三烷基胺反应萃取烟酸的研究(英文)

The distributions of nicotinic acid (NA) between water and trialkylamine (N235) dissolved in n-octanol was studied. The complexes of N235 and NA were investigated by Fourier transformation infrared spectrometry to deduce the reaction mechanism. It was found that N235/n-octanol was an efficient extractant for extracting nicotinic acid. The favorable operation conditions were equilibrium aqueous pH 4.2 to 5.5 and initial N235 concentration<0.42 mol·L-1 . The reaction processes included the reaction between neutral N235 and neutral NA and the reaction between protonated N235 and anionic NA. Based on the mass action law and some assumptions, an expression for distribution coefficient D was proposed. The apparent extraction equilibrium constants were calculated by fitting the experimental data and the results were satisfactory.     

气-液-液萃取传质效率的研究

在液-液萃取过程中,提高分散相的表面更新速率可有效提高萃取的传质效率.研究发现,在萃取过程中使用气体搅拌可以增加液液之间的接触面积,促进液相内的湍动和循环.据此,本文在气-液-液萃取条件下对不同填料的传质性能进行了测定.实验表明,通入气相后分散相液滴呈现稳定的“油包气”空心状态,这种结构大大降低了分散相液滴的传质层厚度,减小了传质距离,极大地强化传质效率.在适宜气速下,气-液-液萃取效率较传统萃取效率提高20％～40％.通过与散装填料对比,发现规整填料更利于强化萃取效果,传质效率提高约50％.     

以蓖麻油酸作为萃取剂回收处理癸二酸工业废水的萃取过程(英文)

Wastewater containing high concentrations of phenol and sodium sulfate is generated in sebacic acid （SA） industry. Castor oil acid, a raw material for producing SA, can be used to extract phenol from wastewater in order to reduce the amount of phenol used in the process and discharge of phenol. The results show that the extrac- tion mechanism is that hydroxyl group of phenol is linked to carboxyl group of castor oil acid by hydrogen bond. The extraction process approaches equilibrium in 30 min. Extraction ratio increases with the increase of sodium sulfate and castor oil acid, and decreases as phenol increases. When the oil-water ratio is 1 ： 3, the optimal distribu- tion coefficient of 40 is obtained. Phenol saturation concentration in castor oil acid is 1.03 mol.L-1 after extraction for 4 times. The equilibrium constant （Kex） at 25℃ is 8.41 and the endothermic enthalpy （AH） is 1.513 kJ.mo1-1. The Gibbs free energy （AG） is -5.277 kJ. tool-1 and the value of AS is calculated to be 22.3 J. mo1-1. K-1.     

计算传质法预测精馏塔效率(英文)

A computational mass transfer model is proposed for predicting the concentration profile and Murphree efficiency of sieve tray distillation column. The proposed model is based on using modified two equations formulation for closing the differential turbulent mass transfer equation with improvement by considering the vapor injected from the sieve hole to be three dimensional. The predicted concentration distributions by using proposed model were checked by experimental work conducted on a sieve tray simulator of 1.2 meters in diameter for de-sorbing the dissolved oxygen in the feed water by blowing air. The model predictions were confirmed by the ex-perimental measurement. The validation of the proposed model was further tested by comparing the simulated re-sult with the performance of an industrial scale sieve tray distillation column reported by Kunesh et al. for the strip-ping of toluene from its water solution. The predicted outlet concentration of each tray and the Murphree tray effi-ciencies under different operating conditions were in agreement with the published data. The simulated turbulent mass transfer diffusivity on each tray was within the range of the experimental result in the same sieve column re-ported by Cai et al. In addition, the prediction of the influence of sieve tray structure on the tray efficiency by using the proposed model was demonstrated.     

稀土萃取过程组分含量分布控制方法(英文)

Considering that the on-line measurement and automatic control of element component content (ECC) are dif-ficult to perform in rare earth cascade extraction process, the ECC distribution profile is dynamical y regulated at al stages to assess the effect of product purity control. Focusing on the theory of countercurrent extraction, the technology parameters and pre-setting flow-rates during the extract process are designed. Under varying process parameters, a novel step by step model is also proposed for each stage to analyze the impact on the distribution profile change. Combining the mass balance model and ECC changing trend at the monitoring stage, the ECC dis-tribution profile can be automatical y regulated by dynamical y compensating the related extract or scrubbing liquid flow-rate. To this end, the required product purity at the two outlets is achieved. Based on Wincc and Matlab dynamic simulators, a specific Pr/Nd cascade extraction process is used to illustrate and demonstrate the application of the present approach.     

熔融结晶精制高纯对甲酚的参数优化研究(英文)

Laboratory-scale experiments were carried out to evaluate the influences of operational parameters on the melt crystallization efficiency for p-cresol purification.The optimal crystallization conditions were determined:dynamic pulsed aeration at 90 L·h-1 and the cooling rate of 0.6-0.8 ℃·min-1,followed by sweating at 0.2-0.3 ℃·min-1 for 40 min.Results also demonstrate that the melt crystallization efficiency is sensitive to feed concentration,which highlights this technology for separation and purification of high purity products.     

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.     

第三相的加入对气液传质过程的影响

系统地介绍了气液传质过程中,固体小颗粒或第二分散液相(有机相)所形成的第三相的加入对传质过程的影响.分别论述了在不同的气-液接触器(搅拌釜、鼓泡塔)中,固体小颗粒和第二分散液相的加入对体系的传质系数、传质速率及界面面积等的影响,叙述并讨论了传质机理及模型的最新进展.     

指甲花萃取物对镍从瓦特镀液中电沉积的影响(英文)

采用赫尔槽试验、分散能力测定法、扫描电镜、X射线衍射、能谱分析、硬度测量及交流阻抗谱,研究指甲花萃取物(主要成分为2-羟基-1,4-萘醌)对镍从瓦特镀液中电沉积(以低碳钢为基体)的影响。在温度40~50°C和pH4.5~5.0的条件下,从含60mL/L指甲花萃取物的瓦特镀镍液中得到的镀层具有良好的耐蚀性和硬度。指甲花萃取物作为瓦特镀镍液的添加剂,极大地提高了镀液的分散能力和电流效率。在最佳指甲花萃取物浓度下所得的镀镍层为晶态,结晶细致。     

介电电泳分离稀土氧化物微粒(英文)

A challenge in chemical engineering is the separation and purification of rare-earth elements and their compounds. We report the design and manufacture of a dielectrophoresis (DEP) microchip of microelectrode arrays. This microchip device is constructed in order to use DEP to capture micro-particles of rare-earth oxides in petroleum. Dielectrophoretic behavior of micro-particles of rare-earth oxides in oil media is explored. The dielectrophoretic effects of particles under different conditions are investigated. It is showed that the prepared microchip is suitable for use in the investigation of dielectrophoretic responses of the rare-earth oxides in oil media. The factors such as frequency, particle size and valence of rare-earth metal are discussed. When the frequency is fixed, the translation voltage decreases as particle size increases. Lower frequencies are more effective for manipulation of inorganic particles in oil media. Particles of the same rare-earth oxide with different size, as well as particles of different rare-earth oxides, are captured in different regions of the field by regulating DEP conditions. This may be a new method for separation and purification of particles of different rare-earth oxides, as well as classification of particles with different size.     

液-液-液三相萃取研究进展及其在生化分离中的应用

对液—液—液三相萃取体系的研究进展进行了综述,并按照其特点进行分类,讨论了液—液—液三相萃取方法在各种复杂体系中的应用。重点介绍了该新型萃取体系用于生化产品分离的研究进展,同时还展望了其将来的应用及研究前景。     

机械搅拌萃取塔中影响传质效果的几个因素

对浆叶旋转式和筛板振动式两种机械搅拌萃取塔进行了传质方面的研究。通过测试大量的实验数据。及计算绘制的图表,校系统地考察分析了旋转（振动）频率,筛板振幅,两相界面,停留时间即取样时间等因素对传质效果的影响,并确定出了最适宜的操作条件。     

Kinetic Mass Transfer Between Non-aqueous Phase Liquid and Gas During Soil Vapor Extraction

The mass transfer between non-aqueous phase liquid(NAPL) phase and soil gas phase in soil vapor ex-traction(SVE) process has been investigated by one-dimensional venting experiments. During quasi-steady volatilization of three single-component NAPLs in a sandy soil, constant initial lumped mass transfer coefficient (λgN,o) can be obtained if the relative saturation (ξ) between NAPL phase and gas phase is higher than a critical value (ξc), and the lumped mass transfer coefficient decreases with ξ when ξ<ξc. It is also shown that the lumped mass transfer coefficient can be increased by blending porous micro-particles into the sandy soil because of the increasing of the interfacial area.     

土壤气相抽提过程非水相液体与气相的传质动力学研究

The mass transfer between non-aqueous phase liquid(NAPL) phase and soil gas phase in soil vapor extraction(SVE) process has been investigated by one-dimensional venting experiments. During quasi-steady volatilization of three single-component NAPLs in a sandy soil, constant initial lumped mass transfer coefficient (λgN,0) canbe obtained if the relative saturation (ξ) between NAPL phase and gas phase is higher than a critical value (ξc), andthe lumped mass transfer coefficient decreases with ξ when ξ＜ξc. It is also shown that the lumped mass transfercoefficient can be increased by blending porous micro- particles into the sandy soil because of the increasing of theinterfacial area.     

正丁醇萃取磷酸的微分散过程与传质系数研究

采用受力分析的方法建立了微分散液滴直径计算模型,以正丁醇/磷酸/水为实验体系,研究了微分散法萃取磷酸的传质特性,依据传质理论计算出了各实验条件下的传质系数及传质速率。研究结果表明:在微分散条件下,液滴直径随分散相流量的增大而减小;直接影响传质系数的因素主要是进口酸浓度、物性、相比、液滴直径、两相流量;采用准数关联出传质系数关联式为:Sh=9.01×10-8Sc1.612Re0.6876p1.027,计算值与实验值相对误差小于10%,为微分散萃取磷酸技术的深入研究提供了理论基础。     

超临界流体萃取塔的流体力学和传质性能

New models for describing hydrodynamics and mass transfer performance in supercritical fluid extraction columns were proposed.Those models were proved by experimental data,which were obtained in supercritical fluid extraction packed column,spray column and sieve tray column respectively.The inner diameter of those columns areΦ25mm,These experimental systems include supercritical carbon dioxideisopropanol-water and supercritical carbon dioxide-ethanol-water,in which supercritical carbon dioxide was dispersed phase,and another was continuous phase.The extraction processes were operated with continuous countercurrent flow.The predicted values are agreed well with experimental data.     

气体搅拌下微分萃取过程的传质及流体力学性能的研究

在装有静态分布器的萃取塔中 ,对有气体搅拌下的水、煤油 (苯甲酸 )萃取系统的滞液率、气含率和传质系数进行了实验研究 ,从而得出气体搅拌下传质更充分的结论。分析了滞液率、气含率和传质系数的影响因素及分布规律。     

Mass Transfer Simulation of Gold Extraction in Membrane Extractors

The extraction of gold in membrane extractors was theoretically investigated. Extraction of gold in the form of $ {\rm Au(CN)}_2^- $ in a solution of n‐heptane and synergistic extractants of LIX79+TOPO was studied. The membrane extractor consists of three sections: the tube side, the membrane, and the shell side. Conservation equations were derived for $ {\rm Au(CN)}_2^- $ in the membrane module and were numerically solved based on finite element method. Simulations were conducted through solving the momentum and mass transfer equations simultaneously. It was indicated that as the feed flows within the tube side, it moves into the membrane due to the concentration difference, and then gets swept by the moving extractants within the shell side. The distribution of solute concentration in the membrane contactor was obtained. Simulation results showed increasing the feed flow rate reduces the extraction efficiency, while doing the same for the organic phase flow rate does not change the extraction efficiency.     

超声对超临界CO2萃取传质的影响

自行设计了超声强化超临界CO2萃取装置,并以人参为原料,研究了超声的功率密度、频率和超声的辐照方式对超临界CO2萃取人参皂甙传质的影响。萃取压力、萃取温度、萃取时间和CO2流量分别为25 MPa、45℃、4 h和2.5 L/h。实验结果表明,当功率密度、超声频率和辐照方式分别为100 W/L、20 kHz和3 s/6 s时,人参皂甙的萃取率是不使用超声时的1.51倍;皂甙的萃取率随超声功率的增大而升高;低频超声较高频超声更有利于萃取;超声辐照时间对皂甙的萃取率影响较小;在高压下超声对超临界CO2萃取传质强化作用更明显;在适当的低温下更有利于超声强化超临界CO2萃取。