Ablative materials are used in thermal protection systems for atmospheric re-entry vehicle heat shields. Adetailed chemical equilibrium heat and mass transport model for porous ablators is presented for the first time. The governing equations are volume-averaged forms of the conservation equations for gas density, gas elements, solid mass, gas momentum, and total energy. The element (gas) fluxes are coupled at the surface of the material with an inlet/outlet boundary condition, allowing modeling either atmospheric gases entering the porous material by forced convection or pyrolysis gases exiting the material. The model is implemented in the Porous material Analysis Toolbox based on OpenFOAM (PATO). The thermodynamics and chemistry library Mutation++ is used as a third party library to compute equilibrium compositions, gas properties, and solve the state-of-the-art boundary layer approximation to provide the ablation rate and the element mass fractions at the surface of the material.