碩士 / 國立清華大學 / 動力機械工程學系 / 101 / In this study, a species of high lipid content microalgae：Chlorella pyrenoidosa, or called Chlorella sp. is used to be the lipid source of biodiesel production. From the variety of cell disruption and lipid extraction methods, we choose the sonication method to proceed the cell-wall disruption experiments.
There are two parts of experiment set-up, one is microalgae cultivation and another is sonication experiment. We use the open- tube cultivation method to cultivate the Chlorella sp. The temperature is maintained at 32 ℃, the flow rate of CO2 and air are 35 c.c/min and 1000 c.c/min. The light cycle is 14 hours in light, and 10 hours in dark. The cultivation time is 8-9 days. In sonication experiment part, it can be divided to single-frequency part and dual- frequency part. The experiment parameters are frequency, power, sonication time, cell concentration and temperature. We used the Trypan-blue method, fluorescent dye Calcofluor White Stain and the rate of radius reduction to evaluate the experiment results. Finally, we found that the cell disruption rate can reach 7 %, when the sonication parameters are: conservation time in 1.5 month, unbaked algae, sonication frequency at 40 kHz, power at 300 W, temperature between 40 and 50 ℃, and concentration of 1 %, This is the best disruption parameters in single-frequency experiment.
The mechanism of sonication method to disrupt the cell is cavitation. When the cavitation bubbles explode, it can generate the high temperature and pressure so that it can make algae to be disrupted. In addition to sonication experiments, we also do the numerical analysis about the cavitation bubble. The Matlab software and 4-order Runge-Kutta method are applied to solve equation. The results showed that the single frequency parameters with 40 kHz, power of 300 W, and the power intensity of 7.639 W/cm^2, the bubble can reach the maximum radius about 0.173 mm, the ratio of the maximum radius and the initial radius can reach 150, and the collapse pressure can reach 9.69×〖10〗^7 atm. The results of numerical analysis are used to put sonication experiment results to the proof.
| Identifer | oai:union.ndltd.org:TW/101NTHU5311105 |
| Date | January 2013 |
| Creators | Chuang, Yu-Ying, 莊于瑩 |
| Contributors | Tsai, Hung-Yin, 蔡宏營 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 71 |
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