| 摘要 |
1302454 Hydrocarbons ASAHI KASEI KOGYO KK 14 Aug 1970 [14 Aug 1969 25 Aug 1969] 39272/70 Heading C5E [Also in Divisions B1 and C1] Benzene, toluene and polymethylbenzenes are obtained by contacting at an elevated temperature a vapour-phase feedstock containing aromatic hydrocarbons of nine or more carbon atoms and having one or more alkyl groups of two or more carbon atoms as nuclear substituents with a catalyst comprising alumina treated with one or more of MgSiF 6 , ZnSiF 6 and CaSiF 6 to incorporate 0À01 to 10% by weight of fluorine. The feedstock may be a catalytic reformate or an aromatic extract thereof or a fraction thereof obtained by extraction and distillation. The aromatic hydrocarbons obtained can be separated from one another by distillation. Olefinic gases, e.g. ethylene and propylene, are obtained as by-products. The catalyst may be made by treating activated alumina with an aqueous solution of the fluosilicate, or by adding the fluosilicate to an alumina sol to cause gelation, and then drying and calcining the gel. The feedstock may be diluted with hydrogen, nitrogen, steam, methane, ethane, propane or a mixture of these. The catalyst can be reactivated by burning off carbonaceous deposits in air. |
