| 초록 |
Because sewage sludge (SS) has as high as 25% of lipids, it can be a promising feedstock of biodiesel. However, since the free fatty acids (FFA) content of the lipids is about 60%, alkaline catalysts which as many advantages over acid ones cannot be used in biodiesel production. The FFA content of the lipids from waste coffee grounds (WCGs) is about 2.0 and that from waste cooking oil (WCO) is about 2.5. We elaborately manipulated the mixing ratio of these feedstocks (SS lipids, WCGs lipids and WCO) to make it possible to use alkaline catalysts in biodiesel production. Contrary to homogeneous alkaline catalysts such as NaOH, solid catalysts have the significant advantage of enabling the possible reuse and easy separation from the reaction mixture, which would substantially decrease catalyst requirements and wastewater discharge. In this study, we prepared alkaline solid catalysts from waste scallop shells, and produced biodiesel from the mixture of the three feedstocks. |
