Verfahren zur Herstellung von Acrylnitril und Methacrylnitril

摘要

Acrylonitrile or methacrylonitrile is produced by reacting propylene or isobutylene, with ammonia and oxygen at 400 DEG to 520 DEG C. in a solid bed in the presence of a catalyst which contains bismuth phosphomolybdate on a silicic acid support and applying this as a coating to compact crystalline cores of natural or artificial inorganic minerals or mixtures of minerals, having a grain size of 1 to 8 mm. and a maximum porosity of 10%. The catalyst may also contain compounds of beryllium, calcium, strontium, barium, zinc, cadmium, lithium, sodium and/or silver up to an atomic ratio of 30:100 with respect to molybdenum. The inorganic minerals may be aluminium silicate, corundum, quartz, feldspar, granite, or sintered magnesite. The reaction mixture may be contacted successively with catalysts of increasing thickness of coating on the cores.ALSO:A catalyst for preparing acrylonitrile or methacrylonitrile contains bismuth phosphomolybdate on a silicic acid support, the catalyst being applied as a coating to compact crystalline cores of natural or artificial inorganic minerals or mixtures of minerals, having a grain size of 1-8 mm. and a maximum porosity of 10%. The catalyst may also contain compounds of beryllium, calcium, strontium, barium, zinc, cadmium, lithium, sodium and/or silver up to an atomic ratio of 30 : 100 with respect to molybdenum. The crystalline cores may be formed from compactly fired predominantly crystalline aluminium silicate, corundum, quartz, feldspar, granite, or sintered magnesite. The catalyst is prepared by spraying the crystalline cores at 100-200 DEG C. with a mixture of phosphoric acid and molybdic acid, or phosphododecamolybdic acid, with bismuth nitrate, nitric acid, and silicic acid in sol form and possibly one or more nitrates of the above mentioned metals and then heating the coated cores for several hours at 300-500 DEG C.