Effect of styrene–butadiene–styrene copolymer modification on properties of Saudi bitumen

This research investigates the effects of styrene-butadiene-styrene (SBS) copolymer and other plastomers on the behavior of Saudi bitumen. Three bitumen samples, extracted from three Saudi oil refineries, namely Ras Tanura, Riyadh, and Yanbu, were used in this study. The bitumen samples were mixed with different modifiers in various compositions, forming polymer modified bitumens (PMBs). Elasticity parameters, such as ductility and elastic recovery were measured and evaluated. Characteristics of raw bitumen were analyzed to observe the compatibility of bitumen with SBS and plastomers. Bitumen samples were suitable for SBS modification and SBS PMBs showed superior elasticity behaviors compared to plastomer blends.     

Dependence of composition of asphaltene–resin–wax deposits on the water cut value

The deposit formation process in water/oil emulsions based on waxy high-resin oils with different amounts of the aqueous phase has been studied. It has been shown that the deposition rate greatly increases with an increase in the relative amount of the aqueous phase. Relationships of the component composition of paraffin hydrocarbons and the structural group composition of asphaltenes in asphaltene–resin–wax deposits with the water content of the emulsions have been revealed.     

Modeling of the Fischer–Tropsch process using a Fe–Cu–K catalyst

In a bid to increase Fischer–Tropsch product selectivity, inorganics substances, such as copper, potassium, and others, were added to the catalyst. Although this approach in Fischer–Tropsch synthesis is very important, it has not been discussed widely. Isothermal product models in this type of synthesis and effective parameters are the same as pressure, while the H₂/CO feed ratio and space velocity have been studied over the spray-dried Fe–Cu–K catalyst by using statistical methods with experimental data. P = 1.0–2.5 MPa, H₂/CO feed ratio = 0.6–2.0, and space velocity = 0.07–0.1 1/h are the range of operating conditions in the spinning basket reactor. The experiment was carried out at a constant temperature of 523 K. The models can predict the reaction's product. Through these the optimal conditions in the reactor models can be determined, while the maximum and minimum amounts of products for oil, wax, and water are obtained under the optimized conditions. The models showed that the interaction between parameters played a key role. The main interactions for products are pressure and space velocity.     

Predicting PVT properties of Egyptian crude oils by a modified Soave–Redlich–Kowng equation of state

The study aims to predict the physical properties of Egyptian crude oils using modified Soave–Redlich–Kowng equation of state. The modification was theoretically developed and then performed by using data of 43 black oil samples representing all active oil producing areas of Egypt. The equation enables to predict the bubble-point pressure, oil formation volume factor, gas–oil ratio, oil density, crude oil gravity, gas gravity and gas formation volume factor of black oils with average relative errors ranging from 0.01% to 10.713%.Calculation sensitivity of the proposed MSRKE is determined by testing four oil samples collected from different locations in Egypt and comparing the measured PVT properties with those calculated from MSRKE. These evaluations show an excellent agreement between the measured properties and calculated ones.The estimation of reservoir liquid and gas properties from MSRKE is often needed when detailed laboratory PVT data are not available.     

Gasification property of coal–oilfield wastewater–slurry and microscopic mechanism analysis

Oilfield wastewater was used to prepare coal slurry, which is called coal–oilfield wastewater–slurry. The gasification properties of coal–oilfield wastewater–slurry and coal water slurry were studied by using the thermogravimetry method, and the promoting effect of oilfield wastewater on gasification was also determined at the micro level. Results showed that coal–oilfield wastewater–slurry and coal water slurry both exhibited a similar gasification process. However, compared with coal water slurry, all the gasification parameters of coal–oilfield wastewater–slurry were better, thereby suggesting that oilfield wastewater play a positive role in promoting gasification. Sodium ions and potassium ions were distributed on the coal particle surfaces and also in the pores, and they provided active sites and enhanced the gasification activity.     

The study of catalytic performance of silica-supported three metallic Fe–Co–Ce catalyst prepared using impregnation procedure for Fischer–Tropsch synthesis

We apply the wet impregnation procedure to prepare the Fe–Co–Ce catalyst supported by silica. The effects of operational conditions such as temperature, pressure, and the feed ratios of reaction on the selectivity and yield were studied. The production of light olefins from syngas (CO and H₂) over this catalyst in a fixed bed reactor via Fischer–Tropsch synthesis (FTS) was investigated. The reactor tests were determined through the design experiments.The optimum condition was determined in a way that the selectivity of methane was the least and other olefins have the maximum selectivity. The results indicated that the catalyst at 350°C, 3 bar, and syngas with H₂/CO ratio 1/1 has shown the better catalytic performance for FTS.     

Study on the characteristics of palm oil–biodiesel–diesel fuel blend

Palm oil/palm oil methyl esters are blends with diesel fuel, the blends were characterized as an alternative fuels for diesel engines. Density, kinematic viscosity, and flash point were estimated according to ASTM as key fuel properties. Palm oil and palm oil biodiesel were blended with diesel. The properties of both blends were estimated. The results showed that the fuel properties of the blends were very close to that of diesel till 30% unless other characteristics are within the limits. The experimental data were correlated as a function of the volume fraction of oil/biodiesel in the blend. Different correlations were developed to predict the properties of the oil/bio-oil-diesel blends based on our experimental results. The developed correlations were validated by comparing the correlation prediction with experimental data in literature. A good agreement was found between modeled equations prediction and experimental data in literature. The developed equations can be used as a guide for determining the best blending mixture to be used for diesel engines.     

Numerical Aspects of the Convection–Dispersion Equation

Virtually all reservoir simulators obtain solutions to fluid flow equations, usually nonlinear partial-differential equations, by making discrete approximations to derivatives. Whether finite-difference or finite-element methods are used, these approximations always introduce truncation errors that often can distort the accuracy and stability of the solution. The truncation error is often referred to as numerical dispersion because, to the lowest order, it can be represented as a second spatial derivative term added to any true dispersion term in the problem.

Distortion of the numerical solution is most significant in the simulation of enhanced oil recovery (EOR) processes where sharp displacement, concentration, and/or temperature fronts are an important part of the efficiency of the processes, and artificial smearing as a result of numerical dispersion can render the simulation meaningless.

In this work, two different methods, namely, finite difference and method of line, are considered to investigate numerical dispersion. The effect of grid sizes on smearing and oscillation is investigated by selecting various values for grid size. The results indicate that numerical dispersion can be minimized using the method of line as a solution method for the general difference equation.     

Rheology of modified binders under varying doses of WMA additive–Sasobit

Use of warm mix asphalt (WMA) technology to reduce construction temperatures of asphalt mix has gained strong interest worldwide. However, the technology is still in its inception stage in India. Present study evaluated the rheological properties of polymer- and crumb rubber-modified bitumen with various doses of WMA additive Sasobit (1%, 2%, and 3% by binder weight). Frequency sweep and temperature sweep results showed that increase in Sasobit content improved elastic properties of binders. Creep, repeated creep recovery, and multiple stress creep recovery results showed better resistance toward permanent deformation for Sasobit-modified binders in comparison to control binders.     

Effect of Intermolecular Interaction on Stability of Asphaltene–Hydrogen Donor System

The stability of three asphaltene–hydrogen donor systems, namely asphaltene–1-methylnaphthalene, asphaltene–tetralin, and asphaltene–decalin, with a mass ratio of 1:10 was investigated using the Turbiscan stability analyzer. The interactions between hydrogen donor molecules and asphaltene units were simulated and calculated using Gaussian and Multiwfn, and then, noncovalent interaction analysis was performed. The results showed that the stability of the three asphaltene–hydrogen donor systems de...     

Enhancement of Separation of Water–Oil Emulsion Using Unipolar Corona-Treated Polysulfonamide Membranes

The influence of unipolar-corona discharge treatment on the efficiency of separation of a model oil-in-water emulsion using polysulfonamide membranes with a molecular weight cut-off of 20 kDa (pore size ≈ 0.01 μm) has been investigated. It has been shown that the corona discharge treatment of the membranes leads to the intensification of the separation of water–oil emulsions and the process parameters depend on the processing time and the voltage applied to the corona electrode. The maximum value of the efficiency (95.4%) is noted in the case of the membrane treated in a corona discharge for 5 minutes at a voltage of 5 kV applied onto the electrode. The trends observed have been explained. It has been shown that the corona treatment promotes the hydrophilization of the membrane surface: the contact angle of water is α = 55° for the initial membrane and α = 50° after the corona treatment. Atomic force microscopy has shown a change in the structure of the membrane surface by the corona treatment—an increase in the roughness. A small decrease in the crystallinity of polysulfonamide by its treatment in a unipolar corona discharge has be been revealed.     

The “Iodine Number” of TS–1 Fuel. On Elimination of the Index from GOST 10227–86

It was shown that unsaturated hydrocarbons in concentrations characteristic of TS–1 fuel weakly affect sludging in this fuel but significantly increase the existent gum content, and the rejected standard based on this limits the concentration of unsaturated hydrocarbons in fuel to a much greater degree than the iodine number index. Scientifically substantiated recommendations are given for eliminating the iodine number index from GOST 10227–86 for TS–1 fuel.     

Deep desulfurization of gasoline by electrochemical oxidation–distillation

An electrochemical oxidation?distillation method with constant current 500 mA was proposed to reduce the sulfur content in gasoline in this work. After electrochemical oxidation?distillation, the sulfur content of gasoline decreased from 514.65 to 10.20 μg/g. On the basis of these experimental results, an oxidation mechanism of electrochemical oxidative desulfurization for gasoline was proposed.     

Effect of Temperature on Hydrogen–Free Atmospheric Reforming

Hydrogen–free reforming of naphtha cuts under pressure of 1.5–3 MPa, called zeoforming, was studied in detail in [1, 2]. We created a process for hydrogen–free catalytic reforming at atmospheric pressure, called KATRIFAT, as a result of selecting a mixture of dehydrocyclization, cracking, and isomerization catalysts [3, 4].     

Modelling the multiphase flow of an oil–gas–condensate system in porous media

The “Black oil” model is extended to describe the four-phase flow of the oil-gas–condensate systems in porous media, by considering the solubilities of gas in the condensate, water, and oil phases and condensate evaporation into the gas phase. The three-dimensional transient-state model equations are reduced to one-dimensional transient-state forms by the partial integration method. The finite-difference method is used for solution of this model. The calculations of the hydrodynamical parameters of an oil–gas–condensate reservoir element are carried out for several cases, involving a water table in its natural state of the development, water flooding under water–oil contact, combined state of water flooding under water–oil contact and gas pumping into gas zone of the reservoir. This study provides a comparison of the effect of the different exploitation methods of the reservoir fluids production. The present simulation studies indicate that the combined flooding method yields faster recovery.     

Enhancement of the Fischer–Tropsch process for producing long-chain hydrocarbons on a cobalt–alumina–silica gel catalyst

The effects of the H₂/CO ratio, pressure, temperature, and the reaction-gas recycle ratio on the selectivity for hydrocarbons (HCs), including long-chain C₃₅₊ HCs, in the Fischer–Tropsch synthesis over a supported industrial cobalt–silica gel catalyst have been studied. The synthesis parameters have been as follows: a pressure of 2.0 or 6.0 MPa, an H₂/CO ratio of 1–5, a recycle ratio of 2–6, a temperature of 150–240°C, and a gas hourly space velocity of 1000 h^?1. It has been shown that gas recycling provides thermal stability in the catalyst bed, significantly increases the yield of C₃₅₊ HCs, and makes it possible to control the group and fractional composition of the synthesis products.     

A pH Model for Calculating the pH Value of Mixed–Acid–Base Equilibria of Overhead Condensing Systems in Crude Distillation

A pH predictive model based on acid–base equilibria and ion equilibria was proposed to calculate the pH value of the overhead condensing system of crude distillation unit. The pH model could be used to predict the appropriate amounts of neutralizers by measuring the Cl-ion concentration of the overhead knockout drum. The pH values of various neutralized streams were estimated by this model. The results showed that the predicted pH values were in good agreement with the experimental ones. The trend of the corrosion inhibition efficiency decreases in the following order: ethylenediamine N,Ndimethylethanolamine triethylamine 3-methoxypropylamine morpholine. The difficulty in the accurate control of corrosion was solved, and a good instruction was provided for mitigating corrosion in refinery.     

Kinetic Pecularities of Benzene Production from the Benzene–Toluene–Xylene Fraction of Pyrolysis Gasoline by Catalytic Hydrodealkylation at High Temperature

Abstract

Hydrodealkylation (HDA) of the benzene–toluene–xylene (BTX) fraction of pyrolysis gasoline is an industrial route to produce benzene. Complicated kinetics of aromatic and nonaromatic hydrocarbon reactions has been experimentally investigated at the conditions of this process, employing a polyfunctional Al–Cr–KF catalyst with a high benzene selectivity, model feeds and BTX. The study reports effects of nonaromatic hydrocarbons on high temperature catalytic conversion of toluene. Above 525°C the process is found to be thermo-catalytic meaning that reactions take place on the catalyst surface and between catalyst pellets. The “pure” catalytic component of conversion is taken to be the difference between a thermo-catalytic and a thermal (i.e., without catalyst) run at the same conditions. Nonaromatic hydrocarbons substantially boost interpellet toluene HDA which is explained by a mechanism involving very fast decomposition of the nonaromatics into active radicals. The accompanying slight fall in catalytic toluene HDA, on the other hand, is considered to be due to nonaromatics and/or their hydrocracking products impeding toluene diffusion to the catalyst surface whose active centers they partially occupy. There is evidence that the C6–C8 nonaromatics of BTX influence the toluene conversion in the same manner as n-octane and cyclohexane. Benzene seems to render a small fall in surface conversion of toluene probably by inhibiting its diffusion. It apparently has no significant influence on nonaromatic hydrocracking or thermal toluene HDA. The hydrocracking products of the model feeds and BTX are 97–99 mol% C1–C4 alkanes and 1–3 mol% C2–C4 alkenes irrespective of the run type (i.e., thermal or catalytic). Moreover, given more time the hydrocracking reactions in the voids surpass those on the catalyst surface. Changing hydrogen:BTX molar ratio from 1.5 to 10 raises thermal (respectively “pure” catalytic) contribution significantly (respectively slightly) to conversions of toluene, C8 aromatics, n-octane, cyclohexane, and other C6–C8 nonaromatics.     

Synthesis of nickel–tungsten sulfide hydrodearomatization catalysts by the decomposition of oil-soluble precursors

Nickel–tungsten sulfide catalysts for the hydrogenation of aromatic hydrocarbons have been prepared by the in situ decomposition of an oil-soluble tungsten hexacarbonyl precursor in a hydrocarbon feedstock using oil-soluble nickel salt nickel(II) 2-ethylhexanoate as a source of nickel. The in situ synthesized Ni–W–S catalyst has been characterized by X-ray photoelectron spectroscopy. The activity of the resulting catalysts has been studied in the hydrogenation of bicyclic aromatic hydrocarbons and dibenzothiophene conversion in a batch reactor at a temperature of 350°C and a hydrogen pressure of 5.0 MPa. It has been shown that the optimum W : Ni molar ratio is 1 : 2. Using the example of the hydrofining of feedstock with high sulfur and aromatics contents, it has been shown that the synthesized catalyst exhibits high activity in the hydrogenation of aromatic hydrocarbons.