胆碱类低共融溶剂在CO_2捕集与分离中的应用

胆碱类低共融溶剂是一种新型的离子液体。它不仅具有传统离子液体的优点,还具有价格低廉、低毒、生物可降解等优势。对胆碱类低共融溶剂在CO2捕集与分离中所涉及的物理性质,如气体的溶解度、CO2的吸收-解吸、密度、稳定性、黏度和表面张力等进行考察,并分析了胆碱类低共融溶剂的结构对各物性的影响。通过与传统离子液体的对比,胆碱类低共融溶剂在CO2捕集与分离中的应用具有一定的优势,如CO2溶解度高,黏度低。然而,胆碱类低共融溶剂在气体的选择性分离、表面张力等的研究还不足,且热稳定性方面还存在瓶颈,因此,其在CO2捕集和分离中的应用还有待进一步探讨。     

CO2-H2O和CO2-H2O-NaCl 体系的相平衡研究进展

To study the feasibility of CO2 geological sequestration,it is needed to understand the complicated mul- tiple-phase equilibrium and the densities of aqueous solution with CO2 and multi-ions under wide geological condi- tions（273.15—473.15K,0—60MPa）,which are also essential for designing separation equipments in chemical or oil-related industries.For this purpose,studies on the relevant phase equilibria and densities are reviewed and analyzed and the method to improve or modify the existing model is suggested in order to obtain more reliable predictions in a wide temperature and pressure range.Besides,three different models（the electrolyte non random two-liquid（ELECNRTL）,the electrolyte NRTL combining with Helgeson model（ENRTL-HG）,Pitzer activity coefficient model combining with Helgeson model（PITZ-HG））are used to calculate the vapor-liquid phase equilib- rium of CO2-H2O and CO2-H2O-NaCl systems.For CO2-H2O system,the calculation results agree with the experimental data very well at low and medium pressure（0—20MPa）,but there are great discrepancies above 20MPa.For the water content at 473.15K,the calculated results agree with the experimental data quite well.For the CO2-H2O-NaCl system,the PITZ-HG model show better results than ELECNRTL and ENRTL-HG models at the NaCl concentration of 0.52mol·L ^-1 .Bur for the NaCl concentration of 3.997mol·L ^-1 ,using the ELECNRTL and ENRTL-HG models gives better results than using the PITZ-HG model.It is shown that available experimental data and the thermodynamic calculations can satisfy the needs of the calculation of the sequestration capacity in the temperature and pressure range for disposal of CO2 in deep saline aquifers.More experimental data and more accurate thermodynamic calculations are needed in high temperature and pressure ranges（above 398.15K and 31.5MPa）.     

溶解和离子交换反应中K+的快速测定

离子溶液中快速传递及反应动力学过程的跟踪研究在实验上较为困难 ,为此基于离子选择性电极建立溶液中离子活度即时采集系统 ,并结合活度系数模型准确计算离子浓度 .该方法测定速度快 ,最小间隔为 1s,且所得离子浓度最大偏差小于 2 % .用此方法测定了硫酸钾溶解过程以及钛酸钾离子交换反应过程中钾离子浓度的变化 ,获得传统方法难以测定的数分钟内相关动态过程受溶剂、pH值的影响结果 .该方法可推广应用于研究其他各种动态过程 (如溶解、结晶、沉淀、离子交换、吸附和扩散等过程 )     

复杂流体-固体界面相互作用热力学机制

具有复杂结构的纳微界面往往是界面复杂作用和宏观实验现象的主导因素。要准确描述界面处复杂流体的行为,需要引入能描述复杂流体-固体界面相互作用的分子热力学模型。本综述围绕分子热力学模型化方法拓展至纳微界面传递问题,提出“分子热力学建模+分子模拟+纳微实验”三者有机配合新思路。并针对复杂流体-固体界面相互作用的定量研究,着重综述了作者在热力学建模,分子模拟以及采用原子力显微镜 (atomic force microscopy,AFM) 实验方面的研究进展,创新性地提出将AFM定量化分析作为桥梁,用于构建分子模拟模型,描述复杂界面作用,揭示分子热力学机制,为构建纳微界面传递模型以及分子热力学模型由体相拓展至界面提供了可能。     

混合电解质水溶液固液平衡计算

用Lu-Maurer活度系数模型在不增加任何模型参数的前提下回归出18种晶体的溶度积,在此基础上预测了H~+、Mg~(2+)、K~+、Na~+、NH_4~+、Ca~(2+)、Cl~-、SO_4~(2-)、NO_3~-等离子所组合的13种体系在不同温度(最低温度为273.15 K,最高温度为378.15 K)及最高离子强度为34.55 mol·kg~(-1)下的固液平衡.预测结果较为满意.从而说明了该模型的良好普适性和可靠的温度外推性.可以为工业结晶过程提供相平衡的预测估计.     

芒硝法生产硫酸钾工艺的模拟与分析

硫酸钾生产工艺中，钾离子转化率和能耗是二个最重要的指标，过去由于缺少可靠的电耗计算模，对能耗只能停留在定性分析上，本文利用ＰＨＥＥＳ软件，对各种芒硝法工艺路线进行了稳态模拟，给出了理论转化率和理论能耗之间的定量指标。通过发现，随着转化率的提高，能耗随之大幅度增长，由此得出结论不要片面追求高转化率，应综合考虑转化订与能耗的关系，达到优选之目的，能过模拟分析，为新工艺的研究和开发提供理论指导。     

固液相平衡级的通用算法

从热力学原理出发,建立了一种固液相平衡级计算的通用方法,通过自动判别平衡时的相数及析出固相的种类,经过较少的迭代次数就可获得固液相平衡时各相分率和组成,从而满足化工过程模拟计算与实际生产的需要。由于该解法为虚拟的等温蒸发过程,在判别平衡相数的同时给出了过程中晶体的析出顺序与各晶体刚析出时溶液组成,这些中间结果为分离过程的模拟计算提供了理论指导。此算法不仅完全不依赖于相图,而且还可通过对不同进料配比的计算,绘制出全范围内的固液相图。通过实例计算证明该方法可适用于目前文献中尚难以处理的复盐、含结晶水盐以及多离子体系。     

存在反应的电解质溶液相平衡研究

从应用的角度出发,对电解质溶液模型、相平衡计算的现状与发展进行了简要的回顾,并系统地介绍和讨论了作者在这方面的工作。指出对P itzer模型和作者提出的电解质溶液水化平衡模型建立各自相应的普遍化温度关系,结合所提出的固液平衡级计算方法,可以预测工业过程所涉及的高温、高压、高浓度范围内复杂体系的热力学性质,解决此类过程集成模拟优化的瓶颈问题。此外,还介绍了离子选择性电极测定弱电解质体系热力学的方法。     

Progress in the Study on the Phase Equilibria of the CO2·H2O and CO2-HeO-NaCI Systems

To study the feasibility of CO2 geological sequestration,it is needed to understand the complicated mul- tiple-phase equilibrium and the densities of aqueous solution with CO2 and multi-ions under wide geological condi- tions（273.15—473.15K,0—60MPa）,which are also essential for designing separation equipments in chemical or oil-related industries.For this purpose,studies on the relevant phase equilibria and densities are reviewed and analyzed and the method to improve or modify the existing model is suggested in order to obtain more reliable predictions in a wide temperature and pressure range.Besides,three different models（the electrolyte non random two-liquid（ELECNRTL）,the electrolyte NRTL combining with Helgeson model（ENRTL-HG）,Pitzer activity coefficient model combining with Helgeson model（PITZ-HG））are used to calculate the vapor-liquid phase equilib- rium of CO2-H2O and CO2-H2O-NaCl systems.For CO2-H2O system,the calculation results agree with the experimental data very well at low and medium pressure（0—20MPa）,but there are great discrepancies above 20MPa.For the water content at 473.15K,the calculated results agree with the experimental data quite well.For the CO2-H2O-NaCl system,the PITZ-HG model show better results than ELECNRTL and ENRTL-HG models at the NaCl concentration of 0.52mol·L ^-1 .Bur for the NaCl concentration of 3.997mol·L ^-1 ,using the ELECNRTL and ENRTL-HG models gives better results than using the PITZ-HG model.It is shown that available experimental data and the thermodynamic calculations can satisfy the needs of the calculation of the sequestration capacity in the temperature and pressure range for disposal of CO2 in deep saline aquifers.More experimental data and more accurate thermodynamic calculations are needed in high temperature and pressure ranges（above 398.15K and 31.5MPa）.     

离子交换法可控合成四钛酸钾衍生物

利用四钛酸钾(K2Ti4O9)离子交换平衡热力学模型预测了获得K2Ti4O9纯相衍生物的最优条件,并以K2Ti4O9晶须为前驱体,以目标产物的固相Ti与K摩尔比为控制目标,通过调节离子交换过程中溶液平衡pH值和用K+选择性电极控制液相K+浓度,成功合成出纯相的水合四钛酸H2Ti4O9·1 2H2O、TiO2晶须、K2Ti8O17晶须、K2Ti6O13晶须,用实验验证了预测的准确性。同时实验结果表明,只要控制了离子交换中间产物的固相化学组成,就可以控制最后产物的形式,初步探索了反应过程中组成和结构的关系。