Design and dynamic behaviour investigation of a novel VOC recovery system based on a deep condensation process

Abstract

Emission of volatile organic compounds (VOCs) is a major source of air pollution, and condensation is an ideal method for VOC recovery. However, with the increasingly strict regulations on VOC emissions, the traditional condensation method cannot meet the requirements of the existing VOC emission standards due to its restriction of the refrigeration temperature. In this paper, a novel VOC deep condensation recovery system (VOC-DCR system) is designed to overcome the shortcomings of the traditional condensation recovery system, and its steady-state simulation shows that the VOC recovery rate is 99.97% and the energy consumption is 35.67 kW. In addition, the VOC emission concentration after the treatment of the novel system is 45.17 mg/Nm3, which is far below the emission limit. Moreover, to verify the security and effectiveness of the actual running of the system, the dynamic model of the system is established to study its dynamic behaviours under external disturbances. The dynamic simulation results show that the novel system can overcome some disturbances and operate in a stable state. On this basis, this paper also predicts the operational risk of the system under extreme disturbances of −50% to 50%. The prediction results show that in order to ensure the safe and effective operation of the system, the disturbance of feed temperature and flow rate should be controlled within −33% to 8% and −2% to 8% respectively. Moreover, the disturbance of feed pressure and concentration should be controlled within −8% to 50% and −50% to 18% respectively. The conclusions of this study are of great significance for promoting the industrial application of the VOC-DCR system and guiding its safe operation.