Iranian Journal of Chemical Engineering (IJChE)

Abstract In this study, the process of capturing CO₂ by using an aqueous MDEA solution under the operating conditions of the concentration range of 10-98 wt% of MDEA, temperature range of 303-323K and atmospheric pressure is investigated. Most researchers have measured the effect of pressure changes on the loading, but in this work, we have investigated the effect of changing the concentration of amine on the loading. We employed the apparatus introduced by Pahlavanzadeh et al. to evaluate the solubility of carbon dioxide in the aqueous solutions of N-methyldiethanolamine (MDEA). The results indicate that the maximum absorption of CO₂ takes place in concentration of between 40-50 wt% of MDEA. Subsequently, the Cubic-Two-State Equation of State (CTS EoS) was improved and used to describe the solubility of CO₂ in aqueous MDEA solutions in a wide range of concentrations and temperatures. This equation, referred to as CTS^DH, includes three terms relating to the different intermolecular interactions happening in electrolyte solutions. The same EoS was used for vapor and liquid phases. Model parameters were adjusted according to the experimental results of this work and other researches. Using the adjustable parameters from this work, the model successfully approximated CO₂ loading under a wide range of functional conditions. The evaluation of model results with experimental data showed the average absolute percent deviation (AAD%) to be 7.05%, indicating a satisfactory alignment between model predictions and Measured results.

Abstract The Ethanol-water separation involves a well-known azeotrope that confines the achievement of the ethanol purity to the values higher than 95 wt% using straightforward distillation. Many attempts have been made to identify how it can be possible to produce ultra-pure ethanol (99.95 wt%) for various valuable applications. In practice, minimizing the total cost of the process is of high importance beside having the finished product with utmost purity. As a consequence, finding the best process conditions imposed to apply the simulation and statistical optimization methods in combination. Numerical optimization provides the best trade-offs to achieve the goals. In this research, the separation of the ethanol/water mixture (87 wt%) was simulated using azeotropic distillation in Aspen plus^© environment. Indeed, cyclohexane was chosen as an effective azeotrope-former. The UNIQUAC equation was used to describe the phase behavior. The two-column arrangement, in which the first column was used to dehydrate ethanol and the second to recover the entrainer, was applied in this simulation. The effect of important process variables, including the number of the trays in columns and the feed-tray position in each tower on the total capital cost were investigated. Finally, the process variables were optimized via the Response Surface Methodology to minimize the total cost of the process. The results uncovered that the total capital cost would be minimized if the number of the trays in the azeotropic (C1) and recovery (C2) columns were set to 34 and 40, whereas, the feed-tray numbers were adjusted to 19 and 9 respectively.

Abstract Time-consuming and costly experiments to measure the cetane number (CN) of biodiesel make computations even more valuable. In the current study, two artificial intelligence (AI) models have been used to predict the biodiesel CN by using comprehensive datasets (440 datasets). They were the gradient-based artificial neural network (GB-ANN) and the multi-layer-perceptron ANN optimized by the genetic algorithm (GA-ANN) for the first time. The three input variablesof the model for predicting the target variable of the biodiesel CN are the average number of carbon atoms, average number of double bonds, and average molecular weight of the fatty acid methyl esters. The learning function, transfer function, number of hidden layers, and number of neurons in the hidden layers are some of the optimized parameters in the current AI-models. The developed models were compared using statistical criteria such as the coefficient of determination (R²), mean square error (MSE), average absolute relative deviation (AARD), standard deviation (STD) and mean absolute percentage error (MAPE). The resulting outcomes revealed that the highest R² and the lowest MSE were related to the GB-ANN model with two hidden layers, trainbfg learning method and logsig-tansig-purelin transfer function. The R² and MSE for the optimized model are equal to 0.9296 and 0.0005 respectively. Although the GA-ANN achieved acceptable outcomes, its statistical analyses produced weaker outcomes than the AI-model based on GB-ANN.

Abstract The dehydrogenation of propane to propylene over Pt-Sn-K/γ-Al2O3 catalysts prepared by sequential impregnation was studied. Three drying rates, that is, 5, 10 and 15 °C/min were applied after incipient wetness impregnation of the support (1.6–1.8 mm in diameter) with KNO3. The obtained catalysts were characterized by N2 physisorption, SEM-EDAX analysis and XRF for textural and chemical properties. Catalytic performance tests were performed in a fixed-bed quartz reactor under kinetically controlled conditions for proper catalyst screening. The EDAX measurement results illustrated that the potassium concentration profile changed with drying rate with the catalyst prepared by lower drying rate exhibited highest K concentration at the center as well as highest propylene yield. These were attributed to the retraction of impregnation solution during drying at slow rates which results in lower concentration of acidic sites in catalyst center, thereby reducing the contact time of the propylene product with strong acid sites during reaction.

Abstract Lithium-ion batteries are widely used in various electronic devices and typically discarded after their service life, causing significant environmental damage and resource wastage. Therefore, recycling the valuable components of the batteries, such as graphite, is essential. Graphite, employed as the anode material, is one of the key components targeted for recovery. In graphite recycling operations from spent batteries, critical hydrometallurgical processes are primary and secondary leaching stages using sulfuric acid. In this research, both leaching processes were systematically optimized. The optimal conditions identified for primary leaching were the temperature of 77 °C, concentration of 1.75 M of sulfuric acid, leaching duration of 4 hours, and liquid-to-solid graphite powder ratio of 5. Under these conditions, the graphite purity after the primary leaching process was 99.56 wt%. Subsequently, in the secondary leaching stage, a final high purity of 99.98% was achieved for the graphite product. To evaluate the electrochemical performance of the recycled graphite, galvanostatic charge-discharge tests, which demonstrated the specific capacity of 350 mAh/g, were conducted. This capacity is comparable to that of the commercial graphite, confirming the effectiveness of the developed recycling process.

Abstract The synthesis of methanol is a key industrial process, but its performance is constrained by equilibrium conversion, heat dissipation, and energy inefficiencies. This study simulated the multi-bed adiabatic reactor of the Methanol and Derivatives Complex (CP1Z) located in Arzew, Algeria by Aspen HYSYS. Two reactor models were evaluated: the Equilibrium Reactor (ER), based on Gibbs free energy minimization, and the Plug Flow Reactor (PFR), which incorporates detailed kinetics. Both models were validated against industrial plant data to assess predictive accuracy. The ER model demonstrated better agreement with industrial data, particularly for the concentration of methanol (0.36% deviation), and was therefore selected for process improvement studies. Two modifications were introduced. First, recycling unreacted syngas increased the production of methanol from 613 kmol/h to 1800 kmol/h, a 193% improvement. Second, replacing air coolers with a heat exchanger–steam turbine system enabled the recovery of 1100 kW of electricity without reducing the methanol yield. When both modifications were applied simultaneously, the methanol output rose to 1917 kmol/h (+213%), and electricity generation increased to 1763 kW. The integration of the recycling of syngas and waste heat recovery substantially enhances the conversion efficiency, energy utilization, and sustainability of the production of methanol. Since these modifications require no major hardware changes, they offer a practical and scalable strategy for improving the technical, economic, and environmental performance of existing industrial methanol plants. 

Abstract To enhance the efficiency of oil recovery, a combination of multiple methods or materials can be utilized. This study aimed to investigate a hybrid method of smart water and polymer to improve water flooding. Moreover, this paper investigates the influence of sulfate on polymer performance for increasing the performance of this method. To this end, we examine mechanisms affecting oil recovery, including changes in viscosity and interfacial tension (IFT). To assess the impact of the injected fluid on oil recovery, a micro-model consisting sand packs prepared from carbonate rock grains was employed as a two-dimensional simulated porous medium. The Response Surface Methodology (RSM) and Central Composite Design (CCD) were used as the most precise methods to design the experiments. The design was based on five levels and three variables including three parameters of polymer concentrations ranging from 1000 to 3000 ppm, ion of smart water concentrations ranging from 12210 to 54180 ppm, and temperatures between 25–75°C. Considering the defined conditions, the effects of the prepared compositions on viscosity, IFT, and oil recovery were evaluated. The highest final oil recovery obtained for the polymer-smart water without NaCl (Sw-NaCl) solution, reported at about 60.32% of oil originally in place (OOIP), while the lowest one was reported about 50.67% of OOIP.

Abstract In this work, the separation of carbon monoxide (CO) from a synthesis gas (syngas) mixture was modeled. It was considered a copper-based adsorbent consisting of cuprous chloride (CuCl) on an activated carbon (AC) support (CuCl/AC) in a pressure swing adsorption (PSA) process. First, the adsorption of syngas components on the CuCl/AC adsorbent at 303.15 K was simulated to determine the required data. Next, the PSA process to separate CO from syngas using CuCl/AC absorbent at ambient temperature and pressure of 1000 kPa was evaluated by computational fluid dynamics simulation. The simulation results showed that with an adsorption bed of 2 m in height and 1 m in diameter, CO with appropriate purity (~ 99.5%) is separated from syngas by CuCl/AC. In addition, reducing the inlet feed pressure, or in other words, its velocity or flow can increase the efficiency of the operation (e.g, with a shorter bed height of 0.5 m, a CO purity of more than 99.8% can be achieved at 700 kPa, but with a significant increase in operating cost).

Abstract In this study, the effect of the presence of a magnetic field (MF) on the thermal conductivity of the nanofluid (NF) ( ) containing spinel ferrite nanoparticles (NPs) (MFe₂O₄, M=Fe, Co) was investigated. CoFe₂O₄ NPs were concentrated by the coprecipitation method. Both NPs were characterized by SEM, EDX, XRD, and VSM. The thermal conductivity was investigated and compared in the presence and absence of an MF. In addition to the intensity of MF (100, 200, 300, and 400 G), the effect of the concentration of NPs (from 0.25 to 2 Vol%) on  at a constant temperature of 25 °C was investigated. According to the results, in the absence of MF, the  of CoFe₂O₄/water ferrofluid (FF) was higher than that of Fe₃O₄/water FF in different concentrations. Furthermore, as the intensity of the MF increased, the  of both Fe₃O₄/water and CoFe₂O₄/water FFs increased. This increase was more observed for the FFs containing Fe₃O₄ NPs. At the highest concentration (2 Vol%), with the increase of MF up to 400 G, the  of Fe₃O₄/water has increased by about 3.2%, while this increase was about 1.8% for CoFe₂O₄/water. Increasing the volume percentage of NPs also had a positive effect on the thermal conductivity coefficient. Finally, according to the obtained results, correlations were presented to predict the  of both FFs according to the intensity of the MF and the concentration of NPs. The proposed correlations had a satisfactory accuracy with R² values of 0.98 for both FFs.

Abstract In the present study, a new method has been suggested to solve the problems of the very low solubilityof sulfide ores in acidic solution and also the production of toxic impurities for the first time. In this work, the polyoxometalate (POM) oxidizer was applied for the dissolution of sulfide ores, extraction of metals, and removal of toxic and harmful wastes. In this procedure, POMs were used as strong oxidizers of sulfur compounds to dissolve sulfide ores. Also, acid was applied as a solvent and catalyst to increase the reaction rate. The Taguchi experimental design along with the ProMax simulation software was applied for studying the leaching of sulfide ores by POM oxidizers as a novel plan in experimental to industrial scales. The optimum data achieved by the Taguchi method was used as the input data to the simulation and sensitivity analysis of the process was executed by the ProMax software. The effects of curicital operating parameters such as the concentration of acid (C_A) in the 60-90 g/l range, the  reaction temperature (T_R) with the values of 60-90 ºC, the rotation rate (R) with the amounts of 50- 300 rpm, the retention time (τ) in the 0.5-2.0 h range, the concentration of polyoxometalate oxidizer with the values of 0.1- 0.5 g/l, the acid types of H₂SO₄, HNO₃, HCl, H₃PO₄, the grain sizes of sulfide ores (Sparticle) in the 0.5-3.0 mm range and polyoxometalate with the types of [Mo₆O₁₉]^2-, [Mo₈O₂₆]^4-, [V₁₀O₂₈]^6- and [H₂W₁₂O₄₀]^10- on the extraction efficiency of metals and removal of toxic heavy metals from sulfide ores by polyoxometalates were investigated. The optimum conditions to extract maximize metals from the sulfide ores were obtained as the C_A; 80 g/l, T_R; 90 ºC, R; 300 rpm, τ; 1.0 h, m POMs; 0.5g/l, acid type of H₂SO₄, S_grain;1.0 mm and POMs type of [H₂W₁₂O₄₀]^10-. Under optimized conditions, the extraction efficiency of zinc, copper, and lead and the removal of toxic heavy metals from sulfide ores were determined as above 85%, 81%, 83%, and 99.9% receptivity.

Abstract In this paper, CFD modeling of ferrofluid convection heat transfer in a micromixer with static magnetic field (SMF) and rotating magnetic field (RMF) is investigated. Applying a magnetic field and the existence of magnetic nanoparticles lead to the creation of transverse vortices in the micromixers by movement of nanoparticles, that improves heat transfer. There is a cylindrical pit in the microcmixer with heat source that is applied to its bottom wall. Top wall of the pit is adjacent to a fixed permanent magnet, which creates the SMF. CFD modeling first is done for heat transfer process in the micromixer in the absence of the magnetic field. Secondly, simultaneous effect of the SMF and magnetic nanoparticles on the flow pattern and heat transfer rate of ferrofluid is evaluated. Results showed that ferrofluid leads to the improvement of the heat transfer rate compared to pure water. The secondary flows induced by nanoparticles’ motion toward SMF decreases the velocity in the area of application of the magnetic field, so the heat transfer coefficient decreases. But, in the case of RMF, applying the magnetic field causes the nanoparticles to rotate inside the pit, which leads to an increase in the heat transfer coefficient. CFD results of heat transfer coefficient are compared with experimental results in a reliable reference and acceptable agreement between them is observed.

Abstract  Magnetorheological fluids contain suspended magnetic particles that arrange in chains in the presence of a magnetic field, causing the conversion of the fluid from a liquid state to a quasi-solid state. These fluids can be used in valves as a tool for pressure drop and flow interruption. This research aims to investigate the feasibility of using magnetorheological fluid (MRF) in industrial valves. The rheological properties of the MRF sample were measured with the MCR300 rheometer in the presence of a magnetic field. In this connection, the Bingham plastic continuous model was used to predict fluid behavior, and model coefficients were obtained using MATLAB software. Then, the model's coefficients were used to simulate the behavior of the magnetorheological fluid in the presence of the magnetic field in the valve. The geometry and dimensions of the valve were designed according to the dimensions of industrial samples. Then the CFD simulation with Fluent software was done by using the Bingham model and fluid characteristics obtained from experimental results. The results showed that the pressure increased by increasing the magnetic field at the center of the sleeve. The magnetic field up to 0.5 Tesla, increases pressure and decreases amplitude. Therefore, as the magnetic field increase, the amplitude of the maximum pressure on the sleeve was significantly reduced.

Abstract In this novel study, various heat exchangers are compared to identify the most efficient one for heat transfer. This investigation involves shell and tube, double pipe, and plate heat exchangers, of which each is filled with different nanofluids. Following several hours of operation, output temperatures are recorded. The effects of nanofluids, containing aluminium oxide, magnesium oxide, and silicon oxide, at concentrations of 0.2%, 0.4%, and 0.6% are simulated. These simulated results are then compared with laboratory findings. Among the tested nanofluids, the most significant enhancement in the heat transfer coefficient is demonstrated by magnesium oxide, achieving a 40% improvement. Additionally, graphs illustrating the increase in the heat transfer coefficient and Nusselt number for Reynolds numbers of 900, 600, 300, and 1800 are obtained and compared. Finally, tables summarizing the tests performed on different heat exchangers using various nanofluids are presented. Using laboratory-obtained temperatures, several parameters are calculated, including the logarithmic mean temperature difference, heat loss from hot water, heat gain by cold water, overall heat transfer coefficient, and total heat transfer. Based on these analyses, the shell and tube heat exchanger was purposed as the most efficient heat exchanger with the overall heat transfer coefficient of 5.06 W/m²K.

Abstract The impact of bed loading on minimum spouting velocity (ums) of polydispersed TiO2 particles was studied in a conical fluidized bed. The experiments were performed at different bed loadings according to Gaussian and narrow-cut particle size distribution (PSD). The bed consisted of simple-agglomerates in size range of 30-90 µm belonging to Geldarts’ group A classification. The effect of PSD and interparticle force (IPF) on the predicted ums and hysteresis in the pressure profiles were studied through a combination of computational fluid dynamics and discrete element method (CFD-DEM). The experimental data showed that the choice of bed with Gaussian PSD-type led to more accurately predicting ums than the narrow-cut particle PSD. The impact of IPF on the expected ums became more critical than the PSD type because of an increase in bed loadings. The lowest deviations the results were obtained in the low bed loadings, which is confirmed the accuracy of simulation results. The simultaneous effects of PSD-type and IPF led to a change in the fluidization behavior of the bed. The bed with narrow-cut PSD has a hydrodynamic behavior similar to spouting and slugging regimes, while the fluidization quality of the bed improves by fine particles.

Abstract A low cost and environmentally friendly process for the synthesis of the disodium salt of hydroquinone (DSH) is presented. This novel synthesis technique employs water as solvent. Compared to the well-established synthesis techniques which utilize methanol, the presented technique is safer and environmentally friendly. First, a DSH sample is synthesized using the customary synthesis technique by employing methanol as solvent. Then, the technique introduced in this study is implemented under three different scenarios differing in the way the drying step is performed. The resulting DSH powders are then compared using FTIR  analyses. It is shown that all the synthesis techniques yield acceptable results, However, drying at higher temperatures yield better results. Furthermore, the crystal structure of the DSH sample is investigated using an XRD analysis and compared to the simulated diffraction pattern of DSH. The results indicate the correct synthesis of DSH. Finally, a DSC-TGA test is performed to further confirm the correct synthesis of DSH.

Abstract In this study, the fluid flow together with solid particles has been studied using Computational Fluid Dynamics (CFD). The gas-solid flow (air and sand particles with the size of 150 µm) inside a 76.2 mm diameter pipe with various bend angles including 45, 60, 90, 120, 135, and 180° was modelled at the fluid flow velocity of 11 m/s. The k-ω turbulence model was employed to model the flow turbulence and the E/CRC erosion model have been used to predict erosion rates. The hydrodynamics of the flow, the particles motion as well as the probable erosion regions were predicted. The CFD simulation results showed that increasing the curvature angle increases the erosion rate. While, increasing the pipe diameter, decreases the erosion rate. The maximum erosion rate was predicted at the end part of the curvature for 45 and 60 ° angles, while it was observed in the middle region for 120 and 135 ° curvatures. Finally, the maximum erosion rate for the 180 ° curvature was observed in two regions at the end of the first and second half. Using these results, precautionary considerations for the erosion, and the suitable plans for the repair and maintenance of the equipment can be offered.

Abstract This study simulated the production of bioethanol from mixed microalgae to the assess economic feasibility on an industrial scale. For the first time, the kinetic study of the chemical hydrolysis of mixed microalgae was carried out using the AQUASIM software. The chemical hydrolysis for the pretreatment of microalgae was carried out using H₂SO₄ (2.5%, 5%, 10% (v/v)), H₃PO₃ (2.5%, 5%, 10% (v/v)), and NaOH (1%, 2%, 4% (v/v)) at the different biomass concentrations (25 to 100 g/L) at the temperature of 121 ℃ for 70 min. Kinetic constants were calculated using experimental data and the AQUASIM software. It was found that the optimum yield of sugars, which was obtained, was about 93%. From the comparison of the values ​​of the reaction rate constant (k), it was observed that the hydrolysis rate ​​at 50 g/L by using H₂SO₄ 2.5% (v/v), is higher compared to 25, 75, and 100 g/L, and the higher reaction rate constant supports the faster hydrolysis of algal biomass. These kinetic constants were applied in simulating the process on an industrial scale using the SuperPro Designer software. Experimental and simulation results showed that 3.6 g/L of bioethanol is produced from the 9.3 g/L of glucose under optimal conditions. Also, simulation results using the SuperPro Designer software demonstrated that eliminating the algal biomass drying stage has the potential to save up to 713,000 $ in operational expenses.

Abstract In contemporary society, a plethora of human industries are fundamentally dependent on the antibacterial capabilities of various nanoparticles, rendering their absence in contemporary applications nearly unimaginable. Silver nanoparticles (AgNPs) are widely used for their potent antibacterial properties in various applications, including medical and industrial settings. Controlling microbial growth is critical to prevent health and environmental issues. In this study, AgNPs is biosynthesized using the Celtis caucasica leaf extract, optimizing synthesis parameters to achieve high purity and uniform particle size. The ideal synthesis parameters involved combining 1.5 mL of plant leaf extract with 10 mL of a 3 mM AgNO3 solution, maintaining a pH of 7, and heating the mixture at 70 °C for 45 minutes.UV-Vis, FTIR, and TEM analyses verified the synthesis of nearly spherical AgNPs with a mean size of approximately 20 nm, displaying a typical SPR absorption peak at 425 nm. FTIR data revealed key bioactive groups in the extract that enabled Ag⁺ ion reduction. The AgNPs showed robust antibacterial effects against Staphylococcus aureus (MIC 12.5 µg/mL) and Escherichia coli (MIC 25 µg/mL).

Abstract Liners serve as both a barrier layer and an adhesive, bonding the insulation to the propellant. Plasticizer migration is a frequently observed phenomenon in solid propellants, often leading to detrimental effects on mechanical stability and performance.  Absorbent plasticizer liners have emerged as a next-generation solution, offering both anti-migration properties and adhesive capabilities. In this study, the anti-migration effects of three polyethers, including polyethylene glycol (PEG), polypropylene glycol (PPG), and polytetrahydrofuran (PTHF) as liners in the presence of plasticizers 1,2,4-butanetriol trinitrate (BTTN),  trimethylolethane trinitrate (TMETN), and triethylene glycol dinitrate (TEGDN), were studied using NPT-molecular dynamics simulation (NPT-MD) with the Compass III force field. The binding energy, solubility parameter, and radial distribution function of polyethers containing 20% plasticizers were calculated.  The mixture of PEG and TEGDN exhibited the highest binding energy and compatibility. The solubility parameter reflects the strength of non-bonded intermolecular forces, indicating compatibility. The radial distribution function analysis showed strengthened van der Waals interactions, confirming compatibility. Molecular dynamics simulation results showed that polyethylene glycol is a suitable liner with anti-migration properties in propellants.

Abstract In this study, Nano filtration (NF) membranes, composed of polyethersulfone (PES) modified with titanium dioxide (TiO₂) nanoparticles, were fabricated using the phase inversion method. By grafting aniline oligomers onto the surface of the modified membrane, the final membrane with the structure of PES NF/TiO₂/AO was fabricated. The morphology of the final membrane was investigated using FESEM, EDX and FTIR analyses. The membrane separation performance was evaluated through measuring the contact angle and pure water flux (PWF), flux recovery ratio (FRR%), and salt rejection tests using Na₂SO₄ and MgSO₄ solutions. The highest PWF (3.66 kg/(m^2.h)) was obtained with the final modified membrane compared to the initial membrane at an operating pressure of 4.5 bar, which can be attributed to the increased hydrophilicity caused by the surface modification of the initial membrane. The removal efficiencies for heavy metals Pb and Cu using the pristine membrane were measured to be 28.2% and 43%, respectively, while the optimized membrane showed the significantly improved rejection rates of 99.97% and 94%. Furthermore, the total fouling rate of the original membrane was approximately 70.4%, which was reduced to 47.4% in the modified membrane. The irreversible fouling was reduced from 44.5% in the original membrane to 32.6% in the optimized membrane, indicating an improvement in the antifouling performance of the modified membrane. The results suggest that the PES NF/TiO₂/AO modified membrane can be considered an effective approach for enhancing the physical and chemical properties of membranes, as well as their separation performance, particularly for the removal of heavy metals.

Abstract Due to the dangerous effects of sulfur in hydrocarbon compounds and its impact on environmental health, a new formulation based on surface-modified carbon nanotubes and a cobalt oxide has been prepared. Oxidative desulfurization is the main section of this process that is utilized to reduce this impurity. After decorating cobalt oxide on the surface of nanotubes, the TEM images and Thermogravimetric analysis were studied to evaluate the structure of this complex. The results show that the combination of metal oxide and functionalized nanoparticles presents better efficiency in sulfur removal. In addition, the reaction rate raised by increasing the number of functional groups on the surface of nanotubes. Then, the influence of temperature, reaction time and the concentration of the oxidizing agent in the sample was investigated. The results show that the higher temperature and higher number of oxidizing agents could provide better efficiency in the desulfurization process. Due to the presence of CNTs in the synthesized catalyst, it is possible that sulfur compounds adsorbed with CNT. By matching the data with the Pseudo first and second order adsorption kinetic, it was found that the adsorption is done as a Pseudo first order adsorption kinetic. Since the ODS process is performed by a chemical reaction, the reaction kinetics were adapted to the first order equation and calculate the activation energy required for the reaction. This result can be utilized for better desulfurization of hydrocarbon fuels for different applications.

Abstract In recent years, the development of nanoparticles has received much attention in the controlled drug release and biomedicine fields. This research aims to develop new methods for the physical modification of Fe₃O₄ superparamagnetic nanoparticles with polymers through the physical retention. In this study, first, the degradable polycaprolactone-ethylene glycol copolymer and magnetic nanoparticles were synthesized. The anticancer drug doxorubicin was prepared using a dual-emulsion (w/o/w) copolymer containing magnetic iron nanoparticles. FT-IR, NMR, XRD, VSM, and, SEM analyzes were used to characterize copolymers and magnetic nanoparticles with drug-containing copolymer coatings. The results showed that nanoparticles had superparamagnetic properties and their particle size was between 70-150 nm. The drug encapsulation efficiency was about 96 %. The influence of pH and temperature on the drug release curve was investigated. The drug release was 31 % and 26 % after 144 hours in pH = 5.8 and 7.4 respectively. Since the extracellular fluid of the tumor is acidic, the rate of the drug release in these media will be better than the same in other cells. The kinetics of the drug release was also studied based on zero-order, first-order, Higuchi and Korsmeyer-Peppas models. Among the kinetic models, Higuchi was found to be the best model based on the correlation coefficient. The performance of the drug-loaded magnetic-copolymer nanoparticles with that of other similar studies was compared. The results revealed that the magnetic PCL-PEG copolymer with pH-sensitive properties can be used as an effective carrier for anticancer drugs delivery.

Abstract Drug delivery systems (DDSs) have become a crucial aspect of cancer therapy, and researchers are continuously striving to identify the optimal methods for targeted delivery and release of therapeutic agents. Metal-Organic Frameworks (MOFs) have emerged as a promising class of materials for DDSs due to their exceptional storage capacity, unique characteristics, and high durability. This comprehensive review explores the wide-ranging applications of MOFs in various fields, including catalysis, gas separation and storage, fuel purification, water treatment, medication administration, and imaging. The review paper evaluates different approaches to synthesize MOFs, such as self-assembly of metal ions and clusters and the solvothermal method, to optimize their performance characteristics.
The present study aims to shed light on the numerous challenges associated with utilizing MOFs in clinical settings. However, MOF nanocomposites that incorporate reinforcement phases represents a promising strategy for addressing these issues. With the incidence of cancer on the rise, targeted MOFs offer a potential solution to the lack of selectivity of certain drugs by virtue of their distinctive physical and chemical properties. This investigation delves into how MOFs can be employed to regulate drug release in DDSs and presents research on key applications of MOFs in the realm of cancer therapy. The application of UiO-66 for drug delivery systems and explore the different physical characteristics and chemical structures of dicarboxylate ligands incorporated into UiO-66 topology MOFs were investigated. Overall, the review paper provides a comprehensive overview of the diverse applications of MOFs and their potential for drug delivery systems in cancer therapy.

Abstract This study was conducted to decrease the concentration of acetic acid in wastewater of acetic acid plants through the photocatalytic oxidation method. This process employed commercial Titanium dioxide powder (TiO₂) as a photocatalyst, utilizing a UV lamp as the light source within a batch reactor system for advanced oxidation. Various experimental parameters were modified, including the concentration of acetic acid, the amount of catalyst, the volume of waste, temperature, and reaction time. The residual acid concentration and COD values were recorded as results of the process. The percentage of acetic acid remaining in the solution was determined by using a gas chromatography (G.C) device. Experiments were conducted with different volumes, from 200 ml to 35 ml, and utilized varying amounts of photocatalyst: 0.01 g, 0.005 g, 0.0025 g, and 0.001 g. Additionally, the experiments were carried out over two-time intervals of 2 hours and 5 hours. The wastewater concentration contained 3% by mass of acetic acid, and the average COD value was 13300. After experiments, it was found that the optimal conditions for removing acetic acid were a volume of 35 ml and 0.0025 g of catalyst used for 2 hours. In this condition, the percentage of acetic acid decreased from 3% to 0.2%, which is a 93% decrease, and the COD decreased from 13,300 to 2,800, which is a 79% decrease.

Abstract Natural gas (NG) is one of the cleanest and safest sources of energy transmitted in a high pressure that must be reduced before entering City Gas Station (CGS). Identifying the effective parameters in creating the hazardous areas of CGS is essential to crisis and management. This study using PHAST version 7.11(created by DNV Company) conducted a consequence modelling in three scenarios at three CGS stations in Qazvin Province, by actual data including weather conditions, gas pressure and temperature. The main results for the modeling in all three scenarios were jet fire, flash fire, and explosion. Based on the modeling results, most flame length was obtained in Avaj station with 10 meters more than others. Most radiation levels were also in Avaj station in about 150 m downwind distance, which can be caused by the longer flame length in this station.
The results showed that in fire jet modeling, an increase in air temperature can lead to an increase in gas pressure and temperature, which in this study increased the flame length of 2 to 3 meters. However, the flame length and the hazardous area was higher during the day and summer. The use of PHAST modeling software can provide useful information including high-risk operational area, hazard area, high-risk time period (day, night and season) for the management team to respond to emergency situations in process industries. In addition, it is necessary to consider the combination of different operating parameters such as gas pressure and gas temperature with different weather conditions.