Opportunities to Valorize Waste from the Olive Oil Industry

Abstract

The European Union produces two-thirds of the world's olive oil, with Spain being the world's leading producer. Olive oil is highly valued on the market for its organoleptic and nutritional properties. However, its production generates very large quantities of waste, which is difficult to manage and has a negative impact on the environment. This paper examines the generation of waste in this sector and analyses its current management practices. It then novel opportunities for the integral valorization of olive pomace, a biomass that represents the main waste from olive oil production. The aim of valorization is to obtain compounds and materials of high interest and to minimize the environmental impact associated with olive pomace management. We propose the following valorization routes: use of clay and fresh olive pomace to produce building materials, recovery of compounds of interest from the liquid fraction of olive cake by thermal hydrolysis, production of low-cost adsorbent materials from the solid fraction obtained from the hydrolysis of olive cake for the removal of pollutants from wastewater, and production of fuel gas by gasification of the solid fraction obtained from the thermal hydrolysis of olive cake. The aim of this work is to integrate the olive pomace valorization processes into the olive oil industry, upgrading existing production plants into olive oil biorefineries and thus promoting circularity in this key sector of the Southern European economy.