Synthesis of Potassium Ionic Sieve Membrane and Its Selectivity to Potassium Ion in Seawater

摘要

Potassium ionic sieve membrane was synthesized on porous α-Al_2O_3 tube support by the hydrothermal synthesis. The zeolite membranes were characterized by means of XRD and SEM. And the single-gas permeability through the membranes and selectivity to K~＋, Na~＋, Ca~(2＋), Mg~(2＋) were measured. The results show that the ideal separation factor is 3.68, which is close to Knudsen diffusion ratio 3.74 for H_2/N_2; the separation factors of the potassium ionic sieve membrane are α＝93.5, α_(K~＋/Ca~(2＋)) = 1244.9 2, α_(K~＋/Mg~(2＋) ＝ 161.1 2 α respectively, indicating its high separation selectivity to potassium ion.