| 摘要 |
A sheletal glass or porous alumina/silica catalyst (see Group III), is used in the dealkylation or isomerization of hydrocarbons and in the dehydration of alcohols. Examplified are (a) isomeric butylbenzenes are catalytically converted at 400 DEG C. to benzene and butene; (b) a mixture of isomeric oxylenes, 95 per cent para-xylene, is isomerized, using a catalyst at 430 DEG C., to a product containing 40 per cent para-xylene; (c) isopronanol is dehydrated to propylene using a catalytic bed at 240 DEG C.ALSO:A skeletal glass or porous catalyst containing silica and alumina and substantially free from alkali metals is produced by fusing a uniform mixture of silica, alumina, boric oxide and an alkaline earth, or suitable substitutes, such as alkaline earth silicates, aluminates, or borates, to produce a glass and heating, preferably between 650 DEG and 950 DEG C., to form at least two phases at least one of which is soluble. Decomposable alkaline earth metal salts, such as calcium carbonate, may provide the alkaline earth, which includes magnesia. The glass is then treated with an extracting medium e.g. hydrochloric acid, to remove at least part of the soluble phase. Prior to extraction the glass should preferably have a composition of 10-35 per cent alumina, 30-60 per cent silica, 5-20 per cent alkaline earth and 12-22 per cent boric oxide. |
