New recycling method of lubricant oil and the effect on the viscosity and viscous shear as an environmentally friendly

The present investigation adopts a new method to recycle the oils. The used and recycled lubricants were compared to fresh oil. Accordingly, an investigation was carried out to evaluate the viscous shear of different oil grades at each certain temperature using the Walther formula of the viscosity–temperature relationship. The investigation indicates acceptable and fair results in front of a technical point of view and environmental improvement by reducing pollution. The results show lower viscosity of the recycling oil than the used oil, which affects the viscous shear as it is directly proportional to the velocity gradient and the fluid’s viscosity at ascertaining temperature. In the present investigation, alum (Al (SO (H O) ) was used, which gives good precipitation according to the practical results mentioned in this work. The used oils of grades 5w20, 5w30, and 10w30 under consideration are collected from the local internal combustion engines. Both kinematic viscosity and viscous shear for 10w30 oil grade record the highest values, and 5w20 records the lowest values for all oil types (fresh, recycled, and used oil).