Semnan University Progress in Engineering Thermodynamics and Kinetics 1 2 2024 04 01 A packed distillation column performance simulation by modified equilibrium stage model based on multicomponent packing efficiencies 8650 10.22075/jpetk.2024.26680.1009 EN Hadi Poortalari Department of Chemical Engineering, School of Engineering, Damghan University, Damghan, Iran Farshad Varaminian Faculty of Chemical, Petroleum and Gas Engineering, Semnan University, Semnan, Iran Javad Karimi Sabet Material and Nuclear Fuel Research School (MNFRS), Nuclear Science and Technology Research Institute, Tehran Journal Article 2022 03 22 In this work, a modified equilibrium approach based on calculation of multicomponent efficiencies is implemented for packed columns simulation. In this modified approach, distillation process non-idealities due to interphase mass transfer are considered while the algorithm remains simple and efficient. The whole method consists of a segment wise procedure which is performed iteratively in a computational MATLAB code to simulate an experimental packed distillation column with structured packings. In each iteration, the component efficiencies are determined to consider mass transfer effects through the packed segments. According to obtained profiles for temperature and component compositions, good agreement is observed between reported experimental data and simulation results, so that the average deviations are about 0.5% and 19% for temperature and compositions, respectively. This confirms that the presented modified equilibrium model can properly predict the performance of multicomponent distillation in the packed columns and therefore it can be employed as a valid and reliable tool for design and simulation of real distillation towers.

http://jpetk.semnan.ac.ir/article_8650_3e5f592f8595b22cbffb9ef9f83f6290.pdf

Semnan University Progress in Engineering Thermodynamics and Kinetics 1 2 2024 05 01 Nitrate adsorption from synthetic aqueous solutions by Ca(OH)2 and clinoptilolite zeolite nano-particles 8710 10.22075/jpetk.2024.25827.1006 EN Faezeh Ghodrati MIHAN Industrial Group, Tehran, Iran. Azadeh Hemmati Semnan University, Semnan University Morteza Faghihi Chemistry & Process Engineering Department, Niroo Research Institute, Tehran, Iran Ziba Ashrafi Mohaghegh Ardebili University, Ardebil, Iran Journal Article 2022 01 07 In this research article, the authors utilized a ball mill to grind Clinoptilolite zeolite 98% and Ca(OH)2 nanoparticles, and subsequently characterized the resulting adsorbents using SEM, TEM, XRD, and FTIR analyses. To optimize the adsorption process, they employed the Box-Behnken Design (BBD) of Response Surface Methodology (RSM) to evaluate the impact of various parameters, including pH (ranging from 5 to 9), adsorbent amount (ranging from 0.5 to 2 g), and temperature (ranging from 25 to 45 °C). The authors determined that the optimal temperature for nitrate adsorption was 45°C at a pH of 5, using 2g of adsorbent. Applying the pseudo-second-order dynamic model for investigation, the optimal retention time was determined to be 15 min. The maximum amounts of nitrate removed by Ca(OH)2 and zeolite were found to be 60.34% and 58.04%, respectively, with the the absorption equilibrium equation fitting well to the Langmuir model. Under optimal conditions, a mixture of Ca(OH)2 and zeolite (at a ratio of 1:3) removed a maximum of 56.70% of nitrates. These findings demonstrate the significant potential of natural zeolite and Ca(OH)2 for nitrate adsorption.

http://jpetk.semnan.ac.ir/article_8710_804fdb62041c2b0c1b0c9b0781c79f1f.pdf

Semnan University Progress in Engineering Thermodynamics and Kinetics 1 2 2024 05 01 Spectrophotometric and kinetic studies on electro-chemical decolorization of dyes in mixtures: combination of classical least squares and hard modelling approaches 9176 10.22075/jpetk.2024.30499.1014 EN Seyedeh Maryam Sajjadi a)Faculty of Chemistry, Semnan University, Semnan, Iran. b)Lamerd Higher Education Centre, Lamerd, Fars Province, Iran. Journal Article 2023 04 29 In this study, kinetic electro-oxidations of four dyes were simultaneously evaluated on Ti/ ZnO-multi-walled carbon nanotubes anode. The mixture of dyes includes acid red 33 (AR33), reactive orange 7 (RO7), acid yellow 3 (AY3) and malachite green. The kinetic processes were monitored spectrophotometrically. A time-spectral data was analyzed in the time range 0 to 80 min and wavelength range of 220-700 nm which suffer signal overlapping of components problem. To obtain the kinetic degradation profiles of the components, the whole data was resolved by classical least squares method as a reliable method for analysis of the data in which there are no selective responses for the analytes. Then, the kinetic rate constant of each dye decolorization together with its uncertainties were estimated by applying hard modelling approach. The obtained rate constants were 0.0675 s-1, 0.0262 s-1, 0.0168 s-1 and 0.0158 s-1 for MG, AR33, AY3 and RO, respectively, revealing that MG is the most degradable dye.

http://jpetk.semnan.ac.ir/article_9176_7e38b43bc873341773c39981b103217a.pdf

Semnan University Progress in Engineering Thermodynamics and Kinetics 1 2 2024 05 01 Roles of acidic deep eutectic solvents in synthesis of silica nanoparticle 9572 10.22075/jpetk.2025.27667.1010 EN Maryam Daraee Nano compound Semnan Dara Company. Mohammad Daraee Semnan University Ata Feyzizadeh Iran University of Science & Technology Journal Article 2022 06 30 This article examined the preparation and production of silica nanoparticles using the sol-gel method with two types of deep eutectic solvents (DESs). The DESs were synthesized from choline chloride, urea, and citric acid. To determine the physicochemical properties of the nano-silica, X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Brunauer–Emmett–Teller analysis were employed. Analysis revealed that the SI structure (choline chloride (ChCl)-citric acid) exhibited a higher surface area and pore volume compared to the SII structure (choline chloride (ChCl)-urea), while also demonstrating a smaller particle size. This difference can be attributed to the role of acidic eutectic solvents in metal oxide nanoparticle production. These results suggest that the SI structure demonstrates promising potential for adsorption and catalytic applications.

http://jpetk.semnan.ac.ir/article_9572_d9d35b20c5ba8ed78f81918df3e38f52.pdf

Semnan University Progress in Engineering Thermodynamics and Kinetics 1 2 2024 05 01 Optimization of saffron drying parameters to achieve a higher drying rate and improved product quality 9587 10.22075/jpetk.2025.36068.1019 EN Marzieh Khodadadi School of Mathematics and Computer Science, Damghan University, Damghan, Iran Hanif Heidari School of Mathematics and Computer Science, Damghan University, Damghan, Iran Hadi Baseri School of Chemistry, Damghan University, Damghan. Iran Journal Article 2024 11 27 The optimization of the saffron drying process parameters significantly affects the quality of the final product. In this article, the saffron essential oil is extracted and characterized, and fresh and dried saffron quality is compared. The impact of parameters such as drying temperature, light source during the drying process, and the use of vacuum in the drying process on the rate of drying and color intensity of dried saffron is investigated. The results obtained from GC-MS, FT-IR, and UV-Vis tests indicate that over 60% of the concentration of the essential oil derived from saffron consists of 14 main compounds, among which safranal and picrocrocin are the most significant. Throughout the drying process, the quality of the dried saffron does not change significantly, and a drying temperature of 120°C and the absence of direct light improve the quality of the dried saffron. Additionally, a temperature of 70°C is the optimal temperature for drying saffron under 0.3 atmospheric vacuum conditions.

http://jpetk.semnan.ac.ir/article_9587_0999f6e22cd4560c1c565c300c1ad462.pdf

Semnan University Progress in Engineering Thermodynamics and Kinetics 1 2 2024 05 01 Investigation of γ' precipitates growth kinetics in CMSX-4 based on the Johnson-Mehl-Avrami model 10059 10.22075/jpetk.2025.36480.1023 EN Sana Rabbani Fard Malek Ashtar university of Tevhnology Masumeh Seifollahi malek ashtar university of technology Seyed Mahdi Abbasi Malek Ashtar university of Technology Adly AKhondzadeh Malek Ashtar university of technology Journal Article 2025 01 07 CMSX-4 is a second-generation single-crystal nickel-based superalloy. Through aging heat treatments, the characteristics of γ’ precipitates, including their size, volume fraction, and morphology, can be controlled in this alloy. Therefore, the main goal of this research is to investigate the effect of aging temperatures (800-1140 ℃) and times (1-24 h) on the kinetics of γ’ precipitate formation and growth. As the aging temperature increases, the morphology changes from an irregular shape to a cubic one. The most regular cubic morphology is observed at 900 ℃. Due to the competition between diffusion and matrix supersaturation, the volume fraction of precipitates initially increases and then decreases with increasing temperature and time. Kinetic studies of γ’ precipitate growth and formation using the Johnson –Mehl -Avrami method show that, the rate of transformation and growth of γ’ precipitates increases with increasing aging temperature. The average value for the Avrami exponent (n) is approximately 4 in the range of 835-900 ℃, which indicates regular and cubic growth of γ’ precipitates within this temperature range. Based on this model, a TTP diagram was plotted for CMSX-4. The nose of TTP curve, indicating the optimal conditions for γ’ phase formation, which is obtained at approximately 850 °C.

http://jpetk.semnan.ac.ir/article_10059_551b01566d4ea463b27b9013d8ce0462.pdf