactor (R02). Examples Continuous experiments on the synthesis of prapene from refining II Example i Continuous experiment on the cross-metathesis of l-butene with 2-butene in raffinate II Raffinate II (407; of l-butene, 45% cis / rans-2-butene) passes continuously through a ROI tube reactor loaded with a heterogeneous catalyst Re207 / A 1203 at a temperature of 60 ° C, 25 bar and a spatial veilability in the catalyst of 4500 kg / m2h. The product of the reaction is separated by means of a KiOl pressure distillation column (20 bar) in a low boiling point C2 / 3 composite phase, an intermediate boiling point composite fraction comprising C4 olefins and butanes , and a fraction of high boiling compounds comprising 2-penthene and 3-hexene. The percentages reported are offered in mass - L ^ _. C4 C5 / 6% m / m 21 56 EXAMPLE 2 Continuous Experiments on the Etenolysis of the High-Boiling C5 / C6 Product The high-boiling product comprising 2-peppene and 3-hexena of K101 is continuously passed through a charged R02 tube reactor. a heterogeneous catalyst Re207 / A12Q3 at a temperature of 60 ° C and under a pressure of 60 bar ethene (initial material content C2sC5, C6 = i. is I) at an average residence time of 5 minutes. The product of the reaction is separated by means of pressure distillation K201 (20 bar) in a phase of low boiling C2 / 3 compounds, a fraction of boiling intermediate compounds comprising l-butene and a fraction of high-boiling compounds comprising unreacted 2-pentene and 3-hexene. The percentages reported are in mass; C2 / 3 1-butena C5 / 6% m / m 41 EXAMPLE 3 Continuous Partial Samerization of 1-Butene The intermediate boiling point product product comprising 1-butene from column K201 continuously passes in the presence of 0.17. hydrogen gas through a flow tube loaded with a PdO / A12Q3 heterogeneous catalyst at 1000C and 15 bar with average residence time of 30 minutes »The product of the reaction is analyzed by gas chromatography and consists of 607. of -butene and 40% of 2-butanes.

Claims

CLAIMS 1. A process for the preparation of propene and, if desired, 1-butene mediating a) the reaction of i-butene and 2-butene to provide propene and 2-pentene in the presence of a metathesis catalyst comprising at least a compound of a transition metal of groups VIb, Vllb or VIII of the Periodic Table of the Elements, b) the subsequent separation of the prapene and 2-pentene formed, c) the subsequent reaction of 2-peptene with ethene to provide propene and 1-butene in the presence of metathesis catalyst comprising at least one metal compound of the transition groups VIb, Vllb to VIII of the Periodic Table of the Elements, d) the subsequent separation of the propene and the 1 -butena formed, e) the discharge of at least a part of the i-butene formed and / or the at least partial isamerization of the i-butene formed. to provide 2-butene in the presence of an isamerization catalyst and the subsequent return of the discharged l-butene and the 2-butepo formed together with a part of the C4 fraction that was reacted in step a) to step a).
2. A process according to claim 1, wherein the 1-butene formed in step c) is at least partially bristled in the presence of an isomerization catalyst to provide 2-butene and the resulting mixture of 1-butene and 2-butene. -butena is returned to step a).
3. A process of compliance with claim 1, wherein at least a certain part of the l-butene formed in step c) is discharged and the discharged 1-butenal is returned to step a).
4. A process according to any of claims 1 to 3, wherein step b) is a distillation that can be carried out in a dividing wall column, a side column or an array of 2 columns where it is obtained a phase of low boiling compounds containing propene, passtically a butene boiling intermediate compound phase, and a bottom phase containing L2-pentene, and / or in step d) is a distillation which it can be carried in a column with a dividing wall where a low-boiling compound phase containing propene is obtained, a phase of boiling intermediate compounds containing i-butena and passtically a bottom phase containing 2-pentene, dapde steps b) and d) are carried out in a distillation column.
5. A process according to any of claims 1 to 4. wherein the reaction in steps a) and / ac) na is carried out until its completion and in steps b) and / ad) a phase of C2 / 3 low-boiling compounds, a C4 intermediate-boiling compounds phase and a bottom phase containing C5 + compounds, where the phases of low-boiling compounds, which can be combined, are separated by distillation at phases C2 and C3 and phase-C2 is returned to step c), at least a certain part of the intermediate-boiling-stage phases, which can be combined, returns to step a) and at least a part of the Background phases, which can be combined, return to step c).
6. A process according to any one of claims 5 to 5, wherein 1-butene and 2-butene are used as a mixture in a stream of C4, preferably from a still or a refinery, in particular as refined II, where the C4 stream can pass over absorbent materials before the reaction to purify it.
7. A process according to claim 6, wherein the molar ratio between l-butene and 2-butene is 10 if ai: 10. A process according to any of claims 1 to 7, where use is made. of a heterogeneous metathesis catalyst comprising up to rhenium or ruthenium compound, preferably a rhenide oxide, in an inorganic soup. 9 »A canfarity process can claim 8, wherein the metathesis catalyst comprises or consists of Re2Q7 in a part of A12Q3, and the content of rhenium oxide is 1 to 20% by weight, preferably 3 to 10% by weight, based on the total weight of the catalyst »10. A process according to any of claims ia 9, wherein the reaction of i-butene and 2 ™ butena and / the reaction of 2-entene with etena are carried as reactive distillation »11» A process of canfarmidad with any of claims 1 to 10, where the isamerization catalyst used is a composite of noble metal or its oxidized , which may be present in a support, in the presence of an inert gas to well in a hydrogen atmosphere. 12. A process according to any of claims ia 11, wherein between steps b) and c), the product of high A boiling point comprising 2-pentene and 3-hexene which has been separated is subjected to distillation to separate 2-pentene and 3-hexepa »13. A process for the preparation of propene mediating a) the reaction of l-butene and 2 ~ butene to provide propene and 2 ~ pentene in the presence of a metathesis catalyst comprising at least one compound composed of a transitional group of the groups Vlb, Vllb or VIII of the Periodic Table of the Elements, b) the subsequent separation of the formed and 2-pentene and the butenes without reacting, c) the subsequent reaction of the 2-enanthene with etena to farme prapene and l-butene in the presence of a metathesis catalyst comprising at least one metal compound of the transition groups VIb, VILEb or VIII of the Table Periodic of the Elasties, d) the sub-sequential transfer of the unreacted mixture to step b) to separate the propene and 1-butenes formed, e) the discharge of at least a certain part of the unreacted C4 fraction separated in step b) and / or to the partial orevasation of the 1-butene present in this C4 fraction to provide 2-butene in the presence of an isomerization catalyst and by the subsequent return of the mixture obtained to step a). 14. A device for carrying a process according to any of claims 1 to il, comprising a metathesis reactor (ROI) for reacting 1-butene can 2-butene whose exit. leads to a distillation column (K101), which can be configured as a dividing wall column, a side column, or a 2-column arrangement, to separate phases of low-boiling C2 / 3 compounds, pointed C4 compounds boiling intermediate and high boiling point C5 + compounds, where the low-boiling compound output leads to a column (OO1) to separate ethene and propene, the output of the intermediate boiling point leads to the reactor ( ROI) or the discharge and exit of the high-boiling point compounds leads to a reactor (R02) for reacting 2-pentene with ethene whose outlet leads to a distillation column (K201), which can be configured as a column of dividing wall, a lateral column to an arrangement of 2 columns, to separate the phases of low boiling point C2 / 3 compounds, intermediate point C4 boiling compounds and high point ebulous C5 + compounds When the exit of the low-boiling compounds leads to the column (K301), the output of the intermediate-boiling compounds leads to an isomerization reactor (R03) for the partial isomerization of l-butene at 2 ° C. -butene and, if desired, additionally, to the discharge, dande the output of the reactor of isation (R03) together with the output of the compounds of intermediate point of boiling (K101) leads to the reactor (ROI) and output of high boiling point compounds leads to the return to (R02) or to the discharge, where the outlet of the column (K301) and an ethene feed line lead to the reactor (R02).