Abstract: Methanol to olefin (MTO) technology is of great significance to China's coal chemical industry.In the actual operation of MTO plant, the blockage of water system is a common problem, and the water washing system is an important part of the water system of MTO unit. Because of the fine catalyst particles, wax in the product gas, and other dirt material in the water scrubber tray and the cold exchange equipment pipeline deposition, it is easy to cause problems such as the increase of pressure drop of the water scrubber and the decrease of heat exchange efficiency of the water washing water cooling equipment. Taking a MTO unit as an example, the process flow of the washing water system in the MTO unit was introduced, and the sources and origin of the fine catalyst particles, oil and wax substances were analyzed. Finally, several solutions were proposed to better ensure the safe, stable and long-term operation of the washing water system in the methanol to olefins industrial unit.

Key words: methanol to olefin, washing water system, catalyst particles, oil wax