(144b) ZLC Studies for Methanol, Benzene and 1,3,5-Triisopropylbenzene in Hierarchical ZSM-5 Zeolite Samples USED for Mth (METHANOL TO HYDROCARBONS) Reactions

Hierarchical zeolites are a group of aluminosilicates that have a structural profile composed of a combination of micro- and mesopores, with active sites that allow their use as catalysts in reactions involving molecules of size C₇ to C₁₁, such as the reactions for conversion of methanol into hydrocarbons, MTH (Methanol to Hydrocarbons). The diffusion behavior of methanol and hydrocarbons in hierarchical zeolites might help with understanding their catalytic performances. Samples of hierarchical ZSM-5 zeolites, synthesized through desilication methods (samples D-0.4, D-0.8 and D-0.8ac) and with interruption of their crystallization (samples S-4h, S-15h and S -24h), were evaluated using methanol, benzene and 1,3,5-triisopropylbenzene (1,3,5-TIPB), representing the reactants and products of the MTH reactions, at low temperatures (60-100ºC) to avoid MTH reactions during the experiments. The Zero Length Column-ZLC method, proposed by Eic and Ruthven (1988), was used to estimate effective diffusivities (D) and equilibrium constants (K) from ZLC desorption curves obtained at different flow rates.