11Manufacture of Lubricating Oil
1.2.1.6 Catalytic Dewaxing and Hydroisomerization
The rst catalytic dewaxing and wax hydroisomerization technologies were com-
mercialized in the 1970s (Kramer et al. 2001). Catalytic dewaxing was a desirable
alternative to solvent dewaxing especially for conventional neutral oils because
it removed n-parafns and waxy side chains from other molecules by catalyti-
cally cracking them into smaller molecules. This process lowered the pour point
of the base oil so that it owed at low temperatures, like solvent dewaxed oils.
Hydroisomerization also saturated most of the remaining aromatics and removed
most of the remaining sulfur and nitrogen species.
In 1993, the rst modern wax hydroisomerization process was com ...