2. Introduction
Ｓｙｓｔｅｍ
Municipal Life
Heating
Forest
都市生活
Organic Waste Cooling
系
Electricity
Adsorb Heat
Gas Turbine
Heat Pump Exchanger
High Temperature Furnace
（MGT）
H2, CO
Woody Fuel Cell
Pre- Gas
（MCFC）
Treatment Purification
Biomass
Steam
Exhaust Heat
Boiler
3. Research Purpose
To provide practical data and a
theoretical perspective for scale-up
from both pilot-scale experimental
study of high temperature gasification
of organic waste materials in down-
flow furnace and mathematical
modeling
4. Schematic Diagram of
High Temperature Furnace
Furnace Characteristics
• Down-flow furnace
• High temperature operation (T
A
around 1473 K)
B 255
• Equipped with organic waste
φ255
C
1000
D 800
powder feeding nozzles (60
E
mesh under)
F
• Operating pressure (P = 0.05
900
G
MPa (gauge))
H
Gas exit
5. Assumption in this Model
• Introducing Global Gasification Reaction
• Material Balance Component of C, H, and O
• Considering Two Equilibrium Reaction
• Overall Energy Balance including Considering
Energy Loss
• Introducing Carbon Conversion
6. Global Gasification Reaction : Diagram Flow of
Gasification Process
p CHαOβ+ y CH4 + m O2 + n N2
x1 CO2 + x2 CO + x3 H2 +
INPUT
x4 H2O + x5 CH4 + n N2
CHαOβ is the chemical OWM
representation of Organic CH4
Waste Materials (OWM). Down-
flow
O2
The subscripts and are gasifier OUTPUT
determined from the ultimate CO2
N2
CO
analysis of the OWM H2
feedstock (e.g., = 1.59 and H2O
CH4
= 0.69 for powdered wood) N2
7. Material Balance
C balance :
p.N C y.N CH 4 CO2 CO CH 4
H balance :
. p.N H 4. y.N CH 4 2. H 2 2. H 2O 4. CH 4
O balance :
. p.N O 2.m.N O2 2. CO2 CO H 2O
Where Ni is the number of moles of reactant
i, and hj is the number of moles of product j
9. Temperature Distributions inside the Furnace
• TE is assumed as
A
equilibrium temperature
B
C
• In this model, temperature
D
simulation is to estimate
E
TE
F
G
• Overall energy balance and
H
energy loss based on TE
900 1100 1300 1500 1700
condition
Temperature [K]
Applied for :
• Wood feed rate = 23 kg/h
• O/C ratio = 1.6
• Supplement Methane = 1.8 Nm3/h
10. Overall Energy Balance
I I
N .HV N i .H (T feed , i )
i feed feed
i 1 i 1
J J
. HV prod j . H prod (T ) Q loss (T )
j
j 1 j 1
(i = 1, 2, . . ., I)
Energy Loss
• Energy loss is considered in this model as non-
equilibrium factor
• Energy loss is calculated from experimental data
through:
Qloss U . A.(T To )
Where Qloss is energy loss of the system, U is overall coefficient, A is
area of the furnace, T and To is temperature
• Calculated U is 24.79 W/m2.K
11. Carbon Conversion
• Carbon conversion is introduced in this model as
non-equilibrium factor
• Carbon conversion is applied from experimental
data to this model
12. Research Condition
Simulation developed in this study is evaluated and
compared to experiment data at defined condition
Condition:
1. Oxygen-gasification
2. Wood feed rate 23 kg/h (also 10 kg/h and
15 kg/h)
3. Supplement methane = 1.8 Nm3/h
4. O/C ratio = 1.23 - 1.86
5. Area of furnace = 1.67 m2
14. Gasification Temperature
1600
Temperature [K]
Texp (10 kg/h)
1200
Tsim (10 kg/h)
Texp (15 kg/h)
800 Tsim (15 kg/h)
Texp (23 kg/h)
400 Tsim (23 kg/h)
0
1.0 1.2 1.4 1.6 1.8 2.0
O/C [-]
• The gasification temperature increases with the
increasing of O/C molar ratio
• The gasification temperature increases with the rising
of powdered wood feeding rate
15. Produced Gas Composition
50
Produced Gas Composition [CO2]
40 [CO]
[H2]
30 [CH4]
[%]
CO2
20
CO
10 H2
CH4
0
1.0 1.2 1.4 1.6 1.8 2.0
O/C [-]
• A good agreement on CO2 and CO produced gas composition
• Deviations show on H2 and CH4 produced gas composition at low
O/C ratio (1.2 - 1.7)
• Good precisions for H2 and CH4 produced gas composition at high
O/C ratio (1.71 - 1.9)
16. Chosen Total Produced Gas Composition
30
Produced Gas Composition [%] 25
20 Experiment
Simulation
15
10
5
0
[CO2] [CO] [H2] [H2O] [CH4] [N2]
• Yield gas volume is agree
• H2O produced gas composition is also agree
• CH4 in wood gasification not always reach equilibrium reaction
• Deviation on CH4 made CO2, CO, and H2 composition deviates to
keep balance condition
• Steam methane reforming not always reach equilibrium condition
17. Produced Cold Gas Efficiency
100
Cold Gas Efficiency [%]
80
60 Cg (Sim)
Cg (Exp)
40
20
0
1.0 1.2 1.4 1.6 1.8 2.0
O/C [-]
Cold gas efficiency decreases with the increasing of O/C molar
ratio
18. Produced Gas Heating Value
Produced Gas Heating Value
2500
2000
[kcal/Nm3 ]
1500 HV-O2(sim)
HV-O2(exp)
1000
500
0
1.0 1.2 1.4 1.6 1.8 2.0
O/C [-]
Produced gas heating value decreases with the increasing of
O/C molar ratio
19. Concluding Remarks
• The equilibrium determined model developed in
this study predicts that the product gas
composition depends on the O/C ratio and
temperature
• This model is useful in predicting
thermodynamically attainable at gasification of
OWM in down-flow furnace
• The simulation has shown a good agreement
with the experimental gasification for down-flow
furnace, except for CH4 gas composition
21. Supporting Materials
Input Data
Equilibrium Energy Carbon
Material
Balance Conversion
Balance
Newton-Raphson
Method
Compositions,
Temperature and Heat
Loss
Check
Convergence
Temperature
Evaluation
Copying Results
Gasification Main Program Diagram
22. Experimental Works
Schematic Diagram of
High Temperature Furnace
Temperature Distributions inside
the Furnace
A
A
B
B 255
C φ255
C
1000
D 800
D
E
E
F
900
F
G
G
H
H Gas exit
900 1100 1300 1500 1700
Temperature [K]
Wood feed rate = 23 kg/h Operating Condition
O/C ratio = 1.6
• Pressure = 0.05 MPa (gauge)
Supplement Methane = 1.8 Nm3/h
• Temperature = + 1473 K
23. Carbon Conversion
120
Carbon Conversion Ratio [%]
100
80
60 CC (Exp)
40
20
0
1 1.2 1.4 1.6 1.8 2
O/C [-]
Carbon conversion is observed from simulation and experimental data has same
tend, which it increases with the increasing of O/C molar ratio
24. Chemical Reaction on the Gasification
• Combustion Reaction
– C + ½ O2 CO (1)
– CO + ½ O2 CO2 (2)
– H2 + ½ O2 H2O (3)
• Boudouard Reaction
– C + CO2 2 CO (4)
• Water-Gas Reaction
– C + H2O CO + H2 (5)
• Methanation Reaction
– C + 2 H2 CH4 (6)
• Steam Methane Reforming Reaction
– CO + 3 H2 CH4 + H2O (7)
• CO Shift Reaction
– CO + 3 H2O CO2 + H2 (8)
26. Validation of the Simulation Results (2)
14
12
10
8
ln(K2)
LN(K2) Sim
6
LN(K2) Exp
4
2
0
-2
0 0.001 0.002 0.003 0.004
1/T [1/K]
CO Shift Reaction
K2
CO + 3 H2O CO2 + H2
27. Experimental Works
Experimental Set-Up
Raw materials hopper
(2) Raw
(1)
materials
(FA)
supply nozzle Cyclone
Filter
Gas cooler 2)
(
Ignition
burner
Gas purification
Heating
Thermograph
burner
Hopper
N2
Gasifier
Gas cooler 1)
(
O2
Cooling- water
circuit
CH4
Combustor
Pressure control
valve
City gas
Cooling tower
Cooling-water
circulating pump
28. Experimental Works
Chemical Analysis of Raw Material
Woody biomass PP PET
Fuel type
Proximate analysis (wt%)
Moisture 10.61 0.01 0.31
Volatile matters 82.12 99.99 95.16
Fixed carbon 17.10 0 4.82
Ash 0.78 <0.01 0.02
Ultimate analysis (%)
Carbon 48.40 84.50 61.20
Hydrogen 6.40 14.10 4.40
Nitrogen 0.12 0.70 0.03
Oxygen 44.11 0 34.32
Heating value (MJ/kg) 18.2 52.12 21.90
The mean size (µm) 100 190 100
29. Future Works
• Simulation in the scale-up case to predict the performance
of the gasification process both of oxygen and air
gasification
• Simulation for other fuel types in the establish gasifier
