United States Patent (19) 11) 4,339,395 Barnette et al. 45) Jul. 13, 1982

(54) TREATMENT OF OLEFIN 56) References Cited PRODUCTS U.S. PATENT DOCUMENTS (75) Inventors: Willie J. Barnette; Farland E. Henry; 3,496,218 2/1970 Drinkard, Jr. et al...... 260/465.8 R 3,766,237 10/1973 Chia et al...... 260/464 X Morris Rapoport, all of Orange, Tex. 3,766,241 10/1973 Drinkard, Jr...... 260/465.8 R

3,773,809 11/1973 Walter ...... 260/465.8 R (73) Assignee: E. I. Du Pont de Nemours and 3,903,120 9/1975 Shook, Jr. et al...... 260/465.3 X Company, Wilmington, Del. 4,080,374 3/1978 Corn ...... 260/465.8 RX 4,082,811 4/1978 Shook, Jr...... 260/465.8 RX 21) Appl. No.: 254,487 Primary Examiner-Joseph Paul Brust (57) ABSTRACT (22. Filed: Apr. 15, 1981 Use of ammonia to control interfacial rag formation when olefin hydrocyanation products are contacted 51 Int. Cl...... C07C 120/00; C07C 121/20 with a hydrocarbon. (52) U.S. Cl...... 260/465.8 R 58) Field of Search ...... 260/465.8 R 4. Claims, No Drawings 4,339,395 1. 2 after removal of volatile components is contacted with TREATMENT OF OEFN HYDROCYANATION an aliphatic or alicyclic hydrocarbon can be obtained PRODUCTS from the hydrocyanation of any nonconjugated, ethyl enically unsaturated organic nitrile of from 4 to 20 car BACKGROUND OF THE INVENTION 5 bon atoms. Of particular interest is the hydrocyanation 1. Field of the Invention of pentenenitriles, e.g., cis- and trans-3-pentenenitrile The present invention relates to the recovery of cata (3-PN's), 4-pentenenitrile (4-PN) and mixtures thereof lyst components and, more particularly, to a process for (3,4-PN's) to produce (ADN) which is an the recovery of zero-valent nickel complexes from the intermediate used in the production of hexamethylene stream obtained by the hydrocyanation of olefins, e.g., 10 diamine. This diamine is used to produce polyhexame from the preparation of adiponitrile by hydrocyanation thyleneadipamide, a commercial polyamide useful in of using nickel complexes as catalysts with forming fibers, films and molded articles. triarylboranes, e.g., triphenylborane as the catalyst pro Typically, the catalyst which is employed in the hy noters. drocyanation is a zero-valent nickel (Ni) catalyst pre 2. Description of the Prior Art 15 pared according to U.S. Pat. No. 3,903,120 issued on The hydrocyanation process to which the present Sept. 2, 1975. Of particular interest is catalyst having invention is particularly applicable is described in U.S. the general formula NiL4 where L is a neutral ligand Pat. No. 3,496,218 issued on Feb. 17, 1970. Catalyst used such as a triarylphosphite of the formula P(OAr)3 in the process is zero-valent nickel; a particular form of wherein Ar is an aryl group of up to 18 carbon atoms. which is described in U.S. Pat. No. 3,766,237 issued on 20 Illustrative of the aryl groups are methoxyphenyl, tolyl, Oct. 16, 1973. xylyl and phenyl. Meta- and para-tolyl and mixtures U.S. Pat. No. 4,082,811 issued on Apr. 4, 1978 dis thereof are the preferred aryl groups. Usually excess closes a hydrocyanation process coupled with a method ligand is employed. for recovery of the catalyst. The particular operation to The promoters which are used with the above de which the present invention is applied is found in col 25 scribed catalyst are triarylboranes including those of the umn 2, lines 39-42 of this patent. formula BR3 wherein R is an aryl or substituted aryl The feasibility of extracting nickel catalyst mixture group having 6 to 12 carbon atoms, e.g., phenyl, ortho from dinitriles and specifically from adiponitrile is dis tolyl, para-tolyl, napthyl, methoxyphenyl, biphenyl, cussed in detail in U.S. Pat. No. 3,773,809 issued on chlorophenyl and bromophenyl. Triphenylborane Nov. 20, 1973. This patent discloses several organics 30 (TPB) is preferred. which may be employed in the extraction process along A representative analysis of a hydrocyanation reac with detailed analyses of the phases which are obtained tion product before removal of volatiles and showing upon extraction. In column 4, lines 3-15 the use of an the ranges of concentrations of the components is given arylborane compound as a catalyst promoter is dis in Table I. The concentrations will vary according to closed. 35 reaction conditions. SUMMARY OF THE INVENTION TABLE I In a process for the production of dinitriles, e.g., Compound Amount (% by weight) adiponitrile, by the hydrocyanation of nonconjugated, Neutral Ligand (L) 15-35 ethylenically unsaturated organic nitriles having 4-20 3,4-PN's . 20-60 carbon atoms, e.g., 3- and/or 4-pentenenitriles in the Adiponitrile (ADN) 15-50 presence of a zero-valent nickel catalyst promoted with Other Dinitriles <3 Soluble Catalyst and an organoborane, e.g., triphenylborane and containing Promoter (Ni-BR3) <1 excess neutral ligand to produce a reaction product Solids 0.1-4 comprising unreacted nitriles, dinitriles, catalyst, neu 45 Other Organics 4-8 tral ligand and deactivated catalyst wherein the reac *Generally as defined in U.S. Pat. No. 4,082,811 at column 3, lines 55-60, tion product is contacted with an aliphatic or alicyclic hydrocarbon, the improvement which comprises inject Usually at least 50-95% of the mononitriles present in ing at least about 150 parts per million of essentially the product are removed by methods obvious to those water-free ammonia into said reaction product before 50 skilled in the art, e.g., by flash distillation to permit the the reaction product is contacted with said hydrocar formation of two liquid phases when the product is bon. contacted with the hydrocarbon. Suitable hydrocar DETAILED DESCRIPTION OF THE bons include paraffins and cycloparaffins (aliphatic and INVENTION alicyclic hydrocarbons) having a boiling point in the 55 range of about 30 C. to about 135 C. including n-pen The prior art referred to hereinabove describes hy tane, n-hexane, n-heptane and n-octane as well as the drocyanation processes to which the present invention corresponding branched chain paraffinic hydrocarbons is applicable. Specifically this invention applies to the having a boiling point within the range specified. Useful treatment of the hydrocyanation product with an ali alicyclic hydrocarbons include cyclopentane, cyclohex phatic or alicyclic hydrocarbon to recover catalyst ane and cycloheptane as well as alkyl substituted alicyc from mono- and dinitriles as described in U.S. Pat. No. lic hydrocarbons having a boiling point within the spec 4,082,811, e.g., in column 2, lines 23-42 and in U.S. Pat. ified range. Mixtures of hydrocarbons may also be used No. 3,773,809 which disclosures are incorporated such as, for example, mixtures of the hydrocarbons herein by this reference. In all instances a substantial noted above or commercial heptane which contains a portion, e.g., 50% to 95% of the volatile components of 65 number of hydrocarbons in addition to n-heptane. Cy the reaction product, e.g., unreacted mononitriles are clohexane is the preferred . removed, e.g., by flash distillation before the stream is The lighter (hydrocarbon) phase is directed to suit contacted with the hydrocarbon. The stream which able equipment to recover catalyst, reactants, etc. for 4,339,395 3 4. recycle to the hydrocyanation while the heavier connected in series with the overflow from the first (lower) phase containing principally dinitriles is di reactor directed by gravity to the second reactor and rected to product recovery after removal of the solids the overflow from the second reactor directed by grav which accumulate in the heavier phase. These solids ity to the third reactor. Overflow from the last reactor contain valuable components which are also recovered, 5 is retained in a product receiver which is periodically e.g., by the process set forth in U.S. Pat. No. 4,082,811. changed. Each reactor is equipped with an individually It has been discovered that during extended periods controlled electrical heating means and side arms for of continuous extraction a minor amount of the solids sampling the contents during the course of a run. The tends to collect at the interface between the two liquid first reactor is provided with an inlet port for catalyst phases and coat the heavy liquid droplets passing from 10 the lighter to the heavier phase eventually resulting in solution, promoter solution and pentenenitriles. Each the formation of a cellular mixture of globules which reactor is also equipped with a port for introductions of are coated with these solids. The solids, when dried, are hydrogen cyanide below the liquid contents of the a grey powder of 0.1-20 micron particle size and can flasks. A nitrogen inlet is provided to the vapor space of contain about 0.1-3% boron. It is believed that their 15 each reactor and the product receiver to provide a chemical composition is quite similar to the solids de non-oxidizing atmosphere. The pentenenitriles which scribed in U.S. Pat. No. 4,082,811 (see Table I of the are introduced to the reactor and are used to prepare patent). This cellular mixture, or interfacial rag, hin the solutions described hereinbelow contains about ders, if not halts, the phase separation. This rag must be 98% 3PN and 12 4PN with trace amounts of other removed from the interface as it accumulates if phase nitriles. Pentenenitriles of lesser purity can be employed separation is to be conducted continuously. 20 with essentially similar results. Catalyst solution which It has been discovered that the presence of minor is introduced into the first reactor is prepared by react amounts of substantially water-free ammonia will cause ing a mixture containing 77% TTP, 20% PN's, 3% a breakdown of the rag or at least retard its formation to nickel powder, to which mixture is added 100 ppm the extent that effective phase separation is realized on 25 chloride catalyst as phosphorous trichloride. The mix a continuous basis. At least about 150 and preferably, at ture is heated for 16 hours at 80 C., cooled and filtered least 200 parts per million by weight of ammonia based to yield a solution containing approximately 2.7% by upon the weight of the reaction product is required to weight zero-valent nickel (Ni). The promoter solution achieve this result. Although the upper limit of the is prepared by dissolving a mixture of dry TPB in the amount of ammonia employed is not critical and, in 30 above described nitriles to yield a solution containing deed, sufficient ammonia can be added to dissolve the about 20% by weight triphenylborane. Hydrogen cya solids, it is generally unnecessary to introduce more nide employed in the examples is essentially free of than about 500 ppm of ammonia to eliminate or at least sulfuric acid and contains only trace amounts of sulfur control rag formation. dioxide. The hydrogen cyanide is cooled to about O' C. The presence of water in the hydrocyanation system 35 to prevent degradation prior to introduction. The sys is undesirable and for this reason the ammonia should be tem is started up by adding catalyst solution, penteneni water free, i.e., contain less than 0.3% water based upon the weight of ammonia. Commercially available anhy triles and promoter solution to each reactor at room drous ammonia is quite satisfactory. The form in which temperature. Agitation is then started. After warming the ammonia is introduced is not critical. the reactors to 60 C. introduction of hydrogen cyanide, The temperature of the stream into which the ammo catalyst and promoter solutions and pentenenitriles is nia is introduced can vary over a wide range but usually commenced and regulated to achieve an overall ratio of it is convenient to maintain the temperature in the range hydrogen cyanide to Nio, TPB, TTP, 3,4-PN's of 25.0, of about 25'-80' C. Methods to obtain adequate contact 390.7, 2.90, and 0.192 respectively. Approximately of the ammonia with the stream are apparent to those 0.378 weight percent Nio is present in the ingredients as skilled in the art, 45 fed. ADN is produced at a rate of 3.43 grams/cc The following examples and comparatives are pres /minx 10-4. The product contains 58.4 weight percent ented to illustrate but not to restrict the present inven 3,4-PN's; the conversion to ADN is 20% and the yield tion. Parts and percentages are by weight unless other to ADN is 87.4 The yield to 2-PN is 8.4%. wise noted. The reaction product is collected and then distilled 50 under vacuum to remove a major portion of unreacted EXAMPLES 1 AND 2 AND COMPARATIVES mononitriles. It has the analysis set forth in Table II. The following abbreviations and definitions are used TABLE I herein: Compound Amounts (% by weight) 55 Neutral Ligand (TTP) 44.2 TTP = the reaction product of PCl3 and 3,4-PN's 7.5 commercially available mp-cresol ADN 37.9 which contains minor amounts of Other Dinitriles <3 related phenols. Other Organics < Soluble Catalyst and sia - mois of 3- and 4-PN's consumed Promoter (as Ni and TPB) <1 Conversion = unificial x 100 60 Solids

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