  A new class of asynchronous discrete-event simulation schemes for
advection-diffusion-reaction equations are introduced, which is based on the
principle of allowing quanta of mass to pass through faces of a Cartesian
finite volume grid. The timescales of these events are linked to the flux on
the the face, and the schemes are self-adaptive, local in time and space.
Experiments are performed on realistic physical systems related to porous media
flow applications, including a large 3D advection diffusion equation and
advection diffusion reaction systems. The results are compared to highly
accurate results where the temporal evolution is computed with exponential
integrator schemes using the same finite volume discretisation. This allows a
reliable estimation of the solution error. Our results indicate a first order
convergence of the error as a control parameter is decreased.
