Iranian Journal of Chemistry and Chemical Engineering
Volume:41 Issue: 1, Jan 2022

In this study, copper nanoparticles (Cu-NPs) were synthesized through green and economic techniques. The Centaurea cyanus plant extract was used as an appropriate reducing and stabilizing agent in this process. The synthesized nanoparticles were characterized by Fourier-Transform InfraRed (FT-IR) spectroscopy, X-Ray powder Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Transmission Electron Microscopy (TEM), and N2 adsorption porosimetry analysis. The analysis showed that the average size of spherical nanoparticles was around 11.9 nm, with 74.2 m2/g and 0.36 cm3/g mane surface area and pore size, respectively. Then, Cu-NPs were studied as a low-cost adsorbent to remove Methylene Blue (MB) dye from aqueous solutions. For this purpose, Central Composite Design (CCD) under the Response Surface Methodology (RSM) was applied to design the experiments, model the data, and optimize the operating conditions. The effect of various operating parameters such as pH, MB initial concentration, adsorbent amount, and contact time on the MB removal was practiced. Analysis of variance (ANOVA) showed a good agreement between the experimental data and the predicted ones obtained from the quadratic model. The optimum conditions for MB removal (63.20 %) were found at pH of 6.6, MB initial concentration of 30 mg/L, adsorbent amount of 0.15 g, and time of 101.5 min. The results showed that the Langmuir isotherm with a maximum adoption capacity of 21.9 mg/g and pseudo-second-order kinetic models with a rate constant of 0.359 (g/mg) (1/min) can properly legitimize the experimental data.

A novel immobilized sparteine palladium (II) complex on the bio α-Fe2O3 nanoparticles was synthesized (Pd-Sparteine- α -Fe2O3). XPS, FT-IR, and ICP were used to determine compositional information. TGA and VSM, respectively proved high thermostability and magnetic properties of it. The size and morphology of this heterogeneous catalyst were investigated using SEM and TEM. Photoluminescence spectrum, BET, DRS, and EDAX of this novel nanocomposite were evaluated for further investigations. The synthesized magnetic nanohybrid was successfully exploited as a new recyclable heterogeneous photocatalyst in the degradation of 2,4- dichlorophenol under visible light irradiation. It exhibited better photocatalytic efficiency of Pd-Sparteine-α-Fe2O3 than that of pure iron oxide nanoparticles. This catalyst's high yield and the low reaction time indicated that Pd-Sparteine-α -Fe2O3 could be a promising catalyst for direct photocatalyst applications.

Two drugs have been authorized by the Algerian health Ministry to be used in Algeria to treat coronavirus disease 2019 (COVID-19) patients, once is Hydroxychloroquine (HCQ) and the other is Chloroquine (CQ). These drugs have been theoretically studied in order to know their active sites, and vibrational and electronic properties using Density Functional Theory (DFT) at the B3LYP/6-31G (d.p) level. The optimized molecular structures, the vibrational spectra, the HOMO and LUMO properties, dipole moments, Molecular Electrostatic Potentials (MEP), and atomic charges are calculated. In addition, the reactivity of drug molecules has been discussed by calculating some descriptors such as energy gap, hardness, local softness, electronegativity, and electrophilicity.

The substitution of fossil fuels with renewable energies is a meaningful way to mitigate global warming and air pollution. Phase change materials could store and release a high amount of energy. The solidification phenomenon is an essential factor that should be considered for choosing Phase Change Materials (PCMs). In this work, attempts have been made to improve the thermophysical properties of paraffin as a PCM during the solidification process. 1-3 wt.% of Al2O3, CuO, TiO2, and graphene nanoparticles were used during the solidification process. No reports had yet been made on the effect of graphene nanoparticles versus metal oxide nanoparticles on the thermal properties of Nanoparticle-Enhanced Phase Change Materials (NEPCMs). The DSC, TGA, SEM, and FT-IR analyses were done to investigate the transition temperature, nanoparticle distribution, and nanocomposites morphology, respectively. It was seen that the addition of nanoparticles could effectively increase the thermal conductivities of paraffin. The maximum and minimum increases were in thermal conductivities were recorded in samples with 3wt.% of graphene and 1wt.% of TiO2. The results showed that selecting suitable nanocomposites depended on various parameters, such as the type of nanoparticles and the weight percentage of nanoparticles. The PCM nanocomposites can be used to control the thermal management of different systems. The results can be applied in thermal design and management concepts, especially in the solidification process.

An immobilized copper (II) complex on micro cellulose (Cell-DABCO-Cu) was synthesized and characterized by FT-IR, TGA, and SEM. The catalytic activity of Cell-DABCO-Cu was evaluated as a recoverable and green catalyst for the four-component synthesis of 2H-indazolo[1,2-b]phthalazine trione derivatives in solvent-free conditions. The notable advantages of this procedure include excellent yields, short experimental time, and easy preparation of the catalyst. The feature of this work is using of Cell-DABCO-Cu as a starting material to prepare single-phase CuO nanoparticles (CuO NPs) via a solid-state decomposition procedure. The CuO nanoparticles with an average size of 40 nm were obtained by the direct calcination of Cell-DABCO-Cu.

In this work, the interaction of two synthesized complexes [Tb(phen)2Cl3.OH2] and [Yb(phen)2Cl3.OH2] (phen is 1,10-phenanthroline) with bovine serum albumin (BSA) were studied by UV-Vis, fluorescence, and molecular docking examinations. The experimental data indicated that these lanthanide complexes have a high binding affinity with BSA by effectively quenching the fluorescence of BSA via the static mechanism. The binding parameters, the type of interaction, the value of resonance energy transfer, and the binding distance between complexes and BSA were estimated from the analysis of fluorescence measurements and Förster theory. The thermodynamic parameters suggested that van der Waals interactions and hydrogen bonds play an important role in the binding mechanism. While the energy transfer from BSA molecules to these complexes occurs with high probability, the binding constants showed that the binding affinity ranked in the order Tb-complex > Yb-complex, which has been related to the radius of Ln3+ ion. Also, the results of competitive experiments and molecular docking calculations assessed the microenvironment residues around the bound mentioned complexes and represent site 3 of BSA, located in subdomain IB, as the most probable binding site for these complexes. The computational results kept in good agreement with experimental data.

Precipitated CaCO3 (PCC) with calcite and aragonite phases have been successfully synthesized using natural limestone. Synthesis of PCC was carried out by the simple method of carbonation using slurry Ca(OH)2 with a variation of CO2 gas flow rate at room temperature and variation of temperatures at a constant  CO2 gas flow rate. The raw material used is a very high purity Madura Island limestone. The PCC product was characterized by X-Ray Diffraction (XRD), Fourier Transform Infra-Red (FT-IR), and Scanning Electron Microscope (SEM). PCC on CO2 gas flow variation produced the same phase, calcite with the characteristic of 2θ = 29.23° (104), rhombohedral cubic morphology, and a wavenumber of 712 cm-1 as displayed from the FTIR spectra. The mixture of aragonite and calcite phase was observed in PCC products with temperature variations of 60 - 90°C. The characteristic aragonite was observed at 2θ = 26.2° with needle-like morphology. The highest fraction of aragonite was at the temperature of 60°C at 71.35%.

Solvent extraction is an economically efficient method widely used in the purification of wet phosphoric acid. In this study, a microchannel was applied to promote the mixing and purification of phosphoric acid during continuous production. For this aim, solvent extraction was conducted to purify phosphoric acid via methyl isobutyl ketone/tri-butyl phosphate mixtures. Additionally, the Box-Behnken design method was used to survey the solvent extraction process. The effect of various operational parameters such as solvent concentration (45–65 %wt.), temperature (18-28˚C), and organic/aqueous phase ratio (2:1–6:1) at a constant flow rate of 70 mL/L was examined. Experimental results indicated that the microchannel at the residence time of 6.85 min could promote the extraction percentage of and sulfate removal of more than 98% and 60%, respectively, compared to the batch extractor.

In the plastic industry, distinctive handling hardware like expulsion, infusion trim, Calendaring, and thermoforming are utilized to fabricate various products. This equipment is fundamentally the improvement of Standard Injection Molding which Injection Molding is significant. This procedure is utilized for the assembling of the hollow section part and the part with thin wall thickness. This research aimed to develop a halogen-based Headlamp for a two-wheeler vehicle. The essential objective of an automotive headlight is to enhance safety and protection in low light and poor climate conditions. It is the first time that a halogen-based headlamp for a two-wheeler vehicle has been created for the first time in Pakistan. The product in our project consists of three major components, reflector, halogen bulb, and lens. Material selection and processing were the two major tasks in this project. The product was manufactured through injection molding, a high vacuum metallization process, and then finally assembling of parts. To determine the quality of the product, six tests were performed according to the Japanese standard JIS-D5500.

This work consists of studying the influence of the desamerization of the albedo on the composition, the antioxidant potential, and the sensorial quality of the jam, based on the grapefruit. Salt, heat, and water are considered driving elements in the operation of desamerization process. The desamerization was carried out by different concentrations of NaCl relative to the fresh weight of the fruit (0.3125%, 0.625%, 1.25% 2.5%, and 5 %). The result of the various analyzes shows that the desamerization does not influence the rate of sugars and pectins, decreases the titratable acidity and the protein contents, and increases the ash contents. With regard to antioxidants, the results show that desamerization decreases vitamin C levels, carotenoids, and phenolic compounds. Concerning the sensory analysis of the jams, the results show that the salt significantly reduces the bitterness of the jams. The hedonic analysis shows that the tasters preferred significantly the desamerized jam NaCl 5% to all the other samples.

Acrylamide is one of the potential environmental public health problems, resulting from its increased accumulation in the process of cooking foods containing high levels of carbohydrates that are fried or cooked at high temperatures. So, developing a precise and sensitive analytical method for detecting and determining acrylamide in foods is absolutely necessary and inevitable. Gas Chromatography (GC) and Liquid Chromatography (LC) are two main laboratory techniques for acrylamide determination. In this study, we tried to use a cheaper, faster, accurate method for measuring acrylamide in real food samples. P540 and P503 were used as fluorescent reagents to detect the concentration of acrylamide in potato chips samples from 4 companies. Fluorescence spectroscopy was used in this work. The results obtained for the detection of acrylamide in comparison with the HPLC-MS method showed that there is an acceptable overlap between the fluorescence spectroscopy and HPLC method. The amount of acrylamide in four potato chips samples, obtained from the market in Tehran city, was determined using the proposed method. The optimum values of different parameters were determined. Comparisons between two methods, HPLC-MS and fluorescence spectroscopy were also described. The figures of merit for the proposed method were in the ideal range. The developed methods showed a high correlation coefficient (R2= 0.991). According to the results of the fluorescence emission spectroscopy and its comparison with HPLC-MS, the performance and reliability of the proposed method as a simple, efficient, and rapid method with reduction of cost and time for determining acrylamide in potato chip samples were demonstrated.

In the present work, the Headspace-Solid Phase MicroExtraction (HS-SDME) process was established utilizing a novel version of Deep-Eutectic-Solvents (DESs) for extracting and preconcentrating essential oils in plants followed by GC-FID determination. DESs seem to be a cost-effective and attractive alternative for the usage of ionic solvents in biotransformation. DESs are usually developed through gentle warming and stirring of two (low-cost and bio-based) salts. DESs have several superiorities over ionic liquids such as their ease of preparation, low production cost, and permit for large-scale applications. HS-SDME was made in the current research in order to extract volatile compounds by the use of Deep Eutectic Solvents (DESs) serving as extraction solvents. HS-SDME was constructed as a solvent-minimized extraction method. However, there are a rare number of studies investigating the Deep Eutectic Solvents (DESs) applications to the HS-SDME of bioactive compounds. Deep eutectic solvents, created by mixing choline chloride (ChCl) and p-Chlorophenol at varying ratios were utilized for extracting essential oils from Echinophora  platyloba  DC via HS-SDME in the present study. Afterward, headspace single-drop micro-extraction (HS–SDME) was conducted, being connected to gas chromatography. HS-SDME is a quick and simple method in comparison with heat reflux extraction. In addition, it is possible to use DESs in HS-SDME for extracting various volatile compounds.

The efficiency of Pterocarpus Anglolensis sawdust, an abundantly available waste product of the timber industry, capacity as an adsorbent for mercury was investigated. A series of batch experiments was carried out with experimental conditions of metal concentration, adsorbent concentration, pH, and contact time being changed. The concentration of the metal ion was deduced using spectrophotometric means. The adsorption efficiency was found to be pH-dependent with pH 4 being the optimum. 90 minutes was found to be the equilibrium time with particle size range 90-124 μm being the most efficient. Maximum adsorption of mercury was evaluated at 80.33 %. The experimental data was best modeled by the Freundlich isotherm and Pseudo second-order kinetic models. The calculated adsorption parameters are Kf = 0.0002 L/mg, bF = 3.0 and k2 = 0.00016 g/μg.min.

The exaggerated release of industrial wastes especially those containing phenol into the environment led to the contamination of both surface and groundwater supplies. In the present work a synergistic and combined system technique between three operations, adsorption of phenol via (rice husk or granular activated carbon GAC as adsorbents) together with stripping by airflow and advance oxidation via hydrogen peroxide as the oxidation agent, to evaluate the possibility of using a proposed new design for internal airlift loop reactor for removing the phenol from wastewater. The experiments were set up in a cylindrical Perspex column consisting of a transparent outer column having a 15 cm inside diameter and 150 cm height that included an internal draught tube of 7.5 cm and extending vertically to 120 cm top contains a bed having a dimension (7.5 x 30 cm) filled with adsorbent materials (rice husk, granular activated carbon GAC) and a volume capacity 25 liters. The experiments were conducted under the influence of both of the following variables air flow rate (2-20) (L/min), treatment time (5-60 min), the molar ratio of hydrogen peroxide to phenol,(1:10, 1:15, and 1:20)). The results showed the success of the proposed design with obtaining a removal efficiency (83%),( 81%)when using GAC and the rice husk as adsorbent materials respectively, with a minimum remediation time 60 minutes, airflow rate of 18 L/min, and molar ratio(20) hydrogen peroxide to phenol. This study demonstrated that the proposed synergistic system could be utilized for the remediation of contaminated aqueous systems.

In this study, the potential of SBA-15/di-urea nanoporous silica compound for the removal of Pb2+ and Cu2+ ions was investigated. The presence of organic groups in the silica framework of SBA-15/di-urea was demonstrated by the FT-IR spectrum. The functionalized product showed the BET surface area 518 m2/g and pore diameter 6.5 nm, based on adsorption-desorption of N2 at 77 K. SEM revealed a rod-shaped morphology, and the TEM image showed an ordered array of 2D hexagonal mesoporous SBA-15. The ions in the samples were identified by flame atomic absorption spectrometry. The effect of adsorbent amount, contact time, metal concentration, pH, and presence of other metals on removal efficiency has been studied. Simultaneous removal of Pb2+ and Cu2+ ions from 20 mL of the sample solution containing 60 μg of each ion were completely done at pH greater than 5.0 after stirring for 15 minutes. Langmuir, Freundlich, and Temkin adsorption isotherms were evaluated for both adsorbates and it was determined that the data fitted well with the Langmuir model (R2> 0.98). The maximum capacity of the adsorbent was found to be 147.0 ± 0.6 mg and 77.0 ± 0.5 mg of Pb2+ and Cu2+ ions/g SBA-15/di-urea, respectively. The lowest amount of 3M nitric acid for stripping the target species from adsorbent was determined as 20 mL. The application of this methodology for the real sample was tested by an Industrial wastewater sample.

Adsorption may be used to process significant metal particles in contaminated wastewater by various methods. The authors looked at various adsorbents for the expulsion of Ni(II) particles from an aquatic environment by different researchers. This paper aims to gather scattered open knowledge on a large variety of potentially persuasive adsorbents for the removal of Ni(II) particles. The present work on the usage of nickel by various natural/modified adsorbents was studied profoundly, for example, natural/modified agricultural waste, agricultural activated carbon, algae, fungal and, aquatic plant biomasses. This performance was assessed for removal efficiency and the sorbent capacity of used natural/waste materials in the system processes. Isotherm and kinetic study results were obtained from pH solution equilibrium contact time,  adsorbent dose, initial metal concentration, and temperature of various adsorbents toward the  Ni(II) particles to be examined. A documented analysis of reputed published papers revealed that industrial solid waste products, natural materials, and biosorbents have extraordinary Ni(II) adsorption ability from wastewater.

Activated carbon obtained from cryogenic crushing of used tire prepared and characterized previously was used as an adsorbent for the removal of cationic dye “methyl green dye MG” from an aqueous solution. Batch adsorption studies were carried out as a function of varying parameters of the system such as initial solution pH, adsorbent dosage, initial dye concentration, and temperature. The experimental data were fitted using Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin isotherm models. The Langmuir isotherm model fitted well the obtained experimental data. The maximum adsorption capacity of methyl green dye at pH 7 was found to be 71.43 mg/g. The results of the kinetics study indicated that the experimental data are fitted to the Pseudo-first order model. The thermodynamic properties of ∆G, ∆H, and ∆S were estimated for the adsorption processes and indicated that the latter was exothermic, spontaneous, and favorable. The developed activated carbon might be used in a favorable manner for removing methyl green from an aqueous solution.

In this study, the effect of various concentrations of alkyl polyglycoside (APG), aluminum oxide nanoparticles (Al2O3), and tetra-n-butyl ammonium chloride (TBAC) on the storage capacity of CO2 hydrate formation are investigated. For this aim, a laboratory system is developed. The experiments are carried out in the pressure range of 25 to 35 bar and the temperature range of 275.15 K to 279.15 K. The Experimental results showed that by increasing the system pressure at a constant temperature, the storage capacity increased by 48% on average. Decreasing the system temperature at constant pressure increased the storage capacity by 23% on average. Adding APG to the system at constant temperature and pressure increases the storage capacity by 75% on average, while adding nanoparticles of aluminum oxide increases the storage capacity by 5% and TBAC 38% on average. For statistical analysis of laboratory data, Design-Expert software and Response Surface test design method, and Quadratic model are employed and a mathematical relationship is developed with R2 = 0.9987 to estimate CO2 storage capacity in hydrates. The optimum amount of storage capacity equal to 137.476 has been reached at 34.558 bar, 276.085 K, 2.825 wt% of TBAC, 956.733 ppm APG, 2.436 wt % Al2O3.

In this work, the effect of hydrate promoters on methane hydrate formation in a methane-water-oil system with different initial water cuts from 20 vol% to 100 vol% were studied. For comparison, four promoters based on different promotion mechanisms, sodium dodecyl sulfate (SDS), L-leucine (L-l), tetrabutylammonium bromide (TBAB), and polysorbate 80 (Tween 80) were used. The experimental results show that four hydrate promoters did inhibit the nucleation of methane hydrate in 100 vol% water cut system, but the growth kinetic of methane hydrate was effectively improved compared with the system without a hydrate promoter. The induction time decreased with the increase of initial water cut under the same concentration of hydrate promoter for the methane-water-oil system, and the total methane consumption used for hydrate formation gradually increased with increasing initial water cut (except Tween80). But the current results also show significant improvement in normalized gas consumption per unit of water content with the increase of oil phase volume fraction that upon addition of oil phase the methane dissolution and mass transfer rate in the methane-water-oil system improve further, meaning that the formation rate of methane hydrate is enhanced. Because of the emulsifying property of Tween 80, the emulsion structure of the systems within Tween 80 hindered the hydrate growth process to some extent. Out of the four hydrate promoters used in this study, SDS was found to be most effective in enhancing the formation kinetic of methane hydrate as well as reducing the induction time in the methane-water-oil system under similar conditions.

In this study, we calculate virial coefficients and the Joule-Thomson effect at low pressure for refrigerant fluids in order to evaluate the performance of two models of Equations of State (EOS). The studied refrigerants are R123, R124, R143a, and R152a. The investigated EOSs are van der Waals type consist of van der Waals (vdW), Redlich-Kwong (RK), Soave- Redlich-Kwong (SRK) and Peng-Robinson (PR). In our work, we use Dieterici model of EOS consisting of Dieterici (D) and Dieterici-Carnahan-Starling (DCS). The obtained results show that all EOSs predict the qualitative behavior of the second virial coefficient of refrigerants in wide range temperatures but, cannot provide the qualitative behavior of the third virial coefficient of refrigerants in T£ Tc in comparing with experimental data. Quantitatively, the EOSs on the basis of vdW model present good results in a wide range of temperatures. Both models of equations of state can also predict the qualitative behavior of changing the low-pressure J-T coefficient with respect to temperature. Our study shows that the EOSs on the basis of vdW model, especially PR, present better results than the other model in a wide range of temperatures.

In this study, solubility and tie-line data of ternary system water + glycerol + 1-butanol were determined at 293.2, 298.2, and 303.2 K and atmospheric pressure. This thermodynamic system is relevant for the production and purification of biofuels. Phase equilibrium data have been determined by the cloud-point titration method and the tie-lines were obtained by correlating the refractive index of the binodal curves as a function of mixture composition. All measured LLE data were modeled by UNIQUAC and NRTL activity coefficient equations obtaining a satisfactory accuracy with modeling errors lower than 0.4%. Binary interaction parameters of tested thermodynamic models were estimated to predict the value of tie lines using a hybrid bio-inspired swarm intelligence optimization algorithm, that is, MAKHA without and with closure equation. This hybrid method was reliable to solve the global optimization problem for the binary interaction parameter identification of this ternary system. The results of this paper provide useful information for the design and modeling of industrial units for glycerol recovery, which is a relevant industrial feedstock.

This study focuses on developing a new method that represents user-accessible correlation for the estimation of water-based nanofluids viscosity. For this, an evolutionary algorithm, namely Gene Expression Programming (GEP), was adapted based on a wide selection of literature published databanks including 819 water-based nanofluids viscosity points. The developed model utilized the base fluid viscosity as well as volume fraction and size of the nanoparticles as the inputs of the model. Several statistical parameters integrated with graphical plots were employed in order to assess the accuracy of the proposed GEP-based model. Results of the evaluation demonstrate fairly enough accuracy of the developed model with statistical parameters of AARD%=11.7913, RMSE=0.3567, and SD=0.1851. Furthermore, the trend analysis indicates that the GEP calculated points satisfactorily follow the trend of the nanofluid viscosity variation as a function of different model inputs. To provide more verification, the proposed GEP model was compared with some literature theoretical and empirical correlations leading to the supremacy of the developed model here. The applied sensitivity analysis reveals that the highest impact value is assigned to the volume fraction of the nanoparticle. Moreover, the outlier’s detection by Williams’ technique illustrates that about 96.5% of the GEP estimates are in the applicability domain resulting in the validity of the proposed model in this study. At last, the results of this study demonstrate that the new method here outperforms other literature-published correlations from the standpoint of accuracy and reliability.

Carbon dioxide miscible displacement plays an important role in the field of miscible displacement for enhanced oil recovery. However, there is a very important relationship between the formation of miscible displacement and the minimum miscible pressure. The pendant drop method in the interfacial tension method was firstly used to predict the minimum miscible pressure of the supercritical carbon dioxide and the formation of oil in the test area oilfield. Under the condition of the simulated reservoir temperature 111.5 °C, the interfacial tension of the supercritical carbon dioxide and the formation oil system was tested experimentally by using formation oil samples of the test area oilfield. The range of test pressure was from 10.06 MPa to 28.57 MPa. Besides, the relation curve of the test pressure and the interfacial tension was drawn. The results show that under the reservoir temperature, the interfacial tension between the supercritical carbon dioxide and the formation oil shows an approximately linear downward trend with increasing the test pressure. The mathematical expression was obtained by the linear regression analysis. According to the extrapolation, the vanishing point of the interfacial tension was obtained. Then the minimum miscible pressure of the supercritical carbon dioxide and the formation oil system was determined. The actual test was carried out to verify the result by the pendant drop method. Finally, the minimum miscible pressure of the supercritical carbon dioxide and the formation oil system of the test area oilfield was determined to be 29.4 MPa.

Because of anomalous heat transport behavior in nanofluids, several possible mechanisms suggested by various authors to explain the thermal conductivity and heat transfer coefficient enhancement lack unanimity. Hence, this research article aims to explore convective heat transfer enhancement mechanisms by correlating them with observed experimental data of nanofluids. The analysis is carried out by comparing the order of magnitude of different diffusion mechanisms for different types of nanofluid systems. Four different types of nanofluids, Al2O3/EG-W (0.6, 0.9, 1.2, and 1.5 vol.%.), Al2O3/PG-W (1, 1.5, 2, and 2.5 vol.%.), CuO/PG-W (0.25, 0.5, 0.75 and 1 vol.%) and MgO/PG-W (0.3 and 0.66 vol.%) have been studied in this research. A generalized mechanism-based correlation has been proposed to predict the Nusselt number for these nanofluids, for flow through a straight tube under laminar conditions. Results showed that the Brownian motion is very slow in comparison to nano convection-diffusion and heat diffusion. The proposed model predicted the combined data for all the nanofluids studied well within a range of ±5%. Statistical errors of the proposed model were also calculated. Data from other authors were also validated using the proposed correlation, and the parity plot showed that the relationship predicted the data well within a range of ±15%.

This paper aims to produce freshwater from saline water with the help of solar still. Different solar wick materials still absorb the sunlight and convert the heat energy, such as black sheer mesh fabric, light black cotton fabric, light jute fabric, black velvet fabric, and 4 mm thick sponge sheet. The wick materials sheets were wholly immersed in the saline water covering the total still basin area. The net basin horizontal active area of the solar still is 0.48 m², and the glass cover’s tilted angle was fixed at 36º. From this arrangement, it has been found that by the use of various wick materials, the productivity rate differs from each other, and among these wick materials, light black cotton is the most effective wick material for solar still productivity increment. The pH value measures the final quality of the freshwater.

Phase Change Materials (PCMs) are currently used for many heat management applications. However, the heat transfer performance of PCMs is limited by their low thermal diffusivities. This is a critical issue for high heat flux applications, such as in the thermal management of lithium-ion (Li-ion) batteries. The present work aims the study heat transfer enhancement in a cylindrical Li-ion battery thermal management system consisting of a PCM (paraffin) loaded with randomly distributed and radially oriented carbon fibers. The system was simulated numerically under various cooling conditions, including naturally convecting air, in the presence of pure paraffin, and the presence of carbon fiber-loaded paraffin. The results for orderly arranged carbon fibers were compared with those of random distribution. Numerical results indicated that better battery thermal management can be achieved for the radially distributed carbon fiber arrangement in the PCM. The advantage of radial over random distributions can be due to the constant, uniform, and non-agglomerating distribution of carbon fibers under which thermo-physical properties of carbon fibers are better realized in the composite medium. The presence of carbon fibers with thermal conductivity of k=50W/m K in the PCM has caused more uniform temperature profiles in the radial direction because of the improved thermal conductivities. The results of this research can be used as a guideline for designing a battery thermal management system.

In a refinery flare system is the last defense line for controlling the over-pressurization of process vessels. Mostly power failure is the worst contingency in the refinery, and the flare capacity is evaluated for this case. The data of Pressure Safety Vessels (PSVs), header network, knockout drums, flare stack, and flare tip is to utilize for simulating the flare system of the Oil Refinery Complex (ORC-II). In power failure contingency out of fourteen PSVs, four were found to have higher back pressures than the allowable limits, those PSVs were resized and new models have been proposed. Carbon dioxide (CO2) is a significant benefactor of global warming stances a severe hazard to the environment. The danger of natural contamination might be diminished by downstream usage of post-combustion vent gases which principally originate from power plants, gas, or oil fields, and the cement industry with the essential spotlight on CO2 catch. Post-combustion is a broadly utilized system as a result of its similarity with the existing force plant framework. The procedure was conveyed using 30 wt. % monoethanolamine (MEA) dissolvable and Hollow-fiber cellulose acetic membrane framework. This research consists of two sections. In the initial segment, the capacity evaluation of the flare framework was finished utilizing Aspen Flare System Analyzer V8.4 and the rating of the flare framework was conveyed in which to break down the necessary parameters like Mach number and back weight in the system and the adjustments in the flare framework were made as per API 520. In the second part chemical absorption and membrane separation innovations were looked at for post-combustion carbon catch. The research focuses on conveying a relative investigation of the above-expressed methods for the flow rate of vent gas runs between 1 to 200 MMSCFD. The goal is to accomplish 90% recuperation of CO2 with carbon decrease from 10.66 mole % to 2 mole %. The absorption technique is simulated by ASPEN HYSYS V8.4 and a program for membrane framework is created by connecting values from ASPEN HYSYS to Microsoft EXCEL. For membrane separation, the operating expense is seen as lower than the absorption process, yet from the results, it was concluded that the absorption technique is superior to the membrane technique until the problems concerning the degradation of the membrane and high capital expense would be settled.

A Pickering Oil/Water (O/W) emulsion was formulated based on Algerian bentonite particles with small amounts of synthetic surfactant ranging between 0.01 and 0.05 %. A rheological study was carried out on the emulsions studied after 18 months of aging using a parallel plate geometry. The rheological study, under variable shear, has shown that the viscous behavior of these emulsions is of structural type, with the presence of two Newtonian regions at low and high shear. The oscillatory test revealed that emulsions have the character of a viscoelastic gel which is practically insensitive to frequency decreasing sweep and therefore potentially stable over time. Results showed that 7% of bentonite and 0.015% of cationic surfactant (cetyltrimethylammonium bromide) are necessary to obtain a Pickering emulsion with an adequate rheological behavior for a cutaneous application.