Dynamic Interfacial Tension Method for Measuring Gas Diffusion Coefficient and Interface Mass Transfer Coefficient in a Liquid

2006 ◽  
Vol 45 (14) ◽  
pp. 4999-5008 ◽  
Author(s):  
Daoyong Yang ◽  
Paitoon Tontiwachwuthikul ◽  
Yongan Gu
Keyword(s):  
Mass Transfer ◽  
Diffusion Coefficient ◽  
Interfacial Tension ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Gas Diffusion ◽  
Dynamic Interfacial Tension ◽  
Interface Mass Transfer

scholarly journals Dynamic studies of nitrophenols sorption on perfil in a fixed-bed column

2008 ◽  
Vol 27 (2) ◽  
pp. 123 ◽  
Author(s):  
Zvezdelina Yaneva ◽  
Mirko Marinkovski ◽  
Liljana Markovska ◽  
Vera Meshko ◽  
Bogdana Koumanova
Keyword(s):  
Mass Transfer ◽  
Diffusion Coefficient ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Dispersion Coefficient ◽  
Fixed Bed ◽  
External Mass Transfer ◽  
Fixed Bed Column ◽  
Axial Dispersion Coefficient ◽  
Solid Diffusion

The adsorption of two substituted nitrophenols, namely 4-nitrophenol (4-NP) and 2,4-dinitrophenol (2,4-DNP), from aqueous solutions onto perfil was studied using a fixed bed column. The theoretical solid diffusion control (SDC) model describing single solute adsorption in a fixed bed based on the Linear Driving Force (LDF) kinetic model was successfully applied to the investigated systems. The model parameters of solid diffusion coefficient, DS, axial dispersion coefficient, DL, and external mass transfer coefficient, kf, for the investigated systems were estimated by the means of a best fit approach. Some deviations were found between the predicted and the experimental data which reflect the fact that the assumptions of the model were not quite fulfilled for these experiments. It is necessary to adjust the values of the solid diffusion coefficient, the axial dispersion coefficient and the external mass transfer coefficient in order to obtain a satisfactory agreement between the simulated and the experimental breakthrough curves. A Biot number was used as an indicator for the intarparticle diffusion. The Biot number was found to decrease with the increase of bed depth, indicating that the film resistance increased or the intraparticle diffusion resistance decreased.

Temperature Dependencies of Inter-Diffusion Coefficient and Mass-Transfer Coefficient of Chemical Strengthening

2016 ◽  
Vol 702 ◽  
pp. 32-36
Author(s):  
Maya Hatano ◽  
Satoshi Kanasugi ◽  
Masaaki Konishi
Keyword(s):  
Mass Transfer ◽  
Diffusion Coefficient ◽  
Ion Exchange ◽  
Simulation Model ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Compressive Stress ◽  
Parameter Study ◽  
Fictive Temperature ◽  
Chemical Strengthening

Chemical strengthening is a method of generating compressive stress on the glass surfaces by ion-exchange to improve their strengths since old ages. As its targets have been expanding to larger and thinner glasses recently, different strength profiles are required depending on the applications and selecting appropriate ion-exchange parameters becomes even more important. Therefore, we developed a simulation model of chemical strengthening which enables predicting the stress profiles by ion-exchange in order to help optimizing the ion-exchanging parameters. Parameter study using the simulation model with change of temperature results in precise stress prediction, the compressive stress on the surface with a margin of error of ± 3% and the depth of layer with that of ± 10%. Furthermore, the parameter study introduced following two technical findings; (1) both inter-diffusion coefficient and mass-transfer coefficient could obey the Arrhenius equation, (2) both actual temperature and fictive temperature could influence on the stress relaxation. These findings are of great importance in comprehending the phenomena associated with ion-exchange. It has possibilities for beneficial feedback to the composition development and optimum stress design in accordance with each application.

Kinetic Study for Ion Exchange of Taurine on D290 Anion Exchange Resin

2012 ◽  
Vol 562-564 ◽  
pp. 85-89
Author(s):  
Feng Song ◽  
Shu Juan Zhuang
Keyword(s):  
Mass Transfer ◽  
Diffusion Coefficient ◽  
Ion Exchange ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Anion Exchange ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Experimental Temperature ◽  
Coefficient Increase

The kinetics of ion exchange of taurine on D290 anion exchange resin was investigated. The uptake curves of taurine on D290 anion exchange resin were determined in batch stirred tanks, and the diffusion coefficient and the mass transfer coefficient were computed, and the effects of stirred velocity and experimental temperature on the rate of uptake of taurine on D290 resin were discussed. The results showed that with the experimental temperature and the stirred velocity increasing, the rate of uptake of taurine on D290 anion exchange resin increase. And with the increase of the experimental temperature, the diffusion coefficient and the mass transfer coefficient increase .With the increase of the stirred velocity, the diffusion coefficient increase and the mass transfer coefficient don’t be affected. Based on the Helfferich number of this system, the mass transfer process of taurine taken up on D290 resin is dominated by the film diffusion.

The Effective Diffusion Coefficient and Mass Transfer Coefficient of Nordic Softwoods as Calculated from Direct Drying Experiments

Holzforschung ◽  
1999 ◽  
Vol 53 (5) ◽  
pp. 534-540 ◽  
Author(s):  
Antti Hukka
Keyword(s):  
Mass Transfer ◽  
Diffusion Coefficient ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Effective Diffusion Coefficient ◽  
Effective Diffusion ◽  
Transfer Coefficients ◽  
Medium Temperature ◽  
Whole Process ◽  
Moisture Profiles

Summary The effective diffusion coefficient and mass transfer coefficient of Scot's pine and Norway spruce heartwood are calculated from the measured development of the internal moisture profiles of sawn timber during drying. Measurement is made using the oven-dry method. Calculation of both coefficients is based on using an existing timber drying simulation model to iteratively optimise the parameter values for the diffusion and mass transfer coefficients of prescribed functional form. The results show that the procedure employed is a feasible method to obtain numerical values for the internal and external transfer coefficients as functions of wood moisture content and temperature. The resulting diffusion coefficient and mass transfer coefficient are applicable in the whole moisture range between green and dry states in temperatures 20–80°C thus covering the whole process of medium-temperature wood drying.

scholarly journals MATH SIMULATION OF MASS TRANSFER FROM VIBRATING SURFACE

2020 ◽  
Vol 2020 (1) ◽  
pp. 99-103
Author(s):  
Ivan Semenov ◽  
Marina Chernigovskaya
Keyword(s):  
Mass Transfer ◽  
Diffusion Coefficient ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Transfer Rate ◽  
Mass Transfer Rate ◽  
And Diffusion

Results of modeling of mass transfer from a vibrating cone are given in the paper. Effect of such parameters as frequency, amplitude, height of the cone and diffusion coefficient on mass transfer rate is considered. An equation for calculation of mass transfer coefficient is obtained for similar processes.

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