MXPA97006729A - Process of hidrogenac - Google Patents

Abstract

The present invention relates to: In a process for the hydrogenation of hydrocarbons from 2 to 8 unsaturated carbon atoms of multiple layers in alkynes 2 to 8 carbon atoms and / or alkylenes of 4 to 8 carbon atoms and / or alkadienes of 4 to 8 In particular, in the fluids comprising these by contact with a packing of a catalyst in the presence of free hydrogen, the catalyst packing can be produced by applying at least one substance that is active as a catalyst and / or promoter or activator to meshes or thin sheets non-woven or knitted as a sopor material

Description

"HYDROGENATION PROCESS" The present invention relates to a process for hydrogenating alkynes of 2 to 8 carbon atoms and / or alkynes of 4 to 8 carbon atoms, and / or alkadienes of 4 to 8 carbon atoms in fluids comprising these. Alkynes, eg, acetylene, and dienes are undesired materials in many industrial syntheses due to their tendency to polymerize and their pronounced tendency to form complexes with transition metals. Sometimes they have a very strong detrimental effect on the catalysts used in these reactions. Thus, for example, the acetylene present in the C2 stream of a vapor pyrolyzer interferes with the polymerization of ethylene so that the acetylene content in the C2 stream has to be kept very small, preferably less than 1 part per million. The C3 stream of the vapor pyrolyzer, comprising not only propylene but also from 2 percent to 3 percent propadiene (PD) and approximately the same amount of propyne (methylacetylene, MA), also has to be purified before polymerization to provide the polypropylene. The typical multi-layer unsaturated hydrocarbon content herein is from about 4 percent to 6 percent by weight. A reduction of this content to a maximum of 10 parts per million should be achieved preferably. The C4 stream of the steam pyrolyzer also contains up to 70 percent unsaturated hydrocarbons of multiple layers. These are mainly butadiene, vinylacetylene and ethylacetylene. The total content of multi-layer unsaturated hydrocarbons should be reduced to less than 20 parts per million, preferably to a maximum of 10 parts per million. This is achieved in the industira by selective hydrogenation of the hydrocarbon streams through heterogeneous noble metal catalysts in ceramic supports. The great demands are placed here on the hydrogenation catalysts used in relation to their selectivity and activity, since a very complete hydrogenation of the multi-layered unsaturated hydrocarbons without loss of monounsaturated hydrocarbons such as ethylene, propene or butenes should be achieved. In some cases, a crude C4 stream from a steam pyrolyzer, containing from about 40 percent to 60 weight percent butadiene, must be selectively hydrogenated to form butenes in the highest possible yield. In this case also, industrial heterogeneous noble metal catalysts in ceramic supports are used. For these applications, activated or non-activated noble metal catalysts are used on ceramic supports usually with palladium as the active component, in an amount of 0.01 percent to 1 percent by weight. In known processes, carbon monoxide is often mixed in the reaction mixture for the hydrogenation of acetylene, in order to increase the selectivity of the catalyst. The disadvantage of this method is that the action of increasing selectivity of carbon monoxide depends greatly on the temperature. Large temperature gradients in the catalyst bed therefore result in worsening selectivity. In addition, the relatively high working temperatures that are necessary when carbon monoxide is added and favor the increased formation of unwanted polymers (untreated oil). The known catalysts for the selective hydrogenation of the multilayer unsaturated compounds are generally prepared by impregnation of an inert support with an aqueous solution of a palladium salt, a mixture of a palladium salt with an activating salt or by separate impregnation. successively with aqueous solutions of the active substances such as the catalyst and / or the activator, the subsequent drying and calcination at relatively high temperatures. Most of the available catalysts are reduced with hydrogen after installation in the reactor. Patent Number DE-A 2 107 568 describes a process for purifying hydrocarbons by selective hydrogenation. Multilayer unsaturated compounds such as methylacetylene and propadiene are hydrogenated in the liquid phase in two reaction zones connected in series. In the first reaction zone, part of the liquid evaporates. The catalyst used is Pd on AI2O3. Patent Number EP-AO 653 243 discloses supported catalysts which are obtained by dissolving a solution of palladium nitrate, possibly together with a solution of silver nitrate, in a solvent, mixing the solution with high molecular weight sodium polyacrylate and mixing with aluminum oxide as a support. The composition obtained is shaped, dried and calcined. The catalyst is used for the selective hydrogenation of methylacetylene and propadiene in a stream of C3 in the liquid phase. Patent Number EP-A-0 532 482 describes a process for the selective hydrogenation of crude C4 fractions rich in butadiene. The selective hydrogenation of butadiene to butenes is carried out in the liquid phase via palladium catalysts supported by a fixed bed. The hydrogenation is carried out in two reaction zones connected with series. Patent Number DE-C-31 19 850 describes a process for the selective hydrogenation of butadiene in a C4 fraction. The hydrogenation of the liquid phase is carried out using 0.3 weight percent palladium on an aluminum oxide support in the form of spheres having a diameter of 2 millimeters. Patent Number EP-B-0 288 362 describes a process for the isomerization of l-butene in 2-butenes in a hydrocarbon fraction of 4 carbon atoms comprising butadiene and sulfur-containing compounds. The hydrocarbon fraction is passed through a first bed of a catalyst comprising palladium and gold and / or platinum. The stream is then passed over a second catalyst bed comprising palladium deposited on aluminum oxide or on silicon dioxide. U.S. Patent No. 4,260,840 describes a process for purifying a stream comprising l-butene. Here, butadiene is selectively hydrogenated in butene in a stream of C4 containing at least 30 weight percent l-butene. As the support catalyst, Pd / Cr is used on aluminum oxide in a packed catalyst bed. U.S. Patent No. 5,475,173 discloses a process for the selective hydrogenation of 1,3-butadiene. The catalyst comprises palladium and silver on AI2O3 and also an alkali metal fluoride. Patent Number EP-B-0 064 301 describes a catalyst for the selective hydrogenation of acetylene. The catalyst comprises from 0.01 percent to 0.025 percent by weight of palladium and from 2 to 6 times this amount of silver on an alpha-Al2? 3 support having a surface area of 3 to 7 square meters per gram. The catalyst has a low sensitivity to CO and a long duration of operation. Patent Number EP-B-0 089 252 describes a catalyst for the selective hydrogenation of acetylenic hydrocarbons. The catalyst comprises 0.03 percent to 1 percent by weight of palladium and 0.003 percent to 0.3 percent by weight of gold on a support of I2O3. The North American Patent describes a process for preparing a palladium catalyst on a titanium dioxide support. The palladium content is 0.01 percent to 0.2 percent by weight. The catalyst is suitable for the selective hydrogenation of acetylene in ethene. Patent Number DE-C 1 284 403 describes a process for preparing palladium-heavy metal-alumina catalysts for the removal of acetylenes and diolefins from gas mixtures comprising predominantly monoolefins by selective hydrogenation. The Pd / Cr on the support containing alumina is used to remove methylacetylene and propadiene. Patent Number DE-C 1 299 629 describes a process for removing acetylenes from gas mixtures comprising predominantly olefins by selective hydrogenation. A catalyst of Pd / Cr on alumina is likewise used for the hydrogenation of the propadiene gas phase and methylacetylene gas. Known supported catalysts have the usual disadvantages of oxide-supported catalysts. They present abrasion, are sensitive to mechanical stress in the case of pressure pulses or when a pressure drop occurs across the catalyst bed and are unpleasant to handle when new or depleted catalyst is installed or removed. In Catalysis Today, 24 (1995), pages 181-187 describes the use of an alpha-A1103 monolith having a wall thickness of 0.2 millimeter and a cell density of 110 cells per square centimeter for the selective hydrogenation of acetylene in the current of C2 from a vapor pyrolyzer in the gas phase and liquid. A disadvantage of ceramic monoliths is the absence of cross-mixing in the individual separate channels and the formation of laminar flows for low flow velocities, which leads to more poor selectivities. It is an object of the present invention to provide catalysts for the selective hydrogenation of multi-layered unsaturated hydrocarbons in hydrocarbon stream. A further object of the present invention is the provision of a process for the hydrogenation of multilayer unsaturated hydrocarbons which avoids the above-described disadvantages of the known catalysts. We have found that these objects are achieved by a process for the hydrogenation of hydrocarbons of 2 to 8 unsaturated carbon atoms of multiple layers, in particular alkynes of 2 to 8 carbon atoms and / or alkylene of 4 to 8 carbon atoms and / or alkdienes of 4 to 8 carbon atoms in fluids comprising these by contacting a catalyst packing in the presence of free hydrogen, wherein the catalyst packing can be produced by applying at least one substance which is active as a catalyst and / or activator to woven meshes, with knitted fabric or thin sheets as a support material. The catalysts used in accordance with the present invention have the structure that will be described below.

Support material The support materials that can be used for the catalysts used in accordance with the present invention are many thin sheets and woven meshes, as well as knitted fabrics. According to the present invention, it is possible to use woven meshes having different fabric types, for example plain woven mesh, twill mesh, braided woven mesh, satin woven mesh, five arrows or other special types of fabric . The appropriate woven wire meshes are, according to one embodiment of the invention, meshes made of metal wires capable of weaving such as iron, spring steel, brass, phosphor bronze, pure nickel, Monel metal, aluminum, silver, Nickel, nickel, Nichrome, chrome steel, stainless steel, acid resistant and chrome-nickel steels resistant to high temperature and also titanium. The same applies to knitted fabrics.

It is also possible to use woven or knitted meshes of inorganic materials, for example AI2O3 and / or Si02 Synthetic wires and woven meshes made of plastics can also be used according to one embodiment of the invention. Examples are polyamides, polyesters, polyvinyls, polyolefins such as polyethylene, polypropylene, polytetrafluoroethylene and other plastics that can be processed with woven meshes or knitted fabrics. Preferred support materials are thin sheets of metal or woven metal meshes, for example stainless steels having the material numbers 1.4767, 1.4401, 2.4610, 1.4765, 1.4847, 1.4301, etc. The designation of these materials by material numbers mentioned is in accordance with the material numbers in "Stahleisenliste", published by Verein Dutscher Eisenhüttenleute, Eighth edition, pages 87, 89 and 106, Verlag Stahleisen mbH, Dusseldorf, 1990. The number of 1.4767 materials is known under the name of Kanthal. Thin sheets of metal and woven metal meshes are particularly suitable since they can be roughened by heating the surface before being coated with the catalytically active compounds or activators. For this purpose, the metal supports are heated to a temperature of 400 ° C to 1100 ° C, preferably 800 ° C to 1000 ° C, for 0.5 to 24 hours, preferably 1 to 10 hours, in an atmosphere that it contains oxygen such as air. According to one embodiment of the invention, this pretreatment can be used to control or increase the activity of the catalyst.

Coating the catalyst support In accordance with the present invention, the catalyst supports used in accordance with the present invention can be coated by various methods with catalytically active compounds and activators. According to one embodiment of the invention, substances which are active as a catalyst and / or activator are applied by impregnation of the bulk support, by electrochemical deposition or deposition in the presence of a reducing agent (electrode-free deposition). The catalyst screen or the thin sheet of the catalyst can then, in accordance with one embodiment of the invention, be configured to form the monoliths for installation in the reactor. According to a further embodiment of the invention, the configuration can also be carried out before the application of the active or activating substances. According to one embodiment of the invention, the catalyst supports that can be used in accordance with the present invention, in particular the woven or knitted fabrics, can be coated with "thin layers" of catalytically active compounds and activators. by means of a vacuum vapor deposition technique. For the purposes of the present invention, "thin layers" are coatings within the thickness scale of a few angstrom units (10 um) to a maximum of 0.5 microns. As vacuum vapor deposition techniques, different processes may be employed in accordance with the present invention. Examples are thermal vaporization, flash vaporization, cathode atomization (ion bombardment) and the combination of thermal vaporization and cathode atomization. The thermal vaporization here can be carried out by direct or indirect electric heating. Vaporization by means of an electronic beam can also be used in accordance with the present invention. For this purpose, the substance to be vaporized is heated on the surface in a crucible cooled with water by means of an electron beam so intensively that the metals of high melting temperature and dielectrics are still vaporized. According to one embodiment of the invention, chemical reactions can be carried out during the accumulation of the layers by means of vapor deposition techniques by means of focused additions of appropriate quantities of the reactive gases to the residual gas. An appropriate reaction procedure therefore allows oxides, nitrides or carbides to be produced on the support. Using the process of the present invention, the supports, in particular the woven or knitted fabrics, can be treated with intermittent steam or continuously in a vacuum vapor deposition unit. For example, the steam treatment is carried out by heating the catalytically active component or compound to be applied, for example a noble metal, in a vacuum of 10-2 to 10-l? preferably from 10-4 to 10 ~ 8 torr, by means of an electron beam so intense that the metal vaporizes outside the crucible cooled with water and is deposited on the support. The support or knitted fabric mesh is advantageously positioned in such a way that as much as possible of a portion of the vapor stream condenses on the support. The meshes or knits here can be continuously coated by means of a winding machine. In accordance with the present invention, preference is given to continuous ion bombardment in an air-to-air unit. Suitable parameters and conditions for vacuum vapor deposition techniques can be found, for example, in "Handbook of Thin Film Technology", Maissel and Glang, McGraw Hill, New York, 1970, "Thin Film Processes" by JL Vossen and B. Kern, Academic Press, New York, and also in Patent Number EP-A 0 198 435. Patent Number EP-AO 198 435 discloses the production of a catalyst mesh package by platinum vapor deposition. or plant and rhodium towards a stainless steel mesh. In the production of the catalyst according to the present invention by vacuum vapor deposition techniques, the polycrystalline particles which are as disordered as possible must be produced on the support and the predominant proportion of the atoms of the particles must remain on the surface. The vacuum vapor deposition technique employed here is therefore different from the vapor deposition techniques known in the optical and electrical industries where a high purity of the support and the materials deposited to steam and a condensation temperature have to be ensured. default on the support as well as a specific vapor deposition regime will have to be graduated. In the process of the present invention, it is possible for one or more of the catalytically active compounds or activators to be vapor deposited. According to one embodiment of the invention, the coatings of the catalytically active substance are preferably in a thickness range from 0.2 nm to 100 nm, particularly preferably from 0.5 nm to 20 nm, in particular from 3 to 7 nm. According to one embodiment of the invention, the catalytically active compounds used as the transition group VIII elements of the Periodic Table of the Elements, preferably nickel, palladium and / or platinum, in particular palladium. The activators may be present according to an embodiment of the invention and may be selected according to the present invention from, for example, the elements of the main groups III, IV, V and VI and also the transitional groups I, II, III, VI and VII of the Periodic Table of the Elements. The activator which is used in accordance with a preferred embodiment of the invention is selected from the group consisting of copper, silver, gold, zinc, chromium, cadmium, lead, bismuth, tin, antimony, indium, gallium, germanium, tungsten or mixtures thereof, particularly preferably silver, indium and germanium, copper, gold, zinc, chromium, cadmium, lead, bismuth, tin, antimony. The thickness of the activator or activator layer used according to one embodiment of the invention is from 0.1 to 20 nm, preferably from 0.1 to 10 nm, in particular from 0.5 to 3 nm. Prior to the application of the catalytically active substance and / or the activator, the support can be modified by vapor deposition of an oxidizable metal layer and subsequent oxidation to form an oxide layer. According to one embodiment of the invention, the oxidizable metal used is magnesium, aluminum, silicon, titanium, zirconium, tin or germanium or a mixture thereof. The thickness of this oxide layer, according to the present invention, is within the range of 0.5 to 200 nm, preferably 0.5 to 50 nm. The coated support material can be heat treated after coating, for example a support material coated with palladium at a temperature of 200 ° C to 800 ° C, preferably 300 to 700 ° C, for 0.5 to 2 hours. After the catalyst has been produced, if desired or if necessary, it can be reduced with hydrogen at a temperature of 20 ° C to 250 ° C, preferably 100 ° to 200 ° C. This reduction can also be carried out in the reactor itself, which is preferred. According to one embodiment of the invention, the catalysts can be systematically accumulated for example in a vapor deposition unit using a plurality of different vaporization sources. In this way, for example, an oxide layer or, by means of reactive vapor deposition, a bonding layer can first be applied to the support. The catalytically active or activating components can be vapor deposited on this base layer in a plurality of alternative layers. By introducing a reactive gas into the receptacle during the vapor deposition it allows the activating layers of oxides and other compounds to be produced. The heat treatment steps may also be carried out between them or subsequently. The active substance (s) as a catalyst and / or activator can also be applied by impregnation. The catalysts produced by vapor deposition in accordance with the present invention, in specific catalyst meshes, catalyst knit fabric materials and thin sheets of catalyst have very good adhesion and catalytically active compounds or activators. Therefore, they can be configured, cut and for example processed into monolithic catalyst elements without the catalytically active or activating compounds being separated. The packings of the catalyst of any form for a reactor, eg, through-flow reactor, a reaction column or distillation column can be produced from catalyst screens, knitted products and catalyst from thin sheets of catalyst. the present invention. It is possible to produce catalyst packing elements having different geometries, as are known from distillation and extraction technology. Examples of advantageous catalyst packing geometries according to the present invention which offer the advantage of a low pressure drop during operations are those of the structural type Montz A 3 and Sulzer BX, DX and EX. An example of a catalyst geometry according to the present invention made of thin sheets of catalyst or thin sheets of expanded metal catalyst are those of the Montz BSH type. The amount of the catalyst, in particular the amount of the catalyst mesh, knitted product of the catalyst or amount of thin sheet of the catalyst, processed by unit volume can be controlled within a wide scale, whereby a different size of the openings or channel widths in the catalyst mesh or knitted products of the catalyst or in the thin sheet of catalyst. The appropriate selection of the amount of catalyst mesh, knitted product of the catalyst or thin sheet of catalyst per unit volume allows a maximum pressure drop in the reactor, eg, the through-flow or distillation reactor, that must be graduated and in this way allows the catalyst to be matched with the experimentally determined requirements. The catalyst used in accordance with the present invention preferably has a monolithic form as described for example in Patent Number EP-AO 564 830. Additional suitable catalysts are described in Patent Number EP-AO 218 124 and Patent Number EP -AO 412 415. A further advantage of the monolithic catalysts used in accordance with the present invention is the good fixing capacity in the reactor bed so that, for example, they can be used very well in liquid phase hydrogenations in the form of upflow to a load in high cross section. Compared in the case of conventional catalyst supports, there is the danger of fluidization in the catalyst bed which can lead to possible abrasion or disintegration of the shaped bodies. In gas phase hydrogenation, the catalyst packing is able to withstand shock or vibration. No abrasion occurs.

Hydrogenation The catalysts described above are used in accordance with the present invention in processes for the hydrogenation, in particular the selective hydrogenation, of the hydrocarbons of 2 to 8 unsaturated carbon atoms of multiple layers in fluids comprising these. The multi-layer unsaturated hydrocarbons, for example, can be alkynes of 2 to 8 carbon atoms, alkylenics of 4 to 8 carbon atoms, alkadienes of 4 to 8 carbon atoms and mixtures of these. Preferably they are hydrocarbons of 2 to 6 unsaturated carbon atoms, in particular hydrocarbons of 2 to 4 carbon atoms. According to one embodiment of the invention, these multi-layer unsaturated hydrocarbons are present in the streams of C2, C3, C4, C5 or Cg preferably in streams of a steam pyrolyzer or a catalytic pyrolyzer. These streams generally comprise, as described above, more or less large amounts of the hydrocarbons of 2 to 6 unsaturated carbon atoms of corresponding multiple layers. Using the catalysts of the present invention, these compounds can be converted to the corresponding monounsaturated hydrocarbons with high selectivity and high yield. The selective hydrogenations, according to the present invention, are carried out either adiabatically or isothermally in the gas or liquid phase. The number of reactors depends on the amount of compounds to be hydrogenated in the gas stream or the liquid stream. For example, an adiabatically driven reactor is sufficient for contents of less than 1 weight percent in gas phase hydrogenations, with the multi-layer / hydrogen unsaturated hydrocarbon ratio being 1.8 to 2. If the content of the compounds Multi-layer unsaturates is higher, the hydrogenation is carried out in two or more reactors connected in series. In this case, the hydrogen is fed before in each reactor. Hydrogenation of the C3 stream in the gas phase is usually carried out in three reactors connected in series, with a conversion of 60 percent to 70 percent achieved in the first reactor, and a conversion of 30 percent to 40 percent that is achieved in the second reactor. The remaining conversion is achieved in the third reactor, or the third reactor serves as a safety racer. In the case of hydrogenation in the liquid phase, a reactor operated adiabatically without sufficient recirculation for multi-layer unsaturated hydrocarbon contents up to 3.3 weight percent. At an unsaturated hydrocarbon / multilayer hydrocarbon ratio of about 1 to 1.5, this provides depletion of up to 500 to 1000 parts per million in yield, which corresponds to the conversion from 95 percent to 99 percent. If the content of multi-layer unsaturated hydrocarbons is higher, recirculation is usually necessary. If the content of the multi-layer unsaturated hydrocarbons in the yield will be reduced to less than 10 parts per million, the hydrogenation is usually carried out in two reactors connected in series, with the hydrogen being fed before in each reactor as it is described in the foregoing. At an unsaturated hydrogen / hydrocarbon ratio of about 4 to 8, a total conversion of 99.9 percent is achieved in the second reactor. In the hydrogenation of C2 streams having acetylene contents of more than 2 weight percent, the hydrogenation is usually carried out in an isothermal reactor and one or two adiabatic reactors connected to the isothermal reactors. In the hydrogenation of liquid phase of a stream of C4 with high butadiene content, one or two steps are provided depending on the desired butadiene exhaustion. Above a depletion factor of 200, a two-stage process is generally preferred. In this way, for example, the selective hydrogenation of a crude C4 stream from a steam pyrolyzer containing about 45 weight percent butadiene is carried out in two stages, up to a residual butadiene content of less than 10 parts per million. It is of course possible to remove the low contents of butadiene selectively in the so-called remaining hydrogenation. In this case, a one-step process with depletion factors of more than 1000 is accessible. For example, the hydrogenation of 0.5 percent by weight of butadiene to values of less than 10 parts per million is carried out in a process of one step, where at the same time a maximum of butene-1 can be retained. According to one embodiment of the invention, the hydrogenation is carried out in the gas phase. In particular, the hydrogenation of C2 currents and / or C3 currents is carried out in the gas phase. Examples of the reactors that can be used are tube reactors and shaft reactors as well as tube bundle reactors. In accordance with one embodiment of the invention, a plurality of tube reactors can be connected in series. Here, in accordance with one embodiment of the invention, hydrogen is fed earlier in each reactor. For a further description of the reactors that are suitable in accordance with the present invention, reference is made to the introduction. The selective hydrogenation in the gas phase, according to one embodiment of the invention, is carried out at pressures from 5 to 50 bar, preferably from 10 to 30 bar, in particular from 15 to 25 bar. According to one embodiment of the invention, the space velocities are from 500 to 8000 cubic meters per cubic meter per hour, preferably from 1000 to 5000 cubic meters per cubic meter per hour, in particular from 2000 to 4000 cubic meters per cubic meter per hour. The inlet temperature for hydrogenation, according to one embodiment of the invention, is from -20 ° C to 150 ° C, preferably from 20 ° to 120 ° C, in particular from 20 ° C to 80 ° C. It is possible to use an adiabatically driven or isothermally driven reactor. The hydrogenation can also be carried out in a plurality of reactors connected in series, these being operated isothermally or adiabatically. For example, two adiabatic reactors may follow an isothermal reactor, particularly in the hydrogenation of a stream of C2. In accordance with a modification of the invention, the hydrogenation is carried out in the liquid phase or in a liquid / gas mixed phase. with at least 50 weight percent of the hydrocarbon stream in the liquid phase. Here, in accordance with one embodiment of the invention, the hydrogenation can be carried out in a downflow mode or in an upflow mode. In the upflow mode, the added hydrogen may be present as a solution in the liquid phase. The reactors that can be used here are, for example, tube reactors or tube bundle reactors. According to one embodiment, the hydrogenation is carried out at a pressure of from 5 to 70 bar, preferably from 5 to 40 bar, in particular from 10 to 30 bar. According to one embodiment of the invention, the space velocity is from 1 to 100 cubic meters per cubic meter per hour, preferably from 2 to 40 cubic meters per cubic meter per hour, and in particular from 2 to 20 cubic meters per meter cubic per hour. The inlet temperature for hydrogenation, according to one embodiment of the invention, is from -10 ° C to 150 ° C, preferably from 0 ° to 120 ° C, in particular from 0 ° to 90 ° C. In order to ensure the formation of a liquid phase, it is necessary to select appropriate parameters of temperature and pressure that depend on the mixture of the substances used in each case. According to one embodiment of the invention, the hydrogenation is carried out in a catalytic distillation process. In this process, hydrogenation as described above, it is combined with simultaneous distillation or rectification through the catalyst packing. In this process, hydrogenation and distillation are carried out simultaneously or immediately one after the other. At least one component of the reaction mixture is distilled from the hydrogenation mixture after hydrogenation. The term "catalytic distillation" refers to a chemical reaction, here a hydrogenation, which is combined with a distillation or rectification in an appropriate apparatus. As the reactor, for the catalytic distillation, it is possible to use any suitable distillation apparatus in which the catalyst packing can be installed in the distillation part. This is possible, for example, by installing the catalyst packing in a distillation column in the distillation apparatus. The reaction mixture, ie the hydrocarbon stream, is introduced into the distillation apparatus at an appropriate point, in accordance with a mode at the bottom of the distillation apparatus. This is particularly advantageous in the hydrogenation of a stream of C3, C4, C5 or Cg. The hydrogenated components and the alkenes are extracted from the top of the distillation apparatus. Preferably, the hydrogenation continues selectively and essentially no hydrogenation of alkenes occurs in alkanes. The invention is illustrated by the following examples. In the operating tests for hydrogenation in the gas phase, monolithic catalysts were used in a non-pressurized laboratory apparatus or in a pilot-part apparatus under increased pressures. The temperatures of the gas mixture entering the hydrogenation zone are generally from 15 ° C to about 120 ° C, preferably from 25 ° C to 90 ° C. The volume ratio of hydrogen to the multilayer unsaturated hydrocarbons is generally from 0.5: 1 to 2.5: 1, in the hydrogenation of C2 preferably from 1.1: 1 to 2: 1, in particular from 1.2: 1 to 1.8 : 1, and in the first stage of hydrogenation of C3 is from 0.5: 1 to 0.8: 1. Next, the proportions in volume of gas are the proportions in volume to STP.

EXAMPLE 1 A simple woven wire mesh of material Number 1.4301 and having a mesh opening of 0.125 millimeter and a wire diameter of 0.1 millimeter was heated in air at 800 ° C for 3 hours. After cooling, the support mesh which had been pretreated in this way had first 5 nm of Pd and then 1 mm of Ag vapor deposited on both sides in an electron beam vapor deposition unit at a pressure of 1 to 3. x 10-6 torr. The thickness of the layers was measured by means of a crystal oscillator and the vapor deposition rate was controlled using the crystal oscillator. The amount of palladium deposited was 138 milligrams per square meter and the amount of silver was 19.5 milligrams per square meter. The catalyst mesh produced in this way was manufactured in 3 monoliths that had a height of 90 millimeters and a diameter of 18.6 millimeters. in the middle of the monoliths there was a hole for a thermoelectric pile that has a diameter of 4 millimeters. To produce the monoliths, the mesh strips that are 92 millimeters wide and 37.5 centimeters long were cut and one of these was corrugated by means of a serrated roller (0.5 millimeter module). This corrugated mesh was placed together with a smooth mesh and wound around a 4 mm thick metal rod. This provided a monolithic catalyst that was reinforced by spot welding on the outer edge.

EXAMPLE 2 Gas phase hydrogenation of a C3 stream under pressure. Three monoliths produced as described in Example 1 and having a total surface area of 4219 square centimeters were installed in a reactor for the test phase hydrogenation of methylacetylene gas and propadiene in a C3 stream from a steam pyrolyzer. . The multiple thermoelectric battery was inserted axially into the hole for the thermoelectric stack 4 millimeters wide. The process conditions were graduated according to the conditions of the first step of the selective hydrogenation usually of 3 steps of methylacetylene and propadiene in the C3 stream.

The reactor had a diameter of 18.6 millimeters and a length of 2 meters. The catalyst monolith had a height of 27 centimeters and a volume of 70 milliliters. After being washed with nitrogen and hydrogen at 120 ° C, 660 grams per hour of a gas mixture composed of 6.8 percent propane, 1.7 percent propadiene and 2.2 percent methylacetylene in propylene were mixed with different amounts of hydrogen and it was passed through the catalyst to an inlet temperature of 50 ° C and a pressure of 10 bar. The compositions of the reaction product are summarized in the Table below. Table 1 H2 H2 /% in% in% in% in% in ConverS [1 / h] MA volume volume volume volume volume (prope PD of de de de C6 + (MAPD) no) Propane Propene PropaPropina [%] [%] diene 8. 1 0.5 6.848 91.52 0.737 0.67 0.22 64 90 8. 9 0.55 6.895 91.61 0.653 0.594 0.244 68 88 9. 7 0.6 6.962 91.67 0.567 0.53 0.262 72 86 11. 3 0.7 7.161 91.72 0.439 0.439 0.268 78 81 MAPD is a mixture of multi-layer unsaturated hydrocarbons, namely methylacetylene and propadiene. The ratio of hydrogen to MAPD is the volume ratio. S is the propene-based selectivity. Under the conditions of the first hydrogenation step, the catalyst has very high selectivities.

EXAMPLE 3 A simple woven wire mesh made of material number 1.4767 and having a mesh aperture of 0.18 millimeter and a wire diameter of 0.112 millimeter was heated in air at 900 ° C for 5 hours. After cooling, the support mesh, which had been pretreated in this way, had first 92 milligrams of Pd / square meter and then 26.4 milligrams of Zn / square meter of vapor deposited under the same conditions on both sides in a deposition unit of electronic beam vapor at a pressure of 1 x 10 ~ 6 torr. As described in Example 1, a rolled monolith of 126 cubic centimeters was produced from the catalyst mesh obtained in this manner.

EXAMPLE 4 Pressure-free C2 gas phase hydrogenation The monolith of the catalyst that is obtained as described in Example 3 was installed in a tube reactor as described in Example 2. The catalyst test was carried out under atmospheric pressure using a gas mixture of 1 volume percent acetylene, 2 volume percent hydrogen and 97 volume percent ethylene at a space velocity through the catalyst of 3000 cubic meters / cubic meters (cat) per hour. At 82 ° C, an acetylene conversion of 70 percent was achieved at a selectivity with respect to ethylene of 97 percent. Under otherwise identical reaction conditions, a commercially supported catalyst containing 0.02 weight percent of Pd and 0.01 weight percent of Zn, provided an ethylene selectivity of only 62 percent at a conversion of 70 percent.

EXAMPLE 5 The support material used was of the material described in Example 3 which was pretreated by heating in air at 900 ° C and subsequently had 138 milligrams per square meter of palladium vapor deposited thereon using a method similar to that of Example 3. Rolling together a corrugated and a smooth strip of the catalyst mesh that has a width of 10 centimeters, produced a monolith that has a hole for the thermoelectric pile of 5 millimeters. The resulting monolith had a volume of 71.6 cubic centimeters and consisted of 15.25 square decimeters of catalyst mesh.

EXAMPLE 6 Hydrogenation of gas phase of a C2 stream under a pressure of 20 bar The catalyst monolith produced as described in Example 5 was installed in a tube reactor as described in Example 2. After being washed with nitrogen, the catalyst was reduced with 10 liters per hour of hydrogen for 3 hours at 150 ° C. At an inlet temperature of 82 ° C, 160 liters per hour of a gas mixture comprising 98.824 volume percent ethylene and 1.145 volume percent acetylene, which had been mixed with 1.46 volume percent hydrogen, they were then passed over the catalyst. The reaction product consisted of 99,394 volume percent ethylene, 0.486 volume percent ethane and 0.01 volume percent acetylene (99.1 percent conversion, 58 percent selectivity).

Upon increasing the hydrogen content to 1.67 volume percent, the ethane content in the reaction product was raised to 0.678 volume percent. Acetylene could no longer be detected (100 percent conversion, 43 percent selectivity). The addition of 1.5 parts per million of carbon monoxide allowed the selectivity to be further increased. At an inlet temperature of 84 ° C, an acetylene-free reaction product was obtained. The ethylene content was 99,419 volume percent, the ethane content was 0.442 volume percent.

EXAMPLE 7 Using the method described in Example 1, 138 milligrams of Pd / square meter and then 19.5 milligrams of Ag / square meter were deposited on steam on a support mesh made of material Number 1.4767 that had been pretreated as described in Example 1, heating in air at 900 ° C. The catalyst screen was subsequently manufactured in a monolith having a volume of 126 cubic centimeters.

EXAMPLE 8 Gas phase hydrogenation of a pressure-free C2 stream The catalyst produced as described in Example 1 was used as described in Example 4 for the selective hydrogenation of acetylene. At a conversion of 70 percent, a selectivity to ethylene was achieved with 91 percent.

EXAMPLE 9 Hydrogenation of the liquid phase of the C3 streams The catalyst produced as described in Example 1 was used for the hydrogenation of the liquid phase of methylacetylene and propadiene in a C3 stream from a steam pyrolyzer. The process conditions were selected to correspond to the conditions in the first stage of the hydrogenation usually of 2 stages of the C3 stream. 3 of the monoliths produced as described in Example 1 and having a total surface area of 4219 square centimeters, were installed in an adiabatically operated tube reactor that has a diameter of 20 millimeters. A multiple thermoelectric battery was introduced axially into the hole for the 4-millimeter thermoelectric stack. To ensure good wetting of the catalyst, as ensured in industrial reactors by high cross section loading, the upflow mode was employed. After being washed with hydrogen and hydrogen at 120 ° C, 520 grams per hour of a C3 stream from a composite steam pyrolyser of 6.8 percent by volume of propane, 1.7 percent by volume of propadiene and 2.2 percent by volume of methylacetylene in propylene and 13 standard liters per hour of hydrogen were passed over the catalyst at an inlet temperature of 10 ° C and a pressure of 23 bar. The reaction product consisted of 7.3 volume percent propane and 0.3 volume percent unknown materials (oligomers) in propylene. This corresponds to a selectivity with respect to propylene of 80 percent at a conversion of more than 99.9 percent. The results are summarized in Table 2.

COMPARATIVE EXAMPLE 1 The catalyst produced as described in Patent Number EP-A-0 653 243 was used as the comparison catalyst in the hydrogenation of liquid phase of methylacetylene and propadiene in the C3 stream from a vapor pyrolyzer. The process conditions were selected as in Example 9. 70 milliliters of the catalyst were installed in the adiabatically driven tube reactor. After being washed with nitrogen and hydrogen at 120 ° C, 520 grams per hour of a C3 stream from a composite steam pyrolizer of 5.1 percent by volume of propane, 1.8 percent by volume of propadiene, 2.3 percent by volume of methylacetylene in propylene and 13 standard liters per hour of hydrogen were passed over the catalyst at an inlet temperature of 10 ° C and a pressure of 22 bar. The reaction product consisted of 5.5 percent by volume of propane and 0.5 percent by volume of materials not known in propylene. The unknown materials are oligomers formed. This corresponds to a propylene selectivity of 78 percent at a compression of more than 99.9 percent. The results are summarized in Table 2.

COMPARATIVE EXAMPLE 2 The LD 265 catalyst described in Chem. Eng.

Prog., 70 (1974), 74-80 was employed as a comparison catalyst for the hydrogenation of the liquid phase of methylacetylene and propadiene in a C3 stream from a vapor pyrolyzer. The process conditions were selected as in Comparison Example 1, but the stream contained 8 percent propane, 1.7 volume percent propadiene and 2.1 volume percent methylacetylene. The reaction product consisted of 8.5 percent by volume of propane and 0.7 percent by volume of unknown products in propylene. This corresponds to a propylene selectivity of 69 percent of a conversion of more than 99.9 percent. The results are summarized in Table 2.

Table 2 Catalyst Example 1 Example 2 Example 9 of Catalyst Comparison Comparison of (0.3% Pd, (0.3% Pd, Pd / Ag 0.4 kg / liter) 0.7 kg / liter whsv [kg / liter) ca. 6.5 ca. 6.5 ca, 6.5 Pressure [bar] 22 22 22 H2 / MAPD CALCULATED [mol / mol] < 10 < 10 < 10 t input t C] 10 10 10 MAPD [ppm] < 10 < 10 < 10 S (propene) [%] 78 69 80 Conversion [%] > 99.9 > 99.9 > 99.9 ? Propane [%] 0.5 0.5 0.5 ? Unknown products [%] 0.5 0.7 0.3 In the table, whsv is the hourly space velocity in kilograms per liter. MAPD is the amount of multi-layered unsaturated hydrocarbons namely methylacetylene and propadiene. The indicated H2 / MAPD ratios were calculated from the amounts of H2 consumed in the reaction. The table shows an increase in selectivity from Comparison Example 2 to Comparison Example 1 through Example 9. Even though the thin layer catalyst employed in Example 9 contains only 28 milligrams of Pd and 4 milligrams of Ag in the amount of the catalyst used and, for example, the catalyst of Comparison Example 2 contains 240 milligrams of Pd, has comparable activity and higher selectivity. The formation of oligomers summarized as unknown products is more useful for the catalyst of the invention used in Example 9.

EXAMPLE 10 To produce the catalyst, a simply woven wire mesh made of the material Number 1.4767 and having a mesh opening of 0.18 millimeter and a wire diameter of 0.112 millimeter was heated in air at 900 ° C for 5 hours. After cooling, 138 milligrams of Pd / square meter of mesh was deposited on both sides of the support material at a pressure of 1 x 10".The monoliths were subsequently produced from this catalyst mesh. The width of 20 cm was corrugated by means of a serrated roller (0.5 mm module) and together with a mesh lisa is wound around a metal rod that has a diameter of 4.5 millimeters to provide a roll. The roll was reinforced by welding points on the outer edge and the metal rod was removed to leave the hole in the thermoelectric pile. The monolithic catalyst obtained in this way had a diameter of 16 millimeters and a height of 20 centimeters. The amount of the catalyst mesh in a monolith was 940 square centimeters and 5 monoliths were installed in the hydrogenation reactor.

EXAMPLE 11 Hydrogenation of liquid phase of crude C4 fraction from a steam pyrolyzer Selective hydrogenation of a crude C4 fraction was carried out through the catalyst of Example 10 in a fixed bed reactor of a pilot plant unit that was equipped with a separator of a liquid circuit. The fixed-bed reactor was capable of heating by means of electric heating having a diameter of 16 millimeters and a length of 2 meters. The pardid material was supplied in a regulated manner and the circulation stream by means of a pump and mixed with the necessary hydrogen at a mixing point. The selective hydrogenation was carried out to a fixed bed comprising the monohydric catalyst described in Example 10. The reaction mixture was subsequently sent to a separator where the gas and liquid phases separated. Most of the liquid phase was circulated. A smaller part corresponding to the quantity of the starting material was taken continuously from the system and analyzed by gas chromatography. Before beginning the experiment, the installed monolithic cata- ltalyst was reduced with hydrogen at 120 ° C and pressure of 5 bar for 12 hours. The unit was subsequently operated using a hydrogenated C4 fraction and hydrogen. The results of the experiment in the selected hydrogenation are summarized in Table 3 presented below Table 3 Material Pd Catalyst of Example 10 Item Hydrogenation Product Space velocity [cubic meter / cubic meter / hour] 9.0 9.0 Recycling / Feeding 8.2 8.2 t input f cl 60 60 p [bar] 17.7 18.3 Ratio of H2 / (butadiene + butenin + butyne) 0.98 1.02 Butadiene + butenin + Butyne (% by weight) 34.9 1.8 0.5 l-butene [wt.%] 14.2 40.3 39.5 2-trans-butene [wt.%] 4.5 17.6 18.6 2-cis-butene [wt%] 3.3 5.7 6.2 i-butene [wt%] 23.6 23.6 23.6 ii - bbuuttaannoo [[%% eenn ppeessoo]] 3 3..00 3 3..00 3.0 n-butane [% by weight] 7.2 7.7 8.3 Hydrocarbons of 5 carbon atoms [% by weight] 0.3 0.3 0.3 Conversions [%] 95.9 98.9 Total butene selectivity [%] 98.8 97.5 The catalyst exhibited a very high activity. High conversions could be achieved even at high space speeds. Even in a hydrogenation to a residual butadiene content of 1.8 weight percent, the hydrogenation of n-butane was only 0.5 weight percent. No hydrogenation was affected in i-butene.

EXAMPLE 12 To produce the catalyst, a single woven wire mesh made of material number 1.4767 and having a mesh opening of 0.18 millimeter and a wire diameter of 0.112 millimeter was heated in air at 1000 ° C for 5 hours. After cooling, 92 milligrams of Pd per square meter were vapor deposited on both sides of the support material at a pressure of 1 x 10 ~ 6 torr. To increase the selectivity, the Pd catalyst screen was subsequently adulterated with 0.5 nm germanium by vapor deposition. The thickness of the germanium adulteration layer was measured during the vapor deposition process using a crystal oscillator. Five monoliths were manufactured as described in Example 10 of the catalyst mesh obtained in this manner, and these were installed in the hydrogenation reactor.

EXAMPLE 13 Liquid phase hydrogenation of the crude C4 fraction of a vapor pyrolyzer The catalyst described in Example 12 was also used in the unit described in Example 11. Before starting the experiment, the catalyst was reduced with hydrogen to temperature of 120 ° C and pressure of 5 bar for 12 hours in a manner similar to Example 11. The unit was subsequently operated using the hydrogenated C4 fraction and hydrogen. The results of the experiment on selective hydrogenation are summarized in Table 4, which is presented below.

Table 4 Material Catalyst of Pd / Ge of Item 12 ExampleSpace velocity [m3 / m3 per hour] 9.0 Recycling / Feeding 8.2 ^ input [C] 60 p [bar] 17.2 Ratio of H2 / 0.97 (butadiene + butenin + butyne) Butadiene + butenin + butyne [wt%] 46.4 2.4 l -butene [wt.%] 15.2 42.5 2-trans-butene [wt.%] 5.1 18.9 2-cis-butene [wt.%] 3.8 6.3 i-butene [wt.%] 23.9 23.9 i-butane [wt.%] ] 1.0 1.0 n-butane [% by weight] 4.4 4.8 Hydrocarbons of 5 carbon atoms [% by weight] 0.2 0.2 Conversion [%] 94.8 Total butene selectivity [%] 99.1 The catalyst had a very high activity. During use, it allowed high spatial speeds to be used while at the same time high conversion is achieved. Compared to the catalyst of Example 11, the total selectivity of butene is improved to a certain degree and is above 99 percent. No hydrogenation of the i-butene was carried out.

EXAMPLE 14 Using a method similar to Example 12, the metal mesh made of material number 1.4767 was heated in air at 1000 ° C for 5 hours. After cooling, the support mesh was coated with 50 nm Mg in a described vacuum coating unit. The thickness of the layer was measured during the vapor deposition process using a crystal oscillator. The mesh was subsequently heated to 300 ° C over a period of 60 minutes and allowed to stand at this temperature in air for 30 minutes. Again it was installed in the coating unit, it was coated with 6 nm of Pd at 1 x 10-6 torr. Five monoliths were made from the catalyst mesh obtained in this manner using a similar method as Example 10, and these were installed in the hydrogenation reactor.

EXAMPLE 15 Liquid phase hydrogenation of the crude C fraction of a vapor pyrolyzer The catalyst produced as described in Example 14 was also tested in the unit described in Example 11. Before beginning the experiment, the catalyst was reduced with hydrogen at 100 ° C and pressure of 5 bar for 12 hours in a manner similar to Example 11. The unit was subsequently made work using hydrogenated C4 fraction and hydrogen. The results of the experiment on selective hydrogenation are summarized in Table 5, which is presented below.

Table 5 Material Catalyst of Pd / MgO of heading Example 14 Space velocity [cubic meter / cubic meter per hour] 9.0 Recycling / Feeding) 8.2 T input [° C1 60 p [bar] 16.3 Ratio of H2 (butadiene + butenin + butyne) 0.97 Butadiene + butenin + butyne [wt%] 44.1 2.9 l-butene [wt%] 14.2 39.7 2-trans-butene [wt%] 4.6 17.4 2-cis-butene [wt.%] 3.3 5.8 i-butene [ % by weight] 23.6 23.9 i-butane [wt%] 2.9 2.9 n-butane [wt%] 7.1 7.5 Hydrocarbons of 5 carbon atoms (% by weight) 0.2 0.2 Conversion [%] 93.4 Total butene selectivity [%] 99.0 The catalyst also exhibited high activity and allowed high space velocity to be employed while at the same time high conversion is achieved. The operating data are similar to those of the catalyst of Example 13. No hydrogenation of the i-butene was carried out. As shown by the examples, the catalysts of the present invention are very suitable for the selective hydrogenation of multilayer unsaturated hydrocarbons. Hydrogenation of refined liquid phase 1 containing butadiene from a steam pyrolyzer EXAMPLE 3 COMPARISON A Pd catalyst, AgAl2? 3 produced as described in Patent Number DE-A-31 19 850, Example 3, was used as a comparison catalyst in the hydrogenation of liquid phase of raffinate 1 containing butadiene from a pyrolyzer of steam. The selective hydrogenation of the butadiene was carried out in a pilot plant unit described in Example 11. Before starting the experiment, the comparison catalyst of Pd, Ag was reduced with hydrogen at 120 ° C and pressure of 5 bar for 12 hours. The pilot plant was subsequently operated using refining 1 which contains butadiene and hydrogen. The results of this experiment are summarized in Table 6.

EXAMPLE 16 To produce the catalyst according to the present invention, a single woven wire mesh made of the material Number 1.4301 and having a mesh opening of 0.180 millimeter and a wire diameter of 0.105 millimeter was heated in air at 800 ° C for 3 hours. After cooling, the support mesh which had been pretreated in this way was coated with 5 nm Pd and 1 nm Ag by sputtering in a roller coating apparatus. The monoliths were subsequently produced from the catalyst mesh. For this purpose, a 20 cm wide mesh strip was corrugated by means of a toothed roller (0.5 mm module) and, using a method similar to that of Example 10, five monoliths having a diameter of 16 millimeters were produced, a height of 20 centimeters and a hole of the internal thermoelectric pile that has a diameter of 4.5 millimeters. The amount of catalyst mesh for a monolith was 1180 square centimeters. The five monoliths were finally installed in the hydrogenation reactor described in Example 11. Before starting the experiment, the Pd, Ag catalyst according to the present invention was reduced with hydrogen at 120 ° C and pressure of 5 bar for 12 hours. The pilot plant was subsequently operated using refining 1 which contains butadiene and hydrogen. The results of this experiment are summarized in Table 6.

EXAMPLE 17 To produce the catalyst according to the present invention, the simple woven wire mesh of the material number 1.4767 and having a mesh opening of 0.18 millimeter and a wire diameter of 0.112 millimeter was heated in air at 900 ° C for 5 hours. hours. After cooling, the support mesh which had been pretreated in this way had first 4 nm of Pd and then 2 nm of Ag deposited to steam on both sides at a reduced pressure of 1x10"^ torr.The thickness of the layers was measured by means of a crystal oscillator the vapor deposition rate was controlled using the crystal oscillator.The monoliths of this catalyst mesh were subsequently produced.For this purpose, a 20 cm wide mesh strip was corrugated by means of a toothed roller (module of 0.5 millimeter) and, using a method similar to that of Example 10, five monoliths having a diameter of 16 millimeters, a height of 20 centimeters and an internal hole of the thermoelectric cell having a diameter of 4.5 millimeters The amount of catalyst mesh for a monolith was 940 square centimeters The five monoliths were finally installed in the hydrogenation reactor that is described in Example 11. Before beginning the experiment, the Pd, Ag catalyst according to the present invention was reduced with hydrogen at 120 ° C and pressure of 5 bar for 12 hours. The pilot plant was subsequently operated using refining 1, which contains butadiene and hydrogen. The results of this experiment are summarized in Table 6. Table 6 shows a comparison performance for the conventional catalyst of Comparison Example 3 and two catalysts according to the present invention of Examples 16 and 17. As can be seen, the co-ordination catalyst with the present invention of Example 16 provides a yield of l-butene that is about 3 percent higher than that obtained using the described comparison catalyst at the same final content of butadiene in the hydrogenated product of 20 parts per million . The advantages of the monolithic catalyst according to the present invention of Example 17 are considerably more pronounced having been achieved with a residual butadiene content in the hydrogenated product of 10 parts per million. The yield of l-butene obtained here was more than 97 percent. The performance data reveal four significant advantages of the catalyst according to the present invention in relation to the comparison catalyst described: (i) smaller ratio of ^ / butadiene (1.6 instead of 1.9 for the comparison catalyst) (ii) less overhydrogenation to provide n-butane ( n-butane formation of 0.4 percent by weight instead of 0.8 percent by weight for the comparison catalyst) (iii) significantly higher l-butene yield (97.4 percent instead of 89.2 percent for the comparison catalyst) (iv) significantly lower active component content as high activity (12.3 milligrams of the active component in the amount of catalyst used instead of 480 milligrams for the comparison catalyst). In all the examples, no hydrogenation of the i-butene was found.

EXAMPLE 18 The conventional comparison catalyst described in Comparison Example 3 and the catalyst according to the present invention described in Example 17 were also tested under more serious hydrogenation conditions in the pilot plant unit described in Example 11. Under In these conditions, a residual butadiene content in the hydrogenated product of < 10 parts per million. The results obtained are summarized in Table 7. TABLE 7 Catalyst Concatalyst of Pd, Ag Pd, Ag / Al203 of Example 17 Comparison Example 3 Alimen Product Alimen Product Hydrogenation Hydrogenation Hydration Space velocity [m / m3 / hour] 15 15 Recycling / feeding 1 1 input t t C] 60 60 p [bar] 11.9 11.3 H2 / butadiene ratio 2.7 2.1 Butadiene [% by weight] 0.43 < 0.001 0.54 < 0.001 1-Butene [% by weight] 25.1 20.8 27.2 25.9 trans-2-Butene [wt%] 7.9 10.2 8.4 9.0 cis-2-Butene [wt%] 5.4 7.1 5.7 6.3 i-Butene [wt%] 42.2 42.2 43.9 43.9 i-Butane [wt%] 4.7 4.7 3.0 3.0 n-Butane [% by weight] 14.0 14.8 11.0 11.7 Hydrocarbons of 5 carbon atoms [% by weight] 0.27 0.2 0.26 0.2 Conversion [%] > 99.8 > 99.8 Formation of n-Butane [% by weight] 0.8 0.7 Yield of 1-Butene [%] 82.9 95.2 In a hydrogenation at butadiene values of < 10 parts per million, the catalyst according to the present invention also shows the aforementioned advantages of a small ratio of H2 / butadiene, less overhydrogenation to provide n-butane and a significantly higher l-butene yield. As in the previous examples, no hydrogenation of i-butene was found in this case.

Table 6 Catalyst Conventional Catalyst Catalyst of Pd, Ag / Pd, Ag of Pd, Ag AI2O3 of Example Example of Comparison Example 3 16 17 Alimen- Product Alimen- Product Alimen- Product of Hydro-tion of Hydro-tion of Hydro-genation Space Speed [m3 / m3 / hour] 15 15 15 Recycling / Feeding 1 1 1 t input t cl 60 60 60 p [bar] 11.8 11.5 11.3 H2 / butadiene ratio 1.9 1.9 1.6 Butadiene [% by weight] 0.46 0.002 0.50 0.002 0.54 0.001 1-Butene [% by weight] 25.0 22.3 27.7 25.6 27.2 26.5 trans-2-Butene [% by weight] 7.8 9.1 8.4 9.4 8.4 8.9 cis-2-Butene [% by weight] weight] 5.4 6.4 5.7 6.5 5.7 6.1 i-Butene [% by weight] 42.9 42.9 43.6 43.5 43.9 43.9 i-Butane [% by weight] 4.6 4.6 3.2 3.2 3.0 3.0 n-Butane [% by weight] 13.6 14.4 10.6 11.5 11.0 11.4 Hydrocarbons of 5 carbon atoms [% by weight] 0.24 0.3 0.3 0.3 0.26 0.2 Conversion [%] 99.6 99.6 99.8 Formation of n-Butane [% by weight] 0.8 0.9 0.4 Yield of 1-Butene [%] 89.2 92.4 97.4

Claims (10)

CLAIMS;

1. A process for the hydrogenation of hydrocarbons of 2 to 8 unsaturated carbon atoms of multiple layers, in particular alkynes of 2 to 8 carbon atoms, and / or alkylene of 4 to 8 carbon atoms and / or alkadienes of 4 to 8 atoms of carbon in fluids comprising these by contacting a catalyst packing in the presence of free hydrogen, wherein the packing of the catalyst can be produced by applying at least one substance which is active as a catalyst and / or activator to woven or woven meshes knitted or thin sheets as support material.

2. A process according to claim 1, wherein the active substance (s) as a catalyst and / or activator is applied by vapor deposition and / or sputtering or impregnation.

3. A process according to claim 1 or 2, wherein the catalyst gasket comprises at least one monolith that is made of knitted or woven mesh or a thin sheet that is preferably in the form of a strip.

4. A process according to any of claims 1 to 3, wherein the woven or knitted mesh or the thin sheet comprises metal or an inorganic material. A process according to claim 4, wherein the mesh of woven metal or knitted fabric or thin sheet, before vapor deposition and / or sputtering is heated to a temperature of 400 ° C to 1100 ° C . in an atmosphere that contains oxygen from 0.5 to 24 hours. 6. A process according to any of claims 1 to 5, wherein the active substances such as the catalyst are selected from the elements of transition groups I and / or VII and / or VIII and / or activators that are selected from between the elements of major groups III, IV, V and VI and the transitional groups II, III, VI and VII of the Periodic Table of the Elements. 7. A process according to any of claims 1 to 6, wherein the fluids are streams of C2, C3, C4, C5 or Cg, preferably of a steam pyrolyzer, or a catalytic pyrolyzer wherein the unsaturated hydrocarbons of corresponding multiple layers, in particular alkynes and / or alkylennes and / or alkadienes, are present. 8. A process according to any of claims 1 to 7, wherein the hydrogenation, preferably of C2 and / or C3 streams, is carried out in the gas phase. 9. A process according to any of claims 1 to 7, wherein the hydrogenation preferably of C3, C4, C5 and / or Cg streams is carried out in the liquid phase or in a mixed liquid phase. gas having at least 50 weight percent of the fluid in the liquid phase. 10. A process for the catalytic distillation wherein the hydrogenation as defined in any of the claims of process 1 to 7 is combined with simultaneous distillation or rectification above the catalyst packing, where the fluids may be C3 streams, C4, C5 and / or Cg.