| 摘要 |
In the hydroisomerisation of hydrocarbons in the presence of a catalyst comprising a platinum group metal supported on a refractory metal oxide containing combined halogen, the catalyst is pretreated by reduction for at least an hour at a temperature at least 50 DEG C. above the reaction temperature. Straight chain or slightly branched paraffins having at least 4 carbon atoms per molecule or cycloparaffins or naphthenes containing at least 6 carbon atoms per molecule and at least 5 carbon atoms in the ring, including mixtures, may be isomerised at 250 DEG -475 DEG C., 6,8-100 atmospheres, an LHSV of 0,5-100 in a fixed bed process and a hydrogen to hydrocarbon mol. ratio of 0,25-10. Moving or fluidised catalysts may also be used. The catalyst may comprise 0,01-2% of a platinum metal, particularly platinum, and 0,01-8% fluorine and chlorine deposited on alumina, titania, zirconia, chromia, zinc oxide, chromiaalumina, alumina-boria, bauxite, kaolin, bentonite, montmorillonite, magnesia-alumina spinel, or zinc oxide spinel. The catalyst after calcination is treated with hydrogen, which may be diluted with methane or ethane, preferably at 500 DEG -700 DEG C. for 1-18 hours. Preferably the catalyst is treated in situ first at atmospheric pressure then at operating pressure. |
