POWER September 2020 - 31

TOP PLANT
POWER POINTS
Winning Attributes
✔ Successfully piloting technologies
to produce " green " hydrogen and
synthetic methane.
✔ Developing a novel product
that could play a major role in
decarbonization ambitions.
✔ Demonstrating gas and power
sector coupling for renewable
power and energy storage.
1. This image taken from the roof of the heat transfer container shows the top of the honeycomb
reactor and economizer. The trench for the hydrogen and synthetic natural gas line for the
tie-in to the existing plant is shown in the background. Courtesy: STORE&GO
generation and distribution businesses.
In January 2016, E.ON's massive generation
business was formally spun off
into Uniper SE.
Uniper, which is today majority controlled
by Finnish firm Fortum, has doubled
down on climate neutrality initiatives, hoping
to achieve them in its European generation
business by 2035 and the rest of
the world by 2050. That's even though
about 26% of its 34 GW fleet is coal-fired,
50% is gas-fired, and it owns several gas
storage facilities with a total capacity of 7.5
billion cubic meters (m3). It told POWER in
July that hydrogen will play a major future
role in its asset mix. To realize its decarbonization
ambitions, it plans to invest approximately
€1.2 billion in green technologies
and decarbonization over " the next couple
of years, " it said.
Falkenhagen, notably, has remained
a bedrock for Uniper's research and development,
and demonstration. In March
2016, the company embarked on a second
demonstration phase at the site as
part of the STORE&GO initiative. Armed
with funding from the European Union's
Horizon 2020 initiative, it laid the cornerstone
for a methanation plant next to the
existing pure hydrogen PtG plant in July
2017, and by May 2018, it had begun first
production of 57 m3/hr of synthetic natural
gas (SNG)-or about 600 kWh/hr-as
well as process heat for a nearby veneer
plant. The plant,
built
in
collaboration
with thyssenkrupp Industrial Solutions,
the German Gas and Water Industry
Association (DVGW), and the Karlsruhe
Institute of Technology (KIT), essentially
combines 210 m3/hr of hydrogen from
the PtG facility with 52.5 m3/hr of carbon
dioxide sourced from a bioethanol plant
in Zeitz (provided as a liquid) using the
September 2020 | POWER
Sabatier reaction in a novel reactor designed
by thyssenkrupp and KIT.
The methanation reaction is carried
out in two stages. The first reaction stage
occurs in a tube-type reactor whose
tubes contain honeycomb-like structures
coated with a catalyst, and it generates
a product gas conversion rate of about
80%. After the product gas is cooled, a
second polishing reactor completes the
methanation reaction to achieve the SNG
product quality required for the injection
into the natural gas grid.
" In August 2018, it was shown that
the SNG gas qualities achieved by the
methanation
system were extremely
promising. Although there were challenges
in automatically maintaining the
exact CO2/H2 ratio over longer time periods,
methane concentrations of more
than 98% were reached and reproduced
repeatedly, " said Föcker in the project's
2019 commissioning report. Commissioning
of the plant was considered finalized
when the project achieved " first gas
injection " into the ONTRAS grid in January
2019, he explained. By March 2019,
the project was producing up to 1,400
m3 of SNG per day, comparable to about
14,500 kWh of energy, Uniper said.
Actionable Results
Following
its
24-month
review,
STORE&GO, too, deemed the overall
Falkenhagen project a success-though
it noted some limitations. " The plant
reached an overall PtG efficiency of
53% based on the measurement results.
The methanation unit reached an
overall methanation efficiency of 85%
(including heat usage and electricity demand), "
it said. The relatively low overall
PtG efficiency was attributed to poor
www.powermag.com
performance of the existing alkaline
electrolyser. As a result, STORE&GO
suggested the greatest optimization
potential in Falkenhagen existed in using
a state-of-the-art electrolyser, which
could reach a PtG efficiency of 69%.
The methanation unit, meanwhile, was
reportedly capable of producing highquality
SNG with a volumetric methane
content greater than 99% over a wide
range of loads (from 40% to 100%), it
said. " Also, during load changes, the
SNG quality always fulfilled the limits for
injection of the gas. "
Still, for Uniper, the project's larger success
opens up new and lucrative business
prospects for the use of " green "
methane and hydrogen. Not only do
the gases utilize excess wind and solar
power, they can be used for the supply
of heat and power, manufacturing, and
transportation, it said. " At the same time,
the unrestricted use of existing natural
gas infrastructure opens up new opportunities
for the transport and storage of energy
generated from renewable sources.
The stored energy is always available as
needed, even when the sun and wind are
not available to the required extent. "
Uniper now plans to follow up these
projects by shaping a green hydrogen
economy in Germany's " chemical triangle, "
at Reallabor Bad Lauchstädt, and
then by installing hydrogen-compatible
gas turbines. In tandem, notably, Uniper
is exploring a concept for the use
of regeneratively produced hydrogen in
the refinery process in cooperation with
a refinery site in Lingen. And it is also
involved in " living lab " support projects
" Energiepark Bad Lauchstädt " and " Norddeutsches
Reallabor, " where the largescale
demonstration of sector coupling
and a post-use concept for the WindGas
product will be developed. ■
-Sonal Patel is a POWER senior
associate editor.
31

http://www.powermag.com

POWER September 2020

Table of Contents for the Digital Edition of POWER September 2020