Waste to Energy: Thermochemical Pathways
Isam Janajreh, Associate Professor, Mech. & Mat. Engineering Dept. Masdar Institute, Abu Dhabi, UAE
Muscat, Oman
ijanajreh@masdar.ac.ae
100
5 C/min
10 C/min
15 C/min
20 C/min
95
Weight ( %)
90
Material Characterization:
•
•
•
•
•
•
Proximate (TGA)
Ultimate (CHNSO-Flash)
Chemical Kinetics (TGA)
Thermal properties: Bomb Cal/Cp(STA)
Impurities (GCMS, ICP, FTIR)
Species determination (Drop. Tube)
85
80
75
70
65
60
20
120
220
320
420
520
620
720
820
Temperature (C)
Low Temperature Pathways:
• Digestion : Hydrolysis, acido, Aceto &
Methanogenises
• Transesterification
• Plastic recycling/remoulding
von Mises Strain
Min=0.149
0.1
0.25
Max=0.788
0.38
0.52
0.66
0.8
von Mises Stress
Min=35.0Mpa
40
High Temperature Pathways:
• Incinerations/Combustion
• Gasification (GEK)
• Pyrolysis (Buchi Reactor)
60
80
Max=165.5Mpa
100
120
140
160
Overview :
Country *
Bahrain
EU-7
India
Italy
Japan
Kuwait
Qatar
Spain
UAE
US
2
MSW
(Kg/person/day)
1.3
1.4
0.45
0.95
1.12
1.4
1.3
0.88
1.2
2
Advocating zero waste
Country
Austria
Belgium
Egypt
France
Jordan
Oman
Portugal
Tunisia
Turkey
UK
MSW
(Kg/person/day)
0.89
0.93
0.81
0.89
0.6
0.7
0.7
0.41
0.95
0.95
Type of Waste (Thousands tons/year)
Year Organics Fiber Wood Plastic Paper Glass
Metal Others Total
1995
422
41
41
109
178
29
23
11
854
2000
492
47
47
124
203
32
26
13
984
2005
558
53
53
141
231
37
29
15
1,117
2010
662
63
63
167
273
44
35
17
1,324
2015
736
71
71
185
303
49
38
19 1, 472
2020
830
80
80
209
342
55
43
22
*Al-Salem and Lettiere, European Journal of Scientific ResearchISSN 1450-216X Vol.34 No.3 (2009), pp.395-405
1,661
OVERVIEW
Provide sustainable routes to maximize resource utilization by converting waste to energy, reduce MENA
‘s emission footprint (CO2, NOX, SOX, CH4, etc), fulfill the emerging stringent environmental regulations,
and reduce landfill deposits.
 Use high temp. conversion: Incineration, gasification and pyrolysis of waste stream into syngas
 Promote IGCC as the cleanest and most efficient (50%) power generation technology amenable to
CO2 capturing and co-firing of MSW
 Use trans-esterification of waste cooking and algae oil into biodiesel (2nd and 3rd Generation)
 Use digestion (bioreactor) processes to convert organic waste into bio-fuel/landfill gas and compost
MSW (mixed)
Combustion
Sensible
heat
Gasification
Syngas
Heat
MSW (Dry)
Biomass
Homog. Ind.
Organic Waste
Gas
Pyrolysis
Algae Culture
Waste
Classific
ation
Waste
Oil/ Lipid
P
Oil
Trans/esterification
o
Distillation/Oil
Bio-diesel
Glycerol
Phase-change Material
MSW (Wet)
Digestion
Biogas
Compost/Soil
Waste
Water
Industry
Sludge
Waste Water Treatment
Gray Water
Clean Water
w
e
r
OVERVIEW Cont’d
To Gasify, or Not to Gasify?
Definition: To convert carbonaceous solid
material (CHxOyNzSm) into a mixture of CO and H2 in an O2 deprived environment.
CO shift and
CO2 removal
Gas cleaning
CO2 for
storage
Syngas
H2
CO
CO2
Gas cooler
Sulfur
Stage 2:
2 -4 burners
O2
CnHmOx
CO2,H2O
Stage 1:
2 -4 burners
Slag
Lower: Stoichiometric O2
Ash
1200
1600
Temperature, oC
Advantages
-
Air
Syngas
upper: Lean O2
H2
Combustor
Air Separation
Unit
O2
Gas turbine
Generator
Electric
Power
N2
Gasifier
Heat recovery steam
generator
T=1,000-1,500 C
Steam
P=20-40bar
Flue gas
Control over produced energy
Coal
Capability for carbon capture and storage.
Flexibility in feedstock and products.
Alternative to “bury or burn” policy.
Ash
Hydrogen-based energy systems (near zero-CO2 emissions).
Small scale gasifiers for distributed generation.
Gasific
ation
v
s
Combusti
on
CO
C
CO2
H2
H
H2O
N2
N
Nox
H2S
S
SOx
Steam
turbine
Pump
Condenser
Cycle
Fuel
Temp low (oC) Temp High (oC) Carnot (h) Actual (h) Car(h)/Act(h)%
Conventional Steam Power Plant
Coal
27
540
63
40
63
Ditto Ultra Super Critical
Coal
27
650
67
45
67
IGCC
Coal
27
1350
82
46
56
Open Gas Turbine Cycle
Gas
27
1210
80
43
54
Combined Cycle
Gas
27
1350
82
58
71
Low Speed Marine Diesel (LSMD) Heavy Fuel Oil
27
2000
87
48
55
LSMD with Super Charger
Heavy Fuel Oil
27
2000
87
53
61
Generator
Electric
Power
MATERIAL CHARACTERIZATION
What does the feedstock compose of?
Carbonaceous fuel is a complex collection of organic polymers
consisting mainly of aromatic chains.
100
5 C/min
10 C/min
15 C/min
20 C/min
Heat flow-10 C/min (W)
95
0.1
85
Event 3 (Boudouard reaction/fixed carbon)
80
75
Event 1 (drying/Moisture release)
Heat flow (W)
Weight ( %)
90
1
0.01
Event 2 (devolatization)
70
65
60
0
250
500
750
Temperature, C
0.001
200
1000
220
200
420
400
Temperature,
Temperature (C) C
620
600
800820
100
Drying
50
Pyrolysis
Weight %
75
25
Combustion
Gasification
Temperature, C
0
0
250
500
750
1000
MATERIAL CHARACTERIZATION CONT’D
Proximate Analysis
Summary of the proximate
analysis
Composition Weight (%)
DSC/TGA curve of RTC-Coal with respect to time.
Moisture
0.3001
Volatiles
37.8147
Fixed Carbon
54.6571
Ash
7.2281
Total
100
Simultaneous DSC/TGA Q600
Proximate analysis is used to calculate the weight percentage of
moisture, volatiles, fixed carbon and ash present in the sample.
Thursday, August 07, 2014
MATERIAL CHARACTERIZATION CONT’D
Ultimate analysis
Flash 2000 CHNSO analyzer (TCD)
Sample ID
Nitrogen Carbon Hydrogen Sulphur Oxygen Ash Balance
Wt(%) Wt(%)
Wt(%) Wt(%) Wt(%)
Wt (%)
1
2.2926
76.5178
5.3233
0.8075
8.1136
6.9452
2
2.1930
73.2217
5.0185
1.0848
7.7913
10.6908
3
2.2319
73.8664
5.0861
1.0148
7.6337
10.1671
4
2.1340
66.7894
4.6437
1.0004
7.8425
17.5901
5
2.1348
71.1166
4.7098
1.0794
7.7338
13.2257
2.1972 72.3024
4.9563
0.9974 7.8230
11.7238
Average
Results of ultimate analysis for RTC-coal
Ultimate analysis is used to calculate
the elemental composition of the
sample
Thursday, August 07, 2014
Ultimate Wt(%) Wt(%) Molar
Carbon
analysis Previous New number normalization
Nitrogen
2.49
2.50
0.1784
0.0260
Carbon
81.90
82.17
6.8475
1.0000
Hydrogen
5.58
5.60
5.5967
0.8173
Sulfur
1.13
1.13
0.0354
0.0052
Oxygen
8.57
8.60
0.5376
0.0785
Total
99.68
100
Empirical formula of RTC-coal using
ultimate analysis C H
O
N
0.8173
0.0785
0.0260
MATERIAL CHARACTERIZATION CONT’D
Calorific value analysis
Sample ID
Weight (gms ) HHV (MJ/Kg)
1
3.4027
30.2205
2
1.7868
30.8207
3
1.7145
30.4197
4
1.6064
30.2232
Average HHV (MJ/Kg)
30.4210
Higher heating value of RTC-Coal
𝐻𝐻𝑉
𝑀𝐽
= −0.03 𝐴𝑠ℎ − 0.11 𝑀𝑜𝑖𝑠𝑡𝑢𝑟𝑒 + 0.33 𝑉𝑜𝑙𝑎𝑡𝑖𝑙𝑒𝑠 + 0.35 𝐹𝑖𝑥𝑒𝑑 𝐶𝑎𝑟𝑏𝑜𝑛
𝐾𝑔
𝐻𝐻𝑉
𝑀𝐽
= 0.3491 𝐶 + 1.1783 𝐻 + 0.1005 𝑆 − 0.1034 𝑂 − 0.0151 𝑁 − 0.0211 𝐴
𝐾𝑔
Parr 6100 Bomb calorimeter
H %Wt
O %Wt
N %Wt
RTC coal
83.36
5.52
7.44
2.53
1.15
1.6
Pine needles
48.58
6.30
43.64
1.48
0.00
1.4
Ply-wood
49.59
6.28
43.74
0.39
0.00
Lignite
66.03
4.65
25.64
2.07
1.62
Feedstock
Feedstock
RTC coal
Pine needles
Ply-wood
Lignite
Empirical formula
CH0.7946O0.0670N0.0260
CH1.5550O0.6736N0.0261
CH1.5196O0.6615N0.0067
CH0.8450O0.2912N0.0268
HHV
HHV
KJ/Kmole
MJ/Kg
502928
489784
487566
469939
35.34
19.83
20.14
26.28
Atomic H/C Ratio
C %Wt
S
%Wt
1.8
Biomass
Peat
Lignite
1.2
1.0
Coal
0.8
0.6
Pine needle & ply-wood
Lignite
RTC Coal
0.4
0.2
Anthracite
0.0
0
0.2
0.4
Atomic O/C Ratio
0.6
0.8
MODELING:
Can a zero dimensional model predict the
gasifier performance?
 Simplest level of modeling.
 No dimension nor time is variable.
Entrained flow gasifiers are amenable to equilibrium.
Category
Ash condition
Typical processes
Feed characteristics
Size
Acceptability of fines
Acceptability of caking coal
Prefered coal rank
Operating characteristics
Outlet Gas Temperature
Oxidant demand
Steam demand
Other characteristics
Moving Bed
Dry Ash
Lurgi
Slagging
BGL
6-50mm
Limitted
yes (with stirrer)
any
6-50mm
Better than dry ash
yes
high
Fluid Bed
Dry Ash
Winnkler, HTW, CFB
6-10mm
good
possibly
low
l
low (425-650C)
low (425-650C)
moderate (900-1050C)
low
low
moderate
high
low
moderate
hydrocarbone in gas hydrocarbone in gas lower carbon
Source: Adapted from Simbeck et al. 1993
Entrained-Flow
Agglomerating
KRW, U-Gas
Slagging
Shell, Texaco, E-Gas, Noell, KT
6-10mm
better
yes
any
<100 m m
unlimitted
yes
any
moderate (900-1050C)
moderate
moderate
lower carbon
high (1250-1600C)
high
low
pure gas, high c conversion
LOW FIDELITY SIMULATION
Equilibrium constant approach
Global Gasification reaction
𝐶𝐻𝑥 𝑂𝑦 𝑁𝑧 + 𝑚 𝑂2 + 3.76𝑁2 + 𝑛𝐻2 𝑂 + 𝑝𝐶𝑂2 → 𝑥1 𝐻2 + 𝑥2 𝐶𝑂 + 𝑥3 𝐶𝑂2 + 𝑥4 𝐻2 𝑂 + 𝑥5 𝐶 +
•Elemental balance
1) Combustion reactions
•Carbon balance
•Hydrogen balance
•Oxygen balance
•Nitrogen balance
•Equilibrium constant equation 2) Reduction reactions
•For Bouduard reaction:
•For CO shift reaction:
•For Methanation reaction:
•Energy balance between reactant and product
𝑧
+ 3.76𝑚 𝑁2
2
K1 
x 22
( Equilibriu m const. for Boudouard reaction )
x3 xtotal
K2 
x1 x3
( Equilibriu m const. for CO shift reaction )
x2 x4
•Conversion Metrics
K3 
𝑥1 283800 + x2 283237.12 + x5 889000
𝐶𝐺𝐸 =
𝐻𝐻𝑉𝑓𝑒𝑒𝑑𝑠𝑡𝑜𝑐𝑘
x5 xtotal
( Equilibriu m const. for Methanatio n reaction )
x12
z
xtotal  x1  x 2  x3  x 4  x5  (  3.76m)
2
N
 n (h
i
i _ prod1
o
 hs )  Q 
Thursday, August 07, 2014
N
 n (h
i
i _ react1
o
 hs )
LOW FIDELITY SIMULATION
Results: Equilibrium constant approach
H2O Gasification
Thursday, August 07, 2014
CO2 Gasification
LOW FIDELITY SIMULATION
Gibbs energy minimization approach
Gibbs Energy minimization using Lagrange : GTt , P  g (n1 , n2 ,...., nN )
multiplier
𝑜
Δ𝐺𝑓𝑖
+ 𝑅𝑇 ln
𝑛𝑖
𝑛𝑡𝑜𝑡𝑎𝑙
+
𝜆𝑘 𝑎𝑖𝑘 = 0,
𝑖 = 1,2, … , 𝑛
𝑘
List of species considered in the model
Species
C2 H2 C2 H4 C2 H6 C3 H8
H
H2
CO CO2 OH H2 O H2 O2 HCO HO2
N
N2
C(g) CH CH2 CH3 CH4
O
O2
NCO NH NH2 NH3 N2 O NO
NO2
CN HCN HCNO S(g)
S2 (g) SO SO2 SO3 COS
CS2
HS
CS
H2 S
C(s)
S(s)
HIGH FIDELITY SIMULATION
Reaction kinetics via Arrhenius equation
100
95
(  E / RT )
dX
 K (1  X ) n ; K  A e
dt
E
AR
 ln(1  X ) 
ln 



ln

T2
RT
E


•Direct Arrhenius plot method:
Weight ( %)
•Integral method:
90
0.1
85
Event 3 (Boudouard reaction/fixed carbon)
80
75
Event 1 (drying/Moisture release)
0.01
Event 2 (devolatization)
70
65
60

1  X T2  X T1

ln 
 T T
1

x
2
1



E 1
A




ln




R T 


•Method of approximate temperature integral:
d ln P(u )
c
b
du
u
0.001
20
METHODS:
Heating Rate
20 K/min
10 K/min
5 K/min
Thursday, August 07, 2014
220
420
620
820
Temperature (C)
15 K/min
A and E can be used in high Fidelity simulation
Heat flow (W)
Arrhenius Equation
1
5 C/min
10 C/min
15 C/min
20 C/min
Heat flow-10 C/min (W)
INTEGRAL METHOD
Events
E (KJ/mol)
Drying
15.9
Devolatization
64.5
Boudouard
152.0
Drying
5.9
Devolatization
65.8
Boudouard
173.8
Drying
5.6
Devolatization
65.3
Boudouard
171.2
Drying
10.9
Devolatization
65.8
Boudouard
168.1
A (sec-1)
2.22E-01
2.19E+02
4.71E+05
4.70E-03
2.13E+02
8.03E+06
2.30E-03
1.73E+02
3.25E+06
5.80E-03
1.17E+02
1.61E+06
DIRECT ARRHENIUS
PLOT METHOD
E (KJ/mol)
8.3
60.7
172.0
8.0
64.2
182.2
4.7
60.5
145.3
5.0
56.2
122.2
A (sec-1)
3.26E-02
1.51E+02
7.98E+06
1.96E-02
2.16E+02
2.76E+07
3.90E-03
9.66E+01
1.16E+05
1.60E-03
2.62E+01
4.19E+03
APPROX. TEMP.
INTEGRAL METHOD
E (KJ/mol)
17.0
66.7
155.8
6.9
68.0
177.8
6.6
67.6
175.3
11.9
68.0
172.2
A (sec-1)
3.97E-01
3.02E+02
5.59E+05
1.16E-02
2.92E+02
9.18E+06
5.80E-03
2.38E+02
3.76E+06
1.18E-02
1.60E+02
1.87E+06
HIGH FIDELITY SIMULATION CONT’D
Ultimate Analysis
Ultimate Analysis
(DAF wt. %)
Utah Bituminous
Coal
El-Lajjun Jordanian
Oil Shale
Tires
Carbon
Hydrogen
Nitrogen
Oxygen
Sulfur
81.810
5.610
2.490
8.960
1.130
49.373
4.976
1.001
36.438
8.212
80.06
7.57
0.29
10.72
1.36
Proximate Analysis
Proximate Analysis
(wt. %)
Moisture
Volatile
Fixed Carbon
Ash
Utah Bituminous
Coal
2.304
30.19
57.20
10.306
El-Lajjun Jordanian
Oil Shale
1.82
21.21
13.70
63.27
Tires
1.02
67.31
22.93
8.74
Bomb Calorimetry
Heating Value
(MJ/kg)
Utah Bituminous
Coal
34.38
El-Lajjun Jordanian
Oil Shale
7.66
Tires
29.52
HIGH FIDELITY SIMULATION CONT’D
Kinetics of the Gasification Process
Heterogeneous Reactions
Reaction
Activation Energy
(𝑬𝒂 )
Pre-Exponential
Factor (A)
N
1
𝐶 + 𝑂2 → 𝐶𝑂
2
9.23 × 107
2.3
1
𝐶 + 𝐶𝑂2 → 2𝐶𝑂
1.62 × 108
4.4
1
𝐶 + 𝐻2 𝑂 → 𝐶𝑂 + 𝐻2
1.47 × 108
1.33
1
Homogeneous Reactions
Reaction
Activation Energy
(𝑬𝒂 )
Pre-Exponential
Factor (A)
N
1
𝐶𝐻4 + 𝑂2 → 𝐶𝑂
2
+ 2𝐻2
1
𝐻2 + 𝑂2 → 𝐻2 𝑂
2
1.25 × 108
4.4 × 1011
0
1.67 × 108
6.8 × 1015
-1
1
𝐶𝑂 + 𝑂2 → 𝐶𝑂2
2
1.67 × 108
2.24 × 1012
0
𝐶𝐻4 + 𝐻2 𝑂 → 𝐶𝑂
+ 3𝐻2
𝐶𝑂 + 𝐻2 𝑂 → 𝐶𝑂2 + 𝐻2
1.25 × 108
3 × 108
0
8.37 × 107
2.75 × 109
0
HIGH FIDELITY SIMULATION CONT’D
Mathematical
System:
Coupled CFD
and
reaction kinetics
1) Continuity, Momentum, Energy, TKE (k) & TDR (e):

 ) 
t
 
 
 xi
diffusion

ui )   
xi
xi
Time rate advective

  S

source
2) Transportation equation for mi species:

mi )   ui mi )   Di ,m  mt / Sct ) mi  Ri  Si
t
xi
xi
xi
3) Reaction kinetics:
N
 vi,r Si
i 1
k f ,r

k b ,r
N
 vi,r Si ;
i 1

Ri ,r  M i ,r (vi,r  vi,r ) k

k  A e (  E / RT )
h ,*rj 

C

j ,r 
j 1

N
4) Discrete Lagrangian particle:


 

du P
dxP 
 FD u  u P )  g  P   )  P ;
 up
dt
dt

dm p
dt
mpc p
 Ae ( E / RT ) [m p  (1  f v0 )m 0p ]
dTp
dt
 hAp (T  Tp ) 
dm p
dt
h fg  e p Ap (TR4  Tp4 )
The procedure for the calculation of pulverized feedstock conversion:
(a) Solve the continuous phase
(b) Introduce and solve for the discrete phase
(c) Recalculate the continuous phase flow, using the inter-phase exchange of
momentum, heat, and mass determined during the previous particle
calculation;
(d) Recalculate the discrete phase trajectories in the modified continuous phase
flow field;
(e) Repeat the previous two steps until a convergence solution
HIGH FIDELITY VALIDATION CONT’D
Geometry & Mesh Generation
Reductor
D
13D
Top view
Diffuser
Throat
Combustor
Inputs
1.6D
D/4
D/3
Top view
200t/d two-stage air blown gasifier and nozzle geometry showing blocking topology
and the resulted 3D mesh same geometry of Chen et al. and Bockelie et al.
The 3D mesh consists of 1,500,000 finite volumes.
 Fitted within 30 volumes of surface sweep Boundary
layer (i.e. y+<20).
 Captures the exact gasifier topography.
HIGH FIDELITY SIMULATION CONT’D
Predictive Modeling of the Gasification of Oil Shale in an O2-Blown BYU Atmospheric Gasifier
Boundary Conditions
Schematic Diagram of the O2Blown BYU Atmospheric Gasifier
HIGH FIDELITY SIMULATION CONT’D
Predictive Modeling of the Gasification of Oil Shale in an O2-Blown BYU Atmospheric Gasifier
1010
0.05
0.0166
0.0083
700
0.02
0.0000
400
Temperature (oC)
0.00
Mole Fraction of CO
0.0007030
0.0000352
0.0000000
Mole Fraction of H2
Mole Fraction of CO2
HIGH FIDELITY SIMULATION CONT’D
Predictive Modeling of the Gasification of Utah Bituminous Coal in an O2-Blown BYU
Atmospheric Gasifier
2800
0.3523
0.4913
1600
0.1761
0.2456
400
0.0000
0.0000
Mole Fraction of CO
Temperature (oC)
Mole Fraction of CO2
0.32
0.16
0.00
Mole Fraction of H2
Mole Fraction of H2
HIGH FIDELITY SIMULATION CONT’D
Predictive Modeling of the Gasification of Tire Crumbs in an Air-Blown Drop Tube Reactor
0.1870
0.0934
0.1680
0.0925
0.0000
0.0000
Mole Fraction of CO
0.2300
6.11e-3
0.0104
3.05e-3
0.0000
Schematic Diagram of the DTR at
Masdar Institute
Mole Fraction of CO2
Mole Fraction of O2
0.0000
Mole Fraction of H2
HIGH FIDELITY SIMULATION CONT’D
Comparative Mole Composition of the Product Gases at the
Exit and the Cold Gasification Efficiency
Mole Fraction\Fuel
Coal
Oil Shale
Tire
Hydrogen
0.2832
8.62e-6
4.28e-3
Carbon Monoxide
0.3516
0.0461
0.1523
Carbon dioxide
0.2249
0.0154
0.0836
Cold Gasification
Efficiency
69.6
18.5
43.2
Parametric study for the input velocity of oxidizer:
Reaction
R1
R2
R3
R4
R5
R6
R7
R8
Assembled biomas Gasifier At MI
Geometry and mesh
Temp. distribution (K)
2 𝐶𝑂 + 𝑂2 → 2 𝐶𝑂2
Kinetic Parameters Aj , Ej [kJ/mol]
𝐴 = 1017.6 [(m3mol-1)-0.75s-1], 𝐸 = 166.28
2 𝐻2 + 𝑂2 → 2 𝐻2 𝑂
𝐶𝑂 + 𝐻2 𝑂 ↔ 𝐶𝑂2 + 𝐻2
𝐶 𝑠 + 𝑂2 → 𝐶𝑂2
𝐶 𝑠 + 𝐶𝑂2 → 2 𝐶𝑂
𝐴 = 1𝑒11 [m3mol-1s-1], 𝐸 = 42
𝐴 = 0.0265, E= 65.8
𝐴 = 5.67𝑒9 [s-1], 𝐸 = 160
𝐴 = 7.92𝑒4 [m3mol-1 s-1], 𝐸 = 218
𝐶 𝑠 + 2 𝐻2 → 𝐶𝐻4
𝐶 𝑆 + 𝐻2 𝑂 → 𝐶𝑂 + 𝐻2
𝐴 = 79.2 [m3mol-1 s-1]𝐸 = 218
𝐴 = 7.92𝑒4 [m3mol-1 s-1],𝐸 = 218
𝐴 = 1𝐸15 [m3mol-1 s-1],𝐸 = 1𝐸8
𝑣𝑜𝑙 + 0.4 𝑂2 → 1.317 𝐶𝑂 + 2.09 𝐻2
+ 0.064 𝑁2
Velocity distribution (m/s)
What you need to know!
• Thermochemical conversions is making a strong comeback as
sustainable energy source and efficiency enhancement.
• This technology can be deployed as renewable source for million of
tons of waste streams disposed of at landfill and risking our ecological
system.
• High fidelity analyses and simulations are needed at the conceptual
level to increase the process efficiency and throughput.
HIGH FIDELITY SIMULATION CONT’D
Model Boundary and Operating
Conditions
Selected Model Parameters & Operating Conditions:
Feedstock Composition
Ultimate (wt%)
C
O
H
N
S
Proximate (wt%)
FC
V
M
A
HHV (MJ/kg)
Gas flow rate (kg/s)
Combustor burners 1
Combustor burners 2
Diffuser burners
Particle loading (kg/s)
Combustor burner 1
Combustor burner 2
Diffuser burner
Wall Temperature (K)
Combustor
Diffuser
Reductor
Pressure (MPa)
Turbulence Model
Taiheiyo Bituminous Coal
77.6
13.9
6.5
1.13
0.22
35.8
46.7
5.3
12.1
27.4
4.708
4.708
1.832
0.472
1.112
1.832
1897
1073
873
2.7
K-e Standard
Modeled Reactions:
Overview :
Country *
Bahrain
EU-7
India
Italy
Japan
Kuwait
Qatar
Spain
UAE
US
26
MSW
(Kg/person/day)
1.3
1.4
0.45
0.95
1.12
1.4
1.3
0.88
1.2
2
Advocating zero waste
Country
Austria
Belgium
Egypt
France
Jordan
Oman
Portugal
Tunisia
Turkey
UK
MSW
(Kg/person/day)
0.89
0.93
0.81
0.89
0.6
0.7
0.7
0.41
0.95
0.95
Type of Waste (Thousands tons/year)
Year Organics Fiber Wood Plastic Paper Glass
Metal Others Total
1995
422
41
41
109
178
29
23
11
854
2000
492
47
47
124
203
32
26
13
984
2005
558
53
53
141
231
37
29
15
1,117
2010
662
63
63
167
273
44
35
17
1,324
2015
736
71
71
185
303
49
38
19 1, 472
2020
830
80
80
209
342
55
43
22
*Al-Salem and Lettiere, European Journal of Scientific ResearchISSN 1450-216X Vol.34 No.3 (2009), pp.395-405
1,661
To Gasify, or Not to Gasify?
Challenges
Current needs
& technology
challenges
Physical aspect
Modeling implementation
Feedstock flexibility
•Dynamic and intrinsic behavior
•Feedstock and char characterization –proximate&ultimate
analysis
Accurately models fuel switching
and associated reactions
Slag
blockage/removal
•Turbulence-chemistry-radiation interactions
•Accurate Slag characterization
Accurately models slag flow,
composition and temperature
distribution and turbulence
Downstream fouling
and poisoning
•Particle dispersion and inhomogeneous distribution
•Agglomeration, swelling and fragmentation particle
mechanisms
•Nitrogen and sulfur production
Accurately flow modeling,
conversion, ash distribution and
pollutant formation
Wall/refractory
failure
•Particle dispersion and inhomogeneous heat distribution
•Turbulence-chemistry-radiation interactions
•Slag wall build up
Accurately model wall
interactions, thermal stresses,
pressure effects and abrasion
Injector failure
•Turbulence-chemistry-radiation interactions
Accurately model flow and
temperature distribution
Space efficiency
•Particle dispersion
•Turbulence-chemistry-radiation interactions
Accurately model flow and
conversion
Cycle
Fuel
Temp low (oC) Temp High (oC) Carnot (h) Actual (h)
Conventional Steam Power Plant
Coal
27
540
63
40
Ditto Ultra Super Critical
Coal
27
650
67
45
IGCC
Coal
27
1350
82
46
Open Gas Turbine Cycle
Gas
27
1210
80
43
Combined Cycle
Gas
27
1350
82
58
Low Speed Marine Diesel (LSMD) Heavy Fuel Oil
27
2000
87
48
LSMD with Super Charger
Heavy Fuel Oil
27
2000
87
53
Car(h)/Act(h)%
63
67
56
54
71
55
61
Model Sample Results
A
B
C
 Temperature field distribution. (A)
Showing complete geometry. (B, C)
Closer look at the combustor and diffuser.
 Average gasifier temperature = 1493 K
Model Sample Results
a:T (K)
d:CO wt fraction
b:CO2 wt fraction
c:H2O wt fraction
Velocity (m/s*100)
e:H2 wt fraction
f: Oxygen wt fraction
g: Volatiles wt fraction
h: Char concentration (kg/s)