BE699043A - - Google Patents

Description

       

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  "Selective hydrogenation catalysts",
The present invention relates to solid catalysts, in particular to improved catalysts intended for. selective hydrogenation, in which palladium is used with an alumina support. The catalysts prepared in accordance with the present invention are especially useful for the hydrogenation of acetylenes, in particular the hydrogenation of acetylenes from a gas stream containing olefins,
Palladium-based hydrogenation catalysts

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 are well known in the.

     convenient. They are prepared in many ways, for example by impregnating an absorbent support with a solution of noble metal salt and then by evaporating the solution of said salt in the presence of the support. Another method comprises precipitating palladium hydroxide in the presence of an inert support by adding a solution of palladium chloride to a hot solution of sodium arbonate, in which the support is suspended.

   Another method is to add carbonate to the palladium chloride solution. The catalysts prepared by means of these known methods are active hydrogenation catalysts, but since their use does not result in high hydrogenation rates when used with low concentration gas streams they are not fully effective.



   A wide variety of supports have been used in catalysts for the selective hydrogenation of acetylenes, particularly the supports normally employed in catalysis or hydrogenation reactions. As an example, infusoria earth, such as kie-selgur, and other siliceous materials may be cited; inorganic salts, such as barium sulphate, and carbonaceous materials, such as activated carbon. Large amounts of alumina are used as supports for hydrogenation catalysts based on a noble metal, in particular as a support for palladium catalysts.

   However, it is now recognized that the physical properties of the different aluminas, such as for example the surface area, the pore size or the distribution of the pore size and the like, must be within narrow limits for the different reactions. Thus, by selectively processing a molecule

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      of a particular order of magnitude, it is often advantageous to have a particular alumina pore size. On the other hand, a special surface area has advantages in some circumstances and disadvantages in others.

   Thus, US Pat. No. 3,113,980 relates to catalysts for moderate hydrogenation reactions, in which the catalysts should have a small surface area and a medium, narrow and specific pore radius. The catalysts, contemplated in U.S. Patent 3,113,980, contain palladium in the range of 0.01 to 5% by weight, supported by an alumina support.



    Nevertheless, the support should have a surface area of 5 to 65 square meters per gram, in addition to the narrow distribution of the pore radius. These catalysts, described in U.S. Patent 3,113,980, have an average pore radius of 100 to 1400 Anghstrom units and a surface area of 65 to 5 square meters per gram, preferably 30 to 10 square meters per gram,
In accordance with the present invention there is provided a catalyst suitable for various hydrogenation reactions and a catalyst which in particular behaves as well as a selective hydrogenation catalyst under the conditions expired in Bre @ and U.S. 3,113,980.

   This catalyst also contains palladium in the order of 0.01 to 5% by weight relative to the weight of the total catalysts, preferably 0.01 to 0.5%,
However, the physical properties of the catalysts of the present invention constitute a modification of those of U.S. Patent 3,113,960. The catalysts according to the invention are characterized by three desiderat
The palladium should be evenly distributed throughout the entire catalyst support.

   It can only be found on

 <Desc / Clms Page number 4>

 
 EMI4.1
 r- y.; r. :: '; ";". '' t. la, surface., d: 11Jf, b. rô. ', .. o7: 1le-Oi, 2.> -. "" P- L' impor; l't, p: 01nf!? e 'of porèadoi't be smaller than; 1, ü2 1 n ; ^ '"' 800 Arl) .6 '" (r)' 1) e 'prefix, more than 50% of 3 rd T av. pores Bont K "Ô r ...; 1 A. o pores are '; Lnfér1aÚFS" at;', 3'SO A ..
 EMI4.2
 



  The alumina "should have a surface area of about 80 meters cîaLr-r6B ', - ar gram, preferably more than 100.



  Aluminas with these physical properties
 EMI4.3
 relating to .a = pores and to the surface area are available and in U.S. Patent 2,894,898. However, the preferred alumina is that obtained by the calcination of alumina containing a predominant amount of crystalline alumina trihydrate in admixture with an amorphous alumina monohydrate, prepared in accordance with the application of Bre. - vet n 503.021 filed on January 7, 1966. This alumina is
 EMI4.4
 obtained by precipitation of llal-umine in hydrated form from an aqueous solution of an al- metal aluminate -. #. ";.;

   This alumina reacts with carbon dioxide in controlled coasts, this alumina has a very small range of pores larger than 800 Angstrtim units. The pore size further reduces the size of the pores, so that the majority of these are in order less than 350 Angstrom units.



   As indicated above, the palladium activator cannot be found only on the surface of the support. It should be evenly distributed throughout the entire alumina support. There are careful procedures to ensure that the palladium activator is evenly distributed throughout the entire alumina supports. One of these is to mixing or grinding the composition before it is dried. However, the preferred method of ensuring that the palladium is evenly distributed comprises the selection of a noble metal salt. it was found, for example, that if PdCl2

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 is used, the palladium is not distributed in the whole alumina.

   If alumina pellets are immersed in a solution of PdCl2, the palladium remains on or near the surface of the alumina support. However, if alumina tablets or pellets are immersed in an aqueous solution of Pd (NH3) 2Cl2, palladium penetrates into the carrier and is evenly distributed throughout the whole tablets after drying.



   A preferred process for the preparation of the catalysts according to the invention comprises the following stages:
1. Extrusion of special alumina into pellets of a desired size;
2. Drying of the tablets;
3. Calcination of the pastillies at 2000 F (1093 C);
4. Determination of the volume of water required to completely saturate the support, without excess water or free water remaining (usually 100 pounds of support per batch load, or 45.3592 kg);
5. For every 100 pounds of support (45.3592 kg), place 0.03 to 0.1 pounds (0.0136) to 0.0453 kg) of palladium (as amine chloride) in a container. , then dilution to the predetermined volume;
6.

   Complete submersion of 100 pounds of support (45.3592 kg) in the Pd (NH3) 2Cl2 solution;
7. Self-leaving the catalyst for 30 minutes; drying at 250 F (121 C);
8. Calcination of the catalyst impregnated with palladium at 650-1200 F (343 to 677 C).



   The effect of the physical properties of the support according to the invention and of the uniform distribution of the palladium in the entire support is best demonstrated by specific examples. These are given, of course, by way of example only.

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 EMI6.1
 



  "'Exem'Ple' 1.. 1 - '- \' <- - t 'Two catalysts were prepared by respecting the t eight phases set out above :. In the case of catalyst A,
 EMI6.2
 sufficient Pd (NH 3) 2C was used in binding with the alumina tablets to give an oatalyzer containing 0.035% palladium. During the submersion process, the palladium fully penetrated the carrier tablets. Catalyst B was prepared from an aqueous solution of PdCl2 in a similar manner. This catalyst has 0.035% palladium deposited in a layer on its surface.

   Alumina used as a support for
 EMI6.3
 the two catalysts A and B was prepared by precipitation of carbon dioxide in accordance with Example 1 of the application.
 EMI6.4
 of Patent No. 532,021, It had a surface area of (S, A.) 119 M2 / gram and about 90% of these pores were on the order of magnitude of 0-350. The results of the selective hydrogenations carried out using catalysts A and catalysts B are given in the table below. The composition of the gas stream, the process conditions and the results are also shown in the table. The hydrogenation was carried out by passing the gas stream, which contains hydrogen, through a reactor comprising particles of oatalysts.



   Table I.



   Selective hydrogenation.



  Gas composition
 EMI6.5
 C2H2 OP244% CO t 0.17%
 EMI6.6
 a 2 H 4 39.3% c 3 H 6 t 10.0 '% "' 1, H2 t 15.4, N2: 34-, 906% J - .. 1 ':,'. j r

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      Process conditions
 EMI7.1
 Space velocity 5000 or.ft./cu.ft./hour (14.158 m3 / 1 28.317 m3 / hour) Pressure:

   175 psig (12.30 kg / cm2) Temperature: as given in the table.
 EMI7.2
 Catalyst A PD (NE 3) 2 ci2 palladium in Temp. Input C2 H2 output .8ulp full port¯¯¯ 9 C Loss of CPH4
 EMI7.3
 
<tb> 100 <SEP> 37.8 <SEP> 1720
<tb>
<tb> 120 <SEP> <SEP> 49 <SEP> <SEP> 952 <SEP> 0
<tb>
<tb> 130 <SEP> <SEP> 54 <SEP> <SEP> 829 <SEP> 0
<tb>
<tb> 140 <SEP> 60 <SEP> <SEP> 326 <SEP> 0
<tb>
<tb> 150 <SEP> 66 <SEP> <SEP> 0 <SEP> 0
<tb>
 
 EMI7.4
 Catalyst B pdo'2 Layer of pal 1 adium Temp, input C2H2 out, ppm on surface
 EMI7.5
 
<tb> Loss <SEP> in <SEP> C2H4 <SEP>%
<tb>
 
 EMI7.6
 1000P 25.0
 EMI7.7
 Table 1 shows that if the palladium is not firmly distributed in the entire alumina support,

   Even though the support exhibits the physical characteristics expected - a catalyst of this type does not function adequately in the selective, selective acetylene process in the presence of ethylene. 0: (', trr, njc? Table If the 25 1- of ethylene was h, Vd1 "'; generated in addition to acetylene, when palladium,. tr 1: 1 t Iml.: rU :: slow on the surface <.u support. Therefore, :: '1. (;' il in Vi .. :: et {'necessa: "ê to increase the temperature, since ce..i leads to an h-rdr" t, .. enation additional amounts of ethyl.



  The other 0 "" ";:" distribution of the palladium, uniformly distributed, to that deroti6 only BW the area is given in table I A. LOb c.-to.Lys: uz s Ç t- +, 1.were prepared

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   firmly to the example using the same alumina source.



  In Catalyst C, the palladium is distributed throughout the entire carrier, while in Catalyst D it is located on the surface thereof.



   Table IA
Selective hydrogenation,
 EMI8.1
 
<tb> Composition <SEP> of the <SEP> gas <SEP> (percent)
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> C2H2 <SEP> 0.19
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> CO <SEP> 0.17
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> C3H6 <SEP> 10.0
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> C2H4 <SEP> 38.0 <SEP>.
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>



  H2 <SEP> 16.3
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> N <SEP> 35.34
<tb>
 
 EMI8.2
 Procedure conditions Space speed: 1 5000 Pressure! 175 psig (12.30 kg / cm2) Temperature! As given ..



  Catalyst 0
Pd
 EMI8.3
 fully distributed Time 02% "PL2" otï Loss in a2 "4 S.A..117 i.000? incoming 21.0-M 5
 EMI8.4
 
<tb> (ppm)
<tb> (37.8 C) <SEP> 1900 <SEP> 225 <SEP> 0
<tb>
 
 EMI8.5
 Catalyst D Pd on the SsA surface. 116 1000? 1300 0 34.7
 EMI8.6
 
<tb> (37.8 C)
<tb>
 
Table 1A again shows the advantages of distributing palladium throughout the catalyst tablets or pellets. In both examples, the at least 50% of the pores were on the order of magnitude of 0 to 350.



   The two tables I and I A illustrate the preferred method for obtaining a distribution of palladium

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 in the entire medium. However, as indicated above, a somewhat less efficient distribution of the palladium can be obtained by intimate mixing. This is demonstrated in Example 2,
Example 2.



   A catalyst was prepared by intimately mixing palladium chloride with alumina prepared according to Example 1 of Patent Application No. 532,021. This particular aluminum has a surface area of 86 mm 2 / gram and at least 80% of its pores are of the order of 0 to 350. A final catalyst contains 0.035% palladium based on the catalyst. Results of a selective hydrogenation process are given in Table II.



   Table II
Selective hydrogenation Composition of gas H2: 14 CO t 0.1 C2H2: 775 ppm C4H6: 0.33 C3H6: 15 CH2H4: 40 N2 t balance Reaction conditions Space velocity 5000 Pressure: 150 psig (10.54 kg / om2) Temperature t as given
 EMI9.1
 
<tb> Temperature <SEP> C2H2 <SEP> incoming <SEP> C2H2 <SEP> out <SEP> Loss in <SEP> C2H4 <SEP> ()
<tb>
<tb>
<tb>
<tb>
<tb> F <SEP> C
<tb>
<tb>
<tb>
<tb> 100 <SEP> 37.8 <SEP> 775 <SEP> ppm <SEP> 590 <SEP> ppm <SEP> 0
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> 1 <SEP> 125 <SEP> 51.5 <SEP> 775 <SEP> 414 <SEP> 0
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> 150 <SEP> 66, <SEP> 775 <SEP> 75 <SEP> 0.7
<tb>
 

 <Desc / Clms Page number 10>

 
The effect of the orientation of palladium has been illustrated by the following examples.

   Another requirement, along with a surface area greater than 80 m2 / gram, is the essential pore structure of the catalyst, at least 50% of the pores of which are smaller than 800 1. Preferably, the 50-98%. of the pores are smaller than 350, although not more than 5% of the pores are larger. than 800 A. In order to show the effect of the pore size, Example 3 is given below.



   Example
The catalysts used in these acetylene hydrogenation tests are both commercially available, impregnated alumina catalyst bases.
 EMI10.1
 of Pd (NH3) 2012 in accordance with Example 1, each of the two catalysts (E and F) oontaining 0.035% palladium by weight.



  Catalyst E and Catalyst II both have surface areas greater than 80 m2 / gram. However, in catalyst E, the 39% of its pores are only of the order of 0 to 800. the remainder being greater than 800.



  In catalyst F, the 84% of the pores are of the order of 0 to 800. The results of the hydrogenations of acetylene, carried out using these two catalysts, are as follows:
Table III
 EMI10.2
 Selective cyclrogenation
 EMI10.3
 gas composition (percent)
 EMI10.4
 
<tb> C2H2 <SEP> 0.21
<tb> CO <SEP> 0.12
<tb>
<tb>
<tb> C2H4 <SEP> 30.0
<tb>
<tb> C3H6 <SEP> 10.0
<tb>
<tb> H2 <SEP> 16.3
<tb>
 
 EMI10.5
 N2 43.37. .. "

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 Space speed conditions:

   5000 pressure 175 psig (12.30 kg / om2)
 EMI11.1
 
<tb> Catalysts <SEP> Temperature <SEP> C2H2 <SEP> out <SEP> Loss <SEP> in <SEP> C2H4
<tb>
<tb>
<tb>
<tb> E <SEP> plus <SEP> of <SEP> 120 F <SEP> runaway <SEP> of <SEP> the <SEP> temperature
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> (49 C) <SEP> attributable <SEP> to <SEP> the hydrogenation <SEP> of
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> F <SEP> C <SEP> ethylene
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> F <SEP> 130 <SEP> 54 <SEP> 618 <SEP> 0
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> 145 <SEP> 63 <SEP> 75 <SEP> 0
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> 150 <SEP> 66 <SEP> 38 <SEP> 0
<tb>
<tb>
<tb>
<tb>
<tb> 162 <SEP> 72 <SEP> 0 <SEP> 0
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> 170 <SEP> 77 <SEP> 0 <SEP> 0
<tb>
 
According to Table III,

   it is evident that even though the two palladium catalysts exhibit areas on the
 EMI11.2
 Perfumes greater than 6om2 / grammet, different results are nevertheless obtained in the case of different sizes of pore sizes. Thanks to these two catalysts, having the same order of surface area, the
 EMI11.3
 large number of small pores results in good selectivity. However, the selectivity is so low in the case of the catalyst comprising a large majority of large
 EMI11.4
 pores, i.e. two above 800 A, that the 3 'û hyrog- x .: n. j 1 tne creates an excessive increase in the sort, 5r'j, - !; u.re.



  We now consider the two catalysts G and K each having a large majority of pores of an order of 6., 7ande-ir less than 80111. These caçalyxlurx have, however, das zo Ç. different superficial 4. The catalyst f a '.:.,: zone! J' .. lperfic1el, lt :, dE; .? n2 / gram * The catalyst has a <- surface area ie 119 m2 jgxmms, the results of using 0ea two catalysts in a reactor for 1-ii at "the enation ues coetyiënea are from;: according to the table reads, the

 <Desc / Clms Page number 12>

 catalysts having been prepared according to the catalyst manufacturing process A of Example 1, each catalyst having been completely impregnated with 0.035% palladium.



   Table IV
 EMI12.1
 
<tb> Selective <SEP> hydrogenation
<tb> Composition <SEP> of <SEP> 'gas <SEP> (percent)
<tb>
<tb>
<tb> C2H2 <SEP> 0.224
<tb>
<tb> CO <SEP> 0.17
<tb>
<tb> C2H4 <SEP> 39.3
<tb>
<tb> C3H6 <SEP> 10.0
<tb>
<tb> H2 <SEP> 15.4
<tb>
<tb> N2 <SEP> 34.906
<tb>
 Conditions Space speed: 5000 Pressure ::

   175 psig (12.30 kg / om2)
 EMI12.2
 
<tb> Catalyst <SEP> Temperature <SEP> C2H2 (ppm) <SEP> output <SEP> loss <SEP> in <SEP> C2H4 (%)
<tb>
<tb>
<tb> op <SEP> C
<tb>
<tb> G <SEP> 115 <SEP> '<SEP> 46- <SEP> 0 <SEP> 40.4
<tb>
<tb>
<tb>
<tb> H <SEP> 100 <SEP> 37.8 <SEP> 225 <SEP> 0
<tb>
<tb>
<tb>
<tb>
<tb> 170 <SEP> 77 <SEP> 0 <SEP> 0
<tb>
 
The data again show the advantages of an uplifted surface area in combination with a large number of small pores, these being in the range of 0 to 800, preferably below 350, and the surface areas. - high ones between 80 to 300 m2 / gram, preferably 90 to 200,
During the implementation of the present, pro @ edé,

   an ethylene gas stream, containing acetylene to be removed therefrom, is mixed with a hydrogen gas stream, provided that an excess of hydrogen is not already present in the gas ethylene-acetylene, the resulting mixture being contacted with one of the catalysts described herein. The gas mixture may contain other

 <Desc / Clms Page number 13>

 materials, such as, for example, hydrocarbons which are normally part of the preparation of the gas containing ethylene, as well as nitrogen, carbon dioxide, small amounts of air and water vapor.

   The gas stream should be free of sulfur-containing compounds and, if necessary, a sulfur absorber: known, such as for example an alkaline carbonate solution containing arsenates or equivalent products, can be used to remove sulfur compounds from of the gas mixture, before bringing this mixture into contact with the hydrogenation catalyst.



   It is desirable to use the catalysts contemplated herein and for the hydrogenation of acetylene, prior to the fractionation of the acetylene stream.



   In this example, a large excess of hydrogen is present.



   In other examples, the proportion of hydrogen, which must be present or added to the ethylene gas, is at least equal to the proportion necessary to hydrogenate all of the acetylene present in the mixture, that is to say one mole or more of hydrogen per mole of acetylene. An excess of hydrogen over the amount theoretically necessary to allow reaction with all of the acetylene is ordinarily required in practical operation in each case.



   As noted, the selective hydrogenation of acetylene from an ethylene stream, using palladium supported by activated alumina, is not new. The conditions of the known reaction are contemplated herein. For the purpose of catalyzing the hydrogenation of acetylenes, temperatures of 100 to 400 F (37.8 to 204 C), pressures of 15 to 1000 psig (1.05 to 70.30 kg / cm2) and space speeds of 500 to 7000 volumes of gas per volume of catalyst per hour and even higher speeds. Normally the gas stream contains less than 2% acetylene.

 <Desc / Clms Page number 14>

 



   Thus, the present invention provides a selective catalyst for the hydrogenation of acetylene, which can be compared favorably with the catalyst currently in wide use, By way of example, a comparison of catalyst A, according to the present invention, to a highly selective, commercially available hydrogenation catalyst, Catalyst J, is given under the two sets of conditions of Examples 4 and 5.



   Example 4
 EMI14.1
 
<tb> Composition <SEP> of <SEP> gas flow <SEP>-% <SEP> in <SEP> volume
<tb>
<tb>
<tb> Hydrogen <SEP> 13.9
<tb>
<tb>
<tb>
<tb>
<tb> Acetylene <SEP> 0.24
<tb>
<tb>
<tb>
<tb> Ethylene <SEP> 36.0
<tb>
<tb>
<tb>
<tb> Propylene <SEP> 13.0
<tb>
<tb>
<tb>
<tb> Acetylene <SEP> from <SEP> methane <SEP> 0.073
<tb>
<tb>
<tb>
<tb>
<tb> Butadiene <SEP> 0.156
<tb>
<tb>
<tb>
<tb> Nitrogen <SEP> balance
<tb>
 Process conditions: reactor pressure t 175 psig (12.30 kg / cm2) space velocity: 5500 volumes / hour / volume Catalysts used Catalyst A Catalyst J

 <Desc / Clms Page number 15>

 
 EMI15.1
 
<tb> Cata .. <SEP> Temperatures <SEP> Acetylene <SEP> loss <SEP> of e- <SEP> polymer
<tb>
 
 EMI15.2
 lyser Inlet Outlet in the ethylene gas, c "en in the pro-;

   
 EMI15.3
 
<tb> F <SEP> C <SEP> F <SEP> C <SEP> outgoing <SEP> volume <SEP> duit <SEP> 10 <SEP> in <SEP>
<tb>
<tb>
<tb>
<tb> A <SEP> 110 <SEP> 43 <SEP> 112 <SEP> 44 <SEP> 1100 <SEP> 0 <SEP> 0.0043
<tb>
<tb> 130 <SEP> 54 <SEP> 135 <SEP> 57 <SEP> 562 <SEP> 0 <SEP> 0.005L
<tb>
<tb> 150 <SEP> 66 <SEP> 162 <SEP> 72.2 <SEP> 79 <SEP> 0.28 <SEP> 0.0140
<tb>
<tb> 170 <SEP> 77 <SEP> 230 <SEP> 110 <SEP> Runaway <SEP> 27.5 <SEP> - <SEP> -
<tb>
<tb>
<tb>
<tb> J <SEP> 110 <SEP> 43 <SEP> 114 <SEP> 45 <SEP> 1224 <SEP> 0 <SEP> 0.0040
<tb>
<tb>
<tb> 130 <SEP> 54 <SEP> 137 <SEP> 64 <SEP> 468 <SEP> 0 <SEP> 0. <SEP> 0079
<tb>
<tb> 150 <SEP> 66 <SEP> 160 <SEP> 71 <SEP> 55 <SEP> 0.19 <SEP> 0.0194
<tb>
<tb> 170 <SEP> 77 <SEP> 200 <SEP> 93 <SEP> Runaway <SEP> 25. <SEP> 0 <SEP> - <SEP> - <SEP>
<tb>
 (x) C4- plus material in the gas leaving the reactor.



   Example 5
 EMI15.4
 Composition of the gas flow !. 'i in volume
 EMI15.5
 
<tb> Hydrogen <SEP> 13.6
<tb>
<tb>
<tb>
<tb>
<tb> Acetylene <SEP> 366 <SEP> (ppm)
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> Ethylene <SEP> 36.3
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> propylene <SEP> 13.0
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> scétylène <SEP> du <SEP> m-
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> tnane <SEP> 0.043
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> Butadiene <SEP> 0.006
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> Nitrogen <SEP> balance
<tb>
 
 EMI15.6
 .Q21! Ji +, 1 ') na of the' process reactor pressure - 500 psig (35.15 kgl cm2) Spatial VitE'85C - '55')

  0 vOluIn.ea / hour / vo1'UI1le i "alafLY '$ utilie41? Catalyst A Catalyst J

 <Desc / Clms Page number 16>

 
 EMI16.1
 
<tb> Cata- <SEP> Temperatures <SEP> Acetylene <SEP> Loss <SEP> of ethyl- <SEP> Polymer
<tb>
<tb>
<tb> lyseur <SEP> Input <SEP> Output <SEP> in <SEP> the <SEP> gas <SEP> lene, <SEP> in <SEP> in <SEP> the <SEP> pro
<tb>
<tb>
<tb>
<tb> F <SEP> C <SEP> F <SEP> C <SEP> outgoing <SEP> volume <SEP> "<SEP> duit <SEP>% <SEP> in <SEP>
<tb>
 
 EMI16.2
 1 ¯¯¯¯¯¯¯¯¯¯¯ rpmv volume (:: 1:

  )
 EMI16.3
 
<tb> A <SEP> 110 <SEP> 43 <SEP> 113 <SEP> 44 <SEP> 113 <SEP> 0 <SEP> 0.0048
<tb> 130 <SEP> 54 <SEP> 135 <SEP> 57 <SEP> 39 <SEP> 0 <SEP> 0.0092
<tb> 150 <SEP> 66 <SEP> 155 <SEP> 69 <SEP> 5.1 <SEP> 0 <SEP> 0.0180
<tb> 170 <SEP> 77 <SEP> 235 <SEP> 233 <SEP> Runaway <SEP> 33.0 <SEP> - <SEP> - <SEP>
<tb>
<tb> J <SEP> 110 <SEP> 43 <SEP> 115 <SEP> 46 <SEP> 120 <SEP> 0.0055
<tb> 130 <SEP> 54 <SEP> 136 <SEP> 58 <SEP> 45 <SEP> 0 <SEP> 0.0102
<tb> 150 <SEP> 66 <SEP> 160 <SEP> 71 <SEP> 7.2 <SEP> 0 <SEP> 0.0190
<tb> 170 <SEP> 77 <SEP> 220 <SEP> '104 <SEP> Runaway <SEP> 39.0 <SEP> - <SEP> - <SEP>
<tb>
 (x) C4 - plus matter in the gas exiting the editor.



   Although the preferred support for the catalyst envisioned herein is alumina, a smaller amount, not more than 30%, of kaolin clay can be mixed with the alumina. A comparison of a clay modified catalyst, i.e., catalyst K, to catalysts A and J, is given in Example 6.



  Catalyst K contains 30% Old Hickory figulin clay (No. 5) mixed with the alumina used in Catalyst A. The catalyst has a surface area of 86 square meters per gram and about 68% of its surface area. pores are of the order of 0 to 800,
Example 6
 EMI16.4
 
<tb> Composition <SEP> of the <SEP> gas flow <SEP>, <SEP>% <SEP> volume
<tb>
<tb> Hydrogen <SEP> 13.0
<tb>
<tb>
<tb> Acetylene <SEP> 0.24
<tb>
<tb>
<tb> Ethylene <SEP> 36.0
<tb>
<tb>
<tb> Propylene <SEP> 13.0
<tb>
 

 <Desc / Clms Page number 17>

 
 EMI17.1
 
<tb> Acetylene <SEP> from <SEP> methane <SEP> 0.073
<tb>
 
 EMI17.2
 Butadiene 0.156 Balance nitrogen Balance nitrogen Process conditions Reactor pressure:

   500 psig (35.15 kg / om2) Space velocity 1,5,500 volumes / hour / volume
 EMI17.3
 Catalysts used: Catalyst K Catalyst A Catalyst J
 EMI17.4
 
<tb> Cata- <SEP> Temperatures <SEP> Acetylene <SEP> Loss <SEP> of ethyl- <SEP> Polymer
<tb>
<tb>
<tb>
<tb>
<tb> lyseur <SEP> Input <SEP> Output <SEP> in <SEP> the <SEP> gas <SEP> lene, <SEP>% <SEP> in <SEP> in <SEP> the <SEP> pro
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> F <SEP> C <SEP> F <SEP> C <SEP> outgoing <SEP> volume <SEP> duit% in
<tb>
 
 EMI17.5
 ####.

   ######### pmv volume (x) ¯¯¯¯
 EMI17.6
 
<tb> K <SEP> 110 <SEP> 43 <SEP> 116 <SEP> 47 <SEP> 1038 <SEP> 0 <SEP> 0.0034
<tb>
<tb>
<tb>
<tb> 130 <SEP> 54 <SEP> 139 <SEP> 59 <SEP> 449 <SEP> 0 <SEP> 0.0073
<tb>
<tb>
<tb>
<tb>
<tb> 150 <SEP> 66 <SEP> 161 <SEP> 72 <SEP> 71 <SEP> 0 <SEP> 0.0141
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> A <SEP> 110 <SEP> 43 <SEP> 120 <SEP> 49 <SEP> 827 <SEP> 0 <SEP> 0.0022 <SEP> '<SEP>
<tb>
<tb>
<tb>
<tb>
<tb> 130 <SEP> 54 <SEP> 135 <SEP> 57 <SEP> 212 <SEP> 0 <SEP> 0.0051
<tb>
<tb>
<tb>
<tb>
<tb> 150 <SEP> 66 <SEP> 167 <SEP> 75 <SEP> 7. <SEP> 6 <SEP> 0.35 <SEP> 0.0126
<tb>
<tb>
<tb>
<tb>
<tb> 170 <SEP> 77 <SEP> 265 <SEP> 129 <SEP> Runaway <SEP> 29. <SEP> 2 <SEP> - <SEP> - <SEP>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb>
<tb> J <SEP> 110 <SEP> 43 <SEP> 119 <SEP> 48 <SEP> 792 <SEP> 0.

   <SEP> 0.0018
<tb>
<tb>
<tb>
<tb>
<tb> 130 <SEP> 54 <SEP> 137 <SEP> 56 <SEP> 157 <SEP> 0 <SEP> 0.0048
<tb>
<tb>
<tb>
<tb>
<tb> 150 <SEP> 66 <SEP> 163 <SEP> 73 <SEP> 2. <SEP> 5 <SEP> 0. <SEP> 49 <SEP> 0.0125
<tb>
<tb>
<tb>
<tb>
<tb> 170 <SEP> 77 <SEP> 250 <SEP> 121 <SEP> Runaway <SEP> 32.0 <SEP> - <SEP> - <SEP>
<tb>
 (x) C4- plus material in the gas leaving the reactor.



   The data and the preceding examples show that a selective hydrogenation catalyst, clearly marking,

 <Desc / Clms Page number 18>

 results from the practice of the present invention.



  When used in the compositions according to the invention, the clay of the kaolin type is a material originating from the natural disintegration of feldspar and comprises primary kaolins, such as for example porcelain earth, or secondary kaolins, such as figuline clay. These clays are unique materials that are found in large quantities in nature. Kaolin-type clays are of a natural plastic essence with remarkably high uniformity properties and consist of silicon, oxygen and hydrogen according to the general formula Al2O32SiO22H2O. They are sometimes mentioned as including aluminum silicates, but they probably consist of aluminosilioic acid.



  This modification of these clays and other ramifications will be apparent to those skilled in the art of the present art. These changes are included within the scope of the present invention,
CLAIMS. 1.- A process for the aleotive hydrogenation of acetylenes in gases containing olefins, characterized in that it includes the reaction of gases with hydrogen at an elevated temperature above 400 F (204 C) at con- taot of a hydrogenation catalyst of improved selectivity, activated by palladium, consisting predominantly of alumina and having 0.01 to 5% by weight of palladium on a dry basis, uniformly distributed in the whole of a support containing at least 70% alumina, the remainder being clay, the support having a surface area of approximately 80 m2 / gram,

   a major portion of its pores being of the order of less than 800 Angstrom units.


    

Claims (1)

2. - The method of claim 1; characterized in <Desc / Clms Page number 19> that the palladium catalyst is clay-free. 3, - proceeds according to claim 2, characterized in that the 50 to 98% of the pores are of the order of 0 to 350, only 1 to 5% of the pores are larger than 800, and in that the surface area is of the order of 90) 200 'm2 / gram. 4. A process according to claim 3, characterized in that the catalyst contains less than 0.5% palladium, 5.- Hydrogenation catalyst of improved selectivity, activated by palladium, consisting predominantly of alumina, characterized in that it is provided with 0.01 to 5% by weight of palladium on a basis. dry, uniformly distributed throughout a support containing at least 70% aluminum, the remainder being clay, the support having a surface area of about 80 m2 / gram, at least the 50% of its pores being of an order of less than 800 Angstrom units. 6. - Catalyst according to claim 5, characterized in that the 50 to 98 *, the pores are of the order of 0 to 350, only 1 to 5% of the pores are larger than 800, and in that the surface area is of the order of 90 to 200 m2 / gram. 7. Catalysts according to claim 6, characterized in that the support contains 30% kaolin. 8. A catalyst according to claim 6, characterized in that the support is free of clay. 9. - Catalyst according to claim 8, characterized in that the support is impregnated with 0.01 to 0.5% by weight of palladium based on the catalyst.