| 摘要 |
<p>Normal paraffins containing at least 4 carbon atoms per molecule substantially free from naphthenes are isomerised in presence of a promoter such as halogens, hydrogen halides, alkyl halides, chloroform or carbon tetrachloride, and a catalyst mass formed by treating aluminium chloride under isomerisation reaction conditions with a feed stock containing small amounts of at least one low molecular weight naphthene consisting of cyclopropane, cyclobutane or alkyl derivatives thereof, the treatment being discontinued prior to excessive degradation of the normal paraffins taking place. The catalyst may be treated with a normal pentane feed stock containing cyclopropane or cyclobutane and the activated catalyst is then treated with normal butane free from naphthenes until the activity is substantially completely spent. Alkyl derivatives of naphthenes specified are methyl, dimethyl and ethyl cyclopropane, and methyl, dimethyl, and ethyl cyclobutane. Naphthenes may be removed so as to give a naphthene-free feed stock by treatment with concentrated sulphuric or halosulphoric acid, fresh or partially spent aluminium chloride or by hydrogenation.</p> |
