  We obtain a fast diffusion equation (FDE) as scaling limit of a sequence of
zero-range process with symmetric unit rate. Fast diffusion effect comes from
the fact that the diffusion coefficient goes to infinity as the density goes to
zero. Therefore, in order to capture the behaviour for an arbitrary small
density of particles, we consider a proper rescaling of a model with a
typically high number of particles per site. Furthermore, we obtain some
results on the convergence for the method of lines for FDE.
