Indian Pulp

1
Indian Pulp Paper Technical Association Zonal
Seminar on 13th 14th July, 2006 at
Chandigarh, "Environmental friendly
technologies for heat recovery from waste fuels
and process/industrial wastes" Jalindar
Gaikwad- Thermax Babcock Wilcox Division of
Thermax Limited. PUNE
2
Energy conservation by use of alternate/waste
fuels

• Advantages
• Saving on the main fuel by firing wastes
• Saving on cost associated with disposal
• Environmentally friendly disposal of waste
• Government incentives/ carbon credits
• Lower dependency for supply in case of process
  waste firing

3
Waste that can be fired

• Any waste containing usable heat can be fired
  either independently or in co-firing mode
  depending on the waste properties.
• Paper sludge from paper industry
• Used packaging and waste plastic
• Industrial and domestic wastes
• Coffee waste
• Spent grain
• Washery rejects
• Char
• Agricultural and forest wastes
• etc. etc.

4
Fuel Characteristics

• Highly variable characteristics- No
  generalization
• High Volatile Matter - More combustion in free
  board
• High Moisture- Fuel Handling
• Less Ash
• High Alkaline content of ash
• Low Steam to Fuel weight ratio (Low Specific
  heat content

5
Waste and multi-fuel solutions

• AFBC
• CFBC
• Grate fired

6
AFBC

• First Generation - Conventional design for
  regular fuels and wastes having better heat
  content and easy to fire.
• Second Generation- Hopper bottom for high
  fouling, fuels.

7
CFBC

• Multi-fuel firing capability
• Same design can be used to fire range of fuels
  depending on the availability and economics
• Higher combustion efficiency
• Lower emission levels
• Suitable for low grade fuels

8
Grate fired

• Traveling Grate
• Pusher grate
• Air colled design
• Water cooled design
• Grate selection depends on the fuel
  characteristics

9
Internal Recirculation - Circulating Fluidized
Bed Boilers

• A simplified approach to improved flexibility and
  reliability
• Design Features
• High combustion efficiency
• Compact, economical design
• Higher reliability and availability
• Lower maintenance costs
• Reduced erosion
• Fuel flexibility
• Low emissions

10
Why Build a CFB Boiler to GenerateSteam and
Electric Power

• Fuel Flexible Technology
• Accepts wide range of fuels
• Volatile matter - 4 - 40
• Ash - 0 - 60
• Heating value - gt 1500 Kcal/kg (2700 BTU/lb)
• Moisture - lt 55
• Use of lower rank fuels reduces fuel costs
• Fuel flexibility - minimizes fuel supply
  uncertainties
• Ability to burn low cost and waste fuels

11
Circulating Fluidized Bed Boilers
12
Furnace density profile
13
Solids Collection Schematics
14
U-Beam separators
15
Kanoria Chemicals Ind. Ltd

• One CFB installed in 1996
• Waste coal (45 ash)
• Steam flow -105 TPH
• Pressure - 65 bar
• Temp. 485 C

16
Furnace temperature profile
17
The two-Staged Solids Separation System

• Benefits
• High overall solid collection efficiency More
  than 99.7
• Precise furnace temperature control By
  controlling solid recycle rate from the secondary
  collector
• Extended turndown ratio without use of auxiliary
  fuel (oil/gas) 100 to 20 MCR
• Low auxiliary power requirements compared to
  cyclone-based CFB technologies 50-100 mm w.c.

18
Lower Furnace Refractory Construction
19
IRCFB

• Range 40-500 t/h
• Pressure 66-160 Kg/cm2
• Temperature 540 C
• Fuel fired
• Coal,Petcoke,Char
• lignite
• Washery rejects
• Biomass co-firing

20
Waste fuel firing
Conventional Bed plate design
Hopper Bottom Design
21
General arrangement of JOCIL boiler
22
Waste fuel firing
23
Bhushan-Hopper bottom design

• First boiler parameters
• Capacity - 85 TPH
• Pressure- 87 Kg/cm2
• Temp. - 525deg.cel.
• Fuels- washery rejects Char
• Second boiler parameters
• Capacity - 165 TPH
• Pressure- 87 Kg/cm2
• Temp. - 525 deg.cel.
• Fuels- washery rejects Char

24
Hopper bottom design

• TO name few
• JOCIL
• SARO
• Bhushan
• Nestle
• BMM Ispat
• Jagdamba
• Sagar

25
Hopper bottom design

• Unique design of BW which can handle the
  difficult, agglomerating, high ash low GCV fuels
  (Lignite, Petcoke, Biomass, Char, Washery
  Rejects)
• Allowing uniform draining of agglomerate /
  clinkers through hopper bottom.
• Ease on multiple fuel firing through over bed
  and underbed.
• Number of units in operation firing high
  agglomerating fuels like cotton stalk, chilly
  stalk.
• Number of units under executions for handling
  multifuel capabilities like Char, Coal, Rice
  husk, Petcoke and Biomass.

26
Biomass Power (AFBC)- JOCIL

• OPEN HOPPER BOTTOM AFBC BOILER
• Capacity - 30 tph, 66kg cm2g, 485 Deg C,r 6MW
• Design - Open Hopper Bottom Design
• Fuels- Rice Husk, Cotton Chilly Stalk,
  Juliflora etc.
• Operational since February 2001.
• FEATURES
• Open Hopper Bottom - Babcock Wilcox Unique
  Design instead of conventional bed plate design.
• First Multifuel biomass fired AFBC boiler
  designed to handle high alkali fuels.
• Easy control of bed chemistry ensures high
  availability and continues power generation
• Easy removal of agglomerates,large amount of
  stones and mud ensure trouble free operation
  round the year
• Separate bunkers feeders for storing and
  feeding variety of fuels to meet any interruption
  in fuel availability.
• High fuel flexibility ensures cost effectiveness
  in power generation.
• Staggered air supply arrangement ensures complete
  combustion and high thermal efficiency.

27
Grate fired

• TG
• Pusher grate
• Bagasse co-generation
• Biomass medium fouling/high fouling
• MSW/RDF

28
Biomass Power (TG)- Kalptaru
Power rating - 7.5 MW Boiler MCR - 35 TPH Steam
Pressure- 66Kg/cm2 , Temperature - 485C Fuel
fired - Mustard stalk
29
CHALLENGES IN WASTE FIRING

• Fuel preparation / handling and feeding
• Combustion technology /combuster design
• Furnace wall erosion/corrosion
• Super heater tube life
• Fouling / Slagging of heating surfaces

30
Petcoke Firing Technology

• Challenges
• Low VM
• Low ash
• Low fusion temp
• Clinkering tendency
• High sulfur
• Difficult to burn fuel

31
Petcoke Firing

• Experience
• AFBC technology introduced to suit Indian market
  requirement against conventional CFBC.
• CFBC technology also available
• Exhaustive RD pilot plant testing
• 2 x 18 MW first reference plant in operation for
  past 3 years at Shree cement.
• Number of units in operation

32
Shree cement - Beawar

• Captive power plant
• Power generation 2 x 18 MW
• Boiler capacity 80 TPH
• Steam pressure 66 Kg/cm2
• Steam temperature 485 C
• Fuel Petcoke Coal

33
Thank You!