Catalyst for producing light olefins from C4-C7 hydrocarbons
The present invention relates to a catalyst for producing light olefins from C4-C7 hydrocarbons from catalytic cracking reaction and the production process of light olefins from said catalyst, wherein said catalyst has core-shell structure comprising a zeolite core with mole ratio of silicon to aluminium (Si/Al) between 2 to 250 and layered double hydroxide shell (LDH). The catalyst according to the invention provides high percent conversion of substrate to products and high selectivity to light olefins product.
1. A catalyst for producing light olefins from C4-C7 hydrocarbons, wherein said catalyst has a core-shell structure comprising a zeolite core with mole ratio of silicon to aluminium (Si/Al) between 2 to 250 and a layered double hydroxide shell and said zeolite is a hierarchical zeolite.
2. The catalyst according to claim 1 , wherein said zeolite is the hierarchical zeolite comprising a micropore with size between 0.3 to 0.6 nm, a mesopore with size between 2 to 10 nm, and a macropore with size larger than 50 nm, wherein the mesopore and macropore proportions are greater than or equal to 15 to 60% when compared to a total pore volume.
3. The catalyst according to claim 1 , wherein said zeolite has the mole ratio of silicon to aluminium between 15 to 30.
4. The catalyst according to claim 3 , wherein said zeolite has the mole ratio of silicon to aluminium of equal to 15.
5. The catalyst according to claim 1 , wherein said zeolite is selected from zeolite types ZSM-5, FAU, MOR, BETA or FER.
6. The catalyst according to claim 1 , wherein said zeolite has a crystal size between 100 to 3,000 nm.
7. The catalyst according to claim 1 , wherein the primary metals presented in said layered double hydroxide are the group 2 metals and the group 3 metals.
8. The catalyst according to claim 7 , wherein the primary metals presented in said layered double hydroxide are magnesium (Mg) and aluminium (Al).
9. The catalyst according to claim 1 , wherein said layered double hydroxide has a mole ratio of magnesium to aluminium between 1 to 3.
10. The catalyst according to claim 9 , wherein said layered double hydroxide has the mole ratio of magnesium to aluminium between 1 to 2.
11. The catalyst according to claim 1 , wherein said layered double hydroxide has a thickness between 100 to 1,000 nm.
12. The catalyst according to claim 1 , wherein the catalyst comprises a core and a shell which has a mass ratio of shell:core between 1:1 to 1:7.
13. The catalyst according to claim 1 , wherein the catalyst comprises a core and a shell which has a mass ratio of shell:core between 1:2 to 1:6.
14. A production process of light olefins from catalytic cracking reaction of C4-C7 hydrocarbons comprising: contacting C4-C7 hydrocarbons with a catalyst, wherein said catalyst has a core-shell structure comprising a zeolite core with mole ratio of silicon to aluminium (Si/Al) between 2 to 250 and a layered double hydroxide shell and said zeolite is a hierarchical zeolite.
15. The process according to claim 14 , wherein said process is operated at temperature between 450 to 650° C. and pressure between atmospheric pressure 1 to 5 bars.
16. The process according to claim 14 or 15 , wherein the C4-C7 hydrocarbons are selected from butane, pentane, hexane, or heptane.
17. The process according to claim 16 , wherein the C4-C7 hydrocarbons are pentane.
18. The process according to claim 14 , wherein the light olefins are ethylene and propylene.