CHEMICAL PROCESS DESIGN
Year:2026 | Volume:5 | Issue:1|Papers Count:12

Optimizing energy consumption and gasoline quality in isomerization units has become very important, indicating the need to employ suitable process design methods and energy studies. Aspen HYSYS, Aspen Energy Analyzer, and Aspen Pinch software were utilized for simulation. Optimum heat integration opportunities were identified using composite curves and driving force plots. This study showed significant variations in the minimum approach temperature (ΔTmin.) among the units. Unit 1 showed the lowest ΔTmin. at 8°C, followed by units 2 and 3 at 9 and 10°C, respectively. Consequently, unit 1, with 35.65 MW of hot and 41.24 MW of cold utilities consumption at ΔTmin.= 8°C, demonstrated the highest potential for heat recovery when increasing ΔTmin. from 8 to 10°C. The first heat recovery scenario aimed to examine the Research Octane Number (RON) of the output stream from the Deisopentanizer (DIP) column, and the amount of isopentane recovery to improve the existing processes. Unit 2 has an octane number and isopentane recovery of 85 and 75.24%, respectively, which is the lowest amount among the three units. Economic analysis using Aspen Process Economic Analyzer revealed that unit 1 had the highest fixed (7.6×10+6 USD), operating (7.48×10+6 USD/year), and total costs (13.75×10+6 USD/year). The second scenario showed that 17% and 20% of the total required low pressure steam in Unit 1 and Unit 2 can be provided due to steam generation using process energy pockets, respectively. Results showed that the process design and operating conditions directly influence energy and RON.

This study innovatively investigates the effect of silica nanoparticles on crude oil pipeline flow drag reduction using computational fluid dynamics (CFD). Turbulent flow conditions were assumed for all simulations according to Reynolds number values. The results of the numerical simulations were validated against the experimental measurements, showing a maximum deviation of less than 8.6% in percentage drag reduction (DR%). The effect of some parameters such as fluid viscosity, flow velocity and pipe diameter (defined collectively by the Reynolds number) and pipe materials with various Nano-silica concentrations (0.25–1 wt.%), on drag reduction in the single-phase flow regime was investigated. Among the conditions investigated, optimal agreement with experimental results and highest drag reduction was recorded at 0.75 wt.% Nano-silica concentration at a Reynolds number of 13,931. Drag reduction has been found to increase with increasing concentrations of nanoparticles for fixed Reynolds numbers. For a fixed nanoparticle concentration, higher Reynolds number is also found to yield better drag reduction. These results confirm the effectiveness of the crude oil optimized using the nanoparticles in reducing the flow resistance under turbulent flow.

Green hydrogen is becoming increasingly vital as a clean energy source for reducing pollution and addressing climate change. The Anion Exchange Membrane (AEM) technology is used to produce green hydrogen, combining the benefits of two established methods—Alkaline water electrolysis and Proton Exchange Membrane—while addressing their limitations to create a more efficient and cost-effective process. This study employs DWSIM software to simulate a green hydrogen production facility using AEM technology, which was not previously considered in prior research, particularly for large-scale production. The study also includes a sensitivity analysis for the DWSIM electrolyzer. The simulated facility follows a four-step process: purifying seawater, conducting electrolysis to split water molecules, separating the hydrogen produced, and compressing and storing it. The electrolysis equipment requires 1.5 volts per cell, with a reversible voltage of 1.23 volts. Producing one ton of hydrogen per hour requires 40 MW of renewable energy and five tons per hour of water. Additionally, a WAVE simulation calculates the required seawater, factoring in advanced filtration and ion exchange, estimating a need for 5.5314 tons of seawater. The sensitivity analysis reveals how the voltage applied to the electrolyzer impacts the number of cells, showing that increasing the voltage decreases the current in the electrolysis stack, and examines the relationship between the energy supplied to the electrolyzer and hydrogen production.

Spinning cone distillation column (SCC) is a gas-liquid contacting instrument whose function is in the food processing industries. This technology serves as a complementary approach to conventional packed and plate column distillation, particularly in applications requiring high tolerance to solid contaminants and minimal thermal impact on processed materials. In this research, CFD simulations were conducted using pressure and velocity distributions in a pilot-scale SCC, both in the presence of gas and in the absence of liquid flow (dry column) and in the presence of both gas and liquid (two-phase column). The innovation of this research is the results of the new geometry in the simulation. At the present work, the modeling of four fixed cones and three spinning cones, which is between them, has been performed and the suction effect of the spinning cones at the top and bottom of the tower is also taken into account. This geometry led to more accurate results than the experimental results. An increase in gas flow rate may result in higher pressure drops in both dry and two-phase conditions. By calculating logarithm, the line slope of CFD and experimental data will obtain which is equal to 1.835 and 1.847 respectively. These amounts match with the curve slope of pressure drop regarding passed gas flow velocity from orifice (1.8-2).  The simulation results can be used to predict industrial applications of the SCC.

The deposition of paraffinic and heavy hydrocarbons in pipelines is a major challenge in the petroleum industry during production and transportation of oil products. In this paper, the wax appearance temperature (WAT) in solid-liquid equilibria is calculated based on solid-liquid phase models for binary hydrocarbon systems under high-pressure operational conditions. These models, rooted in Won’s framework for liquid-solid equilibria, employ the ideal activity coefficient to compute fugacity in the liquid phase and the Wilson activity model for the solid phase. The developed model accurately describes solid-phase equilibria in hydrocarbon systems across a wide pressure range (atmospheric to high pressures). For systems where operational temperatures exceed the critical temperature of the light component, forming solid-gas equilibria, the model assumes negligible solubility of the light component in the solid phase (zero concentration). The model predicts WAT for binary mixtures of light and heavy hydrocarbons with high precision, demonstrating an average absolute error of 1.64% and 1.19% across 13 tested systems (617 experimental data points).

A side-absorber distillation column (SADC) model was used for ethanol extractive dehydration (EED) with ethylene glycol (EG) as the solvent for the first time. The model performance was evaluated in terms of product purity, energy consumption rate, and the amount of solvent used. Initially, the system behavior was analyzed from a thermodynamic point of view. Then, the process was simulated, and the effect of all operational and design variables was separately and simultaneously evaluated through sensitivity analysis. By determining the optimal value of each variable, the SADC model was optimized. Using the optimized structure, ethanol with a molar purity of 99.8% and a specific energy consumption rate of 0.325 kWh/kg was extracted. Then, the performance of the SADC structure was operationally compared with classical two-column (CTC) and dividing wall column (DWC) configurations. In addition to maintaining high purity, the SADC model can reduce the reboiler heat duty by 37% and 30%, respectively, compared to the CTC and DWC structures. The amount of solvent consumed in the SADC structure was also reduced by 26.3% compared to the other two configurations. On the other hand, the SADC model is simpler and structurally smaller than other models, and it imposes less investment and operational costs.

Microfluidic devices for efficient blood plasma separation are critical tools in medical diagnostics and disease research, enabling downstream analysis from minute samples. This study specifically investigated the enhancement of the cell-free layer (CFL), a key determinant of separation efficiency and plasma purity, within four novel passive microchannel geometries. These designs featured symmetrical sinusoidal expansions and contractions, leveraging secondary flows to manipulate red blood cell (RBC) trajectories. A rigorously validated Eulerian-Lagrangian multiphase Computational Fluid Dynamics (CFD) approach was employed to model the complex dynamics of RBCs suspended in plasma at physiological hematocrits. Simulations demonstrated that a targeted reduction in the minimum width of the sinusoidal contraction zone significantly enhanced CFL formation adjacent to the channel walls. Quantitatively, narrower throats produced a thicker and more stable CFL. Furthermore, this enhanced CFL development correlated strongly with a consequential increase in wall shear stress, localized specifically within the critical throat region. These findings, linking contraction geometry to CFL magnitude and stress profiles, clearly identify the geometric optimization of sinusoidal contraction features as a promising and effective strategy for designing next-generation, high-performance passive plasma separation microchannels, potentially improving yield for point-of-care devices.

The present paper studies an Integral Test Facility (ITF) using the thermal-hydraulic method in order to determine its safety and reliability. The scaling and thermal-hydraulic design of the Islamic Azad University Test Loop (IAUTL) is conducted, accompanied by the energy scaling methodology for a typical pressurized water reactor (PWR). The scaling findings are authenticated by the experimental data resulting from the pressurized water reactor for pure water and forced circulation (FC) flow in 100% of core nominal power using the RELAP5/MOD3.2 code. From the comparison of the simulation results of core temperature in natural and forced flow, it can be concluded that the maximum outlet temperature of the reactor core in natural and forced flow is 169.4 °C and 174 °C, respectively. This temperature increase in natural flow is due to the increase in the residence time of the fluid in the natural flow regime around the core. Also, the temperature drop in the heat exchanger in natural and forced flow is 20 °C and 13 °C, respectively. This increase in heat loss in natural flow is due to the lower velocity of the natural flow and, as a result, the heat exchange also increases in natural flow. The pressure drop between the inlet and outlet of the reactor core, in both free and forced flow, is approximately 2 bar. The simulation results indicate that the IAUTL core can remove the residual heat from the core using NC flow.

Industrial clay Bentonite consists of the nanostructure and nanoporous mineral montmorillonite. The most important applications of bentonite and its modified types include the absorption and release of salicylic acid (aspirin), the use of Layered Nano Clays (LDH) in combination with biological materials, vitamins, drugs, and DNA; the use in wound healing, disinfectant with 95% absorption of the coronavirus, and prevention and treatment of coronavirus. This study aims to design a jaw crusher and a rotary dryer for extracting valuable minerals, and utilizing the MATLAB software tool for modeling and design calculations. In developing the crusher, based on the guidelines of the references and considering the energy consumption of crushing, the average crushing ratio was selected as 3. Regarding the dryer, the inlet air was at ambient (30°C and 1 bar), and the number of theoretical heat transfer units was assumed to be the average value suggested by the sources, i.e., 2. In the jaw crusher design, the crusher opening distance is calculated to be 6.22 inches. By performing the calculations, the most important results of the dryer are that the diameter and length of the rotary dryer are calculated to be 1.06 and 7.77 m, respectively.

Enhancing the energy performance of liquefied petroleum gas (LPG) recovery units presents a significant challenge for refineries aiming to achieve greater efficiency while minimizing their environmental footprint.  This study focuses on modeling and optimizing the LPG recovery unit at the Refinery using Aspen HYSYS. The aim is to assess its thermodynamic and operational performance.  The simulation included the real setup of the deethanizer, depropanizer, and debutanizer columns, utilizing the Peng–Robinson equation of state to ensure precise predictions of vapor–liquid equilibria.  The validation of the model against actual plant data demonstrated a high level of agreement, with deviations remaining within ±3% for key parameters such as temperature, pressure, and product composition.  Through sensitivity analysis, it was found that the reboiler temperature and column pressure play a significant role in determining the purity of LPG and the overall energy requirements.  By optimizing these parameters, a significant reduction in overall energy consumption was achieved, with a decrease of approximately 12% noted. At the same time, the purity of the LPG product remained above 97mol%, highlighting our commitment to efficiency and quality. The model that has been developed provides a reliable and flexible framework for the evaluation of processes, the integration of energy, and the optimization of operations within current refinery systems. The results play a crucial role in connecting process simulation with real-world industrial practices, resulting in energy management and sustainability efforts across the entire refinery.

Oil and gas producing organizations across the globe compete over resources and reserves. The undeniable fact remains that the application of engineering principles-especially in exploration and production projects such as design, construction, and operation of efficient and economic plants and processes-is crucial. The lack of a viable global or national substitute for crude oil and the essential nature of this commodity in the economic portfolio has heightened the importance of oil and gas development projects. Drilling, well completion, and oil and gas production projects are considered highly complex businesses. The economic analysis of oil and gas operations requires the use of economic techniques and analyses in design and engineering. Economic evaluation of oil and gas investments is one of the core responsibilities in both domestic and foreign investments of oil and gas companies, among which risk assessment and profit evaluation are the most critical. Oil price is a key factor affecting internal company risk and industrial risk. Risk compensation reduces the overall profitability of oil and gas investments both domestically and abroad. The economic structure of the oil industry, due to the high risks and uncertainties associated with oil and gas projects and extremely volatile price levels, is significantly different from other industries. Additionally, the large number of uncertainties in the data used for investment decision-making in oil projects heavily influences decision-making processes. In this study, the Rashadat and Doroud oil fields were examined. Based on the results, investment in the Rashadat field-despite the higher risk of offshore operational conditions-is more justifiable than investment in the Doroud field, such that the profit from investment in the Rashadat field amounts to USD 896 million. Although the initial capital required for the Doroud field is lower than that of the Rashadat field, this is due to the high costs of offshore oil operations.

The growing demand for energy-efficient and environmentally sustainable separation technologies highlights the limitations of conventional distillation. This study examines the separation of a quaternary hydrocarbon mixture n-Butane, n-Hexane, n-Heptane, and n-Nonane using three consecutive distillation columns arranged in direct and indirect sequences. Several heat-integration strategies, including preheating, feed splitting, and multi-effect distillation, were applied individually and in hybrid combinations. Rigorous simulations were performed in Aspen HYSYS with the Peng–Robinson equation of state, and exergy and environmental assessments were conducted using custom MATLAB R2021b (The MathWorks, Inc.) codes. The results show that a hybrid configuration combining direct sequencing with feed splitting and multi-effect distillation delivers the best performance, reducing energy consumption by 57.2% (from 3134kW to 1342kW), increasing exergy efficiency to 50.5%, and decreasing CO₂ emissions by 50.7% (from 670 to 330kg/h). These findings highlight strong synergy between internal heat recovery and pressure-differential optimization. In contrast, some configurations, such as direct sequencing with feed splitting alone, produced higher energy use and lower efficiency due to thermal imbalance and excessive vapor loads.Overall, this study offers a robust methodological framework integrating process simulation, exergy-based optimization, and CO₂-emission evaluation, providing guidance for sustainably designing next-generation distillation systems in the chemical and petrochemical industries.