Crude oil is a kind of water/oil emulsion, which the oil phase consists of organic molecules with different molecular weights such as alkanes, paraffin, asphaltene, and resins. Due to the change in physicochemical conditions during the production, transportation, storage, and refining, heavier molecules can precipitate from crude oil. Thus, viscous sludge formed at the bottom of storage tanks can cause many problems including reduction of storage capacity of tank, oil contamination, corrosion, repair costs, environmental pollution, etc. The reduction of sludge viscosity can be achieved by reduction of its interfacial tension. In this study, different chemical and physical factors, influencing prepared emulsions (made of sludge, water and surfactant), such as surfactants, solvents, temperature, pressure, and mixing conditions were investigated. Results showed that non-ionic surfactants (like bitumen emulsifier), and solvents (such as mixed xylene, AW-400, and AW-402), injection of additives, applying pressure, and mixing operations had a positive effect on reduction of emulsion viscosity. All experiments were carried out with sludge obtained from crude oil storage tanks at Kharg Island, Iran.

TEMPO nanofibrillated cellulose (TNFC) from two underutilized Appalachian hardwoods, Northern red oak (Quercus rubra) and yellow poplar (Liriodendron tulipifera), was prepared to determine its feasibility to be used as template for antimicrobial metallic copper particles. In addition, a comparison of the TNFC from the two species in terms of their morphological, chemical, thermal, and mechanical properties was also performed. The woody biomass was provided in the form of logging residue from Preston County, West Virginia. A traditional kraft process was used to produce the pulp followed by a five-stage bleaching. Bleached pulps were then subjected to a TEMPO oxidation process using the TEMPO/NaBr/NaClO system to facilitate the final mechanical fibrillation process and surface incorporation of metallic copper. The final TNFC diameters for red oak and yellow poplar presented similar dimensions, 3.8 ± 0.74 nm and 3.6 ± 0.85 nm, respectively. The TNFC films fabricated from both species exhibited no statistical differences in both Young's modulus and the final strength properties. Likely, after the TEMPO oxidation process both species exhibited similar carboxyl group content, of approximately 0.8 mmol/g, and both species demonstrated excellent capability to incorporate antimicrobial copper on their surfaces.

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Sodium cocoyl sarcosinate is an important surfactant with a particular chemical structure and many practical applications in various industries. The synthesis of sodium cocoyl sarcosinate involves the reaction of cocoyl chloride and N‐methyl glycine. The influences of reactant molar ratios, temperature, reaction time, pH, and solvent on the reaction yield were investigated and also the kinetics of the reaction was studied. It was found that the reaction follows second order kinetics and the reaction rate constant is 0.0153 mol−1 L s−1 at 35 °C. Also production of sodium cocoyl sarcosinate was carried out at bench and pilot scales which is described in details.

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Summary For decades, asphaltene deposits have been one of the most common problems in the oil industry in production, transportation, refining, processes, and storage. To find a solution, researchers have always faced three intertwined challenges of accurate structure determination, properties investigation, and precipitation prediction because asphaltenes in one oil sample are “a spectrum of complex molecular structures with very close masses.” Various models and theories of the inherent self-association of asphaltenes have been presented. All of them confirm the role of the unique molecular structure of asphaltenes as “the initiator” of the precipitation process. The driving factor for self-association is π-π stacking of aromatic rings. Recent advances in molecular dynamics (MD) calculations confirm the results of recent models. After the molecular structure, thermodynamic parameters (P, T, and composition) are the influencing agents on precipitation. Any change in these parameters causes an increase or decrease in the intensity of the precipitation. Due to the greater importance of molecular structure over other parameters, until the great challenge of characterization of asphaltenes is not specific, the validation of sediment prediction models will undoubtedly be accompanied by errors. In this paper, we review essential types of asphaltene self-association models and precipitation prediction methods. As an introduction and emphasis on the understanding of this inherent phenomenon, the weight, molecular structures, analysis methods, and ambiguities are investigated.

Bitumen emulsions are preferred over conventional pavement systems due to their biologically and environmentally acceptable formulation, safety, low viscosity, storage stability, and cost effectiveness. The present investigation deals with the systematic study to synthesize ortho-cocodi-amido toluene and four quaternary derivatives by amidation of coconut oil and ortho toluene diamine (OTD), followed by quaternization with formaldehyde, formic acid mixture, and acrylonitrile, resulted in a new quaternary compound useful as cationic emulsifier in bitumen emulsions. The roles of temperature and reaction time in determining optimum conditions were investigated as well. Emulsifying behavior of these quaternary compounds was studied by sieve residue test, settlement and storage stability test of emulsified asphalt, and water solubility. The results show that the acrylonitrile imidazolinium derivative of o-cocodi-amido toluene (VI) can be used as a rapid-medium setting emulsifier.