稀释剂对三烷基氧膦萃取草酸的影响

In liquid-liquid solvent extraction processes, diluents have a strong influence on the extraction mechanism and efficiency. In this study, benzene, cyclohexane, trichloromethane, carbon tetrachloride, methyl isobutyl ketone (MIBK), butyl acetate, and 1-octanol were used as diluents in the extraction of oxalic acid by trialkylphos-phine oxide (TRPO). The effects of extractant concentration, initial concentration of oxalic acid and diluent type on the extraction equilibrium partition coefficient are analyzed. The sequence of the extraction ability by different diluents is MIBK > butyl acetate > cyclohexane=benzene > carbon tetrachloride > 1-octanol > trichloromethane. Extraction mechanism was analyzed and extraction model parameters were evaluated.     

预分散溶剂萃取分离苯酚溶液的研究

Predispersed solvent extraction (PDSE) is a new method for separating solutes from aqueous solution by solvent extraction and one which has shown promise for extraction from extremely dilute solution very efficient and very quick. The use of colloidal liquid aphrons in predispersed solvent extraction may ameliorate the problems such as emulsion formation, reduction of interracial mass transfer and low interfacial mass transfer areas in solvent extraction process. In present paper, colloidal liquid aphrons are successfully generated using kerosene as a solvent,tributyl phosphate(TBP) as an extractant, sodium dodecyl benzene sulphate(SDBS) as surfactant in aqueous phase and Tween-80 in oil phase. Extraction of phenol from dilute solution was studied by using colloidal liquid aphrons and colloidal gas aphrons in a semi-batch extraction column. It has been found that the PDSE process is more suitable for extraction of dilute solutions. It has also been discovered that the PDSE process has a great advantage over traditional single-stage extraction process.     

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.     

有机硅表面活性剂对水体中多环芳烃的浊点萃取研究

Cloud point extraction （CPE） processes with two silicone surfactants, Dow Coming DC-190 and DC-193, were studied as preconcentration and treatment for the water polluted by three trace polycyclic aromatic hydrocarbons （PAHs）： anthracene, phenanthrene and pyrene. For all cases, the volumes of surfactant-rich phase obtained by two silicone surfactants were very small, i.e. a lower water content in the surfactant-rich phase was obtained. For example, less than 3% of the initial solution was obtained in a 1% （by mass） surfactant solution, which was much smaller than that of TX-114 in the same surfactant concentration. And TX-114 is known as a high compact surfactant-rich phase among most nonionic surfactants, thus the comparison showed that an excellent enrichment was ensured in the analysis application by the CPE process with the silicone surfactants, and the lower water content obtained in the surfactant-rich phase is also important in the large scale water treatment. The influences of additives and phase separation methodology on the recovery of PAHs were discussed. Comparing with DC-193, DC-190 has a lower cloud point and a higher recovery （near 100%） of all the three PAHs in same surfactant concentration, which was required for application as a preconcentration process prior to HPLC system. However the DC-190 solution is hard to be phase separated only by heating, whereas DC-193 has a relative higher phase separating speed by heating, but a high cloud point （around 360K） limits its application. Due to the phase separation by heating is the only method of CPE suitable to the large scale water treatment, the mixtures of two silicone surfacrants solutions were investigated in this study. A solution containing 1% of mixed DC-190 and DC-193 （in the ratio of 90 ： 10） removed anthracene, phenanthrene and pyrene near 100% with a relative low cloud point and quick phase separating speed.     

三烷基胺萃取氨基磺酸及其废水的特性研究

p-Amino benzene sulfonic acid (PABSA) is selected as the solute with amphoteric functional group, Lewis acid and Lewis base, to be separated from its dilute solutions. An aliphatic, straight chain amine, Alamine 336, is used as the extractant, and kerosene, 1-octanol, chloroform, butyl acetate and benzene as the diluent. The effects of pH value of solution, extractant concentration, salt and types of diluent on the distribution coefficient, D, are studied. There is a peak of D value with pH value of solution, the polar diluents are favorable for extracting PABSA, and the salt in aqueous phase reduces values of D apparently. The extraction equilibrium is described using the mass action law, and the calculated data according to the proposed model agree with the experimental data well. Further, the extraction behavior for other amino benzene sulfonic acids, 1-amino-8-naphtol-3,6-disulfonic acid (H acid) and 4,4′-diaminostilbene-2,2′-disulfonic acid (DSD acid), is investigated in a wide pH value region. Finally. H acid and DSD acid are successfully removed from wastewater by the extraction with Alamine 336.     

Jatropha curcas L. oil extracted by switchable solvent N,N-dimethylcyclohexylamine for biodiesel production

Biodiesel, which is a renewable and environmentally friendly fuel, has been studied widely to help remedy increasing environmental problems. One of the key processes of biodiesel production is oil extraction from oilseed materials. Switchable solvents can reversibly change from molecular to ionic solvents under atmospheric CO_2,and can be used for oil extraction. N, N-dimethylcyclohexylamine(DMCHA), a switchable solvent, was used to extract oil from Jatropha curcas L. oil seeds to produce biodiesel. The appropriate extraction conditions were:1:2 ratio of seed mass to DMCHA volume, 0.3–1 mm particle size, 200 r·min-1agitation speed, 60 min extraction time, and 30 °C extraction temperature. The extraction ratio was about 83%. This solvent extracted the oil more efficiently than hexane, and is much less volatile. By bubbling CO_2 under 1 atm and 25 °C for 5 h, the oil was separated, and DMCHA was recovered after releasing CO_2 by bubbling N_2 under 1 atm and 60 °C for 2 h. The residual solvent content in oil was about 1.7%. Selectivity of DMCHA was evaluated by detecting the protein and sugar content in oil. Using the oil with residual solvent to conduct transesterification process, the oil conversion ratio was approximately 99.5%.     

A NEW PROCESS FOR THE EXTRACTION OF PENICILLIN G FROM THE FILTRATE OF FERMENTATION BROTH WITH TBP IN BUTYL ACETATE

The mixture of neutral phosphorus esters and butyl acetate (BA) can be used, as the extractant for the extraction of penicillin G. The extraction equilibrium pH can be increased to pH3—4 due to the stronger extraction capability of the solvent mixture, instead of pH1.8—2.2 with butyl acetate as solvent. The experimental results indicate that the total recovery of penicillin G can reach 96.6% with the new extraction process, which is 5—6% higher than that obtained with the traditional process using BA as solvent at pH1.8—2.2.     

具有羧酸官能团的功能性离子液体萃取分离钇的研究(英文)

A new kind of hydrophobic ionic liquids [1-alkyl-3-(1-carboxylpropyl)im][PF6] has been synthesized,and their extraction properties for Y(III) in the nitric acid medium was also investigated.The effects of extractant concentration,equilibrium pH of aqueous phase,salt concentration,temperature etc.were discussed.The results show that this kind of Task-Specific Ionic Liquid(TSIL) needs to be saponified before being used for the Y(III) ex-traction,and the extraction is acid dependent,and the extraction efficiency increases with the aqueous phase acidity decreasing.Furthermore,the loaded organic phase is easy to be stripped;more than 95% Y(III) could be stripped from the loaded organic phase when the stripping acidity is higher than 0.07 mol?L?1.The slope analysis technique is used to investigate the extraction mechanism,and a possible cation-exchange extraction mechanism is proposed in the present extraction system.     

Extraction Equilibria of Trimellitic and [ 1,1′-Biphenyl]-2,2′-dicarboxylic Acid with 1-Octanol, 50%TBP,and 10%TRPO in Kerosene

To explore the feasibility of extracting aromatic acid products from oxidizing coal, two aromatic acids, trimellitic and [1,1′-biphenyl]-2,2′-dicarboxylic acid, were selected as the solutes, and the extraction equilibrium of the acids were studied with 1-octanol, 50% tributyl phosphate （TBP） in kerosene, and 10% trialkylphosphine oxide （TRPO） in kerosene. The results showed that the degree of extraction of [1,1′-biphenyl]-2,2′-dicarboxylic acid was larger than that of trimellitic acid for all of the solvent, and the extraction capacity with TRPO is more effective than the one with TBP. The extraction behavior of aromatic polyacid is different from that of carboxylic acid, and the reactive extraction function of aromatic acids with TBP and TRPO is not as effective as that of carboxylic acid. 1-octanol could be used to remove [1,1′-biphenyl]-2,2′-dicarboxylic acid from the mixture of trimellitic acid and [1,1′-biphenyl]-2,2′-dicarboxylic acid. Because the weak hydrogen bond association exists between -OH in 1-octanol and -COOH in aromatic acid, the extractive selectivity of [ 1, 1′-biphenyl]-2,2′-dicarboxylic to trimellitic acid depends on the stoichiometric ratio.     

氯仿萃取回收己内酰胺的研究

以萃取回收甲苯法生产己内酰胺废液中的己内酰胺为目的,选择氯仿作萃取剂,进行了萃取回收己内酰胺的研究。考察了原料液的pH、萃取温度、萃取时间等因素对氯仿萃取己内酰胺过程的影响。结果表明,在酸性条件下该萃取过程分配比随pH的升高而增大,当pH=7时分配比最大;萃取过程为快速过程,20 min即可达到萃取平衡;水相中硫酸铵和1-磺酸基环己烷羧酸对萃取过程有盐析效应,使分配比增大;萃取过程受温度影响不大,焓变值ΔH=2.86 kJ/mol。实验确定了pH=7时己内酰胺在有机相与水相中的分配平衡关系,当有机相和水相体积比为1时,三级错流萃取的萃取率可达到98%以上。同时,进行了工业废水的萃取验证实验,结果表明,氯仿对废水中己内酰胺的萃取效果良好。     

Impurity Distribution Behavior in Caprolactam Extraction with Environmentally Benign Mixed Solvents

In a previous study a solvent mixture of heptane containing 40 mass % heptanol was selected as an alternative in the industrial extraction of caprolactam to replace benzene, toluene, or chlorinated hydrocarbons. This work reports the equilibrium distribution ratio of caprolactam and four model impurities of organic nature, namely, cyclohexanone, aniline, n‐methylcaprolactam, and cyclohexane‐carboxamide, comparing the mixed solvents with toluene as a reference. The resulting phase equilibria were interpreted using the equilibrium stage model. Based on these calculations it was found that, compared to toluene, the co‐extracted fraction of cyclohexanone and aniline was higher, that of n‐methylcaprolactam was comparable, and that of cyclohexane‐carboxamide was lower using the mixed solvent. Overall, the mixed solvent reduced the fraction of co‐extracted impurities by almost 10 %.     

中空纤维更新液膜在己内酰胺精制中的应用

研究了中空纤维更新液膜技术用于己内酰胺精制时的传质性能,考察了两相流速、萃取剂用量对传质的影响,并与大块液膜技术以及萃取塔技术进行了对比。在实验范围内,中空纤维更新液膜过程总传质系数随两相流速的增大而增大,且壳程流速对传质的影响较大。中空纤维更新液膜过程传质通量可达大块液膜的1．5倍,总体积传质系数可达工业萃取塔的2．3倍,萃取剂用量相比于大块液膜、工业萃取塔大幅度降低,具有很大的应用潜力。     

Caprolactam recovery by a column packed with polysulfone microcapsules containing 1-octanol

Caprolactam recovery from its dilute aqueous solution is a challenging task in industry. To save resources and protect environment, a caprolactam recovery technology based on extractant microcapsules as the separation material was introduced. In this new technology, polysulfone microcapsules containing 1-octanol were packed in a column. In the extraction process, recovery ratio of 0.99 was achieved within 0.6 bed volume. More than 10 theoretical plates per meter microcapsule column were realized. In the regeneration process, sulfuric acid aqueous solution was introduced as the stripping agent. Accordingly the new technology can be integrated with existing caprolactam production process because the eluent could be returned to NH₃ causticization section. Caprolactam was successfully stripped and concentrated. Caprolactam concentration of 112 g/L in the eluent was obtained. New technology based on extractant microcapsules shows high efficiency in caprolactam recovery.     

多级错流液液萃取法分离醋酸水溶液的研究

以醋酸正丙酯—正丙醇—NaCl的复合溶液为萃取剂,采用多级错流液液萃取法对醋酸水溶液进行分离。考察了静置时间、溶剂比及萃取级数对分离效果的影响。实验结果表明:当静置时间为60 min,溶剂比(S/F)为3∶1时,经过三级错流液液萃取后,萃余相中醋酸的质量含量为0.54%。文章研究结果为进一步研究提供了基础数据。     

离子液体-分子溶剂复合萃取剂脱除水中酚类化合物

构建了疏水性离子液体-分子溶剂复合萃取剂,并研究了其对酚类化合物的萃取性能。结果表明,与纯离子液体萃取剂相比,三己基十四烷基溴化（[P₆₆₆₁₄]Br）-乙酸乙酯复合萃取剂在显著降低萃取剂黏度的同时,获得了较高的酚类溶质分配系数。当萃取剂中[P₆₆₆₁₄]Br摩尔分数为20%时,苯酚的分配系数为345,是纯乙酸乙酯为萃取剂时的5.3倍,是[omim]BF₄、[C₁₂mim]NTf₂等常规疏水离子液体的9~60倍;比纯[P₆₆₆₁₄]Br为萃取剂时的分配系数下降25.3%,黏度却比纯[P₆₆₆₁₄]Br降低99%以上。COSMO-RS研究表明[P₆₆₆₁₄]Br与苯酚之间较强的氢键作用是获得较高苯酚分配系数的关键因素。该复合萃取剂对间苯三酚、4-氯苯酚和2,5-二硝基苯酚等物质也有良好的萃取能力。上述结果为开发兼具良好热力学性能和动力学性能的脱酚萃取剂提供了新的思路。     

Fractionation of Carboxylic Acids Mixture Obtained by Succinic Fermentation using Reactive Extraction

Formic, acetic, and succinic acids have been selectively separated from their mixture obtained by A. succinogenes fermentation using reactive extraction with tri-n-octylamine (TOA) dissolved in three solvents with different polarities (n-heptane, butyl acetate, and dichloromethane) without and with 1-octanol addition. This technique allows recovering formic and acetic acids from the mixture, the raffinate containing only succinic acid. The extractant concentration and organic phase polarity control the selectivity of acids extraction. Thus, at pH = 1, the selectivity factor increased from 92, in the absence of 1-octanol; to 148, in the presence of this alcohol in organic phase. The corresponding optimum concentrations of TOA in the solvent were 30 and 50 g/l, respectively. The total separation of monocarboxylic acids from the mixture with succinic acid is possible by a multi-stage extraction process, adjusting the extractant concentration in each stage to that stoechiometrically needed for reactions with formic and acetic acids only. The addition of 1-octanol reduces the number of required extraction stages.     

Recovery of aconitic and lactic acids from simulated aqueous effluents of the sugar‐cane industry through liquid–liquid extraction

The recovery of aconitic and lactic acids from dilute aqueous effluents of the sugar‐cane industry by a solvent extraction technique has been investigated in order to reduce environmental pollution and in view of the possible uses of pure solutes in the field of foods and pharmaceuticals. Reactive extraction of carboxylic acids with tributylphosphate dissolved in dodecane was examined. Experiments were performed at 25 °C for three extractant concentrations of 50%, 60% and 70% (mass %) in dodecane. The decrease of specific gravity and viscosity of solvent resulting from the presence of an inert diluent was favourable to the phase settling and the mass transfer. The percentage of acids recovered in the organic phase for a volumetric solvent ratio varying from 0.5 to 5.0 was determined. Taking into account the difference between the partition coefficients for the carboxylic acids under consideration, the selectivity of solvent with regard to aconitic acid also was quantified. Moreover, owing to its water‐insolubility, its availability and its low cost, tributylphosphate can be considered as a promising extractant for large‐scale applications. © 2000 Society of Chemical Industry     

溶剂油萃取深度脱芳烃实验

随着环保要求的日益严格和清洁燃料的需求增加,低芳烃含量溶剂油亦需进一步脱芳烃。液液萃取脱芳技术因具有操作条件缓和、萃取剂可循环利用、可得到芳烃副产品等优势被广泛应用,但针对低芳烃含量的原料,萃取剂的研发是关键问题。本实验采用N,N-二甲基甲酰胺（DMF）+乙二醇复合萃取剂萃取分离低浓度芳烃溶剂油体系,从萃取剂对甲苯的选择性系数（S）和分配系数（K）两方面出发优化了脱芳萃取剂配方,确定乙二醇质量分数为15%的复合萃取剂适用于萃取分离芳烃质量分数小于15%的低芳烃原料。测定了常压、40℃时 DMF-甲苯-正庚烷和复合萃取剂-甲苯-正庚烷体系的液液相平衡数据,并用Othmer-Tobias 方程对实验数据进行关联。相平衡数据证实了复合萃取剂更适用于低芳烃原料油脱芳。将优化的复合萃取剂用于溶剂油脱芳烃,实验结果表明在萃取温度40℃、萃取时间5min、分相时间10min、单级剂油质量比0.5的操作条件下,经7级错流萃取,溶剂油的芳烃质量分数可从9.15%降至0.76%,具有一定的工业应用前景。