Olive pomace in South West Europe: Processing and Biofuel Use

Olive cake, or exhausted olive pomace, is a by-product from olive oil extraction, consisting of residual olive pulp, peel, and stones. After initial oil extraction, reprocessing reduces oil content from 6–7% to ~1.5%. The dry, granular material is pelletizable and used primarily for industrial combustion in biomass plants, cement kilns, and power generation. In SW Europe, Spain, Greece, Italy, and Portugal produce 0.8–1.0 Mt, 0.2–0.3 Mt, 0.2–0.3 Mt, and >0.15 Mt annually, respectively. Bulk density is 600–650 kg/m³, moisture ~15% after drying. High ash, N, S, and Cl levels limit use to energy recovery; EU caps oil content at ≤3% for bioenergy. Pelletisation improves handling and feeding. ISO 17225-1 provides indicative standards. Emerging uses include biochar and phenolic compound extraction.