PTFE中空纤维膜萃取对苯二胺工艺研究

以硫酸溶液为萃取剂,采用PTFE中空纤维膜萃取料液中的对苯二胺,考察了料液相对苯二胺的初始浓度、料液相初始pH、料液相与萃取相流量、萃取剂的初始浓度对对苯二胺萃取率(η)的影响。结果表明,随着料液初始浓度增大,η增大,当对苯二胺浓度0.8 g/L时,η减小,但膜通量基本不变,即存在一个最大膜通量,此时对苯二胺浓度变化对传质无影响;对苯二胺料液的pH增大,η增大;萃取相硫酸浓度增大,η增大。另外,温度升高有利于膜萃取。     

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。     

PTFE中空纤维膜萃取烟酸工艺研究

以氢氧化钠溶液为萃取剂,采用PTFE中空纤维膜萃取料液中的烟酸,考察了料液相烟酸的初始浓度、料液相初始pH值、料液相与萃取相流量比、萃取剂的初始浓度对烟酸萃取率(η)的影响。结果表明,随着料液初始浓度增大,η增大,当烟酸浓度0.9 g/L时,η减小,但膜通量基本不变,即存在一个最大膜通量,此时烟酸浓度变化对传质无影响;烟酸料液存在一个最佳pH值为4~5;萃取相氢氧化钠浓度增大,η增大;存在一个最佳相流量比(Q料/Q萃)为2.1;温度升高有利于膜萃取。     

PTFE中空纤维膜萃取苯甲酸工艺研究

以氢氧化钠溶液为萃取剂,采用PTFE中空纤维膜萃取料液中的苯甲酸,考察了料液相苯甲酸的初始浓度、料液相初始pH、料液相与萃取相流量比、萃取剂的初始浓度对苯甲酸萃取率(η)的影响。结果表明,随着料液初始浓度增大,η增大,当苯甲酸浓度1 g/L时,η减小,但膜通量基本不变,即存在一个最大膜通量,此时苯甲酸浓度变化对传质无影响;料液的pH值下降,η增大;萃取相氢氧化钠浓度增大,η增大;存在一个最佳相流量比(Q料/Q萃)为1.8。另外,温度升高有利于膜萃取。     

膜萃取的应用研究

膜萃取是膜分离与液－液萃取相结合的一种新型分离技术。本文综述了膜萃取在金属萃取、有机物萃取、生化产物及药物萃取以及膜萃取生物降解反应器和酶膜反应器等方面的研究,讨论了膜萃取付诸实施的关键。指出,当前膜萃取过程付诸实施的关键是膜材料的开发和传质的强化并提出中空纤维膜萃取器是实现膜萃取的重要装置。     

中空纤维支撑液膜萃取法提铟工艺比较研究

采用中空纤维支撑液膜(SLM)技术,模拟酸性铟渣浸出液,以磷酸二异辛酯(P204)、磺化煤油体积比3:7为液膜萃取相,盐酸溶液为反萃相,研究了单组件膜萃取系统、双膜组件萃取-反萃系统、双膜组件萃取-超滤系统对酸性浸出液中In的提取与分离效率。结果表明,双膜组件萃取-超滤技术可同时实现浸出液中In的提取与反萃液中In的高纯度富集,浸出液中In的提取率可达90%以上,反萃液中In含量可达浸出液中In含量的70%,In的质量分数高于90%。     

液膜及膜萃取拆分手性物质的研究进展

随着人们对于单一手性物质尤其是手性药物需求的日益增长,手性物质的拆分技术成为热门的研究课题,其中液膜及膜萃取拆分技术作为一种低能耗和易于工业放大的手性拆分技术受到广泛的关注.着重介绍了用于对映体分离的支撑液膜、乳化液膜、厚体液膜、中空纤维膜等技术在手性物质分离方面的近期研究成果和应用开发现状,并总结了各种方法的优缺点.指出了中空纤维膜具有稳定性较好、传质面积大、传质高度低等优点,具有更大的工业应用前景,同时分析了手性物质膜萃取分离基础理论和技术的发展方向.     

膜萃取在含铀废水处理中的应用研究进展

铀水冶和精制过程中会产生大量的低浓度含铀废水,对环境造成了严重污染。本研究对膜萃取技术处理含铀废水进行了综述,主要归纳了液膜、中空纤维膜、聚合物包容膜这3种膜在膜萃取处理含铀废水中的具体应用情况,简要说明了膜萃取技术在含铀废水处理中所具有的优点和应用潜力。同时对膜萃取技术的应用特点、机理进行了分析,并对膜萃取技术未来的发展趋势进行了展望。     

一种新的膜过程—膜萃取

膜萃取是膜过程和液—液萃取相结合的新的分离技术。本文介绍了膜萃取过程的研究状况,分析了这种交叉组合的新的膜过程的特点,说明了膜萃取研究的内容、方法及存在问题。     

纤维膜技术在炼厂废碱液处理方面的应用

详细介绍了纤维膜技术的原理、纤维膜接触器在不互溶液-液两相萃取工艺上应用的优点、以及纤维膜接触器在大连石油化工工程公司废碱液处理装置上的应用状况。指出纤维膜接触器可很好地解决废碱液中高浓度有机物的萃取吸收问题,是炼厂废碱液处理工艺的发展趋势。     

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。     

Co-Ni离子的电反萃实验

电反萃技术是把离子交换,萃取,膜分离过程结合在一起的一种新的分离方法,弱酸性油相萃取剂通过吸附了金属离子的离子交换柱,油相依次萃出树脂相中的各种金属离子,不同萃出部分的油相用充填床电渗析出进行电反萃,回收金属离子,油相萃取剂可反复利用。     

从工业废水中回收乙酸的方法研究进展

随着我国工业水平的不断提高, 含有乙酸的废水产生量越来越大。乙酸的含量一般在1%～30%(质量分数), 使废水不仅表现为强酸性, 而且化学耗氧量高, 不易直接排放。乙酸与水不易分离也使乙酸废水在工业上难以处理, 研究从废水中回收乙酸的方法具有重要意义。本文简要介绍了近几年国内外从工业废水中回收乙酸的进展, 主要包括膜分离法、吸附法、萃取法、萃取酯化法、精馏法, 并分析了每种方法的优缺点以及当前的研究水平。指出:双极膜电渗析和渗透汽化法适合乙酸质量分数在1%左右的废水处理;吸附法和反应萃取法适用于乙酸含量在10%以下的废水处理, 30%以下的乙酸废水可以借助反应精馏进行分离。最后分析了膜分离法和吸附法处理含乙酸废水的工业应用尚需解决的关键问题。     

Extraction of Rhodium Chlorocomplexes and Acid through a Supported Liquid Membrane of Kelex 100

Abstract

The supported liquid membrane (SLM) technique was employed to effect the separation of Rh Chlorocomplexes from hydrochloric acid solutions. The liquid membrane consisted of an alkylated 8-hydroxyquinoline extractant (Kelex 100), tridecanol, and kerosene. The nonaquated Rh complexes were transported through the membrane upon ion-pair formation with protonated Kelex 100 molecules. The ion-pair was then dissociated at the strip side of the membrane, releasing the Rh values. The main driving force for this transport process was the acid activity gradient across the membrane. The permeation of acid and water, which were cotransported with the Rh complexes, was partially prevented upon addition of NaCl to the strip phase. However, the accumulation of Cl^? ions in the strip phase, in turn, slowed down the extraction of Rh. Optimum Rh extraction performance was obtained when a feed of 2.5 M HC1 and a strip solution of pH 1 were used. Under these conditions the membrane was found to be very stable for at least a period of 72 hours (maximum period tested) while the rate of extraction was found to be 2.8 × 10^?6 mol·s^?1·m^?2.     

Selective and Synergistic Extraction of Nickel from Simulated Cr-Ni Electroplating Bath Solutions using LIX 63 and D2EHPA as Carriers

The main goal of the present study is to explain synergistic extraction of nickel from simulated Cr-Ni electroplating bath solutions (SEBS) using 5,8-diethyl-7-hydroxydodecane-6-one oxime (LIX 63) and di-(2-ethylhexyl) phosphoric acid (D2EHPA) as extractants by emulsion liquid membrane (ELM) technique. The importance of membrane composition and aqueous phase properties on nickel extraction percentage has been highlighted for the selective extraction of nickel. Some important parameters like acid concentration, stripping solution type and concentration, mixing speed, extractant concentrations, phase ratio, and surfactant concentration was studied to improve the extraction and stripping efficiencies. Higher than > 99% of nickel was recovered at optimum conditions within 6 min. The higher separation factors (β_Ni/Cr) were obtained as 580. As a result, the nickel extraction kinetic with D2EHPA has been defined as faster than LIX63. So, the kinetic transport of nickel mainly depends on LIX63 than D2EHPA. According to these results, D2EHPA behaves as a synergistic extractant in the present extraction mechanism.     

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.     

A study on reactive extraction equilibrium between acetic acid and bis-succinimide of C9232

C9232 is a typical emulsifier of emulsion liquid membrane and its main component, bis-succinimide, has amine functional groups which react with carboxylic acids. The average numbers of secondary amine groups and isobutylene units in the bis-succinimide were determined through elemental analysis. Acetic acid was extracted by emulsion liquid membrane with use of C9232, and we verified that C9232 was suitable for its extractant in the emulsion liquid membrane systems. Equilibrium experiments for reactive extraction of acetic acid by C9232 were carried out by varying the overall acetic acid concentration and overall C9232 concentration in liquid-liquid extraction systems. Also, an equilibrium model for the reactive extraction of acetic acid was investigated for the purpose of analyzing the emulsion liquid membrane systems for separation of acetic acid from other carboxylic acids or sugars in the future. The calculated results from the equilibrium model were in good agreement with the experimental data.     

三辛胺萃取分离乳酸-醋酸

选择三辛胺为络合剂、正辛醇为稀释剂、乳酸和醋酸为被萃溶质 ,系统地研究了水相pH值及络合剂含量对单组分乳酸、醋酸及其混合物萃取特性的影响。在适当假设条件的基础上 ,建立了考虑络合萃取及物理萃取的单组分及双组分体系的相平衡分配系数表达式。在本文的实验条件下 ,随络合剂含量的升高 ,乳酸、醋酸的单组分及其混合物中各组分相平衡分配系数皆升高 ,分离因子 β增大 ;随水相平衡pH值的升高 ,相平衡分配系数均降低 ,分离因子也呈下降的趋势 .采用本文的模型进行模型参数拟合 ,其精度较好。利用单组分的络合反应平衡常数可成功地预测双组分体系中各组分的相平衡分配系数值     

生物油中络合萃取乙酸的研究

采用三正辛胺（TOA）作为络合剂,异辛醇和煤油分别作为助溶剂和稀释剂,对生物油中的乙酸进行了络合萃取研究。考察了TOA体积分数、异辛醇浓度、萃取剂与生物油轻馏分体积比以及温度对乙酸萃取率的影响,结果表明：温度为0 ℃,萃取体系为40%TOA+40%异辛醇+20%煤油(各组分浓度均为体积分数,下同),萃取剂与生物油轻馏分体积比为3∶1时,乙酸的一次萃取率较高,可达74.6%。