Iranian Journal of Chemistry and Chemical Engineering
Volume:42 Issue: 7, Jul 2023

The separation of CO2 gas is very important to meet environmental standards, this research aims to prepare a membrane that improves the selectivity of CO2 over N2 gas. Polymer (polyether-block amide) has properties that absorb CO2 well. Nano zeolite 4A has tiny pores proportional to the kinetic diameter of CO2. This mineral particle can act as a molecular sieve in the membrane and improve thermal and mechanical stability. By these two materials, Pebax/4A membrane was prepared. The structure of the membranes was evaluated by FESEM, BET, FT-IR, and mechanical strength analyses, and the permeability, selectivity, diffusion coefficient, and solubility coefficient of carbon dioxide were calculated in them. Finally, it was found that by adding 10% by weight of 4A, the selectivity of nanocomposite improved by %28 ​​compared to pure polymer.

Hydrogen as a green fuel has attracted enormous attention recently. Although hydrogen combustion produces no harmful by-products, hydrogen production can be almost disastrous. Hydrogen production mainly originates from fossil fuels, and more than 80% of hydrogen production is produced using fossil fuel reformation with CO2 formation as a by-product. Light hydrocarbon gases, predominantly methane, are extensively used for hydrogen production. While methane reforming is an economical and efficient process, decarburization of flue gas can be a challenge. Processes involving chemical looping can be used to mitigate these challenges, and they are favorable for simultaneous CO2 capture during hydrogen generation. Intelligent models can help have accurate monitoring of such plants. The aim of this paper is to provide an Artificial Intelligence (AI) based approach to model a Sorption-Enhanced Chemical-Looping Reforming (SECLR) unit. To this end first, a SECLR unit was simulated using ASPEN Plus version 11. Then the simulation results were validated by experimental data, and the SECLR unit went through 31000 different scenarios. The derived data from ASPEN Plus was modeled and simulated with machine learning methods to estimate the CH4 conversion, H2 Purity, and CO2 removal in the SECLR process. Artificial neural networks, ensemble learning, and support vector machine methods were developed to predict the CH4 conversion, H2 Purity, and CO2 removal in a SECLR unit. All three models could provide satisfactory results for predicting CH4 conversion, CO2 removal, and H2 Purity. According to statistical evaluations, Artificial Neural Network (ANN) outperformed Support Vector Machine (SVM) and ensemble learning in producing results with lower error values and higher accuracy with an average 5.23e-5 of error and R2 of 0.9864.

A composite, based on poly (acrylic acid‑co‑styrene) and organomodified montmorillonite with hexadecyltrimethyl ammonium bromide (27 wt. % in inorganics), designated as poly(AA-co-St)/HDTMA-MMT was prepared by in situ radical polymerization. The structural and morphological properties were examined by Fourier Transform InfraRed (FT-IR) spectroscopy, X-Ray Diffraction (XRD), and scanning electron microscopy (SEM). The results show the intercalation of poly (acrylic acid‑co‑styrene) in the organomodified montmorillonite layers. The percent of the inorganics in the composite is 27 % as evaluated by ThermoGravimetric Analysis (TGA). The performance of the composite to remove phenol molecules from an aqueous solution was investigated by batch adsorption, under different experimental conditions. The zeta potential of poly(AA-co-St)/HDTMA-MMT composite was calculated to understand the mechanism of phenol adsorption onto poly(AA-co-St)/HDTMA-MMT.The pollutant uptake behavior was determined by UV-Vis spectrophotometry. The best results were obtained for a contact time of 180 minutes, an initial concentration of 30 mg/L, pH 6. The presence of acrylic acid and styrene can modify the surface characteristics of the composite and affect the adsorption capacity as confirmed by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). Interestingly, the maximum adsorption capacity was found to be 150.7 mg/g. Equilibrium modeling of the phenol removal process was carried out using the Langmuir and Freundlich adsorption isotherms. The equilibrium adsorption data were found to be well-fitted with the Freundlich adsorption isotherm. The kinetic of adsorption was best described by a pseudo-second-order expression rather than a first-order model. The interactions between phenol molecules and adsorbent were explained by electrostatic as well as hydrogen bonding interactions, as confirmed by the pseudo-second-order kinetic model. A model for the interactions between a composite and phenol molecule was proposed. Interestingly, the desorption of phenol from the adsorbent using hot water remains stable. The value of the first adsorption/desorption cycle was about 98.1 % and achieved 92.8 % after five cycles.

This work reports the Uranyl (UO22+) extraction from water by the Triton X-100 / Tween-40 / D2EHPA / BMIMMeSO4 by two aqueous phases or Cloud Point Extraction (CPE). The procedure has been developed to extract uranium (VI) using a mixture of non-ionic surfactants: Triton X-100 and Tween-40 in different contexts, and a mixture of lipophilic chelating extracting agent D2EHPA/ BMIMMeSO4. The UO22+ sample was analyzed by UV-Visible spectroscopy. A mixture of 100 µL of Arsenazo III and 100 µL of UO22+ in a medium whose pH was equal to 2.0. The interaction product of Arsenazo III with UO22+ was determined at λmax= 653 nm. Three key variables: initial pH value, ion strength, and initial uranyl concentration have been studied by the 33 factorial design methods, in order to find the optimum conditions for uranium (VI) extraction. The temperature, the time, and the concentrations of Triton X-100 and Tween-40 were fixed: T =25°C, time = 24 hours, Triton X-100 (8%), and Tween-40 (2%). The optimal extraction of uranium (VI) by Micelle-Mediated Extraction (CPE) procedure was obtained for pH= 3.0, Na2SO4 (% w/w) = 9.0, and [UO22+] = 5.50 mM. This system has research value and application in wastewater treatment.

The tin pyrophosphate (SnP2O7) was synthesized from the modification of mono-ammonium phosphate (MAP) by tin chloride (SnCl2). This solid was used as a heterogeneous catalyst for the one-pot multicomponent synthesis of tetrahydrobenzo[b]pyran and dihydropyrano[3,2-c]chromenes derivatives under green reaction conditions. This synthetic protocol offers several advantages such as short reaction times (8-15 min), high product yields (85-97%), easy work‐up procedure, and easy catalyst separation from the reaction mixture. In addition, SnP2O7 can be recycled for up to five cycles without a significant loss of catalytic reactivity. The XRD and IR spectra confirm the stability and heterogeneity of SnP2O7 in the reaction medium even after its reuse.

The N, N'-bis-pyridine-4-ylmethylene-1,2-diamine (Pyen) was prepared by a reaction of ethylene diamine and 4- pyridine carbaldehyde. The DA was synthesized by a reaction of 4- chloromethyl salicylaldehyde and Pyen. The new ionic Schiff base polymer ligand (L) was synthesized by a reaction of DA and ethylene diamine in methanol at refluxed conditions. The ionic Zn2+mettallo Schiff base polymer was synthesized by reaction of L and ZnCl2 in methanol at refluxed conditions. The synthesized compounds were characterized by various analytical and spectral methods. The chemical composition and functional group identification of the synthesized compounds were confirmed by CHN analysis, FT-IR, 1H-NMR spectroscopy, and mass spectrometry. The molecular weight of the L and ZnL was determined by size exclusion chromatography with the results of the Mw= 6441.4 and 14212 for L and ZnL, respectively. The XRD pattern of the L and ZnL exhibited an amorphous character with low crystallinity. The SEM images showed shapeless plates with narrow valleys in the case of L and deep pores in the case of ZnL. The TEM images revealed a cluster of scaffold structures or agglomerated structures of the polymers. The solid-state conductivity of the L and ZnL was studied and the results showed that the conductivity increased by increasing the temperature from 300K to 400K. This behavior confirms the semiconducting properties of L and ZnL. The calculated solid-state conductivity of L in this temperature range (4.18×10-10-1.04× 10-5 Ω−1 m−1) is higher than the calculated solid-state conductivity of ZnL(1.45×10-11-3.12×10-9 Ω−1 m−1) whereas the calculated activation energy (of conductivity) for ZnL (0.19 ev) is lower than the calculated activation energy of conductivity (0.29ev) for L.

Porous bone scaffolds are made by various methods such as membrane lamination, space holder, freeze-drying, and 3D printing techniques. With the advent of 3D printing, this method has emerged as a new tool for designing porous scaffolds.  The porous scaffolds are expected to have a multifunctional effect and changing porosity patterns as an approach to integrating the mechanical properties of different designs into a unique scaffold design. The knees, as a large joint, in addition to helping the limbs, also bear the weight of the body. In this study, the bone scaffold was fabricated using materials such as carboxymethyl chitosan (CCHI) and hyaluronic acid (HLA) using a three-dimensional bioprinter method for repairing the knee joint bone. In this study, Scanning Electron Microscopy (SEM) analysis is used to study morphology.  In order to investigate the existing phases, phase changes due to different content  to determine the absence of space particles in the production scaffold and to determine the size of blocks by X-Ray Diffraction (XRD). The MTT toxicity, apatite formation, as well as cell growth tests, were used to evaluate the biocompatibility and biodegradability of the porous scaffold. The scaffold degradation rate is determined after immersion in Simulated Body Fluid (SBF) as well as Phosphate Buffer Saline (PBS). The outcome shows that the sample with 10 wt% HLA presents suitable mechanical and biological properties compared to the pure sample.

The aim of the current study was to find a reliable joint between Borosilicate glass and Kovar alloys. For this purpose, the Dilatometer test was applied to calculate the thermal expansion coefficient of glass and Kovar alloys, and the materials with lower differences in the thermal expansion coefficient were used to join the Kovar to glass. Due to the nonmetallic properties of glass, it is theoretically impossible to join glass to metal as it shows no wettability. Therefore, a material was applied as a sealer between Kovar and glass to solve this problem. The Kovar samples were oxidized in the N2-H2-H2O atmosphere to control the chemical composition and also form an oxide layer that does not contain Fe2O3. The tensile strength of the produced joints was investigated at different times and temperatures. The results showed that the highest tensile strength was 16.63 MPa which was achieved at 10 min and 1000°C.

Basalt fiber reinforced PLA/CQ hybrid biocomposite is developed by the injection molding technique. Mechanical properties of Basalt fiber reinforced PLA/CQ composites at different weight fractions are investigated. In addition, to analyze the morphological characteristics as well as the fractured and worn-out surface of the raw materials, a Scanning Electron Microscopy (SEM) study is carried out. Poly lactic acid (PLA) is a popular synthetic polymer considered for tissue applications, hence this polymer is proven to support the occurrence of metabolic processes in the human body. PLA parts reinforced with treated basalt fiber seem to be a good selection. Cissus quadrangularis fiber has many medical curing abilities, is first time introduced as a medical filler in short fibers in this hybrid bio-medical composites. The study shows that significant improvement in tensile, flexural, and impact strength of the hybrid composites was observed as the weight percentage of BF and CQ increases. Also, water absorption tests and scanned electron microscopic studies were conducted to further explore the capability of this biocomposite. This composite gives an efficient result as that of bone instead of considering metal as a replacement. This is a novel and innovative finding of new hybrid composites of PLA/BF/CQ biocomposites in the applications of biomedical engineering.

The main goal of this study was to apply chemometrics techniques such as (ANOVA)-Simultaneous Component Analysis (ASCA), Response Surface Methodology (RSM), and Central Composite Design (CCD) to identify important factors in Dexamethasone Sodium Phosphate (DSP) microextraction from plasma samples. This work proposes the pre-concentration and determination of DSP using a Dispersive Liquid-Liquid Microextraction (DLLME) and spectrophotometry in combination with chemometrics approaches. ASCA as a multivariate statistical tool was used to more thoroughly analyze the influencing factors on DLLME and their interactions. By ASCA the diversity of the data matrix was divided into five levels for four variables: the major impact of each experimental component (dispersive and extraction solvent volume, amount of salt, and incubation time), followed by the impact of each second-order interaction. The significance of each factor or interaction effect was determined by a permutation test. The outcomes were compared with the results of the ANOVA approach to determine the ideal circumstances for measuring the trace amount of DSP. Under optimal conditions, a linear calibration curve with a detection limit of 0.071 µg/mL in the 0.1-5 µg/mL range was obtained.

This study examines the use of inductively coupled plasma atomic emission spectroscopy (ICP-AES) combined with chemometric methods in order to determine the trace elements such as Al, Ba, Ca, Cr, Cu, Fe, K, Mg, Mn, Ni, Na, Pb, Sr, Ti and Zn in Kohl samples. The method showed that Kohl exhibited a high lead concentration, indicating that the preparation of Kohl samples is lead sulfide instead of antimony sulfide. Multivariate statistical methods are used to improve our studies. The coefficients calculated for samples exhibited a positive correlation between the trace elements, Sr, Mn, Pb, Na, Fe, Cu, Ti, and Ba indicating a similar behavior of the elements. Also, a negative correlation among Cr, Ca, Ni, K, and Mg was shown. So, no correlation was shown by Zn and Al. In the same way, the principal component analysis shows three groups. The method developed has been successfully applied to the analysis of Kohl samples in order to give the behavior and relationships between variables.

Nimodipine is a Calcium Channel Blocker (CCB) used to treat high blood pressure. CCB worked as an antihypertensive drug. In this study, Nimodipine is used as a CCB to study spectral behavior by spectrophotometric method and further validated by computational methods to correlate with theoretical aspects. It is subjected to stress conditions by applying varying forced degradation parameters including temperature, photolytic, oxidative, acidic, and basic conditions to find the stability of the drug and predict the chemical reactions that take place during degradation. The other parameters including order of reaction, shelf-life, half-life, and their energy of activation are determined. The method validation of a drug is performed according to the International Conference on Harmonization (ICH) guidelines by using parameters i.e. Linearity/ Range, Limit of Detection (LOD), Limit of Quantitation (LOQ), Stability, Accuracy, Precision, Robustness, and Ruggedness. It is observed that the developed method using UV-spectroscopy can be considered a sensitive and fast reproducible method for the determination of Nimodipine. In the degradation study, it is observed that Nimodipine is thermally stable, and in the case of acidic, basic, and oxidative degradation, the reaction followed first-order kinetics whereas zeroth-order kinetics is observed in photolytic degradation. The recovery time of 10% and 50% drug degradation are also calculated. In the validation study, the range of linearity is observed between 2.5 to 40 μg/mL. The LOD and LOQ are calculated and it is found 0.1422 μg/mL and 0.4270 μg/mL in acidic medium and 0.1184 μg/mL and 0.3590 μg/mL in basic medium. Stability, inter-day precision, intra-day precision, robustness, and ruggedness are calculated and results are within the acceptance criteria. This method can be employed to analyze any calcium channel blockers by slight modification. For a better understanding of CCB, the following perspective can be adopted in the future.

Clinopodium umbrosum from Lamiaceae family has been used widely in traditional medicine as an herbal medicine. Due to a lack of phytochemical reports and limited studies on C. umbrosum, this plant species was selected for further phytochemical analysis. The grounded aerial parts of the plant were extracted with petroleum ether, chloroform, and methanol, subsequently. The methanol extract was fractionated via Solid Phase Extraction (SPE), Vacuum Liquid Chromatography (VLC), and reversed Phase High-Performance Liquid Chromatography (HPLC), respectively. 1D and 2D NMR spectral analyses were applied for structure elucidation of the purified compounds. The Gas Chromatography-Mass Spectrometry (GC-MS) technique was used for the analysis of the essential oil of C. umbrosum which was achieved through hydrodistillation. In addition, free radical scavenging activity together with total phenolics and flavonoid content of the methanol extract was assessed. Structure elucidation of the purified compounds revealed the presence of a caffeic acid derivative and two triterpene saponins in C. umbrosum methanol extract. Based on the GC-MS analysis of the essential oil results tolualdehide, palmitic acid, and acetophenone were the main components of the essential oil of this plant. Moreover, a high percentage of phenolic and flavonoid components of the extract seems to be responsible for its antioxidant and free radical trapping activity. Conclusion Overall, the phytochemical analysis of C. umbrosum showed the presence of rosmarinic acid, buddlejasaponin IVa and buddlejasaponin IV as the main constituents of the methanol extract.

Citrus fruit juice especially mosambi demands were raised during non-seasoning time owing to a rich source of vitamin C. Membrane separation was the unique method to store the clarified juice at different operation conditions. Membrane performance such as, flux declined and cake layer formation was enhanced with continuous operation. Such demerit was improved by pretreatment method before clarification of juice. Several pretreatment such as centrifugation, fining agent (gelatin and bentonite), and centrifugation followed with the fining agent were commonly employed. Individually packed columns supported with glass beads and molecular sieves were used for the pretreatment of mosambi juice. During packed column study pretreated juice physicochemical properties depended on packing support, feed flow rate, packing factor, and operating time. The packing factor value was enhanced from 446 to 7625 by replacing the support material glass beads from molecular sieves. Series column operation had a better ability to maximize the removal of high molecular weight compounds (pectin, cellulose, and hemicellulose) from raw juice compared to single column treatment. After series column pretreatment, the average particle size was reduced from 40 to 1 µm. Column pretreated juice was clarified from dead end membrane filtration unit. Polyamide membrane had an average pore size 2.5 µm was used for clarification of juice at 69 kPa transmembrane pressure drops. 95% clarity was enhanced and 97% alcohol-insoluble solids were removed from pretreated juice after the membrane process.

In this current research work, a detailed parametric study has been reported for the Lactic Acid (LA) extraction from the aqueous solution through Emulsion Liquid Membrane (ELM). A designed ELM loaded with tri-n-octyl amine (as a carrier), oleyl alcohol (as a membrane modifier), cyclohexanone (to reduce water co-transportation), hexane (as a diluent), sodium carbonate (as an internal stripping phase reagent), and span 80 (as an emulsifying agent) was formulated and prepared through mechanical agitation mode. The effect of operating conditions of various process parameters affecting the LA extraction efficiency through ELM were examined and elucidated in detail. The results have shown that more than 95±1.5% of LA were successfully extracted within 20 min at the optimum conditions of 0.05 [M] LA concentration, 2000 rpm emulsification speed, 2.0 (v/v) treat ratio, 4% (v/v) span 80 concentration, 1.0 (v/v) phase ratio, 200 rpm stirring speed, 0.25 [M] stripping phase concentration ( ), 2% (v/v) cyclohexanone, 1 [N] sulphuric acid concentration, and TOA concentration: 10 %(v/v). Hence, it could be concluded that these optimized ELM constituents as well as optimized ranges of various desired process parameters may be considered for efficient ELM formulation and LA extraction.

Alpha-tocopherol or vitamin E is well known for its beneficial properties for human health. This bioactive compound can be recovered from various agricultural resources through extraction and separation processes. In order to prolong its shelf-life and maintain its bioavailability, the purified substance can be further encapsulated using a biocompatible reagent. In this work, the encapsulation factors including the concentration of polycaprolactone (PCL), concentration of Tween 20, and the ratio of the organic phase to the aqueous phase were experimentally investigated. The Box–Behnken experimental design was employed to determine the optimal encapsulation condition in a small batch system. The results revealed that, at the adjusted optimal condition, 98.43% encapsulation was achieved using the concentrations of PCL of 6 g/L, concentration of Tween 20 of 0.5 g/L, and the ratio of organic phase to aqueous phase of 1:2. Based on the optimal condition of the batch process, the continuous micro-channel encapsulator was employed for continuous encapsulation with different residence times. For the residence time of 1 s, this system provided an encapsulation efficiency of 92.48% with outstanding productivity of 73.99 mg/mL×min. This work can be further developed to increase the production capacity via parallel processing of micro-channels.

In this study, polystyrene particles with different diameters suspended in deionized water are continuously separated in a novel spiral microfluidic chip using the dielectrophoretic force. The proposed device consists of two curved and straight microchannels. Deionized water and three polystyrene particles with diameters of 10, 15, and 17 μm enter the microchannel. In the curved part, the larger particles are separated from the 10-μm particles due to inertial force. An array of three planar microelectrodes is located on the bottom wall of the straight section. By applying an alternating current to the microelectrodes, a non-uniform electric field is created to separate larger particles (15- and 17-μm ones). Various simulations are performed at Reynolds numbers (Re) from 50 to 150. For Re = 100, 15- and 17-μm particles are completely separated from 10-μm particles. The results demonstrate that at a voltage of 80-100 V, 17-μm particles are separated from 15-μm particles due to negative dielectrophoresis. In addition, increasing the electrical voltage enhances the distance of the 17-μm particle flow from the 15-μm particle flow.

Today, with the increasing need for energy and the limitation of fossil fuels as depleting and polluting sources of the environment, the need to use more renewable energy sources is felt. The use of PCM materials in buildings, power generation, food industry, and automotive applications is presented. This paper presents the melting process time of a Phase Change Material (PCM) to investigate the impact of various Heat Transfer Fluids (HTFs), using the coupled enthalpy-porosity method and VOF approach. The PCM that is considered is a hydrated salt, Sodium Nitrate (NaNO3) which is encapsulated in a stainless steel infinitely long cylindrical capsule and placed horizontally in a laminar cross flow arrangement with air and Therminol/VP-1 as the HTFs. The Finite-volume-based method has been employed to solve the governing equations for the heat transfer inside and outside the encapsulated PCM. With this technique, the algebraic equations (discretization) are replaced by the governing equations. Then, a set of coupled nonlinear algebraic equations has been solved numerically. The results for the dynamic of the liquid/solid interface at different intervals during the PCM’s melting process exhibited that the heat transfer process inside the encapsulated PCM is influenced by HTF types, and PCM melting times are significantly impacted by the flow specifications of HTF on the surface of the capsule.

In the present study, a Gorlov Vertical Axis Wind Turbine (VAWT) in small dimensions was numerically simulated using the Computational Fluid Dynamics (CFD) method. The purpose of this study is to investigate the effect of design and operational parameters on the Gorlov VAWT performance. In order to evaluate the efficiency of this turbine, two parameters of power and torque coefficients are calculated, and their values ​​are compared in the different Tip Speed Ratios (TSR). This paper investigates effective parameters namely inlet wind velocity, blade chord length, helical angle, aspect ratio, and blade airfoil profile. The results show that the turbine with V=15(m/s), c =0.25(m), ψ =30(deg), φ= 2.3 increased maximum Cp by 75%, 273%, 30% and 250%, respectively. In order to find optimal conditions to achieve a higher value of Cp, the Kriging optimization method is provided. The results of Cp show that the highest efficiency of Gorlov VAWT is related to an inlet wind velocity of 15 (m/s), an aspect ratio of 2.3, a helical angle of 30 degrees, a chord length of 0.25 (m), and NACA0018 airfoil profile at TSR of 1.8. Also, sensitivity analysis indicates that blade chord length and helical angle have more effect on mentioned VAWT performance. The Cp and Cm in the mentioned conditions are high enough thus it helps self-starting capability.

Today, with the development of technology, heat transfer, reducing the time of heat transfer, reducing the size of heat exchangers, and increasing the efficiency are considered. Heat exchangers have many applications in the industry. Therefore, increasing the efficiency of heat exchangers will increase the overall efficiency of a system and optimize energy consumption by a system. In the present study, the main goal is the study the effects of the gradual changes in the inner tube geometrical configuration on the thermal performance of the double-pipe heat exchanger on the thermal performance using Computational Fluid Dynamics (CFD) methods based on the finite volume method. For validation, the results are compared with the valid results previously presented in the published papers, and there is a very good agreement between them. In addition to the basic model, six different geometrical designs are used for the inner tube, in the form of a flat tube and a nozzle-like tube. After the numerical simulation, the increase in heat transfer and the Nusselt number of flow, pressure drop, thermal efficiency and the performance index were calculated for each model and compared with the base model and other models. The results show that the nozzle-like inner tube model has a lower performance than the base model. The model with a flat inner tube, and especially case 4 (The case with the flat inner tube with the aspect ratio of 0.3), has a very impressive performance compared to the base case at Reynolds numbers below 6000. But at higher Reynolds numbers, the basic model will have better overall conditions.

Combined Heat and Power (CHP) systems can reduce the energy waste in various industries including oil, gas, and petrochemical plants. In this research, the feasibility of the establishment of a CHP system in A Flare Gas Recovery (FGR) unit is studied. The integration of CHP system in FGR unit is investigated from economical, technical, and environmental viewpoints. The FGR unit of Tabriz Oil Refining Company which is located in northwest Iran is considered as a case study. No such integration has been investigated previously. The simulation of the proposed system is performed using ASPEN-HYSYS software. Rankine cycle is considered for the combined production of heat and power and water is utilized as the Rankine cycle working fluid. The fuel needed by the CHP system is supplied from the FGR unit. In order to more utilization of the fuel energy, the thermal energy of furnace flue gases is recovered through a regenerator heat exchanger. The simulation results showed that the proposed system is able to generate about 4 MW of electrical power and 16 MW of thermal power corresponding to 15.42% and 77.63% electrical and thermal efficiencies, respectively. Moreover, 4,532 kg/h of hot steam with a temperature of 381.4 ˚C is produced by utilizing the furnace flue gases thermal energy. The results of this study showed a promising performance for the integration of a CHP system in FGR unit of Tabriz Oil Refining Company. The present study may be a step forward towards the efficient use of energy sources. Future works in this field can be done with a view to the practical integration of CHP systems in FGR units.

The formation of unwanted oil emulsions during the production, transportation, and processing of crude oil is a major challenging issue. This causes serious technical problems and, subsequently, huge financial losses, which indicate the importance of their separation. The present work investigated the influence of an efficient oil-soluble demulsifier and temperature on the Demulsification Efficiency (DE) of water-in-crude oil emulsions through the bottle test method. The Central Composite Design (CCD) based on Response Surface Mythology (RSM) was applied to design the experiments and optimize the demulsification process. Based on the experimental results, a reduced quadratic model was developed using CCD. In addition, the analysis of variance (ANOVA) was used to evaluate the significance of the developed model and operational parameters. It was found that the P-value of the DE model was less than 0.0001, which confirms the considerable significance of the developed model. Moreover, R2, adj-R2, and pred-R2 were 98.89, 98.15, and 94.34%, which indicates the high accuracy of the proposed model. The result showed that the effect of the demulsifier at low temperatures (25-50 oC) was significantly weak on the separation efficiency of the studied emulsions. In this case, the maximum water removal from the oil emulsions reached approximately less than 50%. In addition, the results demonstrated that the maximum interaction effect between parameters was observed by adding 20-25 ppm of the demulsifier at 75 °C. Moreover, the demulsification efficiency was obtained by more than 75%. Meanwhile, the subsequent addition of the demulsifier to the crude oil emulsions at concentrations greater than 25 ppm has almost not changed the efficiency of the process. Finally, the numerical optimization results obtained by CCD indicated that the maximum separation efficiency of 80.65% was achieved under the following optimal conditions: demulsifier dosage at 25 ppm and temperature at 75 °C.

Solar desalination systems are a kind of water purification system that can be utilized in dry regions. However, the low efficiency and performance of these systems are some of the main challenges of these mechanisms that affect their development. So In this paper, a novel modified model is presented for increasing the efficiency and performance of these systems. This suggested modification is based on a triple action. The first of these actions includes discovering the optimal location for the installation of the solar still water. Increasing the contact surface of the water by spraying and keeping the saltwater in a wide solar still is a second approach for increasing the evaporation of water. In the end, a modern condensing system based on an innovative fog (water particle) trapper/harvester. This system includes fog fences, a cool water pipe loop based on the outdoor temperature, and forced-controlled airflow. Therefore based on this method, a conceptual design of the solar still water is modeled For UAE. The results of this study show that the modified solar still can make 3.94 liter/m2 per day. The cost per liter of each liter of water is $ 0.0344. These results are shown that the efficiency of the proposed model is two times higher than the traditional method with the same cost. Also, these results are in an acceptable range in comparison with the new modified models presented by researchers.

The proposed poly-generation plant, which generates power, cooling, and freshwater, consists of five subsystems. A solid oxide fuel cell (SOFC) plant generates electricity using CH4 as fuel. Steam Reforming happens in the anode to generate the required H2 for the electrochemical process. The thermal energy of these processes enhances the exhaust gas temperature from the solid oxide fuel cell plant, which can be reused using a Kalina cycle and humidification-dehumidification-RO desalination plants. This exhaust gas from the afterburner of a solid oxide fuel cell evaporates the ammonia-water mixture in a Kalina cycle and preheats the feedwater to be entered into the humidifier of the desalination unit. There has been an evaluation of the effect of various system parameters such as turbine inlet temperature, compressor pressure ratio, carbon dioxide to methane molar ratio, steam generator temperature, and mass flow ratio of the desalination system on overall system performance. Also, single- and multi-objective optimization methods have been used to optimize the general system compared to the base model.

This study aims to compare the effectiveness of ElectroCoagulation (EC) and Electro-Fenton (EF) processes in the treatment of high-strength storage leachate. The effect of operating parameters, including initial pH, contact time, and mass ratio of COD: H2O2, on Chemical Oxygen Demand (COD) and Total Organic Carbon (TOC) removal efficiencies of leachate was investigated. For this purpose, a jacketed reactor in which the electrochemical process is performed using monopolar-bonded iron electrodes is designed. As a result of the experimental studies, the optimum operating parameters of the EC process were determined as follows: pH 7, current density 150A/m2, and reaction time 30 minutes. Under these conditions, 37.87% COD and 47.36% TOC were removed respectively. Due to the lack of expected results in the treatment of this wastewater in the EC process, treatability studies were carried out with the EF process. As a result of the study, optimum conditions were found to be pH 3, current density 150 A/m2, H2O2= 500 mg/L (KOI: H2O2@1), and working time 10 min. A higher COD (71.7%) and TOC removal (90.87%) have been obtained with the EF process under optimum conditions. The operating costs of electrocoagulation and electro-Fenton processes under optimum conditions were calculated as 2.26 and 1.78 €/m3, respectively. Experimental findings revealed that, unlike the EC process, the EF process can be a good option for landfill leachate treatment in terms of providing less treatment time, less sludge, more cost-effectiveness, and necessary discharge limits.

Magnesium-doped lithium manganese oxide nanoparticles were modified with 3-aminopropyl-trimethoxysilane and characterized by XRD, FTIR, TGA, and TEM analytical techniques. The sorption of Malachite Green on adsorbent with respect to nanosorbent amount, dye concentration effect, pH influence, and contact time was performed to obtain the maximum adsorption conditions. The pseudo-first-order, pseudo-second-order, and intraparticle diffusion kinetic models were evaluated and found better fitting with the pseudo-second-order (R2 = 0.995). The Freundlich isotherm is found to be suitable (R2=0.989) to describe the sorption process of Malachite Green on prepared adsorbent. Malachite Green spiked Lake Water, NKCM (Na+, K+, Ca+2, Mg+2 containing) water, and Sea Water were tested and evaluated for the adsorption capability and found 46.9 %, 44.6%, and 40.7 % removal performance, respectively.