Fluidized catalytic cracking catalyst with low COKE selectivity

Abstract

Disclosed herein is a catalyst for use in fluid catalytic cracking comprising a zeolite material and a matrix material. In at least one embodiment, the matrix material comprises mullite at a mullite index of about 35% or greater. In at least one embodiment, a matrix surface area is less than about 150 m2 / g.

Description

FLUIDIZED CATALYTIC CRACKING CATALYST WITH LOW COKE SELECTIVITYFIELD OF THE DISCLOSURE

[0001] The present disclosure relates to petroleum refining catalysts and compositions thereof. In particular, the present disclosure relates to fluid catalytic cracking (FCC) catalysts and compositions thereof, methods of their preparation, and methods of their use.BACKGROUND OF THE DISCLOSURE

[0002] Fluid catalytic cracking (FCC) processes aim to catalytically break (crack) large organic molecules into smaller, more useful compounds. Zeolite-containing materials have been used for decades to catalyze FCC processes.

[0003] Practically, the ultimate efficiency of an FCC process is often limited by waste byproduct production, e.g. coke. Decreasing waste byproduct production per mass of useful product provides great economic advantages in terms of reactor active time, value of product produced between maintenance, conversion of feed, etc. There is a need to develop FCC catalyst exhibiting lower coke formation per amount of feed cracked than those currently available.SUMMARY OF THE DISCLOSURE

[0004] The following presents a simplified summary of various aspects of the present disclosure in order to provide a basic understanding of such aspects. This summary is not an extensive overview of the disclosure. It is intended to neither identify key or critical elements of the disclosure, nor delineate any scope of the particular embodiments of the disclosure or any scope of the claims. Its sole purpose is to present some concepts of the disclosure in a simplified form as a prelude to the more detailed description that is presented later.

[0005] In at least one aspect, an FCC catalyst comprises: a zeolite material present at less than about 35 wt% based on total weight of the catalyst; and a matrix material comprising mullite, wherein a matrix surface area (MSA) is less than about 150 m2 / g.

[0006] In at least one embodiment, a mullite index of the matrix material is about 30% or greater, from about 30% to about 40%, from about 40% to about 50%, from about 50% to about 64%.

[0007] In at least one embodiment, the mullite is milled to an average d90 particle size of less than about 5.0 pm, or from about 1.5 pm to about 3.5 pm, prior to forming the catalyst.

[0008] In at least one embodiment, a steamed MSA (SMSA) of the catalyst is less than about 100 m2 / g.

[0009] In at least one embodiment, a ratio of steamed zeolite surface area ZSA (SZSA) to SMSA is less than 1.5, less than 1, or less than 0.5.

[0010] In at least one embodiment, a total surface area (TSA) of the catalyst is less than about 400 m2 / g, less than about 350 m2 / g, less than about 300 m2 / g, less than about 250 m2 / g, or less than about 200 m2 / g.

[0011] In at least one embodiment, a steamed total surface area (STSA) of the catalyst is less than about 200 m2 / g.

[0012] In at least one embodiment, the zeolite material comprises or consists essentially of Y- zeolite.

[0013] In a further aspect, a method of forming a catalyst comprises: forming a slurry precursor from a matrix precursor comprising mullite; forming microspheres from the slurry precursor; and growing a zeolite on the microspheres via in situ crystallization.

[0014] In at least one embodiment, the matrix precursor comprises milled mullite having an average d90 particle size of less than about 5.0 pm, or from about 1.5 pm to about 3.5 pm.

[0015] In at least one embodiment, forming the slurry precursor comprises: combining the matrix precursor with a binder comprising boehmite and / or silicate, wherein the binder is present from about 1 wt% to about 20 wt% based on a total solids weight of the slurry precursor.

[0016] In at least one embodiment, forming the microspheres comprises calcining the microspheres at a temperature of greater than about 700 °C.

[0017] In at least one embodiment, growing a zeolite on the microspheres via in situ crystallization comprises heating the microspheres in the presence of zeolite seeds at a temperature and for a time sufficient to crystallize the zeolite.

[0018] In at least one embodiment, the time to crystallize the zeolite is greater than about 12 hours, and wherein the catalyst is substantially free of fine particles having a size of less than 20 pm.

[0019] In at least one embodiment, the fluid catalytic cracking catalyst further comprises one or more rare earth elements.

[0020] In at least one embodiment, the one or more rare earth elements comprise lanthanum present in the form of lanthanum oxide from about 0.5 wt% to about 3 wt%, or from about 0.5 wt% to about 2 wt%, or from about 0.5 wt% to about 1.25 wt%.

[0021] In at least one embodiment, a steamed unit cell size (SUCS) of the catalyst at least about 24.2 A, or at least about 24.3 A.

[0022] In a further aspect, a method of cracking a hydrocarbon feed comprises contacting a feed with the fluid catalytic cracking catalyst of any one of preceding catalysts.

[0023] In at least one embodiment, bottoms upgrading is increased by at least 5%, at least 10%, or at least 15%, or at least about 20% at constant coke production compared to a catalyst described above but having a mullite index of less than 20%.

[0024] In at least one embodiment, the catalyst, when used in a FCC process, performs such that at constant 5 wt% coke production, remaining bottoms is less than 8%.

[0025] In at least one embodiment, the catalyst may comprise a non-zeolitic matrix comprising one or more of clay, spinel, mullite, boehmite, alumina, silica, titania, zirconia, magnesia, kaolin, metakaolin, halloysite, kaolinite, dickite, nacrite, anauxite, silica-alumina, silica-magnesia, silica-zirconia, silica-thoria, silica-beryllia, silica-titania, silica-alumina-thoria, silica-alumina-zirconia, silica-alumina-magnesia, silica-magnesia-zirconia, silica-doped alumina, gamma-alumina, %-alumina, 5-alumina, 9-alumina, K-alumina, a-alumina, rare earth-modified variations thereof, alkaline earth metal-modified variations thereof, bismuth-modified variations thereof, or a mixture thereof.DEFINITIONS

[0026] As used herein, the singular forms “a,” “an,” and “the” include plural references unless the context clearly indicates otherwise. Thus, for example, reference to “a microsphere” includes a single microsphere as well as a mixture of two or more microspheres, and the like.

[0027] As used herein, the term “about” in connection with a measured quantity, refers to the normal variations in that measured quantity, as expected by one of ordinary skill in the art in making the measurement and exercising a level of care commensurate with the objective of measurement and the precision of the measuring equipment. In certain embodiments, the term “about” includes the recited number ±10%, such that “about 10” would include from 9 to 11.

[0028] As used herein, the term “catalyst” or “catalyst composition” or “catalyst material” refers to a material that promotes a reaction.

[0029] As used herein, the term “fluid catalytic cracking” or “FCC” refers to a conversion process in petroleum refineries wherein high-boiling, high-molecular weight hydrocarbon fractions of petroleum crude oils are converted to more valuable gasoline, olefinic gases, and other products.

[0030] “Cracking conditions,” “FCC conditions,” or “cracking” in the context of a process refers to typical FCC process conditions. Typical FCC processes are conducted at reaction temperatures of 450° to 650° C. with catalyst regeneration temperatures of 600° to 850° C. Hot regenerated catalyst is added to a hydrocarbon feed at the base of a riser reactor. The fluidizationof the solid catalyst particles may be promoted with a lift gas. The catalyst vaporizes and superheats the feed to the desired cracking temperature. During the upward passage of the catalyst and feed, the feed is cracked, and coke deposits on the catalyst. The coked catalyst and the cracked products exit the riser and enter a solid-gas separation system, e.g., a series of cyclones, at the top of the reactor vessel. The cracked products are fractionated into a series of products, including gas, gasoline, light gas oil, and heavy cycle gas oil. Some heavier hydrocarbons may be recycled to the reactor.

[0031] As used herein, the term “feed” or “feedstock” refers to that portion of crude oil that has a high boiling point and a high molecular weight. In some embodiments, the feed employed may include hydrocarbons (e.g., crude oil fractions) and also a second feed, wherein the second feed comprises at least one of biofeed pyrolysis oil, plastic pyrolysis oil, municipal solid waste pyrolysis oil, tire pyrolysis oil, waste biooil, hydrothermal liquefaction product, raw waste, or biomass, or derivatives thereof, or a combination thereof. In some embodiments, the feed may include the second feed in an amount of about 0.1% to about 80%, based on total feed. In some embodiments, the feed may include the second feed in an amount of about 0.1% to about 75%, about 0.5% to about 70%, about 1% to about 65%, about 5% to about 60%, about 10% to about 55%, about 15% to about 50%, about 20% to about 45%, about 25% to about 40%, or about 30% to about 35%, based on total feed. In FCC processes, a hydrocarbon feedstock is injected into the riser section of an FCC unit, where the feedstock is cracked into lighter, more valuable products upon contacting hot catalyst circulated to the riser-reactor from a catalyst regenerator.

[0032] As used herein, microspheres can be obtained by spray drying. As is understood by skilled artisans, microspheres are not necessarily perfectly spherical in shape. The various catalysts described herein may be particles in the form of microspheres.

[0033] As used herein, the terms “matrix” or “non-zeolitic matrix” refer to the constituents of an FCC catalyst that are not zeolites or molecular sieves.

[0034] As used herein, the term “zeolite” refers to a crystalline aluminosilicate with a framework based on an extensive three-dimensional network of silicon, aluminum, and oxygen ions and have a substantially uniform pore distribution.

[0035] As used herein, the term “intergrown zeolite” refers to a zeolite cluster or zeolite clusters that is / are formed by an in situ crystallization process.

[0036] As used herein, the term “no intergrown zeolite” refers to well dispersed single zeolite crystals without any intergrown zeolite is formed by an in situ crystallization process.

[0037] As used herein, the terms “in situ crystallized” or “in situ crystallization” refer to the process in which a zeolite is grown or intergrown directly on / in a microsphere and is intimatelyassociated with the matrix or non-zeolitic material, for example, as described in U.S. Pat. Nos. 4,493,902 and 6,656,347.

[0038] As used herein, the terms “preformed microspheres” or “precursor microspheres” refer to microspheres obtained by spray drying and calcining a non-zeolitic constituent.

[0039] As used herein, the term “zeolite-containing microsphere” refers to a microsphere obtained by in situ crystallizing a zeolite material on pre-formed precursor.

[0040] Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to illuminate certain materials and methods and does not pose a limitation on scope. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the disclosed materials and methods.DETAILED DESCRIPTION

[0041] This disclosure is directed in certain embodiments to a catalyst for use in fluid catalytic cracking (FCC) that includes a zeolite material present at less than about 35 wt% based on the total weight of the catalyst. In at least one embodiment, the catalyst further comprises a matrix material comprising mullite. The matrix may have a matrix surface area (MSA) of less than about 150 m2 / g. In at least one embodiment, a mullite index of the matrix is about 20% or greater (e.g., from about 20% to about 54%), or about 30% or greater (e.g., from about 30% to about 64%). For example, the mullite index may range from about 30% to about 40%, from about 40% to about 50%, or from about 50% to about 64%. Mullite index is a quantitative x-ray diffraction method used to quantify the amount of mullite in a sample. The sample is analyzed for content of mullite phase. The quantification may be done by integrating the area of a peak, or peaks, and comparing the integrated peak intensity of the sample to a reference. The reference is typically kaolinite that has been thermally treated to attain conversion to mullite as complete as possible. Note that the maximum value that the reference can attain is about 64-65% mullite, because the phase transformation of kaolinite to mullite also expels silica from the crystal structure of kaolinite; once kaolinite is converted to mullite, such silica remains in the sample, diluting the total percent of mullite to about 64% or about 65%. The catalyst may be produced by in situ crystallization of the zeolite material (e.g, Y-zeolite) on microspheres comprising mullite and a binder.

[0042] Advantageously, catalysts produced in accordance with embodiments exhibited 10% lower coke at constant bottoms and 15% lower bottoms at constant coke compared to a reference catalyst. In one exemplary catalyst composition, a catalyst was prepared from high temperature calcined clay having a mullite index above 30% as the matrix, which is milled to an average d90 particle size of less than about 5.0 pm (e.g., less than about 3.5 pm) to produce uniform pore diameter and promote zeolite growth within the pores during crystallization. In at least one embodiment, the clay is combined with an alumina sol (e.g., from about 5-10 wt%) to improve attrition resistance and to modify matrix acidity. It was found that the final catalyst included a zeolite content of less than 35 wt% based on total weight of the catalyst with zeolite uniformly distributed throughout the catalyst with no intergrown zeolite clusters.

[0043] In at least one embodiment, the catalyst has a ratio of zeolite surface area (ZSA) to matrix surface area (MSA), also may be referred to herein as Z / M ratio, of less than about 1.5. For example, in at least one embodiment, the Z / M ratio of the catalyst may be less than about 1.4, less than about 1.3, less than about 1.2, less than about 1.1, less than about 1.0, less than about 0.9, less than about 0.8, less than about 0.7, less than about 0.6, less than about 0.5, less than about 0.4, less than about 0.3, or within any range defined by and inclusive of these values.

[0044] To determine the Z / M ratio (or the steamed Z / M ratio), the total surface area (TSA) of the FCC catalyst is obtained following the Brunauer-Emmett-Teller (BET) method, the matrix surface area (MSA) of the catalyst is obtained by measuring the t-plot external surface area, and zeolite surface area (ZSA) is obtained by measuring the t-plot micropore area. In certain embodiments, the TSA of the catalyst ranges from any of about 50 m2 / g, about 75 m2 / g, about 100 m2 / g, or about 125 m2 / g to any of about 150 m2 / g, about 175 m2 / g, about 200 m2 / g, about 250 m2 / g, about 275 m2 / g, about 300 m2 / g, about 350 m2 / g, about 400 m2 / g, about 450 m2 / g, or about 500 m2 / g, or within any range defined by and inclusive of these values. In one embodiment, the TSA of the catalyst ranges from about 50 m2 / g to about 200 m2 / g. In one embodiment, the TSA of the ranges from about 125 m2 / g to about 200 m2 / g. In one embodiment, the TSA of the FCC catalyst ranges from about 160 m2 / g to about 200 m2 / g. In at least one embodiment, the TSA of the catalyst is about 170 m2 / g, about 172 m2 / g, about 174 m2 / g, about 176 m2 / g, about 178 m2 / g, about 180 m2 / g, about 182 m2 / g, about 184 m2 / g, about 186 m2 / g, about 188 m2 / g, about 190 m2 / g, about 192 m2 / g, about 194 m2 / g, about 196 m2 / g, about 198 m2 / g, about 200 m2 / g, or within any range defined by and inclusive of these values.

[0045] In certain embodiments, the MSA of the catalyst ranges from any of about 25 m2 / g, about 50 m2 / g, about 75 m2 / g, or about 90 m2 / g to any of about 110 m2 / g, about 125 m2 / g, about 130 m2 / g, about 140 m2 / g, about 150 m2 / g, about 160 m2 / g, about 170 m2 / g, about 175 m2 / g, about 180 m2 / g, or about 190 m2 / g, or within any range defined by and inclusive of these values. In oneembodiment, the MSA of the catalyst ranges from about 25 m2 / g to about 175 m2 / g. In one embodiment, the MSA of the catalyst ranges from about 50 m2 / g to about 150 m2 / g. In one embodiment, the MSA of the catalyst ranges from about 90 m2 / g to about 120 m2 / g. In at least one embodiment, the MSA of the catalyst is about 90 m2 / g, about 92 m2 / g, about 94 m2 / g, about 96 m2 / g, about 98 m2 / g, about 100 m2 / g, about 102 m2 / g, about 104 m2 / g, about 106 m2 / g, about 108 m2 / g, about 110 m2 / g, about 112 m2 / g, about 114 m2 / g, about 116 m2 / g, about 118 m2 / g, about 120 m2 / g, or within any range defined by and inclusive of these values.

[0046] In certain embodiments, the ZSA of the catalyst ranges from any of about 25 m2 / g, about 50 m2 / g, about 75 m2 / g, or about 90 m2 / g to any of about 110 m2 / g, about 125 m2 / g, about 130 m2 / g, about 140 m2 / g, about 150 m2 / g, about 160 m2 / g, about 170 m2 / g, about 175 m2 / g, about 180 m2 / g, or about 190 m2 / g, or within any range defined by and inclusive of these values. In one embodiment, the ZSA of the catalyst ranges from about 25 m2 / g to about 175 m2 / g. In one embodiment, the ZSA of the catalyst ranges from about 50 m2 / g to about 150 m2 / g. In one embodiment, the ZSA of the catalyst ranges from about 50 m2 / g to about 100 m2 / g. In at least one embodiment, the ZSA of the catalyst is about 60 m2 / g, about 62 m2 / g, about 64 m2 / g, about66 m2 / g, about 68 m2 / g, about 70 m2 / g, about 72 m2 / g, about 74 m2 / g, about 76 m2 / g, about78 m2 / g, about 80 m2 / g, about 82 m2 / g, about 84 m2 / g, about 86 m2 / g, about 88 m2 / g, about90 m2 / g, or within any range defined by and inclusive of these values.

[0047] In certain embodiments, the steam-deactivated Z / M ratio (sZ / M ratio, or SZSA / SMSA ratio), after the catalyst has been subjected to steaming conditions (e.g., 800 °C for, e.g., about 1- 24 hours, at 100% steam), is less than about 1.5. In certain embodiments, the sZ / M ratio may be less than about 0.9, less than about 0.8, or less than about 0.7. In certain embodiments, the sZ / M ratio may range from any of about 0.2, about 0.25, or about 0.3 to any of about 0.4, about 0.5, about 0.6, about 0.7, about 0.8, about 0.9, or about 1.0, or within any range defined by and inclusive of these values. In at least one embodiment, the sZ / M ratio of the catalyst ranges from about 0.2 to about 0.7. In at least one embodiment, the sZ / M ratio of the catalyst ranges from about 0.25 to about 0.6. In at least one embodiment, the sZ / M ratio of the catalyst ranges from about 0.3 to about 0.55. In at least one embodiment, the sZ / M ratio of the catalyst ranges from about 0.65 to about 0.75.

[0048] In certain embodiments, a steam-deactivated TSA (STSA) of the catalyst ranges from about 100 m2 / g to about 200 m2 / g. In at least one embodiment, the STSA of the catalyst is about 120 m2 / g, about 122 m2 / g, about 124 m2 / g, about 126 m2 / g, about 128 m2 / g, about 130 m2 / g, about 132 m2 / g, about 134 m2 / g, about 136 m2 / g, about 138 m2 / g, about 140 m2 / g, about 142 m2 / g, about 144 m2 / g, about 146 m2 / g, about 148 m2 / g, about 150 m2 / g, or within any range defined by and inclusive of these values.

[0049] In certain embodiments, a steam-deactivated MSA (SMSA) of the catalyst ranges from about 50 m2 / g to about 100 m2 / g. In at least one embodiment, the SMSA of the catalyst is about 60 m2 / g, about 62 m2 / g, about 64 m2 / g, about 66 m2 / g, about 68 m2 / g, about 70 m2 / g, about 72 m2 / g, about 74 m2 / g, about 76 m2 / g, about 78 m2 / g, about 80 m2 / g, about 82 m2 / g, about 84 m2 / g, about 86 m2 / g, about 88 m2 / g, about 90 m2 / g, or within any range defined by and inclusive of these values.

[0050] In certain embodiments, a steam-deactivated ZSA (SZSA) of the catalyst ranges from about 20 m2 / g to about 120 m2 / g. In at least one embodiment, the SZSA of the catalyst is about 30 m2 / g, about 32 m2 / g, about 34 m2 / g, about 36 m2 / g, about 38 m2 / g, about 40 m2 / g, about 42 m2 / g, about 44 m2 / g, about 46 m2 / g, about 48 m2 / g, about 50 m2 / g, about 52 m2 / g, about 54 m2 / g, about 56 m2 / g, about 58 m2 / g, about 60 m2 / g, or within any range defined by and inclusive of these values.

[0051] In some embodiments, the zeolite has a unit cell parameter of from about 24.10 A to about 24.80 A (e.g., at least about 24.20 A). In some embodiments, the zeolite has a unit cell parameter of from about 24.30 A to about 24.75 A. In some embodiments, the zeolite has a unit cell parameter of from about 24.50 A to about 24.70 A. In some embodiments, the zeolite has a unit cell parameter of from about 24.50 A to about 24.80 A. Without being construed as limiting, it is believed that a relatively large effective unit cell size results in more liquefied petroleum gas (LPG). LPG has also been increasingly of greater interest in the FCC market.

[0052] In some embodiments, the zeolite has a unit cell parameter or a steam deactivated unit cell (SUCS) parameter of from about 24.30 A to about 24.75 A. In some embodiments, the zeolite has a unit cell parameter or SUCS parameter of about 24.10 A, 24.11 A, 24.12 A, 24.13 A, 24.14 A, 24.15 A, 24.16 A, 24.17 A, 24.18 A, 24.19 A, 24.20 A, 24.21 A, 24.22 A, 24.23 A, 24.24 A, 24.25 A, 24.26 A, 24.27 A, 24.28 A, 24.29 A, 24.30 A, 24.31 A, 24.32 A, 24.33 A, 24.34 A, 24.35 A, 24.36 A, 24.37 A, 24.38 A, 24.39 A, 24.40 A, 24.41 A, 24.42 A, 24.43 A, 24.44 A, 24.45 A, 24.46 A, 24.47 A, 24.48 A, 24.49 A, 24.50 A, 24.51 A, 24.52 A, 24.53 A, 24.54 A, 24.55 A, 24.56 A, 24.57 A, 24.58 A, 24.59 A, 24.60 A, 24.61 A, 24.62 A, 24.63 A, 24.64 A, 24.65 A, 24.66 A, 24.67 A, 24.68 A, 24.69 A, 24.70 A, 24.71 A, 24.72 A, 24.73 A, 24.74 A, 24.75 A, 24.76 A, 24.77 A, 24.78 A, 24.79 A, 24.80 A, or within any range defined by and inclusive of these values.

[0053] The above unit cell sizes may be particularly suitable for zeolites having FAU zeolite structure, such as Y-zeolite. As understood by those skilled in the art, some of the zeolite structures described hereinabove may have different unit cell dimensions from those recited herein.

[0054] In certain embodiments, mullite substantially forms the non-zeolitic matrix of the catalyst. In at least one embodiment, a mullite index of the matrix material is about 30% or greater, from about 30% to about 40%, from about 40% to about 50%, from about 50% to about 64%. Inat least one embodiment, the mullite index is about 30%, about 31%, about 32%, about 33%, about 34%, about 35%, about 36%, about 37%, about 38%, about 39%, about 40%, about 41%, about42%, about 43%, about 44%, about 45%, about 46%, about 47%, about 48%, about 49%, about 50%, about 51%, about 52%, about 53%, about 54%, about 55%, about 56%, about 57%, about 58%, about 59%, about 60%, about 61%, about 62%, about 63%, about 64%, or within any range defined by and inclusive of these values. Without being construed as limiting, it is believed that the presence of mullite in the matrix at a mullite index of at least about 30% results in a well- dispersed matrix with a porosity that promotes uniform zeolite growth throughout the catalyst.

[0055] In one embodiment, the mullite and / or the zeolite in the catalysts described herein are modified with a rare earth element. Suitable rare earth elements include, without limitations, ytterbium, gadolinium, cerium, lanthanum, or a mixture of two or more thereof. In one embodiment, the catalysts described herein are modified a rare earth oxide (e.g., lanthanum oxide, or lanthana) from about 0.1 wt% to about 5 wt% based on a total weight of the catalyst. For example, one or more rare earth oxides may be present at about 0.1 wt%, about 0.2 wt%, about 0.3 wt%, about 0.4 wt%, about 0.5 wt%, about 0.6 wt%, about 0.7 wt%, about 0.8 wt%, about 0.9 wt%, about 1.0 wt%, about 1.1 wt%, about 1.2 wt%, about 1.3 wt%, about 1.4 wt%, about 1.5 wt%, about2.0 wt%, about2.5 wt%, about 3.0 wt%, about 3.5 wt%, about4.0 wt%, about4.5 wt%, about 5.0 wt%, or within any range defined by and inclusive of these values. In certain embodiments, modifying the matrix with lanthanum may beneficially promote bottoms conversion to light cycle oil (LCO) and may contribute to the enhanced LCO yield exhibited by the FCC catalysts contemplated herein.

[0056] In certain embodiments, this disclosure is directed to a method for preparing any of the FCC catalysts described herein by crystallizing, in situ, a zeolite on mullite-containing microspheres, wherein the catalyst has an MSA of less than about 150 m2 / g.

[0057] In an exemplary process, a slurry precursor is formed from a matrix precursor (e.g., mullite). In at least one embodiment, the mullite is first milled (e.g., via dry milling such as, without limitations, chop milling, hammer milling, or ball milling) to an average d90 particle size that less than about 10 pm. In at least one embodiment, the average d90 particle size is about 1.5 pm, about 1.75 pm, about2.0 pm, about 2.25 pm, about 2.5 pm, about 2.75 pm, about 3.0 pm, about 3.25 pm, about 3.5 pm, about 3.75 pm, about 4.0 pm, about 4.25 pm, about 4.5 pm, about4.75 pm, about 5.0 pm, about 5.25 pm, about 5.5 pm, about 5.75 pm, about 6.0 pm, about6.25 pm, about 6.5 pm, about 6.75 pm, about 7.0 pm, about 7.25 pm, about 7.5 pm, about7.75 pm, about 8.0 pm, about 8.25 pm, about 8.5 pm, about 8.75 pm, about 9.0 pm, about9.25 pm, about 9.5 pm, about 9.75 pm, about 10.0 pm, or wi bin any range defined by and inclusive of these values.

[0058] In at least one embodiment, the precursor slurry further includes a binder. In at least one embodiment, the binder comprises boehmite (e.g., peptized boehmite produced through via acid treatment), a silicate, or a combination thereof. Suitable binders may include, but are not limited to, boehmite, alumina derived from pseudo boehmite, alumina derived from flash calcined gibbsite, boehmite, pseudo boehmite, flash calcined gibbsite, calcined flash calcined gibbsite, silica-doped alumina, gamma-alumina (including gamma-aluminas A or B), aluminas C or D, %- alumina, 5-alumina, 0-alumina, K-alumina, a-alumina, rare earth-modified variations thereof, alkaline earth metal -modified variations thereof, bismuth-modified variations thereof, or a mixture of two or more thereof. Suitable silicate binders may include, but are not limited to sodium silicate, colloidal silicate or silicate gel.

[0059] In at least one embodiment, the binder is present in the slurry precursor from about 1 wt% to about 20 wt%, based on the total solids weight of the slurry precursor. In at least one embodiment, the binder is present at about 1 wt%, about 2 wt%, about 3 wt%, about 4 wt%, about 5 wt%, about 6 wt%, about 7 wt%, about 8 wt%, about 9 wt%, about 10 wt%, about 11 wt%, about 12 wt%, about 13 wt%, about 14 wt%, about 15 wt%, about 16 wt%, about 17 wt%, about 18 wt%, about 19 wt%, about 20 wt%, or within any range defined by and inclusive of these values, based on total solids weight of the slurry precursor. In at least one embodiment, mullite substantially makes up the balance of the total solids in the slurry precursor.

[0060] In at least one embodiment, the slurry precursor is spray-dried into precursor microspheres. In at least one embodiment, the precursor microspheres are calcined (e.g., at about 700 °C to about 900 °C, about 750 °C to about 850 °C, or about 800 °C).

[0061] In at least one embodiment, to form the zeolite material in the microspheres via in situ crystallization, the microspheres may be mixed with an aluminum source, a silicon source, water, and optionally sodium hydroxide to obtain an alkaline slurry. Seeds (such as those described in U.S. Patent No. 4,631,262, the teachings of which are hereby incorporated by reference herein in their entirety) may also be added to the slurry. Thereafter, the alkaline slurry may be heated to a temperature, and for a time, sufficient to crystallize the desired wt% of zeolite to form zeolitic microspheres as the catalyst. The zeolite material (e.g., Y-zeolite) may be present from any of about 5 wt%, about 6 wt%, about 7 wt%, or about 8 wt% to any of about 15 wt%, about 17 wt%, about 20 wt%, about 25 wt%, about 30 wt%, about 35 wt%, about 40 wt%, or within any range defined by and inclusive of these values, based on total weight of the catalyst. In at least one embodiment, the zeolite material may be present at about 5 wt%, about 6 wt%, about 7 wt%, about 8 wt%, about 9 wt%, about 10 wt%, about 11 wt%, about 12 wt%, about 13 wt%, about 14 wt%, about 15 wt%, about 16 wt%, about 17 wt%, about 18 wt%, about 19 wt%, about 20 wt%, about 21 wt%, about 22 wt%, about 23 wt%, about 24 wt%, about 25 wt%, about 26 wt%, about 27 wt%,about 28 wt%, about 29 wt%, about 30 wt%, about 31 wt%, about 32 wt%, about 33 wt%, about 34 wt%, about 35 wt%, or within any range defined by and inclusive of these values, based on total weight of the catalyst.

[0062] Suitable sacrificial aluminum sources for the zeolite crystallization may include, without limitations, metakaolin, sodium aluminate, or a combination thereof. In certain embodiments, the method for preparing the catalysts described herein also includes preparation of sacrificial aluminum source particles. In one embodiment, the aluminum source particles are derived from calcining kaolinite at a temperature, and for a duration, sufficient to transform the kaolinite to metakaolin without forming spinel. In one embodiment, the aluminum source is metakaolin.

[0063] Although kaolinite (and the resulting metakaolin) includes aluminum and silicon at an atomic ratio of Si / Al of 1.0, the metakaolin by itself may provide insufficient amount of silicon to crystallize certain zeolites with a Si / Al ratio greater than 1.0. For instance, Y-zeolite has an atomic ratio of Si / Al of 2.5 and would necessitate a secondary silicon source, in addition to metakaolin, to facilitate Y-zeolite growth.

[0064] Suitable sacrificial silicon sources for the zeolite crystallization may include, without limitations, sodium silicate, quartz, silica gel, silica sol, sodium silicate sol, and a combination thereof. In one embodiment, the silicon source used includes sodium silicate sol (e.g., mostly water containing sodium silicate which may be made by dissolving solid sodium silicate in water). In one embodiment, the silicon source used includes silica gel. In one embodiment, the silicon source used includes quartz.

[0065] When sodium silicate sol is used as the sacrificial silicon source for Y-zeolite crystallization, it may be added all at once at the beginning of the zeolite crystallization or zeolite growth reaction. Other sacrificial silicon sources, such as, without limitations, silica gel or quartz, do not bring sodium into the zeolite crystallization reaction and may be used to give more flexibility in tuning the amount of sodium and silica present in zeolite crystallization, since the two constituents (sodium and silica) can be separately added. In contrast, sodium silicate (or sodium silicate sols) already include sodium therein, which provides less flexibility in tuning the amount of sodium and silica present during zeolite crystallization. This may pose some challenges or result in added process steps because the sodium to silica ratio in sodium silicates (or sodium silicate sols) may be high, which may contribute to rapid zeolite growth. A rapid zeolite growth may be less favorable due to its potential adverse effect on the hydrothermal stability of the crystallized zeolite and / or due to its contribution to the growth of less favorable zeolite phase (such as GIS or GME zeolite structures).

[0066] After in situ crystallization, in certain embodiments, the method further includes isolating or separating the zeolitic microspheres from the alkaline slurry. Isolating or separating the zeolitic microspheres may be carried out by commonly used methods such as filtration. In certain embodiments, the zeolitic microspheres may be washed or contacted with water or other suitable liquid to remove residual crystallization liquor.

[0067] In certain embodiments, the method of preparing the catalysts described herein further includes ion-exchanging the zeolite (e.g., ion-exchanging the Y-zeolite) to reduce sodium content in the catalyst and / or to replace the sodium ions with other more favorable ions. For instance, in one embodiment, the Y-zeolite is ion-exchanged to reduce the sodium content of the catalyst to less than about 0.7 wt%, less than about 0.5 wt%, or less than about 0.3 wt% Na?O, based on the total weight of the FCC catalyst. Ion-exchanging may be conducted once, twice, three times, four times, five times, six times, or as many times as needed to arrive at a target sodium content.

[0068] In certain embodiments, the sodium ions may be replaced by other ions, for instance, by ion-exchanging ammonium cations, rare earth metals, or a combination thereof, to arrive at a catalyst that includes a zeolite that is modified with more favorable cations.

[0069] In some embodiments, the method may further include mixing the zeolitic microspheres with an ammonium nitrate solution prior to or subsequent to contacting zeolite in the sodium form prior to the mixing with the ammonium nitrate solution. In some embodiments, the mixing with the ammonium nitrate solution is conducted at acidic pH conditions. In some embodiments, the mixing with the ammonium nitrate solution is conducted at pH of about 3 to about 3.5. In some embodiments, the mixing with the ammonium nitrate solution is conducted at a temperature above room temperature. In some embodiments, the mixing with the ammonium nitrate solution is conducted at a temperature of at least about 80 °C to about 100 °C, including increments therein. In certain embodiments, ion-exchanging the zeolitic microspheres with ammonium cations reduces the sodium content of the zeolitic microspheres to from about 1 wt% Na?O to about 2 wt% Na?O, or less than 1 wt% Na?O, based on total weight of the catalyst.

[0070] In some embodiments, the ammonium exchanged microspheres are further ion exchanged with a rare earth ion solution. In some embodiments, the rare earth ion are nitrates of ytterbium, neodymium, samarium, gadolinium, cerium, lanthanum, or a mixture of any two or more such nitrates. In some embodiments, the rare earth ions are derived from the lanthanides or yttrium. In some embodiments, the microspheres are contacted with solutions of lanthanum nitrate or yttrium nitrate. In particular embodiments, the microspheres are contacted with solutions of lanthanum nitrate. In certain embodiments, the amount of rare earth added to the catalyst as a rare earth oxide will range from about 0.5 wt% to about 5 wt%, or from about 2 wt% to about 3 wt% rare earth oxide (REO), based on the total weight of the FCC catalyst. Lanthana content of thecatalyst material can be estimated by chemical analysis (e.g., ICP chemical analysis). For fresh (i.e., not yet steamed) FCC catalyst material disclosed herein, substantially all lanthana (i.e., 100% within experimental error) is found within the zeolite material.

[0071] In certain embodiments, the method of preparing the catalysts described herein further includes steam-treating the catalyst. In some embodiments, the steam-treating is conducted at a temperature of at least about 700 °C (e.g., about 750 °C or about 800 °C). In some embodiments, the steam-treating is conducted for at least about four hours. In some embodiments, the steamtreating is conducted for about one to about 24 hours.Method of Use

[0072] In certain aspects, the instant disclosure is directed to a method of cracking a hydrocarbon feed by contacting said feed with any of the FCC catalysts contemplated by the instant disclosure (e.g., a catalyst comprising a zeolite and a matrix material comprising mullite with an MSA of less than about 150 m2 / g) or with any of the FCC catalyst compositions described herein.

[0073] In certain embodiments, the methods of cracking a hydrocarbon feed, as described herein, result in improved bottoms upgrading performance. It is believed that the non-zeolitic matrix of the FCC catalyst having a high mullite index improves bottoms conversion compared to traditional matrices. As such, in certain embodiments, the methods described herein result in a bottoms yield that is lower than the bottoms yield resulting from contacting the hydrocarbon feed with a FCC catalyst that includes a non-zeolitic matrix that includes mullite, for example, at a mullite index of about 30% or greater compared to a similarly produced catalyst with a lower mullite index (while otherwise being the same aside from the non-zeolitic matrix material).

[0074] In certain embodiments, the methods of cracking a hydrocarbon feed, as described herein, result in a reduced coke yield. It is believed that forming the non-zeolitic matrix of the FCC catalyst having a high mullite index yields less coke compared to traditional matrices. As such, in certain embodiments, the methods described herein result in a coke yield that is lower than the coke yield resulting from contacting the hydrocarbon feed with a FCC catalyst that includes a non-zeolitic matrix that includes mullite, for example, at a mullite index of about 30% or greater compared to a similarly produced catalyst with a lower mullite index (while otherwise being the same aside from the non-zeolitic matrix material). Finally, in certain embodiments, the present FCC catalyst may be employed as a component in a blend with a second FCC catalyst component (or an FCC additive) that is compositionally different from the first FCC catalyst component; in some embodiments the present FCC catalyst may be present in an amount of from about 10 wt% to about 95 wt% of the blend.ILLUSTRATIVE EXAMPLES

[0075] The following examples are set forth to assist in understanding the disclosure and should not be construed as specifically limiting the invention described and claimed herein. Such variations of the invention, including the substitution of all equivalents now known or later developed, which would be within the purview of those skilled in the art, and changes in formulation or minor changes in experimental design, are to be considered to fall within the scope of the invention incorporated herein.Example 1

[0076] Mullite was milled to an average d90 particle size of 2.5 pm. A slurry was prepared by combining the milled mullite with peptized boehmite as a binder (90 wt% mullite and 10 wt% peptized boehmite based on solids). The slurry was spray dried into microspheres having an average particle size of 80 pm. Calcination was performed between 730°C to 815°C for about 2 hours.

[0077] Y-zeolite was crystallized in situ on the microspheres. 400 g of resultant microsphere, 235 g of Y-zeolite seeds (containing 13 wt% of Na?O and 21 wt% of SiCh and 0.5 wt% of AI2O3), 132 g of 50% caustic, and 486 g of H2O were added with stirring to a 1 liter kettle reactor configured for reflux operation. The Y-zeolite seeds were prepared according to the methods disclosed in U.S. Pat. No. 4,493,902 and U.S. Pat. No. 4,631,262. The mixture was heated to a temperature of either 210 °F (98.9 °C) or 190 °F (87.8 °C) for crystallization. The crystallization reaction was maintained at each respective crystallization temperature with stirring for 10-14 hours, and then quenched to obtain microspheres with in-situ crystallized zeolite. Resultant zeolitic microspheres were then filtered and washed to produce a sodium-ion form Y-zeolite FCC catalyst (NaY form). The zeolitic microspheres NaY was ion exchanged with ammonium nitrate between two and five times (typically twice) at 82 °C (180 °F), rare earth (RE) exchanged at 82 °C and pH of 3 for RE on zeolite loading equivalent to 1.5% REO, followed by first calcination at temperatures between 950 °F and 1450 °F (typically 621 °C, 1150 °F; covered with 25% moisture for 2 hours), then ion exchanged with ammonium nitrate one or two more times at 82 °C (180 °F). The pH was kept constant at 3 using nitric acid or ammonium hydroxide during these ion exchanges. The resultant catalyst was defined as 2x1 form, and was designated as “Catalyst A”.

[0078] A commercially available catalyst, which is comparative, was designated as “Catalyst B.” Catalyst B has a mullite index of about 10-14% and a zeolite yield of below 30%.

[0079] Properties of Catalysts Al and B are shown in Table 1 below the catalyst after steam treatment at 1450 °F for 24 hours with 100% steam.

[0080] Mercury pore volume was measured by a micrometrics apparatus. The mercury porosimetry characterizes a material’s porosity by applying various levels of pressure to the sample which is immersed in mercury.

[0081] As shown in Table 1, Catalyst Al exhibited a lower MSA than Catalyst B, which is believed to contribute to more uniform zeolite distribution.Table 1 : Catalyst Properties

[0082] Catalysts Al and B were further evaluated in an Advanced Catalytic Evaluation (ACE) micro-scale reactor. Table 2 shows results of ACE testing of Catalysts Al and B. At constant coke (3.2%), Catalyst Al showed 31% of bottoms upgrading improvement compared to catalyst B (i.e., catalyst B resulted in 12.1% bottoms in this test, whereas catalyst Al resulted in only 8.4%).Table 2: ACE test results of catalyst AlExample 2:

[0083] Mullite was milled to an average d90 particle size of 3 pm. A slurry was prepared by combining 86.7% of the milled mullite with 13.3% of hydrous clay. Another 10% of peptizedboehmite as a binder was inline injected during spray dry. The slurry was spray dried into microspheres having an average particle size of 80 pm. Calcination was performed between 730°C to 815°C for about 2 hours. Catalyst A2 was crystallized, ion exchanged and steamed the same way as catalyst Al. The properties of catalyst A2 are listed in table 1

[0084] ACE test results of catalyst A2 and catalyst B were shown in Table 3Table 3. ACE test results of Catalyst A2

[0085] As shown in table 3, catalyst A2 more gasoline and LPG compared catalyst B. At constant coke (4%). Catalyst A2 showed about 38% of bottoms upgrading improvement compared to catalyst B.Example 3

[0086] Mullite was milled to an average d90 particle size of 2.5 pm. A slurry was prepared by combining 97% of the milled mullite with 3% of hydrous clay. Another 4% of sodium silicate as a binder was inline injected during spray dry. The slurry was spray dried into microspheres having an average particle size of 80 pm. Calcination was performed between 730°C to 815°C for about 2 hours. Catalyst A3 was crystallized, ion exchanged and steamed the same way as catalyst Al. The properties of catalyst A3 are listed in table 1

[0087] ACE test results of catalyst A3 and catalyst B were shown in Table 4Table 4: ACE test results of Catalyst A3

[0088] As shown in table 4, catalyst A3 more gasoline and LPG compared catalyst B. At constant coke (3%). Catalyst A3 showed about 38% of bottoms upgrading improvement compared to catalyst B.

[0089] In the foregoing description, numerous specific details are set forth, such as specific materials, dimensions, processes parameters, etc., to provide a thorough understanding of the present invention. The particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments. The words “example” or “exemplary” are used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as “example” or “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, use of the words “example” or “exemplary” is intended to present concepts in a concrete fashion. As used in this application, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or”. That is, unless specified otherwise, or clear from context, “X includes A or B” is intended to mean any of the natural inclusive permutations. That is, if X includes A; X includes B; or X includes both A and B, then “X includes A or B” is satisfied under any of the foregoing instances. Reference throughout this specification to “an embodiment”, “certain embodiments”, or “one embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrase “an embodiment”, “certain embodiments”, or “one embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment.

[0090] The present disclosure has been described with reference to specific exemplary embodiments thereof. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. Various modifications of the disclosure in addition to those shown and described herein will become apparent to those skilled in the art and are intended to fall within the scope of the appended claims.

Claims

CLAIMSWhat is claimed is:

1. A catalyst comprising: a zeolite material present at less than about 35 wt% based on total weight of the catalyst; and a matrix material comprising mullite, wherein a matrix surface area (MSA) is less than about 150 m2 / g.

2. The catalyst of claim 1, wherein a mullite index of the matrix material is about 30% or greater, from about 30% to about 40%, from about 40% to about 50%, from about 50% to about 64%.

3. The catalyst of claim 1, wherein the mullite is milled to an average d90 particle size of less than about 5.0 pm, or from about 1.5 pm to about 3.5 pm, prior to forming the catalyst.

4. The catalyst of any one of claims 1-3, wherein a steamed MSA (SMSA) of the catalyst is less than about 100 m2 / g.

5. The catalyst of claim 4, wherein a ratio of steamed zeolite surface area ZSA (SZSA) to SMSA is less than 1.5.

6. The catalyst of any one of the preceding claims, wherein a total surface area (TSA) of the catalyst is less than about 400 m2 / g.

7. The catalyst of any one of the preceding claims, wherein a steamed total surface area (STSA) of the catalyst is less than about 200 m2 / g.

8. The catalyst of any of the preceding claims, wherein the zeolite material comprises or consists essentially of Y-zeolite.

9. A method of forming a catalyst, the method comprising: forming a slurry precursor from a matrix precursor comprising mullite; forming microspheres from of slurry precursor; and growing a zeolite on the microspheres via in situ crystallization.

10. The method of claim 9, wherein the matrix precursor comprises milled mullite having an average d90 particle size of less than about 5.0 pm, or from about 1.5 pm to about 3.5 pm.

11. The method of claim 9 or claim 10, wherein forming the slurry precursor comprises: combining the matrix precursor with a binder comprising boehmite and / or silicate, wherein the binder is present from about 1 wt% to about 20 wt% based on a total solids weight of the slurry precursor.

12. The method of any one of claims 9-11, wherein forming the microspheres comprises calcining the microspheres at a temperature of greater than about 700 °C.

13. The method of any one of claims 9-12, wherein growing a zeolite on the microspheres via in situ crystallization comprises heating the microspheres in the presence of zeolite seeds at a temperature and for a time sufficient to crystallize the zeolite.

14. The method of claim 13, wherein the time to crystallize the zeolite is greater than about 10 hours15. The catalyst of any one of claims 9-14, wherein the zeolite comprises or consists essentially of Y-zeolite.

16. A fluid catalytic cracking (FCC) catalyst comprising: the catalyst of any one of claims 1-8 or prepared according to any one of claims 9-15.

17. The FCC catalyst of claim 16, wherein the fluid catalytic cracking catalyst further comprises one or more rare earth elements.

18. The FCC catalyst of claim 17, wherein the one or more rare earth elements comprise lanthanum present in the form of lanthanum oxide from about 0.5 wt% to about 3 wt% .

19. The FCC catalyst of claim 16, wherein a steamed unit cell size (SUCS) of the catalyst is at least about 24.2 A.

20. A method of cracking a hydrocarbon feed comprising contacting said feed with the FCC catalyst of any one of claims 16-19.

21. The method of claim 20, wherein bottoms upgrading is increased by at least 5%, at least 10%, or at least 20% at constant coke production compared to a catalyst according to claim 2 but having a mullite index of less than 20%.

22. The method of either claim 20 or claim 21, wherein the catalyst, when used in a FCC process, performs such that at constant 5 wt% coke production, remaining bottoms is less than 8%.

23. The FCC catalyst of any one of claims 16-19, wherein the matrix material comprises one or more of clay, spinel, mullite, boehmite, alumina, silica, titania, zirconia, magnesia, kaolin, metakaolin, halloysite, kaolinite, dickite, nacrite, anauxite, silica-alumina, silica-magnesia, silica- zirconia, silica-thoria, silica-beryllia, silica-titania, silica-alumina-thoria, silica-alumina-zirconia, silica-alumina-magnesia, silica-magnesia-zirconia, silica-doped alumina, gamma-alumina, %- alumina, 5-alumina, 0-alumina, K-alumina, a-alumina, rare earth-modified variations thereof, alkaline earth metal -modified variations thereof, bismuth-modified variations thereof, or a mixture thereof.

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