Asia-Pacific Journal of Chemical Engineering最新文献

This work comprises ternary systems of water + SAIL,1-decyl-3-methylimidazolium bromide, and (S)-2-Amino-3-methylbutanoic acid generally identified as L-valine/ (S)-2-(2-Aminoacetamido)-3-methylbutanoic acid usually described as glycyl-L-valine, densities, and sound speed data have been computed at four operating temperatures, i.e., 288.15 to 318.15 K. Calculated density data have utilized for calculation of various thermodynamic parameters like V_ϕ (apparent molar volume), $�V_{\varphi }^0$ (apparent molar volumes at infinite dilution), and calculated speed of sound statistics used to determine K_ϕ,s (apparent molar isentropic compression), K_s (partial molar isentropic compression at infinite dilution). In our systems, the hydrophilic-ionic interactions that are produced by co-sphere overlap models are predominant. The Hepler's constant is used to analyze the solute's capacity to create or destroy solvent structures. The interaction parameter is computed using the McMillan-Mayer theory. Understanding structure-making, solvation characteristics, and numerous modifications in the ternary system of L-valine/Glycyl-L-valine, water, and [C₁₀MIm] [Br] is aided by a variety of thermodynamic factors.

The increasing demand for boron has resulted in its contamination of water supplies. Nanofiltration membranes, particularly thin-film nanocomposite (TFN) membranes, have shown promise in removing contaminants. This study evaluated the boron removal capabilities of negatively and positively charged TFN membranes alongside a control thin-film composite (TFC) membrane without nanoparticles. Piperazine (PIP, for negatively charged membrane) or polyethyleneimine (PEI, for positively charged membrane) aqueous monomer was reacted with trimesoyl chloride (TMC) in n-hexane solution via interfacial polymerization (IP) on the polyethersulfone (PES) membrane substrate to form the TFC membrane. During the TFN membrane preparation, titanium dioxide (TiO₂) and sulfocalix[4]arene (SCA4) were introduced as active nanoparticles to the aqueous monomer. Boron removal performance was evaluated using a 10 ppm aqueous boron solution. The PES substrate gave the highest water flux, which was 307.80 LMH. For the TFC membrane, TFC–PIP had a higher water flux at 113.71 LMH than TFC–PEI. Furthermore, the TFN membranes containing the PEI monomer had a lower water flux than those containing the PIP monomer. These findings highlight the potential of TFN membranes, particularly those incorporating nanoparticles, for effective boron removal. Further research and optimization of TFN membranes can contribute to addressing the challenge of boron contamination in water supplies.

The maximum utilization of hydrocracking tail oil becomes increasingly important for petrochemical industry. The aim of this work is to develop optimized distillation processes to achieve various high-valued qualified oil products from hydrocracking tail oil. Six different oil products is produced and the steady-state distillation process, which aims to fractionate six qualified narrow distillates is established. The algorithm method incorporating divided-wall column (DWC) configuration was introduced into the steady-state design. Compared with traditional separation sequences, the DWC configuration leads to an energy-saving potential up to 11.17%. Furthermore, effective dynamic control strategies were proposed, demonstrating precise and efficient control performance. In the presence of a 15% feed disturbance, the dynamic control structure is capable of maintaining the product distillation range near the set value. This comprehensive study provides a thorough investigation into the efficient utilization of hydrocracking tail oil, establishing a robust theoretical foundation for its industrial application.

An improved hydrothermal method was proposed to rapidly synthesize zeolite W from alkali fusion-activated K-feldspar. The effects of m (KOH)/m (K-feldspar), n (SiO₂)/n (Al₂O₃), n (H₂O)/n (SiO₂), crystallization time, and crystallization temperature on the synthesis of the zeolite W were investigated. The optimal synthesis conditions were m (KOH)/m (K-feldspar) ratio of 1.5:1, the activation time of 2 h, and the activation temperature of 500°C, n (H₂O)/n (SiO₂) ratios of 42, n (K₂O)/n (SiO₂) of 0.90, n (SiO₂)/n (Al₂O₃) of 5, crystallization time of 6 h, and crystallization temperature of 150°C. The mechanism for rapid synthesis of zeolite W was illustrated. In this process, Na₂SiO₃·9H₂O and Al₂(SO₄)₃·18H₂O were first dissolved rapidly in the synthesis system to form an amorphous gel, which contributes to the accelerated crystallization process. Compared with the state-of-the-art synthesis method, this method remarkably decreases the water content to be added in the synthesis process and crystallization time, avoids the pre-preparation process of the xerogel, and enhances the utilization rate of K-feldspar. This work provides an industrial-friendly synthesis process of zeolite W and could realize the highly efficient utilization of K-feldspar.

The flow field of a hydrocyclone was investigated using both computational fluid dynamics (CFD) and particle image velocimetry (PIV). A refractive index matching method was employed to improve the precision of the PIV measurements. The CFD results are in good agreement with PIV measurements. Detailed analysis reveals significant axial asymmetry in the velocity components, with the radial velocity component exhibiting notable disparities. This observation is supported by quantitative data comparing different sections of the hydrocyclone. It is further found that the asymmetry might be mainly attributed to the secondary vortexes with the single inlet of the hydrocyclone. And the secondary vortexes, superimposed on the primary flow rather than existing on its own, spiral downwards from near the inlet towards the underflow orifice. It is hypothesized that specific boundary effects and pressure gradients play a pivotal role in the formation of secondary flows. This assumption is grounded on both theoretical considerations and empirical observations, suggesting that these factors significantly influence the flow dynamics within the hydrocyclone. The insights gained from our measurement methodology and enhanced understanding of secondary flows within hydrocyclones are not only poised to serve as valuable references for fellow researchers but also have the potential to inform the design and operational optimization of hydrocyclones for improved efficiency and performance.

This study unveils a numerical paradigm that amalgamates the partially saturated lattice Boltzmann method (PSLBM) with the non-isothermal quantitative phase-field (PF) model. This innovative integration equips us with a prognostic tool ready to elucidate the progression and motion of solid-air dendritic growth in the presence of both natural and forced convection. The PSLBM is employed to compute the flow of the solution and the interaction forces between the fluid and solid dendrites. Concurrently, the PF model is utilized to simulate the formation of solid-air dendrites. The reliability of calculating of interaction forces between the fluid and solid was confirmed through a numerical case study involving fluid flow around a stationary cylinder. The results indicate that this model is applicable for simulating the growth and evolution of single/multiple solid-air dendrites under the influence of convection, whether they are stationary or in motion. The promotion of the upstream side dendritic arms and the inhibition of the downstream dendritic arms increase with the intensification of natural convection. As the initial undercooling is raised, the capacity of natural convection to reshape dendritic morphology gradually diminishes. With the enhancement of forced convection intensity, due to alterations in the flow pattern, the downstream dendritic arms do not consistently exhibit growth suppression. The motion of solid-air dendrites induced by forced convection counteracts the influence of convection, resulting in slightly faster growth of the downstream dendritic arms compared to the upstream arms. Simultaneously, it fosters the formation of secondary dendritic branches in the upstream zone.

In this study, V₂O₅ nanoparticles with flake or prism-like morphology were synthesized using a two-step solvothermal synthesis and calcination process for the first time. These nanoparticles exhibited intrinsic oxidase-like activity, catalyzing the oxidation of 3,3′,5,5′-tetramethylbenzidine to produce blue oxidized 3,3′,5,5′-tetramethylbenzidine even in the absence of H₂O₂, with a characteristic absorption peak at 652 nm. Upon the introduction of glutathione (GSH), the solution color gradually lightened, correlating with a reduction in absorbance. Leveraging these properties, we developed a simple, sensitive, and highly selective colorimetric biosensor utilizing V₂O₅ nanoparticles for GSH detection in human serum. The developed method demonstrated excellent linearity over a range of 1–30 μM, with a low detection limit of 4.04 nM. Additionally, it exhibited outstanding selectivity against common interfering substances in human serum. Furthermore, this biosensor enabled both naked-eye detection and spectrophotometric quantitative analysis of GSH. Successful application to spiked serum samples yielded recoveries ranging from 97.1% to 101.7%. Overall, this method offers a promising approach for determining GSH content in human serum, with significant potential for biomedical testing applications. Its rapid and accurate detection capability may contribute to early diagnosis and treatment of various fatal diseases, including cancer and cardiovascular diseases.

The synthesis of Cu/Al₂O₃ nanoparticles (NPs) was conducted by the citric acid sol–gel technique. We used the synthesized NPs to enhance PVC membranes and create PVC-Cu/Al₂O₃ nanocomposite membranes. The quantities of NPs utilized were 0, 0.5, 1, 1.5, and 2 wt.% of solid phase. The point of this study was to look into how PVC-Cu/Al₂O₃ membranes can be used to remove natural organic matter (NOM) from polluted water in submerged membrane systems. The membranes treated with NPs exhibited increased porosity, improved hydrophilicity, and smoother surface. Results revealed that the incorporation of 1 wt.% NPs into PVC (PVC-CA1) demonstrated the highest degree of hydrophilicity and porosity. Moreover, PVC-CA1 exhibited an increased number of pores, with larger pores present on the top surface and larger macrovoids on the cross-sectional surface. The PVC-CA1 exhibited the highest flux recovery ratio (FRR) and highest rejection rate for HA, with values of 82.6% and 92.6%, respectively. PVC-CA1, which had an irreversible fouling ratio (IFR) of 17.3%, demonstrated the greatest resistance to fouling. Generally, incorporation of NPs into PVC resulted in increased hydrophilicity, enhanced porosity, uniform dispersion, smoother surface characteristics, and consequently improved antifouling properties. Furthermore, among the fabricated membranes, PVC-CA1 had the most favorable antifouling performance.

Mechanical stirring during the flotation conditioning process is a commonly employed and efficient method to enhance the effectiveness of slurry conditioning. However, excessive stirring intensity can lead to the desorption of collectors from the surface of coal slurry particles, compromising the conditioning efficacy. Thus, determining the optimal range of stirring intensity to enhance conditioning performance is necessary. The influence of stirring speed on the adsorption rate of coal oil and the desorption behavior of coal oil on the surface of coal slurry was investigated. Adsorption rates were measured and calculated using a UV spectrophotometer. An in-house desorption test apparatus and a high-speed motion capture system were employed to study the contact angle, adsorption area, deformation degree, and the forces acting on the adsorbed oil droplets under stirring conditions. Results indicated that the stirring speed significantly impacted the adsorption rate of the coal slurry. On increasing the stirring speed, the adsorption rate exhibited three distinct phases, that is, an increase, decrease, and stabilization. A maximum adsorption rate of 78.37% was observed at a stirrer rotation speed of 800 r/min, highlighting the crucial role of optimal stirring speed during conditioning. Both excessively high and low speeds were found to be detrimental to the conditioning process. As the stirring speed increased, the contact angle and contact area of the adsorbed oil droplets also increased, leading to an enhanced adsorption effect. Furthermore, the degree of deformation of the oil droplets increased with rising speed, accompanied by a reduction in stability.

To discover the “coordinative effect” within MEA-polyamines, the non-catalytic CO₂ absorption-desorption tests were conducted within tri-solvents of “MEA-TETA (triethylenetetramine)-DEEA (N, N-diethylethanolamine)/AMP(2-amino-2-methyl-1-propanol)” at specific concentrations of .1 ~ .5 + 2 + 2 mol/L for the first time. The energy efficient combinations were detected of MEA-TETA based tri-solvents with solid acid catalysts, from catalytic CO₂ desorption experiments onto MEA-TETA-DEEA/MEA-TETA-AMP with several commercial solid acid catalysts: blended γ-Al₂O₃/H-ZSM-5 = 2:1, H-mordenite, H-Beta (Hβ), HND-580, and HND-8. Three parameters were adopted to evaluate desorption activity: average desorption rate, heat duty, and desorption factors (DFs). After analyses, the .1 + 2 + 2 mol/L MEA-TETA-AMP with catalyst HND-8 possessed the best CO₂ desorption at 95–98°C with biggest DF. The desorption ability of DEEA was better than AMP, but with aid of solid acid catalyst, the AMP can release more CO₂ than DEEA due to weak stability of AMP-CO₂⁻ carbamate.