浮选技术在煤泥分选中的应用

文章介绍了煤泥浮选技术的原理,概述了浮选药剂和浮选设备的类型和性能,分析了煤泥浮选的工艺条件,并介绍了几种煤泥浮选技术的应用。最后,从浮选药剂的研发、浮选设备的改造、浮选工艺的改进以及浮选技术的创新等方面,对煤泥浮选技术的发展和应用提出了展望。     

油水乳液体系水合分离塔的模拟计算

在水合物法辅助分离乙烯裂解气流程中,水合物分离塔是非常关键的单元操作设备。气体混合物在塔内的分离过程与气体吸收塔类似,但因涉及气-液-液-固4相,所以计算更加复杂。将速率法和平衡级法相结合,提出了油水微乳体系吸收-水合分离塔的模拟计算方法。模拟计算了一典型乙烯裂解气在水合分离塔内的分离状况。为了确定适宜的操作条件,分别考核计算了操作温度和气液比对分离效果及能量消耗的影响。所得结果对水合分离塔的设计、操作条件的确定以及乙烯裂解气分离流程的制定有很重要的意义。计算结果还表明,通过水合物技术在0℃左右可实现氢气、甲烷和C₂以上组分的有效分离,因此可以节约大量制冷功耗。     

复杂反应的反应-分离集成的研究

对复杂反应体系的反应-分离集成问题进行了研究。以Denbigh反应为例，运用遗传算法对反应-分离循环的复杂流程结构进行了优化设计，分析了工艺参数对流程结构的影响。计算结果表明：对含中间产品的复杂反应体系，存在反应-分离循环圈的现象；反应、分离之间的相互影响主要集中在反应-分离循环圈内。反应-分离含有成流程结构和最佳工艺条件不仅与反应动力学关，而且与反应器投资和分离难易程度有关。不同的反应或分离费用可能对应不同的反应-分离集成流程。     

Drop coalescence on inclined plates in liquids

Inclined plates are often installed as mechanical separation aids in gravity settlers for the separation of liquid-liquid systems. The authors investigated the process of coalescence of single drops on trickling films flowing off inclined plates. The method of investigation was developed by Blass and Rautenberg. It ensures that, under certain conditions, only hydrodynamic parameters influence the coalescence process to any significant extent. The coalescence time of the drops characterizes the process of coalescence. Short time between 1 and 3 seconds provide favourable conditions for coalescence whereas long times, often ten times as long or even longer are unfavourable. This contribution introduces a criterion for clear demarcation between these two ranges and also a determination of separation parameters for favourable conditions for coalescence. Furthermore, the function of the plates is described, which is determined by hydrodynamic and wetting processes. The characteristic operating regions of a plate are shown in a working diagram.     

CO偶联制草酸二乙酯分离工艺的开发

CO气相催化偶联法生产草酸二乙酯是目前正在开发中的一碳化工新工艺。在中试及工业装置设计中开发分离工艺是新工艺的重要组成部分。该文在实验室连续精馏塔上研究工艺条件对草酸二乙酯精制过程的影响 ,为模型参数的修正提供实验数据。通过模拟计算 ,提出了适宜的草酸二乙酯精制分离工艺流程。最佳工艺条件 :闪蒸罐操作温度 90℃ ,压力 10 1.3kPa ;精馏塔常压操作 ,理论板数 14块 ,回流比 11,第7板侧线采出 ;减压蒸馏釜操作压力 3.2kPa。     

吸附法脱除烷烃中少量芳烃工业可行性分析

在实验研究烷烃中少量芳烃的吸附动态过程的基础上，确定该吸附净化过程的吸附一再生条件，探讨该过程实现的可行性，得到如下结论：从技术性能和技术经济这两个指标出发，对脱除循环烷烃中的少量芳烃的吸附分离过程，用固定床吸附过程来实现比用模拟移动床吸附过程来实现更具可行性，吸附法脱除循环烷烃中的少量芳烃具有设备投资少，能耗低的特点，有可能成为一种替代现行脱除少量芳烃的工艺方法，这些结果为在直链烷基苯的生产过程中，降低循环烷烃中芳构化物的含量，实现延长脱氢催化剂的寿命，提高烷基苯的产量提供了技术基础。     

从钼精矿焙烧烟尘中分离回收稀有金属铼

通过采用伯胺N_(1923)与中性膦TBP组成的协同萃取体系,分离回收钼精矿焙烧烟尘中微量铼的工艺流程,比较了此体系在不同条件下对铼（Ⅶ）、钼（Ⅵ）等离子的萃取效率和分离效果。铼在萃取过程中浓缩了20倍以上,整个回收工艺流程简单、分离效果较好。     

Kombination von Eindicker und kontinuierlichem Druckfilter zur Verbesserung von Fest/Flüssig-Trennprozessen

Combination of thickener and continual pressure filter to improve solid/liquid separation processes. The fundamental concept of the proposed process combination, which basically entails a division of the whole solid/liquid separation stage into sub-stages, is presented. The influence of the suspension's concentration on the formation and dewatering of filter cakes under ideal conditions is then discussed, after which possible deviations of the product from the ideal behaviour are described along with their influence on the process results. Actual engineering conditions are then considered, and the consequences of a suspension pre-thickening for the results of a drum filter are demonstrated. The conditions necessary for satisfactory results are discussed. Based on the results of conventional filtration, the further increase in filter efficiency occurring on avoiding the conventionally unavoidable gas throughput by a new process is explained. Finally a conceivable combination of apparatus for performing the described process is sketched.     

Optimisation-based design method for membrane-assisted separation processes

This paper presents a design method for membrane-assisted separation processes based on the concept of process superstructure optimisation, which should be applied to the separation of azeotropic mixtures. The main features of the proposed method are as follows: (i) detailed rate-based modelling of all unit operations; (ii) experimental model identification for membrane separation; (iii) application of an evolutionary algorithm. This method allows the simultaneous determination of optimal process configuration, equipment design and operating conditions for membrane-assisted separation processes.A case study for the separation of a ternary mixture of acetone, isopropyl alcohol and water in a hybrid pervaporation-distillation process is presented using the optimisation-based design method. Detailed rate-based models for the unit operations involved were implemented in a generic process model and necessary membrane model parameters were determined experimentally in a laboratory-scale device for the hydrophilic polymeric membrane Pervap™ 2201D from Sulzer Chemtech. After the identification of an appropriate process superstructure, the process configuration, dimensions of equipment and operating conditions required for the optimal hybrid pervaporation-distillation process were determined simultaneously. The optimisation criterion was the cost for purifying one ton of acetone. The results show that the developed method can be applied successfully for this complex mixed-integer non-linear optimisation problem.     

醋酸甲酯-甲醇-水的分离方法比较及展望

综述了醋酸甲酯-甲醇-水的分离方法,对反应精馏、萃取精馏、加盐萃取精馏等方法进行了概括和总结,比较醋酸甲酯提取工艺、条件、纯度及得率等因素,得出采用液液萃取法,具有工艺简单、能耗低等特点,有较好应用前景.     

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.     

Two classes of anionic surfactants and their significance in hot water processing of oil sands

In hot water flotation of bitumen from Athabasca oil sands, two types of primary oil recovery response to sodium hydroxide addition are identified. Natural carboxylate surfactants can promote bitumen separation and flotation under certain process conditions, while a second, more polar, class of natural anionic surfactants can promote separation and flotation under different process conditions. As a result, some oil sands exhibit two recovery peaks as a function of sodium hydroxide addition. The phenomena are explained in terms of different sodium hydroxide additions required to reach critical surfactant concentrations specific to each surfactant class. The concept provides a means for interpreting a wide range of processibility phenomena.     

Separation of azeotropic mixtures of alcohols and water with FricDiff

FricDiff is an energy efficient separation process based on a difference in transport velocities of the components of a gas or vapor mixture when they diffuse through a sweep gas (‘enhancer’). The separation process takes place inside the pores of a non-selective macro-porous barrier. In this paper the separation of a 2-propanol–water mixture with the FricDiff-principle is studied, using CO₂ as the enhancer. A detailed numerical model is developed that describes the separation process that takes place inside a cylindrical FricDiff-unit. In this unit the vapor mixture to be separated and the sweep gas flow at opposite sides of a porous barrier in a counter current mode. Through the porous barrier selective mass transport of components of the feed mixture through the sweep gas takes place resulting in a separation. The model takes into account axial velocity profiles as a result of laminar flow of the gas and vapor mixtures through the flow channels, radial concentration gradients and radial velocities. The transport through the porous barrier is described with the Binary Friction Model. The influences of process conditions and the characteristics of the porous barrier on the separation process are studied.     

分离过程的能耗分析与选择

在对不同条件下分离过程能耗理论分析的基础上,得到影响分离过程能耗的主要因素,同时对决定分离过程选择的因素进行全面的分析,从而最终确定最佳分离过程。     

Experimental study of a simulated counter-current adsorption system-V. Comparison of resin and zeolite absorbents for fructose-glucose separation at high concentration

The operation of a simulated counter-current adsorption process for separation of fructose-glucose mixtures has been studied experimentally at high concentration under conditions similar to those employed in the commercial process with both CaY zeolite and Duolite resin as the adsorbent. The overall performance of the system is similar for both adsorbents although the flow conditions required to achieve separation are significantly different. At high concentration the equilibrium isotherms deviate somewhat from linearity and this has an important effect on the concentration profile (and therefore the performance) of the counter-current unit. The equilibrium stage model, with due correction for the concentration dependence of the apparent distribution coefficients, is shown to provide a good representation of the system behaviour.     

丙烯丙烷吸附分离材料研究进展

在丙烯的生产过程中,因丙烯/丙烷的分子大小及挥发性较为接近而难以高效分离,其精馏分离过程能耗较高。变压吸附(PSA)技术作为一种高效的气体分离技术,其核心是高效吸附剂的开发。该文综述了近年来国内外关于丙烯/丙烷分离吸附剂的研究进展。重点介绍了分子筛、碳分子筛以及金属-有机骨架材料(MOFs)在丙烯/丙烷分离上的应用。详细阐述了影响多孔材料丙烯/丙烷吸附分离比的关键因素,并对比了几种吸附分离材料的优缺点。研究发现,应根据实际应用场合、原料气体的组成、丙烯/丙烷相对含量以及吸附材料的实际使用条件等来选择合适的吸附剂。最后,对丙烯/丙烷吸附分离材料的开发及其在实际中的应用进行了展望。     

Scientific and engineering principles of membrane gas separation systems development

A key part in development of membrane gas separation is assigned to membrane materials, their properties, such as the separation selectivity and specific performance with respect to individual components of gas mixtures. At the same time, the role of a particular process and its features in the separation of gas mixtures are insufficiently accounted for and are often not considered at all. In this paper, the authors have tried to formulate the engineering principles of membrane systems development based on a specific task taking into consideration the dialectical relationship between the membrane properties and optimal process parameters, such as the mixture composition, pressure, hydrodynamic conditions, and the process organization.     

基于分离系数校正的稀土萃取流程模拟

由于基于稀土萃取机理的流程仿真模型没有考虑萃取槽的萃取效率,导致模型输出的各级组分含量难以符合工业实际工况,为此,本文将机理模型与数据驱动的方法相结合,建立基于分离系数校正的稀土萃取流程模拟。首先,在相对分离系数的稀土萃取流程机理模型的基础上,引入分离系数校正值,实现对稀土萃取机理模型的扩充;其次,运用数据驱动方法,利用斐波那契树优化算法对各级校正值进行优化求解,并使用MATLAB GUI,开发稀土萃取流程模拟系统;最后,结合工业现场实际数据,验证本文流程模拟在工况改变时的动态性能,结果表明本文所建流程模拟符合稀土萃取流程实际工况。     

苦瓜多肽的分离纯化研究

以苦瓜为原料分离纯化制备多肽,通过正交试验确定了酶解的最佳工艺条件:加酶量为4%,温度45 ℃,酶解时间为1 h,料液比为2,多肽得率提高19.7%.采用葡聚糖凝胶G-50纯化得到2组洗脱液.此分离纯化工艺简单可行,成本低,可适用于工业化生产.     

Air Fractionation by Adsorption

Abstract

Pressure swing adsorption (PSA) processes for air separation differ by the modes and conditions of operation of the adsorption, the desorption, and the complementary steps, as well as by the types of adsorbents used. Three commercial PSA processes for air separation are reviewed and compared. The first process uses a zeolitic adsorbent and produces only an oxygen-enriched product gas. The second process uses a carbon molecular sieve and produces only a nitrogen-enriched product gas. The third process uses a zeolite and simultaneously produces both oxygen-and nitrogen-enriched product gases. The performance and separation efficiency of the last process, called the ‘vacuum swing adsorption (VSA) process’, are reported to be superior to the others.