Design of glass capsules for CO2 submarine storage - Desarc ...
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DESARC - MARESANUS
DEcreasing Seawater Acidification Removing Carbon
Design of glass capsules for CO2 submarine storage
M. Cremonesi, C. Fu, N. Cefis, M. Colombo, A. Corigliano, U. Perego
Dipartimento di Ingegneria Civile e Ambientale
Politecnico di Milano
massimiliano.cremonesi@polimi.it
The Submarine Carbon Storage (SCS)
The SCS method consists in five
phases:
1. The emitter setup the CO2 capture
system.
2. Production of glass capsules.
3. CO2 collected from emitter and from
capsules production.
4. Capsules filling and launching.
5. Filled capsules are transported and
released.
Picture from “Evaluation of a new technology for carbon dioxide submarine storage in glass capsules”- Caserini et. al. (2017).
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus. 4-5 febbraio, 2020
The Capsule
From a structural point of view, fundamental questions
• Shape
• Dimensions (height, length and thickness)
• Materials (Glass?)
Picture from “Evaluation of a new technology for carbon dioxide submarine storage in glass capsules”- Caserini et. al. (2017).
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus. 4-5 febbraio, 2020
The filling and launching process
In the filling and launching process what era the most critical aspects from a structural point of
view (e.g. for the safety of the capsules)?
Capsules are very thin containers subjected to very high internal and external pressure
• filling phase: difference between internal and external pressure can be very large
• after the deposition on the seabed: maximum external pressure
Static analysis
In the falling phase, the capsules can impact with the seabed (sand, rocks,…)
or with other capsules leading to possible breakage.
Dynamic analysis
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus. 4-5 febbraio, 2020
The Material
BOROSILICATE GLASS for its chemical resistance in salty environment.
Material properties
Density ρ = 2.20 kg/m3
Elastic modulus E = 64000 MPa
Poisson’s ratio ν = 0.2
Design tensile stress (the Galileo method) (CNR-DT 210/2013)
Practically no tensile strength
Emphirical compressive design stress
Vey high compressive strength
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus. 4-5 febbraio, 2020
Thin capsule container
Structural analysis
Capsule with uniform thickness
Mariotte formula to estimate the thickness = = 3.41 = 3.5
2 ;
Analytical model: Thin shell FEM model: 58696 4-node
structure solved with the force bilinear axisymmetric
method quadrilateral elements (CAX4)
23 elements
along the
thickness
• Pext = 20 MPa: external water pressure at
2000m below the sea level;
U2=U3=UR1=0
• Pint = 10 MPa: internal liquefied CO2 pressure;
• Pnet=Pext - Pint
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus. 4-5 febbraio, 2020
Thin capsule container
stress comparison
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus. 4-5 febbraio, 2020
Thin capsule container
Principal stresses
Lower stresses of about 50% Smaller thickness can
in the spherical region be adopted
s
Safety check
x _ , = 0.86 ≤ ; = 2.03
| _ , | = 438.78 ≤ ; = 440
OK!
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus. 4-5 febbraio, 2020
Thin capsule container
Variable thickness capsule model
Capsule with variable thickness
55854 4-node bilinear axisymmetric
quadrilateral elements (CAX4)
t =2 mm
Smoothing
radius = 120 mm
Entirely compressed capsule
U2=U3=UR1=0 t =3.5 mm _ , | = 437.90 ≤ ; = 440
More effective than the constant thickness capsule
using less material!
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus. 4-5 febbraio, 2020
Thin spherical container
Comparison of containers storage capacity
Best value of L?
Thin spherical container has higher storage capacity than the capsule of
variable thickness.
In the following only spherical capsules will be considered.
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus. 4-5 febbraio, 2020Filling phase
CO2 10 MPa
H2O 10 MPa
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus. 4-5 febbraio, 2020Effect of the plug
Stresses in the filling phase
Plug made of borosilicate glass
Rubber obstructer Ceramic material
Change of the geometry: disturbances
to the membrane response with
additional stresses which vanish after the
wavelength.
Thickness enlargement is required in the
region close to the plug to increase the
The internal CO2 pressure is equilibrated by the bearing capacity.
artificially-imposed external water pressure
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus. 4-5 febbraio, 2020Effect of the plug
Stresses in the filling phase
_ , = 57.68 ≥ ; = 2.03
| _ , | = 460.20 ≥ ; = 440
The safety checks are not fulfilled: high
stresses are generated on the internal upper edge
making the preliminary shape unacceptable.
Topological optimization: minimum strain energy
is imposed in the upper region by reducing the
whole model volume to 85%.
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus. 4-5 febbraio, 2020Optimized shape
FEM stress analyses
_ , = 0.16 ≤ ; = 2.03
| _ , | = 434.70 ≤ ; = 440
The safety check is fulfilled
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus. 4-5 febbraio, 20203D modeling
Shell elements
For a 3D modelling, it is not convenient to model the container as continuum solid body due to the small
thickness, which would require high number of finite elements, hence high computational cost.
3D shell elements are adopted: midsurface is the shell reference surface on which engineering quantities
are computed.
The midsurface is defined as the revolution
of shell midline. Three regions are defined
based on the thickness:
1. 10 mm thickened flat region;
2. Variably thickened region;
3. 2 mm thickened spherical
region with R149 mm.
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus. 4-5 febbraio, 2020Capsule at seabed (2000m)
Pressure at the storage site: 2000 m below the sea level Pext = 20 MPa External water pressure
Pint = 10 MPa Internal CO2 pressure
Minimum principal stresses
External surface SPOS
Internal surface SNEG
| _, | = 403.16 ≤ ; = 440
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus. 4-5 febbraio, 2020Falling phase
Hydrostatic analysis
= = 143.49 Buoyancy force
= + = 136.95 Gravity force
> Additional mass is required to
ensure the container falling.
2200 kg/m3 Sand: low cost and large availability material
930 kg/m3
1035 Kg/m3 Minimum mass of stored material for which balances :
2200 kg/m3
6.43 10
= − = 13.21
1.35 10
1.41 10
1.35 10
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus. 4-5 febbraio, 2020Falling phase
impact analyses
Impact stresses analyses: evaluation of principal
stresses caused by the impact of the container with
seabed at 2000 m below the sea level.
Pext
Impact cases:
• impact with rock soil;
• impact with sand soil;
Pint
• impact against another capsule;
• impact against four stored capsules.
The pressurized container drops with the terminal
velocity.
2 −
= = 121.44 /
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus. 4-5 febbraio, 2020Falling phase
impact with seabed: rigid flat soil
First contact point: Minimum principal stresses
Peak value 390 Mpa < 440 Mpa
The safety check is fulfilled
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus. 4-5 febbraio, 2020Falling phase
impact with seabed: deformable flat soil
Elasto- plastic sand soil with the Dracker-Prager failure criteria
slave surface master surface
clamped surface
First contact point: Minimum principal stresses
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus. 4-5 febbraio, 2020Falling phase
impact against a capsule
Impact of a capsule on a stored capsule on rigid seabed
First contact point: Minimum principal stresses
Peak value 380 Mpa < 440 Mpa
The safety check is fulfilled
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus. 4-5 febbraio, 2020Falling phase
impact against a four stored capsule
terminal
velocity
First contact point: minimum principal stresses
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus. 4-5 febbraio, 2020Design of SCS Glass container
Conclusion
1. Borosilicate glass is used for its high compressive strength and chemical
resistance in salty environment.
2. Thin spherical container is more appropriate than the capsule container in
terms of the storage capacity.
3. The final shape is obtained through a topological optimization.
4. Different loading cases during the filling phase has been analysed.
5. In the falling phase, additional sand is required to guarantee the capsule
falling.
6. At the storage depth, the capsule is totally compressed.
7. Impact analysis with different soils have been studied.
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus. 4-5 febbraio, 2020What next?
• Detailed studied of the material properties of borosilicate glass.
• Experimental tests on the borosilicate glass.
• Possible improvements of the capsule design (surface treatments).
• Simulation of the complete falling phase in a fluid-structure interaction
framework.
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus. 4-5 febbraio, 2020DESARC - MARESANUS
DEcreasing Seawater Acidification Removing Carbon
Design of glass capsules for CO2 submarine storage
A. Corigliano, U. Perego, M. Cremonesi, N. Cefis, M. Colombo, C. Fu
Dipartimento di Ingegneria Civile e Ambientale
Politecnico di Milano
massimiliano.cremonesi@polimi.itOptimized shape
Material usage comparison
After the optimization process, a stiffer and Model Volume [m3] Material surplus [%]
less material demanding shape is obtained. Perfect spherical container 5.58 10 -
Slightly volume increment is observed in Preliminary shaped container 7.84 10 +40.54
the optimized container when compared to Optimized container 6.43 10 +15.30
the perfect spherical container.
Even with the introduction of the plug and the thickness
enlargement, the spherical container remains the most
appropriate shape from the material consumption’s point of view.
Values in mm
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus. 4-5 febbraio, 2020Optimized shape
FEM stress analyses
Overpressures cases: to consider 1. | _ , | = 130. 20 ≤ ; = 440
a reduced balancing effect, two
overpressure cases are analyzed:
1. ΔP = 3 MPa
Pext = 10 MPa
Pint = 7 MPa
2. ΔP = 1 MPa
Pext = 10 MPa
Pint = 9 MPa
2. | _ , | = 49. 80 ≤ ; = 440
A. Corigliano, U. Perego, M. Cremonesi, N. Cefis, M. Colombo, C. Fu
Dipartimento di Ingegneria Civile e AmbientaleFalling phase
Terminal velocity
Hydrodynamic analysis
= Minimum
= −
= = 1.15 sand mass to
= + 1− be added
= +
= 1.20 kg
= 12.04 kg
The terminal velocity can be evaluate
by imposing zero resultants: = 1.42 kg
Dynamic equilibrium = 14.66
1 + =
= Drag force 1
2 + =
2
= 0.47 Drag coefficient
2 −
= = 121.44 /
= 0.07 Cross section area
La rimozione di CO2 dall’atmosfera e il progetto Desarc-Maresanus. 4-5 febbraio, 2020Dynamic analysis
3D impact with seabed: rigid wavily shaped soil
Rocky soil: it is modelled as rigid element for its low deformability.
slave surface
master surface clamped soil
First contact point: Minimum principal stressesDynamic analysis
3D impact with seabed: rigid wavily shaped soil
Overturned container impact
No significant principal stresses
variation are observed in the impactDynamic analysis
3D impact with seabed: deformable shaped soil
Elasto- plastic sandy soil with the Dracker-Prager failure criteria slave surface master surface
First contact point: Minimum principal stressesDynamic analysis
3D impact with seabed: deformable flat soil
Elasto- plastic sandy soil with the Dracker-Prager failure criteria Parameter Symbol Value and unit
Density 1900 kg/m3
= − tan − =0 Elastic modulus 50
Poisson ratio 0.3
Soil strength Ss 0.3
angle of friction in the Drucker-
Prager model;
material cohesion.
tan = =56.41° per = 37°
= angle of friction in the
Mohr-Coulomb plane
= =0 per =0Dynamic analysis
3D impact analysis
Maximum values of minimum principal stresses in the studied impact cases
Impact case σmin_prin SNEG [MPa] σmin_prin SPOS [MPa]
Rigid flat soil -360.17 -390.39
Rigid wavily
-357.63 -394.08
shaped soil
Deformable flat
-368.64 -379.64
soil
Deformable
-367.10 -381.38
wavily shaped soil
Container on
-366.07 -381.45
container
Container on four
-365.73 -383.2
containers
The impact with rigid wavily shaped soil represents the most severe case. Nevertheless, the
safety check is satisfied since:
| _, | = 394.08 ≤ ; = 440
In the impact with rigid soil, damped vibration response can be observed: the stresses
vanish rapidly and the initial stress state is recovered.
A. Corigliano, U. Perego, M. Cremonesi, N. Cefis, M. Colombo, C. Fu
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