碩士 / 國立雲林科技大學 / 環境與安全衛生工程系 / 105 / Microalgae biofuels is currently still facing technical and economic difficulties on commercial roads, where the harvest cost only accounts for 20% of the total cost of technology. The two major reasons to explain why harvest cost is lower than expected is because the diameter of microalgae is extremely small with a typical length of 3 to 30 microns which makes collection is increasingly more difficult, and the fact that the surface potential of micro algae is negatively charged which permits them to increase stability in the medium. The more stable these particles are, the potential of harvest is likely to decrease as demonstrated by a negative correlation. The newly adapted micro-algae harvest method has several improvements from the traditional slow-harvest method. The new methodology facilitates slower treatment within a smaller scope of focus, and its flocculant sedimentation does not usually cause water pollution. However, one disadvantages of the new methodology is that if the surface is exposed to Fe3O4 magnetic particles, it can become more prone for oxidization in the air. This study utilizes the embedding of technology made of acid, bio-phase, and other advantages of Fe3O4-PVA/SA. The purpose of our study is to investigate whether the micro-algae will increase the efficiency to affect the harvest stage, which of the two: Fe3O4 magnetic particles or Fe3O4-PVA/SA magnetic particles, can produce a higher harvest efficiency by a comparative study, and what would be the rate of recovery of Fe3O4 magnetic particles and Fe3O4-PVA/SA magnetic particles. The results showed that the maximum growth rate and biomass were higher than that of the microalgae, and the microalgae was not affected by the addition of magnetic field in the harvested microalgae stage. The yield of Fe3O4 magnetic particles was about 100% under the same condition of a 4.0 pH, while the recovery efficiency of Fe3O4-PVA/SA magnetic particles was 96%. Fe3O4-PVA/SA magnetic particles can take a longer time to harvest microalgae, for example, 180 minutes, whereas Fe3O4-PVA/SA magnetic particles can be harvested in 3 to 5 minutes with a lower turnaround time. Lastly, the dosage of Fe3O4-PVA/SA magnetic particles is smaller than the actual surface area, so the dosage should be increased, for example, to 2400 mg; whereas Fe3O4 magnetic particles is much larger than the surface area, so the amount of dosage required should be decreased, ideally around 120 mg. Fe3O4 magnetic particles and Fe3O4-PVA/SA magnetic particles were both compared and evaluated in terms of their functionality and productivity. Knowing that the immobilized magnetic particles are more resistant to changes in an acidic environment, there are still improvements to be made within the new methodology, such as to strengthen the mechanical aspect of the technology in order to reduce the turnaround harvest time and to yield a higher overall efficiency. With such changes, it is possible to achieve the goal of reducing the commercialization of microalgae biomass fuels.
| Identifer | oai:union.ndltd.org:TW/105YUNT0633020 |
| Date | January 2017 |
| Creators | Chen Hsi, 陳曦 |
| Contributors | Wan, Terng-Jou, 萬騰州 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 81 |
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