- 期刊
利用有機廢水培養Chlorella protothecoides產製生質柴油可行性評估
The Feasibility of Biodiesel Production in Chlorella protothecoides Using Organic Wastewater
摘要
近年來利用藻類產製生質柴油之方法不斷地改進，從目前實廠生產生質柴油現況及各種油脂藻的產油結果發現在藻油生產成本上仍有改善的空間。本研究提出Chlorella protothecoides利用廢水培養產製生質柴油之可行性評估，評估項目為藻種優勢與有機廢水培養，其指標為藻株之生長速率與油脂產量，並藉由成本控制的角度挑選藻株之培養系統。藻株培養系統有開放式環境培養系統(open ponds)和封閉式光生物反應器(PBR),由成本分析以open ponds培養藻類生產生質柴油比PBR節省約2倍的生產成本。異營性藻株Chl. protothecoide與同樣具有高油脂含量和高生長速率的Chl. vulgaris，以及目前應用於實場的Scenedesmus sp.等藻株比較，因Chl. protothecoides、Chl. vulgaris和Scenedesmus sp.的生質產量分別為7.7、0.2及0.74 g L^(-1) d^(-1)，Chl. protothecoide的生質產量比其他二藻株高出39及10倍，顯示Chl. protothecoide具有做為產油藻株之潛能。當Chl. protothecoide於有機廢水中培養時能去除廢水中50%以上的磷及20%以上的氮，同時產生30-55%油脂，比Chl. vulgaris及Scenedesmus sp.於有機廢水中培養的油脂含量高出許多。因此以有機廢水培養Chl. protothecoide是一個很好的選擇，搭配open ponds系統從營養物質降低約50%的生產成本，使藻類生產生質柴油在成本上可與石油相抗衡。
並列摘要
Biofuel of renewable energy has been attached great importance in recent years, among which the raw materials of biodiesel extensively studied are oil-producing algae strains of the freshwater green algal genus. This study is based on the current status of producing biodiesel in factories and growth characteristics of various oil-producing algae, to assess the feasibility of producing biodiesel by cultivating Chlorella protothecoides using organic wastewater. Evaluation terms included advantages of algal species, cultivation in organic wastewater and the choice of microalgae cultivate systems. The indexes of projects were the growth rate and oil production of algal strains and comparing the cost of cultivate system between photo-bioreactors (PBR) and open ponds. Biodiesel production by growing algal in open ponds saves about 2.6 times production cost than PBR. Chl. protothecoides is a heterotrophic algal strain, its growth rate is 0.195 d^(-1) to 0.920 d^(-1) and the lipid content can be up to 58%. Compared with Chl. vulgaris which has high lipid content and high growth rate and Scenedesmus sp. which has been used in a real microalgae production plant, the biomass production rates of Chl. protothecoides, C. vulgaris and Scenedesmus sp. are 7.70, 0.20 and 0.74 g L^(-1) d^(-1) respectively. The biomass production of Chl. protothecoides is 39 times higher than Chl. vulgaris and 10 times higher than Scenedesmus sp. cultivated in the organic wastewater which can remove at least 50% of phosphorus and over 20% of nitrogen in the wastewater, while producing 30-55% oil, which is higher than 30% of the Chl. vulgaris and Scenedesmus sp. in lipid content. Therefore, it is a good choice to cultivate Chl. protothecoides by organic waste water, and production costs can be reduced about 50% by using open ponds system, making algal biodiesel contends with oil on the costs.