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.

The influence of temperature and pH on the ageing of piping made from polyamide 11 (PA-11) was studied using water from an oilfield (pH ¼ 5.5) and deionized water (pH ¼ 7.0) with monitoring by corrected inherent viscosity (CIV) measurements. The hydrolytic degradation was more extensive at high temperatures in oilfield water. When the system reaches equilibrium, the pH affects mainly the CIV plateau values. Thermogravimetry, energydispersive X-ray spectroscopy, differential scanning calorimetry, X-ray diffraction, and scanning electron microscopy measurements were also used to investigate aspects involved in the ageing PA-11. The hydrolytic degradation of PA-11 leads to formation of low molar mass compounds, such as oligomers dispersed in the polymeric matrix. This is a process that occurs preferentially in the amorphous domain of PA-11, which leads to an increase in the degree of crystallinity and the formation of a new c-phase.

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A method for heavy and extraheavy crude oil digestion based on microwave-assisted wet digestion (MW-AD) and ultraviolet (UV) radiation using diluted HNO3 was applied for the determination of rare earth elements (REE) by inductively coupled plasma mass spectrometry (ICPMS) with an ultrasonic nebulizer (USN). Even using pressurized systems conventional acid digestion is not feasible for efficient crude oil digestion, especially for heavy and extraheavy crude oils that generally present high amounts of asphaltenes and resins. In the proposed system, UV radiation is generated in situ by immersed electrodeless Cd discharge lamps positioned inside quartz vessels. The use of diluted solutions (1-14.4 mol L(-1) HNO3 and 1-4 mol L(-1) H2O2) were evaluated for heavy and extraheavy crude oil digestion (API density of 11.1-19.0). With the proposed method the residual carbon content was lower than 13 mg C/100 mg of sample, and it was possible to digest sample masses up to 500 mg using 4 mol L(-1) HNO3 and 4 mol L(-1) H2O2. Interferences caused by excessive acid concentration and carbon content in digests were minimized allowing limits of quantification for REEs as low as 0.3 ng g(-1). Samples were also digested using MW-AD in pressurized systems with concentrated HNO3, but even using 280 °C, 80 bar, and concentrated HNO3, MW-AD method was not suitable for REE determination due to interferences in ICPMS determination. The combination of microwave heating with UV was considered a suitable and effective way to digest crude oil allowing further determination of low concentrations of REE by ICPMS.