The hydrogenation catalyst and a method of catalytic hydrogenation of unsaturated hydrocarbon compounds

 

(57) Abstract:

The invention relates to a catalyst and method suitable for the catalytic hydrogenation of unsaturated hydrocarbon compounds. Described is a catalyst for hydrogenation more unsaturated hydrocarbons, such as, for example, alkyne or diolefin, in a less unsaturated hydrocarbon such as, for example, alkene or monoolefins, which contains palladium, silver and spinel, and each is present in sufficient quantity to affect the hydrogenation of unsaturated hydrocarbon. Optional palladium is present as a shell, distributed on the surface of the spinel. The described method of using such a catalyst. Effect: this catalyst has a high selectivity and a long service life. 2 S. and 6 C.p. f-crystals, 9 PL.

The technical field

The invention relates to a catalyst and method suitable for the catalytic hydrogenation of unsaturated hydrocarbon compounds.

Prior art

Specialists are well aware that the unsaturated hydrocarbon compound can be obtained by using the method of thermal cracking. For example, geedubya two or more of them can be enjoyed in the heat (or pyrolysis) of the cracking furnace. In the furnace saturated hydrocarbon is converted to an unsaturated hydrocarbon compound, such as, for example, ethylene and propylene. Unsaturated hydrocarbons are an important class of chemicals, which find many industrial applications. For example, ethylene can be used as a monomer or co monomer to obtain a polyolefin. Other applications of unsaturated hydrocarbons is well known in the art,

However, unsaturated hydrocarbon, obtained by thermal cracking process, usually contains a significant amount less desirable alkyne(s) or diolefin(s). For example, ethylene, obtained by thermal cracking of ethane, usually contaminated with some amount of acetylene, which must be selectively hydrogencarbon to ethylene, but not before Ethan, when the hydrogenation reaction.

The hydrogenation alkynes usually in industrial production is performed in the presence of palladium catalyst supported on alumina. In the case of hydrogenation of acetylene to ethylene can be applied palladium and silver catalyst supported on aluminum oxide (see, for example, U.S. patent 4404124 and U.S. patent 4484015, which are included in apiaries alkyne, such as, for example, acetylene, hydrogenizing in the corresponding alkene, such as ethylene, whereby remove the alkyne from the product stream, while only a small amount of alkene hydrogenperoxide in alkanes. This method of hydrogenation minimize the loss of the desired unsaturated hydrocarbons and the initial-final and full recerving avoid gas reaction goes out of control, which is difficult to control, as noted in the above patents.

Specialists know that impurities such as carbon monoxide, H2S, COS, mercaptans and organic sulfides present in alkinsoderzhaschim supply flow or the flow of product, can poison and deactivate palladium catalyst. For example, it is well known that carbon monoxide is temporarily poisons or deactivates such a hydrogenation catalyst, thereby making the hydrogenation is less efficient. Developed palladium "superficial" catalyst in which palladium is distributed over the surface or "shell" of the catalyst, which is known that it is more selective and active than poverhnostny catalyst is told in the description by reference). It is well known that the selectivity of the catalyst is determined, in particular, the thickness of the surface. Usually selective hydrogenation catalyst decreases with increasing thickness of the catalyst. Therefore, there is an increasing need to create a catalyst having a large surface area on the catalyst for the best hydrogenation of alkyne to alkene.

Palladium deposited on alumina, has been successfully used in the dry method of hydrogenation for many years. However, in some ways, such as the so-called method of "full recerving gas in which water vapor is not removed from the stream of olefins, hydrogenation of alkyne to alkene must be performed in the presence of water vapor. In such ways the catalyst on aluminum oxide may have a much shorter service life, because the aluminum oxide is unstable in water vapour. Therefore, there is an increasing need for the establishment of a palladium catalyst at a stable in water vapour media.

As such, the development of improved palladium catalyst and method for its use in the selective hydrogenation of alkyne to alkene in the presence of impurities must be significant the Oia is the establishment of a catalyst, which can be used for hydrogenation more unsaturated hydrocarbon to a less unsaturated hydrocarbon, i.e., hydrogenation of alkyne to alkene.

Another objective of the present invention is the creation of a palladium catalyst in which palladium is better distributed over the surface of the catalyst, compared with the known "surface" catalysts. Also the present invention is to provide a method of hydrogenation of alkyne to the corresponding alkene in the presence of impurities. An additional object of the present invention is the implementation of the hydrogenation of acetylene to ethylene in the presence of impurities. Other objectives and advantages will become more clear in the subsequent more complete disclosure of the present invention.

According to the first variant implementation of the present invention created a catalyst that can be used for hydrogenation more unsaturated hydrocarbon, such as, for example, alkyne or diolefin. The catalyst contains palladium, silver and spinel, such as metal aluminate or a titanate of a metal in which the metal spinel is selected from the group consisting of zinc, magnesium, iron, manganese, any metal to"ptx2">

According to the second variant of implementation of the present invention created a method that can be used for hydrogenation more unsaturated hydrocarbon to a less unsaturated hydrocarbon. The method comprises contacting the more unsaturated hydrocarbon with hydrogen in the presence of a catalyst under conditions sufficient to cause hydrogenation of the more unsaturated hydrocarbon. The catalyst may be the same one that disclosed in the first embodiment of the invention.

Detailed description of the invention

Used in the present invention, the term "fluid" means a gas, liquid or a combination of both. The term "saturated hydrocarbon" refers to any hydrocarbon that can be converted into unsaturated hydrocarbons, such as olefinic compound by thermal cracking process. Used the term "unsaturated hydrocarbon" in this application refers to a hydrocarbon having at least one double bond between carbon atoms in the molecule. Usually the example saturated hydrocarbons include, but are not limited to, such as ethane, propane, butane, pentane, hexane, octane, deans, naphtha, and combinations of any two Il is s as ethylene, propylene, butenes, pentene, hexene, octene and decene, aromatic compounds such as naphthalene, alkynes, such as acetylene, propyne and the butins, diolefin, such as BUTADIENES, pentadiene (including isoprene), hexadiene, octadiene and decadiene and combinations of two or more of them. The term "more unsaturated hydrocarbon" refers to a hydrocarbon that contains a triple or two or more double bonds in the molecule. The term "less unsaturated hydrocarbon" refers to a hydrocarbon in which the triple bond in the more unsaturated hydrocarbon hereroense in a double bond, or a hydrocarbon, in which the number of double bonds is one less than the number in the more unsaturated hydrocarbon. The claimed process of hydrogenation refers to this method, which converts more unsaturated hydrocarbon, such as an alkyne or diolefin, in a less unsaturated hydrocarbon such as monoolefins, no less hydrogenation of unsaturated hydrocarbons to saturated or over saturated hydrocarbon such as alkane.

In accordance with the first variant embodiment of the present invention proposes a catalyst, which can be used for hydrogenation of alkyne or diolefin in monore the example, aluminate metal or metal titanate, in which palladium may be present on the catalyst surface, and the silver can be distributed over the surface or throughout the composition, and the metal spinel is the same as disclosed above. In the currently preferred spinel is zinc aluminate, zinc titanate, magnesium aluminate, or combinations of any two or more of them. These spinels are easily accessible and effective. The term "surface" refers to the surface of the composition. "Surface" can be any thickness, this thickness can stimulate the hydrogenation disclosed in this description. Typically, the thickness may be between approximately 1 to 1000, preferably from 5 to 500, more preferably from 5 to 250, most preferably from 10 to 100 μm. Presently preferably, palladium and silver were deposited on the spinel.

Usually palladium may be present in the composition in any percentage, provided that palladium is essentially concentrated on the surface composition and wt.% is effective to selectively gidrirovanii alkyne to alkene or diolefin in monoolefins. Mass%, the content palatilisation 1,5, most preferably from 0.001 to 1.0%. Similarly, the silver may be present in the catalyst in any mass percentage, provided that the percentage by weight may affect the hydrogenation of alkyne to alkene or diolefin in monoolefins. Typically, the silver may be present in the catalyst in the range from approximately 0,0003 to 20, preferably from about 0.003 to about 10, most preferably from 0.003 to 5 wt. %. Optionally the catalyst may also be composed mainly or may consist of palladium, silver, alkali metal or containing alkali metal compounds and spinels, such as a titanate of a metal or a metal aluminate. Alkali metal or containing alkali metal compound may be present in the catalyst in any percentage that may affect the hydrogenation of alkyne to alkene or diolefin in monoolefins, and in the range from about 0.001 to about 10, preferably from about 0.005-about 5, most preferably from about 0.01 to about 2 wt.%. Currently, the preferred compound of the alkali metal fluoride is an alkali metal, such as, for example, potassium fluoride. On the practical shape and size, while the physical shape and size can be used for hydrogenation of alkyne to alkene or diolefin in monoolefins. It is generally preferable to physical shape was spherical or cylindrical, because this form is easier manipulation. The catalyst typically has a size ranging from about 0.1 to about 20, preferably from about 0.5 to about 15, most preferably from 1 to 10 mm in diameter. The catalyst may have a surface area from about 0.1 to about 50, preferably from about 0.5 to about 10 m2/g, as determined by the well known BET method using nitrogen.

Typically, the catalyst may be used any spinel, while the catalyst can affect the hydrogenation of alkyne to alkene or diolefin in monoolefins. As disclosed above, the metal spinels may include magnesium, zinc, iron, manganese, any metal that can form a spinel, and combinations of any two or more of them. Examples of suitable spinel include, but are not limited to, zinc aluminate, magnesium aluminate, zinc titanate, aluminate calcium aluminate manganese, iron aluminate, calcium titanate, amewu any suitable way. Usually palladium can be deposited on the spinel in any way that will give the composition satisfying the above-described parameters. In the currently preferred methods include impregnation spinel aqueous solution of a suitable palladium compounds. Usually the degree of impregnation of palladium can be controlled by regulating the acidity of a solution is acid, such as, for example, hydrochloric acid.

Examples of suitable palladium compounds include, but are not limited to, palladium chloride, palladium bromide, palladium iodide, palladium acetate, palladium nitrate, palladium sulfate, palladium sulfide, palladium acetylacetonate, and combinations of any two or more of them. Currently, the preferred compound of palladium is palladium chloride because of its availability.

You can use any suitable method of determining what is essentially a mass percentage of particles in the container is palladium, concentrated in the area at some distance from the outer surface. One of the currently favored method is electronic microprobe, which is well known in the art. Another method involves the destruction of a significant sample of Obozreniye solution reacts with the oxidized palladium to obtain a red color, which can be applied to estimate the distribution of palladium. Another method involves the destruction of a significant sample of sintered pellets of catalyst with subsequent treatment of the regenerating agent such as, for example, hydrogen, to change the color of the surface.

Silver can be distributed over the surface or inside the composition in any suitable and effective way. Examples of suitable silver compounds include, but are not limited to, silver chloride, silver bromide, silver iodide, silver acetate, silver nitrate, silver sulphate, silver fluoride, perchloric silver and combinations of any two or more of them. At present, it is preferable to use an aqueous solution of silver nitrate in quantities greater than necessary to fill the pore volume of the catalyst. Typically, the weight percent ratio of silver to palladium may be in the range of from about 0.1:1 to about 20:1, preferably from about 1: 1 to about 10:1, most preferably from 3:1 to 8:1.

The impregnated catalyst may be dried at a temperature in the range from approximately 25 to approximately 150oC, preferably from about 25 to preproposition 200 to about 1200oC, preferably from 275 to 850oS, most preferably from 400 to 700oC for from about 1 to 40 hours, preferably from about 1 to about 30 hours, most preferably from 2 to 25 hours.

Any compound containing alkali metal, can be used in the catalyst, if it can affect the hydrogenation of alkyne to alkene or diolefin in monoolefins. Examples of suitable containing alkali metal compounds include sodium fluoride, potassium fluoride, lithium fluoride, rubidium fluoride, cesium fluoride, sodium iodide, potassium iodide, lithium iodide, rubidium iodide, cesium iodide, sodium chloride, potassium chloride, lithium chloride, rubidium chloride, cesium chloride, sodium bromide, potassium bromide, lithium bromide, rubidium bromide, cesium bromide, sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, cesium hydroxide, sodium oxide, potassium oxide, lithium oxide, rubidium oxide, cesium oxide, sodium carbonate, potassium carbonate, lithium carbonate, rubidium carbonate, cesium carbonate, sodium nitrate, potassium nitrate, lithium nitrate, rubidium nitrate, cesium nitrate, and combinations of any two or more of them. Currently preferred, containing alkali metal compound is fluorine is but in spinel by any means, well-known specialists. For example, the alkali metal compound may be impregnated or be sprayed on spinel prior to its impregnation with a suitable palladium compound, and preferably also suitable silver compound. Alternative compound containing alkali metal, can be implemented, for example, by impregnation or spraying on the catalyst simultaneously with or after impregnation with a suitable palladium compound. Containing alkaline metal compound may also be embedded in the spinel between stages palladium and silver impregnation or after impregnation of a suitable palladium and silver compounds. Alternatively, you can apply stage wet restoration", which is the processing of dissolved reducing agents such as hydrazine, barbadoro alkali metal, aldehydes, such as formaldehyde, carboxylic acids, such as formic or ascorbic acid, reducing sugar, such as dextrose.

In the second variant embodiment of the present invention proposes a method of hydrogenation of the more unsaturated hydrocarbon, such as, for example, alkyne or diolefin, in a less unsaturated hydrocarbon, such cavatorta with hydrogen in the presence of a catalyst under conditions sufficient to effect the hydrogenation of alkyne to alkene or diolefin in monoolefins, although any highly unsaturated hydrocarbon can be applied in the way. At present, it is preferable to use alkyne or diolefin containing from 2 to about 12, preferably from 2 to about 10, most preferably from 2 to 6 carbon atoms.

The catalyst may be the same as described above in the first embodiment of the present invention. Hydrogen may be present or in the supply stream containing highly unsaturated hydrocarbon, or hydrogen-containing fluid, which is mixed with the feed stream prior to contacting with the catalyst. If you are using a hydrogen-containing fluid, it can be essentially pure hydrogen or any fluid medium containing a sufficient concentration of hydrogen for the hydrogenation steps. It may also contain other gases, such as nitrogen, methane, carbon monoxide, carbon dioxide, water vapor, or a combination of any two or more of them, while the hydrogen-containing fluid medium contains a sufficient concentration of hydrogen for the hydrogenation steps.

Optional catalyst. This restorative treatment, or activation may be performed at a temperature in the range from approximately 20 to approximately 200oC, preferably from about 25 to about 150oS, most preferably from 30 to 125oWith over a period of time from about 1 minute to about 30 hours, preferably from about 0.5 to about 25 hours, most preferably from 1 to 20 hours. During this recovery processing palladium and silver compounds (primarily oxides) which may be present in the catalytic composition after the step of drying and roasting step, described above, is essentially restored to metallic palladium and silver. When this optional recovery processing is not performed, the hydrogen gas present in the reaction medium, it performs the recovery of oxides of palladium and silver during the initial phase of the hydrogenation reaction of the present invention.

The method of hydrogenation according to the present invention can be made by contacting the fluid, which contains more unsaturated hydrocarbon, in the presence of hydrogen with catague Wednesday, which may be water, steam, water containing soluble or insoluble substance, or a combination of any two or more of them. Preferably, fluid, containing more unsaturated hydrocarbon, was a stream of unsaturated hydrocarbons containing alkyne, diolefin or both as an impurity, usually at the level of approximately 1 mg/kg (ppm - parts per million) to about 50000 ppm of the fluid. Highly unsaturated hydrocarbon can be, for example, alkyne, diolefin or a combination of any two or more of them. Examples of suitable alkynes include, but are not limited to, acetylene, propyne, 1-butyn, 2-Butin, 1-penten, 2-pentyn, 3-methyl-1-butyn, 1-hexyne, 1-heptyn, 1-octane, 1-nonen, 1-decyn and combinations of any two or more of them. Currently, the preferred Alcina is acetylene. These alkynes first hydronaut into the corresponding alkenes. For example, acetylene first hydrogenizing in ethylene, propyne first hydrogenizing in propylene, and the butins first hydrogenizing in the corresponding butenes (1-butene, 2-butene). Examples of suitable diolefins include, but are not limited to, BUTADIENES, isoprene, pentadiene, cyclopentadiene, hexadiene, cyclohexadiene, octadiene, siouxie them monoolefinic.

In order to best achieve essentially complete hydrogenation of the more unsaturated hydrocarbon must be present at least about 1 mol of hydrogen per mol more unsaturated hydrocarbon. Fluid containing more unsaturated hydrocarbon, and hydrogen can be introduced into the reactor. Alternative fluid containing more unsaturated hydrocarbon, and a hydrogen-containing fluid can be introduced into the reactor separately, simultaneously introduced or mixed before introduction into the reactor for contact with the catalyst, which is usually placed in the reactor before the introduction of the fluid (fluid) in the reactor. Hydrogenation in the present invention can be applied to any reactor known in the art. The method according to the present invention can be performed in a periodic, properities or continuous mode.

Used the term "admixture" refers to any compound in the fluid flow, which is not the primary connection. Examples of impurities other than alkynes or diolefins include, but are not limited to, hydrogen sulfide, seraikis carbon (COS), mercaptans (RSH), organic sulfides (RSR), dy, ketones, carboxylic acids, esters, and other oxidized compounds and combinations of any two or more of them, in which each R can be alkyl or cycloalkyl or aryl group containing from 1 to about 15, preferably from 1 to 10 carbon atoms. Typically, each impurity present in the fluid flow in trace quantities. For example, the admixture may be present at less than about 1 wt.%.

The temperature required for hydrogenation of the more unsaturated hydrocarbon, such as, for example, alkyne, in a less unsaturated hydrocarbon such as, for example, alkene, can be any, which may convert, for example, alkyne to alkene. It is usually heavily dependent on the activity and selectivity of the catalyst, the amounts of impurities in the fluid and the desired degree of removal of impurities. Typically, the reaction temperature may be between approximately 10 to approximately 300oC, preferably from approximately 20 to approximately 250oS, most preferably from about 30 to about 200oC. May be used any suitable pressure reaction. Usually the total gauge pressure is in the UP>2. Hourly volumetric rate of gas or liquid supply of the fluid flow may also vary within wide limits. Typically, the volumetric rate of gas can be in the range of from about 10 to 20000 m3fluid 1 m3of catalyst per hour, more preferably from 50 to 12500 m3/m3hour, most preferably from 100 to 8000 m3/m3/hour. The volumetric rate of liquid feed stream may be in the range of from about 0.001 to about 200, preferably from about 0.01 to about 100, most preferably from about 0.1 to 50 m3/m3/hour. The molar ratio of hydrogen to highly unsaturated hydrocarbon is in the range from about 0.5:1 to about 10000: 1, preferably from about 1:1 to about 5000: 1, most preferably from 1:1 to 1000:1. Hourly volumetric rate of hydrogen-containing fluid in separate feeding into a reactor containing a hydrogenation catalyst, chosen so as to provide a molar ratio of H2to highly unsaturated hydrocarbon in the range from about 0.5:1 to about 10000:1, preferably from about 1: 1 to about 5000:1, nagrania in the air (temperature, which preferably does not exceed approximately 700oWith so burnt out any impurities, such as, for example, organic substances and/or coal, which can accumulate on its surface. Optional regenerated using oxidation catalyst restore H2or a suitable hydrocarbon (as described above) prior to its reorganization in the hydrogenation according to the present invention.

The following examples are presented to further illustrate the present invention and should not be construed as unduly limiting its scope.

Example 1

The example illustrates that the catalyst having a large surface area of the palladium, is obtained using the spinel.

Impregnating solution prepared by dissolving 0,018 g of PdCl2in a small vial (approximately 10 ml) with 4 drops of concentrated Hcl. The contents are heated to almost complete drying, at the same time rotating the vial. Distilled water (5 g) is added into the vial for mixing and dissolution of the palladium salt to prepare a solution of PdCl2. Portion (0,94 g) thus prepared solution of PdCl2add to the media on the basis of aluminum oxide (1,02 up from UCI (United Catalist Inc. , Louisville, Kentucky) to form a mixture in the same vial. The media on the basis of aluminum oxide is soaked in a solution of PdCl2within approximately 30 minutes at 25oWith rotation. Then the excess liquid is drained and the aluminum oxide having applied thereto palladium, placed in a porcelain Cup approximately 7.62 cm in diameter, dried at 125oC for 2 hours and then calcined at 538oWith in an oven with forced draft within 2 hours. Get the surface of the catalyst Pd/Al2O3.

In a separate test, 1.07 g of the above solution of PdCl2mixed with 1,159 g of zinc aluminate (in the form of tablets 0,32 cm, the surface area of 7.3 m2/g), which is produced from Calsicat Division of Catalist of Mallinckrodt Specialty Chemicals Company, Erie, Pennsylvania). The mixture is then treated exactly as described above, when receiving surface of the catalyst Pd/ZnAl2O4.

Both the surface of the catalyst is made in the form of tablets and granules tablets restore a current of hydrogen at about 65,56oWith up until the color of the granules will change to gray-black. Meanwhile, the media remain snow-white. Change to gray-black color is due to recovery axiale see the surface of palladium. It was found that the surface of the zinc aluminate was much better than the surface of aluminum oxide. Used the term "better" applies to more concentrated on the surface and less penetrated in the media.

Example 2

This example illustrates the receiving surface of the catalyst Pd/Ag/ZnAl2O4.

The palladium chloride (PdCl20,0229 g) dissolved in 5 g of N2O with 10 drops of concentrated Hcl to form a solution in the beaker. The solution is heated to almost complete dryness on a hot plate. Water (being 9.61 g) then add for the education and preparation of a solution of PdCl2.

The zinc aluminate (58,63 g, after extrusion the size of 0.32 cm), obtained from Calsicat, which opened similar to example 1, impregnated with all the contents of the formed solution of PdCl2. After subsequent drying at 71,11oC for 16 hours, the catalyst restore wet2(hydrogen, which was saturated with water at 25oC) for 16 hours at 380oC, and then cooled to 160oS, followed by purging with nitrogen and air for about 3 hours. The dried catalyst is then calcined in air at 380oEnen catalyst for approximately 30 minutes, and then dried at 82,22oWith 16 hours to obtain a dried impregnated Ag catalyst. The dried, impregnated with silver, the catalyst was calcined at 200o16 hours in the air, and then 4 hours at 370oC. the Catalyst surface is the catalyst Pd/Ag/ZnAl2O4.

20 ml of catalyst extrudates are placed in a reactor made of stainless steel for water (1.27 cm inner diameter, the length of 45.72 cm). thermocouple is inserted into thermal reservoir, which passes through the center and is coaxial with the reactor, which is heated using an external water bath. Use hydrocarbon feed stream, are shown in table 1. After the catalyst is treated with H2when the excessive pressure 14,06 kg/cm2(90 cm3/min) at room temperature (25oC) 16 hours, the flow at a gauge pressure 14,06 kg/cm2injected into the reactor at 38,89oC. the flow Rate is approximately 900 cm3/min. In between taking samples of discharge flow reactor and analyzed by gas chromatography. The test results are shown in table 1.

Example 3

This comparative example illustrates the hydrogenation with commercially available Korhogo contains 0.018 wt.% Pd, 0,065% wt. Ag and about 99 wt.% aluminum oxide. He has BET/N2the surface area of from 3 to 5 m2/g and it is prepared essentially according to the method described in U.S. patent 4404124 (column 4, lines 32-45), the disclosure of which is given here as a reference. This catalyst is supplied United Catalists Inc. (UCI), Louisville, Kentucky.

The catalyst used in the test hydrogenation, which is performed as disclosed in example 2. The results are shown in table 2.

Example 4

This example additionally illustrates the use of the surface of the catalyst Pd/Ag/ZnAl2O4in the hydrogenation of acetylene to ethylene.

The catalyst is prepared from 30 g of zinc aluminate, 30 g of a solution of PdCl2and use 30 g of a solution of AgNO3. A solution of PdCl2prepare by diluting 12 g 0.1 g Pd/100 g of solution of PdCl2to 60 g of water, and a solution of AgNO3prepare by dissolving 0,2268 g AgNO3in 60 g of water.

A portion of the solution PdCl2(30 g) are added to a zinc aluminate ceramic reservoir for the formation of the mixture. After 1 hour at 23oThe solution is poured, the precipitate is dried at 125oC for 30 minutes, and then calcined for 2 hours at 454oC. Then calcined Keepout, the precipitate is dried at 125oC for 30 minutes, and then calcined for 2 hours at 454oTo prepare the surface of the catalyst Pd/Ag/ZnAl2O4containing 0.02 wt.% Pd, 0,12% Ag and 99,86% wt. ZnAl2O4.

The hydrogenation carry out the same as in example 2, except using the catalyst prepared in this example. The results are shown in table 3.

In a separate comparison test of the catalyst prepared by the same procedure, except that instead of the zinc aluminate is used is aluminum oxide. Thus obtained surface catalyst Pd/Ag/Al2ABOUT3used for the hydrogenation of acetylene, as disclosed in example 2. The results are shown in table 4.

The results in table 3 show that the surface of the catalyst prepared on the aluminate spinel zinc as a carrier, has a very high catalytic activity, as it has a low temperature vacuum equal 41,67oC. the Term "temperature vacuum" is defined as the temperature at which the concentration of acetylene at the output of the reactor is less than 20 ppm no wt. The results are shown in table 3, also shows the pmin "temperature control" is defined as the temperature, above which begins uncontrolled hydrogenation of ethylene. Temperature depression is a measure of catalytic activity: the lower the temperature of the dilution, the more active is the catalyst. The difference between the outlet temperature control and temperature vacuum is a measure of the selectivity of the catalyst: the catalyst with higher selectivity is a big difference.

The results are shown in tables 3 and 4 show that the catalyst Pd/Ag/ZnAl2O4according to the invention has comparable activity and selectivity compared with catalyst Pd/Ag/Al2O3.

Example 5

This example shows the surface of the catalyst Pd/Ag/ZnTiO3and its use in the selective hydrogenation of acetylene to ethylene.

The surface of the catalyst on the carrier of zinc titanate is prepared using the same procedure as in example 4, except that the zinc titanate is used as the carrier. The hydrogenation performed as described in example 2. The results are shown in table 5.

Table 5 also shows that the surface of the catalyst Pd/Ag/ZnTiO3has a very high catalytic activity, i.e., n and the outlet temperature is out of control.

Example 6

This example demonstrates that the magnesium aluminate can be applied to prepare the surface of the catalyst suitable for the hydrogenation of acetylene.

30 g tablets MgAl2O3from Halder-Topsoe CAM-9L (approximately 5.1 x 5.4 mm, obtained from the Halder-Topsoe, Houston, Texas, with N2BET surface area of 22 m2/g and total pore volume of 0.21 cm/g) cut in half with a razor blade and washed contained in the flask H2O three times, and then dried at 85oC for 16 hours. Part of the magnesium aluminate (24,943 g) cover 24,943 g 0.02 wt.% Pd of the solution of PdCl2within 15 minutes, while rotating and stirring. Excess solution is then drained and lightly soak, followed by drying at 85oWith over three hours.

A solution of PdCl2prepared as follows. First 0,100 g of PdCl2poured into 30 ml of chemical glass. Then, in chemical beaker add 50 drops of concentrated Hcl solution. The contents in the beaker gently slowly heated on a hot plate while rotating to an almost complete drying. Distilled H2O (15 ml) is added to a chemical beaker and the contents are again heated under rotation, to give salfetka Kimwipe with subsequent washing chemical glass bottles from three to four times. Add water in the bottle to prepare 300 g of solution.

The dried mixture is calcined 2 hours at 454oC. and Then annealed Pd/MgAl2O4soaked in a solution of AgNO3prepared by dissolving 0,096 g AgNO3in 24,0 g is contained in the flask H2O for 1 hour, stirring every 15 minutes. Excess solution of AgNO3poured. Sediment soak through paper napkins, dried at 85oC for 16 hours and then calcined at 454oC in air for 2 hours.

The catalyst Pd/Ag/MgAl2O4then used for the hydrogenation of acetylene, as described in example 2. The results are shown in table 6.

Table 6 shows that the surface of the catalyst supported on magnesium aluminate, also has high activity and selectivity.

The results in tables 2-6 are summarized in the following table 7.

The results in table 7 indicate that the catalyst according to the invention, using spinel as a carrier, is as good or better than the catalyst using alumina as the carrier.

Example 7.

The example illustrates the measurement of the thickness of the palladium surface or deep sample representative of granules embedded in epoxy (obtained from Buehler, Ltd., Lake Bluff, Illinois) and allow to cure overnight. Make a thin cut with a diamond saw from Buehler Isomet in order to expose the inner part of the embedded granules. This open the polished surface of the polishing medium with successively smaller solid particles, is subjected to lapping with submicron colloidal silicon dioxide. Each polished sample is coated with a thin layer of carbon in a vacuum evaporator to provide conductivity to assess in electronic microprobe.

The instrument used for the analysis is the electron microprobe JEOL 733 with cascade Noran Voyager and spectrometric equipment. The device parameters include accelerating voltage 20 kV, beam current 40 and the focused electron beam. To determine the position of the metal in the inner part of the tablet beginning of the stroke line put on the outer edge, and the end in the center or near it. The intervals between the points of change analysis to determine the deposition profile. For external 200 microns stroke interval change from 2 to 10 μm. From the latter point to the center of the tablet interval of approximately 120 μm. For examples that do not have silver inclusions were made moves to centre pills only the time of analysis.

To determine the maximum depth of the effective deposition of palladium concentration in each point of analysis to normalize the maximum concentration in this course. For comparison, believed that the depth of penetration of the palladium is the point where the sediment falls to the normalized values of 0.1, compared with 1.0 for the maximum concentration. This distance is typically located at the point where the end of a rapid decrease in deposits of palladium and always before the concentration drops below the limit of detection by the method of analysis (0.02 wt.%). To obtain more accurate data length, which corresponds to a normalized value of 0.1, interpolate using neighboring points.

The results in table 8 show that the deposition of palladium on a carrier of alumina is deeper in the tablet (69 µm) compared to 24 microns in zinc aluminate and 33 in magnesium aluminate. The average depth of deposition of palladium on a carrier of zinc aluminate actually is statistically the same as the carrier of magnesium aluminate.

Example 8

This example illustrates the superior selectivity of the surface of the catalyst before not is the emer 6. Poverhnostny the catalyst is prepared as follows. First, prepare a solution of PdCl2by placing strength of 0.159 g of PdCl2in 10 ml of chemical beaker and then adding in chemical glass of 1.0 g of concentrated Hcl. After heating for 30 minutes before drying liquid PdCl2/HCl transferred into the bottle and dilute it to 100 g water stored separately.

Secondly, prepare 25,87 g of magnesium aluminate, prepared as in example 6. In part (7,998 g) solution of PdCl2prepared previously in a 10 ml beaker, add 32 drops of concentrated Hcl (1,059 g) for the preparation of acidified PdCl2. The magnesium aluminate starts wetted by 7,187 g acidified PdCl2followed by drying at 85oC for 2 hours, at 100oC for 4 hours, and then 454oC for 2 hours in air flow 200 cm3/min for the preparation of Pd/MgAl2O4.

Thirdly, the solution of AgNO3prepared by dissolving 0,100 g AgNO324,89 g separately stored water, pour over Pd/MgAl2O4. After 1 hour under stirring every 15 minutes, the excess solution of AgNO3drained and the sediment get wet on a paper napkin, what and when 454oC.

The surface of the catalyst and poverhnostny the catalyst, deposited on both MgAl2O4test for hydrogenation as described in example 2. The results are shown in table 9 below.

The results in table 9 show that the surface of the catalyst has a much lower temperature depression (T1) and higher selectivity (S) than poverhnostny catalyst.

The results of the above examples clearly demonstrate that the present invention is well adapted to perform tasks and achieves marked, as well as the inherent, purposes and advantages. While experts may be made of various modifications, such modifications are within the scope of the present invention, which is defined by the description and the claims.

1. The hydrogenation catalyst more unsaturated hydrocarbon to a less unsaturated hydrocarbons containing palladium and silver supported on a carrier, where the palladium is distributed on the surface of the carrier as the shell, characterized in that as the carrier of the catalyst contains spinel selected from the group consisting of zinc aluminate, alumina is s, wt. %:

Palladium is 0.0001 - 3

Silver is 0.001 - 3

Spinel - Rest

2. The catalyst p. 1, characterized in that the thickness of the specified shell is in the range from 5 to 500 μm, preferably from 10 to 100 microns.

3. Catalyst under item 1 or 2, characterized in that palladium is contained in the range from 0.0005 to 1.5 wt. %, preferably from 0.001 to 1.5, more preferably from 0.001 to 1.5 wt. %.

4. The catalyst according to any one of the preceding paragraphs, characterized in that the mass ratio of silver to palladium is in the range from 0.1: 1 to 20: 1, preferably from 3: 1 to 8: 1.

5. Method of catalytic hydrogenation of unsaturated hydrocarbons, which consists in contacting more unsaturated hydrocarbon with the catalyst in the presence of hydrogen to the formation of the less unsaturated hydrocarbon at a temperature from 10 to 300oC, a pressure of from 4,45 PA to 104,5 105PA, hydrogen flow rate of reagents from 10 to 20,000 m3/m3/h and the bulk velocity of the fluid supply flow from 0.001 to 200 m3/m3/h, wherein the used catalyst according to any of paragraphs. 1-4.

6. The method according to p. 5, characterized in that the catalyst is treated with the tives such as those hydrogen served separately and mixed with the more unsaturated hydrocarbon prior to contacting with the catalyst.

8. The method according to any of paragraphs. 5-7, characterized in that the more unsaturated hydrocarbon contains the fluid selected from the group consisting of water, water vapor, and combinations thereof.

 

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