藻类水热液化产物生物油分离纯化及组分分析

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。

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

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.