Alexis Bouza

Modeling of a three-phase reactor for bitumen-derived gas oil hydrotreating

A three-phase reactor model for describing the hydrotreating reactions of bitumen-derived gas oil was developed. The model incorporates the mass-transfer resistance at the gas-liquid and liquid-solid interfaces and a kinetic rate expression based on a Langmuir-Hinshelwood-type model. We derived three correlations for determining the solubility of hydrogen (H2), hydrogen sulfide (H2S) and ammonia (NH3) in hydrocarbon mixtures and the calculation of the catalyst effectiveness factor was included. Experimental data taken from the literature were used to determine the kinetic parameters (stoichiometric coefficients, reaction orders, reaction rate and adsorption constants for hydrodesulfuration (HDS) and hydrodenitrogenation (HDN)) and to validate the model under various operating conditions. Finally, we studied the effect of operating conditions such as pressure, temperature, LHSV, H2/feed ratio and the inhibiting effect of H2S on HDS and NH3 on HDN.

A mathematical model for the evaluation and prediction of the mean energy level of traffic noise in Caracas

The increase of the population in capital cities has provoked a serious increase in the acoustical pollution, where the real cause is the traffic noise. Over ten years, sound levels have been measured in several points in the city of Caracas. The main objective was to establish a mathematical model for the mean energy level of traffic noise. This model is a modification and improvement of the model that was used in Germany and Italy. Parameters of the fundamental equations were obtained by the use of large experimental data. In the particular case of Venezuela, an innovation was introduced by the consideration of the motorcycle noise. The obtained model can be used to predict noise pollution in cities and contour maps can be made as well.