Process Intensification: a key to synthetic carbon-based fuels
Enrico Tronconiwith Gianpiero Groppi, Carlo G. Visconti, Alessandra Beretta, Luca Lietti, Matteo
Maestri, Matteo Ambrosetti, Mauro Bracconi, Riccardo Balzarotti, Laura Fratalocchi
Dipartimento di Energia, Politecnico di Milano, Milano (Italy)
November 12th, 2020
Intensifying heat transfer in multitubular catalytic reactors
EU Patent 1 110 605 B1; US Patent 7,678,342
ERC Advanced Grant 2015 Action 694910: INTENT
“Structured Reactors with INTensified ENergyTransfer for Breakthrough Catalytic Technologies”
From a slow convective mechanismto fast heat conduction in the solid matrix
G. Groppi & E. Tronconi, Chem. Eng. Sci. 55 (2000) 2161E. Tronconi et al., Curr. Opinion Chem. Eng. 5 (2014) 55
Tronconi, Groppi, Visconti, Curr. Opinion Chem. Eng. 5 (2014) 55
Flow independent
Flow dependent
a) b) c) d)
OutlineConcept: conductive structured catalysts in heat transfer-limited processes for energy vectors
Fischer-Tropsch synthesis:• conductive honeycombs• conductive open-cell foams• conductive Periodic Open Cellular Structures (POCS)
Methane Steam Reforming:• conductive open-cell foams• conductive Periodic Open Cellular Structures (POCS)
Packed bed Honeycomb Foam POCS
1. Conductive structured catalysts for the Fischer-Tropsch Synthesis: honeycombs
Sasol, Oryx GTL (Qatar) 17000 BPD/reactor Shell, Pearl GTL (Qatar) 5833 BPD/reactor
Associated gas and stranded oil
Market analysis reveals over 800 oil fields globally, onshore and offshore, where associated gas is problematic,
and conditions suit a modular GtLsolution.
There is an estimated total of over 73Bn bbls of crude reserves across these assets.
Gas flaring in Nigeria
GTL = Gas-To-Liquids
180-280ºC5-30 bar
Catalyst
CnH2n+2
CnH2n
CnH2n+1OH
H2O , CO2
CO + H2
and jet fuel…
BTL = Biomass-To-Liquids
www.fischer-tropsch.org
Sasol, Oryx GTL (Qatar) 17000 BPD/reactor Shell, Pearl GTL (Qatar) 5833 BPD/reactor
Scaling down
Technologically feasible Economically sustainable
Modular, eggshell catalystsbut...thermally unmanageable on
a small-scale
Isothermal, no intraporous resistancesbut...not modular and not suitable for
small-scale units
Gas to Liquid (GtL) Processes: Fischer-Tropsch reactors
Scaling down
Technologically unfeasible Economically unsustainable
Heat removal is critical in FTS
The FTS is highly exothermal (∆H0R ≅ −165 kJ/molCO), an inefficient T-control would lead to:
Drop of the selectivity Fast catalyst deactivation Thermal runaway of the reactor
• Hot-spots • Strong axial and radial T-gradients
Improved Heat Transfer is crucial
How to manage the heat removal in compact MTPBRs?
The FTS is highly exothermal (∆H0R ≅ −165 kJ/molCO), an inefficient T-control would lead to:
Drop of the selectivity Fast catalyst deactivation Thermal runaway of the reactor
• Hot-spots • Strong axial and radial T-gradients
Improved Heat Transfer is crucial:
K. Pangarkar, T. J. Schildhauer, J. R. van Ommen, J. Nijenhuis, J.A. Moulijn, F. Kapteijn, Cat. Today 147S (2009) S2-S9.
“Solving the Heat Transport Issue in FTS Fixed-Bed Reactors with Structured Catalysts”
Al foamε = 0.90
Knitted wireε = 0.90
OCFSε = 0.84
CCFSε = 0.95
Honeycombs
Development of a washcoating procedure
Selection of materials
Chem. Eng. J. 171 (2011) 1294
Lab-scale catalysttesting (at PoliMi’s site)
Industrial reactor modeling
Appl. Catal. A 370 (2009) 93Appl. Catal. A 370 (2009) 93
PHAS
E 1
PHAS
E 2
Design & manufacturing of improved materials
Lab-scale catalysttesting (at PoliMi’s site)
Pilot-scale testing (at Eni’s site)
Demo scale reactor design
WO/2010/130399 WO/2014/102350
Conductive monoliths for FTS in small-scale MT-FBRs?
p
p
p
p
Washcoated monolith
channels
PROs• Higher catalyst inventory
CONs• Higher pressure drop• (Longer diffusion lengths)
p
p
p
p
Monolith channels packed with small catalyst pellets
How to increase the “activity in the reactor”:“Packed monolith” concept
US Patent 9,387,456
Pilot-scale testing @ Eni
packed honeycomb
monolith28mm
syngas
products
Tube ID28 mm
thermocouplethermowell
dch= 4 mm
~300 gcat, dp=300 µm
An example of data collected in the FTS pilot reactor
P0=25 bar, H2/CO=2.1
∆P < 1 bar
Outstanding heat transfer performance of a compact reactor (1 m long tube):
U ≈ 1.5 kW/m2/K
2. Conductive open-cell foams: application to the Fischer-Tropsch synthesis
NASA Space Center, Houston (TX):
Foam sandwich as protective shieldfor aerospace applications
Honeycomb vs. Foam!
Conductive Metallic Foams for the FTS
Conductive structured catalysts
G. Groppi & E. Tronconi, Chem. Eng. Sci. 55 (2000) 2161E. Tronconi et al., Curr. Opinion Chem. Eng. 5 (2014) 55 Monoliths, micromonoliths, foams, POCS, microchannel blocks...
Almeida et al. Cat. Today 215(2013)103 ISSUES OF WASHCOATED FOAMS: • the overall load of catalytically active phase is much less (20-25
vol.%) than in a bed of bulk pellets (65 vol.%) (thin catalyst layer, high void fraction)
• improved washcoating techniques are needed: the macropores of the foam may be partially clogged
From slow convective mechanism to the fast heat conduction in the solid matrix
Improved Heat Transfer
40 ppi 20 ppiεfoam= 0.886 εfoam= 0.885
Packed open-cell foam catalysts for FTS
Al-foams packed with Co/Pt/Al2O3 catalyst
Foams acquired from ERG Aerospace, USA
US Patent 9,890,333
Heat transfer measurements:C.G. Visconti et al., Cat. Today 273 (2016) 178–186
dp = 300 µm
Catalyst activity: Packed-foam reactorP= 25 bar, H2/COin= 2 mol/mol, GHSV= 6410 cm3(STP)/h/gcat, inerts= 24 vol.%. T = 180-240°C
• Catalyst active even at low T:ΧCO= 12.1% @195°C; ΧCO= 16.5% @200°C
• Catalyst reaches high CO conversions(55-67 % @230-240°C)
• Catalyst does not deactivate even after 800 h of T.o.S.
Fratalocchi et al., Chem. Eng. J. 349 (2018) 829-837Fratalocchi et al., RC & Eng.ng, 4 (2019) 1917-1921
Catalyst activity: Packed-bed reactorP= 25 bar, H2/COin= 2 mol/mol, GHSV= 6410 cm3(STP)/h/gcat, inerts= 24 vol.%. T = 180-240°C
• Catalyst active even at low T (ΧCO= 12.1% @195°C; ΧCO= 16.5% @200°C)
• Catalyst reaches high values of CO conversion (55-67 % @230-240°C)
• Catalyst does not deactivate even after 800 h of T.o.S.
18 20 22 24 26 28150
160
170
180
190
200
210
220
230
240 packed-bed packed-foam
Tcat
[°C]
time [h]
Runaway during the T-ramp from 190 to 195°C
Fratalocchi et al., Chem. Eng. J. 349 (2018) 829-837
T-Profiles along the catalyst bed: Packed-foam reactor
Tcat [°C] XCO[%]
Q[kW/m3]
∆Tcat[°C]
180 4 80.61 0.2
190 8 161.23 0.5
195 12 243.86 1
200 16.5 332.53 0.9
205 22 427.25 1.2
210 28 566.31 2.1
215 33.4 675.14 3.3
220 44 900.86 3.8
225 50 1013.71 4.5
230 54.5 1098.36 5.4
240 67.5 1360.35 6.4
𝑄𝑄 𝑘𝑘𝑊𝑊/𝑚𝑚3 =−∆𝐻𝐻𝑅𝑅0 � 𝐹𝐹𝐶𝐶𝐶𝐶𝑖𝑖𝑖𝑖 � 𝑋𝑋𝐶𝐶𝐶𝐶
𝑉𝑉𝑐𝑐𝑐𝑐𝑐𝑐
1.0 1.5 2.0 2.5 3.0175180185190195200205210215220225230235240245250
180 190 195 200 205 210 215 220 225 230 240
Tcat
[°C]
Catalyst bed [cm]
3. Conductive Periodic Open Cellular Structures (POCS) for the FTS
0 200 400 600 800 1000 1200 1400 1600 1800 200002468
101214161820222426
packed-FOAMpacked-POCS packed-POCS (with the skin)
∆Tex
t [°C
]
Q [kW/m3]
POCS from METAMAT-lab @ PoliMI
3D printing of different cell geometries in Aluminium
TKKD CELL DIAMOND CELL CUBIC CELL
Prof. Stefano Beretta
Packed-POCS with metallic skin for FTS
εpocs≈ 0.890; dcell≈ 3 mm (diamond cell) made by 3D printing (AlSi7Mg0.6)
PackedFoam
PackedPOCS
PackedPOCS(skin)
Catalyst weight [g] 7.2 7.2 7.2
Catalyst volumetricdensity [g/cm3] 0.63 0.63 0.69
Cata
lyst
2 cm
α-A
l 2O3
1.1
cmα
-Al 2O
31.
1 cm
TaxTrad Text
L= 4
.2 c
m
OD= 2.78 cm
t= 0.05 cm
Fratalocchi et al., Cat. Today, submitted
0 200 400 600 800 1000 1200 1400 1600 1800 200002468
101214161820222426
packed-FOAMpacked-POCS packed-POCS (with the skin)
∆Tex
t [°C
]
Q [kW/m3]
Thermal Behaviour in FTS: Packed-POCS with skin
• POCS and POCS with the skin have similar geometrical properties: 𝜺𝜺𝑷𝑷𝑷𝑷𝑷𝑷𝑷𝑷 = 𝟎𝟎.𝟖𝟖𝟖𝟖; 𝒅𝒅𝒄𝒄𝒄𝒄𝒄𝒄𝒄𝒄 = 𝟑𝟑 𝒎𝒎𝒎𝒎; R = 1
𝑷𝑷𝒄𝒄𝑺𝑺𝑺𝑺𝒄𝒄 𝑷𝑷𝑷𝑷𝑷𝑷𝑷𝑷𝑷𝑷𝒄𝒄𝑺𝑺𝑺𝑺𝒄𝒄 𝑷𝑷𝑷𝑷𝑷𝑷𝑷𝑷 𝒘𝒘𝒘𝒘𝒘𝒘𝒘𝒘 𝒘𝒘𝒘𝒘𝒄𝒄 𝒔𝒔𝒔𝒔𝒘𝒘𝒔𝒔= 1.9
𝑷𝑷𝒄𝒄𝑺𝑺𝑺𝑺𝒄𝒄 𝑭𝑭𝑷𝑷𝑭𝑭𝑭𝑭𝑷𝑷𝒄𝒄𝑺𝑺𝑺𝑺𝒄𝒄 𝑷𝑷𝑷𝑷𝑷𝑷𝑷𝑷 𝒘𝒘𝒘𝒘𝒘𝒘𝒘𝒘 𝒘𝒘𝒘𝒘𝒄𝒄 𝒔𝒔𝒔𝒔𝒘𝒘𝒔𝒔= 2.8
∆𝑻𝑻𝒄𝒄𝒆𝒆𝒘𝒘(𝑭𝑭𝑺𝑺𝑭𝑭𝒎𝒎) > ∆𝑻𝑻𝒄𝒄𝒆𝒆𝒘𝒘(𝑷𝑷𝑷𝑷𝑷𝑷𝑷𝑷)> ∆𝑻𝑻𝒄𝒄𝒆𝒆𝒘𝒘(𝑷𝑷𝑷𝑷𝑷𝑷𝑷𝑷 𝒔𝒔𝒔𝒔𝒘𝒘𝒔𝒔 )
Fratalocchi et al., Cat. Today, submitted
New semi-pilot FTS rig with cooled reactor
Under testing, to be installed at B 18C
4. Cu-foam catalystsfor Methane Steam Reforming
Temperature profiles: comparison at dp = 600 μm
600 650 700 750
Cu10 PF10 ppi, εF=0.91, dp=0.6mm
GHSV = 10000 h-1
χ = 97.7 %Q = 56.2 W
Central T Central T (No reaction) Radial T Radial T (No reaction) Wall T Wall T (No reaction)
Cu40 PF40 ppi, εF=0.88, dp=0.6mm
GHSV = 10000 h-1
χ = 98.5 %Q = 56.0 W
Temperature (°C)
T oven = 800 °C
550 600 650 700 7500
1
2
3
4
5
6
7
8
9
10
11
12
Dist
ance
from
the
botto
m [c
m]
Temperature (°C)600 650 700 750
Packed beddp=0.6mm
GHSV = 10000 h-1
χ = 94.4 %Q = 48.9 W
Central T Central T (No reaction) Radial T Radial T (No reaction) Wall T Wall T (No reaction)
FeCr PF12 ppi, εF=0.92, dp=0.6mm
GHSV = 10000 h-1
χ = 95.9 %Q = 52.0 W
Temperature (°C)
T oven = 800 °C
550 600 650 700 7500
1
2
3
4
5
6
7
8
9
10
11
12
Dist
ance
from
the
botto
m [c
m]
Temperature (°C)
Gas
flow
= SiC filling
= Empty foam (spacing)= Catalytic bed
R. Balzarotti et al., Reaction Chemistry & Engineering, 4 (2019) 1387 – 1392
Conductive monolith, foam & POCS catalysts in tubular reactors offer great potential for the intensification of energy-related, heat transfer-limited processes:
• Fischer-Tropsch Synthesis (GtL, BtL, WtL, PtL)• COx methanation & CO2 hydrogenation (PtG)• Methanol and DME synthesis (PtC)• Selective oxidations, Hydrodeoxygenations (Biorefinery)• Methane steam & dry reforming (Blue Hydrogen)• Dehydrogenations (LOHC) …
Tronconi, Groppi, Visconti, Current Opinion in Chem. Eng.ng, 5 (2014) 55-67Kapteijn, Moulijn, Cat. Today (2020), doi: 10.1016/j.cattod.2020.09.026
Keywords for the requested new process technologies to enablemore flexible and down-scaled high-performance processing:
• Suitable for small-scale production (e.g. to exploit stranded gas)• Flexible (e.g. flow independent, RES: load changes) /modular• Enabling efficient process intensification (e.g. enhanced heat transfer) • Drop-in technology: can be inserted readily within current infrastructures
(e.g. multitubular fixed-bed vs. microchannel reactors)
Outlook
Acknowledgments
ERC AdG 2015 – Action 694910: INTENT«Structured Reactors with Intensified Energy
Transfer for Breakthrough Catalytic Technologies»