盐湖MgCl2在混合溶剂体系中相平衡及其在Z-N型催化剂载体制备中应用

The utilization of the abundant MgCl2 resource in the Qinghai salt lake are urgent. MgCl2-supported Ziegler-Natta catalyst is the most common used catalyst in the polyofelin industry.In the synthesis of the Ziegler-Natta catalyst,electron donors such as alcohol are reacted with MgCl2 to form the MgCl2-adduct, which destroys the crystalline structure of anhydrous MgCl2. Then it is possible to incorporate of TiCl4 onto the MgCl2 surface. The phase equilibria of MgCl2 in the corresponding mixed-solvent system are of vital importance in the process control and optimatization of the catalyst synthesis. In this work, the phase equilibria data of MgCl2 in various alcohol and their mixtures as well as in the co-solvent such as toluene will be determined.A new speciation-based chemical model for the phase equilibria data of MgCl2 in various mixed solvent system will be established via the regression of the experiment data. On the basis of accurately estimation of the activity coefficient of related species by the established chemical model, the reaction process of the MgCl2-alcohol adducts will be studied in the point view of reactive crystallization theory, and the effect of various parameters such as temperature, alcohol type, solution concentrations will be investigated. The results can provide data and theoretical support for the synthesis of MgCl2 supported Ziegler-Natta catalyst.

我国青海盐湖中有大量MgCl2资源急需利用。目前以MgCl2为载体的Zeigler-Natta催化剂是聚烯烃合成中最重要的高活性催化剂。这类催化剂的合成过程是通过MgCl2与醇类等给电子体反应生成MgCl2-醇加合物，破坏MgCl2的晶格结构，得以负载TiCl4。MgCl2在醇类等溶剂组成的混合溶剂体系中相平衡性质对合成过程的控制是关键基础数据，然而文献中至今少见报道。本项目拟测定MgCl2在多种醇类（甲醇、乙醇、异丙醇等）及其他例如甲苯等助溶剂组成的混合溶剂中溶解度和汽液平衡数据。对于所测得的相平衡数据，采用基于全组分的化学模型统一进行计算。在对溶液中各组分活度系数等性质使用建立的模型进行精确估算的基础上，从反应结晶角度对MgCl2和醇类的加和反应进行研究，考察结晶温度、所用醇类、溶液浓度等因素的影响。为以MgCl2为载体的Zeigler-Natta催化剂的制备过程提供基础数据和理论支持

我国青海盐湖中有大量MgCl2资源急需利用。目前以MgCl2为载体的Zeigler-Natta催化剂是聚烯烃合成中最重要的高活性催化剂。这类催化剂的合成过程是通过MgCl2与醇类等给电子体反应生成MgCl2-醇加合物，破坏MgCl2的晶格结构，得以负载TiCl4。MgCl2在醇类等溶剂组成的混合溶剂体系中相平衡性质对合成过程的控制是关键基础数据，然而文献中至今少见报道。本项目测定MgCl2在乙醇和甲醇类等及其他例如甲苯等助溶剂组成的混合溶剂中溶解度和汽液平衡数据。对于所测得的相平衡数据，采用基于全组分的化学模型统一进行计算。在对溶液中各组分活度系数等性质使用建立的模型进行精确估算的基础上，从反应结晶角度对MgCl2 和醇类的加和反应进行研究，考察结晶温度、所用醇类、溶液浓度等因素的影响，得到了六乙醇氯化镁的纯净晶体，并测定了这个晶体的结晶成核动力学，为以MgCl2为载体的Zeigler-Natta催化剂的制备过程提供了有力的基础数据和理论支持。