单个SMR填料的高径比及倾斜度对流场的影响

INTRODUCTION Random packing is widely used in many unit operations[1].Flow field inside a random packed bed affects the hydrodynamic and mass transfer efficiency.Study on the flow field of random packing is essential for improving hydrodynamic and mass transfer performance,while flow field investigation of single SMR packing is a foundation for random packed bed.Computational fluid dynamics (CFD)[2] may best serve for this purpose.     

液液萃取塔研究的若干新进展及展望

液液萃取是应用广泛的分离技术,在石油化工、制药提取、金属分离等领域都有重要的应用。萃取塔作为常见的分离设备当前的设计还十分依赖于以往的经验,需要进行大量的实验。文章综述了萃取塔设备的研究现状,总结了对塔内流场、液滴和浓度场的实验测量技术,介绍了基于液滴的模型化方法和多尺度计算流体力学模拟方法,归纳了过程强化的相关研究进展。并对萃取塔未来的研究发展进行了展望,在数字化和可持续的发展背景下,未来在实验方面可以关注实时测量和优化,模型化方面关注于微观界面行为和传质影响的描述,在基于先进的实验和模拟技术基础之上,结合新萃取体系进行萃取设备和内构件的开发,从而实现过程强化,以解决化工过程面临的共同挑战。     

混合澄清槽研究进展

混合澄清槽是应用最早、使用最广泛的逐级接触式萃取设备,具有级效率高、适应性强、放大简单及操作性强等优点.文章综述了近年来研究者们普遍关注的新型混合澄清槽形式,介绍其工作原理,剖析了不同槽体的优缺点,总结了当前混合澄清槽的三大研究方向分别是高混合效率、低搅拌转速和小占地面积.此外,随着对混合澄清槽的研究不断深入,国内外学者利用先进的技术深入地剖析设备内部的流体力学特性,如桨叶的抽吸效应、分散相液滴直径分布等,文中对此也进行了介绍,提出计算流体力学方法是改进混合澄清槽混合与澄清性能的重要手段.     

CO_2捕集的吸收溶解度计算和过程模拟

为了降低CO2吸收法捕集技术的能耗和成本,以目前常用的单乙醇胺(MEA)溶液吸收CO2为例,采用电解质非随机双流体热力学模型(E-NRTL),对溶液中的CO2气体溶解度进行计算,计算过程包含了化学反应平衡和汽液平衡,计算结果和文献数据相吻合。在此基础上,建立了CO2吸收过程模拟程序和包括解吸能耗、气体压缩能耗以及液体输送能耗的过程总体能耗的计算方法,继而通过过程模拟分析了吸收塔和解吸塔压力、溶液浓度和流量等因素对吸收捕集过程的总体能耗的影响,获取了最优的工艺条件,为以后新CO2吸收捕集过程提供能耗分析方法基础。     

萃取体系滴内和两相阻力控制的单液滴传质实验和数值模拟研究

Numerical simulation of transient mass transfer to a single drop controlled by the internal resistance or by the resistance in both phases was mathematically formulated and simulated in a boundary-fitted orthogonal coordinate system. The simulated results on the transient mass transfer dominated by the internal resistance are in good agreement with the Newman and Kronig-Brink models for drops with low Reynolds number. When the drop Reynolds number is up to 200, the mass transfer coefficient from numerical simulation is very low as compared with the Handlos-Baron model. The cases with mass transfer resistance residing in both the continuous and drop phases were simulated successfully and compared with the experimental data in three extraction systems recommended by European Confederation of Chemical Engineering (EFCE). For single drops with Re ＜ 200, the numerically predicted values of the extraction fraction and overall mass transfer coefficient are in reasonable coincidence with the experimental data. It is concluded that the numerical simulation can be resorted in some cases of solvent extraction for conducting numerical experiments and parametric study. Nevertheless, for better resolution as higher Reynolds number drops are simulated, more sophisticated techniques should be developed and incorporated to deal with the large deformation and transient shape oscillation as well as possible Marangoni effect.     

关于筹建青海大规模光伏发电与水电结合的国家综合能源基地的建议

中国科学院学部组织有关院士与专家进行了青海省大规模光伏发电与水电结合的国家综合能源基地的研究。本文论述了光伏与水电结合综合能源基地的重要意义;在青海筹建基地的已有基础和特殊意义;面临的问题与所需采取的措施等,提出了筹建青海光伏与水电结合的国家综合能源基地的建议。     

CO_2在碳酸二甲酯中的溶解度及强化途径

采用恒定容积法测定了283.15—303.15 K CO2在碳酸二甲酯(DMC)中的溶解度。结果表明,溶解度随压力升高而增大,随温度升高而减小。与碳酸丙烯酯(PC)相比,在283.15 K及288.15 K条件下,CO2在DMC中的溶解度比在PC中平均约高50%。并且常温下DMC的吸收性能优于低温下甲醇的吸收性能。因此,DMC是一种性能更为优越的溶剂。加入1.5 g金属-有机骨架化合物(MOF)ZIF-69后,温度为283.15 K及288.15 K时对DMC吸收CO2具有增强作用,而在295.15 K及303.15 K时无影响。这种特性也有利于CO2吸收和解吸循环过程的节能。     

流化造粒生产非均质尿基复合肥

简要介绍了流化造粒生产高浓度非均质尿基复合肥新工艺的开发和试验过程,结果表明可采用磷酸 一铵、磷酸二铵、普钙或重钙等原料生产尿基复合肥,养份可根据用户需求进行调整。在普钙和重钙颗粒 上喷涂熔融尿液生产的尿基复合肥还能防止吸湿。     

Preparation and Characterization of Copolymer Micelles Formed by Poly(ethylene glycol)-Polylactide Block Copolymers as Novel Drug Carriers

Diblock copolymer poly(ethylene glycol) methyl ether-polylactide (MePEG-PLA) micelles were prepared by dialysis against water. Indomethacin (IMC) as a model drug was entrapped into the micelles by dialysis method. The critical micelle concentration (CMC) of the prepared micelles in distilled water investigated by fluorescence spectroscopy was 0.0051 mg/mL which is lower than that of common low molecular weight surfactants. The diameters of MePEG-PLA micelles and IMC loaded MePEG-PLA micelles in number-averaged scale measured by dynamic light scattering were 52.4 and 53.7 nm respectively. Transmission electron microscope and scanning electron microscope observation showed that the appearance of MePEG-PLA micelles was in a spherical shape. The content of IMC incorporated in the core portion of the micelles was 18 wt.%. The effects of the synthesis method of the copolymer on the polydispersity of the micelles and the yield of the micelles formation were discussed.     

A General Equation for Calculating the ’True’ Height of Transfer Unit in Extraction Columns

Based on single drop mass transfer models and two phase flow equation,a general equationfor calculating the‘true’height of transfer unit of extraction columns was derived and tested withfour types of extraction columns with some different working systems.The calculated results fittedwell with those obtained by experiments.