John Bøgild Hansen, Haldor Topsøe A/S
Christian Dannesboe, Aarhus University
Brintbranchens Årsmøde, April 18, 2018
SOEC Enabled Biogas Upgrading
AARHUSUNIVERSITY
DEPARTMENT OF ENGINEERING
Biogas upgrade by means of SOEC
CH4 + CO2 + 3H2O + El 2CH4 +H2O + 2O2
DEPARTMENT OF ENGINEERING
Fuel Cell and Electrolyser
½O2
H2 H2O
½O2
H2O + 2e- → H2 + O2-
O2-
O2- → 2e- +½O2
H2 + O2- → H2O + 2e-
O2-
½O2 + 2e- → O2-
SOFC SOEC
H2H2O
H2 + CO + O2 H2O + CO2 + electric energy (∆G) + heat (T∆S)SOF
C
SOECDEPARTMENT OF ENGINEERING
SOEC more efficient than present Electrolysers
Internal waste heat used to split water
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Deg C.
kW
h p
er
Nm
3 H
2
Minimum Electricity Input
Waste heat which can be utilised to split water
Energy needed to evaporate water
CO2 + 4H2 ↔ CH4 + 2H2O (-∆H = 165 kJ/mol)
Syngas = SNG + heat
Energy: 100% = 80% + 20%
SNG100%
80%
20%Heat
SNG Technology
Methanation generates a lot of heat
DEPARTMENT OF ENGINEERING
Synergy between SOEC and fuel synthesis
SOEC Synthesis
CO2
H2O
Syn
Gas
Product
Steam
DEPARTMENT OF ENGINEERING
Biogas to SNG via SOEC and methanation
of the CO2 in the biogas
Biogas
Oxygen
Water
Condensate
SNG
SteamMethanator
SOEC
DEPARTMENT OF ENGINEERING
EUDP project
50 kW SOEC and 10 Nm3/h methane
Participants:
Haldor Topsøe A/S
Aarhus University
HMN Naturgas
Naturgas Fyn
EnergiMidt
Xergi
DGC
PlanEnergi
Ea Energianalyse
Coordinator:
Duration:
June 2013 -
December
2017
Project sum:
5.3 mio €
Location:
Foulum
Methanation and SOEC at Foulum
DEPARTMENT OF ENGINEERING
Major events during the Project
Topsoe Stack Platform (TSP-1) 8 Stacks
75 cells combined with interconnects, spacers and sealings in one stack
Internal fuel
manifold
External air
manifold
Cell group voltage
probing
Compression free
handling (cold)
DEPARTMENT OF ENGINEERING
Heat up of SOEC unit from cold10-11 hours, but full production on/off within seconds
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Vo
lt o
r A
mp
per
15
0 c
ells
Deg
. C
Hour
Out Preheater
In Stacks
Out Stacks
Volt
Amps
Volt
Current
Temperatures
DEPARTMENT OF ENGINEERING
Screen dump from Cores
8 Stacks of 75 cells
1.28 V per cell, 65 A = 50 kW
Hydrogen production = 16.3 Nm3/h
3.06 kWh/Nm3
Tinlet = 726 °C
DEPARTMENT OF ENGINEERING
Production (100 % = 10 Nm3/h CH4)
vs hours on stream. 3.1 kWh/Nm3 H2
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Perc
en
t o
f D
esig
n p
rod
ucti
on
Hours on Electrolysis
Screen dump from methanator start up
Transient operation of methanator
DEPARTMENT OF ENGINEERING
Methanator catalyst very active and stable
DEPARTMENT OF ENGINEERING
Average gas compositions June 2, 2016
Position CH4 CO2 N2 H2
Inlet 56 43 1 0
Exit 1st
stage
94.58 0.27 0.91 4.23
Product
gas
97.69 0.00 0.95 1.36
DEPARTMENT OF ENGINEERING
Exergy Flows in CO2 case
DEPARTMENT OF ENGINEERING
Efficencies
Configuration
Percent effciency
A
CO2 Meth.
Exergy eff gas 80.2
District heating 0.8
Oxygen 2.1
Exergy eff Total 83.1
LHV eff gas 76.3
LHV DH 14.0
LHV eff total 90.3
Demonstration Plant - Conlusions
Process values very close to design simulations
Better than SNG quality:
Catalyst for CO2 methanation have high activity and durability
Boiling water reactor design robust and flexible
SOEC close to 100% efficiency (LHV)
Hot start and stop within seconds
Integration of SOEC and methanation unit
Completely automated including all utilities
Operating Strategy:
– Thermoneutral Voltage – Full Production
– Increase Temperature to Counteract Degradation
DEPARTMENT OF ENGINEERING
New EUDP project
50 kW SOEC and 10 Nm3/h methane
Participants:
Haldor Topsøe A/S
Aarhus University
Xergi
Duration:
November
2017 -
April 2020
Project sum:
1.5 mio €
Location:
Foulum