An MFI zeolite (Si/Al = 40) was desilicated by alkaline treatment in order to generate mesopores. Temperature, alkali concentration and treatment duration were adjusted to maximize mesoporosity while preserving the zeolite structure. Special attention was paid to the characterization of the strength and accessibility of the acid sites. The catalysts were tested in the isobutane/butene alkylation, a reaction typically catalyzed by zeolites but limited by coke deposition. Additionally, glycerol esterification with acetic acid was used as test reaction, due to the requirement of large pores to take part. The results confirmed that mesopores were successfully generated in the MFI zeolite, and the diffusion through the solid was enhanced, but the active sites remained mainly confined in the micropores.

The goal of this work is to develop a sustainable value chain of carbonaceous adsorbents that can be produced from the solid fibrous digestate (SFD) of biogas plants and further applied in integrated desulphurisation-upgrading (CO2/CH4 separation) processes of biogas to yield high purity biomethane. On this purpose, physical and chemical activation of the SFD derived biochar was optimised to afford micro-mesoporous activated carbons (ACs) of high BET surface area (590-2300 m2g−1) and enhanced pore volume (0.57-1.0 cm3g−1). Gas breakthrough experiments from fixed bed columns of the obtained ACs, using real biogas mixture as feedstock, unveiled that the physical and chemical activation conclude to different types of ACs which are sufficient for biogas upgrade and biogas desulphurisation respectively. Performing breakthrough experiments at three temperatures close to ambient it was possible to define the optimum conditions for enhanced H2S/CO2 separation. It was also concluded that the H2S adsorption capacity is significantly affected by restriction to gas diffusion. Hence, the best performance was obtained at 50 oC and the maximum observed in the H2S adsorption capacity vs the temperature is attributed to the counterbalance between adsorption and diffusion processes.