Iranian Journal of Chemistry and Chemical Engineering
Volume:40 Issue: 2, Mar-Apr 2021

The performance of sulfonated-titanomagnetite nanoparticles (Fe3-xTixO4-SO3H NPs)as useful and recyclable nanocatalyst for the synthesis of dihydroquinazoline and hexahydroquinoline derivatives through multi-component reaction approach in solvent-free condition were investigated extensively. The successful synthesis of mentioned derivatives was confirmed using Fourier-Transform InfraRed (FT-IR) as well as 1H/13C nuclear magnetic resonance (NMR) spectroscopies. According to the results, the employed nanocatalyst has some advantages such as high catalytic activity in short reaction time, good-to-excellent isolated yields in most cases, easy workup process, smooth processing feature of the reactions, facile recovery using an external magnetic field,  and re-usability for four times without significant loss in its activity.

Nano Encapsulated Phase Change Materials (NEPCMs) are a crucial part of solar energy systems due to their high thermal storage density. The particle size of the NEPCMs is especially of great importance due to its effect on heat transfer and long-term use during applications. In this study, nanocapsules containing Phase Change Material (PCM) n-dodecanol as core and polymethyl methacrylate (PMMA) as shell were synthesized by miniemulsion polymerization with Graphene Oxide (GO) nanosheets as an extra protective screen situated at the interface between the core and the shell. The experiments were designed with the Central Composite Design (CCD) of Response Surface Methodology (RSM). The nanocapsules synthesis experiments were conducted as per the statistical design to determine the optimum process conditions. The effect of initiator/Methyl methacrylate(MMA) mass ratio (BPO/MMA wt.%), n-octadecane/MMA mass ratio (PCM/MMA), stabilizer/MMA mass ratio (triton X-100/MMA wt.%), water/MMA mass ratio (H2O/MMA) and GO/MMA ratio on the nanocapsule properties were investigated. The correlation between nanocapsule properties (melting latent heat and average particle size of nanocapsules) and affecting factors were evaluated and verified. The numerical optimization showed that the optimum nanoparticle size (110 nm) and latent heat (148.5 J/kg) can be obtained at H2O/MMA of 11.3 wt%, PCM/MMA mass ratio of 1.88wt%, X-100/MMA of 10.81wt.%, and BPO/MMA of 2.96 wt.% and GO/MMAof 3.79wt%.  The optimized nanocapsules were characterized by Fourier Transform InfraRed (FT-IR) spectroscopy, Transmission Electron Microscope (TEM), Differential Scanning Calorimetry (DSC), ThermoGravimetric Analysis (TGA), and laser particle diameter analyzer. The thermal cycling tests indicate the high thermal resistance of the prepared core-shell system, even after 100 heating/cooling cycles, and have an excellent potential for energy storage and release performance of the system.

Considering the antimicrobial properties of silver and its enhanced level at nanoscale scale, it can be used to combat the various pathogens and microbial agents. The aim of this study was to investigate the antimicrobial effect of silver nanoparticles synthesized with Bougainvillea Glabra extract on standard strains of Staphylococcus aureus and Escherichia coli. In this study, silver nanoparticles were biosynthesized using the aquatic Bougainvillea Glabra extract under optimal conditions. The synthesis of silver nanoparticles was confirmed using UltraViolet-Visible (UV-Vis) spectroscopy and X-Ray Diffraction (XRD). Based on the X-ray diffraction pattern, the silver nanoparticles crystallite size was 21 nanometers. Transmission Electron Microscopes (TEMs) and Scanning Electron Microscopes (SEM) showed the synthesis of silver nanoparticles of about 23 nm in size and spherical morphology. Revitalizing and stabilizing agent groups were identified using Fourier-Transform InfraRed (FT-IR) spectroscopy. The mean diameter of the inhibition zone and the Minimum Inhibitory Concentration (MIC) were 27.6 mm and 3.12μg/mL for S. aureus and 19.3mm and 12.5μg/mL for E. coli, respectively. Biological synthesis using Bougainvillea Glabra aquatic extract is a very inexpensive and cost-effective method. The ability of Bougainvillea Glabra to synthesize silver nanoparticles makes it possible to use this plant as a useful biological source for the synthesis of silver nanoparticles with suitable and practical sizes for medical and microbicide applications.

The main challenge in bacterial cellulose nanofibers production is low yield and high cost. The aim of this work is to optimize bacterial nano-cellulose production in the bench-scale rotating biofilm contact (RBC) bioreactor using experimental design. At all of experiments the Acetobacter Xylinum BPR2001 and culture medium molasses – CSL were used. Three effective factors in the three levels including rotation (10, 13 and 16 rpm), aeration (0.2, 0.5 and 0.8 vvm) and disk distance (1, 1.5 and 2 cm) were optimized by response surface experimental design. The optimum conditions of biocellulose production were rotation rate 13 rpm, aeration 0.5 vvm and disk distance 1.5 cm. The maximum dry weight of bacterial cellulose production reached 11.65 g/l in the 7th day, Which is one of the highest amounts of bacterial cellulose ever reported. Reduced quadratic models were used to final dry weight and moisture content of bacterial cellulose responses. ANOVA results showed the p-values were less than 0.05 that are significant models.

In this research, we investigated the effects of parameters, including reaction time, reaction temperature, the mass ratio (mcat./mfeed), and volume ratio (VH2O2/Vfeed) on sulfur removal conversion of light naphtha under oxidative desulfurization (ODS) reaction. So to achieve this goal, several active catalysts are prepared while molybdenum (Mo) was used as an active metal. Nickel (Ni) was the promoter. 𝛾-alumina (𝛾-Al2O3) was used as a support and modified by chelate agents such as citric acid (C6H8O7), ethylene diamine tetraacetic acid (EDTA), polyethylene glycol (PEG), Sorbitol, and urea ((NH4)2CO). These catalysts were synthesized by using the wetness impregnation in-situ method. Then they were applied to the ODS process for light naphtha. These catalysts were characterized by N2adsorption-desorption isotherms (BET, BJH), Scanning Electron Microscope (SEM), temperature-programmed desorption (NH3-TPD), and FT-IR analysis. The catalyst that synthesized in the presence of sorbitol, had the best performance.  The optimization conditions for this catalyst were m (catalyst)/m (feed)= 0.013, reaction temperature of 35 °C, 50 mL of feed, 0.5 g of catalyst, 1 hour reaction time, and V (H2O2)/VFeed = 0.045.  It revealed the maximum performance for ODS reaction of the real feed. Under these circumstances, the sulfur of light naphtha decreased from 160 ppm to 38 ppm during the reaction.

Polyaniline, polyaniline/SiO2, and poly(4-vinylpyridine) are highly effective base catalysts for the synthesis of tetrahydrobenzo[b]pyran and 3,4-dihydropyrano[c]chromene derivatives by the one-pot three-component condensation reaction of aryl aldehydes, malononitrile and α-hydroxy or α-amino activated C–H acids such as 1,3-cyclohexanedione, dimedone, 4-hydroxy-6-methylpyrone, 4-hydroxycoumarin, 1,3-dimethylbarbituric acid, and 1,3-dimethyl-6-amino uracil. The remarkable advantages of this new procedure are high yields, short experimental time, mild reaction condition, low cost and easy preparation of the catalysts, and no need for any workup and purification after completion of the reaction. In addition, these catalysts exhibited excellent recoverability without a negligible decrease of their activities after at least six cycles of reaction.

An eco-friendly, highly efficient, and tandem reaction between 2-hydroxy-1,4-naphthoquinone and quinolinium salts in the presence of DABCO, 1,4-diazabicyclo[2.2.2]octane, in an aqueous medium is developed for the synthesis of functionalized polycyclic naphthooxazocines. The advantageous features of this operationally simple procedure along with good to excellent yields of products highlighted this method for the preparation of oxazocine. Moreover, the products obtained without the need for column chromatography. In order to reduce the hazards of chemicals and solvents, the reaction was conducted in the green solvent, water. All newly synthesized compounds were characterized by different methods involving IR, 1H NMR, 13C NMR spectroscopy.

In this study, N-(2,4,6-tribromophenyl)maleimide (TBPMI) was synthesized using three different catalysts, including stannous chloride, anhydrous acetic acid, and phosphoric acid, respectively. Comparative analysis was carried out on the synthesis conditions and the yields of TBPMI synthesized using different catalysts. Infrared spectroscopy and nuclear magnetic resonance spectroscopy were employed to characterize TBPMI. Results showed that the use of phosphoric acid as the catalyst required harsh reaction conditions and also the catalytic efficiency was poor. On the other hand, under similar conditions, the catalytic efficiency of anhydrous acetic acid was higher than that of stannous chloride, along with the reduction in problems associated with erosion and pollution.

With the aim to enhance the charge transport, optoelectronic and semiconducting properties various multifunctional pyrano[3,2-c]chromene derivatives were synthesized and characterized. To shed light on the various properties of interests, the ground state geometries were optimized by Density Functional Theory (DFT). The effect of different substituents, e.g., thiophen-2-yl, 5-bromothiophen-2-yl, 1H-indol-3-yl, pyridin-3-yl, and benzo[d][1,3]dioxol-5-yl was studied on the structural stability, electronic properties, and absorption wavelengths by DFT and Time-Domain DFT (TDDFT). The experimental excitation energies were successfully reproduced at TD-PBE/6-31G** level in DMSO. The electron injection barrier, ionization potential, electron affinity, and reorganization energies for hole and electron were calculated and compared systematically. The smaller electron reorganization energies of pyrano[3,2-c]chromene derivatives except indole substituted one is illuminating that these materials would be efficient to be used in n-type semiconductor devices.

Different perovskite-based materials are proposed as cathode materials for solid oxide fuel cells (SOFCs) working at low temperatures (~600 oC). In this research work,   a set of perovskite cathode materials, such as Sm1-xCexCoO3-δ, Sm1-xCexMnO3-δ, Gd1-xCexCoO3-δ andGd1-xCexMnO3-δ (x = 0.1–0.2)were prepared for SOFC applications by co-precipitation method with sodium hydroxide solution as the precipitating agent. The precipitated hydroxides were calcined at 300, 600, 750, 900, and 1100 oC /2 hours in the air using a thermolyne furnace. The calcined powder particles were characterized by XRD, FT-IR, Particle Size, SEM, and EDAX techniques. XRD patterns revealed the presence of orthorhombic primitive phases in the samples. Crystallite sizes of the materials were also determined with XRD method. The presence of M-O bond was confirmed by FT-IR spectroscopy. Particle size analysis proved the presence of samples in the range of 247-976 nm. However, the SEM images revealed the presence of nano-sized particles. The atomic percentage of elements present in the materials was measured by EDAX.  Pellets of cathode samples were made and sintered at high temperatures. The conductivity values of the specimens were measured with electrochemical impedance spectroscopy at different temperatures. The cathode specimen, Gd1-xCexCoO3-δ (x=0.1 and 0.2) exhibited better electronic conductivity than other samples. It was found that the prepared cathode samples are stable at moderate temperatures and suitable for Low-Temperature Solid Oxide Fuel Cell (LTSOFC) application.

The new piperazine-based Schiff base hydrazone with N, O donor set of atoms, LPE, has been prepared by the condensation reaction of new piperazine-based diamine, APE, with salicylaldehyde. The structure of newly prepared compounds was characterized by using FT-IR, UV-Vis, 1H NMR, and 13C{1H]-spectroscopic methods as well as elemental analysis data. Furthermore, the structure of piperazine-based compounds, APE and LPE, has been optimized and the geometrical structures of a diamine compound, APE, and Calcium atom have been investigated at the level of density functional theory (DFT). The 6-311++G(d,p) basis set was utilized for ligands in the gas phase. The optimized structures contain N…Ca interactions and piperazine rings have boat structure in most of them.  The chelating structures of piperazine rings show most stabilization among other interactions, the stabilization energy is -1493.9667 kJ mol-1. Also, the prepared compounds were evaluated for preventive effect on apoptotic motor neurons in adult mouse spinal cord slices. The APE inhibited apoptosis in the motor neurons and significantly increased viability in these neurons.

In this study, the effects of solvent on the electrode potentials of menthol and carvacrol species were investigated experimentally and computationally and their antioxidant properties were compared in different solvents by calculating the half-wave potential E1/2 of species, Vand Dissociative Energy (BDE), Ionization Energy (IE), and Electron Affinity (EA). Electrochemical behavior of menthol and carvacrol species in four solvents (MeOH, EtOH, DMSO, and Heptane) were studied using cyclovoltametric technique in a glass electrode as a working electrode and the calculations for obtaining the electrode potential were performed using DFT functional including B3LYP with 6-311+G(d,p)basis set and PCM and IEFPCM models for calculation of solvent energy. Finally, the results were compared and confirmed by experimental methods. Where in the compound carvacrol represent more properties antioxidant than menthol due to lower values E1/2 in gas and solution phases. Also, the lower BDE in the gas phase is 80.19 kcal/mol compared with menthol (98.91 kcal/mol). Moreover, compound carvacrol has the IE value of 1.12 eV smaller than menthol and has the EA value of 0.35 eV higher than menthol. Calculations show that the model had no effect on computational results. Also, according to the results, the antioxidant properties of carvacrol in non-polar solvents were higher due to the smaller amount of E1/2.

In the current study, disperse red 60 (DR60) dye was selected for dyeing of polytrimethylene terephthalate (PTT) under influence of ultrasonic radiation. For this purpose, the disperse dyes were placed under ultrasonic for 15-90 minutes, and the measurements of some parameters including particle size, the influence of temperature, and time were investigated. The results illustrated that ultrasonic has a good effect to decrease particle size of the dye and the smallest particle size for the DR60 dye was obtained at the time of 45 minutes and the temperature of 20 °C. The adsorption process under ultrasonic irradiation was exhibited maximum efficiency of dye at the optimal conditions including adsorption temperature (80 °C), PTT amount (0.1 g), irradiation time (120 min), pH = 6, and initial dye concentration (40 ppm). All experiments indicate that ultrasonic has a significant effect on the adsorption of DR60 dye to PTT. As results show, the Nernst model was fitted properly to the experimental data in comparison to other isotherm models as presented. Furthermore, the achieved thermodynamic parameters including the negative value of ΔG (-0.85 to -1.58 kJ/mol) at all temperatures, positive values of ΔH (11.32 kJ/mo1) and ΔS (36.51 J/mol.K), indicate that adsorption of DR60 dye to PTT is spontaneous and endothermic in nature.

This study presents the feasibility of used untreated Scolymus hispanicus as a low-cost adsorbent for the adsorptive removal of Basic Blue 41 (BB41), a common pollutant in textile wastewater. The Scolymus hispanicus adsorbent was characterized by Fourier Transform InfraRed (FT-IR) spectroscopy, Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray (EDX) analysis, and pH zero of point charge (pHzpc) method. The ability of the Scolymus hispanicus in removing the dye color was dependent on contact time, adsorbent dose, initial dye concentration, and solution pH. The optimum adsorption was found at around pH 7; contact time 75 min; adsorbent dose 4 g/L. The maximum percentage dye removal value was 81, 92 % with an initial dye concentration at 5 mg/L.  The adsorption kinetics was best described by pseudo-second-order model for different initial concentrations and the adsorption isotherm follows the Freundlich model.  Thermodynamic parameters such as enthalpy change (∆Hº), free energy change (∆Gº), and entropy change (∆Sº) were studied, and the adsorption process of Basic Blue 41 was found to be endothermic, spontaneous, and physical in nature. The study revealed that the Scolymus hispanicus is a potential adsorbent for effective removal of BB41 from an aqueous solution.

In this study, a composite of Cu, N co-doped TiO2@SiO2 aerogel as a photocatalyst with enhanced optical absorption in the visible region as well as high specific surface area was synthesized by the sol-gel method and ambient pressure drying process for degradation of Ethylbenzene. The physicochemical properties of the photocatalyst were examined by X-Ray Powder Diffraction, Scanning Electron Microscope, Photoluminescence, Fourier Transform Infrared Spectroscopy, Diffuse Reflectance Spectroscopy, Brouner Emmet Teller Isotherm/Barrett Joyner Halenda analysis. The structure of samples consisted of titanium dioxide crystalline phases in the dominant phase of the rutile and the amorphous structure of silica. The appearance of the Ti-O-Si peak confirmed the formation of TiO2@SiO2 composite. Based on the results of the characterization analysis, the type and concentration of dopants can be effective on the crystalline structure, bandgap energy, particle size, specific surface area, and the recombination of charge carriers. The sample contains 3 at. % of copper and nitrogen was able to degrade Ethylbenzene more efficiently in comparison with mono-doped TiO2@SiO2 nanocomposite under visible-light irradiation. The synergistic effects of Cu and N co-dopants were responsible for strong visible light absorption and effective separation of electron/hole.

The oxidation of 4-Nitrophenol (4-NP) has been studied using recirculating fluidized-bed Fenton process. The effect of various parameters such as pH, the concentration of hydrogen peroxide, the concentration of ferrous ions, various types of carriers, and dosage of the carrier were investigated on the oxidation of 4-NP. Al2O3 and SiO2 were used as two different carriers for the oxidation of 4-NP. The experimental results are reported in terms of degradation percentage of 4-NP, Chemical Oxygen Demand (COD), and Total Organic Carbon (TOC). The results showed that the degradation and COD removal of 4-NP in the presence of Al2O3 carrier was higher as compared to SiO2 carrier. The degradation of 96% was achieved under the optimal operating conditions of pH 3, 0.2 mM Fe2+, 4 mM H2O2, and 5g/L of Al2O3 as a carrier. The TOC and COD removals were 70% and 55%, respectively after 1 h of reaction time. The presence of Fe-O bond onto Al2O3 carrier after the reaction was confirmed by the FT-IR studies. The total iron remained in the solution after reaction using fluidized-bed Fenton process was lower (8.5%) than homogeneous Fenton process (17%). The fluidized bed Fenton process also showed higher TOC and COD removal as compared to the homogeneous Fenton process.

Silica fume, also known as micro silica, is a by-product of the reduction of high-purity quartz with coal in electric furnaces in the production of silicon and ferrosilicon alloys. This material and laccase-modified silica fume used as alternative low-cost adsorbent materials for dye removal from aqueous solutions. The silica fume was modified to maximize its adsorption capacity. For this purpose, the laccase enzyme was purified and immobilized on silica fume. Batch adsorption experiments have been performed as a function of pH, contact time, temperature, and adsorbent dosage. The equilibrium data were analyzed using Langmuir and Freundlich adsorption isotherms. The Langmuir adsorption model provided a better fit to the data. The kinetic data were evaluated with pseudo-first-order and pseudo-second-order kinetic models. The adsorption process undergoes pseudo-second-order kinetic as proved by the high value of R2. The thermodynamic parameters such as free energy, enthalpy, and entropy were also determined. These parameters indicated that the adsorption of Acid Fuchsin dye onto silica fume and laccase-modified silica fume was a spontaneous, endothermic, and entropy-driven process. The results show that both of them, especially laccase-modified silica fume, can be used as alternative low-cost adsorbents for dye removal from aqueous colored solutions or effluents.

Layered double hydroxide functionalized biochar and hydrochar composites are environmentally friendly and low-cost adsorbents for the removal of phosphate from aqueous solutions. In the present study, Mg-Al layered double hydroxide functionalized apple wood biochar and hydrochar were prepared and their phosphate adsorption characteristics were examined through batch experiments. Moreover, important factors affecting adsorption including initial phosphorus concentration (25-200 mg/L), contact time (5-120 min), ionic strength (deionized water, and 0.001, 0.01, and 0.1 mol/L KCl), pH (3-10), and adsorbent dosage (1, 2, 3, and 4 g/L) were investigated. Based on the results, the phosphate adsorption by Mg-Al layered double hydroxide modified biochar and hydrochar were comparable with Mg-Al layered double hydroxide and were greater than biochar and hydrochar. As expected, phosphate adsorption was decreased by increasing solution pH and ionic strength. The highest phosphate removal was attained at pH 4, adsorbent dosage of 4 g/L, and in the presence of deionized water as a background solution. Determination of adsorption characteristics of the adsorbents revealed that the phosphate adsorption mechanism involved a combination of electrostatic attraction, interlayer anion exchange, and formation of surface complexes. The Mg-Al layered double hydroxide modified biochar and hydrochar composites as cost-effective and efficient adsorbents suggest alternative biochar- and hydrochar-based composites for the phosphate removal from contaminated waters that could be used as P-fertilizers.

In the current research, NaY zeolite with a molar ratio of Si/Al=2.5 was grafted chemically with amines like monoethanolamine, tetraethylenepentamine, and morpholine.The modified NaY zeolites were characterized by XRD, FT-IR, TGA, EDAX, BET, FESEM, CO2-TPD, and Volumetric analysis. Modification of the NaY surface with amine groups led to a remarkable rise in CO2   adsorption capacity. CO2 adsorption studies of  NaY and modified NaY zeolite by CO2-TPD technique revealed that, the dominant mechanism involves the interaction of CO2 with amine groups on the surface of NaY zeolite, at ambient pressure and at a temperature of 323 K. The volumetric method was also used to investigate CO2 adsorption onto the amine grafted NaY zeolite at 5, 7 bar pressures and at temperatures of 298 and 343 K. The adsorption process is thermal dependence and results of adsorption studies indicate that increasing temperature leads to higher adsorption of CO2 onto the amine grafted NaY zeolites.

The present study provides a novel process flowsheet for CO2 compression and purification unit (CPU) in order to improve its product quality and control performance. Unlike the previous process flowsheet, the number of cold-boxes has been reduced to one, which in turn decreases investment costs and improves energy integration. The performance of the proposed flowsheet was compared with two recently suggested ones for a given feed. The results showed that, compared with the other process flowsheet, the new one not only can operate at lower operating pressure but also needs a significantly smaller heat-transfer area. Also, the dynamic behavior and controllability of the proposed process flowsheet are analyzed to ensure proper functioning. The control loops used in the new flowsheet were simpler than those used in the previous flowsheet, and controllability was achieved using proportional (P) and Proportional-Integral (PI) controllers, which offers a performance advantage over the other process flowsheet. Using step changes, the effects of disturbances in feed temperature, flow rate, and composition on the final product specifications were also investigated. The proposed flowsheet process proved to be robust against the disturbances, and the control structure was able to handle them appropriately. The proposed process flowsheet was also able to maintain purity and recovery rates of 96.74% and 90.08%, respectively, in the face of disturbance.

The current study focuses on gas storage performance using the industrial internet of materials. A series of inorganic-organic coordination polymers made by lanthanide (III) and asymmetric ligands the pyridine-2,4-dicarboxylate were prepared in hydrothermal synthesis. The goals of this study were to investigate the gas adsorption/desorption behaviors and to measure the surface areas of the as-synthesized samples. These materials possess BET (Brunauer-Emmett-Teller) surface areas of approximately 480-610 m2/g, which is verified by the surface area measurement based on the N2 adsorption at 77 K. The adsorption isotherm of H2 at 77 K exhibited a stable uptake of 1.35w % both at low pressure and high pressure, providing evidence for the robust framework of compounds with 0.7 nm pore size. Especially, the Cerium ion compound shows the highest H2 uptake of 154 cm3/g (1.35 wt %) among other samples, which is relatively low in comparison with that of Al-TCBPB and Zn4O (BDC)3, but higher than that of Zn4O (BTB)2.

Roasted watermelon seeds are consumed as snack foods. In this research, the Response Surface Methodology (RSM) was used in order to examine the effect of roasting on some physicochemical properties of watermelon seeds. The Central Composite Design (CCD) was applied to investigate the effects of two independent variables, i.e. temperature (180-260 °C) and time (5-15 min), on moisture content, texture, color, total phenol, and antioxidant activity. According to the results, increasing the temperature and prolonging the duration of roasting caused reductions in the moisture content, DE and texture hardness. Meanwhile, the total phenol content and antioxidant activity increased. The linear, quadratic, and interactive effects between the independent variables (temperature and time) were significant on moisture content and texture hardness (p <0.05). All variables, except the quadratic effect of time and the quadratic effect of the two independent variables, caused significant changes to the antioxidant activity and total phenol content. However, the total difference in color was only significantly affected by the linear effect of the two variables. Finally, roasting conditions (i.e. roasting temperature and time) were optimized in a manner that the acquired model-generated results akin to the experimental data (desirability=0.74).

The study obtained the Liquid – Liquid Equilibrium (LLE) for Aqueous Two-Phase Systems (ATPSs) containing poly (vinyl pyrrolidone) (PVP) (10000, 24000, and 40000) and zinc sulfate at 298.15 K. The phase area is expanded according to the increased molecular weight of the polymer. Density and refractive indices were employed as the physical properties for obtaining phase composition and end of tie-line evaluations. The effect of molecular weight is discussed in relation to binodal curve, Tie-Line Length (TLL), and Slope of Tie Line (STL) determinations. Following the increase in polymer molecular weight value, the TLL increased and STL slightly decreased. Accordingly, Pirdashti’s equation was used to correlate binodal curve evaluations of these systems. Furthermore, tie-line data points were correlated by Othmer-Tobias, Hand, and Bancroft equations. Finally, the study determined the Effective Excluded Volume (EEV) of salt into the PVP aqueous solution.

PCM-based thermal energy storage in conjunction with an electric air source is offered as a potential tool to support domestic energy demand reduction while at the same time minimizing supply challenges for the electricity utilities. This study is to advance the use of hybrid ventilation concepts in building design by assessment of PCM storage unit with an operation of the evaporative ventilation system. RSM CCD methods was employed to evaluate and optimize the individual/interactive effect of parameters on the cooling efficiency of the proposed system. Optimization results indicate that maximum efficiency can be achieved when inlet air temperature and velocity of 28 oC and 1.2 m/s when PCM coils number was set to 28, respectively. This research compared the effectiveness of the passive and free cooling application of PCM when applied to a duplex brick veneer building in Melbourne. It was observed that during the studied period, the free cooling application method is more effective than the passive application method in reducing the peak zone temperature.

Modeling and simulation of a distillation column are very important in many chemical industries where ever it requires separation or purification of a liquid mixture into its pure components. Particularly in the context of improving efficiency, process scale-up, intensification and control it requires a validated model. In this work, both experimental results and simulation results are obtained. A batch distillation equipment that consists of a reboiler, a packed column, and a top condenser is used to distill a mixture of benzene and toluene with various heat inputs to the reboiler. The distillation process in the column is modeled by an evaporation rate-based approach using Raoult’s law for driving force. This particular feature is different from the stage-wise equilibrium model. The evaporation mass transfer coefficients are obtained for benzene and toluene in lab-scale apparatus. The material balance equations for the two components are solved using a finite difference method. The distillate compositions at total reflux obtained from experiments and the simulations are compared for validating of model proportionally. Further insights are obtained in regard to throughput and distillation efficiency.

This study aimed at investigating liquid-liquid extraction of the three-component n-hexane + benzene + sulfolane system in a micro extractor. Experiments were carried out in a microtube with a diameter of 800μm using a T-shaped micromixer at a residence time of 15s. Temperature and the ratio of solvent (sulfolane) to feed (95% n-hexane + 5% benzene) investigated as operational variables. The temperature was investigated at (313.15, 323.15, and 333.15) K, and the solvent to feed ratio was investigated in five states including (0.33, 0.50, 1.00, 2.00, and 3.00) mL/mL. The results of experimental design and statistical analysis showed that operational variables had a significant impact on the distribution coefficient and selectivity. It was found that distribution coefficient and selectivity reached their highest levels at (313.15 and 32315) K, respectively. In addition, in the low volumetric solvent to feed ratio (0.33ml/ml), the highest levels of distribution coefficient and selectivity were been obtained. Finally, the results obtained for liquid-liquid extraction of n-hexane + benzene + sulfolane were assessed using NRTL and UNIQUAC models, and the results confirmed the high accuracy of both models.

The shape deformation of three bubbles with equilateral triangle arrangement continuously rising in shear-thinning non-Newtonian fluids was numerically investigated using the three-dimensional volume of fluid method (3D-VOF). The shape deformation of three continuously rising bubbles was compared with that of a single bubble under consistent operations to analyze the effect of interaction between bubbles. The influences of bubble diameter, initial bubble distance, bubble formation frequency, and liquid rheological property on the aspect ratio of the bubble were investigated. The results indicate that the aspect ratio of the bubble for multi-bubble systems with greater bubble diameter, initial bubble distance, and more intense shear-thinning effect of the liquid decreases, and the shape of the bubble deforms flatter. However, as the bubble formation frequency increases, the deformation of the bubble weakens, and the bubble aspect ratio increases. In comparison with the single bubble rising freely, the aspect ratio of the bubble for the multi-bubble systems is larger. Moreover, a modified model of the aspect ratio of the bubble was proposed by considering the interaction between bubbles for the multi-bubble system.

Adding flame retardant into leather is an effective way to improve the flame resistance of leather products. In this paper, a Nitrogen-Phosphorus Intumescent (NPI) flame retardant was synthesized and then added to the fatliquoring process to modify leather. The effect of NPI flame retardant on the flame-retardant properties of leather was investigated using Limiting Oxygen Index (LOI), smoke density, vertical combustion, cone calorimeter tests, and SEM. The results revealed that LOI of leather modified with NPI flame retardant increased with the increase of flame retardant. The flame and flameless combustion time of the modified leather was effectively reduced. Compared with unmodified leather, HRR of the modified leather with 6% NPI flame retardant decreased from 80.32 MJ/m2 to 63.45 MJ/m2; the peak HRR dropped from 108.71 MJ/m2 to 77.23 MJ/m2. Moreover, the fire growth index of the modified leather with 6% NPI flame retardant is close to half of that of the unmodified sample. The results certified the enhancing effect of NPI flame retardant added in the fatliquoring process on flame retardancy of leather samples.