Alternative feedstock for the biodiesel and energy production: The OVEST project

A large share of the vegetable oil market is today shifting from food to the energy sector. This trend led to discussions about the chance of confliction between these two chains and its possible social and environmental consequences. Moreover the increasing interest in pure vegetable oils for energy and biodiesel production are associated to a period of market volatilities and high prices. The economics of the biodiesel production is suffering the actual market situation. In this framework, the present work presents the results of the OVEST(ESTerified Vegetable Oils) project, which is supported by the Tuscany region. Aim of the project is the investigation of the use of waste oil streams and by-products from food industry to obtain an alternative feedstock for bioliquids and biofuels production. In the current food market, a number of secondary streams are available from the food industry: oleins and fatty acids, sludge oils and WCO (Waste Cooking Oils), represent several examples of these potential alternative feedstock. Most of these materials are characterized by high free fatty acid compositions. In the OVEST project, vegetable oil is obtained from waste materials by the re-esterification process, in order to obtain a new feedstock for biodiesel production and for power generation. A market analysis has been carried out in OVEST, to estimate the economic viability and the potential of each waste streams. Test on a modified Micro Gas Turbine (30 kW(el)) and in small scale co-generator (5 kW(el)) have been carried out. Performances and pollutant missions were monitored. The results of the experimentation confirmed the viability of these fuels for the energy production. From the environmental point of view, the use of these feedstock allows to meet the requirements of the European Directive EC/28/2009 (RED), that introduces minimum targets in terms of GHGs saving for bioliquids and biofuels. The present work showed that most of the input materials to the esterification process may be classified as wastes or residues, and that assuring an accurate traceability for each treatment and transport phase is a really complex issue. However the high GHG savings potential, as indicated in the RED for bioliquids from wastes, was confirmed by the work here carried out. Therefore OVEST project demonstrates the viability of the use of esterified oils as biodiesel feedstock or for direct energy generation, starting from a renewable source, non competing with food market and with a high GHG saving potential. (C) 2013 Elsevier Ltd. All rights reserved.