sugercane to sugar production

2.  Introduction
 Sources of sugar
 Composition of canestalk
 Conditions and quality of Sugarcane:
 Factors affecting quality of sugarcane
 Manufacture of White Crystalline Sugar
 Flow chart of sugar production in factory
 Sugar mill Byproduct

3. INTRODUCTION
 Belongs to the grass family (Poaceae)
 The main product of sugarcane is sucrose.
 Sugarcane is the world’s largest by production
quantity.
 In 2012, FAO estimates it was cultivate about 26.0
million hectares, in more than 90 countries, with a
worldwide harvest of 1.83 billion tons.
 Brazil was the largest producer of sugar cane in the
world.
 The next five major producers were India, China,
Thailand, Pakistan and Mexico.

4. SUGARCANE PRODUCING COUNTRIES IN
THE WORLD

5.  This plant is a tropical, perennial grass that forms
lateral shoots at the base to produce multiple stems,
 Typically there to four meters high and about five cm
in diameter
 A mature stalk is typically composed of 11-16% fiber,
12-16% soluble sugars, 2-3% non-sugars, and 63-73%
water.
 A sugarcane crop is sensitive to the climate, soil type,
irrigation, fertilized, insects, disease control, varieties,
and one the harvest period.
 The average yield of sane stalk is 60-70 tons per
hectare per year.
 Sugarcane is a cash crop, but it is also use as livestock
fodder.

6. SOURCES OF SUGAR
 There are two major sugar crops: sugar cane and sugar
beets
 Sugar cane is a perennial grass (replanted at intervals using
pieces of the cane stalks) that is cultivated mainly in the
tropics.

7.  Sugar beet is an annual crop that is propagated by the
seeds of the flowers.
Pic: SUGER BEET

8.  Suger beet is cultivated in cooler climates than
sugar cane, mainly above the 35th parallel of the
Northern Hemisphere.
 Both sugar beets and sugar cane have high water
content, accounting for about 75 percent of the
total weight of the plants.
 The sugar content of sugar cane ranges from 10 to
15 percent of the total weight,
 While that of sugar beets is between 13 and 18
percent.
 The protein and fat content of both beets and cane
is almost nil.

9.  Another sugar producing plant, Stevia is a sweetener and
sugar substitute extracted from the leaves of the plant
species Stevia rebaudiana.
 The active compounds of stevia are steviol glycosides
(mainly stevioside and rebaudioside), which have up to 150
times the sweetness of sugar. Stevia's taste has a slower
onset and longer duration than that of sugar

10. sugarcane sugar beet stevia
Saccharum officinarum Beta vulgaris subsp. vulgaris Stevia rebaudiana

11. Composition of canestalk
 Materials Percentage
Water 70-75
Sucrose 10-15
Saccharose 13.30
Soluble impurities 2.70

12. Conditions and quality of Sugarcane:
 The sugarcane productivity and juice quality are profoundly
influenced by weather conditions.
 Sugar recovery is highest when the weather is dry with low
humidity
 Bright sunshine hours, cooler nights with wide diurnal variations
and very little rainfall during ripening period. These conditions
favour high sugar accumulation.
 Sugarcane is grown in the world from alatitude 30.70 N and 3193
from sea level to 1000m of altitude or little more
 It is a long duration crop and thus it encounters all the seasons viz,
rainy, winter and summer during its life cycle.
 A total rainfall between 1100 and 1500 mm is adequate provided
the distribution is right

13.  During the active growth period rainfall encourages rapid
cane growth cane elongation and interned formation.
 During ripening period rainfall encourages rapid cane growth,
cane elongation and internodes formation.
 But during ripening high rainfall is not desirable because it
leads to poor juice quality
 High humidity (80-85%) favors’ rapid cane elongation during
grand growth period.
 A moderate RH value of 45-65% coupled with limited water
supply is favourable during the ripening phase.
 It also grows well in areas receiving solar energy from 18-36
MJ/ m2.
 Being a C4 plant, sugarcane is capable of high photosynthetic
rates

14. Factors affecting quality of sugarcane
1. Inclement weather
 Rainfall
 Temperature
a. Emergence of shoots (35-38)
b. Grand growth phase (32-38)
c. Maturity (10-21)
 Lack of R & D activities
2. Poor Agronomic Practices
 Selection of soil
 Selection of cane varieties
 Land preparation
 Time of plantation

15.  Plant population
 Plant protection
 Nutrient management
 Irrigation management
 Harvesting time
 Extraneous matter
 Staling losses
 Ratoon management
3. Trash unclean cane
4. Interval between cut to crush
5. Process losses inside factory

16. Manufacture of White Crystalline Sugar
 The manufacture of cane sugar is based on gradual removal
of fibre, non sugar, water, coloring matter and non
crystalizable sugars. The processing of the cane can
conveniently be considered under the following heads:
1) Crushing (Milling)
2) Clarification/Juice parification
3) Concentration
4) Crystalization
5) Separation
6) Dying

17.  Extraction of the juice or separation of the
fibre from the juice (Miolling):
The process of extraction consists of :
A. Cutting of the stalk and leaves
B. Cutting of the cane by means of sharp rapidly revolving nives
(550-600rpm). the caies more on a carrier under the knives
which make diagonal cats, converting the canes into ehips in
which the soft portion is exposed to the maximum.
C. The chips are then brought to the extractor consisting of one
two roller toothed crusher and four three grooved mills.
When the chips are fed into the crusher, the chips during their
passage through the rollers are pressed to extract about 50% of
the juice in the cane.

18. Extraction of the juice or separation of the fibre from the juice (Miolling)

19. The baggasse (the fibre) containing 50% of the juice is fed into the
first mill. the baggasse still containing some juice pass successively
through the 2nd , 3rd and 4th mills then to the storage.
 Cane juice contains
Water 78-86%
Sucrose 10-20%
Organic Matter 0.5-1.0%
Reducing Sugar 0.05-2.5%
Ash 0.3-0.77%

20.  Clarification/ Juice purification:
 The mixed juice contains in solution the sucrose and other
soluble matter, including glucose and fructose, mineral
salts and amino-acids.
 Insoluble material includes smallo pieces of fibre and
earth. As much as possible the insoluble and large
suspended matter is removed by screening, after which
the mixed juice is weighed.
 The mixed juice is treated with milk of lime; it is added in
two stages, before and after heating.
 The purpose of adding the milk of lime is twofold: to
prevent the inversion of sucrose
 Clarified juice, straw coloured and low turbidity, is drawn
form the top of the clarifier and sent to the evaporators

21. Clarification/Juice purification

22.  Evaporation/ Concentration
 The clear juice from the clarifier and the liltrate from the muds are
heated by steam and sent to the multiple effect evaporators in which
the clear juice converted in to raw syrup. It is pale yellow colour and
contains about 75% solid.
Evaporation/ Concentration

23.  Crystallization:
 The syrup is next treated for forming crystalline sugar. This is
done by removing most of the water by heating. The
crystallization takes place in the following two steps:
i. The syrup is finally concentrated in a vessel under high vacuum,
called a vacuum pan.
ii. After graining point the seed crystals which are already formed
grow more and more in size by seeding; the addition of small
sugar crystals of powder size.

24. sugar crystallization process

25.  Separation: The massecuite is passed from the crystallizers to the
centrifugals, in which sugar crystals are separated from molasses by centrifuging
and washed with a greater quality of hot water.
Separation process

26. Sugar Drying Process
 Drying:
 The sugar from the centrifugals contains 1-2% moisture and dried in a
granulator, heated by stream of hot air. Thus producing a dry, white, free-
flowing crystal sugar of a purity closely app. 100%.

27. Flow chart of sugar production in factory

29.  Sugarmill Byproduct
 Other than sugar product derived from sugarcane include
falernum, molasses, rum, cachaca (a traditional spirit from
Brazil), bagasse and ethanol.
 In some regions, people use sugarcane reeds to make pens mats,
screens, and thatch. The young unexpected inflorescence of
tebutelor is eaten raw, steamed or toasted, and prepared in
various ways in certain island communities of Indonesia.
The byproduct of sugar industry are-
1) Bagasse
2) Filter Cake
3) Molasses

30.  Bagasse
 The residue obtained by crushing cane in one or more mills is called
bagasse consisting largely of fibre with some mineral matter,sugars
not extracted in the milling process and various other substances.
It is one of the most important by product of sugar industry. Of all
the by product of sugarcane bagasse is produced in the large
quantity.
 Uses of Bagasse
 Uses as fuel
From many years ago bagasse is used as fuel. It is used as fuel for heat
collection /production before applying of stream power which is used
for cleaning and conditioning of cane. At present, it is used as fuel
for the boilers. In many case it is the most suitable fuel. In a well
balanced raw sugar factory the quality of final bagasse is usually more
than sufficient to supply all the fuel required, leaving a surplus to be
disposed of. It is used for control of electric power.

31. Bagasse

32.  Industrial use
(A) Electricity
 The more straightforward solution is to produce electricity from
the bagasse saved via a high pressure boiler and condensing
turbo-alternator. This solution has found favour in a number of
cane producing countries such a Hawaii, Australia, Reunion and
Mauritius and with modern equipment some 450 kWh can now be
produced per tonne of mill-run bagasse.

33. (B) Particle board
 The production of particle board from bagasse is a well-proven
technology but it has to compete with plywood and fibreboard.
Its main difficulty is the high cost of imported synthetic resins
which serve as a binder to the bagasse fibres composing the
board.
 (C) Paper :Good quality wrapping and magazine paper can be
produced with a high percentage of depithed bagasse as raw
material. The availability of a fair size internal market, sufficient
surplus bagasse and fair quality industrial water are the usual
constraints, apart from the high capital intensity of paper plants
and the necessity to handle polluting effluents.

34. (D) Furfural
 Furfural is a colourless, inflammable, volatile, aromatic liquid
produced from a number of plant materials containing pentosans -
in the case of bagasse, 90 percent being xylan. With acid
hydrolysis the xylan yields xylose which subsequently loses 3
water molecules to form furfural according to the following
simplified equation:
C5H8O4 + H2O C5H10O5 C5H4O2 + 3H2O
Xylan Xylose Furfural
In practice about 25 tonnes of mill-run bagasse are required to
produce 1 tonne of furfural.

35.  (E) Methane
 Much has been written on the production of methane or biogas and very
often sugarcane producers have been under the impression that a good
opportunity was being lost in the production of an economic gaseous fuel
from their surplus bagasse.
 Producer gas
 The gas use for bagasse for making producer gas has been described
by Tromp (1940). The composition of the gas with 30-50% moisture and
caloric value are given below
 Composition % :
Caloric value:
666 B.T.U./lb or 1200 cal/kg
or 120 B.T.U./cu ft
CO2 11.2%
CO 17.0%
CH4 6.2%
Hydrogen 5.9%
Oxygen 0.3%
Nitrogen 59.4

36.  Mulching: Farmers are used bagasse for mulching
2) Filter Cake
 The residue obtained by filtration of the muds which is settle out in
the process of clarification of the mixed juice from sugarcane is known
as filter cake.
 Uses of Filter cake:
 The precipitated impurities contained in the cane juice, after removal
by filtration, form a cake of varying moisture content called filter
muds. This cake contains much of the colloidal organic matter anions
that precipitate during clarification, as well as certain non-sugars
occluded in these precipitates.
 The weight of wet filter muds (80 percent water) averages about 3.4
percent cane.
 Filter cake is mainly used as fertilizer. It is a useful fertilizer especially
when applied to phosphate-deficient soils and to fields in which the
top soils has been removed or redistributed for any reason: for
example where drainage patterns have been altered to accommodate
mechanical harvesters.

37.  Composition of Filter cake
Moisture 60.4-78.2
Sucrose 2.1-7.3
Wax 3.0-3.1
Fat 2.5-2.7
Nitrogen 0.8-1.4
P2O5 1.1-1.4
K2O 0.1-0.1
Pic: Filter cake

38.  3) Molasses
 Molasses, or black treacle (British, for human consumption; known
as molasses otherwise), is a viscous product resulting from refining
sugarcane or sugar beets into sugar. The result of this first boiling
is called first syrup, and it has the highest sugar content. First
syrup is usually referred to in the Southern states of the United
States as cane syrup, as opposed to molasses. Second molasses is
created from a second boiling and sugar extraction, and has a
slightly bitter taste.

39.  Composition of molasses
The composition of molasses varies also within fairly wide limits
but, on average, would be as follows:
Water 20%
Other
carbohydrates
4%
Sucrose 35%
Nitrogenous
compounds
4.5%
Fructose 9%
Non-
nitrogenous
acids
5%
Glucose 7% Ash 12%
Other reducing
sugars
3% Others 5%

40.  Different Types of Molasses
There are several different types to choose from:
 Light
 Dark
 Blackstrap

41.  Light– Produced by the first boiling of the sugar cane (or
sugar beet). This type is lighter in color and can be sulphured
or un-sulphured. Sulphured Molasses treated with sulphur
dioxide acts as a preservative. Typically this type is extracted
from young sugar cane.It is also sometimes referred to as
“Barbados” or “mild” molasses.
 Dark– This is the product of the second boiling after more
sugar has been extracted. It is less sweet than light molasses
and is often used in cooking and baking. This is the type
that most people are familiar with as it is often used in
gingerbread cookies.
 Blackstrap– The healthiest form that is produced by the third
boiling. It contains the most vitamins and nutrients, but is
also the least sweet and does not work well in many recipes.
Blackstrap molasses is the highest in Iron, Manganese,
Copper, Magnesium, Calcium and other nutrients.

42.  Uses of molasses:
 Industrial use: Molasses is a most industrially important raw
material in manufacturew of a variety of products in fermentation
and distillation industries such as-ethyl alcohol, potable alcohol,
industrial alcohol, butyl alcohol,Other secondary products are – ethyl
acetate, butyl acetate, amyl acetate, vinegar, CO2 in compressed and
solid forms etc.
 Cattle feed: Molasses is used as cattle feed. It contains sugar in the
form of sucrose and invert sugar which is together total 50% or rather
more. It also contains some protein, calcium, phosphorus, trace
elements and vitamins. It is a common practice to add molasses to
food materials used for making Silage.
 Fertilizer and soil improver: Molasses is extensively used as a
fertilizer and improver. It is a source of potash, organic matter and
minor elements.
 Domestic fuel: Molasses can be used as a fuel by mixing it in small
proportion with bagasses. It burns well and products profitable
calories.