UNIVERSITY OF PORT HARCOURT
SCHOOL OF
SCIENCE
LABORATORY TECHNOLOGY
THE
DETERMINATION OF THE POTASH-ALKALI POTENTIALS OF EMPTY-OIL-PALM BUNCH (EOPB)
RESIDUES
A
FINAL YEAR PROJECT REPORT
PRESENTED
BY
OKWE VINCENT NYEBUCHI
U2008/5681372
SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENT
FOR THE AWARD OF BACHELOR DEGREE OF TECHNOLOGY IN INDUSTRIAL CHEMISTRY AND
PETROCHEMICAL TECHNOLOGY
APRROVAL PAGE
We
approval this project of OKWE
VINCENT NYEBUCHI as having satisfied the requirements of the School of Science Laboratory Technology,
University of Port Harcourt for the award of Bachelor of Technology (B.TECH)
degree in Industrial Chemistry and Petrochemical Technology.
___________________ ___________________
DR.,
Lucky, Uyigue. DR.,
Boma, Kinigoma.
Project supervisor Head
of Department
_____________________ _______________________
External
Supervisor
DEDICATION
This work is dedicated
to the Lord God almighty for the gift of life and wisdom and also to my Parent,
for all their care, support, and understanding throughout the duration of this
work.
ACKNOWLEDGEMENT
My sincere and deepest gratitude goes to the Lord
Almighty, the author and finisher of all things.
Special thanks go to my supervisor Dr. LUCKY UYIGUE,
whose creative intelligence guided me on the
course of this project. I also thank him for the diligent supervision of
this work. I am also very thankful to my lecturers for imparting knowledge to
me
In a very special way, my sincere and heartfelt
gratitude goes to my parents Mr
&Mrs. Victor Okwe for their encouragement throughout the various
stages of this work. Their parental care, patience and trust in my abilities
made my work a huge success.
My heartfelt gratitude goes to my siblings Chinedu.,
Chime; Ibekwe my lovely twin sister
Cynthia, victory, and Mr. and Mrs. Endurance Worlu.
I want to thank my lovely friends paschal, Daniel,
Sunny, Imoh, Eme, asuku ugbana who stood
as my brothers and sister all through the struggles.
also, lots of appreciation goes to all my pals Glory,
Awajimija, Tessy and my beloved Pst &Mrs kingsley Wordu, for their concern
and encouragement. A word of thanks also goes to Mr &Mrs Elechi Udochi A.
Your words made me stronger.
ABSTRACT
This study elucidated the chemical
composition of ash made from empty-oil-palm bunch (EOPB) residues. Measured
EOPB residues were subjected to pretreatment process such as drying and
incineration. This resulted to the formation of EOPB-ash, the ash was digested
in distilled water at 60c for 48hours amidst frequent agitation. The recovered
EOPB-ash extract was evaporated and dried to form the solid potash. An analyses
of the EOPB residues preparatory process showed moisture content 51.92%, dry
matter content 48.07% and ash content 7.27% also using the method of atomic
absorption spectrophotometer (AAS). The
results of chemical analyses on the
sample revealed that
it contains metals such as potassium 99.82%, sodium 0.10%, calcium 0.05%, lead 0.03% and trace of
other metals this results confirmed the potash-alkali potentials of the
empty-oil-palm bunch (EOPB)-ash. The potash-alkali content of the solid potash
was analyzed as KOH 37.07 g/dm3 and 
91.37% g/dm3
while its composition in the solid potash and EOPB-ash were- and- respectively.
CHAPTER 1
1.1 INTRODUCTION
The
oil palm is a tropical plant that grows in warm climates at altitudes below 500
meters above sea level. It comes
from the Gulf
of Guinea in
West Africa, which
explains its scientific name, Elaeis guineensis and
its popular name,
the African oil
palm. In Nigeria, oil palm is
widely grown and is a valuable economic crop that provides a source of
employment. It allows many small landholders to participate in the cash
economy. Oil palm is a major source of
edible oil which is extracted from fruits (Lua and Gua, 1998). However, palm
oil mills produce a large amount of solid wastes, the remainder of
the oil palm consists of
huge amount of
lignocellulosic materials
such as oil
palm fronds, trunks, palm
kernel and empty
oil palm bunches. The
residues contain 7.0 million
tonnes of oil
palm trunks, 26.2 million tonnes
of oil palm
fronds and 23% of
empty oil palm bunch (EOPB) per tonne of fresh fruit bunch (FFB), processed in oil palm mill. Palm oil is source of
income and is also used as food. Palm kernel produces palm kernel oil and palm
kernel shell when processed. The palm kernel oil is a source of income while
the palm kernel shell can be used as a source of heat energy. The leaves
are used for
the production of
brooms and for
the construction of local fence. The trunk can be used as fire wood and can
be sewn into planks for use in roofing. Empty oil palm bunch (EOPB) is one of
the byproducts left in the palm oil mil. This residue may cause environmental pollution
problems and spread diseases. Other researches stated that empty oil palm bunch
is a lignocellulosic source which is available as a substrate in cellulase
production (Akamatsu et al., 1987, Rajoka and Malik, 1997). The empty
oil palm bunch can also be used as local fertilizer. The ash
produced from empty
fruit bunches is sprayed on
crops to prevent insects from destroying the crops,
it is also used for washing of
plates and pots. The filtrate obtained from the filtration of
the mixture of this ash and water
normally has a brown colour can
emulsify oil, thus
producing an emulsion with
it. It is
slippery to touch, giving
an impression that
it is alkali.
also slippery to touch
just like soap, suggesting that
the reaction that produced
it may have been a
saponification reaction.
1.2 BACKGROUND
OF STUDY
Empty
oil palm bunch EOPB-ash extract, potash-alkali content
1.3 METHOD
OF STUDY
The
method of this study is using atomic absorption spectrophotometer (AAS) and
volumetric analysis the overall physicochemical analysis of the ash will not be considered.
1.4 OBJECTIVE
OF STUDY
The
main objectives of this study are to determine the potash-alkali potential of
the ashes obtained from empty oil palm bunch ( EOPB) residues
CHAPTER 2
2.0 LITERATURE
REVIEW
2.1 OIL
PALM INDUSTRY
Research
and development work in many disciplines - biochemistry, chemical and
mechanical engineering - and the establishment of plantations, which provided
the opportunity for large-scale fully mechanized processing, resulted in the
evolution of a sequence of processing steps designed to extract, from a
harvested oil palm bunch, a high yield of a product of acceptable quality for
the international edible oil trade. The oil winning process, in summary,
involves the reception of fresh fruit bunches from the plantations, sterilizing
and threshing of the bunches to free the palm fruits, mashing the fruit and
pressing out the crude palm oil. The crude oil is further treated to purify and
dry it for storage and export. (kwasi 2002).
Large-scale
plants, featuring all stages required to produce palm oil to international
standards, are generally handling from 3 to 60 tonnes of FFB/hr. The large
installations have mechanical handling systems (bucket and screw conveyers,
pumps and pipelines) and operate continuously, depending on the availability of
FFB. Boilers, fuelled by fibre and shell, produce superheated steam, used to
generate electricity through turbine generators. The lower pressure steam from
the turbine is used for heating purposes throughout the factory. Most
processing operations are automatically controlled and routine sampling and
analysis by process control laboratories ensure smooth, efficient operation.
Although such large installations are capital intensive, extraction rates of 23
- 24 percent palm oil per bunch can be achieved from good quality Tenera.
Conversion
of crude palm oil to refined oil involves removal of the products of hydrolysis
and oxidation, colour and flavour. After refining, the oil may be separated
(fractionated) into liquid and solid phases by thermo-mechanical means
(controlled cooling, crystallization, and filtering), and the liquid fraction
(olein) is used extensively as a liquid cooking oil in tropical climates,
competing successfully with the more expensive groundnut, corn, and sunflower
oils.
Extraction
of oil from the palm kernels is generally separate from palm oil extraction,
and will often be carried out in mills that process other oilseeds (such as
groundnuts, rapeseed, cottonseed, shea nuts or copra). The stages in this process
comprise grinding the kernels into small particles, heating (cooking), and
extracting the oil using an oilseed expeller or petroleum-derived solvent. The
oil then requires clarification in a filter press or by sedimentation.
Extraction is a well-established industry, with large numbers of international
manufacturers able to offer equipment that can process from 10 kg to several
tonnes per hour.
Alongside
the development of these large-scale fully mechanized oil palm mills and their
installation in plantations supplying the international edible oil refining
industry, small-scale village and artisanal processing has continued in Africa.
Ventures range in throughput from a few hundred kilograms up to 8 tonnes FFB
per day and supply crude oil to the domestic market.
Efforts
to mechanize and improve traditional manual procedures have been undertaken by
research bodies, development agencies, and private sector engineering
companies, but these activities have been piecemeal and uncoordinated. They
have generally concentrated on removing the tedium and drudgery from the
mashing or pounding stage (digestion), and improving the efficiency of oil
extraction. Small mechanical, motorized digesters (mainly scaled-down but
unheated versions of the large-scale units described above), have been
developed in most oil palm cultivating African countries. . kwasi (2002)Palm
oil processors of all sizes go through these unit operational stages. They
differ in the level of mechanization of each unit operation and the
interconnecting materials transfer mechanisms that make the system batch or
continuous. The scale of operations differs at the level of process and product
quality control that may be achieved by the method of mechanization adopted.
The technical terms referred to in the diagram above will be described later.
The
general flow diagram is as follows:
PALM OIL PROCESSING UNIT OPERATIONS
.
(FAO Corporate Document 2011)
2.1.1 PRODUCTION PROCESS
2.1.2 HARVESTING TECHNIQUE AND HANDLING EFFECTS
In
the early stages of fruit formation, the oil content of the fruit is very low.
As the fruit approaches maturity the formation of oil increases rapidly to
about 50 percent of mesocarp weigh. In a fresh ripe, un-bruised fruit the free
fatty acid (FFA) content of the oil is below 0.3 percent. However, in the ripe
fruit the exocarp becomes soft and is more easily attacked by lipolytic
enzymes, especially at the base when the fruit becomes detached from the bunch.
The enzymatic attack results in an increase in the FFA of the oil through
hydrolysis. Research has shown that if the fruit is bruised, the FFA in the
damaged part of the fruit increases rapidly to 60 percent in an hour. There is
therefore great variation in the composition and quality within the bunch,
depending on how much the bunch has been bruised. .
Harvesting
involves the cutting of the bunch from the tree and allowing it to fall to the
ground by gravity. Fruits may be damaged in the process of pruning palm fronds
to expose the bunch base to facilitate bunch cutting. As the bunch (weighing
about 25 kg) falls to the ground the impact bruises the fruit. During loading
and unloading of bunches into and out of transport containers there are further
opportunities for the fruit to be bruised. .
In
Africa most bunches are conveyed to the processing site in baskets carried on
the head. To dismount the load, the tendency is to dump contents of the basket
onto the ground. This results in more bruises. Sometimes trucks and push carts,
are unable to set bunches down gently, convey the cargo from the villages to
the processing site. Again, tumbling the fruit bunches from the carriers is
rough, resulting in bruising of the soft exocarp. In any case care should be
exercised in handling the fruit to avoid excessive bruising.
One
answer to the many ways in which harvesting, transportation and handling of
bunches can cause fruit to be damaged is to process the fruit as early as
possible after harvest, say within 48 hours. However the authors believes it is
better to leave the fruit to ferment for a few days before processing.
Connoisseurs of good edible palm oil know that the increased FFA only adds “bite” to the oil flavour. At worst, the
high FFA content oil has good laxative effects. The free fatty acid content is
not a quality issue for those who consume the crude oil directly, although it
is for oil refiners, who have a problem with neutralization of high FFA content
palm oil. 2.1.3 BUNCH RECEPTION
Fresh
fruit arrives from the field as bunches or loose fruit. The fresh fruit is
normally emptied into wooden boxes suitable for weighing on a scale so that
quantities of fruit arriving at the processing site may be checked. Large
installations use weighbridges to weigh materials in trucks.
The
quality standard achieved is initially dependent on the quality of bunches
arriving at the mill. The mill cannot improve upon this quality but can prevent
or minimize further deterioration.
The
field factors that affect the composition and final quality of palm oil are
genetic, age of the tree, agronomic, environmental, harvesting technique,
handling and transport. Many of these factors are beyond the control of a small-scale
processor. Perhaps some control may be exercised over harvesting technique as
well as post-harvest transport and handling. .
2.1.4 THRESHING (REMOVAL OF FRUIT FROM THE BUNCHES)
The
fresh fruit bunch consists of fruit embedded in spikelet’s growing on a main
stem. Manual threshing is achieved by cutting the fruit-laden spikelet’s from
the bunch stem with an axe or machete and then separating the fruit from the spikelet’s
by hand. Children and the elderly in the village earn income as casual
labourers performing this activity at the factory site. . In a mechanized system a rotating drum or
fixed drum equipped with rotary beater bars detach the fruit from the bunch,
leaving the spikelets on the stem
Most
small-scale processors do not have the capacity to generate steam for
sterilization. Therefore, the threshed fruits are cooked in water. Whole
bunches which include spikelet’s absorb a lot of water in the cooking process.
High-pressure steam is more effective in heating bunches without losing much
water. Therefore, most small-scale operations thresh bunches before the fruits
are cooked, while high-pressure sterilization systems thresh bunches after
heating to loosen the fruits.
Small-scale
operators use the bunch waste (empty bunches) as cooking fuel. In larger mills
the bunch waste is incinerated and the ash, a rich source of potassium, is
returned to the plantation as fertilizer. .
2.1.5 STERILIZATION OF BUNCHES
Sterilization
or cooking means the use of high-temperature wet-heat treatment of loose fruit.
Cooking normally uses hot water; sterilization uses pressurized steam. The
cooking action serves several purposes:
i.
Heat treatment destroys oil-splitting
enzymes and arrests hydrolysis and auto oxidization.
ii.
For large-scale installations, where
bunches are cooked whole, the wet heat weakens the fruit stem and makes it easy
to remove the fruit from bunches on shaking or tumbling in the threshing
machine.
iii.
Heat helps to solidify proteins in which
the oil-bearing cells are microscopically dispersed. The protein solidification
(coagulation) allows the oil-bearing cells to come together and flow more
easily on application of pressure.
iv.
Fruit cooking weakens the pulp
structure, softening it and making it easier to detach the fibrous material and
its contents during the digestion process. The high heat is enough to partially
disrupt the oil-containing cells in the mesocarp and permits oil to be released
more readily.
v.
The moisture introduced by the steam
acts chemically to break down gums and resins. The gums and resins cause the
oil to foam during frying. Some of the gums and resins are soluble in water.
Others can be made soluble in water, when broken down by wet steam
(hydrolysis), so that they can be removed during oil clarification. Starches
present in the fruit are hydrolyzed and removed in this way.
vi.
When high-pressure steam is used for
sterilization, the heat causes the moisture in the nuts to expand. When the
pressure is reduced the contraction of the nut leads to the detachment of the
kernel from the shell wall, thus loosening the kernels within their shells. The
detachment of the kernel from the shell wall greatly facilitates later nut
cracking operations. From the foregoing, it is obvious that sterilization (cooking)
is one of the most important operations in oil processing, ensuring the success
of several other phases.
vii.
However, during sterilization it is
important to ensure evacuation of air from the sterilizer. Air not only acts as
a barrier to heat transfer, but oil oxidation increases considerably at high
temperatures; hence oxidation risks are high during sterilization.
Over-sterilization can also lead to poor bleach ability of the resultant oil.
Sterilization is also the chief factor responsible for the discolouration of
palm kernels, leading to poor bleach ability of the extracted oil and reduction
of the protein value of the press cake.
2.1.6 DIGESTION OF THE FRUIT
Digestion
is the process of releasing the palm oil in the fruit through the rupture or breaking
down of the oil-bearing cells. The digester commonly used consists of a
steam-heated cylindrical vessel fitted with a central rotating shaft carrying a
number of beater (stirring) arms. Through the action of the rotating beater
arms the fruit is pounded. Pounding, or digesting the fruit at high
temperature, helps to reduce the viscosity of the oil, destroys the fruits’
outer covering (exocarp), and completes the disruption of the oil cells already
begun in the sterilization phase. Unfortunately, for reasons related to cost
and maintenance, most small-scale digesters do not have the heat insulation and
steam injections that help to maintain their contents at elevated temperatures
during this operation.
Contamination
from iron is greatest during digestion when the highest rate of metal wear is
encountered in the milling process. Iron contamination increases the risk of
oil oxidation and the onset of oil rancidity. .
2.1.7 PRESSING (EXTRACTING THE PALM OIL)
There
are two distinct methods of extracting oil from the digested material. One
system uses mechanical presses and is called the ‘dry’ method. The other called
the ‘wet’ method uses hot water to leach out the oil.
In
the ‘dry’ method the objective of the extraction stage is to squeeze the oil
out of a mixture of oil, moisture, fibre and nuts by applying mechanical
pressure on the digested mash. There are a large number of different types of
presses but the principle of operation is similar for each. The presses may be
designed for batch (small amounts of material operated upon for a time period)
or continuous operations.
2.1.8 CLARIFICATION AND DRYING OF OIL
The
main point of clarification is to separate the oil from its entrained
impurities. The fluid coming out of the press is a mixture of palm oil, water,
cell debris, fibrous material and ‘non-oily solids’. Because of the non-oily
solids the mixture is very thick (viscous). Hot water is therefore added to the
press output mixture to thin it. The dilution (addition of water) provides a
barrier causing the heavy solids to fall to the bottom of the container while
the lighter oil droplets flow through the watery mixture to the top when heat
is applied to break the emulsion (oil suspended in water with the aid of gums
and resins). Water is added in a ratio of 3:1.
The
diluted mixture is passed through a screen to remove coarse fibre. The screened
mixture is boiled from one or two hours and then allowed to settle by gravity
in the large tank so that the palm oil, being lighter than water, will separate
and rise to the top. The clear oil is decanted into a reception tank. This
clarified oil still contains traces of water and dirt. To prevent increasing
FFA through autocatalytic hydrolysis of the oil, the moisture content of the
oil must be reduced to 0.15 to 0.25 percent. Re-heating the decanted oil in a
cooking pot and carefully skimming off the dried oil from any engrained dirt
removes any residual moisture. Continuous clarifiers consist of three
compartments to treat the crude mixture, dry decanted oil and hold finished oil
in an outer shell as a heat exchanger.
The
wastewater from the clarifier is drained off into nearby sludge pits dug for
the purpose. No further treatment of the sludge is undertaken in small mills.
The accumulated sludge is often collected in buckets and used to kill weeds in
the processing area. . (FAO Corporate Document 2011)
In
large-scale mills the purified and dried oil is transferred to a tank for
storage prior to dispatch from the mill. Since the rate of oxidation of the oil
increases with the temperature of storage the oil is normally maintained around
50°C, using hot water or low-pressure steam-heating coils, to prevent
solidification and fractionation. Iron contamination from the storage tank may
occur if the tank is not lined with a suitable protective coating.
Small-scale
mills simply pack the dried oil in used petroleum oil drums or plastic drums
and store the drums at ambient temperature. .
The
residue from the press consists of a mixture of fibre and palm nuts. The nuts
are separated from the fibre by hand in the small-scale operations. The sorted
fibre is covered and allowed to heat, using its own internal exothermic
reactions, for about two or three days. The fibre is then pressed in spindle
presses to recover a second grade
(technical) oil that is used normally in soap-making. The nuts are usually
dried and sold to other operators who process them into palm kernel oil. The
sorting operation is usually reserved for the youth and elders in the village
in a deliberate effort to help them earn some income.
Large-scale
mills use the recovered fibre and nutshells to fire the steam boilers. The
super-heated steam is then used to drive turbines to generate electricity for
the mill. For this reason it makes economic sense to recover the fibre and to
shell the palm nuts. In the large-scale kernel recovery process, the nuts
contained in the press cake are separated from the fibre in a depericarper.
They are then dried and cracked in centrifugal crackers to release the kernels.
The kernels are normally separated from the shells using a combination of
winnowing and hydrocyclones. The kernels are then dried in silos to a moisture
content of about 7 percent before packing. During the nut cracking process some
of the kernels are broken. The rate of FFA increase is much faster in broken
kernels than in whole kernels. Breakage of kernels should therefore be kept as
low as possible, given other processing considerations. .
2.2.1 WASTE MATERIALS OF THE OIL PALM INDUSTRY
Oil
palm industry is facing challenges with
growing concern on environmental degradation as well as sustainable development
in agriculture. For one hectare of land constitute an average of 142 palm trees
and for one tree the oil constitutes only 10% of the total biomass. Hence
leaving 90% of the oil palm biomass during felling for replanting
or further land development activities. Currently, these felled palm trees
are being shredded and left in the field for mulching/soil regeneration
purposes. In the process of extraction crude palm oil (CPO) from 1000 kg
palm fresh fruit bunches will be produced 220 kg empty fruit bunches (EFB,
22-23 %), 120 kg mesocarp fiber, 70 kg endocarp and 30 kg palm kernel cake as
solid wastes, and 670 kg fluid waste as palm oil mill effluent (POME).(Ferisma
et..al and Danold et..al 2012) These both wastes have a potential usage as
compost (fertilizer) or mulch to improve soil conditions effectively . Oil Palm
Research Institute (OPRI) has developed a minimum waste concept in palm
oil processing which incorporate the production of compost from empty fruit
bunches. In this process, compost is produced by chopping EFB to small pieces
by a chopping machine then formed into heap in open air or roofed area for composting.
During the composting process POME was use for watering to keep the EFB
wet and after 6 to 8 weeks the compost is ready to use. This high quality
compost can be returned to plantation area or to be sold for horticulture
farm. ).(Ferisma et..al and Danold et..al 2012).
Indonesia
is amongst the world’s top producers of palm oil with the current planted area
is expanding to around 6.0 million hectares. Success of palm oil industry is
from the confluence of government and private sector strategies and policies.
In spite of the huge production, the oil consists of only about 10% of the
total biomass produced in the plantation. The remainder consists of huge
amount of oil. Oil palm wastes such as oil palm shells, mesocarp fibers and empty
fruit bunch (from the mills) and oil palm fronds and oil palm trunk (from the
field during replanting). At the palm oil mill, the sterilized fresh fruit
bunches go through a threshing process to separate the fruit nuts. .(Ferisma
et..al and Danold et..al 2012) The emptied
fruit bunch mainly consists of a main stalk (20 – 25%) and numerous
spikelets (75 – 80%) with sharp spines at their tips. Basically, the
oil palm biomass contains about 18 – 21% of lignin, and 65-80% of
holocellulose (a-cellulose and hemicelluloses), which are more or less
comparable with that of other wood or lignocellulosic materials. This
makes the oil palm biomass is also suitable as a raw material for the
production of pulp and paper, composites, carbon products and chemicals
extraction. A palm oil plantation yields huge amount of biomass wastes in the
form of empty fruit bunches (EFB), palm oil mill effluent (POME) and palm
kernel shell (PKS). ).(Ferisma et..al and Danold et..al 2012) In a typical palm oil mill, empty fruit
bunches are available in abundance as fibrous material of
purely biological origin. EFB contains neither chemical nor mineral
additives, and depending on proper handling operations at the mill, it is
free from foreign elements such as gravel, nails, wood residues, waste etc. However,
it is saturated with water due to the biological growth combined with the steam
sterilization at the mill. Since the moisture content in EFB is around67%,
pre-processing is necessary before EFB can be considered as a good fuel.
Currently, recovery of renewable organic-based product is a new approach in
managing POME. The technology is aimed to recover by-products such as volatile
fatty acid, biogas and poly-hydroxyalkanoates to promote sustainability of
the palm oil industry. .(Ferisma et..al and Danold et..al 2012) It is envisaged that POME can be sustainably
reused as a fermentation substrate in production of various metabolites through
biotechnological advances. In addition, POME consists of high organic acids and
is suitable to be used as a carbon source. Palm Oil processing gives rise to
highly polluting waste-water, known as Palm Oil Mill Effluent (POME), which is
often discarded in disposal ponds, resulting in the leaching
of contaminants that pollute the groundwater and soil, and in the release
of methane gas into the atmosphere. POME is an oily wastewater generated by
palm oil processing mills and consists of various suspended components. This
liquid waste combined with the wastes from sterilizer condensate and
cooling water is called palm oil mill effluent (POME). .(Ferisma et..al and
Danold et..al 2012) On average, for each
ton of FFB (fresh fruit bunches) processed, a standard palm oil mill generate
about 1 tone of liquid waste with biochemical oxygen demand (BOD) 27 kg,
chemical oxygen demand(COD) 62 kg, suspended solids (SS) 35 kg and oil and
grease 6 kg. POME has a very high Biochemical Oxygen Demand (BOD) and Chemical
Oxygen Demand (COD), which is 100times more than the municipal sewage. POME is
a non-toxic waste, as no chemical is added during the oil extraction process,
but will pose environmental issues due to large oxygen depleting capability in
aquatic system due to organic and nutrient contents. The high organic matter is
due to the presence of different sugars such as arabinose, xylose, glucose,
galactose and manose. .The suspended solids in the POME are mainly oil-bearing
cellulosic materials from the fruits. Since the POME is non-toxic as no
chemical is added in the oil extraction process, it is a good source of
nutrients for microorganisms. Anaerobic digestion is widely adopted in the
industry as a primary treatment for POME. Biogas is produced in the processing
the amount of 20m3 per ton FFB. This effluent could be used for biogas
production through anaerobic digestion. At many Palm-oil mills this process is
already in place to meet water quality standards for industrial effluent. The
gas, however, is flared off. .(Ferisma et..al and Danold et..al 2012)
2.2.2 SOURCE OF FUEL
There
is a large potential of transforming EFB into renewable energy resource that could
meet the existing energy demand of palm oil mills or other industries.
Pre-treatment steps such as shredding/chipping and dewatering (screw pressing
or drying) are necessary in order to improve the fuel property of EFB.
Pre-processing of EFB will greatly improve its handling properties and reduce
the transportation cost to the end user i.e. power plant. Under such
scenario, kernel shells and mesocarp fibres which are currently utilized for
providing heat for mills can be relieved for other uses off-site with higher
economic returns for palm oil millers. The fuel could either be prepared by the mills
before sell to the power plants, or handled by the end users based on
their own requirements. Besides, centralized EFB collection and pre-processing
system could be considered as a component in EFB supply chain. It is evident
that the mapping of available EFB resources would be useful for EFB resource
supply chain improvement. This is particular important as there are many different
competitive usages. With proper mapping, assessment of better logistics and EFB
resource planning can lead to better cost effectiveness for both supplier
and the user of the EFB. . As fossil
fuel is depleting, there is an urgent need to exploit any type of biomass as
renewable sources by converting them to various transportable forms of green
fuels. Technologies to transform biomass into bio energy vary from normal combustion
to thermal processes requiring higher temperature and pressure such as pyrolysis
and gasification. Pyrolysis is a thermal decomposition process that occurs at
moderate.(Ferisma et..al and Danold et..al 2012)
2.3.1 ALKALI
Alkali
refers to a soluble base, usually the hydroxide or carbonate of potassium or
sodium. Locally, it could be produced from ashes by extraction with water, when
produced this way, it is usually referred
to as potash, it is generally
believed that the highest soluble metal is potassium,
though this depends on the species of
the plant material and the type
of soil where the plant grown, in previous
works on plant materials, Taiwo and Osinowo (2001), Kevin (2002) and
Afrane (1992) reported that the alkalis from the ash were mainly carbonate of potassium and sodium. In
the work of Onyegbado et.. .al (2002), Nwoko (1980), Onyekwere (1996) and kuye and okorie (1990), it was reported
that the alkalis were hydroxides of
potassium and sodium, Adewuyi et..al (2008), confirmed that the alkalis were mainly carbonates of sodium and potassium it could be observed that the
soluble minerals in ashes is not always mainly alkali, high potash
content may yield very low alkali, depending on the sources of the ashes
2.3.2 CAUSTIC ALKALI
Caustic
alkali refers to alkali which major source is from metals like carbonate and
calcium
2.3.3 POTASH
Potash
is the common term for fertilizer forms of the element potassium (K). The name
derives from the collection of wood ash in metal pots when the beneficial
fertiliser properties of this material were first recognised many centuries
ago.
2.3.3.1 Potash in Nature
Potassium
occurs abundantly in nature. It is the 7th most common element in the earths
crust. Certain clay minerals associated with heavy soils are rich sources of K,
containing as much as 17% potash. Sea water typically contains 390 mg/l K
representing a huge total amount of the element globally. Small quantities of K
naturally occur in rain - up to 4 ppm. Large potash bearing rock deposits occur
in many regions of the world deriving from the minerals in ancient seas which
dried up millions of years ago. Most potash for fertiliser is derived from one
of these potash rocks, sylvinite, requiring only separation from the salt and
other minerals and physical grading into a form suitable for fertiliser
manufacture or farm spreading.
2.3.3.2 Functions of potash
Potassium
fulfils many vital functions in a wide variety of processes in plants, animals
and man. It is typically taken-in in greater quantities than required and
surpluses are naturally excreted. This process occurs in animals & humans
via the kidneys and urine and in plants by the return of potash in senescent
tissue at the end of each season - leaves from trees, cereal stubble and roots,
etc. K is therefore naturally recycled widely and in large quantities. Soil
reserves are an essential requirement for adequate nutrient supply of K to
plants which commonly contain more potassium than any other nutrient including
nitrogen
2.4.1 ASH
Ash
is a powdery residue left after burning also an ash is a by product of combustion obtained primarily
from the open burning of combustible materials such as biomass
2.4.2 SYNTHETIC PRODUCT ASH
This
referred to synthetic product from polymeric material like rubbers, plastic and
fly ashes which are gotten when this material are burnt, typically from any
kind of thermal installation two main kinds of ashes emerges. Bottom ashes
gotten below the fire and fly ashes removed from the flue gases
BOTTOM
ASHES are mostly used in building
products, in particular road construction due to low nutrient content while for
fly ash the situation is more difficult
2.4.3 BIOMASS ASH
Oil
palm tree (Elaeis guineensis) originated from the tropical rain forests of West
Africa. It was introduced into Malaysia in 1870 through the Singapore Botanic
Gardens as an ornamental tee. When its commercial value was realized, it was
grown in plantations. Palm oil from the fruit is an important export commodity
for Malaysia. The commodity is exported in the form of crude palm oil (CPO) and
palm kernel oil (PKO). Palm oil is the second Gross National Income (GNI) of
Malaysia after electronics with a total contribution of RM52.7 billion
annually. The worldwide production of palm oil is about 4.3 million tons in
2008 (USDA statistics) making them the most produced plant oil with Malaysia
and Indonesia accounting for approximately 88% of the worldwide production
(USDA statistics). Today, there is about 4.96 million ha total land planted
under oil palm which represents about 14% of the total land area. For one
hectare of land constitute an average of 142 palm trees (Husin, 2000). For one
tree the oil constitutes only 10% of the total biomass. Hence, leaving 90% of
the oil palm biomass during felling for replanting or further land development
activities. Currently, these felled palm trees are being shredded and left in
the field for mulching/soil regeneration purposes.
The
major part of oil palm tree is trunk which comprise of about 70% of the total
weight. The outer part of this oil palm
trunk (OPT) is partially utilized for plywood manufacturing. The inner part
which is not strong enough for use as lumber was discarded in large amounts.
The sap that can be extracted from waste oil palm trunk (Waste Oil Palm Trunk
Sap - WOPTS) has a significant amount of fermentable sugar comparable to those
usually obtained from sugar cane (Yamada et al., 2010).
Ash
source: Ash is sourced from various materials. Several agro-wastes of vegetable
origin have been shown to yield high potash when combusted. These materials
include plantain peel, cocoa-pod husk, palm bunch and wood (Edewor,
1984).
Traditional folks who major in the production of potash as a trade, especially
for the production of local soap, either collect the ashes from wood industries
where mixed sawdust of various species of wood as a waste is combusted, or from
houses as domestic ash waste from combustion of firewood. It is very important
to know that the plant material determines the potash yield. The process of
combustion also contributes to the quality and quantity of ashes and
consequently the quality and quantity of potash. When the vegetable materials
are combusted slowly and at low temperature, the materials are not totally
combusted to ashes; some black particles and some particles not combusted at
all may be observed. These may impart colour to the extracted potash. Hence,
most potash produced traditionally is usually coloured brown. To show an
improvement in combustion, some experts have used special combustion pans;
however, combustion in a temperature-controlled furnace could give the best
result because there will be a fast and complete combustion.
2.4.4 APPLICATION OF BIOMASS ASH
Palm oil production is on a steeply rising
path. The empty fruit bunches (EFB) are waste by-products that are being
investigated for further uses. Currently, palm oil mills typically use the
shell and the drier part of the fibre product stream, rather than EFB, to fuel
their boilers, as the raw EFB contain nearly 60% water.1
Fast
pyrolysis represents a potential route to upgrade the EFB waste to value added
fuels and renewable chemicals. For example, the pyrolysis of woody feedstock at
temperatures around 500ºC, together with short vapour residence times, will
produce bio-oil yields of around 70% and char and gas yields of Characterisation
of Oil Palm EFB 2 around 15% each.2–4 Bio-oil is a high-density oxygenated
liquid, which can be burned in diesel engines, turbines or boilers, though
further work is still required to evaluate the long-term reliability.5 It is
also used for the production of speciality chemicals, such as flavourings,
which are the main products. N. Abdullah1 et al 2011. Renewable resins and slow
release fertilisers are other potential applications, which have been the
subject of research.6 At this stage, fast pyrolysis is a novel and relatively
untested technology. There are several pilot plants in North America and
Europe, but there is no consistent track record yet outside of the manufacture
of flavourings. N. Abdullah1 et al 2011
2.5.1 ENCYCLOPEDIA REVIEW OF PREVIOUS WORK
Potash
has been described as a white crystalline residue that remains after aqueous
extract from ashes is evaporated (Kevin,
2003).
It is an impure form of potassium carbonate mixed with other potassium salts (Wikipedia,
2007).
The production and use of potash date from the ancient times in several
countries of the world. It was first used in crude way as a domestic cleansing
agent (Nwoko,
1980)
by using ashes mixed with water to wash oil-stained materials. Potash has found
a considerable use in Africa and Nigeria in particular, from the primitive till
date (Onyegbado
et al., 2002). There had been trades in potash (Townships
Heritage WebMagazine, 2002); used as active ingredient in the
production of local soap (Taiwo
and Osinowo, 2001) and a useful raw material for some
potash-based industries. With time, improvement in its production gave rise to
extraction with water, which some times was boiled down or concentrated by
evaporation. If the concentrated solution is left for some days, some crystals
could be observed growing either on the wall of the container, or as a layer on
the solution, or settling at the bottom of the container
2.5.2 Potash content:
2.5.2
Wood ash: Studies of chemical
composition of wood ash in the past have primarily
been restricted to the elemental composition (Baker
et al., 1964) because the focus had always been on
agricultural application of wood ash in which it was used as a liming agent and
as a source of nutrients for agricultural plants (Campbell,
1990).
Analysis of extracts from ashes by Nwoko
(1980) and others (Onyegbado
et al., 2002; Onyekwere,
1996;
Kuye
and Okorie, 1990) showed that the extract was chiefly
potassium hydroxide with some quantities of sodium hydroxide, while other
metallic ions constituting about 2% were Ca2+, Cr2+, B3+, Zn2+, Fe3+, Pb2+ and
Ni2+. Naik
et al. (2003) tested different sources of wood ash
from USA and Canada; the major elements in the wood ashes tested were carbon (5
to 30%), calcium (7 to 33%), potassium (3 to 4%) and sodium (0.2 to 0.5%).
CHAPTER 3
3.1 Materials
and method
3.2 MATERIALS
AND SAMPLE COLLECTION
The
main material used for this work is the empty-oil-palm-bunch (EOPB) residues were obtained
from a palm
oil mil at Omuike -Aluu in
Ikwerre Local government area of Rivers
State.
3.2.1 PREPARATION OF SAMPLE
4253.3g ( 
) sample of EOPB
residues were sun-dried for 5 weeks over an average daily sunshine duration of
6 hours by routinely re-exposing the inside and outside of the bunches to sunlight.
The EOPB residues sample was again re-weighed ( 
)
3.2.2 DETERMINATION OF MOISTURE CONTENT (MC), DRY MATTER CONTENT (DM)
calculation
were carried out as follows:
Where
MC and DM are respectively the percentage moisture and dry matter content of
the EOPB residues sample. also ( ) and ( ) are respectively
the gram weight of the EOPB residues
sample before and after drying
3.2.3 EXTRACTION OF ALKALI
2044.6g
sample of sun-dried EOPB residues were placed on a flat
metal pan which was inserted into a muffle furnace and the EOPB residues
were burnt at furnace operating
temperature of 450c, the burning process lasted for 4 hour, after which the
furnace was allowed to cool to room temperature for another 3 hour
3.2.4 ASH CONTENT (AC), LOSS IN WEIGHT (LW)
After
cooling the weight (
) of the ash residues
was determined the ash content was calculated using the following Relationship.
Where,
(
) and () are the weight before
and after burning the EOPB residues sample.
Furthermore
110g of the recovered ash was poured into a clean 2 liter plastic container
while 1 liter distilled water was added amidst vigorous agitation. The
container was then covered and kept in a constant temperature water bath order
to allow its ash-water mixture to digest for 48 hours while the mixture was
stirred on an intermittent basis the mixture was then filtered repeatedly with
the aid of ash less filter paper to recover a measured volume of alkali extract
of a brown coloration, slippery-to-touch and viscous consistency
3.2.5 CHEMICAL COMPOSITION ANALYSIS
The
EOPB-ash obtained from this work and its extract was subjected to some chemical
composition analysis
3.2.6 ANALYSIS OF INORGANIC ELEMENTS (METAL CONTENT)
1g
of sample was weighed and placed in a
beaker 30ml of 1:1 HN
(10ml + water + 10ml concentrated HN) were added and boiled gently on a hotplate until the volume
was reduced to approximately 5ml while stirring. A further 10ml of 1:1 HN were added and the process repeated, it was
cooled and the extract filtered through
a whatman no 41 paper, and the filter
paper and beaker were washed with successive 0.25M HN portions the filtrate was transferred to a
50ml volumetric flask and diluted to the mark with de-ionized water, A blank solution of distilled water containing no ash was also prepared, while
standard solution of metals to be analyzed for were equally prepared the sample was analyzed by atomic absorption
spectroscopy (AAS) G.B.C Avanta
3.2.7 POTASH CONTENT
500ml
of the EOPB-ash extract was measured into a 1 liter capacity beaker the extract
was slowly heated to about 100c using a heating mantle, this resulted to
the evaporation of about ¾ of its water volume. The resulting extract was
cooled and further reheated to a dry crystallized solid, the recovered solid
was again weighed while the potash
content was estimated based on this equation
Were
(
) is the weight of solid potash, PCA is the
potash content with respect to ash and PCP is the potash content with respect
to dry EOPB residues
3.2.8 ANALYSIS OF CARBONATE AND HYDROXIDE CONTENT
(POTASH-ALKALI CONTENT)
5g
of the crude potash were dissolved in water and made up to mark in a 250ml
standard flask. A double-indicator method was used in the acid-base titration
analysis of the mixture alkali hydroxide and carbonate (ojokuku 2001), 10ml
of the sample solution was pipette into
conical flask, 2 drop of the phenolphthalein indicator was added and the
mixture was titrated with 0.1m HCL until a colourless solution was obtained at
that point the whole of the hydroxide and
half of the carbonate had been
titrated giving a burette reading (
) the equation of the
reaction is as shown below
HCL(aq)+
KOH(aq) →KCL(aq)+ 
O (L)
HCL(aq)+
(aq)
KCL(aq) + KHC(aq)
Methyl
orange was added to the resulting colourless solution and titrated until the
colour changed from yellow to orange, at that point, the remaining bicarbonate was neutralized by the
Acid the burette reading now becomes (
)the equation of
the reaction is as follows
HCL(aq)
+ KHC(aq)KCL(aq) +O(L)+C
The
corresponding endpoint volume of HCL was a mean of three different reading
The
concentration of KOH and were respectively measured based on the
equations belows
CKOH 
=
56
C =
CKHC =
Where
CKOH , C and CKHC concentration of KOH, and KHC g/dm3 , = mean endpoint volume of HCL for KOH and neutralization cm3, - = mean end point volume of HCL for KHC neutralization the amount of impurities in the
solid potash was estimated by subtracting the concentration of potash solution
from that of KOH and
CHAPTER 4
4.1 DISCUSSION
OF RESULTS
The
results obtained from the research work are presented in the tables below. The
empty-oil-palm-bunch (EOPB) residues collected from a local oil mill in Omuike
Aluu in Rivers State were subjected to preparatory treatments, drying and
incineration. The analysis of the result
obtained from these treatment as show in Table 1 is presented as follows
Moisture content (MC) 51.92%, Dry matter content(DM):48.07%, Ash content (AC):
5.38%, loss in weight (LW): 94.61% and potash content (in dry matter) :0.39%
and potash content( in EOPB ash): 7.27% . these result infer strongly that
the fresh EOPB residues contained a
large amount of moisture while the
potash content in its dried and ash
residues varied widely from each other which implied a lesser potash contents
in its dried EOPB residues than in the
ash
Table 1: Showing
physical parameter of Empty-Oil-Palm Bunch (EOPB)
residues.
|
PARAMETERS
|
VALUE
|
|
Moisture
content MC
|
51.92
|
|
Dry
matter content DM
|
48.07
|
|
Ash
content AC
|
5.38
|
|
Loss
in weight LW
|
94.61
|
|
Potash content
Dried
EOPB
EOPB
ash
|
0.39
7.27
|
From
the results of the physical parameters, one may infer that EOPB residues share
similar characteristics with hardwood and agro waste biomass (bingh 2004)
EOPB- ASH EXTRACT ANALYSIS
The EOPB-ash was analyzed using the method of
atomic absorption spectroscopy(AAS) the result obtained from this method showed the presence of several metals having different absorbance and relative concentration Table 2, potassium,
sodium, calcium and lead respectively had the
highest concentration as follows: 99.82, 0.10, 0.05 and 0.03% .this
result confirmed the potash alkali potentials of EOPB ash also this result is
however a strong indication that
potassium metal is highly evident in EOPB-ash, this inference share similar characteristics by
the work of manhendral et al (1993) Onyegbado et.al (2002) and uyigue et.al
2013 wherein the analysis of different
wood ashes and agro-waste biomass ashes shared high concentration of
potassium.
Table 2: Showing metalic content of Empty-Oil-Palm
Bunch EOPB-Ash using atomic absorption Spectroscopy (AAS).
|
METAL
|
ASORBANCE
|
CONCENTRATION
IN ASH EXTRACT
|
|
|
|
(g/dm3)
 103
|
Percentage
(%)
|
|
Potassium
|
0.715
|
6274
|
99.82
|
|
Sodium
|
1.189
|
6.31
|
0.10
|
|
Calcium
|
0.033
|
1.97
|
0.05
|
|
Magnesium
|
0.344
|
0.52
|
0.00
|
|
Lead
|
0.014
|
1.13
|
0.03
|
|
Iron
|
0.021
|
0.24
|
0.00
|
|
Zinc
|
0.025
|
0.16
|
0.00
|
|
Copper
|
0.019
|
0.14
|
0.00
|
|
Cadmium
|
0.040
|
0.59
|
|
|
|
|
6285.06
|
100.00
|
POTASH ALKALI CONTENT IN Empty-Oil-Palm
Bunch (EOPB-ASH) EXTRACT
From
the preparatory know fact on the content
of the potash solution were first
deduced from its evident pink coloration
due to the initial addition of phenolphthalein indicator, showing the presence
of hydroxide and carbonates, while the
yellow coloration of the titrate evident in the second titration with
methyl-orange as indicator showing the presence
of bicarbonates.
The
actual concentrations of the potashes ( ie KOH and ) in the EOPB-ash
extract were measured using the double-indicator titration method, wherein
0.1MHCL was titrated against a diluted
solution of solid potash the endpoint volumes of HCL in the first and second titration were respectively
165.5 and 38.5cm3 given rise to a total potash-alkali concentration in the
solid potash as 128.43g/dm3 and distributed as 37.07 and 91.36g/dm3 for KOH and
respectively (Table3. Also note that
quantitative estimates of potash-alkali in the
solid potash and EOPB-ash were given as
and respectively the remaining portions were impurities. The results of the
endpoint volume of acid for titration in relation to the potash-alkali
concentration were confirmed by the works of Islam 2010 and Uyigue 2013 where
in they complement the presence of hydroxide and carbonates in potash solution
to the endpoint volumes of the acid for titration in it, the presence of
hydroxide and carbonates were identified based on the endpoint volume of acid
in the first titration being greater than that in the second titration.
The
purity level of_ obtained for solid potash relative to its potash-alkali
content was confirmed by the works of Taiwo et.al 2008 and Uyigue et.al 2013
wherein a purity level for potash-alkali of not less than 85% was recommended
as the appropriate concentration of potash- alkali
Table
3: Showing results for MEAN
ENDPOINT VOLUME AND POTASH-ALKALI CONTENT OF Empty-Oil-Palm Bunch EOPB-ASH
USING DOUBLE-INDICATOR TITRATION METHOD
|
Parameters
|
Value
|
Mean endpoint volume of HCL for KOH
and neutralization cm3
|
165.5
|
Mean endpoint volume of HCL for KHC neutralization cm3
|
38.5
|
|
Potash-Alkali content
KOH content g/dm3
content g/dm3
KHCcontent g/dm3
|
37.07
91.37
50.8
|
|
Quantitative estimate of potash-
Alkali
In solid
In EOPB-ash
|
|
CHAPTER 5
5.0 SUMMARY,
CONCLUSION AND RECOMMENDATION
5.1 CONCLUSION
Based
on the results obtained from this work,
the empty-oil-palm-bunch (EOPB) ASH are confirmed to have potash-alkali potential and source of
high purity potash alkali, the KOH and are the predominate consitutents of the
empty-oil-palm-bunch residues
5.2 RECOMMENDATION
1. I
recommend that a follow-up study to this project work should be carried out.
2. I
recommend that
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