Groundnuts / Peanuts Solvent Extraction Plant
We are engaged in manufacturing and exporting Groundnuts / Peanuts Solvent Extraction Plant with our manufacturing facilities in Ludhiana ( Punjab ), India.
Everyone knows that groundnuts also called peanuts. Linnaeus described the domesticated peanut species as Arachis (derived from the Greek ‘‘arachis,’’ meaning a weed) hypogaea (meaning a underground chamber) or a weed with fruit produced below the soil.
Peanuts are produced in more than 30 countries and India, China and United States of America are the largest producers of Groundnuts. In Africa Nigeria, Senegal, Sudan and Gambia are the major producers of peanuts
The decorticated peanuts are used as direct food, roasted peanuts and many other food applications. Out of which major part of the groundnuts are used to extract the Oil and the cake used as poultry and animal feed. The Oil is widely accepted as cooking oil, salad oil and also for the production of other applications in cosmetics and pharmacy.
The Peanuts whole called as pods which contains 30% Shell and 70% Kernels. This will vary country to country whereas bold peanuts contain 21% shell and 79% kernels. Average kernel yield from different locations identified that kernel content around 70% moisture around 7-8%.
Ground Kernels are the main source of oil and also protein. The Process of Extraction will be carried out as under.
Specifications of Standard Groundnuts
| Moisture | 6 – 8% |
| Impurities | 2- 3% |
| Oil in Kernels | 46 – 52% |
| Shell | 18-29% |
Groundnut Pods
These pods are collected from the harvester or farmers and allowed to dry either in the sun or the hot air drier.
Cleaning of Groundnut Pods
The pods are stick with some mud, sand and impurities. These are cleaned with help of rotary drum and the fine particles and sand are to be removed from the pods.
Deshelling of the Groundnut Pods
Shelling is the removal of the groundnut from its pod by impact action, compression and shearing or combination of two / more of these methods. The shelling operation is majorly divided into two. After shearing the shells are separated by using aspiration system and the shells and kernels are separated.
Groundnut Kernel Oil Extraction System
There are two types of methods for extraction of oil. First mechanical pressing using screw presses and second solvent extraction method.
Under mechanical pressing the kernels will be carried out by two methods.
- Pre-press method followed by Solvent Extraction
- Full press extraction followed by solvent extraction
Special types are of extraction systems are also used to extract the oil and use the cake for edible purpose for making snacks and chutneys in India. And also Cake will be used for protein isolate to make an ingredient for filled milk powder and some other applications in food processing.
Second Cleaning of Kernel
The Groundnut kernel are available in agro hubs and markets as the farmers are deshelling the Groundnut in their farms. This will have some impurities like sand other stones. These kernels are cleaned with drum type cleaning machines to remove fine sand and bigger size of stones.
De-stoning
Either gravity or belt type de-stoners are used to remove stones similar size to the kernels. Highly efficient de-stoners are available to remove the stones from the kernels.
Magnetic Separation
The Iron particles and magnetic materials if any are removed with this process. Permanent magnets or rotary drum magnets or electro magnets are used to remove the Iron and magnetic particles. Removal of iron and magnetic particles improves the life of the machines and also iron content in the oil and meal will be minimized.
Conditioning / Cooking
Groundnut kernels are required to condition to make it soften. A vertical stack cooker or horizontal rotary cookers are used to condition the cracked seeds by heating with jacketed and live steam to 65°C to 70°C and increasing the moisture to 11% to 12%.
Method 1 : Pre Press
This is a screw press fitted with four stage cooker / conditioner. The destoned kernel are send to the cooker / conditioner where the kernels are heated upto 60°C and passed through the pre-press.
Where the kernels are pressed and more than 25% to 30% Oil will be drained at this stage and the cake with 15% to 18% Oil will be obtained. The cake will be discharged at 65°C will be cooled to 50°C.
In case of higher size cake, the breaker will be used to reduce the size of the cake to 2 inches to 4 inches size. The cooled and sized cake will be transferred to solvent extraction process to extract the balance oil of 17% plus leaving the residual oil less than 1% in cake.
Method 2 : Full Press
Full press itself indicating that the seed is totally pressed to drain out maximum oil. The groundnut kernel contains 46 to 52% of oil. Due to its nature its difficult to extract the complete oil in single stage
The kernels is cleaned, destoned, separated the magnetic particles and cooked then allow to the screw press 1st stage where some oil content drained cake will be the by product. 15 – 18% oil will be left in the cake during the 1st press.
The cake again passed to the second stage screw press where again some quantity of oil will be drained out leaving 5- 6% oil in the cake. The Oil extracted through mechanical pressing is having some natural ingredients un affected improves the nutritional factors. This type of method is widely used under small scale where solvent extraction is not viable.
A mechanical full pressing machine available from 2.5 tons per day allows mini and micro industries set up. The filtered oil is widely accepted for human consumption. After full pressing the balance cake with 5 – 6% of oil will be transferred to solvent extraction process where the balance 6% oil will be extracted leaving 0.5% to 0.7% will remain the cake after solvent extraction process.
Solvent Extraction Process
The Groundnut kernels can be directly solvent extracted or pressed cake or fully pressed cake. For direct solvent extraction two types of alternative processes are explained in the above. Apart from above two processes another process is there in which the mustard seeds are fully pressed and cake obtained from full press will be used to extract the balance oil 6% to 7% by using solvent extraction Process. The Pre-pressed cake // expanded collets // fully pressed cake from preparatory section is carried by Redler Conveyor and fed to Extractor Either through rotary valve or Plug O Seal to extractor feed hopper incorporated with high and low level arrangement to ensure proper level of material filled in the Hope and seal for the system. The material through the intake hopper moves on the endless band conveyor chain of moving deep bed extractor and the Hexane is sprayed counter currently over the moving bed material. The solvent percolates n penetrates through the bed and dissolves oil with it. The solvent oil mixture is called as Miscella. Miscella from last hoper will be transferred to miscella holding tank through miscella filter or hydro cyclones fixed above Extractor. The de-oiled seed material with solvent is discharged from extractor discharge hopper and is transferred to desolventisor toaster through leak proof sealed solvent tight conveyor.
Pre-pressed cake as FEED
| Feed Material | Groundnut Cake with less than 0.5% Fines |
|---|---|
| Moisture | 8% -9 % |
| Oil Content | 15% – 18% |
Full Pressed Cake as FEED
| Feed Material | Groundnut with less than 0.5% Fines |
|---|---|
| Moisture | 8% -9 % |
| Oil Content | 5% – 6% |
Meal Conditioning and Bagging
The groundnut de-oiled meal obtained from the DT discharged at 110°C will be cooled to 10°C above the ambient temperature. This cooled groundnut meal contains some quantity of lumps around 10% to 15% based on the operation and quality of steam. These lumps are sieved out and grinded to the specific size of sieve. This is the final product which called de-oiled groundnut meal. This will be bagged in 50 to 75 kg through an automatic bagging machine.
Specifications of Solvent Extracted Groundnut Oil:
| Specifications | Groundnut Oil |
|---|---|
| Moisture | 10 – 11% |
| Residual oil in cake | <1% |
| Protein | 45% – 55% |
| Temp after conditioning | + 10°C above ambient |
| POP test/td> | Negative |
Groundnut Solvent Extraction Plant Process
- Meal Desolventization
- Miscella Distillation System
- Condensation and Solvent Recovery
- Recuperation (Absorption and Desorption) Unit
