Le patrimoine de l’Université

Impact of pore topology and crystal thickness of nanosponge zeolites on the hydroconversion of ethylbenzene

“…The indicated catalyst formulation was based on long-term literature results and well- established patent data available for the industrial process. [10][11][12][13]15 The hydrogenating phase was prepared by ion exchange of γ-Al 2 O 3 with a hexachloroplatinic acid solution in the presence of 0.2 M HCl following literature reports. 11,12 The hydrogenating phase was then calcined under 2 dm 3 g −1 min −1 of dry air flow at 773 K for 4 h (1 K min −1 ).…”

“…9 This process is nonetheless accompanied by numerous reactions, e.g., naphtha ring opening, hydrocracking, aromatization, and polymerization of aliphatic hydrocarbon chains, as well as dealkylation, disproportionation, and transalkylation reactions of alkyl-aromatics. 10 With a focus on the acid component of the bifunctional catalyst, continuous research has described the impact of the zeolite topology on the catalytic performance. 11,12 In particular, recent studies highlighted the dependence of the selectivity on the size, dimensionality, presence of large cavities, and even the shape and tortuosity of zeolitic pore systems.…”

“…11,[14][15][16][17] Yet, zeolites with narrow non-intersected 10-R channels have recently emerged as a new generation of more selective catalysts. [8][9][10]12,13,18,19 Sensitivity to coke retention in the core of the zeolite crystals has been a crucial factor for choosing a catalyst where ethylbenzene is preferentially hydroisomerized. For the simultaneous hydroisomerization of xylenes and ethylbenzene, the zeolite-based catalyst is required to balance desired shape-selectivity, a tendency toward fast deactivation by coke formation, and limited molecular transport.…”

Modeling of Mid-Frequency Reverberation in Very Shallow Water

“…Such analysis has shown, in particular, that the impact of large shells on reverberation may be substantial at reasonable assumptions, suggesting more effort for collecting such shells during field experiments to provide sufficient ground truth for model/data comparisons. First results of this effort have just appeared [9,10], as well as first results of environmental and acoustic measurements performed during the TREX13 [11][12][13]. In particular, available by now data on TREX13 shell size analysis shows much higher concentrations (up to 20% in volume [9]) than at SAX04.…”

“…First results of this effort have just appeared [9,10], as well as first results of environmental and acoustic measurements performed during the TREX13 [11][12][13]. In particular, available by now data on TREX13 shell size analysis shows much higher concentrations (up to 20% in volume [9]) than at SAX04. Estimations based on these data confirm that the contribution of shells (and other discrete scatterers) may be an important mechanism of the TREX13 reverberation.…”