Used oil recycling by short path molecular evaporation process

Lubricating ( motor oil, engine oil, hydraulic, gear box oil, turbine oil etc.) oil is widely used in the fields of manufacturing, transportation, chemical industry ect. With the development of national economy, the demanded quantity is increasing. Lubrication oil is used for lubricating, cooling, anti-rust, sealing, buffering purpose in all sorts of machineries. Because contaminated by dust, metal from environment, and working in high speed parts, contacting with air and polymerization, condensation, oxidation ect reactions occurred. The lubricating oil is gradually deteriorating during using, the main appearance is the color become darker, acidity number increasing, odor discharging, and oil sludge, precipitate produced. In fact, lubricating oil is deteriorated 1-10% of its hydrocarbons, most of the rest hydrocarbons are still the viscosity performer and effective components, this is the potential motivation of waste lubricating oil regeneration.
Used lubricating oil contains oxygen-carrying, nitrogen-carrying, sulfurate-carrying organic compound, and chemical additives, dumping or burning these lubricants would generate a lot of pollution and waste energy resource. With the increasingly dried-up of petroleum resource and strengthening of environmental consciousness
as well rising of oil price, regeneration of used oil is attached importance by the countries worldwide. Regeneration of used oil could safe energy resource, change waste in to valuables, reduce its pollution to environment, has great economic and social benefits.
Recent years, the advanced countries in the world deeply researched the used lube oil recycling process, placeing emphasis on environment protection, making used oil not pollute environment, no secondary pollution during regeneration, saving energy consumption, pollution free, upsizing, high recovery rate is the trend.
Our company is providing used lube oil re-refining equipment concentrating on capacities 15kt- 150kt/a.
The first cell is pretreatment unit, water mechanical contaminants removed oil is put in to tubular reactor and add a certain quantity of chemical to avoid the coking of oil during evaporation.
The second cell is degasification and dehydration unit: Remove water and gasoline from feedstock through evaporator.
The third cell is fuel refining unit: Remove diesel fraction of feedstock through packaged distillation column.
The forth cell is short path distillation unit: The main purpose is to separate different viscosity raw base oil fractions. The procedure is : De-diesel feedstock is pre-heated by falling film evaporator and send in to the first short path evaporator, because the short path evaporator is working under high vacuum, the low viscosity fraction of oil is distilled out at a lower temperature, through the built-in condenser, gas phase cooled and became liquid phase, it will be sent to raw base oil storage tank as the first session of base oil. The rest un-evaporated oil will be directly pumped in to the second short path evaporator, it will be evaporated out though a higher temperature than the first stage evaporator to flow in to medium viscosity base oil tank as a higher viscosity raw base oil. After the second stage evaporation, the rest un-evaporated oil will be pumped in to the third short path evaporator to have the heaviest oil distilled out as the heaviest raw base oil send in to the heavy base oil tank. The un-evaporable residuum of oil will be discharged to residue tank( asphalt, colloid, ect.).
The fifth cell is supplemental refining unit: According to different quality requirement, the distilled raw base oil can be supplemental refined by the below three methods:
1)Activated clay adsorption refining: reactor batch treatment type or fixed bed type.
2)solvent extraction-activated clay adsorption refining.
3)Hydro-treatment: suspension bed type or fixed bed type.
  • Pretreatment to ensure the flash point of base oil.
  • Molecular distillation technology and wiped film evaporator: reducing distilling temperature, reducing duration under high temperature.
  • Solved the coking, polymerization problem of raw materials.
  • Multi-treatment process, mature technology.
  • Open type steel frame.
  • Compact layout.
  • Easy operation.
  • Low operation cost.