Hydrodynamics and oxygen mass transfer characteristics of petroleum based micro-emulsions in a packed bed split-cylinder airlift reactor

CATEGORY: WASTEWATER TREATMENT
Braz. J. Chem. Eng. vol.30 no.3 São Paulo July/Sept. 2013, http://dx.doi.org/10.1590/S0104-66322013000300012
Hydrodynamics and oxygen mass transfer characteristics of petroleum based micro-emulsions in a packed bed split-cylinder airlift reactor
M. Keshavarz Moraveji (I), E. Mohsenzadeh (II); M. Ebrahimi Fakhari; R. Davarnejad
moravejii@yahoo.com
I Department of Chemical Engineering, Amirkabir University of Technology (Tehran Polytechnic), 424 Hafez Avenue, Tehran 15875-4413, Iran.
II Department of Chemical Engineering, Faculty of Engineering, Arak University, Arak 38156-8-8349, Iran
ABSTRACT
The effects of aeration velocity and liquid properties on the pertinent hydrodynamic and mass transfer parameters in a split-cylinder airlift reactor (with and without packing) were examined. Four different oil-in-water micro-emulsion systems containing kerosene, heavy naphtha, light naphtha and diesel as the oil at the concentration of 7% (v/v) were used in the experiments and the results were compared with pure water. The experimental results showed that the gas (air) hold-up and the volumetric gas-liquid oxygen transfer coefficient values for the micro-emulsion systems were usually greater than those of pure water.
The packing installation increased the overall gas-liquid volumetric mass transfer coefficient by increasing the flow turbulence and Reynolds number, compared to the unpacked column. The packing increased the gas hold-up and decreased the bubble size and liquid circulation velocity. Furthermore, two empirical correlations were developed to predict the overall gas hold-up and volumetric oxygen transfer coefficient. A good agreement was observed between the experimental and correlated data.
Introduction
The aim of this research is to investigate the effect of aeration velocity and liquid properties on the hydrodynamic parameters and volumetric mass transfer coefficient in a packed split-cylinder airlift reactor. The packing was installed in the riser section of the airlift reactor.
Four different oil-in-water micro-emulsions containing kerosene, heavy naphtha, light naphtha, and diesel as the oil at a concentration of 7 % (v/v) were prepared and their behavior was carefully studied. The surface tension of the bulk liquid decreases and smaller bubbles were produced in micro-emulsions in comparison with pure water. Therefore, the gas hold-up and mass transfer coefficient increased in micro-emulsions; however, adversely liquid circulation velocity decreased.
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Catalytic hydrotreatment in reverse microemulsions under microwave irradiation

CATEGORY: HYDROTREATMENT
Fuel, Volume 112, October 2013, Pages 338–346
Catalytic hydrotreatment in reverse microemulsions under microwave irradiation
Lorean Madriz (a), Hermes Carrero (a), José Ramón Domínguez (b), Ronald Vargas (c), Lenys Fernández (a)
a Universidad Simón Bolívar, Department of Chemistry, Laboratory of Electroanalysis, Apartado 89000, Caracas 1080A, Venezuela
b Universidad Simón Bolívar, Department of Chemistry, Laboratory of Spectroscopy, Apartado 89000, Caracas 1080A, Venezuela
c Universidad Simón Bolívar, Department of Chemistry, Laboratory of Electrochemistry, Apartado 89000, Caracas 1080A, Venezuela
Abstract
Reports a hydrocatalytic process developed in a reverse microemulsion using microwave irradiation. Researchers fabricated CoMo/Al₂O₃ and NiMo/Al₂O₃, in the laboratory. They analyzed the effectiveness of the procedure using such model compounds as nickel (II) phthalocyanine tetrasulfonate tetrasodium salt (NiPcTSNa₄), nickel tetraphenylporphyrin (NiTPP) and thiophene.
They dematallized the first two model compounds to a percentage around 85% and 60% respectively. Desulfurization of the latter was greater than 90%. These values are higher than most of the values reported in the literature for this type of process. In addition, they applied this catalytic hydrotreating to an actual sample of Venezuelan heavy oil (Hamaca), achieving high conversion in a relatively short time. The results show the advantage of using this type of hydrotreating in less extreme conditions and in a shorter time than that used in other hydrocatalytic procedures.
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