A new method (improved shooting method) is used for effectiveness factor calculation by the diffusion-reaction approach.

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Hydrotreating processes for diesel fuels are becoming increasingly important, owing to environmental regulations limiting sulfur and aromatic compounds, which are becoming more strict. Among investigations into hydrotreating modeling, most of the studies use a homogeneous model to simulate the reactor. However, for a real industrial reactor, that is not always an accurate assumption. Furthermore, reports of efforts to find the best operating conditions are very scarce. In this study, a heterogeneous model of three main reactionshydro-desulfurization, hydro-denitrogenation, and hydro-dearomatizationwas applied to simulate the hydrotreating reactor. The model results show a good agreement with literature experimental data. The effects of important operational parameters such as temperature, pressure, liquid hourly space velocity, and H 2 /oil ratio on various hydrotreating reactions are also evaluated. Finally, a multi-objective optimization based on non-dominated sorting genetic algorithm II is carried out to find the best operating conditions for a diesel fuel hydrotreating reactor.

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The effects of ultrasound-related variables on the catalytic properties of sonochemically prepared SAPO-34 nanocatalysts in methanol to olefins (MTO) reactions were investigated.

Conventional hydrogen production plants consist of natural gas steam reforming to CO+3H 2 on Ni catalysts in a furnace, water-gas shift reaction for converting CO into CO 2 and CO 2 absorption. A new alternative method for highly endothermic steam reforming is autothermal reforming (steam reforming with air input to the reactor) without the need for external heating. In this study, hydrogen production by autothermal reforming for fuel cells (base case) was simulated based on a heterogeneous and one-dimensional model. In addition, the effect of operating variables on the system behavior was studied. Finally, Pareto-optimal solutions for the maximum molar flow rate of the produced hydrogen and methane conversion were determined by NSGA-II. There was a huge increase in the produced hydrogen molar flow to the base case, which showed the importance of optimizing autothermal reformers for hydrogen production.