Solutions / Waste Mineral Oil High-Vacuum Distillation Pretreatment
Lubricants & Reclamation
Waste Mineral Oil High-Vacuum Distillation Pretreatment
Waste Lubricant Resource Recovery
Key outcomes
- Distillation equipment cleaning cycle extended approximately 1x: downstream distillation equipment cleaning cycle extended approximately 1x (customer feedback)
- Reclaimed base oil quality improved: output reclaimed base oil quality improved, achieving higher market premium
- 30m³/h high-flow pre-purification: approximately 30m³/h pre-purification, meeting regional centralized disposal demands
Case Study
Stage 1 · Customer Problem
📋 Customer Background & Pain Points
The customer is an environmental technology enterprise located in the Southwest region, responsible for the centralized recovery and reclamation of waste mineral oil (mainly waste lubricants) generated by the regional machinery manufacturing, mining, and transportation industries. Under complex industrial and mining conditions, the recovered waste oil composition is unstable, posing significant challenges for downstream distillation and reclamation processes.
The following four pain points drove the customer to seek a high-flow dedicated pre-purification solution:
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High-Load Solid Contaminants
Waste oil from mining equipment carries high levels of mud and wear-metal debris (iron, aluminum, copper), causing frequent scaling and blockage of downstream heat exchangers and distillation tower bottoms.
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Carbon Black & Gum Deposition
Carbon black and oxidized resins (sludge) generated after high-temperature lubricant failure are highly adhesive, making ordinary centrifugal equipment unable to physically separate them at high flow rates.
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High Maintenance Costs
Inadequate pre-purification allows impurities into the distillation tower, triggering bottom coking. Forced shutdowns for tower cleaning result in heavy production losses and consumable waste.
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Limited Reclaimed Oil Grade
Waste oil that is not deeply purified yields reclaimed base oil with poor color and excessive impurity content, failing to meet the blending requirements for high-end industrial lubricants.
Stage 2 · Fuel Analysis (NEW)
🔬 Waste Oil Contaminant Analysis — Before / After Pretreatment
Representative feedstock sampled from the customer's incoming waste lubricant stream was characterized before and after the 30m³/h pretreatment unit. The table below summarizes the key quality parameters that govern downstream vacuum-distillation performance and reclaimed base-oil value.
| Parameter | Before Pretreatment | After Pretreatment | Improvement |
|---|
| ISO 4406 Cleanliness | 24/22/19 | 16/14/11 | ~3 codes lower |
| TAN (Total Acid Number) | ~3.0 mgKOH/g | ≤0.5 mgKOH/g | >83% reduction |
| Water Content | ~800 ppm | ≤100 ppm | ~87% reduction |
| Appearance / Color | Black, opaque | Amber, translucent | Significant brightening |
| Viscosity @ 40°C | Out of spec (unstable) | Within spec range | Stabilized |
| Particle Composition | Wear metals, oxides, gums, carbon black | Residual fine particles only | Gradient interception |
Note: Values are representative of the customer's typical waste lubricant feed; actual results vary by batch composition. Reduced TAN and water content directly lower the distillation tower's coking tendency and acid-load burden.
Stage 3 · Solution
🛠️ 30m³/h Waste Oil Dedicated Process Purification Unit
A 30m³/h waste oil dedicated process purification unit was customized for this environmental production line. The system integrates high-viscosity compatibility, staged gradient interception, anti-corrosion construction, and intelligent differential-pressure management to deliver constant throughput on highly contaminated feedstock.
Throughput
30 m³/h constant
Filtration Stages
10–25 μm gradient interception
Wetted Material
316L stainless steel
Heating System
Viscosity-reduction heating
Pressure Control
Differential-pressure compensation + alarm
Regeneration
Gas-pulse regeneration (brief 5-15 min safety pause)
Seal Compatibility
Acid / additive resistant
Residue Class
HW08 hazardous waste compliant
Process logic: large metal debris is captured first by coarse stages, then micron-level carbon black and sludge are removed by high-precision media. Concentrated sludge is classified as hazardous waste (HW08) for compliant disposal, while the clarified oil proceeds to high-vacuum distillation at substantially reduced contamination load.
📈 Operational & Quality Outcomes
After commissioning the 30m³/h purification system, the customer's waste-oil reclamation line saw measurable improvements in throughput stability, distillation uptime, and reclaimed base-oil marketability.
~1x
Distillation Cleaning Cycle Extended
30 m³/h
Pretreatment Throughput
>90%
Waste-Oil Resource Recovery Rate
| Metric | Before | After | Result |
|---|
| Distillation Tower Cleaning Cycle | Baseline | Extended ~1x | Less downtime |
| Reclaimed Base-Oil Color | Poor / dark | Brightened, amber | Higher market premium |
| Reclaimed Base-Oil Grade | Below blending spec | Meets high-end lubricant blending | Grade uplift |
| Annual Consumables / Cleaning Cost | High (frequent shutdowns) | Significantly reduced | Lower OPEX |
| Waste-Oil Resource Utilization | Partial (low-grade outlets) | High-grade resource recovery | Circular economy value |
Per customer feedback, the output purity now ranks at a good level within the region, and distillation efficiency has improved since installation.
Stage 5 · Lessons Learned (NEW)
💡 Key Insights for Waste-Oil Reclamation Projects
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Key Success Factor
Matching the purification train to the real viscosity and contaminant profile of waste lubricants — combining a heating system for viscosity reduction with staged 10–25 μm gradient interception — was decisive. It enabled stable 30 m³/h throughput on highly adhesive, carbon-black-laden feed that conventional equipment could not sustain.
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Common Pitfall
Relying solely on traditional centrifuges or plate-and-frame filter presses for waste-oil pretreatment. These methods struggle with sub-micron carbon black and oxidized gums, allowing fine colloids to break through into the distillation tower and accelerate bottom coking — shortening cleaning cycles and degrading reclaimed-oil color.
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Replication Advice
This staged-interception plus intelligent differential-pressure approach transfers directly to other waste-oil streams — waste hydraulic oil, transformer oil, and mixed industrial used oils. Always characterize TAN, water, and particle composition first, then size the heating and gradient-filtration stages to the most adhesive contaminant class present.
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Customer feedback
In the circular economy, waste oil is not garbage but a resource. This 30m³/h system is the core equipment of our factory's pre-treatment line. It handles relatively dirty waste oil, preparing it for reclamation. Since installation, our distillation efficiency has improved, and the final output purity is at a good level within the region.
Lubricants & Reclamation
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