KR20240024911A - Method and system for producing light olefins with high yield and selectivity - Google Patents

Abstract

1. A process for forming olefins, comprising: introducing a hydrocarbon feed stream into a reactor comprising a dehydrogenation catalyst; reacting the hydrocarbon feed stream with a dehydrogenation catalyst in the reactor to form a high temperature dehydrogenation product comprising at least a portion of the dehydrogenation catalyst; separating at least a portion of the dehydrogenation catalyst from the high temperature dehydrogenation product in a primary separation device and a secondary separation device downstream of and in fluid communication with the primary separation device; After the high temperature dehydrogenation product is discharged from the secondary separation device, combining the high temperature dehydrogenation product with a quenching stream containing hydrocarbons to cool the high temperature dehydrogenation product and form an intermediate temperature dehydrogenation product; and cooling the intermediate temperature dehydrogenation product to form a cooled dehydrogenation product.

Description

Method and system for producing light olefins with high yield and selectivity

Exemplary embodiments of this technological advance relate to chemical treatment systems, and more particularly to dehydrogenation chemical treatment systems.

Cross-reference to related applications

This application claims priority and the benefit of U.S. Provisional Application No. 63/222,733, filed on July 16, 2021, and U.S. Provisional Application No. 63/329,006, filed on April 8, 2022, the disclosures of which are: All are incorporated herein by reference in their entirety.

Light olefins can be used as a base material for manufacturing many types of products and materials. For example, ethylene can be used to produce polyethylene, ethylene chloride, or ethylene oxide. These products can be used in product packaging, construction, textiles, etc. Accordingly, there is an industrial demand for light olefins such as ethylene, propylene and butene. Light olefins can be produced by a variety of reaction processes depending on a given chemical feed, which may be a product from a crude oil refining operation or a renewable product from a biorefinery or natural gas component stream. Many light olefins can be produced through catalytic processes, such as catalytic dehydrogenation, in which a feed stream is contacted with a fluidized catalyst that promotes conversion of the feed stream to light olefins. In these systems, reaction selectivity toward light olefins can be important to overall process efficiency.

Patent International Publication No. WO 2020/263599, which is incorporated herein by reference in its entirety, involves introducing a hydrocarbon feed stream into a reactor, reacting the hydrocarbon feed stream with a dehydrogenation catalyst in the reactor to achieve high temperature dehydration. forming a digestion product, separating at least a portion of the dehydrogenation catalyst from the high temperature dehydrogenation product in a primary separation device, combining the high temperature dehydrogenation product with a quench stream to cool the high temperature dehydrogenation product and intermediate temperature dehydration. A process for forming light olefins is described comprising forming a digestion product, and cooling the intermediate temperature dehydrogenation product to form a cooled dehydrogenation product.

Patent International Publication No. WO 2018/236630, which is incorporated herein by reference in its entirety, comprises contacting a feed stream with a catalyst in an upstream reactor section of a reactor having an upstream reactor section and a downstream reactor section, producing an intermediate product. conveying the stream to a downstream reactor section, and introducing a riser quench fluid into the downstream reactor section, upstream reactor section, or transition section to contact the intermediate product stream and catalyst to slow or stop the reaction. Describes the stream processing method. The method includes separating at least a portion of the catalyst from the product stream, passing the product stream to a product processing section, cooling the product stream, and separating a portion of the riser quench fluid from the product stream. The riser quench fluid separated from the product stream may be recycled back to the downstream reactor section, upstream reactor section, or transition section as riser quench fluid.

The present invention provides a process for forming olefins, comprising: introducing a hydrocarbon feed stream into a reactor comprising a dehydrogenation catalyst; reacting the hydrocarbon feed stream with a dehydrogenation catalyst in the reactor to form a high temperature dehydrogenation product comprising at least a portion of the dehydrogenation catalyst; separating at least a portion of the dehydrogenation catalyst from the high temperature dehydrogenation product in a primary separation device and a secondary separation device downstream of and in fluid communication with the primary separation device; After the high temperature dehydrogenation product is discharged from the secondary separation device, combining the high temperature dehydrogenation product with a quenching stream containing hydrocarbons to cool the high temperature dehydrogenation product and form an intermediate temperature dehydrogenation product; and cooling the intermediate temperature dehydrogenation product to form a cooled dehydrogenation product.

The present invention also provides a system for forming olefins from a hydrocarbon feed stream, comprising: a reactor configured to receive the hydrocarbon feed stream under reaction conditions with a dehydrogenation catalyst, wherein the reaction conditions are such that at least a portion of the dehydrogenation catalyst A reactor producing a high temperature dehydrogenation product comprising; a plurality of separation devices configured to separate at least a portion of the dehydrogenation catalyst from the high temperature dehydrogenation product, the plurality of separation devices comprising a primary separation device and a secondary separation device downstream of and in fluid communication with the primary separation device; a quench system configured to combine the high temperature dehydrogenation product with a quench stream comprising hydrocarbons to cool the high temperature dehydrogenation product and form an intermediate temperature dehydrogenation product; and a heat transfer system configured to cool the intermediate temperature dehydrogenation product to form a cooled dehydrogenation product.

Figure 1 is a graph showing the loss of propylene yield per second due to secondary pyrolysis at different temperatures.
Figure 2 is a graph showing the loss of propylene selectivity per second due to secondary pyrolysis at different temperatures.
3 shows an exemplary embodiment of a generalized flow diagram of a reactor system with a recycle quench stream.
Figure 4 shows a more detailed example of an exemplary reactor implementing this technological advance.
Figure 5 is a graph showing the PDH performance of a typical PDH catalyst associated with this technological advancement.
Figure 6 is a graph showing C ₃ H ₆ yield of product A versus reaction zone temperature.
Figure 7 is a graph showing C ₃ H ₆ selectivity of Product A versus reaction zone temperature.
Figure 8 shows a catalyst composition (Catalyst 8) that maintained its performance for 204 cycles.

Justice

As used herein, the term "hydrocarbon", unless otherwise specified, refers to a class of compounds containing hydrogen bonded to carbon, including (i) saturated hydrocarbon compounds, (ii) unsaturated hydrocarbon compounds, and (iii) different n values. Includes mixtures of hydrocarbon compounds (saturated and/or unsaturated), including mixtures of hydrocarbon compounds having

As used herein, “no formation” means product formation in a reactor with a selectivity (relative to the propane feed) of 0.1 mole percent carbon or less, where (moles of carbon in product) / (carbon converted in feed) (mol of) = carbon mol% selectivity of the product. For example, if 2 moles of ethylene are produced when 3 moles of propane are converted, the carbon mol% selectivity of ethylene is 44.4%.

“Olefins,” also alternatively referred to as “alkenes,” are linear, branched, or cyclic compounds of carbon and hydrogen with at least one double bond.

“Plenum” means a region of a reactor that facilitates fluid communication between pipes or ducts carrying the hot product stream from the reactor to the outlet stream. The plenum may also serve as a conduit to collect gases from several sets of cyclones before they exit the reactor. As described below, a reactor may have multiple plenums (e.g., a first plenum and a second plenum as illustrated in Figure 4), with the term plenum referring to the first plenum unless otherwise stated. or one of the secondary plenums.

For the purposes of this disclosure, the nomenclature of elements follows the version of the Periodic Table of the Elements (new notation) provided in Hawley's Condensed Chemical Dictionary, ^16th Ed., John Wiley & Sons, Inc., (2016), Appendix V. . For example, Group 2 elements include Mg, Group 8 elements include Fe, Group 9 elements include Co, Group 10 elements include Ni, and Group 13 elements include Al. As used herein, the term “metalloid” refers to the elements B, Si, Ge, As, Sb, Te, and At. In this disclosure, when a given element is indicated as being present, it may exist in the elemental state or as any of its chemical compounds, unless otherwise specified or the context clearly indicates otherwise.

The term “mixed metal oxide” refers to a composition comprising at least two different metal atoms mixed on an atomic scale with oxygen atoms. For example, a “mixed Mg/Al metal oxide” has O, Mg, and Al atoms mixed on an atomic scale, and has the general chemical formula (At this time, A is the counter anion of negative charge n, x is in the range of greater than 0 and less than 1, and m is greater than or equal to 0). A material consisting of nm-sized MgO particles and nm-sized Al ₂ O ₃ particles mixed together is not a mixed metal oxide because the Mg and Al atoms are not mixed on an atomic scale but instead are mixed on a nm scale.

The term “selectivity” refers to the production (based on moles of carbon) of a particular compound in a catalytic reaction. For example, the phrase “the alkane hydrocarbon conversion reaction has 100% selectivity for olefin hydrocarbons” means that 100% of the alkane hydrocarbons (based on moles of carbon) converted in the reaction are converted to olefin hydrocarbons. When used in reference to a specific reactant, the term "conversion" refers to the amount of reactant consumed in the reaction. For example, if the specified reactant is propane, 100% conversion means that 100% of the propane is consumed in the reaction. In another example, when the specified reactant is propane, if 1 mole of propane is converted to 1 mole of methane and 1 mole of ethylene, the methane selectivity is 33.3% and the ethylene selectivity is 66.7%. Yield (in moles of carbon) is the product of conversion and selectivity.

For brevity, only certain ranges are explicitly disclosed herein. However, ranges from any lower limit may be combined with any upper limit to recite ranges not explicitly stated, and ranges from any lower limit may be combined with any other lower limit to enumerate ranges not explicitly stated. and, in the same way, ranges from any upper limit can be combined with any other upper limit to enumerate ranges not explicitly stated. Additionally, a range includes all points or individual values between endpoints, even if not explicitly stated. Accordingly, every point or individual value can serve as a unique lower or upper limit that can be combined with any other point or individual value or any other lower or upper limit to enumerate a range not explicitly stated.

Although phrases such as hot, high temperature, and medium temperature are used herein to describe reactors and various streams, these degree terms are used to distinguish streams based on their relative temperature characteristics. Those skilled in the art will understand that no specific temperature is implied and that the relative temperature of the streams will be understood in relation to the reactor temperature and heat flow, which are determined by thermodynamics.

Exemplary Embodiments

Light olefins (e.g., propylene) can be produced by catalytic processes, such as dehydrogenation, in which a feed stream (e.g., propane) is contacted with a fluidized dehydrogenation catalyst at elevated temperatures. The feed stream may originate from crude oil refining (e.g., propane). The resulting product mixture may contain a mixture of highly reactive molecules and catalyst particles. Exemplary embodiments of this technological advance can separate catalyst particles from a hot product stream (e.g., at approximately the temperature of the reactor) and then cool the hot product stream using direct liquid quenching to initiate secondary thermal and catalytic reactions. Describe the reactor configuration that can prevent selectivity loss due to .

The selectivity of light olefins from the dehydrogenation reactor is negatively affected due to secondary reactions. Secondary reactions involve continued thermal and catalytic reaction of the reactants through side-reactions and/or over-reactions of the products. To avoid this, the catalyst particles must be separated from the hot product stream, and the resulting hot product stream must be cooled to an intermediate temperature sufficiently low to slow or stop the thermal reaction.

Yield and selectivity losses after propylene production by a propane dehydrogenation (PDH) reactor can occur due to thermal and catalytic reactions. These secondary reactions can be minimized by efficiently separating the catalyst particles from the hot product stream and quenching the hot product stream immediately after catalyst separation. The preferred sequence is nearly complete catalytic separation (i.e., greater than about 98% separation) using primary and secondary cyclone separators, followed by hydrocarbon quenching. This can be contrasted with the existing approach of intermediate quenching using partial catalytic separation as described in WO 2020/263599.

Dehydrogenation reactors constructed in accordance with the present technological advancements may include some or all of the following features: (a) immediate removal of catalyst particles from the product stream after the riser prior to cooling using primary and secondary cyclone separators; (b) cooling the hot product stream using direct liquid/gas quenching after catalyst separation; (c) The use of quenching fluids, which are gases or saturated or supercooled liquids that vaporize/flash in fluid contact with the hot product stream providing efficient contact for heat transfer; (d) separating the product stream in a downstream separation unit, wherein at least a portion of the by-product stream (e.g., benzene) from the separator is recycled as a quench fluid; (e) the quenching fluid may be derived from the product stream, may be an external fluid not formed in the reactor (e.g., a heavy aromatic solvent), or may be water; (f) reaction temperature ranging from 600°C to 700°C; (g) use of Pt catalyst supported on mixed magnesium aluminum oxide; (h) Integration of heat and/or recovery processes with steam crackers; and (i) removal of fines from the product stream after initial quenching.

Reactor systems implementing this technological advance can provide some or all of the following advantages: (a) primary and secondary cyclones have very high catalyst separation efficiencies (>98%) from the hot product stream prior to quenching; can be achieved, which minimizes secondary catalytic reactions that may occur even after rapid cooling; (b) the separated catalyst particles can be cycled to the regenerator at 800°C, where the higher separation efficiency before quenching avoids sensible heat loss of the catalyst particles; and (c) injecting quenching fluid into the plenum of the reactor reduces reactor design complexity compared to the conventional system in WO 2020/263599, which requires multiple quenching lines for each separation series.

Experiments were performed to study the effect of secondary thermal and catalytic reactions on propylene (C ₃ H ₆ yield) in a laboratory fixed bed reactor. To determine the yield loss due to secondary thermal decomposition, experiments were performed in a tube reactor without catalyst loading. Figure 1 is a graph showing the loss of propylene yield due to secondary thermal decomposition per residence time after the reactor at reactor outlet temperatures at two different pressures. For example, a post-reactor residence time of 5 seconds at 640°C, 26 psia will result in a propylene yield loss of 2.5 mole carbon. Figure 2 is a graph showing the loss of propylene selectivity due to secondary thermal decomposition per residence time after the reactor at reactor outlet temperatures at two different pressures. These yield and selectivity losses can be attributed to secondary thermal decomposition reactions from unconverted propane to non-propylene products and thermal decomposition reactions of propylene itself. These yield and selectivity losses can have a significant impact on the overall economics of propylene production.

3 shows an exemplary embodiment of a generalized flow diagram of a reactor system with a recycle quench stream. Note that many process and equipment details of one or more embodiments of the system of Figure 3 are described herein with reference to Figure 4.

With continued reference to FIG. 3 , reactor system 102 may include a reactor 202 , a separation device 220 and a plenum section 204 . The reactor system is coupled with the catalyst treatment unit 300. Typically, the main reaction, such as the dehydrogenation reaction, occurs in reactor 202, where a reactant stream 280 from outside the system shown (sometimes referred to herein as a hydrocarbon feed stream) is fed to the regenerated catalyst stream from the catalyst treatment section. It is combined with 282 and delivered to reactor 202. After reaction, the catalyst, unreacted chemicals, and product chemicals are passed through stream 284 to separation device 220. It should be understood that the “product stream” may include both reaction products and unreacted components from reactant stream 280. Reactant stream 280 may include one or more of propane, n-butane, iso-butane, ethane, or ethylbenzene.

Stream 284 is often referred to herein as the high temperature dehydrogenation product. Typically, stream 284 has a temperature approximately the same as the temperature at the outlet of reactor 202. Temperatures may vary depending on the reaction and catalyst system used. In one or more embodiments, stream 284 has a temperature ranging from 600° C. to 700° C. and a pressure ranging from 1.0 bara to 4.0 bara for propane dehydrogenation.

Separation device 220 may include a primary separation device 402 and a secondary separation device 404. In further embodiments, primary separation device 402 and/or secondary separation device 404 may be, but is not limited to, a cyclone, filter, or other suitable device for separating solids, such as catalysts, from gases. After separating at least a portion (usually most) of the catalyst in stream 284 from the gaseous reactants and product chemicals in primary separation device 402, the catalyst is passed to catalyst treatment 300 via stream 294 and the product and reaction gases (sometimes referred to as hot dehydrogenated products) may be passed out of primary separation device 402 via stream 286. The temperature of stream 286 may be approximately the same as the temperature of stream 284.

After the high temperature dehydrogenation product 286 is discharged from the primary separation device 402, the product 286 is passed to the secondary separation device 404. Catalyst may be delivered to catalyst treatment section 300 via stream 298. No quenching fluid is applied to the output of primary separation device 402. The primary and secondary separation devices can operate at temperatures ranging from 600°C to 700°C and pressures ranging from 1 bara to 4 bara.

After the hot dehydrogenation product exits stream 288 from the secondary separation device, the hot dehydrogenation product (or reactor effluent) is combined with quench stream 296 in plenum section 204 of reactor system 102. The high temperature dehydrogenation product is cooled and forms stream 289 (sometimes referred to as the intermediate temperature dehydrogenation product). The intermediate temperature dehydrogenation product preferably has a temperature below 620°C. The quench stream can be a gas or liquid stream that is part of stream 288 that can be separated in a downstream separation system detailed herein, or a stream that is provided from an external source. The quench stream may include one or more of ethylene, propylene, butene isomers, or benzene (eg, reaction products). The quench stream may contain liquid hydrocarbons and the intermediate temperature product may be entirely vaporous.

For example, quench fluid 296 may include steam, liquid water, liquid hydrocarbons (e.g., quench oil, fuel oil, or other hydrocarbons), or combinations thereof. Liquid hydrocarbons may include hydrocarbons having 6 or more carbon atoms, such as 6 carbon atoms to 25 carbon atoms, or 6 carbon atoms to 20 carbon atoms. In some embodiments, quench fluid 296 may include water. Alternatively, in other embodiments, quench fluid 296 may include liquid hydrocarbons. In another embodiment, quench fluid 296 may include one or more of benzene, toluene, pyrolysis gas, or combinations thereof. The quench stream may contain aromatics that are not formed in the hot dehydrogenation product. Quenching may include kerosene, light coker gas oil, coke still (coker) distillate (CSD), hydrotreated distillate, or new raw virgin feedstocks such as virgin gas oil, heavy virgin naphtha, light virgin naphtha, but , preferably heavy aromatic solvents such as light catalytic cycle oil (LCCO or LCO), heavy catalytic cycle oil (HCCO or HCO) or heavy catalytic naphtha (HCN), aromatic 100 (A100) solvent, aromatic 150 (A150) solvent, Aromatic 200 (A200) solvent or any combination thereof.

Quenching fluid 296 can lower the temperature of stream 289 to about 620° C. to 580° C., with stream 289 experiencing a pressure change of less than 0.1 bar due to vaporization.

The temperature of quench fluid 296 may be at least 100°C, at least 200°C, at least 300°C, at least 400°C, or at least 550°C below the temperature of the intermediate stream and catalyst in stream 288. The temperature of the quench stream and the location of the nozzle injecting the quench stream can be optimized as needed to sufficiently slow or stop the secondary heat and catalytic reactions discussed above.

Stream 289 is then processed to cool its contents, for example, through heat exchanger 406. In further embodiments, cooling may include the addition of another liquid quench system 408 or other known means for cooling the stream. This alternative quenching system 408 may use any of the quenching fluids described above. Generally, the heat transfer system may include one or both of a heat exchanger 406 and another quenching system 408 (or optionally any other means of cooling the stream). The product stream of heat exchanger 406 is stream 290, which may be referred to as cooled dehydrogenation product. The temperature of stream 290 may be approximately the same as the temperature described for quench stream 296. It should be understood that stream 290 and/or stream 296 may experience an increase in pressure to flow in a desired direction.

To form quench stream 296, at least a portion of stream 290 is recycled back to the system through separation unit 407 (which may be any suitable type of separation means or means for diverting a portion of the stream). do. It should be noted that the chemical content of stream 296 may be similar or identical to the chemical content of stream 286 (i.e., no further reaction has occurred other than some residual thermal decomposition after the reaction in reactor 202). ). Quenching stream 288 by contacting it with quench stream 296 may cool the contents of stream 286 to a temperature that substantially reduces the reaction rates of thermal decomposition and other secondary reactions. Stream 286 may be at a temperature where thermal decomposition occurs, which may reduce the selectivity of the desired reaction product.

Heat exchanger 406 may be configured to heat feed stream 280 through heat transfer from product stream 289.

According to one or more embodiments, the catalyst particles separated by separation device 220 and/or catalyst particles (not shown) recovered from stream 289 are treated by one or more steps before being delivered to catalyst treatment section 300. It can be.

Figure 4 shows an exemplary reactor implementing this technological advance. The reactor design illustrated in Figure 4 minimizes the secondary reactions discussed above. In this configuration, the propane feed is brought into contact with a dehydrogenation catalyst in the riser section of the reactor at elevated temperature (600° C.). The dehydrogenation catalyst is separated from the hot product stream in primary and secondary separators. The resulting hot product stream includes dehydrogenation products (propylene), by-products (methane, benzene, etc.) and unconverted propane. This stream output from the secondary separator is immediately quenched into a liquid quench stream. The liquid quench stream may contain by-products of the dehydrogenation reaction (benzene) or other external fluids (water or A150). The quench liquid is vaporized in contact with the hot stream in the plenum section of the reactor. Direct heat transfer reduces the temperature of the product stream and the rate of secondary reactions.

Although Figure 4 is described in relation to the propylene/propane embodiment, this technological advance can be applied to the production of other olefins. Additionally, although in some cases the same numbers are used in FIG. 4 in conjunction with FIG. 3, it should be understood that the embodiment of FIG. 3 may utilize a wide variety of reactor types, and FIG. 4 is only an example of one of those types. .

FIG. 4 illustrates an embodiment of a portion of the reactor system 102 of FIG. 3 , sometimes referred to as reactor vessel 410 , where the separation device includes a primary separation device 420 . Primary separation device 420 is contained within shell 430 and has a body 421, an inlet 422, an outlet 424, and a solids discharge dipleg 426. The fluidized solids stream enters the primary separation device 420 through inlet 422. In the primary separation device 420, a major portion of the entrained solids, such as catalyst particles, are separated from the fluidized solids stream. Separated solids are discharged from the primary separation device through discharge diplex 426 to produce a primary separation device effluent containing solids and fluids not removed by primary separation device 420, such as gaseous products. leave it behind Primary separator effluent passes vertically upwardly out of primary separator 420 through outlet 424, enters secondary separator 440 through primary separator outlet tube 442 and then through cross duct. Passes through (not shown). The secondary separation device 440 further includes a body 441, an outlet 444, and a solid discharge diplex 446. Secondary separation unit 440 further separates solids from the primary separation unit effluent. The solid separated in the secondary separation device 440 is discharged downward through the diflex 446.

As shown in Figure 4, quench stream 296 may enter the upper portion of secondary separation device outlet tube 444 located above secondary separation device 440. This arrangement provides adequate mixing of the quench stream and the effluent from secondary separation device 440 and the outlet of secondary separation device 440 and the inlet or nozzle of quench stream 296. It is believed that this may be desirable to reduce residence time between locations. In some embodiments, the residence time of the high temperature dehydrogenation product in each of the primary and secondary separation devices is less than 1 second.

Secondary separator outlet 444 is fluidly connected to second plenum 450. The second plenum allows secondary separator effluent to exit vessel 410 through outlet 470. As shown in Figure 4, the second plenum is housed within a larger, higher volume first plenum 460. Primary separation device 420 may be supported by first plenum 460.

The exact location of the inlet or nozzle relative to the quench stream 296 may vary depending on the actual reactor used, but is necessary to minimize secondary catalytic cracking in the hot dehydrogenation product and/or to remove olefins (i.e., propylene) in the hot dehydrogenation product. may be placed in a location within the first plenum 460 or second plenum 450 that minimizes yield loss (pipes, ducts or conduits for 296 of the secondary plenum may Note that it is partially shown as a dashed line as it is behind the metal plate defining (450)). Preferably, quench stream 296 can be configured to minimize required piping so that all secondary separation devices can be quenched by a single inlet or nozzle; It is therefore quenched in the second plenum 450 region to provide a simplified reactor design. Accordingly, Figure 4 illustrates two possible locations for the inlet or nozzle for the quench stream 296, and in practice either or both may be used. However, it is important to note that the output region of primary separator 420 (i.e., output 424) is not provided with a quench stream.

As also shown in FIG. 4, the shell 430 additionally accommodates a riser 435. A stream of unseparated fluidized solid particles enters the shell through riser 435. Riser 435 is fluidly connected to the inlet 422 of primary separation device 420 so that a stream of unseparated, fluidized solid particles can enter primary separation device 420 from riser 435, i.e., fluidization. Allows passage of solid particles. 4 schematically illustrates only one primary separation device and one secondary separation device, it will be understood that additional primary and secondary separation devices may be placed around the riser. For example, the second plenum 450 may be connected to another secondary separation device (not shown), which in turn is fed by the primary separation device 420 or another primary separation device (not shown).

Experiment to prove catalyst stability

Those skilled in the art will recognize that any catalyst suitable for their purposes may be used in the reactor implementing the present technological advancement. In some embodiments, the catalyst has 0.001%, 0.002%, 0.003%, 0.004%, 0.005%, 0.006%, 0.007% by weight of the Group 10 element disposed on the inorganic support, based on the weight of the inorganic support. %, 0.008 wt%, 0.009 wt%, 0.01 wt%, 0.015 wt%, 0.02 wt%, 0.025 wt%, 0.03 wt%, 0.035 wt%, 0.04 wt%, 0.045 wt%, 0.05 wt%, 0.055 wt%, 0.06% by weight, 0.065% by weight, 0.07% by weight, 0.075% by weight, 0.08% by weight, 0.085% by weight, 0.09% by weight, 0.095% by weight, 0.1% by weight, 0.2% by weight, 0.3% by weight, 0.4% by weight, 0.5% by weight %, 0.6% by weight, 0.7% by weight, 0.8% by weight, 0.9% by weight, or 1% by weight to 2% by weight, 3% by weight, 4% by weight, 5% by weight, or 6% by weight. In some embodiments, the catalyst has 5.5% or less, 4.5% or less, 3.5% or less, 2.5% or less, 1.5% or less, 1% by weight of a Group 10 element disposed on the inorganic support, based on the weight of the inorganic support. Weight% or less, 0.9 weight% or less, 0.8 weight% or less, 0.7 weight% or less, 0.6 weight% or less, 0.5 weight% or less, 0.4 weight% or less, 0.3 weight% or less, 0.2 weight% or less, 0.15 weight% or less, 0.1 Weight% or less, 0.09 weight% or less, 0.08 weight% or less, 0.07 weight% or less, 0.06 weight% or less, 0.05 weight% or less, 0.04 weight% or less, 0.03 weight% or less, 0.02 weight% or less, 0.01 weight% or less, 0.009 It may be included in weight% or less, 0.008 weight% or less, 0.007 weight% or less, 0.006 weight% or less, 0.005 weight% or less, 0.004 weight% or less, 0.003 weight%, or 0.002 weight% or less. In some embodiments, the catalyst has greater than 0.001 weight percent, greater than 0.003 weight percent, greater than 0.005 weight percent, greater than 0.007 weight percent, greater than 0.009 weight percent, greater than 0.01 weight percent of a Group 10 element disposed on the inorganic support, based on the weight of the inorganic support. Greater than 0.02 weight%, greater than 0.04 weight%, greater than 0.06 weight%, greater than 0.08 weight%, greater than 0.1 weight%, greater than 0.13 weight%, greater than 0.15 weight%, greater than 0.17 weight%, greater than 0.2 weight%, 0.2 greater than 0.23 weight %, greater than 0.25 weight %, greater than 0.27 weight %, or greater than 0.3 weight % and less than 0.5 weight %, less than 1 weight %, less than 2 weight %, less than 3 weight %, less than 4 weight %, It may contain less than 5% by weight, or less than 6% by weight.

In some embodiments, the Group 10 element may be or include Ni, Pd, Pt, combinations thereof, or mixtures thereof. In at least one embodiment, the Group 10 element can be or include Pt. When two or more Group 10 elements are disposed on an inorganic support, the catalyst may contain 0.001% by weight, 0.002% by weight, 0.003% by weight, or 0.004% by weight of the two or more Group 10 elements disposed on the inorganic support, based on the weight of the inorganic support. Weight %, 0.005 weight %, 0.006 weight %, 0.007 weight %, 0.008 weight %, 0.009 weight %, 0.01 weight %, 0.015 weight %, 0.02 weight %, 0.025 weight %, 0.03 weight %, 0.035 weight %, 0.04 weight % , 0.045% by weight, 0.05% by weight, 0.055% by weight, 0.06% by weight, 0.065% by weight, 0.07% by weight, 0.075% by weight, 0.08% by weight, 0.085% by weight, 0.09% by weight, 0.095% by weight, 0.1% by weight, 0.2% by weight. Weight %, 0.3 weight %, 0.4 weight %, 0.5 weight %, 0.6 weight %, 0.7 weight %, 0.8 weight %, 0.9 weight %, or 1 weight % to 2 weight %, 3 weight %, 4 weight %, 5 weight %, or may be included in a combined amount of 6% by weight. In some embodiments, the active components of a regenerated catalyst capable of performing dehydrogenation of a hydrocarbon feed stream may include a Group 10 element.

The inorganic support may be or include one or more Group 2 elements, a combination thereof, or a mixture thereof, but is not limited thereto. In some embodiments, Group 2 elements may exist in elemental form. In other embodiments, Group 2 elements may exist in the form of compounds. For example, Group 2 elements include oxides, phosphates, halides, halates, sulfates, sulfides, borates, nitrides, carbides, aluminates, aluminosilicates, silicates, carbonates, metaphosphates, selenides, tungstates, and molybdates. , may exist as chromate, chromate, dichromate, and silicide. In some embodiments, mixtures of any two or more compounds comprising Group 2 elements may exist in various forms. For example, the first compound may be an oxide and the second compound may be an aluminate, where the first compound and the second compound include the same or different Group 2 elements.

The inorganic support is 0.5% by weight or more, 1% by weight or more, 2% by weight or more, 3% by weight or more, 4% by weight or more, 5% by weight or more, 6% by weight or more, 7% by weight or more, 8% by weight or more, 9% by weight or more, 10% by weight or more, 11% by weight or more, 12% by weight or more, 13% by weight or more, 14% by weight or more, 15% by weight or more, 16% by weight or more, 17% by weight or more, 18% by weight or more, 19% by weight or more, 20% by weight or more, 21% by weight or more, 22% by weight or more, 23% by weight or more, 24% by weight or more, 25% by weight or more, 26% by weight or more, 27% by weight or more, 28% by weight or more, 29% by weight or more, 30% by weight or more, 35% by weight or more, 40% by weight or more, 45% by weight or more, 50% by weight or more, 55% by weight or more, 60% by weight or more, 65% by weight or more, It may contain at least 70% by weight, at least 75% by weight, at least 80% by weight, at least 85% by weight, or at least 90% by weight of Group 2 elements. In some embodiments, the inorganic support is 0.5%, 1%, 2%, 2.5%, 3%, 5%, 7%, 10%, 11% by weight, based on the weight of the inorganic support. , 13% by weight, 15% by weight, 17% by weight, 19% by weight, 21% by weight, 23% by weight, or 25% by weight to 30% by weight, 35% by weight, 40% by weight, 45% by weight, 50% by weight, It may comprise a Group 2 element in the range of 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 92.34% by weight. In some embodiments, the molar ratio of Group 2 elements to Group 10 elements is 0.24, 0.5, 1, 10, 50, 100, 300, 450, 600, 800, 1,000, 1,200, 1,500, 1,700, or 2,000 to 3,000, 3,500. , 4,000, 4,500, 5,000, 5,500, 6,000, 6,500, 7,000, 7,500, 8,000, 8,500, 9,000, 9,500, 10,000, 15,000, 20,000, 25,000, 30,00 0, 35,000, 40,000, 45,000, 50,000, 55,000, 60,000, 65,000, 70,000 , 75,000, 80,000, 85,000, 90,000, 95,000, 100,000, 200,000, 300,000, 400,000, 500,000, 600,000, 700,000, 800,000, or 900,000 It may be a range.

In some embodiments, the inorganic support may comprise a Group 2 element and Al and may be in the form of a mixed Group 2 element/Al metal oxide with O, Mg, and Al atoms mixed on an atomic scale. In some embodiments, the inorganic support may be or include a Group 2 element in oxide form and Al, or one or more oxides of a Group 2 element that are miscible on the nm scale and Al ₂ O ₃ . In some embodiments, the inorganic support may be or comprise oxides of Group 2 elements, such as MgO and Al ₂ O ₃ mixed on a nm scale.

In some embodiments, the inorganic support may or may include a first amount of a Group 2 element and Al in the form of a mixed Group 2 element/Al metal oxide, and a second amount of the Group 2 element in the form of an oxide of the Group 2 element. You can. In this embodiment, the mixed Group 2 element/Al metal oxide and the oxide of the Group 2 element may be mixed on the nm scale, and the Group 2 elements and Al in the mixed Group 2 element/Al metal oxide may be mixed on the atomic scale. You can.

In another embodiment, the inorganic support comprises a first amount of a Group 2 element and a first amount of Al in the form of a mixed Group 2 element/Al metal oxide, a second amount of a Group 2 element in the form of an oxide of the Group 2 element, and Al. It may be or contain a quantity of Al in the form of ₂ O ₃ . In this embodiment, the mixed Group 2 element/Al metal oxide, the oxide of the Group 2 element, and Al ₂ O ₃ may be mixed on the nm scale, and the Group 2 element and Al in the mixed Group 2 element/Al metal oxide may be They can be mixed on an atomic scale.

In some embodiments, when the inorganic support comprises a Group 2 element and Al, the weight ratio of the Group 2 element to Al in the inorganic support is 0.001, 0.005, 0.01, 0.05, 0.1, 0.15, 0.2, 0.3, 0.5, 0.7, or 1 to 3, 6, 12.5, 25, 50, 75, 100, 200, 300, 400, 500, 600, 700, 800, 900, or 1,000. In some embodiments, when the inorganic support comprises Al, the inorganic support has 0.5%, 1%, 1.5%, 2%, 2.1%, 2.3%, 2.5% by weight based on the weight of the inorganic support. %, 2.7%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or 11% to 15%, 20% by weight. , may include Al in the range of 25% by weight, 30% by weight, 40% by weight, 45% by weight, or 50% by weight.

In some embodiments, the catalyst can be prepared by depositing Pt and Sn on a support containing at least one alkaline earth metal oxide or one or more mixed metal oxides comprising at least one alkaline earth metal. The composition of the catalyst includes 0.001% to 6% by weight of Pt based on the weight of the support; Sn may be 0% to 10% by weight based on the weight of the support; The support includes at least one alkaline earth metal oxide. The total alkaline earth metal content may be at least 0.5% by weight based on the weight of the support. The catalyst may be Geldart A or B type depending on Geldart particle classification.

Other catalysts may be used and may be at least partially deactivated at some point during implementation of the method and/or system. The catalyst may include a Group 10 element, an inorganic support, and a contaminant, wherein the Group 10 element has a concentration ranging from 0.001% to 6% by weight based on the weight of the inorganic support. The Group 10 element may be or include Pt, wherein the inorganic support includes at least 0.5% by weight of the Group 2 element based on the weight of the inorganic support. The Group 2 element may include Mg, and at least a portion of the Group 2 element may be in the form of MgO or a mixed metal oxide containing Mg. The catalyst may further include up to 10% by weight of an accelerator based on the weight of the inorganic support, where the accelerator may include one or more of Sn, Ag, Cu, combinations thereof, or mixtures thereof. The catalyst may further include up to 5% by weight of an alkali metal element disposed on the inorganic support, where the alkali metal element may include at least one of Li, Na, K, Rb, and Cs. Additional examples of catalysts functioning in conjunction with this technological advance can be found in Application No. 63/195966, filed June 2, 2021, the entire content of which is incorporated herein by reference.

Catalyst 1 : Calcined Mg/Al hydrotalcite An Mg/Al oxide support was prepared by spray drying an aqueous slurry containing PURALOX® MG 70/170 (Sasol) and aluminum chlorohydrate (ACH). After calcining, the final support contained 80% by weight of calcined hydrotalcite and 20% by weight of ACH-derived alumina. An aqueous solution of tin(IV) chloride pentahydrate (Acros Organics) and chloroplatinic acid hexahydrate (BioXtra) was impregnated on the support. The impregnated material was kept in a sealed container at room temperature for 45 hours, then dried in air at 110°C for 6 hours, and calcined in air at 800°C for 12 hours. The final product contained nominally 0.3% by weight Pt and 1.5% by weight Sn.

Unless otherwise specified, fixed bed experiments were performed at approximately 100 kPa (absolute pressure). The composition of the reactor effluent was determined using gas chromatography (GC). The C ₃ H ₆ yield and selectivity were then calculated using the concentration of each component in the reactor effluent. The C ₃ H ₆ yields and selectivities reported in these examples were calculated on a mole carbon basis.

In each example, an amount of catalyst “M _cat ” was mixed with an appropriate amount of quartz diluent and placed in a quartz reactor. The amount of diluent was determined so that the catalyst bed (catalyst + diluent) overlaps the isothermal zone of the quartz reactor and the catalyst bed is substantially isothermal during operation. The dead volume of the reactor was filled with quartz chips/rods.

C ₃ H ₆ yield and selectivity were calculated using the concentration of each component in the reactor effluent. The C ₃ H ₆ yield and selectivity at the start of t _rxn and the end of t _rxn are denoted by Y _ini , Y _end , S _ini , and S _end, respectively, and are reported as percentages in the data table below.

Example 1: 1. The system was flushed with inert gas. The inert material passed through the reaction zone, while the flow rate (F _oxi ) of oxygen-containing gas (O _gas ) passed through the bypass of the reaction zone. The reaction zone was heated to the oxidation temperature (T _oxi ). 3. Then, oxygen-containing gas was passed through the reaction zone for a certain period of time (t _oxi ) to oxidize the catalyst. After t _oxi , the temperature in the reaction zone was changed from T _oxi to the reduction temperature (T _red ) while maintaining the oxygen-containing gas flow. 4. The system was flushed with inert gas. While the flow rate (F _red ) of H ₂ -containing gas (H _gas ) passed through the bypass of the reaction zone for a certain period of time, the inert material passed through the reaction zone. Then, H ₂ -containing gas was flowed through the reaction zone of T _red for a certain time (t _red ). 6. The system was flushed with inert material. During the above process, the temperature of the reaction zone was changed from T _red to a reaction temperature of 655°C. A hydrocarbon-containing (HC gas) feed containing 81% by volume of C ₃ H ₈ , 9% by volume of inerts (Ar or _Kr ), and 10% by volume of steam is passed through the bypass of the reaction zone for a certain period of time. During this time, inert material passed through the reaction zone. The hydrocarbon-containing feed was then passed through a reaction zone at 655° C. for 10 minutes. GC sampling of the reaction effluent began as soon as the feed was diverted from the reaction zone bypass to the reaction zone.

The above process steps were repeated periodically until stable performance was obtained. Table 1 shows that Catalyst 1 was active/selective for propane dehydrogenation and could be effectively regenerated by using this two-step oxidation scheme for 60+ cycles. Figure 5 shows that Catalyst 1 was stable over 60 cycles for propane dehydrogenation.

catalyst One M _cat (g) 0.3 F _{r x n} (sccm) 17.6 Hgas 10% H ₂
90%Ar F _red (sccm) 46.6 T _red (℃) 800 t _red (minutes) 0.05 Ogas 90% air
10% H ₂ O
after
dry air F _oxi (sccm) 93.2
after
83.9 _Toxi (℃) 800 t _oxi (minutes) One
after
10 Performance Y _ini 62.4 Y _end 59.8 S _ini 94.5 S _end 96.1

Example 2: Simulated propane dehydrogenation products were fed into a reaction zone filled with inert quartz chips to study thermal decomposition under various temperatures and pressures. The molar composition of the simulated propane dehydrogenation products is shown in Table 2.

ingredient mole% H ₂ 38.0 Ar 6.0 CH ₄ 1.32 C.O. 0.80 C ₃ H ₈ 18.0 C ₃ H ₆ 34.2 _CO2 0.30 C ₂ H ₄ 0.49 C ₂ H ₆ 0.80

The simulated propane dehydrogenation products correspond to propylene yields and selectivities of 63.7% and 95.5%, respectively.

Components of the simulated propane dehydrogenation product were further decomposed as they passed through the reactor. Degradation rates were calculated under differential conversion and expressed as loss of propylene yield and selectivity per second. Figure 1 is a graph showing the loss of propylene yield per second at different temperatures (x-axis is temperature in degrees Celsius, y-axis is %). Figure 2 is a graph showing the loss of propylene selectivity per second at different temperatures (x-axis is temperature in degrees Celsius, y-axis is %).

The above experiments were performed using approximately 5 mol% to 10 mol% of steam supplied with the simulated propane dehydrogenation product. Small amounts of steam were found to have minimal effect on the decomposition rate. The minimal effect on the cracking rate can be attributed to the low hydrocarbon partial pressure due to the presence of steam.

Example 3: The following experiment was performed to understand the reaction of the catalyst-entrained propane dehydrogenation product that was not separated by the cyclone device as the product flowed through equipment downstream of the cyclone device at various temperatures. carried out.

Feed A, consisting of a simulated propane dehydrogenation product and an appropriate amount of steam, was fed into a reaction zone filled with inert quartz chips and varying amounts of catalyst 2 to study the hydrogenation, thermal cracking, and catalytic cracking of feed A at various temperatures. . Catalyst 2 was prepared according to the following procedure: 2.3 g of PURALOX® MG 70/170 (Sasol), a MgO-Al ₂ O ₃ mixed metal oxide obtained by calcining hydrotalcite, was prepared. The mixed metal oxide contained 70% by weight of MgO and 30% by weight of Al ₂ O ₃ . According to Sasol, the BET surface area was 170 m ² /g. A solution was made by mixing tin(IV) chloride pentahydrate (0.103 g) (Acros Organics), chloroplatinic acid hexahydrate (0.0184 g) (BioXtra), and deionized water (2.2 mL) in a small glass vial. The PURALOX® MG 70/170 support was impregnated with the solution. The impregnated material was dried at 110°C in air for 6 hours and calcined at 800°C in air for 12 hours. The final product contained nominally 0.3% by weight Pt and 1.5% by weight Sn.

The molar composition of Feed A is shown in Table 3.

ingredient mole% H ₂ 33.8 Ar 5.3 CH ₄ 1.2 C.O. 0.7 C ₃ H ₈ 16.0 C ₃ H ₆ 30.5 _CO2 0.3 C ₂ H ₄ 0.4 C ₂ H ₆ 0.7 steam 11.0

Feed A corresponds to the simulated propane dehydrogenation product with propylene yield and selectivity of 63.7% and 95.5%, respectively.

The total pressure of feed A was approximately 100 kPa absolute. React so that the weight hourly space velocity (WHSV), calculated by dividing the mass flow rate of the C-containing component of feed A by the weight of catalyst 2 in the reaction zone, varies from 121 h ^-1 to 350 h ^-1 and to infinity (no catalyst). The flow rate of feed A and the amount of catalyst 2 in the zone were varied.

The flow rate of Feed A was also varied such that the thermal residence time of Feed A in the reaction zone, calculated by dividing the void volume of the reaction zone by the volumetric flow rate of Feed A at the reaction temperature/pressure, was 2 seconds. The reaction zone was largely isothermal. The temperature outside the reaction zone dropped rapidly.

Upon passing through the reaction zone, feed A may be further cracked (thermal or catalytic), dehydrogenated, or hydrogenated to form product A. The propylene yield and selectivity of 63.7% and 95.5% of feed A may change after the reaction. For example, if hydrogenation of propylene occurs in the reaction zone, the propylene yield of product A decreases.

Figure 6 (x-axis temperature in degrees Celsius, y-axis % propylene yield) shows the propylene yield of product A versus reaction zone temperature when the heat residence time was maintained at 2 seconds. WHSV varied from 121 h ^-1 (orange, line (b)), 350 h ^-1 (blue, line (a)) and infinite (no catalyst) (gray, line (c)). In the absence of catalyst, the propylene yield loss at T > 600°C was entirely due to thermal decomposition of propylene. When the catalyst was present, a large loss in propylene yield occurred at T < 600° C., mainly due to hydrogenation of propylene. The extent of hydrogenation reaction decreases rapidly as the WHSV increases, i.e. the amount of catalyst not separated by the cyclone device decreases in the propane dehydrogenation product. Propylene yield loss due to hydrogenation was greatest at T = about 500°C.

Figure 7 shows the propylene selectivity of Product A versus reaction zone temperature when the heat residence time was maintained at 2 seconds. WHSV varied from 121 h ^-1 (orange, line (b)), 350 h ^-1 (blue, line (a)) and infinite (no catalyst) (grey, line (c)). In the absence of catalyst, the loss of propylene selectivity at T > 600°C was entirely due to thermal decomposition of propylene. Interestingly, propylene selectivity was higher when the WHSV was 121 h ^-1 . This may be because thermal decomposition by catalyst 2 was suppressed.

Figures 6 and 7 show the avoidance of hydrogenation of propylene during quenching. The following tactics may be used: (1) Reduce the amount of catalyst entrained in the propane dehydrogenation product before quenching the product. (2) When T < 320°C, the hydrogenation rate is slow, so the propane dehydrogenation product is rapidly cooled to below 320°C. (3) Use quenching to reversibly deactivate the entrained catalyst.

Catalyst compositions 3 to 16 were prepared according to the following procedure. For each catalyst composition, PURALOX® MG 80/150 (3 g), a mixed Mg/Al metal oxide containing 80% by weight of MgO and 20% by weight of Al ₂ O ₃ and having a surface area of 150 m ² /g ( Sasol) was calcined in air at 550°C for 3 hours to form a support. A solution containing an appropriate amount of tin(IV) chloride pentahydrate if used in the preparation of the catalyst composition (Acros Organics) and/or chloroplatinic acid if used in the preparation of the catalyst composition (Sigma Aldrich), and 1.8 ml of deionized water was placed in a small glass. Manufactured in vials. Calcined PURALOX® MG 80/150 support (2.3 g) for each catalyst composition was impregnated with the corresponding solution. The impregnated material was allowed to equilibrate in a closed container at room temperature (RT) for 24 hours, dried at 110°C for 6 hours, and calcined at 800°C for 12 hours. Table 1 shows the nominal Pt and Sn contents of each catalyst composition based on the weight of support.

catalyst Pt
(weight%) Sn
(weight%) 3 0.4 One 4 0.3 One 5 0.2 One 6 0.1 One 7 0.05 One 8 0.025 One 9 0.0125 One 10 0 One 11 0.1 0.5 12 0.1 One 13 0.1 2 14 0.0125 0 15 0.0125 0.5 16 0.0125 2

Example 4 - Fixed bed experiments were performed at approximately 100 kPa (absolute pressure) using catalysts 3 to 16. The composition of the reactor effluent was determined using gas chromatography (GC). The C ₃ H ₆ yield and selectivity were then calculated using the concentration of each component in the reactor effluent. The C ₃ H ₆ yields and selectivities reported in these examples were calculated on a mole carbon basis. Example 4 - Fixed bed experiments were performed at approximately 100 kPa (absolute pressure) using catalysts 3 to 16. The composition of the reactor effluent was determined using gas chromatography (GC). The C ₃ H ₆ yield and selectivity were then calculated using the concentration of each component in the reactor effluent. The C ₃ H ₆ yields and selectivities reported in these examples were calculated on a mole carbon basis.

In each example, 0.3 g of catalyst composition was mixed with the appropriate amount of quartz diluent and placed in a quartz reactor. The amount of diluent was determined so that the catalyst bed (catalyst + diluent) overlaps the isothermal zone of the quartz reactor and the catalyst bed is substantially isothermal during operation. The dead volume of the reactor was filled with quartz chips/rods.

The C ₃ H ₆ yield and selectivity at the start of t _rxn and the end of t _rxn are expressed as percentages in Tables 5 and 6 below for catalysts 3 to 10, denoted by Y _ini , Y _end , S _ini , and S _end, respectively. It has been reported.

The process steps for catalysts 3 to 10 were as follows: 1. The system was flushed with inert gas. Inert material passed through the reaction zone while dry air at a flow rate of 83.9 sccm passed through the reaction zone bypass. The reaction zone was heated to a regeneration temperature of 800°C. 3. The catalyst was then regenerated by passing dry air at a flow rate of 83.9 sccm through the reaction zone for 10 minutes. 4. The system was flushed with inert gas. 5. A 46.6 sccm flow rate of H ₂ -containing gas with 10 vol% H ₂ and 90 vol% Ar was passed through the bypass of the reaction zone for a period of time, while the inert material passed through the reaction zone. Then, H ₂ -containing gas was flowed through the reaction zone at 800° C. for 3 seconds. 6. The system was flushed with inert gas. During the above process, the temperature of the reaction zone was changed from 800°C to a reaction temperature of 670°C. 7. A hydrocarbon-containing (HC _gas ) feed containing 81% by volume of C ₃ H ₈ , 9% by volume of inert gas (Ar or Kr), and 10% by volume of steam at a flow rate of 35.2 sccm was introduced into the reaction zone for a certain period of time. While passing through the bypass, the inert gas passed through the reaction zone. The hydrocarbon-containing feed was then passed through a reaction zone at 670° C. for 10 minutes. GC sampling of the reaction effluent began as soon as the feed was diverted from the reaction zone bypass to the reaction zone.

The above process steps were repeated periodically until stable performance was obtained. Tables 5 and 6 showed that Catalyst 8, containing only 0.025% by weight of Pt and 1% by weight of Sn, had both similar yields and similar selectivities compared to Catalyst 3 containing 0.4% by weight of Pt and 1% by weight of Sn. This was surprising and unexpected. Catalyst 10, which contained no Pt, did not give significant propylene yield.

catalyst 3 catalyst 4 catalyst 5 catalyst 6 Performance Y _ini 61.7 61.7 60.7 63.7 Y _end 55.2 55.7 54.2 56.7 S _ini 97.3 97.2 97.0 97.1 S _end 98.1 98.0 97.7 98.3

catalyst 7 catalyst 8 catalyst 9 catalyst 10 Performance Y _ini 62.4 62.0 56.7 2.0 Y _end 57.2 54.6 45.7 1.7 S _ini 96.7 97.3 96.9 64.2 S _end 97.7 98.0 97.6 49.5

Catalysts 11 to 16 were also tested using the same process steps 1 to 7 described above for Catalysts 3 to 10. Table 7 shows that for optimal propylene yield for a catalyst composition containing 0.1% by weight Pt based on the weight of the support, the level of Sn should not be too low or too high.

catalyst 11 catalyst 6 catalyst 12 catalyst 13 0.5 wt% Sn 1% Sn by weight 1% Sn by weight 2% Sn by weight Performance Y _ini 58.4 63.7 63.4 56.5 Y _end 49.5 56.7 55.5 47.7 S _ini 96.9 97.1 97.2 97.8 S _end 97.6 98.3 98.1 98.2

Table 8 shows that for optimal propylene yield for a catalyst composition containing 0.0125% Pt by weight based on the weight of support, the level of Sn should not be too high or too low.

catalyst 14 catalyst 15 catalyst 9 catalyst 16 0 wt% Sn 0.5 wt% Sn 1% Sn by weight 2% Sn by weight Performance Y _ini 2.6 44 56.7 55.4 Y _end 1.7 24.4 45.7 44.1 S _ini 63.9 96.7 96.9 96.8 S _end 61.1 95.6 97.6 97.6

Process steps 1 to 1 were the same as described above for Catalysts 3 to 10 except that for Catalyst 8 containing only 0.025 wt% Pt and 1 wt% Sn, a flow rate of 17.6 sccm instead of 35.2 sccm was used in Step 7. Lifespan tests were performed using 7. Figure 8 shows that Catalyst 8 maintained performance for 204 cycles (x-axis is time, y-axis is C ₃ H ₆ yield and selectivity to C ₃ H ₆ , both in mole % carbon).

All documents described herein, including priority documents and/or test procedures, are incorporated herein by reference to the extent they are not inconsistent with this document. Although forms of the disclosure have been illustrated and described as will be apparent from the foregoing general description and specific embodiments, various modifications may be made without departing from the spirit and scope of the disclosure. Accordingly, the present disclosure is not intended to be limited thereby. Likewise, whenever a composition, element or group of elements is followed by the transitional phrase “comprising,” the description of the composition, element or elements is followed by “consisting essentially of,” “consisting of,” or “group consisting of.” It is understood that the transitional phrases "selected from" or "is" contemplate the same composition or group of elements, and vice versa.

Although this disclosure has been described in connection with a number of embodiments and examples, those skilled in the art having the benefit of this disclosure will understand that other embodiments may be devised without departing from the scope and spirit of the disclosure.

Claims (20)

As a method for forming olefins,
introducing a hydrocarbon feed stream to a reactor comprising a dehydrogenation catalyst;
reacting the hydrocarbon feed stream with the dehydrogenation catalyst in the reactor to form a high temperature dehydrogenation product comprising at least a portion of the dehydrogenation catalyst;
separating at least a portion of the dehydrogenation catalyst from the high temperature dehydrogenation product in a primary separation device and a secondary separation device downstream of and in fluid communication with the primary separation device;
After the high temperature dehydrogenation product is discharged from the secondary separation device, combining the high temperature dehydrogenation product with a quenching stream containing hydrocarbons to cool the high temperature dehydrogenation product and form an intermediate temperature dehydrogenation product; and
Cooling the intermediate temperature dehydrogenation product to form a cooled dehydrogenation product.
Method, including. According to paragraph 1,
The method of claim 1, wherein the quench stream comprises liquid hydrocarbons and the intermediate temperature product is entirely vaporous. According to claim 1 or 2,
The method of claim 1, wherein the combination of the hot dehydrogenation product and the quench stream occurs within a plenum section of the reactor. According to paragraph 3,
The method of claim 1, wherein the combination comprises combining the hot dehydrogenation product from the plurality of secondary separation devices with a quench stream at a location within the plenum that minimizes secondary catalytic cracking in the hot dehydrogenation product. According to any one of claims 1 to 4,
The method of claim 1, wherein the quench stream comprises aromatics that are not formed in the hot dehydrogenation product. According to any one of claims 1 to 5,
Further cooling the intermediate temperature dehydrogenation product downstream of the reactor to obtain a cooled dehydrogenation product in a heat exchanger or secondary quench stream.
The method further comprises, wherein the quench stream comprises at least a portion of the cooled dehydrogenation product after being further cooled by the heat exchanger or the secondary quench stream. According to any one of claims 1 to 6,
The method of claim 1, wherein the quench stream is not provided to the output area of the primary separation device. According to any one of claims 1 to 7,
Wherein the first separation device and the second separation device are each a cyclone separator, and together remove at least 98% of the dehydrogenation catalyst present in the high temperature dehydrogenation product. According to any one of claims 1 to 8,
wherein the hydrocarbon feed is propane, the olefin is propylene, the dehydrogenation catalyst comprises a PtSn/MgO catalyst, the Pt content is in the range from 0.001% to 6% by weight, and the Sn content is from 0% to 10% by weight. and the catalyst satisfies the requirements of Geldart A or Geldart B classification, and the reaction temperature in the reactor is 600°C to 700°C. According to any one of claims 1 to 9,
The method of claim 1, wherein the high temperature dehydrogenation product is at least 620°C. According to any one of claims 1 to 10,
The method of claim 1, wherein the intermediate temperature dehydrogenation product is below 620°C. According to any one of claims 1 to 11,
The method of claim 1 , wherein the residence time of the high temperature dehydrogenation product in each of the primary and secondary separation devices is less than 1 second. According to any one of claims 1 to 12,
The dehydrogenation catalyst includes Pt, an inorganic support, and a contaminant, and the Pt has a concentration ranging from 0.001% to 6% by weight based on the weight of the inorganic support,
The inorganic support comprises at least 0.5% by weight of a Group 2 element based on the weight of the inorganic support,
The group 2 element includes Mg,
At least some of the Group 2 elements are in the form of mixed metal oxides containing MgO or Mg,
The method of claim 1 , wherein the catalyst further comprises up to 10% by weight of an accelerator based on the weight of the inorganic support, wherein the accelerator comprises one or more of Sn, Ag, Cu, combinations thereof, or mixtures thereof. 1. A system for forming olefins from a hydrocarbon feed stream, comprising:
a reactor configured to receive the hydrocarbon feed stream under reaction conditions with a dehydrogenation catalyst, wherein the reaction conditions produce a high temperature dehydrogenation product comprising at least a portion of the dehydrogenation catalyst;
a plurality of separation devices configured to separate at least a portion of the dehydrogenation catalyst from the high temperature dehydrogenation product, the plurality of separation devices comprising a primary separation device and a secondary separation device downstream of and in fluid communication with the primary separation device;
a quench system configured to combine the high temperature dehydrogenation product with a quench stream comprising hydrocarbons to cool the high temperature dehydrogenation product and form an intermediate temperature dehydrogenation product; and
A heat transfer system configured to cool the intermediate temperature dehydrogenation product to form a cooled dehydrogenation product.
system, including. According to clause 14,
The system of claim 1, wherein the quench stream comprises a liquid hydrocarbon and the intermediate temperature product is entirely vapor phase. According to claim 14 or 15,
wherein the quench system is configured to combine the hot dehydrogenation product and the quench stream within a plenum section of the reactor. According to any one of claims 14 to 16,
wherein the quench system is configured to inject the quench stream at a location within the plenum that minimizes secondary catalytic cracking in the hot dehydrogenation product. According to any one of claims 14 to 17,
The system of claim 1, wherein the heat transfer system includes a heat exchanger or nozzle configured to supply a secondary quench stream. According to any one of claims 14 to 18,
The system of claim 1, wherein the quench system is configured to not provide a quench stream to the output region of the primary separation device. According to any one of claims 14 to 19,
The system of claim 1, wherein the primary separation device and the secondary separation device are each a cyclone separator, and together are configured to remove at least 98% of the dehydrogenation catalyst present in the high temperature dehydrogenation product.

Images