Understanding thermal processes inUnderstanding thermal processes in many nanoparticle-related applicationsDonggeun Lee,Donggeun Lee, Professor at School of Mechanical Engineering, PNU
Page 1BRL ON DCFC
Summary of on-going researches: what & howSummary of on going researches: what & how
• One step continuous synthesis1
Material Synthesis
• de-NOx & de-SOx catalysts
• Catalytic regneration of DPF
• Sulfur effect on slagging
• One-step continuous synthesis
• Flame, Aerosol-gel, Spray pyrolysis
• Under control of microstructure,
size & compositionENVIROMENT :CATALYSTS
POWER PLANTHYDROGEN
ENERGY : PEMFCDCFC
THERMITES
gg g
•Thermochemical cycle for H2p
• Pt/C & PtRu/C Inks
• Wet-surface electrode
• Energetic combustion
3
Online & Offline
AEROSOL‐BASEDAPPLICATIONS
2
N i l Online & Offline Characterization
INSTRUMENTATION :SPMS
NumericalAnalysis
• CFD : Particle-laden flow
• CFD : Atomization
MC ti & i t t
• Single particle mass spectro.
• T-jump mass spectrometryT‐JUMP MS• MC : aggregation & microstructure
• LB : heterogenueous multi-component
structure
T jump mass spectrometry
• Insitu thermal analyser (hot stage)
• Physicochemical & electrochemical
Page 2BRL ON DCFC
1. Energy 1) Pt catalyzed fuel electrode of PEMFC1. Energy
Key factors for commercialization
1) Pt catalyzed fuel electrode of PEMFC
- long-term reliability- a minimal use of Pt
Potential Solutions Potential Solutions- make smaller Pt particles - enhance Pt surface dispersion
d l t ff ti th d- develop more cost-effective method- find less-expensive catalysts (Ru, Co, Y)
e -H2
e -e -
e -
O2Bip
ola
r Pla
te
An
od
e
Ele
ctro
lyte
Ca
tho
de
Bip
ola
r Pla
teH+
H+
H+
Page 3BRL ON DCFC
O2
1. Energy 1) Pt catalyzed fuel electrode of PEMFC1. Energy 1) Pt catalyzed fuel electrode of PEMFC
a) b)a)a) b)
20 nm20 nm20 nm20 nm
c) d )60
70
60 mm
20 nm20 nm20 nm20 nm20 nm20 nm20 nm20 nm20 nm20 nm
c)c) d )60
70
60 mm
30
40
50
oun
ts
85 mm 120 mm
30
40
50
oun
ts
85 mm 120 mm
0
10
20
Co
0
10
20
Co
Page 4BRL ON DCFC
20 nm20 nm 0 2 4 6 8 10 12 14-10
dp [nm]
20 nm20 nm20 nm20 nm20 nm20 nm 0 2 4 6 8 10 12 14-10
dp [nm]
1. Energy 1) Pt catalyzed fuel electrode of PEMFC1. Energy 1) Pt catalyzed fuel electrode of PEMFC
20
2 adsRu H O Ru OH H e
2ads adsPt CO Ru OH CO Pt Ru H e
10
15 CommercialSynthesis
cm-2 MOR test
0
5
I/mA
c
-50 0.2 0.4 0.6 0.8 1 1.2 1.4
E / V (vs RHE)
*Onset point : 0.61V, 0.65V
0.5
0
cm-2
-0.5
Synthesis
I/mA
c
CO strippingEAS(m2/g) Onset point
Page 5BRL ON DCFC-1
0 0.2 0.4 0.6 0.8 1 1.2
Commercial
E / V (vs RHE)
CO-strippingSynthesis 72.94 0.604V
Commercial 65.67 0.641V
1. Energy 2) Basic Research Lab on DCFC1. Energy 2) Basic Research Lab on DCFC
Anode : C + 2CO32- → 3CO2 + 4e-
C th d O 2CO 4 2CO 2Cathode : O2 + 2CO2 + 4e- → 2CO32-
Net reaction : C + O2 → CO2
• no need of CO2 separationno need of CO2 separation
• Highest theoretical electrochemical efficiency
• easy retrofitting to MCFC or SOFC
till i id d l i t• still in an idea-developing stage
• suffer from limitted triple-phase interfaces
• unknown thermal stabilities of various coals
Page 6BRL ON DCFC
1. Energy 2) Basic Research Lab on DCFC1. Energy 2) Basic Research Lab on DCFC
연료공급장치기술
애노드 가공기술
• 주형을 이용한 다공성 전극 제조
MC/CFD 다차원 해석 >기공도제어• 순환형 연료공급장비 설계 및 제작
• 불순물 제거 및 억제기술 개발
• 가스의 확산제거 해석기술
• MC/CFD 다차원 해석->기공도제어
• 삼상계면 형성의 최적 제어기술
애노드 평가 기술
• 애노드 전극의 전해질증발문제 해결
• 산화물코팅을 통한 젖음성 향상
• 고온 전기화학특성 평가• 고온 전기화학특성 평가
열관리 기술석탄 특성 평가
Page 7BRL ON DCFC
• 다공성 전극의 열전달 특성해석
• 용융탄산염의 고온유지(열교환기)
• 유기적제어를 통한 운전최적화
• 미분탄의 탄종별 특성 분석
• 미분탄/용융탄산염 고온특성 최적화
• 석탄의 가스화 특성 해석
1. Energy 2) Basic Research Lab on DCFC1. Energy 2) Basic Research Lab on DCFC
Ce (blue) oxygen (green), nickel (red)
CeCl3 + citric acid + ethanol (50ml)
Sol-gel reaction for CeO2 coating0.01mol%(b) (b1)0.01mol%
Ce (blue) oxygen (green), nickel (red)
Stirring_3000ppm (30min)
Ni foam dipped into sol solution for several time 0.1mol%(c) (f)(c1)0.1mol%
Dried at 60℃ for 15min
Calcination at 500℃ for 30minCalcination at 500 ℃ for 30minIn a Ar atomsphere
Page 8BRL ON DCFC
1. Energy 2) Basic Research Lab on DCFC1. Energy 2) Basic Research Lab on DCFC
Contact angle: 101.5o
On Ni electrode
Contact angle: 29.5o
CeO2 0.01mol%
Case 1Carbon black
Contact angle: 20.4o
CeO2 0.1mol%
Case 2 Carbon black
Case 3 CeO2
Page 9BRL ON DCFC
1. Energy 2) Basic Research Lab on DCFC1. Energy 2) Basic Research Lab on DCFC
Case 1Carbon black
80Data 10
Case 1
Case 2 Carbon black60
70
m2)
Case 3-0.01%)
Case 3 CeO2
40
50
60
ty (
mW
/cm
Case 2
20
30
40
Case 1
C 2ower
den
si
Improved max power density by
10
20 Case 2
Case 3 - 0.01mol%
Case 3 - 0.1mol%
Po
Case 1
Case 3- maximizing triple-phase boundary
- enhancing electrode wetness
Further study00 50 100 150 200 250
Current density (mA/cm2)
Further study
- Test for various coating materials
(better conductivity & stability)
Page 10BRL ON DCFC
1. Energy 3) Energetic materials : Thermite1. Energy 3) Energetic materials : Thermite
Explosives
Al + MO > Al O + M
Rocket propellant
Al + MOx -> Al2O3 + M
O2-free welding
Page 11BRL ON DCFC
1. Energy 3) Energetic materials : Thermite1. Energy 3) Energetic materials : Thermite
Al + MO > Al O + MAl + MOx -> Al2O3 + M
Page 12BRL ON DCFC
1. Energy 3) Energetic materials : Thermite1. Energy 3) Energetic materials : Thermite
Ref [11]: 73.3% of Al volume melts
at bulk Tm-0.5
0.044 nm
a)
Ref. [6]Refs. [8-10]
Ref [11]: 88.9% of Al volume melts
at bulk Tm
-1.0
-0.5
0.0
(Hea
t Flo
w).
mW
/mg
Calculations
80 nm
Melting pt
Ref. [11][ ]
Ref [11]: 92.7% of Al volume melts
at bulk Tm
-1.0D
SC
Sig
nal
Experiment
121 nm
-1.0
-0.5
0.0
Page 13BRL ON DCFC
500 550 600 650 700 750
Temperature, o C
b) HR-TEMc) DSC
1. Energy 3) Energetic materials : Thermite1. Energy 3) Energetic materials : Thermite
Page 14BRL ON DCFC
1. Energy 3) Energetic materials : Thermite1. Energy 3) Energetic materials : Thermite
Page 15
2. Environment 1) de-NOx catalysts2. Environment 1) de NOx catalysts
Aerosol-gel process to produce Pt/MOx Pt/SiO2
M
OH
M
MM
MM
MO
OO
O
O
OOO
O
O
O
O
O
O
O
O
O
H H
H
H
H
HHH
H
H
H
H
H H
H
O
O
OO
OO
O
OO
OOOO
OO
OO
O
OOO
O
M
MM
MM
M
M
ROHOHSiHOHORSi hydrolysis
ROHSiOSiORSiOHSi
HOHSiOSiOHSiOHSioncondensatialcohol
oncondensatiwater
HHHHOOO
ROHSiOSiORSiOHSi oncondensatialcohol
20 nm20 nm
Pt/Al2O3
Page 1610 nm
2. Environment 1) de-NOx catalysts2. Environment 1) de NOx catalysts
HydroCarbon-based Selective Catalytic Reduction : aNO+bC3H6+cO2 dN2+eNO2+fN2O+gH2O+hCO23 6 2 2 2 2 g 2 2
0.9
1
1.1
NO
2
O 2O
CO
2
H6
Pt/SiO2
0.9
1
1.1
NO
2
O 2O
CO
2
H6
Pt/Al2O3
0.5
0.6
0.7
0.8
% a
bs (
a.u.
)
NO N
2
C3H
275
300
350
400
0.5
0.6
0.7
0.8
% a
bs (
a.u.
)
NO N
2
C3H
275
300
350
400
0.1
0.2
0.3
0.4%
In le t
150
200
250
275
0.1
0.2
0.3
0.4%
In le t
150
200
250
275
0800 1200 1600 2000 2400 2800
W avenum ber (cm -1)
In le t0800 1200 1600 2000 2400 2800
W avenum ber (cm -1)
In le t
Page 17BRL ON DCFC
2. Environment 1-1) Colloidal system2. Environment 1 1) Colloidal system
Experimental parametersInteraction between
Particle growthExperimental parameterscolloidal particles
Solution (pH, T, I) DLVO theory Suspension stabilityCharged functional
groupHelmholtz plane
Charged functionalgroup
Helmholtz plane
Particle growth
Surface charge state- protonation Kp
- deprotonation Kd
Electrostatic repulsion Van der Waals attraction Total interaction
Particle collision kinetics
-OH2+
-OH
O- C+ A-
C+
A-
Helmholtz plane
A-
A-
H2O-OH2+
-OH
O- C+C+ A-A-
C+C+
A-A-
Helmholtz plane
A-A-
A-A-
H2O 20b
tot
)xr2(
dx
Tk
Eexpr2W
HMOMOH
MOHHMOH
Kd
2KpCuO-O
-OH2+
-OH
-OH2+
A-
C A A
C+
A-
ShearC+
C+CuO
-O
-OH2+
-OH
-OH2+
A-A-
CC AA AA
C+C+
A-A-
ShearC+C+
C+C+
repulsive
W3
Tk8
W
kkk bdiff
diff
Microstructure control 0
d
Shear plane 0
d
Shear plane
repulsive
attractive
0 d sx
0 d
0 d sx
0 d
Page 18BRL ON DCFC
2. Environment 1-1) Colloidal system2. Environment
a)
)
d)
1 1) Colloidal system
b)
c)
e)
f)
400
500
MonomerDimer
200
300
TrimerTetramer8~10mer
r N
um
er(#
)
100
200
Clu
ster
Page 19
00 0.01 0.02 0.03 0.04 0.05
Time (s)
2. Environment 1-2) Link systematic parameters w/ suspension stability2. Environment 1 2) Link systematic parameters w/ suspension stability
pH566.0pH566.0PZC
ptot
pH566.0pH566.0P
PZC
pH566.0pH566.0
tot0 101010
KF
)1010(K/10
1010F
P )(
pH434.0c
pH566.0
pH434.0a
pH566.0
pH566.0pH566.0P
PZCtot
s 10)C(aK1
10
10)A(aK1
10
)1010(K/10
F
pH434.0c
pH566.0
pH434.0a
pH566.0
PZC
ptot
10)C(aK1
10
10)A(aK1
10
10
KF
2d22
3d
ds TR
IF7.1051
RT2
Fsinh
FI4000
pH5660pH566022 1010KTR
pH434.0c
pH566.0
pH434.0a
pH566.0
PZC2Ptot
222d 10)C(aK1
10
10)A(aK1
10
10IF7.1051
KTR
)(2U 2el )xexp(r2U 2dr0
el
)xexp(1010KrRT803.3
UH4340
pH566.0
H4340
pH566.0
PZCPtotel
Page 20
)p(10)C(aK110)A(aK110 pH434.0
cpH434.0
aPZC
BRL ON DCFC
2. Environment 1-2) Link systematic parameters w/ suspension stability2. Environment 1 2) Link systematic parameters w/ suspension stability
)xexp(10)C(aK1
10
10)A(aK1
10
10
KrRT803.3U
pH434.0
pH566.0
pH434.0
pH566.0
PZCPtotel
8(a)
x12
rAU 132vdW
10)C(aK110)A(aK110 ca
4
6
2.05
2.1(b)
x12
rA)xexp(
10)C(aK1
10
10)A(aK1
10
10
KrRT803.3U 132
pH434.0c
pH566.0
pH434.0a
pH566.0
PZCPtot
tot
2
CuO (25nm)
ln W
1 9
1.95
2
fx
)x1(x
)xexp(
dU -2
0CuO (25nm)
SiO2 (25nm)
1.8
1.85
1.9
CuO (25nm)
d f
/X0dx
dUmax
maxx
tot
20 4.25 10-12 8.5 10-12 1.275 10-11 1.7 10-11
|/r/|1.7
1.75
0 4 25 10-12 8 5 10-12 1 275 10-11 1 7 10-11
( )
SiO2 (25nm)
2x
)x1(Umax
maxmax,tot
21U
)Wl ( maxtot
0 4.25 10 8.5 10 1.275 10 1.7 10|/r/|
Page 21
2TkTk
)Wln(bb
max,tot
BRL ON DCFC
2. Environment 2) S effect on slagging2. Environment 2) S effect on slagging
Slagging & Fouling Trouble at Pulverized Coal Fired Boiler
R. Webber et. al., 2011
Ash deposition at furnace wall, super heater & reheater tube surface
• Degrade heat transfer efficiency• Boiler damage by fallen clinker (5 tons)• Blockage at the bottom of PC boiler• Blockage at the bottom of PC boiler
Need to understand the mechanism of
Page 22
the slagging & fouling & clinker formation
2. Environment 2) S effect on slagging2. Environment 2) S effect on slagging
As
SpeciesMelting
Point (oC)Element Si Fe Al Ca K Na
At i % 48 29 5 6 11 4 3 2 2 0ICP-AESsh com
pos
Fe2O3 1566
SiO2 1600
CaSO4 1460
MgO 2852
Atomic % 48 29 5.6 11.4 3.2 2.0
Phase Fe2O3 Al2O3 CaSO4
% Mol 58.4 8.6 33XRD
1200°C
ition
MgO 2852
Al2O3 2072
CaO 2572
Major species : glassy SiO2 + Fe2O3+ CaSO4
Minor species : Al2O3 + Alkali metal compounds
1200 C
No. CrystallinePhase
JCPDSNo.
1 CaSO4 86-22701
at 600 oCr2 = 0.91 Peak observation w/ ramping T
CaSO4, Fe2O3, SiO2
2 Al2O3 88-0826
3 Fe2O3 84-0309
4 SiO2 87-2096
5 Ca2Fe2O5 18-0286ensi
ty (
cps)
2
3
4
5
Ca2Fe2O5, CaFe3O5,
CaFe4O7, Fe2SiO4,6 Fe3O4 82-1533
7 Fe2SiO4 [2] 80-1625
8 Fe2SiO4 [1] 87-0315
Inte
6
7
8
9
4 2 4
Fe3O4 at 1100-1150oC
Page 23
9 CaFe3O5 31-0274
20 30 40 50 60 702 (degree)
9
BRL ON DCFC
2. Environment 2) S effect on slagging2. Environment 2) S effect on slagging
B l R ti ZHT-XRD Indicates Below Reaction Zone: < 800°C
HT XRD IndicatesZone A
40Zone A Zone B Zone C
C Reaction Zone: 800~1150°C CaSO4 reacts w/ Fe2O3 to form various forms of Calcium ferrite formation
Zone B30
CaSO4Fe2O3Fe3O4CaFe4O7CaFe3O5%
)
o at o
Melting Zone: > 1200°C
C fZone C
20
CaFe3O5Ca2Fe2O5
mo
l (%
Calcium ferrite begins to meltZone C
0
10
Potential Reaction pathway1. CaSO4 + 3Fe2O3 CaF3O5 + Fe3O4 + SO2 + O2
2. CaSO4 + 2Fe2O3 CaFe4O7 + SO2 + 0.5O2
3 2CaSO +Fe O Ca Fe O +SO +2O
0
600 700 800 900 1000 1100 1200 1300
Temperature (oC)
Page 24
3. 2CaSO4+Fe2O3 Ca2Fe2O5+SO2+2O2
4. 2CaSO4+4Fe2O3 Ca2Fe2O5+2Fe3O4+SO2+2.5O2
2. Environment 2-1) Percolation theory, EMT vs LBM2. Environment 2 1) Percolation theory, EMT vs LBM
LBM
EMT
Page 25
2. Environment 3) de-SOx catalysts2. Environment 3) de SOx catalysts
Indirect sulfation Direct sulfation
CaCO3 CaO + CO2↑--------- DecompositionCaCO3 CaO + CO2↑--------- Decomposition
CaO + SO2 + 1/2O2 CaSO4---- SulfationCaCO3 + SO2 + 1/2O2 CaSO4 + CO2↑
0.1CO2(23%)Vertical Isothermal Furnace at 700~1000 oC
Direct-0.1
0
x100
%) Air(100%)
2( )CO2(100%)
Indirect3 104
4 104
CaSO4CaCO3CaO
CaSO3
1000oC
sulfation
Indirectsulfation
-0.4
-0.3
-0.2
Air100 Air+200 SO230 Air+200 SO2+70CO2100CO2
Wei
ght L
oss (
x
Direct
1 104
2 104
Cou
nts
1000oC
900oC
800oC
Indirect
Flu gas condition-0.5
400 500 600 700 800 900 1000
100 CO2
Temp (oC)0
1 104
20 30 40 50 60 70 80 90Angle (2 Theta)
800oC
700oC
Direct
Flu gas conditionㆍT : 800∼1500oCㆍCO2 : 23%
• TGA indicates that T > 800oC to decompose CaCO3
• XRD indicates that below 800oC, Direct sulfation occurs
Page 26
ㆍO2 : 5~6%ㆍN2 : 70~75% BRL ON DCFC
• above 900oC, Indirect sulfation occurs w/ CaSO3 formation
2. Environment 3) de-SOx catalysts2. Environment 3) de SOx catalysts
80DeSOx Performance at Iso-thermal at Vertical Furnance (90mg) 700oC 800oC
60
70
80
No Sample, switching effect700 oC800 oC900 oC%
)
30
40
50 1000 oC
Perfo
rman
ce (%
700oC : size < 1m700oC : size < 1m 800oC: size > 1m800oC: size > 1m
900oC 1000oC
0
10
20
DeS
Ox
P
(C S O)00 2 4 6 8 10 12
Time (min) 900oC : smallest size900oC : smallest size 1000oC : largest size1000oC : largest size
(Ca, S, O)
CaOCaSOO2/1CaSOSOCaOCaCO C1000T4
C1000T23
C900T2
C800T3
oooo
When T > 1000oC,
de SOx (indirect sulfation) efficiency degraded due to sintering & decomposition of CaSO
Page 27BRL ON DCFC
de-SOx (indirect sulfation) efficiency degraded due to sintering & decomposition of CaSO4
2. Environment 4) C-free H2 production2. Environment 4) C free H2 production
Concept of two-step thermo-chemical cycle• Easy scale-up like CFB + CYRO
O2/1ZnZnO
• Low-temperature splitting is possible
• Various MOx can be used
Quenching gas2O2/1ZnZnO
Zn nanoparticlesGeneration Furnace
Carrier gas
Quenching gas
Ar
Flow meter
Filter
Zn
Quenching length, xq
Generation Furnace
a) 100nm 100nmb) 100nm)
22 HZnOOHZn
222 H)1(COZnOOH)1(COZn
a) 100nm b) 100nmc)
Page 28BRL ON DCFC
2. Environment 4) C-free H2 production2. Environment 4) C free H2 production
Carrier gas
Quenching gas Quenching length, xq
Zn nanoparticlesGeneration Furnace
Ar
Flow meter
Filter
Zn
a) 100nm
550
600
650
700
-2
0
2
e [K
]
lo
J > 102 # cc-1 s-1
Nucl.
quenching
Fi
a)
550
600
650
700
-2
0
2
e [K
]
lo
quenching
J > 102 # cc-1 s-1
Nucl. Fi
b)
350
400
450
500
550
-10
-8
-6
-4
Temp. w/ quenchingTemp w/o quenching
PZn
PZn, satT
emp
era
ture
og
10 P
[Pa]
ilter
350
400
450
500
550
-10
-8
-6
-4
Temp. w/ quenchingTemp w/o quenching
PZn
PZn, satT
emp
era
ture
og
10 P
[Pa]
coagulationilter
100nmb)
300 -1215 20 25 30 35 40
Temp. w/o quenching
xq [cm]
300 -1220 30 40 50 60 70
Temp. w/o quenching
xq [cm]
650
700
0
2quenchingc)
• 25cm : nucleation & condensation
450
500
550
600
-8
-6
-4
-2
Pemp
era
ture
[K
]
log
10 P
[Pa
]
J > 102 # cc-1 s-1
Nucl.coagulation
Filter
25cm : nucleation & condensation
• 55cm : nucleation & coagulation
• 85cm : sintered hexahedral crystal
Page 29BRL ON DCFC
100nmc)
300
350
400
-12
-10
-8
20 30 40 50 60 70 80 90 100
Temp. w/ quenching
Zn
PZn, sat
Te
xq [cm]
r
3. Instrumentation 1) SPMS3. Instrumentation 1) SPMS
linear-time-of-flight tube, Z-stuck MicrochannelPlates (MCP) a 500-MHz
200
Na+
(a)
Aerodynamic lens collimate particles to
ti l b ( 1 )
Plates (MCP), a 500-MHz digital oscilloscope
Ion trajectory100
150
ens
ity [a
.u.]
H+ Na2+
Cl+
particle beam (~ 1 mm) that can be intesected with a free firing laser (~0.3 mm)
0
50
Inte
O+
Cl2+
( 0.3 mm)0 10 20 30 40 50
m/z
Particle trajectory
A frequency-doubled Nd:YAGlaser operated at 10 Hz, 532 nm wavelengths laser power
Particle trajectory
allo
catio
n(m
m)
0
5
Page 30
wavelengths, laser power intensity: 1.71010 W/cm2 (~100 mJ/pulse)Distance from barrel inlet (cm)
Rad
ia
0 10 20 30
-5
3. Instrumentation 2) T-jump MS3. Instrumentation 2) T jump MS
Page 31
AcknowledgementAcknowledgement
Page 32