Process for preparing a base oil having a reduced cloud point

A process for preparing a residual base oil from a hydrocarbon feed which is derived from a Fischer-Tropsch process, the process comprising the steps of:

• (a) providing a hydrocarbon feed which is derived from a Fischer-Tropsch process;
• (b) subjecting the hydrocarbon feed of step (a) to a hydrocracking/hydroisomerisation step to obtain an at least partially isomerised product;
• (c) separating at least part of the at least partially isomerised product as obtained in step (b) into one or more lower boiling fractions and a hydrowax residue fraction;
• (d) catalytic dewaxing of the hydrowax residue fraction of step (c) to obtain a highly isomerised product;
• (e) separating the highly isomerised product of step (d) into one or more light fractions and an isomerised residual fraction;
• (f) mixing of the isomerised residual fraction of step (e) with a diluent to obtain a diluted isomerised residual fraction;
• (g) cooling the diluted isomerised residual fraction of step (f) to a temperature between 0° C. and −60° C.;
• (h) subjecting the mixture of step (g) to a centrifuging step at a temperature between 0° C. and −60° C. to isolate the wax from the diluted isomerised residual fraction;
• and
• (i) separating the diluent from the diluted isomerised residual fraction to obtain a residual base oil, wherein the residual base oil is haze-free at 0° C. and has a reduced cloud point compared to the cloud point of the base oil prior to the centrifugation step (h).