Methanol Production from biomass and intermittent power
Lund University, March 17th 2015
Søren Højgaard Jensen, Senior researcher at DTU Energy
Content
• About DTU Energy
• Thermochemical conversion of biomass to MeOH
• Electrolyser Cells
• Solid Oxide Cell
• Dynamic Operation
• Cost Estimation
• Conclusion
DTU Energy, Technical University of Denmark
Department of Energy Conversion and Storage
• About 250 employees
• Sustainable technologies for energy conversion and storage
• Focus on
– R&D
– Innovation
– Education
DTU Risø Campus
DTU Energy, Technical University of Denmark
DTU Lyngby Campus
Department of Energy Conversion and Storage
Technologies
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
DTU Energy, Technical University of Denmark
Methanol Production from biomass and intermittent power
-Thermochemichal Synthesis
CO2 + 3H2 = CH3OH + H2O
CO + 2H2 = CH3OH
41 kJ/mole
91 kJ/mole
M = (H2 – CO2)/(CO + CO2) ≅ 2
Conventional Cu/ZnO-Al2O3 methanol catalysts operates at 200 °C - 300 °C at 45 – 60 bar
GreenSynFuels Report: http://www.hydrogennet.dk/groennesynfuels/
DTU Energy, Technical University of Denmark
Various Types of Electrolysis Cells
6
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
DTU Energy, Technical University of Denmark
18 March 2015
Methanol Dream Cell: Stable at 200 – 300 °C and 45-60 bar
H2O
Porous anode
e-
eH+
CO2
Porous cathode
Solid or immobilized electrolyte,
e.g. H+ conductor
O2, H2O
CH3OH, H2O, CO2, …
Gas diffusion electrodes
7
DTU Energy, Technical University of Denmark
18 March 2015
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
Potential [V]
1.80
130ºC
1.70
1.60
1.50
1.40
•
•
E500
150
mA/cm2
1.625 V
Ambient pressure,
PFSA membrane (Aquivion) doped with H3PO4
1.30
1.20
iTN
0
PBI not stable
Ta coated steel felt
200
400
600
800
1000
Current density [mA cm-2]
DTU Energy, Technical University of Denmark
Source; J.O.Jensen , DTU Kemi
Bridging the Norby gap: HT-Alkaline Electrolyser Cell
High temperature
and pressure alkaline
electrolysis
• Electrolyte:
-aqueous KOH immobilized in a
porous structure
• Gas diffusion electrodes:
- porous Nickel, Raney-Nickel
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
Performance of cells with immobilized KOH(aq.) at 40 bar
F. Allebrod, C.
Chatzichristodoulou, M.B.
Mogensen, J. Power Sources,
229 (2013) 22, and in Proc. of
this meeting, paper A0705.
DTU Energy, Technical University of Denmark
The Solid Oxide Cell
DTU Energy, Technical University of Denmark
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
DTU Energy, Technical University of Denmark
YSZ = Zr0.84Y0.16O1.92
Solid Oxide Electrolysis Cell
+
O2
1.3 V
−
H2O (and CO2)
H2 (and CO)
O2
0.8 V
+
−
H2 (and CO)
H2O (and CO2)
Solid Oxide Fuel Cell
DTU Energy, Technical University of Denmark
Electrode Reaction Kinetic
H2 +
νf
-O 
νb
H2O + 2e -
νf
½O2 + 2e-  O-ν
b
DTU Energy, Technical University of Denmark
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
H2O → H2 + ½O2
Electrical
200
energy de
1.30
mand (G
)
1.04
150
Gas
f
50 bar
1 bar
0.78
Gas
100
0.52
a
Heat dem
50
nd (TS f )
0
0.26
0.00
0
100 200 300 400 500 600 700 800 900 1000
Temperature (ºC)
DTU Energy, Technical University of Denmark
1/(2·n·F) · Energy demand (Volt)
1.55
Total energy demand (Hf )
250
Liquid
Energy demand (KJ/mol)
300
Ecell = Etn
Steam Electrolysis Thermodynamics
Steam Electrolysis at Elevated Pressure
Experimental data,
DTU Energy
DTU Energy, Technical University of Denmark
Electrode Reaction Kinetic
H2 +
νf
-O 
νb
H2O + 2e -
νf
½O2 + 2e-  O-ν
b
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
DTU Energy, Technical University of Denmark
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
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)
GreenSynFuels Report: http://www.hydrogennet.dk/groennesynfuels/
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
DTU Energy, Technical University of Denmark