Valorization of agro-industrial by-products: analysis of biodiesel production from porcine fat waste

Recycling of residual animal fat from industrial meat processing for biodiesel production is an attractive alternative, since provides a renewable energy source and minimizes environmental impact of waste disposal. In this work, we propose a valorization strategy of rendering facilities animal fat by investigation of the optimal parameters for ester production using chemical as well as enzymatic catalysis. Although transesterification reactions for biodiesel production have been previously reported, this is the first report of ester production using waste derived animal fat as substrate. The best-obtained yield for chemical catalysis was 90.72-95.76% conversion using alcohol: potassium hydroxide molar ratios ranging from 1:5 to 1:7. For enzymatic catalysis using commercial lipases, obtained yields were 99.77% using methanol and 76.04% using ethanol as substrates. We have also shown here the feasibility of enzymatic catalysis using immobilized lipases. Catalysis using immobilized enzymes produced the best yields, which is advantageous since enzyme can be directly separated from reaction mixture, yielding cleaner products and allowing enzyme recycling. The valorization strategy presented here can be applied for waste recycling of animal fat in meat processing industries. (C) 2015 Elsevier Ltd. All rights reserved.