A CATALYST FOR LIGHT OLEFINS PRODUCTION AND A PROCESS OF LIGHT OLEFINS PRODUCTION BY USING A CATALYST THEREOF

Abstract

The present invention relates to a catalyst for light olefins production from catalytic cracking of hydrocarbon having 4 to 7 carbon atoms, wherein said catalyst has core-shell structure comprising zeolite core selected from ferrierite, ZSM-5, or mixture thereof, and silicalite shell having MFI structure, and said catalyst has the following characteristics: a) the weight ratio of shell to core greater than 0 but less than 4; b) the mole ratio of silica to alumina (SiO2/Al2O3) from 60 to 550; c) the hierarchical pores comprising micropores having pore size in the range of 0.1 to 2 nm, mesopores having pore size in the range of 2 to 50 nm, and macropores having pore size greater than 50 nm, wherein the proportion of volume of mesopores and macropores to the total pore volume is in the range from 0.35 to 0.90, and said mesopores comprise pores having pore size from 2 to 5 nm, wherein the proportion of volume of pores having pore size from 2 to 5 nm to the total pore volume is in the range from 0.08 to 0.30.

The catalyst according to the invention provides high conversion of the reactant and especially high selectivity to light olefins. Moreover, this invention also relates to the process of light olefins production by using the catalyst thereof.

Claims

1. A catalyst for light olefins production from catalytic cracking of hydrocarbon having 4 to 7 carbon atoms, wherein said catalyst has core-shell structure comprising zeolite core selected from ferrierite, ZSM-5, or mixture thereof, and silicalite shell having MFI structure, and said catalyst has the following characteristics: a) the weight ratio of shell to core greater than 0 but less than 4; b) the mole ratio of silica to alumina (SiO.sub.2/Al.sub.2O.sub.3) from 60 to 550; c) the hierarchical pores comprising micropores having pore size in the range of 0.1 to 2 nm, mesopores having pore size in the range of 2 to 50 nm, and macropores having pore size greater than 50 nm, wherein the proportion of volume of mesopores and macropores to the total pore volume is in the range from 0.35 to 0.90, and said mesopores comprise pores having pore size from 2 to 5 nm, wherein the proportion of volume of pores having pore size from 2 to 5 nm to the total pore volume is in the range from 0.08 to 0.30.

2. (canceled)

3. The catalyst according to claim 1, wherein said mesopores comprise pores having pore size from 2 to 5 nm, wherein the proportion of volume of pores having pore size from 2 to 5 nm to the total pore volume is in the range from 0.10 to 0.20.

4. The catalyst according to any one of claims 1 or 2, wherein said mesopores further comprise pores having pore size from 5 to 8 nm and pores having pore size from 8 to 18 nm.

5. The catalyst according to claim 1, wherein said zeolite core has the hierarchical pores comprising micropores having pore size in the range of 0.1 to 2 nm, mesopores having pore size in the range of 2 to 50 nm, and macropores having pore size greater than 50 nm, wherein the proportion of volume of mesopores and macropores to the total pore volume is in the range from 0.30 to 0.90

6. The catalyst according to any one of claims 1 or 4, wherein said zeolite core has the hierarchical pores and is arranged in nano-sheet.

7. The catalyst according to claim 1, wherein said silicalite shell has the hierarchical pores and is arranged in nano-sheet.

8. The catalyst according to claim 1, wherein said zeolite core has the mole ratio of silica to alumina in the range from 35 to 320.

9. The catalyst according to claim 1, wherein said zeolite core is the ferrierite having the flower shape-like particle arrangement when analyzed by the scanning electron microscope (SEM) technique at the accelerating voltage of 20 kV with SEI mode.

10. (canceled)

11. The catalyst according to claim 1, wherein said catalyst has the mole ratio of silica to alumina in the range from 100 to 400.

12. The catalyst according to claim 1, wherein said catalyst comprises the ZSM-5 core having the mole ratio of silica to alumina in the range from 120 but no more than 300 and the silicalite shell, and said catalyst has the weight ratio of shell to core greater than 0 but less than or equal to 1.5.

13. The catalyst according to claim 1, wherein said catalyst comprises the ZSM-5 core having the mole ratio of silica to alumina in the range from 50 but no more than 120 and the silicalite shell, and said catalyst has the weight ratio of shell to core greater than 0 but less than or equal to 3.

14. The catalyst according to claim 1, wherein said catalyst comprises the ferrierite core having the mole ratio of silica to alumina in the range from 150 but no more than 300 and the silicalite shell, and said catalyst has the weight ratio of shell to core greater than 0 but less than or equal to 2.

15. The catalyst according to claim 1, wherein said catalyst comprises the ferrierite core having the mole ratio of silica to alumina in the range from 50 but no more than 150 and the silicalite shell, and said catalyst has the weight ratio of shell to core greater than 0 but less than or equal to 2.

16. The catalyst according to claim 1, wherein said catalyst further comprises manganese (Mn).

17. The catalyst according to claim 14, wherein said catalyst further comprises manganese (Mn) in an amount of from 1 to 15% by weight when comparing with the weight of zeolite core.

18. (canceled)

19. The catalyst according to claim 1, wherein said zeolite core further comprises manganese (Mn).

20. The catalyst according to claim 16, wherein said zeolite core further comprises manganese (Mn) in an amount of from 1 to 15% by weight when comparing with the weight of zeolite core.

21. (canceled)

22. The catalyst according to claim 1, wherein said hydrocarbon is selected from butane, pentane, hexane, or heptane.

23-24. (canceled)

25. A process of light olefins production from catalytic cracking of hydrocarbon having 4 to 7 carbon atoms, comprising the contact of the hydrocarbon having 4 to 7 carbon atoms to the catalyst at the temperature in the range from 400 to 700 C. and the pressure in the range from 0.1 to 10 bars, wherein said catalyst has core-shell structure comprising zeolite core selected from ferrierite, ZSM-5, or mixture thereof, and silicalite shell having MFI structure, and said catalyst has the following characteristics: a) the weight ratio of shell to core greater than 0 but less than 4; b) the mole ratio of silica to alumina (SiO.sub.2/Al.sub.2O.sub.3) from 60 to 550; c) the hierarchical pores comprising micropores having pore size in the range of 0.1 to 2 nm, mesopores having pore size in the range of 2 to 50 nm, and macropores having pore size greater than 50 nm, wherein the proportion of volume of mesopores and macropores to the total pore volume is in the range from 0.35 to 0.90, and said mesopores comprise pores having pore size from 2 to 5 nm, wherein the proportion of volume of pores having pore size from 2 to 5 nm to the total pore volume is in the range from 0.08 to 0.30.

26. (canceled)

27. The process of light olefins production according to claim 19, wherein said mesopores comprise pores having pore size from 2 to 5 nm, wherein the proportion of volume of pores having pore size from 2 to 5 nm to the total pore volume is in the range from 0.10 to 0.20.

28. The process of light olefins production according to any one of claims 19 or 20, wherein said mesopores further comprise pores having pore size from 5 to 8 nm and pores having pore size from 8 to 18 nm.

29. The process of light olefins production according to claim 19, wherein said zeolite core has the hierarchical pores comprising micropores having pore size in the range of 0.1 to 2 nm, mesopores having pore size in the range of 2 to 50 nm, and macropores having pore size greater than 50 nm, wherein the proportion of volume of mesopores and macropores to the total pore volume is in the range from 0.30 to 0.90.

30. The process of light olefins production according to any one of claims 19 or 22, wherein said zeolite core has the hierarchical pores and is arranged in nano-sheet.

31. The process of light olefins production according to claim 19, wherein said silicalite shell has the hierarchical pores and is arranged in nano-sheet.

32. The process of light olefins production according to claim 19, wherein said zeolite core has the mole ratio of silica to alumina in the range from 35 to 320.

33. The process of light olefins production according to claim 19, wherein said zeolite core is the ferrierite having the flower shape-like particle arrangement when analyzed by the scanning electron microscope (SEM) technique at the accelerating voltage of 20 kV with SEI mode.

34. (canceled)

35. The process of light olefins production according to claim 19, wherein said catalyst has the mole ratio of silica to alumina in the range from 100 to 400.

36. The process of light olefins production according to claim 19, wherein said catalyst comprises the ZSM-5 core having the mole ratio of silica to alumina in the range from 120 but no more than 300 and the silicalite shell, and said catalyst has the weight ratio of shell to core greater than 0 but less than or equal to 1.5.

37. The process of light olefins production according to claim 19, wherein said catalyst comprises the ZSM-5 core having the mole ratio of silica to alumina in the range from 50 but no more than 120 and the silicalite shell, and said catalyst has the weight ratio of shell to core greater than 0 but less than or equal to 3.

38. The process of light olefins production according to claim 19, wherein said catalyst comprises the ferrierite core having the mole ratio of silica to alumina in the range from 150 but no more than 300 and the silicalite shell, and said catalyst has the weight ratio of shell to core greater than 0 but less than or equal to 2.

39. The process of light olefins production according to claim 19, wherein said catalyst comprises the ferrierite core having the mole ratio of silica to alumina in the range from 50 but no more than 150 and the silicalite shell, and said catalyst has the weight ratio of shell to core greater than 0 but less than or equal to 2.

40. The process of light olefins production according to claim 19, wherein said catalyst further comprises manganese (Mn).

41. The process of light olefins production according to claim 32, wherein said catalyst further comprises manganese (Mn) in an amount of from 1 to 15% by weight when comparing with the weight of zeolite core.

42. (canceled)

43. The process of light olefins production according to claim 19, wherein said zeolite core further comprises manganese (Mn).

44. The process of light olefins production according to claim 34, wherein said zeolite core further comprises manganese (Mn) in an amount of from 1 to 15% by weight when comparing with the weight of zeolite core.

45. (canceled)

46. The process of light olefins production according to claim 19, wherein the contact of the hydrocarbon having 4 to 7 carbon atoms to the catalyst is performed at the temperature in the range from 500 to 700 C.

47. The process of light olefins production according to claim 19, wherein said hydrocarbon is selected from butane, pentane, hexane, or heptane.

48-49. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG. 1 shows the characteristics of the crystalline structure tested by scanning electron microscope (SEM) technique.

[0027] FIG. 2 shows the pore size distribution analyzed by Barrett-Joyner-Halenda adsorption (BJH adsorption).

[0028] FIG. 3 shows the conversion of the reactant and the selectivity to each product of different catalysts in the catalytic cracking of isobutane.

[0029] FIG. 4 shows the conversion of the reactant and the selectivity to each product of the catalysts having core-shell structure in which the zeolite core was the ferrierite comparing with the comparative sample catalysts in the catalytic cracking of isobutane.

[0030] FIG. 5 shows the conversion of the reactant and the selectivity to each product of the catalyst having core-shell structure in which the zeolite core was the ZSM-5 comparing with the comparative sample catalysts in the catalytic cracking of isobutane.

[0031] FIG. 6 shows the conversion of the reactant and the selectivity to each product of the catalysts having the manganese addition in different ways comparing with the comparative sample catalyst in the catalytic cracking of isobutane.

DETAILED DESCRIPTION

[0032] The present invention relates to the catalyst for the light olefins production from catalytic cracking of hydrocarbon having 4 to 7 carbon atoms and process of light olefins production by using the catalyst thereof, wherein said catalyst is suitable to be used in the process of light olefins production, provides high conversion of the reactant, and especially high selectivity to light olefins, which will be described in the following aspects of the invention.

[0033] Any aspect being described herein also means to include the application to other aspects of this invention unless stated otherwise.

[0034] Technical terms or scientific terms used herein have definitions as understood by an ordinary person skilled in the art unless stated otherwise.

[0035] Any tools, equipment, methods, or chemicals named herein mean tools, equipment, methods, or chemicals being operated or used commonly by those person skilled in the art unless stated otherwise that they are tools, equipment, methods, or chemicals specific only in this invention.

[0036] Use of singular noun or singular pronoun with comprising in claims or specification means one and also including one or more, at least one, and one or more than one.

[0037] All compositions and/or methods disclosed and claims in this application are intended to cover embodiments from any operation, performance, modification, or adjustment any factors without any experiment that significantly different from this invention and obtain with object with utility and resulted as same as the present embodiment according to person ordinary skilled in the art although without specifically stated in claims. Therefore, substitutable, or similar object to the present embodiment, including any minor modification or adjustment that can be apparent to person skilled in the art should be construed as remains in spirit, scope, and concept of invention as appeared in appended claims.

[0038] Throughout this application, term about means any number that appeared or expressed herein that could be varied or deviated from any error of equipment, method, or personal using said equipment or method, including variations or deviations occurred from changes in reaction conditions of uncontrollable factors such as humidity and temperature. Zeolite in this invention means the microporous alumino-silicate compound comprising silicon, aluminium, and oxygen in the structure. It may further comprise other elements. Zeolite may be commercial zeolite, natural zeolite, or zeolite prepared by any method.

[0039] Silicalite in this invention means the zeolite compound having multi-crystalline structure, wherein the silica to alumina ratio is infinity (SiO.sub.2/Al.sub.2O.sub.3=).

[0040] Hereafter, invention embodiments are shown without any purpose to limit any scope of the invention.

[0041] The present invention relates to the catalyst for light olefins production from catalytic cracking of hydrocarbon having 4 to 7 carbon atoms, wherein said catalyst has core-shell structure comprising zeolite core selected from ferrierite, ZSM-5, or mixture thereof, and silicalite shell having MFI structure, and said catalyst has the following characteristics: [0042] a) the weight ratio of shell to core greater than 0 but less than 4; [0043] b) the mole ratio of silica to alumina (SiO.sub.2/Al.sub.2O.sub.3) from 60 to 550; [0044] c) the hierarchical pores comprising micropores having pore size in the range of 0.1 to 2 nm, mesopores having pore size in the range of 2 to 50 nm, and macropores having pore size greater than 50 nm, wherein the proportion of volume of mesopores and macropores to the total pore volume is in the range from 0.35 to 0.90, and said mesopores comprise pores having pore size from 2 to 5 nm, wherein the proportion of volume of pores having pore size from 2 to 5 nm to the total pore volume is in the range from 0.08 to 0.30.

[0045] In one aspect of the invention, said catalyst has the hierarchical pores comprising micropores having pore size in the range of 0.1 to 2 nm, mesopores having pore size in the range of 2 to 50 nm, and macropores having pore size greater than 50 nm, wherein the proportion of volume of mesopores and macropores to the total pore volume is in the range from 0.40 to 0.90, preferably in the range from 0.40 to 0.70.

[0046] In one aspect of the invention, said mesopores comprise pores having pore size from 2 to 5 nm, wherein the proportion of volume of pores having pore size from 2 to 5 nm to the total pore volume is in the range from 0.10 to 0.20.

[0047] In one aspect of the invention, said mesopores further comprise pores having pore size from 5 to 8 nm and pores having pore size from 8 to 18 nm.

[0048] In one aspect of the invention, said mesopores further comprise pores having pore size from 5 to 8 nm and pores having pore size from 8 to 18 nm, wherein the proportion of volume of pores having pore size from 5 to 8 nm to the total pore volume is in the range from 0.05 to 0.20, preferably in the range from 0.05 to 0.15.

[0049] In one aspect of the invention, said mesopores further comprise pores having pore size from 5 to 8 nm and pores having pore size from 8 to 18 nm, wherein the proportion of volume of pores having pore size from 8 to 18 nm to the total pore volume is in the range from 0.05 to 0.30, preferably in the range from 0.05 to 0.20.

[0050] In one aspect of the invention, said zeolite core has the hierarchical pores comprising micropores having pore size in the range of 0.1 to 2 nm, mesopores having pore size in the range of 2 to 50 nm, and macropores having pore size greater than 50 nm.

[0051] In one aspect of the invention, said zeolite core has the hierarchical pores comprising micropores having pore size in the range of 0.1 to 2 nm, mesopores having pore size in the range of 2 to 50 nm, and macropores having pore size greater than 50 nm, wherein the proportion of volume of mesopores and macropores to the total pore volume is in the range from 0.30 to 0.90, preferably in the range from 0.30 to 0.80.

[0052] In one aspect of the invention, said zeolite core has the hierarchical pores and is arranged in nano-sheet.

[0053] In one aspect of the invention, said silicalite shell has the hierarchical pores comprising micropores having pore size in the range of 0.1 to 2 nm, mesopores having pore size in the range of 2 to 50 nm, and macropores having pore size greater than 50 nm.

[0054] In one aspect of the invention, said silicalite shell has the hierarchical pores and is arranged in nano-sheet.

[0055] In one aspect of the invention, said silicalite shell has the mole ratio of silica to alumina of infinity.

[0056] In one aspect of the invention, said zeolite core has the mole ratio of silica to alumina in the range from 35 to 320.

[0057] In one aspect of the invention, said zeolite core is the ferrierite having the flower shape-like particle arrangement when analyzed by the scanning electron microscope (SEM) technique at the accelerating voltage of 20 kV with SEI mode.

[0058] In one aspect of the invention, said catalyst has the weight ratio of shell to core greater than 0 but less than or equal to 3.

[0059] In one aspect of the invention, said catalyst has the mole ratio of silica to alumina in the range from 100 to 400.

[0060] In one aspect of the invention, said catalyst has the specific surface area (S.sub.BET) in the range from about 300 to 800 m.sup.2/g, preferably from about 400 to 700 m.sup.2/g.

[0061] In one aspect of the invention, said catalyst has the external specific surface area (S.sub.ext) in the range from about 50 to 300 m.sup.2/g, preferably from about 70 to 250 m.sup.2/g, most preferably from about 80 to 200 m.sup.2/g.

[0062] In one aspect of the invention, said catalyst comprises the ZSM-5 core having the mole ratio of silica to alumina in the range from 120 but no more than 300 and the silicalite shell, and said catalyst has the weight ratio of shell to core greater than 0 but less than or equal to 1.5.

[0063] In one aspect of the invention, said catalyst comprises the ZSM-5 core having the mole ratio of silica to alumina in the range from 50 but no more than 120 and the silicalite shell, and said catalyst has the weight ratio of shell to core greater than 0 but less than or equal to 3.

[0064] In one aspect of the invention, said catalyst comprises the ferrierite core having the mole ratio of silica to alumina in the range from 150 but no more than 300 and the silicalite shell, and said catalyst has the weight ratio of shell to core greater than 0 but less than or equal to 2.

[0065] In one aspect of the invention, said catalyst comprises the ferrierite core having the mole ratio of silica to alumina in the range from 50 but no more than 150 and the silicalite shell, and said catalyst has the weight ratio of shell to core greater than 0 but less than or equal to 2.

[0066] In one aspect of the invention, said catalyst further comprises manganese (Mn).

[0067] In one aspect of the invention, said catalyst further comprises manganese (Mn), wherein said manganese is in an amount of from 1 to 15% by weight when comparing with the weight of zeolite core. Preferably, said manganese is in an amount of from 5 to 10% by weight when comparing with the weight of zeolite core.

[0068] In one aspect of the invention, said zeolite core further comprises manganese (Mn).

[0069] In one aspect of the invention, said zeolite core further comprises manganese (Mn), wherein said manganese is in an amount of from 1 to 15% by weight when comparing with the weight of zeolite core. Preferably, said manganese is in an amount of from 5 to 10% by weight when comparing with the weight of zeolite core.

[0070] In one aspect of the invention, said hydrocarbon is selected from butane, pentane, hexane, or heptane. Preferably, said hydrocarbon is butane, most preferably isobutane.

[0071] In one aspect of the invention, said light olefins are ethylene and propylene.

[0072] In one aspect of the invention, the catalyst as described above is used for the process of light olefins production from catalytic cracking of hydrocarbon having 4 to 7 carbon atoms, preferably hydrocarbon having 4 carbon atom selected from, but not limited to butane.

[0073] In another aspect of the invention, the process for preparing the catalyst for light olefins production from catalytic cracking of hydrocarbon having 4 to 7 carbon atoms may comprise the following steps: [0074] a) preparing the mixture comprising the compound for preparing the first zeolite and the first soft structure-directing agent, and subjecting to the hydrothermal process at the determined temperature and time in order to transform said mixture into zeolite; and [0075] b) preparing the mixture comprising the compound for preparing the silicalite, the second soft structure-directing agent, and the zeolite obtained from step a), and subjecting to the hydrothermal process at the determined temperature and time in order to transform said mixture into zeolite having the core-shell structure.

[0076] In one aspect of the invention, each step of said process for preparing the catalyst may further comprise the calcination step at the temperature in the range from 400 to 650 C.

[0077] In one aspect of the invention, said process for preparing the catalyst may further comprise the drying step.

[0078] Drying may be performed by conventional drying method using oven, vacuum drying, stirred evaporation, and drying by rotary evaporator.

[0079] In one aspect of the invention, each step of said process for preparing the catalyst may further comprise the ion exchange by contacting with ammonium salt solution.

[0080] In one aspect of the invention, said ammonium salt solution is selected from, but not limited to ammonium nitrate (NH.sub.4NO.sub.3) or ammonium hydroxide.

[0081] In one aspect of the invention, the compound for preparing the first zeolite is the mixture of alumina compound selected from aluminium isopropoxide, sodium aluminate, aluminium sulfate, aluminium nitrate, or aluminum hydroxide, and silica compound selected from tetraethyl orthosilicate (TEOS), sodium silicate, or silica gel.

[0082] In one aspect of the invention, said first soft structure-directing agent is selected from pyrrolidine, quaternary ammonium salt containing silane group, or quaternary ammonium salt. In one aspect of the invention, quaternary ammonium salt containing silane group may be selected from, but not limited to 3-(trimethoxysilyl)-propyl-octadecyl-dimethyl-ammonium chloride (TPOAC).

[0083] In one aspect of the invention, said quaternary ammonium salt may be selected from, but not limited to tetraalkylammonium salt selected from tetrapropylammonium hydroxide, tetrapropylammonium bromide, or tetrabutylammonium hydroxide.

[0084] In one aspect of the invention, said quaternary ammonium salt may further comprise long-chain quaternary ammonium surfactant that may be selected from, but not limited to cetyltrimethylammonium bromide (CTAB) or cetyltrimethylammonium chloride (CTAC).

[0085] In one aspect of the invention, said compound for preparing the silicalite may be selected from, but not limited to tetraethyl orthosilicate, sodium silicate, or silica gel.

[0086] In one aspect of the invention, said second soft structure-directing agent is selected from quarterly phosphonium salt or mixture of the quaternary ammonium salt further comprising long-chain quaternary ammonium surfactant.

[0087] In one aspect of the invention, said quarterly phosphonium salt is selected from tetrabutylphosphonium hydroxide (TBPOH) or tributyl hexadecyl phosphonium bromide.

[0088] In one aspect of the invention, mixture of the quaternary ammonium salt further comprising long-chain quaternary ammonium surfactant, wherein said quaternary ammonium salt may be selected from, but not limited to tetraalkylammonium salt selected from tetrapropylammonium hydroxide, tetrapropylammonium bromide, or tetrabutylammonium hydroxide.

[0089] In one aspect of the invention, mixture of the quaternary ammonium salt further comprising long-chain quaternary ammonium surfactant, wherein said long-chain quaternary ammonium surfactant may be selected from, but not limited to cetyltrimethylammonium bromide (CTAB) or cetyltrimethylammonium chloride (CTAC).

[0090] In another aspect of the invention, this invention relates to the process of light olefins production from catalytic cracking of hydrocarbon having 4 to 7 carbon atoms, comprising the contact of the hydrocarbon having 4 to 7 carbon atoms to the catalyst at the temperature in the range from 400 to 700 C. and the pressure in the range from about 0.1 to 10 bars, wherein said catalyst is selected from the catalyst according to the invention as described above or the catalyst obtained from the process for preparing the catalyst as described above.

[0091] In one aspect of the invention, the contact of the hydrocarbon having 4 to 7 carbon atoms to the catalyst is performed at the temperature in the range from 500 to 700 C., preferably at the temperature in the range from 550 to 680 C.

[0092] In one aspect of the invention, the contact of the hydrocarbon having 4 to 7 carbon atoms to the catalyst is performed at the pressure in the range from about 1 to 10 bars, preferably at the pressure in the range from about 1 to 7 bars.

[0093] In one aspect of the invention, said hydrocarbon is selected from butane, pentane, hexane, or heptane. Preferably, said hydrocarbon is butane, most preferably iso-butane. In one aspect of the invention, the products obtained from the catalytic cracking of hydrocarbon having 4 to 7 carbon atoms are the light olefins, preferably ethylene and propylene.

[0094] In one aspect of the invention, the process of light olefins production from catalytic cracking may be performed in the reactor but not limited to the fixed-bed reactor which may be performed in batch or continuous manner, or may be performed in fixed bed system, moving bed system, fluidized bed system, or batch system.

[0095] The weight hourly space velocity (WHSV) of the feed line of the hydrocarbon in the catalytic cracking is in the range of about 1 to 50 per hour, preferably in the range of about 1.5 to 16 per hour.

[0096] Generally, any person skilled in this art can adjust the condition of catalytic cracking of hydrocarbon having 4 to 7 carbon atoms to be suitable for type and composition of feed line, catalyst, and reactor system.

[0097] The following examples are only for demonstrating one aspect of this invention, not for limiting the scope of this invention in any way.

Preparation of the Catalyst

[0098] The preparation of the catalyst may be performed by the following methods.

Preparation of the Ferrierite (FER) Zeolite Catalyst

[0099] The preparation of the ferrierite zeolite catalyst could be prepared by hydrothermal method using pyrrolidine as the structure-directing agent of the zeolite as follows.

[0100] The first solution comprising sodium silicate, pyrrolidine, and water and the second solution comprising aluminium sulfate, concentrated sulfuric acid, and water were prepared. Then, the second solution was dropped into the first solution under continuous stirring. After that, said obtained mixture was subjected to the hydrothermal process at the temperature about 130 to 180 C. in order to transform said mixture into zeolite.

[0101] Then, the obtained zeolite was washed with deionized water, dried, and calcinated at the temperature about 500 to 650 C. to obtain zeolite which was white powder.

[0102] After that, said zeolite was subjected to the ion exchange by contacting the obtained zeolite with 1 M ammonium nitrate (NH.sub.4NO.sub.3) solution at the temperature about 60 to 90 C. under continuous stirring. Then, it was washed with deionized water, dried, and calcinated at the temperature about 500 to 600 C. to obtain the ferrierite zeolite catalyst.

Preparation of the ZSM-5 Zeolite Catalyst

[0103] The preparation of the ZSM-5 zeolite catalyst could be prepared by hydrothermal method using tetrapropylammonium hydroxide (TPAOH) as the structure-directing agent of the zeolite and cetyltrimethylammonium bromide (CTAB) as the agent for making hierarchical pores as follows.

[0104] The first solution comprising tetraethyl orthosilicate (TEOS) and the second solution comprising aluminium hydroxide, tetrapropylammonium hydroxide, sodium hydroxide, cetyltrimethylammonium bromide, and water were prepared. Then, the second solution was dropped into the first solution under continuous stirring. After that, said obtained mixture was subjected to the hydrothermal process at the temperature about 100 to 180 C. in order to transform said mixture into zeolite.

[0105] Then, the obtained zeolite was washed with deionized water, dried, and calcinated at the temperature about 500 to 650 C. to obtain zeolite which was white powder.

[0106] After that, said zeolite was subjected to the ion exchange by contacting the obtained zeolite with 1 M ammonium nitrate (NH.sub.4NO.sub.3) solution at the temperature about 60 to 90 C. under continuous stirring. Then, it was washed with deionized water, dried, and calcinated at the temperature about 500 to 600 C. to obtain the ZSM-5 zeolite catalyst having hierarchical pores.

Preparation of the Silicalite Catalyst

[0107] The preparation of the silicalite catalyst having silica to alumina ratio of infinity (SiO.sub.2/Al.sub.2O.sub.3=) could be prepared by hydrothermal method using tetrabutylphosphonium hydroxide (TBPOH) as the structure-directing agent of the zeolite and nanosheet structure as follows.

[0108] The first solution comprising tetraethyl orthosilicate (TEOS) and the second solution comprising tetrabutylphosphonium hydroxide, sodium hydroxide, and water were prepared. Then, the second solution was dropped into the first solution under continuous stirring. After that, said obtained mixture was subjected to the hydrothermal process at the temperature about 100 to 200 C. in order to transform said mixture into zeolite.

[0109] Then, the obtained zeolite was washed with deionized water, dried, and calcinated at the temperature about 500 to 650 C. to obtain zeolite which was white powder.

[0110] After that, said zeolite was subjected to the ion exchange by contacting the obtained zeolite with 1 M ammonium nitrate (NH.sub.4NO.sub.3) solution at the temperature about 60 to 90 C. under continuous stirring. Then, it was washed with deionized water, dried, and calcinated at the temperature about 500 to 600 C. to obtain the silicalite catalyst having hierarchical pores, wherein said silicalite catalyst having hierarchical pores was arranged in nano-sheet.

Preparation of the Ferrierite Zeolite Catalyst Comprising Manganese (Mn)

[0111] The preparation of the ferrierite zeolite catalyst comprising manganese (Mn) could be prepared by hydrothermal method using the preparation process of the ferrierite zeolite catalyst as described above and the addition of manganese sulfate into the mixture in the step before subjecting the mixture to the hydrothermal process.

Preparation of the Catalyst Having Core-Shell Structure

[0112] The preparation of the catalyst having core-shell structure could be prepared by hydrothermal method as follows.

[0113] The first solution and the second solution were prepared. Then, the second solution was dropped into the first solution under continuous stirring. Then, the zeolite catalyst being used as the core was added under continuous stirring at room temperature. After that, said obtained mixture was subjected to the hydrothermal process at the temperature about 100 to 200 C. in order to transform said mixture into zeolite.

[0114] Then, the obtained zeolite was washed with deionized water, dried, and calcinated at the temperature about 500 to 650 C. to obtain zeolite which was white powder.

[0115] After that, said zeolite was subjected to the ion exchange by contacting the obtained zeolite with 1 M ammonium nitrate (NH.sub.4NO.sub.3) solution at the temperature about 60 to 90 C. under continuous stirring. Then, it was washed with deionized water, dried, and calcinated at the temperature about 500 to 600 C. to obtain the catalyst having core-shell structure.

Preparation of the Comparative Catalyst and the Catalyst According to the Invention

Comparative Catalyst CAT A

[0116] The comparative catalyst CAT A could be prepared using the preparation process of the ferrierite zeolite catalyst as described above. Said comparative catalyst had the mole ratio of silica to alumina of about 61.

Comparative Catalyst CAT B

[0117] The comparative catalyst CAT B could be prepared using the preparation process of the ZSM-5 zeolite catalyst as described above. Said comparative catalyst had the mole ratio of silica to alumina of about 143.

Comparative Catalyst CAT C

[0118] The comparative catalyst CAT C could be prepared using the preparation process of the silicalite catalyst as described above.

Comparative Catalyst CAT D

[0119] The comparative catalyst CAT D was the catalyst having core-shell structure, wherein the shell was ferrierite zeolite and said core-shell structure had the weight ratio of shell to core of about 1. The comparative catalyst CAT D could be prepared using the preparation process of the catalyst having core-shell structure as described above. Pyrrolidine was used as the structure-directing agent of the zeolite. The first solution comprising sodium silicate, pyrrolidine, and water and the second solution comprising aluminium sulfate, concentrated sulfuric acid, and water were prepared. The zeolite catalyst being used as the core was the comparative catalyst CAT B having the mole ratio of silica to alumina of about 143. While said ferrierite zeolite shell was prepared at the mole ratio of silica to alumina of about 60.

Comparative Catalyst CAT E

[0120] The comparative catalyst CAT E was the catalyst having core-shell structure, wherein the shell was ZSM-5 zeolite having hierarchical pores and said core-shell structure had the weight ratio of shell to core of about 1. The comparative catalyst CAT E could be prepared using the preparation process of the catalyst having core-shell structure as described above. Tetrapropylammonium hydroxide (TPAOH) was used as the structure-directing agent of the zeolite and cetyltrimethylammonium bromide (CTAB) was used as the agent for making hierarchical pores. The first solution comprising tetraethyl orthosilicate (TEOS) and the second solution comprising aluminium hydroxide, tetrapropylammonium hydroxide, sodium hydroxide, cetyltrimethylammonium bromide, and water were prepared. The zeolite catalyst being used as the core was the comparative catalyst CAT A having the mole ratio of silica to alumina of about 61. While said ZSM-5 zeolite shell having hierarchical pores was prepared at the mole ratio of silica to alumina of about 160.

Comparative Catalyst CAT F

[0121] The comparative catalyst CAT F was the catalyst having core-shell structure, wherein the shell was the conventional silicalite having silica to alumina ratio of infinity (SiO.sub.2/Al.sub.2O.sub.3=) and said core-shell structure had the weight ratio of shell to core of about 1. The comparative catalyst CAT F could be prepared using the preparation process of the catalyst having core-shell structure as described above. Tetrapropylammonium hydroxide (TPAOH) was used as the structure-directing agent of the zeolite. The first solution comprising silica and tetrapropylammonium hydroxide solutions and the second solution comprising sodium hydroxide were prepared. The zeolite catalyst being used as the core was the comparative catalyst CAT A having the mole ratio of silica to alumina of about 61.

Comparative Catalyst CAT G

[0122] The comparative catalyst CAT G was the catalyst having core-shell structure, wherein the shell was silicalite having hierarchical pores that was arranged in nano-sheet and having silica to alumina ratio of infinity (SiO.sub.2/Al.sub.2O.sub.3=) and said core-shell structure had the weight ratio of shell to core of about 4. The comparative catalyst CAT G could be prepared using the preparation process of the catalyst having core-shell structure as described above. Tetrabutylphosphonium hydroxide (TBPOH) was used as the structure-directing agent of the zeolite and nanosheet structure. The first solution comprising tetraethyl orthosilicate (TEOS) and the second solution comprising tetrabutylphosphonium hydroxide, sodium hydroxide, and water were prepared. The zeolite catalyst being used as the core was the comparative catalyst CAT A having the mole ratio of silica to alumina of about 61.

Comparative Catalyst CAT H

[0123] The comparative catalyst CAT H was the catalyst having core-shell structure, wherein the shell was the conventional silicalite having silica to alumina ratio of infinity (SiO.sub.2/Al.sub.2O.sub.3=) and said core-shell structure had the weight ratio of shell to core of about 1. The comparative catalyst CAT H could be prepared using the preparation process of the catalyst having core-shell structure as described above. Tetrapropylammonium hydroxide (TPAOH) was used as the structure-directing agent of the zeolite. The first solution comprising silica and tetrapropylammonium hydroxide solutions and the second solution comprising sodium hydroxide were prepared. The zeolite catalyst being used as the core was the comparative catalyst CAT B having the mole ratio of silica to alumina of about 143.

Comparative Catalyst CAT I

[0124] The comparative catalyst CAT I was the catalyst having core-shell structure, wherein the shell was the conventional silicalite having silica to alumina ratio of infinity (SiO.sub.2/Al.sub.2O.sub.3=) and said core-shell structure had the weight ratio of shell to core of about 1. Moreover, the catalyst was further comprised manganese in the amount of about 5% by weight when comparing with the weight of zeolite core. The comparative catalyst CAT I could be prepared using the preparation process of the catalyst having core-shell structure as described above. Tetrapropylammonium hydroxide (TPAOH) was used as the structure-directing agent of the zeolite. The first solution comprising silica and tetrapropylammonium hydroxide solutions and the second solution comprising sodium hydroxide were prepared. The zeolite catalyst being used as the core was the catalyst prepared from the preparation process of the ferrierite zeolite catalyst comprising manganese (Mn) as described above. Said ferrierite zeolite catalyst comprising manganese had the mole ratio of silica to alumina of about 72.

Catalyst According to the Invention CAT 1

[0125] The catalyst according to the invention CAT 1 was the catalyst having core-shell structure, wherein the shell was silicalite having hierarchical pores that was arranged in nano-sheet and having silica to alumina ratio of infinity (SiO.sub.2/Al.sub.2O.sub.3=) and said core-shell structure had the weight ratio of shell to core of about 1. The catalyst according to the invention CAT 1 could be prepared using the preparation process of the catalyst having core-shell structure as described above. Tetrabutylphosphonium hydroxide (TBPOH) was used as the structure-directing agent of the zeolite and nanosheet structure. The first solution comprising tetraethyl orthosilicate (TEOS) and the second solution comprising tetrabutylphosphonium hydroxide, sodium hydroxide, and water were prepared. The zeolite catalyst being used as the core was the comparative catalyst CAT A having the mole ratio of silica to alumina of about 61.

Catalyst According to the Invention CAT 2

[0126] The catalyst according to the invention CAT 2 was the catalyst having core-shell structure, wherein the shell was silicalite having hierarchical pores that was arranged in nano-sheet and having silica to alumina ratio of infinity (SiO.sub.2/Al.sub.2O.sub.3=) and said core-shell structure had the weight ratio of shell to core of about 2. The catalyst according to the invention CAT 2 could be prepared using the preparation process of the catalyst having core-shell structure as described above. Tetrabutylphosphonium hydroxide (TBPOH) was used as the structure-directing agent of the zeolite and nanosheet structure. The first solution comprising tetraethyl orthosilicate (TEOS) and the second solution comprising tetrabutylphosphonium hydroxide, sodium hydroxide, and water were prepared. The zeolite catalyst being used as the core was the comparative catalyst CAT A having the mole ratio of silica to alumina of about 61.

Catalyst According to the Invention CAT 3

[0127] The catalyst according to the invention CAT 3 was the catalyst having core-shell structure, wherein the shell was silicalite having hierarchical pores that was arranged in nano-sheet and having silica to alumina ratio of infinity (SiO.sub.2/Al.sub.2O.sub.3=) and said core-shell structure had the weight ratio of shell to core of about 2. The catalyst according to the invention CAT 3 could be prepared using the preparation process of the catalyst having core-shell structure as described above. Tetrabutylphosphonium hydroxide (TBPOH) was used as the structure-directing agent of the zeolite and nanosheet structure. The first solution comprising tetraethyl orthosilicate (TEOS) and the second solution comprising tetrabutylphosphonium hydroxide, sodium hydroxide, and water were prepared. The zeolite catalyst being used as the core was the ZSM-5 zeolite catalyst prepared from the preparation process of the ZSM-5 zeolite catalyst as described above. Said ZSM-5 zeolite catalyst had the mole ratio of silica to alumina of about 104.

Catalyst According to the Invention CAT 4

[0128] The catalyst according to the invention CAT 4 was the catalyst having core-shell structure, wherein the shell was silicalite having hierarchical pores that was arranged in nano-sheet and having silica to alumina ratio of infinity (SiO.sub.2/Al.sub.2O.sub.3=) and said core-shell structure had the weight ratio of shell to core of about 1. The catalyst according to the invention CAT 4 could be prepared using the preparation process of the catalyst having core-shell structure as described above. Tetrabutylphosphonium hydroxide (TBPOH) was used as the structure-directing agent of the zeolite and nanosheet structure. The first solution comprising tetraethyl orthosilicate (TEOS) and the second solution comprising tetrabutylphosphonium hydroxide, sodium hydroxide, and water were prepared. The zeolite catalyst being used as the core was the comparative catalyst CAT B having the mole ratio of silica to alumina of about 143.

Catalyst According to the Invention CAT 5

[0129] The catalyst according to the invention CAT 5 was the catalyst having core-shell structure, wherein the shell was silicalite having hierarchical pores that was arranged in nano-sheet and having silica to alumina ratio of infinity (SiO.sub.2/Al.sub.2O.sub.3=) and said core-shell structure had the weight ratio of shell to core of about 2. The catalyst according to the invention CAT 5 could be prepared using the preparation process of the catalyst having core-shell structure as described above. Tetrabutylphosphonium hydroxide (TBPOH) was used as the structure-directing agent of the zeolite and nanosheet structure. The first solution comprising tetraethyl orthosilicate (TEOS) and the second solution comprising tetrabutylphosphonium hydroxide, sodium hydroxide, and water were prepared. The zeolite catalyst being used as the core was the comparative catalyst CAT B having the mole ratio of silica to alumina of about 143.

Catalyst According to the Invention CAT 6

[0130] The catalyst according to the invention CAT 6 was the catalyst having core-shell structure, wherein the shell was silicalite having hierarchical pores that was arranged in nano-sheet and having silica to alumina ratio of infinity (SiO.sub.2/Al.sub.2O.sub.3=) and said core-shell structure had the weight ratio of shell to core of about 1. Moreover, the catalyst was further comprised manganese in the amount of about 5% by weight when comparing with the weight of zeolite core. The catalyst according to the invention CAT 6 could be prepared using the preparation process of the catalyst having core-shell structure as described above. Tetrabutylphosphonium hydroxide (TBPOH) was used as the structure-directing agent of the zeolite and nanosheet structure. The first solution comprising tetraethyl orthosilicate (TEOS) and the second solution comprising tetrabutylphosphonium hydroxide, sodium hydroxide, and water were prepared. The zeolite catalyst being used as the core was the catalyst prepared from the preparation process of the ferrierite zeolite catalyst comprising manganese (Mn) as described above. Said ferrierite zeolite catalyst comprising manganese had the mole ratio of silica to alumina of about 72.

Catalyst According to the Invention CAT 7

[0131] The catalyst according to the invention CAT 7 was the catalyst having core-shell structure, wherein the shell was silicalite having hierarchical pores that was arranged in nano-sheet and having silica to alumina ratio of infinity (SiO.sub.2/Al.sub.2O.sub.3=) and said core-shell structure had the weight ratio of shell to core of about 1. Moreover, the catalyst was further comprised manganese in the amount of about 5% by weight when comparing with the weight of zeolite core. The catalyst according to the invention CAT 7 could be prepared using impregnation method of magnesium sulfate onto the catalyst according to the invention CAT 1 and then calcination at the temperature about 500 to 600 C.

Testing for the Catalytic Cracking of Hydrocarbon Having 4 to 7 Carbon Atoms to Produce Light Olefins

[0132] The testing for the catalytic cracking of hydrocarbon having 4 to 7 carbon atoms for light olefins production might be performed using the following conditions.

[0133] The catalytic cracking was performed in the fixed-bed reactor using about 0.3 g of the catalyst. Prior to the reaction, the catalyst was contacted with hydrogen gas having the flow rate of about 50 mL/min for about 3 hours. Then, the hydrocarbon having 4 carbon atom, that is 99% iso-butane, were fed at the flow rate of about 10 mL/min together with nitrogen gas at the flow rate of 20 mL/min. The reaction was employed at the temperature about 600 to 650 C. at the atmospheric pressure and the weight hourly space velocity (WHSV) of about 5 per hour.

[0134] Then, the reaction was monitored by measuring the conversion of the reactant and the formation of the product composition after passing the catalyst at different reaction times using gas chromatography connected to the outlet of the fixed-bed reactor. The detector used was flame ionization detector (FID) and the column used was the HP Innowax and a HP-Plot Al.sub.2O.sub.3 capillary column for the separation and analysis of each composition of said substances.

[0135] From FIG. 1 that shows the characteristics of crystalline structure tested by scanning electron microscope (SEM) technique at accelerating voltage of 20 kV using SEI mode, it shows that the comparative catalyst CAT A used as the core in the catalyst according to the invention had flower shape-like particle arrangement and had the porosity which was different from the commercial ferrierite zeolite, whereas the comparative catalyst CAT B used as the core in the catalyst according to the invention had hierarchical pores and clearly organized porosity which was different from the conventional ZSM-5 zeolite. When considering the catalysts according to the invention having core-shell structure, it was found that the surface of the catalysts according to the invention had hierarchical pores and beautiful and organized porosity more than the comparative catalysts.

[0136] From the testing of the specific surface area of micropores, mesopores, and macropores as shown in Table 1, it was found that the catalysts according to the invention had the proportion of volume of mesopores and macropores to the total pore volume in the range from 0.35 to 0.90. When comparing with the comparative catalyst having core-shell structure in which the shell was the conventional silicalite, it was found that the catalyst according to the invention having core-shell structure in which the shell was silicalite having hierarchical pores that was arranged in nano-sheet had the proportion of volume of mesopores and macropores to the total pore volume more than the comparative catalyst having core-shell structure in which the shell was the conventional silicalite.

[0137] When considering the pore size distribution analyzed by Barrett-Joyner-Halenda adsorption (BJH adsorption), it was found that the results of pore size distribution are shown in FIG. 2 and Table 2. The catalyst according to the invention had clearly different distribution of mesopores and macropores from the comparative catalyst. The catalysts according to the invention had the pore size distribution of mesopores having pore size in the range of 2 to 5 nm mostly and further comprised mesopores having pore size in the range of 5 to 8 nm and in the range of 8 to 18 nm. The catalyst according to the invention gave the proportion of volume of mesopores having pore size in each range to the total pore volume more than the comparative catalyst.

[0138] To study the effect of the structure of catalyst having core-shell structure comprising zeolite core selected from ferrierite, ZSM-5, or mixture thereof, and silicalite shell having MFI structure on the efficacy of light olefins production from catalytic cracking of hydrocarbon having 4 to 7 carbon atoms, the catalysts according to the invention were studied and compared with the comparative catalysts. Results were shown in FIG. 3 to FIG. 6.

[0139] FIG. 3 shows the conversion of the reactant and the selectivity to each product of different catalysts in the catalytic cracking of butane. It was found that the catalyst according to the invention gave better efficacy than the comparative samples, providing both of high selectivity to light olefins and high conversion of the reactant.

[0140] FIG. 4 shows the conversion of the reactant and the selectivity to each product of the catalysts having core-shell structure in which the zeolite core was the ferrierite comparing with the comparative sample catalysts in the catalytic cracking of butane. It was found that the catalysts according to the invention gave better efficacy than the comparative samples, providing increased selectivity to light olefins. In addition, the weight ratio of shell to core was the factor affecting the conversion of the reactant. It could help to increase the conversion of the reactant without decreasing the selectivity to light olefins.

[0141] FIG. 5 shows the conversion of the reactant and the selectivity to each product of the catalysts having core-shell structure in which the zeolite core was the ZSM-5 comparing with the comparative sample catalysts in the catalytic cracking of butane. It was found that the catalysts according to the invention gave better efficacy than the comparative samples, providing higher selectivity to light olefins. In addition, the mole ratio of silica to alumina of ZSM-5 and the weight ratio of shell to core were the factors affecting the conversion of the reactant. This could help to increase the conversion of the reactant.

[0142] FIG. 6 shows the conversion of the reactant and the selectivity to each product of the catalysts having the manganese (Mn) addition in different ways comparing with the comparative sample catalyst in the catalytic cracking of butane. It was found that the catalysts according to the invention showed increased selectivity to light olefins when comparing with the comparative sample.

[0143] From the experimental results above, it could be said that the catalysts having core-shell structure according to the invention gave high conversion of the reactant and especially high selectivity to light olefins product for the catalytic cracking of hydrocarbon having 4 to 7 carbon atoms as stated in the objective of this invention.

TABLE-US-00001 TABLE 1 Mole ratio of silica to alumina, specific surface area, and porosity properties of the comparative samples and samples according to the invention BET External Proportion specific specific of volume of Mole surface surface mesopores and ratio of area area macropores to silica to (S.sub.BET) (S.sub.ext) total pore Sample alumina (m.sup.2/g) (m.sup.2/g) volume CAT A 61 297 60 0.38 CAT B 143 436 83 0.37 CAT C 359 117 0.82 CAT E 87 364 47 0.47 CAT F 116 424 58 0.50 CAT G 484 580 124 0.57 CAT H 301 30 0.49 CAT I 136 368 70 0.70 CAT 1 130 592 177 0.66 CAT 2 173 534 100 0.45 CAT 3 241 610 100 0.40 CAT 4 352 485 179 0.70 CAT 5 528 532 134 0.61 CAT 6 220 514 145 0.66 CAT 7 173 486 112 0.64 Note: BET specific surface area (S.sub.BET) and total pore volume (V.sub.total) were obtained from N.sub.2 physisorption; S.sub.ext: external specific surface area; V.sub.meso+macro: mesopore volume and macropore volume were calculated from the BJH adsorption analysis.

TABLE-US-00002 TABLE 2 Pore size distribution analyzed by Barrett-Joyner- Halenda adsorption (BJH adsorption) of the comparative samples and samples according to the invention Volume of Volume of Volume of pores having pores having pores having pore size of pore size of pore size of 2-5 nm to 5-8 nm to 8-18 nm to total pore total pore total pore Sample volume volume volume CAT F 0.08 0.06 0.08 CAT G 0.13 0.08 0.09 CAT H 0.05 0.04 0.09 CAT I 0.06 0.07 0.08 CAT 1 0.16 0.08 0.12 CAT 2 0.15 0.09 0.06 CAT 3 0.15 0.07 0.07 CAT 4 0.17 0.12 0.19 CAT 5 0.13 0.12 0.14 CAT 6 0.12 0.10 0.18 CAT 7 0.10 0.09 0.14

[0144] Best mode or preferred embodiment of the invention is as provided in the description of the invention.