WO2020026119A1

WO2020026119A1 - Method of processing alkanes

Info

Publication number: WO2020026119A1
Application number: PCT/IB2019/056453
Authority: WO
Inventors: Sivakumar SREERAMAGIRI; Eswara Rao MUPPARAJU; Mohammad Basheer AHMED; Bhanu Kiran Vankayala; Vikas NARAYAN; Ashwin Ravi SANKAR; Asiff Apdul Supahan; Shailesh Singh Bhaisora
Original assignee: Sabic Global Technologies B.V.
Priority date: 2018-07-30
Filing date: 2019-07-29
Publication date: 2020-02-06

Abstract

A method of processing alkanes includes: passing a first feed stream comprising a C1 alkane, a C2 alkane, a C3 alkane, a C4 alkane, or a combination comprising at least one of the foregoing through a first catalyst bed within a reactor shell; passing the first feed stream exiting the first catalyst bed and a second feed stream through a second catalyst bed within the reactor shell; passing the combined first feed stream and the second feed stream exiting the second catalyst bed, and a third feed stream through a third catalyst bed, within the reactor shell; producing a product within the reactor shell and withdrawing the product via a product stream from the reactor shell; wherein the first, second, and third feed streams are heated prior to passing through the reactor shell and wherein a total temperature drop across the reactor shell is 40°C to100°C.

Description

METHOD OF PROCESSING ALKANES

BACKGROUND

[0001] Aromatic compounds are of great industrial importance. Aromatic hydrocarbons of commercial interest include benzene, toluene, ortho-xylene and para-xylene. Approximately 35 million tons of aromatics are produced worldwide every year. These compounds can be extracted from complex mixtures obtained by the refining of oil or by distillation of coal tar, and are used to produce a range of important chemicals and polymers, including styrene, phenol, aniline, polyester, and nylon.

[0002] In particular, aromatic compounds can be produced via the dehydroaromatization of alkanes. This process is highly endothermic and requires significant energy to sustain. The endothermic nature of the process therefore creates many engineering challenges. For example, an initial feed stream to the reactor can require heating to over l000°C. This high feed temperature can increase unwanted coke formation and decrease product conversion rates. The high initial temperature also demands special materials for the reactor that can be costly. The endothermic nature of the reaction and high feed temperature also result in a severe temperature drop across the reactor. Multiple reactor configurations and multiple heat exchangers are often required to prevent this severe temperature drop. This approach also leads to excessive cost, product degradation, and an overall inefficient use of energy.

[0003] Thus, it is desirable to provide a method of processing alkanes that allows for minimal temperature drop across a reactor without the need for multiple reactor configurations or excessive initial feed temperatures.

SUMMARY

[0004] Disclosed, in various embodiments, are methods of processing alkanes.

[0005] A method of processing alkanes includes passing a first feed stream comprising a Cl alkane, a C2 alkane, a C3 alkane, a C4 alkane, or a combination comprising at least one of the foregoing through a first catalyst bed within a reactor shell; passing the first feed stream exiting the first catalyst bed and a second feed stream comprising a Cl alkane, a C2 alkane, a C3 alkane, a C4 alkane, or a combination comprising at least one of the foregoing through a second catalyst bed within the reactor shell; passing the combined first feed stream and the second feed stream exiting the second catalyst bed, and a third feed stream comprising a C 1 alkane, a C2 alkane, a C3 alkane, a C4 alkane, or a combination comprising at least one of the foregoing through a third catalyst bed, within the reactor shell; producing a product within the reactor shell and withdrawing the product via a product stream from the reactor shell; wherein the first, second, and third feed streams are heated prior to passing through the reactor shell and wherein a total temperature drop across the reactor shell is 40°C to l00°C.

[0006] A method of processing alkanes includes passing a first feed stream comprising methane through a first catalyst bed within a reactor shell; passing the first feed stream exiting the first catalyst bed and a second feed stream comprising methane through a second catalyst bed within the reactor shell; passing the combined first feed stream and the second feed stream exiting the second catalyst bed, and a third feed stream comprising methane through a third catalyst bed within the reactor shell; producing a product comprising benzene within the reactor shell and withdrawing the product via a product stream from the reactor shell; wherein the first, second, and third feed streams are heated prior to passing through the reactor shell; wherein a flowrate of the second and/or third feed stream is greater than a flowrate of the first feed stream; wherein at least one of the first, second, and third catalyst beds is a dehydroaromatization catalyst bed; wherein a total temperature drop across the reactor shell is 40°C to 80°C; and wherein a temperature drop across at least one of the first, second, and third catalyst beds is 50°C to 60°C.

[0007] These and other features and characteristics are more particularly described below.

BRIEF DESCRIPTION OF THE DRAWING

[0008] The following is a brief description of the drawing wherein like elements are numbered alike and which is presented for the purposes of illustrating the exemplary

embodiments disclosed herein and not for the purposes of limiting the same.

[0009] FIG. 1 is a simplified schematic diagram representing a unit configuration used in a method of processing alkanes.

[0010] FIG. 2 is a simplified schematic diagram representing an alternate unit configuration used in a method of processing alkanes.

DET AIDED DESCRIPTION

[0011] The present method can solve the many engineering challenges created by the highly endothermic nature of alkane dehydroaromatization. In some embodiments, the method disclosed herein for processing alkanes can allow for minimal temperature drop across a reactor without the need for multiple reactor configurations or excessive initial feed temperatures. For example, an initial feed stream to a reactor can be at a temperature of 500°C to 800°C. The low initial temperature can eliminate the need for costly special materials for the reactor. The present method can also allow for minimal temperature drop across a reactor. For example, a total temperature drop across a reactor shell can be 40°C to l00°C, whereas in other reactor configurations utilizing multiple reactors in series the temperature drop can be l50°C to 250°C. Additionally, the present method can allow for a single reactor configuration. With such an approach, costs can be minimal, product degradation reduced, and more efficient use of energy can be realized.

[0012] The method disclosed herein for processing alkanes can include multiple feed streams. For example, the method can include a first feed stream, a second feed stream, and a third feed stream. The compositions of the streams can be the same or different from each other. For example, at least one of the first, second, and third feed streams can comprise alkanes, for example, a Cl alkane, a C2 alkane, a C3 alkane, a C4 alkane, or a combination comprising at least one of the foregoing. The streams can comprise natural gas and/or liquefied petroleum gas. The streams can comprise methane, ethane, propane, butane, or a combination comprising at least one of the foregoing.

[0013] The feed streams can have a molar flow rate. The molar flow rates of the streams can be the same or different from each other. For example, a molar flow rate ratio between streams can be varied in any proportion depending on the extent and heat of the reactions involved. For example, a molar flow rate ratio between streams can be 20:40:40, 30:30:40, 20:20:40, 30:40:40, or 40:40:20. For example, a first feed stream can have a molar flow rate of 20 moles per hour, a second feed stream can have a molar flow rate of 40 moles per hour, and a third feed stream can have a molar flow rate of 40 moles per hour. A flowrate of the second and/or third feed stream can be greater than a flowrate of the first feed stream, for example, a flowrate of the second and/or third feed stream can be at least double a flowrate of the first feed stream.

[0014] The first, second, and third feed streams can be heated prior to passing through a reactor shell. The temperature of the first, second, and third feed streams can be varied in any proportion depending on the extent and heat of the reactions involved. For example, prior to passing through a reactor shell, at least one of the first, second, and third feed streams can be heated to a temperature of 500°C to 900°C, for example, 600°C to 800°C. Prior to passing through a reactor shell, a temperature of the second and/or third feed stream can be greater than a temperature of the first feed stream, for example, the temperature of the second and/or third stream can be greater than the first stream by greater than or equal to 5%. [0015] A temperature of the second and/or third feed stream can be adjusted to compensate for any endothermic heat loss that occurs in a proceeding catalyst bed. For example, prior to passing through a reactor shell, a temperature of the second and/or third feed stream can be adjusted to compensate for any endothermic heat loss that occurred in the first catalyst bed and/or the second catalyst bed. For example, prior to passing through a reactor shell, a temperature of the second and/or third feed stream can be adjusted to compensate for 50% to 80% of any endothermic heat loss that occurred in the first catalyst bed and/or the second catalyst bed.

[0016] The feed streams can be passed through a reactor. For example, the reactor can be a dehydroaromatization reactor for the dehydroaromatization of alkanes to aromatics. A temperature within the reactor can be 500°C to 900°C, for example, 600°C to 800°C. The reactor can comprise a gas distributor, reflux liquid distributor, feed tray, packing tray, vacuum jacket, inner thermocouples located along a height of the reactor, spiral-prismatic packing, automated flow rate control, automated temperature control, automated pressure control, automated level control, automated composition control, or a combination comprising at least one of the foregoing. The dehydroaromatization reactor can comprise computer-controlled

pumps/compressors. These pumps can control the reactor parameters, for example, flowrates of streams entering and exiting the reactor. The reactor and related streams can be heated using heat exchangers, for example, a Proportional-Integral-Derivative (PID) controlled electronic heater.

[0017] The reactor can comprise multiple catalyst beds. For example, the reactor can comprise at least one of a first, second, and third catalyst bed. A catalyst bed can be a zone, vessel, or chamber comprising catalyst particles through which at least one of the first, second, and third feed streams flow and a reaction occurs. The reactor can comprise a fixed catalyst bed, moving catalyst bed, fluidized catalyst bed, or a combination comprising one of the foregoing. For example, at least one of a first, second, and third catalyst bed can be a fixed catalyst bed, moving catalyst bed, fluidized catalyst bed, or a combination comprising one of the foregoing. Reaction products can flow out of a catalyst bed and be collected.

[0018] A fixed bed reactor can be a reactor in which the catalyst remains stationary in the reactor and the catalyst particles are arranged in a vessel, e.g., a vertical cylinder, with the reactants and products passing through the stationary bed. In a fixed bed reactor, the catalyst particles can be held in place, e.g., stationary, with respect to a fixed reference frame. The fixed bed reactor can be an adiabatic single bed, a multi-tube bed surrounded with heat exchange fluid, or an adiabatic multi-bed with internal heat exchange, among others. [0019] In a moving bed catalytic reactor, gravity can cause the catalyst particles to flow while maintaining their relative positions to one another. The bed can move with respect to the reactor in which it is contained. The reactants can move through this bed with concurrent flow, countercurrent flow, or cross flow. The moving bed can allow withdrawal of catalyst particles continuously or intermittently so they can be regenerated outside the reactor and reintroduced later on. A moving bed reactor can comprise at least one tray as well as a supporting means for one or more catalyst beds. The supporting means can be permeable to gas and impermeable to catalyst particles.

[0020] A fluidized bed reactor can be used to carry out a variety of multiphase chemical reactions. In this type of a reactor, a gas can be passed through the particulate catalyst at high enough velocities to suspend the solid and cause it to behave as though it were a fluid. The catalyst particles can be supported by a porous plate. The gas can be forced through the porous plate up through the solid material. At lower gas velocities, the solids can remain in place as the gas passes through the voids in the material. As the gas velocity is increased, the reactor can reach a stage where the force of the fluid on the solids is enough to balance the weight of the solid material and above this velocity the contents of the reactor bed can begin to expand and swirl around much like an agitated tank or boiling pot of water. A fluidized bed reactor can provide uniform particle mixing, uniform temperature gradients, and the ability to operate the reactor in a continuous state. The catalyst can leave the reaction zone with the reaction products and can be separated therefrom in order to be regenerated before being recycled back to the reaction zone.

[0021] At least one of a first, second, and third catalyst bed can be a

dehydroaromatization catalyst bed. For example, at least one of a first, second, and third catalyst beds can comprise a dehydroaromatization catalyst comprising a metal on a zeolite support. The metal can comprise zinc, nickel, iron, rhodium, rhenium, platinum, or a combination comprising at least one of the foregoing.

[0022] The zeolite support can comprise aluminosilicate zeolites. For example, an aluminosilicate zeolites can comprise materials having the framework types MFI (e.g., ZSM-5 and silicalite), MEL (e.g., ZSM-11), MTW (e.g., ZSM-12), TON (e.g., ZSM-22), MTT (e.g., ZSM-23), FER (e.g., ZSM-35), MFS (e.g., ZSM-57), MWW (e.g., MCM-22, PSH-3, SSZ-25, ERB-1, ITQ-1, ITQ-2, MCM-36, MCM-49 and MCM-56), IWR (e.g., ITQ-24), KFI (e.g., ZK- 5), BEA (e.g., zeolite beta), ITH (e.g., ITQ-13), MOR (e.g., mordenite), FAU (e.g., zeolites X,

Y, ultra- stabilized Y and de-aluminized Y), LTL (e.g., zeolite L), IWW (e.g., ITQ-22), and VFI (e.g., VPI-5), as well as materials such as MCM-68, EMM-1, EMM-2, ITQ-23, ITQ-24, ITQ-25, ITQ-26, ETS-2, ETS-10, SAPO-17, SAPO-34 and SAPO-35. Mesoporous materials include MCM-41, MCM-48, MCM-50, FSM-16 and SBA-15. For example, the zeolite support can comprise ZSM5, ZSM 11, ZSM 12, MCM 22, or a combination comprising at least one of the foregoing.

[0023] A temperature drop across at least one of the first, second, and third catalyst beds can be 40°C to 80°C, for example, 50°C to 60°C. A total temperature drop across the reactor shell can be 40°C to l00°C. For example, the total temperature drop across the reactor shell can be less than or equal to 80°C, for example, less than or equal to 60°C. A pressure within the reactor can be 0 kiloPascals to 1000 kiloPascals, for example, 300 kiloPascals to 800 kiloPascals. For example, a pressure within at least one of a first, second, and third catalyst bed can be 0 kiloPascals to 1000 kiloPascals, for example, 300 kiloPascals to 800 kiloPascals, for example, 400 kiloPascals.

[0024] The feed streams can be injected into, and passed through, the reactor in an intermittent fashion. For example, the feed streams can flow downward through catalyst beds within a vertically oriented reactor shell (as illustrated in FIG.l). For example, a first feed stream can be passed through a first catalyst bed within a reactor shell. The first feed stream exiting the first catalyst bed and a second feed stream can then be passed through a second catalyst bed within the reactor shell. The combined first feed stream and the second feed stream exiting the second catalyst bed, and a third feed stream can then be passed through a third catalyst bed within the reactor shell. The present method can further comprise passing the first feed stream, the second feed stream, the third feed stream, and a fourth feed stream through a fourth catalyst bed within the reactor shell.

[0025] At least one of the first, second, and third feed streams can be passed through a catalyst bed via a plurality of interspersed tubes, for example, interspersed radial tubes. Radial can refer to flow outward from a center of the reactor.

[0026] The reactor shell can be oriented horizontally, wherein the feed streams as described herein can flow outward from a center of the reactor shell and through two sets of catalyst beds on either side of the center (as illustrated in FIG. 2). These sets of catalysts beds can be the same or different from each other. Each set of catalyst beds can comprise a first catalyst bed, a second catalyst bed, a third catalyst bed, a fourth catalyst bed, or a combination comprising at least one of the foregoing.

[0027] An aromatic product stream comprising an aromatic product can be withdrawn from the reactor. The aromatic product can be, for example, a mono-aromatic comprising benzene, toluene, xylene, or a combination comprising at least one of the foregoing. The conversion rate from alkanes to an aromatic product within the reactor shell can be greater than or equal to 10%, for example, greater than or equal to 50%. The conversion rate from Cl alkane to product within the reactor shell can be 10% to 20%. The conversion rate from C2 alkane to product within the reactor shell can be 20% to 50%. The conversion rate from C3 alkane to product within the reactor shell can be greater than or equal to 50%. Conversion energy can vary depending on the extent and heat of the reactions involved. The conversion from alkanes to an aromatic product within the reactor shell can require less than or equal to 100 kilojoules per mole alkane, for example, less than or equal to 85 kilojoules per mole alkane.

[0028] The product stream can be passed through additional processing equipment located downstream from the reactor. For example, individual alkane products can be isolated from the product stream via downstream processing equipment. The downstream processing equipment can be, for example, a distillation column. A purity of an individual alkane product isolated downstream can be greater than or equal to 99% by weight, for example, greater than or equal to 99.5% by weight.

[0029] A more complete understanding of the components, processes, and apparatuses disclosed herein can be obtained by reference to the accompanying drawings. These figures (also referred to herein as“FIG.”) are merely schematic representations based on convenience and the ease of demonstrating the present disclosure, and are, therefore, not intended to indicate relative size and dimensions of the devices or components thereof and/or to define or limit the scope of the exemplary embodiments. Although specific terms are used in the following description for the sake of clarity, these terms are intended to refer only to the particular structure of the embodiments selected for illustration in the drawings, and are not intended to define or limit the scope of the disclosure. In the drawings and the following description below, it is to be understood that like numeric designations refer to components of like function.

[0030] Referring now to FIG. 1, this simplified schematic diagram represents a unit configuration 10 used in a method of processing alkanes. The unit configuration 10 can include passing a first feed stream 14 comprising Cl to C4 alkanes through a first catalyst bed 16 within a reactor shell 12. The first feed stream 14 exiting the first catalyst bed 16 and a second feed stream 18 comprising Cl to C4 alkanes can be passed through a second catalyst bed 22 within the reactor shell 12. The first feed stream 14 and the second feed stream 18 exiting the second catalyst bed 22, seen as a single combined stream 20, and a third feed stream 24 comprising Cl to C4 alkanes, can be passed through a third catalyst bed 28 within the reactor shell 12. A product, for example, an aromatic, can be produced within the reactor shell and the product can be withdrawn via a product stream 30 from the reactor shell 12. The first feed stream 14, second feed stream 18, and third feed stream 24 can also be passed through a catalyst bed (16, 22, or 28) via a plurality of interspersed tubes 32. The first feed stream 14, second feed stream 18, and third feed stream 24 can be heated prior to passing through the reactor shell 12. A total temperature drop across the reactor shell can be 40°C to l00°C.

[0031] Referring now to FIG. 2, this simplified schematic diagram represents an alternate unit configuration 11 used in a method of processing alkanes. The unit configuration 11 can include a reactor shell 12 oriented horizontally, wherein feed streams (14, 18) can flow outward from a center 34 of the reactor shell 12 and through two sets of catalyst beds (16, 22) on either side of the center 34. For example, the unit configuration 11 can include passing a first feed stream 14 comprising Cl to C4 alkanes through a first catalyst bed 16 within a reactor shell 12. The first feed stream 14 exiting the first catalyst bed 16 and a second feed stream 18 comprising Cl to C4 alkanes can be passed through a second catalyst bed 22 within the reactor shell 12. The first feed stream 14 and the second feed stream 18 can exit the second catalyst bed 22, seen as a single combined stream 20. A product, for example, an aromatic, can be produced within the reactor shell and the product can be withdrawn via a product stream 30 from the reactor shell 12. The first feed stream 14 and the second feed stream 18 can also be passed through a catalyst bed (16, 22) via a plurality of interspersed tubes 32. The first feed stream 14 and the second feed stream 18 can be heated prior to passing through the reactor shell 12. A total temperature drop across the reactor shell can be 40°C to l00°C.

[0032] The following examples are merely illustrative of the method of processing alkanes disclosed herein and are not intended to limit the scope hereof.

EXAMPLES

[0033] Experimental trials 1-3 were conducted using a dehydroaromatization reactor in accordance with the unit configuration 10 as seen in FIG.l for processing alkanes. The results are shown in Tables 1-3 respectively. In each example, the total temperature drop across the reactor shell 12 was calculated as the difference between the initial temperature of the first feed stream 14 and the temperature of the product stream 30.

Example 1

[0034] A first feed stream 14 comprising a methane flow of 20 moles per hour was heated to 850°C and passed through a first catalyst bed 16 within a reactor shell 12. The temperature drop across the first catalyst bed 16 was 66°C. The first feed stream 14 exiting the first catalyst bed 16 had a temperature of 784°C. A second feed stream 18 comprising a methane flow of 40 moles per hour was heated to 900°C and combined with the first feed stream 14 exiting the first catalyst bed 16. The combined streams had a temperature of 862°C and were passed through a second catalyst bed 22 within the reactor shell 12. The temperature drop across the second catalyst bed 16 was 70°C. The combined first and second feed streams exiting the second catalyst bed 22 had a temperature of 792°C. A third feed stream 24 comprising a methane flow of 40 moles per hour was heated to 900°C. The first and second feed streams exiting the second catalyst bed 22, seen as a single combined stream 20, were combined with the third feed stream 24 and passed through a third catalyst bed 28 within the reactor shell 12. This combined third stream had a temperature of 836°C. The temperature drop across the third catalyst bed 28 was 66°C. A product was withdrawn from the reactor shell 12 via a product stream 30. The product stream 30 had a temperature of 770°C. The product stream 30 comprised a flow of 90.5 moles per hour methane, 1.6 moles per hour benzene, and 14.3 moles per hour hydrogen. A total temperature drop across the reactor shell 12 was 80°C.

Example 2

[0035] A first feed stream 14 comprising a methane flow of 30 moles per hour was heated to 850°C and passed through a first catalyst bed 16 within a reactor shell 12. The temperature drop across the first catalyst bed 16 was 66°C. The first feed stream 14 exiting the first catalyst bed 16 had a temperature of 784°C. A second feed stream 18 comprising a methane flow of 30 moles per hour was heated to 900°C and combined with the first feed stream 14 exiting the first catalyst bed 16. The combined streams had a temperature of 843 °C and were passed through a second catalyst bed 22 within the reactor shell 12. The temperature drop across the second catalyst bed 16 was 70°C. The combined first and second feed streams exiting the second catalyst bed 22 had a temperature of 773 °C. A third feed stream 24 comprising a methane flow of 40 moles per hour was heated to 900°C. The first and second feed streams exiting the second catalyst bed 22, seen as a single combined stream 20, were combined with the third feed stream 24 and passed through a third catalyst bed 28 within the reactor shell 12. This combined third stream had a temperature of 824°C. The temperature drop across the third catalyst bed 28 was 70°C. A product was withdrawn from the reactor shell 12 via a product stream 30. The product stream 30 had a temperature of 755°C. The product stream 30 comprised a flow of 90.0 moles per hour methane, 1.7 moles per hour benzene, and 14.9 moles per hour hydrogen. A total temperature drop across the reactor shell 12 was 95°C.

Example 3

[0036] A first feed stream 14 comprising an ethane flow of 30 moles per hour was heated to 500°C and passed through a first catalyst bed 16 within a reactor shell 12. The temperature drop across the first catalyst bed 16 was 59°C. The first feed stream 14 exiting the first catalyst bed 16 had a temperature of 441 °C. A second feed stream 18 comprising an ethane flow of 30 moles per hour was heated to 600°C and combined with the first feed stream 14 exiting the first catalyst bed 16. The combined streams had a temperature of 522°C and were passed through a second catalyst bed 22 within the reactor shell 12. The temperature drop across the second catalyst bed 16 was 62°C. The combined first and second feed streams exiting the second catalyst bed 22 had a temperature of 460°C. A third feed stream 24 comprising an ethane flow of 40 moles per hour was heated to 600°C. The first and second feed streams exiting the second catalyst bed 22, seen as a single combined stream 20, were combined with the third feed stream 24 and passed through a third catalyst bed 28 within the reactor shell 12. This combined third stream had a temperature of 5l7°C. The temperature drop across the third catalyst bed 28 was 6l°C. A product was withdrawn from the reactor shell 12 via a product stream 30. The product stream 30 had a temperature of 456°C. The product stream 30 comprised a flow of 90.0 moles per hour ethane, 3.3 moles per hour benzene, and 19.9 moles per hour hydrogen. A total temperature drop across the reactor shell 12 was 44 °C.

[0037] As demonstrated, the method disclosed herein for processing alkanes can allow for minimal temperature drop across a reactor without the need for multiple reactor

configurations or excessive initial feed temperatures. For example, an initial feed stream to a reactor can be 500°C to 800°C. The low initial temperature can eliminate the need for costly special materials for the reactor. The present method can also allow for minimal temperature drop across a reactor. For example, a total temperature drop across a reactor shell can be 40°C to l00°C. The present method can allow for a single reactor configuration. This approach leads to minimal cost, reduced product degradation, and a more efficient use of energy.

[0038] The processes disclosed herein include(s) at least the following aspects:

[0039] Aspect 1: A method of processing alkanes, comprising: passing a first feed stream comprising a Cl alkane, a C2 alkane, a C3 alkane, a C4 alkane, or a combination comprising at least one of the foregoing through a first catalyst bed within a reactor shell;

passing the first feed stream exiting the first catalyst bed and a second feed stream comprising a Cl alkane, a C2 alkane, a C3 alkane, a C4 alkane, or a combination comprising at least one of the foregoing through a second catalyst bed within the reactor shell; passing the combined first feed stream and the second feed stream exiting the second catalyst bed, and a third feed stream comprising a Cl alkane, a C2 alkane, a C3 alkane, a C4 alkane, or a combination comprising at least one of the foregoing through a third catalyst bed, within the reactor shell; producing a product within the reactor shell and withdrawing the product via a product stream from the reactor shell; wherein the first, second, and third feed streams are heated prior to passing through the reactor shell and wherein a total temperature drop across the reactor shell is 40°C to l00°C. [0040] Aspect 2: The method of Aspect 1, wherein a flowrate of the second and/or third feed stream is greater than a flowrate of the first feed stream, preferably, wherein a flowrate of the second and/or third feed stream is at least double a flowrate of the first feed stream.

[0041] Aspect 3: The method of any of the preceding aspects, wherein prior to passing through the reactor shell, a temperature of the second and/or third feed stream is greater than a temperature of the first feed stream, preferably, by greater than or equal to 5%.

[0042] Aspect 4: The method of any of the preceding aspects, wherein at least one of the first, second, and third feed streams comprises methane, ethane, propane, butane, or a combination comprising at least one of the foregoing.

[0043] Aspect 5: The method of any of the preceding aspects, further comprising passing at least one of the first, second, and third feed streams through a catalyst bed via a plurality of interspersed radial tubes.

[0044] Aspect 6: The method of any of the preceding aspects, wherein a temperature within the reactor is 500°C to 900°C, preferably, 600°C to 800°C.

[0045] Aspect 7: The method of any of the preceding aspects, wherein the total temperature drop across the reactor shell is less than or equal to 80°C, preferably, less than or equal to 60°C.

[0046] Aspect 8: The method of any of the preceding aspects, wherein a temperature drop across at least one of the first, second, and third catalyst beds is 40°C to 80°C, preferably, 50°C to 60°C.

[0047] Aspect 9: The method of any of the preceding aspects, wherein at least one of the first, second, and third catalyst beds comprises a dehydroaromatization catalyst comprising a metal on a zeolite support.

[0048] Aspect 10: The method of Aspect 9, wherein the metal comprises zinc, nickel, iron, rhodium, rhenium, platinum, or a combination comprising at least one of the foregoing and wherein the zeolite support comprises ZSM 5, ZSM 11, ZSM 12, MCM 22, or a combination comprising at least one of the foregoing.

[0049] Aspect 11: The method of any of the preceding aspects, wherein at least one of the first, second, and third feed streams is heated to a temperature of 500°C to 900°C, preferably, 600°C to 800°C.

[0050] Aspect 12: The method of any of the preceding aspects, wherein the product is an aromatic, preferably, a mono-aromatic comprising benzene, toluene, xylene, or a combination comprising at least one of the foregoing. [0051] Aspect 13: The method of any of the preceding aspects, wherein the first feed stream, the second feed stream, the third feed stream, or a combination comprising at least one of the foregoing, comprises a Cl alkane, wherein the conversion rate from Cl alkane to product within the reactor shell is 10% to 20%.

[0052] Aspect 14: The method of Aspect 1, wherein the first feed stream, the second feed stream, the third feed stream, or a combination comprising at least one of the foregoing, comprises a C2 alkane, wherein the conversion rate from C2 alkane to product within the reactor shell is 20% to 50%.

[0053] Aspect 15: The method of Aspect 1, wherein the first feed stream, the second feed stream, the third feed stream, or a combination comprising at least one of the foregoing, comprises a C3 alkane, wherein the conversion rate from C3 alkane to product within the reactor shell is greater than or equal to 50%.

[0054] Aspect 16: The method of any of the preceding aspects, wherein at least one of the first, second, and third catalyst beds is a dehydroaromatization catalyst bed.

[0055] Aspect 17: The method of any of the preceding aspects, further comprising passing the first feed stream, the second feed stream, the third feed stream, and a fourth feed stream comprising alkanes through a fourth catalyst bed within the reactor shell.

[0056] Aspect 18: The method of any of the preceding aspects, further comprising passing the product stream through downstream equipment and isolating an individual alkane product from the product stream, wherein a purity of the individual alkane product is greater than or equal to 99% by weight, preferably, greater than or equal to 99.5% by weight.

[0057] Aspect 19: The method of any of the preceding aspects, wherein the reactor shell is oriented horizontally and the feed streams flow outward from a center of the reactor shell.

[0058] Aspect 20: A method of processing alkanes, comprising: passing a first feed stream comprising methane through a first catalyst bed within a reactor shell; passing the first feed stream exiting the first catalyst bed and a second feed stream comprising methane through a second catalyst bed within the reactor shell; passing the combined first feed stream and the second feed stream exiting the second catalyst bed, and a third feed stream comprising methane through a third catalyst bed within the reactor shell; producing a product comprising benzene within the reactor shell and withdrawing the product via a product stream from the reactor shell; wherein the first, second, and third feed streams are heated prior to passing through the reactor shell; wherein a flowrate of the second and/or third feed stream is greater than a flowrate of the first feed stream; wherein at least one of the first, second, and third catalyst beds is a

dehydroaromatization catalyst bed; wherein a total temperature drop across the reactor shell is 40°C to 80°C; and wherein a temperature drop across at least one of the first, second, and third catalyst beds is 50°C to 60°C.

[0059] In general, the invention can alternately comprise, consist of, or consist essentially of, any appropriate components herein disclosed. The invention can additionally, or alternatively, be formulated so as to be devoid, or substantially free, of any components, materials, ingredients, adjuvants or species used in the prior art compositions or that are otherwise not necessary to the achievement of the function and/or objectives of the present invention. The endpoints of all ranges directed to the same component or property are inclusive and independently combinable (e.g., ranges of“less than or equal to 25 wt%, or 5 wt% to 20 wt%,” is inclusive of the endpoints and all intermediate values of the ranges of“5 wt% to 25 wt%,” etc.). Disclosure of a narrower range or more specific group in addition to a broader range is not a disclaimer of the broader range or larger group. “Combination” is inclusive of blends, mixtures, alloys, reaction products, and the like. Furthermore, the terms“first,” “second,” and the like, herein do not denote any order, quantity, or importance, but rather are used to denote one element from another. The terms“a” and“an” and“the” herein do not denote a limitation of quantity, and are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. “Or” means“and/or.” The suffix“(s)” as used herein is intended to include both the singular and the plural of the term that it modifies, thereby including one or more of that term (e.g., the film(s) includes one or more films). Reference throughout the specification to“one embodiment”,“another embodiment”,

“an embodiment”, and so forth, means that a particular element (e.g., feature, structure, and/or characteristic) described in connection with the embodiment is included in at least one embodiment described herein, and may or may not be present in other embodiments. In addition, it is to be understood that the described elements can be combined in any suitable manner in the various embodiments.

[0060] The modifier“about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (e.g., includes the degree of error associated with measurement of the particular quantity). The notation“+ 10%” means that the indicated measurement can be from an amount that is minus 10% to an amount that is plus 10% of the stated value. The terms“front”,“back”,“bottom”, and/or“top” are used herein, unless otherwise noted, merely for convenience of description, and are not limited to any one position or spatial orientation. “Optional” or“optionally” means that the subsequently described event or circumstance can or cannot occur, and that the description includes instances where the event occurs and instances where it does not. Unless defined otherwise, technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which this invention belongs. A“combination” is inclusive of blends, mixtures, alloys, reaction products, and the like.

[0061] All cited patents, patent applications, and other references are incorporated herein by reference in their entirety. However, if a term in the present application contradicts or conflicts with a term in the incorporated reference, the term from the present application takes precedence over the conflicting term from the incorporated reference.

[0062] While particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are or may be presently unforeseen may arise to applicants or others skilled in the art. Accordingly, the appended claims as filed and as they may be amended are intended to embrace all such alternatives, modifications variations, improvements, and substantial equivalents.

Claims

CLAIMS What is claimed is:

1. A method of processing alkanes, comprising:

passing a first feed stream comprising a Cl alkane, a C2 alkane, a C3 alkane, a C4 alkane, or a combination comprising at least one of the foregoing through a first catalyst bed within a reactor shell;

passing the first feed stream exiting the first catalyst bed and a second feed stream comprising a Cl alkane, a C2 alkane, a C3 alkane, a C4 alkane, or a combination comprising at least one of the foregoing through a second catalyst bed within the reactor shell;

passing the combined first feed stream and the second feed stream exiting the second catalyst bed, and a third feed stream comprising a Cl alkane, a C2 alkane, a C3 alkane, a C4 alkane, or a combination comprising at least one of the foregoing through a third catalyst bed, within the reactor shell;

producing a product within the reactor shell and withdrawing the product via a product stream from the reactor shell;

wherein the first, second, and third feed streams are heated prior to passing through the reactor shell and wherein a total temperature drop across the reactor shell is 40°C to l00°C.

2. The method of Claim 1, wherein a flowrate of the second and/or third feed stream is greater than a flowrate of the first feed stream, preferably, wherein a flowrate of the second and/or third feed stream is at least double a flowrate of the first feed stream.

3. The method of any of the preceding claims, wherein prior to passing through the reactor shell, a temperature of the second and/or third feed stream is greater than a temperature of the first feed stream, preferably, by greater than or equal to 5%.

4. The method of any of the preceding claims, wherein at least one of the first, second, and third feed streams comprises methane, ethane, propane, butane, or a combination comprising at least one of the foregoing.

5. The method of any of the preceding claims, further comprising passing at least one of the first, second, and third feed streams through a catalyst bed via a plurality of interspersed radial tubes.

6. The method of any of the preceding claims, wherein a temperature within the reactor is 500°C to 900°C, preferably, 600°C to 800°C.

7. The method of any of the preceding claims, wherein the total temperature drop across the reactor shell is less than or equal to 80°C, preferably, less than or equal to 60°C.

8. The method of any of the preceding claims, wherein a temperature drop across at least one of the first, second, and third catalyst beds is 40°C to 80°C, preferably, 50°C to 60°C.

9. The method of any of the preceding claims, wherein at least one of the first, second, and third catalyst beds comprises a dehydro aromatization catalyst comprising a metal on a zeolite support.

10. The method of Claim 9, wherein the metal comprises zinc, nickel, iron, rhodium, rhenium, platinum, or a combination comprising at least one of the foregoing and wherein the zeolite support comprises ZSM 5, ZSM 11, ZSM 12, MCM 22, or a combination comprising at least one of the foregoing.

11. The method of any of the preceding claims, wherein at least one of the first, second, and third feed streams is heated to a temperature of 500°C to 900°C, preferably, 600°C to 800°C.

12. The method of any of the preceding claims, wherein the product is an aromatic, preferably, a mono-aromatic comprising benzene, toluene, xylene, or a combination comprising at least one of the foregoing.

13. The method of any of the preceding claims, wherein the first feed stream, the second feed stream, the third feed stream, or a combination comprising at least one of the foregoing, comprises a Cl alkane, wherein the conversion rate from Cl alkane to product within the reactor shell is 10% to 20%.

14. The method of Claim 1, wherein the first feed stream, the second feed stream, the third feed stream, or a combination comprising at least one of the foregoing, comprises a C2 alkane, wherein the conversion rate from C2 alkane to product within the reactor shell is 20% to 50%.

15. The method of Claim 1, wherein the first feed stream, the second feed stream, the third feed stream, or a combination comprising at least one of the foregoing, comprises a C3 alkane, wherein the conversion rate from C3 alkane to product within the reactor shell is greater than or equal to 50%.

16. The method of any of the preceding claims, wherein at least one of the first, second, and third catalyst beds is a dehydro aromatization catalyst bed.

17. The method of any of the preceding claims, further comprising passing the first feed stream, the second feed stream, the third feed stream, and a fourth feed stream comprising alkanes through a fourth catalyst bed within the reactor shell.

18. The method of any of the preceding claims, further comprising passing the product stream through downstream equipment and isolating an individual alkane product from the product stream, wherein a purity of the individual alkane product is greater than or equal to 99% by weight, preferably, greater than or equal to 99.5% by weight.

19. The method of any of the preceding claims, wherein the reactor shell is oriented horizontally and the feed streams flow outward from a center of the reactor shell.

20. A method of processing alkanes, comprising:

passing a first feed stream comprising methane through a first catalyst bed within a reactor shell;

passing the first feed stream exiting the first catalyst bed and a second feed stream comprising methane through a second catalyst bed within the reactor shell;

passing the combined first feed stream and the second feed stream exiting the second catalyst bed, and a third feed stream comprising methane through a third catalyst bed within the reactor shell;

producing a product comprising benzene within the reactor shell and withdrawing the product via a product stream from the reactor shell;

wherein the first, second, and third feed streams are heated prior to passing through the reactor shell;

wherein a flowrate of the second and/or third feed stream is greater than a flowrate of the first feed stream;

wherein at least one of the first, second, and third catalyst beds is a dehydroaromatization catalyst bed;

wherein a total temperature drop across the reactor shell is 40°C to 80°C; and

wherein a temperature drop across at least one of the first, second, and third catalyst beds is 50°C to 60°C.