LCA of Energy Recovery of the Solid Waste of the Olive Oil Industries

In the last six years the average annual amount of olive-oil produced in the world was 2.8 million tonnes, just over 94% of which was produced by Mediterranean countries, especially Spain (39%), Italy (24%) and Greece (13.6%). From the olive-oil industrial process, a by-products: pomace and a waste: olive-mill wastewater result. The former is constituted by the water contained in the olives and, in some cases, by the water added during the process. The solid residue, including pits, makes up the pomace (virgin pomace) from which the residual oil content can be extracted, thus obtaining the crude olive-pomace oil and the de-oiled pomace. The recovery of this by-products is one of the most important objectives in resolving the environmental problems related to olive-oil processing. Moreover, the utilisation of this by-products is also very important for the profitability of the business operators. This study focuses on the possibility of using the exhausted pomace and pit as fuel. According to the Ministerial Decree of March 8 th, 2004, the de-oiled pomace may be utilized for this purpose, provided it has certain characteristics and the emissions do not exceed the limits stated by the legislation. By means of LCA methodology, this analysis aims to assess the environmental performance of these alternative fuels compared to that of wood pellets used in boilers smaller than 150 kWt. The assessment will broaden the perspective from a more economical point of view towards one which also considers environmental factors.