Asia-Pacific Journal of Chemical Engineering最新文献

To address information loss during network stacking and capture the temporal characteristics of industrial process data, this paper proposes a soft sensor method named Self-Supervised Stacked Isomorphic Hierarchical Mapping Autoencoder Based on Dual-Constraint Mechanism (SSIHMAE). The model's decoder directly reconstructs the original input. Additionally, it projects each encoder layer's output back to the corresponding input dimension through a mapping layer. By incorporating the cosine similarity between the mapped values and the input into the loss function, the model effectively mitigates information loss in deep networks. At the top layer of the network, self-supervised temporal contrast learning is introduced. Data pairs adjacent in time serve as positive samples, while interval-separated data pairs act as negative samples. The model minimizes the distance between the features of anchor samples and temporally adjacent samples by optimizing the InfoNCE objective function, while rejecting samples separated by intervals. In this way, multi-scale temporal features are captured. Finally, a fully connected layer constructs the prediction model. Simulation results on sulfur recovery and coal-fired power generation datasets demonstrate that the proposed method achieves 12.4% and 5.1% higher prediction accuracy than the traditional SAE model. These results validate the method's efficacy.

Industrial wastewater treatment is a growing concern due to the discharge of pollutants/contaminants originating from different industrial sectors such as textiles, fertilisers, pharmaceuticals and dyes. These substances may adversely affect both ecological systems and living organisms. To minimise these effects, many treatment methods have been proposed, and out of all, photocatalysis is the most promising technology. This review offers a comprehensive examination of various photocatalytic materials and the underlying mechanisms governing the photocatalysis process. Factors that influence the photocatalysis process were also discussed. The study further reviews the advancements in the synthesis of photocatalytic materials using doping and heterojunction strategies. Finally, the study presents a comprehensive review of different photocatalysts used for various wastewater treatment applications.

This study explores a method to improve the performance of PVDF membranes used in wastewater treatment by reducing membrane fouling. The membranes were prepared using PVDF polymer and modified using nanoparticles based on TiO₂, MWCNT-COOH, and TA to reduce membrane fouling. The antifouling properties were evaluated with two different solutions: a protein solution (BSA) and real-world municipal wastewater. The given research involves preparing a PVDF membrane (M sample) and improving it with CTi (MC sample) and CTiTA (MCT sample). The base membrane (M) included 17-wt.% PVDF with 0.5% PEG, LiCl, and double distilled water as additives. In addition, MC and MCT membranes contained 0.5% CTi and CTiTA, respectively. The characterization of membrane and nanoparticle samples was performed by ATR-FTIR, SEM–EDX, DRS, TEM, TGA, tensile, WCA, and performance tests. According to the results, embedding membranes with CTi and CTiTA resulted in better surface hydrophilicity. The MC membrane decreased total fouling about 10.6% and increased reversible fouling and flux recovery ratio about 18.6% and 29.3% for BSA, respectively. In addition, it reduced total fouling about 11% and boosted reversible fouling and flux recovery ratio about 23.4% and 34.4% for municipal wastewater feed in the MBR process, respectively. Further modification of CTi with TA (CTiTA) gained a nanoparticle with higher hydrophilicity; results in declining the total fouling about 17.1% and climbing the reversible fouling and flux recovery ratio about 19.9% and 37% for the MCT membrane against BSA feed, respectively. In addition, the MCT diminished total fouling about 18% and enhanced reversible fouling and flux recovery ratio about 27% and 45% for municipal wastewater feed in the MBR process, respectively. This research suggests that incorporating composite nanoparticles like CTi and CTiTA into PVDF membranes is a promising approach for reducing membrane fouling in filtration processes.

To address the limited information available on bubble shapes and motion trajectories in flotation systems, this work investigates the three-dimensional motion and morphology of bubbles using high-speed imaging and a virtual binocular stereoscopic vision system based on dual-view imaging principles. First, the relationship between bubble shape and dimensionless numbers was established using experimental data and compared with other experimental records. The results show that the predicted correlation between the Weber number and Morton number in this study aligns more closely with experimental values. In the bubble motion experiments, two types of three-dimensional trajectories were observed: “linear” and “spiral.” The amplitude of the horizontal oscillation of the bubbles was found to be negatively correlated with reagent concentration and positively correlated with the orifice size of the bubble generator. For dual-bubble motion, three interaction patterns were identified: no interaction, approach–separation–reapproach, and intersecting ascent.

Microchannel heat sinks (MCHS) have emerged as a reliable solution for effective thermal management in compact and high-performance electronic devices. This study presents a detailed investigation of a porous/solid compound wavy microchannel heat sink, designed with varying wavelengths and amplitudes, and operating within a Reynolds number range of 50 to 300. The performance of this innovative design is benchmarked against traditional straight-channel heat sinks to assess its advantages. The thermal–hydraulic characteristics of the wavy MCHS and the flow behavior within its porous zones are analyzed using the finite volume method and Darcy–Forchheimer flow models, respectively. The heat sink structure, including its walls and fins, is constructed from copper, with water serving as the working fluid flowing through the channels. The study further examines how changes in amplitude and wavelength influence the heat sink's performance. Results reveal that hydraulic efficiency is maximized at higher wavelengths with lower amplitudes, while superior thermal performance is achieved with lower wavelengths and higher amplitudes. These enhancements are attributed to improved coolant mixing, driven by Dean vortices, and the permeation effects inherent to the porous zones. Consequently, the CWMCA200W2.0MM heat sink exhibits a PEF value of 2.22 at a Re of 300 when compared to straight-channel heat sinks. Among the designs studied, the CWMCA200W2.0MM model stands out for its exceptional thermal and hydraulic performance, making it a highly effective solution for heat dissipation in advanced electronic devices.

This study improves a computational fluid dynamics (CFD) model for CO₂ absorption using a monoethanolamine (MEA) solution in a rotating packed bed (RPB) with porous media. It analyzes the impact of different liquid inlet nozzle designs and operational parameters on mass transfer and decarbonization performance. Results show that varying nozzle configurations have a negligible effect on the overall gas phase mass transfer coefficient and CO₂ removal rate, with deviations under 10% compared with uniform liquid distribution. However, nozzle design significantly influences temperature distribution within the packing. Increasing the number of nozzles, their axial height, and hole count helps mitigate temperature unevenness. The study identifies five nozzle structures that improve mass transfer efficiency. Moreover, increasing the liquid inlet flow rate and MEA concentration enhances mass transfer, while higher rotational speeds promote more uniform liquid distribution and reaction. This research offers valuable insights for optimizing nozzle design and operational parameters in RPB systems for mass transfer applications.

This study addresses the high-purity separation demands for specialty chemicals by designing separation strategies for a four-component mixture based on a rigorous batch distillation (BD) model. A method is proposed that integrates a multi-objective optimization algorithm with a PID temperature control structure, aiming to minimize equipment costs, energy consumption, and operational time while maximizing overall yield. The relationship between the decision variables and the objective functions was analyzed. The optimization of the constant reflux ratio model of the BD was performed using a multi-objective optimization algorithm. Additionally, the optimal reflux curve under the variable reflux model was explored. Three typical case validations were used to demonstrate the significant advantages of this approach in improving operational strategies and equipment performance. The results show significant improvements in the number of trays, operating time, energy consumption, and yield optimization, providing a universal approach for solving BD synthesis problems.

This study observes the evolution of Bacillus subtilis biofilm in two microfluidic channels containing nonuniform and uniform porous medium, revealing dynamic changes in flow paths (areas without biofilm). In the nonuniform porous medium, flow paths shift towards macropore throat regions: The qualitative form of flow paths remains unchanged, but their overall positions undergo displacement; while in the uniform porous medium, flow paths undergo reorganization: After clogging, the new flow path suddenly opens, manifested as significant changes in geometry and position. By inputting digital images obtained from microscope images, we use mathematical modeling to study the effects of biofilm permeability (k_b) (from 10⁻¹⁵ to 10⁻⁹ m²) and porosity (ε_b) (from 0.1 to 0.9) on dynamic changes in flow paths. The simulation results indicate that the physical properties of biofilms affect the flow in porous media, and nonuniform porous medium induces the formation of more impermeable biofilm structures. With the decrease in biofilm permeability, the boundary shear stress along the flow paths increases, and the position of the boundary migrates towards the macropore throat regions. When porous media are clogged by low-permeability biofilms, a greater pressure difference is generated, making it easier to form new flow paths. Furthermore, increasing the porosity of low-permeability biofilms has no significant effect on the flow in porous media. High-permeability biofilms experience greater internal shear stress, leading to the detachment of regions with low cohesive strength and the formation of new flow paths.

In this study, high gravity, regarded as a process intensification technology, is integrated into the conventional cyclone through a rotary drum, leading to the design of a novel gas–liquid separator called high-gravity cyclone separator (HGCS) for natural gas dehydration and purification. The flow field is numerically investigated to characterize the separation performance. A novel quality factor is proposed to assess the relationship between the separation efficiency and pressure drop, where the effects of operating parameters and drum dimensions are experimentally evaluated to determine the optimal conditions. The results indicate that both the velocities and pressures within the rotary drum can be enhanced by increasing the radial position. Specifically, an increase in inlet velocity leads to a reduction in tangential velocity while simultaneously improving axial velocity. In the barrel and conical regions, a lower inlet velocity significantly influences the quasi-free vortex and the ascending gas, whereas a higher inlet velocity may worsen the pressure distribution. For optimal separation with the highest quality factor, it is recommended that the inlet velocity be maintained at 12 m/s, with ideal high-gravity factors and liquid concentrations of 59.4 and 57 g/m³, respectively. Furthermore, increasing the radial height can enhance separation performance, with a height of 8 mm being optimal for low velocities. It is crucial to avoid excessively short or long drums that a length of 190 mm is recommended.

This study explores Sn-doped CsPbBr₃ perovskites as advanced semiconductor materials for radiation detectors. Using density functional theory, we reveal tunable band gaps from 2.803 eV (undoped) to 1.139 eV ($�50�\%$ Sn), enabling broad-spectrum detection from visible light to gamma rays. Optical analysis highlights high absorption coefficients in the 4- to 6-eV range and enhanced visible-light absorption, ensuring efficient photon-to-electron conversion. Anisotropic dielectric properties, with increasing refractive indices and dielectric constants, improve directional sensitivity and photon capture. Phonon analysis confirms dynamic stability, ensuring robustness under operational stresses and high radiation flux. The substitution of Sn for Pb reduces toxicity, offering an eco-friendly alternative for sustainable detector technologies. These findings establish Sn-doped CsPbBr₃ as a versatile material for $�\gamma$-ray spectroscopy, X-ray imaging, and directional photodetectors, combining tunable optoelectronic properties, structural stability, and environmental sustainability to advance next-generation radiation detection applications.