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QSAR analysis was applied to obtain the water removal efficiency (WRE) values of triblock copolymers functionalized with tertiary amines, employed as demulsifier agents of crude oil. Taking into account the evaluation of F- and G-series reported by Zamora et al., the H-series was synthesized based on a triblock copolymer of 1920 g mol−1, and evaluated in CM1 and CM2 crude oils (7.5 and 18.7 °API). In addition, quantum and QSAR parameters, physicochemical properties of crude oil were included in the QSAR analysis. 66 WRE values were considered in the training set. Q2 value was established to weigh up an equation as acceptable, achieving eight equations, T1 – T8, for the training set. About external validation, F-, G- and H-series were assessed in CM3 heavy crude oil (16.9 °API), considering an overall of 33 WRE values for the validation. For the external validation, the coefficient of the prediction set (R2EXT), the predictive squared correlation coefficient (Q2Fn), the metric value (r2m), the concordance correlation coefficient (CCC), and the regression line slopes (k and k') criteria were obtained. Only two equations, T1 and T8, complied with threshold established in the validation criteria. About r2m criterion, T8 equation gave a better correlation, 0.62, than that of T1 equation, 0.58. However, both equations could be optimal to calculate the water removal efficiency. Regarding physicochemical parameters of crude oil, number average molecular mass and run-off temperature were the unique parameters showing a clear effect over the calculated water removal efficiency. Equation T8Log WRE = 0.05313 – 38.58707S + 0.27904ω – 2.77429ACN + 0.06309MR –0.14811α – 0.012 TROR2=0.6369, SD = 0.4112, F = 17.2457, Q2=0.6369 [ABSTRACT FROM AUTHOR]

Although normally the copolymers used to remove water from crude oil have a block structure, two series of random acrylic copolymers were evaluated as petroleum demulsifiers. These acrylic copolymers, with two different butyl acrylate (BuA) and 2-ethylhexyl acrylate (2-EHA) contents, were synthesized by semi-continuous emulsion polymerization. Their weight-average molar mass () was varied by modifying the amount of chain transfer agent relative to the monomers from 0 to 8 wt%. FTIR and 13C-NMR spectroscopies confirmed that the conversion of the monomers was complete. The synthesized acrylic copolymers were subsequently evaluated as demulsifier agents in a Mexican heavy crude oil (10.24°API). Copolymers with 70 wt% butyl acrylate monomer and a weight-average molar mass above of 11 000 g mol−1 presented the greatest ability to remove emulsified water from the system. The demulsifying capability of the copolymer was evidenced to be strongly dependent on their molecular mass. Synthesis of random acrylic copolymers (BuA-co-2-EHA) of different average molar mass (). Evaluation of random acrylic copolymers as demulsifiers of heavy crude oil. Weight-average molar mass () and monomer composition play an important role on the performance of random acrylic copolymers as demulsifiers. [ABSTRACT FROM AUTHOR]

The main actinobacterial genera able to degrade polycyclic aromatic hydrocarbons (PAHs) include Mycobacterium , Nocardia , Rhodococcus , and Gordonia . However, it is unknown if other actinobacterial genera can degrade PAHs. In this work, three actinobacteria strains that utilize PAHs as the sole source of carbon and energy, were isolate and termed Amycolatopsis sp. Poz14, Gordonia sp. Poz20, and Rhodococcus sp. Poz54. The strains use low-molecular-weight (LMW; naphthalene and anthracene) and high-molecular-weight (HMW; pyrene and fluoranthene) PAHs at 50 mg L −1 as the sole carbon and energy sources; except Amycolatopsis sp. Poz14 which tolerate up to 200 mg L −1 . Amycolatopsis sp. Poz14 exhibited higher degradation percentages for LMW-PAH than HMW-PAH, from 100% for naphthalene, 37.87% for anthracene, 25.10% for pyrene, and 18.18% for fluoranthene within 45-day. Degradation efficiency of PAHs by Amycolatopsis sp. Poz14 improved by adding tween 20 to 1000 mg L −1 . Moreover, degradation kinetics of binary mixtures of PAHs were conducted, Amycolatopsis sp. Poz14 used both PAHs from the beginning of the kinetics, and degradation efficiencies in binary mixtures were better than those achieved in single PAH. To the best of our knowledge, this is the first report involving to genus Amycolatopsis in the degradation of LMW- and HMW-PAHs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Random acrylic terpolymers as demulsifying agents for crude oil. • Trifunctional molecule with exceptional dehydrating and clarifying capacities. • Higher performance to dehydrate crude oils than commercial formulations. • Prediction of dehydrating efficiency as function of the crude oil properties. A novel kind of random acrylic terpolymers based on butyl acrylate (B), 2-(dimethylamino)ethyl acrylate (Ae), and 2-carboxyethyl acrylate (Ce) monomers was obtained by emulsion polymerization. Monomers' weight ratios were varied, keeping in all cases a higher content of butyl acrylate (60, 70, 80, and 90 wt%) and controlling the number average molecular mass (M ¯ n) during polymerization. The random acrylic terpolymers were characterized by spectroscopic techniques; subsequently evaluated as demulsifier agents in three aged heavy crude oils of 7.55, 6.11, and 3.33 °API (apparent gravities), which form very stable water-in-oil (W/O) emulsions. The best performance for removing the emulsified water at 80 °C was obtained with terpolymers containing 90–80 wt% of the hydrophobic monomer B and small amounts of the hydrophilic monomers Ae and Ce (BAeCe-9551 and BAeCe-8111), being more efficient than two commercial demulsifiers (FDH-1 and F-46 TRETOLITE™). Moreover, the BAeCe-9551 terpolymer was evaluated in a fresh heavy crude oil of 20.2 °API at 60 °C — temperature of separation tanks —, showing better performance as breaker, coalescer, and clarifier than FDH-1. Finally, a quantitative structure–activity relationship (QSAR) analysis was carried out employing terpolymers' molecular parameters and crude oils' physicochemical parameters. Only one equation fulfilled all thresholds for Q F 1 2 , Q F 2 2 , Q F 3 2 , and r m 2 parameters, proving to be the most accurate to predict the water removal efficiency (WRE) of BAeCe-1 and BAeCe-2 series terpolymers when added to heavy crude oils. This correlation will allow selecting the best terpolymer for demulsifying a petroleum stream as a function of its physicochemical characteristics. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel demulsifiers for heavy and extra-heavy crude oils based on acrylic monomers. • Chemical demulsifiers to treat and destabilize complex crude oil emulsions. • Superior dehydrating and clarifying capacity to that of polyethers formulations. • DPD simulation to stablish the dehydrating mechanism of new acrylic demulsifiers. In this work, a series of novel random alkyl acrylic-amino alkyl acrylic bipolymers was synthetized by semi-continuous emulsion polymerization technique. The obtained bipolymers were characterized mainly by Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), 1D and 2D nuclear magnetic resonance (NMR) and size exclusion chromatography (SEC). Afterwards, these bipolymers were evaluated as demulsifying agents in four heavy crude oils. The evaluations revealed that the efficiency of the synthesized acrylic bipolymers to break the emulsion, induce the drop coalescence and clarify the remaining aqueous phase depends strongly on their alkyl acrylic/amino alkyl acrylic ratio in the chain and average molecular mass. Likewise, it could be noted in three samples of heavy crude oils from Motul field that a greater content of the amino alkyl acrylate monomer in the bipolymer chain and a higher molecular mass allowed reaching higher emulsion removal efficiencies, with good water clarification. It was also shown that, in all the cases, a single acrylic bipolymer is able to remove the water dispersed in petroleum in a more efficient way than a commercial formulation of four triblock bipolymers based on ethylene and propylene oxide, when it possesses convenient structural features. In addition, for a better understanding of the improved dehydrating efficiency of the new acrylic demulsifiers reported in this study, a mechanism of bridge formation between water drops to provoke coalescence was established by dissipative particle dynamics (DPD) simulation. This theoretical technique was also applied to calculate the decrease of the interfacial tension as a function of the number of alkyl acrylic-amino alkyl acrylic chains at the water/crude oil interface. [ABSTRACT FROM AUTHOR]