Nael N. Zaki

Surfactant stabilized crude oil-in-water emulsions for pipeline transportation of viscous crude oils

Abstract The present work deals with studying the various factors affecting the stability and viscosity of a surfactant-stabilized viscous crude-oil-in-water emulsion for pipeline transportation. The study revealed that the stability of the oil-in-water emulsion stabilized by an anionic surfactant increases as the surfactant concentration increases with a subsequent decrease in the crude-oil-water interfacial tension. Increasing the oil content, the speed and the temperature of mixing of the emulsion resulted in an increased emulsion stability. The maximum sodium chloride concentration in the aqueous phase of the emulsion, above which surfactant precipitation occurred, was 1M at a surfactant concentration of 0.5% in the aqueous phase. For all sodium chloride concentrations of less than 1M, no emulsion resolution took place. The viscosity of the studied Geisum-crude-oil-in-water emulsion was decreased by decreasing the oil content and the speed of mixing and increasing the temperature. The pour-point values for oil-in-water emulsions having different oil contents were always less than those of the Geisum crude oil. Demulsification of the stable crude-oil-in-water emulsion was achieved by treatment with 60 ppm alkyl phenolformaldehyde oxyalkylated chemical demulsifier at 50°C.

Formation of fluid heavy oil-in-water emulsions for pipeline transportation

Abstract The diverse factors affecting the viscosity of a surfactant stabilized viscous crude oil-in-water emulsion for pipeline transportation were studied. The study discloses that the stability of the oil-in-water emulsion stabilized by a nonionic surfactant Nonyl Phenol Ethoxylate increases as the surfactant concentration increases with a subsequent decrease in the crude-oil–water interfacial tension (IFT). Increasing the oil content and the speed of mixing of the emulsion resulted in an increased emulsion stability. Fresh water and synthetic formation water were used to study the effect of aqueous phase salinity on the stability and viscosity of the emulsion. Surfactant dissolved in synthetic formation water was utilized to find out the possibility of injecting the surfactant into a well bore to effect emulsification in the pump or tubing for the production of heavy crude oils as oil-in-water emulsion. The effective viscosity of a viscous Egyptian crude oil (Geisum crude oil) decreased when it was emulsified with water in the presence of a nonionic surfactant in the form of an oil-in-water emulsion. It was possible to form stable emulsions with synthetic formation water characterized by a low dynamic shear viscosity. This will enhance the production of viscous crude oils by injecting surfactant dissolved in formation water to affect downhole emulsification. Further, the produced crude oil-in-water emulsion is characterized by its low effective viscosity which will facilitate its pipeline transportation to the refiner.

Propylene oxide-ethylene oxide block copolymers as demulsifiers for water-in-oil emulsions, I. Effect of molecular weight and hydrophilic-lipophylic balance on the demulsification efficiency

SummaryA series of propylene oxide (PO)-ethylene oxide (EO) block copolymers with differentEO/PO ratios and molecular weights have been prepared and tested for their demulsification potency in breaking synthetic water-in-benzene emulsions stabilized by asphaltenes. Their partition coefficients between benzene and water were determined by means of UV absorption. NMR spectroscopic analysis was used for determining the actualPO/EO ratios of these block copolymers. The effects of hydrophilic-lipophilic balance (HLB) and molecular weight of the prepared surfactants on their demulsification efficiency were investigated. It was found that the demulsification efficiency is directly proportional to both HLB and molecular weight.ZusammenfassungEine Reihe von Propylenoxid (PO)-Ethylenoxid (EO) Blockcopolymeren mit verschiedenenEO/PO-Verhältnissen und Molekulargewichten wurden hergestellt und auf ihre Effizienz bezüglich des Brechens von durch Asphalt stabilisierten synthetischen Wasser/Benzol-Emulsionen untersucht. Ihre Verteilungskoeffizienten zwischen Benzol und Wasser wurden mittels UV-Spektroskopie ermittelt. DasPO/EO-Verhältnis wurde NMR-spektroskopisch bestimmt. Die Effekte von Hydrophilie-Lipophilie-Gleichgewicht (HLB) und Molekulargewicht auf die Effizienz der Wirkung wurden untersucht. Das Emulsionsbrechungsvermögen ist direkt proportional zu HLB und indirekt proportional zum Molekulargewicht.

STABILITY AND RHEOLOGY OF HEAVY CRUDE OIL-IN-WATER EMULSION STABILIZED BY AN ANIONIC- NONIONIC SURFACTANT MIXTURE

ABSTRACT The stability and rheology of an Egyptian Heavy crude oil-in-water emulsions stabilized by an anionic (TDS) and a nonionic (NPE) surfactants individually or in a mixture have been studied. The study reveals that, the viscosity of the crude oil decreases when it is emulsified with water in the form of an oil-in-water type of emulsion. The stability of the oil-in-water emulsion increases as the surfactant concentration and speed of mixing of the emulsion increases. Fresh water and synthetic formation water have been used to study the effect of aqueous phase salinity on the stability and viscosity of the emulsion. Surfactant dissolved in synthetic formation water has been utilized to find out the possibility of injecting the surfactant into a well bore to effect emulsification in the pump or tubing for enhancing the production of heavy crude oils as oil-in-water emulsion. The study revealed that, the viscosity of the emulsion containing fresh water is always less than that containing formation water...

Propylene oxide-ethylene oxide block copolymers as demulsifiers for water-in-oil emulsions, II. Effects of temperature, salinity,pH-value, and solvents on the demulsification efficiency

SummaryThe effects of temperature, NaCl concentration (salinity),pH value, and solvents on the demulsification efficiency of propylene oxide (PO)-ethylene oxide (EO) block copolymers in the breaking of synthetic water-in-benzene emulsions stabilized by petroleum asphaltenes have been thoroughly investigated. The demulsification efficiency of the studied polymeric surfactants was found to increase with increasing temperature and decreasing salinity of the aqueous phase. A neutralpH value of the aqueous phase of the emulsion was found to be optimat for efficient demulsification. Water and water compatible solvents were found to be the best solvents for the prepared demulsifiers with respect to demulsification properties.ZusammenfassungDie Einflüsse von Temperatur, NaCl-Konzentration,pH-Wert und Lösungsmitteln auf die Fähigkeit von Propylenoxid-Ethylenoxid-Blockcopolymeren (PO-EO), durch Asphalte stabilisierte Wasser-in-Benzol-Emulsionen zu brechen, wurden eingehend studiert. Die Wirksamkeit der untersuchten polymeren oberflächenaktiven Substanzen steigt mit steigender Temperatur und sinkendem Salzgehalt der wäßrigen Phase. Am besten verläuft die Demulsifikation bei neutralempH-Wert. Wasser und vergleichbare Lösungsmittel eignen sich am besten zur Erzielung einer hohen Wirksamkeit der verwendeten Emulsionsbrecher.

Polyoxyalkylenated amines for breaking water‐in‐oil emulsions: effect of structural variations on the demulsification efficiency

In the present work, different aliphatic and aromatic amines were ethoxylated after a previous propoxylation (PPPEA) with different degrees of propoxylation and ethoxylation in order to obtain polymeric surfactants having different hydrophilic–lipophilic balance (HLB) values. The influence of the structural variations in the prepared PPPEA on their efficiency as demulsifiers for water-in-oil emulsions was investigated. Synthetic water-in-benzene emulsions stabilized by petroleum asphaltenes was utilized for the completion of this study. The actual propylene oxide (PO)–ethylene oxide (EO) ratios of the PPPEA under investigation was elucidated via 1H NMR spectroscopy. It was found that each demulsifier practices a maximum demulsification efficiency at an optimum concentration. At this concentration, the demulsifiers’ molecules were believed to form a monolayer by adsorbance at the benzene–water interface. The influences of the number of aromatic rings in the molecule, the degree of substitution in the aromatic rings, the number of amine groups, the number of PO–EO chains and HLB on the demulsification efficiency were accomplished.

POLYOXYALKYLENATED AMINES FOR BREAKING OF WATER-IN-OIL EMULSIONS STABILIZED BY ASPHALTENES AND CLAY

ABSTRACT The main objective of this paper is lo emphasize the efficiency of synthesized polyo.xyalkylenated amines (PPPEA) having different hydiophilic-lipophilic balance (HLB) values in breaking synthetic water-iu-benzene emulsions stabilized by both pelroleum asphaltenes and clay (EAC). It was found that the presence of clay and asphaltenes in a certain ratio (1:1 summing 0 5 wt / vol. % with respect to the total emulsion volume ) offers maximum emulsion stability. This was attributed to the effect of asphaltenes in converting water-wet particles (such as clay) into oil-wet panicles, which then act as emulsifying agents for waler-in-oil emulsions. This explains the synergistic effect resulting from the mutual interactions between asphaltenes and clay in stabilizing Eac. It was found that the most efficient demulsifiers for breaking Eac are the aromatic PPPEA having low HLB. This is attributed to the capability of the aromatic PPPEA demulsifiers lo form well developed interactions with the aromatic asphaltenes. This enhanced interaction will drag the asphaltenes and clay from the interlace increasing the demulsification efficiency.

SODIUM LIGNIN SULFONATE TO STABILIZE HEAVY CRUDE OIL-IN-WATER EMULSIONS FOR PIPELINE TRANSPORTATION

ABSTRACT The efficiency of sodium lignin sulfonate (SLS) as an anionic surfactant derived from waste wood pulping industry in stabilizing an Egyptian heavy crude oil (Geisum)-in-water emulsions for pipeline transportation has been investigated. The stability and rheology of the emulsions stabilized by SLS or with a nonionic surfactant nonyl phenol diethylenetriamine formaldehyde ethoxylate (NDFE) individually or in a mixture have been studied. It has been found that the dynamic shear viscosity of the crude oil decreases substantially when it is emulsified with water in the form of an oil-in-water type of emulsion. The stability of the oil-in-water emulsion increases as the surfactant concentration increases. Potable water and saline water containing different molar concentrations of NaCI have been used to study the effect of aqueous phase salinity on the stability and viscosity of the emulsion. Surfactant dissolved in saline water has been utilized to find out the possibility of injecting the surfactant into a well bore to effect emulsification in the pump or tubing for enhancing the production of heavy crude oils as oil-in-water emulsion. The study revealed that, the viscosity of the emulsion containing potable water is always less than that containing saline water and the viscosity increases as the salt content increased.

Polyoxyethylenated bisphenol-A for breaking water-in-oil emulsions

Polyethylene glycol (PEG) of different molecular weights, namely, 600, 1000 and 4000 g/mol was reacted with bisphenol A to form compounds having different hydrophile–lipophile balances and hence different surface activities. The interfacial tension at the aqueous/benzene interface was determined. It was found that the concentrations of demulsifiers required to cause a minimum interfacial tension are always less than those inducing a maximum demulsification efficiency. The demulsification efficiency of the prepared surfactants in breaking synthetic water in benzene emulsions stabilized by petroleum asphaltenes was evaluated. The data revealed that the demulsification efficiency increases with increasing demulsifier concentration, contact time and hydrophilicity.

LIQUEFACTION OF CELLULOSIC WASTE V. WATER FORMATION AND EVALUATION OF PYROLYTIC CHAR AS A BY —PRODUCT OF PYROLYSIS REACTION

ABSTRACT Liquid hydrocarbon oil and water have been produced from the liquefaction of cellulosic matter present in municipal solid wastes (MSW). Gases and residual char have also been produced as by-products resulting from the pyrolysis reaction of cellulose. Quantities of water and pyrolytic char were estimated at different conditions of the process (temperature pressure of hydrogen, carrier oil medium and concentration of boric acid). From the results obtained, it was suggested that the formation of water seems to be sensitive to the operational conditions which enhance a water-gas shift reaction (in which water molecules are consumed to produce carbon dioxide and hydrogen). Decreasing of the undesired chary by-product could be achieved by increasing the concentration of boric acid that catalyzes the liquefaction reaction. Two petroleum distillates, namely gas oil and residual fuel oil, were used as carrier media of a solid refuse. It was found that fuel oil is more efficient as a buffering medium that ...