疏水硅沸石吸附1,3-丙二醇的研究

FX-Ⅱ型沸石对1,3-丙二醇单组分溶液中1,3-丙二醇的静态饱和吸附量达到121.1 mg/g;在1,3-丙二醇和甘油的混合溶液中,研究了甘油质量浓度、吸附时间、吸附温度和盐离子质量浓度对1,3-丙二醇吸附的影响,实验结果表明高的甘油质量浓度对1,3-丙二醇吸附影响较大,吸附时间为14 h时1,3-丙二醇吸附达到平衡,低温及低盐离子质量浓度有利于1,3-丙二醇吸附;对实际发酵液的静态吸附结果表明,增大发酵液pH值可以减少有机酸对1,3-丙二醇的竞争吸附;pH值为7时,1,3-丙二醇吸附量达到102.5 mg/g;筛选了与吸附剂相关的脱附剂,用体积分数50%的乙醇解吸,解吸率达到86%。在此基础上初步研究了沸石对发酵液中1,3-丙二醇的动态吸附,1,3-丙二醇解吸率为82%。与传统的蒸馏法相比,沸石吸附法工艺简单,具有较大的研究和应用前景。

Study on adsorption of 1,3-propanediol using hydrophobic zeolite

The saturation adsorption capacity of FX-Ⅱ-type zeolite for 1,3-propanediol in single component solution is 121.1 mg/g.The influences of glycerol mass concentration,adsorption time,adsorption temperature and salt ion mass concentration on 1,3-propanediol adsorption in the 1,3-propanediol and glycerol solution were investigated.The result shows that the high mass concentration of glycerol has great influence on 1,3-propanediol adsorption.The 1,3-propanediol adsorption achieves saturation after 14 h adsorption.The low adsorption temperature and low salt ion mass concentration are favorable for 1,3-propanediol adsorption.According to the results of the static adsorption,the increase of broth pH will avoid the organic acids adsorption on the zeolite.The adsorption capacity for 1,3-propanediol can reach 102.5 mg/g when pH is 7;by screening a series of desorbent matched with the adsorbent and using desorbent of volume fraction 50% ethanol,desorption ratio of 1,3propanediol is 86%.The dynamic adsorption of 1,3-propanediol was investigated and the desorption ratio for 1,3-propanediol was 82%.Compared with the conventional distillation,the simplified separation process with the zeolite adsorption has a significant research and application value.