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 Arabian Journal for Science and Engineering   [SJR: 0.345]   [H-I: 20]   [5 followers]  Follow         Hybrid journal (It can contain Open Access articles)    ISSN (Print) 1319-8025    Published by Springer-Verlag  [2335 journals]
• Study Governing the Impact of Long-Term Water Immersion on Coal
Spontaneous Ignition
• Authors: Yongliang Yang; Zenghua Li; Leilei Si; Fanjun Gu; Yinbo Zhou; Qiangqiang Qi; Xuming Sun
Pages: 1359 - 1369
Abstract: Abstract Oxidation of air-dried coal in mined-out areas is one leading factor contributing to coal spontaneous ignition during exploitation. Although some related work has been done, there is still some space for improvement. We screened out three coal samples with different ranks of coal and immersed them in distilled water for 200 days. Afterward, we identified some changes in pore structure and oxygen consumption characteristics of coal samples after water immersion. Additionally, we analyzed the composition of dissolved substance, both organic and inorganic. The results demonstrated that some parameters of three different residual coal samples increased, including average pore size, specific surface area and pore volume. In regard to the composition of dissolved substance, we identified Na+ and Cl−, which accounted for the largest proportion, along with some organic functional groups. We found that higher rank leads to a smaller total amount of dissolved substance. Additionally, we performed some experiments concerning coal oxidation rate and the amount of CO, CO2 and C2H4 generated during oxidation. The results showed that water immersion does play a significant role, along with coal rank. Considering all results and analysis, long-term water immersion is responsible for pore structure development in coal and the degree of reduction in spontaneous-ignition-proof substance, which helps to boost coal spontaneous ignition.
PubDate: 2017-04-01
DOI: 10.1007/s13369-016-2245-9
Issue No: Vol. 42, No. 4 (2017)

• Low-Pressure Chemical Vapor Deposition Copper Nanodendrites Growth Design
• Authors: Hatem Abuhimd
Pages: 1371 - 1379
Abstract: Abstract In this paper, chemical vapor deposition (CVD) method was used to grow long crystalline dendrites of copper with controlled grain morphology and lengths of up to 1 $${{\rm \mu}}$$ m. The grown copper nanodendrites (CuND) were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), Raman, and X-ray photoelectron spectroscopy (XPS) analyses. The influence of the methane and hydrogen concentrations during growth was evaluated. SEM and AFM results revealed the high-quality grain morphology. XPS studies showed sharp peaks after 900 eV which was attributed to the presence of CuND. Raman spectra revealed the characteristics band at 150, ~200, and ~600 cm−1 for CuND. Analysis of the marginal means showed that growth temperature and flow are the two most significant control variables and that flow has a two-level effect on the length of CuND. Similarly, at the highest flow rate, i.e., 15 sccm, the CVD led to the growth of longer CuNDs. In particular, the length of CuNDs was found to increase when the flow rate was increased from 5 to 15 sccm by keeping fixed the temperature at 900 $${{^\circ}}$$ C and growth time for 30 min. Surprisingly, when the temperature was increased to 1000 $${{^\circ}}$$ C at a flow rate of 5 sccm and growth time of 30 min, the length of CuNDs was slightly increased, while at high flow rate there is no change in the length.
PubDate: 2017-04-01
DOI: 10.1007/s13369-016-2246-8
Issue No: Vol. 42, No. 4 (2017)

• Synthesis of Nanocatalyst for Hydrodesulfurization of Gasoil Using
Laboratory Hydrothermal Rig
• Authors: Mohammed I. Mohammed; Adnan A. Abdul Razak; Mohammed A. Shehab
Pages: 1381 - 1387
Abstract: Abstract This study presents a simple fabrication procedure for obtaining a nanocatalyst by homogeneously implanting CoMo within the structure of multiwall carbon nanotubes. The nanocatalyst efficiency was determined by applying the catalyst in a laboratory hydrothermal testing rig to remove sulfur from gasoil using various methods. The conventional catalyst (CoMo/Al2O3) was also used as a reference. Scanning electron microscope (SEM), high- resolution transmission electron microscope (HRTEM), an X-ray diffractometer (XRD), and Brunauer, Emmett, and Teller (BET) method were used to study the morphology and the structure of prepared samples, and the X-ray fluorescence technique (XRF) was used to determine the sulfur content in gasoil. After preparation, the nanocatalyst composite structure observed the formation of network structure between metal catalysts and CNTs, and almost all CoMo particles were homogeneously decorated within the bulk of CNTs. Experiments using nanocatalysts reveal better results than the conventional catalyst (CoMo/Al2O3) in removal of sulfur from gasoil. As a result, an improvement of about 10% (73.5% max. HDS) in hydrodesulfurization (HDS) over conventional catalyst was obtained with a 10 h contact time, 280 °C reactor temperature, 10 bar system pressure, and 2h−1 space velocity of gasoil, which may be an optimum condition for removal of sulfur from gasoil within the conditions and design parameters of our experimental system.
PubDate: 2017-04-01
DOI: 10.1007/s13369-016-2249-5
Issue No: Vol. 42, No. 4 (2017)

• Coagulation/Flocculation Potential of Polyaluminium Chloride and Bentonite
Clay Tested in the Removal of Methyl Red and Crystal Violet
• Authors: E. Fosso-Kankeu; A. Webster; I. O. Ntwampe; F. B. Waanders
Pages: 1389 - 1397
Abstract: Abstract This study investigated the influence of the physico-chemical properties of methyl red (MR) and crystal violet (CV) on their removal by bentonite clay and polyaluminium chloride (PACl). Different dosages of bentonite clay, PACl and a combination of PACl and bentonite clay were applied. Dye concentration, dosage, pH and slow mixing timing were varied to find optimum removal conditions. Due to the high charge and solubility of dyes, dye solutions were pre-treated by increasing the turbidity and adjusting the pH prior to the treatment with PACl. PACl-lab removed MR better than the commercial PACl (PACl-com), and this could be ascribed to the lower basicity of PACl-lab compared to PACl-com. Bentonite clay showed greater affinity to CV, exhibiting an optimum removal of 99.2 % for CV and 98.8 % for MR. The optimum removal efficiency of PACl-lab for CV was 99.4 and 97.0 % for MR. The combination of PACl-lab and bentonite clay had higher removal efficiency than PACl-lab for MR but not for CV. The dyes’ charge, structure and solubility influence how well the dye will be removed with the flocculation/coagulation technique.
PubDate: 2017-04-01
DOI: 10.1007/s13369-016-2244-x
Issue No: Vol. 42, No. 4 (2017)

• Removal of F and Cl from Zinc Oxide Fume from Fuming Furnace by Microwave
Roasting
• Authors: Chenhui Liu; Jinhui Peng; Zhiqiang Li; Libo Zhang; Tu Hu
Pages: 1413 - 1418
Abstract: Abstract The work addresses the removal effectiveness of F and Cl in the zinc oxide fume produced in fuming furnace, by application of microwave roasting, taking advantage of the difference in microwave absorbing characteristics of halides, lead and zinc oxides in combination with the advantage of selective microwave heating. The effectiveness of defluorination and dechlorination was discussed in detail addressing the effect of all the influencing parameters such as roasting temperature, holding time and stirring speed. SEM and XRD were utilized to understand the removal mechanism of F and Cl. The results show that a nearly 92.8 % defluorination efficiency and 90.3 % dechlorination efficiency could be achieved at roasting temperature of 700 °C, holding time of 80 min and stirring speed at 120 rpm, satisfying the requirements of the wet smelting electrolysis process.
PubDate: 2017-04-01
DOI: 10.1007/s13369-016-2243-y
Issue No: Vol. 42, No. 4 (2017)

• Evaluation of Base for Catalytic Hydrodechlorination of 2,4-Dichlorophenol
in Cocurrent Downflow Contactor Reactor
• Authors: Asim Rehman; Arshad Chughtai; Aamir Ijaz; M. Arif Butt
Pages: 1419 - 1425
Abstract: Abstract The catalytic hydrodechlorination of 2,4-dichlorophenol (2,4-DCP) as a model pollutant has been conducted for evaluation of optimum base in laboratory scale cocurrent downflow contactor reactor (CDCR). 2,4-DCP was completely dechlorinated with an initial concentration of 3.0 and 6.0 mmol, at 303 K temperature and 0.1 MPa pressure. Hydrogen flow rate was remained at 0.3 L/min, and catalyst loading of 0.2 g/L of 5 % Palladium/carbon (Pd/C) catalyst was used. Different bases like triethylamine $$(\hbox {N(CH}_{2}\hbox {CH}_{3})_{3})$$ , sodium acetate trihydrate $$(\hbox {CH}_{3}\hbox {COONa}\cdot 3\hbox {H}_{2}\hbox {O})$$ , sodium hydroxide (NaOH), ammonium hydroxide $$(\hbox {NH}_{4}\hbox {OH})$$ and potassium hydroxide (KOH) were used for evaluation of optimum base. The same reaction was studied without base, and it was observed that more reaction time was required for hydrodechlorination of 2,4-DCP as compared to the presence of a base as production of HCl decreased the rate of reaction. During the hydrodechlorination reaction, 4-chlorophenol (4-CP) was also formed as an intermediate product along with 2-chlorophenol (2-CP). Significant amount of 4-CP produced when no alkali or weak alkalis like $$\hbox {N(CH}_{2}\hbox {CH}_{3})_{3}$$ , $$\hbox {CH}_{3}\hbox {COONa}\cdot 3\hbox {H}_{2}\hbox {O}$$ were used. No inhibitory effects of $$\hbox {N(CH}_{2}\hbox {CH}_{3})_{3}$$ were observed during hydrodechlorination reaction of 2,4-DCP in CDCR. The addition of strong inorganic base helped with dechlorination of 2,4-DCP in predominantly fast reaction, and rate of neutralization using different bases was observed and found that the KOH had highest rate of reaction and $$\hbox {CH}_{3}\hbox {COONa}\cdot 3\hbox {H}_{2}\hbox {O}$$ had lowest, whereas NaOH, $$\hbox {NH}_{4}\hbox {OH}$$ and $$\hbox {N(CH}_{2}\hbox {CH}_{3})_{3}$$ had intermediate reaction time. The presence of strong base kept pH in the basic region after neutralization of all HCl formed during the reaction.
PubDate: 2017-04-01
DOI: 10.1007/s13369-016-2300-6
Issue No: Vol. 42, No. 4 (2017)

• Evaluating the Chemical Reaction of Chelating Agents with Xanthan Gum
• Authors: Salaheldin Elkatatny
Pages: 1427 - 1434
Abstract: Abstract Xanthan gum is a polysaccharide natural polymer that is used heavily as a viscosifier in oil and gas industry especially with fracturing and gravel pack fluids. Numerous additives are required to control the properties of the fracturing and gravel pack fluids such as biocides, clay stabilizers, and some other additives to maintain the viscosity at high temperature during the fracturing operations. These additives have their limitations, and they will increase the cost of the operation. The objective of this research is to evaluate the chemical reaction of xanthan gum with different chelating agents [ethylenediaminetetraacetic acid (EDTA), glutamic acid diacetic acid (GLDA), and diethylenetriaminepentaacetic acid (DTPA)] at different conditions of pH, concentrations, temperature, and time to determine the optimum conditions for removing the polymer filter cake after fracturing and gravel pack operations . The results obtained showed that mixing chelating agents (DTPA, EDTA, and GLDA) with xanthan gum had a big effect of increasing the viscosity of the solution. DTPA and EDTA at different pH and shear rates over long time (36 h) did not break the XC-polymer solution at $$200~^{\circ }\hbox {F}$$ . GLDA (20 wt%, pH 12) increased the viscosity of the xanthan gum solution from 33 to 45 cP for 11 h at $$200~^{\circ }\hbox {F}$$ and a shear rate of $$170.3\, \hbox {S}^{-1}$$ . Under the same conditions, GLDA worked as a breaker after 11 h as the apparent viscosity of the GLDA-XC solution was decreased from 45 cP to 11 and 3 cP after 24 and 36 h, respectively. The optimum concentration of GLDA was found to be 20 wt%, and the optimum pH was found to be 12.
PubDate: 2017-04-01
DOI: 10.1007/s13369-016-2299-8
Issue No: Vol. 42, No. 4 (2017)

• Textile Effluent Treatment Plant Sludge: Characterization and Utilization
in Building Materials
• Authors: Md. Mostafizur Rahman; Md. Maksudur Rahman Khan; Md. Tamez Uddin; Md. Akhtarul Islam
Pages: 1435 - 1442
Abstract: Abstract The main objective of this study is to characterize and find a potential use of textile effluent treatment plant (ETP) sludge produced in Bangladesh. Textile ETP sludge collected from the local textile industries have been characterized in the laboratory. The physicochemical and engineering properties of the sludge have been studied. Collected ETP sludge has been processed to get cement-like fine powder that has been used for partial replacement of Portland cement/sand in the composition of the mortar and concrete specimens. Different mechanical (compressive and flexural strength), physical (water absorption) and morphological (porosity) properties of the test specimens have been evaluated. The test result shows that the addition of sludge in the mortar and concrete composition as a substitution of Portland cement or sand decreases the compressive strength and flexural strength, and increases the water absorption and porosity of the mortar and concrete specimens. Leaching study, conducted for the sludge-based mortar and concrete specimens following tank leaching test procedure, reveals that the concentration of leached metals is quite low than the limits specified by the Department of Environment in Bangladesh. These results amply demonstrate that textile ETP sludge can be utilized for making non-structural building components where lower strength is justified.
PubDate: 2017-04-01
DOI: 10.1007/s13369-016-2298-9
Issue No: Vol. 42, No. 4 (2017)

• Treatment of Sulfidic Wastewater Using Iron Salts
• Authors: Farooq Ahmad; Saikat Maitra; Naveed Ahmad
Pages: 1455 - 1462
Abstract: Abstract Sulfides are often found to be present in the effluents generated from some chemical and petrochemical industries as well as from tanneries. Beyond a certain permissible limit, sulfides are generally toxic to living bodies. In the present work, solution of sodium sulfide was first mixed with $$\hbox {Fe}^{+2}/\hbox {Fe}^{+3}$$ salt solutions in different ratios which resulted in precipitation of sulfide from the solution. This was followed by aeration of the residual solution. The maximum sulfide removal efficiency of the $$\hbox {Fe}^{+2}/\hbox {Fe}^{+3}$$ treatment was approximately 70 %. However, upon aeration, the residual sulfide was eventually removed. The precipitate formed was characterized as ferrous sulfide, applying scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy and X-ray power diffraction. The role of sulfide concentration, $$\hbox {Fe}^{+2}/\hbox {Fe}^{+3}$$ ratio and temperature on the kinetics of sulfide removal from the aqueous solution was investigated. Effect of air flow rate during aeration of remaining sulfide was also investigated. The rate equation and activation energy for the precipitation reaction were calculated from the experimental results. The results of this study hold promise for effective treatment of sulfidic wastewater in chemical and allied industries.
PubDate: 2017-04-01
DOI: 10.1007/s13369-016-2315-z
Issue No: Vol. 42, No. 4 (2017)

• Removal of NO Using a Dielectric Barrier Discharge Reactor in a Cycled
Adsorption–Desorption and Decomposition System
• Authors: Fang Wang; Honghong Yi; Xiaolong Tang
Pages: 1463 - 1474
Abstract: Abstract Removal of nitrogen oxides (NO $$_x$$ ) from a cycled adsorption–desorption and decomposition system was studied at ambient temperature, which allows low concentration and high flow rate emissions. This system exhibited excellent recyclability and showed high performance through repeated cycling, with 85.4% NO conversion after eight cycles. Different metal oxide supports on activated carbon were used to remove NO by nonthermal plasma assisted catalytic adsorption–decomposition. The Cu/AC showed a large adsorption capacity, and copper ions increased the decomposition of NO, resulting in high energy efficiency. FTIR and TPD results showed that NO adsorption on the catalyst surface states is mainly as nitrate. The textural characteristics of catalysts for cyclic operation were investigated, and the catalytic activity relied on O atoms, Cu atoms and $$\hbox {Cu}^{2+}$$ on the catalyst surface. The discharge voltages and several frequencies of the electric source were also investigated. As injection power energy increased, the reactor plasma chemical reaction process was increased.
PubDate: 2017-04-01
DOI: 10.1007/s13369-016-2344-7
Issue No: Vol. 42, No. 4 (2017)

• Energetic Performance Optimization of a SOFC–GT Hybrid Power Plant
• Authors: Salha Faleh; Tahar Khir; Ammar Ben Brahim
Pages: 1505 - 1515
Abstract: Abstract Analytic study based on energy analysis is conducted on a solid oxide fuel cell (SOFC) integrated in a gas turbine power plant GT. The Tunisian natural gas is used as fuel for the SOFC and the GT cycle. An external pre-reforming system is installed before the SOFC. Heat recovery systems are adopted to valorize the waste heat at the SOFC and GT exhausts. The gas from the SOFC exhaust is also used as additional supply of the combustion chamber. The equations governing the electrochemical processes and the energy balances of the power plant components are established. Numerical simulations using EES software are performed. The influences of key operating parameters, such as ambient temperature, air flow, pre-reforming fraction and fuel utilization on the performance of the SOFC–GT hybrid system, are analyzed. The integration of the SOFC enhances the hybrid cycle efficiency of about 50%. The increase of the ambient temperature reduces the system efficiencies. The utilization factor has a negative effect on the SOFC temperature and voltage which leads to a decrease in the system performances, while the pre-reforming fraction has a positive effect on the indicated parameters. The SOFC voltage increases with the air molar flow rate. However, required air compressor power becomes important. That reduces significantly the SOFC efficiency. A small improvement of about 2% is obtained for the hybrid cycle efficiency SOFC–GT.
PubDate: 2017-04-01
DOI: 10.1007/s13369-016-2363-4
Issue No: Vol. 42, No. 4 (2017)

• The Production of $$\hbox {Al(OH)}_{3 }$$ Al(OH) 3 from Indigenous
High-Silica Bauxite
• Authors: Rofice Dickson; Mahmood Saleem; Muhammad Arif Bhatti
Pages: 1529 - 1535
Abstract: Abstract Aluminum hydroxide finds many industrial applications. Bauxite contains minerals from which aluminum hydroxide $$\hbox {Al(OH)}_{3}$$ is leached through Bayer process. Impurities present in it are crucial toward the yield and purity of the end product. Indigenous bauxite ore found at Khushab, Punjab Quarry, was analyzed by X-ray fluorescence (XRF) and X-ray diffraction techniques. Effect of molar ratio, temperature and lime on product yield and purity of the product was investigated. Product samples were characterized by XRF spectroscopy method. Results revealed a product yield of 86% at $$245\,^{\circ }\hbox {C}$$ , 1.95 molar ratio and 10% lime. The silica content of the product was below 0.4% under these conditions. Lime was found helpful in controlling the solubility of impurities in the caustic soda solution.
PubDate: 2017-04-01
DOI: 10.1007/s13369-016-2388-8
Issue No: Vol. 42, No. 4 (2017)

• Influence of Clay Contents on Rheology of Syndiotactic Polypropylene/Clay
Composites
Pages: 1537 - 1543
Abstract: Abstract The high sensitivity of rheology to microstructure properties of polymer has drawn attention of many researchers from last few decades. A set of syndiotactic polypropylene/clay (sPP/clay) composite samples was used to study the influence of clay contents on the rheological behavior of sPP/clay composites in the melt phase. Small amplitude oscillatory shear experiments were performed using Advanced Rheometric Expansion System. The plateau modulus was found to increase with increasing the clay loading. Consequently, both entanglement molecular weight and packing length were found to decrease with increasing the clay loading. This result confirms that clay contents in the polymer/clay composites affect chain dimensions and parameters and consequently all the chain dynamics.
PubDate: 2017-04-01
DOI: 10.1007/s13369-016-2389-7
Issue No: Vol. 42, No. 4 (2017)

• Equilibrium and Kinetic Studies of Hexavalent Chromium Removal Using A
Novel Biosorbent: Ruellia Patula Jacq
• Authors: N. Saranya; E. Nakkeeran; S. Shrihari; N. Selvaraju
Pages: 1545 - 1557
Abstract: Abstract The present work utilized Ruellia patula Jacq leaves as biosorbent for hexavalent chromium removal. Sulfuric acid modification was done and checked for enhanced biosorption capacity. Electron microscopy–energy-dispersive X-ray spectroscopy, Fourier transform infrared spectrometry, elemental analysis were performed for characterization of biosorbents. Batch experiments were conducted to optimize contact time, solution pH, initial Cr(VI) concentration, biosorbent dose, agitation speed and temperature for maximum Cr(VI) removal. Also, the study attempted to show polyphenols present in the biosorbent reduce Cr(VI) through adsorption. Equilibrium data were analyzed using Langmuir, Freundlich and Dubinin–Radushkevich isotherms. Monolayer adsorption capacities of raw and acid-modified biosorbents were found to be 37.03 and 62.50 mg/g, respectively. Pseudo-second-order kinetic model suited well than other models like pseudo-first-order and intraparticle diffusion models examined. Determination of $$\Delta {H}^{\circ }, \Delta {S}^{\circ }$$ and $$\Delta {G}^{\circ }$$ from thermodynamic studies showed that the biosorption is exothermic, stable and thermodynamically feasible. Desorption studies using NaOH as desorbing agent showed considerable performances up to three cycles. These findings revealed that Ruellia patula leaves serve as potent biosorbent for the removal of hexavalent chromium from aqueous solutions.
PubDate: 2017-04-01
DOI: 10.1007/s13369-017-2416-3
Issue No: Vol. 42, No. 4 (2017)

• Studying Two Series of Ternary Deep Eutectic Solvents (Choline
Chloride–Urea–Glycerol) and (Choline Chloride–Malic
Acid–Glycerol), Synthesis and Characterizations
• Authors: Mohammed A. Kadhom; Ghassan H. Abdullah; Noor Al-Bayati
Pages: 1579 - 1589
Abstract: Abstract Deep eutectic solvents are a recent class of solvents that started to get attention to replace the ionic liquids and, of course, the traditional organic solvents. In this work, two series mixtures of choline chloride–urea–glycerol and choline chloride–malic acid–glycerol, liquids at room temperature, were synthesized in different molar ratios and their properties were studied. Electrochemical characterization test was performed using Pt/C catalyst and the results showed an interesting electrochemical stability for choline chloride–urea–glycerol mixture within the potential range of −1 to 1 V. The viscosity was reported as a function of temperature for mixtures which behaved as Newtonian fluids and as a function of shear rate for those which behaved as non-Newtonian fluids. For instance, 1–1–1 choline chloride–urea–glycerol viscosity was decreased from 706.8 to 26.9 cP when the temperature was increased from 20 to 80  $${^{\circ }}$$ C, respectively. While for the same mixture at 10  $${^{\circ }}$$ C, it was decreased from 30,933 to 3948 cP by increasing the shear rate from 0.03 to 0.38 S $$^{{-}1}$$ , respectively. Thermogravimetric analysis, differential scanning calorimeter and density measurements were all reported in detail in this paper.
PubDate: 2017-04-01
DOI: 10.1007/s13369-017-2431-4
Issue No: Vol. 42, No. 4 (2017)

• Comparison of Indium and Gallium Dissolution from Zinc Oxide Concentrate
in Different Acidic Solutions
• Authors: Masoud Pourrahim; Bahram Rezai; Mahdi Gharabaghi
Pages: 1591 - 1600
Abstract: Abstract While some of leaching experiment data on dissolving indium and gallium from sphalerite has been performed during the prior years, no comparison of different acidic solutions has ever been made. This study is generally divided into two sections, with each section devoted to impact aspects of acid type on prominent parameters with focus on the dissolution of gallium and indium from zinc oxide concentrate. Secondly, the study is concentrated on complex formation and stability constant to justify the consequences. Maximum dissolution of the indium and gallium was occurred with nearly results of each other as follows: hydrochloric acid > sulfuric acid > nitric acid; hence, the hydrochloric acid had relatively a little more potential rather than other acids to dissolve indium and gallium whose differences in dissolution could be explained by differences in stability constants. The dissolution optimal conditions were determined for zinc oxide concentrate including acid concentration of 6 molarity, leaching in 90  $$^{\circ }$$ C temperature for 4 h, solid-to-liquid ratio of 1:20 g/mL, particle size of +38–53  $$\upmu$$ m and agitation speed of 600 r/min. The results showed that relation between changing of (dissolution time, temperature, acid concentration) values and kind of the employed acid has prominent effect on the amount of dissolution variation, while relation between changing of (agitation speed, solid-to-liquid ratio, particle size) values and kind of the employed acid has not important effect on the amount of dissolution variation.
PubDate: 2017-04-01
DOI: 10.1007/s13369-016-2407-9
Issue No: Vol. 42, No. 4 (2017)

• Study of the Effect of Rock Type and Treatment Parameter on Acid Fracture
Conductivity Using an Intelligent Model
• Authors: M. R. Akbari; M. J. Ameri; M. Pournik
Pages: 1601 - 1608
Abstract: Abstract One of the fundamental ways to stimulate and increase the production rate of a well completed in a carbonate reservoir is acid fracturing. The amount of rock dissolved, fracture surface etching patterns, rock strength, and closure stress impacts the conductivity of the resulting acid fracture. A model of acid fracturing conductivity must accurately anticipate fracture conductivity versus closure stress. There are two parts for an acid fracture model: fracture conductivity at zero closure stress and the rate of conductivity change with closure stress. The fracture conductivity is substantially influenced by rock type. A serious challenge in recent studies has been to predict behaviour of different formations under various closure stresses. Furthermore, treatment parameters like acid injection rate and acid strength have different effects on fracture conductivity, depending on formation type. This study develops artificial neural network models to precisely predict fracture conductivity by incorporating experimental data from various formations, thereby resulting in a good match between model predictions and experimental data. The effects of rock type and treatment parameters on fracture conductivity are investigated and show that different formations have different responses under various closure stresses. There is an optimum point at which maximum fracture conductivity is achieved, but finding this point is difficult because it is distinct for different formations.
PubDate: 2017-04-01
DOI: 10.1007/s13369-016-2283-3
Issue No: Vol. 42, No. 4 (2017)

• Bubble Point Simulation of Reservoir Oil and Carbon Dioxide Mixtures
• Authors: Rashid S. Mohammad; Xinzhe Zhao; Shicheng Zhang; Syed Jamal-ud-Din Shah
Pages: 1633 - 1641
Abstract: Abstract Accurate knowledge of the multicomponent phase behavior of carbon dioxide ( $$\hbox {CO}_2$$ ) with hydrocarbon fluids is needed in the design, operation and development of carbon dioxide-based enhanced oil recovery (EOR) techniques, in particular, understanding the phase behavior of $$\hbox {CO}_2$$ and hydrocarbon fluids system. In recent years, the possibility of sequestering $$\hbox {CO}_2$$ (a greenhouse gas) in underground (oil) reservoirs has been proposed. The feasibility will also be affected by the phase behavior of $$\hbox {CO}_2$$ in the presence of chemical species present in the reservoirs (Al-Marri in PVT, phase behavior and viscosity measurements and modeling of the ternary and binary systems of carbon dioxide  $$+$$  heavy hydrocarbon (n-eicosane)  $$+$$  light gas (ethane or propane), Ph.D. Thesis, University of Southern California, 2006). PVT viscosity and vapor–liquid equilibria are important in EOR process, reservoir simulations and process design. Phase behavior consists of two parts, in the first part the recombination process takes place by inserting the data of surface fluids into the PVT simulation to determine various fluid properties and especially the bubble point at reservoir temperature. In the second part, the swelling test is introduced by inserting the data of carbon dioxide (99.6% purity) as injection fluid into the recombined fluid to investigate the swelling factors. The modified Peng–Robinson equation of state was used for predicting saturation pressure. For fluid mixtures, the Van Der Waals mixing rules are commonly used. Results of the simulation were compared with the experimental data showing that the saturation pressure of the recombined fluid/ $$\hbox {CO}_2$$ system was strongly affected by the concentration of carbon dioxide. Thus, this enhanced the oil recovery from heavy oil reservoirs.
PubDate: 2017-04-01
DOI: 10.1007/s13369-016-2347-4
Issue No: Vol. 42, No. 4 (2017)

• Erratum to: On Controllability Problems of High-Order Dynamical
Multi-Agent Systems
• Authors: Ning Cai; Junwei Cao; Minghua Liu; Haiying Ma
Pages: 1675 - 1675
PubDate: 2017-04-01
DOI: 10.1007/s13369-015-1671-4
Issue No: Vol. 42, No. 4 (2017)

• Erratum to: Effect of the CNT Content on Microstructure, Physical and
Mechanical Properties of Cu-Based Electrical Contact Materials Produced by
Flake Powder Metallurgy
• Authors: T. Varol; A. Canakci
Pages: 1677 - 1677
PubDate: 2017-04-01
DOI: 10.1007/s13369-015-1995-0
Issue No: Vol. 42, No. 4 (2017)

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