Liquid–liquid equilibrium extraction of ethanol with mixed solvent for bioethanol concentration

The extraction of ethanol with the solvents of aldehydes mixed with m-xylene was studied for the bioethanol concentration process.Furfural and benzaldehyde were selected as extraction solvents,with which the solubility of water is small,expecting large distribution coefficient of ethanol.The liquid–liquid two-phase region was the largest with m-xylene solvent,followed by benzaldehyde and furfural.The region of two liquid–liquid phase became larger with the mixed solvent of m-xylene and furfural than that with furfural solvent.The NRTL model was applied to the ethanol–water–furfural–m-xylene system,and the model could well express the liquid–liquid equilibrium of the system.For any solvent used in this study,the separation selectivity of ethanol relative to water decreased as the distribution coefficient of ethanol increased.The separation selectivity with m-xylene was the largest among the employed solvents,but the distribution coefficient was the smallest.The solvent mixture of furfural and m-xylene showed relatively high distribution coefficient of ethanol and separation selectivity,even in the higher mass fraction of m-xylene in the solvent phase.The ethanol extraction with a countercurrent multistage extractor by a continuous operation was simulated to evaluate the extraction performance.The ethanol content could be concentrated in the extract phase with relatively small number of extraction stages but low yield of ethanol was obtained.     

Simple separation method of Zn(Ⅱ) and Cd(Ⅱ) from brine solution of zinc plant residue and synthetic chloride media using solvent extraction

In this work, the possibility of separation of Zn~(2+) and Cd~(2+) metal ions from chloride(brine) solutions was examined. For this purpose, simple solvent extraction(SX) experiments by di-2-ethylhexyl phosphoric acid(D2EHPA)in kerosene as a diluent was performed on synthetic and industrial chloride solution obtained from brine leaching of zinc filter cakes(by-product of zinc hydrometallurgical processing). The optimal conditions for separation were determined. The zinc extraction efficiency was 99% with negligible co-extraction of cadmium.Therefore, a high ΔpH_(0.5) value for Zn(Ⅱ) and Cd(Ⅱ) was achieved. FT-IR and slope analysis indicated that ZnClA·3HA and CdClA·3HA species were probably extracted.     

Design aspect of a novel L-shaped pulsed column for liquid–liquid extraction applications: Energy consumption and the characteristics velocity concept

This article deals with the evaluation of the consumption of energy for a steady state solvent extraction in a novel L-shaped pulsed sieve-plate column,which is highly required for design and optimization of the periodic flow processes for industrial applications.In this regard,a comprehensive evaluation on the energy consumption in case of a pulsed flow for three different chemical systems is conducted and besides the influence of pulsation intensity,the effect of geometrical parameters including the plate spacing and the plate free area is investigated as well.Moreover,the concept ofcharacteristic velocity models at flooding points is evaluated with respect to the variation of pressure drop along the column at different operational conditions.     

Waste glass in civil engineering applications—A review

Each year, hundreds of thousands of tons of industrial wastes are being stockpiled, landfilled, and disposed of in storages occupying large areas of land that would otherwise be available for productive use. Recycling of such wastes is now becoming of urgent global interest due to an increasing population, the rise in anthropogenic activities, and the need for more efficient resource and waste management systems. Among many wastes, the generation of glass is dramatically increasing, particularly in the municipal, industrial, and construction sectors. In civil engineering, in general, crushed waste glass has been mainly investigated as a substitute for sand and fine-grained aggregate in concrete production. In geotechnical engineering, in particular, the application of glass wastes is mainly limited to road pavements or as an additive to different soils for subgrade improvement. While glass wastes are relatively inert and potentially offer several opportunities for recycling as a substitute for diminishing and increasingly expensive sand supplies, their potential use yet remains relatively under-researched. This paper systematically reviews the current status of knowledge on the use of glass wastes in various civil engineering applications and discusses the suitability assessment of waste glass for use as a sustainable alternative to traditional civil engineering materials.     

The separation and recovery of copper(Ⅱ), nickel(Ⅱ), cobalt(Ⅱ), zinc(Ⅱ),and cadmium(Ⅱ) in a sulfate-based solution using a mixture of Versatic 10 acid and Mextral 984H

We studied the separation and recovery of copper(Ⅱ), nickel(Ⅱ), cobalt(Ⅱ), zinc(Ⅱ), and cadmium(Ⅱ) from magnesium and calcium, using synergistic solvent extraction(SSX) in a typical hydrometallurgical waste solution. A mixture of Versatic 10 acid and Mextral 984 H, diluted with Mextral DT100, was used to obtain fundamental data on p H and distribution isotherms, as well as the kinetics of extraction and stripping. We also investigated the main effects and interactions of common solvent extraction factors: the extraction p H at equilibrium, the temperature, and the extractant concentration. The synergistic effect for extracting metals was confirmed. The results showed that the addition of Mextral 984 H enhanced the separation factors of copper, nickel, cobalt,zinc, and cadmium over magnesium and calcium. Compared with Versatic 10 acid alone, for a mixture of0.5 mol·L~(-1) Versatic 10 acid/0.5 mol·L~(-1)Mextral 984 H, Δp H50 values of copper, nickel, cobalt, zinc, and cadmium were found to be N 2.0, 3.30, 2.85, 0.95, and 1.32 p H units, respectively. The Δp H_(50)(Zn–Mg)and Δp H_(50)(Zn–Ca)values were 3.27 and 2.25, respectively, indicating easy separation and recovery of copper, nickel, zinc, cobalt,and cadmium. The extraction and stripping of copper, cobalt, zinc, and cadmium were fast, with 90% of the metal transferred in 2 min. We next studied whether the metals could be stripped from the extracted liquid selectively in sequence, by using sulfuric acid at different concentrations. The influence of the molecular structure of the oxime and carboxylic acid components upon the synergistic effects was identified by numerical analysis.Excellent separation of copper, nickel, cobalt, and zinc over magnesium and calcium was achieved with this synergistic solvent extraction system.     

Measurements and thermodynamic modeling of liquid–liquid equilibria in ternary system 2-methoxy-2-methylpropane+p-cresol+water

Liquid–liquid equilibrium(LLE)data for the ternary system 2-methoxy-2-methylpropane(methyl tert-butyl ether)+ p-cresol + water was measured at atmospheric pressure and temperatures of 298.15 K and 313.15 K.From the distribution coefficients and selectivity,it was found that 2-methoxy-2-methylpropane is an efficient solvent to extract p-cresol from wastewater.The consistency of the experimental tie-line data was verified with the Hand and Bachman equations.These data were also correlated with the non-random two liquid(NRTL)and universal quasi-chemical correlation activity coefficient(UNIQUAC)models to yield binary interaction parameters for p-cresol extraction process evaluation.Both models agreed with experiments very well,yet the NRTL model showed even smaller average deviation than the UNIQUAC model.     

Kinetic study on selective extraction of HCl and H3PO4 in a microfluidic device☆

In the extraction method for preparing KH2PO4, one of the key processes is the selective extraction of HCl over H3PO4. In our work, extraction kinetic studies have been carried out in a microfluidic device with a coaxial microchannel, using the extractant of 33.3%(by volume) trioctylamine (TOA) dissolved in n-octanol, with differ-ent aqueous phases:the HCl solution, the H3PO4 solution, and H3PO4 and KCl solutions of different concentra-tions. The changes of the extraction efficiency of HCl and H3PO4 and the selectivity for HCl along with the residence time were investigated. We found that fast extraction kinetics could be realized in microfluidic devices, and that HCl could be extracted faster than H3PO4 due to smaller mass transfer resistance and much stronger re-action between HCl and TOA. For the extraction of H3PO4 and KCl solutions, the selectivity for HCl first increased and then decreased when TOA was in excess of H3PO4 in the initial feeds, and in contrast, always increased when H3PO4 was in excess of TOA in the initial feeds. The diverse changes of selectivity for HCl along with the residence time indicate that a dynamic control of selectivity in microfluidic devices may be important and accessible for im-proving the KH2PO4 conversion efficiency in extraction method.     

The use of microplants in process development—Case study of etherification of 2-ethoxy-2-methylbutane

The successful development of a laboratory scale integrated trial plant, a microplant, was demonstrated. The operation was evaluated using the etherification of 2-ethoxy-2-methylbutane as a demonstration case. The experimental results were validated against the literature data with good correlation thus proving that the microplant can be used efficiently for the scale-up of chemical industry processes.As the hold-up of the microplant was 50 cm³ and the minimum residence time was 2 h, the effects of positive feedback could be observed very rapidly thus reducing research costs.     

溶剂墨专用酞菁绿的开发应用

普通加工方法获得的通用型酞菁绿适用于涂料、油墨、塑料等各种领域。这种铜酞菁绿颜料在一些专用领域,如以硝化纤维、聚酰胺等树脂为基础的溶剂油墨体系中,亲和性不好,颜料分散后所得到的体系流动性低,成膜的光泽度不好。要改进颜料在上述领域的应用性能需要对颜料粒子的大小、形状,粒径分布及颜料粒子的表面极性做进一步优化。     

离子液体在溶解方面的研究进展

离子液体作为一种新型的“绿色溶剂”,广泛应用于化学反应、萃取分离等化工过程。介绍了绿色溶剂——离子液体发展状况,详细讨论了离子液体在溶解方面的研究进展,包括离子液体在萃取分离方面的研究、离子液体作为反应过程中的溶剂以及离子液体作为高分子溶剂的研究。     

离子液体--未来化学工业中的绿色溶剂

对于大多数使用挥发性有机化合物作为溶剂的合成过程来说 ,离子液体是挥发性有机化合物的有效替代品。本文介绍了离子液体的特点、制备方法和现阶段的应用情况     

The action of solvents on coal at low temperatures: 2. Medium- and high-rank coals

The dissolution behaviour of three medium-rank and three high-rank coals in various solvents has been studied. Aqueous KOH is a non-solvent up to 180 °C. Dissolution of medium-rank coals into aliphatic amines and pyridine is not influenced by mass transfer effects in the 120–180 °C temperature range-although it is at room temperature-and does not involve the breaking of chemical bonds. This sets them apart from low-rank coals, where ester bonds have to be broken before dissolution can take place. An extraction limit of ≈50% seems to exist. Of the solvents studied, nonoethanolamine is the best for low-rank bituminous coals but rather poor for higher-rank coals, while the reverse is true of pyridine. Extract yields in hexylamine and ethylenediamine remain approximately constant in the medium-rank range. Low-volatile bituminous coals and semi-anthracites still contain some soluble matter, the extraction of which is diffusion-limited, at least up to 180 °C. From the results a hypothesis concerning the basic physical constitution of coal is derived and a model of the coalification process rationalizing the conjectured changes in constitution with rank is suggested.     

Extraction Chromatography Versus Solvent Extraction: How Similar are They?

Abstract

Over the last decade, extraction chromatography (EXC) has emerged as a versatile and effective method for the separation and preconcentration of a number of metal ions. Frequently, EXC is described as a technique that combines the selectivity of solvent extraction (SX) with the ease of operation of chromatographic methods. Despite this, the extent to which EXC actually provides the selectivity of SX and to which solvent extraction data can be used for the quantitative prediction of the retention of metal ions on an EXC column has remained unclear. To address these questions, the extraction chromatographic and solvent extraction behavior of lanthanides using three different acidic organophosphorus extractants bis‐(2‐ethylhexyl) phosphoric acid (HDEHP), 2‐ethylhexyl 2‐ethylhexylphosphonic acid (HEH[EHP]), and bis‐(2,4,4 trimethylpentyl)phosphinic acid (H[DTMPeP])) have been compared. Specifically, the rate and extent of uptake of selected lanthanides by the three extractants have been examined. In addition, the relationship between the volume distribution ratios obtained in the chromatographic and liquid–liquid extraction modes have been compared and their utility in predicting the chromatographic parameter, k′, the number of free column volumes to peak maximum determined.     

微波辅助萃取洋葱精油的研究

本实验以精油产率为评价指标,进行了洋葱精油的微波辅助萃取工艺研究,考察了萃取溶剂种类、温浸时间、萃取温度、萃取时间和料液比对精油产率的影响,并在单因素考察基础上,通过正交实验设计得出优化工艺条件。结果表明,在以二氯甲烷为萃取溶剂,萃取温度25℃,萃取时间45s,酶解时间1.5小时,料液比1∶5的条件下可得到最优工艺条件。与传统的溶剂浸提法、索氏提取法相比较,微波辅助提取具有提取时间短、效率高、节约能源、产品质量高、原料利用率高、无污染等优点,并且明显提高了洋葱油中二丙基二硫醚组分的含量。     

湿法冶金中锌的萃取工艺研究进展

本文主要综述了国内外近些年对锌萃取的大量基础性研究,对不同种类的锌萃取剂进行了简要介绍。介绍了近些年热点研究的新的萃取工艺和萃取技术。并对工业上不同的锌的原料的萃取过程和方法进行介绍了相关介绍。对锌萃取工艺的工业应用前景进行了评述。     

Production of clean fuels by solvent skimming of coal at around 350 °C

The authors have recently presented a new coal extraction method by which various kinds of coals ranging from brown coals to bituminous coals could be extracted up to 80% of the parent coals in a flowing stream of tetralin or a coal derived oil, carbol oil, under 10 MPa at 350 °C. The extract obtained by this method was almost free from inorganic materials. In this study the effect of solvent recycling on the extraction behavior was examined to make the method practically applicable. The solvent recycling was found to be effective in enhancing the extraction yield and in decreasing further the inorganic fraction in the extract. The extract and residue obtained were characterized through various analyses. To examine how inorganic materials are removed by the extraction, the contents of inorganic elements, including harmful trace elements, in the extract were investigated. It was clarified that the presented method was effective in the removal of most of the inorganic elements including even harmful trace elements from coals, although the degree of removal was dependent on the kind of element.