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Antonio Montes M. Dolores Gordillo Clara Pereyra Enrique J. Martínez de la Ossa 《化学工程与技术》2014,37(1):141-148
Nanosystems based on polymers have attracted much attention due to the almost infinite diversity. In the past decades, the application of supercritical fluids for polymeric particle precipitation has been developed as an alternative to conventional processes. Here, precipitation of an acrylic copolymer was attempted by the rapid expansion of supercritical solutions (RESS) and successful by supercritical antisolvent (SAS) processes. In addition, the nanoparticles were characterized with different techniques. The polymer concentration, pressure, temperature, liquid solution flow rate and nozzle diameter effects were also evaluated with regard to particle size and the particle size distribution of this polymer. 相似文献
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Supercritical fluids and ionic liquids offer attractive opportunities for modifying and applying zeolites as adsorbents and catalysts. After a brief introduction to the most important properties of these solvents, examples of zeolite applications in supercritical fluids and ionic liquids from the recent literature are discussed. Particular emphasis is put on the influence of reaction media on the processes occurring in the zeolitic pore systems, e.g., during shape‐selective conversions in zeolite catalysts. The present potential and future challenges for the application of zeolites in supercritical fluids and ionic liquids are identified. Most attractive process options arise from a combined use of both ionic liquids and supercritical fluids in integrated reaction schemes. 相似文献
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文章阐述了超临界流体分离技术的原理、流程与特点.综述了该技术在分离工程领域的应用方向、存在的问题及未来的发展前景.指出了该技术兼具精馏和萃取两种分离作用效果,在天然资源成份的分离提取、脱除有害成份或杂质、清洗、色谱分析等诸多领域部有着其独特的开发应用优势. 相似文献
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Hooman Fatoorehchi Randolph Rach Hossein Abolghasemi 《Chemical Engineering Communications》2013,200(3):402-407
In this study, an efficient iterative algorithm is devised to handle a nonlinear equation arising in estimation of thermodynamic properties at supercritical conditions. The approach is based on a synergistic combination of the classic Newton-Raphshon algorithm and the Adomian decomposition method. We demonstrate that the proposed method enjoys a higher degree of accuracy while requiring fewer iterations to reach a specific solution compared to that by the Newton-Raphson algorithm. To illustrate the efficiency of the aforementioned solution technique, several numerical examples are provided. The proposed method has been easily implemented in computer codes to provide parametric, not just numeric, solutions to the model equations. Consequently, one can derive other thermodynamic properties, which have not been treated parametrically to date, based on our new combined approach. 相似文献
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Loubna Nasri 《Polycyclic Aromatic Compounds》2018,38(3):244-256
Since developing mathematical models is extremely useful to determine solubilities of various solutes in supercritical fluids (SCFs); in this work, the “expanded liquid” approach is adopted to predict the solubility of some polycyclic aromatic solutes (with different size, functionality, and polarity) in diverse SCFs. A modified form of the Wilson's model is proposed for predicting the solubilities of the considered binary systems by computation of the activity coefficient based on the local composition concept. Effect of high operating conditions is considered via the variation of the molar volume of the solute. The proposed correlation achieves an overall and average AARD of 9.2% and 7.8%, respectively, on a range of 1.14% to 19.9%, these results show that the predicted solubility data are in good agreement with the experimental ones. Moreover, dependence of binary parameters on density and some solute's characteristics is discussed on the base of their course versus solvent reduced density. 相似文献
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超临界流体在化学反应中的应用 总被引:1,自引:0,他引:1
综述了临界流体的性质及超临界流体在化学反应中一的些应用。主要介绍了超临界流体在F-T合成反应、1-己烯异构化反应、氧化反应和烷基化反应中的应用。 相似文献
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热力学超临界流体换热计算与分析 总被引:1,自引:0,他引:1
超临界流体技术是新兴的化工技术之一 ,换热是其工程应用研究的重要方向。该文以水作为超临界流体的代表 ,以逆流操作的套管式换热器为对象建立简化的物理模型 ,再通过微元热量平衡分析 ,建立数学模型 ,并用数值方法求解。文中研究了 2 5MPa、 30MPa和 35MPa ,及 2 5— 6 0 0℃范围内冷热流体的温度、总传热系数和热流密度沿管长的变化 ,结果显示了在近临界区由于物性变化剧烈 ,使占整个管长的 1/ 3— 1/ 2的区段换热效率变低的独特规律。压力升高有利于换热的进行 ,并讨论了管径的影响。 相似文献
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For technical applications, those reactions in supercritical fluids are of particular interest which have significant advantages over conventional methods or which are impossible in classical solvents or in the gas phase. This last part of the trilogy deals with heterogeneously catalyzed reactions in supercritical fluids other than carbon dioxide or water. 相似文献
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何潮洪 《高校化学工程学报》1998,12(2):183-185
1引言扩散系数是重要的化工基础数据,由于测定较困难,它的预测就显得很重要。近几年这方面的研究热点之一是预测溶质在超临界溶剂中的扩散系数“-’‘。作者最近以roush-hard-sPhere扩散理论为基础,结合大量文献数据,提出了一种预测溶质在超临界溶剂中扩散系数的方法,其形式如下「‘’:用上述方法曾对107个溶质一溶剂系统(共1167数据点)的扩散系数作了预测,平均相对偏差约7.5%,精度较高[’‘。但它不适用于CO。一醒系统(现有的文献预测方法中均存在着这个问题)。此外,当溶质含卤原子较多时,误差也较大。本文的目的是… 相似文献
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介绍了超临界流体中化学反应的特点及基础理论研究,简要评述了超临界流体作为反应介质的酶催化反应、超临界水氧化反应、金属有机反应和超临界流体作为反应原料的超临界CO2、超临界CO加氢反应。 相似文献