M.R. Noor El-Din

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.

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.

Investigation of the Demulsification Efficiency of Some Ethoxylated Polyalkylphenol Formaldehydes Based on Locally Obtained Materials to Resolve Water-in-Oil Emulsions

Fourteen ethoxylated polyalkylphenol formaldehyde surfactants were prepared from locally sourced raw materials. These surfactants were used as demulsifiers to resolve asphltenic crude oil emulsions. Different factors affecting demulsification efficiency such as water:oil ratios, surfactant concentration, surfactant molecular weight, ethylene oxide content, alkyl chain length, and asphaltene content were investigated. From the data obtained it was found that the demulsification efficiency increases by increasing the concentration, alkyl chain length and water content in the emulsion. Also it was found that the increase of asphaltene content in the crude oil impeded the demulsification efficiency. The effect of molecular weight was studied and it was found that the demulsification efficiency was controlled by an optimum range of molecular weight between 3640 to 3810 for the family of demulsifiers studied. Regarding the effect of ethylene oxide content in the demulsifier structure, it was found that the maximum demulsification efficiency was obtaind at 40 units ethylene oxide. The maximum demulsification efficiency was obtained by TND5 (m.wt. = 3800, eo = 40 units). With this demulsifier 100% water separation was exhibited after 35 minutes at 150 ppm demulsifier concentration and 50% w/o emulsion. The surface, interfacial tension, and hydrophilic lipophilic balance (HLB) of the invistigated demulsifers were studied. The obtained results justified that they are strongly related to the demulsification effeciency.

Study of the Inhibition Efficiency for Some Novel Surfactants on the Carbon Steel (Type H-11) Pipelines in 0.5 M HCl Solution by Potentiodynamic Technique

In this article, three deferent surfactants as corrosion inhibitor were prepared in two steps. In the first step, maleic anhydride was amidated with dodecylamine to produce 2-ene-4-dodecanamide butanoic acid. In the second step, the resulting product was further esterified with different molecular weights of polyethylene glycol (m.wt. = 200, 400, and 600), namely, polyoxy ethylenyl-x-ene-4-dodecanamide butanoic acid, where x = 2, 4, or 6 according to molecular weights of polyethylene glycol used). The chemical structures of these inhibitors were confirmed by FTIR and 1H NMR. The corrosion inhibition effect of the synthesized inhibitors has been investigated on the carbon steel (type H-11) pipelines in 0.5 M HCl solution by the potentiodynamic polarization method. From the obtained results, it was found that the maximum inhibition efficiency (90.44%) was exhibited by polyoxy ethylenyl-6-ene-4-dodecanamide butanoic acid, while the minimum inhibition efficiency (79.84%) was obtained by polyoxy ethylenyl-2-ene-4-dodecanamide butanoic acid at 200 ppm and 35°C. Also, the values of activation energy and thermodynamic parameters were calculated and discussed. Adsorption of the synthesized inhibitors was found to follow the Langmuirs adsorption isotherm. Mixed physical and chemical adsorption mechanism is proposed.

The Interfacial Tension and Alkane Carbon Number (nmin) of Alkyl Benzene Sulfonates in Relation to Enhanced Oil Recovery. Part I: Effect of Surfactant Molecular Weight/Temperature and Electrolyte on nmin

Twelve anionic monoisomeric surfactants based on the alkyl benzene sulfonic acid were prepared. In two sets of experiments, the (nmin) values were determined at 28 and 70°C for them. The n-hydrocarbon scans (n-C5 to n-C18) against the interfacial tension were used to determine the (nmin) values. The factors affecting (nmin) such as; molecular weight, branching of side chain, temperature and electrolyte addition were investigated. From the obtained results, it was found that the surfactants which has the highest molecular (8φ C15 ABS) gave (nmin) equal 8, so it can be used in the enhanced oil recovery(EOR) without additives (the suitable (nmin) for EOR between 7-9). Otherwise, the lowest molecular weight surfactant (7φ C13 ABS) gave (nmin) equal 5 without addition of alcohols or electrolyte. This case needs some additives to adjust the (nmin) in the range of 7 to 9. By investigation the factors affecting (nmin), it was found that the side chain of alkyl benzene shifted the (nmin) to the highest values. The increasing of temperature decreased the (nmin) values. Also, it was found that the (nmin) increased to high value by adding the electrolytes and alcohols. The mixture between surfactants with and without side chain shifted the (nmin) to the highest value. Using these parameters, the alkane carbon number (nmin) can be used to select the suitable solvent during the preparation of emulsion to get the minimum interfacial tension at which the maximum emulsion stability should be obtained and also to select the surfactant for EOR.

Synthesis and Evaluation of Some Modified Polyoxyethylene‐Polyoxypropylene Block Polymer as Water‐in‐Oil Emulsion Breakers

This article mainly concentrates on synthesis of five novel demulsifiers. The demulsifiers were prepared in two steps; the first was carried out by reaction between oleic acid and maleic anhydride to form oleic acid‐maleic anhydride adduct OM and the second step was carried out by reaction of OM with polyoxyethylene‐polyoxypropylene block polymers with M.wts.; 3×103, 4×103, and 5×103 (BP3, BP4, and BP5 respectively) to produce the following compounds; ([OMBP3], [OMBP4], and [OMBP5], respectively). The OM adduct was reacted with [BP4] in presence of lauryl alcohol (LA) and triethylenetetramine (TETA) to produce [(OMBP4)‐LA] and [(OMBP4)‐TETA], respectively. The demulsification efficiency of these demulsifiers was tested on water‐in‐oil emulsions (w/o) at 10, 30, 50% water content. From the obtained results, it has been found that, the investigated demulsifiers have a great potential to complete resolving the w/o emulsions in short times. The results were compared with the existing demulsifier formulation (nonyl phenol formaldehyde resin), which currently used today in petroleum fields. The data, showed that, the demulsification efficiency of the undertaken demulsifier mixtures are better than the currently used demulsifier. The results were discussed on the light of demulsifier structures and crude oil composition.

Highly Efficient Nano-Structured Polymer-Based Membrane/Sorbent for Oil Adsorption from O/W Emulsion Conducted of Petroleum Wastewater

Wastewater disposal has been an important issue from an environmental perspective in terms of the serious damages and harms its contaminants may cause. Treatment of the wastewater, through the pollutants removal, either before disposal or for the reuse in certain industrial or agricultural purposes, is an essential process. In response to this environmental claim, a novel nano-structured, macro-porous, polymer-based membrane/sorbent was prepared, in terms of its highly open and porous structure with nano-structured sorbent interconnecting walls and based on high internal phase emulsion polymerization. This sorbent was used to remove the oil from polluted wastewater in a laboratory-scale through the application of a new method called flotation–nano-filtration. In order to avoid the water flux decline and simultaneously enhance the oil removal efficiency from the wastewater, the polymeric material, after being prepared and used in sheet form (membrane), was ultimately introduced to the wastewater system as small pieces, as with the intention of physically increasing the area of surface for the oil removal. The material performance studies applied several variables, namely, the physical sectioning of the material surface area, sorbent concentration, mixing speed, and mixing time. An efficiency of 99.75% for the oil removal from the polluted water was successfully achieved at 75 minutes mixing time, a sorbent concentration of 0.158 g/200 mL (each piece with dimensions of 2 mm × 3 mm × 1 mm), and 300 rpm mixing speed. The sorbent structure before and after the oil removal process was examined using scanning electron microscope and x-ray diffraction analysis.

Synthesis and Evaluation of Ethoxylated Alkyl Sulfosuccinates as Oil Spill Dispersants

The surface properties particularly, Krafft point, foam stability and emulsion stability for the synthesized series of ethoxylated sodium monoalkyl (octyl-, dodecyl-, and cetyl-) sulfosuccinate surfactants were investigated comparing with those of sodium dioctyl sulfosuccinate. The prepared surfactants were evaluated as oil spill dispersants using screen test method. The results show that, the ethylene oxide units in the mixed moiety surfactant system (anionic–nonionic) effect on the depression of the Krafft point. Also, the increasing of ethylene oxide units in the prepared surfactants decreases the foam ability of these surfactants. The results of emulsion stability show that, the increasing in ethylene oxide units owing to the emulsion stability decreases. The prepared surfactants show a dispersion capability at different content of ethylene oxide units (9, 14, 23, and 90) and at different concentrations. The dispersion capability for these surfactants in the sea water is better than in the fresh water. The results show that, the increase of ethylene oxide units increases the dispersion efficiency of the synthesized surfactants.

Formation and Stability of Water-in-Diesel Fuel Nanoemulsions Prepared by High-Energy Method

In this work, water-in-diesel fuel nanoemulsions were prepared with mixed nonionic surfactants. Five emulsions with different water contents: 5, 6, 7, 8, and 9% (wt/wt) were prepared using high-energy method. Several mixtures of sorbitan monooleate, and polyoxyethylene (20) sorbitan monooleate, results in different hydrophilic-lipophilic balance (HLB) values (9.6, 9.8, 10, 10.2, and 10.4) were prepared to achieve the optimal HLB value used in the preparation of nanoemulsions. The effect of water, mixed surfactant concentration and HLB value on the droplet size has been studied. Droplet size of the prepared nanoemulsions was determined by dynamic light scattering, and the nanoemulsion stability assessed, measuring the variation of the droplet size as a function of time. From the obtained results, it was found that the mean droplet sizes formed between 49.55 and 190.1 nm depend on the water content, the concentration of the emulsifiers blend and HLB value.

ENHANCEMENT OF ETHANOL PRODUCTION BY SIMULTANEOUS SACCHARIFICATION AND FERMENTATION (SSF) OF RICE STRAW USING ETHOXYLATED SPAN 20

In this work, four nonionic surfactants based on sorbitan monolaurate (Span 20) were synthesized by introducing ethylene oxide gas (n = 20, 40, 60, 80 ethylene oxide units) into Span 20 to give four new surfactants with different hydrophilic–lipophilic balance (HLB), namely, E(20), E(40), E(60), and E(80). The structures of the prepared nonionic surfactants were elucidated using Fourier-transform infrared (FT-IR) and 1H-nuclear magnetic resonance (NMR) spectroscopy. The surface-tension measurements were recorded. The effects of the prepared nonionic surfactants on the simultaneous saccharification and fermentation (SSF) of microwave/alkali-pretreated rice straw to produce ethanol were investigated. From the obtained data, it was found that the addition of the nonionic surfactants at 2.5 g/L had a positive effect on SSF. The maximum ethanol yield (76 and 55%) was obtained after 72 hr for rice straw using Kluyveromyces marxianus and Saccharomyces cerevisiae, respectively. Also, it was found that the ethanol yield increases with increasing HLB of the prepared nonionic surfactants by increasing ethylene oxide units. The adsorption of nonionic surfactants on lignocelluloses is proposed to be due to hydrophobic and hydrogen bonding interactions between nonionic surfactants and the lignin part in the lignocelulose. It can be concluded that additions of surface-active compounds, such as nonionic surfactants, increase enzymatic conversion of rice straw for bioethanol purposes.