Toluene disproportionation using enhanced UZM-44 aluminosilicate zeolite

Abstract

The present invention describes a toluene disproportionation process using treated UZM-44 zeolite. The process produces an effluent stream comprising p-xylene and benzene. The molar ratio of benzene to xylene (Bz / X) in the effluent stream can be in the range of 1.00 to 1.14, the molar ratio of p-xylene to xylene (pX / X) in the effluent stream can be in the range of 0.80 to 1.0, and the conversion of toluene can be 20% to 40%.

Description

[0001] Priority declaration

[0002] This application claims priority to U.S. application No. 16 / 793,530, filed on February 18, 2020, which is incorporated herein in its entirety. Background Art

[0003] Zeolites are crystalline aluminosilicate compositions that are microporous and formed by corner-sharing AlO2 and SiO2 tetrahedra. A variety of naturally occurring and synthetically prepared zeolites are used in various industrial processes. Synthetic zeolites are prepared via hydrothermal synthesis using suitable sources of Si, Al and structure directing agents (such as alkali metals, alkaline earth metals, amines or organic ammonium cations). The structure directing agents reside in the pores of the zeolite and are primarily responsible for the specific structure that is ultimately formed. These materials balance the framework charge associated with aluminum and can also serve as space fillers. Zeolites are characterized by having pore openings of uniform size, having significant ion exchange capacity, and being able to reversibly desorb adsorbed phases dispersed throughout the internal voids of the crystal, but without significantly displacing any atoms that make up the permanent zeolite crystal structure. Zeolites can be used as catalysts for hydrocarbon conversion reactions, which can occur on the external surface as well as on the internal surface within the pores.

[0004] A specific zeolite, IM-5, was first disclosed by Benazzi et al. in 1996 (FR96 / 12873; WO98 / 17581), which describes the synthesis of IM-5 from flexible dicationic structure directing agents, 1,5-bis(N-methylpyrrolidinium)pentane dibromide or 1,6-bis(N-methylpyrrolidinium)hexane dibromide in the presence of sodium. After the IM-5 structure was solved by Baerlocher et al. (Science, 2007, 315, 113-6), the International Zeolite Structure Commission provided an IMF code for this zeolite structure type, see the Atlas of Zeolite Framework Types maintained by the International Zeolite Association Structure Commission at http: / / www.iza-structure.org / databases / . It was also found that the IMF structure type contains three sets of mutually orthogonal channels, each of which is defined by a 10-membered ring of tetrahedrally coordinated atoms. However, the connectivity in the third dimension is interrupted every 2.5 nm; therefore, diffusion is limited to a certain extent. In addition, there are multiple 10-membered ring channels of different sizes in the structure.

[0005] Applicants have successfully prepared a new family of materials named UZM-44. The topology of the material is similar to that observed for IM-5. The material is prepared by using a mixture of simple commercially available structure directing agents such as 1,5-dibromopentane and 1-methylpyrrolidine and has been described in US 8,609,920 and US 8,623,321. UZM-44 has been used as a catalyst in several reactions, including methane conversion (US 8,921,634), dehydrogenation cyclodimerization (US 8,889,939), catalytic pyrolysis (US 8,609,911 and US 8,710,285), transalkylation (US 8,609,921 and US 8,704,026) and conversion of aromatic compounds (US 8,609,919, US 8,748,685 and US 8,716,540). UZM-44 can be used as a catalyst in the disproportionation reaction of toluene.

[0006] Xylene isomers are produced in large quantities from petroleum as a feedstock for use in a variety of important chemicals. The most important xylene isomer is para-xylene, the main feedstock for polyester, which continues to enjoy high growth rates due to large base demand. Ortho-xylene is used in the production of phthalic anhydride, which has a high volume but mature market. Meta-xylene is used less frequently, but its use is increasing in products such as plasticizers, azo dyes and wood preservatives.

[0007] Among aromatic hydrocarbons, xylenes are comparable to benzene in overall importance as an industrial chemical feedstock. The amount of xylenes and benzene produced from petroleum by reforming naphtha is insufficient to meet demand. Therefore, the conversion of other hydrocarbons is necessary to increase the production of xylenes and benzene. Typically, toluene is selectively disproportionated to produce benzene and to recover C8 aromatic compounds of the individual xylene isomers therefrom.

[0008] Para-selective toluene disproportionation is a process commercialized in the 1980s that aims to convert toluene to benzene and xylenes at a high para-xylene to total xylenes molar ratio (pX / X molar ratio) typically greater than 0.85. This technology is particularly needed when there is a demand for polyesters and other chemicals derived from para-xylene, but the demand for other xylenes is limited. High pX / X was initially achieved by "selecting" the catalyst with carbon and / or coke to narrow the MFI pore size and cover the acid sites on the outer surface of the MFI crystals. Later, it was learned that depositing silica on the catalyst achieved similar results.

[0009] US 4,016,219 B1 (Kaeding) discloses a process for the disproportionation of toluene using a catalyst comprising a zeolite which has been modified by adding at least 0.5% by mass of phosphorus. The zeolite crystals are contacted with a phosphorus compound to achieve a reaction of the zeolite and the phosphorus compound. The modified zeolite can then be incorporated into a specified matrix material.

[0010] US 4,097,543 Bl (Haag et al.) teaches toluene disproportionation using zeolites that have undergone controlled pre-coking for the selective production of para-xylene. Zeolites can be ion exchanged with various elements from Groups IB to VIII and composited with various clays and other porous matrix materials.

[0011] US6,114,592 B1 (Gajda et al.) teaches an improved process combination for the selective disproportionation of p-toluene. The combination comprises selectively hydrogenating a toluene feedstock and then contacting it with a zeolite catalyst that has been oil-dropletized in an aluminum phosphate binder to achieve a high yield of p-xylene.

[0012] US 6,429,347 Bl (Boldingh) teaches the disproportionation of toluene to selectively produce para-xylene using a catalyst comprising an MFI zeolite bonded to aluminophosphate after selective pre-coking of the catalyst by contacting the catalyst with a coke-forming feed under pre-coking conditions.

[0013] In these methods, the zeolite of choice is ZSM-5 with an MFI framework. Using these catalysts, the molar ratio of p-xylene to xylene (pX / X) can be increased from an equilibrium level of 0.24 to 0.90 or higher by depositing a sufficient amount of coke or silica. Although this increases the pX / X molar ratio, it is always accompanied by an increase in the molar ratio of benzene to xylene (Bz / X), which is significantly greater than the theoretical value of 1. The higher the pX / X molar ratio, the higher the Bz / X molar ratio.

[0014] Although not wishing to be bound by theory, it appears that the increase in the Bz / X molar ratio is caused by a loss in the total xylene yield. Generally speaking, when the p-xylene yield increases beyond a certain level, the total xylene yield generally decreases. This is considered unavoidable, and many studies are directed to optimizing the use of coke or silica to minimize the Bz / X molar ratio. Using optimal silica deposition technology to increase the pX / X molar ratio to 0.90 or greater, it is quite common to have a Bz / X molar ratio value of up to 1.4 under disproportionation conditions at 30% toluene conversion, H2 / HC=2, WHSV=4, and 400 psig pressure.

[0015] Therefore, there is a need for an improved toluene disproportionation process wherein the pX / X molar ratio is high (eg, 0.70 or greater) and the Bz / X molar ratio is less than 1.2. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic representation of one embodiment of a toluene disproportionation process.

[0017] Figure 2 is a graph showing the Bz / X molar ratio as a function of the pX / X molar ratio for various catalysts at 30% conversion.

[0018] Figure 3 is a graph showing the selectivity for xylenes of various catalysts as a function of the pX / X molar ratio at 30% conversion.

[0019] Figure 4 is a graph showing the selectivity for light ends (C1-C6) of various catalysts at 30% conversion as a function of the pX / X molar ratio.

[0020] Figure 5 is a graph showing the temperature required to achieve 30% conversion for various catalysts, plotted against the pX / X molar ratio achieved. DETAILED DESCRIPTION

[0021] One aspect of the invention is a toluene disproportionation process. In one embodiment, the process comprises contacting a feed comprising toluene with a microporous crystalline zeolite under disproportionation conditions to produce an effluent stream comprising para-xylene and benzene, wherein the molar ratio of benzene to xylene (Bz / X) in the effluent stream is in the range of 1.00 to 1.14, wherein the molar ratio of para-xylene to xylene (pX / X) in the effluent stream is in the range of 0.80 to 1.0, and wherein the conversion of toluene is 20% to 40%.

[0022] The present invention relates to the catalytic use of an aluminosilicate zeolite named UZM-44. UZM-44 is a material having a three-dimensional framework of at least AlO2 and SiO2 tetrahedral units and an empirical composition represented by the following empirical formula on an as-synthesized and anhydrous basis:

[0023] Na n M m k+ T t Al 1-x E x Si y O z

[0024] wherein "n" is the molar ratio of Na to (Al+E) and has a value of 0.05 to 0.5, and M represents at least one selected from zinc, group 1 (IUPAC 1), group 2 (IUPAC 2), group 3 (IUPAC 3), and a metal of the lanthanide series, and any combination thereof, "m" is the molar ratio of M to (Al+E) and has a value of 0 to 0.5, "k" is the average charge of the one or more metals M, T is one or more organic structure directing agents derived from reactants R and Q, wherein R is an Α,Ω-dihalogen-substituted alkane having 5 carbon atoms, and Q is at least one neutral monoamine having 6 or less carbon atoms, "t" is the molar ratio of N from the one or more organic structure directing agents to (Al+E) and has a value of 0.5 to 1.5, E is an element selected from gallium, iron, boron, and combinations thereof, "x" is the molar fraction of E and has a value of 0 to 1.0, "y" is the molar ratio of Si to (Al+E) and varies from greater than 9 to 25, and "z" is the molar ratio of O to (Al+E) and has a value determined by the following equation:

[0025] z=(n+k·m+3+4·y) / 2.

[0026] As-synthesized UZM-44 is characterized by an x-ray diffraction pattern having at least the d-spacings and relative intensities shown below in Table A. The diffraction patterns herein were obtained using a typical laboratory powder diffractometer with a high intensity x-ray tube operating at 45 kV and 35 ma using a copper K α The flat compressed powder sample is scanned continuously at 2° to 56° (2θ). From the position of the diffraction peak represented by the angle 2θ (2θ), the Bragg equation can be used to calculate the distance d between the characteristic surfaces of the sample hkl As will be appreciated by those skilled in the art, the determination of the parameter 2θ is subject to both human and mechanical errors, the combination of which can impart an uncertainty of ±0.4° to each reported 2θ value. This uncertainty is of course also reflected in the reported d-spacing values, which are calculated from the 2θ values. Such imprecision is common in the art and is not sufficient to eliminate the differentiation of the crystalline materials of the present invention from each other and from prior art compositions.

[0027] The intensity is calculated based on a relative intensity scale that attributes a value of 100 to the line representing the most intense peak on the X-ray diffraction pattern, and then: very weak (VW) means less than 5; weak (w) means less than 15; medium (M) means in the range of 15 to 50; strong (S) means in the range of 50 to 80; very strong (VS) means more than 80. The intensity can also be shown as a range including the above-mentioned end values. The X-ray diffraction pattern from which the data (d spacing and intensity) are obtained is characterized by a large number of reflections, some of which are broad peaks or peaks that form shoulders on peaks of higher intensity. Some or all of the shoulders may not be resolved. This may be the case for samples of low crystallinity, samples with specific coherently grown composite structures, or for samples with crystals that are small enough to cause significant broadening of the X-rays. This may also be the case when equipment and operating conditions are used to produce diffraction patterns that are significantly different from those used in the present case.

[0028] The zeolite can be characterized by an x-ray diffraction pattern having at least the d-spacings and intensities shown in Table A.

[0029] Table A

[0030]

[0031]

[0032] As shown, in one embodiment, the zeolite is thermally stable at temperatures up to above 600°C, and in another embodiment at least 800°C.

[0033] When synthesized, the UZM-44 material will contain some exchangeable or charge-balanced cations in its pores. These exchangeable cations can exchange other cations, or in the case of organic cations, they can be removed by heating under controlled conditions. It is also possible to directly remove some organic cations from the UZM-44 zeolite by ion exchange. The UZM-44 zeolite can be modified in a variety of ways to make it suitable for use in specific applications. Modification includes calcination, ion exchange, steaming, various acid extractions, ammonium hexafluorosilicate treatment or any combination thereof, as outlined for the case of UZM-4M in US 6,776,975 B1, which is incorporated herein by reference in its entirety. The conditions can be more stringent than those shown in US 6,776,975. The modified characteristics include porosity, adsorption, Si / Al ratio, acidity, thermal stability, etc.

[0034] The modified microporous crystalline zeolite UZM-44 has a three-dimensional framework of at least AlO2 and SiO2 tetrahedral units and an empirical composition in hydrogen form represented by the following empirical formula, on a calcined, ion-exchanged and calcined and anhydrous basis:

[0035] M1 a N+ Al (l-x) E x Si y’ O z”

[0036] wherein M1 is at least one exchangeable cation selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, zinc, ammonium ions, hydrogen ions, and combinations thereof, "a" is the molar ratio of M1 to (Al E) and varies from 0.05 to 50, "N" is the weighted average valence of M1 and has a value of +1 to +3, E is an element selected from the group consisting of gallium, iron, boron, and combinations thereof, "x" is the molar ratio of E and varies from 0 to 1.0, y' is the molar ratio of Si to (Al + E) and varies from greater than 9 to substantially pure silica, and "Z" is the molar ratio of O to (Al + E) and has a value determined by the following equation:

[0037] z'=(a·N+3+4·y') / 2

[0038] In the hydrogen form, after calcination, ion exchange, and calcination to remove NH3, the modified UZM-44 (UZM-44M) exhibits an x-ray diffraction pattern having at least the d-spacings and intensities shown in Table B. Those of UZM-44

[0039] Characteristic peaks are shown in Table B. Other peaks may also be present, particularly those with very weak intensity. All peaks of moderate or higher intensity present in UZM-44 are shown in Table B.

[0040] Table B

[0041]

[0042]

[0043] Surface area, micropore volume and total pore volume can be determined, for example, by N2 adsorption using conventional BET analysis (J. Am. Chem. 1938, 60, 309-16) in combination with t-plot analysis of the adsorption isotherm as implemented in Micromeritics ASAP 2010 software. The t-plot is a mathematical representation of multilayer adsorption and allows determination of the amount of N2 adsorbed in the micropores of the zeolite material being analyzed. Specifically, for the materials described herein, points at 0.45, 0.50, 0.55, 0.60 and 0.65 P / P0 are used to determine the slope of the t-plot, and the intercept of the t-plot is the micropore volume. The total pore volume is determined at 0.98 P / P0. The UZM-44 used in the present invention has a micropore volume of less than 0.155 mL / g, usually less than 0.150 mL / g and often less than 0.145 mL / g. In addition, by observing a plot of dV / dlog D versus pore size (differential volume of adsorbed nitrogen as a function of pore size), the ... The following features are not included. UZM-44 has In one embodiment, at The differential adsorption is greater than 0.1 mL at a pore size of Preferably, in a range greater than The differential adsorption at the pore size is greater than 0.1 mL The differential adsorption indicates the differential volume of nitrogen adsorbed at a specific pore size.

[0044] When specifying proportions of zeolite starting materials or adsorption characteristics of zeolite products, etc., the "anhydrous state" of the zeolite is intended unless otherwise indicated. The term "anhydrous state" as used herein refers to a zeolite that is substantially free of both physically and chemically adsorbed water.

[0045] UZM-44 or UZM-44M can be enhanced in order to increase the pX / X ratio achieved during toluene disproportionation. Enhancement is intended to indicate a step that increases the pX / X molar ratio significantly above the equilibrium value of 0.24 during toluene disproportionation. Three known examples are depositing carbon, treating with silica, and steaming after depositing the carbon and / or silica.

[0046] It has been surprisingly discovered that a catalyst comprising UZM-44 that has undergone a boosting step until a pX / X molar ratio greater than 0.6 is achieved under disproportionation conditions has a unique combination of high pX / X molar ratio and high total xylene selectivity without producing excess benzene.

[0047] In order to facilitate the manufacture of disproportionation catalyst, the catalyst may also include a refractory binder or matrix, thereby providing strength, reducing manufacturing costs, or a combination thereof. The binder may be uniform in composition, and should be relatively refractory to the conditions used in the method. Suitable binders include inorganic oxides, such as one or more of aluminum oxide, magnesium oxide, zirconium oxide, chromium oxide, titanium dioxide, boron oxide, thoria, zinc oxide, and silicon dioxide. Aluminum oxide and / or silicon dioxide are preferred binders. The amount of zeolite present in the combined catalyst may vary significantly, but is usually present in an amount of 30% to 90% by mass of the catalyst and preferably 50% to 80% by mass.

[0048] An exemplary enhancement step of depositing silica includes exposing the zeolite to a silicon reagent, such as tetraethyl orthosilicate (TEOS), followed by a calcination step. An exemplary enhancement by silica treatment incorporates silica onto the zeolite. Enhancement by depositing silica can be performed by treating the zeolite, either on the zeolite prior to combining with the refractory oxide, or on the combined catalyst.

[0049] In one aspect, UZM-44 can be extruded with a metal oxide binder before strengthening. Zeolite powder through ion exchange can be extruded in cylindrical or trilobal form, wherein the refractory metal oxide comprises SiO , TiO , ZrO , Al O , or their mixture. In one aspect, the refractory metal oxide can be SiO . The relative loading of zeolite and refractory metal oxide can vary. The zeolite content in the catalyst extrudate can be greater than 50 wt %, or greater than 55 wt %, or greater than 60 wt %, or greater than 65 wt %, or less than 95 wt %, or less than 90 wt %, or less than 80 wt %. Extrudate size and shape can vary within known technical limits, wherein preferably 1.6 mm cylindrical and trilobal. Extrudate width can be 0.75 mm to 4 mm, or 1.0 mm to 3 mm.

[0050] The dried extrudate may be calcined in air at a temperature in the range of 350°C to 600°C for 5 minutes to 6 hours. A time of 15 minutes to 4 hours, or 30 minutes to 3 hours may be acceptable. A temperature of 400°C to 550°C, or 450°C to 550°C may be acceptable. Optionally, the extrudate may be ion exchanged at 75°C for 1 hour using a 10:1:1 weight ratio of water: ammonium nitrate: extrudate. If ion exchanged, the extrudate will be rinsed multiple times with deionized H2O. If used, the ion exchange may be repeated as necessary. The final dried extrudate may then be calcined as described above.

[0051] The treatment enhanced by silica can be carried out by placing the sample in a container and adding an organic solvent. In one aspect, the amount of organic solvent to be added can be determined according to Table 1. The container can be heated at the reflux temperature of the organic solvent for 1 hour, during which time water can be removed from the system. The silicon reagent can then be added to the container. In one aspect, the silicon reagent includes but is not limited to silicon alkoxides. Suitable silicon alkoxides include but are not limited to tetramethyl orthosilicate (TMOS), tetraethyl orthosilicate (TEOS), tetrapropyl orthosilicate (TPOS), tetraisopropyl orthosilicate (TiPOS), tetrabutyl orthosilicate (TBOS). The silicon reagent can be a partially hydrolyzed alkoxide of silicon or a siloxane. Suitable sources can be purchased from Evonik. One of the product family. The silicon reagent can be chlorosilane. The concentration of the silicon reagent used can be in the range of 5 wt % to 25 wt % based on the weight of the sample.

[0052] Once the silicon reagent has been added, the contents of the container may be reacted under reflux for 5 minutes to 8 hours, or 30 minutes to 4 hours. After reflux, the solvent may be removed from the sample. Suitable solvent removal methods may involve decantation, distillation, or vacuum distillation. The sample may then be exposed to a thermal treatment step of at least 175°C and up to 600°C to form an enhanced catalyst. The enhancement treatment may be repeated as many times as necessary to achieve the desired pX / X selectivity.

[0053] The enhancement obtained by depositing carbon can be achieved under conditions associated with the subsequent disproportionation step, including one or more of higher temperature, lower pressure, higher space velocity, or higher hydrogen to hydrocarbon ratio. Such carbon deposition conditions may include an absolute pressure of 100 kPa to 4 MPa, and a 0.2 hr -1 Up to 10 hours -1 Liquid hourly space velocity. The conditions may include one or more of the following: an inlet temperature at least 50°C higher than the reaction temperature; a pressure at least 100 kPa lower than the reaction pressure, or preferably a pressure not exceeding half the pressure used in the subsequent disproportionation step. Preferably, the molar ratio of free hydrogen to feedstock (coke-forming hydrocarbon) does not exceed half the molar ratio used in the subsequent disproportionation step. Lower pressures and / or lower hydrogen / hydrocarbon ratios will reduce the proportion of exothermic aromatic saturation reactions and thus limit the temperature rise; the result should be a relatively flatter temperature curve. Therefore, the typical temperature range will be 300°C to 700°C, and the typical hydrogen to coke forming feed ratio range will be 0.01 to 5. The enhancement obtained by depositing carbon may result in a catalyst carbon content between 5% and 40% carbon by mass, and preferably between 10% and 30% carbon by mass. The coke forming feed for depositing carbon may include a feedstock for the disproportionation step as described below. In one aspect, toluene, or other specific hydrocarbons or mixtures known in the art, preferably containing aromatic compounds, may be used as coke forming feed.

[0054] UZM-44 can be enhanced once or multiple times with carbon and / or silica. Enhancement can incorporate carbon or silica into the catalyst comprising zeolite. "Into ... " means in or on its surface, and is intended to represent that carbon or silica enhancement can deposit material onto the outer surface of zeolite crystals, and / or onto the outer surface and / or within the pore structure of any refractory oxide present. Without wishing to be bound by theory, "into ... " does not describe the deposition of material in the micropores of zeolite. In one embodiment, enhancement can be performed on zeolite, can be performed on zeolite before being combined with the refractory oxide, or can be performed on a combined catalyst (including UZM-44 or UZM-44M). A separate enhancement step can be repeated until desired selectivity is achieved under disproportionation conditions. In one aspect, enhancement steps can be performed until pX / X is greater than 0.6, or greater than 0.7, or greater than 0.8, or greater than 0.85, or greater than 0.9.

[0055] After being enhanced by deposited carbon or deposited silica, the enhanced UZM-44 may optionally undergo a steaming treatment. Steaming after enhancement may increase the pX / X achieved during disproportionation. However, steaming may also reduce the activity of the zeolite or catalyst. In one aspect, the steaming treatment conditions may utilize a temperature of 100°C to 750°C, or 200°C to 700°C, or 450°C to 650°C; a water partial pressure of 0.1 to 0.5, or 0.15 to 0.35; and a time of 10 minutes to 26 hours, or 30 minutes to 6 hours. In one aspect, a high pX / X ratio during disproportionation may be achieved by one or more enhancement steps or by a combination of one or more enhancement steps with one or more steaming steps. The steaming step and the enhancement step may be performed in any order found to achieve a high pX / X.

[0056] The enhanced UZM-44 zeolite of the present invention may also be used as a catalyst or catalyst support in a toluene disproportionation process.

[0057] The toluene disproportionation process comprises contacting a feed stream comprising toluene with a catalyst comprising a zeolite under disproportionation conditions to produce an effluent stream comprising benzene and xylenes. In a selective disproportionation process such as the present invention, the catalyst may have been enhanced by one or more treatment steps so as to increase the molar ratio of para-xylene to xylenes (pX / X) from an equilibrium level of 0.24 to 0.60 or higher by depositing a sufficient amount of coke or silica. Although this enhancement increases the pX / X molar ratio, it has previously been accompanied by an increase in the molar ratio of benzene to xylenes (Bz / X) to a theoretical value significantly greater than 1. Using optimal silica deposition technology to increase the pX / X molar ratio to 0.90 or higher is common in processes that can contain 30% toluene conversion, H2 / HC=2, WHSV=4hr -1Under the disproportionation conditions at a pressure of 2.8 MPa(g), the Bz / X molar ratio is at most 1.4.

[0058] Ideally, the toluene disproportionation process operates at the highest toluene conversion while maximizing the xylene yield from the reaction. In one aspect, the toluene conversion can be greater than 20 wt%, or greater than 25 wt%, or greater than 28 wt%, or greater than 30 wt%, or greater than 32 wt%, or greater than 35 wt%, or less than 50 wt%, or less than 40 wt%, or less than 35 wt%.

[0059] The feed of the disproportionation reaction may include toluene, which is optionally combined with C9 aromatic compounds, and is suitably derived from one or more sources. The feedstock may be produced, for example, by catalytic reforming from naphtha synthesis, or by pyrolysis, followed by hydrotreatment to produce a product rich in aromatic compounds. The feedstock may be derived from such products with a suitable purity by extracting aromatic hydrocarbons from a mixture of aromatic hydrocarbons and non-aromatic hydrocarbons and fractionating the extract. For example, aromatic compounds may be recovered from the reformate. The feedstock may include at least 80% by mass of toluene, or more than 85% by mass of toluene, or more than 90% by mass of toluene, or more than 95% by mass of toluene, or even more than 98.5% by mass of toluene. The feedstock may include more than 90% by mass of aromatic compounds, or more than 95% by mass of aromatic compounds, or more than 98% by mass of aromatic compounds, or more than 99% by mass of aromatic compounds, or even more than 99.5% by mass of aromatic compounds. In one aspect, the feedstock may contain no more than 10% by mass of non-aromatic compounds. In one aspect, the feed may contain no more than 10% by mass of benzene. In one aspect, the feed may contain no more than 10% by mass of xylene. In one aspect, the feed may contain no more than 10% by mass of A9 aromatic compounds. Advantageously, non-aromatic compounds, benzene, xylene and A9 aromatic compounds are close to 0% by mass. In one aspect, all or a mixture of any conditions listed in this paragraph may be applicable to the characterization of the feed.

[0060] The disproportionation reaction conditions may include a temperature in the range of 200°C to 600°C, or 300°C to 450°C, or 350°C to 425°C. The pressure may be in the range of 1.0 MPa to 7.0 MPa, or 1.4 MPa(g) to 4.5 MPa(g), or 2.0 MPa(g) to 3.5 MPa(g). The disproportionation reaction may be carried out over a wide range of space velocities, wherein a higher space velocity achieves a higher para-xylene ratio at the expense of conversion. The weight hourly space velocity (WHSV) may be 0.5 hr -1 Up to 10 hours -1 , or 1.0hr -1 Up to 7 hours -1 , or 1.0hr -1 Up to 5 hours-1 The ratio of hydrogen to hydrocarbon is calculated based on the molar ratio of free hydrogen to feed hydrocarbon. Periodically increasing the ratio of hydrogen to hydrocarbon above 0.5, and preferably within the range of 1 to 5, may allow catalyst regeneration by hydrogenating the soft coke. The ratio of hydrogen to hydrocarbon may be within the range of 0.25 to 10 or 0.5 to 5.

[0061] The molar ratio of para-xylene to xylene (pX / X) in the effluent is an important factor in the selective toluene disproportionation process. Under toluene disproportionation conditions, the equilibrium pX / X is 0.24, so the para-selective toluene disproportionation process produces an effluent containing a pX / X greater than 0.25 or greater than 0.30. The effluent from the toluene disproportionation process may have a pX / X molar ratio greater than 0.60, or greater than 0.70, or greater than 0.75, or greater than 0.80, or greater than 0.85, or greater than 0.90, and may be less than 0.98, or less than 0.96, or less than 0.94.

[0062] Ideally, the toluene disproportionation process is operated at a benzene to xylene molar ratio (Bz / X) of 1.00 in the effluent. Bz / X of 1.00 means that for each mole of benzene produced, one mole of xylene is produced. Preferably, the Bz / X ratio is closer to 1.00, and in one aspect, the Bz / X molar ratio can be less than 1.20, or less than 1.16, or less than 1.12, or less than 1.08, or less than 1.06, or less than 1.05, or less than 1.04, or less than 1.03, or less than 1.02, or less than 1.01, and greater than 1.00, or greater than 0.99, or greater than 0.98. For example, in some embodiments, the Bz / X molar ratio is in the range of 0.98 to 1.20, and the pX / X molar ratio is in the range of 0.25 to 0.95. In some embodiments, the Bz / X molar ratio is in the range of 0.98 to 1.16, while the pX / X molar ratio is in the range of 0.25 to 0.95. In some embodiments, the Bz / X molar ratio is in the range of 0.98 to 1.12, while the pX / X molar ratio is in the range of 0.25 to 0.95. In some embodiments, the Bz / X molar ratio is in the range of 0.98 to 1.08, while the pX / X molar ratio is in the range of 0.25 to 0.95. In some embodiments, the Bz / X molar ratio is in the range of 0.98 to 1.06, while the pX / X molar ratio is in the range of 0.25 to 0.90. In some embodiments, the Bz / X molar ratio is in the range of 0.98 to 1.05, while the pX / X molar ratio is in the range of 0.25 to 0.85. In some embodiments, the Bz / X molar ratio is in the range of 0.98 to 1.02, while the pX / X molar ratio is in the range of 0.25 to 0.85. In some embodiments, the Bz / X molar ratio is in the range of 0.98 to 1.01, while the pX / X molar ratio is in the range of 0.25 to 0.80. In some embodiments, the Bz / X molar ratio is in the range of 1.00 to 1.20, while the pX / X molar ratio is in the range of 0.80 to 0.95. In some embodiments, the Bz / X molar ratio is in the range of 1.00 to 1.16, while the pX / X molar ratio is in the range of 0.80 to 0.95. In some embodiments, the Bz / X molar ratio is in the range of 1.00 to 1.12, while the pX / X molar ratio is in the range of 0.80 to 0.95. In some embodiments, the Bz / X molar ratio is in the range of 1.00 to 1.08, and the pX / X molar ratio is in the range of 0.80 to 0.95. In some embodiments, the Bz / X molar ratio is in the range of 1.00 to 1.06, and the pX / X molar ratio is in the range of 0.80 to 0.90.

[0063] When the feed contains benzene or xylene, the amount of benzene or xylene or p-xylene in the feed is subtracted from the amount of product to determine the Bz / X ratio and the pX / X ratio. In other words:

[0064] Bz / X molar ratio = (Bz 产物 –Bz 进料 ) / (X 产物 –X 进料 ).

[0065] In addition, the molar ratio of p-xylene to total xylene can be expressed by pX / X molar ratio = (pX 产物 –pX 进料 ) / (X 产物 –X 进料 )=PXX to determine.

[0066] There is a relationship between the benzene to xylene molar ratio Bz / X and the para-xylene to xylene molar ratio pX / X, where Bz / X increases as pX / X increases. Surprisingly, catalysts comprising UZM-44 suffer much less from this problem than previously known catalysts. Therefore, when pX / X is in the range of 0.60 to 1.0, Bz / X can be in the range of 1.00 to 0.375*PXX+0.825, where PXX is the para-xylene to xylene molar ratio. Without being bound by theory, this equation allows one skilled in the art to calculate that when pX / X is 0.60, Bz / X can be in the range of 1.00 to 1.05. When pX / X is 0.80, Bz / X can be in the range of 1.00 to 1.13. When pX / X is 0.90, Bz / X can be in the range of 1.00 to 1.16.

[0067] Very high selectivity for para-xylene at all pX / X molar ratios can be achieved with enhanced catalysts prepared using UZM-44, even when the pX / X molar ratio is greater than 0.8. The selectivity for xylene can be greater than 52% when the pX / X molar ratio is in the range of 0.3 to 0.9 or higher, or greater than 53% when the pX / X molar ratio is in the range of 0.3 to 0.85 or higher, or greater than 54% when the pX / X molar ratio is 0.3 to 0.85 or higher, or greater than 55% when the pX / X molar ratio is 0.3 to 0.8 or higher. In one aspect, all or a mixture of any of the conditions listed in this paragraph can be applied when the pX / X molar ratio is in the range of 0.6 to 0.95 or when the pX / X molar ratio is in the range of 0.8 to 0.95.

[0068] Very low selectivity for light fractions (e.g., C1-C6 hydrocarbons) can be achieved using enhanced catalysts prepared using UZM-44 at all pX / X molar ratios, even when the pX / X molar ratio is greater than 0.8. The selectivity for light fractions can be less than 3.5 wt% when the pX / X molar ratio is in the range of 0.3 to 0.9 or more, or less than 3 wt% when the pX / X molar ratio is in the range of 0.3 to 0.9 or more, or less than 2 wt% when the pX / X molar ratio is in the range of 0.3 to 0.85 or more, or less than 1.5 wt% when the pX / X molar ratio is in the range of 0.3 to 0.80 or more, or even less than 1 wt% when the pX / X molar ratio is in the range of 0.3 to 0.8 or more. In one aspect, all or a mixture of any of the conditions listed in this paragraph can be applied when the pX / X molar ratio is in the range of 0.6 to 0.95 or when the pX / X molar ratio is in the range of 0.8 to 0.95.

[0069] The enhanced catalysts of the present invention can have low ring loss. Ring loss can be calculated by subtracting the number of moles of monocyclic aromatic compounds in the product from the number of moles of monocyclic aromatic compounds in the feed divided by the number of moles of monocyclic aromatic compounds in the feed multiplied by 100. Therefore, Ring Loss = (Ar 产物 –Ar 进料 ) / (Ar 进料 )*100. Monocyclic aromatic compounds may include benzene, toluene, xylene, 9 carbon aromatic molecules, 10 carbon aromatic molecules, etc. Monocyclic aromatic compounds do not include naphthalene. Without being bound by theory, the selection and ring loss for light ends may be proportional to cracking. That is, a catalyst with high selectivity for light ends may also have high ring loss. Light ends refer to non-aromatic hydrocarbons with 1 to 6 carbon atoms. In one aspect, methane, ethane, propane, butane, pentane, hexane and cyclohexane may constitute light ends. In one aspect, the ring loss may be less than 1.5%, or less than 1.4%, or less than 1.3%, or less than 1.2%, or less than 1.1%, or less than 1.0%, or less than 0.8%, or less than 0.65%, or less than 0.5%.

[0070] In one aspect, the industry expects to retain methyl groups during disproportionation. Benzene has zero moles of methyl groups / mole benzene, toluene has 1 mole of methyl groups / mole toluene, xylene has 2 moles of methyl groups / mole xylene, etc. The ratio of methyl to phenyl in the stream can be calculated by dividing the number of moles of methyl groups in the stream by the number of moles of monocyclic aromatic compounds in the stream. In one aspect, the methyl to phenyl ratio of the product can be similar to the methyl to phenyl ratio of the feed. MPP is calculated by dividing the methyl to phenyl ratio of the product stream by the ratio of the feed stream. MPP can be greater than 0.96, or 0.97, or 0.98, or 0.99, and less than 1.0.

[0071] The enhanced UZM-44 zeolite can be used in toluene disproportionation processes such as Figure 1 As shown in. The toluene disproportionation process may include multiple modules. In one aspect, a feed stream 100 comprising toluene is mixed with a second stream 304 to form a mixed feed stream 102 that is transmitted to a reaction zone 200. In the disproportionation process, the feed stream or mixed feed stream may first be heated by indirect heat exchange with the effluent of the reaction zone, and then further heated in a fired heater. The resulting steam stream is then passed through the reaction zone, which may include one or more separate reactors. The feed advantageously contains less than 10% by mass of benzene, less than 10% by mass of xylene, less than 10% by mass of A9 aromatic compounds and less than 10% by mass of non-aromatic compounds. In the mixed feed stream 102, benzene, xylene, A9 aromatic compounds and non-aromatic compounds may be less than 5% by mass. Advantageously, all of these are close to 0% by mass.

[0072] Reaction zone 200 may include one or more reactors. The one or more reactors may be fixed bed reactors in which one or more fixed beds of catalyst comprising UZM-44 are located. It is preferred to use a single reaction vessel with a fixed cylindrical bed of catalyst, but other reaction configurations utilizing a moving bed of catalyst or a radial flow reactor may be employed if desired. The reaction conditions in reaction zone 200 may include disproportionation reaction conditions as previously described.

[0073] Mixed feed stream 102 passes through reaction zone and realizes the generation of steam effluent 204, and described steam effluent contains hydrogen, product hydrocarbon and unconverted feed hydrocarbon.Produce effluent 204 from reaction zone 200, wherein effluent 204 has pX with higher concentration than pX present in mixed stream 102.In one aspect, pX can be higher than 0.6, or higher than 0.7, or higher than 0.8, or higher than 0.85, or higher than 0.9.Effluent 204 can be sent to separation zone 300 to separate unreacted toluene from product benzene and xylene.This effluent can be cooled usually by indirect heat exchange with the stream entering reaction zone, and then further cooled by using air or cooling water.Can reduce the temperature of effluent stream by sufficient heat exchange, to realize the condensation of product hydrocarbon with six or more carbon atoms of substantially all feed and every molecule. The resulting mixed phase stream may be passed to a vapor-liquid separator wherein the two phases are separated and the hydrogen-rich vapor thereby recycled to the reaction zone in the form of a first recycle stream.

[0074] Separation zone 300 may include one or more distillation towers. Condensate from the separator may be sent to a stripping tower, in which substantially all C5 and lighter hydrocarbons present in the effluent are concentrated into the overhead stream and removed from the process. A rich aromatic compound stream referred to as a disproportionated effluent stream may be recovered as a net stripper bottom. In one aspect, a benzene tower and a toluene tower may be present. The disproportionated effluent stream may be fed to the benzene tower and the toluene tower in the separation zone. A first stream 302 comprising benzene may be separated and used for other reaction operations of an aromatic complex, or may be transported to a tank for sale. In one aspect, the first stream 302 may be an overhead stream from a benzene tower. A second stream 304 comprising toluene may be separated. In one aspect, all or part of the second stream 304 may be recycled to the reaction zone as a part of a mixed feed stream 102. In one aspect, the second stream 304 comprises less than 10% by mass of benzene, or less than 5% by mass of benzene, or less than 3% by mass of benzene, or less than 1% by mass of benzene. In one aspect, the second stream 304 is substantially free of benzene. So-called "substantially free of" means less than 0.1 mass %. In one aspect, the second stream 304 comprises less than 10 mass % of xylene, or less than 5 mass % of xylene, or less than 3 mass % of xylene, or less than 1 mass % of xylene. In one aspect, the second stream 304 is substantially free of xylene. In one aspect, the second stream 304 can be the overhead stream of a toluene tower. In one aspect, the bottoms stream from a benzene tower can be fed to a toluene tower. The third stream 306 comprising xylene can be separated.

[0075] Depending on the desired paraxylene purity, the third stream 306 may be utilized as is or may be sent to a pX purification section 400. In one aspect, the separation zone or pX purification section may also include a catalytic alkyl-aromatic compound zone for ethylbenzene conversion and dealkylation. The purification section 400 may include one or more pX purification units. Many pX purification units are known, and these include, but are not limited to, crystallization processes and adsorption separation processes, such as the Parex® 1000 available from UOP. TM process. In each case, a purified pX stream 404 comprising up to 100% pX may be formed. The purification section 400 may also produce a waste stream 402 comprising meta-xylene (mX) and ortho-xylene (oX). The waste stream 402 may also comprise ethylbenzene (EB). The waste stream may be purged from the process. An exemplary use of the waste stream may be as a feed for a xylene isomerization process, such as Isomar available from Universal Oil Products (UOP). TM The xylene isomerization product may be recycled back to the purification section 400.

[0076] One aspect of the invention is a toluene disproportionation process. In one embodiment, the process comprises contacting a feed comprising toluene with a catalyst comprising a microporous crystalline zeolite under disproportionation conditions to produce an effluent stream comprising para-xylene and benzene, wherein the molar ratio of benzene to xylene in the effluent stream is in the range of 1.00 to 1.14, wherein the molar ratio of para-xylene to xylene in the effluent stream is in the range of 0.80 to 1.0, and wherein the conversion of toluene is 20% to 40%.

[0077] In some embodiments, the molar ratio of benzene to xylenes is in the range of 1.00 to 1.08.

[0078] In some embodiments, the microporous crystalline zeolite comprises a three-dimensional framework of at least AlO 2 and SiO 2 tetrahedral units and an empirical composition in hydrogen form represented by the following empirical formula:

[0079] M1 a N+ Al (l-x) E x Si y’ O z”

[0080] and wherein M1 is at least one exchangeable cation selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, zinc, ammonium ions, hydrogen ions, and combinations thereof, "a" is the molar ratio of M1 to (Al E) and varies from 0.05 to 50, "N" is the weighted average valence of M1 and has a value of +1 to +3, E is an element selected from the group consisting of gallium, iron, boron, and combinations thereof, "x" is the molar ratio of E and varies from 0 to 1.0, y' is the molar ratio of Si to (Al + E) and varies from greater than 9 to substantially pure silica, and "Z" is the molar ratio of O to (Al + E) and has a value determined by the following equation:

[0081] z'=(a·N+3+4·y') / 2

[0082] wherein the zeolite is characterized in that it has an x-ray diffraction pattern having at least the d-spacings and intensities shown in Table B:

[0083] Table B

[0084]

[0085]

[0086] In some embodiments, the catalyst has been enhanced using at least one enhancement treatment step.

[0087] In some embodiments, at least one enhancement treatment step includes at least one treatment for incorporating silica.

[0088] In some embodiments, the catalyst is steamed after at least one enhancement treatment step.

[0089] In some embodiments, the molar ratio of benzene to xylenes is in the range of 1.00 to 1.08, and the molar ratio of para-xylene to xylenes is in the range of 0.80 to 0.95.

[0090] In some embodiments, when the molar ratio of para-xylene to xylene is in the range of 0.80 to 0.9, the selectivity for xylene is greater than 52%.

[0091] In some embodiments, when the molar ratio of para-xylene to xylene is in the range of 0.80 to 0.9, the selectivity to light ends is less than 3.5%.

[0092] In some embodiments, the disproportionation conditions include one or more of the following: a temperature in the range of 200°C to 600°C; a pressure in the range of 1.4 MPa(g) to 4.5 MPa(g); -1 Up to 10 hours -1 or a hydrogen to hydrocarbon ratio in the range of 0.25:1 to 10:1.

[0093] In some embodiments, the ring loss is less than 1.5%.

[0094] Another aspect of the invention is a toluene disproportionation process. In one embodiment, the process comprises contacting a feed comprising toluene with a catalyst comprising a microporous crystalline zeolite under disproportionation conditions to produce an effluent stream comprising para-xylene and benzene, wherein the molar ratio of benzene to xylene in the effluent stream is in the range of 1.00 to 1.20, wherein the molar ratio of para-xylene to xylene in the effluent stream is in the range of 0.60 to 1.0, the zeolite having a three-dimensional framework of at least AlO2 and SiO2 tetrahedral units and an empirical composition in hydrogen form represented by the following empirical formula:

[0095] M1 a N+ Al (l-x) E x Si y’ O z”

[0096] and wherein M1 is at least one exchangeable cation selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, zinc, ammonium ions, hydrogen ions, and combinations thereof, "a" is the molar ratio of M1 to (Al+E) and varies from 0.05 to 50, "N" is the weighted average valence of M1 and has a value of +1 to +3, E is an element selected from the group consisting of gallium, iron, boron, and combinations thereof, "x" is the molar ratio of E and varies from 0 to 1.0, y' is the molar ratio of Si to (Al+E) and varies from greater than 9 to substantially pure silica, "Z" is the molar ratio of O to (Al+E) and has a value determined by the following equation:

[0097] z'=(a·N+3+4·y') / 2

[0098] wherein the zeolite is characterized in that it has an x-ray diffraction pattern having at least the d-spacings and intensities shown in Table B:

[0099] Table B

[0100]

[0101]

[0102] In some embodiments, the conversion of toluene is between 20% and 40%.

[0103] In some embodiments, the zeolite is enhanced with at least one enhancement selected from: a treatment for depositing carbon, a treatment for depositing silica, or both.

[0104] In some embodiments, the catalyst is steamed after at least one enhancement treatment step.

[0105] In some embodiments, the molar ratio of benzene to xylenes is in the range of 1.00 to 1.08, and the molar ratio of para-xylene to xylenes is in the range of 0.80 to 0.95.

[0106] In some embodiments, when the molar ratio of para-xylene to xylene is in the range of 0.80 to 0.9, the selectivity for xylene is greater than 52%.

[0107] In some embodiments, when the molar ratio of para-xylene to xylene is in the range of 0.80 to 0.9, the selectivity to light ends is less than 3.5%.

[0108] In some embodiments, the disproportionation conditions include one or more of the following: a temperature in the range of 200°C to 600°C; a pressure in the range of 1.4 MPa(g) to 4.5 MPa(g); -1 Up to 10 hours-1 or a hydrogen to hydrocarbon ratio in the range of 0.25 to 10.

[0109] Another aspect of the invention is a toluene disproportionation process. In one embodiment, the process comprises contacting a feed comprising toluene with a catalyst comprising a microporous crystalline zeolite under disproportionation conditions to produce an effluent stream comprising para-xylene and benzene, wherein PXX is the molar ratio of para-xylene to xylenes in the effluent stream, wherein BX is the molar ratio of benzene to xylenes in the effluent stream, and wherein when PXX is in the range of 0.60 to 1.0, BX is in the range of 1.00 to 0.375*PXX+0.825.

[0110] In some cases, the purity of a synthetic product can be assessed by reference to its x-ray powder diffraction pattern. Thus, for example, if a sample is described as pure, it is intended only to mean that the x-ray pattern of the sample contains no lines attributable to crystalline impurities, not that amorphous material is absent.

[0111] In order to more fully illustrate the present invention, the following examples are presented. It should be understood that these examples are merely illustrative and are not intended to overly limit the broad scope of the present invention as set forth in the appended claims.

[0112] Example

[0113] UZM-44 zeolite material was prepared according to the procedures described in US 8,609,920 and US 8,623,321 with a SiO2 / Al2O3 ratio of 28. MFI#1 is an MFI zeolite with a SiO2 / Al2O3 ratio of 38, which was purchased from Universal Oil Products (UOP). MFI#2 is an MFI zeolite with a SiO2 / Al2O3 ratio of 23, which was purchased from Zeolyst.

[0114] Standard Catalyst Extrusion

[0115] The zeolite was typically extruded prior to reinforcement. Unless otherwise noted, the ion-exchanged zeolite powder was extruded in the form of 1 / 16" cylinders or trilobes with 35 wt% SiO2 and dried overnight. The dried extrudates were calcined at 550°C in air for 2-4 hours. In some cases, the extrudates were ion-exchanged at 75°C for 1 hour using a 10:1:1 weight ratio of water:ammonium nitrate:extrudate. If ion-exchanged, the sample was rinsed multiple times with deionized H2O. The ion exchange was repeated 3 times and the final dried extrudates were calcined at 450°C-500°C in air for 4 hours.

[0116] General Enhancement Program :

[0117] The sample to be enhanced is placed in a glass round-bottom flask, and an appropriate amount of organic solvent from Table 1 is added. A Dean-Stark water trap and a condenser are attached to the round-bottom flask, which is filled with additional solvent and insulated with tin foil. The flask is heated with a heating jacket and refluxed for 1 hour, after which the Dean-Stark water trap is drained and removed from the flask. Unless otherwise stated, tetraethyl orthosilicate or other silicon reagents are added to the flask in an amount of 14% by weight based on the weight of the sample. The condenser is reattached, and the contents of the flask are reacted under reflux for 2 hours. The solvent is then removed from the sample by decantation, distillation or reduced pressure distillation. Then, the sample is subjected to a heat treatment step of at least 175°C to form an enhanced catalyst. The enhanced treatment is repeated as needed to achieve the desired pX / X selectivity.

[0118] Table 1: Weight ratio of solvent to base extrudate for various solvents

[0119] Solvents Solvent to base weight ratio Hexane 1.76 Toluene 1.65 Mesitylene (1,3,5-trimethylbenzene) 2.45 n-octane 2.53 n-Decane 2.91 Cyclohexane 1.76

[0120] Example 1. UZM-44 was used in a standard preparation with 3 processing cycles using rotary evaporation as the solvent removal method.

[0121] Example 2. UZM-44 was used in a standard preparation with 6 processing cycles using rotary evaporation as the solvent removal method.

[0122] Example 3. UZM-44 was used in a standard preparation with 5 processing cycles using rotary evaporation as the solvent removal method.

[0123] Example 4. UZM-44 was used in a standard preparation with 6 treatment cycles at 14% TEOS concentration and a 7th treatment cycle at 6% TEOS concentration using rotary evaporation as the solvent removal method.

[0124] Comparative Examples 5-31. Example 5-24 was made from MFI #1. Examples 25-31 were made from MFI #2.

[0125] Comparative Example 5. MFI #1 was used for a standard preparation with 3 processing cycles using hexane as solvent.

[0126] Comparative Example 6. MFI #1 was used for a standard preparation with 3 treatment cycles.

[0127] Comparative Example 7. MFI #1 was used for a standard preparation with 3 treatment cycles.

[0128] Comparative Example 8. MFI #1 was used for a standard preparation with 4 treatment cycles.

[0129] Comparative Example 9. MFI #1 was used for a standard preparation with 3 treatment cycles.

[0130] Comparative Example 10. MFI #1 was used for a standard preparation with 4 treatment cycles.

[0131] Comparative Example 11. MFI #1 was used for a standard preparation with 3 treatment cycles.

[0132] Comparative Example 12. MFI #1 was used for a standard preparation with 4 treatment cycles.

[0133] Comparative Example 13. MFI #1 was used in a standard preparation with 3 processing cycles in which the solvent was removed by distillation.

[0134] Comparative Example 14. MFI #1 was extruded with TiO2 at 70% zeolite content and treated with 4 standard treatment cycles.

[0135] Comparative Example 15. MFI #1 was used for a standard preparation with 3 treatment cycles.

[0136] Comparative Example 16. MFI #1 was used for a standard preparation with 2 processing cycles.

[0137] Comparative Example 17. MFI #1 was used for a standard preparation followed by 3 treatment cycles using 20% ​​TEOS in hexane.

[0138] Comparative Example 18. MFI #1 was used for a standard preparation with 3 processing cycles using hexane as solvent followed by a 190°C heating step.

[0139] Comparative Example 19. MFI #1 was used for a standard preparation with 3 processing cycles using hexane as solvent and distillation as the solvent removal method.

[0140] Comparative Example 20. MFI #1 was used for a standard preparation with 2 processing cycles using n-octane as solvent and decantation as solvent removal method.

[0141] Comparative Example 21. MFI #1 was used for a standard preparation with 3 processing cycles using n-decane as solvent and decantation as the solvent removal method.

[0142] Comparative Example 22. MFI #1 was used for a standard preparation with 3 treatment cycles using 10.2% TMOS in cyclohexane.

[0143] Comparative Example 23. MFI #1 was used for a standard preparation with 2 processing cycles using 14% TBOS in toluene using rotary evaporation as the solvent removal method.

[0144] Comparative Example 24. MFI #1 was used in a standard preparation with 4 treatment cycles of Dynaslan Silbond (TEOS derivative from Evonik).

[0145] Comparative Example 25. MFI #2 was used for a standard preparation with 3 processing cycles.

[0146] Comparative Example 26. MFI #2 was used for a standard preparation with 3 processing cycles.

[0147] Comparative Example 27. MFI #2 was prepared with ZrO2 at 70% zeolite content in spherical form using the method described in US Patent 4,629,717. The 70 / 30 MFI / ZrO2 spheres were then enhanced using 3 treatment cycles.

[0148] Comparative Example 28. MFI #2 was used for a standard preparation with 1 processing cycle using rotary evaporation as the solvent removal method.

[0149] Comparative Example 29. MFI #2 was used for a standard preparation with 2 processing cycles using rotary evaporation as the solvent removal method.

[0150] Comparative Example 30. MFI #2 was used for a standard preparation with 3 processing cycles using rotary evaporation as the solvent removal method.

[0151] Comparative Example 31. MFI #2 was used for a standard preparation with 1 cycle using 14% TEOS in mesitylene (1,3,5-trimethylbenzene) as the solvent and decantation as the solvent removal method.

[0152] Catalyst Testing Procedures :

[0153] The catalyst was tested in a disproportionation reaction using a nominal 100 wt% toluene feed. The disproportionation reaction conditions were as follows: WHSV was 4 hr -1 , a hydrogen to feed molar ratio of 2, a pressure of 2.8 MPa(g) (400 psig), and a temperature of 350° C. to 460° C. The results achieved are shown in Table 2 and are compared to a target overall toluene conversion of 30 wt %.

[0154] Figure 2The results of Table 2 are shown, which are plotted as a graph of the benzene to xylene molar ratio (Bz / X) in the product relative to the p-xylene molar ratio (pX / X) achieved. The catalyst made using MFI#1 is shown with a black trend line in black circles, those made using MFI#2 are shown with a gray trend line in white circles, and the catalyst of the present invention made using UZM-44 is shown with a dotted trend line in white boxes. Under all pX / X ratios, the enhanced catalyst made using UZM-44 shows a very low Bz / X ratio, even when pX / X is greater than 0.8. When the pX / X ratio is greater than 0.85, the catalyst made using the MFI zeolite has a Bz / X ratio greater than 1.17.

[0155] Figure 3 The results of Table 2 are shown, which are plotted as a relationship diagram of the xylene selectivity in the product relative to the p-xylene molar ratio (pX / X) achieved. The catalyst made using MFI#1 is shown with a black trend line in black circles, those made using MFI#2 are shown with a gray trend line in white circles, and the catalyst of the present invention made using UZM-44 is shown with a dotted trend line in white boxes. Under all pX / X ratios, the enhanced catalyst made using UZM-44 shows a very high selectivity for xylene, even when pX / X is greater than 0.8. The catalyst made using UZM-44 has a selectivity for xylene greater than 52%, greater than 53%, or greater than 54% when pX / X is greater than 0.8, or greater than 0.85, or greater than 0.9.

[0156] Figure 4 The results of Table 2 are shown, which are plotted as a relationship diagram of the selectivity for light fractions (C1-C6 non-aromatic hydrocarbons) in the product relative to the p-xylene molar ratio (pX / X) achieved. The catalyst made using MFI#1 is shown with a black trend line in black circles, those made using MFI#2 are shown with a gray trend line in white circles, and the catalyst of the present invention made using UZM-44 is shown with a dotted trend line in white boxes. Under all pX / X ratios, the enhanced catalyst made using UZM-44 shows a very low selectivity for light fractions, even when pX / X is greater than 0.8. The catalyst made using UZM-44 can have a selectivity for light fractions of less than 3.5 wt %, or less than 3 wt %, or less than 2 wt %, or less than 1.5 wt %, or even less than 1 wt % when pX / X is greater than 0.8, or greater than 0.85, or greater than 0.9.

[0157] Figure 5The results of Table 2 are shown, plotted as the temperature required to achieve 30% toluene conversion versus the para-xylene mole ratio achieved (pX / X). Catalysts made using MFI#1 are shown as black circles with a black trend line, those made using MFI#2 are shown as white circles with a grey trend line, and catalysts of the invention made using UZM-44 are shown as white squares with a dashed trend line.

[0158] The enhanced UZM-44 catalyst is completely unique. In addition to its surprisingly low Bz / X molar ratio, it also shows higher xylene yields, lower ring losses, less light ends (e.g., C1-C6 hydrocarbons), and better methyl / phenyl retention than any of the other catalysts with similar pX / X molar ratios.

[0159] Table 2 :

[0160]

[0161]

[0162] Specific implementation plan

[0163] While the following is described in conjunction with specific embodiments, it should be understood that this description is intended to illustrate and not to limit the scope of the foregoing description and the appended claims.

[0164] A first embodiment of the present invention is a toluene disproportionation process comprising contacting a feed comprising toluene with a catalyst comprising a microporous crystalline zeolite under disproportionation conditions to produce an effluent stream comprising para-xylene and benzene, wherein the molar ratio of benzene to xylene in the effluent stream is in the range of 1.00 to 1.14, wherein the molar ratio of para-xylene to xylene in the effluent stream is in the range of 0.80 to 1.0, and wherein the conversion of toluene is 20% to 40%. An embodiment of the present invention is one, any one, or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, wherein the molar ratio of benzene to xylene is in the range of 1.00 to 1.08. An embodiment of the present invention is one, any one, or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, wherein the microporous crystalline zeolite comprises a three-dimensional framework of at least AlO2 and SiO2 tetrahedral units and an empirical composition in the form of hydrogen expressed by the following empirical formula:

[0165] M1 a N+ Al (l-x) E x Si y’ O z”

[0166] and wherein M1 is at least one exchangeable cation selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, zinc, ammonium ions, hydrogen ions, and combinations thereof, "a" is the molar ratio of M1 to (Al E) and varies from 0.05 to 50, "N" is the weighted average valence of M1 and has a value of +1 to +3, E is an element selected from the group consisting of gallium, iron, boron, and combinations thereof, "x" is the molar ratio of E and varies from 0 to 1.0, y' is the molar ratio of Si to (Al + E) and varies from greater than 9 to substantially pure silica, "Z" is the molar ratio of O to (Al + E) and has a value determined by the following equation:

[0167] z"=(aπN+3+4πy') / 2

[0168] wherein the zeolite is characterized in that it has an x-ray diffraction pattern having at least the d-spacings and intensities shown in Table B:

[0169] Table B

[0170]

[0171] One embodiment of the invention is one, any or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, wherein the catalyst has been enhanced with at least one enhancement treatment step. One embodiment of the invention is one, any or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, wherein the at least one enhancement treatment step comprises at least one treatment for incorporating silica. One embodiment of the invention is one, any or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, wherein the catalyst is steamed after the at least one enhancement treatment step. One embodiment of the invention is one, any or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, wherein the molar ratio of benzene to xylene is in the range of 1.00 to 1.08, and the molar ratio of para-xylene to xylene is in the range of 0.80 to 0.95. One embodiment of the invention is one, any or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, wherein the selectivity for xylene is greater than 52% when the molar ratio of para-xylene to xylene is in the range of 0.80 to 0.9. One embodiment of the present invention is one, any or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, wherein when the molar ratio of para-xylene to xylene is in the range of 0.80 to 0.9, the selectivity for light fractions is less than 3.5%. One embodiment of the present invention is one, any or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, wherein the disproportionation conditions include one or more of the following: a temperature in the range of 200°C to 600°C; a pressure in the range of 1.4 MPa(g) to 4.5 MPa(g); a temperature in the range of 0.1 hr -1 Up to 10 hours -1 or a hydrogen to hydrocarbon ratio in the range of 0.251 to 101. An embodiment of the invention is one, any or all of prior embodiments in this paragraph through the first embodiment in this paragraph, wherein the ring losses are less than 1.5%.

[0172] A second embodiment of the present invention is a toluene disproportionation process comprising contacting a feed comprising toluene with a catalyst comprising a microporous crystalline zeolite under disproportionation conditions to produce an effluent stream comprising para-xylene and benzene, wherein the molar ratio of benzene to xylenes in the effluent stream is in the range of 1.00 to 1.20, wherein the molar ratio of para-xylene to xylenes in the effluent stream is in the range of 0.60 to 1.0, the zeolite having a three-dimensional framework of at least AlO2 and SiO2 tetrahedral units and an empirical composition in hydrogen form represented by the following empirical formula:

[0173] M1a N+ Al (l-x) E x Si y’ O z”

[0174] and wherein M1 is at least one exchangeable cation selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, zinc, ammonium ions, hydrogen ions, and combinations thereof, "a" is the molar ratio of M1 to (Al E) and varies from 0.05 to 50, "N" is the weighted average valence of M1 and has a value of +1 to +3, E is an element selected from the group consisting of gallium, iron, boron, and combinations thereof, "x" is the molar ratio of E and varies from 0 to 1.0, y' is the molar ratio of Si to (Al + E) and varies from greater than 9 to substantially pure silica, "Z" is the molar ratio of O to (Al + E) and has a value determined by the following equation:

[0175] z"=(aπN+3+4πy') / 2

[0176] wherein the zeolite is characterized in that it has an x-ray diffraction pattern having at least the d-spacings and intensities shown in Table B:

[0177] Table B

[0178]

[0179] One embodiment of the present invention is one, any one or all of the previous embodiments in this paragraph to the second embodiment in this paragraph, wherein the conversion of toluene is 20% to 40%. One embodiment of the present invention is one, any one or all of the previous embodiments in this paragraph to the second embodiment in this paragraph, wherein the zeolite has been enhanced with at least one enhancement selected from a treatment for depositing carbon, a treatment for depositing silica, or both. One embodiment of the present invention is one, any one or all of the previous embodiments in this paragraph to the second embodiment in this paragraph, wherein the catalyst is steamed after the at least one enhancement treatment step. One embodiment of the present invention is one, any one or all of the previous embodiments in this paragraph to the second embodiment in this paragraph, wherein the molar ratio of benzene to xylene is in the range of 1.00 to 1.08, and the molar ratio of para-xylene to xylene is in the range of 0.80 to 0.95. One embodiment of the present invention is one, any or all of the previous embodiments in this paragraph to the second embodiment in this paragraph, wherein when the molar ratio of para-xylene to xylene is in the range of 0.80 to 0.9, the selectivity for xylene is greater than 52%. One embodiment of the present invention is one, any or all of the previous embodiments in this paragraph to the second embodiment in this paragraph, wherein when the molar ratio of para-xylene to xylene is in the range of 0.80 to 0.9, the selectivity for light fractions is less than 3.5%. One embodiment of the present invention is one, any or all of the previous embodiments in this paragraph to the second embodiment in this paragraph, wherein the disproportionation conditions include one or more of the following: a temperature in the range of 200°C to 600°C; a pressure in the range of 1.4 MPa(g) to 4.5 MPa(g); a temperature in the range of 0.1 hr -1 Up to 10 hours -1 or a hydrogen to hydrocarbon ratio in the range of 0.25 to 10.

[0180] A third embodiment of the present invention is a toluene disproportionation process comprising contacting a feed comprising toluene with a catalyst comprising a microporous crystalline zeolite under disproportionation conditions to produce an effluent stream comprising para-xylene and benzene, wherein PXX is the molar ratio of para-xylene to xylenes in the effluent stream, wherein BX is the molar ratio of benzene to xylenes in the effluent stream, and wherein when PXX is in the range of 0.60 to 1.0, BX is in the range of 1.00 to 0.375*PXX+0.825.

[0181] Although there is no further detailed description, it is believed that those skilled in the art can utilize the present invention to the greatest extent by using the foregoing description and can easily determine the essential characteristics of the present invention without departing from the spirit and scope of the present invention to make various changes and modifications of the present invention and adapt it to various usages and conditions. Therefore, the aforementioned preferred specific embodiments should be understood as merely illustrative and not to limit the rest of the present disclosure in any way, and are intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.

[0182] In the foregoing, all temperatures are set forth in degrees Celsius and all parts and percentages are by weight unless otherwise indicated.

Claims

1. A toluene disproportionation process comprising contacting a feed comprising toluene with a catalyst comprising a microporous crystalline zeolite under disproportionation conditions to produce an effluent stream comprising para-xylene and benzene, wherein the zeolite is UZM-44, wherein the molar ratio of benzene to xylenes in the effluent stream is in the range of 1.00 to 1.14, wherein the molar ratio of para-xylene to xylenes in the effluent stream is in the range of 0.80 to 1.0, and wherein the conversion of toluene is in the range of 20% to 40%; and wherein the catalyst has been enhanced with at least one enhancement treatment step selected from a treatment for depositing carbon, a treatment for depositing silica, or both.

2. The method according to claim 1, wherein the microporous crystalline zeolite comprises a three-dimensional framework of at least AlO2 and SiO2 tetrahedral units and an empirical composition in hydrogen form represented by the following empirical formula: M1 a N+ To the (l-x) AND x Yes y’ OR z” and wherein M1 is at least one exchangeable cation selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, zinc, ammonium ions, hydrogen ions, and combinations thereof, "a" is the molar ratio of M1 to (Al+E) and varies from 0.05 to 50, "N" is the weighted average valence of M1 and has a value of +1 to +3, E is an element selected from the group consisting of gallium, iron, boron, and combinations thereof, "x" is the molar ratio of E and varies from 0 to 1.0, y' is the molar ratio of Si to (Al+E) and varies from greater than 9 to substantially pure silica, And "Z" is the molar ratio of O to (Al+E) and has a value determined by the following equation: z'=(a·N+3+4·y') / 2 wherein the zeolite is characterized in that it has an x-ray diffraction pattern having at least the d-spacings and intensities shown in Table B: Table B 。 3. The method of claim 1, wherein the at least one enhancement treatment step comprises at least one treatment for incorporating silica.

4. The method of claim 1, wherein the catalyst is steamed after the at least one enhancement treatment step.

5. The process according to any one of claims 1 to 4, wherein the molar ratio of benzene to xylene is in the range of 1.00 to 1.

08.

6. The process according to any one of claims 1 to 4, wherein the molar ratio of benzene to xylene is in the range of 1.00 to 1.08, and wherein the molar ratio of para-xylene to xylene is in the range of 0.80 to 0.

95.

7. The process of any one of claims 1-4, wherein the selectivity for para-xylene is greater than 52% when the molar ratio of para-xylene to xylene is in the range of 0.80 to 0.90; or wherein the selectivity for light fractions is less than 3.5% when the molar ratio of para-xylene to xylene is in the range of 0.80 to 0.90; or both.

8. The method according to any one of claims 1 to 4, wherein the disproportionation conditions include one or more of the following: a temperature in the range of 200°C to 600°C; a pressure in the range of 1.4 MPa(g) to 4.5 MPa(g); a temperature in the range of 0.1 hr -1 Up to 10 hours -1 or a hydrogen to hydrocarbon ratio in the range of 0.25:1 to 10:

1.

9. The method according to any one of claims 1 to 4, wherein the ring loss is less than 1.5%.

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