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Cuckoo Search Optimization and Application to Liquid–Liquid Equilibrium
Published in Anand Bharti, Debashis Kundu, Dharamashi Rabari, Tamal Banerjee, Phase Equilibria in Ionic Liquid Facilitated Liquid–Liquid Extractions, 2017
Anand Bharti, Debashis Kundu, Dharamashi Rabari, Tamal Banerjee
This chapter uses a new variant of the optimization technique, namely Cuckoo Search (CS) algorithm, to generate the liquid–liquid equilibrium (LLE) data. Liquid–liquid extraction is an important separation technology with a wide range of applications in chemical, petrochemical and pharmaceutical industries. The LLE data of multi-component systems are essential for proper understanding of the extraction process and for the designing and optimization of separation processes. Excess Gibbs free energy models, such as the nonrandom two-liquid (NRTL; Renon & Prausnitz, 1968) and the UNIversal QUAsiChemical (UNIQUAC; Abrams & Prausnitz, 1975) models, are commonly used to predict the LLE as they provide good agreement with experimental data (Banerjee, Singh, Sahoo, & Khanna, 2005; Santiago, Santos, & Aznar, 2009; Vatani, Asghari, & Vakili-Nezhaad, 2012). For LLE prediction, each of these models requires binary interaction parameters. These parameters are generally estimated from the known experimental LLE data by the optimization of an objective function. Mathematically, the aim of optimization is to find the set of inputs that either maximizes or minimizes the output of the objective function. In LLE modelling, the objective function is nonlinear and highly nonconvex having multiple local optima which makes most conventional methods (deterministic algorithms) inefficient and stuck in the wrong solutions. For the correct LLE prediction in liquid–liquid phase equilibria, finding the global optimum (reliable interaction parameters) thus becomes a necessary requirement.
Methods for the Determination of Organics
Published in V. Dean Adams, Water and Wastewater Examination Manual, 2017
Liquid-liquid extraction is the method most widely employed in separating organic compounds from aqueous mixtures in which they are found or produced. This procedure involves the distribution of a solute between two immiscible solvents. The oils and greases are extracted from the aqueous solution by direct contact with an immiscible organic solvent, trichlorotrifluoroeťhane. The organic solvent is then separated from the aqueous phase, dried, and evaporated to determine the extractable residue by gravimetric techniques. This method is not applicable to light hydrocarbons that volatilize below 70°C (i.e., petroleum fuels from gasoline through #2 fuel oils). Some crude oils and heavy fuel oils contain nonextractable residues so the recoveries will be low.
Holdup and regime transition in reciprocating and rotating sieve plate column (RRSPC) for C6(mim)PF6 ionic liquid –water system
Published in Solvent Extraction and Ion Exchange, 2022
Liquid-liquid extraction is widely used in the front-end as well as in back-end process of nuclear, chemical, and pharmaceutical industries.[1] Mixer-settler is the most widely used liquid-liquid extractor because of its simplicity, reliability, operating flexibility and high throughputs. Mixer-settler can handle difficult-to-disperse systems, such as those having high interfacial tension and/or large phase density difference. However, mixer-settlers have some disadvantages too. These include, (i) larger size, ii) high hold-up (i.e., high material inventory) within equipment, (iii) large foot print area etc.[2] On the other hand, columnar equipments are of compact and small sizes, required less foot print area, but need to select judiciously and design precisely.
Dispersive liquid-liquid microextraction of zinc from environmental water samples using ionic liquid
Published in Chemical Engineering Communications, 2021
Preethi A, Vijayalakshmi R, Brinda Lakshmi A
Numerous strategies are used to eliminate the heavy metals from liquid effluents such as chemical sleet, adsorption, ion exhange, and membrane processes (de los Ríos et al. 2012). However, these methods are limited due to the following reasons. The chemical sleet method is expensive whereas the ion exchange process is highly sensitive to the pH of the solution. In adsorption, the metal selectivity is low and generates large quantity of sludges, whereas the membrane processes may end up with membrane fouling (Eljaddi et al. 2017; Kloskowski, et al. 2009). The liquid-liquid extraction methods, currently in use, involve conventional organic solvents which are generally toxic and high risk to living organisms and habitat. To avoid the usage of huge volumes of noxious and untreated solvents, Dispersive Liquid-Liquid Microextraction (DLLME) method was proposed (Al-Saidi and Emara 2014). This method is a fast, efficient, and cost-effective one that works based on miniature sampling with advantages such as high retrieval principles without the usage of sophisticated equipment (Cheng 2010; Kakhki 2017). There are numerous solvents involved in the extraction techniques such as chlorobenzene, chloroform, carbon tetrachloride, and tetrachloroethylene (Akhtar and Iram 2014). But these organic solvents are toxic resulting serious health issues to the environment. However, it is desirable to use an extractant which is cost-effective, highly efficient, and nontoxic.
Population Balances for Extraction Column Simulations—An Overview
Published in Solvent Extraction and Ion Exchange, 2020
Hans-Jörg Bart, Hanin Jildeh, Menwer Attarakih
Liquid–liquid extraction process is widely used in biochemical, hydrometallurgical, nuclear and petrochemical industries. It is an interesting alternative to distillation, especially for the separation of azeotropic or close boiling systems or with non-volatile constituents. The separation process is based on the different solute solubility between two immiscible or almost immiscible liquid phases.[1] In a two-phase liquid system, the selection of the dispersed phase and continuous phase is based on physical properties, settling characteristics and operating conditions. As a rule of thumb, the dispersed phase should have a higher viscosity and should not wet the internals to achieve a higher throughput operational window and to obtain a better dispersion. Moreover, the available mass transfer interfacial area can be enhanced via a higher inlet flow or (as a free parameter) by additional power input, as is with stirred and pulsed liquid-liquid extraction columns.