優養化水體藻類發酵產製生質酒精技術之研發

Fermentation of microalgae in eutrophicated lakewater for production of bioethanol

林威志(Wei-Chih Lin)

指導教授 ： 蔡勇斌

國立暨南國際大學/科技學院/土木工程學系/碩士(2015年)

摘要

自然水體中因氮磷廢水排入使得水中藻類大量繁生成為一優養化水體。優養化伴隨著大量的微藻，若可將藻類做適當收集，並進一步製成生質酒精，不但可解決優養化問題並淨化水質，更達到廢棄物資源再利用之綠色科技精神，具有一舉兩得之效。
本研究收集現地優養化藻類，經由適當的前處理(乾燥、破碎、研磨、過篩)後以稀酸水解產糖並進行發酵，探討藻類生物質生產乙醇之經濟效益，以不同的發酵條件探討發酵效果，並進一步分析水解產物之組成、水解副產物之影響及生質能源之效益。藻類生物質透過酵母菌Pichia stipitis (BCRC 21775)在最佳發酵條件為25℃、初始發酵pH 6、以pH 8去除金屬、酵母菌濃度2 g yeast/L，最大酒精產量721 mg/L，酒精轉化率可達90%之理論產量，最終酒精產率為0.023 g ethanol/g biomass。收集優養化藻體製成生質能具有可行性且同時能有效去除水中藻類淨化水質，為一符合綠色精神之技術。

關鍵字

優養化 ； 藻類生物質 ； 發酵 ； Pichia stipitis

並列摘要

he waste water with nitrogen and phosphorus was discharged into natural water and made water body become an eutrophication water. There are a lot of algae in eutrophication water, if the algae can be collected and made into bio-ethanol can not only solve eutrophication problem and purify water but also achieve the spirit of green technology by reusing the wastes.
This study collected microalgae from eutrophicated lake water, after suitable pre-treatment (drying, crushing, grinding and sieving), acid hydrolysis and fermentation, algae collected from eutrophicated lake water can be made into bioethanol. The effect of fermentation conditions, compose of hydrolysate and by-products was discussed. Optimum ferment conditions by Pichia stipitis (BCRC 21775) are 25 ℃, initial pH 6, pH 8 for iron removal and initial cell density 2 g yeast / L. Under optimum conditions, the largest ethanol production is 721 mg / L and conversion rate can achieve 90% of theoretical yield, the final alcohol yield is 0.023 g ethanol / g biomass. Microalge-bioethanol is feasible technology and it can achieve the green spirit by purifying water and reusing the wastes.

並列關鍵字

eutrophicated ； microalgae ； fermentation ； Pichia stipitis

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