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This work attempts to utilize sodium chlorite to clean up NO x and SO 2 gases simultaneously from flue gas in a novel swirl scrubber system. Experiments were carried out to evaluate the effects of various operating parameters such as initial SO 2 concentration, scrubbing medium pH, sodium chlorite concentration, and liquid and gas volumetric flow rates at 35 °C. In addition, reaction mechanisms of simultaneous denitrification and desulfurization using sodium chlorite in acidic and basic solutions are proposed. Complete oxidation of NO into NO 2 occurred using 0.2 M sodium chlorite solution as the scrubbing medium. Complete (100%) SO 2 and 81% NO x removal efficiencies were achieved under optimized conditions. The NO x removal increased with decreasing pH. Input SO 2 enhanced the NO x absorption. The effect of the SO 2 concentration on NO x removal was more intense at higher pH values. Using sodium chlorite as the scrubbing medium in the novel swirl scrubber was found to be quite promising for the simultaneous removal of NO x and SO 2 .

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.