Solvent extraction & deasphalting
Study selective solubility to separate an oil-rich fraction from less-soluble heavy material and contaminants. Solvent selection changes both separation and oil loss.
Chemical recycling research
Chemical treatment
& deasphalting
of used engine oil.
R&D support for used and waste engine oil recycling: investigate chemical separation, solvent extraction and re-refining feasibility through measured laboratory evaluation.
Intended for R&D purposes only.Feedstock-specific studies. Evidence before scale-up.
Used & waste engine oilSolvent deasphaltingChemical treatmentRe-refining feasibility
Understand the scope
Used-oil treatment,
deasphalting & re-refining.
Chemical treatment of used engine oil investigates how selected contaminants can be separated from an oil-rich fraction. Solvent deasphalting is one separation approach. Re-refining is a wider processing and quality-validation route. The research question determines which stages belong in a study.
| Approach | Research focus | Evidence still needed |
|---|---|---|
| Chemical treatment | Compare contaminant separation through extraction, flocculation or adsorption. | Analytical change against the untreated oil, recovery and treatment residues. |
| Solvent deasphalting | Separate less-soluble heavy material from an oil-rich phase using selective solubility. | Oil lost with the residue, residual solvent and the composition of both fractions. |
| Re-refining | Assess the processing and finishing needed for a candidate base-oil fraction. | Suitability for its intended use; finished engine oil also needs formulation and performance qualification. |
These are study distinctions, not guaranteed outcomes. EPA guidance on recycling and re-refined lubricants explains why recovered oil requires qualification for its intended use.
The research question
Chemical treatment routes
for used & waste oil.
Used oil contains more than dirt. Water, soot, wear metals, degraded additives and oxidation products can change how a sample responds to treatment. Start with its composition and the intended recovered fraction.
Chemical-assisted flocculation
Evaluate whether selected treatment agents help dispersed contaminants form separable aggregates. Some feedstocks can form gels or persistent emulsions instead of settling cleanly.
Adsorption & polishing
Screen adsorbents for selected residual polar compounds or colour bodies after separation. Track useful oil retained by the media and the resulting spent solids.
Re-refining route assessment
Assess how chemical pretreatment could fit alongside solvent recovery and further finishing, such as distillation or hydrotreatment where appropriate. Define the test gates for a candidate base-oil fraction.
Research basis: hydrocarbon-solvent extraction and feedstock-dependent extraction–flocculation studies. Published observations guide screening; they are not results for your oil.
Inside chemical deasphalting
Solvent deasphalting
of used engine oil.
In used-oil research, “chemical deasphalting” commonly describes solvent-based separation of less-soluble heavy material from an oil-rich phase. It is a separation mechanism, not a promise that a chemical converts every waste oil into new engine oil.
The separated residue may contain oxidation products, soot, additive-derived material and oil carried out with the solids. Its composition needs analysis; it should not automatically be treated as pure asphalt.
A clearer sample is an observation.
Lower contamination, recovered oil quality and residual solvent are analytical questions. Appearance alone cannot answer them.
Published extraction–flocculation research reports different responses for oils with different properties. That is why the study begins with your sample.
A structured study
From an unknown oil
to a defensible decision.
A research sequence with clear evidence gates. Each stage informs whether the next stage is justified.
- 01
Characterise
Identify the oil source, water, solids, viscosity and contamination profile.
- 02
Screen
Compare selected chemistry routes against an untreated reference sample.
- 03
Separate
Assess phase behaviour, settling, filtration and oil retained in the residue.
- 04
Recover
Evaluate solvent recovery, carry-over and the whole-study material balance.
- 05
Validate
Test the candidate fraction and document limitations and the next research step.
Research boundary
Bench results do not establish plant feasibility. A scale-up decision also needs solvent-cycle performance, residue management, equipment compatibility, energy assessment and applicable site approvals.
Measure what matters
Testing treated oil
& recovered fractions.
Agree the analytical plan before comparing treatment candidates. Use an untreated baseline, consistent preparation and repeat studies for the routes worth pursuing.
- Feedstock condition
- Water, sediment, viscosity, fuel dilution and relevant contamination screening.
- Separation performance
- Solvent-free oil recovery, dry residue, oil loss to solids and repeatability.
- Candidate fraction quality
- Viscosity, acid number, metals, ash or carbon residue, residual solvent and oxidation indicators as relevant.
- Research feasibility
- Recovered solvent quality, reuse-cycle behaviour, treatment cost drivers and residue handling.
The exact methods and acceptance criteria depend on the feedstock and intended use. For test-plan support, explore laboratory testing & quality control.
Scope your R&D engagement
A useful study ends
with documented evidence.
For researchers, technical teams and recyclers investigating chemical treatment of used engine oil. The agreed scope defines the study work and deliverables.
A feedstock-specific plan
Research objective, sample requirements, chemistry shortlist, comparison matrix and acceptance criteria.
A comparison you can assess
Observations, analytical comparisons and material balances for the candidates included in the study.
A clear research handover
Route limitations, remaining tests and a recommendation to investigate further, revise the approach or stop.
R&D scope, clearly defined.
This page concerns research and feasibility assessment. It does not offer a universal chemical recipe, certify recovered base oil, or guarantee yield, commercial throughput or finished engine-oil performance. Sample shipment and any lab work are arranged after the project scope is agreed.
Before you begin
Good research
starts with
good questions.
Can used engine oil be treated with chemicals?
Chemical-assisted separation, solvent extraction and adsorbent treatment are studied for removing selected contaminants from used lubricants. Their effectiveness depends on the oil composition and treatment route. Additional recovery, finishing and qualification may be needed.
Is chemical deasphalting the same as complete re-refining?
No. Deasphalting is a separation stage. Complete re-refining aims to produce a suitable base-oil fraction through the required processing and validation. A finished engine lubricant also needs the right formulation and performance qualification.
Which chemical or solvent is best?
There is no universal choice. Selectivity, emulsion or gel formation, oil losses, recovery behaviour, compatibility, cost and residue generation need comparison on representative feedstocks. Published solvent rankings should not be transferred directly to a new oil sample.
Does acid–clay treatment belong in the discussion?
It is a historical treatment route that may be reviewed when comparing technologies. Corrosive chemistry and contaminated acid sludge make residue handling a central concern. A literature comparison is not a recommendation to adopt it.
Can a treated sample go straight back into an engine?
A laboratory-treated fraction should not be assumed fit for engine service. EPA guidance explains that re-refined lubricants must satisfy refining, compounding and performance requirements. Removing colour or visible solids is not an engine-oil approval.
What should I share for an initial R&D discussion?
Share the oil source, service history, known contamination, available analysis, research goal and proposed study location. Start with a project description; sample acceptance and shipment instructions should be agreed before sending material.
Published research & guidance
The evidence behind
the research approach.
Literature review compiled on 3 October 2026. These references explain mechanisms and study considerations; their findings are not performance claims for a Lubechem process. About Lubechem Consultant.
US EPA / 2026 update
Managing, reusing, and recycling used oil
Used-oil contamination, recycling routes and the performance requirements for re-refined lubricants.
Hamad et al. / 2005Used lubricating oil recycling using hydrocarbon solvents
Solvent extraction and demulsifier-assisted treatment; solvent recovery remains part of the feasibility question.
Pinheiro et al. / 2018Regeneration by extraction–flocculation
Different waste lubricants can respond differently to the same separation route. Publisher abstract reviewed.
Altaee et al. / 2022Treatment of used lubricant oil by solvent extraction
A study of used power-station lubricant illustrating condition sensitivity; not validation of engine-oil feedstocks.
Start with a research brief
What would you like
to learn from
your used oil?
Tell us about your feedstock and the question you want the study to answer. We can discuss a suitable R&D scope and the evidence needed to evaluate it.
Email your research brief →R&D purposes only · Scope agreed before sample shipment