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Chemical engineering Thesis and Dissertations
2018
Antimicrobial solid soap production
Mequanint, Gashanew
http://hdl.handle.net/123456789/11103
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Antimicrobial solid soap production
BiT 5TH-CHED Thesis project Page i
Declaration
We declare that the final thesis project is the production of antimicrobial solid soap from the
blending of castor oil and beef tallow in partial fulfillment of the requirements for the degree
of Bachelor of Science in chemical engineering. We have satisfactorily completed this thesis
project.
This is approved by our academic adviser Mr. Natnael Girma as a supervisor of the
experimental works. And also we certify that this thesis project is carried out under our
supervision to the best of our knowledge.
Adviser name:
Mr. Natnael Girma Date …………..
Signature ……....
Name of students:
1. Gashanew Mequanint Date …………..
Signature ……..
2. Habtamu Argew Date ………….
Signature …….
3. Habtamu Tilahun Date ………….
Signature …….
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Acknowledgement
In the successful accomplishment of this project, many people have best owned upon us their
blessing and the heart pledged support, this time we are to thank all the people who have been
concerned with this thesis project.
Primarily we would thank God for being able to complete this project with success. Then we
would like to thank our advisor Mr. Natnael Girma, whose valuable continuous guidance has
helped us for the completion of thesis project and make it full proof success. And also the
continuous support of our adviser makes us to implement this thesis project with the given
period of time.
Then we would like to thank our parents and friends who have helped as with their valuable
suggestions and guidance has helpful in various phases of the completion of the project.
Lastly, we would like to thank our classmates and laboratory assistants, who have helped us
for the end up of this thesis project.
And also we would like to thank Bahir Dar university faculty of chemical and food
engineering that helped us by giving necessary information’s and materials, starting from the
raw material for this thesis project.
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Abstract
Antimicrobial solid soap as the name implies, product designed to kill germs on the hands or
body, soap in solid form and it has antimicrobial properties. It is a cleansing agent and also
it is a multipurpose cleanser. The production of antimicrobial solid soap from the mixing of
animal fat and castor oil, through serious of main production steps, those are saponification,
glycerin removal, soap purification, finishing with different ratio fats and castor oil. During
the production process the ratio which is 50:50, 25:75 and 0:100 percent of castor oil and fat
was taken respectively. The specific parameters of the product, percent inhibition of bacterial
growth, specific gravity, hardness, foam length, power of clearance, yield of soap and,
moisture content of solid soap, was characterized. The following results were obtained,
percent inhibition of growth of bacterial 31.1%, specific gravity 0.97, hardness 1cm, foam
length 7.75 cm, power of clearance relatively good & higher, yield of soap 40%, moisture
content 17% and the alkalinity of solid soap is about 8.6 and also from this experiment the
eucalyptus oil have been extracted and characterized, specifically boiling point (0 c), specific
gravity, refractive index at 200c, dynamic viscosity at room temperature (pa.s) and yield of
the extracted oil with the values 155.30c, 0.952, 1.338, 0.0009 pa.s and 20% respectively.
The product characteristics were compared with other commercial (roha) antimicrobial
soaps and the product is found to have relatively equivalent characteristics to that of the
commercial soap. Finally best result in production of antimicrobial soap was obtained with
physical characteristics of medium softness and odor at the ratio of 25% of castor oil, 75% of
animal fat and 3% of eucalyptus oil in order to produce 50 gram of antimicrobial solid soap.
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CONTENTS
Declaration .................................................................................................................................. i
Acknowledgement ..................................................................................................................... ii
Abstract .................................................................................................................................... iii
List of figure ............................................................................................................................ vii
List of table ............................................................................................................................ viii
List of abbreviation ................................................................................................................... ix
CHAPTER ONE ........................................................................................................................ 1
1. Introduction ............................................................................................................................ 1
1.1 Background ...................................................................................................................... 1
1.2 Problem of statement ....................................................................................................... 4
1.3 Objectives ........................................................................................................................ 5
1.3.1 General objective ...................................................................................................... 5
1.3.2 Specific objectives .................................................................................................... 5
1.4 The scope and limitation of the project............................................................................ 6
1.4.1 Scope of the project .................................................................................................. 6
1.4.2 Limitation of the project ........................................................................................... 6
CHAPTER TWO ....................................................................................................................... 7
2. Literature Review................................................................................................................... 7
2.1 History of beef tallow ...................................................................................................... 8
2.2 History of castor oil ......................................................................................................... 9
2.3 History of eucalyptus oil ................................................................................................ 10
2.4 The chemistry of soap .................................................................................................... 10
2.4.1Soap manufacturing process .................................................................................... 12
CHAPTER-THREE ................................................................................................................. 15
3. Material and Methods .......................................................................................................... 15
3.1 Equipment’s used ........................................................................................................... 15
3.2 Chemical’s used ............................................................................................................. 15
3.3 Experimental works ....................................................................................................... 16
3.3.1 Raw material collection .......................................................................................... 16
3.3.2 Treatment of beef tallow ......................................................................................... 16
3.3.3 Deodorization .......................................................................................................... 18
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3.4 Extraction of eucalyptus oil ........................................................................................... 18
3.4.1 Collection of eucalyptus leaves .............................................................................. 18
3.4.2 Drying of eucalyptus leaves .................................................................................... 19
3.4.3 Size reduction of leaves .......................................................................................... 20
3.4.4 Soxhlet extraction ................................................................................................... 20
3.4.5 n-hexane recovery ................................................................................................... 21
3.5 Characterization of eucalyptus oil ................................................................................. 21
3.5.1 Determination of refractive index ........................................................................... 21
3.5.2 Determination of viscosity ...................................................................................... 22
3.5.3 Determination of specific gravity ........................................................................... 22
3.5.4 Determination of yield ............................................................................................ 22
3.5.5 Determination of boiling point................................................................................ 23
3.6 Antimicrobial solid soap production .............................................................................. 23
3.7 Characterization of the product ...................................................................................... 25
3.7.1 Determination of moisture content ......................................................................... 25
3.7.2 Foam ability test ...................................................................................................... 25
3.7.3 PH analysis.............................................................................................................. 26
3.7.4 Hardness test ........................................................................................................... 27
3.7.5 Power of clearance test ........................................................................................... 27
3.7.6 Determination percent inhibition of microbial growth ........................................... 28
3.7.7 Determination of specific gravity ........................................................................... 30
3.7.8 Determination of yield of the product ..................................................................... 31
CHAPTER FOUR .................................................................................................................... 32
4. Feasibility study ................................................................................................................... 32
4.1 Plant capacity and production process ........................................................................... 34
4.2 Material balance ............................................................................................................. 35
4.3 Energy balance on major equipment’s ........................................................................... 38
4.4 The size of major equipment.......................................................................................... 41
4.5 Estimation of total capital investment............................................................................ 47
4.6 Estimation of total production cost ................................................................................ 48
4.7 Production cost............................................................................................................... 53
4.8 Break Even Analysis ...................................................................................................... 53
4.9 Gross income ................................................................................................................. 54
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4.10 Rate of return ............................................................................................................... 55
4.11 Payback period ............................................................................................................. 55
CHAPTER FIVE ..................................................................................................................... 56
5. Plant Location & Site Selection ........................................................................................... 56
5.1 Plant Location and Site Location ................................................................................... 56
5.2 Plant Layout ................................................................................................................... 56
CHAPTER SIX ........................................................................................................................ 58
6. Result and Discussion .......................................................................................................... 58
CHAPTER SEVEN ................................................................................................................. 69
7. Conclusion and Recommendation ....................................................................................... 69
7.1 Conclusion ..................................................................................................................... 69
7.2 Recommendation ........................................................................................................... 70
Reference ................................................................................................................................. 71
Appendix .................................................................................................................................. 72
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List of figure
Fig 1 Process flow diagram of soap production....................................................................... 14
Fig 2 Raw beef tallow .............................................................................................................. 16
Fig 3 Pre-treatment of beef tallow ........................................................................................... 17
Fig 4 Melting of beef tallow .................................................................................................... 17
Fig 5 Beef tallow fat after refrigerate ...................................................................................... 17
Fig 6 Deodorizing of pure fat by melting again and again ...................................................... 18
Fig 7 Fresh leaves of eucalyptus tree ....................................................................................... 19
Fig 8 Drying of leaves using oven ........................................................................................... 19
Fig 9 Size reduction of leaves .................................................................................................. 20
Fig 10 Oil extraction using soxhlet .......................................................................................... 21
Fig 11 Determination of refractive index of the oil ................................................................. 21
Fig 12 Viscosity determination of eucalyptus oil .................................................................... 22
Fig 13 Measurement of boiling point....................................................................................... 23
Fig 14 Antimicrobial solid soap preparation ........................................................................... 24
Fig 15 Moisture content determination of the product ............................................................ 25
Fig 16 Determination of foam length ....................................................................................... 26
Fig 17 Alkalinity determination ............................................................................................... 26
Fig 18 Hardness test ................................................................................................................. 27
Fig 19 Power of clearance test ................................................................................................. 28
Fig 20 Media for the bacterial growth ..................................................................................... 29
Fig 21 Applying of different concentration of soap on the bacterial media ............................ 29
Fig 22 Determination percent inhibition of microbial growth ................................................. 30
Fig 23 Specific gravity determination ...................................................................................... 31
Fig 24 Soap production process flow diagram ........................................................................ 34
Fig 25 Plant layout ................................................................................................................... 57
Fig 26 Effect of time on the foam length of soap .................................................................... 60
Fig 27 Effect of beef fat on the hardness of soap .................................................................... 61
Fig 28 Hardness comparison of soaps ..................................................................................... 62
Fig 29 Effect of antimicrobial soap on bacteria ....................................................................... 64
Fig 30 Comparison of anti-microbial activity .......................................................................... 65
Fig 31 Comparison of alkalinity .............................................................................................. 66
Fig 32 Effect of eucalyptus oil ................................................................................................. 67
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List of table
Table 1 Percentage amount of oil and fat for soap making ..................................................... 24
Table 2 Supply of laundry soap (tones) ................................................................................... 33
Table 3 Mass balance on dryer ................................................................................................ 41
Table 4 Estimation of FCI and TCI ......................................................................................... 47
Table 5 Operating manpower required .................................................................................... 51
Table 6 Characterization of eucalyptus oil .............................................................................. 58
Table 7 Weight of soap during moisture content determination .............................................. 63
Table 8 Specific gravity determination data ............................................................................ 63
Table 9 Ratio of oils and its effect ........................................................................................... 68
Table 10 Equipment specifications .......................................................................................... 72
Table 11 Purchased equipment cost ......................................................................................... 73
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List of abbreviation
W weight of sample, gm
W/v weight per volume, g/ml
M.C moisture content (%)
A area of clear zone (m2)
B area of bacterial zone (m2)
F mass flow rate (kg/batch)
X mass fraction
G air flow rate (kg/h)
g dry air mass flow rate(kg/h)
L slurry mass flow rate (kg/batch)
Y humidity (kg of water /kg of air)
S product mass flow rate (kg/batch)
Cp specific heat capacity (kJ/kg.0k)
T temperature, (0c)
d diameter (m)
h height (m)
r radius (cm)
TCI total capital investment
FCI fixed capital investment
WCI working capital investment
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TPC total production cost
TDPC total direct production cost
MC manufacturing cost
GE general expense
NRE Reynolds number
Np power of impeller
NQ flow number
NFr fround number
D vessel diameter
N rpm of Impeller shaft
P horse power input
Q volumetric pumping rate
S specific gravity
td blending time
µ viscosity
Hp horse power
PDA potato dextrose agar
FDC food drug cosmetics
Pa. s Pascal second
Oc degree Celsius
MIC minimum inhibition concentration
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Antimicrobial solid soap production
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CHAPTER ONE
1. Introduction
1.1 Background
Soap is the combination of fatty acids and alkalis obtained by reacting various animal and
vegetable fats and oils with caustic soda or potash. The soap‐making reaction is called
saponification. Soap prepared from caustic soda is hard while soap from caustic potash is
soft. Both soaps are readily soluble in hot water. However, they dissolve very slowly in cold
water forming a turbid solution owing to slight decomposition.
The word “soap” came from the Latin word “Sapo.” it is believed that the name derived from
Mount Sapo in Rome. The first production of soap happened around 2800BC in ancient
Babylon. The Babylonians combined wood ashes with animal and plant fat, and got a
substance that was effective for cleaning. "The cold process method" is the most popular soap
making process today. Some soap makers use the hot process, which was much more
significant in past centuries. Soap is the term for a salt of a fatty acid or for a variety of
cleansing and lubricating products produced from such a substance. Household uses for soaps
include washing, bathing and other types of housekeeping, where soaps act as surfactants,
emulsifying oils to enable them to be carried away by water [1]. The earliest recorded
evidence of the production of soap-like materials dates back to around 2800 BC in ancient
Babylon. A formula for soap consisting of water, alkali, and cassia oil was written on a
Babylonian clay tablet around 2200 BC. The Ebers papyrus indicates the ancient Egyptians
bathed regularly and combined animal and vegetable oils with alkaline salts to create a soap-
like substance. Egyptian documents mention a similar substance was used in the preparation
of wool for weaving [2]. Until the Industrial Revolution, soap making was conducted on a
small scale and the product was rough. In 1780, James Keir established a chemical works at
Tipton, for the manufacture of alkali from the sulfates of potash and soda, to which he
afterwards added a soap manufactory. The method of extraction proceeded on a discovery of
Keir's. Andrew Pears started making a high-quality, transparent soap in 1807 in London. His
son-in-law, Thomas J. Barratt, opened a factory in Isle worth in 1862 [3].
During the restoration era (February 1665 – August 1714) a soap tax was introduced in
England, which meant that until the mid-1800s, soap was a luxury, used regularly only by the
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well-to-do. The soap manufacturing process was closely supervised by revenue officials who
made sure that soap makers' equipment was kept under lock and key when not being
supervised. Moreover, soap could not be produced by small makers because of a law which
stipulated that soap boilers must manufacture a minimum quantity of one imperial ton at each
boiling, which placed the process beyond reach of the average person [4].
There are many types of soaps, depending upon the usage. There are hard and soft, and
everything in-between soaps. Hardness of soap is often achieved through the addition of
hardening agents, so many natural soaps tend to be softer. They are further categorized into
two: cleansers and detergents.
Cleansers: Those are often made with mild abrasives and they are formulated to eliminate
heavy oil or solid particles and hard-to-remove stains. The cleansers come in many different
types depending on the type of abrasives they contain.
Detergents: Dish detergents are made to remove tough grease and release the solid dirt
particles in the foam that is produced by the detergent. There are two types of dish detergents:
machine dishwasher detergents and hand dishwashing detergents.
Laundry soap: It is formulated to eliminate grease, solid particles and organic compounds
from clothes. They can be found in liquid, powder and gel forms.
Cleaning soaps: Cleaning soaps have different formulations to clean grease and soil. The
difference between cleansers and cleaning soaps is that cleaning soaps don't contain harsh
abrasives.
Personal soaps: This kind of soap is made in many forms and special formulations for
specific personal hygiene needs. One type of the personal soap is the antibacterial soap that is
made to prevent bacteria and viruses from spreading. There are also body and hair soaps that
have a mix of ingredients that cleans both the skin and hair. An antibacterial solid soap is a
cleansing product designed to kill germs on the hands or body. These soaps are made in
either liquid or bar form by blending detergent additives with ingredients which have
antimicrobial properties.
The same types of detergent ingredients used in common household and personal care
cleansing products are used to make antibacterial soaps. Detergents and soaps are technically
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known as surfactants which are materials that have the ability to solubilize dirt and oil.
Surfactants are responsible for a product's ability to generate foam.
The major ingredients that are used for the production of antimicrobial soap are base (sodium
hydroxide), triglycerides, sodium sulphate, water, sodium silicate and citric acid. But for the
production of soap the raw materials imported with high cost so, it is possible to produce the
antimicrobial soap by domestically raw materials.
Poor sanitation and hygiene is one of the major causes of diseases and infections all around
the world. But sanitation and hygiene impact more than just health. A lack of sanitation takes
dignity away and can keep people locked in the cycle of poverty. As recent study shows, in
Ethiopia, only 52% of the population has access to sanitation facilities.
For the people, excess intake of beef fat is hazardous for human health, because excess intake
of fat induces hyper-lipidemia and cholesteraemia which result in coronary heart disease and
cancer [5].
The well-known domestic raw material used for the production of soap is animal tallow
mostly, discarded to the environment and having environmental effect.
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1.2 Problem of statement
In our country the raw material for soap production is basically imported from other
countries which is soap noodles with higher cost and when we observe the sanitation activity
of the society in our country is poor, so that to alleviate those problems we have intended to
prepare antimicrobial solid soap from different domestic raw materials such as animal fat,
castor oil etc. thereby gaining economic profit. And also the discarded animal tallow has its
own effect on the environment as source of air pollution, so that preparing antimicrobial soap
from this animal fat minimizes those problems. The major raw materials are animal fat, castor
oil and eucalyptus oil for antimicrobial soap production these are cheap, easily extracted and
accessible in our surrounding, where animal fat (beef tallow) and castor oil used us a raw
materials and eucalyptus oil as antimicrobial agent.
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1.3 Objectives
1.3.1 General objective
Production of antimicrobial solid soap from the blending of castor oil & beef
tallow
1.3.2 Specific objectives
To prepare and treatment of raw materials
To produce soap
To determine percentage yield of soap from beef tallow
To characterize the product (percent inhibition of bacteria, specific gravity
,hardness, power of clearance, alkalinity, moisture content, percentage yield and
foam length)
To characterized the eucalyptus oil (dynamic viscosity, refractive index, specific
gravity and boiling point)
To conduct the feasibility of the project.
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1.4 The scope and limitation of the project
1.4.1 Scope of the project
The scope of the project is to produce antimicrobial soap by substituting the soap noodles by
local ingredients of soap. In the previous study solid soap was produced from caster bean oil
with the objective of use of this oil as a substitution of soap noodles.
In these thesis project characterizing the product specifically specific gravity, alkalinity,
power of clearance, hardness, determining the percent inhibition of microbial growth by
antimicrobial solid soap, percentage yield of soap from beef tallow, moisture content, the
foam length of the product and to conduct the feasibility of the project. And also extract
eucalyptus oil which is used for an agent to inhibit the growth of micro-organism and specific
parameters of the oil is characterized typically the dynamic viscosity, refractive index,
specific gravity and boiling point of the oil.
1.4.2 Limitation of the project
The following terms are the limitation during performing of the experimental works;
Unavailability of equipment’s that is used for testing the percentage of microbes
removed by directly applying the microorganism on clothes.
Unavailability of PDA the most widely used medium for culturing fungus.
Unavailability of chloroform for characterization of fatty matter of the product.
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CHAPTER TWO
2. Literature Review
Khalid M. et al studied on the extraction and modeling of oil from Eucalyptus camadulensis
by organic solvent. During that study he investigated the effect at different values of
extraction time (100-250min), temperature (45˚C, 55˚C and65˚C), solvent to solid ratio from
5:1ml/g to 8:1ml/g and particle sizes range of (0.5cm to 2.5cm) finally hexane gives slightly
better oil yield at 65˚C with the particle size of 0.5 cm and solvent to solid ratio of 7:1 (v/w)
for 210 min [6].
Hajer Naceur M. et al studied on antimicrobial and antioxidant activities of the eucalyptus
oils from different plant parts (stems, leaves, flowers and fruits). The antimicrobial activity of
essential oils from different parts (stems, adult leaves, fruits and immature flowers) of E.
oleosa were tested at various concentrations (0.5–20 mg/ml) and their antimicrobial potency
was assessed by MIC values. The result shows that the essential oil of all the plant parts of E.
oleosa had great potential antimicrobial activity against all micro-organisms. All parts (stems,
adult leaves, fruits and immature flowers) of E. oleosa exhibited antibacterial activity,
although the immature flowers presented a larger prevalence of activity (0.93–3.72 mg/mL)
[7].
The strongest antifungal activity was observed using the essential oil from E.oleosa immature
flowers and stems, with MIC values between 2.79–3.88 mg/ml. At the time of antimicrobial
soap production different type of additives were used to optimize the quality of the product
such as: thickener, pearlizing agent, antibacterial agent (triclosan) and preservatives were
commonly used effectively at levels ranging from 0.1-1%, less than or equal to 1%, less or
equal to 0.5% respectively [8].
Umar M et al. studied the pH value of the prepared nut fat soap and foam ability of prepared
soap. Soap being salt of strong base and weak acid should be weakly alkaline in aqueous
solution. The pH value of 8.33 was obtained for the prepared soap however; soap with free
alkali (pH 11-14) can cause irritation to the skin. The value is lower than the ph. range of 9-
11 and higher than the pH range of 3-5, which are considered as high and low levels
respectively. The foam ability was 4.2 cm higher than that of 2.0 for neem oil soap 1.6cm for
castor oil based soap [9].
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2.1 History of beef tallow
The other common raw material for detergent production is beef tallow. It is a rendered form
of beef or mutton fat and is primarily made up of triglycerides. It is solid at room
temperature. Unlike suet, tallow can be stored for extended periods without the need for
refrigeration to prevent decomposition provided, it is kept in an airtight container to prevent
oxidation. In industry, tallow is not strictly defined as beef or mutton fat. In this context,
tallow is animal fat that conforms to certain technical criteria. It is common for commercial
tallow to contain fat derived from other animals. The quality characteristics of soap grade
tallow are similar to edible tallow for many of the same reasons. Soap-grade tallow is not
refined before use and does not suffer the refining losses which occur with edible tallow.
However, high free fatty acid levels in soap tallow reduce the recovery of glycerol which is
an important by-product of soap-making industry.
Industrial tallow: - Beef tallow is the common fat used in soap making. Most of the market-
famous soaps contain an ingredient called ’sodium tallowate’ which is nothing but rendered
beef fat. Though many modern manufacturers prefer vegetable oils to prepare soaps, not all
do as vegetable oil soaps do not give much lather. Beef tallow soaps are harder, give rich
lather and make better soaps. Animal tissue containing fat is converted to tallow by a process
called rendering. Rendering involves crushing the raw material followed by the indirect
application of heat. Pure tallow is a creamy‐white substance. Basically, rendering is a
procedure by which lipid material is separated from meat tissue and water under the influence
of heat and pressure. There are two principal methods of rendering: In the wet rendering
process (old method) the animal tissue is placed in an enclosed pressure vessel (cooker) and
superheated steam is injected to provide both heat and agitation.
At the end of this period, the mixture settles into three phases, a top fat layer which is drawn
off an intermediate water layer and a bottom layer consisting primarily proteinaceous
material. This method is no longer in wide usage. Protein and fat quality were more easily
compromised during the extended cooking time. In dry rendering process the fatty tissue is
heated in jacketed containers, mechanical agitation is provided and the water is evaporated
either at atmospheric or at increased pressure. More modern rendering plants feature a
continuous rendering process with automated operation and highly sophisticated air and
water pollution prevention equipment [9].
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2.2 History of castor oil
Castor bean (Ricinus communis L.) has been used for many years as an industrial oil seed
crop because of its high seed oil content (45%~60%), unique fatty acid composition (high in
ricinoleic acid) and lubricity potentially high oil yields and its ability to grow under varying
moisture and soil conditions. The use of castor is limited to some extent because the
unprocessed seed contains a highly toxic protein ricin.
Nevertheless with appropriate processing and handling along with new efforts to breed ricin-
free seeds, castor holds promise as a biodiesel fuel along with its current industrial and
pharmaceutical uses but, the high viscosity may limit its use to lower percentages in biodiesel
blends [10].
Castor Oil: It is obtained from extracting or pressing the seed of castor plant which has
the botanical name Ricinus communis. Castor oil is viscous, light yellow, non-volatile and
non-drying oil with a bland taste and is sometimes used as a purgative. Relative to other ten
given vegetable oils, it has a good shelf life and it does not turn rancid unless subjected
to excessive heat. Hence this paper focused on using of this oil for production of solid soap.
From different study shows that castor oil is known to consist of up to 90% ricinoleic, 4%
linoleic, 3% oleic, 1% stearic and less than 1% linolenic fatty acids. The usage of castor oil
can be divided into industrial, solid soap, detergent, medicine, biodiesel and bio-fuel
industries.
Castor oil is unique among all fats and oils. It is the only source of 18-carbon hydroxylated
fatty acid with a double bond between the ninth and tenth carbons and also known as
dodecahydroxyoleic acid. No other vegetable oil contains such a diverse and high proportion
of fatty hydroxyl acids. The castor oil has its own physical and chemical properties. Among
those physical properties with light yellow color, specific gravity (0.957-0.963), refractive
index (1.477-1.479) acid value 10, saponification value range of (177-182), viscosity of
castor oil is very high 3.114 poise and iodine value of (82-89) [11].
The castor oil has four basic components, those are 3% of oleic Acid, 4.2% of linoleic acid,
0.3% of linolenic acid and 90% of ricinoleic acids. But 1, 8- cineole is the most widely used
antiviral effect.
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2.3 History of eucalyptus oil
Eucalyptus essential oil can act directly as a natural insect repellent and the study lists
numerous pieces of research that demonstrate this property. For example, previous research
has found that eucalyptus essential oil can protect plants against rice weevils and mushroom
flies. The study also lists examples of research which have found that eucalyptus essential oil
is toxic to microbes including bacteria and fungi. Eucalyptus essential oil could therefore
have a role to play in the protection of crops against mold, mildew and wood root fungi [12].
The eucalyptus oil has its own physical and chemical properties. Among those physical
properties specific gravity at 250 C is about (0.870 to 0.912), viscosity at 200 c (pa.s) is about
(0.00246 - 0.0337) and refractive index at 200 c (1.457 - 1.467). Eucalyptus oil is beneficial
for our health that it’s surprising that not many people are aware of it. Eucalyptus oil can be
used as, analgesic, antibacterial, anti-infectious, antiviral agent and insecticidal. It is an
organic compound and cyclic ether. The main chemical components of eucalyptus oil are a-
pinene, b-pinene, a-phellandrene, 1, 8-cineole, limonene, terpinen-4-ol, aromadendrene,
epiglobulol, piperitone and globulol.
Eucalyptol is a natural constituent of a number of aromatic plants and their essential oil
fraction. Limonene is one basic components of the oil it is used as to give fragrance and
flavor.
2.4 The chemistry of soap
Soap making involves the hydrolysis of a triglyceride (fat or oil) using an alkaline solution
usually sodium hydroxide (lye). Triglycerides are typically tri-esters consisting of 3 long-
chain aliphatic carboxylic acid chains appended to a single glycerol molecule. This process of
making soap is known as saponification. The common procedure involves heating animal fat
or vegetable oil in lye (sodium hydroxide) therefore, hydrolyzing it into carboxylate salts
(from the combination of carboxylic acid chains with the captions of the hydroxide
compound) and glycerol. The basic structure of all soaps is essentially the same, consisting of
a long hydrophobic (water-fearing) hydrocarbon “tail" and a hydrophilic (water loving)
anionic "head”.
All soaps contain a surfactant as their active ingredient. This is an ionic species consisting of
a long, linear, non-polar 'tail' with a cationic or anionic 'head' and Counter ions. The tail is
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water insoluble and the head is water soluble. When the presence of calcium, magnesium,
iron and some other mineral salts can form insoluble precipitates with the long‐chain fatty
acids, this kind of reaction is responsible for the problems which arise when soap is used with
hard water (water containing appreciable amounts of dissolved calcium, magnesium or iron
salts).
Common primary surfactants include alkyl sulfates, alkyl ether sulfates, olefin sulfonates and
amphoteric. Blends of these materials can typically comprise 20-40% of the formula.
Secondary surfactants may be materials such as amides, betaines, sultaines and alkyl
polyglucosides. These are typically blended to optimize foam and cleansing characteristics
while maintaining cost guidelines. They are typically used in the range of 1-10% depending
on the requirements of the formula. A variety of other ingredients are added to modify
different aspects of the formula. These include thickeners, fragrances, colorants, pearlizing
agents, preservatives and featured ingredients.
Thickeners increase the viscosity of the product. Salt can be added to thicken systems
containing anionic surfactants. The first ingredient added to the tank is typically water
because it is usually the most plentiful ingredient. The other ingredients are added to the tank
as specified by the manufacturing procedure. Ingredients that are heat sensitive are added as
the batch is cooled to room temperature.
Fragrances are aroma chemicals, which are added to mask the odor of the base and increase
consumer appeal. These may be a variety of natural and synthetic materials blended together.
In fact, a fragrance may consist of dozens of individual components. The compounded
fragrance must be checked to make sure it is compatible with the detergent base.
Colorants may also be included to improve the product's appearance. Some detergents have
an inherent yellow color and dyes may be added to improve how the product looks. Colorants
used in cosmetic products are controlled by the food and drug administration and are
designated as FD & C.
Pearlizing agents are included to opacity the formula and give it a more pleasing appearance.
These are typically fatty alcohol type materials such as glycol stearate, although titanium
coated mica can also be used to give the product an attractive pearled appearance.
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Preservatives are added to liquid soaps to prevent microbial growth. While the product
contains other antibacterial agents, these are designed to kill skin organisms and may not be
adequate to protect the product from other microbes such as molds and fungus. Therefore,
additional preservatives may be added to the formula to provide broad spectrum protection
[8].
Soap is integral to our society today, and we find it hard to imagine a time when people were
kept sweet-smelling by the action of perfume rather than soap. However, the current
widespread use of soap is only a very recent occurrence, despite the fact that it has been made
for more than 2500 years. The first recorded manufacture of soap was in 600BC, when Pliny
the Elder described its manufacture by the Phoenicians from goats tallow and ash. Early this
century the first synthetic detergents were manufactured and these have now taken the place
of soap for many applications. The need for soap a cleansing agent has been felt ever since
man became aware of the necessity to clean his body and environment in the primitive
ages. Soap has therefore acquired the status of a basic necessity in the modern civilized
world.
Fats and oils are esters of different fatty acids and glycerol. Fats and oils are divided
into three classes, fixed oils, mineral oils and essential oils. Fixed oils form the main
raw materials for soap making as they decompose into fatty acids and glycerol when
strongly heated and can be easily saponified by alkali.
2.4.1Soap manufacturing process
The length of the hydrocarbon chain ("n") varies with the type of fat or oil but is usually quite
long. The anionic charge on the carboxylate head is usually balanced by either charged
potassium (K+) or sodium (Na+) cations. In making soap, triglyceride in fat or oils are heated
in the presence of a strong alkali base such as’ sodium hydroxide producing three molecules
of soap for every molecule of glycerol, the process is called saponification. The equations
below represent typical saponification reactions;
C3H5 (OOCR)3 + 3NaOH NaOOCR + C3H5 (OH)3
Fat Sodium hydroxide Soap Glycerol
Or
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Soap is produced industrially in four basic steps;
1. Saponification
A mixture of tallow (animal fat) and oil is mixed &heated with sodium hydroxide then the
soap produced is the salt of a long chain carboxylic acid.
2. Glycerin removal
Glycerin is more valuable than soap, so most of it is removed. Some is left in the soap to help
make it soft and smooth. Soap is not very soluble in salt water whereas glycerin is soluble;
salt is added to the wet soap causing it to separate out.
3. Soap purification
Any remaining sodium hydroxide is neutralized with a weak acid such as, citric acid and two
thirds of the remaining water is removed.
4. Finishing
Additives such as preservatives, color and perfume are added and mixed with the soap and it
is shaped into bars for the market. Detergents are similar in structure and function to soap and
for most uses they are more efficient than soap. In addition to the actual 'detergent' molecule,
detergents usually incorporate a variety of other ingredients that act as water softeners, free-
flowing agents etc.
The major factors related to cleansing property of soaps are foam quality, speed of foaming,
rinsability and skin feel. In addition, the product's aesthetic qualities (how it looks and
smells) must also be evaluated.
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There are two ingredients commonly used in the industry at this time as antibacterial agents.
One is 3, 4, 4’-trichlorocarbanilide (commonly called trichlocarban) which is used in bar
soaps. These ingredients work by denaturing cell contents or otherwise interfering with
metabolism of microbes. Both are effective against a broad range of microorganisms.
Fig 1 Process flow diagram of soap production
saponification Glycerin removal
Soap purificationFinishing
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CHAPTER-THREE
3. Material and Methods
3.1 Equipment’s used
Oven m40-vf (to dry the sample), PH meter ph-010 (to measure the acidity and basicity of the
product), cutter 4D905A-2 (for size reduction of the eucalyptus leaves), mass balance (to
measure the weight of samples), beaker 500ml (to take samples), volumetric flask 250 ml (to
hold the sample ), ruler (to measure the length of foam & length of clear zone during
microbial inhibition), measuring cylinder 100 ml (to measure the volume of the solution),
soxhlet (to extract the antimicrobial oil from eucalyptus leaves), Petri dish (to see the effect
of antimicrobial solid soap on staphylococcus aurous bacteria), incubator DHP-9052 (to
maintain the bacteria at constant temperature during culturing), mold (to give the required
shape of the product) and incubation loop (to insert small amount of staphylococcus bacteria
to the media), test tube 100ml (to diluents the bacteria), micro pipette (to add antimicrobial
soap solution on a petri dish), stove (to heat the solution for complete mixing), spedel 4 200
rpm visco-meter (to measure the viscosity of eucalyptus oil), refracto-meter Rx-5000i-plus
(to measure the refractive index of oil), P T-1 thermometer ( to measure the boiling point of
oil) and autoclave BT-19,T (for sterilizing all materials used for bacteria culturing).
3.2 Chemical’s used
Castor oil and animal fat (used as a raw materials), distilled water (forming of solution
during the characterization of the product and preparing media for bacteria), caustic soda 93-
97% (used as surfactant substance and balance the Ph-value), brake oil (to check the power of
clearance), sodium sulphate (to increase the viscosity and density of soap), citric acid (to
preserve the soap), sodium silicate (used to produce foam and soften of soap), eucalyptus oil
(for antimicrobial agent), sodium chloride (to precipitate different impurities during fat
freezing), mueller hinton agar (for media preparation for the bacteria), McFarland standard
solution (used as a standard for comparing the bacteria on the maximum recovery solution)
and maximum recovery diluents (for providing the nutritious properties of the
microorganism).
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3.3 Experimental works
Experimental work was done in chemical engineering department laboratory rooms.
3.3.1 Raw material collection
The raw materials for antimicrobial solid soap production are castor oil, beef tallow and
eucalyptus oil. The castor oil and beef tallow (as a fat source) were bought from Bahir Dar
city by the faculty of chemical and food engineering.
3.3.2 Treatment of beef tallow
The beef tallow was cut to smaller parts by knife to remove unwanted impurities, meets and
then the beef tallow was melted slowly in pots. When melted each liquid fat was strained
through a paper towel lined strainer to filter out any unwanted particles. Warm tap water was
added to the fat in the pot. The water/oil combination was brought to boil and then simmers
on lower rate for 15 minutes. Then it was poured in one quart of cooled water, stir and
refrigerate overnight. After one day the hardened fat was lifted out from the refrigerator. The
excess water was removed and then the solid fat well wrapped and stored in the freezer until
ready to use for soap making.
Fig 2 Raw beef tallow
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Fig 3 Pre-treatment of beef tallow
Fig 4 Melting of beef tallow
Fig 5 Beef tallow fat after refrigerate
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3.3.3 Deodorization
Natural fats contain substances that contributing to undesirable flavor and odor these
substances must be removed. Thus is achieved by a technique known as steam distillation
under reduced pressure, but we have used boiling of the fat three times and washed with raw
cold water to remove unwanted impurities and its odor instead of steam distillation.
Triglycerides have extremely low vapor pressures and are therefore non-volatile whereas
aldehyde, ketone, alcohol and free fatty acids which contribute to the flavors and odor of fats
those are removed by steam distillation or heating repeatedly [13].
Fig 6 Deodorizing of pure fat by melting again and again
3.4 Extraction of eucalyptus oil
3.4.1 Collection of eucalyptus leaves
Fresh leaves of Eucalyptus tree was collected from the gardens of around Debre Tabore gena-
mechawocha kebele south Gondar, Amhara, Ethiopia and its geographical coordinates are
11° 51' 0" North, 38° 1' 0" East. The leaves were taken into Bahir Dar University chemical
engineering laboratory room and cut out by a pair of scissors into small parts.
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Before cutting After cutting using scissors
Fig 7 Fresh leaves of eucalyptus tree
3.4.2 Drying of eucalyptus leaves
The eucalyptus leaves were dried using an oven M40-V Fat 1050c to remove the moisture and
volatile matters for about 12 hours and also in order to easily crush and extracted the oil from
the eucalyptus leaves.
Fig 8 Drying of leaves using oven
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3.4.3 Size reduction of leaves
The sizes of the dried leaves were reduced by cutter, 4D905A-2 machine in the unit operation
laboratory room and the sizes were arranged by sieve to 0.7 mm after cutting.
During cutting After cutting
Fig 9 Size reduction of leaves
3.4.4 Soxhlet extraction
Normal hexane was poured into round bottom flask and 50 gm of the sample was placed in
the thimble and was inserted in the centre of the extractor. The soxhlet having 400 ml of
solvent was heated using stove. This was allowed to continue for 210 minutes with a particle
sizes of 0.7 mm. The experiment was repeated by placing the same amount of the sample into
the thimble.
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Fig 10 Oil extraction using soxhlet
3.4.5 n-hexane recovery
At the end of the extraction, the resulting mixture containing the oil and n-hexane was heated
to recover solvent from the oil. N-hexane was heated at 69.90 c, since it is the boiling point of
normal hexane, in order to vaporize the n-hexane from the mixture using water bath and then
the vaporized hexane was cooled using condenser. Finally the cooled n-hexane was collected
in beaker and it is used for further extraction of that oil.
3.5 Characterization of eucalyptus oil
3.5.1 Determination of refractive index
Refractive index of eucalyptus oil was measured directly by refractor meter, Rx-5000i-plus.
First the refractor meter was appropriately cleaned and then the prism was filled by
eucalyptus oil. Finally the refractive index of the eucalyptus oil at 25o c was recorded.
Fig 11 Determination of refractive index of the oil
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3.5.2 Determination of viscosity
A test tube was prepared, cleaned and dried. 25 ml of eucalyptus oil was poured into the test
tube and the viscosity at a temperature of 25o c was measured by using spedel 4 200 rpm
viscometer.
Fig 12 Viscosity determination of eucalyptus oil
3.5.3 Determination of specific gravity
The specific gravity of the eucalyptus oil was calculated by measuring the mass and volume
of the sample and finally, the specific gravity of eucalyptus oil was calculated by using the
following formula:
Density of sample (kg
m3) =
mass of sample (kg)
volume of sample (m3)
Then the specific gravity of the sample will be;
Specific gravity =density of sample (
kg
m3)
density of water (kg
m3)
3.5.4 Determination of yield
The yield of eucalyptus oil was calculated by dividing the weight of the eucalyptus oil
produced by the initial weight of the eucalyptus leaves taken multiplied by 100. It is
calculated the product.
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Yield (%) =weight of eucalyptus oil produced, gm
weight of intial eucalyptus leaves used, gm∗ 100 %
3.5.5 Determination of boiling point
25 ml of eucalyptus oil was poured in to 100 ml of glass beaker and then P T-1 thermometer
was inserted and placed on the stove, it was observed that the eucalyptus oil in the
glass beaker started to circulating and the temperature on thermometer was recorded.
Fig 13 Measurement of boiling point
3.6 Antimicrobial solid soap production
In order to produce solid soap, 24gm of NaOH and distilled water was measured with ratio of
1:2 respectively using mass balance, was mixed and invert those into mixing beaker (1) with
a capacity of 500 ml. After measuring 7gm of sodium sulfate using mass balance, it was
added and mixed in another beaker (2) with castor oil and beef fat until the sodium sulphate
was disappeared in the solution. 9gm of citric acid was measured and mixed with 3gm of
distilled water in another beaker (3). At the end all the three beaker solution was mixed in
anther beaker (4), 4gm of sodium silicate was added into beaker (4), finally eucalyptus oil
was added in the range of (2-4) % of the oil as antimicrobial action. At the end the solution
was stirred well using a stirring rod until it forms uniform slurry. The final solution was
poured into prepared mold.
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Fig 14 Antimicrobial solid soap preparation
When we blend the given amount of fat to that of castor oil by the addition of eucalyptus oil
as antimicrobial agent looks like as follow;
Table 1 Percentage amount of oil and fat for soap making
Ratio
% of Eucalyptus to the total oil used
2.5 3 3.5
(50:50)a * * *
(25:75)b * * *
(0:100)c * * *
Where;
(50:50)a = 50% of castor oil & 50 % of beef fat
(25:75)b = 25% of castor oil & 75 % of beef fat
(0:100)c = 25% of castor oil & 75 % of beef fat
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3.7 Characterization of the product
Solid soap has different quality standards from one producer to other producer
depending on the surfactant and additives used for the production. In this project the
characterization is focused on different parameters.
3.7.1 Determination of moisture content
A sample of the 10g scrapped soap was put into a petri dish and place in M140-VF oven for 1
hour at 105°C. It is allowed to cool down and then weighted. The moisture content in
percentage is calculated as.
𝑀𝑛 =Ww − Wd
Ww∗ 100
In which:
Mn = moisture content (%) of the product soap.
WW = wet weight of the sample, and
Wd = weight of the sample after drying.
Fig 15 Moisture content determination of the product
3.7.2 Foam ability test
2 gm. of the soap was dissolved in 50 ml of distilled water in a 100 ml measuring cylinder
and shaken vigorously for 2 minute. It was allowed to stand for 10 minute after which the
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height of the foam was determined. It was repeated three times for the soap sample and the
mean was computed as;
𝑀𝑒𝑎𝑛(𝑎𝑣𝑒𝑟𝑎𝑔𝑒) =The sum of test results
The number of results
Fig 16 Determination of foam length
3.7.3 PH analysis
The pH values of the product were analyzed using PH-010 pH meter. 2gm of the produced
soaps was dissolved in 50 ml of de-ionized water then its ph was measured directly by ph
meter. This was repeated three times for each soap sample and the mean was computed.
Fig 17 Alkalinity determination
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3.7.4 Hardness test
To determine the hardness of the soap a needle were prepared. A weight of 130gm sample
was prepared and is attached onto the top of the needle and then the distance into which the
needle penetrates the soap after 30 second is recorded as a measure of its hardness. This is
repeated three times for each soap sample and the mean will be computed as;
𝑀𝑒𝑎𝑛(𝑎𝑣𝑒𝑟𝑎𝑔𝑒) =The sum of test results
The number of results
Fig 18 Hardness test
3.7.5 Power of clearance test
Initially 2.6gm of soap was measured and dissolved with 100 ml of water to form the solution
for three samples. A drop of used brake oil was placed on three separate thin strips of white
cloth. It was made sure that the strips of white cloths were fit in the test tubes. One white
cloth with oil spot was inserted in the tube containing soap solution in water. Another was
placed in the tube containing roha eucalyptus soap solution and the third strip of cloth was
placed in the tube containing only pure water. Each one was shaken well and made sure that
the white cloth was immersed in the solution then after 2 minute, the white cloth was
removed and rinsed with tap water. Finally check whether the oil get washed out of from the
strip of white cloth or not in each solution.
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Before immersion After immersion
Fig 19 Power of clearance test
3.7.6 Determination percent inhibition of microbial growth
In order to determine percent inhibition of staphylococcus bacteria first the media for
culturing was prepared using Mueller agar. First 5.7gm of Mueller Hinton agar was dissolved
in 150 ml of distilled water and it was boiled until the solution was mixed completely. The
resulting solution and all other working material were sterilized at 121o c for 15 minutes by
using DHP-9052 autoclave and cooled into room temperature and then equal amount of
media was added onto eight petri-dishes. It was converted into gel like mass. A small hole
was punched in each center of the media. The bacterial solution was prepared by taking 6 ml
of maximum recovery diluents and a small amount of staphylococcus aurous bacteria in the
test tube using nucleation loop, mixed until similar to McFarland standard solution, where
standards are suspensions of either barium sulfate or latex particles that allow visual
comparison of bacterial density, finally the prepared bacterial solution was smeared over jelly
like mass of the media for to insert the staphylococcus aurous bacteria. Then 0.03micro-liter
of 5% of prepared soap solution was added onto the three Petri dish holes by using micro
pipette and also 5% of commercial antiseptic soap solution was added in one Petri dish as for
comparing purpose, third petri dish was left without antimicrobial soap solution, as such as
“control”. But also 10%, 15% and 20% was used in order to determine the percentage
amount of bacterial inhibition or percent reduction of staphylococcus aurous bacteria on a
given specific area by increasing the concentration of antimicrobial soap.
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Then each petri dish was placed in the incubator at 370 c. After 48 hours of incubation, zone
of inhibition of sample was observed.
Antimicrobial activity can be calculated by following formula;
Percent inhibition or reduction (%) =A
B ∗ 100%
Where,
A is the area of clear zone in the sample region.
B is the total area of bacterial zone in the control.
Fig 20 Media for the bacterial growth
Fig 21 Applying of different concentration of soap on the bacterial media
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Fig 22 Determination percent inhibition of microbial growth
3.7.7 Determination of specific gravity
It is calculated by measuring the mass and volume of the sample and finally calculates the
specific gravity of soap using the following formula:
Density of sample (kg
m3) =
mass of sample (kg)
volume of sample (m3)
Finally it is possible to find the specific gravity of the sample as:
Specific gravity =density of sample (
kg
m3)
density of water (kg
m3)
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Fig 23 Specific gravity determination
3.7.8 Determination of yield of the product
The percentage yield of the product was calculated for the soap samples prepared from the
beef tallow. The yield of solid soap is calculated by dividing the weight of the soap by the
weight of the initial oil taken multiplied by 100, the formula looks like;
Yield (%) =weight of the pure fat for soap
the initial weight of beef tallow*100%
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CHAPTER FOUR
4. Feasibility study
4.1 Market study
4.1.1 Past supply and present demand
Soap which is used for cleaning clothes as well as household utensils is a necessity in
urban households. The demand for the product is, therefore, mainly associated with
urbanization. The country’s requirement for laundry soap has been met through domestic
production and import. Table 2 shows the supply of the product from domestic production
and imports during 1989-2002. During the period the total supply averaged at 64,293 tones,
of which 12,301tones constituted domestic production and the remaining 14,992 tones is met
from imports. Thus, on the average domestic production accounted for 44 per cent of the
country's requirement for soap indicating much of the demand for the product (56%) is still
met through imports [14].
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Table 2 Supply of laundry soap (tones)
Assuming supply was driven by demand, the average annual supply of soap for the period
which constitutes domestic production and import is considered as the effective demand
for the product for the year 2002. Since the consumption of soap is associated with
the growth of urban and rural population.
Year Domestic
Production
Import
Total
supply
Market share (%)
Domestic
production
Imports
1989 9529 15661 25190 37.8 62.2
1990 7743 14706 22449 34.5 65.5
1991 3729 12537 16266 22.9 77.1
1992 4947 19592 24539 20.2 79.8
1993 15546 8856 24402 63.7 36.3
1994 13495 14149 64644 48.8 51.2
1995 13641 7838 21479 63.5 36.5
1996 16547 15229 31776 52.1 47.9
1997 12908 13766 26674 48.4 51.6
1998 9787 12910 22697 43.1 56.9
1999 13135 17504 30639 42.9 57.1
2000 17194 14200 31394 54.8 45.2
2001 14766 19792 34558 42.7 57.3
2002 19249 23147 42396 45.4 54.6
Average 12301 14992 64293 44 56
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4.1.2 Projected demand: The future demand for soap estimated as follow by considering the
past demand of the product. The demand for the product is assumed to grow by 4% in
minimum that corresponds to the annual growth rate of the population. The imported soap is
assumed to be the demand for the society it was 14,992 tons in 2002 but it will be 15591.68
tons in 2011.
4.1.3 Pricing: Currently, soap factories in Ethiopia and the imported soaps for almost the
same price which is in the range of 10-35 birr/piece.
4.1.4 Plant Capacity: According to the market study (projected demand) and the economic
scale of soap manufacturing, the rated capacity of the plant is proposed to produce 1000 kg
per day of soap.
4.1 Plant capacity and production process
As we know the process of production starts from determination of raw material and
quantitatively analyzing those necessary inputs. The rough process diagram looks like as
follow;
Fig 24 Soap production process flow diagram
Antimicrobial solid soap production plant with annual capacity of 300,000 kg of
antimicrobial solid soap detergent per year is investigated on the basis of a production
schedule 300 days per annum and two shifts of eight hours a day. The plant capacity is
determined by considering the unsatisfied demand and economy of scale limitations.
Mixer
/Blender/
Conveyor Extruder Av -cutter
Dryer Packaging
Caustic
soda tank
Storage
/warehouse/
Isolate fat Other ingredients
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Assume;
The plant having a capacity of 1000 kg/day.
The system is batch process.
The plant operates 2 shifts/day.
The plant operates 2 batch/shift.
4.2 Material balance
4.2.1 Mixing tank 1: Material balances are nothing more than the application of the
conservation law for mass, matter is neither created nor destroyed.
Accumulation = output + consumption – input – generation
Since there is no reaction, the generation and consumption terms are zero, no accumulation.
So, input is equal to the output.
The crystal form of sodium hydroxide in a metal dilution tank is diluted with water to form
its solution.
NAOH
Water Solution
Items Input (kg/batch) Output (kg/batch)
Water 54 -
NaOH 27 -
Solution - 81
Dilution
tank (1)
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4.2.2 Mixer/Blender/
The amounts of ingredients required in the production of the desired amount of solid
antimicrobial soaps are sodium hydroxide, water, sodium silicate (9kg), citric acid (9 kg),
sodium sulphate (5 kg), animal fat (102.75 kg), castor oil (34.25 kg) and eucalyptus oil (3.425
kg).
Solution, (kg/batch)
Total ingredients, (kg/batch) Slurry, (kg/batch)
Total amount of ingredients (kg/batch) is the sum of all ingredients of soap except to that of
the solution. So that;
Total ingredients (kg/batch) = [9+9+5+102.75+34.25+3.425]kg/batch =163.425kg/batch
Items Input 1(kg/batch) Input 2(kg/batch) Output (kg/batch)
Total ingredient - 163.425 -
Solution 81 - -
Slurry - - 244.425
4.2.3 Dryer
Slurry (F1) water out (F2)
Product (F3)
Assume;
Let the efficiency of dryer be 70%.
Dryer
Blender
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From laboratory result, the final moisture content of antimicrobial soap was 17% but
the product is somehow soft in relative to commercial (roha) soaps therefore removal
of 2% of water is assumed to achieve the desired hardness quality.
From the above mass balance on the blender 244.425 kg/batch of antimicrobial solid soap is
feed into the dryer. So that the amount of water removed (F2) by dryer is;
F2 = (F1) *(% of water removed)*(dryer efficiency)
= (244.425 kg) (2%) (70%)
= 3.4 kg/batch
So, applying overall balance on dryer;
F1 = F2 + F3
F3 = F1 – F2
= 244.425– 3.4
= 241.025 kg/batch
Applying component balance on water;
(x1)*(F1) = (x2)*(F2) + (x3)*(F3)
Where,
X1 = mass fraction of water in the feed.
X2 = mass fraction of removed water.
X3 = mass fraction of water in the product.
(0.17)*(244.425kg/batch) = (1) (3.4kg/batch) + (x3) (241.025kg/batch)
X3 = 0.158
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4.3 Energy balance on major equipment’s
A. Dryer
Slurry, L (kg/hr) Air exhaust, Go, (kg/hr)
Hot air, Gi (kg/hr) Product, S (kg/hr)
Assume;
100 kg/h of soap containing 15% moisture are produced in a continuous tray dryer. The
feed solution contains 95% in weight soap solids and enters at 150 C.
Atmospheric air with humidity = 0.005 kg water/kg the air is heated to 1200 C before
entering the dryer.
The air stream leaves the dryer at 900 C and the soap product leaves at 700 C.
Neglecting any heat losses
Data;
Mean heat capacity of dry air = 1 kJ/kg K
Mean heat capacity of water vapor = 1.996 kJ/kg K
Mean heat capacity of soap = 0.01 kJ/kg K
Mean heat capacity of liquid water = 4.2 kJ/kg K
Latent heat of evaporation of water at 00 c = 2,500 kJ/kg.
L = slurry feed rate (kg/h).
g = dry air rate (kg/h).
Gi = total air flow in (kg/h).
Go = total air flow out (kg/h).
S = product rate, kg/h.
Dryer
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Basis: 100 kg tray dried product.
1. Balance on dry solids
Solids in = Solids out.
0.95L = 85
Therefore, L = 89.47 kg/h.
Water in the feed = 0.5L => 44.7 kg/h.
2. Water balance
Water in hot air + Water in the slurry feed = Water out in exit air + Water in dried soap solids
0.005 *g +44.7 = Y*g +15
g *(Y- 0.005) = 29.7………………(*)
Where,
Y = humidity of exit stream. Thus,
3. Enthalpy balance
The energy balance is;
Enthalpy of L + Enthalpy of Gi = Enthalpy of Go + Enthalpy of S…………. (**)
Where;
The enthalpies are respectively:
L (feed): [Mw + cpw + Ms + cps]*T
= (44.7*4.2 + 75 *0.01) *15
= 744.75 kJ
Gi: Tin*g+Y*g (cpwv *T+ latent heat)
Gi (gas in): [120 g + 0.005*g (1.996*150 + 2,500)] = 134g kJ
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G0 (gas out): [90*g + g*Y*(1.996*90 + 2,500)] = (90 + 2679.64*Y) g kJ
S (product): [75*0.01 + 2*4.2]*70 = 640.5kJ
By using the concept of equation (**);
744.75 kJ+134g kJ = (90 + 2679.64*Y) g kJ+640.5kJ
g*(2679.64Y-44) = 104.25………………….(***)
Solving the equation (*) and equation (***) simultaneously;
79585.308Y-1306.8 = 104.25Y- 0.52125
Y = 0.01644kg/kg dry air
g = 2596.154kg hot air/hr.
Gi = 2596.154*(1+0.005) = 2609.1347kg/hr.
Go = 2596.154*(1+0.01644) = 2638.834772kg/hr.
The moisture (in) = 0.005*2596.154 =>13
The moisture (out) = 0.01644*2596.154 => 32.68
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Table 3 Mass balance on dryer
Component In, kg/hr. Out, kg/hr.
Soap solid 75 75
Water 44.7 15
Total, liquid streams 119.7 100
Hot air 2596.154 2596.154
Moisture 13 32.68
Total, air stream 2609 2638.8
Sum 2729 2728.8
From the table, the total amount energy and mass flow rate into the dryer is approximately
the same as to the total amount energy outlet.
4.4 The size of major equipment
4.4.1 Size of castor oil storage tank [11]
VO = [(mass of castor oil)*(1+ safety factor)]/ (density of castor oil)
Where,
Vo- is the volume storage tank
VO = [(137kg)*(1+0.15)]/ (956.1kg/m3)
= 0.165m3
Assuming the height of castor oil storage tank is 1meter and from the geometry of material
with cylindrical form, the volume = π*R2*h
So that the diameter will be;
0.165 m3 = Πd2/4* h
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d = 0.5m
4.4.2 Size of caustic soda solution tank
Vm = [(mass of input ingredients) *(1+ safety factor)]/ (average density of input ingredients)
Where;
Vm- is the volume of caustic soda solution (dilution) tank
Now we have daily feed of 108 kg of NAOH and 216 kg of water and safety factor is 15%.
Vm = [(108 kg + 216 kg)*(1.15)]/ [(997 kg/m3 + 2130 kg/m3)/2] = 0.24m3
Assuming the height is 1meterandfrom the geometry of material with cylindrical form, the
volume = π*R2*H
The diameter will be calculated as;
0.24m3 = Πd2/4* H
d = 0.6m
4.4.3 Mixer (blender) design
Vm = [(mass of input ingredients)*(1+ safety factor)]/ (average density of input ingredients).
Where;
Vm - is the volume of mixer
Now we have daily feed of 108 kg of NAOH, 216 kg of water, 36 kg of sodium sulphate, 36
kg of citric acid, 20 kg of sodium silicate, 411 kg of animal fat, 137 kg of castor oil, 13.7 kg
of eucalyptus oil and their density are 2130 kg/m3, 997 kg/m3, 2660 kg/m3, 1660 kg/m3,
2400 kg/m3, 216.4 kg/m3, 956.1 kg/m3, 909 kg/m3 respectively. Let’s take an average of
15% as safety factor and hence the volume requirement of the mixing tank per day will be:
Vm = [(108 kg + 216 kg + 36 kg + 36 kg+ 20 kg + 411 kg +137 kg + 13.7 kg)*( 1+0.15)]/[
(2130 kg/m3 + 997 kg/m3 + 2660 kg/m3 + 1660 kg/m3 +2400 kg/m3 +216.4 kg/m3 +956.1
kg/m3 +909 kg/m3)/8] = 0.85m3
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Assume, the height of mixing tank is 1meter and from the geometry of material with
cylindrical form volume = π*R2*H
The diameter will be calculated as;
0.85m3 = Πd2/4* h.
d = 1.04m
4.4.3.1 Design of impeller size and power consumption
Design considerations
I. Baffles
A baffle width one-twelfth the tank diameter w = D/12, a length extending from one half the
impeller diameter, d/2 from the tangent line at the bottom to the liquid level.
II. Impeller size
For the popular turbine impeller the ratio of diameter of impeller and vessel falls in the range,
d/D = 0.3-0.6
III. Impeller speed
With commercially available motors and speed reducer standard speeds are 37, 45, 56, 68,
84, 100, 125, 155,190 and 320rpm.
IV. Impeller location
As a first approximation, the impeller can be placed at l/6 the fluid level off the bottom. In
Some cases there are provisions for changing the position of the impeller on the shaft. For
bottom suspension of solids an impeller location of l/3 of the impeller diameter of the bottom
is satisfactory. Criteria developed by Dickey (1984) are based on the viscosity of the liquid
and the ratio of the liquid depth to the vessel diameter, h/D.
Power input and other factors are interrelated in terms of certain dimensionless groups.
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NRe = 10.75Nd2S/ μ, Reynolds number
Np = 1.523 (1013) P/N3d5S, Power number
NQ = l.037 (1013) Q/Nd3, Flow number
Tb*N, Dimensionless blend time
NFr = 7.454(10p4) N2d, Froude number,
Where,
D = impeller diameter, m
d = vessel diameter, m
N = rpm of impeller shaft
P = horsepower input
Q = volumetric pumping rate, cubic ft/sec
S = specific gravity
tb = blend time, min
μ = viscosity, cP
From the design volume of vessel = 0.85m3
From the result specific gravity = 0.965
Viscosity (μ) = 8000 mPa.s
For blending operation, take Horse power per 1000 gal to be in a range of 0.2-0.5. By taking
an average value of 0.35 Hp.
Power P = Hp*V
= 0.35*224.4
= 78.54hp
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The ratio of diameter of impeller and vessel falls in the range d/D, 0.3 - 0.6 and by taking the
average value 0.4
d = 0.4D
= 0.16m
Select impeller speed, N = 84rpm
N Re = 10.75Nd2S/μ
= 10.75 × 0.162×84 rps×60s ×0.965/8000 mcpa.s
= 0.16731
NQ = Q/Nd3 is equal to 0.3, this value is taken from figure 10.7 of chemical process
equipment selection and design text book (Stanleywalas)
Q = Volumetric pumping rate
Q = NQ*N*d3
= 0.3 × (84/60sec) × (0.4056m)3=0.028m3/sec
V = Q/A
= (0.028 m3/sec)/ (π) × (1.014m) 2/4) = 0.03467 m/s
To calculate power consumption of impeller
Np = power consumption
Np = 1.523(1013) P/N3d5S
= 1.523(1013) (78.54)/ (843×0.165×0.965)
= 2020.4hp
4.4.4 Size of molder tip
Since the product rectangular shape the molder shape should be rectangular. The volume flow
rate of the slurry can be estimated from its mass flow rate and density relation.
Mass feed rate of slurry = 1000 kg/day = 41.667 kg/hr and density = 963.7 kg/m3.
Volumetric flow rate of slurry = 0.043 m3/hr but for molding one piece of soap assuming it
requires 20 seconds.
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The volume of the molder = Volumetric flow rate * residence time
= 0.043 m3/hr * 20 seconds
= 0.24litter, this is the capacity of the top tip of molder.
Assuming total 20% safety factor = 0.24liter* 0.2
= 0.05 litter
Therefore total volume of the molder = 0.05+0.024
= 0.074L
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4.5 Estimation of total capital investment
Table 4 Estimation of FCI and TCI [15]
Items Solid Processing plant Cost ($)
Purchased equipment delivered 100% 240791.55
Purchased-equipment installation 45% 108356.1975
Instrumentation and controls (installed) 9% 21671.2395
Piping (installed) 16% 38526.648
Electrical(installed) 10% 24079.155
Buildings(including services) 25% 60197.8875
Yard improvements 13% 31302.9015
Service facilities(installed 40% 96316.62
Land 6% 14447.493
Total direct plant cost 264% 635689.692
Engineering and Supervision 33% 79461.2115
Construction expenses 39% 93908.7045
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Indirect costs 72% 173369.916
Total direct and indirect plant costs 336% 809059.608
Contractor’s fee (about 5% of direct
and indirect)
17% 40934.5635
Contingency(about 10%(D+I) 34% 81869.127
Fixed capital investment 387% 931863.2985
Working Capital ( About 15 % of TCI ) 68% 163,738.254
Now the total capital investment will be;
TCI = FCI + WCI
= 931863.2985$ + 163738.254$
= 1095601.553$
4.6 Estimation of total production cost
Total production cost = Manufacturing cost + General expenses
Manufacturing cost
A. Fixed charges
1) Depreciation : it is 10% of FCI = 0.1*931863.2985$ = 93186.33$
2) Local tax: it is 2.5% of FCI = 0.025*931863.2985$ = 23296.6$
3) Insurance: it is 1% of FCI = 0.01* 931863.2985$ = 9318.633$
4) Rent: it is 6% of rented land = 0.06*14447.493$= 867$
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5) Royalties and License Fee = 5% of fixed capital cost
= (5%) ×931863.2985$
= 46593.2$
Total fixed charges = 173262.2$
B. Direct production cost
1) Raw material cost (10% – 50% of TPC), Now, we have fixed charges (10 – 20 % of
total production cost). Let fixed charge cost =15% of total production cost.
TPC = 173262.2$ /0.15
= 1155081.33$
Sodium Silicate
Sodium silicate cost = 16 birr/kg
Sodium silicate used = 0.001 kg/piece
Total cost = 0.0288 birr/piece
NAOH
NAOH cost = 65 birr/kg
NAOH used = 0.0054 kg/piece
Total cost = 0.351 birr/pieces
Sodium sulphate
Sodium sulphate cost = 40 birr/kg
Sodium sulphate used = 0.0018 kg/piece
Total cost = 0.072 birr/piece
Animal fat (beef fat)
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Beef fat cost = 30 birr/kg
Fat used = 0.02055 kg/piece
Total cost = 1.233 birr/piece
Castor bean
Castor bean cost = 15 birr/kg
Castor oil used = 0.00685 kg/piece
Total cost = 0.2055 birr/piece
Eucalyptus oil
Assume, the fresh eucalyptus leaves costs about 0.5 birr/kg.
1000gm = 200gm of oil = 0.5 birr
Eucalyptus oil used = 0.000685 kg/piece
Total cost = 1.7*10^-6 birr/piece
Citric acid
Citric acid cost = 60 birr/kg
Citric acid used = 0.0018 kg/piece
Total cost = 0.108 birr/piece
Process water
Cost of water = 0.25 birr/ 20 L
Water used = 0.0108 kg/piece
Total cost = 0.000135 birr/piece
Total raw material cost = 2.005 birr/piece = 0.07426$
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Total raw material cost = 2.005 birr/piece*20,000 pieces/day*300 days/year
= 445,560 $/year
2) Operating labor cost (10 – 20 % of TPC), but we have to use our estimated amount of
labor costs which is described as follow;
Table 5 Operating manpower required
No Job Quantity
(No)
Monthly
payment ($)
Annual salary($)
1 General manager 1 166.66 1999.92
2 Secretary 1 50 600
3 Production
manager
1 129.63 1555.55
4 Production 22 1222.1 14665.2
5 Accountant and
controller
2 55 660
6 Cashier 1 30 360
7 Purchaser 3 90 1080
8 Store keeper 2 60 720
9 Cleaner 3 78 936
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10 Driver 3 166.66 1999.92
11 Guard 4 148 1776
12 Shift leader 2 59.2 710.4
Total amount 45 2,255.19 27,062.99
3) Direct supervisory and clerical labor(10 – 25 % of operating labor cost)
= 0.175*27,062.99$
= 4736.02$
4) Utilities( 10 – 20 % of TPC ) = 0.15*1155081.33$ = 173262.2$
5) Maintenance and repair( 2 – 10 % of FCI), 0.1* 931863.2985$ = 93186.33$
6) Operating supplies ( 10 – 20 % maintenance &repair) = 0.15*93186.33$ = 139780$
7) Laboratory charges (10 – 20 % operating labor cost) = 0.15 *27,062.99$ = 4059.45$
Total direct production cost, TDPC = 887,647$
C. Plant overhead cost: It is 60 % of (operating labor cost + maintenance cost +
supervision cost)
= 0.6* (27,062.99$+ 93186.33$+4736.02$)
= 124,985.34$
Thus, manufacturing cost = direct production cost + fixed charges + plant overhead cost
= 887,647$+173262.2$ + 124,985.34$
= 1,185,895.54$
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General expense
1) Administrative cost ( 2 – 6 % of TPC) = 0.04 * TPC
2) Distribution and selling cost (2-20 % of TPC) = 0.11*TPC
3) Research and development cost ( 5% of TPC) = 0.05*TPC
4) Research and finance (0–10 % TCI) = 0.05 *1095601.553$ = 54780.1$
The total production cost is the sum of manufacturing cost and general expense.
Now, TPC = MC + GE
TPC = 1,185,895.54$+ 0.04TPC + 0.11TPC + 0.05TPC + 54780.1$
Solving for TPC = 1,550,844.55 $/year.
4.7 Production cost
Production cost($
piece) =
Annual production cost
Annual production rate
Production cost =1,550,844.55$/year
1000 (kg
day) ∗ 300 (
days
year) ∗ 1000 (
gm
kg) ∗ (
piece
50gm)
= 0.26 $/piece
4.8 Break Even Analysis
It is to determine the point at which sale revenues equal with the cost of products sold. When
sales are below this point, the plant is making a loss and above this point, the plant is making
a profit. The break-even production is the number of units necessary to produce and sell in
order fully to cover the annual fixed costs [16]. It can be computed as:
Total product cost = Total income
Product-selling price of 0.4$/kg were considered. The break-even point was calculated as
[17],
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(Fixed charges + General expenses + Plant overhead costs) + 0.26n = 0.4n
Where n is the number of kg of product produced.
173262.2 + 0.04TPC + 0.11TPC + 0.05TPC + 54780.1+ 124,985.34 + 0.26n = 0.4n
663,196.55 = 0.14n
n = 4,737,118.2kg.
Then, [4,737,118.2/6,000,000]*100% = 78.95%
This is the quantity of product at break-even point. It is 78.95% of the plant capacity. Based
the break-even production capacity is at 52%, showing that there is good profit margin.
4.9 Gross income: Our selling price should be greater than 0.26 $/piece and will be set
comparatively to the commercial market antimicrobial soap by selling price with our profit so
that the selling price is about 0.4 $/piece.
Total income from product = unit selling price *production capacity
= 0.4 $/piece *300,000 kg/year*20 pieces/kg
= 2,400,000 $/year.
Gross income = total income – TPC
= 2,400,000 $/year - 1,550,844.55 $/year
= 849,155.45 $/year.
Let the tax rate be 35% (income tax of Ethiopia).
Net profit = Gross income (1 – tax rate) = 849,155.45 $/year (1-0.35)
= 551,951 $/year.
Net profit after deprecation = net profit - depreciation
= 551,951 $/year - 93,186.33 $/year
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= 458,752.7 $/year
4.10 Rate of return
ROR = (net profit after deprecation/TCI) *100%
= (458,752.7/1,095,601.553)* 100%
= 41.9%
4.11 Payback period
Payback period = TCI/ Net profit after deprecation
=1,095,601.553/ 458,752.7
= 2.4 years
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CHAPTER FIVE
5. Plant Location & Site Selection
5.1 Plant Location and Site Location
The location of the plant can have a crucial effect on the profitability of a project, and the
scope for future expansion. Many factors must be considered when selecting a suitable site
and only a brief review of the principal factors will be given in this section. The general
principal factors for plant and site location to be considered are:-
Raw material supply.
Transport facilities.
Availability of labor force.
Availability of utilities: water, fuel, power.
Availability of suitable land and for future expansion.
Environmental impact and effluent disposal.
Local community considerations.
Climate, political and strategic considerations
Then by considering those factors, the best possible location is in Addis Ababa city because
of the availability of raw material mostly solid ingredients soap processing are located in the
city as well as cheap labor cost etc.
5.2 Plant Layout
The economic construction and efficient operation of a process unit will depend on how well
the plant and equipment specified on the process flow-sheet is laid out. The principal factors
to be considered are:
Economic considerations
Construction and operating costs.
The process requirements
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Convenience of operation
Convenience of maintenance
Safety
Future expansion.
When we see the layout of the plant, it looks like as follow;
Fig 25 Plant layout
Water
supply Raw material storage Security Workshop
Car
entrance
Productio
n manager
Laboratory
room
Utility room
Flag
Clinic
Toilet and
showering
room
Reserve raw material
storage
Process room
Management
office
Product
storage
Garden
Workers
entrance Security
room
Cafeteria
Land for future expansion of the plant
or free space
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CHAPTER SIX
6. Result and Discussion
I. Eucalyptus oil
For the eucalyptus oil some specific parameters are characterized during the extraction of
eucalyptus oil;
Table 6 Characterization of eucalyptus oil
Characteristics Results obtained Standard
Boiling point, oc 155.3 176 – 177
Viscosity at 200 c, Pa.s 0.0009 0.00246 - 0.0337
Refractive index at 200 c, 1.338 1.457 - 1.467
Specific gravity 0.952 0.870 - 0.912
Odour Characteristic
odor
Characteristic odor
Color black yellow
liquid
Colorless to pale yellow
Solubility in water Insoluble Insoluble in water
Yield (%) 20 15 - 45
From viscosity test: It is the resistance to motion or flow. Temperature, pressure (at very
high value) and concentration are the factors on which viscosity of a fluid depends.
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Temperature is one of the main factors that affect the viscosity of eucalyptus oil. Viscosity is
getting higher as the temperature decreases. By increasing the temperature, the viscosity of a
fluid decreases to increase in molecular motion as a result the decrease of the inter-chain
liaisons. The size of molecules is also necessary to have a high or low viscous effect.
Moreover, in the mixtures, a fraction of each phase affects the viscosity. Concentration has
also direct relation with the viscosity because of higher concentration leads to higher the
viscosity.
From solubility test: Solubility is the ability of the substance to dissolve into another
substance using the principle of "like dissolves like". This statement indicates that a solute
will dissolve best in a solvent that has a similar chemical structure to itself. The overall
solvation capacity of a solvent depends primarily on its polarity [18]. Highly polar solute is
very soluble in highly polar water and practically insoluble in non-polar solvents. So that
eucalyptus oil is an organic non polar compound, it does not dissolve by polar solvent.
From refractive index test: it is the measure of the bending of a ray of light as it passes from
one medium to another. The refractive index of organic chemical compounds that are liquids
usually decrease with temperature rise. The actual decrease in refractive index for a wide
range of organic compounds at about 0.00045 per degree celsius temperature rise. So the final
result of refractive index of eucalyptus oil may be changed from the actual value.
From boiling point test: Boiling point is dependent upon the strength of the bonds between
its molecules. Intermolecular bonds among them is the strength of the bonds between
molecules the bonds between its molecules are comparatively strong at lower temperature.
The simplest way to change the boiling point of a liquid is to change the surrounding
pressure. A closed system to artificially increase that pressure will raise the boiling point of a
fluid. Lowering the surrounding pressure, either by increasing altitude or artificially creating
a vacuum, will lower the same liquid’s boiling point. In an open system, the outside pressure
is most likely the earth’s atmosphere. Generally the boiling point of eucalyptus oil is lower
than its actual value because of the operation performed to determine the boiling point is
open system.
II. product
From foam test: In this test the prepared and commercial (roha) sample of antimicrobial
soap was taken and allowed to form foam and the foam length was measured.
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In this paper the disappearance of foam in the prepared soap to that of the commercial (roha)
soap solution was compared depending up on the time taken. During the experiment the
following results were recorded.
Fig 26 Effect of time on the foam length of soap
From the above graph the foam length and the time taken too disappeared has inverse
relationship, i.e. as the time increased the length of foam will be decreased because of it will
disappear out through a period of time. And the foam length for the prepared soap initially
was higher than the commercial (roha) soap which indicates that the prepared soap has
medium foaming capacity compared to the commercial. And also the washing efficiency of
soap depends upon it foaming capacity. The foaming capacity also depends upon the quality
of water used.
So that soft water is used in order to check the washing efficiency. That means the washing
efficiency in the sample is medium because it depends on the foaming capacity and the nature
of the soap. Finally the average foam length of 7.75 cm with average time to disappear is
about 3minute for the product but an average foam length of 7.825 cm with the same average
time to disappear for the commercial (roha) soap.
3
4.5
6
7.5
9
10.5
12
0 1 2 3 4 5 6 7
Foam
len
gth
(cm
)
Time to disappeared (min)
Time vs Foam length
Product
Commercial
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From power of clearance test: The power of clearance of antimicrobial solid soap was
relatively good and higher than the commercial (roha) medical soaps, when compared to the
two soaps by visualization with necked eye.
From hardness test: The hardness test was performed using three different ratio of fats, that
means 50%, 75% and 100% of fats and the value is about 1.5 cm, 1.1 cm and 0.5 cm
respectively and the average hardness value of soap prepared from different ratio of fat was
1.033 cm. The average hardness value for 75% of fat (1 cm, 1.1 cm and 0.9 cm) was 1 cm.
Fig 27 Effect of beef fat on the hardness of soap
00.10.20.30.40.50.60.70.80.9
11.11.21.31.41.51.61.71.81.9
2
25 50 75 100 125
Len
gth
of
pen
trat
ion (
cm)
Amount of fat (%)
Effect of fat on hardness of soap
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Fig 28 Hardness comparison of soaps
From the above graph (fig 27), the hardness of solid soap prepared was directly related to the
amount of beef fat used. Because of the amount of fat used was increased the length of
penetration of the needle was lower as a result of its hardness. Using of only fat to prepare the
required product, the result of the product was hard relative to the other ratio of fats. At the
end 25% of castor oil and 75% of fat were used for best quality of the product in terms of cost
and specific parameters like that of foam, power of clearance and alkalinity.
From the above graph (fig 28), the comparison shows that roha eucalyptus soap having an
average hardness value of 0.9 cm but for the product its hardness was about 1 cm.
From moisture content test: From the experiment that was performed, the average moisture
content of the product was determined from the following data’s. The total moisture content
of the product was 17% this result shows that the product is in the range of the standard
moisture content of solid soaps.
Where
Ww is the wet weight of soap, gm
Wd is the dry weight of soap, gm
0.5
0.6
0.7
0.8
0.9
1
1.1
1.2
Catagories
Har
dnes
s (c
m)
Hardness comparison
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Table 7 Weight of soap during moisture content determination
Runs Weight of soap
Ww (gm) Wd (gm)
1 10 8.7
2 10 8.69
3 10 7.5
From the table the dry weight of soap was decreased throughout the time, indicating that the
moisture content on the soap is reduced by the heat applied and the water content is
evaporated as a vapor from the product.
Determination specific gravity of the product: It can be evaluated using by quantifying the
amount of mass and volume of the product. The following results were recorded;
Table 8 Specific gravity determination data
The average specific gravity value of antimicrobial solid soap produced was 0.97 but for the
roha eucalyptus soap is about 0.952. Finally, the antimicrobial solid soap is approximately the
same to that of commercial (roha) eucalyptus soaps.
Product Commercial (roha)
No of runs Mass (gm.) Volume (ml) Mass (gm.) Volume (ml)
1 3.2 3.3 2 2.2
2 3.4 3.5 2.5 2.6
3 3.23 3.4 4 4.1
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From antimicrobial activity test: From the experimental result the concentration of
antimicrobial solid soap increases from 5%, 10%, 15% and 20%, the length of clear zone of
the test on the petri dish was also increased, meaning that antimicrobial soap has an ability to
kill or inhibit the growth of bacteria on a specific area, where the soap is applied and also its
effectiveness to resist growth of bacteria was increased with the concentration of solid soap.
Graphically;
Fig 29 Effect of antimicrobial soap on bacteria
The graph shows that if the concentration of antimicrobial soap increases, the growth of
staphylococcus aurous bacteria in that area was highly inhibited by antimicrobial soap
directly, not survive or it was killed by the prepared soap.
1
1.2
1.4
1.6
1.8
2
2.2
2.4
2.6
2.8
3
3 5.5 8 10.5 13 15.5 18 20.5
Len
gth
of
clea
r zo
ne
(cm
)
Soap concentration(%)
Effect of soap concentration on bactreia
Antimicrobial solid soap production
BiT 5TH-CHED Thesis project Page 65
Fig 30 Comparison of anti-microbial activity
As shown from this graph the average capacity of antimicrobial soap to resist the growth of
bacteria was estimated. 31.1% (radius = 1.4 cm) of staphylococcus aurous bacteria was
removed from the given area of bacterial zone by the prepared product but for commercial
(roha) antimicrobial solid soap was about 40% (radius = 1.8 cm) of staphylococcus aurous
bacteria was removed by taking 5% of antimicrobial soap.
From yield determination: The yield of soap from beef fat was estimated by dividing the
amount of clear fat to that of the amount of raw beef fat. 10 kg of beef fat was bought, among
this 4 kg of clear fat was isolated which is used directly for soap production. So that 40% of
yield of soap was obtained.
From alkalinity test: From the experiment basicity or alkalinity value of prepared soap after
measuring with ph meter was recorded as the values of alkalinity.
1 2
Series1 1.8 1.4
Roha
Product
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Len
gth
of
clea
r zo
ne
(cm
)
Anti microbial activity comparison
Antimicrobial solid soap production
BiT 5TH-CHED Thesis project Page 66
Fig 31 Comparison of alkalinity
From the above graph, there was a fluctuation of its value during measurement, because of in
accuracy of the ph meter. Both the prepared and commercial (roha) soap is basic in nature
and the average alkalinity value of prepared antimicrobial soap is about 8.6 but for the
average alkalinity value of roha eucalyptus soap is about 8.58.
From eucalyptus oil ratio: The amount of eucalyptus oil used for soap production was in the
range between 2% to 4% [19]. The amount of eucalyptus oil used has a major factor on the
growth of bacteria, meaning that if the amount of eucalyptus oil used is higher, than the
length of clear zone of the bacteria was also increased by taking 25:75 ratio, which is 25%
castor oil and 75% of animal fat.
1 2 3
Series1 8.6 8.5 8.72
Series2 8.62 8.73 8.4
Product
Product
Product
Roha
Roha
Roha
8.35
8.4
8.45
8.5
8.55
8.6
8.65
8.7
8.75
PH
val
ue
Comparison of alkalinity of soap
Antimicrobial solid soap production
BiT 5TH-CHED Thesis project Page 67
Fig 32 Effect of eucalyptus oil
From the above graph, that amount of eucalyptus oil used is directly related to that of length
of zone of inhibition until 3% of the total oil used in the production. If someone uses higher
amount of eucalyptus oil above 3% as antimicrobial agent, the percent inhibit of the growth
of bacteria approaches to a constant value, but it might have an effect on human body
because of its higher concentration and the cost is increased. So that in order to limit its effect
on human body and the cost, the eucalyptus oil must be reduced to an optimum value.
1.1
1.17
1.24
1.31
1.38
1.45
1.52
1.59
2.25 2.5 2.75 3 3.25 3.5 3.75 4
Len
gth
of
inhib
itio
n (
cm
Percentage of oil used (%)
Effect of eucalyptus oil on sthapylococus bacteria
Antimicrobial solid soap production
BiT 5TH-CHED Thesis project Page 68
Table 9 Ratio of oils and its effect
Ratios
Eucalyptus oil (%)
2.5 3 3.5
(50:50)a Medium softness
& lower odor
Medium softness
& medium odor
Medium softness
& higher odor
(25:75)b Lower softness
& lower odor
Lower softness
& medium odor
Lower softness
& higher odor
(0:100)c Very hard
& lower odor
Very hard &
medium odor
Very hard &
higher odor
From the above table, at lower rate of eucalyptus oil and animal fat the product has higher
ability to become soft whereas, using higher animal fat the nature of the product is very hard.
That means the amount of fat increased as a result its softness will decrease.
Antimicrobial solid soap production
BiT 5TH-CHED Thesis project Page 69
CHAPTER SEVEN
7. Conclusion and Recommendation
7.1 Conclusion
In this thesis project work production of antimicrobial solid soap was carried out under a
series of steps starting from pretreatment of animal fat. Animal fat to castor oil ratio and
percentage amount of eucalyptus oil were considered as factors to see their effects on the
quality antimicrobial solid soap. Based on the experimental result, best quality of
antimicrobial solid soap was prepared at 25% castor oil, 75% animal fat and 3% of
eucalyptus oil to that of total used oil. By doing nine experiments with the characterization of
percent inhibition of growth of bacteria, specific gravity, hardness, power of clearance, PH
value and foam ability was estimated. From the prepared soap in this thesis project it has
higher suds or foam which indicates that the concentration of soap in the mixture is higher,
results the prepared soap has good cleaning capacity. At the end almost all the parameters for
the prepared soaps were the equivalent to that of roha eucalyptus soap and the final
antimicrobial effect in terms of percent inhibition was around 31.1%. The production of
antimicrobial solid soap can be regarded as one area of business that is lucrative and needs
only little capital to start with the vast available resources.
Antimicrobial solid soap production
BiT 5TH-CHED Thesis project Page 70
7.2 Recommendation
In this project work, the effects of temperature was not studied due to the lack appropriate
equipment’s, therefore, further study is need on these effects and also it is better to use heat
integration equipment’s in order to save the waste heat which is released from exothermic
reactions. Also the efficiency of antimicrobial soap was not directly measured by applying
bacteria on the clothes using direct washing method so that it better to use washing method
and use steam distillation for the pretreatment of animal fat and extraction of eucalyptus oil.
The optimum dosage of eucalyptus oil that are used for production of antimicrobial solid soap
is not studied, the further study is required to know its optimum dosage. And also aloe Vera
and garlic are used as antimicrobial agent, it might be better using it, so that further study on
aloe Vera and garlic plants are required.
During extraction of eucalyptus oil only normal hexane was used to extract it, but further
study is required to search other solvents that are used for extraction, that will give higher
yield of eucalyptus oil.
Antimicrobial solid soap production
BiT 5TH-CHED Thesis project Page 71
Reference
[1]. S. Tumosa, Charles (2001-09-01), "A brief History of Aluminum Stearate as a Component of Paint".
[2]. Willcox M et al (2016), "Soap", In Hilda butler, Poucher's Perfumes, Cosmetics and soaps (10th ed.).
[3]. Pears, The Skin, Baths, Bathing and Soap, the author, pp. 100, Archived from the original, Francis, 2016-
05-04, 1859.
[4]. Ansard et al (1864), Hansard's Parliamentary Debates, Uxbridge, England, Forgotten Books, pp. 363–374.
[5]. Akira Tajima et al (1995), Is beef tallow really hazardous to health, accepted for publication April 1'2.
[6]. Khalid M. et al (2015), Extraction and Modeling of Oil from Eucalyptus camadulensis by Organic Solvent,
University of Baghdad, Baghdad, Iraq, published August 7.
[7]. Hajer N. et al (2011), Eucalyptus oleosa essential oils, chemical composition and antimicrobial and
antioxidant Activities of the Oils from Different Plant Parts, Tunisia, Published, February 17.
[8]. http://www.madehow.com/Volume-4/Antibacterial-Soap, html.
[9]. Umar M. et al (2002), Cosmetics, soaps, detergents and NAFDAC’s regulatory requirements, Maiduguri,
Borno State, Nigeria.
[10]. Pocket information manual a buyer's guide to rendered products, Published by the national renderers
association, Inc, Virginia, 2003.
[11]. D. S. Chinchkar et al, “Castor Oil as Green Lubricant, A Review” International Journal of Engineering
Research and Technology (IJERT), Vol, 1 Issue 5, July, (2012).
[12]. Eucalyptus essential oil as an alternative to chemical pesticides.
[13]. Mattil KF (1964), Deodorization in bailey’s industrial oil and fat products, (3rdedition), John Wiley, New
York, USA.
[14]. Customs authority, external trade statistics, various years CSA, statistical abstract, 1990 - 2002.
[15]. Plant design and economics for chemical engineers, McGraw-Hill, 4th edition (Timmerhaus).
[16]. Richard W. Felder, Elementary Principles of Chemical Process, 3rd Edition, 2005.
[17]. Perry J. H, Chemical Engineers Handbook, Mcgraw - Hill, New York, 1997.
[18]. The solvent polarity is defined as its solvation power according to reichards.
[19]. Calculating your essential oil usage rate in soap making (following ifra standards).
[20]. www.mache.com equipment cost.
Antimicrobial solid soap production
BiT 5TH-CHED Thesis project Page 72
Appendix
Table 10 Equipment specifications [20]
Equipment’s’ Type Material of
constriction
Productio
n capacity,
kg/hr
Power
required
Volume
,πr2h (m3)
Pres
sure
Cost($)
Dryer Tray
vacuum
Stain less
still
- - - - 34,100
Storage tank 1 Vertical,
small
Stainless
still
- - H: 1m
D:0.5m
atm 3100
Caustic-soda solution
tank
Vertical,
small
Stainless
still
- - 0.78 atm 1100
Mixer/Blender Kneader,
stationary,
double
arm
Stainless
still 304
100 - 250 2020hp - atm 172000
Soap extruder
,SYJ- model
Duplex
vacuum
plodder
extrude
- 500 – 600
- - -
10,000
Conveyor
Belt, long Carbon
Steel
- - L:30M,
W/D:0.05
inches
- 100
Centrifugal pump,
mechanical seal
Horizont
al,
1-stage
Stainless
still
- - Pipe
diameter:
0.1inch
- Cost:
1500
Wrapping machine
250B-model
Stand
- - - - - 4,591.5
5
Cutter machine,
XQK/L300 model
Pneumatic
stainless
steel
120peices/
min
1.3kw - -
13000
Antimicrobial solid soap production
BiT 5TH-CHED Thesis project Page 73
Table 11 Purchased equipment cost
Type of equipment’s Quantity Equipment cost ($ )
Dryer 1 34100
Wrapping machine 1 4,591.55
Cutter machine 1 13000
Centrifugal pump 1 1500
Soap extruder 1 10,000
Conveyor 3 300
Mixer/Blender/ 2 172000
Castor oil storage tank 1 1 3100
Caustic soda solution tank 2 2200
Total purchased equipment cost 240,791.55