Mass Transfer Coefficient Research Articles

Point defects in complex inorganic compounds, spinel inverted, Kirkendall ‒ Frenkel effects

New technologies require new materials. One of the ways to find such materials are normal, reversed and partially reversed materials, which are used in spinels. Some such compounds are considered in oxygen-containing spinels, in particular, magnetic materials. Spinel inversion often results in structural defects, including antistructural exchange of cations. The preparation of solid solutions in aluminamagnesia spinel and mullite, which are not presented in the phase diagram, but have a higher diffusion mass transfer coefficient during the synthesis of a complex oxide, is considered. For spinel it is MgO, for mullite it is SiO2. For this, additives and the Kirkendall ‒ Frenkel effect were used. So far, there is no complete certainty that these are not composites, in which a material with a high diffusion mass transfer coefficient is distributed in a matrix of the main complex oxide (MgO·Al2O3, or 3Al2O3·2SiO2). The application of these approaches can expand the scope of materials for various applications.

Carbon dioxide capture in sodium carbonate solution: Mass transfer kinetics and DTAC surfactant enhancement mechanism

Sodium carbonate solvent absorbent has been widely studied for CO2 reduction to deal with global warming because of its green, low cost, and non-corrosive advantages. However, in the application of sodium carbonate as an absorbent for CO2 capture, there is no unified cognition of the mass transfer process, which leads to the lack of guidance for the industrial large-scale process. Moreover, the mechanism of mass transfer enhancement of surfactants, which can effectively improve the mass transfer performance, has not been effectively explored in the literature. Based on this, this paper firstly adopts the molecular dynamics method to analyze the solution characteristics after surfactant addition and optimize the surfactant. Subsequently, a classical dissolved oxygen test method was used to measure the gas-liquid mass transfer coefficient for CO2 absorption into sodium carbonate solution. And based on this mass transfer coefficient measurement method, the mass transfer process of sodium carbonate solution with surfactant was analyzed. The results showed that the sodium carbonate solution with 5 wt% concentration and 10 wt% concentration at 30 °C did not satisfy the pseudo first-order fast chemical reaction kinetics assumption. To improve CO2 absorption mass transfer rate, dodecyl trimethyl ammonium chloride (DTAC) surfactant was introduced, which was improved by 119 % compared with non-enhanced solvent at 5 wt% concentration solution, and the assumption of pseudo first order fast chemical reaction was satisfied. After the introduction of surfactant, the barrier effect decreased the liquid phase mass transfer coefficient, but the Marangoni effect happened in the 5 wt% concentration of sodium carbonate solution, which enhanced the liquid-phase mass-transfer coefficient. This finding reveals the mechanism of mass transfer promotion of sodium carbonate by the surfactant DTAC, which is of great engineering significance for the application in the field of decarbonization after the introduction of surfactant.

Experimental and 4NTU-Le heat and mass transfer model theoretical analysis based on a novel internally cooled liquid desiccant dehumidifier

A microchannel flat tube-rectangular corrugated fin type new internally cooled liquid desiccant dehumidifier (NIC-D) was designed. It was found that the existing NTU-Le heat and mass transfer model is not well adapted to its physical phenomena. To respond to the study gap, this study proposed a new 4NTU-Le heat and mass transfer model based on the physical characteristics of NIC-D in the dehumidification process. Through theoretical derivation and experimental verification, the heat and mass transfer process between air, liquid desiccant and cooling water was analyzed, and the heat and mass transfer mechanism among the three fluids was deeply revealed. On this basis, a new method for calculating heat and mass transfer coefficients was given in combination with the model, which was more adapted to the calculation of the 4NTU-Le model in terms of concept. In addition, this method summarised the correlation between heat and mass transfer from experimental data to predict and characterize the performance of the NIC-D dehumidification process. The results show that the 4NTU-Le mathematical model, the new method for calculating heat and mass transfer coefficients, has high accuracy, in addition to the applicability of the Nu and Sh correlations. According to the analytical results of the validation experiments, the errors between the calculated and experimental values of air outlet temperature, liquid desiccant outlet temperature, cooling water outlet temperature, and air outlet humidity content are within 8.0 %, 15.0 %, 10.0 %, and 10.0 %, respectively, and the absolute average errors AAD are 1.73 %, 6.35 %, 1.46 %, and 3.18 %, respectively. Decreasing the temperature of imported liquid desiccant is a valuable way to improve dehumidification efficiency and energy effectiveness. For every 1.0 °C reduction in the temperature of imported liquid desiccant, the dehumidification efficiency and energy effectiveness increased by 2.6 % and 1.1 %, respectively.

Analysis of thermal significances of nanofluids in inclined magnetized flow with Joule heating source and slip effects

The growing need for effective thermal management systems in engineering applications will improve performance by using nanofluids. Nanofluids, which show enhanced thermal characteristics compared to typical fluids, offer an effective way for heat transmission processes in industries. This study is particularly useful for systems where traditional fluids are insufficient for improving thermal performance. Understanding the overall impacts of Joule heating, magnetic fields, and slip conditions would be beneficial in fields such as aircraft, microelectronics, and biomedical engineering.The thermal significances of nanofluids in an inclined magnetized flow are analyzed in this work, taking slip effects and the Joule heating source into account. The motivation behind the current research is to investigate the flow and heat transfer behavior of magnetohydrodynamic (MHD) nanofluid under the influence of Joule heating in the presence of slip conditions.Based on conservation laws and suitable boundary conditions, the governing formulas for mass, momentum, energy, and nanoparticle concentration are developed. In this thermal investigation, unsteady nanofluid flow in two dimensions via a nonlinear stretched configuration is studied numerically together with an example of a non-uniform heat source. Using similarity transformation, the governing partial differential equation for chemical radiation and slip effects parameters for hydromagnetic flow is transformed into a set of ordinary differential equation (ODE). To solve these equations, a numerical method is applied. This study found that the velocity, mass transfer, temperature, concentration, heat transfer, and skin friction coefficient are significantly influenced by the chemical reaction, radiation parameter, and velocity slip. A graphical representation of the parameters influencing the heat transfer and the velocity changes in calculation is observed.

Effect of impinging angles of liquid–liquid distributor on the extraction and mass transfer performance in a rotating packed bed

Liquid-liquid extraction is a typical separation process that is widely used in various chemical processes. However, the effect of two-liquid feeding mode on the liquid–liquid Murphree efficiency (E) of rotating packed bed (RPB) remains unclear, limiting its applications. In this work, liquid–liquid distributor with different impinging angles (2θ) of two feeding liquid jets in the RPB was designed to evaluate the E, taking water as the extractant to extract benzoic acid from kerosene into the aqueous phase. The effects of operating conditions such as the 2θ, high gravity level (β), and liquid initial velocity (u0) on the E and overall volumetric mass transfer coefficient (KLa) of the RPB were studied. Experimental results revealed that both E and KLa increased with the increase of 2θ, β, and u0. In particular, when 2θ = 90°, E and KLa exhibit optimal values. At β = 49.25, u0 = 1.75 m/s, and 2θ = 90°, since the average diameter of the daughter droplets was smaller and the effective mass transfer area was larger, E reached a maximum of 64.7 % and KLa was 0.489 s−1. A correlation for predicting KLa has been established, with deviations falling within ± 20 %. This work provides theoretical basis for guiding the enhancement of mass transfer in liquid–liquid systems.

Comparison of Homogeneous Anion-Exchange Membrane Based on Copolymer of N,N-Diallyl-N,N-dimethylammonium Chloride and Commercial Anion-Exchange Membranes in Electrodialysis Processing of Dilute Sodium Chloride Solutions

In this study, we investigated the electrodialysis process for treating a dilute sodium chloride solution using various anion exchange membranes – specifically, the commercial heterogeneous MA-41 and homogeneous Neosepta AMX, along with the experimental homogeneous membrane MA-1. We observed an increase in the desalting rate and the limiting current for the studied anion-exchange membranes in the series MA-41, MA-1, and AMX. We found that with commercial membranes, the decrease of the solution concnetration leads to the development of conjugated effects of concentration polarization. For the AMX membrane, useful mass transfer due to electroconvection increases, whereas for the MA-41 membrane, the flux of salt ions decreases due to the occurrence of the water dissociation reaction. For the MA-1 membrane, a decrease in the solution concentration leads to a transition of the system to the underlimiting current mode. This behavior may be associated with a significant contribution of equilibrium electroconvection to the process of ion transfer in dilute solutions in electromembrane systems with this membrane. Due to these differences in membrane properties, the mass transfer coefficients for the MA-1 membrane are higher compared to the AMX membrane at potential drops of 1 and 2 V. Our findings suggest that the most optimal operating mode for the MA-1 membrane is at a potential drop of 1 V in the electromembrane system, which results in a specific energy consumption of 0.24 kWh/mol. Contrastingly, under comparable conditions for the AMX membrane, the specific energy consumption is 0.34 kWh/mol.

Modulation of the local mass and heat transfer of turbulent double-diffusive convection under stable thermal stratifications

We report on numerical studies of bounded double-diffusive turbulent convection, which involves the combined effects of concentration/solutal and thermal buoyancy forces. Our study focuses on an intermediate range of the characteristic non-dimensional numbers, specifically 107≤Rac≤109, and 0≤Raθ≤106. We use fixed values for the concentration and temperature Prandtl numbers (i.e. Prc=700, Prθ = 7), which approximately correspond to seawater properties. We apply wall-resolved Large Eddy Simulations (LES) and compare the obtained results with available Direct Numerical Simulations (DNS) in the literature. Our findings show an overall good agreement in predicting the global wall mass and heat transfer coefficients, achieved with significantly reduced computational costs. Furthermore, the local mass and heat transfer distributions reveal a high sensitivity to the strength of the vertically imposed stable thermal stratification. Finally, we present the vertical profiles of the long-term time-averaged first and second moments.

Experimental study of a novel design bi-fluid based photovoltaic thermal (PVT)-assisted heat pump dryer

This study evaluated the performance of a novel design bi-fluid (air and refrigerant)-based photovoltaic thermal assisted heat pump dryer (BfPVTA-HPD), combining a compact bi-fluid PVT using curved directional fins that direct air at different points to the evaporator/waste aluminum material and HP system with a PVT air outlet mounted micro-channel condenser. BfPVTA-HPD was analyzed regarding energy, exergy, and drying characteristics at two different times, in clear and partially cloudy weather conditions. Mint leaves (Mentha piperita L.) were dried to evaluate BfPVTA-HPD's drying capabilities. The average electrical, thermal, and exergy efficiencies of PV and PVT for Exp-1 and Exp-2 varied to 15.97, 16.54 %, 18.21, 18.23 %, 55.36 %, 42.04 %, 30.95 %, and 25.08 %, respectively. In Exp-1 and Exp-2, respectively, while an increase of 12.32 % and 9.29 % in the average electrical efficiency was achieved by using PVT, an average of 3.15 and 2.86 were reached in the coefficient of performance (COP) of the heat pump. The exergy indicators (the improvement potential, sustainable index, and waste exergy ratio) for the Exp-1 are 839.52, 1.39, and 0.82. The exergy indicators for the Exp-2 are 1166.14, 1.30, and 0.84, respectively. The experiment's average mass transfer coefficients were obtained as 1.17 × 10−8 and 7.75 × 10−9 m/s respectively. The experiment's average effective diffusivity coefficients were obtained as 2.90 × 10−11 and 2.04 × 10−11 m2/s, respectively. The recommended BfPVTA-HPD can be used as a new model to improve the ecological footprint and green manufacturing. Furthermore, the electricity and heat production required for the sustainability of the drying system in spring and winter can be realized.

Assessment of mass transfer performance using the two-film theory and surrogate models for intensified CO2 capture process by amine solutions in rotating packed beds

CO2 capture is a crucial aspect of attempts to mitigate climate change. The purpose of this study is to investigate the impacts of essential operating parameters on the mass transfer performance of absorbing CO2 in rotating packed beds (RPBs). A multilayer perceptron neural network (MLPNN) model with the Levenberg-Marquardt learning algorithm, a mass transfer model using the two-film theory, and an empirical correlation model were developed to predict the overall gas-phase volumetric mass-transfer coefficient (KGaV) for RPB-based CO2 absorption. The developed MLPNN model showed excellent agreement with the actual data, with an MSE of 0.0357, an AARD of 7.4%, and an R2 of 0.9839. A sensitivity analysis was conducted using Taguchi orthogonal array design on distinct mass transfer correlations. The results of the two-film theory and surrogate models for the diethylenetriamine (DETA) solvent were compared. The MLPNN model provided better predictions than other developed models with an AARD of 13% for CO2H2O-DETA system. Therefore, the effects of operating parameters such as concentration, temperature, solvent flow rate, and rotational speed on KGaVand CO2 removal efficiency were evaluated using the MLPNN model. Finally, an empirical correlation was proposed to predict KGaVas a function of operational parameters.

Novel sparging strategies to enhance dissolved carbon dioxide stripping in industrial scale stirred tank reactors

Aerated stirred tank reactors are widely used in bio-process engineering and pharmaceutical industries. To supply the organisms with oxygen and control the pH value, oxygen is transferred from air bubbles into the liquid phase, and, at the same time, carbon dioxide is stripped from the liquid phase with the same gas bubbles. The volumetric mass transfer coefficients for oxygen and carbon dioxide are, therefore, of crucial importance for the design and scale-up of aerated stirred tank reactors. In this experimental work, the volumetric mass transfer coefficients for oxygen and carbon dioxide are investigated simultaneously to study their mutual influence. The mass transfer performance for oxygen and carbon dioxide is conducted in stirred tank reactors on the 3 L laboratory scale, 30 L pilot scale, and 15,000 L production scale. First, the influence of dissolved carbon dioxide on the oxygen mass transfer performance is investigated in a 30 L pilot scale stirred tank reactor. The results show that the volumetric mass transfer coefficient of oxygen is not affected by the concentration of dissolved carbon dioxide, but the total mass flux of oxygen decreases with increasing carbon dioxide concentration due to the decreasing partial pressure difference. With rising gassing rate and volumetric power input, both mass transfer coefficients for oxygen and carbon dioxide show the same increasing trend. Although this trend can also be observed when scaling down to the 3 L laboratory scale reactor, a significantly different effect must be considered for the scale-up to the 15,000 L industrial scale reactor. The limited absorption capacity for carbon dioxide of the gas bubbles during the long residence time in the industrial scale reactor is noticeable here, which is why the specific interfacial area is of negligible importance. This effect is used to develop a method for independent control of oxygen and carbon dioxide mass transfer performance on an industrial scale and to increase the mass transfer performance for carbon dioxide by up to 25%.

MATHEMATICAL MODELING OF THE PROCESS OF SEPARATION OF MIXTURES BY LIQUID EXTRACTION

While designing liquid-phase extraction processes, one of the main conditions is to determine the kinetic characteristics of the exchange processes necessary to determine the flows and masses of the components. Existing mass transfer models describe mass transfer processes on a semi-empirical and empirical basis with a limited range of applications, simplifying the real picture in most cases. In this regard, the development of models that more widely describe the processes of liquid-phase extraction and allow their application is considered one of the important tasks. Based on the generalization of the Chilton-Colborne hydrodynamic analogy in gradient flows and further development of the Landau-Levich boundary layer model, a mathematical model has been developed to determine the mass transfer coefficients in the extraction process in continuous and dispersed phases using minimal experimental data obtained at the stage of hydrodynamic studies

Accelerated weathering of construction‐grade limestone for CO2 absorption

AbstractAccelerated weathering of limestone (AWL) process efficiently captures CO2 from point source emissions. However, despite achieving an outstanding capture efficiency of 73.51 %, lab‐grade (LG) limestone with 99.90 % CaCO3 as an absorbent is costly ($2757.70/t), making commercialization of AWL impractical. This work delves into the viability of utilizing construction‐grade (CG) limestone (93.26% purity) for the AWL process facilitated by potable water in an absorption tower for post‐combustion capture. The result shows that CG limestone achieves comparable CO2 capture efficiency of 8.0–74.68% and bicarbonate (Ca(HCO3)2) concentration of 0.63–3.10 mM compared with LG limestone. However, LG limestone has 0.29 mol CO2/mol CaCO3 higher CO2 absorption capacity and a faster absorption rate than CG limestone, indicating a somewhat better CO2 capture performance. Nevertheless, CG limestone offered a more cost‐effective alternative, with a $2735.24 lower cost per ton of CaCO3 and a $2651.63 per ton CO2 lower CO2 capturing cost at the highest carbon capture efficiency (HCCE) condition compared to LG limestone. The kinetic analysis shows that the forward reactions in the AWL process are significantly faster at elevated CO2 concentration, with the mass transfer coefficient affirming that CO2 dissolves faster than CaCO3, in line with prior research. Thus, this work validates that CG limestone‐based AWL achieves comparable CO2 capture performance to that of LG limestone, offering a cost‐efficient alternative. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.

Novel dissolved oxygen distribution model of a full-scale aeration tank for a municipal wastewater treatment plant in a cold climate region

ABSTRACT Aeration is the most energy-intensive process in wastewater treatment plants (WWTP). Seasonal variation in hydraulic flow and load has a significant effect on WWTP's aeration energy efficiency. High flow and temperature variations are common in cold climate regions, and with climate change increasing, extreme weather events will accentuate these situations. The prediction of oxygen mass transfer is crucial for minimizing the energy consumption of the aeration tank. This study presents a computational fluid dynamics model for a turbulent flow regime, simulating the hydraulics and dissolved oxygen (DO) concentration distribution of two phases, water and air bubbles, in a full-scale, as-built activated sludge tank. Model validation error was less than 15%. Different seasonal flows and temperatures were investigated by fixing liquid side oxygen mass transfer coefficient (kL) to 0.7 × 10–5 m/s and initial bubble diameter (dB) to 0.0025 m in the gas phase. The results show that variating hydraulic flow causes noticeable differences in DO distribution and higher flow could be more effective levelling in DO gradients. More even DO distribution could result in using up to a 10% lower DO setpoint value, using 3% less air for the same treatment result, thus lowering aeration energy cost.

Application of a Film Model to Mass Transfer and Chemical Reaction at a Plasma-Liquid Interface

Plasma electrodes provide novel ways of conducting electrochemical processes in liquids, in particular because of the ability to generate unique reactive radical species. However, the radicals injected into the liquid and their ensuing reactions are often confined to a narrow region near the interface of the plasma and the liquid. Thus, mass transfer has been found to play an important role in the observed kinetics and a modeling framework that includes both transport and kinetics is required to interpret experimental data. Here, we apply the idea of a film model for interphase mass transfer to plasma-liquid electrochemical processes, whereby transport is described by a stagnant film that is inherently linked to the concentration boundary layer and the mass transfer coefficient. Equations that govern the transport and reaction of radicals and substrates within the film are solved assuming a quasi-steady state approximation. The model is applied to specific case studies from the literature to estimate important parameters that are difficult to measure experimentally, such as the mass transfer coefficient. Our study shows that a film model can elucidate the effect of mass transfer on observed conversion rates and allow the intrinsic kinetics to be unraveled.

Continuous [C] content prediction model in molten steel of the all-scrap electric arc furnace

The continuous [C] content prediction model in molten steel of the all-scrap electric arc furnace was established through the explicit finite difference method combined with numerical simulation based on the thermodynamics and kinetics of the decarburization reaction. Initially, a method to figure out the average [C] content of mixed input scrap was proposed, which provided a basis for subsequent calculations. Furthermore, scrap melting rate, mixing side-blowing/bottom stirring, and oxygen blowing intensity adjustment of oxygen lance had been considered as the three key elements. Decreasing scrap melting time was beneficial to improving the EAF efficiency because it accounts for 80% of the total operation time. The research found that the scrap melting rate was mainly affected by the solid-liquid phase heat transfer and [C] content transfer, and the heat transfer played a dominant role. Applying mixing side blowing/bottom stirring could lead to an improvement in the mass transfer coefficient of the decarburization reaction, and the value was increased from the range of 0.0059 s−1-0.021 s−1 by using single side-blowing to the range of 0.0079 s−1-0.023 s−1. The mass transfer coefficient could be enhanced by the oxygen intensity adjustment of oxygen lances when mixing side blowing/bottom stirring was used. This was a benefit of deeper jet impact zones on the molten steel surface caused by high oxygen flow. After the model was applied to an industrial site, the prediction accuracy of the endpoint [C] content within the error range of ±0.02% and ±0.01% reached 91.2% and 85.7%, respectively.

A multi-approach study on CO2 absorption in packed beds: Theoretical, experimental, and CFD perspectives on gas phase pulsation

This work seeks to improve CO2 absorption efficiency in packed bed columns by substituting amine-based solvents with sodium hydroxide and implementing gas phase pulsation to enhance mass transfer coefficients. Experimental analysis and computational fluid dynamics modeling were employed to investigate the impact of pulsation on absorption efficiency under various conditions. Essential parameters comprised superficial liquid velocity (1.2–4.6 cm/s), pulsation frequency (0–10 Hz), amplitude (0–20 mm), and NaOH concentration (0.25 N to 2 N), while maintaining a constant superficial gas velocity of 120 cm/s and a solute gas concentration of 13 %. Three packing materials—glass spheres, ceramic Raschig rings, and ceramic Pall rings—were evaluated. The results demonstrated that ceramic Pall rings exhibited the greatest efficiency. Pulsation, namely at 9.06 Hz and 20 mm amplitude, enhanced the volumetric mass transfer coefficient by as much as 4.53 times for Pall rings. Increased column diameters (from 7.00 cm to 11.5 cm) enhanced performance. The findings show advancement of more efficient CO2 absorption (by switching from chemical absorption using amine based solvents to classical chemical absorption using aqueous NaOH solution) for industrial applications, aiding climate change mitigation initiatives.

Effects of internals on macroscopic fluid dynamics in a bubble column

The effects of internals on liquid mixing and gas–liquid mass transfer have rarely been investigated in bubble columns, and the commonly used measurement method overestimates significantly overall gas holdup. Firstly, gas holdup measurement method is improved by conducting multi-point liquid level measurement and using net fluid volume instead of bed volume to calculate gas holdup. Then, a stable conductivity method for liquid macromixing has been established by shielding large bubbles using #16 nylon mesh. Subsequently, the influences of internal coverage (=12.6%, 18.9% and 25.1%) on macroscopic fluid dynamics in a bubble column with a free wall area are systematically investigated. It is found that the presence of internals has a notable effect on macroscopic fluid dynamics. The overall gas holdup and gas–liquid volumetric mass transfer coefficient decrease, and the macromixing time decreases with the increase of internal cross-sectional area coverage. These are mainly caused by the uneven distribution of airflow due to the low resistance in the free wall area. This design makes maintenance easier, but in reality, the reactor performance has decreased. Further improvements will be made to the reactor performance based on such a configuration through flow guidance using baffles.

Investigation of magnetite water nanofluid flow through a stretching sheet using the Hamilton and Crosser model for nanoparticle shape factor and effective thermal conductivity

The main objective of this current investigation is to study the heat and mass transfer of the convective MHD Fe3O4−H2O nanofluid through an expanding sheet in the presence of thermal radiation. The Hamilton and Crosser model describes the shape and effective thermal conductivity. The fluid flow governing PDEs has been transformed into a system of ODEs by utilizing appropriate similarity transformation. We used SQLM or Spectral Quasilinearization method to solve them numerically and draw the graphical conclusion using MATLAB software. The skin friction, the Nusselt number and the Sherwood number have been determined numerically and portrayed graphically for the pertinent parameter. It has been observed that for the increment of the volume fraction of Fe3O4 nanoparticles, the fluid velocity tends to reduce while the thermal profile is enhanced. We also observed that for the increment of the buoyancy parameter, the mass transfer is enhanced. Additionally, for the enhancement of the Schmidt number from 0.1 to 1.2, the rate of mass transfer coefficient increases very rapidly. The outcome of the current study has been compared with previously published data, and there is a satisfactory agreement.

Reactive Extraction of Carboxylic Acids (Lactic, Propionic and Succinic Acids) using Tri-n-Butyl Amine Dissolved in Various Diluents

The current study intends to look into the extraction of lactic acid, propionic acid and succinic acids from aqueous solutions of these substances utilizing various solvent-extractant combinations to ascertain the most effective composition for the reactive extraction. The commercial value of succinic, propionic, and lactic acids in industrial processes led to their selection as the carboxylic acids. The process of recovering carboxylic acids from their aqueous solutions is accomplished by the Process Intensification method of reactive Tri-n-Butyl Amine was employed in the experiments because it has better stability, a lower water solubility, and is more eco-friendly than other extractants of the amine type. The extractants were dissolved in various diluents with various chemical structures, including 1-octanol, chloroform, and dimethylene chloride. Each experiment was conducted at 298.15 K. The distribution coefficient (KD), loading factor (Z), and extraction yield (%E) were used to compare the results in the range of 0.1 to 0.4 N acid concentration at various concentrations of Tri-n-Butyl Amine (10% to 40%). It was observed that at 0.1N and 40% amine concentration succinic acid attains a maximum distribution coefficient KD is 8.01 and equilibrium complexion KE1 is 7.5 for Tri-n-Butyl Amine, followed by propionic acid and lactic acid and a (1:1) type of acid amine complex was observed. The kinetic studies that were carried out using stirred cells to figure out the kinetic parameters such as order of the reaction with respect to acid and amine, mass transfer coefficient, and rate constant are also reported. The reaction with the highest Hatta number, MH=14, occurs in an instantaneous regime in 1-octanol when succinic acid and Tri-n-Butyl Amine interact.

Process Intensification in Distillation using HiGee Rotating Packed Bed

For decades, improving the gas-side mass transfer coefficient in rotating packed beds has been a formidable challenge. Distillation, often limited by gas-phase resistance, requires substantial innovation to enhance these coefficients. Rotating packed beds offer a distinct advantage over conventional columns, primarily due to the intense micro-mixing within fluid channels. This micro-mixing significantly boosts mass transfer between phases and facilitates rapid attainment of steady-state conditions, making them a superior choice for processes where gas-side resistance is the bottleneck. The current study emphasis on the mass transfer performance of rotating packed for acetone water system with two different packing materials viz., wire mesh and ceramic beads. Working principle of HiGee, typical flow pattern, modeling equations have been discussed in this paper. The effects of rotational speed, gas flow rates and radial thickness of the packing on mass transfer performance were also investigated. The mass transfer coefficients of the rotating packed bed HiGee were increased with increasing the rotational speed. The Height Equivalent to Theoretical Plates (HETP) of the rotating packed bed used in this study was 5-6 times less than the conventional packed columns. This study contributes to significantly advancing the industrial applications of rotating packed beds.