SiO_(2)-ZrO_(2)溶胶修饰晶种法制备丝光沸石膜及性能

Preparation and Performance of Mordenite Membranes by SiO_(2)-ZrO_(2) Sol Modified Seed Method

通过在晶种液中引入多羟基的SiO_(2)-ZrO_(2)纳米溶胶,提高在大孔a-Al_(2)O_(3)载体上晶种层的连续性,从而制备出高性能的丝光沸石膜。研究了晶种中SiO_(2)-ZrO_(2)溶胶的添加量对晶种层及沸石膜的影响。结果表明:在晶种中添加SiO_(2)-ZrO_(2)溶胶制备的丝光沸石膜与未添加的相比,均表现了较高分离性能。随着含量的增加,通量和分离因子稍有下降。当晶种中添加0.5%(质量分数)的SiO_(2)-ZrO_(2)溶胶时,75℃渗透汽化分离90%(质量分数)的乙酸/水溶液,渗透通量和分离因子可分别达到0.94 kg/(m^(2)·h)和5285。通过电势测定发现SiO_(2)-ZrO_(2)溶胶还增加了晶种在溶液中的分散性。利用该方法制备的丝光沸石膜具有较好的重复性,平均通量为0.93 kg/(m^(2)·h),渗透侧水含量均在99.8%(质量分数)以上,且在100 h的渗透汽化测试中性能保持稳定。

The integrity of the seed layer was improved by adding SiO_(2)-ZrO_(2) nano-sized sol into the seed solution on macroporous a-Al_(2)O_(3) carrier for the preparation of high-performance mordenite membranes.The effect of SiO_(2)-ZrO_(2) sol amount added in the seed crystal on the seed layer and zeolite membrane was investigated.The results show that the pervaporation performance of mordenite membranes is improved by the addition of SiO_(2)-ZrO_(2) sols.The flux and separation factor decreases slightly as the concentration increases.When 0.5%(in mass fraction)SiO_(2)-ZrO_(2) sol is added into the seed crystal,the permeation flux and separation factor can reach 0.94 kg/(m^(2)·h)and 5285 by a pervaporation of 90%(in mass fraction)acetic acid/water solution at 75℃.It is indicated that Si O_(2)–ZrO_(2) sol improves the dispersion of the seed in the solution.The mordenite membrane prepared by this method has good repeatability and acid resistance.