The Workshop on Thermochemical Solar Conversion was held in Seville on October 18-19 where the SOCRATCES project was presented.

1. This Project has received funding from European
Commission by means of Horizon 2020,the EU
Framework Programme for Research & Innovation,
under Grant Agreement no.727348.
This presentation reflects only the author's
view and that the INEA is not responsible
for any use that may be made of the
information it contains.
SOCRATCES project
Solar Calcium-Looping Integration for
Thermochemical Energy Storage

2. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Outline
• Introduction: project context
• The SOCRATCES project
• Technical approach
• Expected results

3. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Workshop CSIC 20/11/2017 3
CSP PLANTS UNDER OPERATION AND CONSTRUCTION
20 plantas (1.7 GWe) 50 plantas (2.3 GWe)
2 plantas (180 MWe)
2 plantas (350 MWe)
3 plantas (300 MWe)
4 plantas (400 MWe)
3 plantas (225 MWe)
4 plantas (275 MWe)
23 plantas (1349 MWe)
2 plantas (200 MWe)
1 planta (100 MWe)
2 plantas (370 MWe)
2 plantas (93 MWe)
2 plantas (231 MWe)
1 planta (10 MWe)
Operating
Construction/
promotion
Introduction SOCRATCES project Technical approach Expected results

4. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Operation
(4939 MWe)
Tower
(623.7 MWe)
PT
(4130 MWe)
With Storage
(224.8 MWe)
Without Storage
(390.6 MWe)
With Storage
(1709.3 MWe)
Without Storage
(2251.1 MWe)
With Storage (42%)
Construction/
planed
(10641 MWe)
Tower
(6132 MWe)
PT
(3683 MWe)
With Storage
(2447 MWe)
Without Storage
(625 MWe)
With Storage
(2129 MWe)
Without Storage
(307 MWe)
With Storage (83%)
CSP PLANTS UNDER OPERATION AND CONSTRUCTION
Introduction SOCRATCES project Technical approach Expected results

5. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
• Solar photovoltaics (PV) plants are today a competitive alternative to power plants based on fossil fuels.
• Cost reduction in PV modules, scalability (from kW to MW) and ease of installation
IRENA (2016b), Renewable Capacity Statistics 2016
Power production in the world
Introduction SOCRATCES project Technical approach Expected results

6. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
6
Introduction SOCRATCES project Technical approach Expected results

7. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Daily power production. “Duck curve” by the California
Independent System Operator (CAISO). Conventional power
generation technologies back-up.
• Renewables dispatchability still remains as
the major challenge to be overcome due to
intrinsic variability of solar energy.
• By 2030 the expected PV installed
capacity will be nine times higher than
in 2013.
Introduction SOCRATCES project Technical approach Expected results

8. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
8
• Dispatchability
• Integration with thermal energy storage
• Potential for waste heat integration
Introduction SOCRATCES project Technical approach Expected results
CSP

9. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Introduction SOCRATCES project Technical approach Expected results
Research priority lines
Increase efficiency and reduce generation, operation and maintenance costs
Improve environmental profile
Improve dispatchability
• Improve design and component manufacturing processes
• O&M costs reduction
• Enhance overall plant efficiency
• New heat transfer fluids (HTFs)
• ENERGY STORAGE
• Forecasting tools
• Reduction of water consumption
• Currently, over 40% of CSP plants in operation have
energy storage systems. Among which are planned/ in
development, roughly 80%
• In most of the cases, energy storage based on molten
salts systems
Solar Thermal Electricity Strategic research
agenda 2020-2025 (ESTELA, 2012)

10. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Introduction SOCRATCES project Technical approach Expected results
• CSP already installed~ 5 GWe
Renewable Power Generation
Costs in 2017 (IRENA 2017)
Technology Roadmap Solar Thermal Electricity (IEA 2014)
According to IEA scenarios
260 GWe by 2030
980 GWe by 2050
R&D
High technology evolution potential

11. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Introduction SOCRATCES project Technical approach Expected results
Molten-salt based plants
Mature technology
Proper integration in both CCP and tower plants
Acceptable efficiency
Currently, up to 16 hours of storage
Cost
O&M issues (Corrosion, toxicity)
Maximum temperature limitation
Minimum temperature limitation
Alternative energy storage systems?
Thermochemical energy storage?

12. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
• Recently Tesla built a Li-ion battery
(100MW/129MWh) as demonstrator of
large scale penetration of RES in Australia.
• However the technology is based on scarce
raw materials and in direct competition for
them with other applications as the
electrical vehicle.
• By 2030 the expected PV installed capacity
will be nine times higher than in 2013.
• In addition to resource scarcity, another
major challenge of batteries is to prolong
the lifetime of the system. Because of the
variability of solar input, batteries are
subjected to continuous charge and
discharge cycles, which increases their
complexity and cost for large scale
facilities.
Introduction SOCRATCES project Technical approach Expected results

13. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
¿Is there enough Lithium/ Cobalt for massive implementation of electricity
systems? (power, automotive, houses, IT,...)
Nature Reviews Materials
• Electrochemical Energy Storage Systems (ECES), best positioned systems . High efficiencies:
- 85-95% efficiency for Li-ion batteries to 60-65% efficiency for Polysufide bromide batteries.
• Batteries lifetime. Because of the variability of solar input, batteries are subjected to continuous charge and
discharge cycles, which increases their complexity and cost for large scale facilities.
Introduction SOCRATCES project Technical approach Expected results

14. Solar Calcium looping integRAtion
for Thermo-Chemical Energy Storage
DEVELOPING THE NEXT GENERATION TECHNOLOGIES OF
RENEWABLE ELECTRICITY
https://socratces.eu/

15. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Project Scope and Goals
Introduction SOCRATCES project Technical approach Expected results
The Ca-Looping (CaL) process based upon the reversible carbonation/calcination
of CaO is one of the most promising technologies for thermochemical energy
storage (TCES).
⟶
∆ =+178 kJ/mol
⟶
∆ =-178 kJ/mol
calcination
carbonation

16. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Global Objective
Develop a prototype that will reduce the core risks of scaling up the technology and
solve challenge
R & D
Engineering
&
Construction
Scaling-Up
Assessment
Introduction SOCRATCES project Technical approach Expected results

17. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Project Scope and Goals
Introduction SOCRATCES project Technical approach Expected results
SOCRATCES is aimed at demonstrating the feasibility of CSP-CaL integration by
erecting a pilot-scale plant that uses cheap, abundant and non-toxic materials as
well as mature technologies used in the industry, such as solid-gas reactors, cyclones
or gas-solid heat exchangers.
SOCRATCES global objective is to develop a prototype that will reduce the core
risks of scaling up the technology and solve challenges; further understand and
optimise the operating efficiencies that could be obtained; with the longer-term goal
of enabling highly competitive and sustainable CSP plants.

18. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
SOCRATCES Technical Approach
New
materials
Reactions
(Ch/Ph)
Power
Systems
technologies
Systems
integration
& control
Systems
development
Introduction SOCRATCES project Technical approach Expected results

19. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
SOCRATCES Consortium
SOCRATCES is an integral and multidisciplinary approach where different knowledge
areas are involved
Multidisciplinary
R&D groups
SMEs
Companies
Associations and Stakeholders offer the opportunity for wide dissemination of the
project and will link the consortia with the relevant industries in Europe
Introduction SOCRATCES project Technical approach Expected results

20. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Related projects
Solar calcination
Introduction SOCRATCES project Technical approach Expected results
Energy storage
High-temperature solar receivers
Carbon Dioxide Shuttling Thermochemical
Storage Using Strontium (ELEMENTS; DOE)
Regenerative Carbonate-Based Thermochemical
Energy Storage System for Concentrating Solar
Power (ELEMENTS; DOE)
Demonstration of High-Temperature Calcium-Based
Thermochemical Storage System for use with
Concentrating Solar Power Facilities (APOLLO;
DOE)
CSP2: Concentrated solar power in particles
(H2020)
TCSPower: Thermochemical Energy Storage
for CSP Plants (H2020)
SOLPART: High temperature Solar-Heated Reactors
for Industrials Production of Reactive Particulates
(H2020)
NEXT-CSP: High Temperature concentrated solar
thermal power plant with particle receiver and direct
thermal storage (H2020)
SOCRATCES: Solar calcium-looping integration for
thermo-chemical energy storage (H2020)

21. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Introduction SOCRATCES project Technical approach Expected results
Why CaCO3/CaO?
Group Example
Hydrogen systems
∆ ↔
2
∆ ↔
Carbonate systems
∆ ↔
∆ ↔
∆ ↔
Hydroxide systems
∆ ↔
∆ ↔
∆ ↔
Redox systems
∆ ↔
2
2 ∆ ↔ 2
2 ∆ ↔ 6
Ammonia systems 2 ∆ ↔ 3
Organic systems " ∆
↔ 3
With a side reaction:
"
↔ ∆
∆ ↔ 2 2
With a side reaction:
∆ ↔
Sulfur systems
∆ ↔
1
2
A proper TCES system for CSP storage should
meet (Wentworth and Chen, 1976)
• The reaction for storing the energy should occur with a high
yield at T < 1000°C
• The reverse reaction for generating heat should occur with a
high yield at T >555°C
• Large AH° to maximize storage capacity
• Reaction should be completely reversible with no side
reactions
• The compounds should be commercially available. Low cost
• Reactions should be fast enough

22. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Thermochemical energy storage candidates
Group Example
Hydrogen systems
∆ ↔
2
∆ ↔
Carbonate systems
∆ ↔
∆ ↔
∆ ↔
Hydroxide systems
∆ ↔
∆ ↔
∆ ↔
Redox systems
∆ ↔
2
2 ∆ ↔ 2
2 ∆ ↔ 6
Ammonia systems 2 ∆ ↔ 3
Organic systems " ∆
↔ 3
With a side reaction:
"
↔ ∆
∆ ↔ 2 2
With a side reaction:
∆ ↔
Sulfur systems ∆
↔
1
2
• Cheap
• Widely available
• Environmental friendly
• Non corrosive. Non dangerous
• High reaction temperatures
Introduction SOCRATCES project Technical approach Expected results

23. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Calcium Carbonate for
thermochemical energy storage
⟶
∆ =+178 kJ/mol
⟶
∆ =-178 kJ/mol
calcinación
carbonatación
Calcium-Looping (CaL)
Introduction SOCRATCES project Technical approach Expected results

24. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Calcium-Looping: CaCO3/CaO
Energy input storage Energy release
Introduction SOCRATCES project Technical approach Expected results

25. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Introduction SOCRATCES project Technical approach Expected results

26. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Calcium-Looping: CaCO3/CaO
calcination reaction is the basis of the cement industry
Dates back to 6500 B.C., when Syrians discovered lime as a building material
Introduction SOCRATCES project Technical approach Expected results

27. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Previous studies about calcination under
different atmospheres, etc.
27
Patent use of Ca compound for CO2
capture
Williams, R. Hydrogen Production. U.S. Patent 1,938,202, 1933
1933
1999CO2 capture from CaO
T. Shimizu, T. Hirama, H. Hosoda, K. Kitano, M. Inagaki and K. Tejima, A
Twin Fluid-Bed Reactor for Removal of CO2 from Combustion Processes,
Chem. Eng. Res. Des., 1999, 77(1), 62–68
2016
CaL Pilot plants CCS
CCS Project CaOling
1.7Mw prototype en la Pereda
2009
Calcium-looping on SCOPUS
CaL R&D
⟶
⟶
Introduction SOCRATCES project Technical approach Expected results

28. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Calcium-Looping: CaCO3/CaO
Introduction SOCRATCES project Technical approach Expected results
60s
• CaCO3/CaO proposed as solar energy storage system
80s
• Solar calciners
90s
• CaL as post-combustionCO2 capture system
2010s
• CSP-CaL integration schemes
Flammant et al. (1980)
CaOLING project (La Pereda)

29. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
CSP-CaL: Advantages and opportunities
NH3/N2
CH4/H2O
SO3/SO2
CaO/H2O
Li2/H2O
NH4HSO4/NH3
CaO/CO2
SrO/CO2
0
500
1000
1500
2000
2500
3000
3500
4000
4500
100 300 500 700 900 1100 1300
Volumentricenergydensity(MJ/m3)
Turning temperature (°C)
1. High energy storage density
2. Products can be stored at ambient temperature
Lower thermal losses
Lower utilities consumption
Possibility for storing energy in long-term
Molten salts→ T minimum storage ~200ºC
Introduction SOCRATCES project Technical approach Expected results

30. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
3. Materials limestone, dolomite
Neccesary conditions for the massive development
of any thermal storage system
Low Price
Widely available throughout he world Non-toxic
Non-corrosive
Introduction SOCRATCES project Technical approach Expected results
CSP-CaL: Advantages and opportunities

31. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Introduction SOCRATCES project Technical approach Expected results
4. High temperature for releasing energy
Energy production at very high temperature (650-1000ºC) depending of CO2 partial presssure
Integration of high-efficiency power cycles
0
0,01
0,02
0,03
0,04
0,05
0,06
0,07
0,08
0,09
0,1
400 600 800 1000
Reactionrate(1/s)
T ºC
P=3atm
P=2atm
P=1atm
CSP-CaL: Advantages and opportunities

32. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Introduction SOCRATCES project Technical approach Expected results
32
Solids (CaCO3 /CaO)
CaO
CO2
g4
CaO
storage
CaCO3/CaO
storage
HE4
g5
s1
c1
g6
M-TURB
g7
g8
g3
HE5
g9
HE3
g2
CO2
storage
HE1
HE2
g1
I-TURB
COMP
g10
CARBONATOR
Solids (CaCO3 /CaO)
CaO
CO2
CaO
storage
CaCO3/CaO
storage
s1
c1
g4
g3
g2
CO2
storage
HE1
HE2
g1
I-TURB
CARBONATOR
To storage
Power
block
carbonationheat
Direct (Brayton CO2)
Indirecta
5. Direct and indirect integration of power cyles
Design flexibility
High temperatura of teactio
CSP-CaL: Advantages and opportunities

33. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Introduction SOCRATCES project Technical approach Expected results
33
30%
32%
34%
36%
38%
40%
2 2,3 2,6 2,9 3,2 3,5 3,8 4,1 4,4 4,7 5
overallplantefficiency
PR
case 1 case 3 (3 intercoolers)
CSP-CaL: Advantages and opportunities

34. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Introduction SOCRATCES project Technical approach Expected results
34
5. Materials and equipment already used at industrial scale
- Closeness with the cement industry
- Calciner (particles solar receiver)
- Carbonator: Fluidized bed, entrained flow reactor, etc.
- Closed Brayton cycle for power production
- High-temperature solids handling
- Cyclones
- Storage vessels
Arias et al. (2013)
BAT for cement industry (2013)
CSP-CaL: Advantages and opportunities

35. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
1. High-temperatura solar receiver
i) Enough residence time to calcination occurs
ii) Adequate particles size for proper handling
iii) The system has to be closed to avoid CO2 losses
iv) Thermal gradient over the particles must be avoided
v) Continuous operation
Limestone calcination only occurs fast
under high CO2 partial pressure for
reaction temperatures around 930-950ºC.
Technological challenge
Introduction SOCRATCES project Technical approach Expected results
CSP-CaL: Challenges

36. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Calcium-Looping: Challenges
2. Multicyclic CaO conversion
CaO deactivation is highly dependent
on the reactor conditions, CaO
precursors and particles size
Introduction SOCRATCES project Technical approach Expected results

37. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Introduction SOCRATCES project Technical approach Expected results
• Prototype demonstration of capacity for energy storage. System tested at TRL5.
• Validated kinetics models for both calcination and carbonation.
• Successful calcination at prototype scale by means of flash calcination technology.
• Successful carbonator design with possibility to scale-up.
• Particles attrition, agglomeration and fouling analysis.
• Successful solids conveying and control system management.
• At commercial scale design, high CaL-power cycle efficiencies are expected (>45%)
• At commercial scale, energy storage TCES cost expected are <12€/kWh

38. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
Prototipe constrcution in Seville (2019-2020)
Introduction SOCRATCES project Technical approach Expected results

39. This Project has received funding from European Commission
by means of Horizon 2020,the EU Framework Programme for
Research & Innovation, under Grant Agreement no.727348.
CaO precursors:
Low price
wide availability
harmlessness
Reactants and products can be
stored at ambient temperature
Carbonation for generating
heat ~650-100ºC
High efficient
generation of
electricity
High energy density to
maximize storage capacity
Materials and process equipment
Ambient
temperature
Well-known in the
cement industry
SOCRATCES’ highlights

40. Solar Calcium looping integRAtion
for Thermo-Chemical Energy Storage
THANK YOU FOR
YOUR ATTENTION
https://socratces.eu/

41. Solar Calcium looping integRAtion
for Thermo-Chemical Energy Storage

42. Solar Calcium looping integRAtion
for Thermo-Chemical Energy Storage