Valorization of diverse low-value wastes into biodiesel

This study investigates the potential of various types of wastes as feedstocks in the transesterification of triglycerides into fatty acid methyl esters, commonly referred to as biodiesel. These wastes include waste olive oil, waste chicken fat and waste coffee oil. These types of virtually free and readily available materials are drawing growing attention in light of the global trend to develop sustainable energy and lessen the impact of fossil fuels on the environment. Furthermore, turning these wastes into a biofuel offers a more appealing alternative to ordinary low-value processings such as landfilling, composting and incineration. Optimization of the feedstock extraction was performed and extraction yields of 8.3%, 9.0%, 75.2% and 10.9% were obtained for olive pomace, olive mill wastewater (OMW), chicken fat and coffee oil respectively. The highest yields obtained in the conversion of these feedstocks in their refined form into biodiesel were 71%, 86% and 56% for olive oil, chicken fat and coffee oil respectively. The biodiesel produced was characterized for its FFA content, density, Gross Calorific Value and TLC profile. Results were compared with literature as well as European specifications EN14214. Finally a conclusion concerning the economic viability of the process was drawn.