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Nagendra N Gandhi - One of the best experts on this subject based on the ideXlab platform.

  • Effect of Hydrotropes on Solubility and Mass Transfer Coefficient of Chlorobenzene
    2012
    Co-Authors: Natarajan Arunodhaya, C. Jayakumar, Nagendra N Gandhi
    Abstract:

    A comprehensive investigated on the solubility and Mass Transfer Coefficient enhancement of chlorobenzene through hydrotropy has been undertaken. The solubility and Mass Transfer Coefficient studies were carried out using hydrotropes such as citric acid, sodium benzoate and urea under the influence of a wide range of hydrotrope concentrations (0 to 3.0 mol/L) and different system temperatures (303 to 333 K). It has been observed that the solubility of chlorobenzene increases with increase in hydrotrope concentration and also with system temperature. A minimum hydrotrope concentration (MHC) in the aqueous phase was required to initiate significant solubilization of chlorobenzene. Consequent to the increase in solubilization of chlorobenzene, the Mass Transfer Coefficient was also found to increase with increase in hydrotrope concentration at 303 K. A threshold value of MHC is to be maintained to have an appreciable enhancement in the Mass Transfer Coefficient. The maximum enhancement factor, which is the ratio of the value in the presence and absence of a hydrotrope, has been determined for all sets of experimentations. The performance of hydrotropes was measured in terms of setschenow constant (K s) and reported for all hydrotropes used in this study.

  • effect of hydrotropes on solubility and Mass Transfer Coefficient of 1 2 dichloroethane
    2012
    Co-Authors: Antony Bertie Morais, Nagendra N Gandhi
    Abstract:

    A comprehensive investigation on the solubility and Mass Transfer Coefficient enhancement of 1,2-dichloroethane through hydrotropy has been undertaken. The solubility and Mass Transfer Coefficient studies were carried out using hydrotropes such as urea, citric acid, nicotinamide and sodium salicylate under the influence of a wide range of hydrotrope concentrations (0 to 3.0 mol/L) and different system temperatures (303 to 333 K). It has been observed that the solubility of 1,2-dichloroethane increases with increase in hydrotrope concentration and also with system temperature. A Minimum Hydrotrope Concentration (MHC) in the aqueous phase was required to initiate significant solubilization of 1,2- dichloroethane. Consequent to the increase in solubilization of 1,2-dichloroethane, the Mass Transfer Coefficient was also found to increase with increase in hydrotrope concentration at 303 K . A threshold value of MHC is to be maintained to have an appreciable enhancement in the Mass Transfer Coefficient. The maximum enhancement factor, which is the ratio of the value in the presence and absence of a hydrotrope, has been determined for all sets of experimentations. The performance of hydrotropes was measured in terms of setschenow constant (Ks) and reported for all hydrotropes used in this study.

  • Effect of Hydrotropes on Solubility and Mass Transfer Coefficient of Methyl Salicylate
    Mathematical Models and Methods in Applied Sciences, 2009
    Co-Authors: M. Dharmendira Kumar And, Nagendra N Gandhi
    Abstract:

    This paper presents a comprehensive study on the effect of citric acid, sodium benzoate, sodium salicylate, and urea (hydrotropes) on the solubility and Mass Transfer Coefficient for the extraction of methyl salicylate in water. A Minimum Hydrotropic Concentration (MHC) in the range between 0.20 and 0.90 mol/L was found essential to show a significant increase in the solubility and Mass Transfer Coefficient for the methyl salicylate−water system. The solubility of methyl salicylate has been increased to a maximum value of 22.84 in the presence of citric acid as hydrotrope at concentration of 2.00 mol/L and temperature of 333 K. The maximum enhancement factor for the Mass Transfer Coefficient was found to be 7.88 in the presence of citric acid as hydrotrope at a concentration of 2.00 mol/L at 303 K at 600 rpm. The Setschenow constant, Ks, a measure of the effectiveness of the hydrotrope, has been determined for each case, and the highest value has been observed as 0.743 in the case of citric acid.

  • Effect of hydrotropes on solubility and Mass Transfer Coefficient of amyl acetate
    Bioprocess Engineering, 2000
    Co-Authors: M. Dharmendira Kumar, Nagendra N Gandhi
    Abstract:

    This paper presents a comprehensive study on the effect of citric acid, sodium benzoate, sodium salicylate and urea (hydrotropes) on the solubility and Mass Transfer Coefficient for the extraction of amyl acetate in water. The influence of a wide range of hydrotrope concentration (0–3.0 mol/l) and different temperatures (303–333 K) on the solubility of amyl acetate has been studied. The influence of different hydrotrope concentrations on the Mass Transfer Coefficients for amyl acetate–water system has been ascertained. Setschenow constant, Ks, a measure of the effectiveness of hydrotrope has been determined for each case. The solubility of amyl acetate increases with increase in hydrotrope concentration and also with system temperature. Consequent to the increase in the solubility of amyl acetate, the Mass Transfer Coefficient was also found to increase with increase in hydrotrope concentration. A Minimum Hydrotropic Concentration (MHC) was found essential to show a significant increase in the solubility and Mass Transfer Coefficient for amyl acetate–water system. The enhancement factor, which is the ratio of value in presence and absence of a hydrotrope is reported for both solubility and Mass Transfer Coefficients.

  • Effect of hydrotropes on solubility and Mass-Transfer Coefficient of butyl acetate
    Journal of Chemical & Engineering Data, 1998
    Co-Authors: Nagendra N Gandhi, M. Dharmendira Kumar, N Sathyamurthy
    Abstract:

    This paper presents a comprehensive study on the effect of citric acid, sodium benzoate, sodium salicylate, and urea (hydrotropes) on the solubility and Mass-Transfer Coefficient for the extraction of butyl acetate in water. The influence of a wide range of hydrotrope concentrations (0-3.0 mol/L) and different temperatures (303 K to 333 K) on the solubility of butyl acetate has been studied. The influence of different hydrotrope concentrations on the Mass-Transfer Coefficient for the butyl acetate +water system has been ascertained. The Setschenow constant, K s , a measure of the effectiveness of hydrotrope, has been determined for each case. The solubility of butyl acetate increases with increase in hydrotrope concentration and also with temperature. Consequent to the increase in the solubility of butyl acetate, the Mass-Transfer Coefficient was also found to increase with increase in hydrotrope concentration. A minimum hydrotrope concentration was found essential to show a significant increase in the solubility and Mass-Transfer Coefficient for the butyl acetate + water system. The enhancement factor, which is the ratio of the value in the presence and absence of a hydrotrope, is reported for both solubility and Mass-Transfer Coefficient.

Vincenzo Cappello - One of the best experts on this subject based on the ideXlab platform.

  • bubble size and liquid side Mass Transfer Coefficient measurements in aerated stirred tank reactors with non newtonian liquids
    Chemical Engineering Science, 2020
    Co-Authors: Vincenzo Cappello, Cecile Plais, Christophe Vial, Frederic Augier
    Abstract:

    Abstract Oxygen Transfer is a key element in aerobic fermentations, especially if the culture broth’s rheology is non-Newtonian, as in the case of cultures of filamentous fungi. Viscosity negatively affects the volumetric Mass Transfer Coefficient ( k L a ), but mechanisms involved in terms of change of interfacial area (a) and liquid-side Mass Transfer Coefficient ( k L ) have still not been clearly identified. This lack of knowledge is in part due to the difficulty in measuring bubble size in viscous fluids. In this study, an innovative technique was used to measure bubble Sauter diameter ( d 32 ) in water and in xanthan gum solutions. Additional experiments were carried out to obtain the volumetric Mass Transfer Coefficient and the global gas holdup ( α G ). It was then possible to obtain the liquid-side Mass Transfer Coefficient and to compare it with existing models. Finally, empirical correlations were proposed to estimate d 32 , α G , k L a and k L in a mechanically stirred tank.

Sunando Dasgupta - One of the best experts on this subject based on the ideXlab platform.

  • Mass Transfer Coefficient with suction for turbulent non-Newtonian flow in application to membrane separations
    Journal of Food Engineering, 2004
    Co-Authors: Rajiv Ranjan, Sunando Dasgupta
    Abstract:

    The expression of Mass Transfer Coefficient is derived from first principles for the turbulent non-Newtonian fluid flow in the membrane modules. The effects of suction are incorporated in the Mass Transfer Coefficient from a theoretical basis. The analysis is carried out for a power law fluid, the common rheology for fruit juices and other food products. The analysis shows that there is significant effect of suction on Mass Transfer Coefficient. The effects of the operating conditions, e.g., Reynolds number, permeate flux and the rheological nature of the fluid (pseudoplastic or dilatant) on the Mass Transfer Coefficient are also investigated. Both rectangular thin channel and tubular modules are considered.

  • prediction of Mass Transfer Coefficient with suction for turbulent flow in cross flow ultrafiltration
    Journal of Membrane Science, 1999
    Co-Authors: V S Minnikanti, Sunando Dasgupta
    Abstract:

    Sherwood number relations for the prediction of the Mass Transfer Coefficient for developing concentration boundary layer have been obtained for turbulent flow regime from first principles. The common flow modules, namely, rectangular channel, tubular and radial cross flow are considered. The relationships developed include the effect of suction through the membrane. Relevant relations for the estimation of Mass Transfer Coefficient for cross flow ultrafiltration are formulated. The proposed Sherwood relations are used in conjunction with the osmotic pressure model to predict the permeate flux in osmotic pressure governed ultrafiltration. The simulated results are compared with the experimental data obtained from the literature. A detailed parametric study has been performed to observe the effects of the operating conditions on the filtration performance in terms of the permeate quantity and quality.

N. Nagendra Gandhi - One of the best experts on this subject based on the ideXlab platform.

  • Solubility and Mass Transfer Coefficient Enhancement of Stearic Acid through Hydrotropy
    Journal of Chemical & Engineering Data, 2010
    Co-Authors: S. Theneshkumar, D. Gnanaprakash, N. Nagendra Gandhi
    Abstract:

    The effect of various hydrotropes such as sodium salicylate, sodium benzoate, and nicotinamide on the solubility and Mass Transfer Coefficient of stearic acid was investigated under a wide range of hydrotrope concentrations, (0 to 3.0) mol·kg−1, and different system temperatures, T = (303 to 333) K. It was found that the solubility and Mass Transfer Coefficient of stearic acid increase with the increase in hydrotrope concentration and also with system temperature. All hydrotropes used in this work showed an enhancement in the solubility and Mass Transfer Coefficient to different degrees. The order of increase in the solubility and Mass Transfer Coefficient of stearic acid with respect to different hydrotropes was found to be sodium salicylate > sodium benzoate > nicotinamide. The maximum enhancement factor value has been determined for both the solubility and the Mass Transfer Coefficient. The effectiveness of hydrotropes was measured in terms of Setschnew constant Ks and reported for all hydrotropes used...

  • Enhancement of solubility and Mass Transfer Coefficient of salicylic acid through hydrotropy
    Polish Journal of Chemical Technology, 2009
    Co-Authors: S. Theneshkumar, D. Gnanaprakash, N. Nagendra Gandhi
    Abstract:

    This study deals with the effect of hydrotropes on the solubility and Mass Transfer Coefficient of salicylic acid. The solubility and Mass Transfer studies were performed using the hydrotropes, i.e., sodium acetate, sodium salicylate, citric acid, and urea at concentrations of 0∼3.0 mol/L and system temperatures of 303∼333 K. It was found that the solubility and Mass Transfer Coefficient of salicylic acid increases with increase in hydrotrope concentration and also with system temperature. All hydrotropes used in this work showed an enhancement in solubility and Mass Transfer Coefficient to different degrees. The maximum enhancement factor values were determined for all hydrotropes used in this study. The highest value was 28.08 for solubility studies and 10.42 for Mass Transfer studies. The performance of hydrotropes was measured in terms of the Setschenow constant (Ks). The highest value observed was 0.696.

  • Enhancement of Solubility and Mass Transfer Coefficient Through Hydrotropy
    2008
    Co-Authors: N. Varagunapandiyan, N. Nagendra Gandhi
    Abstract:

    This paper presents a comprehensive study on the effect of hydrotropes on the solubil- ity and Mass Transfer Coefficient of ethyl acetate in water. The solubility and Mass Transfer studies were performed using hydrotropes such as tri-sodium citrate, urea, sodium benzoate, and sodium salicylate under a wide range of concentrations (0 to 3.0 mol/L) and system temperatures (303 to 333 K). The performance of the hydrotropes was measured in terms of the Setschenow constant (Ks). It was found that the solubility of ethyl acetate increases with increase in hydrotrope con- centration and also with system temperature. A Minimum Hydrotrope Concentration (MHC) in the aqueous phase was found required to initiate significant solubilization of ethyl acetate. Con- sequent to the increase in solubilization of ethyl acetate, the Mass Transfer Coefficient was also found to increase with increase in hydrotrope concentration. All hydrotropes used in this work showed an enhancement in the solubility and Mass Transfer Coefficient to different degrees. The maximum enhancement factor, which is the ratio of the value in presence and absence of a hy- drotrope, has been determined for both solubility and Mass Transfer Coefficient. These character- istics would be much useful in increasing the rate of output of the desired product made from ethyl acetate. In addition, the separation of ethyl acetate from any liquid mixture which is found to be difficult can be carried out effectively using this technique.

Frederic Augier - One of the best experts on this subject based on the ideXlab platform.

  • bubble size and liquid side Mass Transfer Coefficient measurements in aerated stirred tank reactors with non newtonian liquids
    Chemical Engineering Science, 2020
    Co-Authors: Vincenzo Cappello, Cecile Plais, Christophe Vial, Frederic Augier
    Abstract:

    Abstract Oxygen Transfer is a key element in aerobic fermentations, especially if the culture broth’s rheology is non-Newtonian, as in the case of cultures of filamentous fungi. Viscosity negatively affects the volumetric Mass Transfer Coefficient ( k L a ), but mechanisms involved in terms of change of interfacial area (a) and liquid-side Mass Transfer Coefficient ( k L ) have still not been clearly identified. This lack of knowledge is in part due to the difficulty in measuring bubble size in viscous fluids. In this study, an innovative technique was used to measure bubble Sauter diameter ( d 32 ) in water and in xanthan gum solutions. Additional experiments were carried out to obtain the volumetric Mass Transfer Coefficient and the global gas holdup ( α G ). It was then possible to obtain the liquid-side Mass Transfer Coefficient and to compare it with existing models. Finally, empirical correlations were proposed to estimate d 32 , α G , k L a and k L in a mechanically stirred tank.