Chemical Engineering & Technology最新文献

Benzotriazole (BTA), a widely used industrial corrosion inhibitor, is recalcitrant and toxic, hindering its removal in conventional wastewater treatment. This study employed an electrochemical advanced oxidation process (EAOPs) with a boron-doped diamond (BDD) anode to degrade BTA, investigating key operational and water quality parameters. Under optimized conditions (4 mg/L BTA, 0.05 M Na₂SO₄, 10 mM Cl⁻, pH 8, 40°C, 6 V, 259 mL/min, 90 min), 94.80% degradation was achieved. Quenching experiments identified hydroxyl radicals (•OH) as the dominant species. Combined with density functional theory (DFT) calculations, the mechanism primarily involved benzene ring opening. Fourteen intermediates were identified, suggesting three degradation pathways. This work provides theoretical support for EAOPs application in treating BTA-containing wastewater.

Non-Hg catalyst is vital for the cleaner production of polyvinyl chloride (PVC), whereas the usual pure metal or pure metal salt precursor is too expensive for non-Hg catalysts preparation. Herein, a relatively cheap electronic waste (E-waste) leaching solution was employed as precursor to prepare acetylene hydrochlorination catalyst (EWC) for the first time. Resultantly, relatively better catalytic performance than that of pure metal salt-based catalysts was achieved on EWC. Additionally, Au, Ni, Sn, and S could play a positive role than other coexisting ions, whereas other elements would hardly have any impact at all. After Brunauer–Emmett–Teller (BET), x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), and H₂-temperature-programmed reduction (TPR) studies, it was proved that catalytic performance of EWC is mainly attributed to the efficient dispersion effect of other metals on active species like copper. Moreover, density functional theory (DFT) study further revealed that other metal components “solvent” role hindered the agglomeration of the active Cu component. This study offered a new route for decreasing the cost of vinyl chloride monomers (VCMs) in non-Hg preparation.

Solar energy utilization is a cost-effective solution to reduce the volume of industrial wastewater. A rotating drum solar unit enhanced by forced air convection was designed, built, and tested. The unit may be operated under batch, semicontinuous, and continuous modes of operation. The effect of various operating parameters was investigated. The results showed that increasing the air flow rate resulted in a 62% increase in the evaporation rate, respectively. Increasing the drum rotation from 0 to 0.75 rpm increased the evaporation rate by seven-folds. Higher rotational speeds reduced the evaporation rate. The evaporation increases by 1.5% upon reducing the mass in the basin by 1 kg. The evaporation rate ranges between 1.06 and 2.12 kg m⁻² h during the cold and hot seasons, respectively. Comparing the experimental results with those theoretical ones calculated from models derived shows an excellent agreement. Economic analysis of the unit showed that it is feasible.

The Co/Nb₂O₅ catalyst demonstrated high performance for the hydrogenation-rearrangement of furfural to cyclopentanol in water, achieving 95.8% selectivity at full conversion. However, in alcoholic solvents, the main product was furfuryl alcohol, and the rearrangement reaction did not proceed. Acidic additives (FeCl₃, CH₃COOH) inhibited hydrogenation steps, whereas basic conditions (NaOH, Na₂CO₃) suppressed the rearrangement step. Catalyst deactivation occurred due to Co agglomeration.

The Co/Nb₂O₅ catalyst demonstrated high performance for the hydrogenation-rearrangement of furfural to cyclopentanol in water, achieving 95.8% selectivity at full conversion. However, in alcoholic solvents, the main product was furfuryl alcohol, and the rearrangement reaction did not proceed. Acidic additives (FeCl₃, CH₃COOH) inhibited hydrogenation steps, whereas basic conditions (NaOH, Na₂CO₃) suppressed the rearrangement step. Catalyst deactivation occurred due to Co agglomeration.

Equivalent series resistance (ESR) is a critical factor limiting the performance and longevity of asymmetric supercapacitors (ASCs). Failed ASC analysis shows ESR imbalance as a major cause of degradation. This study uses statistical design of experiment (DoE) models for vertical and horizontal setups to tightly control ESR. A high coefficient of determination value confirms the validity of the model over a significant data variance. Accurate electrode loading control influences ESR variance more than metal oxide content, though their interaction also significantly affects ESR. With precise loading, ESR remains within a narrow, stable range across configurations. Controlled ESR directly influences the design and cost of cell balancing circuits. The study identifies better alternatives to metal oxides and activated carbon for enhanced performance. Finally, COMSOL thermal simulations show asymmetric cooling is a key for ASC performance and reliability.

A sustainable biocomposite (chitosan-oxalate/pomegranate peel-H₂SO₄ [CH-OX/PP-HS]) of crosslinked CH-OX and treated pomegranate (Punica granatum L.) peel was developed for high-efficiency adsorption of rhodamine B (RhB) dye from water. Box–Behnken design (BBD) was implemented to examine the adsorption variables. Optimal conditions for RhB dye removal (78.41%) were achieved at pH ∼10, a CH-OX/PP-HS dose of 0.056 g, and 60 min contact time. Textural analysis revealed that CH-OX/PP-HS possesses a specific surface area of 13.85 m²/g, a pore volume of 0.0673 cm³/g, and an average pore width of 19.43 nm. Adsorption followed the Freundlich isotherm and pseudo-first-order kinetics. The CH-OX/PP-HS composite exhibited a maximal adsorption capacity of 174.5 mg/g. The production cost of CH-OX/PP-HS is approximately $173/kg. These findings support CH-OX/PP-HS as a sustainable and cost-effective adsorbent for cationic dye removal, advancing green chemistry and water treatment strategies.

This study examines the thermal dynamics of Carreau trihybrid nanofluid flow on a bidirectional stretchable sheet immersed by variable porous medium, while incorporating the influence of an exponential heat source and Cattaneo–Christov flux. The nanoparticles are dispersed in water to form the trihybrid nanofluid. Through appropriate similarity transformations, the governing equations were converted to dimension-free form and then evaluated numerically by using bvp4c method in MATLAB. Thermal profiles have escalated with progression in thermophoresis factor, Brownian number, and radiation factor while declining with thermal relaxation factor. The results obtained in this work have aligned with established dataset by confirming a fine agreement among all the results. The outcomes of this work provide novel insights into controlled thermal transport mechanisms, relevant to microelectromechanical systems, polymer manufacturing, and advanced energy conversion technologies.

The off-centered stagnation point flow (S-PF) phenomenon is important in many technical domains where flow patterns affect efficiency and performance. In these systems, the interplay between asymmetric flow and disk rotation influences the temperature boundary layer and concentration gradients, either augmenting or impeding heat and mass transfer rates. Earliest studies focused on stagnation flows or considered only a few thermal or chemical effects, leaving the combined influence of off-centered asymmetry. Hence, this work fills that gap by examining the significance of thermophoretic particle deposition on the off-centered S-PF of fluid via a rotating disk subjected to activation energy. Moreover, the artificial neural network is used to estimate the heat transmission rate as a function of various factors. Increased magnetic field and permeability parameters decrease the momentum field. The concentration profile decreases as the thermophoretic coefficient increases.

In this work, steam co-gasification of Tunçbilek lignite and olive kernel was investigated in a lab-scale fluidized bed gasifier to evaluate the effects of temperature on gasification mechanism and synergy between lignite and olive kernel. Experiments were carried out at temperatures ranging between 600°C and 900°C. Fuels were prepared with different mass fractions (0:100, 25:75, 50:50, 75:25, and 100:0 olive kernel/lignite). As a result of this study, as temperature increased, the H₂ concentration in syngas increased. The optimum gasification temperature was obtained as 800°C for both fuels and also for their co-gasification. In addition, potassium content in olive kernel enhanced the co-gasification as a natural catalyst.