GB1573281A - High temperature vapour phase dimerization of acralonitrile - Google Patents

Description

(54) HIGH TEMPERATURE VAPOR PHASE DIMERIZATION OF ACRYLONITRILE (71) We, THE STANDARD OIL COMPANY, a corporation organised under the laws of the State of Ohio, United States of America of Midland Building, Cleveland, Ohio 44115, United States of America, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to the high temperature vapor phase dimerization of acrylonitrile to form isomeric 1,4-dicyanobutenes and adiponitrile.

Much work has been recently done on the catalytic dimerization and hydrodimerization of acrylonitrile to 1,4-dicyanobutenes and adiponitrile. See, for example, the following Japanese and German patent publications: JA 077686, JA 7115494, JA 7125726, JA 7121369, JA 7127729, JA 7115485, DT 1945780, JA 7139330 and DT 2446641.

As disclosed in these patents, acrylonitrile can be dimerized into 1,4-dicyanobutenes and/or adiponitrile by contacting acrylonitrile in the gaseous phase optionally together with hydrogen with a catalyst selected from a wide variety of different materials. In many of these references, it is necessary or preferable to subject the catalyst prior to use to reduction in hydrogen gas so that the metallic components of the catalyst are present essentially in elemental form. Alternatively, the metallic catalyst can be employed in some of the processes in the form of a chloride, sulfate, nitrate, acetate or other organic compound.

Against this background, it has been discovered that a catalyst comprising activated alumina containing inorganic sulfide ion exhibits a substantial and unexpected activity in the catalytic vapor phase dimerization of acrylonitrile.

Therefore, in accordance with the present invention, a process for the vapor phase catalytic dimerization of acrylonitrile to 1 ,4-dicyano- butenes and adiponitrile is provided, the process comprising contacting gaseous acrylonitrile with a catalyst comprising activated alumina containing inorganic sulfide ion. The present invention also provides a process for the vapor phase catalytic dimerization of acrylonitrile to 1,4-dicyanobutenes and adiponitrile in which acrylonitrile in the gas phase is contacted with an inorganic sulfide ion-containing activated alumina catalyst formed by contacting activated alumina at an elevated temperature of at least 5000F with a material capable of decomposing to liberate inorganic sulfide ion at the elevated temperature.

In another embodiment, the present invention also provides a process for the vapor phase catalytic dimerization of acrylonitrile to 1,4dicyanobutenes in which acrylonitrile in the gas phase is contacted with a catalyst comprising an activated alumina carrier having supported thereon a catalytically effective amount of a sulfide of a metal or metalloid, the metal or metalloid being selected from Groups IA, IIA, IVB, VB, VIB, VIIB, VIII, IB, IIB, IIIA, and IVA of the Periodic Table (Handbook of Chemistry of Physics, Chemical Rubber Company), the rare earth metals, scandium and hafnium.

The accompanying drawing is a partial Periodic Table illustrating the results obtained in a number of the following working examples.

In carrying out the invention process, acrylonitrile in the vapor phase is contacted with a catalyst as described below for effecting the dimerization reaction. The reaction can be carried out either in the batch mode or continuously and either with a fixed bed or a fluidized bed.

The reaction temperature is generally from 500 to 1 1000F, 800 to 10000F being preferred. The reaction pressure is normally maintained at from 1 to 100 atmospheres with a reaction pressure of 2 to 50 atmospheres being preferred.

The apparent contact time between the catalyst and the reactant may vary from 0.1 second to 30 seconds. In general, lower reaction temperatures tend to benefit from longer contact times, and at higher temperature shorter contact times tend to be optimum.

Preferably, the gaseous acrylonitrile feed fed to the reactor contains a carrier gas for sweeping the relatively heavy reaction products out of the reactor. Hydrogen, nitrogen or any gas inert to the reaction can be employed as the carrier gas.

Preferably, the amount of carrier gas mixed with the acrylonitrile feed is such that the acrylonitrile/carrier gas molar ratio in the feed is 0.5:1 to 25:1, If desired, hydrogen sulfide in a molar ratio of greater than zero to 30 mole %, preferably 2 to 20 mole %, and optimally 15 mole %, with respect to the total amount of carrier gas fed, can be included in the carrier gas to insure that the alumina catalyst of the present invention remains rich in sulfide ion during the dimerization reaction. The preferred carrier gas is hydrogen since hydrogen insures that the metal or metalloid in the catalyst remains in a reduced state.

The reaction product obtained upon completion of the reaction is composed primarily of propionitrile, adiponitrile, cis- and trans-l ,4dicyanobutene-l, cis- and trans-1,4-dicyanobutene-2 and unreacted acrylonitrile. Also present may be small amounts of succinonitrile, acetonitrile and pyridine. The reaction product can be subjected to suitable known separation techniques to yield the desired end products, namely the 1 4-dicyanobutenes and adiponitrile.

As is well known in the art, adiponitrile can be readily converted into either hexamethylenediamine or adipic acid, which are both starting materials for nylon 66, by simple and straightforward procedures. See U.S. Patents 3,056,837, 3,272,866 and 3,272,867. Also, 1,4-dicyanobutenes can be converted into adiponitrile by known hydrogeneration procedures. See, for example, M. J. Astle, Chemistry of Petrochemicals, Reinhold Chemical Co., copyright 1956, pp. 240, 247 and 256;and U. S. Patent 2,518,608 and U.S. Patent 2,451,386.

The catalyst employed in the process according to the invention for the high temperature vapor phase catalytic dimerization of acrylonitrile comprises activated alumina containing the inorganic sulfide ion, the alumina being used alone or in combination with a metal or metalloid promoter. Thus, in one embodiment of the present invention, unpromoted activated alumina when activated so as to contain inorganic sulfide ion can be used as the catalyst in the inventive process. In this embodiment, activated alumina is sulfuractivated by contacting the alumina at an elevated temperature, normally at least 5000F, with a material capable of decomposing in the presence of activated alumina at the elevated temperature to liberate sulfide ion (hereinafter referred to as a "sulfide ion-yielding material").

Any material which is capable of decomposing in the presence of activated alumina to liberate sulfide ion at a temperature of at least 500"F is useful for this purpose. For example, hydrogen sulfide, carbon disulfide and organic sulfurcontaining molecules decomposing at a temperature of at least 500"F to liberate sulfide ions can be used. Good examples of such organic sulfurcontaining molecules are the mercaptans, specifically alkyl mercaptans in which the alkyl group has 1 to 12 carbon atoms, for example methyl mercaptan, ethyl mercaptan or propyl mercaptan. In this embodiment, the use of hydrogen sulfide or carbon disulfide is preferred while the use of hydrogen sulfide is most preferred.

In order to sulfur-activate the activated alumina catalyst in this embodiment of the invention so that it contains inorganic sulfide ion, activated alumina is heated to an elevated temperature at or above 500"F and contacted with the sulfide ion-yielding material. The activated alumina can be heated to the elevated temperature prior to or simulaneously with contacting the sulfide ion-yielding material. Alternately, the sulfide ion-yielding material can be heated to the elevated temperature. The time period over which the activated alumina must be contacted with the sulfide ion-yielding material is the time necessary for the sulfide ion-yielding material to react with the alumina and form significant inorganic sulfide ion. Normally this takes 0.1 to 5 hours.

In accordance with another embodiment of the present invention, the activated alumina support can be promoted with a suitable metal or metalloid promoter element. In accordance with the present invention, it has been found that sulfur-activated activated alumina promoted with a wide variety of different metals or metalloids will also exhibit a significant catalytic effect in the catalytic dimerization of acrylonitrile to 1,4dicyanobutenes and adiponitrile. In accordance with this embodiment of the invention, elements found useful in exhibiting a promoter effect are metals and metalloids of Groups IA, IIA, IVB, VB, VIB, VIIB, VIII, IB, IIB, IIIA, and IVA of the Periodic Table, rare earth metal, scandium and hafnium. A broadly preferred class of promotor metal or metalloids is lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, chromium, molybdenun manganese, iron, cobalt, nickel, palladium, platinum, copper, silver, zinc, cadmium, tellurium, tin, lead and cerium. A more preferred class of metal or metalloid promoters is composed of those of the foregoing elements in Groups IA, IIA, IB and IIB of the Periodic Table and lead, namely lithium, sodium, potassium, rubidium, cesium, manganese, calcium, strontium, barium, copper, silver, zinc, cadmium and lead. Most preferred metal or metalloid promoters are sodium, strontium, and silver. In each of the above-noted classes, the indicated metals and metalloid can be used individually or in admixture with one another.

The sulfur-activated activated alumina catalysts of this embodiment of the present invention can contain from a great deal to a very little metal or metalloid promoter. The minimal amount of promoter is that amount necessary for the presence of the promoter to exert an in fluence on the catalytic activity of the sulfuractivated catalyst. The maximum amount is approximately 90 weight percent, based on the total weight of the catalyst. Normally, the amount of metal or metalloid promoter is greater than zero percent to 90 weight percent, preferably 0.1 to 50 weight percent, while the most preferred amount is 1 to 10 weight percent.

The catalyst of this embodiment of the present invention can be prepared by depositing the metal or metalloid promoter in elemental form or in the form of an oxide, hydroxide or salt on an activated alumina support or carrier and thereafter subjecting the composites formed to sulfuractivating conditions as described above.

Promoter metals or metalloids can be deposited on an activated alumina support by depositing on the activated alumina support a reducible or irreducible salt, hydroxide or oxide of the metal or metalloid and thereafter reducing the salt or oxide by contact with elemental hydrogen.

Examples of compounds useful for this purpose are Ni(N03 )2 6H2O, P2Os 24MoO3 48H2 0 (for Mo), Ce(NO3)3 6H2O, CrO3, Cu(N03) 2-3H2O, Fe(NO3)3-9H20, Mn(NO3)2-6H20, KOH, U02 (NO3)2-6H2O, Mg(NO3)2-6H2O, TlNO3, AgNO3, and PdC12. Techniques for depositing metals or metalloids on supports are well known in the art and thoroughly described in the various Japanese patents listed above.

Once the metal or metalloid promoter is deposited on the support, the composites so formed can be subjected to sulfur-activating conditions as described above. As in the previous embodiment, the composite can be activated by contacting the composite with a material capable of decomposing in the presence of the activated alumina composite to liberate sulfide ion at an elevated temperature, preferably at least about 500"F. Such materials as hydrogen sulfide, carbon disulfide and decomposable organic sulfurcontaining molecules, such as the mercaptans mentioned above, are also useful in this embodiment of the invention. Moreover, the contact time should, in general, also be 0.1 to 5 hours.

In this connection, in this embodiment of the invention the sulfur activation procedure is accomplished for a time and at a temperature sufficient so that the metal or metalloid in the composite is converted to the corresponding inorganic sulfide. Accordingly, in this embodiment of the present invention the catalyst can be characterized as comprising an activated alumina support having thereon a metal or metalloid promoter in the form of an inorganic sulfide.

From the foregoing, it will be appreciated that the present invention provides a novel process for the catalytic dimerization of acrylonitrile to 1 4-dicyanobutenes and adiponitrile. An important aspect of this process is that the catalyst employed is activated alumina either alone or in combination with a suitable metal or metalloid promoter which has been subjected to a sulfuractivation treatment. Although not wishing to be bound to any theory, it is believed that the novel catalytic effect realized in accordance with the present invention occurs when sulfur is present in the activated alumina catalyst in the form of inorganic sulfide ion. In the second embodiment of the present invention in which the activated alumina is promoted with a metal or metalloid promoter, sulfur-activation of the alumina/promoter composite has the effect of causing the metal or metalloid in the composite to take the form of a sulfide. Therefore, in this embodiment sulfide ion is present as part of the metal compound containing the metal promoter.

In a similar manner, it is believed that small but significant amounts of sulfide ion are present in the activated alumina catalyst of the first embodiment of the present invention in which no metal or metalloid promoter is combined with the activated alumina support. Thermodynamic studies tend to show that alumina, Awl2 03, will not be transformed in major amount to aluminium sulfide by contact with hydrogen sulfide. However, such studies are based on macroscopic analysis. It is believed that although the entire body of an aluminia mass subjected to sulfiding conditions may not form aluminum sulfide, small but significant amounts of aluminum sulfide are formed on the surfaces of the alumina body. It is believed, therefore, that inorganic sulfide ion is also present in the activated alumina catalyst of the first embodiment of the present invention in which no metal or metalloid promoter is added to the alumina.

To further support the view that it is the presence of inorganic sulfide ion in the alumina catalyst of the present invention which provides the novel catalytic effects herein described, it has also been found in accordance with the present invention that sulfide ion can be introduced into the alumina catalyst of the present invention by techniques other than the sulfuractivation treatment discussed above. For example, it has been found that an effective catalyst can also be obtained by introducing sulfide ion during the wet chemistry stage of preparing the catalyst. This may be accomplished by bubbling H2 S gas through an aqueous slurry of activated alumina particles and a salt of the metal or metalloid promoter, whereby a sulfide of the metal or metalloid forms on the activated alumina particles. Still another way of producing an effective catalyst comprises mixing elemental sulfur with a composite comprising the metal or metalloid promoter in reduced or elemental form on an activated alumina support and thereafter heating the mixture to calcining temperatures (e.g. above 5000F) in an inert atmosphere.

Any activated alumina having a surface area of 0.5 to 800 m2/g can be employed as the starting material to form the sulfide ion-containing catalyst employed in the inventive process.

For example, activated alumina having a surface area of 2 to 500 m2/g can be used to advantage in the present invention. As a practical matter, the most common surface area of commercially available alumina is about 200 m2 /g, and therefore the activated alumina used in the inventive process preferably has a surface area of 2 to 200 m2 Ig. The particle size of the activated alumina starting material used to make the catalyst of the inventive process as well as the particle size of the catalyst itself is unimportant, any particle size being effective. When the inventive process is carried out in a fixed-bed reactor on a commercial scale, the particle size of the catalyst can be the conventional particle size for fixedbed commercial catalytic reactors, namely 1/16 inch to 1/2 inch in diameter. Similarly, when the inventive process is carried out in a fluid-bed, the particle size of the catalyst is advantageously the conventional particle size for commercial fluid-bed reactors, namely 20 to 300 microns. In the following working examples the catalyst had a particle size of 9 to 40 mesh, Tyler, since this is a convenient size for laboratory scale testing.

Examples In order to describe more throughly the present invention, the following working examples are presented. In each of these examples, acrylonitrile was dimerized in a reactor constructed of an 8.0 mm inside diameter stainless steel tube.

The reactor had a 10 cc reaction zone, an inlet for reactants and an outlet for products. The reactor was heated in a salt bath to give the desired reaction temperature. In general, the experimental method consisted of pre-reducing a supported metal oxide catalyst with hydrogen and then passing a mixture of hydrogen and acrylonitrile over the catalyst at 8000F at one atmosphere total pressure. Standard run conditions in all the examples unless otherwise indicated comprised a feed rate of 40 STP cc/min. H2, 0.2 cc liquid acrylonitrile per minute and a run time of 5 minutes. In a large number of runs, the used catalyst was sulfided with a mixture of 15% H2 S in H2 and a second run was made with an acrylonitrile/hydrogen mixture.

In all runs, the off-gas was scrubbed in 11.0 cc of acetone at ice temperature and an aliquot was analyzed by gas liquid chromotography and mass spectroscopy for the degree of acrylonitrile conversion and the composition of the converted product.

For the purposes of this application, the following definitions are used: moles of acrylonitrile reacted % Conversion= x 100 moles of acrylonitrile fed moles of acrylonitrile converted to % Yield=a specific product moles of acrylonitrile reacted x 100 The following experiments, of which Examples 2,4,5,8,10,12,14,16,1 8,20,22,24,26,28,30,32,34, 36,38,40,42,44,46,48,50,52,54,56,58,60,62,64, 65 and 69 represent the present invention and the rest of which are outside the scope of the invention and presented for the purposes of comparison, were conducted: Example 1 An aqueous solution of NH40H was added to an aqueous copper nitrate solution to produce a precipitate of hydrous CuO. The precipitate was recovered, filtered, washed, dried, crushed, screened, calcined and reduced at 8000F in H2 to produce 9 to 40 mesh (Tyler) copper particles.

The reactor was charged with 3 cc of copper particles, and the charge was sulfided by passing a 20% H2 S in H2 stream through the reactor for one hour at 8000F. A total of 1.0 cc acrylonitrile was then fed through the reactor over a period of five minutes. Along with the acrylonitrile, H2 was fed through the reactor at a rate of 40 STP cc/min. The reaction temperature was maintained at 8000F. The reaction product was recovered and analysed with the following results: acrylonitrile conversion = 0% propionitrile yield = 0% adiponitrile yield = 0% 1 ,4-dicyanobutene-1 yield = 0% 1 ,4-dicyanobutene-2 yield = 0% Example 2 4 cc gamma activated alumina having a surface area of 180 to 200 m2 /g and a particle size of 9 to 40 mesh was fed into the reactor and the reactor heated to a temperature of 8000F. A gas mixture comprising 15% 112S in H2 was fed to the reactor to effect sulfiding of the alumina catalyst. After 15 minutes, acrylonitrile was also fed to the reactor, a total of 1 cc acrylonitrile being uniformly fed to the reactor over a period of 5 minutes. The reaction product was recovered and analyzed with the following results: acrylonitrile conversion = 35.2% propionitrile yield = 1.1% adiponitrile yield = -0% 1,4-dicyanobutene-l yield = 5.6% 1,4-dicyanobutene-2 yield = 0% Example 3 Example 2 was repeated except that the reactor was charged with 4 cc of 14 to 28 mesh (Tyler) Alundum (Alcoa T-61). (Alundum is a Registered Trade Mark). The following results were obtained: acrylonitrile conversion = 0% propionitrile yield = 0% adiponitrile yield = 0% 1 ,4-dicyanobutene-1 yield = 0% 1,4-dicyanobutene-2 yield = 0% material balance = 100% Example 4 2.47 g. Co(NO3)2 6H2O was dissolved in 5 cc water, and the solution obtained thereby was used to impregnate 5 grams of 9 to 40 mesh activated alumina having a surface area of 180 to 200 m2/g. The resultant composite was dried at a temperature of 1500C, heated in air for one hour at 5000C and then charged into the reactor.

H2 was fed to the reactor for a period of one hour at 800"F to reduce the cobalt in the composite.

Thereafter, the composite was sulfided by passing a mixture of 15% H2 S in 112 through the reactor for 30 minutes at 8000F. The dimeri zation reaction was accomplished by passing 1.0 cc acrylonitrile through the reactor uniformly over a period of five minutes. Along with the acrylonitrile a carrier gas comprising 15% 112S in H2 was fed to the reactor at a rate of 40 STP cc/min. The reaction temperature was 800"F.

The reaction product was recovered and the following results were obtained: acrylonitrile conversion = 31.5% propionitrile yield = 13.8% adiponitrile yield = 0% 1,4-dicyanobutene-l yield = 7.5% 1,4-dicyanobutene-2 yield = 0% Example5 After completion of Example 4, the catalyst was left in the reactor and stripped with 112 for one hour at 8000F. After the stripping operation, 1.0 cc acrylonitrile was fed to the reactor uniformly over a period of five minutes. Along with the acrylonitrile, 40 STP cc/min H2 was fed to the reactor. The reaction temperature was maintained at 800cF. The reaction product was recovered and the following results were obtained: acrylonitrile conversion = 12.9% propionitrile yield = 36.5% adiponitrile yield = 0% l,4-dicyanobutene-l yield = 12.5% 1,4-dicyanobutene-2 yield = 0% Example 6 Example 4 was repeated except that the catalyst in the reactor was not subjected to sulfiding conditions with 15% H2S in 112 after cobalt was reduced. Also, H2S was not included in the carrier gas. The following results were obtained: acrylonitrile conversion = 58.9% propionitrile yield = 23.8% adiponitrile yield = 0% 1,4-dicyanobutene-l yield = 1.7% 1 ,4-dicyanobutene-2 yield = 0% Example 7 5.0 grams of 9 to 40 mesh (Tyler) high surface area (180 to 200 m2 /g) gamma alumina particles were impregnated with 0.97 grams P2 Os 24MoO3 48H2O in sufficient amount of water to just wet the surface of the alumina particles. The alumina particles so impregnated were dried for two hours at 1500C and calcined in air at 5000C for one hour to yield activated alumina particles having thereon 9.1% Mo in the form ofmolydena. 3 cc of the catalyst were charged into the reactor and subjected to hydrogen reduction conditions at 800 F for two hours.

1.0 cc acrylonitrile was uniformly fed to the reactor over a period of five minutes, 112 also being fed to the reactor during the reaction at 40 STP cc/min. The reaction temperature was 800"F. The reaction product was recovered and the following results were obtained: acrylonitrile conversion = 49.0% propionitrile yield = 58.5% adiponitrile yield = 0% 1,4-dicyanobutene-l yield = 2.0% 1 ,4-dicyanobutene-2 yield = 0% Example 8 After the completion of Example 7, the catalyst in the reactor was sulfided by passing 15% 112S in 112 over the catalyst for two hours at 800"F. 1.0 cc acrylonitrile was then fed to the reactor uniformly over a period of five minutes, H2 at a rate of 40 STP cc/min also being fed to the reactor during this period. The reaction temperature was 8000F. The reaction product was recovered and the following results were obtained: acrylonitrile conversion = 70.1% propionitrile yield = 96.3% adiponitrile yield = 0% 1 ,4-dicyanobutene-1 yield = 2.3% 1,4-dicyanobutene-2 yield = 0% Examples 9 to 104 The foregoing general procedure was repeated with many different catalysts, and the results of these experiments are set forth in the following Table 1. In most of these experiments, a starting material comprising a support and an amount of decomposable salt, decomposable hydroxide or oxide thereon was first produced, and then the starting material was calcined in air at elevated temperature so that the metal or metalloid was present in the composite in oxide form. The composite was then subjectde to an atmosphere of hydrogen at 8000F to reduce the metal or metalloid oxide. The catalyst so produced was used in a first dimerization reaction. After completion of the first dimerization reaction, the catalyst remaining in the reactor was subjected to sulfiding with H2S at elevated temperature and used in a second dimerization reaction. Unless otherwise indicated in Table 1: - the catalyst support was 9 to 40 mesh, Tyler; - activated alumina was a gamma activated alumina having a surface area of 180 to 200 m2/g; -activated carbon supports were about 10 mesh, Tyler (Nitco Grade 718); -in those cases in which the support was silica, the usual method of preparation was by forming a solution of decomposable metal salt in a silica sol (Nalco 1034 A), gelling with ammonium nitrate and calcining the dry gel in air at a temperature of 350 to 5000C; -in those experiments in which the catalyst contained more than one promoter and the support was other than silica, the promoters were applied individually by aqueous solution in the order noted in the table, the composite being dried after each promoter application; -in those experiments in which the catalyst contained more than one promoter and the support was silica, an aqueous solution containing all of the indicated impregnant materials was made and mixed with a silica sol, which in turn was gelled and dried as described above; - in the column labeled "Starting Material" the indicated percent is the weight percent of the metal or metalloid in the catalyst ultimately obtained, with the weight of the metal or metalloid plus the weight of the support being taken at 100% (for example, in Example 4 the catalyst ultimately produced contained 9.1 weight % Co and 90.9 weight % A1203); - calcination was done in air; hydrogen reduction was done at 8000F with 100 mole percent H2; -the total amount of catalyst charged into the reactor was 3 cc; -sulfiding of the catalyst was done at 800"F with a gas comprising 15 mole percent H2S and 85 mole percent H2; -a total of 1.0 cc liquid acrylonitrile was fed to the reactor uniformly over a period of five minutes so that the acrylonitrile feed rate was 0.2 cc/min; - 40 STP ccfmin. 112 was also fed to the reactor during the dimerization reaction; and - the indicated percents for gases are mole percents.

Also, in Table 1 the following abbreviations are used: "AN" means "acrylonitrile" "propio" means "propionitrile" "adipo" means "adiponitrile" "1,4-DCB-1 means "1 ,4-dicyanobutene-l" "1,4-DCB-2" means "1 ,4-dicyanobutene-2" "succino" means

Claims (20)

This and all other modifications are intended to be included within the scope of the present invention, which is to be limited only by the following claims: WHAT WE CLAIM IS:

1. A process for forming 1 ,4-dicyanobutene by catalytically dimerizing acrylonitrile in the vapour phase in which acrylonitrile is contacted with a catalyst comprising activated alumina containing inorganic sulfide ion.

2. A process as claimed in claim 1 in which the acrylonitrile is contacted with the catalyst at a temperature of 500 to 11000F.

3. A process as claimed in claim 1 or claim 2 in which the acrylonitrile is contacted with said catalyst for an apparent contact time of 0.1 to 30 seconds at a pressure of 1 to 100 atmospheres.

4. A process as claimed in any of claims 1 or 3 in which said alumina has a surface area from 0.5 to 800 m2/g.

5. A process as claimed in claim 4 which the catalyst is formed by contacting activated alumina optionally as a support at an elevated temperature of at least about 500"F with a material capable of decomposing to liberate sulfide ion at said elevated temperature.

6. A process as claimed in claim 5 in which the catalyst is formed by contacting activated alumina with H2 S, CS2 or an organic sulfurcontaining molecule decomposing at said elevated temperature to liberate a sulfide ion.

7. A process as claimed in claim 6 in which the period of contact with the alumina is from 0.1 to 5 hours.

8. A process as claimed in claim 4 in which the catalyst consists essentially of alumina and an inorganic sulfide of a metal of metalloid selected from (a) metals and metalloids of Groups IA, IIA, IVB. VB, VIB, VIIB, IB, IIB, IIIA and IVA of the Periodic Table; (b) Rare Earth metals; (c) scandium; and (d) hafnium.

9. A process as claimed in claim 8 in which said metal or metalloid is selected from lithium, sodium, potassium, rubidium, cesium, magnesium calcium, strontium, barium, chromium, molybdenum, magnanese, iron, cobalt, nickel, palladium, platinum, copper, silver, zinc, cad TABLE 1 Calcining H2 Red. Sulfiding AN Exp. Temp Time Time Time Con- 1,4- 1,4- Matl No. Starting Material ( F) (Min) (Min) (Min) version Propio Adipo DCB-1 DCB-2 Bal. Comments 1 9-40 mesh Cu particles - - - - - - 60 ~0 0 0 0 0 ~100 Catalyst sulfided with 20%H2S in H2 2 Act Al2O3 - - - - - - 15 35.2 1.1 0 5.6 0 - - Carrier gas comprised 15% H2S 3 14-28 mesh T-61 Alcoa 15 0 0 0 0 0 ~100 Alundum 4 9.1% Co(NO3)-6H2O on 500 60 60 30 31.5 13.8 0 7.5 0 - Act Al2O3 5 Ex 4 catalyst - - - - 60 - - 12.9 36.5 0 12.5 0 - 6 9.1% Co(NO3)-6H2O on 500 60 60 - - 58.9 23.8 0 1.7 0 - Act Al2O3 7 9.1% P2O5-24MoO3-48H2O on 500 60 120 - - 49.0 58.5 0 2.0 0 - - (Catalyst contains Act Al2O3 9.1% Mo) 8 Ex 7 catalyst - - - - - - 120 70.1 96.3 0 2.3 0 ~100 9 9.1% CrO3 on Act Al2O3 500 60 180 - - 34.0 13.9 0 5.8 0 - 10 Ex 9 catalyst - - - - - - 120 27.8 35.7 0 9.8 0 - - TABLE 1 (cont) Calcining H2Red. Sulfiding AN Exp. Temp Time Time Time Con- 1,4- 1,4- Matl.

No. Starting Material ( F) (Min) (Min) (Min) version Propio Adipo DCB-1 DCB-2 Bal. Comments 11 9.1% Ce(NO3)3.6H2O in 500 60 120 - - 34.0 1.8 0 4.7 0 - Act Al2O3 12 Ex 11 catalyst - - - - - - 120 9.2 4.1 0 17.6 0 - 13 9.1% KOH on Act Al2O3 500 60 60 - - 82.6 0.5 0 0 0 - 14 Ex 13 catalyst - - - - - - 60 73.8 8.4 1.4 4.6 0.5 - - Unknown at 8.0 minute ref. time 3.2% 15 9.1% Mg(NO3)2.6H2O on 500 60 120 - - 34.0 1.8 0 6.9 0 - Act Al2O3 16 Ex 15 catalyst - - - - - - 60 9.2 TR TR 29.7 TR - 17 9.1% AgNO3 o Act Al2O3 500 60 OVNT - - 30.3 3.3 0 5.3 0 - 18 Ex 17 catalyst - - - - - - 60 3.0 12.5 0 54.2 TR - 19 9.1% T1NO3 on Act Al2O3 500 60 60 - - 32.8 1.9 0 7.2 0 - 20 Ex 19 catalyst - - - - - - 30 11.7 3.2 0 20.2 TR - 21 9.1% UO2(NO3)2.6H2O on 500 60 240 - - 11.7 5.3 0 13.8 0 - Act Al2O3 22 Ex 21 catalyst - - - - - - 60 0 TR 0 TR TR - 23 20.6%PdCl2 on Act Al2O3 500 60 60 - - 75.1 83.0 0 4.5 0 ~90 TABLE 1 (cont) Calcining H2Red. Sulfiding AN Exp. Temp Time Time Time Con- 1,4- 1,4- Matl.

No. Starting Material ( F) (Min) (Min) (Min) version Propio Adipo DCB-1 DCB-2 Bal. Comments 24 Ex 23 catalyst - - - - - - 30 41.4 +100 0 9.0 0 ~100 25 9.1% Mn(NO3)2.6H2O on 500 60 60 - - 30.3 1.3 0 5.8 0 - Act Al2O3 26 Ex 25 catalyst - - - - - - 40 5.5 TR 0 18.2 0 - 27 9.1 Fe(NO3)3.9H2O on 500 60 60 - - 40.2 4.6 0 3.4 0 - Act Al2O3 28 Ex 27 catalyst - - - - - - 30 15.4 60.5 0 12.9 0 - 29 9.1% Cu(NO3)2.3H2O on 500 60 60 - - 30.3 2.0 0 6.6 0 - Act Al2O3 30 Ex 29 catalyst - - - - - - 45 7.9 4.7 0 17.2 0 - 31 32.1% PtCl2 on Act Al2O3 500 120 120 - - 75.1 87.1 0 3.6 0 ~90 32 Ex 31 catalyst - - - - - - 30 34.5 +100 0 2.3 0 ~100 33 9.1% Ni(NO3)2.6H2O on 500 60 60 - - 95.0 35.4 0 0 0 - - NH3 odor in off gas Act Al2O3 34 Ex 33 catalyst - - - - - - 30 54.0 96.3 TR 6.2 TR ~100 35 9.1% LiNO3 on Act Al2O 500 60 30 - - 25.3 TR 0 14.7 0 - - TABLE 1 (cont) Calcining H2Red. Sulfiding AN Exp. Temp Time Time Time Con- 1,4- 1,4- Matl.

No. Starting Material ( F) (Min) (Min) (Min) version Propio Adipo DCB-1 DCB-2 Bal. Comments 36 Ex 35 catalyst - - - - - - 30 10.4 0 0 26.2 0 - 37 9.1% CH3-COO-Rb on 500 60 30 - - 81.4 3.0 0 TR 0 - Act Al2O3 38 Ex 37 catalyst - - - - - - 30 75.1 6.3 0.9 5.0 0.5 - 39 9.1% Ba(OH)2 on Act Al2O3 500 60 30 - - 47.8 2.1 TR 6.2 TR - 40 Ex 39 catalyst - - - - - - 30 15.4 2.4 0 24.2 0 - 41 9.1% ZnCl2 on Act Al2O3 500 60 45 - - 10.4 3.6 0 6.0 0 - 42 Ex 41 catalyst - - - - - - 30 10.4 TR 0 6.0 0 - 43 9.1% Cu(NO3)2.4H2O on 500 60 30 - - 40.2 0.9 0 5.9 0 - Act Al2O3 44 Ex 43 catalyst - - - - - - 30 12.9 TR 0 21.2 TR - 45 9.1% Cd(NO3)2.4H2O on 500 60 30 - - 34.0 13.9 0 4.0 0 - Act Al2O3 46 Ex 45 catalyst - - - - - - 30 6.7 TR 0 20.4 0 - 47 9.1% Pb(NO3)2 on Act Al2O3 500 60 60 - - 35.2 2.8 0 7.0 0 - 48 Ex 47 catalyst - - - - - - 30 3.0 TR 0 54.2 0 - 49 9.1% SnCl2.2H2O 500 60 60 - - 5.5 0 0 11.5 0 - Act Al2O3 50 Ex 49 catalyst - - - - - - 60 12.9 0 0 7.7 0 - - TABLE 1 (cont) Calcining H2Red. Sulfiding AN Exp. Temp Time Time Time Con- 1,4- 1,4- Matl.

No. Starting Material ( F) (Min) (Min) (Min) version Propio Adipo DCB-1 DCB-2 Bal. Comments 51 9.1% CsC2H3O2 on Act 500 60 60 - - 85.1 3.6 0 0.4 0 - Al2O3 52 Ex 51 catalyst - - - - - - 30 66.4 3.7 0.5 11.5 0.5 - 53 9.1% NaOH on Act Al2O3 500 60 60 - - 83.9 2.7 0.4 4.8 0 - - Unknown at 8.1 min. ret. time ~ 2% 54 Ex 53 catalyst - - - - - - 60 44.0 5.6 0.75 18.5 0.75 - 55 9.1% Bi(NO3)3.5H2O on 500 60 120 - - 15.4 4.0 0 12.9 0 - Act Al2O3 56 Ex 55 catalyst - - - - - - 60 0 TR 0 TR 0 ~100 57 9.1% Sr(OH)2.8H2O 500 60 60 - - 41.4 3.8 0 6.6 0 - 58 Ex 57 catalyst - - - - - - 30 9.2 4.3 0 40.5 0 - 59 7.5% P2O5.24MoO3.48H2O 300 OVNT 60 - - 63.9 1.9 TR 2.5 TR - and 17.5% NaOH on Act Al2O3 60 Ex 59 catalyst - - - - - - 30 60.2 14.4 1.0 4.5 0.6 - 61 26.75% PtCl2 and 17.67% 300 OVNT 60 - - 54.0 2.3 0.7 6.2 0.7 - NaOH on Act Al2O3 62 Ex 61 catalyst - - - - - - 30 25.3 3.9 1.5 24.0 1.5 - 63 7.5% Ni(NO3)2.6H2O and 300 OVNT 120 - - 82.6 59.5 0 0.5 0 - 17.5% NaOH on Act Al2O3 TABLE 1 (cont) Calcining H2Red. Sulfiding AN Exp. Temp Time Time Time Con- 1,4- 1,4- Matl.

No. Starting Material ( F) (Min) (Min) (Min) version Propio Adipo DCB-1 DCB-2 Bal. Comments 64 Ex 63 catalyst - - - - - - 30 34.0 82.5 1.1 9.9 0 ~90 65 Ex 64 catalyst - - - - 60 - - 12.9 TR 0 26.0 0 - - Ex 64 catalyst contacted with 100 mol % H2 for 1 hour while temp. lowered to 500 F. Experiment conducted at 500 F.

66 2% H2 TeO3, 5% Pt and 300 60 60 - - 21.8 98.3 0.7 0 0 ~100 0.5% NaOH on Mathesen Grade 95 silica gel 67 Ex 66 catalyst - - - - - - 20 7.3 42.9 TR 0 0 ~100 57.1% Succino, TR Pyridine 68 7.5% CrO3 and 17.5% NaOH 300 OVNT 30 - - 50.2 17.3 0.7 0.7 0 36.8% aceto, 5.9% on Act Al2O3 succino, 6.7% pyridine 69 Ex 68 catalyst sulfided - - - - - - 30 35.4 25.6 1.8 1.8 0 18.6 aceto, 16.2% succino 70 26.7% PdCl2 and 16.6% 300 OVNT 120 - - 78.8 43.0 TR 0 0 - - 20.5 aceto, 2% NaOH on Act Al2O3 succino TR pyridine 71 Ex 70 catalyst - - - - - - - - 74.6 84.4 TR 0 0 ~100 Carrier gas 15% H2S in H2, 15.6% succino 72 12.5% KOH on SiO2 350 OVNT 30 - - 60.2 15.5 1.6 - - - - - - 33% aceto, 5% succino, 45% pyridine 73 Ex 72 catalyst - - - - - - 30 44.0 29.0 1.4 TR - - - - 27% aceto, 16.1% succino, 8.5% pyridine TABLE 1 (cont) Calcining H2Red. Sulfiding AN Exp. Temp Time Time Time Con- 1,4- 1,4- Matl.

No. Starting Material ( F) (Min) (Min) (Min) version Propio Adipo DCB-1 DCB-2 Bal. Comments 74 12.5% Mg(NO3)2.6H2O on 350 OVNT 60 - - 5.0 63.6 0 0 0 - - 36.4% succino SiO2 75 Ex 74 catalyst - - - - - - 30 3.7 69.4 0 0 0 - - 30.6% succino 76 12.5% Zn(C2H3O2)2 on 350 OVNT 60 - - 3.0 71.4 0 0 0 - - 28.6% succino SiO2 77 12.5% CrO3 on SiO2 350 OVNT 30 - - 2.7 88.5 0 0 0 - - 11.5% succino 78 12.5% Cd(NO3)2.4H2O on 350 OVNT 60 - - 1.0 100 0 0 0 - SiO2 79 12.5% KOH on graphite 250 48 hr. 120 - - 2.4 85.7 0 14.3 0 - - Support-Petroleum carbon derived Graphite Carbon ~ 10 mesh 80 12.5% H3PO4 on graphite 250 48 hr. 30 - - 0.3 ~100 0 0 0 - carbon " 81 12.5% KOH on activated 200 OVNT 30 - - 97.5 21.4 0 0 0 - - 27.1% aceto, 2.4% carbon pyridine 0.4% succino 82 12.5% Ba(OH)2 on SiO2 350 OVNT 30 - - 2.2 75 TR 0 0 - - 25% succino 83 Type 4A molecular sieves - - - - 60 - - 3.0 75 - - TR aceto - 1/16 "pellets 84 12.5% NaOH on SiO2 350 OVNT 60 - - 0.6 ~100 - - - - - - ~100 85 12.5% (20MoO3 2H3PO4) 200 OVNT 60 - - 32.8 93.7 TR TR 0 1.8% succino, on Act carbon unknown at 12.2 RT 86 12.5% Cu(NO3)2.3H2O on 200 OVNT 60 - - 13.5 88 9% succino, Act carbon unknown at 12.2 RT TABLE 1 (cont) Calcining H2Red. Sulfiding AN Exp. Temp Time Time Time Con- 1,4- 1,4- Matl.

No. Starting Material ( F) (Min) (Min) (Min) version Propio Adipo DCB-1 DCB-2 Bal. Comments 87 12.5% Mg(NO3)2.6H2O on 200 OVNT 60 - - 98.8 18.2 0 0 0 - - 17.3% aceto, Act carbon 0.4% succino 88 12.5% Ca(NO3)2.4H2O on 200 OVNT 30 - - 45.3 19.2 TR - - - - - - 25.5% aceto, Act carbon 4.4% succino 89 6.2% Ru on Al2O3 modified 300 OVNT 60 - - 3.4 75.8 8.0 TR 16.1 - SiO2 90 Ex 89 - - - - - - 0 TR - - - - - - Ex 89 catalyst air oxidized for 30 min.

800 F and then purged with N2 carrier gas was 20 STP cc/min N2 91 12.5% (NH4)2W4O13.H2O 500 OVNT 120 - - 1.3 ~100 - - - - - - - on SiO2 92 12.5% NH4VO3 on SiO2 500 OVNT 120 3.3 90.9 - - - - - - - - 9% succino 93 11.2% (20MoO3.2H3PO4. 500 240 60 - - 5.6 ~100 - - - - - - ~100 48H2O) and 10.1% AgNO3 on SiO2 94 10.8% (20MoO3.2H3PO4. 500 240 60 - - 7.3 88.2 ~11% succino 48H2O) and 14.7% SnCl2 .2H2O on SiO2 95 11.6% (20MoO3.2H3.PO4. 500 240 60 - - 2.6 87.0 - - - - - - - - ~13% succino 48H2O) and 7.0% FeCl3 on SiO2 TABLE 1 (cont) Calcining H2Red. Sulfiding AN Exp. Temp Time Time Time Con- 1,4- 1,4- Matl.

No. Starting Material ( F) (Min) (Min) (Min) version Propio Adipo DCB-1 DCB-2 Bal. Comments 96 11.6% (20MoO3.2H3PO4. 500 240 60 - - 95.0 23.0 6.9 aceto 48H2O) and 7.2% Ni(NO3)2 .6H2O on SiO2 97 11.5% (20MoO3.2H3PO4. 500 240 30 - - 3.6 84.8 - - - - - - - - ~15% succino 48H2O) and 7.7% Zn(CH3 CO2)2.2H2O on SiO2 98 12.1% (20MoO3.2H3PO4. 500 240 60 - - 4.3 80.5 - - - - - - - - ~19% succino 48H2O) and 3.0% LiNO3 on SiO2 99 11.5% (20MoO3.2H3PO4. 500 240 60 - - 9.2 ~100 - - - - - - ~100 48H2O) and 7.6% Cu(NO3)2 .3H2O on SiO2 100 11.6% (20MoO3.2H3PO3. 500 240 60 - - 9.5 94.1 - - - - - - - - ~5% succino 48H2O) and 7.2% Co(NO3)2 .6H2O on SiO2 101 11.0% (20MoO3.2H3PO4. 500 240 60 - - 6.0 90.6 - - - - - - - - ~9% succino 48H2O) and 11.6% Cd(NO3)2 .4H2O on SiO2 102 12.0% (20MoO3.2H3PO4. 500 240 30 - - 3.6 75.8 - - - - - - - - ~24% succino 48H2O) and 3.9% Mg(NO3)2 .6H2O on SiO2 103 12.5% NH4VO3 on Act 200 OVNT 60 - - 9.4 96.4 - - - - - - - - ~3% succino carbon 104 12.5% (NH4)2W4O13.8H2O 200 OVNT 60 - - 13.9 97.6 - - - - - - - - ~2% succino on Act carbon mium, tellurium, tin, lead and cerium.

10. A process as claimed in claim 8 or claim 9 in which the amount of said inorganic sulfide in said catalyst is at least sufficient so that the presence of said inorganic sulfide exhibits an effect on the catalytic activity of said catalyst in the dimerization of acrylonitrile.

11. A process as claimed in any of claims 8 to 10 in which said inorganic sulfide is present in said catalyst in an amount such that the amount of metal or metalloid in said catalyst is 0.1 to 50 percent by weight, based on the total weight of such catalyst.

12. A process as claimed in claim 11 in which the amount of sulfide in said catalyst is such that the amount of metal or metalloid in said catalyst is 1 to 10 percent by weight, based on the total weight of said catalyst.

13. A process as claimed in any of claims 8 to 12 in which said metal or metalloid is selected from metals in Groups IA, IIA, IB and IIB of the Periodic Table and lead.

14. A process as claimed in claim 13 in which said metal or metalloid is selected from sodium, strontium and silver.

15. A process as claimed in any of claims 8 to 14 in which the catalyst is formed by depositing the metal or metalloid on the alumina to form a composite and thereafter contacting the composite at an elevated temperature of at least 5000F with a material capable of decomposing to liberate sulfide ion at said elevated temperature so that said metal or metalloid is converted at least in part to a sulfide.

16. A process as claimed in claim 15 in which the material is selected from H2 S, CS2 and an organic sulfur-containing molecule decomposing at an elevated temperature to liberate a sulfide ion.

17. A process as claimed in claim 16 in which the material is H,S or CS2.

18. A process as claimed in any of claims 15 to 17 in which the contact time is from 0.1 to 5 hours.

19. A process as claimed in claim 1 substantially as herein described with reference to any of Examples 2,4,5,8,10,12,14,16,18,20,22,24, 26,28,30,32,34,36,38,40,42,44,46,48,50,52, 54,56,58,60,62,64,65 and 69.

20. 1 '4-Cyanobutene when prepared by a process as claimed in any of claims 1 to 19.