Biofilter and regenerative thermal oxidizer controls for olive oil mill volatile organic compounds in Crete

Abstract

Olive oil mills emit volatile organic compounds from malaxation, decantation, and storage, which affect local air quality and sensory nuisance in Mediterranean settlements. This article evaluates end-of-pipe controls based on biological filtration and regenerative thermal oxidation for medium-scale mills in Crete. The objective is to compare pollutant removal, energy demand, greenhouse gas emissions, and costs under realistic exhaust compositions and operating profiles. Using open operational statistics for 2012-2024 and mass-balance models, we simulate three configurations: biofilter, regenerative thermal oxidizer, and a hybrid system with biological filtration followed by a polishing oxidizer. Indicators include removal efficiency for total volatile organic compounds, odor abatement, specific energy use, carbon dioxide equivalent per thousand cubic metres treated, and levelized cost. Results show that biological filtration achieves high average removal with the lowest energy burden, while regenerative thermal oxidation guarantees peak compliance at higher costs; the hybrid configuration balances reliability and climate impact for operators.