Modeling and experimental results of heavy oil injection
into a high pressure entrained flow gasifier
André Bader1, Paul Tischer1, Peter Seifert1, Andreas Richter2, Bernd Meyer1
Institute of Energy Process Engineering and Chemical Engineering
14th June 2016, Cologne, Germany
1. Experiments: Setup and Results
2. Simulation of non-reacting oil-injection
3. Impact of the particle size on the gasifier simulation
4. Summary
Content
2
Experiments are conducted at IEC’s 5 MWth HP POX test plant
Process application:
• Entrained flow gasifier
• Autothermal non-catalytic partial
oxidation
(one of three operation modes)
Feedstock:
• (Natural gas)
• Light and heavy oils
• Heavy residues from crude oil
processing
Operating parameters:
• Temperature: up to 1450 °C
• Pressure: up to 100 bar (g)
• Input: up to 500 kg/h liquid feeds
• Syngas output:
up to 1500 m³(STP)/h
3
Not drawn to scale
Experiments: Setup und Results
Optical access
Reactor top
Rotating device
Hydraulic unit
Flange
connection
Optical eye
Camera
4
Experiments: Setup und Results
Observation of oil injection at reactor top / nozzle tip
Visual window
Experimental setup:
• Reactor volume: 460 liter
• Pressure: 55 bar
• Steam inlet: 161 kg/h total
• Oil inlet: 330 kg/h
5
Small spray angle
Experiments: Setup und Results
Experimental results
Recirculation
detected after 2 s
injection
6
Simulation of non-reacting oil-injection
Model setup
General setup:
• ANSYS Fluent 15.0
• 3D geometry
• Euler-Lagrange approach
• DPM Model two-way coupling
• k-ω-SST turbulence model
• P-1 radiation model
• Incompressible ideal gas
Injection modeling:
• Wave model (suitable for high Weber numbers
whereby Kelvin-Helmholz instabilities dominate
droplet breakup)
• Use model settings from validated case for oil
injection from Vuokila et al 1
• Initial droplet diameter is set to the inner nozzle
diameter
1 A. Vuokila et al, CFD-Modeling of Heavy Oil injection into Blast Furnace, Steel Research Int., No. 11, 2014 7
Simulation of non-reacting oil-injection
Model validation with particle recirculation time
8
9
Result comparison
0,00%
0,05%
0,10%
0,15%
0,20%
0,25%
0,30%
0,35%
0,40%
0,45%
0,50%
800
734
668
603
537
471
405
339
273
208
142
76
pro
bab
ility
de
nsi
ty f
un
ctio
n, %
/µm
d, µm
Set 1
Set 2
Set 3
1 D. Ulber, PhD-Thesis, 2001
Typical applied Rosin-Rammler-Sperling-Bennett distribution
for initial droplet size, determined at “small scale experiments”
and applied in gasifier simulations 1
After secondary breakup:
Diameter Range: 13-18 µm
Median ~ 15 µm
Direct after injection
Diameter Range: 90-150 µm
Median ~ 100 µm
Simulation of non-reacting oil-injection
Previous detailed model considers multiple effects:
• secondary droplet breakup
• transient droplet heating
• temperature dependent fuel viscosity
• liquid surface tension in the surrounding
gasification gas atmosphere
• fuel conversion into solid coke particles
(pyrolysis kinetics)
• …
Non-reactive oil-injection without breakup
Measured and extrapolated temperature dependent
viscosity of applied fuel
10
Simulation of non-reacting oil-injection
Now the application of simplified model:
• mono-dispers, inert particles without breakup
• focus on particle size impact
Evaluation of characteristic particle size using recirculation time validation
Recirculation
detected after 2 s
injection
0,900
1,000
1,100
1,200
1,300
1,400
1,500
1,600
1,700
0,1 1 10 50 75 100 200
d, mµ
after 2.5 s
0,900
1,000
1,100
1,200
1,300
1,400
1,500
1,600
1,700
0,1 1 10 50 75 100 200
d,µm
after 1.5 s
Simulation of non-reacting oil-injection
Simulation results
Ma
ss in
vis
ua
l w
ind
ow
/
inje
cte
d m
ass
Ma
ss in
vis
ua
l w
ind
ow
/
inje
cte
d m
ass
11
Impact of the particle size on the gasifier simulation
Reactive simulation: Model setup
Pyrolysis Mass
Yield
• ANSYS Fluent 15.0
• EDC using DRM-22 Mechanism
• Euler-Lagrange approach
• DPM Model two-way coupling
• k-ω-SST turbulence model
• P-1 radiation model
• Incompressible ideal gas
• Initial droplet model comparison:
• RRSB distribution
• Breakup model
• 10 µm mono-dispers particles
12
Reactive simulation
Reactor zones
plug-flow
zone
recirculation
zone
flame
zone
Comparison with non-reactive breakup model Reactive model with initial RRSB distribution
13
plug-flow
zone
recirculation
zone
Breakup
zone
Impact of the particle size on the gasifier simulation
Comparison of the temperature contour for different fuel injections
10 µm Flame Breakup Flame RRSB
Temperature, K
Outlook
Goal is a clear observation of the
oil gasification flame in future
experiments to enable validation of
modeling results
(limited flame visibility in former
experiments due to soot deposits at the
optical eye)
10 µm Flame Breakup Flame
Classical RRSB
Temperature, K
Summary
1. The evaluation of the validated CFD model for the large scale experiment indicates a
characteristic particle size distribution >1 µm and <75 µm.
2. Reactive entrained flow gasifier models show a high sensitivity concerning the particle in the
flame region The large scale experiment helps to understand the process by delivering
validation data.
