| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for producing a lower olefin from a raw material containing dimethyl ether, capable of producing the lower olefin, especially propylene economically in a good yield by inhibiting the carbonaceous substance precipitation on a catalyst for lengthening the time until the temporary inactivation of a zeolite catalyst, also inhibiting the permanent inactivation of the catalyst, reducing the recycling amount of water to improve the thermal efficiency of the process, and also enabling the elimination or marked small-sizing of equipment associated with the recycling of the water and steam generation and the simplification of its operation. <P>SOLUTION: This method for producing the lower olefin is provided by introducing feed gas consisting of raw material gas containing dimethyl ether and diluting gas, and having 5-30 vol.% ratio of steam based on the total amount, into an olefin producing reaction vessel, making a contact with the zeolite catalyst to produce a hydrocarbon product containing 2-5C olefins, recovering/separating propylene, etc., from the obtained hydrocarbon product, and using at least a part of residue obtained by separating the propylene, etc., from the hydrocarbon product, at least as a part of the diluting gas. <P>COPYRIGHT: (C)2007,JPO&INPIT |
