1. DEPT OF MECHANICAL ENGINEERING,
A.V.C COLLEGE OF ENGINEERING DEPARTMENT OF MECHANICAL ENGG. Main project review
PROJECT MEMBERS:BATCH NO: 1
B.Sathyabalan
S.Sathiyaraj
S.Gopi
K.Vinothraj
PROJECT GUIDE:
Mr. S.VIJAYARAJ, M.E.,(Ph.D.,)
ASST PROFESSOR,
DEPT OF MECHANICAL ENGINEERING,

2. PROJECT TITLE FLUIDIZED BED GASIFICATION OF PADDY STRAW

3. ABSTRACT
The energy needs of a developing country like India increasing day by day in an alarming manner and the non conventional energy sources are gaining importance due to the depletion of the fossil fuel reserves paddy straw, biomass which is available in large quantities can be used as an effective manner with the help of an fluidized bed gasification process.
In fluidized bed gasifier system the particles are maintained in a suspended state, which results in better gasification which less emission.

4. In this work, a fluidized bed gasifier using our fuel is designed, fabricated and tested at our college. The gasifier is provided with suitable instrumentation to measure the parameters such as temperature, pressure drop, flow rate of air, and also to get the clean gas by separating ash and other dust particles using cyclone separator.
The paddy straw is gasified in the fluidized bed gasifier. Various parameters like volume flow rate of air, mass flow rate of fuel were calculated for various equivalence ratios of the paddy straw and gasification was done. The cold test and hot test were conducted for the above gasifier, the bed temperature and free board temperature were noted continuously for some period of time and temperature profiles were drawn for the paddy straw

5. OBJECTIVE To satisfy the growing energy demand
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

6. PROBLEM Energy is an important input in all sectors.
Energy is primary and most universal of all kinds of work.
Energy is an important input in all sectors.
The standard of living of a country can be directly related to per capita energy consumption.
Energy crisis increased due to the standard of living of human beings.

7. In addition the conventional source of energy are depleting and will be exhausted by the end of this century.
The non conventional energy sources are widely used to compensate the energy requirements.
Methods have to be developed to utilize the biomass sources from our agricultural residues like paddy straw

8. INTRODUCTION Fuel Availabilit y Consumpt ion
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
Availabilit y
Consumpt ion
Coal
Oil
Natural gas
80,950 million tons
1100 billion tons
350 billion tons
200
million
tons/year
40 million
14 million

9. 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
Energy generation

10. Method of obtaining biomass

11. 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.

12. THEORY OF GASIFICATION:
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 1000˚C. 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

13. Gasification Principle
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.

14. Fluidized bed gasifier

15. INERT MATERIAL USED IN THE FBG SYSTEM 1. Sand 2
INERT MATERIAL USED IN THE FBG SYSTEM 1.Sand 2.Lime stone or dolomite 3.Fused alumina and 4.Sintered ash  

16. In the fluidized 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.

17. 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.

18. 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.

19. 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

20. THE ELEMENTAL ANALYSIS OF PADDY STRAW:
Carbon-39%
Hydrogen-4.8%
Nitrogen-0.3%
Sodium-0.02%
Potassium-0.03%
Calcium-0.08%
Magnesium-0.17%
Silica-15.6%
CHEMICAL COMPOSITION OF PADDY STRAW ASH:
Silica-94.23%
CaO-2.27%
MgO-0.12%
K2O-2.22%

21. H2O-3.5% PROXIMATE ANALYSIS OF PADDY STRAW: Fixed carbon-19.9%
Volatile matter-60.6%
Ash-19.9%
Calorific value MJ/Kg
ULTIMATE ANALYSIS OF AVAILABLE PADDY STRAW:
Carbon-39.9%
Hydrogen-4.8%
Oxygen-34%
Nitrogen-0.2%
Sulphur-0.1%
H2O-3.5%

22. DESIGN OF FLUE GAS DUCT:
Temperature=650˚C
Amount of gas formed=fuel+air-ash = = Kg/Kg of fuel
Exhaust Gas density = Kg/m3
Q= /0.2279=60.55 m3/hr

23. CYCLONE SEPARATOR DESIGN STEPS
GENERAL PURPOSE FLAT TOP DESIGN
CALCULATE INLET AREA
A=Q/CV
CALCULATE INLET DIAMETER
D=√(A/Π)
BODY DIAMETER= INLET DIAMETER×4
BODY HEIGHT= INLET DIAMETER×2.33
CONE HEIGHT= INLET DIAMETER×4
CLEAN AIR OUTLET DIAMETER=INLET DIAMETER×2
WELL LENGTH=BODY HEIGHT

24. CYCLONE SEPARATOR 1: Inlet area A =Π/4(d2) Where
d=diameter of exhaust duct = m
Inlet area A = *10-3 m2
Inlet diameter D = m
Body diameter =D*4
= m
Body height = D*2.33
= m
Cone height = D*4
Clean gas outlet diameter = D*2
= m

25. CYCLONE SEPARATOR 2:
Inlet area A
Where
d=diameter of exhaust duct = mm
Inlet area A = *10-3 m2
Inlet diameter D = m
Body diameter =D*4
= m
Body height = D*2.33
= m
Cone height = D*4
Clean gas outlet diameter = D*2
= m

26. CALCULATION OF FUEL FEED RATE:
THE DESIGN STEPS:
CALCULATION OF FUEL FEED RATE:
Stoichiometric air required for gasification
=100/23(8/3*C+8*H2+S -O2 )
=100/23((8/3*0.39) + (8*0.048)+(1* ))
=5 Kg of air/Kg of PS

27. CALCULATION OF ACTUAL AIR REQUIRED
Gasification is conducted at the obtained minimum fluidization velocity m/sec
For ER=0.15:
ER=actual air required/ stoichoimetric air required
Actual air required per kg=ER* stoichoimetric air required
=0.15*5
=0.75 kg/hr

28. Volume flow rate of air Cd=0.63 where d=16.2mm Volume = Area*3600*Vf
=0.0144*3600*0.952
=49.37 m3/hr
Mass=volume* density; at 40º C
=49.37×1.125
Mass of air supplied =55.54 kg/hr

29. MASS FLOW RATE AND AIR FUEL RATE OF FUEL
Fluidization velocity
Equivalent ratios
0.15
0.20
0.25
0.30
0.952 m/s
Mass of fuel gasified in kg/hr
74.05
55.5
44.45
37.02
Mass of air supplied in kg/hr
55.54

30. DESIGN OF BLOWER: Pressure drop in the air duct:
Pressure drop in the air duct= 4flv^2 / 2gd
f=0.0036*0.26(Re)-0.4
Re=vdρ/μ
Where Re=Reynolds number=22559
F=0.0083
Assume the length of air duct=3 m
The pressure drop in the air duct=57.55 per mm of WC

31. PRESSURE DROP IN THE DISTRIBUTOR PLATE: Pressure drop in the nozzle=(1
PRESSURE DROP IN THE DISTRIBUTOR PLATE: Pressure drop in the nozzle=(1.5v2ρ/2g) Where v=velocity of air in the nozzle outlet=48 m/s Density (ρ) of air=1.125 Kg/m3 Pressure drop= 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

32. Δpo= Δpb( (1-exp(-D)/2hmf)) Δpb bed pressure drop= ρs g hmf (1-εmf) hmf –height of the expanded bed= 170 mm εmf –sphericity = 0.4 Δpb = 2100*9.81*0.17(1-0.4) = mm of WC Δpo =2101.3*( (1-exp(-0.12/2*0.17))) Δpo = mm of WC

33. PRESSURE DROP IN CYCLONE SEPARATOR:
=4.26 mm of WC
Pressure drop in cyclone separator 2
=1.20 mm of WC
Total pressure drop=
= 407 mm of WC

34. D =Equivalent diameter of the bed Minimum distributor pressure drop Δpo= Δpb( (1-e(-D)/2hmf)) Δpb=bed pressure drop= ρs g hmf (1-εmf) hmf=height of the expanded bed εmf =sphericity Power required (P) ή =Blower efficiency = 40% P =0.067 kW Therefore the required blower capacity is 1 HP

35. EXPERIMENTAL SETUP

36. ISOMETRIC VIEW

37. PLANE VIEW

38. Expanded Bed Eight (mm)
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.
211
175
1.7 6.
200
224
225
1.8

39. Pr. Drop In The distrib utor plate
HOT TEST
S.No
Fuel used
Equiva lent ratio
Mass Flow Rate Of Air
(Kg/hr)
Fuel
Feed rate In
Pr. Drop In The distrib utor plate
mm of WC
Pr. drop in the bed 1.
PADD Y STRA W
0.15
55.54
74.05
407
0.20
0.25
44.45
0.30
37.02

41. EXPERIMENTAL VALUE OF PADDY STRAW FOR EQUIVALENT RATIO:0.15
SNO
Time
sec
Bed temperature ˚C
Free board
temperature˚ C 1. 20
258
958 2. 40
252
718 3. 60
253
658 4. 80
702 5.
100
244
693 6.
120
241
631 7.
140
238
529 8.
160
237
541 9.
180
235
539
10.
200
234
560

43. EXPERIMENTAL VALUE OF PADDY STRAW FOR EQUIVALENT RATIO 0.20
SNO
Time
sec
Bed temperature ˚C
Free board
temperature 1. 20
321
652 2. 40
312
610 3. 60
288
461 4. 80
278
790 5.
100
267
671 6.
120
259
628 7.
140
253
643 8.
160
252
544 9.
180
438

45. EXPERIMENTAL VALUE OF PADDY STRAW FOR EQUIVALENT RATIO:0.25
SNO
Time
sec
Bed
temperature ˚C
Free board 1. 20
493
973 2. 40
470
1098 3. 60
429
1086 4. 80
405
1026 5.
100
378
1073 6.
120
365
1241 7.
140
355
1244 8.
160
337
864 9.
180
332
790

47. EXPERIMENTAL VALUE OF PADDY STRAW FOR EQUIVALENCE RATIO 0.30
SNO
Time
sec
Bed temperature ˚C
Free board
temperature 1. 20
448
270 2. 40
317
822 3. 60
485
845 4. 80
495
1085 5.
100
500
941 6.
120
525
847 7.
140
537
861 8.
160
573
888 9.
180
621
945

48. OVERALL OBSERVATION S.No Name of the fuel Equiva lence ratio
Total Amount of fuel
Taken in gram
Time of gasificatio n
min
Maximum Free board temperatu re °C
Maximum Bed temperatu re 1.
PADDY STRAW
0.15
500
7.16
958
258
0.20
1000
8.83
790
321
0.25
1244
493
0.30
1085
621

50. CONCLUSION
Biomass gasification offers the most attractive alternative energy system for agricultural for agricultural purpose.
Most preferred fuels for gasification have been charcoal and wood. However biomass residues are the most appropriate fuels for on farms and offer the greatest challenge to researchers and gasification system manufacturer.
Very limited experience has been gained in gasification of biomass residues.
Most extensively used and reached systems have been based on downdraft gasification. However it appears that for fuels with high ash content fluidized bed combustion may offer a solution. At present no reliable and economically feasible systems exist.

51. Paddy straw is gasified in the fluidized bed gasifier successfully
Paddy straw is gasified in the fluidized bed gasifier successfully. Various parameters like volume flow rate of air, mass flow rate of fuel were calculated for various equivalence ratios of the above fuels and gasification was done. The cold test and hot test were conducted for the above gasifier and bed temperature and free board temperature were noted continuously for some period of time and temperature profiles were drawn for the above fuels.
From The temperature Vs time graph we concluded paddy straw better for gasification, because it is easily fired in the bed. The fly ash collected in the cyclone separator and now exhaust is free from fly ash.
During the gasification of paddy straw, the more amount of ash is accumulated in the bed, so the bed temperature gradually reduces with the increase of free board temperature.

52. FUTURE SCOPE OF THE PROJECT
By modifying ash collection system like ceramic filters and dry scrubber instead of cyclone separator.
The calorific value of syngas will be calculated.
The volume flow rate of gas will be calculated.
By varying the fluidization ratio, efficient gasification will be produced.
The constituents of syngas will be analzed in future.

53. BIBLIOGRAPHIE
Anil K. Rajvanshi, Biomass gasification Chapter (No. 4) book “Alternative Energy in Agriculture”, Vol. II, Ed CRC Press, 1986, pgs
Thomas Reed and Ray Desrosiers, The Equivalence Ratio: The Key To Understanding Pyrolysis, Combustion And Gasification of Fuels.
E. G. Baker,M. D. Brown,R. H. Moore,L. K. Mudge , D. C.Elliot, Engineering analysis of biomass gasifier product gas cleaning technology Prepared f o r the Biomass Energy Technology Division , U.S. Department o f Energy,2007.
Rajeev Jorapur and Anil K. Rajvanshi, sugarcane leaf-Bagasse gasifiers for industrial heating applications, Biomass and Bio energy Vol 13., No. 3, pp , 1997.
Jared P. Ciferno, John J. Marano, Benchmarking Biomass Gasification Technologies for Fuels, Chemicals and Hydrogen Production, Prepared for U.S. Department of Energy, National Energy Technology Laboratory, 2002.

54. COST ANALYSIS DESCRIPITION AMMOUNT
Proximate and ultimate test our fuel
8500/-
Blower 1HP
4500/-
Cyclone separator
2000/-
Thermocouples and temperature indicator
2300/-
Fabrication of reactor
4000/-
Manometer
500/-
Other Fittings
2500/-
Total
24300/-

55. Thank you !!!