CHAPTER ONE

INTRODUCTION

1.1 BACKGROUND INFORMATION

In the earlier stage of Science and Technology

education in Nigeria, students were graduating from

their respective institution without any technical

knowledge or work experience. It was in this view

that students undergoing Science and Technology

courses where mandated for students in different

institution in the view of widening their horizons so

as to enable them have technical knowledge or working

experience before graduation.

The student industrial work experience scheme (SIWES)

is the acceptable skill training program, which forms

part of the approved minimum academic standard in the

various degree programs for all the Nigerian

universities. It is an effort to bridge the gap

between theory and practice of engineering and

technology, sciences, agriculture, medical,

1

management and other professional educational

programs in Nigerian tertiary institutions. It is

aimed at exposal to machines and equipments,

professional work areas and workers in industries and

other organizations. The minimum duration of the

program is directed by the industrial training fund

(I.T.F) and the National universities commission

(N.U.C). The scheme is a tripartite program involving

the students, universities and industries (employers

of labour). It is founded by the federal government

of Nigerian and jointly coordinated by I.T.F and

N.U.C.

1.2 BRIEF HISTORY OF THE SIWES UNIT

The Industrial Training Fund (ITF) established

Student Industrial Work Experience Scheme (SIWES) in

1973 to solve the problems of lack of adequate

practical skills preparatory for employment in the

industries by Nigeria graduates of tertiary

2

institutions. The scheme was designed to expose

students to industry based skills necessary for

smooth transition from the classroom to the world of

work and enable them develop occupational

competencies so that they can readily contribute the

quota to national economic and technological

development after graduation. It offers students of

tertiary institutions the opportunity of being

exposed familiarized and exposed to the needed

experience in real time job demands.

1.3 OBJECTIVES OF SIWES

Specifically the objectives of the student’s

industrial work experience scheme are to:

i. Provide an avenue for students in Nigerian

universities to acquire industrial skills and

experience in their course of study.

ii. Prepare students for the work situation they

are likely to meet after graduation.

3

iii.Expose students to work methods and techniques

in handling equipments and machinery that may

not be available in their universities.

iv. Make the transition from the university to the

labour world easier and thus enhance students’

contacts for later job placement.

v. Provide students with an opportunity to apply

their theoretical knowledge in real work

situation, thereby bridging the gap between

universities and actual practices.

vi. Enlist and strengthen employers’ involvement

in the entire educational processes of

preparing university graduates for employments

in the industries.

4

CHAPTER TWO

2.1 BRIEF HISTORY OF DANGOTE SUGAR REFINERY

The Dangote Sugar Refinery is a subsidiary of Dangote

Group located in Lagos State, at Nigeria’s largest

port, The Apapa Wharf. The company commenced business

in March 2000 and the sugar refining plant was

commissioned in 2001, with an initial capacity of

600,000MT p.a. The company imports raw sugar from

Brazil and refine it into white granulated sugar

5

which is divided into two types; FORTIFIED and NON –

FORTIFIED sugar.

The fortified white sugar contains Retinol (vitamin A)

while the non-fortified white sugars are for industrial

use and it is not fortified with retinol. Dangote

Sugar Refinery PLC is in the business of refining

white sugar using new technology of ION EXCHANGE

RESIN (I.E.R).

The Dangote Sugar Refinery has excellent facilities

designed and installed by TATE and Lyle for

production of refined sugar. TATE and TYLE is the

largest sugar refinery in Europe and its refining

technology is regarded as one of the best in the

world.

The company’s operation comprises two key business

areas; refining of raw sugar imported from Brazil and

marketing and distribution for direct consumption and

industrial needs. In compliance with the National

Agency For Food Drug Administration And Control

6

(NAFDAC) policy, which makes the fortification of

staple foods mandatory in Nigeria, Dangote Sugar

Refinery PLC produces and packages fortified refined

white sugar in 1kg, 500grams, 250grams and 50kg bags

for direct consumption under the brand name ‘DANGOTE

SUGAR’ as well as the unfortified white sugar for

industrial use and sells its product across Nigeria.

Interestingly, ‘D.S.R’ is one of the very few sugar

refined in the world that produces RETINOL fortified

white sugar at its Apapa factory under strict NAFDAC

policy.

2.2 OBJECTIVE OF DANGOTE SUGAR REFINERY

Touch the lives of people by providing their

basic needs.

To become a global, integrated, low cost sugar

producer focused on maximizing long term

shareholder returns while establishing a leading

7

presence in domestic and regional African

market.

2.3 ORGANOGRAM OF DANGOTE SUGAR REFINERY

8

2.4 INDUCTION ON SAFETY WHICH IS VERY NECESSARY IN

THE REFINERY

9

Safety is an act of being safe in the line of duty.

It ensures that all staffs must observe and adhere to

all protocols, precautions and procedures in order to

avoid accidents and injuries. Safety entails in using

what is known as P.P.E that is ‘personal protective

equipments’ which includes:

Wearing of Hand-gloves to avoid chemicals eating

up the fingers etc, then eye goggles to avoid

spillage of chemical or light rays.

Safety boots to avoid metals or nails

perforating through your soft shoes.

Nose mask to avoid inhaling the chemicals.

Helmet to prevent any metal drop or accidental

hit on the head.

Laboratory coat to prevent spillage of chemicals

on the body.

Hair net to avoid contamination of the sugar.

10

The basic precaution is the use of our hand

sanitizers to get rid of germs and to prevent the

dangerous disease called EBOLA. There is always a

penalty for staffs that are reported for lack of

P.P.E. and if an accident is reported also, the first

question is if the P.P.E is on or not on use.

PICTORIAL VIEW OF DANGOTE RAW SUGAR

11

12

CHAPTER

THREE

PROCESS

DEPARTMENT

STAGES IN THE REFINERY

13

PRE- MELTING STAGE

MELTING STAGE

CLARIFICATION STAGE

DECOLORIZATION STAGE

EVAPORATION STAGE

CRYSTALLIZATION STAGE

14

CENTRIFUGATION STAGE

DRYING STAGE

BLENDING/ROTEX STAGE

FORTIFICATION STAGE

BAGGING STAGE

PRE-MELTING STAGE

This stage is the first unit in Dangote Sugar

Refinery and is also known as the VERY HIGH POLARITY

[V.H.P] STAGE. The pay loaders conveys the raw sugar

into the oban pan which have a hole underneath that

allows sugar to drop on the belt drag out conveyor,

then it drags the sugar down to the elevator and

inside the drag out there is a magnet which magnets

any metal found in the raw sugar before it goes to

the elevator. The elevator, which have a bucket

inside now transfers the raw sugar to the silo [V.H.P

sugar hoppers], then the screw drag out conveyor

drags the sugar to the pre melting tank which have a

15

sever that sieves all the unwanted particles from the

raw sugar. Inside the boiling tank there is a rod

stirrer that spins around to dissolve the sugar once

it gets to the tank to avoid clots/lumps of sugar.

The water used in boiling the sugar is called sweet

water after boiling the slurry pump will open and

transfers the liquor to the next stage. Expected Brix

here is 66-67.

MELTING STAGE

This stage detects and corrects the carryovers done

in the first stage. If the brix is too high or too

low this stage will report to the first stage and

they will make amendment. They use steam to control

the brix, the higher the steam the lower the brix and

vice versa. There is Lin catchers here that further

detects the carryover dirt from the first stage and

then trap them. At this stage it is assumed that the

16

sugar has been completely dissolved before it goes to

the next stage.

N.B: At every stage there is an expected range of

brix. Expected brix here is 62-64.

TALOCLARIFICATION STAGE

17

This is where the Dangote Sugar Refining unit place

more emphasis in removing the impurities present in

the melted liquor, this stage is an essential part of

the raw sugar processing. Taloclarification is the

removal of color and turbidity from melted liquor

through the process of flocculation, floatation and

separation techniques. The main objective here is

removal of 90percent of turbidity and 40percent of

color then the main parameters we check here is the

brix, temperature, and the pH. When we have a low

brix it creates high turbidity of the liquor and when

it’s too low it creates filtration problem. The

expected brix in taloclarification is 62-63.Also when

we obtain a high temperature it tends to increase the

expected color of the liquor while low temperature

will result to incomplete reaction of the liquor.

Expected temperature here is 80-84. PH of the liquor

is very important here, when the pH is low the sugar

will be very wet and will not dry well because it is

18

acidic, and also it will cause inversion of sugar

that is the splitting of sucrose to glucose and

fructose. It will be inform of dust and the expected

grain size will be lost. But when the pH is high it

causes high color formation. Expected pH here is 6.9-

7.2.

NOTE; When we discover a high pH and high temperature

in the liquor solution we recycle it back to the

melting stage for curing.

4 chemicals are added here in talo-clarification

namely;

Phosphoric acid which is colorless and odorless. It

serves as a neutralizing agent.

Hydrated lime; it helps in the decolorization of

the liquor.

Talofloc; this is the main decolorizing agent that

further breaks down the particles into smaller

19

particles and they come together with the aid of

stirrer in the reaction tank.

Taloflote[flocculants]; this makes the aggregated

particles in the liquor solution to float on the

liquor thus enable proper separation of the scum

from the clarified liquor .flocculants are

advantageously use in the sugar clarification cause

it helps to float the scum present in the liquor

solution.

SCUM

This is a layer of dirt formed on the surface of a

liquid, or the firmly layer of an impure matter that

rises to the surface of the liquor solution.

HEAT EXCHANGER: This is a device in taloclarification

process that increases the temperature of the liquor

solution to the expected temperature [80-84] so that

a complete reaction can take place as the liquor gets

20

to the reaction tank. Shell and tubes heat exchanger

is used such that the liquor will run through the

heated tubes and the steam flows through the shell so

that heat can be exchanged between the two fluids. In

Dangote Sugar Refinery we have about 144 tubes in one

heat exchanger.

DECOLORIZATION STAGE

This stage makes use of ion exchange resin and resin

is the chemical that mainly extracts all the

colorants from the liquor solution. By definition;

ion exchange resin or ion exchange polymer is an

insoluble matrix normally in form of small [0.5-1mm

diameter] beads, usually white or yellow in color.

The beads are typically porous, providing a high

surface area. The trapping of ions occurs with

concomitant releasing of other ions thus the process

is called ion exchange. Resins are widely used in

different separation, purification and

decontamination processes.

21

We have two types of resin commonly use in ion

exchange process. Namely; the cation resin and anion

resin.

Cat ion resin are those resins that attract the

positively charge ions in a solution. Anion resins

are those resins that attract the negatively charged

ions in a solution, and that is the one we make use

of in Dangote Sugar Refinery because the liquor is

cationic in nature. The resin inside the batteries is

what carries out the decolorization process because

it attracts all the cationic ions and colorants to

itself and an improved state of liquor will be

obtained. In this stage we are focusing on bringing

down the turbidity of the liquor sample by 30-40 with

the help of our pressure filters. One pressure filter

pan in Dangote Sugar Refinery contains about 36filter

beds and the membrane is about 46micron meter in

space that can hardly allow any form of impurity to

penetrate. Normally once the pressure filters absorb

22

much impurity it will automatically stop functioning

until the beds are changed. The liquor gotten from

the pressure filters are named polished filter liquor

because it is now free from any form of impurity and

thus ready for crystallization.

EVAPORATION STAGE

Evaporator is a device in Dangote Sugar Refinery that

is used to brix up the liquor solution by eliminating

excess water from the liquor solution thereby

providing a fine liquor very thick example pap. The

expected brix in this stage is about 70-80.from this

stage we get our massecuite which is the mixture of

syrup and the sucrose then it goes to the next stage

which is crystallization stage

CRYSTALLIZATION STAGE

23

Crystallization is done under vacuums in Dangote

Sugar Refinery to avoid color formation, to reduce

the rate of steam consumption, to avoid excess loss

of sucrose, to lower the evaporative equipment and to

reduce the operative temperature. Slurry is added in

this stage for crystal formation and the slurry

timing determine a good grain size of the sugar. One

vacuum pan contains about 600-750bags of sugar per

yield batch. In this stage liquor boils at about 1;

30minutes per strike before it goes on to the next

stage called centrifugal stage

PREPARATION OF SLURY

Take 1.620kg of sieved sugar [600micron or 0.6mm]

with 3.6 liters of Isopropyl alcohol. Put into the

slurry machine and switch the machine on for 24hours

then slurry is formed.

24

CENTRIFUGAL STAGE

This is the stage were separation of sugar crystals

from the mother syrup takes place using a batch

centrifuge. Batch centrifuges consist of a metal

basket1220mm in diameter, the holes of which are

smaller moving towards the centre. A thin perforated

copper plate called a mesh or cloth with 0.5mm

diameter holes is placed on the side. The basket is

mounted on a vertical shaft through a bearing which

connects to an overhead drive motor. There will be

between 20-26batches or cycles per hour, each cycle

starts by charging the basket with massecuite as it

rotates at 250rpm. An evenly distributed full charge

of massecuite would be 203mm thick and weigh 1250kgs.

The basket accelerates to 1500rpm for a present

period then decelerates to 50rpm at which speed the

spun sugar is removed by a ploughing mechanism. The

unit is then ready for the next cycle. During the

25

cycle, a wash is applied to centrifugal machine to

remove residual syrup adhering to the crystals. From

the centrifuge the sugar is then conveyed to the next

stage which the sugar dries

DRYER

Sugar leaves the centrifuges containing between ½ and

11/2 moisture. The majority of water is driven off in

the driers. There are three driers in Dangote Sugar

Refinery each capable of drying 30 tones of sugar per

hour. The driers are horizontal cylindrical vessels

approximately 2.7m in diameter by 12m long [9 feet in

diameter by 40 feet long]. The driers are of co-

current design, that is the air and the sugar both

travels through the driers in the same direction.

Both hot air and cold air are applied to the drier

for drying and subsequent cooling of the product. The

hot air enters the drier through a vent inside the

vessel and passes through a bed of sugar. The air

26

then travels down the air space inside the drier. As

the drier drum is rotating at 10rpm, sugar is carried

up to a height and then falls to the bottom forming a

curtain down the length of the drier. The hot air

passes through the curtain of sugar. Typical hot air

temperatures are 50 to 60’c. Air at ambient

temperature is applied to the drier to cool the

sugar.

BLENDING STAGE

This is a unit in Dangote Sugar Refinery were the

grain sizes of the sugar sent from driers are

determined before going to the fortification section.

They make use of a Rotex machine which have a screen

mesh opening of 0.067mm.it sieves the sugar and send

the lumps to be recycled.

FORTIFICATION STAGE

27

Fortified sugar is made by adding the vitamin A

premix to the sugar either in the centrifuge at the

end of centrifugation, over the belt conveyor that

leads the sugar to the drying turbines or after

drying when the sugar is moving down to the packing

chutes. A reliable mechanism is used to ensure that

homogeneity of the vitamin A content in sugar is

maintained. Premix contains sugar, retinyl palmitate,

vegetable oil, and an antidioxidant. The premix is a

free flowing product that is light yellow in color,

slightly oily to touch, and smells like retinol.

Premix that is stored for more than 2months or that

is badly prepared or inadequately stored can develop

an unpleasant rancid smell indicating that the oil

has been oxidized. The premix is prepared inside the

v-shaped blender and the range at which we add it is

1kg of vitamin into 1000kg of sugar. The cremix

(coconut oil) we use in dangote sugar refinery is

28

imported from Malaysia.

BAGGING SECTION

The sugar leaves the driers and is conveyed to silo,

which is capable of storing a maximum of 80 tones of

sugar each. From the silo the sugar passes over

magnets to further check if there is trace of any

metal object, then is sieved again to remove coarse

lumps of sugar, and finally bagged in 50kilo bags.

Then the belt conveyor carries it down to where the

trucks are packed.

THE TYPES OF SUGAR WE GET IN THE REFINERY.

HIGH GRADE SUGARS

- R1 == This is the very first sugar and is very

white.

- R2 == This is the second run off sugar and is

not as white as R1

29

- R3 == This is called run off 3 sugar not as

white as R2 but closer

- R4 == This is run off 4 sugar more or less

like a brown sugar

LOW GRADE SUGAR

A- SUGAR= This is gotten from the R4 sugar and is

brownish in color just like the raw sugar.

NOTE: From A Sugar we get our molasses which some

industries order to make their chocolate, malt,

biscuit and other foods.

30

CHAPTER FOUR

QUALITY ASSURANCE DEPARTMENT

ANALYSIS CARRIED OUT IN THE LABORATORY

pH determination; collect your samples and

cool to room temperature then using your glass

beaker take some samples out and immerse the

probe of the electrode inside the sample and

take the reading on the display of the meter.

Calibration of pH meter; this is a process

whereby the pH meters are standardized or made

31

ready for efficient measurement via buffer

solutions. (i.e. 7,4,10 etc) to forestall

deviations and/or correct errors.

Types of buffer for

calibration of the pH:

1). Buffer 4 solution: This is used to calibrate

the pH meter based on the acidity level or range.

2). Buffer 7 solution: This is used to calibrate

the pH meter based on the neutral range.

3). Buffer 10 solution: This is used to calibrate

the pH meter based on the alkalinity range.

32

Pictorial View Of the p.H meter.

DETERMINATION OF COLOR AND TURBIDITY IN SUGAR

SAMPLES

EQUIPMENTS USED: spectrophotometer

- spectrophotometer cells

33

- brixometer

- vacuum filtration apparatus, capable of

supporting 0.45um filter pads

- vacuum filtration flasks 250ml or 500ml capacity

- vacuum pump

- filter pads 0.45um

- beakers

- shakers/stirrers

- analytical balance

- distilled water

PROCEDURE:

Weigh 50g of sugar sample into your conical

flask, dilute with 50g of distilled water

making it 100g.

Using your orbital shaker, dissolve properly

until no trace of sugar grains

Check the brix on the brixometer

machine.

34

Using the vacuum pump filter the sample

through a membrane filter of pore

size/diameter 50mm respectively into a clean

dry conical flask

Using the talameter machine, determine

absorbance of filtered solution with 10cell

lens

Take your readings and calculate the

results.

Formula: IU= A/BC, where A is the absorbance

B is the cell length

C is the brix factor

IU is ICUMSA, unit for measuring colour

ICUMSA stands for international commission for

uniform method of sugar analysis.

35

Determine absorbance of unfiltered solution

and calculate the turbidity using

AU= (Aunf --Afil) *f/b where Aunf is unfiltered

absorbance

A fil

is filtered absorbance

f

is the brix factor from turbidity table

b

is the cell length and AU is absorbance unit, unit

for measuring turbidity.

DETERMINATION OF VITAMIN PRESENT IN THE SUGAR.

SAMPLE; BAGGING LINES.

Equipments; Orbital Shaker, Weighing balance, Text

tubes, Text tube rack, Glass beaker, Distilled water

and Spatula.

Procedure:

36

Using ratio 1:1, weigh your sample and

dissolve with distilled water

Place on the orbital shaker and switch it on

to further dissolve the solution evenly

Using your text tube rack, pour small quantity

of the dissolved sample

Add 5ml of chromogenic reagent and take your

reading immediately you see color change. If

no color change it means vitamin is absent.

37

Orbital Shaker

ANALYSIS ON A- SUGAR SAMPLE

EQUIPMENT: metal beaker, hot plate stirrer,

brixometer, distilled water, weighing balance and

spatula.

38

Procedure:

Place your metal beaker on the weighing

balance and tare

Measure 30g of sample and dilute with 70g of

distilled water

Put magnetic stirrer into the sample and place

on the hot plate stirrer and dissolve

Check your brix using the brixometer machine

Filter straight using the vacuum pump

Check the absorbance using the talameter

machine with 1cm cell lens

Take your readings and calculate your result.

Formula; filtered absorbance/cell length/brix

factor

ANALYSIS ON MOLASSES ALSO KNOWN AS RECOVERY

The molasses include; A molasses, B molasses, C

molasses and final molasses.

39

Procedure; using your metal beaker weigh ratio 1:1 of

sample and distilled water

- add your magnetic stirrer and place on the hot

plate then dissolve

- allow to cool to room temperature and check your

brix

- using your 50mil flask place on the weighing

balance and tare then measure out 13gram of

diluted sample

- add octapol to it and fill the flask up to the

mark with distilled water

- filter straight using the acetate filter paper

then take the filtrate

- using the saccharimeter machine place the sample

and check the polarity

- Then calculate your readings using the formula:

4 multiply by the polarity/2 multiply by brix

factor then multiply by 100/1.

40

Vacuum Pump

ANALYSIS ON SCUM

- Using your 50ml flask place on the weighing

balance and tare

- Measure 26g of sample add octapol and dilute

with distilled water up to the mark

- Filter using the acetate filter paper and

collect the filtrate

41

- Using the saccharimeter machine place the sample

on it and take your readings

- From the polarity we determine if the impurity

is high or not.

DETERMINATION OF THE SUGAR SIZES (MA/CV)

- Arrange preweighed sieves of varying apertures

sizes, 850u, 600u, 500u, 425u, 300u, 212u and

base pan in descending order recording the

weights.

- Weigh in 100g of the refined sugar sample into

the first sieve and cover

- place on the mechanical shaker, shake for

15minutes

- Reweigh and record the final weight and take

the readings

- With the result the sugar analyst will determine

if the grain sizes are okay or if is too dusty.

42

SPECIAL LABOURATORY ANALYSIS ON LOW POUR FUEL OIL

(LPFO)

A). FLASH POINT

This is the temperature at which the vapor of the

fuel wills a flame. This analysis is carried out to

check the burning ability of automated gas oil

(A.G.O) and the burning ability is the temperature

explosion of the product.

PROCEDURE:

-Fill the sample chamber to the mark with the sample

- Ignite the gas source

- Switch on the tester

- Insert the thermometer

- Stir the sample with the stirrer checking the

temperature at intervals

43

- Note and record the exact temperature at which the

vapor of the sample flashes

- Then you switch off the tester.

REDUCING SUGAR ANALYSIS (INVERT SUGAR)

Inverted or invert sugar syrup is a mixture of

glucose and fructose, it is obtained by splitting

sucrose into two components. Compared with its

precursor, sucrose, inverted sugar is sweeter and its

product tends to retain moisture and is less prone to

crystallization. Sucrose is a disaccharide which

means that it is a molecule derived from two simple

sugars (monosaccharide). In the case of sucrose,

these monosaccharide building blocks are fructose and

glucose. The splitting of sucrose is a hydrolysis

reaction and hydrolysis is a chemical reaction in

which a molecule breaks down by the addition of

water.

44

The essence of carrying out this analysis is to stop

inversion of sugar from taking place in the sugar

refinery because once inversion of sugar takes place

we term to have a very low yield of the sugar. Things

that could stop inversion of sugar from taking place

may include regulation of the temperature to the

expected range and pH.

PREPARATION OF SOME REAGENTS USED:

A). EDTA solution: prepare a solution containing

0.930g per liter of the disoldium salt of

ethylenediaminetetra-acetic acid (EDTA) as required

and discard after use. Alternatively dilute 50ml of

o.o1mol\L EDTA solution to 200ml as required.

B).MUREXIDE INDICATOR: Prepare by grinding with

pestle mortal 0.5g of the murexide which is in powder

form and store in a dessicator over silica gel

because humid conditions tend to cause caking. A

solution of an indicator is not stable.

45

PROCEDURE:

- Weigh accurately 5g of sugar into a text tube

- Dissolve in 5ml of distilled water by shaking

without warming

- Add exactly 2ml of alkaline copper solution

- Thoroughly mix the tube and immerse in a boiling

water bath for 5minutes

- Cool immediately in a cold bath

- Transfer the tube contents and washings to a

white conical flask

- Add approximately 0.1g of the indicator by means

of a small spatula or flattened glass rod

- Titrate the solution with the EDTA solution

while stirring with a glass rod

NOTE: EDTA should be added from the burette to the

conical flask continuously through the titration

procedure and maintain the stirring of the solution

46

at all times. As the end point is approached the rate

of addition of EDTA can be slowed to 2-3drops per

second but should never be stopped, until the end

point is reached. The reason for this is that the

color formed can disappear due to oxidation, meaning

that if the titration is stopped an incorrect

estimation of the end point may be made, after

restarting the titration. The colour change during

the titration is gradual, the solution starts from

green, will turn to grey and finally purple. These

changes are gradual, but the end point can be

considered to be reached when the first full purple

colour (i.e. ., when the body of he whole solution is

purple) has been reached.

On stopping the titration, there should be no concern

if the colour starts disappearing. This is due to

oxidation and no more EDTA should be added, every

sample should be analyzed in duplicate to ensure

47

accurate estimation of reducing sugars. The reducing

sugar content is obtained from the table.

MOISTURE ANALYZER

This is one important aspect in final stage of

granulated white sugar before the bagging stage in

order to avoid caking of sugar because we cannot bag

a wet sugar. The normal sugar

Moisture value should not exceed 0.04.

OPERATING INSTRUCTIONS:

- Switch on the moisture analyzer

- Open the sample chamber and place an unused

sample pan on the support

- When “g” appears, press enter key to tare the

sample pan.

- Weigh approximately 10g of your sample

- Close the sample chamber

- When “g” appear again, press the enter key to

start the analysis

48

- The machine will make a sound and indicate end

then you take your readings.

LIQUOR ANALYSIS

1). BRIX

- Pace the liquor in the sample compartment of the

meter

- Take direct reading from the brixometer as

displayed on the screen

2). pH

- Cool the liquor in a cold water bath

- Insert the pH probe into the liquor

sample

- Take the reading displayed on the screen

when the meter beeps

3). COLOR/TURBIDITY

- Take the original brix of the liquor

- Weigh 30g of melt and 50g for other liquors

49

- Add distilled water to make to a weight

equivalent to the original brix and mix well

with your spatula

- Filter the sample solution under vacuum through

a membrane filter of pore size 0.45um/50mm

respectively into a clean dry conical flask

- Turn on the talameter, set the wavelength at

420nm and zero with distilled water using your

cell lens

- Determine absorbance of filtered and unfiltered

solution

- Take your readings and calculate its colour and

turbidity.

MICROBIOLOGY DEPARTMENT

This is another department in Quality Assurance that

sees to the progress of dangote sugar refinery.

Equipments used in carrying out analysis

in microbiology laboratory:

50

Autoclave: This is a machine used to sterilize

our prepared agar under heat and pressure at a

temperature of 121%C.

Incubator: This is a machine where we incubate

or culture our plates.

Laminar flow cabinet: This is a hood where we

carry out analysis because is said to be free

from microorganisms.

Lumitester: This is a machine used to carry out

swab test.

Ultra violet light: This helps in sterilizing

the environment before an analysis is carried

out.

Air conditioner: This machine prevents the

growth of microorganisms because some microbes

grow at a higher temperature so with the help of

air conditioner we regulate their temperature.

Colony counter: This is a machine used in

counting our incubated plates.

51

Refrigerator: This is a place where we store our

Petri dishes, Agar, Sterilized swab sticks,

Spatula etc.

Microscope: This machine is used to view

organisms that can not be seen with naked eyes.

Magnetic stirrer/hotplate: This is a machine

used to dissolve a substance.

Analytical weigh balance and Top weigh balance:

This is machine used to take measurement of

samples.

Thermometer: This is an instrument used to

measure the temperature of products.

Hot air oven: An instrument used in drying our

equipments examples; conical flask, spatula,

glass Petri dishes, sampling bottles, pipettes,

etc.

Analysis carried out in microbiology

laboratory:

52

Raw sugar analysis

Refined sugar analysis

In process liquors

Water analysis

Sanitation

Environmental hygiene monitoring (swab test)

Miscellaneous.

Determination of temperature of all the equipments

used in the microbiology labouratory. All the

equipment has a standard temperature for example:

Incubator 25*C

Big incubator 35*C

Refrigerator 4*C

Thermometer 100*C

Air conditioner 18*C

Hot air oven 50*C

NOTE: This analysis is done every

Monday before carrying out analysis of that

week.

53

Procedure:

Using ethanol and cotton wool clean your

thermometer very well to sterilize it.

Insert or place the thermometer on the

equipment

Allow to stand for 5minutes

Take your readings in that equipment before

bringing it out so that the temperature in

the environment will not affect your

readings.

Using your Hot plate machine, boil water

until bubbles appear

Insert the thermometer in the hot water,

once the red mark reach 100* then is ready

Allow to cool and store in the

refrigerator.

Water Analysis

SAMPLES: Boreholes

54

Aqua - plant A, B, C

Treated water tank

Refinery taps

Canteen/kitchen taps

Control: negative and atmospheric

Frequency: Weekly

SAMPLING:

Samplings are carried out using sterilized 25ml

capacity universal sampling bottle with caps. Clean

disposable hand gloves and nose masks should be worn

during sampling. Samples are collected aseptically

from representative points within the refinery.

METHOD:

Clean and disinfect the working area with

ethanol before commencing the analysis.

Prepare and sterilize your agar medium in the

Autoclave at 121^C for 15minutes

55

Aseptically expose two poured plates of plate

count agar (PCA) and potato dextrose agar (PDA)

on work surface area to serve as atmospheric

control.

Pipette 1ml of water sample into sterile marked

plates with dates for PCA and MCA

Cool sterilized agar (medium) to about (45-47)*C

in a water bath, then pour about 20ml each of

molten prepared agar of PCA and MCA into marked

plates.

Tilt/mix plate by rotating gently to avoid

spilling of content, pour about 20ml of same

molten prepared agars of PCA and MCA into

another sterile labeled plates without water

samples. These represent the negative control

and if any growth is found in this control, it

invalidates the result of the analysis done.

56

Allow plate to solidify then invert and incubate

plate. PCA plate and MCA plate are incubated at

30*C for 48hrs.

Count colonies and record.

NOTE; Results are reported in colony forming unit

(CFU) per ml.

57

CHAPTER FIVE

WATER TREATMENT DEPARTMENT

Water treatment is, collectively, the industrial

scale processes that make water more acceptable for

end-use, which may be drinking, industry, or

medicine.

In Dangote sugar refinery, we have 3 divisions of

Aqua plants in water treatment department and each

comprises of 3 different sections.

The reaction tank chamber

The sedimentation chamber

The filtration chamber.

REACTION TANK CHAMBER:

Here the chemical added is known as the caustic soda

(NaOH). The essence of adding this chemical is to

58

boost the pH of the water from 6.5 to 7.0 normally

the source of the water we used in the Dangote sugar

refinery is from boreholes and there are about 7

boreholes in the refinery and the pH of the different

boreholes are very acidic and thus not good for human

consumption and industrial use. We therefore add this

chemical to increase it to be neutral.

Another chemical that is being added in this stage is

known as sodium Aluminates (Alum). This serves as a

catalyst and catalyst are chemical reaction that

changes the state of a substance. So the sodium

Aluminate’s removes the charges of the microorganisms

found in water thereby rendering them immobile and

thus coagulate together to form clogs, and this will

then make their density to be very heavy than water

and they will sediment at the bottom of the chamber.

Coagulation removes dirt and other particles

suspended in water. Alum and other chemicals are

added to water to form tiny sticky particles called

59

“floc” which attracts the dirt particles. The

combined dirt and the alum {floc} become heavy enough

to sink to the bottom during sedimentation.

SEDIMENTATION CHAMBER:

As the water and the floc particles progress through

the treatment process, they move into the

sedimentation basins where the water moves slowly and

the heavy particles (floc) settle to the bottom and

the clear water moves to filtration.

In this chamber, chlorine is added to the tank

to further perform the following functions:

Render the microorganisms present in water

inactive but doesn’t kill them.

It helps to clarify the water and thus making it

colourless.

FILTRATION CHAMBER

60

The water flows through a filter designed to remove

particles in the water, some made of layers of sand,

gravel, and charcoal that help remove even smaller

particles. Filtration collects the suspended

impurities in water and enhances the effectiveness of

disinfection. The filters are routinely cleaned by

backwashing.

Sand, stones, and gravels of various sizes are

used to make beddings example:

0.5-0.8mm

1-2mm

2-6mm

6-14mm

14-20mm

They are arranged in layers to aid proper filtration

of water as it flows from the sedimentation chamber.

Only filtrate is allowed to pass through the

61

filtration chamber and then enters into the sand

filters with the aid of filter pumps with pipes.

DISINFECTION

Water is disinfected before it enters the

distribution system to ensure that any disease

causing bacteria, viruses, and parasites are

destroyed. Chlorine is used because it is a very

effective disinfectant, and residual concentrations

can be maintained to guard against possible

biological contamination in the water distribution

system.

STORAGE: Water is placed in a closed tank or

reservoir in order for disinfection to take place.

The water then flows through pipes to all round the

refinery where it is needed.

62

CHAPTER SIX

CONCLUSION

My Industrial training in Dangote Sugar Refinery at

Apapa whorf in Lagos State was indeed a remarkable

one. I was able to put into practice all I was taught

in school and also learnt more. I was able to acquire

all the necessary skills and by God’s grace today am

proud to say that I can cope in any industry I find

myself after graduation because Dangote Sugar

Refinery Industry is one of the best Industries in

the whole world wide. Thanks to Student Industry Work

Experience Scheme (SIWES) for organizing the program

and Federal University of Technology Owerri (FUTO)

for granting me the opportunity to participate in the

program.

Finally, the aim of the training was achieved as

necessary training has been acquired.

63

RECOMMENDATION

Organizations should try as much as possible to

encourage students participate in this training

exercise by making Job placement easy after

graduation. Research has shown that industrial

training is important for student to acquire

practical experience of the theoretical skills.

In every organizations student should be appreciated

and supervisors should be pleased to correct them.

However, student should take this program very

serious because the merits are more than the

demerits.

64

Organizations should Endeavour to pay students well

during this training and make provision of staff bus

for the students who comes from a far distance.

GLOSSARY OF SOME TERMS USED IN SUGAR REFINING

BRIX : Percentage by weight of sugar present in

a solution

65

CAKE: The solid waste material from a filter

press or pressure filter

COLOUR: Complex molecules of impurity

CRYSTALLISATION: Production of sugar crystals

from a solution

EVAPORATION : Increase in the concentration of

a sugar solution by removing water through

boiling.

FILTRATION: Removal of suspended solids from a

liquid.

FINE LIQUOR: Liquor after the final

purification.

LIQUOR: Solution of sugar before

crystallization.

MASSECUITE: Mixture of crystals and its mother

syrup boiled in a vacuum pan, often shortened as

*masse*.

MOLASSES: Sugar from the last boiling in the

recovery process.

66

pH: Measurement of how acidic or alkaline a

solution is. A neutral solution is 7 pH.

RAW SUGAR: The product of a raw sugar factory. A

raw sugar has between 96 and 95% sucrose. The

rest is impurity.

RESIN: This is a man-made compound used to

remove colour and impurities from liquor.

SYRUP: Sugar solution that contain high amount

of impurities.

VACUUM PAN: Vessel for crystallization of sugar.

APPENDICES

67

School supervisor and industrial based supervisor

68