FLUIDIZED BED GASIFICATION OF GARDEN WASTES

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FLUIDIZED BED GASIFICATION OF GARDEN WASTES

• BATCH B12
• S.VISHNURAJA 80106114047
• G.RAJARAJAN 80106114308
• G.SATHEESHKUMAR 80106114310
• S.SURESHKUMAR 80106114314

Under the Guidance of Mr.S.VIJAJARAJ
M.E.,(Ph.D.,) Asst.PROF.ESSOR, Dept of Mech
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STATEMENT ABOUT PROBLEM

• Generally garden waste (crushed leafs) are bio
  degradable, they are digested in soil without any
  energy conversion
• The garden waste are highly available in nature
• The garden waste contain some amount of energy we
  should burn to obtain it
• Our proposed idea will reduce some amount of
  present fuel demand

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• OBJECTIVE
• To utilize the agricultural waste from paddy
  fields like paddy straw for synthetic gas
  production to replace the conventional energy
  requirements.
• To satisfy the growing energy demand
• To control the CO2 emission

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PROCESS

• Segregating and Chopping the dried leafs from
  garden waste and crushing the leafs into fine
  particles
• The crushed particle are fed into the FBG and it
  is gasified
• Air is being supplied from the other side of FBG
  with the controlled valve.
• This is done by using a blower which supplies the
  required air
• A amount air supplied can be varied by adjusting
  the valve attached blower
• The gasification is controlled effectively by
  variation in the air supply
• The combusted gas is being sent to the cyclone
  separator where it is purified.

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• INTRODUCTION
• Coal is an oldest fuel and still used on large
  scale throughout world for power generation. Most
  of the power industries are shifted from oil to
  coal. But the availability of coal is limited
  amount.
• So there is a need for non-conventional energy
  sources to over come this energy demand.

Fuel Availability Consumption
Coal Oil Natural gas 80,950 million tons 1100 billion tons 350 billion tons 200 million tons/year 40 million tons/year 14 million tons/year
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• Bio-mass
• Bio mass is a organic matter produced by plants,
  both in land and water. It includes forest crops
  and animal manure. It is an alternative source of
  energy in our country. It is the solar energy
  stored by the way of photosynthesis
• Solar energy
• Photosynthesis
• Bio-mass
• Energy generation

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Method of obtaining biomass
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Gasification Gasification is a process that
convert carbonaceous material such as coal,
petroleum, biofuel or biomass, into
carbon-monoxide and hydrogen by reacting the raw
material such as house waste or compost at high
temperature with the controlled amount of O2 and
stream. The resulting gas mixture is called
synthesis gas.
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THEORY OF GASIFICATION The production of
generator gas (producer gas) called gasification,
is partial combustion of solid fuel (biomass) and
takes place at temperature of about 1000C. The
reactor is called a gasifier. The combustion
products from complete combustion of bio mass
generally contain nitrogen water vapor, carbon
dioxide and surplus of oxygen. However in
gasification where is a surplus of solid fuel
(incomplete combustion) the products of
combustion are combustible gases like carbon
monoxide (CO), hydrogen (H2), and traces of
methane and non useful products like tar and dust
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Gasification Principle In principle,
gasification is the thermal decomposition of
organic matter in an oxygen deficient atmosphere
producing a gas composition containing
combustible gases, liquids and tars, charcoal,
and air, or inert fluidizing gases. Typically,
the term "gasification" refers to the production
of gaseous components, whereas pyrolysis, or
pyrolization, is used to describe the production
of liquid residues and charcoal. The latter,
normally, occurs in the total absence of oxygen,
while most gasification reactions take place in
an oxygen-starved environment.
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Fluidized bed gasifier
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INERT MATERIAL USED IN THE FBG SYSTEM1.Sand
2.Lime stone or dolomite 3.Fused alumina and
4.Sintered ash  
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• In the fluidised bed combustor the paddy straw
  is being burnt which is stocked from feed stock.
• Air is being supplied from the other side of FBC
  with the controlled valve.
• This is done by using a blower which supplies the
  required air
• A amount air supplied can be varied by adjusting
  the valve attached blower
• The gasification is controlled effectively by
  variation in the air supply
• The combusted gas is being sent to the cyclone
  separator where it purified.

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• Cyclone separator
• It is a mechanical type of dust collector a high
  velocity gas stream carrying the dust particles
  enters at high velocity and tangential-to the
  conical cell
• This produces a whirling motion of the gas within
  the chamber and throws heavier dust particles to
  the sides and fall out of gas stream and
  collected at the bottom of the collector.

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• Data Needed to Design the System
• The ultimate analysis of fuel
• The proximate analysis of fuel
• Bed material characteristics
• Size distribution of particles
• Porosity of the material
• Density of the materials
• Sphericity of the particle
• Paddy straw is choosen as a fuel for designing a
  system the to choose the paddy straw is ash
  fusion temperature of paddy straw is high and so
  there is no risk of clinger formation in the bed.

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• Design Steps
• Calculation of fuel feed Rate
• Calculation of reactor dimensions
• Design of distributor plate
• Calculation of minimum fluidization velocity
• Design of duct
• Design of blower

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PROXIMATE ANALYSIS BIOMASS FUELS BIOMASS FUELS BIOMASS FUELS
PROXIMATE ANALYSIS NEEM LEAF BASSIA LONGFONIA GRASS POWDER
Moisture 10.33 9.01 8.41
Ash 7.17 8.86 7.86
Volatile matter 63.48 59.78 66.38
Fixed carbon 19.02 22.35 17.35
Gross calorific value in Kcals/kg 5610 5094 4698
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ULTIMATE ANALYSIS BIOMASS FUELS BIOMASS FUELS BIOMASS FUELS
ULTIMATE ANALYSIS NEEM LEAF BASSIA LONGFONIA GRASS POWDER
Moisture 10.33 9.01 8.41
Mineral matter 7.89 9.75 8.65
Carbon 73.96 72.40 73.32
Hydrogen 5.82 5.66 6.13
Nitrogen 0.34 0.52 0.33
0.03 0.11 0.04
Oxygen by difference 1.63 2.55 3.12
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• DESIGN OF FLUE GAS DUCT
• Temperature650C
• Amount of gas formedfuelair-ash 86-0.199
  13.801 Kg/Kg of fuel
• Exhaust Gas density 0.2279 Kg/m3
• Q 13.801/0.227960.55 m3/hr

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• CYCLONE SEPARATOR DESIGN STEPS
• GENERAL PURPOSE FLAT TOP DESIGN
• CALCULATE INLET AREA
• AQ/CV
•  
• CALCULATE INLET DIAMETER
• Dv(A/?)
• BODY DIAMETER INLET DIAMETER4
• BODY HEIGHT INLET DIAMETER2.33
• CONE HEIGHT INLET DIAMETER4
•  
• CLEAN AIR OUTLET DIAMETERINLET DIAMETER2
• WELL LENGTHBODY HEIGHT

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• CYCLONE SEPARATOR 1
• Inlet area A
• Where
• ddiameter of exhaust duct 0.0508 m
• Inlet area A 2.026810-3 m2
• Inlet diameter D 0.0508 m
• Body diameter D4
• 0.20316 m
• Body height D2.33
• 0.1183 m
• Cone height D4
• 0.20316 m
• Clean gas outlet diameter D2
• 0.1016 m

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• CYCLONE SEPARATOR 2
• Inlet area A
• Where
• ddiameter of exhaust duct 0.1016 mm
• Inlet area A 2.026810-3 m2
• Inlet diameter D 0.1016 m
• Body diameter D4
• 0.4064 m
• Body height D2.33
• 0.9469 m
• Cone height D4
• 0.4064 m
• Clean gas outlet diameter D2
• 0.2032 m

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• THE DESIGN STEPS
• CALCULATION OF FUEL FEED RATE
• Stoichiometric air required for gasification
• 100/23(8/3C8H2S -O2 )
• 100/23((8/30.39) (80.048)(110-3 -0.34 ))
• 5 Kg of air/Kg of PS

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NEEM LEAF FUEL CALCULATION CALCULATION OF
FUEL FEED RATE Stoichiometric air required for
gasification 10.51 kg/kg of air

• CALCULATION OF ACTUAL AIR REQUIRED
• Gasification is conducted at the obtained minimum
  fluidization velocity of 0.95 m/s
• For ER0.15
• ER Actual air required per kgER stoichoimetric
  air required
• 0.1510.51
• 1.57 kg/hr
• Volume flow rate of air
• Cd0.63
• D16.2mm
• Volume Area3600Vf
• 0.014436000.952
• 49.37 m3/hr
• Massvolume density at 40º C
• 49.371.125
• Mass air supplied 55.54 kg/hr
• Mass of fuel gasified 55.54/1.57
• 35.37 kg/hr

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• Volume flow rate of air
• Cd0.63
• where d16.2mm
• Volume Area3600Vf
• 0.014436000.952
• 49.37 m3/hr
• Massvolume density at 40º C
• 49.371.125
• Mass of air supplied 55.54 kg/hr

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MASS FLOW RATE AND AIR FUEL RATE OF NEEM
FLUIDIZATION RATIO VELOCITY EQULIZATION RATIO- ER EQULIZATION RATIO- ER
FLUIDIZATION RATIO VELOCITY 0.15 0.30
0.952 Mass of fuel 35.37kg/hr Mass of fuel 17.63kg/hr
0.952 Mass of air 55.54 kg/hr Mass of air 55.54 kg/hr
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MASS FLOW RATE AND AIR FUEL RATE OF MAHUVA AND
GRASS
FLUIDIZATION RATIO- FR EQULIZATION RATIO- ER EQULIZATION RATIO- ER
FLUIDIZATION RATIO- FR 0.15 0.30
0.952 Mass of fuel 36.30kg/hr Mass of fuel 18.06 kg/hr
0.952 Mass of air 55.54 kg/hr Mass of air 55.54 kg/hr
FLUIDIZATION RATIO- FR EQULIZATION RATIO- ER EQULIZATION RATIO- ER
FLUIDIZATION RATIO- FR 0.15 0.30
0.952 Mass of fuel 35.29 kg/hr Mass of fuel 17.64kg/hr
0.952 Mass of air 55.54 kg/hr Mass of air 55.54 kg/hr
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• DESIGN OF BLOWER
• Pressure drop in the air duct
• Pressure drop in the air duct 4flv2 / 2gd
• f0.00360.26(Re)-0.4
• Revd?/µ
• Where ReReynolds number22559
• F0.0083
• Assume the length of air duct3 m
• The pressure drop in the air duct57.55 per mm of
  WC

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• PRESSURE DROP IN THE DISTRIBUTOR PLATE
• Pressure drop in the nozzle(1.5v2?/2g)
• Where vvelocity of air in the nozzle outlet48
  m/s
• Density (?) of air1.125 Kg/m3
• Pressure drop198.165 mm of WC
• PRESSURE DROP IN BED
• Orifice diameter dor 3 mm
• Equivalent diameter of the bed D 0.12 m
• Minimum distributor pressure drop

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• ?po ?pb(0.010.2(1-exp(-D)/2hmf))
• ?pb bed pressure drop ?s g hmf (1-emf)
• hmf height of the expanded bed 170 mm
• emf sphericity 0.4
• ?pb 21009.810.17(1-0.4)
• 2101.3 mm of WC
• ?po 2101.3(0.010.2(1-exp(-0.12/20.17)))
• ?po 145.38 mm of WC

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• PRESSURE DROP IN CYCLONE SEPARATOR
• Pressure drop in cyclone separator 1
  
• 4.26 mm of WC
• Pressure drop in cyclone separator 2
  
• 1.20 mm of WC
• Total pressure drop57.55198.165145.384.261.20
  
• 407 mm of WC

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• D Equivalent diameter of the bed
• Minimum distributor pressure drop
• ?po ?pb(0.010.2(1-e(-D)/2hmf))
• ?pbbed pressure drop ?s g hmf (1-emf)
• hmfheight of the expanded bed
• emf sphericity
• Power required (P)
• ? Blower efficiency 40
• P 0.067 kW
• Therefore the required blower capacity is 1 HP

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• EXPERIMENTAL SETUP

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ISOMETRIC VIEW
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PLANE VIEW
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• OBSERVATIONS

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COLD TEST
S.No Bed Height (mm) Expanded Bed Eight (mm) Bed Pressure Drop (mm) Superficial Velocity (m/s)
1. 100 149 75 1.3
2. 120 165 112 1.4
3. 140 180 133 1.5
4. 160 196 161 1.6
5. 180 211 175 1.7
6. 200 224 225 1.8
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EXPERIMENTAL VALUE OF HOT TEST
S.No Fuel used Equivalence ratio Mass Flow Rate Of Air (Kg/hr) Fuel Feed rate In (Kg/hr) Pr. Drop In The distributor plate mm of WC Pr. drop in the bed mm of WC
1. Neem leaf 0.15 55.54 35.37 198.165 405.47
1. Neem leaf 0.30 55.54 17.63 198.165 405.47
2. Mahuva leaf 0.15 55.54 36.30 198.165 405.47
2. Mahuva leaf 0.30 55.54 18.06 198.165 405.47
3. Grass 0.15 55.54 35.29 198.165 405.47
3. Grass 0.30 55.54 17.64 198.165 405.47
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EXPERIMENTAL VALUE OF NEEM LEAF FOR EQUIVALENCE
RATIO 0.15
SNO Time sec Bed temperature C Free board temperature C
1. 10 203 383
2. 20 234 414
3. 30 250 476
4. 40 276 502
5. 50 330 505
6. 60 342 599
7. 70 346 686
8. 80 370 723
9. 90 368 786
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EXPERIMENTAL VALUE OF NEEM LEAF FOREQUIVALENCE
RATIO 0.30
SNO Time sec Bed temperature C Free board temperature C
1. 10 345 523
2. 20 380 285
3. 30 460 432
4. 40 532 877
5. 50 546 756
6. 60 570 796
7. 70 638 712
8. 80 784 892
9. 90 790 923
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• Thank you