Mass Transfer in Liquid in an Apparatus with Mobile Packing. Application of a Dispersion Model

1993 ◽  
Vol 58 (5) ◽  
pp. 1078-1086
Author(s):  
Zdeněk Palatý
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Empirical Equation ◽  
Dispersion Model ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients

The paper deals with the mass transfer in a liquid on a plate with mobile packing. A procedure has been suggested which enables estimation of the mass transfer coefficients from experimental data considering the dispersion flow of the liquid. The results obtained from the desorption of CO2 from water are presented graphically and in the form of empirical equation.

A Method for Estimating Mass Transfer Coefficients in a Packed Column Using Reactive Absorption Data

2005 ◽  
Vol 70 (3) ◽  
pp. 383-402
Author(s):  
Valery A. Danilov ◽  
Il Moon
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Optimization Technique ◽  
Packed Column ◽  
Effective Area ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients ◽  
Model Calculations ◽  
Unit Model ◽  
Reactive Absorption

This paper is devoted to the development of a new method for estimating mass transfer coefficients and effective area in packed columns in the case of reactive absorption. The method is based on a plug-flow model of reactive absorption of carbon dioxide with sodium hydroxide solution. The parameter estimation problem is solved using an optimization technique. Some mass transfer parameters are found to be correlated. Global sensitivity analysis by Sobol's technique showed that the unit model with the defined objective function is sensitive to the estimated parameter. Case studies of reactive absorption with different packings illustrate application of the proposed method for estimating mass transfer coefficients and effective area from column operation data. The model calculations are compared with experimental data obtained by other authors. The concentration profiles calculated by the unit model with the estimated parameters are shown to match well with experimental profiles from literature. A good agreement between estimated values and experimental data from literature confirms the applicability of this method.

New Correlations of Volumetric Liquid-Phase Mass Transfer Coefficients in Gas-Inducing Agitated Tank Reactors

2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Hesheng Yu ◽  
Zhongchao Tan
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Liquid Phase ◽  
Power Input ◽  
Liquid Volume ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients ◽  
Liquid Phase Mass Transfer ◽  
Gas Dispersion ◽  
Tank Diameter

Abstract Volumetric liquid-phase mass transfer coefficient (kLa) is one of the most important parameters for the evaluation of the performance of a gas-inducing agitated tank (GIAT). In this paper, two equations in terms of power input per unit liquid volume (P/VL) and relative gas dispersion parameter (NI/Ncd), respectively, are developed according to data in literature. They can correlate existing kLa values within ±20% of measured ones for bladed impellers with different impeller submergence to tank diameter ratios in the range of 0.5 -1.23. In order to validate these equations, the liquid phase mass transfer coefficients in a continuous GIAT equipped with a 4-blade straight impeller were measured by removal of oxygen from water. It was found that the equation in P/VL criterion could correlate kLa values within ±12% of the experimental data, and the equation in NI/Ncd criterion could correlate kLa values within ±15.6% with an exception of 26.8% for NI = 16.7 Hz.

Determination of Gas Diffusion and Interface-Mass Transfer Coefficients for Quiescent Reservoir Liquids

SPE Journal ◽  
2006 ◽  
Vol 11 (01) ◽  
pp. 71-79 ◽  
Author(s):  
Faruk Civan ◽  
Maurice L. Rasmussen
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Gas Diffusion ◽  
Drilling Mud ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients ◽  
Gas Diffusivity ◽  
Completion Fluids ◽  
Interface Mass Transfer

Summary A physically and mathematically rigorous transient-state equilibrium diffusion model is applied for simultaneous determination of the gas-diffusion and interface-mass-transfer coefficients from pressure de-cline by dissolution of gas in quiescent liquids involving petroleum reservoirs. The short- and long-time analytical solutions of this model are reformulated to enable direct determination of the best-estimate values of these parameters by regression of experimental data. Typical experimental data are then analyzed by means of the present improved methods, and the values obtained are compared with the re-ported values. The present methodology is proven practical and yields unique and accurate parameter values. Introduction Gas-diffusivity and interface-mass-transfer coefficients are important parameters determining the rate of dissolution of the injection gases in oil during secondary recovery, and the rate of dissolution and separation of light gases in reservoir oil and brine, water tables associated with depleted-reservoir gas storage, drilling mud, and completion fluids (Hill and Lacey 1934; O'Bryan et al. 1988; O'Bryan and Bourgoyne 1990; Bodwadkar and Chenevert 1997; Bradley et al. 2002; Liu and Civan 2005). In order to develop proper gas-injection strategies, accurate values of these parameters are required for reservoir simulation and prediction of oil recovery by miscible flooding and the optimization of miscibility for best recovery. Laboratory measurement of gas diffusivity in quiescent liquids is usually accomplished through the measurement of the pressure of gas in contact with certain liquids, such as oil, brine, drilling mud, and completion fluids in a closed PVT cell (see Fig. 1) during gas dissolution in the liquid phase. The accuracies of the available models, including those by Riazi (1996), Sachs (1997, 1998), and Zhang et al. (2000), are limited by the inherent simplifying assumptions involved in the analytic treatment and the subsequent interpretation of such experimental data. As judged by the reported studies, there appears to be no consensus among the available analytical approaches used for diffusivity measurement. In addition, the previous studies focused mostly on the determination of gas diffusivity and did not account for interface-mass-transfer effects. The methodology offered by Civan and Rasmussen (2001, 2002, 2003), and further elaborated in the present paper, allows for both interface mass-transfer effects and for bulk diffusivity. It is a novel and practical approach that determines parameters describing both effects from a given set of pressure-decline data. The best estimate of the coefficient of diffusion of gas species (solute) in a given liquid medium (solvent) is usually inferred indirectly by matching the prediction of a suitable mathematical model involving the species transfer by diffusion to experimental data under prescribed conditions. For this purpose, Sachs (1998) resorts to the numerical solution of the nonlinear model equations incorporating the dependency of the diffusion coefficient on concentration without clearly describing the boundary conditions used in the solution.

Murphree vapor efficiency prediction in SCC columns by computational fluid dynamics analysis

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mortaza Zivdar ◽  
Nasim Shahrouei
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Mass Transfer ◽  
Computational Fluid Dynamics ◽  
Liquid Film ◽  
Radial Distance ◽  
Dynamics Analysis ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients ◽  
Computational Fluid Dynamics Analysis

Abstract The spinning cone columns (SCC) are one of the distillation columns with increasing applications in food industries. The geometrical complexity and different flow regimes, besides the presence of moving parts, make the design and analysis of these columns challenging. Computational fluid dynamics analysis of SCC columns has shown promising results in analyzing the performance of these towers. The majority of previous works were pertinent to the air/water systems. Therefore, the application of these results to real systems is not very clear. In this study, the liquid film thickness, mass transfer coefficients, HETP, and Murphree vapor efficiency for the water/ethanol system have been predicted in a pilot-scale column. The results show that by increasing the radial distance from the axis, the thickness of the liquid film gradually decreases. This finding is also in consistent with the experimental results. The maximum thickness of the liquid film is <1 mm and is near the axis. Mass transfer coefficients in the liquid phase and in the gas phase increase slightly with increasing flow velocity and remain almost unchanged. The average values of these coefficients in the liquid and gas phases are 0.023 (s−1) and 1.21 (s−1), respectively. HETP increased with increasing gas velocity, the range of which varies between 0.092 and 0.375 m. Also, Murphree vapor efficiency at three rotational speeds of 550, 750, and 1000 rpm are predicted and compared with the experimental data. The results show that the efficiency has been decreased by increasing the strip ratio and increased by increasing the rotational speed. Minimum and maximum efficiencies obtained are 3.48 and 24.56% corresponding to strip ratio = 27.1% and RPM = 550 plus strip ratio = 9.15% and RPM = 1000, respectively. The predicted efficiencies are in a reasonable agreement (within 10.3%) with experimental data.

Henry's constants and mass transfer coefficients of halogenated organic pollutants in an air stripping packed column

1998 ◽  
Vol 38 (6) ◽  
pp. 287-294 ◽  
Author(s):  
Pen-C. Chiang ◽  
Chung-H. Hung ◽  
J. C. Mar ◽  
E. E. Chang
Keyword(s):  
Mass Transfer ◽  
Methylene Chloride ◽  
Packed Column ◽  
Transfer Coefficients ◽  
Chlorinated Organic Compounds ◽  
Air Stripping ◽  
Mass Transfer Coefficients ◽  
Equilibrium Partition ◽  
Henry's Constants ◽  
Chlorinated Organic

Both Henry's constants and volumetric mass transfer coefficients (KLa) of eight priority chlorinated organic compounds including 1,1-dichloroethene, methylene chloride, chloroform, carbon tetrachloride, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethylene, and 1,4-dichlorobenzene in an air stripping packed column were investigated in this study. The liquid and gas phase EPICS (Equilibrium Partition in Closed System) and direct calculating methods were applied to determine the Henry's constants of VOCs. The interference of co-solute on Henry's constants was also investigated. Experimental results indicated that decrease in Henry's constants of VOCs was observed in the presence of humic acid but no apparent effect on Henry's constants was detected when there was NaCl and surfactant in solution. Four different configurations of packing media including Intalox Saddle, Super Intalox Saddle, Telleret, and Hedgehog made of polypropylene were respectively packed in the air stripping tower and investigated in the study. The dependence of hydraulic loading, air-water ratio, and configurations of packing media on mass transfer coefficients of VOCs was discussed.

Transport of chlorinated hydrocarbons between sewage and sewer atmosphere

1996 ◽  
Vol 34 (3-4) ◽  
pp. 557-564 ◽  
Author(s):  
Bettina S. Haas ◽  
Reimer Herrmann
Keyword(s):  
Mass Transfer ◽  
Aromatic Compounds ◽  
Chlorinated Hydrocarbons ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients ◽  
Sewerage System ◽  
Mass Fluxes ◽  
Single Compound

Sewage containing volatile contaminants is a potential VOC-source in cities. Thus we tried to evaluate volatilization out of the sewerage system by measurements of contaminants in sewer gas and sewage. Our results from a medium sized town with little industry showed that sewer gas is mainly contaminated with alkanes, small aromatic compounds and chlorinated hydrocarbons. For three chlorinated hydrocarbons (chloroform, trichloroethene, tetrachloroethene) we determined mass transfer coefficients out of sewage and used these data to estimate mass fluxes from sewage and emissions out of the sewerage system for two sewer stretches. Considerable emission of chlorinated hydrocarbons from sewage, i.e. fluxes of some 10 to 100 g per m2·d, occurred only when the contaminant input via sewage was between some g and mg per litre for a single compound. For concentrations that were about 3 orders of magnitude less, emissions were negligible.

Sign in / Sign up

Export Citation Format

Share Document