摘要
采用等温溶解平衡法和浊点法分别测定了308.2 K时三元体系KCl+PEG10000/20000+H_(2)O的固液平衡组成和液液平衡组成,同时测定了固液平衡时体系的密度和折射率。根据实验数据,绘制了两个三元体系308.2 K时的完整相图、双液线对比图和结线-组成图。研究发现:三元体系KCl+PEG10000/20000+H_(2)O 308.2 K时的完整相图均包含6个区域:不饱和液相区(L),2个一固一液区(L+S),双液相区(2L),两液一固区(2L+S),两固一液区(L+2S);其中,一液两固区(L+2S)中的两种固相分别为KCl和PEG10000/20000。在完整相图中,一固一液区面积最大,双液相区面积最小。对比308.2 K时聚乙二醇分子量为1000、4000、6000、10000和20000的KCl+PEG+H_(2)O体系可知:分子量为1000、4000和6000时,体系中仅存在固液相平衡关系;分子量为10000和20000时,体系中同时存在固液和液液相平衡关系,且随着聚乙二醇分子量的增加,双液线向原点移动,双液相区(2L)和两液一固区(2L+S)增大,不饱和液相区(L)和一固一液区(L+S)均减小。采用Chen-NRTL-PDH热力学模型进行了液液相平衡计算,计算结果与实验数据吻合较好。
For the ternary systems KCl+PEG10000/20000+H_(2)O at 308.2 K,the composition of equilibrium liquid at solid-liquid equilibrium was measured by the isothermal dissolution method,and turbidimetric method was adopted for liquid-liquid equilibrium.Meanwhile,the density and refractive index of the equilibrated solution were also determined.According to the experimental data,the phase diagrams,comparison diagram of binodal curve,and tie-line diagrams were plotted.In terms of phase diagrams of both ternary systems mentioned above,they were all consisted of 6 regions which respectively were region of unsaturated liquid phase(L),two regions of one liquid and one solid phase KCl(L+S),region of two-liquids phase(2L+),two liquids with one solid KCl(2L+S),and region of one liquid with two solids of KCl and PEG10000/20000(L+2 S).Among those regions,the area of(L+S)was the largest,and the area of(2L+)was the smallest.Also,this paper compared phase diagrams of ternary systems KCl+PEG+H_(2)O where the molecular weight of PEG respectively was 1000,4000,6000,10000,and 20000 at 308.2 K,respectively.The results showed that there was only solid-liquid equilibrium when the mixed solvents were composed of PEG1000,PEG4000,or PEG6000 in ternary systems at 308.2 K,while the solid-liquid equilibrium and liquid-liquid equilibrium coexisted in the systems containing PEG10000 or PEG20000 at 308.2 K.It also could be found that with an increase of the molecular weight of PEG,the binodal curve was closer to the original point,the region of two-liquids phase(2L+)and two liquids with one solid KCl(2L+S)enlarged,while the region of unsaturated liquid phase(L)and two regions of one liquid and one solid phase KCl(L+S)shrank.The Chen-NRTLPDH thermodynamic model is used to calculate the liquid-liquid equilibrium,and the calculated results are in good agreement with the experimental data.
作者
黄琴
于旭东
李茂兰
郑洪
曾英
HUANG Qin;YU Xudong;LI Maolan;ZHENG Hong;ZENG Ying(College of Materials and Chemistry&Chemical Engineering,Chengdu University of Technology,Chengdu 610059,Sichuan,China;Mineral Resources Chemistry Key Laboratory of Sichuan Higher Education Institution,Chengdu 610059,Sichuan,China)
出处
《化工学报》
EI
CAS
CSCD
北大核心
2021年第4期1895-1905,共11页
CIESC Journal
基金
国家自然科学基金项目(U1507111)
四川省科技创新人才项目(2019JDRC0016)。
