What is Used Oil Re-Refining?
India's Complete Guide 2026

How India's waste oil becomes high-quality base oil again — the process, the regulations, the economics, and why re-refining is the only compliant, environmentally responsible path for used oil disposal.

The Problem with Used Oil in India

India's lubricant market consumes approximately 2.5–3 million tonnes per year of lubricating oil — engine oils, hydraulic oils, transformer oils, gear oils, and industrial lubricants. After use, all of this oil becomes contaminated with water, fuel dilution, oxidation products, wear metals, and degraded additives. It can no longer perform its function. It must be disposed of.

Under the Hazardous and Other Wastes (Management and Transboundary Movement) Rules 2016, used oil is classified as Schedule-II hazardous waste. This means it cannot be dumped, burned casually, or handed to informal collectors. Every litre must be tracked via Form-10 manifests and handed to a CPCB-authorized recycler.

Scale of India's Used Oil Problem

~2.5–3 million tonnes of lubricants consumed per year → ~1.5–2 million tonnes of waste oil generated → Only ~33 CPCB-registered re-refiners exist nationally (as of 2025) to handle this volume. The capacity shortage is extreme and is the core reason EPR certificate prices are rising rapidly.

What is Re-Refining?

Re-refining is an industrial process that restores used lubricating oil to base oil quality by removing all contaminants accumulated during use. The output — Re-Refined Base Oil (RRBO) — is functionally equivalent to virgin base oil and can be re-formulated into fresh lubricants, transformer oil, or other petroleum products.

Re-refining is fundamentally different from:

  • Re-burning / co-processing — burning waste oil as a fuel substitute in cement kilns or boilers. This destroys the valuable base oil molecules and generates air pollution.
  • Blending / dilution — mixing waste oil with fresh oil to extend its life. This is illegal under HW Rules 2016 if done without authorization.
  • Informal recycling — roadside "oil changers" who sell used engine oil back as lubricants without processing. This is illegal and generates contaminated products.

How Used Oil Re-Refining Works — The Process

Modern re-refining uses a combination of physical and chemical processes to restore base oil quality. The typical process sequence used at plants like BIOCIL's Jaipur facility:

Step 1: Incoming Inspection & Segregation

Collected waste oil is tested for water content, viscosity, flash point, and contamination level. Different oil types (transformer oil, engine oil, hydraulic oil) are stored separately as they require different processing parameters.

Step 2: Pre-Treatment — Dehydration

Water and light fuel contaminants (diesel, petrol, solvents) are removed by heating the oil to 100–120°C under atmospheric pressure. Water evaporates; light hydrocarbons are driven off. This reduces the volume by 5–15% depending on the input quality.

Step 3: Atmospheric Distillation

The dehydrated oil is heated further (200–300°C) to separate remaining light fractions from the base oil. This removes degraded additives and short-chain hydrocarbons that cannot be reformed into base oil.

Step 4: Vacuum Distillation (Key Step)

Under reduced pressure (vacuum), the base oil fractions are separated by boiling point into light, medium, and heavy grades. This is where the actual "re-refining" happens — separating clean base oil molecules from heavy residue and contaminants. The vacuum prevents thermal degradation of the valuable base oil fractions.

Step 5: Hydrotreating / Clay Treatment

The distilled fractions are purified using hydrogen (hydrotreating) or activated clay (clay treatment) to remove colour, odour, sulfur compounds, and remaining polar contaminants. This step determines the quality and colour of the final RRBO.

Step 6: Blending & Quality Testing

Re-refined fractions are blended to meet target viscosity grades. Final RRBO is tested against BIS specifications before dispatch to customers.

StageWhat's RemovedTemperatureOutput
DehydrationWater, light fuel100–120°CDry oil
Atm. DistillationLight hydrocarbons, degraded additives200–300°CPre-cleaned oil
Vacuum DistillationHeavy residue, asphaltenes250–350°C (vacuum)Base oil fractions
Hydrotreating/ClayColour, sulfur, odour250–320°C (H₂)RRBO — finished product

Re-Refining vs Re-Burning: Why It Matters

✅ Re-Refining (BIOCIL)
  • Recovers 70–90% as base oil
  • 65–70% less energy than virgin refining
  • CPCB EPR weightage: 1.0 (maximum)
  • Generates EPR certificates for producers
  • Zero air pollution from base oil fraction
  • Circular economy — oil re-enters use
  • BIS-grade RRBO output
❌ Re-Burning / Co-processing
  • Destroys the base oil permanently
  • Generates SOx, NOx, particulate emissions
  • CPCB EPR weightage: 0.5 (half credit)
  • Only half the EPR compliance value
  • No base oil recovery — economic waste
  • Cement kilns require special permits

What is RRBO (Re-Refined Base Oil)?

RRBO is the primary commercial output of the re-refining process. It meets the same BIS specifications as virgin base oil and is used for:

  • Re-Refined Transformer Oil (RRTO) — sold to power utilities and transformer oil buyers including HPCL
  • Re-blended lubricants — RRBO is sold to lubricant manufacturers who add fresh additives to produce branded engine and industrial oils
  • Hydraulic oils, gear oils, compressor oils — specific viscosity grades for industrial use

BIOCIL's Jaipur plant produces RRBO from transformer oil, lubricants, and industrial oils with a combined capacity of 3,600 MTA (20 MT/day). Output is sold to national oil companies including HPCL and leading petrochemical processors.

Environmental Impact of Re-Refining

  • Saves 65–70% energy compared to refining the same volume of virgin crude oil
  • Avoids 3–4 tonnes of CO₂ equivalent per tonne of oil processed
  • Prevents soil and groundwater contamination from improper disposal
  • Contributes to India's CCTS (Carbon Credit Trading Scheme) offset mechanism
  • Reduces India's crude oil import dependency

CPCB Regulations for Re-Refiners

To legally operate a re-refinery in India, a plant must hold:

  • CPCB Category IV Authorization under HW Rules 2016 — issued by the Central Pollution Control Board
  • State PCB (RPCB/MPCB/etc.) Consent to Operate — issued by the respective state pollution control board
  • EPR Recycler Registration on eprusedoil.cpcb.gov.in — required to generate and transfer EPR certificates under GSR 677(E) 2023
  • GeM Registration — recommended for bidding in government body forward auctions for used oil

BIOCIL's Authorizations

CPCB Category IV Authorization (active) · RPCB Consent to Operate (Auth No. RPCB/HWM/2025-2026/Jaipur(N)/HSW/16, valid June 2030) · EPR Registration BHA20250073R (capacity 3,240 MTA) · GeM Registered · Est. 1986, Jaipur, Rajasthan

Frequently Asked Questions

What is used oil re-refining?
Re-refining is an industrial process that restores used lubricating oil to base oil quality by removing water, fuel, degraded additives, and oxidation products through distillation and hydrotreating. The output — Re-Refined Base Oil (RRBO) — meets BIS specifications and can be reformulated into fresh lubricants.
Is re-refining better than re-burning used oil?
Yes, significantly. Re-refining recovers 70–90% as base oil, saves 65–70% energy vs virgin refining, and receives maximum CPCB EPR weightage of 1.0. Re-burning (co-processing in cement kilns) destroys the base oil, generates air pollution, and receives only 0.5 EPR weightage — half the compliance value.
What regulations govern used oil re-refining in India?
Used oil re-refining is regulated under: (1) Hazardous and Other Wastes Rules 2016 — classifies used oil as Schedule-II hazardous waste; (2) GSR 677(E) dated August 2, 2023 — Extended Producer Responsibility for lubricant producers; (3) CPCB Authorization Category IV required for all re-refiners.
What is RRBO?
RRBO (Re-Refined Base Oil) is the finished product output from re-refining used lubricants. BIOCIL produces RRBO meeting BIS standards from re-refined transformer oil, lubricants, and industrial oils. It is sold to national oil companies including HPCL and petrochemical processors for re-blending.
How much waste oil does India generate per year?
India's lubricant market consumes ~2.5–3 million tonnes per year. Approximately 60–70% of this becomes waste oil — meaning 1.5–2 million tonnes needs compliant disposal annually. With only ~33 registered re-refiners nationally, there is a significant supply-demand imbalance in compliant recycling capacity.