Antônio Tavernard Pereira Neto

A new correlation for hazardous area classification based on experiments and CFD predictions

A correlation developed by the authors for prediction of hazardous area extension due to fugitive emissions is described in this work. The correlation is based on computational fluid dynamic (CFD) simulation data. The CFD simulation setups were obtained from a Computational Design of Experiments. The CFD model has been validated experimentally. The transport properties, orifice size, temperature, pressure, gas molar mass, and lower explosive limit (LEL) were varied in a range of practical interest using the statistical Technique Latin hypercube to spread the simulation setups. The effect of each variable on hazardous area extension was obtained from the CFD results leading to an analytical correlation for practical use in estimating the extension of the hazardous area. The results showed that the extension of hazardous area in still ambient is merely a function of the leaking gas molar flow rate and gas volume fraction at LEL. The results from the correlation described in this work were compared to results from correlations existing in the literature.

Modeling of the Fischer-Tropsch Synthesis Aiming to Predict the Production of Paraffins and Olefins

The growing concern with the global environmental issues has resulted in a constant demand for the production of clean fuels. Therefore, researches were carried out in order to improve the gas-to-liquids technology, well represented by the Fischer-Tropsch synthesis. This synthesis is able to produce liquid fuels from syngas, a mixture of carbon monoxide and hydrogen which is obtained through the processing of the methane gas. Based on literature data, this paper suggests a kinetic model developed by making use of the Matlab® commercial application. The goal was to predict the production of hydrocarbons such as paraffins and olefins with up to six carbons in each chain. The Fischer-Tropsch synthesis was conducted with the catalyst 20% Co/ MCM-41 in fixed bed reactor at the temperature of 270 °C and atmospheric pressure. The results obtained by the model for both paraffins and olefins were compared with experimental data found in the literature.