Bio-Energy Research Team, Research Institute of Industrial Science and Technology (RIST), Kwang-Yang-City, Cholla-Nam-Do 540-090, South Korea.
Bioresour Technol. 2013 May;136:475-80. doi: 10.1016/j.biortech.2013.03.052. Epub 2013 Mar 16.
The sequential co-production of bioethanol and biodiesel from spent coffee grounds was investigated. The direct conversion of bioethanol from spent coffee grounds was not found to be a desirable option because of the relatively slow enzymatic saccharification behavior in the presence of triglycerides and the free fatty acids (FFAs) found to exist in the raw materials. Similarly, the direct transformation of the spent coffee grounds into ethanol without first extracting lipids was not found to be a feasible alternative. However, the crude lipids extracted from the spent coffee grounds were themselves converted into fatty acid methyl ester (FAME) and fatty acid ethyl ester (FAEE) via the non-catalytic biodiesel transesterification reaction. The yields of bioethanol and biodiesel were 0.46 g g(-1) and 97.5±0.5%, which were calculated based on consumed sugar and lipids extracted from spent coffee grounds respectively. Thus, this study clearly validated our theory that spent coffee grounds could be a strong candidate for the production of bioethanol and biodiesel.
从废咖啡渣中连续生产生物乙醇和生物柴油的研究。由于在存在甘油三酯和原料中发现的游离脂肪酸（FFA）的情况下，生物乙醇的直接转化酶糖化行为相对较慢，因此直接从废咖啡渣中转化为生物乙醇并不是一个理想的选择。同样，不先提取脂质而将废咖啡渣直接转化为乙醇也不是可行的替代方法。然而，从废咖啡渣中提取的粗脂质本身通过非催化生物柴油酯交换反应转化为脂肪酸甲酯（FAME）和脂肪酸乙酯（FAEE）。根据消耗的糖和从废咖啡渣中提取的脂质计算，生物乙醇和生物柴油的产率分别为 0.46gg(-1)和 97.5±0.5%。因此，这项研究清楚地验证了我们的理论，即废咖啡渣可以成为生产生物乙醇和生物柴油的有力候选物。
