分子筛VP800-5分离氢同位素的动态实验与模型

Dynamic Experiments and Model of Hydrogen Isotopes Separation with Molecular Sieve VP800-5

液氮温度下用分子筛VP800-5在自行设计的单塔变压吸附装置上进行氢同位素气体分离的研究,考察了气体流量、压力与吸附床长度对分离效果的影响;在总压0.40MPa、总流量129.79cm3·min-1与吸附床长度1.0m时氢氘同位素混合气的分离因子可达到1.63。然而压力为0.0139MPa和0.0175MPa时D2和H2在分子筛VP800-5上的平衡吸附量比值仅分别为1.14和1.11。结合平衡吸附、动态吸附和分离的结果,低温吸附法能有效分离氢同位素主要是由于两者之间存在显著的动力学吸附速率差异。运用建立的柱动力学模型对氢氘吸附分离过程进行了模拟,结果表明模拟结果与实验结果吻合较好。

The separation of hydrogen isotope gases was studied on a single-column pressure＇ swing adsorption apparatus with molecular sieve VP800-5 as adsorbent at the liquid nitrogen temperature. The effects of gas flow rate, operating pressure and length of the adsorption bed on separation efficiency were investigated. The results show that the separation factor of hydrogen and deuterium mixture can be up to 1.63 at total pressure of 0.4 MPa, flow rate of 129.79 cm^3·min^-1 and with the adsorption bed length of 1.0 m. However, the ratios of equilibrium adsorption capacity between deuterium and hydrogen are only 1.14 and 1.11 at 0.0139 MPa and 0.0175 MPa, respectively. Based on the results of equilibrium adsorption, dynamic adsorption and separation, it shows that the hydrogen isotopes can be separated effectively by the adsorption method at low temperature, which mainly depends on the significant difference of kinetic adsorption rate between hydrogen isotopes. Moreover, a dynamic model was proposed to simulate the adsorption process of hydrogen and deuterium separation, and the simulation results agree well with the experimental results.