Palm Oil Industries

OIL PALM AND PALM OIL - Oil Palm is the tree and the tree bears the fruit from which the palm oil is obtained. - The principle oil palm of commerce is Elaise Guineensis which is a tribe of cocoainae (coconut) family. family. - Oil palm is first nurtured at the nursery after pollination  transfer to plantation when the young plants reaches about 8 inches in height. - Suitable area for growth: plenty of rainfall and good drainage system - Harvest the tree after 3 years of planting.

OIL PALM AND PALM OIL - The fruit can be harvesting after 2 months of ripening. r ipening. - The mature bunch contains a few hundred to a few thousand fruit depending on the genetic and environmental factors and palm age. (young poor palms: 5 kg fruit, 15 year old healthy tree: 40 kg fruit, individual fruit: 8-10 g / fruit).

OIL PALM AND PALM OIL

OIL PALM AND PALM OIL - The fruit is made up of exocarp (skin), mesocarp (which contains palm oil and water in a fibrous matrix), endocarp (shell) and kernel (the seed, which contains oil and meal)

OIL PALM AND PALM OIL

OIL PALM AND PALM OIL - Bunch production is continuously and partially unsynchronised between palms. - Oil starts to accumulate in the bunch from relatively early its development and build up rapidly from 130 days after ripening. The quantity maximises and eventually starts to decline due to the breakdown of oil to free fatty acid (FFA) and loss of actual bunch tissue. - Regular harvesting is required taking only the ripes ones. This can be recognised based on fruit detachment which commences about 140 days after ripening. - Once the fruit are harvested, they need to be transported to the mill for extraction of oil.

OIL PALM AND PALM OIL -

Eight processes involve in the extraction of palm oil industries:

1) Bunch reception 2) Loading ramp 3) Sterilization 4) Threshing 5) Digestion 6) Oil extraction 7) Clarification and purification of CPO 8) Nut and kernel station

EXTRACTION OF CRUDE PALM OIL What is crude palm oil (CPO)? It is the oil obtained from the mesocarp part of palm oil fruit Several processes involve in the extraction of the oil. 1. Bunch reception - Bunch are transported to the mills by road truck or lorries, or cages running on specially built railway system. - Upon reception at the mill, the fruit is graded to ensure a high standard of harvesting. Grade as follows: (a) Fruit bunch < 10 loose fruitlets → unripe (b) Fruit bunch ≥ 10 loose fruitlets → ripe (c) Fruit bunch with excessive loose fruits detached → overripe (d) Bunch with loose fruits completely detached → rotten (e) Bunch with long stalk and consignment with excessive trash are also noted.

- Appropriate action will be taken by mill and estate management based on the grading. - Fruit will carried by trucks to the loading ramp.

EXTRACTION OF CRUDE PALM OIL

EXTRACTION OF CRUDE PALM OIL 2. Loading Ramp - The fresh fruit bunch (FFB) is loaded directly into the ramp hopper with minimum handling. - Fruit from the hopper are loaded into the fruit cages waiting underneath. Each cage hold about 2½ tons of fruit and these are pushed in a train of three by a locomotive or skid loader to the sterilizer yard. - Purpose of ramp operation: to ensure that old fruits are first taken out for processing, to avoid accumulation of old fruit which otherwise will rot over a short period and thus creating high FFA problem (should not exceed 5%). - Loose fruits on the ramp top, ramp bottom and around the marshalling yard should be removed to avoid being crashed and prevent unnecessary problems arising.

EXTRACTION OF CRUDE PALM OIL

EXTRACTION OF CRUDE PALM OIL

EXTRACTION OF CRUDE PALM OIL

Fruits are loaded into the fruit cage

EXTRACTION OF CRUDE PALM OIL 3. Sterilization - The fruit arriving inside the cages are then charged into the sterilizer to be ‘cooked’ under saturated steam at 40 psig. - Quality of the cooked fruit is very important for subsequent process. - Objective of sterilization: (a) Prevention of any further rise in FFA due to enzyme action by inactivation of the lipolytic enzymes (b) Facilitation of mechanical stripping. To loosen fruit still attached to the bunch stalk, sufficient heat must penetrate to the points of attachment of the fruits to the spikelets to bring about hydrolysis at these points (c) Preparation of the fruit pericarp for subsequent processing. (d) Preconditioning of the nuts to minimize kernel breakage during both processing and nut cracking (e) Coagulations of the protein material and hydrolysis of the mucilaginous material present in the palm fruit.

EXTRACTION OF CRUDE PALM OIL - The operation is manual except the actual ‘cooking’, hence any delay in closing or opening the door or inadequate steam pressure will disturb the sterilizing cycle. - Inefficient sterilization will give to several problems is subsequent process: (a) stripping of the fruits  – fruits are not loosened enough (b) digestion and pressing  – pericarp is not softened enough (c) cracking – higher tendency of nuts cracking and thus broken kernels, difficult to separate them later. (d) clarification of the extracted oil  – poor oil recovery

EXTRACTION OF CRUDE PALM OIL

Fruit to be ‘cooked’ under saturated steam in sterilizer 

EXTRACTION OF CRUDE PALM OIL

EXTRACTION OF CRUDE PALM OIL

EXTRACTION OF CRUDE PALM OIL 4. Threshing - Purpose: Threshing or stripping is done to separate the sterilized fruits from the sterilized bunch stalks. - The sterilized fruit together with the fruit cage is lifted by a hoisting crane and then poured on to the threshing machine. - The threshing machine consists of 2 parts, (a) Thresher hopper or feeder  – designed so that the sterilized bunches can slide freely down the hopper and large enough to accommodate a maximum of two cages full of bunches in capacity. The hopper is simple with good control device. (b) Thresher drum – a rotary cylinder made up of small section channel bars at equal intervals.

EXTRACTION OF CRUDE PALM OIL

The fruit cage is lifted by a hoisting crane and then the sterilized fruit is poured on to the threshing machine.

EXTRACTION OF CRUDE PALM OIL - The rate of rotation of the drum is set to ensure the bunches of normal size are lifted by centrifugal action assisted by lifting bars fitted inside the drum. - Once the bunches have reached the top of the drum, they then fall freely, passing approximately through the axis of the drum and striking the bottom with sufficient force to dislodge much of the fruits. - As the action repeats several times during the rotation of the drum, while moving along to the end of the drum, the fruit finally drop out. - The drum discharge: empty bunches (normally discharge to an incinerator yielding an ash) and sterilized fruits (proceed to digestion)

EXTRACTION OF CRUDE PALM OIL

EXTRACTION OF CRUDE PALM OIL

Empty bunches normally discharge to an incinerator

EXTRACTION OF CRUDE PALM OIL

Incinerator

EXTRACTION OF CRUDE PALM OIL 5. Digestion - Process: reheat, pericarp loosened from the nuts and prepared for pressing. - Digestion take place in steam heated vessels provided with stirring arms known as digester or kettles. - Temperature ≈ 100ºC, the arms stir and rub the fruit, loosening the pericarp from the nuts and breaking open as many of the oil cells possible. - The digester converts the stripped fruits into a homogeneous mash. The digester is kept full as the digested fruit is drawn off continuously at the same rate as the freshly stripper fruit is added.

EXTRACTION OF CRUDE PALM OIL

Digestion take place in steam heated vessels

EXTRACTION OF CRUDE PALM OIL 6. Oil Extraction - Palm oil is extracted by pressing in the screws press- consist of perforated cage in which runs a single or double screw - Press screw: tough and wear resistant steel; press cage: stainless steel. - The outlet end of perforated cage is restricted by a cone and it is this restriction of the discharge that creates a pressure in the cage. - The pressing of the digested mesh is done with minimum nut breakage. - Discharge from screw press: crude palm oil liquor and matte of oily fibre and nuts - Fibre and nuts: carried by the steam jacketed conveyor - Crude oil: passed on to the vibrating screens to be separated from the accompanying solids.

EXTRACTION OF CRUDE PALM OIL

Palm oil is extracted by pressing in the screw press

EXTRACTION OF CRUDE PALM OIL

Discharge from screw press

EXTRACTION OF CRUDE PALM OIL 7. Clarification and Purification of CPO - Purpose: to give a clear stable product of acceptable appearance. Water and impurities must be removed. - Extracted crude palm oil contains varying amount of water together with impurities (vegetable matter  – some in form of insoluble solids and some dissolved in the water). - Average composition of crude palm oil, 66% oil, 24% water and remainder is lumped as non-oily solids. - Water can be removed by settling or centrifuging. - Clarification for palm oil are ‘gravity settling’ or ‘direct process’.

EXTRACTION OF CRUDE PALM OIL The crude oil is diluted first with hot water to reduce its viscosity.

The diluted crude oil is screened to remove any coarse fibrous material which is returned to digester.

The screened crude oil is heated (90-95 °C) and pumped to the continuous settling tank.

Retention of the crude liquor in settling tank enables the oil to rise to the surface and overflow continuously into a reception tank.

Settled oil purified by centrifuging  – reduce the dirt content to 0.01% or less

EXTRACTION OF CRUDE PALM OIL - A small portion of the moisture content of the oil is dissolved in the oil and can only be removed by evaporation in a dehydrator with or without the use of a vacuum. - The underflow from the continuous settling tank is sludge containing some oil which can be recovered by centrifuging. - The rest of the sludge is discharge to the effluent treatment plant. - In effluent treatment process, the anaerobic digestion of palm oil mill effluent (POME) produce methane which can be used to generate inhouse electricity.

EXTRACTION OF CRUDE PALM OIL 8. Nut and Kernel Station - Pressed fibres uses as fuel to the boiler. - Nuts are normally not processed for the oil content in the same mill. Hence, the nuts need to separate the shell from the kernel. Prior to this, separation of nuts from the accompanying fibre is done in depericarper station. - Function of depericarper: nut polishing, partial drying of fibre, transport of fibre to the boiler house, grading out of oversize foreign material e.g wood, stones, metal bits and stalks - The wet nuts are elevated to the nut bin which is maintained at 6077ºC. Upon drying, the dry nuts are then transported by dry nuts elevator to the nut cracking machines. The separated shells are sent to the yard as fuel to the boiler whereas the kernels are then sorted in kernel silo dryer before final storage in the bulk kernel silo.

EXTRACTION OF CRUDE PALM OIL

Separation of nuts from the accompanying fibre

EXTRACTION OF CRUDE PALM OIL

EXTRACTION OF CRUDE PALM OIL

REFINING OF CRUDE PALM OIL - The crude palm oil obtained from the mill is dark orange in colour, contain many form of fatty acids. - Water, insoluble impurities, free fatty acids, oxidation product should be kept a minimum level. - Thus, purification or refining process are needed to reduce the contaminants. - The refining treatment should retain as much as possible the tocopherols  and tocotrienols  because of their antioxidant effect to the product. - Two methods of refining: physical or chemical refining. - A refined oil is the crude oil which has been exposed to the following treatment: (a) Degumming, neutralization, washing and drying (if used) (b) Bleaching and filtration

REFINING OF CRUDE PALM OIL CHEMICAL METHOD

PHYSICAL METHOD

Crude oil storage

Crude oil storage

Gum conditioning

Gum conditioning

Neutralization

Water washing

Drying

Bleaching

Bleaching

Filtration

Filtration

Pretreated oil storage

Pretreated or neutralized and bleached storage

Steam refining

Polishing

Cooling

Deodorization

Polishing

Cooling

REFINING OF CRUDE PALM OIL (a)Degumming, Neutralization, Washing and Drying Impurities: phophatides, protein fragments, gummy and mucilaginous substances - soluble in the oil only in hydrous form. - can be precipitated by centrifuge - Hydration is accomplished during the production of palm oil by admission of steam and water prior to the oil being purified in sludge separators and clarifiers.

REFINING OF CRUDE PALM OIL Degumming - Some of the gums in the palm oil are not hydratable gums or phosphatides, which cannot be removed from the oil by water degumming in the palm oil factory. - Gums containing Ca and Mg, which if found in the oil after refining, give the oil an inferior quality and therefore a shorter shelf-life. Therefore it should be completely removed. - Concentrated phosphoric acid 0.1% by weight is sufficient to remove a significant amount of phosphatides and about 25 ppm of soap in washed oil.

REFINING OF CRUDE PALM OIL Neutralization - The losses during neutralization normally be attributed to the following factors (a) FFA (b) The mucilage, coloring matter and other impurities in the oil (c) The saponification losses which arise through saponification of neutral oil - Neutralized used NaOH - The resulting soapstock is separated from the oil by centrifuging and washing with water. - Any soap retained in the washed oil is removed by adding citric of phosphoric acid to the final wash prior to drying of the oil.

REFINING OF CRUDE PALM OIL

Drying - Oil discharged from the water washing centrifuge contains about 0.25% moisture, this cause a rise in FFA due to catalytic hydrolysis. - Therefore, the oil is dried in a vacuum dryer to reduce the moisture contain (