@article {44044, title = {Recovery of radio-cesium from actual high level liquid waste using solvents containing calix[4]arene-crown-6 ligands}, journal = {Journal of Environmental Chemical Engineering}, volume = {5}, year = {2017}, month = {AUG}, chapter = {4134-4140}, abstract = {

This paper gives two methods, viz. a solvent extraction method and a hollow fiber contactor based liquid membrane method, for the separation of radio-cesium from actual high level liquid waste (HLLW) solutions using calix[4]arene-crown-6 based solvent systems. While the solvent extraction method involved calix[4]arene-bis-benzo-crwon-6 (CBC) in PTMS (phenyltrifluoromethyl sulphone), the hollow fiber supported liquid membrane method used a polysulphone fiber containing contactor and bis-octyl-benzo-calix[4]arene-mono-crown-6 (CMC) in 40\% iso-decanol + 60\% n-dodecane. Both methods reported selective radio-cesium separation with almost no contamination from the associated fission product radionuclides. The radiolytic stability of the hollow fiber contactor was checked by keeping the contactor module in contact with the diluted HLLW for 50 days. The second run carried out after 50 days resulted in excellent reproducibility suggesting efficacy of this method for radioactive waste remediation.

}, keywords = {137Cs, Calix-crown-6, Cesium, fibers, Fission products, Hollow fiber contactor, Liquid membranes, liquids, PUREX-HLLW, Radioactive wastesSolvent extraction, solvent extraction, Solvents}, issn = {2213-3437}, doi = {10.1016/j.jece.2017.07.055}, author = {Jagasia, P. and Dhami, P. S. and Mohapatra, P. K. and Ansari, S. A. and Jadhav, S. Y. and Kalyankar, G. K. and Gandhi, P. M. and Kharul, U. K.} } @article {44012, title = {Study of the effect of operating parameters on the extractive distillation of isopropyl alcohol{\textendash}water mixture using dimethyl sulphoxide as an entrainer}, journal = {Indian Chemical Engineer}, volume = {60}, year = {2017}, month = {MAY}, pages = {141-161}, type = {Journal Article}, chapter = {1-21}, abstract = {

Abstract: In this paper, the simulation analysis of separation of isopropyl alcohol (IPA){\textendash}water via extractive distillation by using dimethyl sulphoxide as an entrainer is presented. The steady-state simulation for this process was done using Aspen Plus simulator. The aim of this work is to study the effect of various operating parameters such as number of stages, molar reflux ratio, binary feed stage number, entrainer feed stage number, temperature of entrainer feed and entrainer to feed molar ratio on the purity and energy consumption. The sensitivity of these parameters serves as a basis to choose the optimum operating conditions to maximize the IPA purity and minimize the energy requirement. In this analysis, among various operating parameters, those which directly affect the IPA purity and the parameters which affect the reboiler duty, for the given separation task, are identified. Simulation results with optimum operating conditions and their economic analysis are also presented.

}, keywords = {Aspen Plus Simulators, Azeotrope, Computer software, Distillation, Energy requirements, Energy utilization, Extractive distillation, Isopropyl alcohol/water, Isopropyl alcohols, Operating parameters, Optimum operating conditions, Sensitivity analysis, simulation, SimulationSteady-state simulations, Solvents}, issn = {0019-4506}, doi = {10.1080/00194506.2017.1322923}, author = {Ghuge, Pravin D. and Mali, Nilesh A. and Sirsam, R. S.} } @article {46677, title = {Understanding the role of solvent properties on reaction kinetics for synthesis of silica nanoparticles}, journal = {Chemical Engineering Journal}, volume = {398}, year = {2020}, month = {OCT}, pages = {125427}, type = {Article}, abstract = {

The effect of various alcoholic solvents and their compositions on the size of silica particles synthesized through hydrolysis and condensation of tetraethyl orthosilicate (TEOS) is studied. The alcohols used are: Methanol, ethanol, propanol, i-propanol, butanol, pentanol, hexanol, octanol, decanol and do-decanol. Ethanol was used as a co-solvent with the higher molecular weight alcohols. Silica particles of size between 100 nm and 2 mu m were obtained by changing solvent composition. Concentrations of total soluble silica and silicic acid were measured and used for exploring the kinetics of hydrolysis and condensation reactions. Polarity, steric hindrance and viscosity of solvent were found to have a strong influence on the rate constants and size of silica nanoparticles. An attempt is made to correlate both final particle size and rate constants with dielectric constant, Wiener index and viscosity of the solvent.

}, keywords = {condensation, Hydrolysis, kinetics, silica particles, Solvents, Stober process}, issn = {1385-8947}, doi = {10.1016/j.cej.2020.125427}, author = {Bari, Atul H. and Jundale, Rajashri B. and Kulkarni, Amol. A.} }