Biochemical Methane Potential of Mechanically and Enzymatically Pretreated Solid Olive Mill Waste

Olive cake, the solid byproduct of three-phase centrifugation olive oil production, has a high organic and polyphenol content, rendering it an environmental threat when landfilled as well limiting its animal feed potential. This residue can be good candidate for biomethane production due to rich polysaccharide content (pectin, hemicellulose, cellulose). Two strategies were compared maximize production: destoning (i.e., removal seed fragments via mechanical means) enzymatic pretreatment pulp. After 30 days batch anaerobic digestion at 35 °C, both enzymatically pretreated destoned cakes produced similar amounts methane (~295 mL CH4/g volatile solids (VS)), 42% more than control. A comparison cake’s yields with broad range agricultural residues in literature demonstrated suitability production. Additionally, digestate recovered from cake had Kjeldahl nitrogen contents (3.6%, db) low concentrations (0.02 mg gallic acid equivalent (GAE)/g), qualifying ingredient soil amendment. study diverted landfills second-generation biofuel that resulting may have value