Current Issue : April - June Volume : 2012 Issue Number : 2 Articles : 5 Articles
A modified loquat leaves (MLL) for the removal of copper(II) and lead(II) ions from aqueous solutions\nhas been investigated. The biosorption of copper(II) and lead(II) ions was found to be dependent on\nsolution pH, initial metal ion concentrations, biosorbent dose, contact time, and temperature. The\nexperimental equilibrium biosorption data were analyzed by three widely used two-parameters;\nLangmuir, Freundlich, and Temkin isotherm models. Langmuir isotherm model provided a better fit with\nthe experimental data than other models by high correlation coefficients R2. Kinetic studies showed that\npseudo-second order described the biosorption experimental data better than the pseudo-first order\nkinetic model....
Diesters biolubricant base oil, oleyl 9(12)-hydroxy-10(13)-oleioxy-12(9)-octadecanoate (OLHYOOD) was synthesized based on\r\nthe esterification reaction of 9,12-hydroxy-10,13-oleioxy-12-octadecanoic acid (HYOOA) with oleyl alcohol (OL) and catalyzed\r\nby sulfuric acid (SA). Optimum conditions of the experiment to obtain high yield % of OLHYOOD were predicted at ratio of\r\nOL/HYOOA of 2 : 1 mol/mol, ratio of SA/HYOOA of 0.7 : 1 mol/mol, reaction temperature 110?C, and 7 h of reaction time. At\r\nthis condition, the yield of OLHYOOD was 88.7%. Disappearance of carboxylic acid (C=O) peak has been observed by FTIR\r\nwith appearance of ester (C=O) peak at 1738 cm-1. 13C, and 1HNMR spectra analyses confirmed the result of OLHYOOD with\r\nthe appearance of carbon-ester (C=O) chemical shift at 173.93 ppm and at 4.05 ppm for 13C and 1HNMR, respectively. The\r\nphysicochemical characteristics of the OLHYOOD were also determined, which showed improved low temperature properties\r\n(PP) -62?C, viscosity index (VI) at 192 and also increased oxidative stability (OT) up to 215.24?C....
A general overall feasibility methodology of batch reactive distillation ofmultireaction systems is developed to study all the possible\nconfigurations of batch reactive distillation. The general model equations are derived for multireaction system with any number\nof chemical equilibrium-limited reactions and for any number of components. The present methodology is demonstrated with\nthe detailed study of the transesterification of dimethyl carbonate in two reversible cascade reactions in batch reactive distillation\nprocess. Pure methanol is produced as distillate, and pure diethyl carbonate is produced at the bottom simultaneously in middlevessel\ncolumn; in each section, continuous feeding of ethanol is necessary. The results of feasibility study are successfully validated\nby rigorous simulations....
A reduced chemical kinetic model for Titan�s atmosphere has been developed. This new model with 18 species and 28 reactions\r\nincludes the mainfeatures of a more complete scheme, respecting the radiative fluxes. It has been verified against three key\r\nelements: a sensitivity analysis, the equilibrium chemical composition using shock tube simulations in CHEMKIN, and the results\r\nof computational fluid dynamics (CFDs) simulations....
Processing of dilute liquid streams in the industries like food, agro-, biotechnology, pharmaceuticals, environment, and so forth\nneeds special strategy for the separation and purification of the desired product and for environment friendly disposal of the waste\nstream. The separation strategy adopted to achieve the goal is extremely important from economic as well as from environmental\npoint of view. In the present paper we have reviewed the various aspects of some selected universal separation strategies such\nas adsorption, membrane separation, electrophoresis, chromatographic separation, and electroosmosis that are exercised for\nprocessing of dilute liquid streams....
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