Waste oil recycling base oil/diesel equipment

Description of the operation        

1. Rectification

The raw material medium of the project is waste oil, which is transported from the raw material filling area through the pump body to the pretreatment area. After pretreatment, impurities and part of water are removed from the raw material into the dehydration system, through the dehydration system will be all clean water. Subsequently, the material through the pump body into the lightweight system, out of the light components in the material, after dehydration and lightening is completed, the material is heated and entered into the thin film evaporation system for material heavy component removal. The bottom recombination enters the receiving tank, and the top gas phase enters the rectifying column and is condensed and enriched in the receiving tank.

2. Gas phase cracking

The intermediate oil after rectification first enters the feed heater of the cracking column, and then enters the gas phase cracking column after heating up. At the bottom of the column, the amount of re-boiling gas liquid is maintained. The oil after gasification enters the solid catalyst, and the oil after the catalyst is cracked into diesel components. Then the diesel oil enters the rectification section. After distillation, the diesel oil is condensed by the condenser and enriched to the receiving tank for refining. The material at the bottom of the column is returned to the heavy component removal section for rectification again. The whole operation process is completed under the closed state of vacuum pressure and atmospheric pressure, no leakage and no pollution. The exhaust from the smoke outlet is the gas after desulfurization and dust removal (if there are other requirements to be discussed), no odor, and no other waste emissions.

FAQ

1. What is this process?

It's a technology that converts **used lubricating oil (e.g., engine oil, gear oil, hydraulic oil) – a hazardous waste stream – into a usable **diesel-like fuel through advanced chemical processing, primarily thermal depolymerization (pyrolysis) followed by distillation and hydrotreating.

2. Is this the same as biodiesel?

No.** This is fundamentally different. Biodiesel is made from plant or animal *fats/oils* (like soybean oil or used cooking oil) through a chemical reaction called *transesterification*. The process for ULOs involves breaking down complex hydrocarbon molecules under heat and pressure (*pyrolysis*) and then upgrading the product.

3. How does the process work? (Simplified)

1. Pre-treatment: Used oil is filtered to remove solids (metal shavings, dirt) and dehydrated to remove water.

2. Thermal Depolymerization (Pyrolysis): The clean, dry oil is heated to very high temperatures (typically 350-450°C or higher) *in the absence of oxygen*. This breaks down the long, complex hydrocarbon chains and additives in the used oil into smaller hydrocarbon molecules, forming a vapor.

3. Distillation: The vapor is cooled and condensed. Different fractions (like naphtha, diesel, light gas oil, heavy gas oil) are separated based on their boiling points. The target is the diesel fraction.

4. Hydrotreating/Upgrading (Crucial Step): The raw diesel fraction often contains impurities (sulfur, nitrogen, chlorine from additives, unsaturated compounds) and may have poor stability/octane. Hydrotreating uses hydrogen gas and a catalyst under high pressure/temperature to remove these impurities (desulfurization - HDS, denitrogenation - HDN, dechlorination) and saturate unstable molecules. This step is essential to produce a stable, on-specification fuel.

5. Finishing: Final filtration and stabilization may occur. Additives might be blended to meet specific standards.

4. What is the final product called?

The upgraded fuel meeting diesel specifications is typically referred to as "Recycled Fuel Oil" (RFO)"Processed Fuel Oil" (PFO)"Hydrotreated Pyrolysis Oil", or "Diesel Substitute". It is generally NOT called "Biodiesel" to avoid confusion. It aims to meet standard diesel fuel specifications like ASTM D975 (US) or EN 590 (Europe), potentially as a blend component.

5. Can this fuel be used directly in diesel engines?

Only if it meets strict fuel quality standards (like ASTM D975 or EN 590).

The hydrotreating step is absolutely critical for this. Untreated or poorly treated pyrolysis oil ("pyrolysis diesel") is generally NOT suitable for direct use in modern diesel engines. It can cause severe damage due to:

* High sulfur content (damages emissions systems - DPF, SCR, catalysts).

* Low cetane number (poor combustion, knocking).

* Presence of acids, chlorine, metals (corrosion, injector fouling).

* Poor stability (forms gums and sediments).

* High aromatic/polycyclic aromatic hydrocarbon (PAH) content.

Properly hydrotreated fuel meeting specifications can be used, often blended with conventional diesel.

6. What are the main benefits?

Waste Reduction & Resource Recovery: Diverts a significant hazardous waste stream from landfills or improper disposal (burning, dumping).

Energy Security: Creates a valuable liquid fuel from a waste product, reducing reliance on virgin crude oil.

Environmental Protection (Potential): Proper recycling prevents soil and water contamination from used oil dumping. Compared to virgin diesel production, it can have a lower overall carbon footprint, though lifecycle analysis is complex (depends on process efficiency, energy sources). Reduces demand for crude oil extraction.

Economic Opportunity: Creates value from waste, potential cost savings for fuel users (if competitively priced), and supports a circular economy.

7. What are the challenges and concerns?

High Capital Cost: Setting up advanced plants with pre-treatment, pyrolysis, distillation, and especially hydrotreating units is expensive.

Complex Technology & Operation: Requires sophisticated engineering and skilled operation to ensure consistent fuel quality and meet emissions standards.

Feedstock Quality & Consistency: ULOs are highly variable (contaminants, additives, mixed sources). Consistent pre-treatment is vital.

Strict Environmental Regulations: Plants must comply with stringent air emissions (VOCs, NOx, SOx, particulates), wastewater, and hazardous residue (coke, spent catalyst) disposal regulations. Permitting can be challenging.

Fuel Quality & Market Acceptance: Achieving and consistently meeting diesel specs requires significant investment. Gaining market trust and acceptance for the final fuel product is crucial. Blending is often necessary.

Residue Management: The process generates solid residues (coke, spent catalyst) and potentially wastewater streams that require proper, often costly, disposal or treatment.

8. Is this process environmentally friendly?

It has significant potential environmental benefits** by reducing hazardous waste and recovering energy. However, it is not inherently "green":

The process itself consumes energy (often natural gas or fuel gas).

Air emissions from the plant (combustion gases, process vents) must be rigorously controlled.

Hydrotreating consumes hydrogen (often produced from natural gas).

Residues require safe disposal.

Its overall environmental footprint depends heavily on plant efficiency, emission control technology, and energy sources. Life Cycle Assessment (LCA) studies are needed for specific facilities.

9. What regulations govern this?

Waste Handling: Classified as hazardous waste in many jurisdictions (e.g., EPA regulations in the US, Waste Framework Directive in EU). Strict rules for collection, transport, storage, and processing apply.

Fuel Quality: The final fuel product must meet applicable diesel fuel standards (e.g., ASTM D975, EN 590) if sold as such or blended.

Plant Operations: Subject to air pollution control regulations, water discharge permits, hazardous waste handling permits for residues, and occupational safety standards. Permitting is complex and location-specific.

10. Where is this technology used?

Commercial-scale plants exist, primarily in Europe, North America, and parts of Asia, though the market is still developing. Success depends heavily on supportive regulations, waste oil collection infrastructure, and market conditions for the fuel.

11. Can I do this at home/small scale?

Strongly discouraged and often illegal. Small-scale pyrolysis units without proper emission controls, safety systems, and hydrotreating capability produce low-quality, unstable, and highly polluting fuel unsuitable for engines. They also generate hazardous waste (pyrolysis residue/coke) that requires proper disposal. Handling used oil and operating pyrolysis equipment involves significant safety hazards (fire, explosion, toxic fumes). This is an industrial process requiring professional facilities and permits.

12. Is the fuel cheaper than regular diesel?

Pricing depends on numerous factors: cost of collecting/pre-treating ULOs, plant operating costs (energy, catalysts, maintenance, labor), scale of operation, local diesel prices, and government incentives/taxes. It can be competitive, but it's not guaranteed. The high capital cost is a significant factor.

13. What happens to the non-diesel fractions?

The lighter fraction (similar to naphtha) might be used as a fuel gas or further processed. Heavier fractions might be used as heavy fuel oil (HFO) for industrial burners or recycled back into the pyrolysis reactor. Coke is removed and disposed of or potentially used as fuel.

14. Does this process remove all contaminants?

Pre-treatment removes solids and water. Pyrolysis breaks down many organic molecules and additives. Hydrotreating is specifically designed to remove heteroatoms like Sulfur (S), Nitrogen (N), Chlorine (Cl), Oxygen (O), and metals, and to saturate unstable compounds. A well-designed and operated hydrotreater is essential for removing contaminants to meet fuel specs.