Interdepartmental Research Centre for Environmental Sciences (CIRSA), University of Bologna, via S. Alberto 163, 48123 Ravenna, Italy.
Bioresour Technol. 2010 May;101(9):3274-9. doi: 10.1016/j.biortech.2009.12.068. Epub 2010 Jan 13.
Lipid extraction is a critical step in the development of biofuels from microalgae. Here a new procedure was proposed to extract hydrocarbons from dried and water-suspended samples of the microalga Botryococcus braunii by using switchable-polarity solvents (SPS) based on 1,8-diazabicyclo-[5.4.0]-undec-7-ene (DBU) and an alcohol. The high affinity of the non-ionic form of DBU/alcohol SPS towards non-polar compounds was exploited to extract hydrocarbons from algae, while the ionic character of the DBU-alkyl carbonate form, obtained by the addition of CO(2), was used to recover hydrocarbons from the SPS. DBU/octanol and DBU/ethanol SPS were tested for the extraction efficiency of lipids from freeze-dried B. braunii samples and compared with n-hexane and chloroform/methanol. The DBU/octanol system was further evaluated for the extraction of hydrocarbons directly from algal culture samples. DBU/octanol exhibited the highest yields of extracted hydrocarbons from both freeze-dried and liquid algal samples (16% and 8.2% respectively against 7.8% and 5.6% with n-hexane).
脂质提取是从微藻中开发生物燃料的关键步骤。在这里，提出了一种新的方法，通过使用基于 1,8-二氮杂双环[5.4.0]-十一-7-烯（DBU）和醇的可切换极性溶剂（SPS）从干燥和水悬浮的 Botryococcus braunii 微藻样品中提取碳氢化合物。DBU/醇 SPS 的非离子形式对非极性化合物的高亲和力被利用来从藻类中提取碳氢化合物，而通过添加 CO(2) 获得的 DBU-烷基碳酸盐形式的离子特性则用于从 SPS 中回收碳氢化合物。测试了 DBU/辛醇和 DBU/乙醇 SPS 从冻干的 B. braunii 样品中提取脂质的效率，并与正己烷和氯仿/甲醇进行了比较。DBU/辛醇系统进一步评估了直接从藻类培养物样品中提取碳氢化合物的效果。DBU/辛醇从冻干和液体藻类样品中提取的碳氢化合物的产率最高（分别为 16%和 8.2%，而正己烷的产率分别为 7.8%和 5.6%）。
