碩士 / 中原大學 / 生物環境工程研究所 / 103 / In recent years, fossil fuels are gradually depleted due to massive developments of the industry. Therefore, we need to search alternative energy sources. Today, there are four major energy resources: coal, fossil oil, natural gas, and biomass energy. In this situation, biomass energy is the only renewable resource that makes it a great subject to solve the problem of energy shortage. In different kinds of biomass energy resources, microalgae are regarded as the feedstock of sustainable biodiesel because of their higher lipid contents, faster growth and carbon fixing rates compared to regular terrestrial plants which have been used to produce biomass energy.
In this study, Chlorella sp. S-A of faster growth rate and higher oil content among candidates were selected and cultivated in a two-stage procedure. Three different concentrations of nitrogen and NaCl supplements were treated, and investigated their effects on lipid and carbohydrate productivities in Chlorella sp. S-A. The first stage was designed to optimize biomass productivity by using modified artificial wastewater in which nitrogen concentrations were adjusted to 40, 177, 300 mg/L, respectively. After 6 days, system was shifted to the second stage. In the second stage, we added NaCl and adjust concentrations to 0, 10, 20 g/L, respectively. The optical density, cell numbers and dry weights were measured daily. After 12 and 24 hours of culturing, we harvested algae for measuring the oil and carbohydrate contents. By using response phase method to analyze the data, we got the best conditions for accumulating oil and carbohydrates, and the results may provide optimum information of bioenergy productions.
The highest oil productivity (75.9 mg/L/day) was obtained at the initial nitrogen feed of 177 mg/L NO- 3, and 10 g/L NaCl at the later stage. The highest carbohydrates productivity (47.9 mg/L/day) was obtained at the initial nitrogen feed of 300 mg/L NO- 3. These results indicated that culturing algae S-A under appropriate salinity can increase oil content and productivity, but concentration of NaCl was not related to the accumulation of carbohydrates. The experimental data applied in the polynomial regression equation of response surface methodology was used to obtain the best solution of bioenergy raw materials. The best solution of oil productivity was 195 mg/L NO- 3 and 4.9 g/L NaCl. The best solution of carbohydrate productivity was 279.6 mg/L NO- 3 and 0.17 g/L NaCl. To achieve the maximum bioenergy production efficiency from different feedstock, culturing parameters may be adjusted according to the results of this study.
| Identifer | oai:union.ndltd.org:TW/103CYCU5404011 |
| Date | January 2015 |
| Creators | tzu-kang Hung, 洪子剛 |
| Contributors | yu-tzu Huang, 黃郁慈 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 86 |
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