Zeolite-based VOC Rotor-Concentrators are suitable for high flow rate of process gas with low inlet concentration of pollutants. The organic compounds in the process gas are concentrated by adsorption in the zeolite-based Rotor-Concentrator, while the cleaned airflow is sent directly to the exhaust stack in compliance with legislation emission limits. The pollutants concentrated in the rotor-concentrator are released from the rotor by a small, heated air stream and treated by an oxidizer with reduced size. The aim of a Roto-Concentrator is to send the oxidizer an airflow up to 20-times lower than the initial volume to be treated with a sufficient VOC concentration while allowing the process to be auto-thermal with a significant reduction of the operating costs of the system.