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 |
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:
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 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 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.