An-Najah Staff

During steam assisted gravity drainage for heavy oil recovery aqua-thermolysis reactions take place, whereupon gaseous hydrogen sulfide, H2S(g), is produced. A method to capture H2S(g) and convert it into a chemically inactive species is deemed necessary for sustaining in-situ recovery and upgrading. Part I of the current study explored the formation and stabilization of colloidal FeOOH particles in heavy oil matrices. In this Part, we evaluate the H2S(g) sorption ability of these particles as well as other metal oxide/hydroxide particles. Furthermore, the effect of mixing and temperature on H2S(g) sorption was investigated. Results showed that the rate and capacity of H2S(g) sorption increased as the concentration of FeOOH increased. Mixing, on the other hand, had insignificant effect on the sorption capacity, however it improved the sorption kinetics. In addition, in-situ prepared colloidal particles showed better reactivity towards H2S(g) than commercial α-Fe2O3 nanoparticles. Temperature had an adverse effect on the H2S(g) sorption capacity of FeOOH. This was attributed to a change in chemical structure of FeOOH as the temperature increased. Nevertheless, in-situ prepared ZnO colloidal particles completely removed H2S(g) even at high temperatures.

Water-in-oil (w/o) microemulsions are very appealing reaction media due to their ability to provide huge surface of contact between water-soluble and oil-soluble reactants. Their application as reaction media, including the preparation of nanoparticles, is, however, limited to water soluble precursors. In this study, we present a first step scheme in a two-step process for the preparation of metal oxide nanoparticles starting from their water-insoluble metal oxide bulk powder. This step involves solubilizing the metal oxide in the water pools of the microemulsion with the aid of a solubilizing agent. The variables affecting the solubilizing capacity of iron and copper oxides,as examples of important metal oxides, in single HCl-containing AOT/water/isooctane microemulsions were investigated. The effect of the following variables on the solubilization capacity is reported, namely, mixing time, surfactant concentration, water to surfactant mole ratio (R),and the nominal concentration of HCl in the water pool. At 300-rpm, time-invariant concentration of the metals in the microemulsions was achieved in about 6 hours. These values were quoted as the solubilization capacity of the metal oxide at the corresponding conditions.Solubilization capacity increased linearly with the surfactant concentration and R, and portrait a power function with the nominal concentration of HCl in the water pool. A mathematical model previously derived to describe nanoparticle uptake by single microemulsion accurately accounted for the effect of the aforementioned variables on the solubilization capacity.