french institute of science and technology for transport ... - Ifsttar

Research orientation W_Conserving energy and natural resources
cases and design stresses (limit state stresses, verification
of design criteria), a chapter on geotechnical engineering
and design parameters (minimum survey, geotechnical data
and geotechnical model). Another deals with the different
types of foundation that are possible (gravity base, gravity
base, gravity base on soils that have been strengthened
with ballasted columns or rigid inclusions, pile foundations,
composite foundations). This chapter is based on recent
recommendations for ballasted columns (CFMS, 2011)
and rigid inclusions following the National ASIRI Project
(Soil Improvement by Rigid Inclusions) in which IFSTTAR
took part, in particular by conducting reduced-scale centrifuge
model tests.
@ CONTACT
luc.thorel@ifsttar.fr
CO 2 sequestration
in Coal seams
Molecular simulation comes
to our assistance
In order to mitigate climate change, the world’s experts
agree that we need to halve greenhouse gas emissions,
mainly CO 2, by 2050. Awaiting the massive exploitation
of renewable energy sources which have no greenhouse
effect, a bright future seems to be in store for the
geological sequestration of CO 2 in coal seams, which is
one of the principal techniques that can help reduce
the problem. But in order to implement this emerging
technology we have to understand the complex
processes at work.
An example
of the adsorption
of carbon dioxide in
a three-dimensional
molecular structure
typical of coal.
Pilot projects have shown that reservoir permeability is
reduced subsequent to CO 2 injection due to swelling of the coal
because CO 2 is adsorbed preferentially to the methane (CH 4)
which is naturally present in the seam. In spite of the extremely
small size of its pores, frequently less than a nanometre, coal
can absorb large amounts of gas. This is explained by the
forces of interaction between the gas molecules and the solid
which, at this scale, become greater than those which result
from gas pressure. These forces depend on the nature of the
gas that is present in the coal, in this case CH 4 or CO 2.
By applying molecular-scale simulation and studying macroscopic
poromechanical behaviour, Laurent Brochard has
studied, with Massachusetts Institute of Technology (Roland
Pellenq), the close coupling that exists between adsorption and
strain. New constitutive equations for microporous media have
been developed. These equations have been validated then
calibrated for geological conditions by molecular simulation.
5 nm
The study will continue in 2012 in the Navier Laboratory (a
research unit that is jointly run by IFSTTAR, École des Ponts
ParisTech and CNRS), in the form of theoretical and numerical
modelling of the coal seam (S. Nikoosokhan’s doctoral
research) and experimental studies (post-doctoral research
by N. Espinoza on the adsorption of CO 2 in coal under triaxial
loading), in collaboration with Total.
@ CONTACTS
teddy.fen-chong@ifsttar.fr & matthieu.vandamme@enpc.fr
41
THESES
Quentin Barral_Navier
Superimposition of orthogonal
flows in complex fluids:
setting up the experiment,
application to suspensions
and yield stress
fluids (02/12/2011)
Sébastien Brisard_NAVIER
Morphological analysis
and numerical homogenization:
application to cement paste
(05/01/2011)
Laurent Brochard_NAVIER
Moromechanics and absorption:
Application to the swelling
of coal during geological carbon
sequestration (31/10/2011)
Coralie Brumaud_MAT
Microscopic origins of the rheological
consequences of adding cellulose
ethers to a cementitious suspension
(14/10/2011)
Jean-François Camenem_MAT
Influence of particle shape on the
structure of dense granular stacks
(09/12/2011)
Duc Tung Dao_MAT
100% recycling of pavement concrete
(10/10/2011)
Thanh Toan Le_MAT
A geolocalized technique for evaluation
the integration of road projects within
areas and the selectionof alternations
(12/10/2011)
José Munoz-Castelblanco_NAVIER
Hydromechanical behaviour
of a natural loess (28/03/2011)
Firas Sayed Ahmad_NAVIER
Prestressing of Ultra-High Performance
Fibre-Reinforced Concrete (UHPFRC)
with Carbon Fibre Composite Materials_
CFCM (15/12/2011)
Fabien Szymkiewicz_GER
Evaluation of the mechanical
properties of soil-mixing material
(04/10/2011)
ANNUAL REPORT 2011 ifsttar.fr