Abstract
Starting from a self-consistent stellar and nebular model of the planetary nebula IC 418, we aim to reproduce the IR dust emission with Cloudy models. We use the optical properties of different dust grains and their corresponding emission features. We investigate the degeneration between the size of the dust grains and their distance to the central star, both acting on the dust temperature, and therefore the dust emission. IR emission shows two broad features at 11.5 and 30 μ m. We explored different morphologies of SiC & MgS dust grains as posible carriers for these features. This carbon rich nebulae has the highest observed Fe depletion (-3 dex), and a less important depletion for other elements (-0.5 to -1 dex). From the best fit model for the dust emission, we determine the posible depletion factor for C, Si, Mg and S.
