Thermal Sciences Group, National Renewable Energy Laboratory, Golden, Colorado 80401, United States.
Anal Chem. 2020 Mar 3;92(5):3598-3604. doi: 10.1021/acs.analchem.9b04301. Epub 2020 Feb 19.
A commercial blend of mainly carnallite (KCl·MgCl·6HO) is considered as a next-generation heat transfer fluid in solar thermal plants. Corrosive properties of MgCl hydrates must be addressed at the operating temperatures of 500-720 °C. For successful chemical monitoring of the carnallite heat transfer fluid, an experimental method was developed to separate and titrate for MgO and MgOHCl from solid carnallite. This new method was assessed for error and accuracy. The method's relative error for MgOHCl was -7.0% for a mass fraction of 9.0 wt % MgOHCl in the carnallite salt. The method's relative error for MgO was less than +1.0% for a mass fraction of 12.0 wt % MgO in the carnallite salt. Titration results were used to track changes in the MgOHCl concentration in carnallite salt through the carnallite's dehydration and purification.
一种主要由光卤石（KCl·MgCl·6HO）组成的商业混合物被认为是太阳能热电站中的下一代传热流体。在 500-720°C 的工作温度下，必须解决 MgCl 水合物的腐蚀性问题。为了成功地对光卤石传热流体进行化学监测，开发了一种从固体光卤石中分离和滴定 MgO 和 MgOHCl 的实验方法。对该新方法进行了误差和准确性评估。对于质量分数为 9.0wt%MgOHCl 的光卤石盐，该方法对 MgOHCl 的相对误差为-7.0%。对于质量分数为 12.0wt%MgO 的光卤石盐，该方法对 MgO 的相对误差小于+1.0%。通过光卤石的脱水和纯化，利用滴定结果来跟踪光卤石盐中 MgOHCl 浓度的变化。
