What Base Oil Quality Can Be Achieved Through Solvent Extraction?
At our facility, we don’t just build base oil solvent extraction plants — we optimize every step to deliver high-quality base oils that meet demanding industry standards. If you’re considering solvent extraction for used or virgin oils, this guide explains exactly what kind of base oil quality you can expect, based on real parameters, not assumptions.
Why Solvent Extraction for Base Oil Refining?
Solvent extraction selectively removes harmful compounds — aromatics, sulfur, nitrogen, and resins — while preserving valuable hydrocarbons. The result is a cleaner, more stable base oil that’s both high in yield and performance.
Unlike acid clay or traditional thermal cracking, our solvent-based process:
- Targets specific impurities without damaging molecular chains
- Enables Group I and Group II base oil production
- Achieves consistent color, viscosity, and oxidation resistance
Key Quality Metrics of Solvent-Extracted Base Oils
We evaluate oil quality from five critical technical perspectives:
Color and Clarity
- Final product color: L0.5 – L2.5 (ASTM D1500 scale)
- No visible residue or suspended solids
- Crystal-clear appearance even under cold conditions
This makes the oil ideal for industrial lubricants, engine oils, and white oil applications.
Viscosity Index (VI)
- VI Range: 90–105
- Stable viscosity over temperature changes
- Suited for multigrade lubricant formulation
High VI means better thermal behavior — essential for engines and hydraulic systems.
Sulfur and Aromatics Content
- Sulfur: <0.03% wt
- Aromatics: <0.5% wt
- Reduced sludge, improved thermal oxidation stability
These levels outperform conventional Group I base oils and are within Euro VI emission specs.
Pour Point
- As low as -15°C to -30°C (post dewaxing unit)
- Ensures flow in cold climates
- Widely used in low-temp lubricants, gear oils, and marine fluids
Optional dewaxing upgrades improve flowability for cold environments.
Oxidation and Thermal Stability
- Extended service life under stress
- Higher resistance to viscosity breakdown
- Lower additive consumption over time
These qualities matter for long-drain interval lubricants and high-load applications.
What Determines Final Base Oil Quality?
Several input and process factors impact output quality:
| Parameter | Impact on Oil Quality |
| Feedstock (used oil, SN500) | Base molecule integrity matters |
| Solvent selection (NMP, furfural) | Defines extraction efficiency |
| Plant design & control system | Affects yield, separation accuracy |
| Post-treatment units (dewaxing, hydrofinishing) | Elevate product to Group II standard |
We optimize every stage — from feedstock filtration to solvent recovery — to maximize oil performance and minimize energy and waste.
Application-Ready Base Oil
Our solvent-extracted base oils are fully compliant with:
- API Group I+ and Group II classification
- ASTM D6074, D2896, D445, D92, D97 testing standards
- ISO and OEM specifications for engine and industrial oils
Common applications include:
- Engine and gear oils
- Transformer and turbine oils
- Metalworking fluids
- Process oils for rubber and plastics
Why Our Solvent Extraction Plants Stand Out
We design modular, scalable systems for 30TPD to 200TPD capacities. Our plants consistently deliver:
- 98% base oil recovery rate
- <1% solvent loss
- Minimal environmental emissions
- User-friendly automation with SCADA/PLC
All installations are backed by training, commissioning, and full technical support.
