نشریه شیمی و مهندسی شیمی ایران
سال چهل و دوم شماره 4 (پیاپی 110، زمستان 1402)

Curcumin is a yellow polyphenol extracted primarily from the plant Curcuma longa, but also from several other members of the ginger family.Many nanoscale systems have been extensively used for drug loading and release to get around curcumin's low bioavailability and aqueous solubility, highlight its functional properties, and broaden its applications in the pharmaceutical industry.Chitosan has been used as a natural biopolymer extensively for many years. Its polycationic properties, biocompatibility, biodegradability, non-toxicity, and lack of allergenicity all led to studies on it. The main focus in the discovery of curcumin involves its anti-cancer properties. It is well known that curcumin inhibits the signal transmission of cancer cell growth and thus angiogenesis and also causes tumor cell apoptosis. The modification of chitosan for various applications can be easily achieved due to the abundant active groups (NH2 and OH) in the main chainFor the release of curcumin, numerous chitosan-based nanocarriers with distinct properties have been developed, including nanocomposites, nanoemulsions, nanotubes, and nanofibers. The controlled release of the drug is to maintain the optimal therapeutic concentration of the drug in the blood, which increases the shelf life and duration of activity of drugs with a short half-life. Controlled drug release makes the drug release rate predictable and repeatable for prolonged release drugs. Therefore, the development of colloidal systems for curcumin release encapsulation is a promising strategy to overcome the limitations of drug release. The physical and chemical characteristics of chitosan-based nanocarriers, including surface charge, morphology, encapsulation driving force, and release characteristics, are examined in this study and the effectiveness of chitosan-based nanocarriers for pharmaceutical applications is determined by these characteristics.

In this work, gelatin-polyvinylalcohol hydrogel was prepared using K2S2O8 in aqueous media in the presence of N,N′-methylenebisacrylamide. The gelatin-polyvinylalcohol hydrogel was characterized by FT-IR, SEM and swelling studies. Then, loading and release of fluvoxamine maleate drug was investigated using gelatin-polyvinylalcohol hydrogel. The effects of temperature and pH on the loading and release of fluvoxamine maleate drug in gelatin-polyvinylalcohol hydrogel were studied. FT-IR results confirmed the formation of gelatin and polyvinyl alcohol hydrogel. The results showed that the maximum drug release was obtained at pH = 2 at room temperature after 6 hours with a value of 43.98 ppm. Gelatin-polyvinyl alcohol hydrogel shows about 11 times water absorption at room temperature. The gelatin-polyvinyl alcohol hydrogel is sensitive to pH and temperature and provides controlled release of fluvoxamine maleate in the gastric environment.

The self-healing property refers to the ability of a substance to repair damage and restore its original function either intrinsically or non-intrinsically. In this study, the natural hydrophilic substance of the salep was used as a raw material for the preparation of hydrogels, and the free radical polymerization method was used to improve their properties and modify them. Then Fe3O4 magnetic nanoparticles were synthesized and included in the matrix of nanocomposite hydrogels that had self-healing properties. The structure of the synthesized hydrogels was determined by FT-IR, and FE-SEM analysis, and their thermal stability was determined by TGA analysis. The swelling percentage of hydrogel nanocomposites was measured in different conditions. Self-healing properties of hydrogels were also investigated. Modifying the salep hydrogel using polyacrylamide and adding Fe3O4 nanoparticles to its structure increased structural strength, improved swelling, and self-healing properties; So that the salep nanocomposite hydrogel modified with polyacrylamide and containing 7% by weight of Fe3O4 nanoparticles, has the highest percentage of swelling (2335%), high thermal stability (about 550 °C), fast self-healing property (after 30-35 minutes at room temperature), the gel content value is equal to 81%.

Multilayer nanometer substrates based on graphite have emerged as a new field in the design and manufacture of biocatalysts. Layered and self-assembled Nano surfaces can provide a significant accessible surface for the immobilization of drugs, biological systems, and active enzymes and also can be used for the detection of biomarkers. In this study, a new bioelectrode was fabricated by self-assembling a porous graphene pattern with a G-rich polymer (GRP). The highly hydrophobic porous graphene was functionalized with a guanine (G) rich polymer to incorporate glucose oxidase (GOx). Graphene sheet dispersed in water with guanine (G) rich polymer. The electrochemical response of the bioelectrode to glucose was studied as a model for bioelectrocatalysis. The bioelectrode displayed a linear response to glucose concentration ranging from 0.2 to 2 mM, with a detection limit of 0.086 µM and 0.092 µA/µM/cm2 sensitivity. This study illustrates the potential of porous graphene for the construction of bioelectronics interfaces for the fabrication of electrochemical bio-devices.

A microbial fuel cell (MFC) is a device that converts chemical energy into electrical energy through the catalytic processes of microorganisms. In this study, a graphite-based flexible film was obtained by adding of zinc powder to a mixture of multi walled carbon nanotubes-graphite powder-polyvinyl chloride (PVC) and then selectively replacing of palladium (Pd) with Zn in a solution containing PdCl2. Surface morphology studies showed that the flexible film has a porous structure, where palladium and carbon nanotubes as uniform conduction channels are present in composite of the film. Electrochemical studies also showed that porous Pd/MWCNTs-Graphite-PVC film as a cathode in MFC at 22-ohm resistance has a current density and power density of 568 mA/m2 and 18500 µW/m2, respectively (compared to 191 mA/m2 and 810 µW/m2 for Pt foil), showing excellent electrochemical activity of the modified film for O2 reduction. Improved electrocatalytic behavior of the modified film can be attributed to porous structure of film and synergistic effect between CNTs and palladium. The method presented in this research can be employed as a favorite method for preparing of suitable electrocatalysts based on commercial graphite powder in the microbial fuel cells.

In this study, silver nanoparticles (Ag-NPs) as catalysts in the photocatalytic degradation reaction of Sunset Yellow FCF (SYF) azo dye in aqueous solution were investigated. Ag-NPs were prepared by using walnut (Juglans regia L.) leaf extract. The synthesis of Ag-NPs has been done using green chemistry, which is an environmentally friendly, low-cost, fast, and safe method. Extraction was done with a facile method, as well as the synthesis of Ag-NPs in a short period and with high efficiency. The Ag-NPs were characterized by Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDS), X-Ray Diffraction (XRD), and Fourier Transform InfraRed (FT-IR) spectroscopy. Optimum conditions for dye degradation were determined using Taguchi experimental design method with (L9(34)) orthogonal array. Analysis of the response of each experiment was based Signal to Noise (S/NL) ratio calculated. The effects of operational parameters such as catalyst amount, pH, irradiation time, and temperature in three levels for each factor were studied. The Taguchi results showed that catalyst amount= 20 mg/l (level 2), pH= 4 (level 1), irradiation time = 45 min. (level 3) and temperature= 30 °C (level 3) was the optimum conditions for this process. The most influence of each factor on the process was determined using the Analysis of Variance (ANOVA) method. The most significant factor in this process was pH. The interaction between pH×catalyst amount was the most influencing interaction. The analysis of primary ANOVA showed that percent (p(%)) parameters were: catalyst amount (12.002%), pH (46.298%), irradiation time (35.311%), and temperature (6.383%). The contribution of factors in this process was found to be in the following order: catalyst amount (0.142), pH (0.431), irradiation time (0.397), and temperature (0.18). A pseudo-first-order kinetic reaction with rate constant k=0.0721 min−1 was observed for dye photocatalytic degradation.

Three complexes: bis(2,2′-bipyridine)-, bis(1,10-phenanthroline)- and (2,2′-bipyridine)(1,10-phenanthroline)-chlorocopper(II) chloride with molecular formula of [Cu(bpy)2Cl]Cl, [Cu(phen)2Cl]Cl and [Cu(bpy)(phen)Cl]Cl, having trigonal-bipyramidal geometry were prepared according to the reported procedure via the reaction of CuCl2 with bpy and phen ligands. The interaction of these complexes with bovine serum albumin (BSA) was studied by electronic absorption spectroscopy at two temperatures of 296 and 310 K in Tris buffer medium (pH = 7) containing sodium chloride (10 mM). These interactions include the determination of the binding constant of each metal complex to serum albumin (K), the midpoint concentration of each metal complex that can denature half of the BSA molecules present in the medium (L1/2), and the thermodynamic studies. The binding constant values obtained in the range of 2.08 ‒ 65.7 × 104 M‒1 indicate the proper interaction of each complex with BSA. In the titration of BSA with each of the complexes, it was found that the conformation of this protein changed upon the addition of these compounds. It is because the absorbance of BSA at 280 nm showed a significant decrease with increasing the concentration of each compound. While studying thermodynamic parameters: the negative values of Gibbs free energy changes in the interaction of all three complexes with BSA, confirmed the spontaneous nature of the reaction between them. The positive values of standard enthalpy changes for the [Cu(bpy)2Cl]Cl and [Cu(bpy)(phen)Cl]Cl and the negative value for the [Cu(phen)2Cl]Cl indicate that these processes are endothermic and exothermic, respectively. In addition, the positive values of the standard entropy changes for the [Cu(bpy)2Cl]Cl and [Cu(bpy)(phen)Cl]Cl indicate the irregularity of the system (entropy driven) and its negativity for the [Cu(phen)2Cl]Cl indicates ordering. The positive values of ΔH° and ΔS° for the [Cu(bpy)2Cl]Cl and [Cu(bpy)(phen)Cl]Cl and the negative values for [Cu(phen)2Cl]Cl complexes indicate hydrophobic and H-binding + van der Waals interactions, respectively.

In this research, NiTiO3 electrocatalyst was prepared by sol-gel method and coated on graphite surface by electrophoretic method. Several analyzes were performed in order to investigate the microscopic morphology and structural characteristics of NiTiO3. The NiTiO3 particles were obtained in spherical form and in nano size. In addition, the cyclic voltammetry results demonstrated that the NiTiO3/G electrode exhibited superior electrocatalytic activity when compared to the G electrode. The oxidation potential of the NiTiO3/G electrode, 0.3 mV, indicated improved involvement in the anodic oxidation reaction. Conversely, the impedance results revealed a decreased charge transfer resistance for the NiTiO3/G electrode in comparison to the G electrode, thereby accelerating the degradation process. The prepared electrocatalyst was used to remove reactive black 5 (RB5) pollutant from aqueous solution by anodic oxidation process. For this purpose, the reaction reactor with NiTiO3/G anode electrode and graphite cathode electrode was used. The effect of current, initial pH, initial concentration of RB5 and process time on the removal efficiency of RB5 was investigated and the response surface method was used to optimize the anodic oxidation process. The results showed that the maximum removal efficiency of RB5 was observed in applied current, pH, initial concentration of RB5 and process time of, 500 mA, 6, 20 mg/L and 200 minutes, respectively. Based on this, such a method can be used to remove RB5 from polluted water.

A new optical mixed-ligand complex of cadmium(II), [(C15H9O2)(OMe)2(Me2Sn)4O2] (1), was prepared from the reaction of cadmium nitrate with anthracene-9-carboxylic acid and bipyridine ligands by the branched tube method and the prepared compound was fully characterized  by IR, UV spectroscopies and elemental analysis. The solid state structure of 1 was also investigated via single crystal XRD. The results showed that compound 1 is a mononuclear complex crystallized in triclinic system with space group of. The asymmetric unit of 1 is comprised of one cadmium ion, one anthracene-9-carboxylate anion, two bipyridine ligands and one nitrate anion. The thermal stability of the prepared complex was investigated by thermal gravimetric method (TGA). The prepared complex was used as light emission layers in two different concentrations in the fabrication of organic light-emitting diodes. Examining the results showed that the concentration of the complex has a significant effect on the electrical properties of the prepared diodes.

In this research, two tridentate Schiff base ligands 3-((2‐hydroxy‐3 methoxybenzylidene) amino)-2-methylquinazolin-4(3H)-one [HL1] and 3-((5-bromo-2-hydroxy-3-methoxybenzylidene)amino)-2-methylquinazolin-4(3H)-one [HL2] and their mixed-ligand complexes [Cu(L1)(bipy)] and [Cu(L2)(bipy)]; (bipy=2,2 bipyridine) were synthesized and fully characterized using spectroscopic techniques such as FT-IR, UV-Vis, and mass spectroscopy techniques. The element analysis, molar conductivity and melting points of these compounds were also determined. Antibacterial activities of the ligands and Cu(II) complexes were evaluated against Staphylococcus aureus, Bacillus cereus, Escherichia coli and Pseudomonas aeruginosa. According to the results, complexes showed significantly higher antibacterial activities compared to their related ligands

A fast, simple, inexpensive, sensitive, efficient, and environment-friendly magnetic solid phase extraction (MSPE) procedure has been developed to concentrate two polycyclic aromatic hydrocarbons (Acenaphthene and Pyrene) from water samples prior to quantification by UV-vis spectrophotometric. CoFe2O4 nanoparticles modified by aspartic acid have been synthesized by co-precipitation processes.  This adsorbent was analyzed by FT-IR spectroscopy, SEM, and XRD methods. A D-optimal design was used for optimizing the factors and evaluating their influence upon extraction. The optimum experimental conditions were: pH= 3; sorbent dosage= 15 mg; Acenaphthene concentration = 150(µg/L); Pyrene concentration =400(µg/L). Under the experimental conditions, the method presents a good level of relative standard deviation for Acenaphthene and Pyrene, 2.9% and 3.1 % (n = 9; spiking level 5 mg/L) respectively. The detection limit for the Acenaphthene and Pyrene with 9 times measuring was 34 and 25 (µg/L) and the quantities limit was 84 and 114 (µg/L), respectively. Finally, the proposed method was applied to the analysis of four types of water samples, tap water, well water, river water, and effluent wastewater. The samples were previously analyzed and confirmed free of target analytes. At 50 (µg/L) spiking level recovery, values ranged between 80 and 90% for effluent wastewater samples showing that the matrix had a negligible effect upon extraction.

In this Paper, structural , electronic and optical properties in orthorhombic phase o HgO were  studied by using Peduopotential method in the framework density functional theory (DFT) with the different approximations such as LDA and GGA. The electronic calculations showed that the results of the electron state densities and the band structure are in agreement with each other. The different approximations in electronic calculations also predicted the existence of a band gap of about 0.691 to 1.052 volts. Also, optical calculations showed that the static refractive index of mercury oxide is maximized for polarization in the y direction. The optical  gap calculated in the z direction agrees more with the band gap obtained from the band structure calculations. It was also observed that the optical gap of this compound is minimal for its polarization in the y direction.

The pulp and paper industry has historically been one of the world‘s largest consumers of freshwater resources and producers of wastewater, which, can cause serious damage to the water and soil ecosystem if directly discharged into the environment. On the other hand, the use of traditional treatment techniques including biological treatment and coagulation is restricted by the presence of non-biodegradable organic compounds with high molecular masses. The photo-Fenton process is an environmentally friendly, simple, and fast method with low operational cost which could oxidize polluting substances by producing powerful hydroxyl radicals. The most important variables in the effectiveness of this process are the concentration of the oxidant agent, the concentration of Ferro ions, and pH. With three variables; the dimensionless concentration of hydrogen peroxide, the concentration of Ferro ions, and the pH, the experiment's design was carried out by the central composite method based on the response surface method in 18 experiments. pH was adjusted, Ferro ion and hydrogen peroxide were added, and the solution was then immediately exposed to UV light in order to apply the Photo Fenton treatment procedure to the sample. COD was defined as an indicator of wastewater pollution, and sodium sulfite was used to eliminate the effect of hydrogen peroxide on COD test. Effective factors were also optimized for the best performance at the most economical cost. The maximum value of COD removal = 71.51% was obtained experimentally. In the economic optimal state with the initial concentration of dimensionless oxidant dose = 0.369, ferro ion concentration = 98.99 mg/L, and pH = 3.28, 65.21% of COD removal was achieved and 1.37 riyals for removal of 1 COD unit were obtained.

Today, the progress of industries, health, energy and food security, which are the main components of the sustainable development of societies depend on water more than anything else. Moreover, water shortage is a serious problem for human survival and the natural ecosystem. The average amount of raw water consumption in Shahid Montazer Ghaem steam power plant is 25,000 m3/day, which is significant considering the production capacity and the existence of a cooling tower in this power plant. Therefore, it is important to provide effective solutions that is able to be implemented in order to modify the consumption pattern and prevent water wastage in this power plant. Effective proposed solutions according to the in-person visit, receipt of documents and consultation with specialists, experts and operators in this power plant in order to modify the consumption pattern is including the recycling of clean drain (boilers blowdown, backwash of filters, samplers) in the final stage of washing resin filters, purification and recirculation of cooling tower sludge, increasing the degree of concentration and optimization of cooling towers (replacing drippers, changing nozzles, changing the angle of lavers, etc.), the use of ozone in order to purify the water of the cooling tower, water storage during equipment repair, especially in the cooling towers, installation of the RO system in the inlet of the cooling tower's compensating water.  Finally, considering the technical-economic conditions and volume and quality of water, a high priority solution was proposed in this power plant in order to modify the consumption pattern and prevent water wastage.

The use of copper metal and its alloys is increasing day by day due to the unique properties of this metal in the electronics, steel alloys and other applications. One of these methods is the use of microfluidic systems. The use of microfluidic systems in continuous separation processes has received much attention in the last two decades. In this study, first the microfluidic system made of glass was made by laser cutting method and then the solvent extraction of copper metal ion was performed by using the microfluidic technique and using PHOSPHORIC ACID 2-ETHYLHEXYL ESTER (MDEHPA) cation extractor in the Y-Y microchannel and the parameters that affecting it have also been investigated, the experiment was designed by using the response level method and the effect of single and simultaneous operational parameters including volume concentration of the extractor, pH of the aqueous phase and residence ion extraction was investigated. In this regard, the amount of extractor concentration 11% (vol/vol), pH equal to 5 and residence time equal to 20 seconds were obtained as optimal operating conditions. In optimal operating conditions, the amount of copper extraction from the aqueous phase was 88.45%. Also the ratio of two-phase aqueous and organic discharges was changed, which according to the results obtained in the Qorg⁄Qaq ratio equal to 2⁄1 the copper ion extraction efficiency increased from 88.45% to 90.54%. The total volumetric mass transfer coefficients (KLa) were also calculated under different conditions to evaluate the mass transfer performance in the microfluidic system. The results showed that KLa values decreased nonlinearly with increasing residence time. The highest KLa values were observed between (0.13-0.78 1⁄s) during the residence time equal 20 second, which is much higher than the KLa values in batch extraction, which indicates better mass transfer performance of the microfluidic system.

Droplet formation process is one of the most important steps in many microfluidic proceses with biological and chemical applications. Factors affecting the droplet formation process include the geometry of the device, fluid properties, operating parameters and external forces. Since the construction of many samples to optimize the microchannel geometry is required to incur heavy costs, in this study, with the help of computational fluid dynamics technique, the droplet formation process is studied. The purpose of this study is to numerically simulate flow-focusing microchannels to study microchannel dimensions and produce small droplets under the influence of an external electrical field. The innovative aspect of the present work is the study of parameters that have not been considered in open literachar. Numerical simulation of this chip was performed in two-dimensional space. According to the flow physics, the phases of the current are assumed to be incompressible. Two geometric parameters of flow concentrating region length and orifice length were investigated. The results of this study showed that for a length of 100 μm for the flow focusing region at high voltages, the droplet diameter can be reduced to less than 55 μm. The time difference between the formation of two consecutive drops for a length of 200 μm in this region at 300V increases to 0.178 seconds. It was shown that although the length of the orifice has no considerable effect on the droplet diameter, but at the length of 90 μm, droplets are formed after the orifice. It was also shown that when the distance between the electrodes is short, smaller droplets are formed due to the increase in electrical force applied to the common boundary of the two fluids. In fact, smaller droplets can be formed by selecting the appropriate configuration for the electrodes at lower voltages.

Today, it is known that the emission of carbon dioxide as a greenhouse gas is one of the most important causes of global warming. Fossil power plants are known as one of the major producers of carbon dioxide. Due to this, the separation of carbon dioxide from the gases that are released into the atmosphere by the chimney of fossil power plants seems to be necessary as an effective method to control the emission of this gas. In the current project, the separation of carbon dioxide from flue gas using natural chitosan membrane is presented. At first, the mathematical model was used to separate carbon dioxide using the module of hollow fibers; In such a way that the flow of gas inside the shell and inert gas (Argon) in the tube are in an unequal way to minimize the partial pressure of carbon dioxide. The above process as well as the effect of changes in different operating conditions on the process were simulated based on computational fluid dynamics with Comsol 6.0 software. The simulation results show that the carbon dioxide/nitrogen selectivity is 15-5 and the permeability is 1-26 Barrer. Increasing the temperature and pressure of the inlet gas has a positive effect on the separation efficiency; while the input percentage of carbon dioxide has no significant effect and its effect can be ignored.

In this study, a three-dimensional simulation model has been carried out to investigate the flow pattern and the effect of picket fences on the performance of the settler in the solvent extraction plant in the Miduk copper complex. The effect of picket fences on the settler and their arrangements, flow distribution blades, separation of phases and the droplet size distribution has been investigated with CFD simulations.  The simulation has been carried out with an Eulerian-Eulerian method in conjunction with the incorporated MUSIG model which is based on a population balance equation and takes into account the break up and coalescence models of droplets.  The simulation of settler shows that feed spouting velocity was propagated for long distances in the settler and dispersion band continues to the end of the settler. By setting one picket fence in the settler, velocity vectors transmitted and the width of dispersion band decreased which as a result increasing droplet size. By increasing number of picket fences dispersion band almost disappears. The inspection of distribution of droplet size at different points in the settler showed that the presence of picket fences increases the size of droplets. Finally, the effect of closed to opened (C/O) area ratio of the picket fences on the performance of the settler was studied. The results showed that by increasing the C/O ratio, some circulation appears in the flow which causes a negative effect on phase separation.

Generally, gas is known as the main source of energy. In the industry, a lot of energy is used to increase the power of the heaters in the pressure reduction stations. Therefore, in this study, in order to increase the speed of the heat transfer rate in the heaters of the pressure reduction station, parts with special angles (classic twisted tape) have been embedded in the coils. The above study was carried out on the heater of CGS & TBS pressure reduction station of Maviyan (Kamiaran city, Kurdistan province) with a capacity of 2500 2500 m3/h. In this regard, different temperature conditions of the water heater have been carefully investigated. On the other hand, three classic twisted tape with three different steps had been designed. In all models, the length of the classic twisted tape is 200 cm, and the height is 3.8 cm. The length of each step in the first model is 8 cm, the second model is 6 cm, and in the third model is 4 cm. The results shows that the maximum percentage of heat transfer improvement using the classic twisted tape with the third structure in a water temperature of 35º Celsius is 16%. On the other hand, the minimum percentage of heat transfer improvement in the classic twisted tape with the first structure at 60° Celsius is about 3.82%. These results can be effective and practical for increasing heat transfer efficiency and reducing conversion costs.

Cold plasma is one of the food preservation methods in the food industry, which increases the shelf life of food products, the purpose of this research is to investigate the increase in shelf life of oyster mushrooms under cold plasma treatment under the treatment of two gases (argon and air) for the duration of (0, 5, 10, 20) minutes at the pressure of 1 torr and the power of 100 watts, the surface of oyster mushroom was exposed to cold plasma radiation, which led to a decrease in the total count, coliform, mold and yeast and Pseudomonas syringic PV. The results of microbial and physical analyses showed that in five minutes under cold plasma treatment, excited gases of argon and air reduced the microbial load by 99% and caused the least effect on the physical and appearance properties of oyster mushroom products. In the examination of the physical properties of oyster mushrooms (texture and weight), it was shown that the effect of gas type had a significant effect on these indicators. And about ten percent performance improvement. Increasing plasma treatment time to twenty minutes led to a significant difference (p<0.05). Examining the type of gas and its effect on the treatment showed that the type of gas makes a significant difference and the effectiveness of air gas is slightly higher than argon in the overall count (p<0.05). Cold will be a suitable and low-cost method for sterilizing and pasteurizing mushrooms to increase their shelf life.

In this study, a systematic approach is introduced for process hazard Identification and dynamic risk assessment focusing on the process equipment failure as well as control and instrument facilities in a typical gas compressor station. The survey was initially performed via HAZOP analysis for the main process facilities of the case study. Then, the Bow-Tie analysis was proposed as a combination of fault tree and event tree. Because of the static nature of these conventional risk assessment methods and the limitations such as uncertainty in modeling casual relationships between components, this study proposes a dynamic approach using Bayesian networks for safety risk assessment of gas compressor stations. Critical points in the unit were identified after updating the probability of the main event occurrence using sensitivity analysis. The HAZOP results showed that the compressor node had a high potential for loss of containment or compressor failure. The evaluation of human error is also performed using specific data. The results of the quantitative risk assessment show that the probability of compressor damage due to surge conditions is equal to 2.163 × 10-3. It is also found that the probability of jet fire and flash fire is equal to 1.51E-6 and 9.58E-6. The bow tie was mapped to the Bayesian network for dynamic risk assessment. After setting the new evidence, the probabilities of intermediate events and basic events were updated. Sensitivity analysis using the ROV criterion showed that compressor protection system failure, anti-surge control valve failure, and the events associated with the compressor strainer were the main contributors. Finally, suggestions were made to improve the unit's safety and reduce its risk.