Abstract:
In the hydrogen production of iodine-sulfur cycle, a distillation problem of HI concentration separation was selected for the analysis. The NRTL model was used to modify the liquid non-ideal of the ternary mixture of HI-I
2-H
2O system, the two groups of NRTLs were obtained by fitting the binary gas-liquid equilibrium experiment data of H
2O-HI, H
2O-I
2 and HI-I
2 model of binary interaction parameters. The comparison between the H
2O-HI vapor-liquid equilibrium phase diagram was predicted by the obtained binary interaction parameters and the experimental data showed that the prediction results were in good agreement with the experimental data, and the accuracy and reliability of the obtained binary interaction parameters were verified. The optimized operating conditions were obtained by systematic analyses and simulation of the HI rectification column by means of simulation software Aspen Plus. As the number of trays increases, the
Qm of the reboiler heat load per unit mass fraction decreases overall, but when the number of trays increases more than 13, the
Qm decreases slowly, then the 13th was the most suitable tray. As the reflux ratio increases, the
Qm of the reboiler heat load per unit mass fraction increases uniformly at a constant rate. When the reflux ratio is 1.3, the mass fraction of HI distilled has reached 0.96. After that, as the reflux ratio increases, the increase of HI distillate is not obvious. Considering that the reflux ratio is too large, the operating cost and equipment cost will also be increased, indicating that the best reflux ratio was 1.3. The HI mass fraction in the feed needs to be optimized by a specific simulation to obtain an optimum value, and the HI mass fraction and energy consumption of the discharge are not monotonous. The discussion of the number of plates, reflux ratio and feed composition on the separation conditions provides the theoretical basis for the further study of industrial iodine sulfur cycle hydrogen production process.