Compositions including a catalyst and calcium carbonate

Abstract

The disclosure relates to compositions that include a catalyst and calcium carbonate. More specifically, a composition including calcium carbonate and a catalyst that includes molybdenum (Mo), vanadium (V), tellurium (Te), niobium (Nb), and oxygen (O).

Description

[0001] COMPOSITIONS INCLUDING A CATALYST AND CALCIUM CARBONATE

[0002] TECHNICAL FIELD

[0003] The disclosure relates to compositions that include a catalyst and calcium carbonate. More specifically, a composition including calcium carbonate and a catalyst that includes molybdenum (Mo), vanadium (V), tellurium (Te), niobium (Nb), and oxygen (O).

[0004] BACKGROUND ART

[0005] Olefins like ethylene, propylene, and butylene, are basic building blocks for a variety of commercially valuable polymers. Since naturally occurring sources of olefins do not exist in commercial quantities, polymer producers rely on methods for converting the more abundant lower alkanes into olefins. The method of choice for today's commercial scale producers is steam cracking, a highly endothermic process where steam-diluted hydrocarbons are subjected very briefly to a temperature of at least 600°C. The fuel demand to produce the required temperatures and the need for equipment that can withstand that temperature add significantly to the overall cost. In addition, the high temperature promotes the formation of coke, which accumulates within the system, resulting in the need for costly periodic reactor shutdowns for maintenance and coke removal.

[0006] Selective oxidation processes, such as oxidative dehydrogenation (ODH), are an alternative to steam cracking that are exothermic and produce little or no coke. In ODH, a lower alkane, such as ethane, is mixed with oxygen in the presence of a catalyst and optionally an inert diluent, such as carbon dioxide or nitrogen or steam, to produce the corresponding alkene. Various other oxidation products may be produced in this process, including acetic acid, carbon dioxide (CO2) and carbon monoxide (CO). ODH suffers from relatively lower conversion rates when compared to steam cracking.

[0007] SUMMARY OF INVENTION

[0008] The disclosure relates to compositions that include a catalyst and calcium carbonate. More specifically, a composition including calcium carbonate and a catalyst that includes molybdenum (Mo), vanadium (V), tellurium (Te), niobium (Nb), and oxygen (O).

[0009] In a first aspect, the disclosure provides a composition including a catalyst of formula: MoaVbTecNbdPdeOr, wherein a, b, c, d, e, and f are the relative atomic amounts of the elements, Mo, V, Te, Nb, Pd, and O, respectively; and where a = 1, b = 0.01 to 1.0, c = 0.01 to 1.0, d = 0.01 to 1.0, 0.00 < e < 0.10, and f is a number to satisfy the valence state of the catalyst; and calcium carbonate. In some embodiments, b is from 0. 1 to 0.5. In some embodiments, b is from 0.2 to 0.4.

[0010] In some embodiments, c is from 0.05 to 0.4. In some embodiments, c is from 0.08 to 0.3.

[0011] In some embodiments, d is from 0.05 to 0.4. In some embodiments, d is from 0.08 to 0.3. In some embodiments, d is from 0.10 to 0.25.

[0012] In some embodiments, e is from 0.005 to 0.10. In some embodiments, e is from 0.01 to 0.05. In some embodiments, e is from 0.015 to 0.03.

[0013] In some embodiments, the catalyst is of formula Mo1.0V0.12-0.49Te0.06-0.i6Nb0.15-0.20Of; Mo1.0V0.25-0.38Te0.10-0.i6Nb0.15-0.19Of; Mo1.0V0.22-0.33Te0.10-0.i6Nb0.15-0.19Of; Mo1.0V0.12-0.19Te0.14- o.ieNbo. isOr; or Mo1.0V0.17-0.20Te0.06-0.07Nb0.19-0.20Of.

[0014] In some embodiments, the catalyst is of formula Mo1.0V0.12-0.49Te0.05-0.25Nb0.10-0.20Of; or Mo 1.0V 0. 12-0.49Te0.05-0. nNbo. io-o.2oOf.

[0015] In some embodiments, the composition includes about 0.1 wt. % to about 10 wt. % calcium carbonate. In some embodiments, the composition includes about 0.1 wt. % to about 7 wt. % calcium carbonate.

[0016] In some embodiments, the composition further includes alumina.

[0017] In some embodiments, the composition includes about 0.1 wt. % to about 10 wt. % calcium carbonate. In some embodiments, the composition includes about 0.1 wt. % to about 5 wt. % calcium carbonate. In some embodiments, the composition includes about 5 wt. % calcium carbonate.

[0018] In some embodiments, the composition includes about 10 wt. % to about 95 wt. % alumina. In some embodiments, the composition includes about 20 wt. % to about 90 wt. % alumina. In some embodiments, the composition includes about 70 wt. % alumina.

[0019] In a second aspect, the disclosure provides a method of converting ethane to ethylene including contacting a stream including ethane with the composition of the disclosure and converting at least a portion of the ethane to ethylene.

[0020] In some embodiments, a temperature at 35% conversion is at least about 270°C. In some embodiments, a temperature at 35% conversion is about 363°C.

[0021] In some embodiments, the ethylene selectivity at the 35% conversion temperature is at least about 70 mol. % to 99 mol. %. In some embodiments, the ethylene selectivity at the 35% conversion temperature is about 93 mol. %. In a third aspect, the disclosure provides a method of forming the composition of the disclosure, including mechanically mixing the catalyst and calcium carbonate to form a mixture and calcining the mixture.

[0022] In some embodiments, the method further includes, after mechanically mixing the catalyst and calcium carbonate to form the mixture and prior to calcining the mixture, drying the mixture.

[0023] DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 shows a flowchart for a method of preparing an exemplary composition of the present disclosure.

[0025] Figure 2 shows X-ray diffraction (XRD) plots of Versal 250 Alumina (top) and a catalyst dry mixed with calcium carbonate and Versal 250 Alumina (bottom).

[0026] Figure 3 shows a graph of ethylene selectivity and ethane conversion for a baseline material with active phase and alumina.

[0027] Figure 4 shows a graph of ethylene selectivity and ethane conversion for a material with active phase, alumina, and calcium carbonate prepared by dry mixing method.

[0028] Figure 5 shows a graph of ethylene selectivity and ethane conversion for a baseline material with active phase, alumina, and calcium carbonate prepared by paste method.

[0029] DESCRIPTION OF EMBODIMENTS

[0030] Reference will now be made in detail to certain embodiments of the disclosed subject matter. While the disclosed subject matter will be described in conjunction with the enumerated claims, it will be understood that the exemplified subject matter is not intended to limit the claims to the disclosed subject matter.

[0031] Selective oxidation (SO) is generally used in oxidative dehydrogenation (ODH) reactions to form alpha-olefins from corresponding alkanes, such as to form ethylene from ethane. The compositions of the present disclosure can be used for ODH reactions and provide relatively good product yields, product selectivities, and / or reactant conversions, relative to certain other compositions. For example, the compositions of the present disclosure can be used in the conversion of ethane to ethylene and provide relatively good yields of ethylene, selectivities for ethylene, and / or conversions of ethane, relative to certain other compositions that do not include calcium carbonate.

[0032] The compositions can have relatively good processability. The compositions can be pressed in die sets with reduced risk of damaging the die sets relative to certain other compositions. Generally, compositions can be formulated with a processing aid, such as a slip agent, to prevent the seizing of die sets. Seizing occurs when fine particles fill small gaps within the die set, and slip agent help to prevent this. In some embodiments, calcium carbonate acts as a slip agent.

[0033] Without wishing to be bound by theory, it is believed that the calcium carbonate can act as a binder via sintering, a promoter, a pilling aid or pelletizing agent by acting as a lubricating or slip agent to produce relatively strong pellets, and / or as a ceramic flux. It is further believed that shaping heterogenous catalysts for a fixed bed reactor applications can reduce the pressure difference over the length of the bed relative to powder.

[0034] Definitions

[0035] Unless otherwise defined, all technical and scientific terms used in this document have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. Methods and materials are described in this document for use in the present application; other, suitable methods and materials known in the art can also be used. The materials, methods, and examples are illustrative only and not intended to be limiting. All publications, patent applications, patents, sequences, database entries, and other references mentioned in this document are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control.

[0036] Values expressed in a range format should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a range of “about 0.1% to about 5%” or “about 0.1% to 5%” should be interpreted to include not just about 0.1% to about 5%, but also the individual values (for example, 1%, 2%, 3%, and 4%) and the sub-ranges (for example, 0.1% to 0.5%, l.l% to 2.2%, and 3.3% to 4.4%) within the indicated range. The statement “about X to Y” has the same meaning as “about X to about Y,” unless indicated otherwise. Likewise, the statement “about X, Y, or about Z” has the same meaning as “about X, about Y, or about Z”, unless indicated otherwise.

[0037] The term “about”, as used in this disclosure, can allow for a degree of variability in a value or range, for example, within 10%, within 5%, or within 1% of a stated value or of a stated limit of a range.

[0038] As used in this disclosure, the terms “a”, “an”, and “the” are used to include one or more than one unless the context clearly dictates otherwise. The term “or” is used to refer to a nonexclusive “or” unless otherwise indicated. The statement “at least one of A and B” has the same meaning as “A, B, or A and B”. In addition, it is to be understood that the phraseology or terminology employed in this disclosure, and not otherwise defined, is for the purpose of description only and not of limitation. Any use of section headings is intended to aid reading of the document and is not to be interpreted as limiting; information that is relevant to a section heading may occur within or outside of that particular section.

[0039] As used herein, the term “catalyst” generally refers to the active catalyst portion of a catalyst material. The catalyst is generally processed in further steps to form a catalyst material. The catalyst material may also be processed in further steps to form a final catalyst material.

[0040] Compositions Including a Catalyst and Calcium Carbonate

[0041] The compositions of the present disclosure include a catalyst of formula MoaVbTecNbdPdeOr, wherein a, b, c, d, e, and f are the relative atomic amounts of the elements, Mo, V, Te, Nb, Pd, and O, respectively, and calcium carbonate. In some embodiments, the catalyst has the formula MoaVbTecNbdOr.

[0042] In some embodiments, the composition comprises, consists essentially of, or consists of the catalyst and calcium carbonate.

[0043] In some embodiments, a is about 1. In some embodiments, b is about 0.01 (e.g., about 0.02, about 0.03, about 0.04, about 0.05, about 0.06, about 0.07, about 0.08, about 0.09, about 0.1, about 0.2, about 0.3, about 0.4, about 0.5, about 0.6, about 0.7, about 0.8, about 0.9) to about 1.0 (e.g., about 0.9, about 0.8, about 0.7, about 0.6, about 0.5, about 0.4, about 0.3, about 0.2, about 0.1, about 0.09, about 0.08, about 0.07, about 0.06, about 0.05, about 0.04, about 0.03, about 0.02). In some embodiments, c is about 0.01 (e.g., about 0.02, about 0.03, about 0.04, about 0.05, about 0.06, about 0.07, about 0.08, about 0.09, about 0.1, about 0.2, about 0.3, about 0.4, about 0.5, about 0.6, about 0.7, about 0.8, about 0.9) to about 1.0 (e.g., about 0.9, about 0.8, about 0.7, about 0.6, about 0.5, about 0.4, about 0.3, about 0.2, about 0.1, about 0.09, about 0.08, about 0.07, about 0.06, about 0.05, about 0.04, about 0.03, about 0.02). In some embodiments, d is about 0.01 (e.g., about 0.02, about 0.03, about 0.04, about 0.05, about 0.06, about 0.07, about 0.08, about 0.09, about 0.1, about 0.2, about 0.3, about 0.4, about 0.5, about 0.6, about 0.7, about 0.8, about 0.9) to about 1.0 (e.g., about 0.9, about 0.8, about 0.7, about 0.6, about 0.5, about 0.4, about 0.3, about 0.2, about 0.1, about 0.09, about 0.08, about 0.07, about 0.06, about 0.05, about 0.04, about 0.03, about 0.02). In some embodiments, e is 0. In some embodiments, e is about 0.01 (e.g., about 0.02, about 0.03, about 0.04, about 0.05, about 0.06, about 0.07, about 0.08, about 0.09) to about 0.1 (e.g., about 0.09, about 0.08, about 0.07, about 0.06, about 0.05, about 0.04, about 0.03, about 0.02). In general, f is a number to satisfy the valence state of the catalyst. In general, the formula of the catalyst can be measured by any appropriate method, such as particle-induced X-ray emission (PIXE), energy-dispersive X-ray spectroscopy (EDX), or inductively coupled plasma mass spectrometry (ICP-MS).

[0044] In some embodiments, the catalyst is a catalyst as described in U.S. Patent Application Nos. 11,691,130, 11,772,073, or 11,998,895, each of which is incorporated by reference herein in its entirety.

[0045] In some embodiments, the composition includes from about 5 wt. % (e.g., about 10, about 15, about 20, about 25, about 30, about 35, about 40, about 45, about 50, about 55, about 60, about 65, about 70, about 75, about 80, about 85, or about 90 wt. %) to about 95 wt. % (e.g., about 90, about 85, about 80, about 75, about 70, about 65, about 60, about 55, about 50, about 45, about 40, about 35, about 30, about 25, about 20, about 15, or about 10 wt. %) of the catalyst. In some embodiments, the composition includes from about 0.1 wt. % (e.g., about 0.2, about 0.3, about 0.4, about 0.5, about 0.6, about 0.7, about 0.8, about 0.9, about 1.0, about 1.5, about 2.0, about 2.5, about 3.0, about 3.5, about 4.0, about 4.5, about 5.0, about 5.5, about 6.0, about 6.5, about 7.0, about 7.5, about 8.0, about 8.5, about 9.0, or about 9.5 wt. %) to about 10.0 wt. % (e.g., about 9.5, about 9.0, about 8.5, about 8.0, about 7.5, about 7.0, about 6.5, about 6.0, about 5.5, about 5.0, about 4.5, about 4.0, about 3.5, about 3.0, about 2.5, about 2.0, about 1.5, about 1.0, about 0.9, about 0.8, about 0.7, about 0.6, about 0.5, about 0.4, about 0.3, or about 0.2 wt. %) calcium carbonate. Without wishing to be bound by theory, it is believed that excessively high concentrations of calcium carbonate (e.g., greater than 10 wt. %, greater than 30 wt. %), may reduce (e.g., eliminate) catalyst activity.

[0046] In some embodiments, the compositions further include alumina. In some embodiments, the composition comprises, consists essentially of, or consists of the catalyst, calcium carbonate, and alumina. Without wishing to be bound by theory, it is believed that alumina is a diluent or carrier, and can be added to the catalyst to reduce catalyst activity, for example if the catalyst is too active for the specific reactor design (e.g., heat generation from the reaction is too fast for the reactor to remove heat without initiating uncontrollable thermal reaction run away).

[0047] In some embodiments, the composition includes from about 5 wt. % (e.g., about 10, about 15, about 20, about 25, about 30, about 35, about 40, about 45, about 50, about 55, about 60, about 65, about 70, about 75, about 80, about 85, or about 90 wt. %) to about 95 wt. % (about 90, about 85, about 80, about 75, about 70, about 65, about 60, about 55, about 50, about 45, about 40, about 35, about 30, about 25, about 20, about 15, or about 10 wt. %) of the catalyst. In some embodiments, the composition includes from about 0.1 wt. % (e.g., about 0.2, about 0.3, about 0.4, about 0.5, about 0.6, about 0.7, about 0.8, about 0.9, about 1.0, about 1.5, about 2.0, about 2.5, about 3.0, about 3.5, about 4.0, about 4.5, about 5.0, about 5.5, about 6.0, about 6.5, about 7.0, about 7.5, about 8.0, about 8.5, about 9.0, or about 9.5 wt. %) to about 10.0 wt. % (e.g., about 9.5, about 9.0, about 8.5, about 8.0, about 7.5, about 7.0, about 6.5, about 6.0, about 5.5, about 5.0, about 4.5, about 4.0, about 3.5, about 3.0, about 2.5, about 2.0, about 1.5, about 1.0, about 0.9, about 0.8, about 0.7, about 0.6, about 0.5, about 0.4, about 0.3, or about 0.2 wt. %) calcium carbonate. In some embodiments, the composition includes from about 5 wt. % (e.g., about 10, about 15, about 20, about 25, about 30, about 35, about 40, about 45, about 50, about 55, about 60, about 65, about 70, about 75, about 80, about 85, or about 90 wt. %) to about 95 wt. % (about 90, about 85, about 80, about 75, about 70, about 65, about 60, about 55, about 50, about 45, about 40, about 35, about 30, about 25, about 20, about 15, or about 10 wt. %) alumina. In some embodiments, the amount of alumina is selected based on the reactor configuration. ODH Reactions

[0048] The compositions can be used in an ODH reaction to form an alkene from its corresponding alkane. For example, the compositions can be used to form ethylene from ethane.

[0049] As used herein, in the oxidative dehydrogenation of ethane to ethylene, the temperature at 35% conversion is as described in U.S. Patent No. 11,998,897 which is herein incorporated by reference in its entirety.

[0050] In some embodiments, in the oxidative dehydrogenation of ethane to ethylene, the composition has a 35% conversion temperature of from about 270°C (e.g., about 280, about 290, about 300, about 310, about 320, about 330, about 340, about 350, about 360, about 370, about 380, about 390, or about 400°C) to about 410°C (e.g., about 400, about 390, about 380, about 370, about 360, about 350, about 340, about 330, about 320, about 310, about 300, about 290, or about 280°C).

[0051] As used herein, in the oxidative dehydrogenation of ethane to ethylene, the ethylene selectivity is as described in U.S. Patent No. 11,998,897

[0052] In some embodiments, in the oxidative dehydrogenation of ethane to ethylene, the composition has an ethylene selectivity of from about 70 mol. % (e.g., about 71, about 72, about 73, about 74, about 75, about 76, about 77, about 78, about 79, about 80, about 81, about 82, about 83, about 84, about 85, about 86, about 87, about 88, about 89 about 90, about 91, about 92, about 93, about 94, about 95, about 96, about 97, or about 98 mol. %) to about 99 mol. % (e.g., about 98, about 97, about 96, about 95, about 94, about 93, about 92, about 91, about 90, about 89, about 88, about 87, about 86, about 85, about 84, about 83, about 82, about 81, about 80, about 79, about 78, about 77, about 76, about 75, about 74, about 73, about 72, or about 71 mol. %).

[0053] Method of Preparing the Composition

[0054] Figure 1 depicts a schematic for a method 1000 of preparing a composition including a catalyst of formula MoaVbTecNbdPdeOr and calcium carbonate.

[0055] In step 1100, the catalyst and calcium carbonate are mechanically mixed. The mechanical mixing can be performed using any appropriate method or apparatus, such as with a ball mill, blender, mortar and pestle or other mixer. Without wishing to be bound by theory, it is believed that a ball mill may generate a reaction due to the energy released during the process. Generally, water or any other solvent is not employed in the step 1100. Without wishing to be bound by theory, it is believed that significant amounts of water can cause reactions between the catalyst and the calcium carbonate, thereby reducing the catalytic performance of the composition.

[0056] In step 1200, the mixture is dried. The drying can be performed at a temperature of from about 50°C (e.g., about 60, about 70, about 80, about 90, about 100, or about 150°C) to about 200°C (e.g., about 150, about 100, about 90, about 80, about 70, or about 60°C) for from about 1 hour (e.g., about 8 hours, about 12 hours, about 24 hours, about 1 day, or about 2 days) to about 3 days (e.g., about 2 days, about 1 day, about 24 hours, about 12 hours, or about 8 hours). Without wishing to be bound by theory, it is believed that the metal oxides can be hydroscopic and the drying step can help avoid additional side reactions. In some embodiments, the drying step can be performed as part of the calcination step prior to heating to the calcination temperature.

[0057] In step 1300, the mixture is calcined to provide the composition. The calcination can be performed at a temperature of from about 300°C (e.g., about 350, about 400, about 450, about 500, or about 550°C) to about 600°C (e.g., about 550, about 500, about 450, about 400, or about 350°C) for from about 0.5 hours (e.g., about 1, about 2, about 3, about 4, or about 5 hour(s)) to about 6 hours (e.g., about 5, about 4, about 3, about 2, or about 1 hour(s)). Without wishing to be bound by theory, it is believed that calcium carbonate can survive the calcination process and remain in the composition, unlike certain other additives, such as slip agents (e.g., amides, waxes, polyethylene glycols, graphite).

[0058] The composition can be pressed, for example using a die set, before use. EXAMPLES

[0059] Example 1 - Synthesis of Baseline Material (Catalyst + 70 % Alumina)

[0060] To a 1-L beaker was loaded 29.9981 g of catalyst active phase (corresponding to MoaVbTecNbdOr, very dark purple powder) and 69.9957 g of Versal 250 alumina (white powder). The mixture was stirred manually with a stir stick and then about 170 mb of dELO was added. Once the mixture was homogeneously mixed, the beaker was transferred to an oven at 90°C and left overnight, yielding 92.72 g of catalyst material. The powder was broken up using a spatula. The beaker was then transferred to a Lindberg Blue M programmable muffle furnace at 350°C for 2 hours (in addition to a 30-minute ramp to 350°C) and left to cool overnight. This yielded 88.72 g of catalyst material. Approximately 31 g was set aside for pelletizing. Example 2 - Dry Mixing Method

[0061] A third (28.3057 g) of the Baseline Material of Example 1 was loaded into an impact grinder with 1.4905 g of CaCCE (5 wt. %). The mixture was mechanically mixed for approximately 10 minutes. It was then transferred to a beaker and dried in an oven at 90°C overnight. The next morning, it was pressed, and the resulting pellets were calcined in a Lindberg Blue M programmable muffle furnace at 350°C for 2 hours (in addition to a 30- minute ramp to 350°C), then left to cool overnight. Figure 2 shows XRD plots of the resulting product (bottom) and the Versal 250 Alumina (top). Example 3 - Paste Method

[0062] The last third (29. 1163 g) of the Baseline Material of Example 1 was loaded into a 250-mL beaker with 1.5.324 g of CaCCE (5 wt. %). The mixture was stirred manually with a stir stick and then about 50 mb of dELO was added. Mild but consistent bubbling was observed. Once the mixture was homogeneously mixed, the beaker was transferred to an oven at 90°C and left overnight, yielding 30.2343 g of catalyst material. The mixture was ground using an impact grinder, and then loaded into an automatic pellet press (CPR-6 automatic single punch tablet press from DOTT BONAPACE&C) for pressing. The powder would not flow properly; therefore, powder was collected in a beaker and calcined in a Lindberg Blue M programmable muffle furnace at 350°C for 2 hours (in addition to a 30- minute ramp to 350°C), then left to cool overnight. The calcined powder was re-loaded into the automatic pellet press and was pressed.

[0063] Example 4 - Catalytic Performance

[0064] The three samples prepared in Examples 1-3 were tested on a Microreactor Unit (MRU). The experimental conditions are shown in Table 1. The MRU raw data for the materials of Examples 1-3 are plotted in Figures 3-5 and presented in Tables 2-4, respectively. Any 35% conversion temperatures reported over 390°C are extrapolated.

[0065] The Baseline Material was screened with three datapoints at a flow of 58.5 seem.

[0066] The two samples with calcium carbonate were screened at a flow of 76. 1 seem. As the flow was increased, the residence time of the feed gas decreased throughout the catalyst bed. As such, with the same catalyst loading, one would expect the 35% conversion temperature to increase (corresponding to a decrease in activity). However, the activity of the material prepared by the dry mixing method (Example 2) increased by 5 °C. Without wishing to be bound by theory, it is believed that the addition of 5 wt. % calcium carbonate via dry mixing, followed by calcination at 350°C, improved the catalyst’s performance.

[0067] Conversely, the same loading via the paste method (Example 3) resulted in poorer catalyst performance. Without wishing to be bound by theory, it is believed that given the observation of bubbling during wet impregnation (both the paste method and slow evaporation method (slow evaporation of excess water with mixing to prevent settling until a desire consistency of paste is achieved)), the performance of the material of Example 3 suggests that a reaction occurred between the catalyst active phase and calcium carbonate (likely acid-base), which negatively impacted the active phase.

[0068] Table 1. MRU Screen Results for Calcium Carbonate Dry or Wet Mixing Methods

[0069] Table 2, MRU Raw Data for Example 1 Table 3 , MRU Raw Data for Example 2

[0070] Table 4, MRU Raw Data for Example 3

[0071] The results show that calcium carbonate loading of up to 5 wt. % and a 350°C heat treatment would not negatively impact catalyst performance. It also showed that the dry mixing method was more beneficial than the paste method when adding calcium carbonate to the final formulation.

Claims

CLAIMS1. A composition comprising: a catalyst of formula: MoaVbTecNbdPdeOr, wherein a, b, c, d, e, and f are the relative atomic amounts of the elements, Mo, V, Te, Nb, Pd, and O, respectively; and where a = 1, b = 0.01 to 1.0, c = 0.01 to 1.0, d = 0.01 to 1.0, 0.00 < e < 0.10, and fis a number to satisfy the valence state of the catalyst; and calcium carbonate.

2. The composition of claim 1, wherein b is from 0. 1 to 0.5.

3. The composition of claim 1, wherein b is from 0.2 to 0.4.

4. The composition of any one of claim 1 to claim 3, wherein c is from 0.05 to 0.4.

5. The composition of any one of claim 1 to claim 3, wherein c is from 0.08 to 0.3.

6. The composition of any one of claim 1 to claim 5, wherein d is from 0.05 to 0.4.

7. The composition of any one of claim 1 to claim 5, wherein d is from 0.08 to 0.3.

8. The composition of any one of claim 1 to claim 5, wherein d is from 0.10 to 0.25.

9. The composition of any one of claim 1 to claim 8, wherein e is from 0.005 to 0.10.

10. The composition of any one of claim 1 to claim 8, wherein e is from 0.01 to 0.05.

11. The composition of any one of claim 1 to claim 8, wherein e is from 0.015 to 0.03.

12. The composition of claim 1, wherein the catalyst is of formula:Moi .oV o.12-0.49Te0.06-0. leNbo. i5-o.2oOr;Moi .oV o.25-o.3sTeo.10-0. leNbo.15-0. i9Or;Moi .oV o.22-o.33Teo.10-0. leNbo.15-0. i9Or;Moi ,oV 0.12-0. l Teo.14-0. leNbo. isOr; orMoi ,oV 0.17-0.20Te0.06-0.07Nb0.19-0.20Of .

13. The composition of claim 1, wherein the catalyst is of formula:Moi ,oV 0. i2-o.49Teo.o5-o.25Nbo. io-o.2oOr; orMoi ,oV 0.12-0.49Te0.05-0. nNbo. io-o.2oOr .

14. The composition of any one of claim 1 to claim 13, wherein the composition comprises about 0.1 wt. % to about 10 wt. % calcium carbonate.

15. The composition of any one of claim 1 to claim 13, wherein the composition comprises about 0.1 wt. % to about 7 wt. % calcium carbonate.

16. The composition of any one of claim 1 to claim 15, wherein the composition further comprises alumina.

17. The composition of claim 16, wherein the composition comprises about 0. 1 wt. % to about 10 wt. % calcium carbonate.

18. The composition of claim 16, wherein the composition comprises about 0. 1 wt. % to about 5 wt. % calcium carbonate.

19. The composition of claim 16, wherein the composition comprises about 5 wt. % calcium carbonate.

20. The composition of any one of claim 16 to claim 19, wherein the composition comprises about 10 wt. % to about 95 wt. % alumina.

21. The composition of any one of claim 16 to claim 19, wherein the composition comprises about 20 wt. % to about 90 wt. % alumina.

22. The composition of any one of claim 16 to claim 19, wherein the composition comprises about 70 wt. % alumina.

23. A method of converting ethane to ethylene comprising: contacting a stream comprising ethane with the composition of any one of claim 1 to claim 22; and converting at least a portion of the ethane to ethylene.

24. The method of claim 23, wherein a temperature at 35% conversion is at least about 270°C.

25. The method of claim 23, wherein a temperature at 35% conversion is about 363°C.

26. The method of any one of claim 23 to claim 25, wherein the ethylene selectivity at the 35% conversion temperature is at least about 70 mol. % to 99 mol. %.

27. The method of any one of claim 23 to claim 25, wherein the ethylene selectivity at the 35% conversion temperature is about 93 mol. %.

28. A method of forming the composition of any one of claim 1 to claim 22, comprising: mechanically mixing the catalyst and calcium carbonate to form a mixture; and calcining the mixture.

29. The method of claim 28, further comprising, after mechanically mixing the catalyst and calcium carbonate to form the mixture and prior to calcining the mixture, drying the mixture.

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