In this scientific paper, the quantitative and qualitative performances of three different de-stoner machines involved in an industrial olive oil plant were evaluated. The bioenergy production potential for olive stone in Italy was also estimated. The results confirmed that the best performance was obtained using the innovative partial de-stoner machine called "Moliden" because it does not lead to losses in oil extraction efficiency (as opposed to the total de-stoner machine) and it also extracts an amount of olive stone (approximately 65% of the total stone contained in the olives) that is greater than that obtained using the husk de-stoner machine (58%). In addition, the olive stone obtained by using a partial de-stoner machine contains lower oil, fine particle sizes and nitrogen compared to the olive stone obtained by using a husk de-stoner machine. This leads to advantages regarding combustion efficiency and the environment. Considering the olive production in Italy and in the Mediterranean basin, olive stone might be an attractive renewable source for energy production. (c) 2015 Elsevier Ltd. All rights reserved.