Abstract: In order to solve the problem of blockage of production equipment caused by high concentration of fine catalysts in MTO quench water, an ebullated bed filtration (EBF) unit was developed and successfully applied to MTO water system by combining deep filtration and cyclone enhanced desorption technology. Compared with the DMTO unit, the suspended solids content of the quench water in the SMTO unit is higher, the catalyst particle size is smaller and the dispersion is better. Although it is not easy to block, it is more difficult to separate. For the quench water of the DMTO unit, when the suspended solids content in the influent is 400—800 mg/L, the first-stage filtered effluent is reduced to 16—102 mg/L, and the second-stage filtered effluent is reduced to 7—16 mg/L. For the quench water of SMTO unit, when the suspended solids content in the influent is 4 500—9 500 mg/L, the effluent of primary filtration is reduced to 100—862 mg/L, and the effluent of secondary filtration is reduced to 13—160 mg/L. The EBF unit uses discharged quench water to regenerate the filtration medium without additional consumption of fresh water. The excellent separation effect of suspended solids greatly improves the reuse rate of quench water, reduces the cleaning frequency of heat exchange equipment and the cost of production and operation, and provides strong support for the efficient operation of methanol to olefins process.

Key words: DMTO, SMTO, quench water, ebullated bed filtration, suspension content