| 摘要 |
1353544 Acrylonitrile ERDOLCHEMIE GmbH 19 April 1971 [20 Feb 1970] 21124/71 Heading C2C [Also in Division B1] Ammoxidation is effected in the presence of catalyst which consists essentially of support material in association with bismuth, molybdenum and, optionally, phosphorus in oxidic form and which has been heated at a temperature of from 600 to 750‹ C., advantageously from 620 to 670‹ C. for example for a period of from 0À5 to 20 hours, advantageously from 3 to 5 hours, the catalyst being either fresh catalyst or catalyst which has been used in ammoxidation prior to such heating. The support material may constitute less than 85 weight per cent of the catalyst which may contain from 10 to 30 weight per cent bismuth, from 6 to 18 weight per cent molybdenum and up to 1 weight per cent phosphorus and which may have been prepared by a generally conventional procedure involving coprecipitation, impregnation or spray drying. Examples relate to the preparation of acrylonitrile by a procedure wherein a gaseous mixture comprising propylene, ammonia, air and steam is contacted, at a temperature of 460‹ C. and a pressure of 1À2-1À3 atmospheres, with a fluidized bed of catalyst which contains silica support material, bismuth and molybdenum, either with (Examples 1 to 4) or without (Example 5) phosphorus, which has been heated to a temperature in the 500-700‹ C. range and which either has been used in the ammoxidation of propylene prior to such heating (Example 1) or is fresh catalyst (Examples 2 to 5). Reference is made to Specification 867,458 in respect of catalyst preparation. |
