The document discusses energy conservation in the sugar industry, highlighting areas of high power consumption and potential efficiency improvements. It outlines methods for reducing steam and energy consumption, including the adoption of energy-efficient technologies and co-generation systems. The paper emphasizes the importance of energy conservation for enhancing competitiveness and sustainability in the sector.

1. CONSERVATION OF
ENERGY IN SUGAR
INDUSTRIES
Manohar Tatwawadi
total output power solutions
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2. AREAS OF HIGH POWER
CONSUMPTION
• Cane preparation
• Mills
• Condensing and Cooling
• Centrifugal
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3. AREAS OF ENERGY CONSERVATION
Area Existing plant &
process
Energy efficient
plant & process
Energy production Boiler/Turbine
efficient operation
High pressure
boiler/condensing
turbine
Energy consumption Use of VFD,
Helical gears, Anti
friction bearings,
Use of flashes etc.
DC/AC thyristor
controlled motors,
continuous pan,
direct contact
heaters etc.
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4. ENERGY CONSERVATION POTENTIAL IN
SUGAR INDUSTRY
• Indian sugar industry is highly energy-intensive
• Energy efficiency is well below that of other
industrialized countries
• Energy conservation measures shall lead to
reduction in cost of production
• Thus to make Indian sugar Industry more
competitive globally
• The total energy conservation potential is 25%
of total energy consumption
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5. POTENTIAL FOR REDUCTION IN
STEAM CONSUMPTION
• Reduction in direct steam leakages
• Insulation of bare pipes flanges and valves
etc. to reduce surface temperature 55oC
• Reduction in redundant steam pipelines
• Pressure control and syrup Brix control in
the evaporator section
• Adequate changes in steam and juice piping
to ensure juice heating from different
bodies of evaporator
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6. POTENTIAL FOR REDUCTION IN
STEAM CONSUMPTION
• Application of continuous crystallizers for A B
& C massecuites and continuous centrifugals
for B & C curing, high gravity/high capacity
batch centrifugals for a curing etc.
• Improved instrumentation and control for
pressure and temperature of exhaust steam
required for process
• Rationalization of operations of minimize
fluctuations in steam demand
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7. MAJOR ENERGY EFFICIENCY
IMPROVEMENT AREAS IN SUGAR
INDUSTRY
• CANE MILLING
• STEAM GENERATION
• POWER GENERATION
• SUGAR PROCESSING
• LIGHTING SYSTEM
• CO-GENERATION
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8. CANE MILLING
• Use of antifriction bearings at head and tail
shafts of cane carrier and mill transmission
gears
• Use of HT motors for cane cutter and fibrizer
• Use of VFD at cane carriers, rake carriers
• Use of high efficiency planetary gear drive
• Use of hydraulic motor and AC VFD for mill
drive
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9. CANE MILLING
• Use of belt conveyor in place of chain and
slat conveyor
• Optimization of imbibition percent
• Adoption of complete mill house automation
• Proper planning to decrease stoppages
/reduce crushing situation due to shortage of
cane
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10. STEAM GENERATION
• By adopting high efficiency boilers, steam
generation to fuel ratio can be increased
• Reduction in specific steam consumption by
adopting high pressure and high
temperature boilers
• Recovery of heat from flue gas by using
bagasse dryer
• Use of VFD for ID and FD fans
• Use of HP/LP heater for boiler feed water to
increase cycle efficiency
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11. STEAM GENERATION
• Recovery of heat from blowdown
• The amount of blowdown should be
minimized
• Add waste heat recovery unit to blowdown
for flash steam generation
• Adoption of complete combustion
• Control on excess air supply
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12. EFFICIENT BOILER OPERATION
• It may means to reduce the heat losses to minimum
so as to increase the efficiency of boiler
• HEAT LOSSES
1. Heat loss in flue gas
2. Heat loss due to moisture in bagasse
3. Heat loss due to Hydrogen present in bagasse
4. Heat loss due to blowdown
5. Heat loss due to radiation/convection
6. Heat loss due to bad combustion of Carbon
7. Losses in unburned solids
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13. REDUCE STACK TEMPERATURE
• Stack temperature greater than 170 deg. C
indicates potential for recovery of waste heat
• Use of bagasse dryer
• 22deg.C reduction in flue gas temperature
increase boiler efficiency by 1% and reduces
fuel consumption by 1.2%.
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14. COMBUSTION AIR HEATING
• The rise in combustion air temperature
by 20deg.C will improve thermal
efficiency by 1%
• Similarly improved combustion air temp
will cause reduction in unburnts in
Bottom ash and fly ash can improve the
combustion efficiency and thereby
reduction in fuel.
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15. INCOMPLETE COMBUSTION
IT MAY BE DUE TO FOLLOWING REASONS
• Shortage of excess air
• Excess of fuel supply
• Poor distribution of fuel
• Furnace air ingress.
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16. CONTROL ON EXCESS AIR
• The optimum excess air level varies
with furnace design, type of fuel
and process variables
• Excess air % theoretical air should
not exceed to 35%
• For every 1% reduction in excess
air, 0.6% rise in boiler efficiency
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17. RADIATION AND CONVECTION
HEAT LOSS
• The surfaces lose heat to the
surroundings depending on surface area
and the difference in temperature
between the surface and surroundings
• With modern design boiler this loss may
represent only 1.5% on GCV
• Frequent checks for the heat insulation
can check these losses.
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18. BLOWDOWN HEAT LOSS
• This loss varies between 1% to 6% and
depends on number of factors
• Total dissolved solids (TDS) allowable in
boiler water
• Quality of makeup water
• Amount of uncontaminated condensate
return
• Boiler load variations
• Correct checking and maintenance of feed
water and boiler water quality, maximising
condensate return and smoothing load
swings will minimise the loss10/08/2019 total output power solutions 18

19. BLOWDOWN HEAT RECOVERY
• Blowdown of boilers to reduce sludge and
solids contents allows heat to go down the
drain
• The amount of blowdown should be minimised
by allowing a good water treatment program
• Installation of a heat recovery unit (heat
exchanger) in the blowdown line allows the
waste heat to be used in preheating make up
and feed water
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20. AUTOMATIC BLOWDOWN CONTROL
• Uncontrolled continuous blowdown is
very wasteful
• Automatic blowdown control can be
installed that sense and respond to
boiler water conductivity and pH
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21. REDUCTION OF SCALING AND SOOT
LOSSES
• Soot build up on tubes acts as an insulator
against heat transfer. Any such deposits
should be removed on a regular basis.
Elevated stack temperature may indicate
excessive soot build up. Also same results will
occur due to scaling on the water side.
• A 1mm thick scale on water side could
increase fuel consumption by 5 to 8%
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22. REDUCTION OF SCALING AND SOOT
LOSSES
• Stack temperature should be checked and
recorded regularly as an indicator of soot
deposits.
• Every millimeter thickness of soot coating
increases the stack temperature by about 55
deg.C
• 3mm of soot thickness can cause an increase
in fuel consumption by 2.5%
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23. SUGAR PROCESSING
•Optimization of evaporator design to minimize
exhaust steam needs and maximize vapor
bleeding
•Optimization of syrup Brix
•Stepwise recovery of flash heat from the
condensate of evaporator, juice heaters and
pans
•Use of first condensate for wash water heating
at centrifugals.
•Recovery of waste heat from clarifier flash tank
•Selective incorporation of direct contact heater
•Use of continuous pans for massecuite boiling10/08/2019 total output power solutions 23

24. SUGAR PROCESSING
•Seed sugar melting by using syrup and very low
temperature vapour in place of exhaust steam
and hot water
•Use of efficient heat exchanger
•Elimination of direct live steam bleeding in
process
•Adoption of process automation and controls
•Discouraging production of bold grain
•Use of low temperature vapour for pan washing
•Heating of air by hot condensate at sugar dryer /
hopper
•Recovery of heat from non condensable gases
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25. USE OF PLANETARY GEAR DRIVE
• Transmission efficiency is about 90%
• Combined efficiency of conventional
worm and worm wheel with enclosed
worm gear box is hardly 40-50%
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26. HELICAL GEAR DRIVE
• The efficiency of helical gear drive is
approx. 96-97%
• The efficiency of worm gear box is 70-
80%
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27. LIGHTING SYSTEM
• Make maximum use of natural light (Use of
translucent sheets / more windows and
opening)
• Switch off when not required
• Modify lighting layout to meet the need
• Provide lighting transformer to operate at
reduced Voltage
• Install energy efficient lamps, luminaries and
controls
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28. LIGHTING SYSTEM
• Use of gas discharge lamps in place of
incandescent lamps
• Use of Compact Fluorescent lamps (CFL)
• Use of Metal Halide lamps in place of
Mercury/Sodium lamps
• Use of Energy Efficient lights, LED lights etc…
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29. CO-GENERATION
• Sequential production of process heat and
electricity to export with same fuel is
termed as co-generation
• In sugar industry the co-generation is of
TOPPING CYCLE
• TOPPING CYCLE
The steam generated is fed to the turbo
generator and extracted at desired pressure
for process work
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30. BENEFITS OF CO-GENERATION
• The fuel, bagasse is renewable source of
energy
• The sugar industry generates additional
power with the bagasse which is used for
generation of steam to meet process
requirements
• Results in reduced emission levels and
global warming and is therefore
environment friendly
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31. BENEFITS OF CO-GENERATION
• Ensure fuel security
• Co-generation project leads to reduction in
transmission losses considerably and thus
helps in stabilizing the grid voltage because
of their proximity to the load centres
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32. ENERGY EFFICIENCY IMPROVEMENT
• The system upgradation in the entire sugar
manufacturing process for improved energy
efficiency goes for maximizing exportable power
from co-generation plant
• Energy efficiency improvement and energy
conservation is of great importance for making the
co-generation project viable and sustainable in the
long run.
• Implementing energy conservation measures in
respect of both steam and electricity will reduce
captive consumption and help to save additional
quantity of bagasse/electricity.
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33. TURBINE COFIGURATIONS FOR CO-
GENERATION
• Pure back pressure turbine
• Single extraction back pressure turbine
• Double extraction back pressure turbine
• Pure condensing turbine
• Single extraction condensing turbine
• Double extraction condensing turbine
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34. AREAS OF ENERGY CONSERVATION
Steam temperature at the turbine inlet, Deg C
Steam pressure at the
turbine inlet, Kg/cm
40 62 63 100
440 4.25 4.00 3.90 3.86
460 4.03 3.82 3.80 3.76
470 3.98 3.79 3.70 3.60
480 3.94 3.75 3.68 3.57
490 3.90 3.72 3.60 3.50
510 3.80 3.65 3.55 3.35
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35. RENEWABLE ENERGY
Renewable can create a significant impact in electric
power generation.
Indian Renewable energy programme is the largest
and most extensive among the developing country.
Ministry of Non-conventional energy the nodal
Ministry of the Govt. is entrusted with responsibility of
policy making, planning, information and co-
ordination of various aspects of renewable energy. As
per their draft policy set up for the goal is to be
achieved till 2019 an addition of 10% share I.e. 18000
MW through renewable.
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36. RENEWABLE ENERGY SOURCES
• Co-generation from bagasse
• Supplementary fuel such as cane trashes,
wood chips, rice husk and other biomass
material
• Hydro-power
• Wind power
• Sea tides
• Pelamis wave power
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