含盐乙醇-水-异辛醇体系液液平衡

用自制的液液平衡釜测定了乙醇-水-异辛醇体系和乙醇-水-异辛醇-氟化钾/氯化钠体系的液液平衡数据。比较了上述3种体系的乙醇在有机相和水相中的分配系数,其中含盐体系高于无盐体系,含氟化钾体系高于氯化钠体系。对所测液液平衡数据用hand方程进行关联,结果良好。     

丁酮-水-氟化钾及丁酮-水-碳酸钾液液相平衡数据的测定和关联

测定了丁酮 水 氟化钾及丁酮 水 碳酸钾体系在 30℃时的液液相平衡数据 ,用Pitzer理论和Wilson方程对相平衡数据进行了关联计算 ,计算值与实验值符合良好 ,为工业上用盐分离丁酮 水体系提供了基础数据     

碳酸二甲酯-甲醇-氯苯体系汽液平衡数据推算

利用二元体系的汽液平衡数据,选用Ｗｉｌｓｏｎ方程推算了三元体系碳酸二甲酯－甲醇－氯苯的汽液平衡数据,为建立萃取精馏分离碳酸二甲酯和甲醇的数学模型提供了基础数据。     

环己酮-水-氟化钾及环己酮-水-碳酸钾的液液相平衡

采用气相色谱法测定了环己酮-水-氟化钾、环己酮-水-碳酸钾体系在25℃时的液液相平衡数据,相平衡数据表明产生的环己酮相中含有可以忽略的盐、水相中含有可以忽略的环己酮,因此采用氟化钾或碳酸钾可以有效地分离环己酮-水体系。分别采用Pitzer和NRTL方程计算水相和环己酮相中水的活度,将二者结合对液液相平衡进行了数学计算,计算值与实验值吻合较好,说明所选热力学模型对环己酮-水-氟化钾及环己酮-水-碳酸钾体系具有较好的计算精度,为采用氟化钾或碳酸钾分离环己酮-水体系提供了基础数据和设计依据。     

常压下叔丁醇-水-乙二醇体系汽液平衡测定与关联

在常压(101.3 kPa)下,采用改进的Othmer汽液平衡釜测定了叔丁醇-乙二醇体系的汽液平衡数据,对所测得的数据进行热力学一致性检验,结果表明实验数据符合热力学一致性。用NRTL模型对叔丁醇-乙二醇体系的汽液平衡数据进行关联,得到二元交互作用参数,并用这些参数计算汽相组成及平衡温度,计算结果与实验数据吻合。测定了叔丁醇-水-乙二醇三元体系的汽液平衡数据,乙二醇存在下,叔丁醇-水体系的相对挥发度大幅提高,证明乙二醇是萃取精馏分离叔丁醇-水体系的优良溶剂。     

二乙氧基甲烷-乙醇-水-甘油体系部分组分液液平衡

用液液平衡釜测定了二乙氧基甲烷-水、二乙氧基甲烷-甘油2组二元和二乙氧基甲烷-水-甘油、二乙氧基甲烷-乙醇-甘油、二乙氧基甲烷-水-乙醇3组三元体系常温、常压下的液液平衡数据。用NRTL和UNIQUAC方程对所测二元体系的平衡数据进行了处理。采用单参数法关联了乙醇-甘油体系的模型参数。结合三元体系的液液平衡数据,用NRTL和UNIQUAC方程关联出了三元体系中的第3对模型参数。确定了二乙氧基甲烷-乙醇-水-甘油体系合适的模型及参数,为含二乙氧基甲烷体系的实际分离过程提供了依据。     

碳酸二甲酯-碳酸二乙酯-甲醇三元体系相平衡数据的推算

采用双循环汽液平衡釜测定了常压下碳酸二甲酯-碳酸二乙酯、碳酸二甲酯-甲醇、碳酸二乙酯-甲醇三组二元体系的汽液平衡数据,实验数据经Herington面积积分法检验符合热力学一致性。用Wilson模型分别对实验数据进行了关联,利用关联出的模型参数计算相应的汽相组成,并与实验值比较,二者符合良好。利用二元体系的汽液平衡数据,由Wilson方程推算了碳酸二甲酯-碳酸二乙酯-甲醇三元体系的汽液平衡数据。为建立碳酸二乙酯和碳酸二甲酯、甲醇的精馏分离数学模型提供了基础数据。     

常压下正丁醇-异丁醇-醋酸丁酯-水体系汽液平衡测定与关联

文章采用单级循环汽液平衡釜测定了常压条件下正丁醇-异丁醇-醋酸丁酯-水混合液中的二元体系的汽液平衡数据,运用试差法关联Wilson方程中六对二元体系的模型参数,并计算出相应的汽相组成;测定了常压条件下正丁醇-异丁醇-醋酸丁酯-水四元体系的汽液平衡数据,并由六对二元体系模型参数关联出四元体系的汽液平衡数据。比较实验和计算值,结果表明:实验值与计算值的相对偏差均≤5%,说明实验值与计算值一致。文章研究结果为正丁醇、异丁醇、醋酸丁酯及水混合液的分离提供了一定基础数据。     

丙酮-异丙醇-甲基烯丙醇体系气液平衡数据测定及关联

采用双循环气液平衡釜,测定了常压(101.3 kPa)下丙酮-甲基烯丙醇和异丙醇-甲基烯丙醇二元体系以及部分丙酮-异丙醇-甲基烯丙醇三元体系的气液平衡数据。二元气液平衡数据经Herington面积检验法检验,符合热力学一致性。用Wilson和NRTL液相活度系数方程对两个二元体系的气液平衡数据进行关联,效果良好。由关联得到的两个二元体系的Wilson和NRTL模型参数,及Aspen Plus数据库中的丙酮-异丙醇体系的Wilson和NRTL模型参数预示部分三元体系的气液平衡数据,与实验值相比,丙酮、异丙醇和甲基烯丙醇气相摩尔分率平均绝对偏差分别小于0.0137、0.0113、0.0117。实验数据和关联结果为该三元体系的精馏分离提供了一定的基础数据。     

间二甲苯-磷酸-水三元体系的液-液相平衡

实验测定了不同温度下,间二甲苯-水二元体系和间二甲苯-磷酸-水三元体系的液-液相平衡数据。研究了磷酸中的杂质Fe~(3+)、Al~(3+)和Mg~(2+)对间二甲苯-磷酸-水三元体系相平衡的影响,以及杂质在两相中的分配情况。研究结果对共沸精馏浓缩磷酸提供了必要的理论依据和基础数据。     

竹浆纤维溶解过程中的均相水解研究

发现一种含催化剂的甲酸溶液体系能有效溶解竹浆纤维,竹浆纤维在溶解过程中纤维素发生了水解,水解后甲酸能清洁回收循环使用,并得到固体的可溶性糖产物。将竹浆纤维放入含催化剂的甲酸溶液0.5 h后,开始溶胀,1.0 h后逐渐溶解,颜色开始变深,呈浅墨绿色,2.0 h后基本溶解,溶液颜色也逐渐变深,4.0 h后呈完全溶解状态。60℃反应6.0 h后,经过处理可从反应体系中得到葡萄糖、纤维二糖、纤维三糖、纤维四糖、纤维五糖和纤维六糖固体产物,葡萄糖的得率达54.5%。     

含CaCl2的乙酸2-甲基-1-丁酯溶液饱和蒸汽压的测定及关联

The CaCl2 solubility in 2-methyl-butanol acetate and the vapor pressure of 2-methyl-butanol acetate containing CaCl2 were measured in the range of 90-135°C and from very low salt concentration to saturation.The experimental data were correlated with two equations,a modified Antoine equation with the dissolved salt taken into account and a nonrandom two liquid-electrolyte(e-NRTL)model.Both models are in good agreement with the experimental data.This study provides essential physical data for further investigation of vapor-liquid equilibrium system containing salt.     

EXTRACTION KINETICS OF COPPER BY TRILAURYLAMMONIUM CHLORIDE IN TOLUENE FROM AQUEOUS CHLORIDE MEDIA

Abstract

The rate of extraction of copper(II) from aqueous chloride solutions by tri-n-laurylammonium chloride (TLAHC1) dissolved in toluene has been investigated. The extraction rate was evaluated as function of the chemical composition of the system. The experiments were performed by using a stirred cell with constant inter-facial area. The experiments were performed at a stirring rate of the two phases where the influence of film diffusion is minimized. The data have been interpreted by a mechanism which assumes interfacial chemical reactions between the bulk species containing copper(II) and the molecules of TLAHC1 absorbed at the interface as rate determining.     

Surface activity of sucrose palmitates

Interfacial tension data are presented for cotton-seed oil-water and paraffin oil-water systems containing purified sucrose palmitates of different degrees of acylation. Both the monopalmitates and diplamitates effectively reduced interfacial tension. To be effective, the monoesters had to be dissolved in water, the diesters in oil. Although nearly inactive alone, sucrose tripalmitate was active in mixtures with the mono-and dipalmitates. Efficiencies of the sucrose palmitates were also excellent. In general, mixtures of sucrose palmitates were as effective as the most active component. When dissolved in water, the efficiency of sucrose palmitate mixtures was proportional to the monoester content, but when dissolved in oil mono-, di-, and triesters contributed to the efficiency.     

Highly Selective Extraction and Transport through a Bulk Liquid Membrane of L-Cysteine Using [K • DC18C6]+ Complexes

It is shown that dicyclohexyl-18-crown-6 (DC18C6) dissolved in chloroform can extract efficiently and selectively the anionic form of L-cysteine from aqueous solutions containing potassium ions. This ability depends on the aqueous phase pH and type of the salt used in this phase. Under optimized conditions L-cysteine can be quantitatively extracted into the organic phase. In such conditions there was no detectable extraction of amino acids tryptophan, tyrosine, leucine, methionine, arginine, asparagine, aspartic acid, glycine, serine, and threonine. The transport of L-cysteine from potassium chloride/potassium hydroxide solution across a bulk liquid membrane containing DC18C6 dissolved in chloroform has been investigated. The parameters influencing the transport efficiency such as the pH of the feed phase, the kind and concentration of the receiving phase, carrier concentration, the kind of organic diluents, and time were examined and optimized. An efficient stripping at the membrane/stripping phase interface was found using hydrochloric acid as strippant. Selectivity of the proposed system was evaluated by performing a series of competitive transport experiments on the binary mixtures containing L-cysteine with the competitor amino acids noted earlier. This investigation exhibits excellent transport selectivity of the process towards L-cysteine with respect to the examined amino acids.     

SOLUTE REJECTION IN THE ULTRAFILTRATION OF POLYDISPERSE ORGANICS FROM NATURAL PRODUCTS

Solute rejection in the ultrafiltration of solutions containing polydisperse solutes was modeled using a spherical solute/cylindrical capillary model, accounting for steric hindrance and wall drag effects. A power law relationship was used for the solute radius-molecular weight relationship. The three parameters in the nondimensional model are the ratio of mean pore radius/solute radius coefficient, the exponent in the solute radius versus molecular weight relationship, and the standard deviation of the logarithms of the pore diameters. Values of the parameters, obtained by fitting the model to rejection coefficient data for solutions containing dissolved organics from wood, were self-consistent and made physical sense. The model provides a useful tool for evaluating ultrafiltration membranes for specific solute fractionation applications.     

基于无线以太网的溶氧分析仪的设计

为了实现对多路溶氧的实时集中监控,笔者利用无线以太网通信具备的传输速率高、传播距离远及覆盖范围广等特点,将无线以太网通信技术融入到智能溶氧仪中。通过工业自动化信息传输协议Modbus TCP,构建了IP化的溶氧仪无线网络监控系统。实现了人机交互、实时信息通信、历史数据存储及远程无线监控等功能。     

Unsegmented flow approach for on-line monitoring of pH,conductivity, dissolved oxygen and determination of nitrite and ammonia in aquaculture

A fully automated flow system for on-line monitoring of analytes/parameters of interest in aquaculture is described. The approach has been optimized for the photometric determination of nitrite and ammonia and the continuous monitoring of pH, conductivity and dissolved oxygen, but these analytes/parameters are readily changeable as required. The system has been tested by monitoring these species in the input and output sea water streams of tanks at a fish breeding farm and also by monitoring water containing high concentrations of fish feed.     

Mass transfer studies on multiple emulsion as a controlled mass release system

A novel type of multiple emulsions which contain a microemulsion in macrodroplets, was prepared by a two-step emulsification procedure. Mineral oil was used as the oil phase with a mixture of Aerosol OT and Span 20 as primary emulsifiers. A water-in-oil microemulsion was prepared by gradual addition of water in oil containing both these emulsifiers. This microemulsion system, when dispersed in an aqueous solution containing secondary emulsifier, produces water-in-oil-in-water (W/O/W) multiple emulsions. The release rate of solute dissolved in the internal aqueous phase was measured using the dialysis technique. A theoretical model describing the diffusion of a multiple emulsion system was developed, which predicts the half-life for 50% of the internal solute to diffuse to the external phase. Experimental results showed the stability of multiple emulsions improved significantly upon using a thermodynamically stable microemulsion as a primary emulsion and a polymeric surfactant as a secondary emulsifier. As a resull, half-life of these multiple emulsions is greater than that of conventional multiple emulsions.