Civil & Environmental Engineering, Mississippi State University, Mississippi State, MS 39762, United States.
Civil & Environmental Engineering, Mississippi State University, Mississippi State, MS 39762, United States.
Bioresour Technol. 2014 Mar;156:240-7. doi: 10.1016/j.biortech.2014.01.026. Epub 2014 Jan 17.
This study describes the use of microwaves (MW) for enhanced extractive-transesterification of algal lipids from dry algal biomass (Chlorella sp.). Two different single-step extractive-transesterification methods under MW irradiation were evaluated: (1) with ethanol as solvent/reactant and sodium hydroxide catalyst; and (2) with ethanol as reactant and hexane as solvent (sodium hydroxide catalyst). Biodiesel (fatty-acid-ethyl-esters, FAEE) yields from these two methods were compared with the conventional Bligh and Dyer (BD) method which followed a two-step extraction-transesterification process. The maximum lipid yields for MW, MW with hexane and BD methods were 20.1%, 20.1%, and 13.9%, respectively; while the FAEE conversion of the algal lipids were 96.2%, 94.3%, and 78.1%, respectively. The algae-biomass:ethanol molar ratio of 1:250-500 and 2.0-2.5% catalyst with reaction times around 6min were determined as optimum conditions for both methods. This study confers that the single-step non-conventional methods can contribute to higher algal lipid and FAEE yields.
本研究描述了微波（MW）在从干燥藻类生物质（小球藻）中增强提取-酯交换藻类脂质中的应用。评估了两种不同的单步提取-酯交换方法在 MW 辐射下的应用：（1）以乙醇为溶剂/反应物和氢氧化钠催化剂；（2）以乙醇为反应物和正己烷为溶剂（氢氧化钠催化剂）。与传统的 Bligh 和 Dyer（BD）两步提取-酯交换法相比，比较了这两种方法的生物柴油（脂肪酸乙酯，FAEE）产率。MW、MW 与正己烷和 BD 方法的最大脂质产率分别为 20.1%、20.1%和 13.9%；而藻类脂质的 FAEE 转化率分别为 96.2%、94.3%和 78.1%。确定了 MW 和 MW 与正己烷两种方法的最佳条件为：藻类生物质：乙醇摩尔比为 1:250-500，催化剂用量为 2.0-2.5%，反应时间约为 6 分钟。本研究表明，单步非传统方法可以提高藻类脂质和 FAEE 的产量。
