Method for activating hydrogenolysis catalyst

Abstract

A method for activating a hydrogenolysis catalyst is described. The method may include contacting an oxidized catalyst with a butane-containing stream in the presence of H2 to form a treated catalyst. The treated catalyst may then be contacted with H2 to form an activated hydrogenolysis catalyst. The source of the oxidized catalyst may be a fresh catalyst or a deactivated catalyst that has been exposed to, for example, oxygen. Uses of the activated hydrogenolysis catalyst are also described.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to European patent application EP22179046 filed on June 14, 2022. Background of the Invention

[0002] A. Field of the Invention

[0003] The present invention generally relates to a method for activating a catalyst for the hydrogenolysis of hydrocarbon compounds. The method may include contacting an oxidized catalyst with a stream containing one or more hydrocarbon compounds in the presence of H2 to form a hydrocarbon-treated catalyst. The hydrocarbon-treated catalyst may then be contacted with H2 to form an activated hydrogenolysis catalyst. The source of the oxidized catalyst may be fresh catalyst or a deactivated catalyst that has been exposed to, for example, oxygen.

[0004] B. Description of Related Technology

[0005] Light alkanes, especially ethylene, can be obtained by steam cracking of hydrocarbon compounds (e.g., butane (C4)). However, the ethylene yield produced by steam cracking of hydrocarbon compound feedstocks is relatively low. A combination of hydrocarbon compound hydrogenolysis and steam cracking can selectively produce the desired olefins. In some examples, the hydrogenolysis reaction can be advantageous.

[0006] In the hydrogenolysis reaction of hydrocarbon compounds, it is desirable that the hydrocarbon compound hydrogenolysis catalyst preferably has selectivity for ethane to minimize carbon loss of byproducts (e.g., methane and propane). Conventional iridium (Ir)-based catalysts or IrPt-based catalysts can have 60% to 70% ethane selectivity at hydrocarbon compound conversion levels of about 80% to 90%. However, the use of noble metals such as Ir and platinum (Pt) can result in huge capital costs. For example, Ir is not readily available and is difficult to recover from failed catalysts.

[0007] In order to reduce operating costs, the hydrogenolysis catalyst can be regenerated. Traditional catalyst regeneration strategies in hydrocarbon processes mainly involve the combustion of carbon deposits (causing deactivation) in an oxidizing atmosphere. However, due to the sensitivity of the active sites to the oxidation temperature, in order to maintain the dispersion of the active sites, this step is replaced by a complex and capital-intensive oxychlorination step, or is followed by an oxychlorination step. For example, U.S. Patent No. 3,998,755, entitled "Regeneration of a coke-deactivated, acidic bimetallic Pt-Ir catalyst" by John Hayes, and Canadian Patent No. 1,196,623, entitled "Process for reactivating iridium-containing catalysts" by Weissman et al., both describe contacting a deactivated catalyst at high temperature in the presence of oxygen, water and halides.

[0008] Although attempts to reactivate hydrogenolysis catalysts have been described, a need remains for a cost-effective method. Accordingly, the following provides a solution to the problem of a need for an improved method of activating hydrogenolysis catalysts that is relatively simple and cost-effective to implement in a manufacturing operation compared to existing methods. SUMMARY OF THE INVENTION

[0009] A solution to at least one problem associated with activation of a hydrogenolysis catalyst has been found. In one aspect, at least one solution may include contacting an oxidized catalyst with a hydrocarbon-containing stream in the presence of hydrogen (H2) to form a hydrocarbon-treated catalyst. The oxidized catalyst may be a fresh catalyst or a deactivated catalyst that has been treated or exposed to oxidizing conditions (e.g., exposed to oxygen (O2)). The hydrocarbon-treated catalyst may then be contacted with H2 to form an activated hydrogenolysis catalyst. In certain aspects, the H2 used to form the hydrocarbon-treated catalyst and the H2 used to form the activated hydrogenolysis catalyst may come from the same H2 source or H2 stream. In other aspects, the H2 used to form the hydrocarbon-treated catalyst comes from a first H2 source or a first H2 stream, and the H2 used to form the activated hydrogenolysis catalyst comes from a second H2 source or a second H2 stream. Activating the catalyst in this manner may increase the hydrocarbon conversion stability of the catalyst compared to the same catalyst that is not activated in the manner of the present invention for hydrocarbon hydrogenolysis. Activation can include regeneration of a failed catalyst, activation of a mixture of a failed catalyst and a fresh catalyst during the hydrogenolysis reaction (e.g., after some hydrogenation conversion is reduced), or pretreatment of a fresh hydrogenolysis catalyst. Benefits of the methods of the present invention can include activating fresh catalysts and / or failed catalysts in a cost-effective manner. In addition, it is believed that the methods of the present invention can modify the structure of the catalyst active sites so that the catalyst is more stable over time, which can further extend the life of the catalyst and postpone the need to replace or regenerate a failed catalyst.

[0010] One aspect of the present invention describes a method for activating a hydrogenolysis catalyst. The method may include (a) contacting an oxidized catalyst with a stream containing one or more hydrocarbon compounds in the presence of hydrogen to form a catalyst treated with hydrocarbon compounds, and then (b) contacting the catalyst treated with hydrocarbon compounds in step (a) with hydrogen to form an activated hydrogenolysis catalyst. The hydrocarbon compound of step (a) may include hydrocarbon compounds of C2 to C10, preferably hydrocarbon compounds of C2 to C5, more preferably n-butane, isobutane or a combination thereof. In some aspects, the mass ratio of H2 and one or more hydrocarbon compounds in step (a) may be 0.5 to 20. In other aspects, the mass ratio of one or more hydrocarbon compounds to the catalyst may be 1 to 100. The conditions of step (a) may include a temperature of 200°C to 350°C, preferably 275°C to 325°C, and a pressure of 0.5MPa to 1.5MPa, preferably 0.7MPa to 0.8MPa. The time for carrying out step (b) can be longer than step (a), and the conditions of step (b) can include a temperature of 300°C to 500°C, preferably 300°C to 400°C, and a pressure of 0.5MPa to 1.5MPa, preferably, 0.7MPa to 0.8MPa. The catalyst oxidized in step (a) can be produced by the following steps: at a temperature of 200°C to 450°C, preferably 300°C to 400°C, a fresh catalyst, a deactivated catalyst or a mixture thereof is contacted with an oxidation stream, which may contain oxygen (O2) and a diluent. The oxidation stream may contain 0.1% to 30% by volume of O2, preferably 5% to 20% by volume of O2, or more preferably 8% to 12% by volume of O2. In some aspects, the catalyst may include at least two noble metals on a carrier. For example, a fresh hydrogenolysis catalyst containing a noble metal can be pretreated by heating the catalyst to a desired temperature, and then the heated fresh hydrogenolysis catalyst is contacted with a diluted oxygen stream to form the catalyst oxidized in step (a). In another example, a deactivated catalyst (e.g., a hydrocarbon conversion rate of less than 20%, more preferably a hydrocarbon conversion rate of less than 15%, or a hydrocarbon conversion rate of 1% to 20%, or 1%, 5%, 10%, 15%, 20% or any range or any value therebetween) can be heated to a desired temperature and then contacted with a diluted oxygen stream to form an oxidized catalyst in step (a), and then step (b) of the activation method of the present invention can be performed.In yet another example, during the hydrocarbon hydrogenolysis process, when the catalyst (a mixture of fresh catalyst and deactivated catalyst) has lost some activity (e.g., the hydrocarbon conversion rate decreases by more than 20%, more preferably the hydrocarbon conversion rate decreases by more than 20%, or 21% to 50%, or 21%, 25%, 30%, 35%, 40%, 45%, 50% or any range or any value therebetween), the feed can be stopped, the reactor can be purged with nitrogen, and then the catalyst mixture can be contacted with a diluted oxygen stream to form the oxidized catalyst in step (a), and then step (b) of the activation method of the present invention can be performed. Non-limiting examples of noble metals include platinum (Pt), iridium (Ir), palladium (Pd), ruthenium (Rh), silver (Ag), gold (Au), alloys thereof, or combinations thereof, preferably PtIr. The catalyst support can be a zeolite support, preferably ZSM5.

[0011] Another aspect of the invention describes a method for producing ethane. The method for producing ethane may include contacting an activated hydrogenolysis catalyst of the invention with a hydrocarbon compound (e.g., a C3 to C10 hydrocarbon compound, preferably a C3 to C5 hydrocarbon compound, more preferably n-butane, isobutane or a combination thereof) under conditions sufficient to hydrogenolyze the hydrocarbon compound to produce ethane. Advantageously, the stability of the hydrocarbon compound conversion is increased under the same hydrogenolysis conditions compared to hydrogenolysis of the hydrocarbon compound with the original untreated catalyst. Without wishing to be bound by theory, it is believed that the method of the invention modifies the structure of the active site and makes the catalyst more stable. In the example where the catalyst is an expired catalyst, the catalyst activity is restored. The hydrogenolysis contact conditions may include a temperature of 240°C to 350°C, preferably 260°C to 300°C, a pressure of 0.35MPa to 1.4MPa, and a mass space velocity (based on the WHSV of the hydrocarbon compound) of 1 hour -1 Up to 10 hours -1 , preferably 1 hour -1 Up to 4 hours -1 , or a combination thereof.

[0012] Other embodiments of the present invention are discussed throughout the application. Any embodiment discussed about one aspect of the present invention is equally applicable to other aspects of the present invention, and vice versa. Each embodiment described herein should be understood as an embodiment of the present invention applicable to other aspects of the present invention. It is envisioned that any embodiment or aspect discussed herein can be combined with other embodiments or aspects discussed herein, and / or implemented about any method or composition of the present invention, and vice versa. In addition, the composition in the present invention can be used to implement the method of the present invention.

[0013] Included below are definitions of various terms and phrases used throughout this specification.

[0014] The term "about" or "approximately" is defined as close to as understood by one of ordinary skill in the art. In a non-limiting embodiment, these terms are defined as within 10% deviation, preferably within 5%, more preferably within 1%, and most preferably within 0.5%.

[0015] The terms "weight %", "volume %" or "mole %" refer to the weight percentage of a component, the volume percentage of a component or the mole percentage of a component, respectively, based on the total weight, total volume or total moles of the material containing the component. In a non-limiting example, if there are 10 grams of a component in 100 grams of material, the component accounts for 10 weight %.

[0016] The term "substantially" and variations thereof are defined to include ranges within 10%, within 5%, within 1%, or within 0.5%.

[0017] When the terms "inhibit," "reduce," "prevent," "avoid," or any variation of these terms are used in the claims and / or description, it includes any measurable reduction or complete inhibition to achieve the desired result.

[0018] The term "effective," when used in the specification and / or claims, means sufficient to achieve a desired, expected, or intended result.

[0019] When used in conjunction with any of the terms "comprises," "including," "contains," or "having" in the claims or description, the term may mean "one," but also have the meaning of "one or more," "at least one," and "one or more than one."

[0020] The words "comprise" (and any form thereof), "have" (and any form thereof), "include" (and any form thereof) or "contains" (and any form thereof) are inclusive or open-ended and do not exclude additional, unrecited elements or method steps.

[0021] The methods of the present invention may "comprise," "consist essentially of," or "consist of" specific formulations, components, compositions, etc. disclosed throughout the specification. With respect to the transition phrase "consist essentially of," in one non-limiting aspect, the essential and novel features of the methods of the present invention are their ability to activate hydrocarbon hydrogenolysis catalysts. In certain aspects, the methods of the present invention can be implemented without conventional catalyst regeneration strategies such as burning off carbon deposits and / or using halides (e.g., oxychlorination steps).

[0022] Other objects, features and advantages of the present invention will become apparent through the following drawings, detailed descriptions and examples. However, it should be understood that the drawings, detailed descriptions and examples, although indicating specific embodiments of the present invention, are given only in an illustrative manner and are not meant to be restrictive. In addition, it is expected that changes and modifications within the nature and scope of the present invention will be apparent to those skilled in the art based on this detailed description. In other embodiments, features from a specific embodiment may be combined with features from other embodiments. For example, features from one embodiment may be combined with features from any other embodiment. In other embodiments, other features may be added to the specific embodiments described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Advantages of the present invention may become apparent to those skilled in the art from the following detailed description with reference to the accompanying drawings.

[0024] Figure 1 is a schematic diagram of the activation scheme of the present invention.

[0025] Figure 2 is a schematic diagram of a reactor system and process for producing ethane using the activated hydrogenolysis catalyst of the present invention.

[0026] Figure 3 is the n-butane conversion and ethane product selectivity in production as a function of time before and after regeneration (275 ° C, H2 / C4H 10 Molar ratio = 2.5, C4H 10 Mass space velocity = 4 hours -1 , 100psig).

[0027] Figure 4 The conversion of n-butane in production before and after regeneration as a function of time (275 ° C, H2 / C4H 10 Molar ratio = 2.5, C4H 10 Mass space velocity = 4 hours -1 , 100psig).

[0028] Figure 5 is the n-butane conversion and ethane product selectivity in production as a function of time before and after regeneration (275 ° C, H2 / C4H 10 Molar ratio = 2.5, C4H 10 Mass space velocity (WHSV) = 4 hours -1 , schematic diagram of 100psig (0.689MPa)).

[0029] Figure 6Schematic diagram of the comparison of n-butane conversion using two portions of the same catalyst. The top line (pretreatment according to the inventive protocol) shows the n-butane conversion of one portion of the catalyst subjected to the inventive protocol. The bottom line (standard pretreatment) shows the n-butane conversion of another portion of the catalyst subjected to the standard catalyst pretreatment, which involves only H2 reduction at 400°C. The reaction parameters for the two n-butane conversions are: Hydrocarbon WHSV: 4 hours -1 , T: 280℃, P: 100psig (0.689MPa), H2 / hydrocarbon compound under improved pretreatment is 1.5, and H2 / hydrocarbon compound under standard pretreatment is 2.5.

[0030] While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings. The drawings may not be drawn to scale. DETAILED DESCRIPTION

[0031] Although attempts to reactivate hydrogenolysis catalysts have been described, a need remains for a cost-effective method. Accordingly, the following provides a solution to the problem of a need for an improved method of activating hydrogenolysis catalysts that is relatively simple and cost-effective to implement in a manufacturing operation compared to existing methods.

[0032] At least one solution to the problems associated with catalyst activity in the conversion of hydrocarbon compounds to ethane has been discovered. The solution may include a cost-effective method for activating a hydrogenolysis catalyst. The method may increase the stability of the hydrogenolysis catalyst compared to the original untreated hydrogenolysis catalyst under the same conditions. The activation may be used as a pretreatment of fresh catalyst or as a regeneration of a deactivated catalyst.

[0033] These and other non-limiting aspects of the present invention are discussed in further detail in the following sections.

[0034] A. Methods of Activating Hydrogenolysis Catalysts

[0035] Figure 1A schematic diagram of the activation method of the present invention is described. For example, the hydrogenolysis catalyst can be contacted with nitrogen at an elevated temperature (e.g., 200° C. to 280° C., or 200° C., 220° C., 230° C., 240° C., 250° C., 260° C., 270° C., 280° C., or any value or range therebetween) for a period of time (e.g., about 1 minute to 10 minutes, or 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, or any value or range therebetween). The catalyst can be a fresh catalyst, a deactivated catalyst (e.g., a catalyst exposed to the reaction feed for any period of time, and a catalyst that shows reduced hydrocarbon conversion activity during operation) or a mixture of a fresh catalyst and a deactivated catalyst (e.g., a catalyst that loses activity during the hydrogenolysis process).

[0036] Next, oxygen can be introduced into the nitrogen gas stream to form a diluted oxygen gas stream (e.g., 0.1 vol% to 30 vol%, or 0.1 vol%, 1 vol%, 5 vol%, 10 vol%, 15 vol%, 20 vol%, 25 vol%, 30 vol%, or any value or range therebetween, preferably 5 vol% to 20 vol%, more preferably 8 vol% to 12 vol%) and contacted with the heated catalyst at an elevated temperature (e.g., 200°C to 450°C, 275°C to 325°C, or 200°C, 225°C, 250°C, 275°C, 300°C, 325°C, 350°C, 375°C, 400°C, or any value or range therebetween). In certain aspects, the pressure during oxygen contact can be 0.5MPa to 1.5MPa, preferably 0.7MPa to 0.8MPa, or 0.5MPa, 0.7MPa, 0.8MPa, 0.9MPa, 1.0MPa, 1.1MPa, 1.2MPa, 1.3MPa, 1.4MPa, 1.5MPa, or any value or any range therebetween. The heating rate can be 1°C to 5°C per minute, or 1°C, 1.5°C, 2°C, 2.5°C, 3°C, 3.5°C, 4°C, 4.5°C, or 5°C, or any value or any range therebetween. In one aspect, a heating rate of 2.5°C per minute can be used. Once the temperature reaches the target temperature (e.g., 300° C., 325° C., 350° C., or any value or range therebetween), the catalyst can be maintained in the diluted oxygen stream for a period of time (e.g., 1 hour to 5 hours, or 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, or any value or range therebetween) to form an oxidized catalyst. Preferably, the heated catalyst is contacted with the diluted oxygen stream for about 2 hours to form an oxidized catalyst.

[0037] After the oxidation step, the oxidized catalyst may be purged with nitrogen for a period of time (e.g., 1 minute to 5 minutes) to remove loosely bound oxygen and / or any other oxygen in the unit (e.g., reactor) comprising the catalyst. Subsequently, a hydrocarbon stream and a hydrogen stream may be contacted with the oxidized catalyst to produce a hydrocarbon-treated catalyst of the present invention. The streams may be separate streams or mixed streams. The oxidized catalyst may be contacted with a hydrocarbon stream in the presence of H2 and at a desired temperature (e.g., 200°C to 350°C, 275°C to 325°C, or 200°C, 225°C, 250°C, 275°C, 300°C, 325°C, 350°C, or any value or range therebetween) to produce a hydrocarbon-treated catalyst of the present invention. The pressure during hydrocarbon compound / hydrogen contact can be 0.5MPa to 1.5MPa, preferably 0.7MPa to 0.8MPa, or 0.5MPa, 0.7MPa, 0.8MPa, 0.9MPa, 1.0MPa, 1.1MPa, 1.2MPa, 1.3MPa, 1.4MPa, 1.5MPa. In certain embodiments, a temperature of 275°C to 325°C and a pressure of 0.7MPa to 0.8MPa are used. Non-limiting examples of hydrocarbon compounds include hydrocarbon compounds of C2 to C10, or C2, C3, C4, C5, C6, C7, C8, C9, C10, or any range therebetween. In a preferred example, hydrocarbon compounds such as normal butane, isobutane or a combination thereof are used for C4. On the one hand, a mixture of normal butane / isobutane of 70% by volume / 30% by volume can be used. The weight ratio of hydrocarbon compound to catalyst may be from 1 to 100, or 1, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, or any range or value therebetween. The ratio of hydrogen / hydrocarbon compound may be from 0.5 to 20, or 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5, 20, or any range or value therebetween. The oxidized catalyst can be contacted with the hydrocarbon stream and H2 for 20 seconds to 180 minutes (e.g., 20 seconds, 40 seconds, 1 minute, 5 minutes, 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, 60 minutes, 70 minutes, 80 minutes, 90 minutes, 100 minutes, 110 minutes, 120 minutes, 130 minutes, 140 minutes, 150 minutes, 160 minutes, 170 minutes, 180 minutes or any value or any range therebetween) to produce a hydrocarbon-treated catalyst.In one aspect, the catalyst can be contacted with the hydrocarbon stream and H2 for 2 minutes to 7 minutes, or 5 minutes, to produce a hydrocarbon-treated catalyst.

[0038] Next, the hydrocarbon stream can be interrupted, and the hydrocarbon treated catalyst can be contacted with hydrogen (purity 99% to 100%) to produce an activated catalyst of the present invention. In some embodiments, the amount of hydrocarbon can be reduced over time to increase the amount of H2 contacted with the hydrocarbon treated catalyst. In other aspects, once the hydrocarbon treated catalyst is obtained (separated), the hydrocarbon treated catalyst can then be contacted with a separate H2 feed stream. The temperature at which the hydrocarbon treated catalyst and hydrogen are contacted can be 300°C to 500°C, 300°C to 400°C, or 300°C, 325°C, 350°C, 375°C, 400°C, 425°C, 450°C, or 500°C or any value or any range therebetween to produce an activated catalyst of the present invention. The pressure during hydrogen contact can be 0.5MPa to 1.5MPa, preferably 0.7MPa to 0.8MPa, or 0.5MPa, 0.7MPa, 0.8MPa, 0.9MPa, 1.0MPa, 1.1MPa, 1.2MPa, 1.3MPa, 1.4MPa, 1.5MPa or any value or any range therebetween, and the contact lasts for 1 hour to 2 hours. The hydrogen flow and heat can be interrupted to start the cooling process. The activated catalyst can be cooled to about 200°C to 300°C, or 250°C to 275°C, or 200°C, 225°C, 250°C, 275°C, 300°C or any value or any range therebetween. On the one hand, the activated catalyst is cooled to 270°C to 280°C, or about 275°C. In some aspects, the total time of the hydrocarbon compound treatment step and the activation step can be more than the time when oxygen contacts the catalyst. For example, if the catalyst is contacted with oxygen for 2 hours, the catalyst can then be contacted with a hydrocarbon / hydrogen mixture for about 5 minutes and then contacted with substantially pure or pure hydrogen (e.g., 90% or greater, preferably 95% or greater, or more preferably 98% or 99% or greater H2) for 2 hours to produce the activated catalyst of the present invention.

[0039] B. Process for producing ethane from hydrocarbon compounds using an activated catalyst

[0040] Figure 2A schematic diagram of a reactor using an activated catalyst of the present invention for carrying out a hydrocarbon compound hydrogenolysis process is described. System 200 may include a reactor 202, an inlet 204 for H2 reactant feed, an inlet 206 for hydrocarbon compound reactant feed, a reaction zone 208 (e.g., a fixed bed reactor) configured to be fluidly connected to inlet 204 and inlet 206, and an outlet 210 configured to be fluidly connected to reaction zone 208 and configured to remove hydrogenolysis product stream from reaction zone. Reaction zone 208 may include an activated catalyst 212. Activated catalyst 212 may be a fresh catalyst or a deactivated catalyst, which has been placed in reactor 202, and then activated (pre-treated or regenerated) using activation method of the present invention (see above section A) before the start of hydrogenolysis process. In certain embodiments, the activated catalyst is placed in a reactor after activation. H2 reactant feed can enter reaction zone 208 through inlet 204. The hydrocarbon compound reactant feed can be a mixture of butane (e.g., isobutane and normal butane) and enters reaction zone 208 through inlet 206. In certain embodiments, the reactant feed stream comprises butane, propane or trace amounts of C5 (e.g., hydrocarbon compounds comprising 5 carbon atoms). In certain embodiments, the reactant feed is premixed and provided simultaneously. In certain embodiments, the reactant feed can be provided in stages from rich H2 to the ratio of target H2 and hydrocarbon compounds. In certain embodiments, H2 reactant feed and / or hydrocarbon compound reactant feed can be used to maintain the pressure of reaction zone 208. The product stream can be removed from reaction zone 208 through product outlet 210. The product stream can be sent to other process units (e.g., separation units, isomerization units, etc.), stored and / or transported.

[0041] In certain embodiments, the activated catalyst 212 is a fresh catalyst, and loses activity during the hydrogenolysis process to form a mixture of fresh catalyst and deactivated catalyst. At this point, the reactant feed can be interrupted, and nitrogen is added through the nitrogen inlet 214. After hydrogen and hydrocarbon reactant feeds have been flushed out of the system, the diluted oxygen stream can enter the reactor 202 through the oxygen inlet 214, and the activation method of the present invention can be implemented (see, Part A). For example, after treating the catalyst with a diluted oxygen stream to form an oxidized catalyst, the oxygen feed can be interrupted, and the nitrogen stream can enter the reactor through the nitrogen inlet 214. After the catalyst and the reactor have been flushed with nitrogen, the nitrogen stream can be interrupted, and the hydrocarbon stream of C2 to C10 can enter the reactor through the hydrocarbon inlet 206 or a separate feed inlet, and hydrogen can enter through the hydrogen inlet 204. In the presence of H2, the hydrocarbon stream of C2 to C10 is contacted with the catalyst, and the activation method of the present invention is used to form a catalyst treated with hydrocarbons. After the catalyst treated with hydrocarbons is formed, the hydrocarbon feed can be interrupted. Under the conditions of the catalyst activation method of the present invention, the hydrocarbon compound treated catalyst can be contacted with hydrogen to form an activated hydrogenolysis catalyst. After activation, the temperature of the catalyst and the reactor can be adjusted to the reaction temperature, and the hydrocarbon compound reactant feed can enter the reactor 202 through the hydrocarbon compound reactant feed 206 to continue the hydrogenolysis of the hydrocarbon compound. The sequence of hydrogenolysis reaction / regeneration (activation) / hydrogenolysis reaction can be continued as needed.

[0042] Reactor 202 may include one or more heating devices and / or cooling devices (e.g., insulation, electric heaters, jacketed heat exchangers on the wall), or controllers (e.g., computers, flow valves, automatic valves, etc.) that can be used to control the reaction temperature and reaction mixture pressure. Although only one reactor is shown, it should be understood that multiple reactors can be placed in one unit, or multiple reactors can be placed in one heat transfer unit. In certain embodiments, a series of physically separated reactors with interstage cooling devices / heating devices can be used, including heat exchangers, heating furnaces, open-fire heaters, etc.

[0043] The temperature, pressure and WHSV can be varied depending on the reaction to be performed and are within the skill of the person performing the reaction (e.g., an engineer or chemist). The temperature can be from 240°C to about 325°C, from 250°C to 300°C, from 270°C to 290°C, or any value or range therebetween. The pressure can be from about 0.35MPa to 1.4MPa or 0.35MPa, 0.40MPa, 0.45MPa, 0.50MPa, 0.55MPa, 0.60MPa, 0.65MPa, 0.70MPa, 0.75MPa, 0.8MPa, 0.85MPa, 0.9MPa, 0.95MPa, 1.0MPa, 1.1MPa, 1.2MPa, 1.3MPa, 1.4MPa, or any value or range therebetween. The WHSV of a hydrocarbon compound (e.g., butane) can be 1 hour. -1 Up to 10 hours -1 , or 1 hour -1 , 2 hours -1 , 3 hours -1 , 4 hours -1 , 5 hours -1 , 6 hours -1 , 7 hours -1 , 8 hours -1 , 9 hours -1 , 10 hours -1 Or any range or any value therebetween.

[0044] The product stream can include methane, propane, ethane and unreacted reactants. The product can be separated using known separation methods. The methane produced can be used as a fuel for the system or can react with steam to produce hydrogen. The ethane produced can be sent to other process units, such as a steam cracker to produce ethylene. The propane produced can be sent to other process units, such as, sent to a cracking unit together with ethane, or used to produce propylene specifically by propane dehydrogenation. Unreacted butane and / or hydrogen can be circulated in the reactor. In certain embodiments, the unreacted butane comprising isobutane can be sent to a reverse isomerization unit to increase the amount of normal butane in the unreacted feed stream.

[0045] Using the activated catalyst of the present invention, the ethane selectivity can be at least 70%, 50% to 90%, 70% to 80%, or 70%, 75%, 80%, 85%, 90% or any value or any scope therebetween. In a preferred embodiment, the ethane selectivity is at least about 75%. In certain embodiments, when the temperature is 240°C to 290°C, the butane conversion can be at least 50%, 50 to 95%, 70 to 90%, or at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85% or 90% or any value or scope therebetween. In particular, the hydrocarbon compound (e.g., butane) stability of the activated fresh catalyst of the present invention is higher than the hydrocarbon compound stability of the original fresh catalyst under the same hydrogenolysis conditions.

[0046] C. Catalyst

[0047] The catalyst of the present invention may comprise a support and a catalytic bimetallic composition. The catalyst may be purchased (e.g., Zeolyst) or prepared using known catalyst preparation techniques. The specific surface area of ​​the catalyst may be at least 100 m 2 / g, or 100m 2 / g to 500m 2 / g, or 100m 2 / g, 150m 2 / g, 200m 2 / g, 250m 2 / g、300m 2 / g, 350m 2 / g, 400m 2 / g, 450m 2 / g, or 500m 2 / g or any value or range therebetween. The carrier can be aluminum oxide (Al2O3), titanium dioxide (TiO2), silicon dioxide (SiO2), zeolite or a mixture or a combination thereof. Non-limiting examples of zeolites include ZSM-5, ZSM-11, Y, high silicon Y, USY, EU-1, EU-2, β, L, ferrierite, CHA, SSZ-16, Nu-3, σ-1, silicalite-1 and combinations thereof. In certain embodiments, the zeolite is ZSM-5. The catalyst can include two noble metals. Non-limiting examples of noble metals include platinum (Pt), iridium (Ir), palladium (Pd), ruthenium (Rh), silver (Ag), gold (Au), alloys thereof, or combinations thereof, preferably PtIr.

[0048] The catalyst can be prepared using an impregnation method. In a preferred aspect, an incipient wetness impregnation method can be used. The catalytic metal precursor can be dissolved in deionized water to form a respective catalytic metal precursor solution. The catalytic metal precursor can be obtained as a metal nitrate, a metal amine, a metal chloride, a metal coordination complex, a metal sulfate, a metal phosphate hydrate, a metal complex or any combination thereof. Examples of metal precursor compounds include hexachloroiridic acid and ammonium heptamolybdate. These metals or metal compounds can be purchased from any chemical supplier, such as Sigma-Aldrich (St. Louis, Missouri, USA), Alfa-Aeaser (Ward Hill, Massachusetts, USA), and Strem Chemicals (Newburyport, Massachusetts, USA). The two solutions can be mixed to form a combined catalytic metal precursor solution or used alone. The catalytic metal precursor solution or combined catalytic metal precursor solutions can be added to a known amount of a support (e.g., a weighed alumina extrudate) and stirred at room temperature (e.g., 20°C to 35°C) for a period of time (e.g., 2 hours to 24 hours) to form a catalytic metal precursor / support composition. The water can be removed by drying the catalytic metal precursor / support composition at a temperature of 80°C to 100°C, or about 90°C. Once dried, the catalytic metal precursor / support composition can be calcined in air at 275°C to 350°C or 275°C to 285°C, or any value or range therebetween. Calcination of the catalytic metal precursor / support composition forms a catalytic crystalline bimetallic composition and attaches the composition to the support. Example

[0049] The present invention will be described in more detail by specific examples. The following examples are only for illustrative purposes and are not intended to limit the present invention in any way. Those skilled in the art will easily recognize various non-critical parameters that can be changed or modified to produce substantially the same result.

[0050] Example 1

[0051] (Activation of fresh hydrogenolysis catalyst)

[0052] Fresh Pt (0.3 wt%)-Ir (0.3 wt%) / ZSM-5 catalyst (10 g, Zeolyst, USA) was pretreated in hydrogen (Praxair, purity 99.999%) at a flow rate of 400 sccm and a reactor pressure of 110 psig (0.758 MPa) using the temperature schedule shown in Table 1. Subsequently, the catalyst was cooled to the reaction temperature (280°C) in the same hydrogen flow before the feed was introduced. Then, the catalyst was heated to 280°C in a 1% mol / l atmosphere under a pressure of 200 psig (0.758 MPa).10 The molar ratio is 2.5, C4H 10 Mass space velocity = 4h -1 The catalyst activity was studied under the conditions of 100 psig (0.68 MPa) pressure.

[0053] Table 1

[0054]

[0055] Figure 3 The n-butane conversion and ethane product selectivity are shown as a function of time in production. Due to catalyst deactivation, the n-butane conversion decreased from about 65% to about 37% in 6 days. At this time, the reaction was terminated by returning the feed flow rate to zero in the reactor. Subsequently, the catalyst was subjected to the present invention as Figure 1 Prior to the regeneration scheme shown, the catalyst was purged with nitrogen. After reintroduction of the feed, the n-butane conversion increased to about 65% over the next 6 to 7 days and was significantly higher than that of the original untreated catalyst. Figure 4 As shown, the inactivation rate was also slowed down.

[0056] Example 2

[0057] (Regeneration / activation of spent hydrogenolysis catalyst)

[0058] An Ir / Pt hydrogenolysis catalyst was obtained which was operated for two months in a butane hydrogenolysis pilot plant. Before being treated with the regeneration method of the present invention, the catalyst showed a n-butane conversion rate of about 15%. After regeneration, the n-butane conversion rate increased to 42% and was able to be stable for more than 4 days, as shown in FIG. Figure 5 From these data, it can be seen that the regeneration strategy can successfully restore the activity of the spent catalyst.

[0059] Example 3

[0060] (Comparison of the treatment of the present invention with standard pretreatment)

[0061] The fresh Ir / Pt hydrogenolysis catalyst was divided into two parts. One part of the catalyst was treated using the activation treatment of the present invention, the treatment scheme is listed in Table 2. The second part of the catalyst was treated using a standard catalyst pretreatment involving only H2 reduction at 400°C. The n-butane conversion reaction parameters for the two studies were: hydrocarbon compound WHSV: 4 hours -1 , temperature: 280°C, pressure: 100 psig (0.689 MPa), the H2 / hydrocarbon compound ratio of the catalyst treated by the present invention is 1.5, and the H2 / hydrocarbon compound ratio of the catalyst pretreated by the standard is 2.5. The results are shown in Figure 6As shown in the figure, the catalyst that has undergone the pretreatment according to the present invention has a higher conversion rate and a higher carbon-based selectivity (about 40% higher) than the catalyst that has undergone the standard pretreatment protocol.

[0062] Table 2

[0063]

[0064] a) RT refers to room temperature

[0065] Although the embodiments of the present application and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications may be made to the present invention without departing from the essence and scope of the embodiments defined by the appended claims. In addition, the scope of the present application is not intended to be limited to the specific embodiments of the processes, machines, manufactured products, material compositions, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the above disclosure, processes, machines, manufactured products, material compositions, means, methods or steps that currently exist or will be developed later and have substantially the same functions or achieve substantially the same results as the corresponding embodiments described herein may be used. Therefore, the appended claims are intended to include these processes, machines, manufactured products, material compositions, means, methods or steps within their scope.

Claims

1. A method for activating a hydrogenolysis catalyst, the method comprising: (a) contacting an oxidized catalyst with a butane-containing stream in the presence of H2 to form a treated catalyst; Afterwards (b) contacting the treated catalyst with H2 to form an activated hydrogenolysis catalyst.

2. The method according to claim 1, wherein: The stream comprises butane, wherein the butane further comprises n-butane, isobutane, or a combination thereof.

3. The method according to any one of claims 1 to 2, wherein: The weight ratio of H2 to butane in step (a) is from 0.5 to 20.

4. The method according to any one of claims 1 to 3, wherein: The weight ratio of butane to catalyst is 1 to 100.

5. The method according to any one of claims 1 to 4, wherein: The conditions of step (a) include a temperature of 200°C to 350°C, preferably 275°C to 325°C, and a pressure of 0.5 MPa to 1.5 MPa, preferably 0.7 MPa to 0.8 MPa.

6. The method according to any one of claims 1 to 5, wherein: Step (b) is performed over a longer period of time than step (a).

7. The method according to any one of claims 1 to 6, wherein: The conditions of step (b) include a temperature of 300°C to 500°C, preferably 300°C to 400°C, and a pressure of 0.5 MPa to 1.5 MPa, preferably, 0.7 MPa to 0.8 MPa.

8. The method according to any one of claims 1 to 7, wherein: The oxidized catalyst in step (a) is prepared by contacting a fresh catalyst, a deactivated catalyst or a mixture thereof with an oxidizing stream comprising oxygen (O2) and a diluent.

9. The method of claim 8, wherein the contacting conditions include a temperature of 200°C to 450°C, preferably 400°C or below.

10. The method according to any one of claims 8 to 9, wherein: The oxidation stream comprises 0.1 vol% to 30 vol% O2, preferably 5 vol% to 20 vol% O2, or more preferably 8 vol% to 12 vol% O2.

11. The method according to any one of claims 1 to 10, wherein: The catalyst includes at least two noble metals on a support.

12. The method according to claim 11, wherein: The noble metal includes platinum (Pt), iridium (Ir), palladium (Pd), ruthenium (Rh), silver (Ag), gold (Au), alloys thereof, or combinations thereof, preferably PtIr.

13. The method according to claims 11 to 12, wherein: The support is a zeolite support, preferably ZSM5.

14. The method according to claim 1, wherein: The oxidic catalyst is prepared by an impregnation method.

15. The method according to claim 14, wherein: The oxidic catalyst was prepared by incipient wetness impregnation.

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