用支撑液膜法构建三相体系提取洁霉素

摘要：运用支撑液膜技术建立了进料相、膜相、反萃取相三相体系,实现了对洁霉素的分离提纯。该体系采用了洁霉素+异构烷烃（Isopar L）+HCl的反应体系,验证了进料浓度（Cb f）、进料相溶液pH、反萃取相溶液pH、萃取剂组成等因素对分配系数（D）的影响。同时,优化了膜组件实现萃取实验的操作条件,根据传质过程建立了数学模型。结果显示：当洁霉素进料浓度Cb f为11.9mmol/L、Isopar L体积分数VF为80%、进料相pH为10.1、反萃取相pH为1.2时,分配系数D最大为2.34。确定膜组件操作条件为：管程流量Vf=520mL/min,壳程流量Vs=500mL/min。根据所建的数学建模分析了各部分传质阻力,其中管程传质阻力为6.7×105s/m,壳程传质阻力为3.7×105s/m,跨膜传质阻力为2.7×106s/m,跨膜传质阻力为主要的传质阻力。     

磷酸三丁酯/煤油支撑液膜体系中苯酚的传质分离

研究了苯酚在以多孔聚丙烯平板膜(Celgard2500)为支撑体、磷酸三丁酯(TBP)为膜载体和煤油为膜溶剂的支撑液膜体系中的传质过程;用传统萃取法测定了TBP/煤油体系中苯酚络合物摩尔比为1∶1,同时得到25.0℃萃取平衡常数为96.72;考察了原料相pH值、初始质量浓度、膜二侧转速、载体浓度和反萃取相碱浓度对苯酚传质的影响,确定了该体系分离苯酚的最佳条件:原料相pH<9,苯酚初始质量浓度<1 000 mg/L,膜二侧转速>300 r/m in,载体浓度为0.55 mol/L,反萃取相碱浓度0.10 mol/L;根据双膜理论提出苯酚的传质动力学方程,采用直线斜率法计算了苯酚在TBP/煤油支撑液膜体系中的扩散层厚度和膜内扩散系数,计算结果表明动力学方程计算值能较好地与实验值吻合,平均相对误差在2%以内。     

支撑液膜分离技术

本文综述了支撑液膜的渗透机理、不稳定的解释、解决不稳定的方法,最后对支撑液膜的发展前景进行了展望。     

支撑液膜法提取柠檬酸工艺条件的研究

研究用支撑液膜法提取柠檬酸的工艺过程,讨论了:料液相浓度Cf0、反萃相浓度Cs0、搅拌速度n及操作温度T等工艺条件对传递通量的影响。结果表明,以多孔平板聚丙烯膜为支撑体,在由煤油-TOA-Na2CO3所组成的膜体系中,当Cf0=0.10mol/L,Cs0=0.20mol/L,n=200r/min,T=25℃时,提取率E可达61.3%,与传统工艺相比具有深入研究的价值。     

聚丙烯支撑液膜提取柠檬酸的传质条件

用聚丙烯支撑液膜从柠檬酸溶液中提取柠檬酸,通过正交实验考察和分析料液相浓度、反萃取相浓度、搅拌速率、温度等因素的影响,得到最佳传质条件：料液相浓度为0．4mol／L、反萃取相浓度0．1mol／L、搅拌强度300r／min、传质温度25℃。同时对该膜体系进行连续提取实验,结果表明最佳传质条件下膜体系稳定性较好,膜通量下降后可通过重新浸泡得以恢复,继续使用。     

中空纤维支撑液膜法提取林可霉素的研究

研究了反萃相预分散中空纤维支撑液膜技术提取林可霉素的传质过程,实现了林可霉素的萃取和反萃过程的耦合。研究了萃取剂(正辛醇)体积分数、林可霉素质量浓度、原料液pH对分配系数的影响,膜组件操作过程中管程流量、壳程流量对总传质系数的影响,并得到最佳操作条件,建立了数学模型。结果表明,正辛醇体积分数为80%、林可霉素质量浓度为5.5 g/L、原料液pH=11时分配系数最大。膜组件最佳操作条件,原料液∶萃取相=500∶500(mL/min)。利用传质模型求得原料侧水相传质阻力1/kW、跨膜传质阻力1/kM、反萃侧水相传质阻力1/kS在总传质阻力所占比例分别为21%、74%、6%,其中跨膜传质阻力是传质阻力主要部分。     

支撑液膜萃取乳酸传质模型

本文对使用支撑液膜(Supported Liquid Membrane)从水溶液中革取乳酸(HL)的过程进行了理论分析,经过适当的简化,推导出支撑液膜革取乳酸的传质模型。对模型进行了实验验证,测得了膜的弯曲因子及过程的促进因子,模型计算值与实验值相吻合,同时得出膜内载体三烷基氧磷(TRPO)与乳酸形成的萃合物分子式为HL·TRPO。     

支撑液膜法脱除氨氮的动力学

研究了以聚丙烯为支撑膜、以D2EHPA为载体脱除废水中的氨氮的支撑液膜体系。通过实验确定了料液pH值、载体浓度等与铵离子渗透系数之间的关系;建立了动力学方程。     

气液液三相体系的二维非均相传质模型与求解

在柱坐标系中建立了描述分散第二液相增强气液传质的轴对称二维非均相传质模型,采用有限差分法计算了传质组分在液膜区内的轴向和径向浓度分布以及传质增强因子,计算方法快捷、有效,并且能很好地吻合现有文献中的实验数据.     

Cu2+在支撑液膜中的传质过程

研究了以疏水性多孔聚丙烯膜(Celgard 2500)为支撑体和LIX984的煤油溶液为膜液的支撑液膜体系萃取Cu2+的传质过程. 采用双膜理论描述Cu2+通过平板支撑液膜的传质过程,建立了其在稳态下的传质动力学方程,且当反萃取侧酸浓度大于2 mol/L时,反萃取侧的传质阻力可以忽略;利用膜内分传质系数km表征支撑液膜膜液的流失行为,在传质过程中,km先增大而后逐渐减小,且载体的流失速率大于稀释剂煤油的流失速率. 考察了操作条件对传质和膜液流失速率的影响,结果表明,Cu2+初始传质通量随载体初始浓度、料液初始pH值和料液初始Cu2+浓度的增大而增大;载体初始浓度越大,膜液流失越快;料液初始Cu2+浓度增大,膜液流失越慢;料液相pH值的改变对膜液流失速率没有影响.     

Membrane Recovery in Liquid Membrane Separation Processes

Abstract

The use of conventional electrostatic coalescers with bare metal electrodes for the separation of rich water-in-oil emulsions often causes the formation of a sponge-like emulsion. This effect was eliminated by the use of insulated electrodes in a coalescer that allow the application of high electric fields at the oil/water interface, resulting in a clean separation of oil from water.     

Recovery of Nitrophenols from Aqueous Solutions by a Liquid Emulsion Membrane System

Abstract

The application of liquid emulsion membrane technology to the extraction of nitrophenols from aqueous solutions is discussed. The effects of various parameters such as hydrophilic lipophilic balance of the surfactants, speed of agitation, water volume fraction in the water-in-oil emulsion, treatment ratio, and the concentration of surfactant on the extraction of p-nitrophenol are studied, and a suitable formulation for a liquid emulsion membrane is developed. The same formulation was used to extract o-nitrophenol and 2,4-dinitrophenol, and the results are compared with those of p-nitrophenol. The swelling of the emulsion during extraction is minimized by the addition of cyclohexanone to the membrane phase. The demulsification of the emulsion phase after extraction is also carried out by a chemical demulsification technique. Acetone is used for demulsification.     

Recovery of Copper Ions from Wastewater by Hollow Fiber Supported Emulsion Liquid Membrane

Recovery of copper ions from wastewater using a hollow fiber supported emulsion liquid membrane (HFSELM) was studied with LIX984N as carrier, kerosene as diluents, and sulfuric acid solution as strippi...     

Recovery of Tartaric Acid from Aqueous Solution by Liquid Membrane Technique: Optimization by Taguchi Design of Experimental Methodology

Theoretical Foundations of Chemical Engineering - The transport of tartaric acid through a bulk liquid membrane (BLM) was investigated. The effect of solvent type, carrier concentration,...     

膜分离氢回收技术的应用

三明化工有限责任公司合成氨厂的合成氨生产能力为25万t／a。为保证合成气中惰性气体含量处于适宜范围内，需要不断地排放部分循环气，这部分气体称为合成吹除气。吹除气量约4000～5000^m3／h，其组分体积分数为H257．28％、N219．11％、CH416．92％、Ar6．91％、NH39％。吹除气除供三聚氰胺及白炭黑生产所需外，其余均作为生活煤气使用。     

乳酸的乳化液膜萃取与有机溶剂萃取的比较

在乳酸发酵与分离耦合过程中,可以采用乳化液膜萃取法或有机溶剂萃取法提取发酵液中的乳酸。本文比较了这两种方法的传质机理和操作过程,并实验分别研究了它们的最佳工艺条件,提出：在最佳操作条件下,提取相同量的乳酸,有机溶剂萃取有机相的消耗量为乳化液膜法的３－４倍,乳化液膜法萃取率高,而且能得到浓缩的乳酸。     

Recovery of Plutonium from Analytical Laboratory Waste using Hollow Fiber Supported Liquid Membrane Technique

Plutonium from analytical laboratory waste was recovered on liters scale using Hollow Fiber Supported Liquid Membrane (HFSLM) technique using 30% TBP/n-dodecane as the carrier. The technique is faster, gives lower radiation exposure to the working personnel, and generates lower volume of secondary waste as compared to traditional precipitation/ion-exchange technique. The recovery of plutonium was carried out in two stages from waste containing a mixture of 3.22 g/L Pu, 110 g/L U, and 60.2 mg/L Am. In the first stage, >96% Pu(IV) and U(VI) were transported into the receiver phase in two hours. The Am(III) contamination in the Pu(IV) and U(VI) fraction was <0.1%. In the subsequent stage, plutonium was reduced to Pu(III) and U(VI) was selectively transported in to the receiver phase. In this method, a pure fraction of uranium was also obtained along with pure fraction of plutonium. The purity of plutonium fraction was confirmed by ICP-AES analysis.     

含浸液膜烟气脱硫试验

研究了以柠檬酸钠,亚硫酸钠、亚硫酸氢钠溶液为膜液,不同的膜液浓度、膜厚、不同孔径的高分子膜、进料气速等因素对ＳＯ２通过含浸液膜渗透器时通量的影响,分析各种因素对ＳＯ２渗透通量产生影响的原因。采用适宜的膜液及膜液浓度可使ＳＯ２的渗透通量得到极大的提高。