"With the increasing need for efficient, energy-saving, and environmentally friendly procedures, adsorbents with tailored structures and tunable surface properties have to be found. To make an informed choice of material for a given application, one must first have knowledge of its adsorption behaviour as a function of molecular composition and morphology. My aim is to provide new insights for material design with a computational investigation of adsorption and diffusion processes in porous materials. As adsorbents I will focus on zeolites because of their high stability and on MOFs because of their structural diversity and versatility. As adsorbates I am interested on chiral molecules such as ibuprofen or limonene (separation of chiral enantiomers), volatile organic compounds –VOCs- (control of VOCs emissions from industrial processes), water, alcohols (solvent dehydration), carbon dioxide and methane (production of cheap and clean fuel from natural gas).The central focus of this research is that computer simulations can be used not only as a screening tool for known structures, but they can also provide structural design guides even before experimental synthesis. My approach is to perform a classical simulation study to identify the effect of the geometry and the chemical composition of the material on storage/release of molecules and on separation of mixtures. The fundamental information that I am planning to obtain from this study will provide the underlying knowledge from a molecular point of view that may guide to the development of more efficient processes, to fine-tune materials for a particular application and also to steer the experimental effort in successful directions."