脉冲电场辅助下以低毒溶剂提取微藻油脂的研究

发布时间：2018-07-13 10:40

【摘要】：以污水培养富油微藻既可以净化污水,又能得到可以生产生物柴油的微藻。油脂提取是微藻生物柴油产业链中十分重要的环节,但目前其工业化前景并不乐观。本实验的目的是建立一套具有工业化前景的湿法提脂工艺,主要包括在技术和经济上可实现工业化的破壁方法的建立和低毒提取溶剂的选取。本论文首先研究了脉冲电场破壁小球藻过程中各因素的影响作用,其次对影响脉冲电场破壁的因素进行油脂提取的单因子和多因子的优化,得到辅助提取的最佳条件,并探讨了脉冲电场辅助提取的作用机理,然后优化筛选出一种提取效果好、毒性小的能够替代氯仿的溶剂,最后,对整个湿法提脂工艺的工业化可行性进行分析。本论文主要研究成果如下:通过单因子实验和正交实验得到的最佳参数为:场强20 k V/cm,流速5.4L/h,频率130 Hz,脉宽6μs,循环次数3次。该条件下油脂提取率为61.1%,FAME产率为11.2%,与传统方法相比分别提高了15.9%和9.8%。以人工污水培养时,油脂提取率和FAME产率分别为63.2%和11.9%;以实际污水培养时,油脂提取率和FAME产率分别为61.4%和11.5%,二者并无明显差异。通过油脂成分分析,证明脉冲电场辅助法能够提高油脂提取率和FAME产率,但不会改变所提取的油脂的成分。脉冲电场作用下导致的细胞内物质溶出,是脉冲电场使油脂提取率升高的原因之一,细胞内油脂并未损失;荧光染色和扫描电镜实验发现脉冲电场作用下小球藻细胞的细胞膜完整性遭到破坏;脉冲电场处理能够有效地缩短油脂提取时间,与传统方法相比大概缩短了4 h。正己烷/乙醇可以替代氯仿甲醇作为油脂提取的溶剂,提取条件为:溶剂配比3:2,液料比1:1,提取时间28 h。脉冲电场-正己烷/乙醇法的油脂提取率为54.4%,FAME产率为10.5%,分别达到传统方法的106.7%和91.9%。
[Abstract]:Oil-rich microalgae can not only purify sewage but also produce biodiesel. Oil extraction is a very important link in microalgae biodiesel industry chain, but its industrialization prospect is not optimistic. The purpose of this experiment is to establish a set of wet liposuction technology with the prospect of industrialization, mainly including the establishment of the wall breaking method and the selection of low toxicity extraction solvent which can realize industrialization technically and economically. In this paper, the influence of various factors in the process of breaking the wall of Chlorella vulgaris by pulsed electric field was studied, then the factors affecting the breaking of the wall of the pulse electric field were optimized by single factor and multi-factor of oil extraction, and the optimum conditions of auxiliary extraction were obtained. The mechanism of pulsed electric field assisted extraction was discussed, and then a solvent with good extraction effect and little toxicity was selected. Finally, the industrialization feasibility of the whole wet extraction process was analyzed. The main results of this paper are as follows: the optimum parameters obtained by single factor experiment and orthogonal experiment are as follows: field strength 20 kV / cm, flow rate 5.4 L / h, frequency 130 Hz, pulse width 6 渭 s, cycle times 3 times. Under this condition, the oil extraction rate was 61.1% and the yield of facie was 11.2%, which was 15.9% and 9.8% higher than that of the traditional method, respectively. The oil extraction rate and fat yield were 63.2% and 11.9% in artificial sewage culture, and 61.4% and 11.5% in actual sewage culture, respectively. There was no significant difference between them. It is proved by the analysis of oil composition that the extraction rate and fat yield can be improved by pulsed electric field assisted method, but the composition of the extracted oil can not be changed. The dissolution of intracellular substances induced by pulsed electric field is one of the reasons why the extraction rate of oil is increased by pulsed electric field, and the intracellular oil is not lost. Fluorescence staining and scanning electron microscopy showed that the cell membrane integrity of Chlorella vulgaris cells was damaged under pulsed electric field, and the extraction time of oil was shortened by pulsed electric field treatment, which was about 4 hours shorter than that of traditional methods. N-hexane / ethanol can replace chloroform methanol as solvent for oil extraction. The extraction conditions are as follows: solvent ratio 3: 2, liquid-material ratio 1: 1, extraction time 28 h. The extraction rate of oil by pulsed electric field-n-hexane / ethanol method was 54.4% and 10.5%, which reached 106.7% and 91.9% of the traditional method, respectively.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE667

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