Valuable Solvents Research Articles

Green methods for obtaining deep eutectic solvents (DES)

A group of materials with great application potential are deep eutectic solvents (DES). This paper presents an alternative approach to methods of obtaining them, using microwave radiation and ultrasound as energy sources. One of the main challenges associated with DES is to find economical methods to obtain them on an increased scale. By using already finished DES that are in the liquid phase as a medium to initiate energy transfer to raw materials and initiate DES formation, it is possible to obtain DES using ultrasound and microwaves. The time required to obtain selected DES, e.g., choline chloride with urea, has been reduced to 4–5 min, with a 12-fold increase in process yields with further potential for scale-up (30 g/h for the conventional process, to as much as 800 g/h using the microwave process). The heating efficiency of microwave and ultrasonic methods is 74.5% and 53.3%, respectively, while the conventional heating process shows a heating efficiency of 5.0%. The presented results confirm the possibility of increasing the scale of obtaining DES, which will help to use these valuable solvents on a large scale in the future. At the same time, it was confirmed that by designing the process appropriately and relying only on DES raw materials and products, it is feasible to use alternative sources of energy in obtaining processes.

Extractive-dividing-wall column and multi-objective optimizations of green entrainer-based ultra-high-purity recovery of methyl di glycol and N-Methyl-2-Pyrrolidone

The waste solvent is frequently generated from the processes that highly rely on solvents. Diethylene glycol monomethyl ether or methyl di glycols (MDG) and N-methyl-2-pyrrolidone (NMP) are representative valuable solvents used broadly and removed as waste solvents during the semiconductor material manufacturing processes. Although waste solvent can be practically retrieved by distillation, azeotropic waste solvent mixture only can be recovered by advanced distillation process. In this study, optimal extractive distillation and extractive-dividing wall column are used to recover waste solvent. The process is optimized by multi-objective optimization using genetic algorithm by linking Aspen Plus® and MATLAB. All optimal cases are compared in terms of energy, exergy, economic and environmental parameter. As a result, the potential energy, total annual cost saving and exergy efficiency for extractive dividing wall column are 26.29%, 24.15% and 21.02%, respectively. Exergy loss that is associated with the number of trays can be significantly reduced by optimization while exergy loss that is associated with remixing only can be significantly reduced by dividing-wall column. Further, multi-objective optimization using a genetic algorithm and a range of population provides various results that determine process selection.

Recovery of Valuable Solvents from the Pharmaceutical industry Wastewater

Recovery of Valuable Solvents from the Pharmaceutical industry Wastewater

Multi-strategy Ensemble Non-dominated sorting genetic Algorithm-II (MENSGA-II) and application in energy-enviro-economic multi-objective optimization of separation for isopropyl alcohol/diisopropyl ether/water mixture

The separation of isopropyl alcohol (IPA)/diisopropyl ether (DIPE) is crucial for the recovery of valuable solvents from alcohol ether waste liquids, but involves high energy consumption and emissions. Therefore, the multi-objective optimization of energy, economy and environment in the IPA/DIPE/Water separation process is conducive to the sustainable development of the organic solvent industry. Considering the slow convergence and the tendency to fall into local optimum for the most commonly used multi-objective optimization method, namely Non-dominant Sorting Genetic Algorithm-II (NSGA-II), a novel Multi-strategy Ensemble Non-dominated Sorting Genetic Algorithm-II (MENSGA-II) is proposed. In this algorithm, two evolution strategies based on individual neighborhood guidance and random walk are developed, aiming at accelerating convergence speed and enhancing search ability, and a selection strategy based on double space is proposed to improve the distribution of the Pareto front obtained. The MENSGA-II is tested on the benchmark functions and the actual separation process of IPA/DIPE/Water. The results prove that the proposed MENSGA-II algorithm has superiority in robustness, convergence speed and distribution of Pareto front. Compared with the actual operating condition, the annual exergy destruction and carbon emission can be reduced by 20.99% and 17.92% when the annual gross profit increases by 2.34% via multi-objective optimization.

Multi-Strategy Ensemble Non-Dominated Sorting Genetic Algorithm and Application in Energy-Enviro-Economic Multi-Objective Optimization of Isopropyl Alcohol/Isopropyl Ether Separation Process

The separation of isopropyl alcohol (IPA)/isopropyl ether (IPE) is crucial for the recovery of valuable solvents from alcohol ether waste liquids, but involves high energy consumption and emissions. Therefore, the multi-objective optimization of energy, economy and environment in the IPA/IPE separation process is conducive to the sustainable development of the organic solvent industry. Considering the slow convergence and the tendency to fall into local optimum for the most commonly used multi-objective optimization method, namely non-dominant sorting genetic algorithm-II (NSGA-II), a novel multi-strategy ensemble non-dominated sorting genetic algorithm (MENSGA-II) is proposed. In this algorithm, two evolution strategies based on individual neighborhood guidance and random walk are developed, aiming at accelerating convergence speed and enhancing search ability, and a selection strategy based on double space is proposed to improve the distribution of the Pareto front obtained. The MENSGA-II is tested on the benchmark functions and the actual separation process of IPA/IPE. The results prove that the proposed MENSGA-II algorithm has superiority in robustness, convergence speed and distribution of Pareto front. Compared with the actual operating condition, the annual exergy destruction and carbon emission can be reduced by 18.49% and 15.47% when the annual gross profit increases by 3.24% via multi-objective optimization.

The separation of ternary azeotropic mixture: Thermodynamic insight and improved multi-objective optimization

Abstract Acetonitrile (ACN) and Ethanol (EtOH) are important organic solvents and they are frequently used as mobile phase in high performance liquid chromatography resulting in the production of waste ternary mixture ACN/EtOH/water. The separation of such ternary systems is a key to recovery valuable solvents in waste liquid from views on economic and environmental benefits. Thus, we proposed an effective separation strategy of triple-column extractive distillation (TCED) to separate such ternary mixture with three binary azeotropes and a single ternary azeotrope for the first time. The suitable entrainer and the separation sequence were determined by thermodynamic insights (i.e., residue curve maps, isovolatility line, univolatility line and material balance lines). In addition, an improved multi-objective genetic algorithm optimization embedding the weak mutation and detection/deduplication of overlapping solutions was employed to optimize the proposed process with plenty of continuous and discrete decision variables. Finally, DMSO was determined as the most appropriate entrainer to separate such complex ternary mixture. The separation sequence of TCED process was determined as the ACN first, then EtOH and water as the last product. The optimal TCED process with the trade-off benefits between fixed capital investment and annual operating costs was obtained.

Conceptual design of distillation columns sequence for separation of pentane and hexane from C5+ stream of LPG unit

ABSTRACTThe principal role of an LPG (Liquefied Petroleum Gas) unit is the separation of propane and butane from other products in a gas refinery. One of the other main products of the LPG unit is C5+ which is sold at the same price of crude oil after it is added into gas condensate. In this research, sixth refinery (Phases 15 and 16) of South Pars gas filed was selected as a case study example to find an efficient design for enriching the C5+ stream. Analysis of the C5+ stream exited from the LPG unit demonstrates that it contains more than 70 wt. % of valuable solvents such as pentane and hexane which are more expensive than crude oil. Therefore, the main goal of this research is to do calculations related to the separation of these solvents from the C5+ stream using the direct and indirect sequence of distillation columns. For this purpose, an optimum algorithm is recommended based on Fenske-Underwood-Gilliland (FUG) method in which design parameters (column pressure and reflux ratio) are optimized so that the objective function that represents the total annual cost (TAC) is minimized. Programming with MATLAB shows that the theory of the direct sequence of distillation columns is more economical than the indirect sequence (an annual income of 40,309,012$ is estimated with a fixed cost of 1,047,555 $). Economic calculations also revealed that the rate of return (ROR) and annual profit would be 38.48% and 650,000,000 $.year−1, respectively, if the optimal direct sequences of distillation columns are performed in all the gas refineries of South Pars.

Distillation design and optimization of quaternary azeotropic mixtures for waste solvent recovery

The huge amount of solvents used in the semi-conductor and display industry typically result in waste of valuable solvents which often form complex azeotropic mixtures. This study explored a recovery process of a quaternary waste solvent, comprising methyl 2-hydroxybutyrate, propylene glycol monomethyl ether acetate, ethyl lactate, and ethyl-3-ethoxy propionate. In this study, a novel shortcut column method with a graphical approach was exploited for the distillation column design of complex quaternary azeotropic mixtures. As a result, the proposed shortcut method and design procedure solved the complex separation paths successfully with less computational efforts while achieving all requirements for component purity.

Design and modeling of optimal distillation sequence for recovery of valuable components from a waste photoresist stripper

Currently, waste photoresist stripper from the semiconductor industries is generally incinerated at high temperatures or processed as a high-calorie fuel, which can have adverse effects on the environment and economy. Recovery of valuable solvents from waste photoresist strippers is, therefore, very important for thin flat transistor-liquid crystal display (TFT-LCD) manufactures to reduce the production costs and protect the environment against industrial waste. In the present work, systematic laboratory-scale distillation experiments were carried out to regenerate the organic solvents from the waste photoresist stripper and determine if they are feasible to recycle for commercial TFT-LCD grade chemicals: in particular, 1-hydroxyethylpiperazine and methyl diglycol were mainly tried to retrieve. Based on the experiment results, possible alternative distillation sequences were examined through intensive techno-economic analysis using a rigorous process simulator. As a result, an optimal distillation sequence and condition were drawn to separate valuable organic solvents from waste photoresist stripper for a commercial purpose recovery process.

Looking for alternative energy sources

With unrest in oil-exporting countries, backlashes against biofuels and photovoltaics, and a nuclear incident in Japan, the year 2011 rattled confidence in future energy supplies. The search for alternatives is all the more urgent, but some of the solutions investigated hark back to fossil fuels that we can't afford to burn.

Ionic Liquids: Valuable Solvents for Palladium Catalyzed C—P Cross‐Coupling Reactions.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Synthesis of alkylene carbonates

ALKYLENE carbonates, or cyclic esters of carbonic acid and a,~-diols have come to be widely used in industry in recent years as highly efficient ~ lvents for high-molecular-weight compounds, in particular for forming polyaerilonitrile fibres [1-3]. In addition to their use as valuable solvents, extractants, and hydroxyalkylating agents, these compounds are the starting materials for the synthesis of monomers and high-molecular-weight compounds: glycol urethanes, vinylene carbonate, polyesters, polycarbonates, polyurea, polyvinylidene carbonate, polyvinylidene glycol, etc. [4-6]. The high chemical activity and other valuable properties of the alkylene carbonates, together with the availability of the raw material for their production, gives the prospect of their wide use in chemical industry. The simplest representative of the alkylene carbonates is ethylene carbon a t e t h e cyclic ester of carbonic acid and ethylene glycol. This compound can be synthesized by the interaction of ethylene oxide and carbon dioxide:

Valuable Solvents economically recovered by Vacuum Drying

Valuable Solvents economically recovered by Vacuum Drying

Valuable Solvents economically recovered by Vacuum Drying

Valuable Solvents economically recovered by Vacuum Drying

Valuable Solvents economically recovered by Vacuum Drying

Valuable Solvents economically recovered by Vacuum Drying