Chemical Engineering & Technology最新文献

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.

This article proposes a new type of spoiler structure to improve the heat dissipation performance of battery packs. The influences of the spoiler number n, spoiler length d, and spoiler width w in the waist-hole shaped spoiler structure on the maximum temperature, power consumption, and total deformation are analyzed. The results show that the addition of the waist-hole shaped spoiler structure is more beneficial than the non-spoiler structure on the heat dissipation performance of the battery pack, and it has higher structural strength. At inlet mass flow rates of 0.1 kg/s for the waist-hole shaped spoiler structure, the maximum temperature decreased by 5.48 K (8.60%) compared with original structure. In addition, the number of spoiler n, the length of spoiler d, and the width of spoiler w have a significant impact on the heat dissipation performance of the battery. This work has reference significance for the flow passage structural design of power battery packs.

We successfully engineered a cactus-like Co₂P nanocatalyst for overall water splitting by incorporating manganese to modulate its electronic structure. Incorporating Mn into Co₂P enhances both HER and OER through optimized surface adsorption, leading to faster kinetics and improved catalytic efficiency. The Mn-Co₂P catalyst delivers outstanding alkaline HER performance, requiring just 51 mV to drive 10 mA cm⁻² while showing no degradation during a 48-h stability test. Notably, the OER overpotential is just 283 mV at 50 mA cm⁻² with remarkable durability. Remarkably, when utilized as dual-function electrodes in a complete water electrolysis system, the Mn-Co₂P-based system delivers 10 mA cm⁻² at a low cell voltage of 1.523 V, along with brilliant long-term stability.

The present study investigates the steady incompressible natural convective flow of power law fluid in a squared enclosure having a T-shaped fin under the magnetic field and thermal radiation effects. The governing partial differential equations (PDEs) are transformed into nondimensional equations by employing dimensionless variables. The resulting system of dimensionless PDEs is solved numerically. The numerical simulations showed that the velocity and temperature profiles increases at higher Rayleigh number. Further, the addition of a magnetic field, quantified by the Hartmann number, decreases the fluid velocity and kinetic energy, reflecting the resistive effects of magnetic forces on the flow dynamics. The local and average Nusselt numbers decreases for higher radiation parameter. The obtained outcomes provide valuable insights for applications used in advanced thermal management systems, requiring fluid flow control and enhancing heat transfer.