Lube Oils (Minerals and Synthetic) The large number of natural lubricating and specialty oils sold today are produced by blending a small number of lubricating oil base stocks and additives. The lube oil base stocks are prepared from selected crude oils by distillation and special processing to meet the desired qualifications. The additives are chemicals used to give the base stocks desirable characteristics which they lack or to enhance and improve existing properties. The considered important properties are 1. Viscosity 2. Viscosity change with temperature (vicosity Index) VI 3. Pour point 4. Oxidation resistance 5. Flash point 6. Boiling temperature 7. Acidity (neutralization number)

Lube Oils (Minerals and Synthetic)

Lube Oils (Minerals and Synthetic)

Lube Oils (Minerals and Synthetic)

Lube Oils (Minerals and Synthetic) Dispersants :- Are chemicals, which have components of surface-active agents called surfactants. The dispersants aids in the breaking up of the oil slick into smaller droplets. 

Lube Oils (Minerals and Synthetic)

Lube Oils (Minerals and Synthetic) Usually the dispersant and detergent additives are formulated to include alkaline materials which serve to neutralize the acid contaminants.

PROPANE DEASPHALTING The lighter distillate feed stocks for producing lubricating oil base stocks can be sent directly to the solvent extraction units Atmospheric and vacuum still bottoms require deasphalting to remove the asphaltenes and resins before undergoing solvent extraction. Propane usually is used as the solvent in deasphalting Propane has unusual solvent properties in that from 40 to 60°C paraffins are very soluble in propane.

PROPANE DEASPHALTING A typical propane deasphalting unit (Fig.) injects propane into the bottom of the treater tower, and the vacuum tower bottoms feed enters near the top of the tower. As the propane rises through the tower, it dissolves the oil from the residuum and carries it out of the top of the tower. Between the residuum feed point and the top of the tower, heating coils increase the temperature of the propane–oil extract phase thus reducing the solubility of the oil in the propane. This causes some of the oil to be expelled from the extract phase creating a reflux stream. The reflux flows down the tower and increases the sharpness of separation between the oil portion of the residuum and the asphaltene and resin portion. The asphaltene and resin phase leaving the bottom of the tower is the raffinate and the propane–oil mixture leaving the top is the extract.

It generally provides superior mechanical and chemical properties than those found in traditional mineral oils. Aircraft turbines, for example, require the use of synthetic oils, whereas aircraft piston engines don't.