农业工程学报2017，Vol.33Issue(17)：248-254,7.DOI:10.11975/j.issn.1002-6819.2017.17.033
超声波辅助离子液体组合物直接制备微藻生物柴油
Preparation of biodiesel from microalgae by direct transesterification under ultrasonic-assisted ionic liquid composite conditions
摘要
Abstract
Microalgae biodiesel can solve these problems of plants materials, such as shortage of arable land, impact of climate change on production and high crop prices. But the production of microalgae biodiesel traditionally involves multiple stages, including oil extraction, purification and subsequent esterification or transesterification, and so on, which cost large quantities of energy and chemicals. The extraction of microalgae oil and the grease ester exchange in the preparation of biodiesel were coupled to a single unit, which was a biodiesel preparation method with great application potential. In this paper, biodiesel from Chlorella was prepared via in-situ ultrasonic assisted transesterification method using ionic liquids as extraction agent and catalyst. The effects of mass ratio of methanol to microalgae powder, reaction temperature, reaction time, ionic liquid type, ionic liquid dosage, ultrasonic power and frequency on the transesterification were investigated, and at the same time, this method was compared with traditional water bath heating mechanical agitation method. The results showed that ultrasonic wave and ionic liquid had synergetic effect on transesterification. Ionic liquid had the effects of catalysis, extraction and solubilization, which could eliminate the interface of methanol and oil, and also could reduce the saponification. The introduction of ultrasound enhanced the transfer process of mass transfer, which could shorten the time of the reaction of esters, decrease the reaction temperature and the dosage of ionic liquid and methanol. When the extractant was ionic liquid [BMIM] [HCOO], the extraction rate of microalgae was the highest. The catalytic effect of acidic ionic liquid was significantly higher than that of alkaline ionic liquids. When the catalyst was ionic liquid [SO3H-BMIM][HSO4], the conversion rate of microalgae was the highest. Under the conditions of mass ratio of methanol to microalgae powder of 6:1, mass ratio of ionic liquid to microalgae powder of 5:1, ultrasonic power of 240 W, ultrasonic frequency of 28 k Hz, reaction temperature of 50 ℃ and reaction time of 50 min, the yield of fatty aid methyl ester reached 69.6%. Preparation of biodiesel from microalgae by direct transesterification under ultrasonic assisted ionic liquid conditions does not need to extract oil from microalgae powder, thus reducing the process cost, and shortening the process, which can make oil-containing microalgae transformed into biodiesel directly by esterification.关键词
超声波/生物柴油/催化/离子液体/微藻/耦合Key words
ultrasonic/biodiesel/catalyzation/ionic liquids/microalgae/coupling分类
能源科技引用本文复制引用
苗长林,李惠文,吕鹏梅,王忠铭,庄新姝,袁振宏..超声波辅助离子液体组合物直接制备微藻生物柴油[J].农业工程学报,2017,33(17):248-254,7.基金项目
国家自然科学基金项目(21506217,21576260) （21506217,21576260）
中科院可再生能源重点实验室基金(Y707j91001) （Y707j91001）
