Carbon capture and storage (CSS) is a recently discussed new technology, aimed at allow-
ing an ongoing use of fossil fuels while preventing the produced CO2 from being released
into the atmosphere. A suitable mathematical model to simulate this process is com-
positional multiphase flow with equilibrium phase exchange. It is able to represent the
important process of solubility trapping. One of the big problems arising in two-phase
two-component flow simulations is the disappearance of the nonwetting phase, where the
saturation cannot be used as independent variable.
In this thesis, a persistent variable formulation is presented, which has the important
advantage that only one set of primary variables can be used for the biphasic as well as
the monophasic case. Using a modified Newton solver, also developed in the course of this
work, the convergence at the single-phase/two-phase interface can be greatly improved.
The persistent variable formulation is implemented in the DUNE simulation framework
with capillary pressure and nonwetting phase pressure as primary variables. The presented
method is verified by numerical test simulations of CO2 injection in saline aquifers. A
fine grid resolution for these large-scale simulations can only be achieved by the use of
heavy parallelization. The numerical results for the recent MoMas benchmark agree with
the output of other groups. For several test cases, grid convergence and scalability are
analyzed numerically. The method scales well and converges with the optimal order of
convergence