Post on 11-Jun-2020
Synthesis of alternative fuels and chemicals from fossil and renewable feedstocks
Andrei Y. Khodakov
UCCS, National Centre for Scientific Research (CNRS),
Université Lille -ENSCL-EC Lille, 59655 Villeneuve d’Ascq, France
University of Lille, ENSCL and EcoleCentrale de Lille
Campus UCCS Pilot Hall
Lille, Grande Place
RealCat HTE centre
Lille
3
SYNGASimportant intermediate can be produced from
all fossil and renewable feedstocks
CO2
CH4
H2
H2SNH3
Major components Minor components Impurities
HCN HCl
Tar
Which feedstocks to produce syngas?
4
5
Energy and Chemical Feedstocks
1G, 2G & 3G Biomasse
Organic and chemical waste
Natural gas
Coal
Oil
Biogas
Energy transition
Unconventional gas
Shale gas and shale oil are hydrocarbons in argillaceous sedimentary rocks, located between 1 and 3 km from depth, which are both compact and waterproof
“New” raw materials: shale gas (USA)
20-30% of gas production in 2015 in the USA compared to only 1% in 2000.
“New” raw materials: coalbed gas: relation between coal and gas
7
Gas extraction by pumping
Gas Concentrations
“New” energy feedstocks: Biogas
8
Constituants % volume
CH4 55-75
CO2 25-45
H2S 0-1.5
NH3 0,05
Biogas composition
Fire-wood
50% of wood production is intended for energy, 50% industrial use
Residue or agricultural waste
Dedicated crops
Crops with short rotation (annual species crops) Perennial undergrowth off wood (miscanthus...)
Waste, the wheat, corn stalks, wood, fibrous biomass (e.g. miscanthus) or macro-algae cultures.
“New” raw materials: 2G biomass, ligno -celullose
3rd generation biofuels differ from the 2nd generation by the type of biomass used. •Microalgae and macroalgae in autotrophic condition (capacity to synthesize organic matters from mineral matter). •In addition to microalgae, 3rd generation include all biofuels which are produced using biomass from water resources
“New” raw materials: 3 GbiomassPhotobioreactors
Open ponds or closed-loop systems
• 17th century first experiments with syngas Thomas Shirley, Dean Clayton
• 1840 First commercially used gasifier in France
• 1850 Streets of London lighted with syngas
• 1878 Gasifiers were successfully used with engines for power generation
• 1901 Passenger vehicle with syngas
• 1940-1945 1 000 000 gasifiers, several 105
cars and tractors
11
History of syngas
Renault AFVH with a Gasifier
Imbert [1941-45]. This tractor
was started with gasoline.
London gas lighting
12
Syngas from conventional and nonconventional gas
Steam reformingendothermicCH4+H2O=CO+3H2
Partial oxidationexothermic 2CH4+O2=2CO+4H2
Autothermic reforming
Dry reformingendothermicCH4+CO2=2CO+2H2
Water gas shift reactionCO+H2O=CO2+H2
Tubular reactor700-1100°C, 3-25 barsNi, Rh, Pt, Pd, Ir, Ru
Non-catalytic PO
Methane,Lighter alkanes
Hydrogen,carbon monoxide,carbon dioxide and impurities
Wabash River Clean Coal Power Plant in USA
Gussing (Austria) biomass gasification plant
CxHyOz=CHs+CO/CO2+CkHlOm
C+H2O=CO+H2
C+CO2=2CO
CO+1/2O2=CO2
H2+1/O2=H2O
CnHm+xO2=nCO2+m/2 H2O
Syngas from biomass and coal gasification
14
Other technologies of syngas production
•Biomass catalytic partial oxidation
•Solar upload (thermochemical cycle)
•Photochemistry
• Combustion, Combined Heat & Power (Gas turbine, electricity generation)
Better than coal!Environmental BenefitsExtremely low SO x, NOx and particulate emissions from burning coal-derived gases.
Carbon dioxide in concentrated gas stream can be captured and sequestered more easily and at lower costs.
Efficiency Benefits35% typical plant efficiency of conventional subcritical pulverized coal (PC) power plant
> 50% fuel efficiency of coal gasification plants
15
Use of Syngas as Fuel
Heavy pollution because of
traditional coal combustion
in China
Puertollano integrated
gasification combined cycle
(IGCC) Plant
Fischer-Tropsch (FT) synthesis is the key step in transformation of syngas into othervaluable products.
16
Biomass
Coal
Natural GasShale GasCoal-bed gas
Syngas
Syngas is an important intermediate for fuels and chemicals
Rh
Cu Fe
Co RuMo
Exothermic reactions
Gas-To-Liquids, Coal-To-Liquids, Biomass –To Liquids : GTL industrial reality
Syngas
H2 + CO
Natural gas (CH4)
Fischer-Tropsch process
Syngas conversion into
hydrocarbons
(LT-FT)
Natural gas Syngas
Production
- Steam reforming
- Partial oxidation
- Autothermal reforming
Final products
-Hydrocracking
-Hydroisomerisation
Pearl (Qatar) - Shell
Oryx (Qatar) – Sasol/QP
140 000 b/j
30 000 b/j
≈ 1100 billon barrels eq.
crude oil
AN INDUSTRIALLY FEASIBLE SUPPORTED COBALT SLURRY PHASE FISCHER-TROPSCH SYNTHESIS (FTS) CATALYST WAS DEVELOPED AND COMMERCIALIZED AT THE ORYX GTL PLANT
S.34
Two slurry phase FTS reactors(Height = 60m; Diameter = 10m)
• Plant was inaugurated on6 June 2006
Copyright reserved 2008, Sasol Technology R&D
Methanol demand Capacity 100 million tons per year
Methanol Synthesis from Syngas
CO+2H2=CH3OH exothermic
CO2+3H2= CH3OH + H2O exothermic
CO+H2O=CO+H2 exothermic
Catalyst: Cu/Zn/Al2O3
T=240-270°C (thermodynamic limitations)P=50-100 bars
3000-5000 t/jICI, Lurgi, Topsoe
Catalysts for syngas conversion: metals, sulfides and carbides
21
Catalyst Products
Fe/FexCy gasoline, olefins, oxygenates
Co diesel and waxes
Ru too expensive and volatile
Ni methanation
Rh ethanol, C2+ oxygenates
Pd methanol
Cu methanol
MoS2/Mo2C alcohols, olefins
Selectivity ?
Selectivity challenge in syngas conversion
From J W (Hans) Niemantsverdriet
Cr Mn Fe Co Ni Cu
Mo Tc Ru Rh Pd Ag
W Re Os Ir Pt Au
CO dissociation = hydrocarbons
no CO dissociation = methanol+other oxygenates
Hydrocarbons or oxygenates?
tp
p
vvv+=α
α is the probability of chain growth,
vp and v t propagation and termination rates
ααα
2
)1( −=
n
n
nS Mass fraction of Cn hydrocarbon
Model of linear polymerization (Schulz, Flory 1935-1936) adapted by Anderson
24
The mechanism of polymerizationAnderson-Schulz-Flory(ASF)
Chain growth factor α
H2 + CO → CnH2n+2 (Paraffins)
H2 + CO → CnH2n (Olefins)
H2 + CO → CnH2n+1OH (Oxygenates)
Main reactions:
Video from ICMS, Eindhoven University of TechnologyChallenge: increasing the C2-4
=, C5-11 and C12-C20 selectivities
Broad Anderson -Schulz-Flory (ASF) distribution
Production of water and carbon dioxide in syngas conversion
25
Water gas shift reaction
CO+H2O↔ CO2+H2
CO2 is thermodynamically favored at FT reaction temperatures (200-300°C)
• CO+2H2=-CH2-+ H2O
• 2CO+H2=-CH2-+CO2
Cobalt, rutheniumcatalysts
Iron, molybdenumsulphide catalysts….
Deactivation as a major challenge
� Higher operational cost� Lower catalyst productivity
� Several possible mechanisms
CHALLENGE: DEACTIVATION OF
CATALYSTS FOR SYNGAS CONVERSION
Two-step catalysts deactivation process in demonstration plants for both cobalt and iron based catalysts (van Berge and Everson, 1997)
Catalyst and reactor effects
27
Deactivation mechanisms
(1) Poisoning
Al2O3
Co 0
S
(5) Carbon deposition
Co 0
C
(3) Mixed compounds
CoAl2O4CoOCo0
Al2O3
oxidation diffusion
(7) Catalyst attrition (catalyst loss in slurry
reactor)
Before After
R. Zhao et al. Applied Catalysis A: General 189 (1999) 99–116
(6) Surface reconstruction
Before
After
J. Wilson, C. de Groot, J. Phys. Chem. 99 (1995) 7860–7866
(4) Sintering
Co 0
Co 0
Co 0
S. Soled, et al, Proc. 11th Int. Symp. 21st
North American Meeting 2009
(2) Metal re-oxidation
Al2O3
Co0 CoO
H2O H2
Selectivity and catalyst stability
28
Which are the important parameters which influence the selectivity and stability?
Examples
Crucial challenges in syngas conversion
29
Tools: Laboratory Reactors for Syngas Conversion
Milli-fixed bed
ID = 0.14 cmL = 32 cm
mcat = 0.5 gNo SiC dilution
Double-shell heatexchanger
Mechanically stirred (100 mL)mcat = 5 g
Catalyst suspended in wax
Slurry stirred tank reactor
High Throughput Flowrence Unitfrom Avantium
16 parallel reactorsID = 1.3 cm
L = 5 cmmcat = 1 g
SiC/Cat = 5:1Electricalheating
Centimetric fixedbed
A High Throughput Technologies REALCAT Platform: Catalyst Synthesis, Characterization and Test
31
●Bifunctional catalysts
Well-dispersed metal particles + Mordenite, Beta and ZSM-5 zeolite
●Using the two stage process =Two catalysts and two
reactors
Fischer-Tropsch synthesis+Hydrocracking
Industry (Oryx, Pearl Qatar)
●Nanoreactors
Metal particle encapsulation, steric effects on chain growth
●Promotion (Iron catalysts)
Selectivity to olefins and alcohols to olefins, alkanes and alcohols
32
Two stage process =Two catalysts and two reactors
Sasol-Qatar Petroleum Oryx PlantQatar
0 10 20 30 40Carbon number
10
8
6
4
2
0
Pro
duct
com
positio
n,
wt
%
after medium-severity hydrocracking
Fischer-Tropschproduct
after high-severity hydrocracking
Hydrocarbon distribution of the Fischer-Tropschproducts over cobalt-based catalysts and by additional hydrocracking (adapted from Sie and Senden)
SyngasFischer-
Tropsch
Hydro-carbons
Hydro-
processing
Refined fuels
-diesel
-Jet fuel
-kerosene
33
Bifunctional catalystsCo/Zeolite
Two reactions ( Fischer-Tropsch and cracking/isomerisation ) on the same catalyst
BetaMordeniteZSM-5
Pore diameter = 5.5 Å Pore diameter = 6.5 ÅPore diameter = 7.6x6.4 Å
Pore diameter
“Small sizes of the pore is a handicap for the ZSM-5 zeolite…”
C. Marcilly, Zeolites in the Petroleum Chemistry
34
Bifunctional catalysts: H ydrocarbon distribution in heavier products
Catalysts prepared by mechanical mixing and by impregnation
● Zeolite porous structure
●The most significant decrease in the fraction of long chain hydrocarbons on the BEA based catalysts, which have the most open pore system .
BEA>MOR>ZSM-5
Wax over Co/BEA is liquid in comparison withsolid wax formed over Co/ZSM-5 and Co/MOR!
35
Nanoreactors: Shape Selectivity Concept
The shape selectivity concept suggests that “the tra nsformation of reactants into products depends on how the processed molecule s fit the active site of the catalyst” [B. Smit, T. L. M. Maesen, Nature 200 8].
Reactant Transition state Products
Shape selectivity concept for Fischer-Tropsch synth esisDeveloped with Dr. V. Ordomsky (UCCS)
commonly used for zeolites
36
Nanoreactors: Synthesis
.
●Surfactant (CTAB) dispersed in hexanol● addition of Co (NO 3)2.6H2O ● Clear emulsion was mixed with NaBH4.● After stirring the appropriate amount (to obtain 90 wt.% of SiO 2) of TEOS was added and allowed to hydrolyze during 5 h for Co@SiO 2-5 or 48 h for Co@SiO 2-48. ● The metal nanoparticles coated with silica were washed thoroughly using ethanol and water, dried and calcined.● Co/SiO 2 prepared using nitrate impregnationCo@SiO2 prepared via impregnation with cobalt nanoparticles
Impregnated samples
Nanoreactors
37
Nanoreactors: Catalytic performance in Fischer-Tropsch synthesis
Slices redrawn from the volume reconstructed from the electron tomography analysis under STEM-HAADF(S. Moldovan and O. Ersen).
240°C, 20 bar, H2/CO= 2, GHSV of 67 L/gCo·hHigh activity per cobalt and better stability
GHSV takes into account different cobalt loading
nanoreactors
Impregnatedcatalysts
38
Nanoreactors: Hydrocarbon selectivity
ASF distribution for both the Co/SiO 2 and Co@/SiO 2 catalysts prepared by impregnation. Significant deviations from the ASF distribution fo r Co@SiO 2-5. Lower selectivities to heavier hydrocarbons than cou ld be expected from the ASF model. No increase in methane selectivity (S CH4=2-4%)Growth of hydrocarbon chain restricted by the nanor eactor volume (C 30H62, d=3.5 nm).
39
Results based on Fe/SiO2 (Commericial silica)
0 10 20 30 40 50 600
20
40
60
80
100
C
O c
onve
rtio
n (%
)
Time on stream (h)
Activated with CO
Activated with H2
CO CO2
H2 H2OFe3O4FeOFe
Selectivity control on iron catalysts : Active phase in iron carbide catalysts
Activation conditions : H2 or CO flow at 623 K for 10 h.Reaction conditions : catalyst, 1.0 g; H2/CO = 2.1; GHSV, 3.6 NL g-1h-1; temperature, 573 K; pressure, 20 bar; time on stream, 60 h.
Supposed to be active phase for FTS.
40
General trends in CO hydrogenation on iron catalysts – HTE Results UCCS(series of mildly promoted Fe/SiO2, Fe/P=100:2, H2/CO=1, p=10 bar)
0
10
20
30
40
50
60
70
0 10 20 30 40 50 60 70 80 90
CO
2 s
ele
ctiv
ity,
%
Conversion, %
0
10
20
30
40
50
60
70
0 20 40 60 80 100
C2-C
4o
lefi
n s
ele
ctiv
ity,
%
Conversion, %
0
10
20
30
40
50
0 20 40 60 80 100
CH
4 s
ele
ctiv
ity,
%
Conversion, %
0
5
10
15
20
25
30
35
40
45
50
0 20 40 60 80 100
C5
+se
lect
ivit
y, %
Conversion, %
Almost Stoichiometric
WGS: CO+H2O=CO2+H2
0
5
10
15
20
25
30
35
40
45
50
0 20 40 60 80 100
C2-C
4p
ara
ffin
se
lect
ivit
y, %
Conversion, %
41
General trends in CO)Trends in CO hydrogenation on Fe/SiO 2
catalysts(promoted Fe/SiO2, H2/CO=1, p=10 bar)
Low conversion High conversion
Very high olefin selectivity Low olefin selectivity
High methane selectivity Moderate methane
selectivity
Low C5+ selectivity High C5+ selectivity
Little trend in light paraffin selectivity
H2/COC2-C4
Cn-Cm
C2-C4 olefins C2-C4 paraffins
oligomerizationC1
Conversion
CH4
Simplified schemaCn-Cm hydrocarbons
hydrogenation
How to improve selectivity to light olefins?
• Slow down surface polymerization
• Decrease the catalyst hydrogenation activity
42
Different effect of Na on the catalytic performance depending on the support
Na addition causes activity decreasing for Fe/CNT, Fe/SiO2, and Fe/CMK-3
Increase in the activity of Fe/Al2O3
Increase in ole/paraffin ratio after promotion with Na
Increase in chain growth probability
CO conversion and ole/para ratio in C2-C4 products depending on Na/Fe ratio
(P = 2 MPa, H2/CO=2.1, GHSV=16 L h-1 g-1, T = 573 K)
Fe/Al2O3
Fe/CNT
Na promotion: Decrease in hydrogenating activity, enhancement of chain growth
Effect of the support
Another way to FT control selectivity: iron -zeolite bifunctional catalysts
43Chain growth factor α
55%
ASF Hydrocarbons
Syngas
Iron carbide Zeolite
FT synthesisCracking/isomerisation
Non ASF Hydrocarbons
•Suitable to reduce the hydrocarbon chain•Not suitable for olefin synthesis because of strong zeolite hydrogenation activity
44
Challenges in synthesis of fuels and chemicals: Catalyst deactivation
Identification of initial deactivation mechanisms using operando techniques
45
Reactor and setup for in-situ synchrotron based
XRD/XAS/Raman measurements
BM01B (SNBL) beamline (ESRF, Grenoble,France)
� Real plug flow reactor (20 bar, 200-300 ° C) with comparable GHSV withlab-scale reactor
� Possibility to follow each step (from the reduction to the re action)
� XRD and EXAFS/XANES operando measurements
25%Co0.1%Pt/Al 2O3 catalyst: Catalytic performance under realistic conditions
46
P=20 bar, T=220°C, GHSV= 25000 Nml.h-1/gcat
XCO = 19% and SCH4 = 4.5%Steady state
0
10
20
30
40
50
60
70
80
100 200 300 400 500
Reaction time (min)
Con
vers
ion
& s
elec
tivity
(%
)Conversion, %
CH4 selectivity, %
Considerable � in the activity during first 4 hours of reaction
XRD synchrotron
operando study
46
Evolution of cobalt phases under standard reaction
conditions
47
13.0 13.5 14.0 14.5 15.0
Inte
nsité
2 Theta
t=478min
t=0 min
Al2O3
Phase HCP du Co0
Phase CFC du Co0
Narrowing XRD patterns
Changes of XRD patterns
Sintering of cobalt particles, traces of
cobalt carbide 47
48
Co FCC
40
45
50
55
60
65
70
75
80
0 100 200 300 400
Time, min
Cry
stal
lite
size
, Å
Evolution of cobalt particle size during the reaction under standard conditions
Modeling operando XRD data
using « Whole Pattern
Matching »
TEM data with spent CoPt/Al2O3
catalyst from slurry pilot plant
(Saib, Catal Today 2011)
0
2
4
6
8
10
12
14
0 20 40 60 80 100 120 140 160 180 200
Days on stream
Po
pu
lati
on
-wei
gh
ted
av
era
ge c
ryst
all
ite
dia
mete
r (n
m)
Karaca, Sadeqzadeh, 2011
48
Few hours of the reaction in fixed bed, longer sintering time in
slurry reactor?
0.0
0.8
1.6
2.4
3.2
4.0
4.8
1 2 3 4 5 6 7 8
ϒ(J
/m2)
dCo (nm)
Surface energy vs. particle size
CoO
Co
Co
Co
Co
CoCo Co
CoCo
Co
Co
Co
Co
CoCoCoCo
Co
Co
CoCo
Co
Co
CoCo Co
Co
Co
Co
CoCo
Co
Co
Co Co
Co
Co
Co
CoCo
Co
Co
CoCo Co
Co
Co
Co
CoCo
Co
Co
Co Co
Co
Co
Co
DIFFUSION
COLLISION/
AGGLOMERATION
CoCo
Co
Co
CoCo Co
Co
Co
Co
CoCo
Co
Co
Co Co
Co
Co
Co
dj
H2
H2OCo
Co
Co
Co
CoCo Co
Co
Co
Co
CoCo
Co
Co
Co Co
Co
Co
Co
OXIDE
FORMATION
CoCo
Co
Co
CoCo Co
Co
Co
Co
CoCo
Co
Co
Co Co
Co
Co
Co
H2O
H2
di
H2O
H2
OXIDE REMOVAL
(di3+dj
3)1/3
Oxidation on particle surface, bulkremains metallic
Sintering mechanism: our concept
*Inspired from (J. Sehested, J. Catal. 2003) for nickel catalysts
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
0 100 200 300 400
Re
lati
ve
CO
co
nv
ers
ion
time (min)
4
5
6
7
8
9
0 100 200 300 400
Me
an
Cry
sta
llit
e S
ize
(n
m)
time (min)
02
46
8
0
10
20
30
40
50
60
70
0
60
120
180
240
300360
CO
Co
nve
rsio
n
tim
e on s
trea
m (m
in)
Reactor length (mm)
Effect of sintering on the catalytic activity (gPROMS model)
Typical Simulation Results
Fixed Bed Reactor Modeling
51
Deactivation of Copper-ZSM -5 catalysts for direct DME synthesis from syngas
30%
40%
50%
60%
70%
80%
90%
0 10 20 30 40 50 60 70 80 90 100
CO
co
nv
ers
ion
Time on stream / h
CZA-ZSM-5@95 CZA-ZSM-5@110 CZA-ZSM-5@80
CZA-ZSM-5@65 CZA-ZSM-5@500 CZA-ZSM-5@800
0%
10%
20%
30%
40%
50%
60%
70%
0 10 20 30 40 50Reaction time /h
CO
Con
vers
ion
water injection for 24 h0.2ml/min without CO
Syngas
(CO+H2)
Hybrid bifunctional catalysts showed noticeable deactivation
Water injection leads to a major drop in the activity
T=260 °C, P=20 bar, GHSV=3600 cm3/gcat h
52
Copper sintering under the reaction conditions: in-situ XRD
X-ray patterns recorded between five XANES scans with position sensitive detector
Reduction in H2 at 290 C, DME Reaction (H2=4 ml/min,CO=2ml/min), P=20 bar, T=260 °C
copper particles size calculated using Scherrer equation at 2θ=43.0
Cu sintering
13 14 15 16 17
13 h
11 h
12 h
9 h
8 h
5 h
3 h
2 h
Inte
nsity
, a.u
.
2 Theta
Reduced
Deactivation mechanism of CZA-HZSM-5
53
Time, h
Cu-Zn-Al-HZSM-5
70
60
50
CO
co
nve
rsio
n, %
2CO + 4H2 CH3OCH3 + H2O
DME
synthesis
H+ H+
H+
H+
H+
H+Zn-O-Al
Cu H+
H+Zn-O-Al
CuCu2+
Cu2+
Cu
H+H+
H+HZSM-5
The reason of deactivation over the hybrid catalyst CZA-HZSM5 is mainly Cu sintering and ion exchange of Cu2+ with the protons of Zeolite HZSM-5
How to solve the problem of Cu sintering and ion exchange ?
Cu
54
TEOSH-ZSM5
SiO2
SiO2
H+ H+
H+
H-ZSM5
H+
H+ H+Liquid phase deposition
Si Si
H-ZSM5
O O O OOSi Si SiSi
OOOOO
Calcination
� Silylated HZSM-5 by tetraethoxysilane (TEOS) modification
� Silylated HZSM-5 by Hexadecyltrimethoxysilane (HTDMS) without calcination
HZSM5
hexadecyl
Hydrophobic HZSM5
HZSM5
HTDMS
Liquid phase deposition
Modified HZSM5 by silane reagents
SiO2/HZSM5
Most important parameters affecting the selectivity and selectivity have been identified
55
Highly selective catalysts
Very stable catalysts
Acknowledgements
56
Thank you for your attention!
UCCS CatEn group
Dr. V. OrdomskyDr. M. VirginieDr. A. GribovalDr. Y. LuoDr. M. Sadeqzadeh (PhD student)Dr. C. Liu (PhD student)Dr K. Cheng (PhD student)Dr. G. de Souza (PhD student)Ms. M. Cai(PhD student)Mr. A. Carvalho (PhD student)
Dr. V. Valtchev, LCS, CaenDr. C. Pham-Huu, ICPEES, StrasbourgProf. O. Ersen, IPCMS, StrasbourgProf. Wang Ye, XiamenProf. P.A. Chernavskii, MoscowDr. O. Safonova, ESRFDr. W. van Beek, ESRFProf. N. R. Marcillio, UFRGSProf. M. Oberson de Souza, UFRGS
Deactivation of CZA-X hybrid catalysts
57
Conditions: Cu-based catalyst / solid acid catalyst(weight ratio) =5/3;
T= 260 C, P=20 bar, H2 /CO=2, SV=3600 ml/(h·gcat)