Process intensification in the demulsification of water-in-crude oil emulsions via crossflow microfiltration through a hydrophilic polyHIPE polymer (PHP)

PhD ThesisIn petroleum industry, highly stable water-in-oil (w/o) emulsions are formed during extraction process and these emulsions are stabilized by the indigenous surface active species in the oil. The recovery of crude oil through emulsion breakdown and subsequent separation (demulsification) should be carried out at source in order to avoid costly pumping and cooling of emulsion which enhances emulsion stability. Although conventional methods available for emulsion breakdown using demulsifiers and electric field separation, in the case of viscous crude oils with large amounts of indigenous surfactants, such methods are not satisfactory to achieve on-site oil-water separation. Therefore, such emulsions may have to be chemically treated. It was previously shown that when hydrophilic micro-porous polymers, known as PolyHIPE Polymers (PHPs) were added to the emulsion, it caused emulsion to separate as a result of selective removal of surfactants. This separation process was further enhanced in the presence of electric field. This current study focuses on cross-flow microfiltration of w/o emulsions through a sulphonated hydrophilic microporous polymeric material in the absence or presence of electric field. However, sulphonated PHPs used in the experiments do not have an active membrane layer with pores at micron- or nano- scale. The thickness of the separation layer is ca. 4 mm and pore size is in 10 micrometer range. We used either 50 or 70 vol. % oil phase in the w/o emulsions. Effect of: pore size, crossflow velocity and electric field strength on permeate flux rate decay and separation efficiency of emulsions which are stable for more than 70 days otherwise was investigated. It was found that the permeate flux rate decayed rapidly with crossflow filtration time before the flux reached steady state. The application of electric field enhanced the permeate flux rate. Under steady state conditions, permeate flux rate was not significantly affected by the PHP pore size. Permeate from the crossflow filtration was collected in glass cylinders and allowed to separate under gravity as a function of time. It was found that the demulsification time was affected primarily by the applied electric field, emulsion water content, crossflow velocity and PHP pore size. Demulsification rate increased with increasing electric field and water fraction of emulsion and with decreasing pore size of PHP. Demulsification was achieved within 6-7 hr. The results were interpreted in terms of ‘confinement phenomenon’ in which it was postulated that the PHP filtration media selectively retained the surface active agents and; thus, causing the demulsification of the emulsions. The surface active agents were deposited within the pores of the separation media and; thus, causing flux decay. Although the deposits of surface active agents could break-up due to permeate flow through the separation media, they could not be re-distributed at the oil-water interface to re-stabilize the emulsion. However, some water can be trapped within the oil as oil-in-water-in-oil multiple emulsion which would be more resistant to demulsification.Higher Education Ministry, Tripoli-Liby

Green Fabrication and Characterization of Zinc Oxide Nanoparticles using Eucalyptus Leaves for Removing Acid Black 210 Dye from an Aqueous Medium

This study uses an environmentally friendly and low-cost synthesis method to manufacture zinc oxide nanoparticles (ZnO NPs) by using zinc sulfate. Eucalyptus leaf extract is an effective chelating and capping agent for synthesizing ZnO NPs. The structure, morphology, thermal behavior, chemical composition, and optical properties of ZnO nanoparticles were studied utilizing FT-IR, FE-SEM, EDAX, AFM, and Zeta potential analysis. The FE-SEM pictures confirmed that the ZnO NPs with a size range of (22-37) nm were crystalline and spherical. Two methods were used to prepare ZnO NPs. The first method involved calcining the resulting ZnO NPs, while the second method did not. The prepared ZnO NPs were used as adsorbents for removing acid black 210 dye (AB210) from simulated wastewater. The removal efficiency using calcinated and uncalcinated ZnO NPs was 57 % and 59 %, respectively

Removal of Ciprofloxacin Antibiotic from Synthesized Aqueous Solution Using Three Different Metals Nanoparticles Synthesized Through the Green Method

This study investigates the possibility of removing ciprofloxacin (CIP) using three types of adsorbent based on green-prepared iron nanoparticles (Fe.NPs), copper nanoparticles (Cu. NPS), and silver nanoparticles (Ag. NPS) from synthesized aqueous solution. They were characterized using different analysis methods. According to the characterization findings, each prepared NPs has the shape of a sphere and with ranges in sizes from of 85, 47, and 32 nanometers and a surface area of 2.1913, 1.6562, and 1.2387 m2/g for Fe.NPs, Cu.NPs and Ag.NPs, respectively. The effects of various parameters such as pH, initial CIP concentration, temperature, NPs dosage, and time on CIP removal were investigated through batch experiments. The results showed that 10 mg/L CIP was removed by 100%, 92% and 79% within 180 min using Fe.NPs, Cu.NPs, and Ag.NPs respectively. In addition to this, kinetic models of the adsorption and mechanism of CIP removal were studied. The cinematic analysis demonstrated that adsorption is a physics adsorption mechanism with an energy of 0.846 kJ.mol-1, 1.720 kJ.mol-1, and 3.872 kJ.mol-1, while the low activation energies of 17.660 kJ.mol-1, 13.221 kJ.mol-1, and 14.060 kJ.mol-1 for Fe.NPs, Cu.NPs, and Ag.NPs respectively. The kinetic removal process follows a pseudo-first-order model following a physical diffusion-controlled reaction. The data on adsorption was analyzed using the Langmuir, Freundlich, Temkin, and Dubinin models, as well as thermodynamic factors, indicating that the process is appropriate and endothermic sorption. The most practical adsorbent was Fe.NPs