PEANUT, NUT and OTHER OILSEEDS PROCESSING
The ABC Hansen Nut Processing program consists of complete systems which normally included one of several of the following actions:
- Shelling of peanuts.
- Grading nuts and peanuts
- Density (gravity separators),
- Plate roasters
- Drum roasters
- Belt roasters
- De-skinning roasted peanuts and removal of germ.
- Blanching nuts for the snack market.
- Water cooled stone mills.
- Plate mills.
- Disc mills.
- Solids dosing.
- Liquids dosing.
Ancillary plant includes:
- Intake, silo storage, soft let-down, aeration for maintaining quality.
- Belt, screw, chain conveyors.
- Bucket, inclined belt, air conveyors.
- Weighbridges, scales.
- Adding value to shells – milling, briquetting.
Expeltec Cold Pressed Oil Expelling Plants
The cold pressing of vegetable oil has been proven in several countries as a viable small industry for the individual entrepreneur or company wishing to add value through vertical integration within its production or distribution chain and especially when targeting niche products. Specialty oils with high value low volume operations are especially viable for small operations due in part to the lack of interest by the large scale industry.
That is not to say that plants in the capacity range of 1 to 5 tons per hour where mechanical expelling or pressing is used, is not viable in the case of the commercial seeds such as sunflower and soy beans where for instance low fat oil cake is required for the processing of animal feed or human foodstuffs. With high quality equipment and the correct pre-processing, viable yields can be obtained.
The Expeltec oil expelling system is presented as a complete turnkey project in terms of plant and equipment supplied, installed and commissioned. Components may also be purchased separately so as to enable the industrialist to make up his own plant. The plant in standard execution provides for extraction of oil from groundnuts and sunflower seeds, soy beans and virtually all oil bearing seeds such as jojoba, apricot kernels, peach kernels, pumpkin seeds, cotton seeds, copra, tomato seeds, castor seeds, almonds, walnuts, macadamia, pecan and virtually all seeds with relatively high oil content are possible feedstocks. The final use of such oil and the required refining to get it to a specification, are of course all individual considerations. Usually in the case of high value oils, no refining other than filtration is required by the end user or oil traders as the oil's attraction usually lies in its natural smell and taste that is concentrated when the oil is pressed.
With the widespread use of biodiesel, various oils may be used that are of low value otherwise, but that may be viable for fuel. Seeds with aflatoxins that are poisonous for human and animal consumption can for instance be used for biofuel very effectively as it has no other commercial value. As such quantities are normally not that big, it can easily be mechanically pressed when the opportunity arises.
The commercial growing of jatropha for biodiesel purposes requires chemical extraction to be viable in the quantities upon which these projects are based.
Expeltec systems would basically consist of the following:
1. Seed intake, storage, aeration, fumigation systems:
It is crucual that seeds be received correctly, dried if too wet to avoid spoiling, stored properly and aerated when required to maintain quality and finally fumigated when necessary to avoid losses and to maintain oil quality and quantity. It may also e necessary to add moisture when seeds are too dry for instance. This can be accomplished by a dampener to be included after cleaning.
2. Seed cleaning:
This process ensures that the equipment further down the line is protected from tramp steel, dust, sand and stones which are all very abrasive as well as poisonous seeds, especially where oil is pressed for human consumption. Normally no warranty would apply to any machine downstream if a proper cleanng system is not installed.
ABC Hansen offers cleaners from 2 -3 ton per hour capacity up to pre-cleaners of 240 tons per hour.
3. Seed dehulling plant
Dehulling is optional in most cases while applying a dehuller would result in higher yields of oil and higher protein of oil cake as the fibrous hull absorbs oil when pressing and is not high in protein by itself. For some oil seeds, some hulls are essential as fibre to get the product firmly through the screw without turning into "butter". This is especially the case where oil content is high.
Various de-hullers can be supplied. In the case of soy beans, a 1 ton per hour abrasive de-huller removes 99.9% of hulls and splits 99.9% of the beans. Sunflower dehullers are available as fllows:
- Capacity 500 kg/hr - 1 ton per hour per machine.
- Power 3 kW 380 V Three phase, Inverter driven
- Aspirator unit for air separation including cyclones
Conditioning may refer to, for instance heat in the form of extrusion, steam, a parcher, warm air etc. being applied to the seeds prior to expelling. It may, again be of crucial importance in some cases while only increasing yield by one or two points in other cases. This may also relate to the extrusion of oil seeds, prior to pressing.
This process, when included in a mechanical oil pressing plant, ruptures the oil cells and ensures the oil is released faster and easier. The seeds are in some cases heated to neutralise the tripsin inhibitor as for soy beans, to allow the processing of low fat oil cake - see section below).
Extruders from InstaPro would generally be used in all ABC Hansen plants from capacities of 600kg per hour and higher.
The InstaPro range includes the following extruders:
- 600 Series extruder with capacity 270 to 365 kg per hour.
- 2000 Series extruder with capacity 1,000 to 1,200 kg per hour.
- 9000 Series extruder with capacity 2,700 to 3,600 kg per hour.
Other than the elected method by which the product is transported between machines, the oil expeller(s) or oil press or expressor (as various companies would call the process) would form the next processing machine.
6. Oil Expellers:
The Expeltec system utilises several presses, depending on the capacity of the system and the type of seed pressed notably:
- The SGC120 for a capacity of around 120kg per hour on sunflower seed intake. This is a low cost machine with low cost of wear parts and usually used for high value specialty seeds. A viable business can usually not be run when pressing commercial oil seeds such as sunflowers or soy on these presses.
- The SGC300 for a capacity of 300kg/hr based on sunflower seed intake. While still relatively low capacity, several presses may form a viable production unit for commercial seeds and may be very profitable when pressing specialty seeds.
- For larger capacities ABC Hansen would
install InstaPro presses which are primarily classed as the
- Model 1000 - 15kw for capacities of 350 - 450 kg per hour.
- Model 2000 - 30kW for capacities 700-900kg per hour.
- Model 5005 - 40kW for capacities 1,800 to 2000 kg per hour.
7. Further processing:
The pressed oil is now pumped to settling tanks and filtered while
the oil cake is usually milled into a meal and bagged after it has
cooled down and used, in most cases, as animal feed. Some vacuum
filters ay be used to extract maximum oil from the sludge.
Filtered cold pressed oil is by far the healthiest oil available as it retains all the vitamins and minerals as well as the key important amino acids the human body needs but can not produce. The Omega amino acids are abundant in some cold pressed oils such as sunflower, sesame and others.
Once filtered, the processor may require that the oil be de-waxed. That is simply removing the waxes that would turn the oil cloudy once the temperature drops to below 24 ° C or lower in some cases. This is done by cooling the oil down and filtering it again.
This is where refining of cold pressed oil should end. All further refining reduces the value of the oil unless of course some harmful elements must be removed as in the case of cottonseed oil.
- It should be noted that large scale producers of oil are interested in selling commodities. Their plants chemically extract from 240 to 1,000 tons and more of seeds per day. These hungry monsters needs to be fed any seed that is economically viable to extract. They therefore neutralize all oils, whether corn oil, cotton seed, sunflower or soy bean simply into fat in order to blend these oils on a continous basis without having a perceptible change in taste, smell or colour should one of the raw material ingredients change.
- Some oils, such as soy bean oil has a dark rusty colour and an unpleasant smell and has to be neutralized in order to blend. The refining process subjects the oil to very high temperatures that starts the oxidization process. The acid wash of oils not only removes the free fatty acids prevalent in decaying oil, but also the valuable amino acids.
The most important processes of refining then include the following:
- Neutralising: The oil is washed with a caustic soda mix through which the free fatty acids binds with the caustic soda and forms soap that is removed from the oil.
- Degumming: The oil is washed with water that binds with the gums in the oil and is then allowed to settle or is centrifuged.
- Deodorising: The oil is heated to around 200° C (260 is flashpoint) under vacuum and dry steam is introduced in the pressure vessel. The volatiles evaporating at this temperature is carried off under vacuum with the steam, rendering the oil tasteless and without smell. At the same time, any water remaining in the oil is evaporated so a "dry" oil results.
- Following these processes, a neutral fat is obtained that is again artificially coloured to the right "sunflower yellow" and preserved through addition of citric acid or other preservatives.
The ABC Africa group is able to install plants for processing of soybeans in various ways.
The soy bean, due to its physiological make-up, requires that its protein be broken down to cook neutralize trypsin inhibitors that prevents the intake of proteins in raw form, of grazing animals. The trick therefore has been to find the most efficient way to heat soy beans in order to neutralize this effect. This can be achieved by heating the bean to a sufficient level and can be done in several ways namely:
- Extrusion: A mechanical screw pressing a large volume of product through a restricted opening thereby generating heat in excess of 150°C, sufficient to cook the bean.
- Steam: Tthe beans are either batch cooked or continuously cooked by means of steam in jacketed vessels.
- Parcher: For smaller applications, the beans are simply heated directly by means of a parcher with either electric, coal, wood, gas or any other inexpensive fuel. The system is crude and normally consist of a heated revolving tube where the beans are heated without being scorched.
- Diesel or oil fired rotary drum roasters are efficient and easy to operate. ABC Hansen offers 1 ton per hour rotary drum roaster.
- Micronising:While this would normally refer to the micro wave oven as we know it in our homes, in practice it usually takes the form of infra red heating over a conveyor - sometimes it just refers to heating elements.
Following the heating of the bean, expelling may take place if a low fat soy bean oil cake is desired, otherwise, simply milling the heated bean (and in the case of extrusion, the mutilated bean is simply cooled) offers a full fat soy bean oilcake.
Full fat soy bean oilcake has only one disadvantage. It has too much fat relative to protein. The trick for the farmer is to turn vegetable protein into animal protein or meat in the most efficient way. He would therefore like to lower the fat in the soy bean and increase the protein. Of course he can do it in one stroke - by expelling the fat.
The soy bean has around 33-38% protein which makes it a great crop. By reducing the fibre - around 15% (through dehulling) and reducing the fat - another 12% (through expelling), protein takes up a bigger percentage of the remaining volume. This can go as high as 46-8 % which increases the price of the remaining soy bean cake tremendously since farmers purchase fodder in accordance with the weight it would add to their animals, or protein.
With some 18% fat in the soy bean, around 10-14% oil can be expelled mechanically. All 18% can be extracted chemically through a hexane process. (Hexane is a petrochemical cousin of benzine, the latter outlawed as a malignant chemical causing cancer while hexane is also targeted for discontinuation in extraction of oil in human food applications. (no alternative has probably been found yet).
However, its efficient, if a very expensive way to extract oil on small scale and the cheapest way to extract oil on a large scale. And the reason is really because hexane is highly flameable, a heavy gas accumulating in corners and can't easily be detected. A small leak in the system would blow the plant sky high - and this happens all the time. (In the years I have had to do with this, I have knowledge of two plants in South Africa exploding and taking lives with it).
On small scale therefore, parching is the least expensive way to go. Probably to around the 120kg per hour level.
Following this, extrusion presents the most viable avenue to around the 600kg per hour level. This could yet again be doubled to around 1,200kg per hour with two extruders and four 300kg/hr presses. The capital cost is still acceptable and running cost and maintenance is not too high. This could be expanded upon by using high quality (and cost) American equipment to levels of around 1.6 tons per hour on a single line and two or three lines may be installed. bear in mind that while extrusion is a fast way to cook soy beans, it is also a high energy user.
Steam cooking is often used beyond this level. Its clean and may use the least expensive energy source such as any biomass to heat the boilers.
Following the heating of the beans, expelling can take place. A safe estimate for oil retained in the cake after expelling is usually around 6 - 8 %. Claims are made for 2-4% by certain processors. While it may be possible it is not the norm, at least not with one pass through the press and if pressed more than once, the viability of the second pressing is normally suspect to say the least.
Low fat soy oil cake has high protein and when below 3% fat, it can be processed further into various products for human consumption such as the TVP's or "textured vegetable proteins" as well as various other products such as tofu, yoghurts, milk replacers etc.
Small scale oil expellers: Model SGC120 and SGC300.
The SGC120 comes complete with 11kW motor.
This economical cold oil press will provide yields of more than 33% on sunflower seed and can expel oil from many different types of seeds and requires only filtration (in the case of sunflower seed) to be edible.
The SGC120 expeller is now available at a ridiculous price to enable you to start your own successful business.
The SGC300 is in turn, a larger size expeller for small to medium scale enterprises and uses a 15 to 18.5kW drive which is included in the price.
Commercial oil expellers - InstaPro Models:
Electrical can be configured to specific needs
|1000||20 hp / 14.9 kW main drive motor||750-1000 lbs
|Inches 76"H x 57"W x 113"L
193H x 203W x 285L
|2000||30 hp / 26 kW main drive motor
3 hp /2.24 kW krammer drive motor
|1,500 - 2,000 lbs 680-909 kg||9,400 lbs 4,273 kg||Inches
90"H x 57"W x 113"L
229H x 203W x 285L
|5005||60 hp / 40 kW main drive motor
5 hp / 3.75 kW krammer drive motor
1 hp / .75 kW variable speed feeder motor
0.5 hp / 0.37 kW (discharge screw)
111"H x 78"W x 161"L
239H x 112W x 335L
Press extraction efficiency (output)
|Oilseed*||Raw Oil Content %||Raw Protein Content||Oil Removal Efficiency%||Extruding Temperature ° F||Expelled Meal Oil Content %||Expelled Meal Protein Content %|
Model 1000 Press
- Versatile equipment with numerous applications.
- Rigid, compact construction.
- 7.2 to 1 cage diameter ratio.
- Ease of operation
- Oil filtration option available
- Scalable to 24 TPD capacity
- Introductory press unit
- Cost efficient operation
- Low maintenance
Model 2000 Press
- Versatile equipment with numerous applications
- 7.2 to 1 cage length to cage diameter ratio
- Rigid, compact construction
- Oil filtration options available
- Most popular model
- Cost efficient operation
- Ease op operation
- Oil transfer pump
- Krammer unit
- Stand and oil tank
Model 5005 Press
- Gear drive with external thrusting housing
- 8 to 1 cage length to cage diameter ratio
- Two oil discharge ports
- Modular design for easy maintenance
- Stainless steel doors and sheilds
- Oil filtration options available
- 8-10% greater oil extraction
- Highest volume output
- Improved productivity
- Most efficient
- Oil transfer pump
Insta-Pro ® Extrusion Technology
Typical Analysis of ExPress ® Soy Oil
|ExPress Soy Oil||National Oil Processors Association Specifications for Crude Degummed Soybean Oil|
|FFA:%as oleic||0.34||0.75 max|
|Chlorophyll, ppm||0.56||1000 max.|
|Phosphorus, ppm||*300.00||200 max.|
|Calcium, ppm||33.50||100 max.|
|Flash Point, °F||300.00||250 min.|
|Moister and Volatile Matter, %||0.15||0.50 max.|
|Viscosity||60.2 Centipoises @ 25° C|
All values are typical analytical results and not garunteed levels.
Insta-Pro ® Extrusion Technology
ExPress ® Soy Meal
|Energy Content (Dry matter basis)|
|Neutral Detergent Fiber||11.00%|
|Acid Detergent Fiber||10.00%|
Typical Inclusion Rates
- May be used as the major source of protein for all specie.
- Inclusion rate will vary with specie and stage of
- Monogastics: Inclusion from 15% to 40% of the complete diet.
- Ruminants: Inclusion up to 25% of the grain mix.
b KSU, 1998
c Calculated based on NRC Dairy, 1989, Page 9
All values are typical analytical results and not guaranteed levels.
Part of the ABC Africa Group of Companies