Abstract: The regeneration standpipe of an industrial methanol to olefins unit had the problem of poor catalyst transport, which led to unstable catalyst circulation, poor propylene and ethylene yield and product distribution.The flow state and pressure characteristics of gas-solid two-phase flow in the standpipe were analyzed by measuring the dynamic pressure and static pressure at different positions of the standpipe, and the reasons for the poor catalyst transport were discussed.The results showed that the main reason for the rapid degassing was the low amount of catalyst circulation in the regeneration standpipe.The catalyst flow patterns in the regeneration standpipe included stratified flow in the inclined pipe, thin phase flow in the top of the vertical pipe and dense phase flow in the lower part of the vertical pipe. Different flow patterns had different pressure characteristics, which could be used to identifythe flow patterns.In addition, the gas-solid linearvelocity in the standpipewas calculated, and the bubble direction was consistent with the analysis result of the flow patterns, which could be used as the basis for operation adjustment of the device.

Key words: methanol to olefins, standpipe, regenerated catalyst, pressure characteristic, flow pattern identification