Pressure Effect on the Rheological Behavior of Waxy Crude Oil with Comb-Type Copolymers Bearing Azobenzene Pendant

Li, Tao; Wang, Tongshuai; Xu, Jun; Zou, Run; Si, Zhongye; Becker, Julian; Li, Li; Stuart, Martien A. Cohen; Prud'homme, Robert Krafft; Guo, Xuhong

doi:10.1021/acs.iecr.7b05217

Cited by 18 publications

(16 citation statements)

References 34 publications

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“…The SP and CFPP of diesel untreated with PPDs are −7 and −2 °C, respectively. In our previous work, the effects of chain length of PPDs were discussed because at the length of near 17.1, the PPD presents a better depression. ,,− Thus, the R 1 MC-MB-NVP (R 1 = C 14 and C 16 ) were prepared and used as PPDs in this study. The effect of R 1 MC-MB-NVP (R 1 = C 14 and C 16 ) on the SP and CFPP of diesel fuel is presented in Tables and .…”

Section: Results and Discussionmentioning

confidence: 99%

“…Many studies have indicated that the main substances used as PPDs include the ethylene and vinyl acetate copolymers (EVA), , ethylene and butene copolymers (PE–PEB), , copolymers of maleic anhydride (MA), − and copolymers of alpha olefins , and their derivatives. − It is well-known that PPDs have appropriate lengths of alkyl side chain and polar groups, which can effectively improve the cold flow properties of diesel fuel. Thus, the molecular structure of PPDs is designed on the basis of the polarity-matching principle and carbon chain-matching principle.…”

Section: Introductionmentioning

confidence: 99%

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Influence of Methacrylate-benzyl Methacrylate-N-vinyl-2-pyrrolidone as Pour Point Depression on Cold Flow Properties of Diesel Fuel

et al. 2020

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The addition of benzyl methacrylate–methacrylate copolymers to diesel significantly improves its cold flow properties, but it is always limited by a large dosage. To improve the depressing efficiency further, N-vinyl-2-pyrrolidone (NVP), as a polar nitrogenous compound, was introduced, and a series of methacrylate-benzyl methacrylate-N-vinyl-2-pyrrolidone terpolymers (R1MC-MB-NVP) was synthesized at different molar ratios (1:1:1, 5:1:1, 10:1:1, 15:1:1, and 20:1:1). Those terpolymers were characterized by Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H-NMR), and thermogravimetric analysis (TGA). Their effects on the cold filter plugging point (CFPP) and solid point (SP) of diesel fuel were evaluated. With 2000 ppm of C14MC-MB-NVP (15:1:1), treated diesel has an improved depression on the solid point (SP) by 23 °C, whereas C16MC-MB-NVP (5:1:1) treated diesel indicates an improved reduction on the CFPP by 14 °C. However, combined PPDs (PPDC-6) of C14MC-MB-NVP (15:1:1) and C16MC- MB-NVP (5:1:1) in a mass ratio of 1:4 present the best depressing effects, and the SP and CFPP of diesel treated with 2000 ppm PPDC-6 are decreased by 29 and 15 °C, respectively. Furthermore, the action mechanism of PPDs was studied by polarizing optical microscopy, differential scanning calorimetry, and rheology analysis. Results showed that the introduction of NVP into PPDs not only improves the solubility and dispersity of wax crystals in diesel but also facilitates the formation of hydrogen bonds between PPDs and other polar substances and further disperses wax crystals into wax crystal molecules by the hydrogen bond ability.

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Section: Results and Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Influence of Methacrylate-benzyl Methacrylate-N-vinyl-2-pyrrolidone as Pour Point Depression on Cold Flow Properties of Diesel Fuel

et al. 2020

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“…Recently, in related work, a high-pressure capillary rheometer for the study of reservoir fluids was developed and the transition from Newtonian to non-Newtonian behavior observed at elevated pressures for some heavy oils . On the modeling side, Li et al , proposed an exponential–law relationship between viscosity and pressure. These last authors furthermore suggested that, at elevated pressure, the conformation transformation from cis to trans of azobenzene groups may destroy the assembly of asphaltenes, disturb the crystallization of paraffins and thus improve the flowability of oils.…”

Section: Introductionmentioning

confidence: 99%

Rheological Behavior of Heavy and Extra-Heavy Crude Oils at High Pressure

Ramírez-González

Quiñones-Cisneros

2020

Energy Fuels

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The processing, production, and transport of heavy crude oils are big challenges for the petroleum industry. Central to this challenge is the fluid viscosity: the key variable responsible for the oil fluidity throughout the entire production process. From the reservoir to delivery conditions, oils undergo large variations in temperature and pressure, which may cause important phase behavior and physicochemical changes, directly affecting the fluid’s thermophysical properties. In the case of heavy oils, such a broad change of conditions categorically results in several orders of magnitude viscosity span, including the possible Newtonian to non-Newtonian rheological behavior transitions. It is, therefore, of primary importance that heavy oils be rheologically well-characterized to ensure their production process is successful and viable. The viscosities of heavy and extra-heavy crude oils in extreme conditions (high pressure, high to low temperature, high to low shear rate) are, however, difficult for most service laboratories to fully measure directly. Several lapses may occur when measuring the full range of required conditions using traditional rheometers; for example, for such viscous fluids, the development of laminar-flow structural anomalies (eddies) and magnetic decoupling in the high-pressure cell are common practical problems. In an attempt to pragmatically address these problems, in this work, a methodology that may allow for the rheological characterization of heavy and extra-heavy oils within the full field operational range, but based on limited laboratory measurements, is proposed. The proposed approach does not follow from a simple extrapolation but is rather derived from the concept of control-variable shifting. For achieving this, the superposition principle is applied to shear-temperature and shear-pressure reliable measurements to construct master curves to rheologically characterize the fluid within conditions that may be too severe for direct laboratory measurements. This methodology has been successfully applied to a database of 20 Mexican fluids, going from extra-heavy to light fluids. The rheologies of the samples were originally studied using three different types of equipment: (1) a strain-controlled rheometer (for the measurement of the fluid rheology at ambient pressure and different temperatures), (2) a sliding piston viscometer for high-pressure and low-shear-rate viscosity measurements, and (3) a hybrid rheometer coupled with a pressure cell for the estimation of the fluids rheological behavior under pressure and high shear rate. The rheological behavior of crude oils could then be obtained at conditions as severe as the equipment allowed (up to 1000 bar and, in some cases, shear rate up to 1000 s–1). The master curves allowed, however, to extend the rheological characterization of the fluids within conditions that were beyond the laboratory capabilities.

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“…Among various viscosity reduction practices, chemical additives serve as a promising solution because of their stable performance and cost efficiency. For example, researchers have widely used amphipathic polymers, such as α-olefins–maleic anhydride copolymers, − ethylene–vinyl acetate copolymers, and poly[ N , N -(dimethylamino) ethyl methacrylate] (PDMA)-poly(lauryl methacrylate) (PLMA) copolymers, to stabilize crude oil in water by forming emulsions, and the effect of internal and external parameters such as chain lengths, hydrophilicity/hydrophobicity balance, as well as pH and ionic strength on the emulsification process, has been extensively investigated.…”

Section: Introductionmentioning

confidence: 99%

Effective Crude Oil Pickering Emulsification by Oil-Soluble Spherical Polymer Brushes

Wang

Zheng

et al. 2020

Energy Fuels

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Crude oil transportation has been increasingly important for chemical industry, and to enhance the flowability of crude oil, various surfactants and amphipathic polymers have been utilized to form oil-in-water emulsions. As an alternative to traditional surfactants, nanoparticulate polymer brushes serve as an ideal scaffold to form Pickering emulsions with crude oil because of their large specific area, excellent stability, and tunable surface property. In our paper, a new type of oil-soluble polymer brushes was utilized to achieve stable crude oil emulsification by forming Pickering emulsions in water. By combining inverse emulsion polymerization and photoemulsion polymerization, poly(N-vinylcarbazole) chains with different lengths were successfully grafted onto the water-soluble poly(acrylic acid) core dispersed in hexane, and the novel series of oil-soluble latex polymer brushes features monodispersity, well-tuned size and fluorescence, and stability, as verified by dynamic light scattering, transmission electron microscopy, UV−vis and fluorescence spectra, as well as small-angle X-ray scattering. More importantly, the amphiphilic nature of the latex particles was successfully utilized to stabilize crude oil droplets in water by forming Pickering emulsions with apparent viscosity reduced by 99%, which is superior to most of the additives used in industry. Therefore, the oil-soluble core−shell latex particles could serve as promising candidates to be applied in petrochemical industry by improving the flowability of heavy crude oil during its exploration, transportation, and recovery process.

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Pressure Effect on the Rheological Behavior of Waxy Crude Oil with Comb-Type Copolymers Bearing Azobenzene Pendant

Cited by 18 publications

References 34 publications

Influence of Methacrylate-benzyl Methacrylate-N-vinyl-2-pyrrolidone as Pour Point Depression on Cold Flow Properties of Diesel Fuel

Influence of Methacrylate-benzyl Methacrylate-N-vinyl-2-pyrrolidone as Pour Point Depression on Cold Flow Properties of Diesel Fuel

Rheological Behavior of Heavy and Extra-Heavy Crude Oils at High Pressure

Effective Crude Oil Pickering Emulsification by Oil-Soluble Spherical Polymer Brushes

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