{HEAD ~ A process} for demetalation, desulfurization and {TAIL ~ dewaxing} of residual oil has been discovered using a two stage process 
for
{ HEAD ~ A process } for demetalation , desulfurization and { TAIL ~ dewaxing } of residual oil has been discovered using a two stage process
HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH