| 摘要 |
The gum stability of gasolines is improved by hydrogenating over a nickel catalyst supported on a carrier having lower polymerisation and cracking activity than gamma alumina under conditions such that the hydrogen consumption is at least 60 SCF/barrel. The gasoline may boil in the range 15-200 DEG C. and is preferably debutanised and free of hydrogen sulphide. It may be a petroleum distillate or one obtained by a steam cracking process favouring the production of olefins, e.g. at 1100-1400 DEG F. and 0-50 p.s.i.g. The hydrogenation may be effected at 0-200 DEG C., 0-1000 p.s.i.g., and LHSV of about 2, and a gas rate of 300-700 SCF/barrel with a hydrogen consumption of 60-140 SCF/barrel. An octane loss of less than 1 (Research clear) is preferred. Specified catalyst supports are CaO, BaO, SrO, MgO, CaCO3, BaCO3, SrCO3, MgCO3, diatomaceous earths or fire brick derived therefrom, silicon carbide, quartz, charcoal, graphite, pumice or deactivated alumina. Nickel in elemented form may constitute 1-60% by weight of the catalyst. Specification 848,232 is referred to. |
