The document discusses raw sugar reprocessing and refining trends and challenges. It provides an overview of Dhampur Group, a leading Indian sugar conglomerate, and describes how India's first backend refinery was established. The document then discusses the need for sugar refining to produce internationally accepted quality sugar. It describes the defecation-remelt process used for refining and its advantages over double sulphitation, including lower costs and more consistent, higher quality sugar. The stages of the refining process are outlined, including melting, clarification, filtration, decolorization through ion exchange, crystallization, and packaging.

1. Raw Sugar Reprocessing ,
Trends and Challenges
Narendra DevNarendra Dev
JuniorTechnical Officer (ST)
National Sugar Institute,Kalyanpur,Kanpur
Mob:9415429330/7376498304
E-mail : ndevgnsas@gmail.com
On : 23.06.2016

2. DHAMPUR Group is a leading Indian
Sugar conglomerate having four sugar mills,
starting with a crushing capacity of 300
TPD has now grown to a crushing capacity
of 38000TPD
India’s 1st backend refinery was setup atIndia’s 1st backend refinery was setup at
Rauzagaon by Dhampur Group. After
successful commissioning of the same it
was replicated in two more units at
Mansurpur and Asmoli.

3. IntroductionIntroduction
In view of the changing scenario in the world sugar
production and consumption pattern and the emerging
requirement of the processed food and beverage industry
in India, it has become necessary to produce quality sugar
tradable in world market whose specification can meet the
requirement of bulk consumers and also the internationallyrequirement of bulk consumers and also the internationally
accepted quality for export. In India 70 – 75% sugar is
consumed by the bulk consumers which need to be good
quality sugar owing to the quality assurance that is
maintained. During the shortage year factories are not
equipped to process raw sugar of various qualities in the
existing plant.
contd….

4. Therefore there is a need for a process to produce
sugar which is internationally accepted and also
can process raw sugar whenever required.
In Indian sugar industry, plant and equipmentsIn Indian sugar industry, plant and equipments
investment becomes idle for about a half of the
year. There is a possibility of making use of
some of the equipments for refinery,
cogeneration etc. to work for the year round.
This would make investment fully realizable
throughout the year. In sub-tropical India this
concept has more relevance.

6. ConsumersConsumers
The per capita sugar consumption in India is
about 20 Kgs./annum.
In India 70 – 75% sugar is consumed by bulk
consumers which need to be good qualityconsumers which need to be good quality
sugar owing to the quality assurance that is
maintained.
26%
13%
30%
31%
Low Income Household
High Income Household
Industrial (Confectionery, soft drinks, etc.
Small Business, sweets, hotels, bakeries, etc.

7. SUGAR QUALITYSUGAR QUALITY
–– COMPARISIONCOMPARISION
DOUBLE DEFECO
SULPITATION RE - MELT
POL % 99.5-99.8 99.9
COLOUR (ICUMSA) 100-150 < 40
METHOD GS-9
ASH % 0.1-0.3 <0.06
INVERT SUGAR % 0.1-0.3 <0.08
FLOCTEST PASSES
SO2 (PPM) 20-80 NEGLIGIBLE
Moisture % max. 0.08 0.04
Turbidity % by weight 15 1

8. DOUBLE SULPHITATION
-LIMITATIONS
High chemical cost
High losses due to high retention & lower
process pH
High inorganics resulting in higher
molasses production
Corrosion due to Sulphur gasesCorrosion due to Sulphur gases
High maintenance costs
Environmentally - unfriendly
Inconsistent quality
Low shelf – life
High percentage of sulphur in sugar

9. JUSTIFICATION OFJUSTIFICATION OF
DEFECO REMELT PROCESSDEFECO REMELT PROCESS
Frequent variation of cane quality
Difficulty in making quality sugar with fluctuating
quality of inputs
Non- sugars/ Sucrose ratio which is low in juiceNon- sugars/ Sucrose ratio which is low in juice
gets transformed to very high, in raw sugar, thus
giving a consistent raw material for refined or DEFECO
REMELT sugar production
Re - Crystallization is accepted as the best method for
purification

10. ADVANTAGES OFADVANTAGES OF
DEFECO REMELT PROCESSDEFECO REMELT PROCESS
Rationalization of the process
• Use of sulphur eliminated
• Optimization of lime consumption
• Reduced scaling in Evaporators resulting in :• Reduced scaling in Evaporators resulting in :
-reduced down time
-steady crush rate
-optimum steam consumption
• No change in injection water pH
• Minimum corrosion, meaning low maintenance
Contd……….

11. ADVANTAGES OFADVANTAGES OF
DEFECO REMELT PROCESSDEFECO REMELT PROCESS
Reduced losses with the help of
Neutral pH
Lower retention time
Lower non – sugars
Improved sugar quality on account of
High purity boiling
Bolder grain
Consistent sugar quality
Higher shelf - life
Low impurities
Negligible SO2
Contd……….

12. ADVANTAGES OFADVANTAGES OF
DEFECO REMELT PROCESSDEFECO REMELT PROCESS
Reduced quantity of molasses
Reduced non-sugars in molasses
Elimination of sulphur makes process eco-friendly
Process versatility
Bolder grain up to 75%
Higher recovery

13. NO IMPACT ON STEAMNO IMPACT ON STEAM
CONSUMPTIONCONSUMPTION
To balance steam bleeding in such a way
that vapour load at condenser is less
than 1 %.
Maintain Syrup brix. at 700 to reduceMaintain Syrup brix. at 700 to reduce
vapour % Raw Massecuite by 30%
Fine liquor is concentrated in IV effect
evaporator to maintain its Bx at 700
which reduces vapour % refined
massecuite by 30 %.

14. N0 IMPACT ON STEAMN0 IMPACT ON STEAM
CONSUMPTION DUETOCONSUMPTION DUETO
HIGHER MASSECUITEHIGHER MASSECUITE
Less melting in raw house
No melting in water, in raw houseNo melting in water, in raw house
Less massecuite % cane in raw house
Low vapour/massecuite ratio in raw house
Raw juice heating by continuous pan vapour and hot
condensate
A and B massecuite boiled on 3rd effect vapor and refined
massecuite boiled on 2nd effect vapor.

15. CHEMICAL COSTCHEMICAL COST
DOUBLE SULPHITATIONVS DEFECO REMELTDOUBLE SULPHITATIONVS DEFECO REMELT
CHEMICAL COST / BAG REMARKS
DOUBLE
SULPHITATION
DEFECO
REMELT
Juice
clarification
12.00 4.00 Lime- Rs. 4,000 PMT
Sulphur-Rs. 4,000
PMT
(Fig. in Rs.)
PMT
Evaporator
cleaning
4.00 3.00 Less number of
cleanings
Pan Station 1.25 1.75 More viscosity
reducer
required
Syrup
clarification
4.00 0
Melt
clarification
0 10.00
TOTAL 21.25 18.75

16. Cost of Refining during offCost of Refining during off--
season in integrated complexseason in integrated complex
Sl.
No.
Particulars Cost in Rs. Per ton
refined sugar
1 Fuel 146
2 Chemicals 20
3 Process Loss 90
4 Packaging 40
5 Sugar handling at refinery 8.50
6 Manpower 10
7 Maintenance / Store 4.50
Total Cost 319
Revenue
1 Power cogeneration 68
2 Alcohol from molasses 5
Total Revenue 73
Net Refining cost per ton 246

17. THE DEFECO REMELTTHE DEFECO REMELT
PROCESS HASTWOPROCESS HASTWO
STAGESSTAGES
1st for1 for
RAW SUGAR
2nd for
REFINED SUGAR

18. MIXED JUICE AFTER
HEATING
RVF
FLOW DIAGRAM
DEFECATION (pH 7.1)
HEATING (1030C)
JUICE CLARIFICATION
RAW SUGAR
MUD
PANS
EVAPORATION

19. RAW SUGAR
FILTERATION
SCUM TO DESWEETNING
MELT CLARIFICATION
MELTER
REFIEND
SUGAR
REFINED SUGAR
MOLASSES SENT
BACK TO RAW SUGAR
PROCESS
MELT CONCENTRATION
CRYSTILLIZATION
DECOLORIZATION

20. DESCRIPTION OF
PROCESS
There are eight discrete stages of the refining
process with various options available at each
stage:
i) RAW SUGAR DELIVERY
ii) MELTING OF RAW SUGAR
i) RAW SUGAR DELIVERY
ii) MELTING OF RAW SUGAR
iii) CLARIFICATION OF RAW MELT
iv) MELT FILTRATION
v) MELT DECOLOURISATION
vi) CRYSTALLIZATION
vii) CENTRIFUGATION
viii) DRYING, STORAGE AND PACKAGING

21. Raw Sugar DeliveryRaw Sugar Delivery
Sugar minglers are positioned below raw
sugar centrifugal machines. The magma
obtained, either is pumped or direct feed
to continuous raw sugar melter.
When imported raw sugar is to be used,When imported raw sugar is to be used,
then these centrifugal machines may be
used as affination machines and affinated
sugar is magmised in these minglers and
sent to melter.

22. Melting of Raw SugarMelting of Raw Sugar
Magma of raw sugar from the raw sugar
minglers is melted with hot condensate
water of 95 C temp. in the continuous
raw sugar melter under controlled brixraw sugar melter under controlled brix
and then screened (to remove large size
foreign insoluble materials). The liquor
thus obtained is then sent for clarification.

23. MINGLERS UNDER RAWMINGLERS UNDER RAW
CENTRIFUGALSCENTRIFUGALS

24. CLARIFICATION OFCLARIFICATION OF
RAW MELTRAW MELT
Clarification of raw sugar melt is
done by phosphofloatation process
in which phosphoric acid, limein which phosphoric acid, lime
sucrate, decolorizing chemical and
floating aid are used
contd…..

25. PRINCIPLE (PHOSPHOTATIONPRINCIPLE (PHOSPHOTATION
PROCESS)PROCESS)
The flotation process works on the principle of forming
low density aggregates of particles and bubbles, and
lower the density, more quickly they float.
Physiochemically, the properties of solid particle’s
surface can be divided into two classes: hydrophobic
and hydrophilic. Particles with hydrophobic surfacesand hydrophilic. Particles with hydrophobic surfaces
repel water, so they become firmly attached to the
bubbles and rise together spontaneously. On the other
hand, hydrophilic particles have surfaces with affinity for
water, so they do not adhere readily to bubbles and are
difficult to float. Thus the floating and the non - floating
particles get separately after the process of
phosphofloatation

26. MELT CLARIFIERMELT CLARIFIER

27. DESCRIPTION
Screened Raw Melt is pumped into a buffer tank from the
melter. At the entry of buffer tank the melt is treated with
cationic polymer (Decoloriser) @ 150 ppm on melt solid
basis. The Decoloriser precipitates out the dissolved
coloring impurities.
This screened raw melt is heated to 80-85 C by direct
contact heater of 2nd /3rd vapor and this heating reducescontact heater of 2nd /3rd vapor and this heating reduces
the viscosity of the liquor and facilitates flotation.
This heated melt then goes to the reaction tank where
phosphoric acid is dosed, typically @ 300 – 350 ppm as P2O5
of phosphoric acid on raw melt solid basis. At the reaction
tank the dosing of milk of lime/Lime sucrate is done to
maintain the pH of 7.1 to 7.2, which forms calcium
precipitate and adsorbs the suspended impurities.
Contd…..

28. From reaction tank, the heated and treated
raw melt is sent to stirring unit where micro
sized air bubbles get emulsified with the
calcium phosphate precipitate, making it
into a lighter precipitate.
Flocculant @ 12 – 14 ppm on melt solids is
added in Flocculator before sending the
treated melt to the clarifier.
added in Flocculator before sending the
treated melt to the clarifier.
This precipitate floats in the clarifier and
clear melt is withdrawn from the bottom
through the telescopic valves and sent to
further process and the scum removed from
the top by scrapping is sent to scum
desweetening system by decanter.

29. Melt FiltrationMelt Filtration
Buffer tank for further clarificationThe
suspended precipitate either of calcium
carbonate or calcium phosphate formed during
the clarification, along with the impurities, is
removed from the treated sugar liquor in two
stages. First multi bed filters and in second stagestages. First multi bed filters and in second stage
bag filter are used. The filtered liquor is then
sent to the decolorization process. When the
filters are chocked with mud (the removed
suspended materials), they are backwashed with
clear melt/hot water and send to raw melt

30. MULTI BED FILTERMULTI BED FILTER

31. Scum Desweetning SystemScum Desweetning System
Scum received from the top of the
melt clarifier is around 3 – 5%.
Sugar has to be recovered beforeSugar has to be recovered before
disposing the scum.
Contd…

33. Melt DecolourizationMelt Decolourization
The classical removal of colorant by affination
and clarification is insufficient to produce the
fine liquor color necessary for refined sugar
crystallization and an adsorption processing
step becomes necessary. The colour removal in
refineries is done by ION EXCHANGE RESINrefineries is done by ION EXCHANGE RESIN
COLUMN which works on absorption
techniques with the liquor being pumped
through columns of resin medium.

34. ION EXCHANGEION EXCHANGE
Cation and anion exchangers, often also already used
as mixtures in mixed bed ion exchangers, remove
charged colorants very well. The effect of ion
exchangers is very specific not only on colorants but
also on removal of salts and therefore it has a
demineralizing effect also. The removal of nonsugarsdemineralizing effect also. The removal of nonsugars
can be almost complete. The various types of resins,
the mechanisms of resin / colorants interactions as
well as the role of resins in the decolorization cycle,
regeneration steps, and the effect of different salts
on the decolorization efficiency of various colorants.
Contd…….

35. Making a case for ion exchange resins as
being flexible, robust and very adjustable to
very low qualities of raw sugar, which can
effectively be decolorized by ion exchange.
Despite these excellent attributes, ion
exchangers suffer the disadvantage of
requiring regeneration, associated with highrequiring regeneration, associated with high
costs for chemicals, water and waste water
treatment. They therefore are used where
high-end decolorization is required and
hydrolysis for the production of liquid invert
sugar rather than for routine decolorization.
The clear, lightly colored liquor is now ready
for crystallization.

36. CLEAR 2ND FILTER FINE
MELT MELT LIQUOR
COMPARISION OF
VARIOUS MELTS
MELT 1ST FILTER 1ST
MELT DECOLORISED
MELT

37. Ion Exchange Resin ColumnIon Exchange Resin Column

38. CRYSTALLIZATIONCRYSTALLIZATION
The most effective decolorization is
achieved by crystallization. Theoretically
only sucrose molecules form sucrose
crystals, but some traces of organic and
inorganic impurities including colorants are
introduced into the lattice of the crystal
inorganic impurities including colorants are
introduced into the lattice of the crystal
structure. Most impurities, however, are
found in the outer layer of the crystal, in
corners and edges, if the crystal structure is
not perfect.
Contd…..

39. Crystallization occurs in a
saturated/supersaturated solution, which
also means that crystals are always
surrounded by a liquid phase.
Color is removed by crystallization,
assuming the syrup separation is executedassuming the syrup separation is executed
well. For high quality massecuites like A and
refined sugar, color removal is at least 90%
Contd…..

40. Crystallization is therefore the most efficient
method of color removal, very high quality
refined sugar for pharmaceutical purposes
undergoes a double crystallization process,
bringing sugar closest to the absolute mark
of 100%.
It is in this process that sugar is crystallized
from the concentrated fine liquor obtained by
It is in this process that sugar is crystallized
from the concentrated fine liquor obtained by
water evaporation under vacuum; the
operation is carried out under vacuum to
prevent the sugar from burning or
decomposing by heat and to obtain the
crystals of adequate size. The refined sugar
is boiled in pans.
Contd….

41. REFINED MASSECUITEREFINED MASSECUITE

43. CENTRIFUGATIONCENTRIFUGATION
Centrifugation requires greatest
attention as it ensures the
effectiveness of crystallization.
Inadequate mode of operation,
badly cleaned screens, andbadly cleaned screens, and
maladjusted washing nozzles, to
mention a few of the key
parameters of centrifugal work,
can offset the good results
obtained in crystallization.

44. Drying, Storage and PackingDrying, Storage and Packing
These three steps should not be taken lightly.
They have little or nothing to do with color
removal but more with secondary color
formation and / or sugar contamination. This
aspect is necessary for hygienic handling of theaspect is necessary for hygienic handling of the
sugar as a food product for human
consumption.

45. REFIEND SUGARREFIEND SUGAR

46. Trends and Challenges:Trends and Challenges:
Need to focus on product diversification and
thus producing wide range of various forms
of sugars like in Amul co-operative
movementmovement
Need to study socio-economic conditions of
neighboring countries for huge variations of
per capita sugar consumption
Exploring and finding out the ways to export
refined sugar .
contd…..

47. ..
One should keep in mind that there is no comparitively
higher sugar loss and steam consumption in Defco –
Remelt process as it is therotically/practically proved
and commercially viable. It is also to be understand
that if it is not so then how it is possible that various
sugar groups go for establishment of next refinery
after set up one likewise Dhampur group installedafter set up one likewise Dhampur group installed
Mansurpur and Asmoli after Rauzagaon, Simbhaoli
installed Brijnathpur, Uttam’s go for two refinery after
Libbarehari and Mawana group installed Nanglamal
afterTitawi. Contd…

48. .. In case of sugar shortage year and import of raw sugar for processing,
there are only 10 – 12 groups in all over India which can properly
reprocessed the raw sugar in terms of quality and viability. Otherwise so
many groups have tried to the reprocessed it with sulphitation plant and
could not get capacity utilisation and viability. So being technologist, we all
should understand need of it.
Twenty years ago when Dhampur installed first backend refinery of India
at Rauzagaon, it was challenge in front of us that how we could establish
market to get extra premium. So we got servey in Punjab and
Haryana market and worked together with some sweet
shopkeepers and observed that it was beneficial to useshopkeepers and observed that it was beneficial to use
our sugar as this required comparatively less fuel and
getting only 25 % impurities on making sugar solution
known as “Chasni”.
Contd…..

49. ..
The shopkeepers felt so happy even though they
had to pay extra for our sugar. So it is miracle
that they like most refined sugar now a days even
they postpone their children’s marriage in case of
non availability of refined sugar .
The above example to understand that it can be
developed 100% refined sugar in Indian market.
The above example to understand that it can be
developed 100% refined sugar in Indian market.
The world sugar prices are highly influenced by
Brazil as it is largest exporter and least cost
producer whereas its opposite in case of India.

50. THANKTHANK
YOU