低水合氯化镁吸水过程的气相色谱热力学研究

利用迎头气相色谱分析、量热法、热重法、X -衍射法和化学分析相结合 ,对氯化镁水合物吸水和脱水过程进行了热力学研究。在不同温度下对MgCl2 ·4H2 O和MgCl2 ·2H2 O对水的吸附等温线所进行的数学模拟结果表明 ,Bolzmann函数是描述该等温线较为理想的方程。两种氯化镁水合物对水的吸附热分别为 -1 3 0 6kJ/mol和 -1 6 1 1kJ/mol。也给出了该吸附过程的吸附平衡常数。从所获得的数据来看 ,以部分脱水的氯化镁水合物为吸附剂来吸附水氯镁石脱水设备尾气中的水蒸气 ,从而使保护性气体HCl得以循环使用 ,从热力学角度而言存在这种可能性。

Gas Chromatographic Thermodynamics Study on Hydration Processes of Magnesium Chloride with Low Water

The dehydration and hydration processes of magnesium chloride hydrates are studied by means of headspace chromatography analysis,calorimetry,thermogravimetry,X-ray diffraction and chemical analysis.The mathematical imitation to the adsorption isotherms of MgCl 2·4H 2O and MgCl 2·2H 2O under different temperatures indicates that Boltzmann Function is the ideal equation to describe those adsorption isotherms.Its adsorption heat for water is -13.06kJ/mol and -16.11kJ/mol,respectively.The adsorption equilibrium constants are given here also.It is shown,from the data obtain in this paper,that it is thermodynamically possible to use partial dehydrated magnesium chloride hydrates as a adsorbance to clean water vapor contained in dehydration equipment for bischophite and let the protection gas HCl recycle in the fluid bed reaction system.