The SOCRATCES project wast presented in the 24th SolarPACES Conference which took place on October 2-5, 2018 in Casablanca (Morocco)

1. This Project has received funding from European
Com m ission by m eans of Horizon 2020,the EU
Fram ework Program m e for Research & Innovation,
under Grant Agreem ent no.727348.
This presentation reflects only the author's
view and that the INEA is not responsible
for any use that m ay be m ade of the
inform ation it contains.
SOCRATCES project
Solar Calcium-Looping Integration for
Thermochemical Energy Storage
Ricardo Chacartegui, Carlos Ortiz, Luis A. Pérez-Maqueda, Thomas Hills, Luis M. Romeo, Gerhard
Schories, Antonia Lorenzo, Marco Grippa, Vittorio Verda, Angeliki Lemonidou and Jose Manuel Valverde

2. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent no.727348.
Outline
• Introduction: project context
• The SOCRATCES project
• Technical approach
• Expected results

3. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent 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

4. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent no.727348.
Introduction SOCRATCES project Technical approach Expected results
Research priority lines
Ø Increase efficiency and reduce generation, operation and maintenance costs
Ø Improve environmental profile
Ø 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 is based on
molten salts systems
Solar Thermal Electricity Strategic research
agenda 2020-2025 (ESTELA, 2012)

5. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent no.727348.
Introduction SOCRATCES project Technical approach Expected results
Molten-salt based plants
Mature technology
Proper integration in both PT 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?

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

7. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent 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

8. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent 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 (~10 kWth) 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.

9. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent 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
New
materials
Reactions
(Ch/Ph)
Power
Systems
technologies
Systems
integration
& control
CSP
systems

10. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent no.727348.
SOCRATCES Consortium
SOCRATCES is an integral and multidisciplinary approach where different knowledge
areas are involved
ü Multidisciplinary
R&D groups
ü SMEs
ü 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

11. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent 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)

12. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent no.727348.
Introduction SOCRATCES project Technical approach Expected results
Why CaCO3/CaO?
Group Example
Hydrogen systems
!"# + ∆"& ↔ ! +
(
2
"*
!+"* ( - ) + ∆"& ↔ !+( - ) + "* ( / )
Carbonate systems
!012 ( - ) + ∆"& ↔ !1( - ) + 01* ( / )
03012 ( - ) + ∆"& ↔ 031( - ) + 01* ( / )
45012 ( - ) + ∆"& ↔ 451( - ) + 01* ( / )
Hydroxide systems
! 1" * - + ∆"& ↔ !1( - ) + "* 1 ( / )
!+ 1" * - + ∆"& ↔ !+1( - ) + "* 1 ( / )
03 1" * - + ∆"& ↔ 031( - ) + "* 1 ( / )
Redox systems
!6 17 ( - ) + ∆"& ↔ 8!( - ) +
9
2
1* ( / )
2:31* ( - ) + ∆"& ↔ 2:31( - ) + 1* ( / )
20;2 1< ( - ) + ∆"& ↔ 60;1( - ) + 1* ( / )
Ammonia systems 2>"2 ( / ) + ∆"& ↔ >* ( / ) + 3"* ( / )
Organic systems 0"< ( / ) + "* 1( @ ) + ∆"&
↔ 01( / ) + 3"* ( / )
With a side reaction:
01( / ) + "* 1( @ )
↔ 01* ( / ) + "* ( / ) + ∆"&
0"< ( / ) + 01* ( / ) + ∆"& ↔ 201( / ) + 2"* ( / )
With a side reaction:
01* ( / ) + "* ( / )
+ ∆"& ↔ 01( / ) + "* 1 ( / )
Sulfur systems
"* 41< ( / ) + ∆"& ↔ 41* ( / )
+ "* 1 ( / ) +
1
2
1* ( / )
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 at T >550°C
• Large ∆H° to maximize storage capacity
• The compounds should be commercially available. Low cost
• Reactions should be fast enough

13. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent 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

14. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent 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)

15. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent no.727348.
Calcium-Looping: CaCO3/CaO
Energy input storage Energy release
Introduction SOCRATCES project Technical approach Expected results

16. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent no.727348.
WP3 WP2 WP4
Research and design
laboratory
WP5: System Integration and Control
WP1: Project Management
WP6: Engineering and prototype construction
WP7: Validation and test
WP8: LCA, Risk analysis… WP9: Dissemination & Exploitation
Introduction SOCRATCES project Technical approach Expected results

17. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent 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/m
3
)
Turning tem perature (°C)
1. High energy storage density
2. Products can be stored at ambient temperature
ü Lower thermal losses
ü Lower utilities consumption
ü Possibility for storing energy in long-term
Molten salts→ T minimum storage ~200ºC
Introduction SOCRATCES project Technical approach Expected results

18. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent no.727348.
3. Materials à limestone, dolomite
Necessary conditions for the massive development
of any thermal storage system
Low Price
Widely available throughout the world Non-toxic
Non-corrosive
Introduction SOCRATCES project Technical approach Expected results
CSP-CaL: Advantages and opportunities

19. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent no.727348.
Introduction SOCRATCES project Technical approach Expected results
4. High temperature for releasing energy
ü Energy production at very high temperature (650-1000ºC) depending of CO2 partial presssure
ü 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
40 0 60 0 80 0 10 00
Reactionrate(1/s)
TºC
P=3at m
P=2at m
P=1at m
CSP-CaL: Advantages and opportunities

20. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent no.727348.
Introduction SOCRATCES project Technical approach Expected results
20
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

21. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent no.727348.
1. High-temperature 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

22. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent 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

23. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent 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

24. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent no.727348.
Prototype construction in Seville (2019-2020)
Introduction SOCRATCES project Technical approach Expected results

25. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent no.727348.
1
2
3
5
4
CaO precursors:
ü Low price
ü wide availability
ü harmlessness
Reactants and products can be
stored at ambient temperature
Carbonation for generating
heat ~650-1000ºC
ü High efficient
generation of
electricity
High energy density to
maximize storage capacity
Materials and process equipment
Ambient
temperature
ü Well-known in the
cement industry
SOCRATCES’ highlights

26. Solar Calcium looping integRAtion
for Thermo-Chemical Energy Storage
THANK YOU FOR
YOUR ATTENTION
https://socratces.eu/
cortiz7@us.es
This Project has received funding from European
Com m ission by m eans of Horizon 2020,the EU
Fram ework Program m e for Research & Innovation,
under Grant Agreem ent no.727348.
This presentation reflects only the author's
view and that the INEA is not responsible
for any use that m ay be m ade of the
inform ation it contains.

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

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

29. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent no.727348.
Calcium-Looping: Ventajas y oportunidades
Introduction SOCRATCES project Technical approach Expected results
29
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
Directa (Brayton CO2 regenerativo)
Indirecta
5. Integración directa o indirecta de ciclos de potencia
ü Flexibilidad para el diseño
ü Punto de partida: Alta temperatura de reacción
ESTA DIAPOSITIVA LA PODRIA DEJAR PARA LA
OTRA PRESENTACIÓN

30. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent no.727348.
Calcium-Looping: Ventajas y oportunidades
Introduction SOCRATCES project Technical approach Expected results
30
IDEM
g1
Solids (CaCO3 /CaO)
CaO
CO2
g8
Solar receiver
calciner
HRSG
g2
steam
v2
v3
ST
cond
v4
P1
v1
cooler-1
g3
g7a
HXG
g9
Carbonator
s1
Active 8h/day (sun mode)
Active 16h/day (night mode)
Active 24h/day
g4
g7b
GS-HE1
s3
g1-1
GS-HE3
GS-HE2 s1-1
g8-1 g8-2
g9-1
g9-2
c1
s2
c2
CaO
storage
Lock
hopper
CO2 storage
CO2
vessel
g5-2
cooler-2
g5
heater
HPS-COMP
HPS-TURB
g6
CO2 storage
CO2
vessel
g5-2
cooler-2
g5
heater
HPS-COMP
HPS-TURB
g6
M-TURB
g10
g11
g12
g13
cooler-3
s1-2
CaCO3/CaO
storage
M-COMP
g1
Solids (CaCO3 /CaO)
CaO
CO2
g8
Solar receiver
calciner
HRSG
g2
steam
v2
v3
ST
cond
v4
P1
v1
cooler-1
g3
g7a
HXG
g9
Carbonator
s1
Active 8h/day (sun mode)
Active 16h/day (night mode)
Active 24h/day
g4
g7b
GS-HE1
s3
g1-1
GS-HE3
GS-HE2 s1-1
g8-1 g8-2
g9-1
g9-2
c1
s2
c2
CaO
storage
Lock
hopper
CO2 storage
CO2
vessel
g5-2
cooler-2
g5
heater
HPS-COMP
HPS-TURB
g6
M-TURB
g10
g11
g12
g13
cooler-3
s1-2
CaCO3/CaO
storage
M-COMP
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
case1 case3 ( 3i nt ercoo ler s)

31. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent no.727348.
Retos
31
Calcinación solar: prototipos y resultados
Receptor de partículas en caída
Ho et al. (2013)
• Prototipo a escala de MW
• ResultadosàDT=300ºC con 80W/cm2
• Alta eficiencia térmica (>50%)
• Sin experimentación con CaCO3
• Rotura/desgaste de partículas
• Necesidad de incrementar el tiempo de residencia

32. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent no.727348.
Retos
32
Calcinación solar: prototipos y resultados
Receptor centrífugo
• Tecnología muy desarrollada en cementeras
• Tiempo de residencia ajustable
• Buenos coeficientes de transferencia
• Limitaciones geométrica para la integración
• Amplia experimentación con CaCO3
Flam m ant et al. (1980)
M eier et al. (2004)
M eier et al. (2006).
2 kW t solar furnace reactor that presented a
total absorptance about 0.9-1
- High relevance of radiative properties of
the solar reactor.
- A therm al efficiency of 0.1-0.3 was
achieved
- m axim um calcination degree of 0.6
- The residence tim e is only dependent on
the rotation speed
- m axim um particles outlet tem perature
reached 1500ºC.
10 kW t solar rotary kiln reactor
A therm al efficiency of 0.2 was achieved
- Residence tim e 3-7 m in
- Calcination tem perature 1050-1150ºC
- m axim um calcination degree >95%
indirect heating 10 kW t m ulti-tube rotary kiln
A therm al efficiency of 0.3-0.35 was achieved
- m axim um calcination degree >98%
- particles outlet tem perature reached 1122ºC.

33. This Project has received funding from European Com m ission
by m eans of Horizon 2020,the EU Fram ework Program m e for
Research & Innovation, under Grant Agreem ent no.727348.
Retos
33
Calcinación solar: prototipos y resultados
Receptor de lecho fluidizado
• Alta inercia térmica
• Reducción gradientes térmicos
• Buenos coeficientes de transferencia
• Limitaciones geométrica para la integración
• Integración tecnología beam-down
• Experimentación con CaCO3
Flammant et al. (1980) Chirone et al. (2013)