Investigation Of Mass Transfer Research Articles

Numerical investigation of heat and mass transfer of SWCNT/MWCNT‐water suspension over a porous stretching sheet using Sisko fluid model

AbstractThis study presents a comprehensive numerical computation of heat‐mass transfer characteristics of single‐walled carbon nanotube (SWCNT)/multi‐walled carbon nanotube (MWCNT)‐water suspension flow over a porous stretching sheet with an inclined magnetic field. The governing equations for fluid flow characteristics are formulated using the Sisko fluid model to capture the Newtonian and non‐Newtonian behavior of the nanotube‐water mixture. The nonlinear coupled partial differential equations are converted into nonlinear dimensionless coupled ordinary differential equations using suitable similarity transformations. These equations are solved using MATLAB by implementing the four‐stage Lobatto IIIa formula. The comprehensive set of computations is performed to explore the influence of pertinent parameters, including Sisko fluid parameters, concentration of nanotubes, stretching sheet velocity, and porous medium characteristics on the flow, heat, and mass transfer profiles. From the graphs and statistical analysis, it is clear that the volume fraction of SWCNT and MWCNTs are strongly correlated. The investigation reveals that increasing the inclination angle affects the fluid velocity. The variation in all flow features is negligible for volume fractions of CNTs between 0% and 10% but a significant effect is observed only beyond 10%. Higher volume fractions of CNTs result in enhanced local heat transfer coefficient. This can be attributed due to the outstanding heat transfer capabilities of CNTs owing to their high thermal conductivity. However, Shear thickening fluids exhibit high heat transfer phenomena when compared to shear‐thinning and Newtonian fluids. This research provides valuable insights into the optimization of CNT‐based nanofluids for efficient heat and mass transfer applications in electronics cooling, heat exchangers, and solar energy systems, offering opportunities to enhance energy efficiency and device performance.

Investigation of Gas-Liquid Mass Transfer in the Fuel Scrubbing Inerting Process Using Mixed Inert Gas

Investigation of Gas-Liquid Mass Transfer in the Fuel Scrubbing Inerting Process Using Mixed Inert Gas

Investigation of gas-liquid mass transfer in slurry systems driven by the coaxial mixer

The coaxial mixer was applied to the gas-liquid mass transfer process in slurry systems containing up to 8 vol% solids. The effects of impeller type, impeller speed, solid content, and gas flow rate were examined, and a correlation for the volumetric mass transfer coefficient was established. The findings indicate that at identical impeller speeds, the combination of an anchor and Rushton turbine exhibited the highest volumetric mass transfer coefficient and gas hold-up among coaxial mixers. However, when the pitched blade turbine with a down-pumping direction was utilized as the inner impeller, the coaxial mixer demonstrated superior performance under the same power consumption conditions. Additionally, the lower anchor speed was found to improve gas-liquid mass transfer, whereas a higher speed would lead to poor dispersion of gas phase, thereby deteriorating the performance of coaxial mixers. Increasing solid content caused a continuous decline in both the volumetric mass transfer coefficient and gas hold-up, while a rise in gas flow rate had the positive effect. Finally, the correlation developed for the volumetric mass transfer coefficient in slurry systems showed a deviation of less than 20% between predicted and measured values.

Dampening Humidifier Effects on Electrochemical Pressure Impedance Spectroscopy (EPIS) Fuel Cell Diagnostics

Fuel cells are versatile, low-emission alternative energy sources, but their optimization and failure analyses are complex due to their black-box nature. Conventional in-situ diagnostic techniques such as electrochemical impedance spectroscopy (EIS), are widely used to deconvolute transient processes within operating fuel cells. EIS is invaluable to understanding some of these processes, but other processes within the cell, such as mass transport and individual water fluxes, get overshadowed and are hard to detect.In an effort to provide information that is currently unattainable with conventional fuel cell diagnostic techniques, this project focuses on the further development of electrochemical pressure impedance spectroscopy (EPIS). EPIS is based on a pressure alternating frequency response analysis (pFRA). This diagnostic method is similar to EIS, except that it implements mechanical perturbations in the form of gas pressure oscillations, rather than voltage or current oscillations, to achieve an electrochemical response. Since EIS is based on electrical perturbations, the results are primarily based on the transport of electrons and provides electron-based performance metrics, including charge transfer, adsorption, diffusion, and double-layer behaviors. Conversely, the mechanical perturbations in EPIS enable the investigation of non-electron-based mechanisms, such as flow and gas transport resistances.This project builds from the work of Zang et al., who developed an experimental setup for EPIS and showed that pressure perturbations affect local reaction rates and transport phenomena within the cell, providing a sinusoidal voltage response.1 Prior work focused on the EPIS signal at the outlet, as the oscillation diminished by the time it reached the inlet of the cell. Shirsath et al. proposed that the excess volume of the humidifier before the fuel cell dampens the pressure oscillation signal and acts as an extra capacitor.2 To mitigate this, this project focused on the implementation of additional hardware between the humidifier and the cell inlet to act as a counter resistance and amplify the inlet pressure oscillation and subsequent EPIS response. The setup was fully explored through a series of targeted tests focused on identifying the most effective system parameters to validate the configuration and achieve optimal results. This hardware implementation aims to reduce the system effects and provide a more consistent pressure oscillation down the channel to further decouple the EPIS response and provide more accurate diagnostics of the cell. 1 Zhang, Q., Homayouni, H., Gates, B. D., Eikerling, M. H., & Niroumand, A. M. (2022). Electrochemical Pressure Impedance Spectroscopy for Polymer Electrolyte Fuel Cells via Back-Pressure Control. Journal of The Electrochemical Society, 169(4), 044510. 2 Shirsath, A. V., Raël, S., Bonnet, C., Schiffer, L., Bessler, W., & Lapicque, F. (2020). Electrochemical pressure impedance spectroscopy for investigation of mass transfer in polymer electrolyte membrane fuel cells. Current Opinion in Electrochemistry, 20, 82–87.

Numerical Investigation of Mass and Heat Transfer in a New Coaxial with Shell-and-Tube Heat Exchanger

Numerical Investigation of Mass and Heat Transfer in a New Coaxial with Shell-and-Tube Heat Exchanger

Mass Transfer Process by Diffusion of RE(III) (RE=La, Pr) in Eutectic LiCl-KCl Salt

Mass transfer is an important link in the entire electrode process. To investigate mass transfer process by diffusion of trivalent rare Earth ions in molten LiCl-KCl system, the electroreduction mechanism, mass transfer kinetics and diffusion layer thicknesses of RE(III) (RE = La and Pr) were studied by a series of electrochemical methods. It was found that RE(III) underwent one-step reduction reaction with the exchange of 3-electron and reversible processes. The diffusion coefficients (D) of RE(III) and limiting current densities (j l ) for RE(III)/RE pair were measured at different temperatures and concentrations by cyclic voltammetry and chronoamperometry, respectively. Based on the results of D and j l , the diffusion layer thickness (δ) of RE(III) was calculated using the simplified Nernst-Planck formula. Furthermore, the impacts of temperature and concentration on δ were explored. The results indicated that as the temperature declined and ions concentration increased, δ decreased. Meanwhile, the relationships between δ and temperature and concentration were also obtained.

Analytical investigation of heat and mass transfer in MHD nano fluid flow past a moving vertical plate

This study aims to derive analytical expressions for temperature, concentration, and velocity in an unsteady MHD convective nanofluid flow past a moving vertical plate. The governing nonlinear differential equations are solved analytically using the Homotopy Analysis Method (HAM). The resulting solutions are presented as concentration, temperature, and velocity profiles, allowing for the analysis of various physical parameters' influence on the flow behavior. Furthermore, our analytical results are validated by comparing them with existing numerical solutions using MATLAB. The impact of these parameters on skin friction, the Nusselt number, and the Sherwood number is presented, demonstrating good agreement with previously reported data. The findings of this research hold significance for industries involving heat transfer processes, such as thermal management systems, electronic cooling, and energy generation applications.

Investigation of conjugate heat and mass transfer in a sleeve-type hollow fiber membrane for liquid desiccant dehumidification

In adiabatic conditions, the dehumidification capacity of hollow fibre membranes decreases as solution temperature rises. To address this limitation, this study proposed a novel approach based on sleeve-type hollow fibre membranes. The study focused on three distinct fluid streams and the sleeve-type hollow fibre membrane tube. A three-dimensional model of the dehumidifier was created, and the dehumidifier's heat transfer, mass transfer, and fluid flow characteristics were thoroughly analyzed and experimentally validated. The results showed that the average values of the Sherwood number and Nusselt number on the air side are significantly influenced by the Reynolds number. On the solution side of the sleeve-type hollow membrane, the average Nusselt number and Sherwood number are approximately 4.0 and 4.6, respectively. According to the research, 76 % of the resistance is accounted for by the mass transfer resistance on the membrane side. The study's conclusions provide insightful information for improving the design of sleeve-type hollow fibre membrane dehumidifiers.

Investigation of heat and mass transfer of oldroyd – 8 constant fluid in wire coating process employing response surface methodology

Wire coating is widely used for electrical insulation, shock protection, preventing leakage, and facilitating smooth current flow. This study aims to evaluate the applicability of Oldroyd-8 constant fluid for wire applications in a magnetic field using a pressure-type die. Based on the Buongiorno model with a constant pressure gradient and temperature-dependent thermophysical properties, governing equations are developed. These equations are transformed into dimensionless form and solved numerically. The study thoroughly investigates key features, including momentum, thermal distribution, nanoparticle volume fraction, and shear stress rate. Also, this study employs Response Surface Methodology to optimize heat transfer and shear stress rates in coated wire. Quadratic models, developed through a central-composite design, determine optimal levels for the Oldroyd-8 constant fluid parameter and nanofluid parameters, ensuring optimal heat transfer and shear stress rates for the melt. Nanofluid parameters contribute to an improvement in the thermal distribution profile. Optimal heat transfer and shear stress rate occur when the nanofluid parameters are minimized, and non – Newtonian fluid parameter is maximized.

Mass Transfer Mechanism Within Commercial PTFE Membranes In Spacer-Filled Direct Contact Membrane Distillation

The mass transfer mechanism within commercial PTFE membrane with various nominal pore sizes in spacer-filled direct contact membrane distillation (DCMD) was determined. Mass fluxes and membrane permeability (MP) values for each commercial PTFE membrane were experimentally measured. The MP values increased insignificantly with 2.3% and 4% when the inlet temperature at feed side rose from 400C to 500C in different membrane pore sizes. All investigated mass transfer models except from Dusty Gas model were good enough to simulate the mass transfer inside smaller membrane pore sizes (0.22 µm, and 0.45 µm). Compared to combined diffusion model, the predicted mass fluxes using the overall mass transfer model including the contribution of Poiseuille flow obtained better agreement with experimental results for larger membrane pore size (1 µm). The mean absolute percentage error (MAPE) values for combined diffusion model were up to 16.5% compared with the Ding et al. model or Schofield et al. model (under 3%). Regarding the root mean square error (RMSE), the combined diffusion model obtains larger values than the mass transfer model considering the Poiseuille flow contribution. Consequently, the contribution of Poiseuille flow in mass transfer mechanism within smaller PTFE membrane pores (0.22 µm, and 0.45 µm) could be ignored, however, the contribution of Poiseuille flow to the overall mass transfer should be included in case of larger membrane pores (1 µm), or the case of applied transmembrane hydrostatic pressure.

Numerical simulation on the MHD time-dependent Williamson nanofluid flow with cross diffusion and heat generation/absorption over a stretching plate

This novel study unfolds the heat and mass transfer investigation of Williamson nanofluid (WNF) through a porous medium past a stretching plate, along with considering heat generation/absorption. Nanoparticles hold significant significance in thermal engineering, industrial operations, and biomedical advancements, contributing to enhanced heat transfer, cooling mechanisms, thermal extrusion processes, and applications in cancer treatment, particularly in addressing brain tumors. The coupled ordinary differential equations (ODEs) are gained from governing partial differential equations (PDEs) by applying sufficient transformations. Then the ODEs of a nonlinear nature, along with boundary conditions, are solved through bvp4c, a built-in MATLAB program. A good agreement has been found in comparing the present study with already published papers. Numerical values for skin friction, mass transfer, and heat transfer are shown through a table against involved physical parameters, especially for both injection [Formula: see text] and suction [Formula: see text] cases, by varying the values of unsteadiness parameter A and Weissenberg number [Formula: see text]. The effects of the physical parameters on velocity, temperature, and mass profile are graphically depicted and illustrated minutely. It is noted that both the magnetic and Williamson parameters cause the thickness of the boundary layer to be reduced. It can be deduced from these findings that the rate of heat transfer over the surface of the plate decreases as the unsteadiness parameter increases. Furthermore, it is observed that an increase in the parameters of thermophoresis and Brownian motion leads to a higher temperature of the nanofluid.

Investigation of Mass Transfer of Ozone in Jet Loop Reactor

Investigation of Mass Transfer of Ozone in Jet Loop Reactor

Catalytic cycloaddition of CO2 to epoxidized methyl oleate over a HBimCl-NbCl5/HCMC: Physicochemical, mass transfer and kinetic investigation

The cycloaddition of CO2 to epoxidized molecules is an ecofriendly strategy for synthesizing aliphatic carbonates. In this study, heterogeneous catalytic synthesis of carbonated methyl oleate was performed. Influences of reaction parameters such as reaction temperature (403.15–443.15 K), pressure (1–3 MPa), concentration of functional groups (1.22–2.88 mol·L−1) and catalyst loading (0.025–0.042 g·mL−1) on the kinetics were evaluated. Gas-liquid mass transfer of CO2 in the methylated oleic acid system was investigated, and a mathematical model was developed. The dissolution of CO2 was found to be exothermic, and the dissolution capacity decreases with increasing temperature and decreasing pressure. The solubility of CO2 follows an order of methylated form > epoxidized form > carbonated form. A high conversion rate (68.45 %) of epoxides was achieved in 6 h at 443.15 K and 3 MPa with a catalyst loading of 0.042 g·mL−1. These results show a potential route for synthesizing aliphatic carbonates by combining methyl oleate with CO2.

Numerical investigation of heat and mass transfer in three-dimensional MHD nanoliquid flow with inclined magnetization

Heat and mass transfer rate by using nanofluids is a fundamental aspect of numerous industrial processes. Its importance extends to energy efficiency, product quality, safety, and environmental responsibility, making it a key consideration for industries seeking to improve their operations, reduce costs, and meet regulatory requirements. So, the principal objective of this research is to analyze the heat and mass transfer rate for three-dimensional magneto hydrodynamic nanoliquid movement with thermal radiation and chemical reaction over the dual stretchable surface in the existence of an inclined magnetization, and viscous dissipation. The flow is rotating with constant angular speed ω∗\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\upomega }^{*}$$\\end{document} about the axis of rotation because such flows occur in the chemical processing industry and the governing equations of motion, energy, and concentration are changed to ODEs by transformation. The complex and highly nonlinear nature of these equations makes them impractical to solve analytically so tackled numerically at MATLAB. The obtained numerical results are validated with literature and presented through graphs and tables. Increasing the Eckert number from 5≤Ec≤10,\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$5\\le Ec\\le 10,$$\\end{document} a higher Nusselt and Sherwood number was noted for the hybrid nanofluid. By changing the angle of inclination α\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\alpha$$\\end{document}, the Nux\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${Nu}_{x}$$\\end{document} performance is noted at 8% for nanofluid and 33% for hybrid nanofluid. At the same time, Shx\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${Sh}_{x}$$\\end{document} performance of 0.5% and 2.0% are observed respectively. Additionally, as the angle of inclination increases the skin friction decreases and the chemical reaction rate increases the mass transmission rate.

Extraction of Alpha-cypermethrin Pesticides from Aqueous Solution by Emulsion Liquid Membrane

This research examines the emulsion liquid membrane (ELM) extraction efficiency and stability to abstraction of alpha-cypermethrin pesticides from aqueous solution when blended surfactants are used in the liquid membrane composition. The stability of the membrane was examined in the aspect of the emulsion breakdown time and distribution of droplet size. The ingredients employed in ELM were Span80 (sorbitan monooleate) and Tween80 (polyoxyethylene sorbitan monooleate) as surfactants and a mixture of kerosene, sunflower oil (3:7) as diluents and stripping agent was used sodium hydroxide (NaOH). Some parameters were assessed, including the value of Hydrophilic Lipophilic Balance (HLB), blended surfactant concentration, homogenizer speed, emulsification time, and NaOH concentration as a stripping agent. According to the results, a stable emulsion was created at HLB (5.37), blended surfactant 3 % (w/v), 12,700 rpm of homogenizer speed, 9 min of emulsification time, and 0.05 N of NaOH. Under these circumstances, 89.2 % of the alpha-cypermethrin was extracted with 1.8 % emulsion breakage. As a result, the combinations of (Span80 with Tween80) have enormous potential as surfactants and they can improve the stability of the emulsion. Additionally, completed was mass transfer investigation and extraction kinetics

Numerical Investigation of Heat and Mass Transfer in Nanofluid-Filled Porous Medium

Numerical Investigation of Heat and Mass Transfer in Nanofluid-Filled Porous Medium

Experimental Investigation of Mass Transfer in NH3 SCR Over Self-Supporting Cu-ZSM-5 Foam

Selective catalytic reduction of NOx by NH3 is an emerging technology for emission control applications worldwide. The development of structured catalysts for process intensification is of growing interest in catalytic...

Investigation of interfacial mass transfer phenomena applying non-invasive Raman imaging and density gradient theory

This study presents a novel non-invasive Raman measurement setup for investigating diffusion and mass transfer processes at liquid/liquid interfaces, based on a photometric setup utilizing customized photon multiplier (CPMs). The results highlight the effectiveness, reliability and applicability of this setup in visualizing and analyzing acetone mass transfer across the aqueous-organic interface. The study focuses on the liquid/liquid extraction of acetone from the aqueous phase into the organic phase, using toluene as the organic solvent. The study's key findings indicate that – in the absence of forced convection – mass transfer across the interface is not the limiting factor in the extraction process; instead, diffusion in the bulk phase takes precedence. Acetone's rapid local transport from the aqueous to the organic phase is observed, with a temporary concentration minimum on the aqueous side of the interface. In the organic phase, local equilibrium is reached near the interface first, only after which acetone disperses into the bulk phase. This dual mechanism—fast interfacial mass transfer and slower bulk-phase diffusion—marks a significant feature of the considered extraction process, which were further substantiated by dynamic concentration gradient theory simulations. The research further demonstrates the feasibility of upscaling interfacial mass transfer simulations using adaptive meshing. However, macroscopic effects like induced convection challenge purely diffusive models. The simulations confirm rapid enrichment of acetone at the interface, followed by slower mass transfer through the interface and bulk phase diffusion, consistent with the experimental data. Experimental and modeled results align well with literature data for liquid/liquid extraction, thereby validating the accuracy of the presented novel diffusion measurement setup and demonstrating its potential to investigate mass transfer phenomena near liquid/liquid interfaces.

Mass transfer enhancement and hydrodynamic performance with wire mesh coupling solid particles in bubble column reactor

It is of vital significance to investigate mass transfer enhancements for chemical engineering processes. This work focuses on investigating the coupling influence of embedding wire mesh and adding solid particles on bubble motion and gas–liquid mass transfer process in a bubble column. Particle image velocimetry (PIV) technology was employed to analyze the flow field and bubble motion behavior, and dynamic oxygen absorption technology was used to measure the gas–liquid volumetric mass transfer coefficient kLa. The effect of embedding wire mesh, adding solid particles, and wire mesh coupling solid particles on the flow characteristic and kLa were analyzed and compared. The results show that the gas–liquid interface area increases by 33% to 72% when using the wire mesh coupling solid particles strategy compared to the gas–liquid two-phase flow, which is superior to the other two strengthening methods. Compared with the system without reinforcement, kLa in the bubble column increased by 0.5–1.8 times with wire mesh coupling solid particles method, which is higher than the sum of kLa increases with inserting wire mesh and adding particles, and the coupling reinforcement mechanism for affecting gas–liquid mass transfer process was discussed to provide a new idea for enhancing gas–liquid mass transfer.

Experimental Investigations of Non-Stationary Heat and Mass Transfer with Reversible Air Flow through Fixed Layers of Absorbent and Heat-Accumulating Packing

Experimental Investigations of Non-Stationary Heat and Mass Transfer with Reversible Air Flow through Fixed Layers of Absorbent and Heat-Accumulating Packing