Asia-Pacific Journal of Chemical Engineering最新文献

Nanofluids have attracted considerable interest for enhancing heat transfer efficiency; however, poor stability remains a challenge. In this study, β-cyclodextrin (β-CD) was grafted onto TiO₂ nanoparticles using nitrogen filling and vacuum drying methods to improve the stability of nanofluids. The modified nanoparticles were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. The stability and thermophysical properties of the nanofluids were evaluated in the temperature range of 20°C to 60°C. The results showed that the nitrogen filling method provided better grafting efficiency and stability, with a 36.62% reduction in settling velocity compared to the vacuum drying method. The β-TiO₂/EG:DI nanofluid exhibited a peak thermal conductivity of 0.579 W/(m·K) at 60°C, a 12.46% increase over the pure base fluid. Thermoeconomic analysis indicated that the β-TiO₂/EG:DI nanofluid has a maximum price-performance factor of 1.206 under laminar flow at 50°C, representing a 23.67% increase compared to the unmodified TiO₂/EG:DI nanofluid. These findings suggest that β-TiO₂/EG:DI nanofluid is suitable for industrial applications in the laminar flow regime.

Due to its high catalytic activity and high selectivity, graphene-based single-atom materials have attracted widespread attention in various fields, such as adsorbent, catalyst, and sensor. The regulation of adsorption characteristics is the foundation of the above applications. Current research on adsorption characteristics is primarily focused on tuning metal species while neglecting the effect of microenvironment for metal centers. Herein, this work systematically investigates the adsorption characteristics of graphene-based single-atom iron catalysts through density functional theory calculation. Through doping different coordinated atoms (B, C, N, O, S, P, and Cl), we analyze the effect of the microenvironment on adsorption configuration, electron transfer mechanism, and adsorption energy for various flue gases (NH₃, H₂O, NO, NO₂, SO₂, and O₂). The differences in stable adsorption configurations of various graphene-based single-atom iron catalysts can be well-understood by the analysis of frontier molecular orbitals. In addition, the system electronegativity is a reliable descriptor of adsorption energy. Therefore, our study has established a correlation between electronic structure and adsorption energy, laying a foundation for further study of the adsorption characteristics of microenvironment-regulated catalysts and providing guidance for the development and design of new nonnoble metal single-atom catalysts for complex flue gas components.

In practical implications for diversified industrial and engineering applications, such as cooling of electronic devices, and coating processes, the precise control over heat and mass transfer is crucial. The present investigation aims at the Marangoni convection in a viscous liquid via a Riga plate by insertion of electrophoresis, non-uniform heat source, and heat radiation. The Marangoni convection effect, driven by the surface tension gradient due to temperature and concentration variations, is significantly influenced by the presence of electrophoretic forces and thermophoretic movement. The main flow equation is altered into a system of ordinary equations by the assumption of particular similarity rules. Further, the traditional shooting-based “Runge–Kutta fourth-order technique” is employed for the solution of the transformed model. The parametric analysis is presented through graphs, and the confirmation of the convergence policy is attained by validating the result with earlier studies in specific cases which confirmations a good correlation. The proposed results indicate that electrophoresis enhances the Marangoni convection by varying temperature as well as velocity profiles, leading to more pronounced convective current. Thermophoresis further contributes to the redistribution of heat transport analysis.

In the current scenario, the heat generation and overheating of the miniature devices are a big problem. Moreover, the excess heat generation due to the reduction in size of the microchips will cause overheating and burning of electronic devices. For resolving this issue, in this article, an air-cooled heat sink for the size of the electronic chip, 10 × 10 × 1 mm, is proposed. The temperature, velocity and pressure contours are found by using a Computational Fluid Dynamics tool. Also, a Nusselt number, heat transfer coefficient and fan power have been calculated to estimate the performance of the heat sink. The inlet air velocity, inlet air temperature and heat generation are three important variables that control the temperature of the chip. Numeric optimization was performed for the chip using Response Surface Methodology (RSM) with the aid of MINITAB and Design Expert software to determine the best operational conditions. In the optimization, the device chip temperature should be below 50°C, and it is the main optimization constraint. The outcomes of the study indicate that as the inlet air velocity increases, the chip temperature reduces, but increasing the inlet air temperature and heat generation enhances the chip temperature. Furthermore, the numerical results are validated with the experimental results of the heat sink at optimum conditions.

In response to growing worldwide energy needs, polyanionic compounds have gained increasing attention as highly potential cathode/anode candidates in sodium-based energy storage systems. These materials exhibit two key advantages: exceptional framework robustness and superior charge-storage characteristics. Nevertheless, their widespread adoption is hindered by inherent limitations, including poor electronic conductivity and vulnerability to detrimental phase transitions during cycling. High-entropy polyanionic cathodes present a compelling solution to these challenges by leveraging an entropy-driven strategy, wherein multiple transition metals or anions are incorporated to achieve high configurational entropy. This approach promotes electronic structure rearrangement, improves conductivity, and mitigates undesirable phase transitions. This review comprehensively examines high-entropy configuration phosphate-based NASICON-type cathodes, evaluating recent research progress and their electronic structure modulation mechanisms. Additionally, it highlights the exceptionally wide-temperature performance of these materials and underscores the untapped potential of pyrophosphate-based systems, which remain underexplored. Finally, the review outlines future research directions to advance high-entropy polyanionic cathodes for next-generation energy storage applications.

The corrosion characteristics and mechanism of CO₂ capture equipment materials in organic amines are the key issues affecting the safety of carbon capture equipment. This work investigated the effect of SO₂ on the corrosion mechanism of 20# carbon steel and 30408 austenitic stainless steel in the aminoethylethanolamine (AEEA)-CO₂-O₂ system, and studied the corrosion characteristics and mechanism of 20# carbon steel in both (i) freshly prepared AEEA solution and (ii) AEEA solution after 120 h of degradation. Weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy, and various product scale characterization methods such as scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis were applied. The results revealed that the corrosion rates of both 20# and 30408 steel increased significantly with the addition of 0.5% SO₂ in a 30% AEEA-12% CO₂-6% O₂ environment. The corrosion rate of 20# steel in dirty solution (after oxidative degradation) without SO₂ was slightly lower than that in fresh solution. With the addition of 0.5% SO₂, the average corrosion rate of 20# steel in fresh solution was 0.174 mm/y, and in dirty solution containing degradation products was 0.012 mm/y; the corrosion rate in dirty solution was significantly reduced compared to fresh solution. These findings indicated that the organic amine degradation products generated under the conditions had a significant corrosion inhibition effect on 20# steel.

Metal oxide nanoparticles (NPs) have gained significant attention due to their wide-ranging applications in wastewater treatment, photothermal, radiation therapy, tissue engineering, pharmaceuticals, antimicrobial activity, electronics, and optics. Amid the various synthesis strategies, green synthesis offers a sustainable alternative to produce NPs within the size range of 1 to 100 nm in an eco-friendly, biocompatibleecofriendly, and cost-effective manner. NPs can be synthesized using the bottom-up or a top-down approach that involves chemical, physical, and biological processes. The characterization of NPs commonly includes techniques such as UV–Vis spectroscopy (UV–Vis), X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), atomic force microscopy (AFM), and transmission electron microscopy (TEM). Overall, this review highlights the green synthesis of Al, Mn, and Bi oxide NPs and their potential as efficient nanomaterials for dye degradation in wastewater treatment.

The oxidative dehydrogenation of ethane (ODHE) to ethylene is a critical reaction in the petrochemical industry, driven by the need for efficient and sustainable production methods. This review article examines advancements in vanadium- and molybdenum-containing catalysts for ODHE, focusing on their unique properties, advantages, and limitations. The key factors of the ODHE process include catalyst composition, structure, and reaction conditions. The performance evaluation of vanadium-containing and molybdenum-containing catalysts highlights the trade-offs between ethane conversion rates and selectivity towards ethylene. Notably, while molybdenum-containing catalysts exhibit higher conversion efficiencies, vanadium-containing catalysts achieve superior selectivity under optimized conditions. Furthermore, the integration of life-cycle assessments and cost analyses is explored to evaluate the environmental impact and economic feasibility of various ODHE technologies. The article emphasizes the necessity for future research to develop robust catalysts, tailor their structures, improve stability, and optimize reaction conditions. By combining innovative catalyst design with sustainability assessments, this review aims to contribute to advancing efficient and environmentally friendly ODHE processes, ultimately enhancing the viability of ethylene production in a rapidly evolving industry.

m-Cresol and p-cresol cannot be effectively separated using conventional distillation because of their proximate boiling temperatures. This study investigated the adsorption separation of cresol using the short b-axis ZSM-5 synthesized via a urea-assisted method. In contrast to the ellipsoidal HZSM-5, which was approximately 1 μm in length, the thickness of the sheet-like HZSM-5 decreased to 36 nm, resulting in an increase in total cresol adsorption capacity from 76 to 122 mg/g. Applying the CLD method, an increase in the TEOS:HZSM-5 ratio from 0 to 0.83 resulted in the increase in p-cresol adsorption capacity from 69 to 106 mg/g, while m-cresol adsorption capacity dropped from 53 to 12 mg/g. The adsorption selectivity significantly rose from 1.3 to 9.7. The adsorption kinetics and isotherms demonstrated that the process was exothermic for p-cresol and endothermic for m-cresol.

Spodumene, a critical lithium-bearing mineral, necessitates high-temperature phase transformation roasting during processing. Transitioning from conventional rotary kilns to fluidized bed reactors offers significant potential to enhance product uniformity and energy efficiency. Gas–solid flow of spodumene particles in a fluidized bed experimental system was studied, with emphasis on minimum fluidization velocity, pressure drop characteristics, and pressure fluctuations. Pressure signal processing methods—including standard deviation and power spectral density analyses—were employed to quantify the influence of key operational parameters: initial bed material height-to-diameter ratio (H/D) (1.0–3.0) and gas velocity (u_g) (0–15.69 cm/s). These findings provide critical insights for scaling spodumene phase transformation processes in industrial fluidized bed systems.