HZSM-5催化剂上超临界乙醇中生物油催化提质及检测方法研究

采用不同硅铝比的HZSM-5催化剂,在不同条件下(超临界、亚超临界、非超临界乙醇)催化提质生物油中的高沸点组分(HBF),应用磷核磁共振(31P-NMR)定量检测了提质前后生物油中醇、酚和羧酸类羟基的质量比(羟基质量/生物油质量)变化,研究和评价了催化剂和超临界条件对生物油催化提质的效果.研究表明,超临界条件有利于生物油中脂肪族羟基的转化,但是不利于非缩合羟基的转化;使用不同酸强度的HZSM-5都能使生物油中的羧基完全转化,增加催化剂的酸强度可以促进脂肪族羟基的转化,而只有酸性较弱的催化剂才能顺利转化非缩合酚羟基.

Study on bio-oil upgrading reaction using HZSM-5 under super-critical ethanol and analysis method

High-boiling point fractions(HBF) of bio-oil upgrading reaction using HZSM-5 with different Si/Al ratios were carried out under different reaction conditions(super-critical,sub-critical,conventional ethanol).Quantitative 31P NMR spectroscopy was used to measure the hydroxyl and carboxyl content in the HBF of bio-oil before and after upgrading.The results showed that super-critical could largely improve the conversion of aliphatic hydroxyl moieties,but could not conducive to the conversion of noncondensed phenolic hydroxyl moieties.Carboxylic acids were almost eliminated under all upgrading reaction conditions.The aliphatic hydroxyl moieties were more easily converted by using stronger acidic HZSM-5,and the amount of the noncondensed phenolic hydroxyl moieties decreased evidently by using weaker acidic HZSM-5(Si/Al=300).