| 摘要 |
Overnight cloud point (ONC) of a catalytically dewaxed lubricating oul stock contg. relatively insoluble petrolatum wax is improved by subjecting the oil to hydroisomerisation using a catalyst with an acidic function and a hydrogenation- dehydrogenation to produce a prod. contg. branched-chain isoparaffins which are more soluble at low temps., provided that the conversion of the oil to lower-boiling components is less than 10 wt.%. The catalyst pref. comprises (a) a combination of a large-pore zeolite with a constraint index of less than 1 and a zeolite with a SiO2:Al2O3 ratio of at least 12:1 and a constraint index of 1-12, esp. a combination of Y and ZSM-5 zeolites, and (b) one or more Gp. VIA and VIII metals, esp. Pt or Pd. The reaction may be effected at 200-450 deg. C and 400-25,000 kPa with a LHSV of 0.1-10. Process avoids the yield losses associated with higher-severity dewaxing. |
