藻类水热液化产物生物油分离纯化及组分分析

Separation, purification and composition analysis of bio-oil from hydrothermal liquefaction of microalgae

杜氏盐藻通过水热液化制备得到的生物油,先采用溶剂分割分别得到正己烷相、二氯甲烷相和乙醚相,再对二氯甲烷相进行柱层析分离纯化。正己烷相和乙醚相直接通过GC-MS和FT-IR进行分析,二氯甲烷相先经柱层析分离后结合GC-MS、二次质谱和FT-IR等确认不同馏分的产物组成。研究结果表明:二氯甲烷相经柱层析分离可得到16个馏分,分别是石油醚馏分(A1),主要是烯烃类;石油醚:乙酸乙酯馏分(A2),主要是酸类化合物;石油醚:丙酮馏分(A3),主要是酰胺类;石油醚:甲醇馏分(A4),主要是烷烃类;甲醇馏分(A5),主要是十八碳烯酰胺。经柱层析分离纯化后,生物油的回收率高达91.38%;获取较全的生物油组分信息,为藻类液化机理的分析和生物油的改质提供了依据。

In the present paper, the bio-oil produced from hydrothermal liquefaction of D. tertiolecta was divided into n-hexane, chloroform and diethyl ether fractions via solvent division at first, and then chloroform fraction was purified by column chromatography. The n-hexane and diethyl ether fractions were directly analyzed by GC-MS and FT-IR, while the separation products obtained from column chromatography of chloroform fraction were combined with secondary mass spectrometry and FT-IR to confirm the product information. The results showed that chloroform fraction can be divided into sixteen components including the petroleum ether fraction （A1） mainly in alkenes, petroleum ether：ethyl acetate fraction （A2） mainly in carboxylic acid, petroleum ether：acetone fraction （A3） mainly in amides, petroleum ether：methanol fraction （A4） mainly in higher alkanes, and methanol fraction （A5） mainly in amides. In addition, the product recovery was reached up to 91.38% after the purification via column chromatography. Meanwhile, some components, which cannot be directly detected by GC-MS, were identified after column chromatography. The results gave a comprehensive insight in the compositions of product obtained from microalgal liquefaction, which provided the basis on further understanding of HTL mechanism and bio-oil upgrading.