The spent cake from olive oil filtration as biomass feedstock

The most widespread method for virgin olive oil filtration at industrial scale is the so-called precoat body-feed filtration by means of filter aids, mainly consisting of perlite and cellulose. The residue of the process is a spent filtration cake, which has the potential for upgrading if it is understood in the context of the biorefining concept. Data about the production and composition of the spent cake were collected from an industrial case-study. The potential availability of the spent cake has been estimated both at local scale (the industrial case-study) and at larger scale based on the Spanish context, that is the world leading virgin olive oil producer. The mean percentage composition of the spent cake is 5% oil impurities, 7% cellulose, 28% perlite, 52% oil and 8% water. About 10 g of spent cake are produced per kilogram of virgin olive oil to be processed; while about 316 and 7482 Mg of spent cake could be potentially available for the local and large scale occasion, respectively. Owing to its composition entailing oil and waxes, cellulose and mineral fractions, the spent cake has the potential as feedstock for the emerging biotechnologies and biorefineries.