Adiponitrile production

Production and Shipment. Estimated adiponitrile production capacities in the U.S. in 1992 were about 625 thousand metric tons and worldwide capacity was in excess of lO metric tons. The DOT/IMO classification for adiponitrile is class 6.1 hazard, UN No. 2205. It requires a POISON label on all containers and is in packing group III. Approved materials of constmction for shipping, storage, and associated transportation equipment are carbon steel and type 316 stainless steel. Either centrifugal or positive displacement pumps may be used. Carbon dioxide or chemical-foam fire extinguishers should be used. There are no specifications for commercial adiponitrile. The typical composition is 99.5 wt % adiponitrile. Impurities that may be present depend on the method of manufacture, and thus, vary depending on the source. 

Hydrocyanation of olefins and dienes is an extremely important reaction [32] (about 75 % of the world s adiponitrile production is based on the hydrocyanation of 1,3-butediene). Not surprisingly, already one of the first Rhone Poluenc patents on the use of water soluble complexes of TPPTS described the Ni-catalyzed hydration of butadiene and 3-pentenenitrile (Scheme 9.10). The aqueous phase with the catalyst could be recycled, however the reaction was found not sufficiently selective. 

Adiponitrile production accounts for 41% of hydrogen cyanide use, methyl methacrylate for 32%. Other uses include sodium cyanide (14%, a... 

Nickel-catalysed addition of HCN to butadiene was developed by du Pont for adiponitrile production [81]. A Ni(0)-phosphite complex is used as the catalyst in the presence of Lewis acids. Oxidative addition of HCN to Ni(0), followed by insertion of butadiene, generates 7r-allyl intermediate 187. Reductive elimination of 187 yields 188 and 189, and isomerization of the double bond in 189 to the terminal position gives 4-pentenonitrile (190). Then, insertion of 190 to H—Ni—CN affords adiponitrile (191). 

Adipic Acid/Adiponitrile, Product Focus, Chemical Week, 161 (9), pg. 31, March 10, 1999. 

Alternatively, caprolactam can be produced from butadiene, via homogeneous nickel-catalysed addition of HCN (DuPont process) followed by selective catalytic hydrogenation of the adiponitrile product to the amino nitrile and vapor phase hydration over an alumina catalyst (Rhodia process) as shown in Fig. 1.49 [137]. 

Fig. 12.5. Adiponitrile production by butadiene hydrocyanntlon. Du Pont process,...

Fig. 12-7. Adiponitrile production by electrodimerizatioa of acrylonitrile. Monsanto process. Schematic view of electrolytic cdt ...

MAJOR USES Used in the manufacture of styrene-butadiene rubbers, plastics, acrylics, latex paints and resins organic intermediate in adiponitrile production. 

The ammoxidation process ( eq. 8 ) displaced the more expensive acetylene-HCN-based route in the early 1960 s (eq. 20). Other obsolete processes also involve more expensive reagents (e.g. ethylene oxide, eq. 19, and acetaldehyde, eq. 21) and oxidants (e.g. NO, eq. 22). The impact of the introduction of the ammoxidation process in 1960 was an immediate drastic reduction in acrylonitrile price and greatly increased production which made possible many of today s high-volume applications of acrylonitrile (Figure 6A). The production of acrylonitrile, which accounts for 17% of the total U. S. propylene consumption, is used extensively in fibers, plastics and resins (ARS/SA) and rubber industries, with a growing number of miscellaneous applications, including the electro-hydrodimerization process for adiponitrile production (Figure 6B). 

Remarkable advances have been made in the past years in the synthesis of isoprenoid Cs-ester units by using 2-methyIbut-3-enenitrile (106) as a starting material. The nitrile 106 is a byproduct or waste product in adiponitrile production and results from direct hydro-cyanation of butadiene. 

The reported demand for hydrogen cyanide in the U.S. A. is now over 550 kt per annum. Possibly one quarter is by-product from acrylonitrile manufacture the remainder is produced by the oxidation of methane/ ammonia mixtures over platinum at about 1100°C. The major use (40-45%) is in DuPont s adiponitrile production, with some 30-35% used for methyl methacrylate (MMA) (methyl 2-methylpropenoate) manufacture and 10% for sodium cyanide. 

The second-generation adiponitrile process is based on an undivided cell. It combined simpler cell design, less complex product extraction and reduced energy consumption to give a much improved process. It was selected for the expansion of adiponitrile production in both the USA and the UK and the world output of adiponitrile by electrolysis now exceeds 200000 ton year". ... 

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