Methanol Production from biomass and intermittent power Lund University, March 17 th 2015 Søren Højgaard Jensen, Senior researcher at DTU Energy
Methanol Production from biomass and intermittent power
Lund University, March 17th 2015 Søren Højgaard Jensen, Senior researcher at DTU Energy
DTU Energy, Technical University of Denmark
• About DTU Energy
• Thermochemical conversion of biomass to MeOH
• Electrolyser Cells
• Solid Oxide Cell
• Dynamic Operation
• Cost Estimation
• Conclusion
Content
DTU Energy, Technical University of Denmark
• About 250 employees • Sustainable technologies for energy conversion and storage
• Focus on
– R&D – Innovation – Education
DTU Risø Campus DTU Lyngby Campus
Department of Energy Conversion and Storage
DTU Energy, Technical University of Denmark
Department of Energy Conversion and Storage
Fuel cells (SOFC, HT-PEMFC, LT-PEMFC)
Electrolysis (SOEC, AEC)
Solar cells (Polymer, CZTS)
Batteries
Membranes for oxygen separation
Magnetocaloric cooling and heat pumps
Thermoelectric generators
Flue gas purification
Superconductors
Technologies
DTU Energy, Technical University of Denmark
Methanol Production from biomass and intermittent power
GreenSynFuels Report: http://www.hydrogennet.dk/groennesynfuels/
-Thermochemichal Synthesis
Conventional Cu/ZnO-Al2O3 methanol catalysts operates at 200 °C - 300 °C at 45 – 60 bar
CO2 + 3H2 = CH3OH + H2O 41 kJ/mole CO + 2H2 = CH3OH 91 kJ/mole M = (H2 – CO2)/(CO + CO2) ≅ 2
DTU Energy, Technical University of Denmark
6 18 March 2015
Type electrolyte Alkaline Acid Polymer Solid oxide
Electrolyte NaOH or KOH
H2SO4 or H3PO4
Polymer Ceramic
Charge carrier OH- H+ H+ O2-
Reactant H2O H2O H2O H2O and/or CO2
Electrodes Ni Graphite with Pt + polymer
Graphite with Pt + polymer
Ni + ceramics
Temperature 80 -150 °C 140 - 180 °C 60 - 80 °C 700 - 900 °C
Various Types of Electrolysis Cells
DTU Energy, Technical University of Denmark
7 18 March 2015
Methanol Dream Cell: Stable at 200 – 300 °C and 45-60 bar
H+
e- e-H2O
O2, H2O
CO2
CH3OH, H2O, CO2, …
H+
e- e-H2O
O2, H2O
CO2
CH3OH, H2O, CO2, …
H+
e- e-H2O
O2, H2O
CO2
CH3OH, H2O, CO2, …
Solid or immobilized electrolyte, e.g. H+ conductor
Gas diffusion electrodes
Porous cathode Porous anode
DTU Energy, Technical University of Denmark
The Norby gap
From T. Norby, Solid State Ionics, 125 (1999) 1
DTU Energy, Technical University of Denmark
Bridging the Norby gap: HT-PEM Electrolyser Cell
1.20
1.30
1.40
1.50
1.60
1.70
1.80
0 200 400 600 800 1000
Po
ten
tial
[V
]
Current density [mA cm-2]
Ambient pressure, PFSA membrane (Aquivion) doped with H3PO4
130ºC
Source; J.O.Jensen , DTU Kemi
iTN E500 150
mA/cm2 1.625 V
• PBI not stable • Ta coated steel felt
DTU Energy, Technical University of Denmark
Bridging the Norby gap: HT-Alkaline Electrolyser Cell
• Electrolyte: -aqueous KOH immobilized in a
porous structure • Gas diffusion electrodes: - porous Nickel, Raney-Nickel
High temperature and pressure alkaline electrolysis
F. Allebrod, C. Chatzichristodoulou, M. Mogensen, submitted paper and filed patent application
DTU Energy, Technical University of Denmark
Bridging the Norby gap: HT-Alkaline Electrolyser Cell
F. Allebrod, C. Chatzichristodoulou, M.B. Mogensen, J. Power Sources, 229 (2013) 22, and in Proc. of this meeting, paper A0705.
Performance of cells with immobilized KOH(aq.) at 40 bar
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The Solid Oxide Cell
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The Solid Oxide Cell
Ni/YSZ support & current collector
Ni/YSZ electrode YSZ electrolyte
LSM-YSZ electrode
LSM current collector
LSM = (La0.75Sr0.25)0.95MnO3 YSZ = Zr0.84Y0.16O1.92
DTU Energy, Technical University of Denmark
Solid Oxide Electrolysis Cell
H2O (and CO2) H2 (and CO)
O2
O2
H2 (and CO)
+
−
+
−
H2O (and CO2)
Solid Oxide Fuel Cell
1.3 V
0.8 V
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Electrode Reaction Kinetic
H 2 + O -- H 2 O + 2e -
½O 2 + 2e - O --
νf
νb
νf
νb
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The Solid Oxide Cell
• Interconnect is usually ferritic stainless steel, ~22 % Cr with a number of small additives. Several commercial (or semi-commercial) steels are available.
• Gas sealing between cells and interconnect is most often a suitable SiO2 based glass
DTU Energy, Technical University of Denmark
0
50
100
150
200
250
300
0 100 200 300 400 500 600 700 800 900 1000
Temperature (ºC)
Ener
gy d
eman
d (K
J/m
ol)
0.00
0.26
0.52
0.78
1.04
1.30
1.55
1/(2
·n·F
) · E
nerg
y de
man
d (V
olt)
Liqu
id
Gas
H2O → H2 + ½O2
Total energy demand (Hf)
Electrical energy demand (Gf)
Heat demand (TSf)
Steam Electrolysis Thermodynamics
E cel
l = E
tn
Gas 1 bar
50 bar
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Steam Electrolysis at Elevated Pressure
Experimental data,
DTU Energy
DTU Energy, Technical University of Denmark
Electrode Reaction Kinetic
H 2 + O -- H 2 O + 2e -
½O 2 + 2e - O --
νf
νb
νf
νb
DTU Energy, Technical University of Denmark
Polarization Ranges for State-of-the-art H2O Electrolysis Cells
Eth,water and Eth,steam are the thermoneutral voltages. Erev is the reversible voltage at standard state. C Graves, SD Ebbesen, M Mogensen, KS Lackner, Renew. Sustain. Energy Rev., 15 (2011) 1
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Fluctuating Electricity Prices
Spot market electricity prices [DK-West] from 2006 to 2013 sorted hour-by-hour, lowest prices first
SH Jensen, et al. Energy & Environmental Science. Under review
DTU Energy, Technical University of Denmark
SOEC Operating Strategy
GreenSynFuels Report: http://www.hydrogennet.dk/groennesynfuels/
Two operating strategies 1. Always at optimal H-C ratio for the synthesis step 2. SOEC operates at 1/3 of nominal power at high electricity prices
(generates enough O2 for gasification)
DTU Energy, Technical University of Denmark
Methanol Production Cost - CAPEX
GreenSynFuels Report: http://www.hydrogennet.dk/groennesynfuels/
DTU Energy, Technical University of Denmark
Methanol Production Cost - OPEX
GreenSynFuels Report: http://www.hydrogennet.dk/groennesynfuels/
DTU Energy, Technical University of Denmark
Methanol Production Cost Estimations
GreenSynFuels Report: http://www.hydrogennet.dk/groennesynfuels/
DTU Energy, Technical University of Denmark
Dynamic Operation of a Solid Oxide Cell
C Graves, SD Ebbesen, SH Jensen, SB Simonsen, M Mogensen. Nature Materials 14 (2015) 239
DTU Energy, Technical University of Denmark
Cell vs. Stack stability
DTU Energy, Technical University of Denmark
Conclusion
• Methanol Production from Biomass can be significantly boosted by H2O electrolysis using intermittent power
• MeOH production prices can be lowered using the above strategy with SOECs, but not dramatically unless
– A: SOEC lifetime is increased beyond 5 year, or – B: The SOEC cost is reduced
• Other types of cells could potentially emerge which can operate
around 200 – 300 °C and 20-60 bar. This could lead to lower costs because of
– A: Possibility for integrated Methanol catalyst – B: Lower costs for auxiliary components
DTU Energy, Technical University of Denmark
Acknowledgement
• Thank you for your attention