Patent ID: 8530714
Filing Date: 2013-09-10
Classification: B01J,C07C,Y02P

Abstract:
1. A method for producing lower olefins comprising: introducing a feed gas, which is composed of a feedstock gas containing dimethyl ether and an additive gas containing steam in which the ratio of steam in the total amount of feed gas is 5 to 30% by volume, into an olefin synthesis reactor, bringing the feedstock gas into contact with a zeolite catalyst in the reactor to produce a hydrocarbon product containing C separating and recovering propylene from the hydrocarbon product, and using at least a part of the remainder after the separation as at least a part of the additive gas, wherein said method comprises multiple reactors connected in parallel, or connected in a combination of series and parallel, wherein the additive gas contains C the ratio of the total amount of the C the ratio of an additive gas excluding steam to the feedstock gas introduced into the olefin synthesis reactor (the number of moles of the additive gas excluding steam:the number of moles of the feedstock gas on a carbon basis) is in the range of 0.2 to 5.0.