Processes for increasing the yield of ethylene and propylene

摘要

A process for increasing the yield of ethylene and propylene, comprising:
(1) feeding a feedstock into a reaction zone with a catalyst to produce (i) a product stream and a catalyst to be regenerated;(2) stripping and then dividing the catalyst to be regenerated into at least two parts, wherein a first part is recycled into the reaction zone at a first position, and a second part is regenerated in the regenerator to form a regenerated catalyst and then recycled into the reaction zone at a second position; and(3) controlling the temperature increase in the reaction zone.

主权项

1. A process for increasing the yield of ethylene and/or propylene, comprising:
(1) feeding a feedstock comprising methanol into a reaction zone, and contacting the feedstock with a catalyst comprising at least one silicon-aluminophosphate molecular sieve to produce (i) a product stream comprising ethylene and/or propylene, and (ii) a catalyst to be regenerated; (2) stripping and then dividing the catalyst to be regenerated into at least two parts, wherein a first part is recycled into the reaction zone at a first position, a second part is regenerated in a regenerator to form a regenerated catalyst, and the regenerated catalyst is recycled into the reaction zone at a second position; and (3) controlling the temperature increase in the reaction zone, comprising (i) vaporizing the feedstock with a vaporizer, and then dividing the feedstock into at least two parts, wherein a first part is fed into the reaction zone at at least one separate position in the axial direction of the reaction zone, and a second part is heated in a heater and then fed into the reaction zone at the bottom of the reaction zone, and wherein the first part in step (2) is recycled into the bottom of the reaction zone, and the regenerated catalyst in step (2) is recycled into the reaction zone at about ¼ to about ¾ of the reaction zone height; or (ii) additionally separating one part of the catalyst to be regenerated into a third part, and cooling and recycling the third part into the reaction zone at a third position, which is at about ⅕ to about ⅗ of the reaction zone height, and wherein the first part in step (2) is recycled into the bottom of the reaction zone, and the difference between the second position in step (2) and the third position is less than ⅙ of the reaction zone height.