The need to produce Hydrogen in an environmentally friendly manner has increased as the transportation industry has started to employ cleaner sources of energy. One of the cleaner ways to produce H_2, is to use the Bunsen S-I cycle. This includes the separation of the H₂ from an ionic mixture of Hydrogen Iodide and water using distillation. In this work, the Pitzer’s model for electrolyte solutions has been employed to represent the vapour-liquid equilibrium (VLE) of the binary system of HI and H₂O. The activity coefficient (γ) is calculated from the equation which indicated the non-ideal nature of the system and aided the calculation of the vapour phase mole fraction. The experimental VLE data was obtained from a recirculating still at 101.3 kPa pressure for the binary system. This experimental data and data from literature was used to estimate the parameters of the Pitzer’s model to represent the activity coefficient of HI in this mixture. These optimized parameters could explain all the variations in the data with more that 90% accuracy for most of the data, with an average standard deviation of about 0.04. Furthermore, the temperature dependent form of the Pitzer’s equation was used to predict the VLE data at higher pressures of 3 and 5.7 bars and higher temperature conditions.

随着运输行业开始采用清洁能源，以环保方式生产氢气的需求增加了。生成H _2的一种更清洁的方法是使用本生SI循环。这包括使用蒸馏从碘化氢和水的离子混合物中分离H ₂。在这项工作中，电解质溶液的Pitzer模型已被用来表示HI和H ₂二元体系的汽液平衡（VLE）O.活度系数（γ）是根据方程式计算得出的，该方程式表示系统的非理想性质，并有助于计算气相摩尔分数。实验VLE数据是从二元系统的101.3 kPa压力下仍通过再循环获得的。该实验数据和来自文献的数据被用于估计Pitzer模型的参数，以代表该混合物中HI的活度系数。这些优化的参数可以解释大多数数据的所有变化，其中大多数数据的准确率超过90％，平均标准偏差约为0.04。此外，Pitzer方程的温度相关形式用于预测在3和5.7 bar的较高压力以及较高温度条件下的VLE数据。