Iranian Journal of Chemistry and Chemical Engineering
Volume:41 Issue: 6, Jun 2022

Melamine is a high nitrogen compound used as an adulteration to high protein foods such as infant formulae. There are many different methods for extraction and analysis of melamine which are time-consuming, complex, and need large volumes of organic solvents. A validated method for extraction and cleanup of melamine (MEL) in infant formulae, water, and powdered coffee creamer was developed using a NanoGraphene Oxide (NGO) assisted with Electro Membrane Extraction (NGO/EME) followed by HPLC-UV detection. Supported Liquid Membrane (SLM) with NGO was used as the adsorbent interface in this study. Synthesized NGO was characterized by Fourier Transform InfraRed (FT-IR) spectroscopy and Scanning Electron Microscope (SEM). Effective parameters such as voltage magnitude, SLM solvent, pH of acceptor and donor phases, extraction time, and stirring rate were optimized. The method provided the LOD and LOQ 0.03, and 0.1µg/kg in infant formula, respectively. The accuracy was in the satisfaction recovery rate between 106-109% with RSD 4.83-5.31 for infant formulae as well as the other tested matrices. The developed method based on NGO/EME extraction presents a reliable and rapid analysis of melamine in infant formula.

In this study, a nanoscale Zero-Valent Iron-Graphene (nZVI-G) composite was synthesized and applied for the removal of diazo Direct Red 81 from an aqueous solution. The prepared nanocomposite was characterized using Scanning Electron Microscopy (SEM), Energy-Dispersive X-Ray Spectroscopy (EDS), X-Ray Diffraction (XRD)analysis, and Fourier-Transform InfraRred (FT-IR) spectroscopy. The particle size was in the range of 20 to 35 nm. The effect of influential experimental variables on dye removal such as contact time, pH, adsorbent dosage, initial dye concentration, and the temperature was investigated. In optimum conditions, including contact time of 10 min, pH = 3, the adsorbent dosage of 0.05 g, and initial dye concentration=10 mg/L, dye removal was achieved 92%. Different adsorption isotherm models (Langmuir and Freundlich) were used and adsorption followed Langmuir isotherm well (R2= 0.9773). The maximum Langmuir adsorption capacity of nZVI-G was obtained 29.07 mg/g. The pseudo-first-order kinetic model with R2=0.9838 fitted well with the experimental data. The thermodynamic parameters ( were calculated and the results revealed that the adsorption of dye was spontaneous and exothermic. The nZVI-G composite was found to be a low-cost potential candidate with high adsorption capability to be applied as an adsorbent for the removal of Direct Red 81 from the aqueous media. Reduction degradation reaction which rapidly produces radicals has a major effect on reaction time. This nano adsorbent has the ability to adsorb, reduce, and degradation of pollutants, so the dye was removed efficiently.

Recently, Schiff base complexes as synthetic antioxidants are widely used instead of natural antioxidants because they are effective and cheaper. In this study, a series of α,ά-Me2-salen, (N,N´-ethylenebis(α methylsalicylideneiminate)) Schiff base derivatives have been investigated for their anti-histone deacetylase (HDAC), anticancer, antibacterial, and antioxidant activities. For anti-HDAC studies, AUTODOCK 4.1 and Molecular Dynamics (MD) simulations have been conducted against these combinations. Cytotoxic test, the ferric reducing ability of plasma (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) ABTS assays and Agar diffusion method have been applied to investigate anticancer, antioxidant and antibacterial activities, respectively. Based on the results, the best docking was obtained for α,ά-Me2-salen against HDAC. Also, MD calculation results demonstrated that the α,ά-Me2-salen is a more effective compound for HDAC inhibiting than SAHA as a known enzyme inhibitor. However, α,ά-Me2-salen, and its derivatives didn't display antibacterial activity against any of the microorganisms. Cytotoxic activity analysis toward MCF 7 cell line was apparent that α,ά-Me2-salen and its Ni (II), Co (II), and Cu (II) derivatives manifested high cytotoxic activity with IC50 5, 2, 2, and 3 µg/mL, respectively. The antioxidant results revealed excellent radical scavenging activities of all these compounds against DPPH, ABTS, and FRAP radicals. The antioxidant activity by DPPH, showed Mn(II) complex (IC50 = 0.13 ± 0.50 mg/mL) was the most active. While, α,ά-Me2-salen (IC50 =0.05±0.003 mg/mL) and its Ni(II) derivative (IC50 =0.049 mg/mL) exhibited the highest ABTS scavenging activity. According to the results, all compounds show acceptable anticancer and antioxidant activity and can be used as drug candidates after further investigations.

In this study, two multivariate calibration methods, including partial least squares (PLS) and principal component regression (PCR), as well as continuous wavelet transform (CWT) along with spectrophotometry technique were developed for the simultaneous analysis of Aripiprazole (ARI) and Quetiapine (QTP) in the pharmaceutical formulation and biological fluid. The linear range of ARI and QTP was 1-3 and 2-10 μg/mL, respectively for the proposed methods. The root means square error (RMSE) of ARI and QTP related to the test set was obtained 0.014, 0.0758, and 0.194, 0.882 for PLS and PCR methods, respectively. Also, the mean recovery of ARI and QTP was 99.95, 100.04%, and 97.38, 98.83% for PLS and PCR models, respectively. Among various families of wavelets in CWT technique, the Coiflet (Coif3) and Symlet (Sym2) families were selected to determine the value of ARI and QTP, respectively. In this method, the Limit of Detection (LOD) and Limit of Quantification (LOQ) values was found 0.0033, 0.0200, 0.2764, 0.3486 μg/mL for ARI and QTP, respectively. The mean recovery values of ARI and QTP in synthetic mixtures for CWT approach were 96.98%, 98.94%, respectively. A one-way analysis of variance (ANOVA) test was applied to compare the results of both mentioned chemometrics models and High-Performance Liquid Chromatography (HPLC) as a reference method. No significant difference was observed between these methods.

The palm fruit husk, an agricultural solid waste does not adsorb Mo(VI). The intent of this endeavor was to estimate the adsorption capacity of the SAPFH towards Mo (VI) in wastewater. Hence the surface was altered using a surface activating group, cetyl trimethyl ammonium bromide (CTAB). The husk of the palm fruit, whose surface was modified, was subjected to evaluate the extent of extracting molybdenum that is present in an aqueous solution. The maximal removal of molybdenum occurs at pH 2.0. The adsorbent dose necessary for the maximum adsorption of MoO42- was lesser for wastewater than for pure aqueous solutions. MoO42- took a long time to attain equilibrium at high concentrations. The stability results were suited to Langmuir, Freundlich, and Dubinin-Raduskevich adsorption isotherms models. Dynamic investigation revealed that the uptake obeyed pseudo-second-order kinetic effigy. The adsorption of adsorbates did not change significantly with an increase in temperature. Desorption of Mo (VI) showed that it is possible to retrieve Mo (VI) from the spent adsorbent. The influence of accompanying negative ions such as chloride, phosphate, sulfate, and chromate on the Mo (VI) uptake was explored and the anions compete with Mo(VI) ions.

Carbon materials are gaining importance in catalytic processes. In this respect, the authors studied the most important characteristics of these materials when employed as catalysts for the removal of pollutants from wastewater. X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Fourier Transform Infrared Spectroscopy (FT-IR) were used to characterize Charcoal Activated (CA) derived from the chemical activation of peanut hulls. The key physical characteristics of the solids used in heterogeneous catalysis are the pore volume, the pore distribution, iodine number, oxygen surface groups, and the specific surface area. The combined microwave radiation-CA catalytic activity was assessed through the degradation of Oxytetracycline (OXT) under different irradiation times, initial concentrations, and acidity of the OXT solution. Furthermore, the effect of additional amounts of derived CA on the degradation was assessed. A higher removal rate of OXT contaminant by a combined MW-CA process was a synergic effect and was achieved at a low concentration of OXT and pH 3 (which is the pH range of OXT solution). Furthermore, an additional amount of CA increased removal efficiency. These favorable properties make carbon a viable alternative for use as a catalyst with no residual intermediates or secondary pollution.

NaY zeolite was impregnated by TiO2 to prepare a novel catalyst for the adsorption and photocatalytic degradation of methylene blue (MB). The samples were characterized by XRD, SEM, EDS, and FT-IR techniques. The percentage adsorption of MB on NaY reaches 88% and an adsorption capacity of 6.55 mg/g under optimized parameters ([MB] = 10 mg/L, pH = 6, S/L = 2 mg/L, and T = 25°C). The MB adsorption process follows Langmuir isotherm. The thermodynamic parameters were investigated and showed an endothermic and physical process. The MB adsorption also follows a pseudo-second-order kinetic. The photo-degradation of the MB dye was successfully carried out on the TiO2/NaY catalyst under sunlight. The MB photo-degradation also follows a Langmuir-Hinshelwood first-order kinetic.

In the present study, the applicability of a bimetallic Pt-Sn/Al2O3 in propane dehydrogenation with different promoters, namely, Ca, Mg, and incorporation of Mg-K and Ca-K was studied. The catalysts were prepared by the sequential impregnation of γ-alumina support and characterized by TPD, SEM, XRD, and UV analysis. The propane conversion and propylene selectivity were evaluated under representative industrial conditions. The results showed that the Pt-Sn-Mg-K/γ-Al2O3 catalyst had a better performance in terms of propane conversion and propylene selectivity and yield, due to the partially neutralized and synergistic effect of Mg and K (probably by increasing the platinum dispersion and preventing side reaction and coke formation). TPD results also showed the effects of all these promoters (Ca, Mg, Ca-K and Mg-K) on the reduction of acidic sites of the catalyst, which are favorable sites for cracking reaction and coke formation. In the meantime, Ca is more effective in reducing strong acidic sites, but also Mg is more effective in reducing weak and medium-strength acid sites. Therefore, alkaline-earth metals and also using them with potassium could reduce side reaction products and lead to a more selective reaction to propylene, and improve catalyst performance compared to industrial catalysts.

In this research, xonotlite was synthesized by a hydrothermal method in the Si-Ca-Na-H2O system. Detailed structural characterization by using the XRD technique revealed that the obtained material contains a small quantity of wollastonite (up to 3 %) as an impurity. Calcination of the obtained sample at 900 ˚C has resulted in a complete transformation of xonotlite to wollastonite which was detected as only a crystal phase. Crystallite size and lattice strain of all crystal phases were calculated using Scherrer and Williamson-Hall method. SEM observation of xonotlite morphology revealed tiny needle-like crystals joined together forming dendritic or globular aggregates. Optimal conditions for electrophoretic deposition of xonotlite on 304-type stainless steel have been achieved by appropriate selection of electric field strengths, dispersing medium, and dispersants. Stable suspension of the material was obtained using isopropanol containing 1 % water as dispersing medium and Ca-nitrate as a charging additive. Native layers of xonotlite have a very smooth morphology, while after calcination, the appearance of small cracks in the coating can be observed but the adhesion strength of the coatings to the substrate is improved.

In this work, a novel composite photocatalyst, KBiO3/nano-Ag3PO4 (K/Ag catalyst), was synthesized, and efficiently degraded methylene blue (MB) under visible light. The various properties of photocatalysts were measured by modern analytical techniques, such as XRD, FT-IR, SEM, XPS, and UV-Vis. We also utilized Density functional theory calculation (DFT) to investigate the photocatalytic degradation mechanism in this reaction process. The multiple characterization findings demonstrated that K/Ag composite catalyst was successfully synthesized using Ag3PO4 and KBiO3, and it displayed excellent absorption of visible light. The photocatalytic results confirmed that K/Ag catalyst greatly promoted the degradation of MB under visible light. The first-order reaction kinetics model could satisfactorily describe the apparent photocatalytic degradation process in this system. In addition, adding electron capture agents to the photocatalytic system highly decreased the degradation efficiencies of the target pollutant. Moreover, K/Ag composite catalyst exhibited perfect photocatalyst stability after recycling three times. By calculating the band structure, Density of States (DOS), and work function, KBiO3 and Ag3PO4 could be considered as n-type and p-type semiconductor materials, respectively. When the composite catalyst was exposed to light, the light-excited electrons would have appeared in both the conduction bands. Furthermore, the transfer trend of electrons and holes made photogenerated electrons concentrate on the conduction band of n-type KBiO3, and photogenerated holes concentrate on the valence band of p-type Ag3PO4, thereby greatly improving the photocatalytic efficiency.

Expandable Polystyrene (EPS) is one of the most used polymers. Preparation of this polymer by the conventional method has some problems which cause the synthesis process to be difficult and also decrease the quality of the prepared EPS. In this study, Styrene-Butadiene-Styrene (SBS) has been added to improve some properties of the prepared polymer and the Multi-stage Initiator Dosing (MID) method has been used to reduce the time of the polymerization which causes the polymer’s production capacity to increase. SBS has been added to EPS in shares of 2%wt, 4%wt, and 6%wt. The polydispersity index (PDI) test and the amount of tension in the yield point of the polymer have been checked. The amount of absorbed pentane on the polymer studied. The amount of residual monomer on the polymer has been investigated. All of the studies happened under different conditions like different percentages of initiator, different numbers of dosings, and different time periods of the first stage of the polymerization. Experimental data have been simulated by Multi-Layer Perceptron (MLP) and Radial Basis Function (RBF) methods of Artificial Neural Networks (ANN). The performance of the simulation for the RBF method was better in comparison to the MLP method due to having a strong scientific foundation and also the ability to filter noises. The experimental data show that a higher amount of SBS causes improvement in properties like elongation at break, better pentane absorption, and PDI amount has improved, which shows the better distribution of molecular weight and a decrease in residual monomer in products.

The use of nanosized-Titanium dioxide (n-TiO2) for the formulation of self-cleaning cement has the associated drawbacks of nano-toxicity, higher cost, and agglomeration in the cementitious material. These drawbacks can be avoided by the replacement of n-TiO2 with microsized TiO2 (m-TiO2). However, m-TiO2 is less photocatalytically active as compared to n-TiO2 . Therefore, in the present work, surface fluorination of m-TiO2 has been studied to enhance its photocatalytic activity for the formulation of self-cleaning white cement. The commercially available m-TiO2 (average size 40 μm) was surface fluorinated using aqueous solutions of different molar concentrations of NaF (sodium fluoride) such as 10, 50, and 100 mmol/dm3. The surface fluorinated m-TiO2 was analyzed using Diffuse Reflectance (DRS) Spectroscopy, PhotoLuminescence (PL) spectroscopy, and X-Ray diffraction (XRD) analysis to observe the improvement in the physiochemical properties and photocatalytic characteristics. Further, the surface fluorinated m-TiO2 along with calcined dolomite was utilized for the formulation of self-cleaning white cement. The hence prepared self-cleaning cement was cast into cement slabs, which were then characterized by Diffuse Reflectance Spectroscopy (DRS) and Energy Dispersive Spectroscopy (EDS). The self-cleaning ability and photocatalytic activity of the as-prepared cement slabs were evaluated through Rhodamine B (RhB) degradation test. It has been found that the use m-TiO2, which was surface fluorinated using 10 mmol/dm3 solution of NaF, remarkably enhanced the photocatalytic performance of the self-cleaning cement.

Dyes, which are increasingly harmful to human health and ecology, are an environmental concern and their removal from wastewater is extremely required. It is also important for researchers to find relevant techniques to process these types of pollutants. This study examines the use of the synthesized imidazolate zeolite frameworks-11 (ZIF-11) by stirring method for the Methyl Orange (MO) dye removal from an aqueous solution. Scanning electron microscopy, thermogravimetry, X-ray diffraction, and Fourier transform infrared spectroscopy, were used for the analysis of ZIF-11 particles, which exhibited highly porous, irregular, and heterogeneous shapes and variable sizes. The MO removal was assessed by batch adsorption with ZIF-11 particles as adsorbent, whose efficiency was achieved at pH=8, stirring speed of 600 rpm, for a contact time of 40min, and a dosage of 800mg/L of MO solution. The thermodynamic and kinetic analysis of the MO adsorption process was achieved successfully with the pseudo-second-order kinetic model as well as Langmuir and Temkin isotherms, indicating the feasibility and spontaneity of the uniform distribution of MO molecules on the active sites of ZIF-11 particles. The calculated maximum adsorption capacity of MO on ZIF-11 particles was 178.57 mg/g, which is indicative of the potential adsorptive properties of the synthesized ZIF-11 for MO dyes.

Non-edible oils are typically applied for multiple uses, especially biofuel production. But, finding new methods that can maximize the extraction of vegetable oils is urgently needed. In this work, natural enzymes present in kiwi fruit and ginger along with the ultrasound waves method were used to extract Bitter Almond Oil (BAO). Important factors affecting extraction were optimized using response surface methodology (Box-Behnken design). Under optimum conditions, the maximum extracted oil with an average of 62.1 wt.% oil/seed was extracted from the bitter almond kernel, which was only 0.87% less than the predicted value by the equation. The optimum conditions were: pH=4.74, Kiwi-Ginger juice to almond of 11.3 mL/g (22.6 mL ethanol), incubation temperature of 52 °C, ultrasonic power of 257 watts, and ultrasonic time of 38 min. The results confirmed the validity of the model. The applied technique in this investigation is economically cost-effective and highly efficient which can be widely used in the edible oil industry due to the absence of toxic and hazardous substances.

Etodolac, Lamotrigine, diazepam, and clonazepamine are four important drugs in the pharmaceutical industry and optimizing the solvent concentration in the least amount can reduce the cost and toxicity of these drugs. Due to the lack of thermodynamic modeling based on the activity coefficient equation in previous studies for solubility of Etodolac, Lamotrigine, diazepam, and clonazepamine in aqueous solution, in this study, based on thermodynamic equations and UNIQUAC model, their solubility is optimized with the presence of water and ethanol. Based on the objective function defined, the error rate of the model optimization value was acceptable for each system. The results of this study can be used to better understand the intermolecular reaction of Etodolac, Lamotrigine diazepam, and clonazepamine in the presence of ethanol and water solvents. Also, the importance of the optimization results of this study in order to design a computer program to predict the solubility of these drugs is significant.

Catching acidic gases, for example, CO2 and H2S from gaseous petrol by alkanolamines are regular in gas cleansing frameworks. In this study, for the first time, we use an additional Gibbs argillic model (N_Wilson_NRF) for thermodynamic demonstration of CO2 dissolvability in the double-part CO2+MDEA and three-part MDEA+H2O+CO2 frameworks. The supposition of an altogether atomic framework with no occurrence of compound responses and immersed gas stage from the CO2 gas were explored for the point of having convenient modeling. To decide the dissolvability of CO2 the action coefficient strategy (γ_φ Approach) and the N-Wilson-NRF model were utilized. The result was 1.38 from experimental emergence attained in the two-component water- CO2 modeling. For the three parts, the water-CO2-MDEA framework with the measure of 6.912, the improvement was created.

Flowability and reduced pressure are some of the economic values in the pipe network and pipeline transportation. In this study, we investigated the functionality of self-made drag coefficients composed of a combination of large molecular weight polymer, Laurel soap, and date palm fiber which were induced into a circulated piping system under turbulent water flow. The proposed combination formulas are proved to be a new cost-effective drag reduction approach, which could be adopted extensively in fluid transportation at an industrial scale. The efficiency of using a mixture of polymer, palm fiber, and soap on the drag reduction was thoroughly evaluated by investigating several case studies. Using pure polyelectrolyte showed that at the highest polymer concentration (50 ppm), the percentage of drag reduction reaches 50% in 10.3 mm pipe diameter and 70% drag reduction in 13.5 mm pipe diameter at a flow of low Reynolds number counted 17166.7. After applying a mixture of polyelectrolytes (50 ppm) and fiber in the range (30-60 ppm), a drag reduction of 63% in 10.3 mm pipe diameter and 76% in 13.5 mm pipe diameter were achieved, respectively. Upon examining a mixture composed of polyelectrolyte (50 ppm) and soap in a range (50-150 ppm), the results showed that the highest drag reduction was achieved at a low concentration of soap and a bulk flow at a low Reynolds number. The aforementioned performance results were exemplified by attaining drag reductions of 70% in 10.3 mm pipe diameter and 96% in 13.5 mm pipe diameter, respectively. This is accomplished by optimizing the applied mixture formulas. Upon examining all cases, the estimated drag reductions were shown higher when applying the polymer mixture compared to that of pure polymer. However, a slight decrease in the attained drag reductions when using polymer soap was observed and attributed to the hindrance from the palm fiber, which ultimately reduces the chance for all soap particles to reach the stagnant wall layer.

A numerical study is executed to analyze the steady-state heatlines visualization, fluid flow, and heat transfer inside a square enclosure with the presence of the magnetic field. The enclosure is divided into three layers, the right and left layers are filled with (Cu-Water) nanofluid while the center layer is sinusoidal porous and filled with the same nanofluid. Constant hot and cold temperature is applied to the right and left walls, respectively, the top and bottom walls are adiabatic. Galerkin finite element approach based on weak formulation is applied to solve the governing equations. The parameters studied are the number of undulation (N=1, 2 and 3), Rayleigh number (103≤Ra≤106), Darcy number (10-5≤Da≤10-1), Hartmann number (0≤Ha≤100) and volume fraction (0≤φ≤0.06). Three cases were provided depending on the number of undulations of the porous medium layer. The results obtained that the absolute value of the maximum stream function decreases with the increase of the Hartmann number and the decrease of the Darcy number for all three cases of the wavy porous layer. Heatlines and isothermal lines increase as the Darcy number is increased. The average Nusselt number grows by increasing the Rayleigh number and decreasing the Hartmann number. The enhancement of heat transfer occurred for case (2) as the Darcy number increased at a constant Ra=105, Ha=40. Also, It can be concluded that there was an excellent agreement between this study and those of Hamida and Charrada, by an approximately maximum absolute error of 2.062%.

In the present study, Computational Fluid Dynamics is used for heat transfer studies in the dimple, and flat plate heat exchangers. By employing water as a working medium (fluid), the same and different flow analyses were numerically studied. SOLID WORKS 2018 software was used for the study. The study primarily investigated the effect of the flow rate of hot fluid on the overall heat transfer coefficient. The study also analyzed the influence of hot fluid’s Reynolds number on cold fluid’s Nusselt number. It was observed that an increase in the mass flow rate of the hot fluid from 0.016 to 0.067 kg/s resulted in an increase in the heat transfer coefficient from 65 to 298 W/(m2.K) for the dimple plate heat exchanger (DPHE). Meanwhile, an increase in the Reynolds number of the hot fluid (from 200 to 1000), induced an increase in the Nusselt number of the cold fluid from 1.9 to 8.7 for DPHE. A correlation was developed to calculate the Nusselt number for the same flow analysis of the flat plate heat exchanger (FPHE). The study also compared the performance of the DPHE with that of the FPHE. The results of the same flow analysis indicated that the DPHE exhibited a Nusselt number value 39% greater than the FPHE at the highest mass flow rate of 0.067 kg/s, while in different flow analysis, the DPHE demonstrated a Nusselt number value 41% greater than the FPHE at the highest mass flow rate of 0.067 kg/s.

High peaks of electrical energy usage during hot summer days have become an issue for the power supply systems causing regional power outages. Cooling demand is the main reason for such energy load, which is majorly supplied by electricity. It is possible to use the night cold air for daytime cooling. Energy storage is necessary for the usage of this night-cold energy. The night ambient temperature is usually not cold enough to provide the required low-temperature heat transfer fluid flow and the daytime cooling demand is generally high. A novel system where a storage unit is connected to a wind catcher has been investigated in this study. The results showed that this new system covers the above-mentioned problems. According to the final results, 12.8 kWh of cold energy was stored in the energy storage unit, presenting 64 % of energy storage efficiency and 6h 3m of the charging required time during the night. It was also revealed that the energy storage unit's thermal performance, is highly relevant to the inlet temperature, where 5 °C decreases in the inlet temperature, increased the stored energy by 17%, and decreased the charging required time by 1h 33m.

Using the Combined Heat and Power (CHP) systems is known as one of the most effective ways to raise the power coefficient and reduce fuel consumption and operational costs. In this study, a CHP system with the prime movers of a gas turbine and a horizontal axis wind turbine under the strategy of providing electric charge has been investigated based on the first and second laws of thermodynamics. This study aims to evaluate the effect of a wind turbine on the CHP system. The results show that the proposed CHP system has significant advantages compared to the CHP system working without the wind turbine. The best operating condition for the wind turbine is at the wind speed of 12 m/s, a pitch angle of 5ο, and a tip speed ratio of 3. Moreover, the effects of the wind speed and tip speed ratio on the exergy efficiency of the total system become considerable when the gas turbine works at high-pressure ratios (more than 10) and the combustion chamber temperature is below 1250 οC. Also, it is shown this integrated system can reduce operational costs and fuel consumption by 55 % and 60%, respectively. Finally, regarding the interest rate, the payback period will be equal to 5.4 years.

In high-exergy demand companies like piping companies, using renewable energies can be very useful in Manning the needed energy. Exergy analysis in thermal energy systems is very important, considering the need to determine the location and magnitude of the inefficiency of the system equipment. Utilizing annual meteorological data for Dezful, located in southwest Iran, this study considered the inefficiency of the solar water heating system. As an innovation, a complete analysis of the inefficiency of the equipment of the solar hot water production cycle was considered and the methods of reducing the inefficiency of the equipment were assessed. Energy consumption quality was calculated based on two parameters of exergy efficiency and exergy destruction using the coding capability of MATLAB software, after embedding the modeling in Aspen HYSYS software. While solar collector with 15701.8 kW and Pump1 with 0.51 kW had the highest and lowest exergy destruction, Heat Exchanger 2 with 99.99% and Pump1 with 75.51% had the highest and lowest exergy efficiency. Among the rotating equipment that consumes electricity, Compressor 2 had the most exgegy degradation with 223.1 kW. Also, the results of investigating the effect of ambient temperature showed that the solar collector had the highest and lowest exergy destruction in the month of JAN with 16125.7 kilowatts and in the month of July with 14927.6 kilowatts, and compressor 2 also had the highest exergy destruction in the month of Jan with 216.11 kilowatts and in the month of July with 235.76 kilowatts. and had the least exergy destruction.

This study presents an energy-exergy analysis of a Humidification-Dehumidification (HD) solar water desalination system. The extensive application of the HD system lies in its low energy consumption and ability to exploit solar energy to supply all the heat energy demands. The unsteady governing equations were solved until the system reached a steady state. The simulations were done with the Euler approach to solving the system of energy balance equations numerically. This study's main goal was to investigate the effect of different configurations of the hybrid system and various operating conditions on the performance of the solar HD water desalination system. The optimum configuration was selected based on thermodynamic and exergy analyses. The effects of important parameters such as inlet water and air mass flow rate in the humidifier and dehumidifier water temperature and mass flow rate on the system's operation were studied. This paper also explored the feasibility of the extra heat as a domestic water heater under various conditions. Based on exergy analysis, it is shown that the solar desalination system with air-water preheater with the power of 1057.9 W had the most exergy destruction in comparison with the two other systems (i.e., water preheater system and air preheater system with the respective exergy destructions of 901.3 W and 75.3 W). Comparing the values of freshwater production, exergy destruction, and exergy efficiency, the solar system with a water preheater was selected as the optimum one.

The delayed Coker process as an upgrading process has the main impact on the productivity of the Refinery Complexes. To determine the impact of different operating conditions on the product yield distribution of the delayed coking process, several experiments were designed and conducted in a prefabricated pilot plant. The experiments were conducted on different Iranian vacuum residues at temperatures ranging from 420°C to 480°C and at atmospheric pressure. Reaction times were within the range of 5-120 minutes. A four lumps kinetic model has been developed based on the experimental results. The lumps—which included Volatile products, coke, feed, and an intermediate phase between coke and feed—were defined to precisely monitor the yield distribution of products throughout the reaction time. The feedstocks utilized were three different vacuum residues and their blends. The mixtures were produced by using different mixing ratios of the three vacuum residues. The Statistical analysis shows that this model has R-squared, RMSE, SSE, and MRE equal to 0.99, 0.022, 0.08, and 3.537%, respectively. This shows that the developed model is sufficiently accurate. The experimental and modeling results in this research reveal that by increasing the temperature, the yield of coke and gas is abated. However, the yield of the distillate is escalated. This investigation illustrates that the production of an intermediate reaction has the highest amount of activation energy in comparison with the other reactions. Also, the results indicate that the production reaction rate of coke has the highest amount compared to other reactions.

A mathematical model was proposed to appropriately describe the fate of multicomponent substrates in porous media, especially soil. The model utilized appropriate biodegradation kinetic expressions that better describe the consumption or degradation rate of the substrate. The Equation, with the second and third type boundary conditions in non-dimensionalized form, was solved using the Finite Volume method and simulated in the Matlab environment. An experiment, using a 5 cm (inside diameter) x 60 cm (height) glass column packed with severally autoclaved soil spiked with 2 % substrate (a mixture of hexadecane, heneicosane, 1-methylnaphthalene, 2- methylnaphthalene, and 1, 3-dimethylnapthalene) and a consortium of organisms (Providential rettgeri, Streptococcus salivarius, Trichoderma harzianum, Aspergillus flavipes, and Candida famata) was set up to validate the model. The result showed that the model describes the fate of each component within the multicomponent substrate. It also indicates that both Peclet and Thiele numbers affect the biodegradation of the substrate. It was observed that a small Peclet number should be allowed for effective biodegradation of the substrate. The model was validated with data obtained for an experiment where a mixture of hydrocarbons was degraded with a mixed culture of microorganisms. The results of the experiment were well described by the model indicating that the model can be used to predict the compositions of components of a mixture during biodegradation.