A.M. Al-Sabagh

Surface active properties of chitosan and its derivatives

This review discusses the definition of surface active agents and specifically natural polymeric surface active agents. Chitosan by itself was found to have weak surface activity since it has no hydrophobic segments. Chemical modifications of chitosan could improve such surface activity. This is achieved by introducing hydrophobic substituents in its glucosidic group. Several examples of chitosan derivatives with surfactant activity have been surveyed. The surface active polymers form micelles and aggregates which have enormous importance in the entrapment of water-insoluble drugs and consequently applications in the controlled drug delivery and many biomedical fields. Chitosan also interacts with several substrates by electrostatic and hydrophobic interactions with considerable biomedical applications.

The relevance HLB of surfactants on the stability of asphalt emulsion

Abstract In this study, 13 non-ionic surfactants were selected; they have been used in wide range of HLB from 4 to 17.6. Asphalt emulsions with individual and some mixtures of surfactants were done. The stability of emulsions was determined via three physical means, batch settling time, particle size analysis and rheological characterization. The optimum stability of w/o emulsions was obtained at HLB range 4–6 with 30% water (dispersed phase). But the maximum stability of o/w emulsions was exhibited at HLB range 10–13, with 70% asphalt (dispersed phase). Five mixtures of surfactants (1:1 molar ratio) with HLB range 11.2–11.7 were formulated. The results reveal that, the mixtures with narrow range of HLB enhance the stability of asphalt emulsions and they exhibited long course of stability (95–155 days). The effect of carbon numbers in the hydrocarbon chain length of the surfactant on the stability of emulsions was classified for Tween 81, G1089 and Tween 85 with narrow HLB range (10–11). The data clears that; the increase of the carbon number in the chain length of surfactant enhances the stability of asphalt emulsions. The rheological parameters shows that, the increase of the carbon numbers in the alkyl chain length acts to increase the viscosity and the stability of asphalt emulsions which hindrance the coalescence rate. By analysis of the data obtained, it has been founded that, there is no discrepancy between the stability of asphalt emulsions related to HLB of the surfactants (emulsifiers), which was determined from the batch settling test and the particle size analysis.

Water‐based non‐ionic polymeric surfactants as oil spill dispersants

In this paper, polyisobutylene succinic anhydride adduct (PIB-SA) was modified by esterification with polyethylene glycol (PEG 600, 1000 and 2000) to obtain mono- and diterminal polyoxyalkynated PIB-SA. The monoterminal products were reacted with pentamethylene-hexamine (PMHA). The structures were confirmed by FT–IR and 1H NMR analysis. The surface properties, interfacial tension and the effectiveness in oil dispersion of the synthesized polymeric surfactants are reported. The maximum efficiency of oil spill dispersants was reached when the surfactant molecule had two moities (polyoxyalkylene and polyamine units). © 1999 Society of Chemical Industry

Functions of Demulsifiers in the Petroleum Industry

There are an increasing number of crude oil fields that are now producing both crude oil and water emulsions; such fields are both onshore and offshore. These emulsions are formed during oil exploitation due to the presence of natural surfactants, such as asphaltenes and resins. These molecules strongly stabilize the water/oil interface and prevent coalescence of water droplets. As water/oil phase separation is necessary before oil transportation and refining, demulsifiers are used to break water-in-oil emulsions. This review presents the crude oil emulsion formation, factors affecting demulsification of crude oil emulsion such as demulsifier chemical structure, water content, partition coefficient (KP), and demulsifier concentration. This review also covers the kinetics and mechanism of the demulsification process.

BREAKING WATER-IN-CRUDE OIL EMULSIONS BY NOVEL DEMULSIFIERS BASED ON MALEIC ANHYDRIDE–OLEIC ACID ADDUCT

ABSTRACT This paper mainly concentrates on synthesis of ten novel demulsifiers and investigate their demulsification efficiency. The demulsifiers were derived from oleic acid–maleic anhydride adduct (OM), which prepared by reaction of oleic acid with maleic anhydride. The reaction was carried out between the OM adduct and the following compounds to form the correspondence demulsifiers; triethanolamine (OMTEA), triglycerol (OMTG), cetylamine (OMCA), triethanolamine with lauryl alcohol (OMTEA–LA), triethanolamine with cetylamine (OMTEA–CA), polyethylene glycol 600 (one mole (OM e.o. 13.6)), polyethylene glycol 600 (two moles (OM e.o. (13.6) 2)), polyethylene glycol 1000 (OM e.o. 22.7), triethanolamine with polyethylene glycol 1000 (OMTEA e.o. 22.7) and triethanolamine with polyethylene glycol 6000 (OMTEA e.o. 136.4). The chemical structures of the OM adduct and some selected demulsifiers were confirmed by 1H NMR and FTIR. A wide range of demulsifier properties can be obtained by changing the degree of functionalization of the base molecules. The demulsification efficiency of these demulsifiers was tested on w/o emulsions with 10, 30 and 50% water content. From the obtained data, it has found that, the investigated demulsifiers are having a great potential to break the w/o emulsions completely in different times. The (OMTEA e.o. 136.4) was exhibited the minimum time taken to complete separation. The data were discussed on the light of the chemical structure of the demulsifiers and the factors, which effect on the demulsification process.

Investigate the Demulsification Efficiency of Some Novel Demulsifiers in Relation to Their Surface Active Properties

In this work seven novel demulsifiers were prepared; the first four compounds were based on maleic anhydride‐oleic acid adduct MO. The first of them is hexaglycerol MO (HGMO) and other three different compounds are ethoxylated MO adduct,(n=30, 45, and 60), namily; E(30)MO; E(45)MO, and E(60)MO. The later three demulsifiers were based on polyethylene‐polypropylene oxide co‐polymer and maleic anhydride‐oleic acid adduct at different molecular weights of copolymer (BP), (8×103, 12×103, and 20×103), namily; MOBP8, MOBP12, and MOBP20. The surface tension (γ) at 30, 40, 50, 60°C of their solutions was measured. The critical micelle concentration (CMC) of theses demulsifiers was determined by the surface tension and the dynamic light scattering. From the obtained data, it was found that, the CMC values of the two methods are nearly closed. Further calculations were made to obtain the surface active properties and thermodynamic parameters of micellization and adsorption. The demulsification efficiency of these demulsifiers was determined on the basis of the time taken for complete water separation of emulsion. The discrepancies of efficiencies were discussed on the light of the chemical structure, the surface and thermodynamic properties.

Direct synthesis and the morphological control of highly ordered mesoporous AlSBA-15 using urea-tetrachloroaluminate as a novel aluminum source

The synthesis of AlSBA-15 under mild acidic conditions was performed through adjusting the molar H2O/HCl ratio, which indicates the formation of Si–O–Al linkages that lead to isomorphous substitution of Si4+ by some Al3+ ions. In this paper, the direct incorporation of Al3+ onto a SBA-15 framework in acid mediated synthesis with a nSi/nAl molar ratio of 7 was optimized using urea tetrachloroaluminate ionic liquid as a new aluminum source. The hydrothermal temperature was varied from 80 to 140 °C and the samples were denoted as AlSBA-15(Ux). The conventional AlSBA-15 also was prepared using direct synthesis [AlSBA-15(D)] and post synthesis [AlSBA-15(P)] aiming to study the influence of aluminum sources and preparation conditions on their structural, textural, and physicochemical properties. The synthesized materials were characterized by N2 physisorption, XRD, FT-IR, Py-FT-IR, NH3-TPD, XRF, HRTEM and SEM. All preparation methods led to the formation of aluminum containing SBA-15 samples with different Si/Al contents. Nevertheless, depending on the preparation methods, the AlSBA-15 samples exhibited different structural, morphology, and surface characteristics, especially in terms of Bronsted and Lewis acid site content. AlSBA-15(U100) had high surface area (813 m2 g−1) and high acidity. TEM images of synthesized AlSBA-15(U100) showed well-ordered hexagonal arrays of uniform cylindrical channels. The effectiveness of AlSBA-15, as an acid catalyst, was studied for the esterification of acetic acid with butanol and cumene cracking. The high activity of AlSBA-15(U100) is attributed to its good ordered structure and high acidity.

Synthesis and evaluation of some polymeric surfactants for treating crude oil emulsions. Part I: treatment of sandy soil polluted with crude oil by monomeric and polymeric surfactants

Abstract In the present work, five surfactants were prepared; two of them were monomeric surfactants, one was anionic (tri-ethanol ammonium salt of dodecyl benzene sulfonic acid, E1) and the second was non-ionic surfactant (nonyl phenol ethoxylate,E2). The other three surfactants were polymeric non-ionic surfactants (ethoxylated polynonyl phenol formaldehyde mono-ethanol amine E3, ethoxylated poly nonyl phenol formaldehyde diethanol amine E4, and ethoxylated nonoyl phenol formaldehyde triethanol amine E5). The gel permeation chromatography (GPC) and the elemental analysis were carried out to determine the molecular weight of the polymeric surfactants. The surface properties for these surfactants were determined by measuring the surface tension, the interfacial tension, the foaming power, cloud point and the emulsification power. The polymeric surfactants were used to treat the polluted sandy soil, which saturated with two types of crude oils (waxy and asphaltenic). From the data obtained it was found that, the increasing of surfactant concentrations led to increase the reclaimation of the waxy and asphaltinic crude oil percentages and decreased the interfacial tension. The reclaimed oil percentage increased with decreasing the hydrophilic-lipophilic balance (HLB) value of non-ionic surfactant. In general behavior, the reclamation of the asphaltenic crude oil was greater than the reclaimation of the waxy crude oil. The data were discussed on light of the chemical structure of the surfactants and composition of crude oil.

Preparation the Esters of Oleic Acid-Maleic Anhydride Copolymer and Their Evaluation as Flow Improvers for Waxy Crude Oil

Five comb-like copolymers derived from oleic acid-maleic anhydride were prepared and then esterified by long-chain fatty alcohol (POMA Cn), where n = 18, 20, 22. These polymers were characterized by FTIR and 1H NMR analysis. The molecular weight was determined by using gel permeation chromatography (GPC). The prepared copolymers were investigated as flow improvers and pour point depressants (PPD) for crude oil. From the evaluation, it was found that, the maximum depression of PP was obtained by (POMA2 C22) with long-chain alcohol (C22–OH) from 27°C to 15°C (ΔPP3000ppm = −12°C). On the other side, it was remarked that no depression obtained by (POMA2 C18), which esterified by alcohol (C18–OH) at the same condition. The depression of pour point effectiveness was discussed on the light of polymers structure, molecular weights, and their concentrations. By analysis the results of the rheological flow properties, it was found that the POMA2 C22 enhanced the Bingham yield values (τβ). The τβ for crude oil without additives against 15, 27, and 39°C were 0.286, 0.131, and 0.075 Pa respectively, whereas the τβ for the treated crude oil with POMA2 C22 were 0.027, 0.022 and 0.010 Pa at 3000 ppm at the same temperatures. By using the photomicrography analysis, it was found that, the wax morphology was greatly modified to fine dispersed crystals of compact size.

Styrene-Maleic Anhydride Copolymer Esters as Flow Improvers of Waxy Crude Oil

Four comb-like copolymers derived from styrene-maleic anhydride copolymer were prepared and characterized by FTIR, 1H-NMR and elemental analysis. The molecular weight was determined using GPC and their intrinsic viscosity was measured. The prepared polymers were investigated as pour point depressants and flow improvers for waxy crude oil and it was found that, the maximum depression was obtained by the sample that has long branch chain (PPD4) from 27°C to −3°C (ΔPP = 30°C, at 10000 ppm). While, the minimum depression was exhibited by short branch chain, PPD1 (ΔPP = 21°C) at the same conditions. The effect of these polymers on the rheology and flow properties of Qarun waxy crude oil was investigated. It was found that the Bingham yield value (τβ) decreased from 6.0 pa.s. to 0.5 pa.s. for PPD4 at 27°C and 10,000 ppm. The dynamic viscosity also decreased from 110 m pa.s. to 24 m pa.s. for the same sample and the same conditions.