Chemical engineering Thesis and Dissertations

DSpace Institution

DSpace Repository http://dspace.org

Chemical engineering Thesis and Dissertations

2018

Antimicrobial solid soap production

Mequanint, Gashanew

http://hdl.handle.net/123456789/11103

Downloaded from DSpace Repository, DSpace Institution's institutional repository


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 …….


BiT 5TH-CHED Thesis project Page ii

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.


BiT 5TH-CHED Thesis project Page iii

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.


BiT 5TH-CHED Thesis project Page iv

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


BiT 5TH-CHED Thesis project Page v

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


BiT 5TH-CHED Thesis project Page vi

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


BiT 5TH-CHED Thesis project Page vii

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


BiT 5TH-CHED Thesis project Page viii

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


BiT 5TH-CHED Thesis project Page ix

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


BiT 5TH-CHED Thesis project Page x

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


BiT 5TH-CHED Thesis project Page xi


BiT 5TH-CHED Thesis project Page 1

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

https://en.wikipedia.org/wiki/Salt_%28chemistry%29

https://en.wikipedia.org/wiki/Fatty_acid

https://en.wikipedia.org/wiki/Washing

https://en.wikipedia.org/wiki/Bathing

https://en.wikipedia.org/wiki/Housekeeping

https://en.wikipedia.org/wiki/Surfactant

https://en.wikipedia.org/wiki/Emulsifying

https://en.wikipedia.org/wiki/Babylon

https://en.wikipedia.org/wiki/Alkali

https://en.wikipedia.org/wiki/Cinnamomum_cassia

https://en.wikipedia.org/wiki/Ebers_papyrus

https://en.wikipedia.org/wiki/Ancient_Egypt

https://en.wikipedia.org/wiki/Wool

https://en.wikipedia.org/wiki/Industrial_Revolution

https://en.wikipedia.org/wiki/James_Keir

https://en.wikipedia.org/wiki/Tipton

https://en.wikipedia.org/wiki/Potash

https://en.wikipedia.org/wiki/Andrew_Pears

https://en.wikipedia.org/wiki/London

https://en.wikipedia.org/wiki/Thomas_J._Barratt

https://en.wikipedia.org/wiki/Isleworth

https://en.wikipedia.org/wiki/Restoration_era



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

http://www.soaphistory.net/soap-history/history-of-soap/

http://www.soaphistory.net/detergent-history-facts/history-of-detergent/

http://www.soaphistory.net/soap-facts/soap-benefits/



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.



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.



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.



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.



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].



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].



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.



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



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.



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



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.



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



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).



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



Fig 3 Pre-treatment of beef tallow

Fig 4 Melting of beef tallow

Fig 5 Beef tallow fat after refrigerate



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.



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



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.



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



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.



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.



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



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



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



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.



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.



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



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)



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%



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].



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



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



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)



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



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



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



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



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



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



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



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.



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



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.



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



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



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$= 867$



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


Animal fat (beef fat)



Beef fat cost = 30 birr/kg

Fat used = 0.02055 kg/piece


Castor bean

Castor bean cost = 15 birr/kg

Castor oil used = 0.00685 kg/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


Process water

Cost of water = 0.25 birr/ 20 L

Water used = 0.0108 kg/piece


Total raw material cost = 2.005 birr/piece = 0.07426$



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



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$



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],



(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



= 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



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



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



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.



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.



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



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



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



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



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



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



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



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



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.



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.



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.



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.

http://cool.conservation-us.org/waac/wn/wn23/wn23-3/wn23-304.html

https://books.google.com/books?id=4HI8dGHgeIQC&pg=PA453

https://books.google.com/books?id=yFlJAAAAYAAJ&pg=PA100

https://web.archive.org/web/20160504074628/https:/books.google.com/books?id=yFlJAAAAYAAJ&pg=PA100

http://www.madehow.com/Volume-4/Antibacterial-Soap,%20html



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



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

Documents

Chemical engineering Thesis and Dissertations