The Science Behind Used Oil Filtration: What Gets Removed and What Doesn’t

Used oil isn’t just “dirty oil.” It’s a complex mix of contaminants that directly affect equipment life, efficiency, and operating costs. Oil filtration can remove many of them—but not. Below is a clear of whacan and cannot be removed.



Industrial Oil Purification Machine & Systems

Solid Particles (Yes — Very Effective)


Examples:

Metal wear debris (iron, copper, aluminum)

Dust, sand, silica

Carbon particles and soot

Rust and corrosion flakes

How filtration works:

Mechanical filters (3–25 microns)

Depth media or absolute-rated filters

Result:
✔ Easily removable
✔ Primary target of oil filtration
✔ Directly reduces wear and component failure

Most equipment damage is caused by particles between 5–15 microns—well within filtration capability.

Water & Moisture (Yes — With the Right Technology)


Forms of water in oil:

Free water

Emulsified water

Dissolved moisture

Removable by:

Coalescing filters (free & emulsified water)

Vacuum dehydration systems (dissolved moisture)

Result:
✔ Effective with proper systems
⚠ Standard particle filters alone are not enough

Removing water dramatically slows oxidation and prevents corrosion.

Sludge & Varnish Precursors (Partially)


What they are:

Oxidation by-products

Degraded oil molecules

Soft contaminants before hard varnish forms

Remo

Fine filtration

Electrostatic oil cleaners

Adsorptive media

Result:
✔ Partially removable
⚠ Once hardened varnish forms, filtration efficiency drops

Oxidation By-Products (Limited)


Examples:

Acids

Insoluble resins

Oil degradation compounds

Filtration capability:

Can remove insoluble oxidation particles

Cannot reverse oil chemical breakdown

Result:
⚠ Limited
✖ Filtration does not restore oil chemistry

Filtration extends oil life—but doesn’t “make old oil new.”

5. Fuel & Chemical Contamination (Mostly No)


Examples:

Diesel dilution

Coolant leaks (glycol)

Additive depletion

Chemical cross-contamination

Filtration capability:
✖ Not removable by standard filtration
✖ Requires oil change or specialized separation processes

What Oil Filtration Cannot Remove


 

Leave a Reply

Your email address will not be published. Required fields are marked *