STUDIES ON NUCLEAR HYDROGEN PRODUCTION BY STEAM COAL GASIFICATION
IN ARGENTINA
“Technical Meeting to Examine the Role of Nuclear Hydrogen Production in the Context of
Hydrogen Economy”
“July, 17th - 19st 2017”
Vienna - Austria
G.G. Fouga, D. Nassini, H.E. Nassini, A.E. Bohé
02/22 Nuclear Hydrogen Production
I. Khamis. Non-Electric Applications of Nuclear Energy.
Nuclear Energy for Hydrogen Production. Reihe Energietechnik / Energy Technology; Band / Volume 58. ISSN 1433-5522.
Hydrogen Production Using Nuclear Energy. IAEA Nuclear Energy Series. No. NP-T-4.2
DFC-CAB-CNEA - Argentina
Heterogeneous Solid-Gas reactions. Solid Fuels Gasification. Halogenation.
03/22 Argentinean Nuclear Power Plants
Nameplate capacity: 357 MW Reactor type: PHWR-Siemens Status: operational.
Atucha 1
Atucha 2
Embalse
Nameplate capacity: 745 MW Reactor type: PHWR-Siemens Status: operational.
Nameplate capacity: 648 MW Reactor type: PHWR-CANDU Status: renovating. Life extension program.
CAREM Nuclear Reactor
CAREM Nuclear Reactor Under Construction
(Videos) CAREM Nuclear Reactor
Characteristic (Videos)
IAEA SMR Booklet 2014
04/22
Gasification involves the possibility of co-generation of electricity,
chemicals and fuels in the same energy facility.
Gasification
Gasification refers to a thermo-chemical process that converts solid
carbonaceous fuels into either fuel gas (usually containing CH4 and
some N2) or syngas (containing mainly H2 and CO).
2 2 2(2 ) n nnCO n H C H nH O+ → +
2 2 1 2(2 ) ( 1)n nnCO n H C H OH n H O++ → + −
2 2 2 2(2 1) n nnCO n H C H nH O++ + → +
Alkenes Alcohols Paraffins
05/22
C(s) + H2O(g) → H2(g) + CO(g)
C(s) + CO2(g) → 2CO(g)
C(s) + 2H2(g) → CH4(g)
∆Gr0 = 95.64 + 0.142 ∙ T (KJ/mol)
CO(g) + H2O(g) → H2(g) + CO2(g) ∆Gr0 = -28.5 - 0.035 ∙ T (KJ/mol)
∆Gr0 = 124.14 + 0.177 ∙ T (KJ/mol)
∆Gr0 = -55.35 - 0.104 ∙ T (KJ/mol)
Gasification
Gasification also involves the possibility of using a wide range of “feed
stocks” including low-cost fuels like: petroleum coke, biomass and also
municipal waste.
06/22
Sub-bituminous coal: Rio Turbio
Ortho-Asphaltite: F4
Meta-Asphaltite: EM
Argentinean Natural Solid
Fuels Evaluated
Asphaltites are complex mixtures containing compounds ranging from non-polar aliphatic and naphthenic hydrocarbons to highly polar aromatic molecules.
Two Steps Gasification Process 07/22
Solid Fuel
Pyrolysis
Volatile Matter
Char Gasification
Gasification
Gasification Syngas
Syngas
Syngas
Step 1
Step 2A
Step 2B
Rate-limiting step
Fluidized Bed Reactor
Pyrolysis Reactor
Volatile Matter
Solid Fuel
Char
Step 1: Pyrolysis
Volatile components of solid fuels are
rapidly released
At T between 300 and 500 ºC Coal
Asphaltites petroleum coke Biomass, etc.
Composed of fixed carbon and mineral matter
08/22
+ H2O(g)
Tars
Pyrolysis gas
H2O(g)
N2(g)
→ H2(g) + CO(g)
Heat Provided by Nuclear Reactor
Two Steps Gasification Process
Step 2A: Volatile Matter Gasification
Light hydrocarbons
CnHm + nH2O ↔ (n+m/2)H2 + nCO CnHm + 2nH2O ↔ (2n+m/2)H2 + nCO2
CH4 + H2O ↔ 3H2 + CO CH4 + 2H2O ↔ 4H2 + CO2
Gasifier Reactor
Char
Gasifying agent (Steam) Provided by Nuclear Reactor
Syngas
Step 2B: Char Gasification
Composed of fixed carbon and mineral matter
Rate-limiting
step
09/22
H2(g) + CO(g)
C(s) + H2O(g) → H2(g) + CO(g)
Ash
Composed of mineral matter
→ To V, Ni and U Recovery
RT: SiO2 and Fe2O3.
EM: SiO2; Fe2O3; CaSO4; Ca3V2O8 and CaSiO3
F4: NaV6O15 and SiO2.
Two Steps Gasification Process
Natural Solid Fuels Deposits in Argentina 10/22
H2O Volatile Material
Fixed Carbon Ash +
Char
Natural Solid Fuels
Pirólisis
+ +
Determination
HT in air. (105 °C)
HT in Ar. (950 °C)
% of Char – % of Ash
HT in air. (950 °C)
ASTM standard
ASTM D3173 – 03
ASTM D3175 – 07
ASTM D3174 – 04
Determination Coal (Río Turbio)
Asphaltites
EM (Meta) F4 (Ortho)
Moisture (wt%) 3.5 11.47 0.26 Volatile Matter (wt%) 36.4 26.18 58.97 Fixed carbon (wt%) 51.2 68.67 40.57 Ash (wt%) 12.3 5.13 0.46 Density (g·cm3) 1.107 0.679 0.412 CT 59.8 64.3 78.0 NT 2.78 3.27 2.92 ST 0.86 2.36 4.5 Calorific Power kJ/kg 25104 24895 39472 Coal Asphaltites Peat
Experimental Program
Objective: characterize the behaviour of Argentine solid
carbonaceous fuels under typical pyrolysis and gasification
conditions, to identify the most suitable operational
parameters in nuclear-assisted two-stage gasifiers.
Scope: Theoretical and experimental studies designed to get
the necessary information about the fundamental
mechanisms and kinetic parameters of pyrolysis and
gasification reactions for hydrogen production, on
laboratory scale.
11/22
Experimental Setup for Pyrolysis 12/22
Drop tube reactor
Silica glass tubular reactor
Powder Fluidizing system for coal particle feeding
Particle-free fall
Preheated Ar/N2
Pyrolysis
Char with high BET area
Char more reactive
Experimental Setup for Pyrolysis 13/22
Fixed bed reactor
Fixed bed reactor after pyrolysis
Effects of pyrolysis conditions as
temperature, heating rate and
holding time on:
Microstructure and gasification reactivity of chars.
Kinetic regime of the gasification reaction.
Yield and composition of the evolved tar and pyrolysis gas.
The gasification with steam needs a complex
experimental setup: it consist of a steam generator,
a gasification reactor and a water condenser;
coupled in series with a GC and a FTIR.
14/22 Fixed Bed Reactor for Solid Fuels Gasification With Steam
Analysis setup for gaseous components. 15/22
Gas Chromatograph CG/MS Perkin Elmer. Model Clarus 600/680 TCD: H2; METANIZER-FID: CO, CO2
Infrared Spectrometer Perkin Elmer, Model: Spectrum 400
Gas cell
nCO(t) is the number of CO(g) moles formed from the beginning until time t. nCO(tf) is the number of total moles formed during the whole reaction.
𝛼𝛼 𝑡𝑡 =𝑛𝑛𝐶𝐶𝐶𝐶 𝑡𝑡𝑛𝑛𝐶𝐶𝐶𝐶 𝑡𝑡𝑓𝑓
Gasification reaction kinetics
Peak areas
Characterised
CO(g) concentration
In chromatograms registered every 5 minutes
0 1 2 3 4 5 6 7
0
10
20
30
40
50
60
70
Sign
al (m
V)
Time (min)
Steam Gasification in Fixed Bed Reactor 17/22
CO (outer column)
CO2
CO (inner column)
H2 CH4
H2 Production: F4 = 0.593 H2 moles/C moles RT = 0.74 H2 moles/C moles EM = 0.943 H2 moles/C moles
5446
CO(g)-CO2(g) Molar relationship
77
23
77
23
EM RT F4
CO
CO2
0 20 40 60 80 100 120
0.0
5.0x102
1.0x103
1.5x103
2.0x103
2.5x103
3.0x103
3.5x103
4.0x103
Sign
al (m
Vx10
3 )
Time (min)
CO2
CO H2
C(s) + H2O(g) → H2(g) + CO(g)
CO(g) + H2O(g) → H2(g) + CO2(g)
Steam Gasification in Fixed Bed Reactor
These results show that Argentinean solid carbonaceous fuels tested are susceptible to
be gasified since their reactivity's are comparable with those of low-rank coals used in
large-scale gasifiers.
16/22
Reactivity Rank
Rate (EM) > Rate (RT) > Rate F4
Determination CHAR
EM RT F4 BET area (m2·g-1) 3.5 96 0.435 C content (wt %) 82.89 66.42 87.88 Ash in Char 6.95 20 1.12
As the rank ↑ the reactivity ↓
Temporal evolution of reaction degree (α)
Reaction kinetics
Affected by Rank
Ash Composition
Batch Fluidized Bed Reactor for Solid Fuels Gasification With Steam 18/22
Continuous gas analyzers
Gas feeding system
Solid feeding system
[CO] [CO2] [CH4]
Non-dispersive infrared (NDIR) Maihak S710/UNOR
Thermal conductivity detector Maihak S710/THERMOR
[H2]
Paramagnetic analyzer Siemens OXYMAT 5E
[O2]
Water dosing + steam generator system.
222 224 226 228 230 232 2340.0
2.0
4.0
6.0
EM Asphaltite
Mol
ar F
low
s (m
ol/s
)
Time (min)
0.0
2.0
4.0
6.0
H2
CO
CO2
0.0
2.0
4.0
6.0
Char Gasification With Steam in a Batch FBR at 950 °C 19/22
240 250 260 270 280 2900.0
2.0
4.0
6.0
Time (min)
0.0
2.0
4.0
6.0
0.0
2.0
4.0
6.0 F4 Asphaltite
CO2
CO
H2
288 290 292 294 296 298 300 302 304 306 3080.0
2.0
4.0
6.0
(
)
Time (min)
0.0
2.0
4.0
6.0
H2
CO2
CO
0.0
2.0
4.0
6.0 Río Turbio Coal
Determination CHAR
EM F4 RT
BET area (m2·g-1) 3.5 0.435 96 C content (wt %) 82.89 87.88 66.42 Ash in Char 6.95 1.12 20
79
147
H2
CO
CO271
16
13
66
29
5
Fluidized bed reactor for solid fuel gasification 20/22
Parameter FBR
φ Int 25,8 mm
Bed mass 40 g
Height of the bed 5 cm
Height of the bed (mfc) 8 cm
Rmf 30 l/min
∆Pfr No detected
Concluding Remarks 21/22
For this purpose, a theoretical and experimental program on laboratory
scale is underway with the objective of characterizing the behaviour of
selected feed materials under typical pyrolysis and gasification conditions.
Solid fuels gasification assisted by nuclear energy is a promissory process
for hydrogen production.
These studies allow to get relevant information about the reaction
mechanisms and kinetic parameters of the pyrolysis and the gasification
reactions, in order to be used in large-scale gasifier design.
The research program included the development of specially-designed
experimental setups for gasification using steam as gasifying agents.
Thank you for your attention!!!
22/22
http://www.barilocheturismo.gob.ar/es/home
Bariloche - Argentina
