Method for producing ethylene and propylene
The invention is to provide a catalyst for long-term, high-yield and stable production of ethylene and propylene in an efficient and simple method of catalytic conversion from a hydrocarbon material. The invention relates to a method for producing ethylene and propylene by contacting a hydrocarbon material that contains an olefin having from 4 to 12 carbon atoms in an amount of at least 20% by weight, with a zeolite-containing shaped catalyst satisfying the following requirements (1) to (4), in a reactor for catalytic conversion of that olefin: (1) the zeolite is an intermediate pore-size zeolite having a pore size of from 5 to 6.5 angstroms, (2) the zeolite does not substantially contain a proton, (3) the zeolite contains at least one metal selected from the group consisting of metals belonging to the Group IB of the Periodic Table, (4) the zeolite has a silica/alumina molar ratio (SiO 2 /Al 2 O 3 molar ratio) of from 800 to 2,000.
1. A method for producing ethylene and propylene by contacting a hydrocarbon material that contains at least one olefin having from 4 to 12 carbon atoms in an amount of at least 20% by weight, with a zeolite-containing shaped catalyst in a reactor for catalytic conversion of the at least one olefin having from 4 to 12 carbon atoms, wherein zeolite in the zeolite-containing shaped catalyst satisfies the following requirements (1), (2), (3) and (4):
(1) the zeolite is an intermediate pore-size zeolite having a pore size of from 5 to 6.5 angstroms,
(2) the zeolite does not substantially contain a proton,
(3) the zeolite contains at least one metal selected from the group consisting of metals belonging to the Group IB of the Periodic Table,
(4) the zeolite has a silica/alumina molar ratio (SiO 2 /Al 2 O 3 molar ratio) of from 800 to 2,000.
2. The method for producing ethylene and propylene as claimed in claim 1 , wherein the hydrocarbon material contains at least one olefin having from 4 to 12 carbon atoms in an amount of at least 50% by weight relative to the weight of the hydrocarbon material.
3. The method for producing ethylene and propylene as claimed in claim 1 , wherein the hydrocarbon material contains at least one diolefin compound having from 3 to 12 carbon atoms in an amount of 2.5% by weight or less relative to the weight of the hydrocarbon material.
4. The method for producing ethylene and propylene as claimed in claim 1 , wherein zeolite in the zeolite-containing shaped catalyst supports silver and an alkali metal and does not substantially contain a proton.
5. The method for producing ethylene and propylene as claimed in claim 1 , wherein zeolite in the zeolite-containing shaped catalyst is selected from the group consisting of ZSM-5, ZSM-8, ZSM-11, ZSM-12, ZSM-21, ZSM-23, ZSM-35 and ZSM-38 zeolites.
6. The method for producing ethylene and propylene as claimed in claim 1 , wherein the zeolite-containing shaped catalyst is heat-treated at a temperature not lower than 500° C. in the presence of water vapor, prior to its contact with the hydrocarbon material.
7. The method as claimed in claim 1 , wherein the reactor is an adiabatic fixed-bed reactor.
8. The method for producing ethylene and propylene as claimed in claim 1 , wherein the catalytic conversion conditions are such that the reaction temperature is from 500 to 580° C., the hydrocarbon material partial pressure is from 0.05 to 0.3 MPa, and the weight-hourly space velocity is from 2 to 10 hr −1 .
9. The method for producing ethylene and propylene as claimed in claim 1 or 3 , wherein the hydrocarbon material contains at least one diolefin compound having from 3 to 12 carbon atoms in an amount of 1.14% or more by weight or more relative to the weight of the hydrocarbon material.