| Summary: | 碩士 === 國立成功大學 === 環境工程學系 === 102 === Bio-resources, such as plants and microorganisms, has become important as raw materials for nutrients, chemicals and fuels. Unlike in exploitation of petro-leum resources, process designers that consider use of bio-resources have oppor-tunity to choose cultivars and methods of cultivation and harvesting that affect the quality and yield over seasons. Conversion processes that are designed to maxim-ize profit assuming a constant, or planned input of petroleum-based raw materials now needs to consider these new design parameters in the design of the whole system.
The integrated cultivation and conversion processes have parameters that are mutually related across the processes, and has relatively greater uncertainty especially when the cultivation process is open air, or in greenhouse, as it is affected by the meteorological conditions. Pilot experiments become important to correctly reflect such uncertainty in the process design. Considering the high cost of pilot experiments, it is important that the system-wide economic and environmental evaluation is performed concurrently at the pilot experiments stage, to leverage the effectiveness of the experiments by identifying the experimental conditions to be explored, and to highlight the need of alternative methods to cut down cost and environmental impacts at the hotspots.
Here, we examine an existing pilot plant constructed within a power plant in Kaohsiung, which aims to produce phycocyanin, a kind of pigment-protein complex from microalgae. Life cycle inventory was constructed based on pilot scale experiments to explore the opportunity for reduction of associated costs and environmental burdens. As a result, need of further study is screened out from among numerous parameters. For example, continuous experiment of two or more cultivation cycles with water and nutrient recycling is recommended as a result of hotspot analysis. In addition, changed of culture environment such as growth within controlled light intensity also suggested on profit optimization of either dried algae yield or phycocyanin content changed. Furthermore, a shifted cultivation period with measurement of phycocyanin content and dried algae yield is found crucial in harnessing maximum economic and environmental potentials of the evaluated system.
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