Motor Oil Recycling
Motor oil recycling is the process of restoring the motor
oil to its original state, removing dirt and chemicals. Industrial and
automotive used oils are recycled at re-refineries. The used oil is first
tested to determine suitability for re-refining. Once a shipment of used oil
is deemed suitable, it is first dehydrated, a process which removes water
which is then treated before being released to the environment. Dehydrating
also removes light fuels that are used to power the refinery and captures
ethylene glycol for re-use in recycled antifreeze.
Next, industrial fuel is separated out of the used oil then
vacuum distillation removes the lube cut (that is, the fraction suitable for
reuse as lubricating oil) leaving a heavy oil that contains the used oil's
additives and other by-products such as asphalt extender. The lube cut next
undergoes hydro treating, or catalytic hydrogenation to remove residual
polymers and other chemical compounds, and saturate carbon chains with
hydrogen for greater stability.
Final oil separation, or fractionating, separates the oil
into three different oil grades: Light viscosity lubricants suitable for
general lubricant applications, low viscosity lubricants for automotive and
industrial applications, and high viscosity lubricants for heavy-duty
The final step is blending additives into these three grades
of oil products to produce final products with the right detergent and
anti-friction qualities. Then each product is tested again for quality and
purity before releasing it to the public for resale.
Re-refining process produces products indistinguishable from
products produced by conventional refining.