Separation of fine waste catalyst particles from methanol-to-olefin quench water via swirl regenerating micro-channel separation (SRMS): A pilot-scale study

Abstract

From the perspective of resource reserves, the development of coal-based methanol-to-olefins (MTO) technology is regarded as an important direction for the sustainable development of the chemical processing industry in China. However, the wastewater generated in the process of industrial operation has a significant impact on the stability of the process. To remove the fine waste catalyst particles from MTO quench water, a swirl regenerating micro-channel separation (SRMS) technology was developed. A 25 m3/h pilot-scale study was conducted to examine the separation and regeneration effects under different operating parameters and verify the feasibility of this technology through a long-duration experiment. Results showed that for filtration velocities ranging from 11 to 15 m/h, the total separation efficiency was 95–99 %, the removal efficiency of 0.2 μm particles was 83–90 %, and the regeneration cycle was 24–40 h while the waste catalyst particle concentration in quench water was 300–600 mg/L. The optimum regeneration water and gas speeds were determined to be 11–15 m/h and 56.6 m/h, respectively. Moreover, the performance of the pilot plant over 600 h continuous operation effect of was tested, and an average separation efficiency > 95 % with excellent regeneration was obtained.