Collaborative removal of fine catalysts particles and insoluble organics from methanol-to-olefins reaction wastewater using horizontal swirl regeneration micro-channel separation (HSRMS)

Abstract

The methanol-to-olefins (MTO) process is regarded as a crucial approach for ensuring the sustainable growth of China's chemical industry. However, the fine catalyst particles and insoluble organics in the water system poses a serious threat to the stability of the MTO process. A novel horizontal swirl regeneration micro-channel separation (HSRMS) method for purifying the MTO reaction wastewater was developed in this study. On-site experiments were conducted using a device with a capacity of 1 t/h to investigate the separation and regeneration effects under various parameters and to verify the feasibility of this method through a long-term observation. The results showed that this method could effectively remove the fine solids and insoluble organics in the reaction wastewater, and the device operated stably with fluctuations in both the quality and quantity of wastewater for 24 consecutive days. The suspended solids in the effluent was maintained below 5 mg/L, and the average removal efficiency for insoluble organics exceeded 75%. Furthermore, the excellent regeneration performance was achieved, with solid particles and oil in the media reduced to less than 0.2% after regeneration. This method could ensure long-term stable operation of the water system and outperform other commonly used reaction wastewater treatment methods in terms of investment, maintenance cost, freshwater supplementation, and energy consumption.