Palm Oil Mill

The concept of Mecpro’s mill is using the latest in palm oil milling technology to enhance efficiency with low operating cost.

Palm oil is extracted from fresh fruit bunches (FFB) by a mechanical process, where a mill commonly handles 2.5 to 150 MT per hour of FFB.

The quality of crude palm oil depends on the care taken after harvesting, particularly in the handling of the FFBs and the process adopted.

A palm oil mill produces crude palm oil and kernels as primary products and biomass as secondary product. The capacity of mills varies between 2.5 - 150 MT FFB/hr. A typical mill has many operational units as shown in Figure 2. This comprises of sterilization, stripping, digestion and pressing, clarification, purification, drying and storage. For the kernel line, there are steps such as nut/fiber separation, nut conditioning and cracking, cracked mixture separation, and kernel drying and storage. The dried kernels are often sold to palm kernel crushers for extraction of crude palm kernel oil. In some integrated plants, kernel crushing facilities exist side by side in the same complex.


Sterilization deactivates the lipases in the fruits, and prevents build-up of free fatty acids (FFA). Vertical sterilizers are also available, which are much cleaner and easier to operate than conventional sterilizers.

Another type of sterilizer technology, the tilting sterilizer, also eliminates much of the machinery associated with conventional sterilizers. The technology is the latest design that offers improved milling efficiency, and reduced labour and maintenance cost.

Two cage tippers are used with the individual Sterilized Bunch Conveyor that feeds two main Threshers. Empty bunches will be recycled by the conveyor to bunch Crushers before being fed to a third thresher for recovery of unstripped fruitlets. With this system, oil and kernel extraction will be enhanced.

Fruitlets are passed to a pressing Station for recovery of oil from the mesocarp. Crude oil is collected in a Crude Oil Tank and pumped to the Clarification Station. The digested mesh is conveyed to the Depricarping Station for the recovery of nuts and fiber used as boiler fuel.

The oil clarification process uses a Static Vertical Clarifier and three phase Decanters, Oil purifiers and an Oil Vacuum Dryer. The use of the Vertical Clarifier will ensure efficient sludge and oil separation whereas the decanter will ensure solid removal for efficient effluent treatment.

The kernel recovery process will utilize efficient ripple mills for nut cracking and a combination of two stages -- cracked mixture winnowing followed by wet separation by Clay bath for efficient kernel recovery.

In conclusion, the mills can improve by adopting the Mecpro process to enhance oil recovery and reduce utility consumption. The new technology with a state of art design has low losses and is easy to operate and maintain. It is a new concept that increases the OER, decreases the effluent and reduces environmental hazards and utility consumption. Besides, it is a clean process that needs less manpower to operate.

Description Present Technology Proposed Technology
Sterilization Batch Continuous
Fruit Separation Thresher Thresher
Cooking of Fruit Digester Digester
Extraction Mechanical Press Mechanical Press
Flow Enhancement of Oil Water Addition Solvent Addition
Separation of Oil Clarifier Solvent Extraction Plant
Solid Separation Decanter NA
Oil skimming an effluent discharge Skimming Pond and Effluent discharge with 1% oil NA
Sterilizer Effluent Skimming Pond and Effluent discharge with 1% oil Solvent Extraction of Oil and Effluent discharge to the pond without oil and solid.
Fibre Kernel Separation Pneumatic with Drum polisher Basket Beater with pneumatic
Palm Fibre Using as Boiler fuel Solvent Extraction then using as boiler fuel
Palm Kernel Nut Cracking Nut Cracking
Shell Separation Wet Separation Dry Separation
Kernel Drying System Thermal Heat NA
Kernel oil Extraction Mechanical Press Solvent Extraction

MECPRO MULTI-EXTRACTION (Recovery of oil from effluent using solvent)

The present invention relates to a novel process for recovery of oil from the emulsified non-emulsified forms of effluent water to reduce the generation of POME alongwith recovering an increased amount of oil in the edible oil stream.

The palm oil mills conventionally have had the following major operational steps, namely, digestion of fruit bunches, sterilization, Oil extraction with mechanical press, clarification press, sludge separation and kernel separation. The extraction process consumes a huge quantity of water and, consequently, results in generation of a large quantity of effluent. Up to 1.2 metric tonnes of fresh water is typically consumed for processing one tonne of fresh fruit bunches. Of the total water consumed, 70% results in palm oil mill effluent while the other 30% is lost as steam, boiler blow down, leakages and wash water from tankers ,etc. This remains separated from the effluent steam that reaches the effluent treatment system.

The present invention discloses a novel process to extract the remaining palm oil from the different streams using a flammable or non-flammable solvent. The process consists of the following steps:

  • Subjecting the oil enriched effluent stream to solvent in a closed chamber to yield a miscella and a de-oiled effluent stream.
  • Separating the oil, solvent and moisture from miscella.

The oil extraction takes place with the first step of mixing of effluent water with n-hexane in a close circuit in a jet mixer. The effluent and n-hexane mixture enter a reactor where a reflux system is provided for equalizing the vapor pressure generated. The floating miscella is separated in another chamber with high concentrations of water and miscella. The remaining oil and solvent are removed from the water in the second step of separation chamber. After removal of miscella the water is desolventized and sent for filtration. Filtered water is taken to the ash stimulator where the water will be sprayed on the ash to correct its pH.

The important features of the process of effluent treatment are as follows:

  • The palm oil mill effluent coming out from the process streams is at a temperature above the boiling point of the solvent used in the process. The water is at around 80-90°c while the n- hexane boiling point is 63°c.
  • Separation of water from the miscella takes place in high turbulence.
  • Recovery of solvent in the presence of oxygen and dissolved oxygen.


The advantage of the new process is that the oil produced will be suitable for refining for making edible oil. There is therefore more 4.5% more oil recovery in the palm oil mill based on the oil recovered or 0.9% based on FFB base The process of the present invention is advantageous as it saves energy, eliminates the decanter process, effluent reduction is more than 50% so that less land surface area is required for effluent treatment, and less processing cost.

The palm oil mill effluent coming out from the process stream is at a temperature above the boiling point of the solvent used in the process. This would minimize the freshwater consumption in the floatation step and consequently the effluent treatment cost is significantly reduced.



The latest technological development is to extract the remaining oil from wet palm fruit fibre. This has been established by Mecpro for the first time in the global market. This extraction technology will improve the productivity and economics of processing palm fruit.


  • Wet Mesocarp fiber oil extraction
  • Oil recovery from effluent with solvent extraction
  • Reduction of Effluent and elimination of Decanter and centrifuge process
  • Continuous palm kernel solvent extraction
  • Continuous flow crystallization and fractionation of palm oil
  • Advanced technology in palm oil mill
  • Continuous Spent Bleaching Earth extraction using flammable and non-flammable solvent
  • Layer esterification of fatty acid, or oil with fatty acid, without any catalyst
  • Bio-diesel production using fatty acid and waste oil or sludge oil as a feedstock
  • Twin bleaching in refinery
  • Constant heat raising deodorizer with falling film