GB1195037A - Ammoxidation of Hydrocarbons - Google Patents

Abstract

1,195,037. Production of aliphatic dinitriles. IMPERIAL CHEMICAL INDUSTRIES Ltd. 23 Oct., 1968 [6 Nov., 1967], No. 50335/67. Heading C2C. Aliphatic acyclic dinitriles are obtained by contacting a gaseous mixture comprising cyclohexane or cyclohexene, singly or in admixture, ammonia and oxygen with a solid catalyst comprising a compound of antimony or molybdenum and oxygen, at an elevated temperature, in the presence of a halogen at the catalyst surface. The presence of a halogen at the surface of the catalyst may be induced either by doping the solid catalyst with a halogencontaining compound, e.g. an inorganic halide, or by incorporating a volatile chlorine-, bromine- or fluorine-containing compound in the feed gases. The reaction is generally effected at a temperature of 300-700‹ C. employing a ratio of hydrocarbon feed to ammonia of 1: 3 to 7: 1, and a ratio of oxygen to hydrocarbon feed of 1: 3 to 8:1, and an inert gas and/or water vapour may also be present. The process is preferably operated on a continuous basis with mean gas feed/catalyst contact times of 0À4-5 sees. The antimony-containing catalyst, which may be present as the trioxide, tetroxide or pentoxide or mixtures thereof, may also be employed in admixture with one or more other metal oxides which may take the form of separate metal oxides or they may be present in chemical combination with the antimony oxide. The molybdenum-containing catalyst, which is molybdenum oxide or a molybdenum compound capable of yielding molybdenum oxide when heated in oxygen at 450-650‹ C., is advantageously employed with an acidic material, e.g. an oxide of phosphorus, arsenic or boron, as a promoter. The catalysts, which may be prepared by conventional methods, may be employed alone or admixed with inert diluents or carriers, and are preferably pre-heated before use. Specific examples describe the production of adiponitrile, succinonitrile and glutaronitrile.