Started in May 2016, it is a five-year demonstration project involving 12 participants based across six EU countries and coordinated by the Aragon Hydrogen Foundation (FHA).
Within BIG HIT, the otherwise curtailed energy generated from tidal and wind turbines (on average more than 30% of the annual renewable output in Orkney) is being used to produce ‘green’ hydrogen from electrolysis, which is then transported across the Orkney islands and used as fuel for transport, heat and power community end-uses.
Formic acid - containing 4.4 weight % of H2, that is 53 g
hydrogen per liter - is suitable for H2 storage.3 We
have shown that in aqueous solutions it can be
selectively decomposed into CO-free (CO < 10 ppm)
carbon dioxide and H2; an industrial prototype has been
built. The reaction4 takes place under mild experimental
conditions and it is able to generate high pressure H2. In
the other hand, the chemical transformation of
carbon dioxide into useful products becomes
increasingly important as carbon dioxide levels in the
atmosphere continue to rise as a consequence of
human activities. The direct hydrogenation of carbon
dioxide into formic acid5 can take place using a
homogeneous ruthenium catalyst, in aqueous solution
and in dimethyl-sulphoxide, without any additives.
The hydrogenation of carbon dioxide to formic acid and the disproportionation of formic acid into methanol can be realized in a homogeneous catalytic reaction6 at ambient temperatures and in aqueous, acidic solution. The formic acid yield is maximized in water without additives, while acidification results in complete (98%) and selective (96%) formic acid disproportionation into methanol.7
1M. Grasemann and G. Laurenczy, Energy Environ. Sci., 2012, 5, 8171–8181.
2A. Dalebrook, W. Gan, M. Grasemann, S. Moret, G. Laurenczy, Chem. Comm., 2013, 49, 8735-8751.
3 a)Céline Fellay, Paul J. Dyson, Gábor Laurenczy, Angew. Chem. Int. Ed., 2008, 47, 3966-3968;
b)Patents WO2008047312 and WO2014134742A1
4A. Boddien, D. Mellmann, F. Gaertner, R. Jackstell, H. Junge, P. J. Dyson, G. Laurenczy, R. Ludwig, M. Beller, Science 2011, 333, 1733-1736.
5 a)S. Moret, P. J. Dyson, G. Laurenczy, Nature Comm., 2014, 5, 4017; DOI: 10.1038/ncomms5017;
6 a)K. Sordakis, A. Tsurusaki, M. Iguchi, H. Kawanami, Y. Himeda, G. Laurenczy, Chem. Eur. J. 2016, 22, 15605-15608;
7K. Sordakis, C. Tang, L. K. Vogt, H. Junge, P. J. Dyson, M. Beller, G. Laurenczy, Chemical Reviews, 2018, 118, 372-433; DOI: 10.1021/acs.chemrev.7b00182
Fuel cell waste heat and post-combustion heat has been used to maintain and control fuel processing
temperature. We obtained a stable hydrogen production at part-load and full load. Between 40% and
45% efficiency obtained from 400 to 950W electrical output. This world first system demonstrate the
potential of the technology for applications for different fuel cell technologies, PEM and SOFCs.
Providing a liquid fuel, formic acid can be reformed with low temperature heat, allowing simple,
lightweight and self-pressurizing hydrogen fuel supply. This latter property allows to design efficient
high pressure hydrogen filling stations.
Formic acid can bring benefits to a new hydrogen economy, offering a good opportunity to store2 at the same time hydrogen and heat in a liquid phase.
1I. Youranov and al. , ACS Sustainable Chem. Eng. 2018, 6, 5, 6635-6643 .
2K. Sordakis, A. Dalebrook, G. Laurenczy, ChemCatChem, 2015, 7, 2332 – 2339.
- Temporal balancing arises due to the inevitable mismatch between renewable electricity
production and demand as a consequence of day/night cycles, weather effects and seasonal
- Spatial balancing is necessary resulting from a possible mismatch between locations of electricity production and consumption.
Energy conversion technologies with storage, such as Power-to-Product (P2X) technologies, represent potential solutions for this multi-dimensional balancing challenge and to enhance the energy system’s flexibility. The term P2X refers to energy conversion technologies that produce synthetic gases, fuels or energy feedstock products using an electro-chemical conversion process. There is a variety of energy outputs that can be produced in P2X technologies, with methane produced in Powerto- Gas (PTG) systems being one of the most prominently discussed options. As such, P2X technology not only offers a possible flexibility solution for the electricity system, they can also connect the electricity sector with other sectors of the economy in a new way (e.g. the transport sector and industry). With the aim to derive a technical, economic and environmental assessment of Power-to-X technology with its systemic interdependencies, this research work specifically investigates the gas market, the mobility sector and the electricity market including the corresponding regulatory and innovation policy aspects. From the analysis we derive essential factors that can contribute to the successful implementation of this technology and to arrive at profitable business cases, as well as key energy market segments for P2X technology.
Cell designs for the electrochemical reduction of CO2 from gas phase at low temperature were
developed and investigated, and the critical elements for an efficient process were identified. Various
types of polymeric membrane and ionomers were used to build membrane electrode assembly (MEA)
adapted for CO2 reduction in gas phase: protonic and anion exchange membrane, bipolar membrane
and a modified bipolar like membrane configuration. Configurations using anion exchange ionomer in
the cathodic catalytic layer in contact with an anion exchange membrane allow for a great
enhancement of the cathode reaction selectivity towards CO. However, a severe problem was
identified when co-electrolysis is performed using only an anion exchange membrane: this type of
membrane acts as a CO2 “pump” meaning that for each molecule of CO2 reduced at the cathode, one
or two CO2 molecules are produced at the anode by oxidation of the carbonate/bicarbonate anion
transported in the membrane. A bipolar membrane system was shown to soften this problem, but only
a newly developed cell design was able to fully prevent the parasitic CO2 pumping. This new cell
configuration made use of a standard Nafion® cation exchange membrane in combination with a
modified cathode catalyst layer containing an additional thin film of alkaline ionomer coated on the
cathode catalyst layer in order to prevent direct contact between the cathode catalyst and the acidic
cation exchange membrane2. Using this cell configuration, the faradaic efficiency of an alkaline
environment towards CO2 reduction is maintained, the parasitic CO2 pumping to the anode side is
completely suppressed, and the overall cell voltage efficiency is highly improved due to the low ohmic
resistance of the acidic membrane, i.e. at -100 mA/cm2, 2.8 V are needed in a full co-electrolyser
system using the new developed cell design compared with 3.9 V when a commercial bipolar
membrane is used.
1 Durst, J.; Rudnev A.; Dutta, A.; Fu, Y.; Herranz, J.; Kaliginedi, V.; Kuzume, A.; Permyakova, A.A.; Paratcha, Y.; Broekmann, P.; Schmidt, T.J. Chim Int J Chem 2015;69:769–76.
2Pătru, A.; Binninger, T.; Pribyl, B.; Schmidt, T.J. Co-electrolysis cell design for efficient CO2
Within SCCER HaE, we are investigating cathode materials for next-generation lithium-ion batteries. Our research focuses on nickel-rich layered oxides with reduced cobalt content. Increasing the nickel content in layered oxides offers significantly improved lithium storage capacity, but at the price of reduced cycling stability. Employing sacrificial electrolyte additives, we were able to demonstrate a NMC811/graphite full cell with a capacity retention of >90% after 200 cycles.2
To improve operational safety and reduced cell production costs, we are also developing concepts to
replace the liquid electrolytes based on highly-flammable organic solvents in lithium- and sodium-ion
batteries by non-flammable aqueous electrolytes. The major disadvantage of water as electrolyte
solvent is its intrinsically narrow electrochemical stability window (thermodynamically only 1.23 V)
limiting maximum cell voltage and consequently the batteries energy density. We recently discovered
an aqueous sodium-ion electrolyte system with a much wider electrochemical stability window of 2.6 V
3 enabling us to demonstrate a NaTi2(PO4)3/Na3(VOPO4)2F full cell with 85% capacity
retention after 500 cycles.4
We are also developing solid-state electrolytes for all-solid-state batteries based on closoborate salts. We were able to stabilize a highly ionically conducting phase at room temperature using anion mixing reaching ionic conductivities on the order of 1 mS/cm at room temperature.5 This achievement further enabled us to assemble an all-solid-state battery with a sodium metal anode and a NaCrO2 cathode delivering a capacity retention of 85% after 250 cycles bringing this class of materials to a technology readiness level comparable to other current all-solid-state battery concepts.6
We are also investigating ionic transport in Na-β’’-Al2O3 ceramics, an archetypical ion conductor, commercially employed as solid-state electrolytes in high-temperature sodium-nickel-chloride and sodium-sulfur batteries, but also promising for applications in future all-solid-state batteries. Although already discovered in the 1960s, Na-β’’-alumina ceramics are challenging to prepare with the desired composition, phase content, and microstructure. These parameters have a direct impact on the ion conductivity, which varies by a factor of 100 at a given temperature when comparing different studies. We developed a comprehensive model identifying the dominant factors governing ion transport in these materials.7
2 Vidal Laveda J., Low J. E., Stilp E., Dilger S., Battaglia C., submitted.
3 Duchêne L., Kühnel R.-S., Rentsch D., Remhof A., Hagemann H., Battaglia C., Chem. Comm., 2017, 53, 4195.
4 Duchêne L., Kühnel R.-S., Stilp E., Cuervo Reyes E., Remhof A., Hagemann H., Battaglia C., Energy Environ. Science, 2017, 10, 2609.
5 Kühnel R.-S., Reber D., Battaglia C., ACS Energy Lett., 2017, 2, 2017.
6 Reber D., Kühnel R.-S., Battaglia C., submitted.
7 Bay M.-C. Heinz M. V. F., Figi R., Schreiner C., Basso D., Zanon N. Vogt U. F., Battaglia C., submitted.
To increase storage density and therefore reduce storage
volume an ice storage allows the storing of solar heat in a compact volume for the later use as source
for a heat pump that provides heat for a building – or as a sink in a cooling system. As an example a
novel ice storage with 2m3 water volume is described which contains heat exchanger plates for
extracting the latent heat. A numerical model for the heat exchanger plates that was implemented into
the Polysun system simulation software will be presented. The model allows the numerical simulation
of an ice storages according a field installation with heat exchanger plates. The field installation will be
used for the validation of the system template. The core elements of the developed model are the heat
transfer values (𝑈𝑈𝐴𝐴𝑖𝑖) between the brine inside the heat exchangers plates and the water inside the
storage2. The UA-values limit the maximum power that can be extracted from or injected to the
storage (ice or fluid) and thus, have a large influence on the simulation results. Sensible heating,
sensible cooling as well as icing are treated individually as they all inflict different physical dynamics in
the fluid on small scales that effect the overall heat (power and energy) balance. In all states, the UAvalues
are derived from general heat transfer correlations. In the model all UA-values represent the
values associated to one control volume (1 knot), while the heat exchanger has a fixed number of
control volumes 12 - of 12 knots - and the water volume is modelled as 1 knot. As a further step in
decreasing thermal energy storage volume an absorption desorption seasonal thermal energy storage
system – a thermo-chemical storage could be applied. Such a closed sorption heat storage based on
water vapour absorption in aqueous slat solutions theoretically achieves a significantly higher
volumetric energy density compared to conventional hot water or ice storage systems. To this purpose,
the development of an absorber-desorber unit - a prototype designed for a power output of 10 kW – is
presented. In this work, the influence of two main parameters on the exchanged power is evidenced.
Furthermore, a comparison with the results of the initial numerical model used to design the heat and
mass exchanger is carried out. Physical explanations of the diverging results encountered during the
absorption process as well as an improved heat transfer coefficient model for the desorption process
1Battaglia, M.; Haller, M. Y. Stratification in large thermal storage tanks. Eurosun 2018, September 10 – 13, Rapperswil, Switzerland.
2Philippen, D.; Battaglia M.; CarbonellD.; Thissen B.; Kunath L. Validation of an ice storage model and its integration into a solar-ice system. Eurosun 2018, September 10 – 13, Rapperswil, Switzerland.
3Daguenet-Frick, X.; Gantenbein, P.; Müller, J.; Fumey B.; Werber, R. Seasonal thermochemical energy storage: comparison of the experimental results with the modelling of the falling film tube bundle heat and mass exchanger unit. Renewable Energy 110 (2017) 162-173.