https://www.ijche.ir/ Iranian Chemical Engineering Journal en daily 1 Mon, 22 Dec 2025 00:00:00 +0330 Mon, 22 Dec 2025 00:00:00 +0330 https://www.ijche.ir/article_241584.html https://www.ijche.ir/article_217550.html The condensate stabilization unit is one of the most important operational units in gas processes. In this unit, the raw condensate is stabilized through a distillation system. This research has investigated the energy, exergy and economic costs by simulating and analyzing the process. In this study, the effect of parameters such as feed flow rate and temperature on energy and exergy performance has been evaluated. The process simulation has been performed using Span Hysys software and the Peng-Robinson equation of state. In order to optimize, the feed preheating method has been used instead of air cooling in the lower part of the column, which has reduced the exergy destruction by 57.91 kW. Also, a heat exchanger has transferred heat by 333.2 kW between the hot and cold streams. The results show that the total process energy consumption has decreased from 1502.98 kW to 1003.94 kW and the exergy efficiency of the stabilization column has increased from 66.11% to 88.21%. In the optimized structure, the total irreversibility of the system has decreased from 257.4 kW to 165.83 kW. This reduction is equivalent to 103.4 kW of exergy destruction of the stabilization tower, which has led to energy storage and improved quality of its consumption. https://www.ijche.ir/article_216835.html This research was conducted with the aim of investigating the influencing factors on column and agitation leaching of copper from a mixture of low-grade oxide and sulphide ores of Sungun copper complex. After sample preparation and identification, agitation leaching experiments were conducted to investigate the effect of time parameters, sulfuric acid concentration and ore particle size on copper recovery and acid consumption by ore in pyrex glass reactor. Copper recovery reached 71.5% in 2 hours, acid concentration 30 g/l, ore particle size -75 microns. The consumption of acid in the mentioned conditions was 84 kg/t ore. Column leaching experiments were carried out in columns with a height of 130 cm and an internal diameter of 11 cm to investigate the effect of parameters of acid concentration, irrigation rate, and ore particle size. The amount of copper recovery in the columns varied from 44.01 to 62.11% and iron recovery from 17.73 to 47.09%. The amount of acid consumption by ore in columns with different leaching conditions was obtained from 31 to 55 kg/t ore. Due to the predominance of copper oxide compounds in the sample, in less than 20 days, almost more than 90% of copper oxide is dissolved and the increase in leaching time increases the recovery of iron in the process and can cause problems in the subsequent copper extraction processes, i.e. solvent extraction and electrowinning. https://www.ijche.ir/article_216476.html This paper examines new approaches in the synthesis of carbon dioxide gas sensors using conductometry. Since 2020, conductive sensors have experienced significant growth due to their specific advantages. These sensors are divided into thermal and electrical categories, each offering specific benefits depending on application needs and environmental conditions; if accuracy and rapid response are crucial, thermal conductive sensors are a better option; however, if cost and compatibility with electronic systems are a priority, electrical sensors can be a suitable choice. Nanomaterials such as metal oxides and polymer nanoparticles are recognized as advanced sensing materials, providing improvements in selectivity, sensitivity, and response time. The study also addresses the conductive properties of nanocomposites and the impact of nanoparticles on them, discussing the advantages and disadvantages of each sensor technology. Studies have shown that metal oxides possess significant conductivity at high temperatures around 600°C. https://www.ijche.ir/article_215498.html In recent years, ceramic membranes have attracted the attention of industries and researchers due to their high mechanical, chemical, and thermal resistance, high porosity and permeability. The main aim of this research, is the production of alumina ceramic membranes by gel casting method for water purification. Based on the results, the manufactured ceramic membrane has 45% open porosity, defect free microstructure, pore size is below 700 nm, bulk density (g⁄cm3) is 1.7, and bending strength is above 3.5 MPa. Performance evaluation of the tubular-shaped ceramic membranes compared to commercial tubular ceramic membranes, indicated that the flux of synthesized membrane was lower than that of the commercial samples, which is likely attributed to the presence of larger pores in the microstructure of the commercial membranes. The absence of larger pores in microstructure of the synthesized membrane confirms its superior performance in removing turbidity and microbial loading compared to commercial samples. https://www.ijche.ir/article_216609.html In this study, carbonate water injection is examined as an effective solution to address carbon emission concerns as a specific technology. In addition to increasing oil recovery, injecting carbonated water into porous media opens a new avenue for reducing greenhouse gases and promoting environmental sustainability. This study comprehensively covers the use of carbonated water to enhance oil recovery, adsorption, and carbon storage in hydrocarbon reservoirs. Furthermore, recent advances in this field, parameters affecting fluid-fluid and rock-fluid interactions in porous media, as well as the synergy of compounds with various techniques to increase oil recovery, have been examined.The results indicate that the combination of carbonated water injection with other additives significantly improves oil recovery. However, this analysis reveals that recent research lacks an investigation into the effects of carbonated water injection on pore structure. Overall, this approach can effectively address both the issues of increasing oil recovery and carbon dioxide storage, making this process economically justifiable. https://www.ijche.ir/article_217155.html This study focuses on the recovery of waste heat from the shell and exhaust gases of the rotary kiln used for calcining magnesium carbonate at the Iranian Refractories Procurement Production Complex.The amount of waste heat from the rotary kiln was calculated to be 565.82 kW. In the first proposed scenario, several heat exchanger tubes were installed around the kiln shell to utilize the waste heat for heating the unit's buildings. An economic analysis revealed that the investment cost of this design could be recovered within six years through savings in diesel fuel consumption. Eliminating diesel fuel usage for winter heating not only reduces environmental pollution but also significantly decreases the unit’s operational costs. In the second proposed scenario, the waste heat from the kiln's exhaust gases was utilized for electricity generation via a Rankine cycle (RC) employing ammonia and water as working fluids. The cycle was simulated using Aspen HYSYS software. The results showed that the electricity generated in the Rankine cycle over a 24-hour period was 734.9 kW using ammonia as the working fluid, and 115.37 kW using water as the working fluid. Furthermore, the cost of electricity generation was 33,750 Toman per kWh for ammonia and 285,000 Toman per kWh for water. A comparative analysis demonstrated that ammonia, in terms of energy efficiency, exergy efficiency, and electricity production cost, is a more suitable working fluid for this application compared to water. https://www.ijche.ir/article_214967.html Among metal oxides, cerium oxide (CeO2) is one of the most promising catalytic materials for chemical transformations, mainly for environmental applications and energy conversion systems. However, cerium oxide nanoparticles tend to aggregate and agglomerate, and their convenient use in solutions can be somewhat limited. Also, due to their wide energy gap, the utilization of free solar energy more efficiently inthe photocatalytic degradation of pollutants is limited. Therefore, in order to improve the properties of cerium oxide such as conductivity for photocatalytic, electrochemical, etc. applications, an effective solution has been presented to integrate it with carbon nanostructures. In this review article, the properties and some recent studies on cerium oxide nanohybrids based on common carbon materials such as graphene, carbon nanotubes, and graphitic carbon nitride are discussed. Studies have demonstrated that the incorporation of cerium oxide with carbon nanostructures, owing to the synergy of the two phases, can significantly improve the photocatalytic properties and performance.The incorporation of carbon nanomaterials with cerium oxide nanoparticles through electrostatic attraction can cause the favorable dispersion and distribution of CeO2 on the surface of carbon nanomaterials, and as a result, it can play a positive role in enhancing the photocatalytic performance by effectively reducing the recombination rate and improving the charge separation. https://www.ijche.ir/article_217157.html In this study, the effect of different ionic liquids on heat transfer in a counter-current double tube micro heat exchanger has been investigated. Experiments were performed in double-tube heat exchanger with a shell diameter of 6 mm, and the tube inner and outer diameter of 0.91 and 2 mm, and the length of 50 cm. Heat transfer using two ionic liquids ([HMIM] BF4 and [HMIM] Cl), saline water, Urmia brine, and tap water as hot streams in the tube side and the tap water as the cold stream in the shell side was studied. Two inlet temperatures of 60 and 70 °C was considered for the hot stream and its volume flow rate varied from 0.5 to 3.3 mL/min. The evaluation of the overall heat transfer coefficient indicated that, at different flow rates, the highest coefficients were observed in the following order: saline water solution, [HMIM] BF4, [HMIM] Cl, Urmia brine, and tap water. Additionally,the best thermal-hydraulic performance was achieved in the following order: saline water solution, Urmia brine, and the ionic liquids [HMIM] BF4 and [HMIM] Cl. https://www.ijche.ir/article_217201.html In this study the osmotic dehydration of green pea in batch and fluidized bed processes was investigated. Mass transfer operation was carried out at the three concentrations 10, 20 and 25 % w/w of water-salt solution and three temperatures 30, 40 and 50°C. In the batch process, the Azuara two-parameter model was applied to determine the values of WL∞ and SG∞, and the values of Dew and Des were estimated using the analytical solution of Fick's second law. Mass transfer process was mathematically modelled in the fluidized bed process. The results of both methods indicated that due to the increase in temperature, concentration of osmotic solution and time, the values of WL and SG increased.The predictions of the mathematical model were in good agreement with the experimental data. Mean relative error (MRE) values between the predictions and experimental data, at 50°C and concentrations of 10, 20, and 25 (%w/w) were 1.5, 1.2, and 1.2% for SG, and 1.6, 1.0, and 1.2% for WL, respectively. The values of WL and SG in the batch method and fluidized bed process reached equilibrium after 180 minutes and 60 minutes, respectively, which reveals the advantage of using the fluidized bed process. https://www.ijche.ir/article_242526.html https://www.ijche.ir/article_153390.html Propylene is the second most widely product in the world after ethylene. The amount of propylene produced by steam cracking processes as the first source of ethylene and propylene production is limited. New methods of propylene production (dehydrogenation of propane, conversion of methanol to olefins, conversion of methanol to propylene, etc.) can supply some of its growing demands. The intermediate conversion processes of olefins can meet part of the market demand by converting some of the lighter or heavier olefins from thermal cracking furnaces and by increasing the amount of propylene product. In this paper, we study the technology and economics of a number of catalytic cracking processes of C4 to C8 carbon olefins. The processes investigated in this report for the catalytic conversion of the by-product of heavier olefins to propylene include omega, OCP, superflex, propylur, and MOI processes. https://www.ijche.ir/article_158657.html Poly (vinyl chloride) or PVC is a commercial and economical polymer thermoplastic that has wide applications in the construction industry, construction, and medical devices. However, PVC exhibits poor thermal stability as it is degraded by a mechanical, thermal or light energy source. Thermal degradation is caused by known zipper decolorization reactions that involve the removal of hydrogen chloride and the formation of conjugated double bonds, leading to a decrease in the mechanical, physical, and chemical properties of the polymer. Studies show that allylic and tertiary chlorides are the most important structural defects in PVC chains that cause thermal degradation in the polymer. In order to increase the thermal stability of PVC, various types of thermal stabilizers are used with different mechanisms including replacement of unstable chlorine atoms, removal of chlorine and hydrogen chloride radicals, reduction in polyone sequences and aromatic alkylation. In the present study, different mechanisms of thermal degradation and various structural defects in the PVC chain are described. Finally, three important categories of thermal stabilizers and their stabilization mechanisms are reviewed. https://www.ijche.ir/article_180983.html Increasing the conductivity as well as the deposition rate leads to acceleration and intensification of corrosion processes that must be controlled and prevented. In this proposed project, the main aim is to provide solutions such as adding coagulants, as well as determining the optimal concentration of reagent, reducing the conduction rate and water deposition factor of the clarifier water. Therefore, by controlling the conductivity and sedimentation rate of the clarifier water, it is possible to control and prevent the corrosion rate of the cooling tower water. According to the experimental data, the optimum chemical condition is obtained in the amount 80 ppm CaOH, 15 ppm FeCl3, 25 ppm Na2CO3 and PAC as the best coagulant in 5 ppm concentration range. The retention time in this test is 50 minutes, which is performed with a fast cycle and a slow cycle. The time of 40 seconds is the initial time to complete the reaction of CaOH and Na2CO3 in water. In these values, the chemical conditions of the water were optimized and the turbidity is reached a value around zero. In the optimization step, the COD of clarifier water is changed within the range of 1 to 40 ppm, while the BOD (Biological Oxygen Demand) value of clarifier water and raw water are kept constant at zero level. https://www.ijche.ir/article_193568.html In the present study, magnetite nanoparticles are synthesized using the co-precipitation method and sequentially these nanoparticles are converted into Fe3O4@SiO2 magnetic core-shell particles with a silica layer and Stöber method. Fe3O4@SiO2 nanoparticles are functionalized using cyanuric chloride and polyvinyl alcohol molecules and they are used as an effective adsorbent to remove Zn2+ from 75 ml of solution with initial concentration of 0.55 mmol. The structural features, size and morphology of nanoadsorbers in different stages of functionalization of magnetite nanoparticles are investigated using X-ray diffraction, X-ray energy diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometer, thermal gravimetric analysis, Transmission electron microscopy and scanning electron microscopy. Afterwards, the effect of pH, adsorbent dosage and adsorbent contact time are evaluated on the absorption performance. In the optimum condition, the adsorption capacity of 92% is achieved in a period of 27 minutes, pH of 7 and using 28 mg of adsorbent. Moreover, the synthetic adsorbent indicates the ability to be recycled and reused in successive cycles of the absorption-desorption process for 8 times without a noticeable decrease in activity and absorption capacity. https://www.ijche.ir/article_195583.html In this research, Fe3O4 nanoparticles are functionalized with 1 and 4-dihydroxyanthraquinone molecules. The aim of this study is synthesis a novel adsorbent for the removal of divalent nickel ions from aqueous solutions. The structural, crystalline, particle size, magnetic properties, and thermal stability of the synthesized nanoparticles are investigated. In order to characterize the synthesized nanomagnetic particles, Fourier infrared spectroscopy, X-ray diffraction, field emission scanning electron microscope, transmission electron microscope, vibrating sample magnetometer and thermal weighing are applied here. Afterwards, the adsorption kinetic of synthesized nanoparticles and the effect of adsorbent dosage are investigated in nickel ion removal process. The adsorption capacity of 36.6 mg/g is obtained at ambient temperature in a period of 28 minutes at pH 7. Finally, the possibility of reusing and recycling of magnetic nanoparticles are investigated in the adsorption-desorption process of divalent nickel ions and the results proved that the synthetic nanocomposite is an effective adsorbent with excellent performance for 7 consecutive cycles. https://www.ijche.ir/article_202508.html Upgrading the building components of vacuum panel insulation enhances superior thermal properties in them. In this article, by making a vacuum panel with an aerogel core, the effect of radiation reflective layers and matting agents on the heat transfer coefficient of the panel has been investigated. Vacuum panels were made with aerogel blanket, aerogel blanket with multi-layer aluminum foil, aerogel blanket containing powder matting and panel containing blanket with foil and matting at the same time. The power loss of the samples was measured and compared by a power meter. Creating a vacuum and adding an aluminum reflective layer and an active carbon matting additive to the insulating panel under vacuum led to a decrease in the aerogel blanket heat transfer coefficient from 0.022 to 0.0127 W/m.K in a vacuum of 15 millitorr. In general, the results showed that creating a normal vacuum in the panel and the use of aerogel blanket and reflector layer and Activated carbon and ironoxide matting materials composite as the central material of the panel causes a 40% reduction in the heat transfer of the insulation panel compared to the aerogel blanket in atmospheric pressure https://www.ijche.ir/article_209627.html In the current research, Fe3O4@SiO2 nanoparticles were synthesized and functionalized with cyanuric chloride and glucosamine molecules as an effective adsorbent in removing Zn2+ ions. These nanoparticles were synthesized by using co-precipitation and Stober synthetic methods. Investigation of the structure, morphology and size of synthetic adsorbent particles were examined using X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopic (FT-IR), Transmission electron microscopy (TEM), Vibrating sample magnetometer (VSM) and Particle size distribution (DLS). Afterwards, adsorbent dosage, contact time and pH of the solution were optimized in order to obtain the best adsorption capacity. The maximum removal of Zn2+ was obtained with the 60 ml of solution in the presence of 20 mg of adsorbent at pH=7 (initial concentration 0.55 mmol/L) with contact time of 16 minutes. Also, the effect of pH on the adsorption rate in the range of 3-8 shows that with increasing pH, the amount of Zn2+ ions absorption increases and the maximum absorption performance was observed at pH=7. Also, the desorption of Zn2+ ions was done by using HCl solution (0.1 mmol/L), which provides the ability to recycle and reuse the adsorbent in consecutive adsorption-desorption processes (8 times) without serious reduction in adsorption activity. https://www.ijche.ir/article_210470.html In this research, a new approach was proposed to analyze water, energy, and environment in the north utility plant of Tehran Oil Refinery. Operating costs were defined as an economic objective function and five scenarios were examined, including the elimination of some equipment such as boilers and turbines. By removing equipment that operates at minimal capacity, increasing the efficiency of other equipment, and importing electricity, a 1-22% saving in operational costs can be achieved. Subsequently, the addition of the organic Rankine cycle to the existing equipment was proposed as a scenario aimed at reducing both economic costs and environmental impacts. The environmental objective function was presented based on life cycle assessment methods, and the multi-objective optimization of the refinery's steam network was performed using the -constraint method. The results showed that the minimum operating costs are equal to 35.09 M$/y, while the most environmental effects are observed at this point (24.68 MPt/y). On the other hand, the minimum value of the environmental objective function is equal to 20.68 MPt/y, while the operating costs of the unit reach their highest value, that is, 35.26 M$/y. The final selection, in terms of prioritizing the importance of each objective function, rests with the decision-makers based on the existing conditions. The scenario of adding the organic Rankine cycle with a payback period of 5 years, is a suitable solution for generating part of the power demand of the network with a lower operating cost and reducing environmental effects. https://www.ijche.ir/article_210471.html In this research, neural network and factorial methods were compared for the green synthesis of silver nanoparticles using fig leaf extract. The examined independent variables included temperature, time, stirrer speed, and pH, each assessed at three distinct levels. The experimental design employed the factorial method. The responses analyzed encompassed average particle size, dispersity index, and zeta potential. The results indicated that the smallest average size of silver nanoparticles (25 nm), alongside the lowest dispersion index (0.189) and the highest zeta potential (20.1 mV), was attained at a temperature of 40 °C, a synthesis time of 30 minutes, a stirring speed of 400 rpm, and neutral pH (7). Furthermore, a neural network was utilized to predict the three dependent variables based on the independent variables. The results of the neural network modeling demonstrated high accuracy in predicting the target variables, with average relative error (MRE) values for mean particle size, dispersion index, and zeta potential being 1.99, 0.51, and 74.2, respectively. In contrast, the factorial method yielded MRE values of 2.43, 0.47, and 8.05, highlighting a significant improvement in the prediction of zeta potential and a relative enhancement in the prediction of average particle size. Among the three considered outputs, the accuracy of the ANNs for estimating the average particle size and especially the zeta potential was better than the factorial model. These results of neural network modeling provide great importance in optimizing nanoparticle synthesis processes and facilitating the design of repeated experiments, https://www.ijche.ir/article_216475.html Molecular imprinted polymer adsorbent is a new material that has attracted attention in the water treatment industry. In this study, a molecular imprinted polymer adsorbent based on a core/shell structure was successfully synthesized to be used for the removal of nickel ions from aqueous media. Magnetite nanoparticles (Fe3O4) were synthesized by co-precipitation method and then the core/shell structure of magnetite silica (Fe3O4@SiO2) was synthesized and after functionalization with an amino group, it was used as a basis for the synthesis of molecular imprinted polymer adsorbent (Fe3O4@SiO2-MIP). The molecular imprinted polymer adsorbent was synthesized in the presence of nickel target ion, Methacrylic acid monomer, initiator and crosslinker by in situ polymerization method. FTIR, XRD, TEM, FE-SEM, BET and VSM tests were used to determine the structure and properties of magnetite nanoparticles, core/shell structure and molecular imprinted polymer adsorbent. Also, adsorption tests were performed including the dose of the adsorbent, pH, initial concentration, isotherm, kinetics and selective adsorption. The results of the tests to determine the properties showed the presence of a magnetic phase and a core-shell structure. Also, the specific surface area and good magnetic properties were observed for the molecular imprinted polymer adsorbent. The optimal adsorption conditions were obtained including the adsorbent dose of 16 mg, pH 7 and the initial nickel concentration of 25 mg/l. The results of the adsorption tests showed that the maximum adsorption capacity of 105.26 mg/g was obtained for the molecular imprinted polymer adsorbent for nickel removal. https://www.ijche.ir/article_216840.html Recycling aluminum from urban waste is a crucial method for reducing energy consumption and preserving the environment. The extraction of aluminum from bauxite is not only costly but also generates significant environmental pollutants. In contrast, recycling aluminum through the remelting of scrap, particularly beverage cans, can reduce the need for raw material extraction while consuming up to 95% less energy. This study examines the aluminum recycling process using the salt flux method. The effects of parameters such as temperature, salt composition in the flux, mixing conditions, and scrap shape on recycling efficiency and aluminum purity were evaluated. The results showed that at 900°C, with a flux composition of 70% sodium chloride and 27% potassium chloride, in the presence of argon gas and proper mixing, the purity of the recovered aluminum reached 98.05%. Reducing the temperature to 800°C significantly lowered energy consumption while having minimal impact on the final product's purity. Additionally, compacted scrap exhibited a higher recycling yield compared to sheet-like scrap. The findings of this study indicate that the use of salt flux not only enhances the recycling process and reduces slag formation but also presents an economical and environmentally friendly solution for industrial-scale aluminum recycling. https://www.ijche.ir/article_216841.html In this article, the effect of operating conditions and aqueous solution on the CO₂ absorption rate was modeled using response surface methodology (RSM) and an artificial neural network (ANN). The network inputs included temperature, pressure, piperazine percentage/potassium carbonate as the solvent, with the mass transfer flux of CO₂ as the output. The MLP (multi-layer perceptron) network was trained with three hidden layers containing 10, 40, and 10 neurons, respectively, using the Levenberg-Marquardt training function. The MLP network with three layers and 60 neurons, trained with the Trainlm learning function, achieved an MSE of 0.0018616 and an R² of 0.99924. The RBF (radial basis function) network also reached an MSE of 0.0004 and an R² of 0.99849 after 200 epochs. Overall, the MLP network showed better results as it achieved high accuracy in less time. https://www.ijche.ir/article_218467.html Controlling the flow path of injected fluids in layered heterogeneous oil reservoirs remains a critical challenge for enhancing the performance of gas-based enhanced oil (EOR) recovery processes. Foaming the injected gas is a promising method to address this challenge by creating selective flow resistance and improving fluid diversion. Foam generates resistance in high-permeability layers, effectively diverting injected fluids toward lower-permeability zones and improving sweep efficiency. To optimize this process, a pore-scale understanding of foam flow behavior and the underlying mechanisms of fluid diversion is essential. In this study, the flow behavior of foam was investigated under two conditions: (1) in the absence of oil (simulating aquifer conditions) and (2) in the presence of water-flood residual oil. A micromodel with two interconnected layers of contrasting permeabilities was designed to simulate layered heterogeneous porous media. Results demonstrated that in the absence of oil, foam generation effectively diverted the injected fluid flow into the lower-permeability layer. In the presence of oil, foam effectively controlled the injected gas front, significantly increasing residual oil production from 3% to 75%. These findings support the significant potential of foam to enhance gas-based EOR processes and increase incremental oil recovery. This study also highlights foam injection as an effective strategy for controlling fluid flow paths in layered heterogeneous porous media and significantly boosting residual oil production. By increasing fluid viscosity and flow resistance in high-permeability layers, foam diverts fluids to low-permeability zones, thereby enhancing the efficiency of gas injection processes. https://www.ijche.ir/article_218501.html Phosphate removal from polluted waters is one of the most important environmental problems. This study aimed to remove phosphate from municipal wastewater by a ternary composite of shrimp shell- chitosan/activated carbon/iron nanoparticles synthesized via the sonochemical method. Chitosan was synthesized from shrimp shell via sonochemical method and then modified using orange peel-activated carbon via synthesis of a ternary composite of chitosan/activated carbon/iron nanoparticles (CACIC). Identification of the composite functional groups, the morphology of its surface and pores, and porosity properties were investigated by FTIR, SEM, and BET techniques. The effect of solution pH (1-6), adsorbent amount (0.05-0.15 g), and pollutant concentration (20-100 mg/L) on the adsorption operation was investigated and the optimal operating conditions were determined using the Central Composite Design (CCD). Pseudo-first-degree, pseudo-second-degree, intra-particle diffusion, and Boyd kinetic patterns were utilized to portray the kinetic data, as well as the Langmuir, Freundlich, and Dubinin-Radushkevitch isotherms to describe the adsorption equilibrium data. The results offered that the adsorption confirmed the pseudo-second-degree kinetics (R2=1). Also, among the studied isotherms, the Langmuir pattern described well the phosphate adsorption upon the composite (R2=0.9996) and the maximum adsorption valence was 312.5 mg of phosphate /g composite. The optimum pH of phosphate uptake was 5.92. The amount of phosphate adsorbed by CACIC under optimal conditions was 97.05 mg/g. In general, it can be said that the composite of chitosan/orange peel-activated carbon/iron nanoparticles performs well in the process of phosphate ion adsorption in discontinuous adsorption. https://www.ijche.ir/article_219388.html Rapid fault diagnosis in complex processes of gas refineries is a key challenge in process engineering and control, due to the strategic importance of this equipment and the high maintenance costs. Despite the vast amount of data generated in these processes, the effective exploitation of this data has been limited so far. In data-driven fault detection methods, two main approaches exist: fault detection and classification, and fault diagnosis and fault measurement, with the latter being achievable through regression techniques or accurate models. This paper presents a machine learning-based approach for the regression modeling of industrial systems with outlier and noisy data, tailored for fault diagnosis applications. For fault diagnosis, two regression methods, including Support Vector Machine Regression and Gaussian Process Regression, have been utilized. These models are capable of predicting the behavior of industrial systems and diagnosis faults without the need for precise physical models. The main innovation of this paper is the introduction of a machine learning framework that can perform more accurately and rapidly compared to traditional expert fault diagnosis methods, particularly in scenarios with outlier and noisy data. https://www.ijche.ir/article_219466.html Spirulina microalgae powder (Spirulina harvested from the culture medium that has been dried and powdered) can be affected by the type of light spectrum, just like Spirulina, during the pre-harvest period (growth period). In this study, the content of phycocyanin and chlorophyll in Spirulina platensis powder was evaluated under radiation of different light spectra. The results showed that the highest phycocyanin content was related to the sample under red LED light and the lowest was related to the sample under blue LED light. But the sample under blue light looked bluer in appearance and the purity of phycocyanin was the highest for this sample. The chlorophyll-a and total cartenoids content in all samples decreased during the test period compared to the control sample, which indicates the destruction of chlorophyll under the radiation of different light spectra. https://www.ijche.ir/article_219618.html Synthetic dyes such as methylene blue, which are cationic and one of the most important and toxic pollutants in water, are resistant to biodegradation. Adsorption is an effective method to remove these dyes from water. Silica aerogels have been considered as efficient adsorbents due to their specific surface area and high porosity. In this research, the adsorption of methylene blue from an aqueous solution of methylene blue in different concentrations from 5 to 150 mg/L and at two temperatures of 25 and 40 °C and using different amounts of silica aerogel as adsorbent has been studied. Within the studied conditions, the highest adsorption capacity of methylene blue on silica aerogel was 42 mg/g, and in different tests, the removal percentage of methylene blue was 38-97%. The kinetics and capacity of adsorption of methylene blue-silica aerogel system were studied. Adsorption kinetics were evaluated through two pseudo-first-order and second-order kinetics models. Based on the correlations and the regression, it was observed that the experimental data are more consistent with the first-order kinetics model. Also, the corelation between the experimental data and the equation of Langmuir and Freundlich isotherms was investigated. The results showed that there is a better agreement between the experimental data and the Langmuir isotherm. https://www.ijche.ir/article_220196.html This study focuses on the optimized synthesis of microgel thickeners derived from sodium acrylate-acrylic acid copolymers through inverse emulsion polymerization. The primary objective was to enhance polymerization efficiency and improve the thickening and rheological properties of these materials by employing optimized synthesis conditions, novel crosslinkers (diglycidyl ether derivatives), modified Cloisite plate-like nanoparticles, and acrylamide comonomers. At equivalent concentrations (0.3 g), the use of a long-chain crosslinker (poly(ethylene glycol) diglycidyl) ether compared to a short-chain counterpart (diethylene glycol diglycidyl ether) resulted in a ~13-fold increase in apparent viscosity (from 1.39 Pa·s to 20.2 Pa·s at a shear rate of 10 rpm). Incorporation of Cloisite nanoparticles as reinforcing agents, up to an optimal concentration of 5 wt%, led to a ~7-fold rise in storage modulus (from 0.65 kPa to 5.61 kPa at 10 Hz) and a significant improvement in copolymer thickening performance. The addition of acrylamide comonomer to the primary copolymer backbone, forming a terpolymer with 40 mol% acrylamide, increased the polymerization conversion yield from 62% to 93% and produced an approximately 4-fold improvement in direct latex viscosity. This study demonstrates that the strategic combination of advanced crosslinkers, nanoparticles, and comonomers represents an effective approach for developing high-performance polymeric thickeners. https://www.ijche.ir/article_221250.html Studies indicate that the uniform distribution of clay nanoparticles within an epoxy matrix, particularly in the presence of chemical modifiers, significantly enhances the properties of nanocomposites. Research findings demonstrate that the modification of clay nanoparticles positively impacts the mechanical properties of epoxy resins. Epoxy nanocomposites containing modified clay nanoparticles with various functional groups exhibit notable increases in tensile strength and Young's modulus. These improvements are attributed to the proper dispersion of nanoparticles and optimal interactions between the resin and clay. This study also investigates the thermal stability and thermal degradation of epoxy nanocomposites, revealing that the incorporation of clay nanoparticles into epoxy formulations can substantially enhance their thermal and mechanical properties. Overall, the research concludes that epoxy nanocomposites utilizing both clay nanoparticles and modified clay significantly improve thermal stability and mechanical characteristics, making them suitable for high-performance industrial applications that require heat and thermal degradation resistance. Additionally, this study explores the effects of modified clay nanoparticles on morphology, mechanical properties, thermal stability, and recent advancements in epoxy resin and hybrid epoxy nanocomposites. https://www.ijche.ir/article_221466.html In this research, the ethanol dehydration process via extractive distillation is investigated using ethylene glycol and glycerol from both economic and controllability perspectives. The research method involves steady-state and dynamic simulations using Aspen Plus software; first, the steady-state simulation is employed to determine the design parameters of the extractive distillation columns, and then closed-loop dynamic simulations are conducted to evaluate the control system’s performance and its sensitivity to disturbances. In addition, the controllability is assessed by calculating the condition number as an index, while the total annual cost (TAC) is estimated as an economic indicator. The results show that although using glycerol yields higher relative volatility, ethylene glycol is a more optimal solvent for ethanol dehydration due to its lower operating costs and better control performance in response to feed composition disturbances. https://www.ijche.ir/article_221730.html The Modified Claus process is the most common method for removing hydrogen sulfide from natural gas. Despite studies conducted on the simulation of catalytic beds in sulfur recovery units, no comprehensive research has yet been carried out on the impact of sulfur capillary condensation on catalyst deactivation. In the present study, dynamic modeling and simulation of sulfur production processes in catalytic beds were performed, considering the Claus reaction and hydrolysis. After validating the proposed mathematical model, the distribution of operational parameters such as temperature, pressure, and component concentrations, taking catalyst deactivation into account, was analyzed. The results from the simulation showed that, for the current case study, approximately 80% of the catalyst deactivates after 300 days of loading in the bed due to sulfur capillary condensation, resulting in a more than 49% reduction in sulfur production. https://www.ijche.ir/article_222918.html Most of the world's oil reserves are in carbonate rocks. In recent years, studies of low-salinity water injection have demonstrated that the salinity of injected water affects increasing oil production. However, optimizing well operating conditions during low-salinity water injection is a major challenge due to the complexity of the process and the time-consuming simulations. Unlike previous studies, this study used a combination of a surrogate model based on machine learning with a multi-objective genetic algorithm to simultaneously model and optimize well operating constraints, including maximum oil production rate, minimum bottom hole pressure, water injection rate, and open and closed perforation conditions. The high-accuracy surrogate model (R-squared value of 0.989 for training data and 0.984 for testing) accelerated the simulation process. Then, considering the net present value, oil recovery factor, and water cut as target parameters, a set of optimal solutions on the Pareto front was obtained. The results showed that choosing the optimal operating conditions could increase the net present value of $135 million and the oil recovery factor up to 65.54%. https://www.ijche.ir/article_222922.html Zwitterionic polymers have emerged as suitable candidates in drug delivery systems due to their unique molecular structures, which feature both positive and negative charges within monomers. The simultaneous presence of opposing charges in the repeating units results in an overall neutral charge for the polymers while also enhancing their interactions with biological systems. This reduces protein adsorption, minimizes nonspecific interactions, prolongs drug circulation time, improves therapeutic targeting, and enhances drug delivery efficacy making them a promising alternative to traditional drug carriers. The unique structure of zwitterionic polymers enables controlled release and targeted drug delivery while facilitating the overcoming of physiological barriers that typically hinder effective treatment. This article introduces zwitterionic polymers and discusses their properties, such as responsiveness to temperature, salt, pH, and antifouling properties. Furthermore, the exceptional capabilities of these polymers as nanoscale drug carriers are examined, including reduced immune opsonization, inhibition of cellular uptake, prolonged in vivo circulation, improved stability, critical micelle concentration, and blood-brain barrier penetration. The presented prospects highlight the tremendous potential of these materials in this field. This review article offers a comprehensive perspective to researchers in the field, to develop and commercialize such technologies for the benefit of the medical community. https://www.ijche.ir/article_222984.html The use of composites in various industries had significantly increased in recent decades. In composite structures subjected to thermal and mechanical loads, microcracks could lead to leakage and failure. To prevent this issue, sealing the structures with coating sealants and polymeric and elastomeric films was essential. These materials were resistant to gas permeation and thermal shocks. In this research, the properties of silicone nanocomposites were improved by adding nanoclay (Cloisite 5) and modifying its surface using APTES (silane agent). The results of TGA, XRD, and FTIR tests indicated the bonding of aminosilane groups with hydroxyl groups in Cloisite, with a bonding percentage of 3.66%. Additionally, the morphological analysis of the nanocomposites showed that the presence of modified nanoclays led to improved dispersion and enhanced mechanical properties. Thermal degradation tests revealed that the modified nanoparticles could increase thermal stability. Furthermore, the surface modification of nanoclays contributed to better rubber curing and reduced permeability in silicone nanocomposites. The results of the time-sweep test indicated that the surface modification of nanoclays further improved the curing of this rubber. Overall, this research demonstrated the positive impact of modified nanoclays on the thermal and mechanical properties of nanocomposites, which could enhance their performance in industrial applications. https://www.ijche.ir/article_223962.html In this study, Fe3O4 nanoparticles are first synthesized using the co-precipitation method. Afterwards, the surface coating of iron oxide nanoparticles is performed to synthesize core-shell Fe3O4@SiO2 nanoparticles using the Stöber method by tetraethoxysilane as a silica source. After functionalization of Fe3O4@SiO2 nanoparticles with theophylline molecules, the synthesized nanoparticles are used as an effective adsorbent to remove cadmium ions from aqueous solutions. Particle size, morphology, magnetic properties, structural properties and surface functional groups are investigated using TEM, FE-SEM, VSM, BET, TGA, EDX, XRD and FT-IR. Finally, the effect of various amounts of adsorbent, contact time, pH and initial concentration of cadmium on the adsorption are investigated. The results of optimization of effective parameters at ambient temperature in the presence of 20 mg of adsorbent dose, pH 7 in 50 mL of solution with an initial concentration of 0.3 mmol/L for a contact time of 25 min resulted in 93.3 mg/g of cadmium adsorption. Moreover, the synthetic nanoadsorbent has the ability to be recovered and reused in successive adsorption-desorption cycles without serious reduction in functional activity. https://www.ijche.ir/article_224785.html This study investigated the performance of a polydimethylsiloxane (PDMS) membrane, commercially known as ELASTOSIL® RT 601 A/B, for separating ethyl acetate from water via pervaporation. The membrane was selected due to its structural similarity to PDMS, excellent hydrophobicity, lower cost, and wider availability. Characterization techniques such as FTIR, FESEM, and water contact angle measurements were employed to evaluate the membrane. Pervaporation experiments were conducted at temperatures ranging from 30 to 50°C and feed concentrations of 5 to 15 wt% ethyl acetate under a vacuum pressure of 200 mbar. The results demonstrated that at 5 wt% feed concentration and 30°C, the membrane achieved a total flux of 0.73 kg/m²·h and a selectivity of 33.2. Increasing the temperature to 50°C nearly doubled the permeate flux but reduced selectivity by 20%. Similarly, raising the feed concentration to 15 wt% doubled the flux but decreased selectivity by 40%. The study highlights the efficacy of ELASTOSIL® RT 601 A/B as a cost-effective and accessible membrane for ethyl acetate-water separation under varying operational conditions. https://www.ijche.ir/article_225633.html The synthesis of a corrosion inhibitor and its application as a replacement of amine corrosion inhibitors in the cooling tower of thermal power plants are proposed here. In the next step, the performance of the proposed inhibitor is compared with other commercial amine corrosion inhibitors from a technical-economic point of view. ABased on the results from the performance tests, the technical-economic justifications of using this inhibitor in the cooling tower of industries and especially power plants are investigated. The corrosion rate in the absence of corrosion inhibitors for corrosion coupons of carbon steel, copper and admiralty is two times higher than the corrosion rate in the presence of commercial inhibitors (PBTC and HEDP) and 4 times higher than the proposed inhibitor (FNSI). Based on the CV results in corrosive environment, the lowest corrosion rates are related to FNSI, PBTC and HEDP, respectively. Therefore, the proposed inhibitor is selected as the superior inhibitor in CV test. To investigate the effect of copper scale inhibition, the HEDP inhibitor has a very good anti sealant effect and other commercial and proposed inhibitors do not have much anti sealant effect. On the other hand, the proposed inhibitor has the ability to be recovered and reused which other inhibitors do not have these properties. This synthetic inhibitor is made from disposable materials, is available, cheap (rice husk), environmentally friendly and can be prepared at a lower cost. https://www.ijche.ir/article_226052.html In this study, the potential for waste heat recovery in the 2600-ton-per-day rotary kiln system of Khash Cement Plant was investigated. A comprehensive mass and energy balance was conducted using operational data. Results indicate that around 40% of the input energy is lost through heat dissipation. The main sources of energy loss are: preheater exhaust gases (28.8%), hot air discharged from the grate cooler (3.6%), and radiation and convection losses from the kiln surface (5%). Two recovery strategies were evaluated: (1) utilizing preheater and cooler exhaust gases through a Waste Heat Recovery System (WHRS) to generate electricity, and (2) recovering heat from the kiln surface using a heat exchanger. Implementing these solutions could increase the thermal efficiency of the system from 50.6% to 67.5%, contributing significantly to energy conservation, operational cost reduction, and environmental sustainability. https://www.ijche.ir/article_226066.html Paraxylene is known as the most important and widely-used isomer within the xylenes due to its wide applications. The presence of ethylbenzene as an undesirable component amongst xylene isomers has long been considered a major challenge in the process of xylene isomerization. To optimize process performance, converting ethylbenzene to other products is essential. On the other hand, in addition to the effective conversion of ethylbenzene, the loss of xylenes must be desirably prevented. Therefore, the catalyst used must have high shape selectivity towards the conversion of ethylbenzene. The use of appropriate hydrogenation metals and various surface modification methods, including silanization, dealumination, and selective poisoning, as well as the use of different binders have been investigated to achieve maximum ethylbenzene conversion while to minimize xylene loss in the design of catalysts for the xylene isomerization. This study, aimed at improving the performance of the process above, examines researches conducted upon the effect of the aforementioned modification methods and changing of the operating conditions upon the catalyst performance of the ethylbenzene conversion and xylene isomerization processes. https://www.ijche.ir/article_226111.html Separation of sulfur-containing compounds from fuel remains one of the major challenges in crude oil refining processes. Extractive desulfurization using deep eutectic solvents (DES) has gained the attention of researchers as an effective method for removing these compounds from fuel. In this study, binary interaction parameters of the Non-Random Two-Liquid (NRTL) model were estimated using equilibrium solubility data of dibenzothiophene in the model fuel and the eutectic solvent (choline chloride and diethylene glycol), applying the Particle Swarm Optimization (PSO) algorithm. Subsequently, the developed thermodynamic model was employed to predict the extractive desulfurization performance. Modeling results indicate that the separation efficiency increases at lower temperatures and with a higher solvent-to-fuel ratio. Specifically, at 20 °C, increasing the solvent ratio from 0.1 to 3 led to an increase in DBT removal from 1.9% to 37%, while at 60 °C, the efficiency increased from 1.7% to 34%. https://www.ijche.ir/article_226466.html Steam-assisted gravity drainage (SAGD) is the most common method for heavy oil extraction which has high energy consumption and carbon dioxide emissions. In this study, the optimal energy consumption for 6 SAGD processes has been targeted using pinch analysis. To ensure that the targeted results are achievable, the design of the heat exchanger network of unit 3 has been presented. The results showed that if the units are designed correctly, the required hot utility and energy consumption in the boiler are 7.3-13 and 4.5-10.6 % lower than the existing condition, respectively. Then, the effects of key parameters on the energy consumption of the process were investigated. The steam to oil ratio in the range of 1.5-7, the steam quality between 65-95 %, the steam injection temperature between 200-350 C, the water recovery rate between 65-95 %, and the emulsion temperature between 140-250°C were changed. Varying the steam to oil ratio had the most significant impact (100.94%) and changing the water recovery had the least effect (1.77%) on the optimal energy consumption of the process. https://www.ijche.ir/article_226947.html Phenolic industrial wastewaters and their release into the environment are environmental problems. Among the various methods for separating phenol from wastewater, the adsorption process is a widely used method. The aim of this study is economic evaluation of industrial production of nano biocarbon adsorbent prepared from peanut shell. The unique capability of this adsorbent, having three features simultaneously, ultra-fast and complete removal of phenol, and high adsorption capacity, has made it a practical and competitive product. Based on the economic evaluation, the production of this adsorbent using the method presented in this study is economically profitable and costs 1440 thousand rials per kilogram of final product. The payback period for different discount rates is 3.3 to 5.9 years. The internal rate of return is 40% for ten years from the time of implementation of the production plant, which is higher than the common bank discount rate (23%) and indicates the profitability of the project. https://www.ijche.ir/article_227683.html In this study, a nanocomposite hydrogel was synthesized from a biodegradable polymer (chitosan), grafted with acrylic acid and crosslinked by polyethyleneimine. The hydrogel was prepared via the sol–gel method to enable selective platinum removal and recovery from aqueous solutions. To enhance adsorption capacity and structural integrity, graphene oxide nanoparticles were incorporated into the network. Characterization by FTIR, BET, XRD and TGA confirmed successful formation of the chitosan–grafted acrylic acid nanocomposite hydrogel. TGA results indicated thermal stability up to 274 °C. Adsorption data were modeled using the Langmuir isotherm, yielding a maximum capacity of 217.4 mg g⁻¹. A Gibbs free energy change of –1,473J mol⁻¹ was calculated, indicating spontaneity of the process. Across three consecutive adsorption cycles, the graphene oxide–reinforced hydrogel achieved platinum uptake efficiencies of 98%, 84.42% and 70.69%. Corresponding desorption stages released 85%, 72% and 60% of the adsorbed platinum, respectively. https://www.ijche.ir/article_229870.html This study focused on developing a stable, effective CO₂ adsorbent from Astragalus biomass for industrial gas treatment. First, the Astragalus root was carbonized at 600°C in a nitrogen and activated with phosphoric acid to produce porous activated carbon (with a specific surface area of 518.34 m2/g and an average pore diameter of 2.46 nm). Then, it was modified with magnesium oxide nanoparticles prepared by the co-precipitation method. For carbon dioxide absorption, cylindrical monoliths (4 x 5 cm) were fabricated using polyvinyl alcohol binder. Experiments in a pilot reactor with a mixed gas (10% CO2 and 90% N2) showed that the CO2 adsorption capacity at operating conditions (25 °C and 1 bar pressure) reached 1.355 mmol/g, which was improved due to the combination of physical (porosity) and chemical (magnesium carbonate formation) adsorption. The fractional order kinetic model (R2 > 0.999) and Freundlich isotherm (R2 > 0.998 at temperatures (25 to 85 °C) were the best fit to the data. This monolith was introduced as a promising option for large-scale industrial CO2 adsorption due to its low cost, structural stability, and high efficiency. https://www.ijche.ir/article_231087.html Access to safe and clean water remains a major global challenge, with a significant portion of the world's population lacking sufficient sources of safe and sanitary water. This study aims to investigate the use of solar desalination as a sustainable and cost-effective method for treating available unsafe water in remote and sparsely populated area for providing safe drinking water. However, due to the lack of sustainable energy sources and the remoteness of such areas, these highly polluted and unhealthy water sources are unfortunately used for drinking purposes without any purification process. In this study, an inclined basin-type solar desalination system with three installation angles (10°, 20°, and 30°) was employed to purify unhealthy water. Furthermore, the efficiency of solar desalination in reducing or eliminating microbial contamination, a largely underexplored aspect, was specifically examined. The results of the analyses showed that the produced freshwater was completely free of microbial contamination and therefore safe for drinking. The highest yield was observed at a 20° angle, with a production rate of 2750 mL/m²/day. https://www.ijche.ir/article_232432.html In this study, silica nanoparticles are initially synthesized using the Stöber method. The synthesized nanoparticles are functionalized with cyanuric chloride and bis(3-aminopropyl) amine molecules and dendrimer molecules are formed. The synthesized nanostructure is applied as a copper ion recognition element in a carbon paste electrode. The presented sensor is applied to identify the amount of copper ions from aqueous solutions of cooling tower of thermal power plant. The structural, morphological and size of the synthesized particles are investigated using XRD, FTIR, FE-SEM, TEM, EDX, TGA and UV-Vis techniques. In order to optimize the performance of the copper ion monitoring sensor, the parameters including graphite, paraffin and detector composition are investigated. The optimum sensor response is achieved at 75% graphite, 20% paraffin and 5% nanostructure. The electrochemical behavior of copper ions is monitored by cyclic voltammetry and the oxidation peak is obtained in the 0.1 V for copper oxidation. The obtained sensor has a detection limit of 10-5 M and a linear range of 0.1-1 mM in the differential pulse voltametric method. The proposed sensor is capable of application in real complex samples such as cooling tower of power plants. The results of this method are in accordance with the atomic absorption reference method for cooling tower sample. The proposed method is able to measure copper ions in the cooling tower sample with very high accuracy and precision. https://www.ijche.ir/article_232433.html Antibiotics are extensively used in pharmaceutical industries and hospitals, leading to the discharge of wastewater containing high levels of these pollutants. In this study, the treatability of pharmaceutical wastewater containing a mixture of three antibiotics clarithromycin, cefixime, and oxytetracycline was investigated using the Fenton advanced oxidation process. The raw wastewater had an initial chemical oxygen demand (COD) of approximately 570 mg/L and a biochemical oxygen demand (BOD) of about 305 mg/L. COD was selected as the target parameter for treatment efficiency assessment. Key operational parameters, including initial pH, hydrogen peroxide (H₂O₂) concentration, ferrous ion (Fe²⁺) dosage, and reaction time, were evaluated to determine their effects on COD removal. Optimization results showed that the best removal was achieved at pH 3, H₂O₂ concentration of 250 mg/L, Fe²⁺ concentration of 500 mg/L, and a reaction time of 45 minutes, with an optimal Fe²⁺/H₂O₂ ratio of 2. Under these conditions, approximately 90% of COD was removed, reducing the final COD to about 56 mg/L. These results indicate that the Fenton process is highly effective for treating antibiotic-contaminated pharmaceutical wastewater to meet environmental discharge standards. https://www.ijche.ir/article_233507.html Providing resources and reducing pollution in environment are the reasons for recovering metals from secondary sources such as filter cakes. Optimization, thermodynamic and kinetic modeling of effective parameters for the simultaneous leaching of four metals from low-grade filter cakes have been carried out. Temperature, particle size, time, pH, solid-to-liquid ratio and air or ozone injection rate on the leaching process are important. These parameters were checked by response surface methodology at five levels. 84.66% nickel, 85.87% copper, 74.86% cadmium and 86.13% zinc were recovered from filter cakes by endothermic and spontaneous acid leaching process. The optimal conditions are: pH 2.5, time 2.5 hr at 50 °C with 88 mic particles and ratio of solid-to-liquid 0.08 g/ml and without air/ozone injection. Four quadratic equations were proposed to relate the independent parameters for maximum recovery. The nickel and copper extraction were controlled by diffusion mechanism. The leaching of zinc and cadmium were controlled by both chemical reaction and diffusion mechanisms. https://www.ijche.ir/article_233595.html Epoxy nanocomposites reinforced with surface-modified aluminum oxide (alumina) nanoparticles, particularly in combination with chemically treated natural fibers, have emerged as an effective approach to enhance the mechanical, thermal, and structural properties of these materials. Surface modification of nanoparticles and fibers using chemical agents such as silane, indole, and sodium hydroxide improves interfacial adhesion, ensures uniform particle dispersion, and reduces porosity, ultimately leading to increased tensile strength, impact resistance, surface hardness, and thermal stability of the composites. Additionally, the presence of alumina nanoparticles restricts polymer chain mobility and delays thermal degradation, resulting in higher decomposition temperatures and improved structural durability under harsh environmental conditions. Studies indicate that optimal loading of alumina nanoparticles in the range of 5–15 wt.% not only enhances mechanical and thermal properties but also provides significant resistance against corrosion and wear. Therefore, the combination of surface-modified alumina nanoparticles with natural fibers, alongside optimization of formulation parameters and processing conditions, represents an efficient, sustainable, and cost-effective strategy for developing advanced multifunctional composites for various industrial applications. In this study, the effects of surface-modified alumina nanoparticles on the morphology, mechanical properties, thermal stability, and thermal degradation behavior of epoxy nanocomposites are comprehensively investigated, and recent advancements in this field are critically reviewed and summarized. https://www.ijche.ir/article_233974.html The aim of this research is to investigate the interaction of nanoparticles and impurities in amine solutions and natural gas in foam formation, as well as their impact on antifoaming performance in the absorption process of acidic gases (CO2/H2S) from natural gas mixtures. The foaming effect of gases such as carbon dioxide, hydrogen sulfide, methane, ethane, and nitrogen on amine solutions was examined. Subsequently, the effect of four nanoparticles, including nano-alumina, nano-silica, graphene oxide nanoparticles, and multi-walled carbon nanotubes, on the foaming properties of the solvent, as well as the interaction of organic impurities (acetic acid, formic acid, valeric acid, and octanoic acid) and nanoparticles on the solvent's foaming behavior, were analyzed. The results showed that the dissolution of acidic gases in amine solutions leads to an increase in foam formation. Moreover, the presence of nanoparticles increases the foamability of the solvent. Among the nanoparticles, carbon nanotubes exhibited the lowest foam formation in the presence of impurities in amine solutions. Simultaneous presence of nanoparticles and organic pollutants in the solvent resulted in an increase in foam formation by 46% to 260%. Additionally, in the presence of silicone-based antifoam agents, nanoparticles reduced the defoaming rate of the amine solution by up to 100%. The defoaming efficiency was observed in the order of multi-walled carbon nanotubes < graphene oxide < nano-alumina < nano-silica. https://www.ijche.ir/article_234147.html The increasing concentration of carbon dioxide (CO2) in the atmosphere, as one of the major environmental challenges of this century, has drawn researchers’ attention to converting this greenhouse gas into valuable carbon materials. This study reviews and compares various methods for converting CO2 into carbon allotropes, with an emphasis on their industrial applicability. Six main carbon allotropes – graphene, carbon nanotubes, carbon nanofibers, fullerenes, diamonds, and porous carbons – have been analyzed in terms of yield, production cost, and operating conditions. The results indicate that carbon nanotubes and nanofibers, with yields of 80–100% and production costs of 800–1600 USD per ton, are economically viable and environmentally friendly options. In contrast, producing high-quality multilayer graphene requires high temperatures and expensive catalysts. Fullerenes and diamonds, due to low yields of 0.2–9.6% and the need for extreme conditions, are primarily limited to laboratory-scale applications. Porous carbons also remain challenging due to operational costs and limited catalyst durability. Overall, molten carbonate electrolysis emerges as a promising route for the industrial conversion of CO2, offering high yield, suitable operating conditions, and compatibility with renewable energy sources. https://www.ijche.ir/article_234220.html Recent progress in supercapacitors—recognized as advanced and high-potential energy storage devices—has drawn considerable interest from both scientific and industrial sectors. In this study, a simple, rapid, and highly effective synthesis method is introduced, offering strong potential for scaling up to industrial production. The research focuses on synthesizing an electrode containing CuCrO₂ nanocomposite using different proportions of CuCrO₂, carbon black (CB), and activated carbon (AC). The resulting nanoparticles and electrodes were analyzed through structural and performance-based assessments. FESEM imaging revealed that the electrode materials were evenly distributed across the nickel foam substrate. Among all the synthesized composites, the one combining CuCrO₂ (0.6 %wt) with a carbon-based material (0.4 %wt) delivered the best electrochemical performance, achieving a specific capacitance of 700 F.g⁻¹ and stability of 91% after 5000 charge-discharge cycles at a current density of 1 A.g⁻¹. https://www.ijche.ir/article_234887.html The present research is CFD simulation of industrial furnace related to Shahid Tondgouyan Petrochemical Company (STPC) to analyze the impact of operating conditions on thermal properties changes of oil and heat transfer phenomenon in the furnace and its distribution manifold with 8 passes. According to the experimental history of the furnace, the presence of more coke particles in some passes has led to their clogging, which according to the simulation results, the geometry of the oil inlet manifold in it has been effective. This manifold has created a different distribution of flow and coke particles in the 8 parallel passes of the furnace, which, in addition to the greater distribution of coke particles in some of them, has caused different oil residence times in the passes. The combustion simulation in the furnace also showed that hot spots have been created in the furnace areas, especially in the exit of combustion gases from the radiation zone to the convection zone, which could be another reason for the destruction of the oil. Also, according to the simulation results, with a decrease of 3/6 kg/s in the flow rate of an oil pass, the outlet temperature of that pass in the radiation section increased by 1/1 degrees Celsius. https://www.ijche.ir/article_235276.html This paper examines the physiological and metabolic characteristics of sulfate-reducing bacteria (SRB), focusing on their energy-generating pathways, electron transfer mechanisms, and roles in the biogeochemical sulfur cycle. Through both heterotrophic and autotrophic metabolisms, SRB can reduce sulfur compounds to sulfide under anaerobic conditions and play a vital role in bioremediation processes and maintaining sulfur balance in the environment. The study also analyzes the energy conservation pathways, sulfate reduction mechanisms, and microbial interactions of SRB across diverse ecosystems. In addition, the biotechnological applications of SRB in treating industrial wastewaters rich in sulfate and heavy metals, as well as the environmental challenges associated with their activity, such as biocorrosion and hydrogen sulfide production, are discussed. Recent advances in utilizing SRB for modern environmental technologies highlight their potential in pollution control, metal recovery, and the synthesis of valuable bio-based compounds. This study provides a comprehensive perspective on the ecological significance, biotechnological potential, and related challenges of SRB. https://www.ijche.ir/article_235714.html In recent years, Iran has faced natural gas shortages during the cold months due to peak demand on cold days and the lack of sufficient imports or storage, making inventory management of gas transmission pipelines a critical solution. Simulating the dynamic behavior of such systems is often time-consuming and costly due to the complexity of interactions among their components. In this study, a data-driven surrogate model based on a Nonlinear Autoregressive Neural Network with eXogenous Inputs (NARX) is developed to analyze and predict the behavior of natural gas transmission networks under peak demand conditions. The quasi-experimental data required for training the NARX model were generated through dynamic simulation of a quasi-real unit in Aspen HYSYS, and the model was trained using the Levenberg–Marquardt algorithm. To evaluate the model’s performance, the Mean Absolute Error (MAE), Mean Squared Error (MSE) and Coefficient of Determination (R²) were calculated on both training and test datasets. The results show that on the test data, the model achieved MAE = 0.01474, MSE = 0.002229, and R² = 0.9968. Compared to full dynamic simulation, the proposed surrogate model is approximately 1133 times faster, corresponding to a 99.911% reduction in computation time, while maintaining high accuracy. This unique combination of speed and precision enables real-time analysis and decision-support applications during peak-demand scenarios, positioning the proposed NARX-based model as an efficient and reliable tool for forecasting and peak-shaving management in natural gas transmission networks. https://www.ijche.ir/article_235715.html Production of an adsorbent for water treatment with minimum energy, with a green method is the purpose of many researchers. MOFs (Metal-Organic frameworks) are a type of novel porous materials that have many applications in different fields. Owing to their outstanding properties such as high porosity, high specific surface area, these materials are able to be used in different applications such as energy storage, hydrogen storage, and to be applied as water pollutant adsorbents from wastewater. But many of them are unstable in water and their structure will collapse. A highly stable Cerium-based MOF (Ce-UiO-66 MOF) was synthesized in water in a short period of time via a green room temperature synthetic method, activated via methanol reflux for three days at 60 °C, and finally it was characterized. In this project anionic Congo red (CR) dye was used as a model pollutant to investigate the influence of different conditions on the adsorption performance of the resulting Ce-MOFs. XRD and FTIR analyses confirmed the successful synthesis and high stability of this adsorbent after soaking in methanol reflux at 60 °C. N2 adsorption/desorption analysis showed that this MOF has a surface area of 572 m2/g and a pore volume of 0.38 cm3/g. The adsorption kinetic and adsorption isotherm of Ce-UiO-66 were described by the pseudo-second-order kinetic model and the Langmuir isotherm model, respectively. The prepared MOF showed good adsorption performance toward anionic CR dye. The highest adsorption capacity was measured to be about 400 mg/g after 2 h. https://www.ijche.ir/article_237056.html In this research, the water quality and the functioning mechanism of the human sewage treatment plant are evaluated at the entry, stages and outlet. In this regard, the microbial, chemical and physicochemical properties of wastewater samples are evaluated at the mentioned points. Afterwards, the relationship in between the microbial and chemical pollutants are investigated. Finally, corrective solutions are presented to improve the performance of the treatment plant by having the detailed information on the microbial, chemical and physicochemical conditions of wastewater at all the points of treatment plant. In this regard, microbial monitoring is performed using the general TBC microbial kit and specific microbial kits including APB, FP, IRB, NRB, Aero, SRB and TRB. The TBC kit is applied to measure the total number of bacteria in wastewater samples and other kits are interrogated to determine each type of bacteria. In the following step, the physicochemical and chemical parameters are monitored using reference techniques. The TBC level is 105 cfu/ml at the entry point of the human sewage and its level reaches to 103 cfu/ml at the second and third stages. Finally, the TBC value reaches to 102 cfu/ml in the outlet. The process of reducing TBC from the inlet to the outlet prove the ideal performance of human sewage treatment plant. The performance trend of the treatment plant is suitable for reducing other types of bacteria. In the most cases, the bacteria level is reached from high to moderate level and in some cases to low level. https://www.ijche.ir/article_237336.html A new type of magnetic ion imprinted polymer nanoparticles was employed to quickly extract, concentrate, and measure Ni(II) ions in urine samples from foundry workers. The Box-Behnken design and response surface methodology were used to optimize the parameters that affect the preconcentration process. The main factors considered for sorption optimization were pH value (8), sorption time (10 min), and the amount of magnetic imprinted polymer (7 mg). The elution step was optimized by investigating four variables: type, volume, and concentration of the eluent, as well as elution time. Mentioned parameters were 3.8 mL of HCl 0.9 M, for 5 min. After the sorption and elution steps, flame atomic absorption spectrometry was used to quantify the Ni(II) ions.Equilibrium isotherms were studied, and two models were utilized to analyze the equilibrium sorption data. The results showed that the sorption process followed the Langmuir model. The maximum monolayer capacity and the Langmuir constant were49.3 mg g-1 and 0.205 L mg-1, respectively. Ultimately this nanosorbent was successfully applied to the selective determination of urinarynickel in foundry workersand satisfactory results were obtained. Under the optimalcondition the limit of detection and the relative standard deviations was 0.25 μg L-1 and were equal or less than 9.5%, respectively. https://www.ijche.ir/article_239758.html The reduction in feed gas supplied to the Sarkhun and Qeshm Gas Refinery caused the refrigeration unit compressors to operate considerably below their design capacity, thereby increasing the risk of process instabilities, particularly compressor surge. In this study, the refrigeration cycle of the refinery was simulated using Aspen HYSYS software in conjunction with the Peng–Robinson thermodynamic equation of state, based on real operating data. Model accuracy was assessed through the sum of squared errors, yielding deviations of 1.516 kmol/h in flow rate, 0.176 kPa in pressure, and 2.861 °C in temperature. To overcome the limitations associated with the unavailability of compressor characteristic curves, operational performance tests were conducted for the first time at three distinct compressor rotational speeds, enabling a realistic evaluation of surge onset conditions. Furthermore, vibration sensors were implemented to continuously monitor dynamic compressor behavior and accurately detect surge events. The experimental findings and simulation outcomes were subsequently integrated into an Excel-based decision-support tool, enabling real-time operational monitoring, enhancing decision-making efficiency, and improving overall process safety. https://www.ijche.ir/article_240588.html In the pharmaceutical industry, solvents account for approximately 80-90% of total material ‎consumption. Selecting the optimum solvent and its binary or ternary mixtures in laboratory ‎experiments requires considerable time and cost. Therefore, the use of semi predictive ‎thermodynamic models can overcome these limitations. In this study, the UNIQUAC SAC ‎activity coefficient model, which is a segment based thermodynamic model, was employed to ‎model the solubility of 123 solid pharmaceutical and non pharmaceutical compounds. First, ‎using reported experimental solubility data, the contribution of conceptual segments for each ‎compound was determined through optimization. These segments were then used to identify ‎the solvent that provides the highest solubility. The obtained results show that the ‎UNIQUAC SAC model is a practical thermodynamic model that can be effectively used in ‎the conceptual design stage of pharmaceutical processes for selecting the optimum solvent.‎ https://www.ijche.ir/article_241388.html Pharmaceutical pollution, especially antibiotics, poses a significant environmental challenge due to their high chemical and biological stability, which hinders their removal by conventional water treatment methods. Ciprofloxacin, a commonly used antibiotic, is frequently detected in aquatic environments and is resistant to conventional degradation. In this study, graphitic carbon nitride (g-C3N4) nanomaterials were synthesized via thermal polymerization under a nitrogen atmosphere at three different gas flow rates of 10, 40, and 80 mL/min (denoted as G-10, G-40, and G-80, respectively). The synthesized samples were characterized using XRD, FTIR, BET, PL, and FE-SEM, confirming the formation of a crystalline structure with favorable porosity and optical properties. BET analysis revealed that G-10 exhibited the highest specific surface area (46.6 m²/g), which resulted in enhanced light absorption and superior photocatalytic activity. Photocatalytic degradation experiments of ciprofloxacin (initial concentration of 10 mg/L) under visible LED light at pH 5 and catalyst dosage of 1 g/L demonstrated that G-10 achieved a removal efficiency of 96.4% within 90 minutes, whereas G-40 and G-80 showed lower efficiencies due to reduced surface area. Kinetic analysis indicated that the degradation followed a pseudo-second-order model. Reusability tests confirmed that the catalyst maintained high performance after several successive cycles. These results indicate that g-C3N4 synthesized under a nitrogen flow of 10 mL/min offers high efficiency and stability as a visible-light photocatalyst for the removal of pharmaceutical contaminants from aqueous systems. https://www.ijche.ir/article_241423.html The Carum carvi essential oil contains volatile constituents with noteworthy biological value. These compounds exhibit strong antibacterial and antifungal properties. Nanoemulsions, by increasing the interfacial area between the oil and aqueous phases, enhance the bioactivity of the essential oil and facilitate its access to target tissues. Production of nanoemulsions via subcritical water methods can contribute to improved efficacy of the active materials.This study focuses on the formulation of a Carum carvi essential oil nanoemulsion using a mixture design. In the present work, Carum carvi essential oil was extracted using a Clevenger apparatus, yielding 3.6 mL. Based on a mixture design, the nanoemulsion formulation of the essential oil was optimized within these ranges: essential oil 0.1–0.9 mL, Tween 80 as emulsifier 1–4 mL, and distilled water 20.1–23.9 mL, under subcritical water conditions at 150 °C for 90 minutes. The results indicate the optimal formulation for oil, emulsifier, and water contents as: 0.62 mL essential oil, 2.75 mL emulsifier, and 21.63 mL water. Dynamic light scattering (DLS) analysis of this formulation showed a mean particle size of 156 nm, polydispersity index (PDI) of 0.196, and zeta potential of −24.1 mV. The application of the product prepared under the optimal conditions, with antifungal activity assessed by diffusion (permeation) method, demonstrated an inhibition of growth of Penicillium expansum by 68.78% and antibacterial activity against the Gram-positive Staphylococcus aureus and the Gram-negative Escherichia coli, with inhibition zone diameters of 1.6 cm and 1.4 cm, respectively. https://www.ijche.ir/article_242391.html The hydrodynamic behavior of a cold-circulating pseudo-2D fluidized bed relevant to the methanol-to-olefins(MTO)process is investigated experimentally and numerically across three geometrically scaled configurations. Experimental measurements of the solid-phase velocity field and volume fraction were obtained using high-speed imaging combined with PIV–DIA techniques. A two-fluid Eulerian–Eulerian CFD model incorporating the Kinetic Theory of Granular Flow(KTGF)was developed in OpenFOAM and validated against the experimental data. The comparison showed that the model accurately captures the core upward flow, reproducing the peak solid velocity with less than 10% deviation, while preserving the near-wall velocity gradients observed experimentally. Following validation, the model was applied to three geometric scales. Results indicate that scaling the geometry by up to a factor of two does not alter the qualitative structure of the hydrodynamics: in all scales, a stable upward core region and downward near-wall recirculation zones persist without meaningful spatial displacement. The solid volume-fraction distributions also retain their characteristic pattern, although the difference between the central dilute region and the denser wall regions decreases by up to 15% in larger scales, indicating enhanced natural mixing. To quantify mixing, the Cluster Mixing Index (CMI) was evaluated for all scales. The CMI in the central region ranged from 0.88to0.94, with a relative variation below5.5%,demonstrating that the degree of solids mixing is effectively scale-independent within the investigated similarity-based geometries. These findings confirm that the validated CFD framework provides a reliable basis for hydrodynamic scale-up and can accurately predict mixing behavior in larger pseudo-2D circulating fluidized beds relevant to industrial MTO applications