Fluidized cracking process for increasing olefin yield and catalyst composition for same

Abstract

This paper discloses an improved process and catalyst composition for cracking hydrocarbons in a fluidized bed cracking process. The process utilizes a regenerated cracking feedstock with a minimum carbon content. The regenerated catalyst comprises a catalyst / additive composition containing a pentasil zeolite, iron oxide, and a phosphorus compound. According to this disclosure, the catalyst / additive contains a controlled amount of iron oxide, which maintains the carbon in an oxidized state by keeping the amount of carbon in the regenerated catalyst feedstock low. In this manner, the catalyst composition has been found to significantly improve the production and selectivity of light hydrocarbons such as propylene.

Description

[Technical Field] Fluid catalytic cracking (FCC) generally refers to the process of converting high-boiling-point, high-molecular-weight hydrocarbon compounds in hydrocarbon feedstocks (such as crude oil) into higher-value products (such as gasoline, diesel, and light olefins). During the process, the hydrocarbon feedstock is fed into a fluidized reactor and combined with a catalyst at high temperatures, causing the high-molecular-weight hydrocarbons to be converted into lower-molecular-weight products. [Previous Technology] The product streams produced by fluid catalytic cracking processes typically contain the majority of hydrocarbons. The amount of light olefins (such as propylene and ethylene) produced during the process can vary depending on various factors. Propylene, as a crucial feedstock for the manufacture of a wide range of chemicals and polymers, has seen a significant increase in demand recently. Despite substantial investments in propylene production capacity, global supply still lags behind demand for light olefins. For example, the use of polypropylene polymers remains one of the fastest-growing synthetic materials for both novel and existing applications. In view of the above, those skilled in the art have attempted to modify fluid catalytic cracking processes to improve the yield of light olefins, such as propylene. For example, U.S. Patent Publication No. 2009 / 0134065 (incorporated herein by reference) describes a fluidized catalyst composition that increases olefin yield compared to other commercially available catalysts. The catalyst composition described in application '065 has made considerable progress in the field of producing light olefins, such as propylene. Light olefins (such as propylene and ethylene) are essential feedstocks for the manufacture of a wide range of chemicals and products, including various polymers. Despite substantial investments in light olefin production capacity, supply still falls short of demand. Therefore, the design of FCC processes and catalyst and / or additive compositions requires further improvement to deliver increased yields and selectivity of light olefin hydrocarbon products. [Summary of the Invention] This disclosure relates to an improved process for producing light olefin products in a fluid catalytic cracking process, wherein the process increases the yield of light olefins (C2- to C4-olefins) compared to previously commercially available FCC processes. Advantageously, the process also increases the selectivity for C2- and C3-olefins. The invention also relates to an improved FCC catalyst and / or additive composition, and its use in an FCC process to increase the yield of light olefins and the selectivity of C2- and C3-olefins over C4-olefins. Therefore, this invention relates to an inventive FCC process comprising: (a) introducing a hydrocarbon feedstock into the reaction zone of a fluid catalytic cracking unit (“FCCU”), the fluid catalytic cracking unit comprising a reactor (also referred to as a “riser”), a stripper, and a regenerator, wherein the feedstock is characterized by having an initial boiling point from about 30°C and an endpoint of about 850°C; (b) catalytically cracking the feedstock in the riser at a temperature of about 400°C to about 700°C by contacting the feedstock with a recycled stock of regenerated catalyst, the regenerated catalyst comprising a five-membered ring (pentasil) catalyst / additive composition comprising: (i) a five-membered ring zeolite having a silica / alumina architecture, (ii) at least 5.0% by weight of phosphorus (P₂O₅), and (iii) ... (c) Using stripping steam in a stripper to strip the recycled catalyst particles in the catalyst stock to remove some hydrocarbon material or coke; (d) Recovering the stripped hydrocarbons from the stripper and recycling the stripped catalyst particles to the regenerator; (e) Regenerating the cracking catalyst particles in the regeneration zone by burning off substantial amounts of coke on the catalyst particles at a temperature sufficient to produce a carbon content of about 0.30% or less of the total regenerated catalyst stock; (f) Recycling the regenerated catalyst stock to the reactor to continue the cracking process. The catalyst / additive composition containing a five-membered ring structure can be used as the sole catalyst or as an additive in the catalyst stock of the FCC process of the present invention. Furthermore, the catalyst / additive composition containing a five-membered ring structure can be used in combination with separate particles of conventional FCC catalysts that do not contain five-membered ring zeolites (e.g., FCC catalysts containing faujasite zeolite). As stated above, the process disclosed herein has been found to significantly increase the yield of light olefins. For example, the product stream may contain propylene in an amount from about 4.5% by weight to about 40% by weight. The product stream may also contain ethylene in an amount from about 0.5% by weight to about 25% by weight. This disclosure also relates to a regenerated fluid catalytic catalyst composition comprising the five-membered ring structure catalyst / additive composition, which, when recycled during a fluidized cracking process, produces hydrocarbon products with increased yield and selectivity of light olefins. In one embodiment, the five-membered ring catalyst / additive composition used for the regenerated catalyst stock comprises at least 10 wt% of a five-membered ring zeolite (such as ZSM-5), about 4.0 wt% or less (preferably about 2.5 wt% or less) of iron oxide, and about 20 wt% (preferably about 19 wt% or less, more preferably about 18 wt% or less, but at least about 5 wt% or more) of phosphorus (measured as P2O5). The regenerated catalyst stock used in the process of the present invention contains, based on the total catalyst stock, less than about 0.30% by weight, preferably less than about 0.25% by weight, more preferably less than about 0.20% by weight, even more preferably less than about 0.15% by weight, most preferably less than about 0.1%, but in any case, contains carbon in an amount not less than about 0.005% by weight. Other features and characteristics disclosed herein will be discussed in more detail below.

Implementation Method

[2010] . Comparative Example 1: Comparative catalysts 1 and 3 were prepared without the addition of iron compounds. Dry ZSM-5 powder was slurried in water. Alumina, kaolin clay, and concentrated (85%) H3PO4 were added to this slurry. The slurry was mixed in a high-shear mixer, ground in a Drais media mill, and then spray-dried. The Bowen spray dryer was operated at an inlet temperature of 400°C and an outlet temperature of 150°C. The spray-dried catalyst was calcined at 593°C for 40 minutes. The formulations and properties of comparative catalysts 1 and 3 are shown in Tables 1 and 2. All Fe2O3 in the catalysts was derived from clay. Comparative Example 2 Catalyst 2 (containing 4.6% Fe2O3) was prepared by the following procedure: Dry ZSM-5 powder was slurried in water. Alumina, kaolin clay, FeCl2·4H2O powder, and concentrated (85%) H3PO4 were added to this slurry. The slurry was mixed in a high-shear mixer, ground in a Drais media mill, and then spray-dried. The Bowen spray dryer was operated at an inlet temperature of 400°C and an outlet temperature of 150°C. The spray-dried catalyst was calcined at 593°C for 40 minutes. The formulations of catalyst 2 and the resulting properties are compared in Table 1. Example 1: 40% ZSM-5 additive, containing 0.6% to 3.4% Fe2O3. A series of ZSM-5 catalysts with 0.6% to 3.4% Fe2O3 were prepared by the following procedure: Dry ZSM5 powder was slurried in water. Alumina, kaolin clay, FeCl2·4H2O powder, and concentrated (85%) H3PO4 were added to this slurry. The slurry was mixed in a high-shear mixer, ground in a Drais media mill, and then spray-dried. The Bowen spray dryer was operated at an inlet temperature of 400°C and an outlet temperature of 150°C. The spray-dried catalyst was calcined at 593°C for 40 minutes. The formulations of catalysts A to C and the resulting properties are shown in Table 1. [Table 1] Comparison of samples Catalyst 1 Catalyst A Catalyst B Catalyst C Comparison of catalyst 2 Five-membered ring zeolite, wt% 40 40 40 40 40 Alumina, wt% 6 6 6 6 6 P2O5, wt% 13 14 15 16 17 Added Fe2O3, wt% 0 1 2 3 4 Clay, wt% 41 39 37 35 33 ABD, g / cm3 0.70 0.70 0.70 0.70 0.71 Davidson abrasion index (DI) 5 8 7 6 6 Al2O3, % 26 25 24 23 22 Na2O % 0.2 0.2 0.2 0.2 0.2 P2O5, % 13 14 15 16 17 Fe2O3, % 0.6 1.6 2.6 3.4 4.6 Properties after deactivation: CPS steam treatment at 1480 F, SA, m2 / g 131 110 96 75 60 Properties after deactivation: Hydrothermal steam treatment at 1500 F (4 hours, 100% steam) SA, m2 / g 125 121 119 122 124 Example 2: 55% ZSM-5 additive with 0.4 to 3.1% Fe2O3 A series of ZSM-5 catalysts with 0.4% to 3.1% Fe2O3 were prepared by the following procedure: Dry ZSM-5 powder was slurried in water. Concentrated (85%) H3PO4, soluble iron salts, alumina, and kaolin clay were added to this slurry. The slurry was mixed in a high-shear mixer, ground in a Drais media mill, and then spray-dried. The Bowen spray dryer was operated at an inlet temperature of 400°C and an outlet temperature of 150°C. The spray-dried catalysts were calcined at 593°C for 2 hours. The formulations of the catalysts (catalysts D to H) and the resulting properties are shown in Table 2. [Table 2] Comparison of Samples Catalyst 3 Catalyst D Catalyst E Catalyst F Catalyst G Catalyst H Five-membered ring zeolite, wt% 55 55 55 55 55 55 Alumina, wt% 6 6 6 6 6 6 P2O5, wt% 13.5 13.7 13.9 14.1 14.4 15.3 Added Fe2O3, wt% 0 0.3 0.6 1 1.5 3 Clay, wt% 25.5 25 24.5 23.9 23.1 20.7 ABD, g / cm3 0.70 0.70 0.70 0.70 0.71 0.72 Davidson abrasion index (DI) 4 7 7 6 4 6 Al2O3, % 19.1 19.3 18.9 18.6 18.4 18.5 P2O5, % 13.9 14.1 14.2 14.6 14.9 15.2 Fe2O3, % 0.4 0.6 0.8 1.2 1.7 3.1 Properties after deactivation: SA treated with CPS steam at 1480 F, m2 / g 202 199 198 188 158 131 Properties after deactivation: SA treated with hydrothermal steam at 1500 F, m2 / g 198 196 195 196 190 188 Example 3: Catalyst steam stability during redox steam deactivation cycle. ZSM-5 catalysts A to H, containing iron oxide, and comparative catalysts 1, 2, and 3 were deactivated using the Cyclic Propylene Steaming (CPS) method (which includes a redox cycle) without any contaminant metals. The CPS method is described in D. Wallenstein, RH Harding, JR D Nee, and LT Boock, "Recent Advances in the Deactivation of FCC Catalysts by Cyclic Propylene Steaming in the Presence and Absence of Contaminant Metals," Applied Catalysis A, General 204 (2000) 89-106. The surface areas of the deactivated catalysts are shown in Tables 1 and 2. The data, plotted in Figure 1, show that the redox cycle has an adverse effect on surface area stability when the catalyst contains a high iron content. This is particularly true above 4% Fe₂O₃, where a >50% loss of surface area was observed compared to the baseline comparative catalysts 1 and 3 (without any added Fe₂O₃). Example 4: Catalyst vapor stability during hydrothermal deactivation. ZSM-5 catalysts D to H and comparative catalyst 3 were deactivated by hydrothermal deactivation using 100% steam at 816°C for 24 hours. Figure 2 shows the surface area of ​​the catalysts after hydrothermal deactivation using 100% steam at 816°C for 24 hours. The data shows that when redox CPS steam treatment was not used, only a very slight loss of surface area occurred in the presence of Fe2O3. Example 5: Performance Tests After Redox Steam Deactivation Cycle Catalysts 1 and 2, and catalysts A through C (deactivated by CPS in Example 3), were compared with Aurora™ cracking catalyst (a commercially available FCC catalyst from WR Grace & Co.-Conn.) as blends. ZSM-5 additive was blended with steam-deactivated Aurora cracking catalyst at 5 wt% and tested in an ACE Model AP Fluid Bed Microactivity unit at 527°C. Several runs were performed on each catalyst using catalyst-to-oil ratios between 3 and 10. The catalyst-to-oil ratio was varied by changing the catalyst weight while keeping the feed weight constant. The feed weight used for each run was 1.5 g and the feed injection rate was 3.0 g / min. ACE hydrocarbon yields were interpolated to a constant conversion for comparison of the catalysts. The feed properties are shown in Table 4. ACE interpolation data (Table 5) show that catalysts A to C of the present invention exhibit improved propylene yields compared to catalysts 1 and 2 with low (0.6% Fe2O3) and high (4.6% Fe2O3) iron content. Example 6: Effect of oxidation versus reduction of Fen+ on the yield of light olefins. Comparative catalysts 1 and 2 (deactivated by hydrothermal steam at 816°C for 24 hours in 100% steam) were tested after deactivation (comparative catalysts 1 and 2) and after reduction in hydrogen at 500°C for 2 hours (comparative catalyst 1 (reduction) and comparative catalyst 2 (reduction)). Fe2O3 was mainly in an oxidized state after deactivation, but in a more reduced state after reduction with hydrogen. Comparative catalysts 1, 1 (reduction), 2, and 2 (reduction) were tested as blends with Aurora™ cracking catalyst (a commercially available FCC catalyst from WR Grace & Co.-Conn.). The test conditions were the same as those outlined in Example 5. ZSM5 additive was blended with the steam-deactivated Adora cracking catalyst at a content of 5 wt%. ACE hydrocarbon yields were interpolated to a constant conversion to compare the catalysts. The properties of the feedstock are shown in Table 4. ACE data (Table 6) show that the low-iron comparative catalyst 1, deactivated under both oxidative and reducing conditions, exhibits very similar propylene yields. However, comparisons with the high-iron comparative catalyst 2 show that the sample deactivated under oxidative conditions has a significantly better propylene yield than the comparative catalyst 2 reduced in hydrogen. Comparative catalyst 2 (reduction) exhibits similar performance to comparative catalyst 1. This indicates that iron needs to be in an oxidized state to enhance the performance of light olefins.[Table 4] Feed Properties: API Specific Gravity 24.7 K Factor 12.01 Sulfur 0.35 Total Nitrogen 0.14 Conradson Carbon 0.32 Simulated Distillation, Volume % IBP 275℃ 10% 366℃ 30% 412℃ 50% 553℃ 70% 498℃ 90% 563℃ FBP 682℃ [Table 5] Comparison of Catalysts Catalyst 1 Catalyst A Catalyst B Catalyst C Catalyst 2 Conversion 75 75 75 75 75 Catalyst to Oil 6.1 5.7 6.3 6.1 5.5 Ethylene, wt% 0.81 1.05 1.15 0.91 0.84 Propylene, wt% 9.0 10.2 10.7 10.1 8.7 C4-Olefins, wt% 9.0 9.4 9.8 9.6 8.7 Moisture, wt% 28.0 30.2 31.9 29.8 27.1 Gasoline, wt% 44.0 41.8 40.0 42.3 45.1 Light Cycle Oil, wt% 19.3 19.2 19.4 19.4 19.3 Bottom Material, wt% 5.7 5.8 5.6 5.6 5.7 Coal Coke, wt% 3.0 3.0 3.1 2.9 2.8 [Table 6] Comparison Comparison Comparison Comparison Catalyst 1 Catalyst 1 (Reduction) Catalyst 2 Catalyst 2 (Reduction) Conversion Rate 76 76 76 76 Catalyst to Oil Ratio 6.1 6.1 6.0 6.2 Ethylene, wt% 0.7 0.7 1.3 0.8 Total Dry Gas, wt% 1.7 1.7 2.2 1.9 Propylene, wt% 8.2 8.3 10.8 8.0 Total C4='s, wt% 9.0 9.2 9.8 8.6 Total moisture, wt% 26.2 26.6 31.0 26.3 C5+ gasoline, wt% 47.1 46.7 42.3 46.6 LCO, wt% 18.4 18.4 18.2 18.5 Substrate, wt% 5.6 5.6 5.8 5.5 Coal char, wt% 2.7 2.6 2.7 3.0 Example 7: The effect of carbon on the performance of regenerated catalysts. Catalysts 3 and F were compared and hydrothermally steam-treated in 100% steam for 24 hours. The steam-treated catalysts were then blended with a laboratory-deactivated FCC base catalyst at a content of 5 wt%. The catalyst blend was then coked in a pilot plant. The measured coke content on the catalyst was >0.6 wt%. The coked catalyst was then calcined at different temperatures to achieve the target coke content on the catalyst. The regenerated catalyst was then evaluated for propylene activity in ACE. Data showed that samples modified with Fe2O3 had significantly higher propylene activity than samples without Fe2O3 modification when carbon content on the regenerated catalyst was below 0.30 wt%. Above 0.30 wt% carbon on the catalyst, propylene activity decreased rapidly, as shown in Figure 3. Example 8: Advantages of C2= and C3= selectivity of the catalyst of the present invention. Catalysts 2 and F were compared and hydrothermally steam-treated in 100% steam for 24 h. The steam-treated catalysts were then blended with a laboratory-deactivated FCC base catalyst at 5 wt%. The catalyst blend was then coked in a pilot plant. The measured coke content on the catalyst was >0.6 wt%. The coked catalyst was then calcined at different temperatures to achieve the target coke content (between 0.05% and <0.5%). The regenerated catalyst was then evaluated for ethylene plus propylene activity and selectivity in ACE. The data in Figure 4 show that, at all coke contents on the catalysts, the Fe2O3-modified catalyst exhibited higher selectivity for ethylene plus propylene under constant total dry gas (hydrogen plus C1 to C2 hydrocarbons) compared to the unmodified sample. Higher selectivity for C2- and C3-olefins is particularly important for units with limited wet gas compressor capacity. This allows refineries to maximize profitability by producing more C2- and C3-olefins under constant dry gas conditions. [Symbol Explanation] none [Simplified Explanation of the Diagram] The full and enabling disclosures are further detailed in the remainder of this specification, in which: [Figure 1] shows the effect of iron oxide content in the catalyst on surface area stability under cyclic propylene steaming (CPS) conditions. A loss of surface area stability is observed with increasing iron oxide content in the catalyst. [Figure 2] shows the surface area of ​​the iron oxide-modified catalyst after 24 hours of hydrothermal deactivation. No loss of surface area is observed with increasing iron oxide content in the catalyst. [Figure 3] shows that with less than 0.30 wt% carbon on the regenerated catalyst, the iron oxide-modified sample exhibits higher propylene activity compared to the unmodified sample. With more than 0.30 wt% carbon on the catalyst, propylene activity decreases significantly. [Figure 4] shows that, at all coke contents on the catalyst, the iron oxide-modified catalyst exhibits higher selectivity for ethylene plus propylene under constant total moisture (hydrogen plus C1 to C4 hydrocarbons) compared to the base catalyst without iron oxide in the catalyst composition.

Claims

1. A fluidized bed cracking process comprising: contacting a hydrocarbon feedstock with a recycled stock of a regenerated fluidized bed cracking catalyst to form a product stream, wherein the regenerated fluidized bed cracking catalyst has a regenerated catalyst composition having a carbon content in the range of about 0.005% by weight to about 0.30% by weight based on the total stock of the regenerated catalyst composition, and comprising a pentasil-containing catalyst / additive composition comprising (a) a five-membered ring zeolite having a silica / alumina architecture; (b) about 0.7% to about 4.0% by weight of iron oxide; and (c) about 5.0% to about 20% by weight of phosphorus (measured as P2O5); wherein the amounts of iron oxide and phosphorus are based on the weight percentage of the pentasil-containing catalyst / additive composition.

2. The procedure of claim 1, wherein the regenerated catalyst composition has an average particle size in the range of about 20 to about 200 micrometers.

3. The procedure of claim 1 or 2, wherein the iron oxide is present in the five-membered ring catalyst / additive composition in an amount of about 0.9 to about 2.5% by weight of the five-membered ring catalyst / additive composition in the regenerated catalyst.

4. The procedure of claim 1 or 2, wherein the phosphorus (measured as P2O5) is present in the five-membered ring catalyst / additive composition in an amount of about 7% to about 18% by weight of the five-membered ring catalyst / additive composition in the regenerated catalyst.

5. The procedure of claim 4, wherein the phosphorus (measured as P2O5) is present in the five-membered ring catalyst / additive composition in an amount of about 9% by weight to about 18% by weight of the five-membered ring catalyst / additive composition.

6. The procedure of claim 1 or 2, wherein the regenerated catalyst composition contains carbon in an amount of about 0.01 to about 0.25% by weight of the regenerated fluid catalytic cracking catalyst stock.

7. The procedure of claim 1 or 2, wherein the feedstock is catalytically cracked in a reactor at a temperature of about 400°C to about 700°C.

8. The procedure of claim 1 or 2, wherein the catalyst / additive composition containing the five-membered ring structure contains the five-membered ring zeolite in an amount greater than about 45% by weight of the catalyst / additive composition containing the five-membered ring structure.

9. The procedure of claim 1 or 2, wherein the product stream contains propylene in an amount greater than about 4.5% by weight of the product stream.

10. The procedure of claim 1 or 2, wherein the product stream contains ethylene in an amount greater than about 0.5% by weight of the product stream.

11. The procedure of request item 1 or 2, wherein the five-membered ring structure zeolite is ZSM-5 or ZSM-11.

12. The procedure of claim 1 or 2, wherein the regenerated catalyst composition has a DI (Davison Attrition Index) of less than about 20.

13. The procedure of request item 1 or 2, wherein the five-membered ring structure zeolite system is ZSM-5.

14. The procedure of claim 1 or 2, wherein the regenerated fluid catalytic cracking catalyst stock further comprises separated particles of an additional cracking catalyst composition suitable for cracking hydrocarbons together with the five-membered ring catalyst / additive composition.

15. The procedure of claim 14, wherein the additional cracking catalyst composition comprises faujasite zeolite.

16. The procedure of claim 15, wherein the octagonal zeolite is selected from the group consisting of Y-type zeolite, REY, REUSY, and mixtures thereof.

17. The procedure as requested in item 1 or 2, wherein the fluidized cracking procedure is selected from one of the following groups: deep catalytic cracking (DCC), catalytic pyrolysis process (CPP), high-severity fluid catalytic cracking (HS-FCC), KBR catalytic olefins technology (K-COTTM), SuperflexTM, and ultimate catalytic cracking (UCC).

18. A regenerated catalyst composition in a circulating catalyst stock during a fluidized bed cracking process, the regenerated catalyst composition comprising a carbon content ranging from about 0.005 wt% to about 0.30 wt% based on the total catalyst stock, and a five-membered ring catalyst / additive composition comprising (a) a five-membered ring zeolite having a silica / alumina architecture; (b) about 0.7 to about 4.0 wt% iron oxide; and (c) about 5.0 to about 20 wt% phosphorus (measured as P2O5); wherein the amounts of phosphorus and iron oxide are based on the amounts of phosphorus and iron oxide in the five-membered ring catalyst / additive composition, respectively.

19. The regenerated catalyst composition of claim 18, wherein the regenerated catalyst composition has an average particle size in the range of about 20 to about 200 micrometers.

20. The regenerated catalyst composition of claim 18 or 19, wherein the iron oxide is present in the five-membered ring catalyst / additive composition in an amount of about 0.9 to about 3.0% by weight of the five-membered ring catalyst / additive composition in the regenerated catalyst composition.

21. The regenerated catalyst composition of claim 20, wherein the five-membered ring catalyst / additive composition contains the iron oxide in an amount of about 0.9 to about 2.5% by weight of the five-membered ring catalyst / additive composition in the regenerated catalyst composition.

22. The regenerated catalyst composition of claim 18 or 19, wherein the phosphorus (measured as P2O5) is present in the five-membered ring catalyst / additive composition in an amount of about 7% to about 18% by weight of the five-membered ring catalyst / additive composition.

23. The regenerated catalyst composition of claim 22, wherein the phosphorus (measured as P2O5) is present in the five-membered ring catalyst / additive composition in an amount of about 9% to about 18% by weight of the five-membered ring catalyst / additive composition.

24. The regenerated catalyst composition of claim 18, wherein the regenerated catalyst composition contains carbon in an amount ranging from about 0.01 to about 0.25% by weight in the recycled catalyst stock.

25. The regenerated catalyst composition of claim 18, wherein the catalyst / additive composition containing a five-membered ring structure comprises five-membered ring zeolite in an amount of about 10% to about 80% by weight of the catalyst / additive composition containing a five-membered ring structure.

26. The regenerated catalyst composition of claim 18 or 19, wherein the five-membered ring zeolite is ZSM-5 or ZSM-11.

27. The regenerated catalyst composition of claim 18 or 19, wherein the catalyst / additive composition containing a five-membered ring structure has a DI of less than about 20.

28. The regenerated catalyst composition of claim 18 or 19, wherein the regenerated catalyst composition further comprises an additional cracking catalyst composition.

29. The regenerated catalyst composition of claim 28, wherein the additional cracking catalyst composition comprises octahedral zeolite.

30. The regenerated catalyst composition of claim 29, wherein the octahedral zeolite is selected from the group consisting of Y-type zeolite, REY, REUSY, and mixtures thereof.

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