The main objective of this work is to investigate the effect of a set of crude oil emulsion variables, including pH and salt and water contents, upon the microwave demulsification process. A series of batch demulsification runs were carried out to evaluate the final emulsified water content of emulsion samples after the exposure to microwaves. Tests were performed at distinct heating temperatures, using water-in-heavy crude oil emulsion samples containing different salt and water contents and pH. Well-defined temperature programs were established to control the amount of energy applied to the emulsion and, ultimately, the viscosity. Higher microwave demulsification efficiencies were achieved for emulsions containing high water contents, except when high pH and salt contents were simultaneously involved.

The main objective of this work is to investigate the role of two types of ionic liquids, omimBF4 and omimPF6, upon the microwave demulsification process. A series of batch demulsification runs were carried out to evaluate the final emulsified water content of emulsion samples after the exposure to microwaves at distinct ionic liquid concentrations. Tests were performed in a commercial microwave reactor system, using high stable water-in-crude oil emulsion samples containing different salt and water contents. Similar separation tests conducted under conventional heating were investigated for comparisons. Results showed that increasing the concentration of each ionic liquid yields improved demulsification results in both microwave and conventional heating processes. However, the microwave process was always much faster and more efficient than the conventional case. Blank tests without ionic liquid have not produced water separation, which indicates the high stability of the investigated emulsions. In particular, the joint use of omimPF6 (even at low concentrations) and microwave irradiation allows for system demulsification with high efficiency at short time, with some cases even reaching water contents in the range of 1−2% in the final emulsion.

The use of ionic liquids (ILs) as demulsifiers of water-in-crude oil emulsions represents a new field of study. The main purpose of this work is to investigate the effect of five ILs, [C 4 and a set of operation parameters on the demulsification process, including the heating type (conventional and microwave), IL concentration (0.74−8.9 μmol/g), effect of alkyl chain length, and effect of cation and anion type on demulsification efficiency. The results indicated that the demulsification was favored when more hydrophobic ILs and longer cation alkyl chains were employed, such as [C 12 mim] + [NTf 2 ] − , reaching values close to 92% of water removal. Moreover, the joint use of microwaves and hydrophobic ILs allowed us to maximize the demulsification efficiency.

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In this work, the stability of water-in-crude oil emulsions generated in laboratory was investigated using a phenomenological mathematical model based on the population balance equation, considering different phenomena such as the binary coalescence of water droplets, the interfacial coalescence with the resolved water phase, the diffusion of the dispersed phase, and droplet settling. The resulting population balance equation (PBE) was a nonlinear hyperbolic integro-partial differential equation, which for our particular case required numerical techniques for resolution. The PBE was converted into a system of partial differential equations using Kumar's fixed-pivot technique. The spatial coordinate was discretized using the finite volume method and a first order upwind scheme, while the discretization of the time coordinate was based on a semi-implicit approach. On the basis of this algorithm, the mathematical model was solved against experimental results of water-in-crude oil emulsion destabilization runs, providing suited predictions of droplet size distribution profiles, and of both emulsified water and free-water volumes.

The stability particles produced by emulsion polymerization and stabilized by the anionic surfactant sodium dodecyl sulfate, an electrosteric surfactant with a short ethylene oxide chain, or simply with sulfate end groups were studied by turbidity measurements. Results are compared to those of electrostatic stability models based on the Derjaguin-Landau-Verwey-Overbeek theory. The good agreement between experimental and theoretical data shows that the electrosteric surfactant could be described through electrostatic approaches and that the steric contributions could be neglected. This model was incorporated into a population balance model in order to describe the coagulation between particles in a stirred tank reactor in the absence of reaction. This model was validated with experiments in which coagulation between polymer particles was provoked by electrolyte addition. The decrease of the number of particles and the resulting monomodal particle size distribution were correctly described by the model, confirming the correct determination of coagulation rates as a function of the particle diameter and surfactant concentration.

The main objective of this work is evaluating the influence of water content and average droplet size upon the near-infrared (NIR) spectra collected during water-in-crude oil emulsions synthesis and observing whether NIR spectroscopy may be used for predicting these properties simultaneously. It is shown that NIR spectra are sensitive to changes of the water content and average droplet size and that standard empirical models [partial least-squares (PLS)] may be built to correlate these properties and total absorbance at the NIR region properly. Finally, it is shown that these models, built with off-line experiments, allow for the online evaluation of average droplet size and water content in water-in-crude oil emulsions with NIR spectroscopy when low water content (<5 wt %) is involved.

Ethane-1,2-diol (monoethylene glycol, MEG) is an important gas hydrate inhibitor used in the petroleum industry. The solubility of gases in mixtures of MEG/water is an important issue considering the MEG regeneration process and strategies for corrosion and salt deposition reduction. In this study the solubility and excess properties of carbon dioxide (CO 2 ) in MEG/water mixtures were assessed using a static methodology. The Henry's constant and solubilites were measured up to 0.5 MPa, from (288 to 348) K, and in molar concentrations of MEG in water of 0.0, 0.1, 0.5, 0.9, and 1.0. The temperature presented a remarkable negative influence on the CO 2 solubility in the liquid mixture, whereas pressure showed a positive linear effect on the gas solubility. The results indicated that MEG concentration has an important role on solubility of CO 2 in the liquid mixture. The excess solution enthalpy and entropy were also determined from the experimental data.