UU-type parallel mini-hydrocyclone group for oil-water separation in methanol-to-olefin industrial wastewater

Methanol to olefin (MTO) process is a chemical technology for producing low-carbon olefins from coal-based or natural gas-based methanol. It has changed the pattern of low-carbon olefins relying on petroleum cracking, and opened a new process for producing low-carbon olefins. However, the wastewater generated in the MTO process is difficult to handle. Numbering-up of mini-hydrocyclone is often used to enhance the processing capacity of wastewater treatment when mini-hydrocyclone is used for oil-water separation in methanol-to-olefin process. In this paper, the efficiency and pressure drop distribution of a single mini-hydrocyclone were studied in the laboratory. In addition, according to the U-U parallel configuration model, 150 mini-hydrocyclones arranged in parallel were established and used for the oil-water separation process of methanol-to-olefin reaction wastewater. The industrial operation results show that the average flow rate of long-period operation is 282 m(3)/h, the average pressure drop was 0.31 MPa, and the average separation efficiency of the mini-hydrocyclone group was 90 %. Especially for heavy components such as alkanes and aromatics, it had a good separation effect. Thus, it is shown that the mini-hydrocyclone group has good applicability in oil-water separation.