Method for producing ethylene and propylene
The invention is to provide a catalyst excellent in product producibility and selectivity, and in coking degradation resistance and regeneration degradation resistance, which is for production of ethylene and propylene through catalytic conversion from a hydrocarbon material. The invention relates to a method for producing ethylene and propylene through catalytic conversion from an olefin, by contacting a hydrocarbon material with a zeolite-containing shaped catalyst satisfying the following requirements (1) to (6), in a reactor: (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-containing shaped catalyst comprises silica as a binder, (5) the zeolite-containing shaped catalyst has a side-crush strength of at least 2.5 N/mm, (6) the zeolite-containing shaped catalyst has a sodium content of 500 ppm or less as an H-exchange type thereof.
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 fixed-bed reactor, to thereby carry out catalytic conversion of the at least one olefin having from 4 to 12 carbon atoms, wherein the zeolite-containing shaped catalyst satisfies the following requirements (1) to (6):
(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-containing shaped catalyst comprises silica as a binder,
(5) the zeolite-containing shaped catalyst has a side-crush strength of at least 2.5 N/mm,
(6) the zeolite-containing shaped catalyst has a sodium content of 500 ppm or less as an H-exchange type thereof.
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 zeolite in the zeolite-containing shaped catalyst supports silver and an alkali metal through ion exchange, and does not substantially contain a proton.
4. 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.
5. The method for producing ethylene and propylene as claimed in claim 1 , wherein zeolite in the zeolite-containing shaped catalyst has a silica/alumina molar ratio of from 800 to 2,000.
6. The method for producing ethylene and propylene as claimed in claim 1 , wherein silica sol having a particle size of from 5 to 40 nm is used as a silica binder source in forming the zeolite-containing shaped catalyst.
7. 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.
8. The method for producing ethylene and propylene as claimed in claim 1 , wherein the fixed-bed reactor is an adiabatic fixed-bed reactor.
9. 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 .
10. A method for producing ethylene and propylene as claimed in claim 1 , wherein the catalytic conversion (reaction) is continued for 38 hours or more.