凝胶色谱电泳分离装置及过程理论的研究

研制成功凝胶色谱电泳(CACE)分离装置,采用标准蛋白质模式混合物进行实验研究。通过理论分析,用体积平均方法建立了过程数学模型,计算并比较了不同条件下目标蛋白质的聚焦过程及分离操作的动态特性,说明了流场与电场强度对分离过程的重要影响。模拟结果与实验数据充分吻合。该模型对CACE分离过程及装置的设计和优化提供了理论依据。     

连续泡沫分离蛋白质

本文以空气-明胶水溶液体系为研究对象，较为详细地考察了通气量、进料流量、进料浓度、进料位置、泡沫高度、溶液pH值等因素对连续泡沫分离明胶过程中明胶富集度变化的影响．     

基于膜技术分离纯化乳清蛋白的研究进展

乳清废水有机负荷高,若直接排放将引起严重的环境污染,且造成蛋白质资源的浪费。因此,乳清废水资源化利用日益受到人们的关注。本文简要介绍了乳清蛋白组成、特性及其应用,归纳了近年来膜技术在乳清资源化利用方面的应用。首先介绍了压力驱动膜技术中超滤和荷电超滤在乳清蛋白分离和浓缩方面的应用,此后重点介绍了电驱动膜过程中电超滤（EUF）和电渗析耦合超滤体系（EDUF）在乳清蛋白以及活性肽分离回收领域的应用最新进展,并针对乳清蛋白分离过程中的膜污染现象进行了分析,提出膜污染过程的影响因素及控制措施,以期为乳清的资源化利用提供有益参考。最后指出了膜技术在单个乳清蛋白的分离回收方面以及工业化放大等方面仍存在一定局限性,并对此提出了解决方案及其未来的发展方向。     

微藻细胞的连续泡沫分离法采收

为考察连续泡沫分离法采收微藻细胞的可行性 ,在一种斜臂泡沫分离装置上 ,以螺旋藻为模型藻种 ,较为详细地研究了载气流率、藻液进料流率、浓度、pH值、离子强度、乙醇浓度、进料位置、泡沫段与液相段高度之比等因素对泡载采收性能的影响。结果表明 :在载气流率、藻液进料流率或藻液浓度较低时采收性能良好 ;当 pH值为 11、离子强度为 1 3× 10 ⁴ μs·cm^-1、乙醇浓度为 3%(体积 )时泡载收率可达 2 5 %～ 45 %;采用泡沫相段进料有利于提高泡载采收性能。提出的连续泡载采收动力学模型与实验值拟合较好 .     

Experimental Investigation of Ethanol Enrichment Behavior in Batch and Continuous Feed Ultrasonic Atomization Systems

The fragmentation of a liquid layer to form a fine droplet mist by high frequency ultrasonic atomization of liquids has been applied to a range of industrial applications such as fine chemical manufacturing, pharmaceutical production, and food processing. A recent development is the separation of alcohol from miscible alcohol‐water mixtures using ultrasonic atomization. In this work, the effect of high frequency ultrasonic atomization at 1.6 MHz on the enrichment of ethanol from ethanol‐water feed mixtures has been studied. Experiments for evaluating this enrichment process were conducted in batch and continuous feed processing systems. The continuous enrichment process generated product concentrations that were higher than the equivalent vapor‐liquid equilibrium curve at feed concentrations greater than 40 mol.‐% in a single stage. The role of the ultrasonic jet formed at the surface of the feed solution combined with the ethanol separation characteristics has been discussed.     

Multifunctional system for treatment of wastewaters from adhesive-producing industries: separation of solids and oxidation of dissolved pollutants using doted microfiltration membranes

To eliminate non-biodegradable organic compounds from wastewater application of semiconductor photocatalysis has been done. Experiments have been performed on immobilizing the photocatalyst titanium dioxide in an organic PAN microfiltration membrane and illuminated by UV-A light in order to improve oxidation performance and avoid particle separation. The organic pollutants are oxidized by in situ-produced hydroxyl radicals or directly by the catalyst. The membrane causes a convective flow of the pollutant towards the catalyst. The separation properties of the membrane can be used in a multifunctional way to extract remaining solid particles. A module containing membranes and a UV light source was developed. 4-Chlorophenol was completely mineralized at a high reaction rate. A two-step process has been developed for the clarification of highly polluted waste waters from adhesive-producing plants. First, the suspended solids which reach up to 10% of the mass stream are precipitated, flocculated and separated by means of a decanting centrifuge and flotation. Then the photocatalytic process was applied on the dissolved organic contents.     

以硅藻土为原料制备Na_2SiO_3·5H_2O工艺条件的研究

采用环境友好的纯碱对硅藻土进行碱熔,通过溶液结晶法制备Na2SiO3·5H2O产品。实验研究了硅藻土的分离提纯过程中的水洗过程包括擦洗次数及分离条件,碱熔过程的原料配比、温度、溶解等工艺条件。结晶过程中母液的浓度、温度、晶种的添加及干燥时的温度和时间等工艺条件,利用XRD、IR、UV、TG等对所得产品进行了表征,分析了结晶水的含量,得出生产Na2SiO3·5H2O的最适宜条件。     

High-performance protein separation by ion exchange membrane partitioned free-flow isoelectric focusing system

The objective of this study is to investigate a combination of ion exchange membranes and free-flow isoelectric focusing (FFIEF) technology for high-selectivity and high-flux protein separation, in which ion exchange membranes are used as the separation media. An FFIEF device has been designed and extensive experiments have been conducted to prove its effectiveness in enhancing the protein separation performance. Three types of membranes were employed in this work and they were commercial microfiltration (MF) ion exchange membranes, commercial neutral UF cellulose membranes, and home-made ultrafiltration sulfonated polysulfone (UF SPSf) ion exchange membranes. The protein separation results show that the home-made UF SPSf membranes have the superior selectivity and flux to other membranes. This is due to the fact that a stable pH gradient across the membranes as well as the interaction between the protein molecules and membrane surface plays an important role in the high-performance protein separation. By applying a semi-batch separation process and optimizing various experimental conditions, a high-purity (>90%) and concentrated target protein is obtained at the permeation side of the home-made UF SPSf membranes with a high flux.     

微生物高效分泌蛋白质的策略与应用

相比于胞内蛋白的生产,利用微生物细胞工厂生产分泌型蛋白具有更快速、便捷和下游分离工艺简单等优势。因此,首先概述了细菌微生物与真菌微生物不同的蛋白分泌系统和分泌机制,并分析了在蛋白分泌过程中,不同蛋白分泌系统、蛋白折叠和分泌过程、代谢负担与发酵培养条件对微生物高效表达分泌蛋白的影响以及导致的一系列瓶颈问题。基于以上瓶颈问题,分别从分泌蛋白表达体系、蛋白分泌途径组分、组学研究与发酵条件等方面进行了系统分析并提出相应的优化策略,为提高分泌蛋白的产量提供更多可用的信息与借鉴,旨在为今后利用微生物作为细胞工厂实现外源蛋白的高效分泌生产提供一定的理论基础与技术支持。     

膜结晶技术的发展及其在蛋白质结晶中的应用

膜结晶技术作为一种新兴的分离净化技术近几年得到了较快发展。阐述了膜结晶技术的产生背景、膜结晶器的类型、膜结晶技术的基本过程、原理及其优点,介绍了膜结晶蛋白质的优点及膜结晶技术在蛋白质结晶中的应用情况,最后展望了膜结晶技术的发展前景。     

Gelcasting of through-pore hydroxyapatite ceramics

Although the near-net-shape forming ability of gelcasting has been well demonstrated, current attention mainly was focused on manufacturing compact ceramics. In this work we demonstrated that the combination of the gelcasting technique and the ceramic sintering process could prepare the near-net-shape through-pore hydroxyapatite (HAP) ceramics, in which the pore diameter at the range of < 2 μm could be adjusted by changing the content of HAP in green bodies and with the aid of alcohol immersion. Experiments demonstrated that the gels in green bodies and alcohol immersion played important roles in improving the strength of green bodies and decreasing the shrinkage and deformation of green bodies, and thus improving the through-pore and near-net-shape forming of HAP ceramics. Such method reported here possibly extends the gelcasting technique to manufacture other through-pore ceramics for precise filtration, protein separation, or high performance liquid chromatography.     

The use of physical modeling in the optimisation of a primary separation vessel feedwell

A physical modeling program was undertaken to assess and eliminate a significant vessel wear problem observed in a primary separation vessel used in the recovery of bitumen from oil sands. A 1:20 scale model was fabricated, and process rates and materials were selected on the basis of dimensional analysis. Experiments showed that the existing feedwell produced poor circumferential distribution and formed a localised jet that entered the vessel over a narrow sector. Tests were then conducted with several different modifications to the feedwell to improve the flow distribution. The final design produced uniform circumferential distribution and a modest improvement in model separation efficiency. This design has been in commercial service for several years and has eliminated the local wear problems.     

The Parastillation Efficiency and Hydrodynamic Behaviour

This paper investigates some aspects of the parastillation process, which employs a unique distillation column. A laboratory scale apparatus was used to study the parastillation column. Experiments were carried out under total and partial reflux conditions, using an ethanol‐water system. Experiments were conducted to analyze the influence of the vapour flow rate and reboiler initial ethanol concentration on the hydrodynamic conditions. Limiting operating conditions were defined. Murphree separation efficiencies were calculated and discussed.     

连续逆向色谱电泳过程

连续CACE过程借助流场和逆向电场的共同作用,使目标蛋白质在分离柱富集区内连续富集。本文提出了连续CACE分离柱内浓度分布微分方程和定解条件,并对方程进行了求解。解决了富集区内目标蛋白质浓度的在线检测,用牛血红蛋白和细胞色素C在两套连续CACE装置上进行实验研究,取得了预期效果。     

Equilibrium properties and crystal growth of D2O + cyclopentane hydrate for sustainable tritium separation

This study reports thermodynamic properties and crystal growth observations of D₂O + cyclopentane hydrate toward the development of a hydrate-based tritium separation process. We employed D₂O as a host of hydrate with respect to the investigation into the formation of D₂O hydrate substrate, which is a core component of the tritium separation process. The hydrate phase equilibrium temperature in the liquid D₂O + liquid cyclopentane system was 3.2°C higher than the corresponding H₂O hydrate. Experiments on crystal growth were conducted at temperatures ranging from 5.1 to 8.5°C under atmospheric pressure. Under each thermodynamic condition, polygonal hydrate crystals appeared, growing along the D₂O/cyclopentane interface. The geometric shape and size of the crystals varied depending on the temperature. The variation in crystal morphology was comparable to that of the H₂O + cyclopentane hydrate. Implications based on the obtained results for the hydrate-based isotopic water separation process design are discussed.     

Chiral separation using a novel combination of cooling crystallization and a membrane barrier: Resolution of DL-glutamic acid

Chiral separation of racemic mixtures is essential in the production of many pharmaceutical compounds. The present work describes a novel chiral separation technique that combines cooling crystallization and a membrane separation that is used in DL-glutamic acid resolution. The process utilizes two crystallization chambers that are separated by a membrane that prevents transport of crystals from one chamber to another. Importantly, conditions must be controlled so that only a pure species crystallizes in each of the chambers. This is done by appropriate addition of seed crystals to each chamber and by restricting the formation of new crystals to secondary nucleation mechanisms. The seed crystals may grow or participate in secondary nucleation, but conditions must be controlled so as to prevent primary nucleation, which would result in the formation of both crystal species in each chamber. Experiments were conducted with different amounts of seed crystals to determine operating conditions that produce the high product yield and purity. The results show that this novel chiral separation process is promising: the product purity was over 94% (with a separation factor of 16) and the product yield was increased by as much as 56% more than could be obtained with simple cooling crystallization.     

Separation of paraffins by membrane extraction combined with crystallization

An integrated mass-exchange process combining liquid-membrane separation with crystallization from solution is experimentally and theoretically investigated. Experiments on separation of binary mixtures of paraffins that have close properties and form mutual solid solutions are carried out. The maximal degree of separation is attained using an aqueous ethanol membrane containing 65 wt % ethanol. From hexadecane-octadecane and hexadecane-tetracosane mixtures containing 86 mol % hexadecane, crystals containing 96.3 and 99.8 mol % hexadecane, respectively, are obtained. The solubility of hexadecane, octadecane, and tetracosane in aqueous ethanol solutions of various concentrations is experimentally studied over a wide temperature range. Using the solubility data, thermodynamic calculations of the liquid-liquid and liquid-crystals equilibria are carried out for the upper and lower boundaries of the aqueous alcohol membrane. A mathematical model of the integrated process is obtained by compiling a set of equations for the diffusion fluxes of the components in the liquid membrane and expressions describing the phase equilibria at the membrane boundaries. A comparison of the experimental data on the separation efficiency with the results of the calculations shows that the diffusion model adequately describes the main features of the integrated process.Translated from Teoreticheskie Osnovy Khimicheskoi Tekhnologii, Vol. 39, No. 2, 2005, pp. 120–127.Original Russian Text Copyright © 2005 by Lipatov, Myasnikov, Kulov.     

三相流化床脱胶工艺及其固体颗粒的流体力学行为

在内径80mm,高1000mm的三相流态化反应器中进行脱胶试验,得到适宜的脱胶状态。分析此状态下双组分固体颗粒的碰撞压力分布规律及对脱胶效果的影响,为实现该技术的产业化提供有益的参考。     

D296树脂分离锆、铪洗脱的效果

介绍了在离子交换固定床上用D296强碱性阴离子交换树脂分离锆、铪的洗脱实验研究。吸附与洗脱实验的温度均控制在2~5℃,洗脱实验在饱和吸附的离子交换柱、过漏的离子交换柱、未过漏的离子交换柱中进行。研究结果表明:离子交换柱吸附状态以及洗脱剂酸度对分离效果有显著的影响。当离子交换柱存在交换区时,用任何酸度的硫酸作为洗脱剂,铪均被先洗脱出来,但高酸度的洗脱剂对分离锆、铪更有利;当离子交换柱为饱和状态时,低酸度和高酸度的洗脱剂洗脱,锆、铪不能得到分离。实验证明了单一的固定床分离锆、铪的效率低,要成功实现锆、铪的分离,需采用连续分离的离子交换移动床。