| abstract |
Lubricant basestocks of high viscosity index, typically with V.I. of at least 130 or higher, and low pour point, typically below 5 DEG F., are produced by hydroisomerizing petroleum waxes such as slack wax or de-oiled wax, over zeolite beta and then dewaxing to target pour point. A preferred process employs a solvent dewaxing after the hydroisomerization step to effect a partial dewaxing with the separated waxes being recycled to the hydroisomerization step; dewaxing is then completed catalytically, typically over ZSM-5 or ZSM-23. |