ES436085A1 - Procedure to produce acrilonitril. (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Process for producing acrylonitrile by reacting propylene with ammonia and oxygen in a fluidized bed reactor, in the presence of a catalyst containing molybdenum oxide, bismuth, iron and phosphorus, on silica support, characterized in that it comprises the steps of: (1) preparing, a slurry of catalyst raw material using first a silica sol containing or not sodium, then phosphoric acid and molybdenum, bismuth, iron and, if necessary, sodium in the form of its water soluble salts or in nitric acid, to finally provide a catalyst having the composition mentioned below, and in addition to provide 40% by weight or less of non-volatile solids in the slurry when dehydrated in the subsequent stage of spray drying; (2) spray drying, the resulting slurry at a temperature of 300ºC or lower; (3) calcining the resulting powder at a temperature of the order of between 650ºC and 710º c, and optionally calcining previously at a temperature of the order of between 250ºC and 500º c, before said calcination; (4) obtain, in this way, a catalyst consisting of oxides of the elements of molybdenum, bismuth, iron and phosphorus and as an additional added component, sodium oxide, on silica support at 45-55% by weight, and has the relation of the components expressed by the general formula mo12biafebnacpd where the subfixes a, b, c, and d are atomic relations gives each of the elements in relation to mo12 and, a is of the order of 4 to 6, b is of the order from 4 to 6, c is of the order of 1.1 to 6 and, c is of the order of 0.5 to 1.5; and (5) fluidizing the catalyst obtained above by a stream of mixed gas comprising propylene, ammonia and air in a volume ratio of 10: 1.0 - 1.3: 9.0 - 11.0, at a time of contact comprised between 1 and 10 seconds, at a reaction temperature of 44º -500ºC and a reaction pressure of 0-1 kg/cm2 (relative). (Machine-translation by Google Translate, not legally binding)