Removal of carbon monoxide, oxygen and acetylene from oxidative dehydrogenation processes

Abstract

1. A method for converting one or more alkanes to one or more alkenes, the method comprising: feeding a first stream comprising one or more alkanes and oxygen to an oxidative dehydrogenation reactor; converting at least a portion of the one or more alkanes to one or more alkenes in the oxidative dehydrogenation reactor to provide a second stream exiting the oxidative dehydrogenation reactor comprising one or more alkanes, one or more alkenes, and one or more of oxygen, carbon monoxide, and acetylene; feeding the second stream to a second reactor comprising a catalyst comprising CuO and ZnO, and reacting the second stream to provide a third stream exiting the second reactor comprising one or more alkanes, one or more alkenes, and lower or undetectable levels of oxygen and acetylene compared to the second stream.

Description

[Technical field]

[0001] The present disclosure relates generally to the oxidative dehydrogenation (ODH) of lower alkanes to their corresponding alkenes. In some embodiments, the present disclosure relates to controlling the emission levels of carbon monoxide, oxygen, and / or acetylene from an ODH process. [Background technology]

[0002] Olefins, such as ethylene, propylene, and butylene, are the basic building blocks of a variety of commercially valuable polymers. Because naturally occurring sources of olefins do not exist in commercial quantities, polymer producers rely on methods to convert the more abundant lower alkanes into olefins. The method of choice for commercial-scale producers today is steam cracking. Steam cracking is an endothermic process in which alkanes diluted with steam are exposed to temperatures of at least 800 °C for very brief periods. The fuel demand to generate the required temperatures, and the need for equipment that can withstand those temperatures, significantly increase overall costs. High temperatures also promote the formation of coke that accumulates in the system, necessitating costly periodic reactor shutdowns for maintenance and coke removal. Summary of the Invention

[0003] Oxidative dehydrogenation (ODH) is an alternative to steam cracking that is exothermic and produces little or no coke. In ODH, lower alkanes such as ethane are mixed with oxygen in the presence of a catalyst to produce the corresponding alkenes.

[0004] Except in the operating examples or where otherwise indicated, all numbers or expressions referring to quantities of ingredients, reaction conditions, and the like used in the specification and claims should be understood to be modified in all instances by the term "about." Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and appended claims are approximations that may vary depending upon the desired properties sought to be obtained by the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be construed at least in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0005] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the disclosure are approximations, the numerical values ​​set forth in the specific examples are reported as precisely as possible, however, any numerical values ​​inherently contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0006] It should also be understood that any numerical range described herein is intended to include all subranges subsumed therein. For example, a range of "1 to 10" is intended to include all subranges therebetween, including the stated minimum of 1 and the stated maximum of 10, i.e., the minimum is equal to or greater than 1 and the maximum is equal to or less than 10. The disclosed numerical ranges are continuous, and therefore include all values ​​between the minimum and maximum. Unless otherwise indicated, the various numerical ranges specified in this application are approximations.

[0007] As used herein, the term "alkane" refers to acyclic saturated hydrocarbons. In most cases, alkanes are composed of hydrogen and carbon atoms arranged in a linear structure in which all carbon-carbon bonds are single bonds. The general chemical formula for alkanes is C n H 2n+2In many embodiments of the present disclosure, alkane refers to one or more of ethane, propane, butane, pentane, hexane, octane, decane, and dodecane. In certain embodiments, alkane refers to ethane and propane, and in some embodiments, ethane.

[0008] As used herein, the term "alkene" refers to an unsaturated hydrocarbon containing at least one carbon-carbon double bond. In many embodiments, alkene refers to an alpha olefin. In many embodiments of the present disclosure, alkene refers to one or more of ethylene, propylene, 1-butene, butadiene, pentene, pentadiene, hexene, octene, decene, and dodecene. In certain embodiments, alkene refers to ethylene and propylene, and in some embodiments, ethylene.

[0009] As used herein, the term “alpha olefin” or “α-olefin” refers to a compound of the chemical formula C x H 2x Alpha olefins refers to a family of organic compounds that are alkenes (also known as olefins) and are distinguished by the presence of a double bond in the primary or alpha (α) position. In many embodiments of the present disclosure, alpha olefins refers to one or more of ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, and 1-dodecene. In certain embodiments, alpha olefins refers to ethylene and propylene, and in some embodiments, ethylene.

[0010] As used herein, the term "diluent" refers to a gas that forms a non-explosive mixture with a hydrocarbon or oxidizing gas. However, in some instances, the diluent may participate in the ODH reaction in the presence of an ODH catalyst. Furthermore, in all cases, the diluent is used to remove heat, thereby keeping the process out of flammable conditions.

[0011] As used herein, the term "essentially oxygen-free" means that the amount of oxygen remaining in the process streams described herein, if any, is sufficiently low so as not to pose a flammable or explosive risk to downstream process streams or equipment.

[0012] As used herein, the term "fixed bed reactor" refers to one or more reactors in series or parallel, often containing cylindrical tubes packed with catalyst pellets through which reactants flow and are converted to products. The catalyst within the reactor can have several configurations, including, but not limited to, one large bed, several horizontal beds, several parallel packed tubes, and multiple beds within their own shell.

[0013] As used herein, the term "fluidized bed reactor" refers to one or more reactors in series or parallel that contain a fluid (gas or liquid) passing through a solid, particulate catalyst, which can take the form of small spheres, at a velocity sufficient to suspend the solids and cause them to behave as if they were a fluid.

[0014] As used herein, the term "gas phase polyethylene process" refers to a process in which a mixture of ethylene, any alpha olefin comonomer, and hydrogen is passed over a catalyst in a fixed bed reactor or in a fluidized bed reactor. The ethylene and any alpha olefins can polymerize to form polyethylene particles that are suspended in the fluidizing gas and exit the reactor. In some embodiments, two or more individual reactors are arranged in parallel or series, each under slightly different conditions, so that different polyethylene properties from the reactors will be present in the resulting polyethylene blend. Often the catalyst system includes, but is not limited to, chromium catalysts, Ziegler-Natta catalysts, zirconocene catalysts, metallocene catalysts, and combinations thereof.

[0015] As used herein, the term "HDPE" refers to high density polyethylene, which generally has a density of 0.941 g / cm 3HDPE has a density of 100 or more. HDPE has a low degree of branching. HDPE is often produced using chromium / silica, Ziegler-Natta or metallocene catalysts.

[0016] As used herein, the term "high pressure polyethylene process" refers to the conversion of ethylene gas into a white solid by heating at very high pressure, about 1000-3000 bar and about 80-300° C., in the presence of trace amounts of oxygen (about <10 mpgv oxygen). Most often, the high pressure polyethylene process produces LDPE.

[0017] As used herein, the term "LDPE" refers to low density polyethylene, which is a long chain, highly branched polyethylene. The density of LDPE is often between 0.910 and 0.940 g / cm. 3 LDPE is produced by free radical polymerization.

[0018] As used herein, the term "linear velocity" is often the linear velocity of the gas stream (m / sec) and refers to the flow rate of the gas stream / cross-sectional area of ​​the reactor / porosity of the catalyst bed. Often, the flow rate refers to the sum of the flow rates of all gases entering the ODH reactor, measured at the temperature and pressure at the point where the oxygen and alkane first contact the ODH catalyst. The cross-sectional area of ​​the reactor is also measured at the inlet of the ODH catalyst bed. The "porosity" of the catalyst bed refers to the volume of voids in the catalyst bed / total volume of the catalyst bed. "Void volume" refers to the voids between the catalyst particles and does not include the volume of the pores in the catalyst particles. Often, the linear velocity can range from 5 cm / sec to 1500 cm / sec, and sometimes from 10 cm / sec to 500 cm / sec.

[0019] As used herein, the term "LLDPE" refers to linear low density polyethylene, which is a polyethylene that may have a significant number of short chain branches resulting from the copolymerization of ethylene with at least one alpha-olefin comonomer. In some cases, LLDPE has a density of 0.915 to 0.925 g / cm 3LLDPE has a density in the range of 0.5 to 12 mole percent, in some cases 1.5 to 10 mole percent, and in other cases 2 to 8 mole percent, relative to ethylene. Often, the LLDPE is an ethylene hexene, ethylene octene, or ethylene butene copolymer. The amount of comonomer incorporated can be 0.5 to 12 mole percent, in some cases 1.5 to 10 mole percent, and in other cases 2 to 8 mole percent, relative to ethylene.

[0020] As used herein, the term "long chain branching" refers to the situation during α-olefin polymerization where vinyl terminated polymer chains are incorporated into growing polymer chains. Long chain branches often have a length greater than the average critical entanglement distance of linear (no long chain branches) polymer chains. Long chain branching often impacts melt rheological behavior.

[0021] As used herein, the term "low pressure polyethylene process" refers to the polymerization of ethylene with an aluminum-containing catalyst, often at a pressure generally lower than that of the high pressure polyethylene process. Often, low pressure polyethylene processes are carried out at about 10-80 bar and about 70-300°C. Often, low pressure polyethylene processes provide HDPE. In certain cases, an α-olefin comonomer is included in the low pressure polyethylene process to provide LLDPE.

[0022] As used herein, the term "MDPE" refers to medium density polyethylene, which has some short chain branching and / or long chain branching and has a density between 0.926 and 0.940 g / cm 3 MDPE can be produced using chromium / silica, Ziegler-Natta or metallocene catalysts.

[0023] As used herein, the term "monomer" refers to a small molecule containing at least one double bond, which reacts in the presence of a free radical polymerization initiator to chemically combine with other monomers to form a polymer.

[0024] As used herein, the term "moving bed reactor" refers to a reactor in which the catalyst material flows with the reactants and is then separated from the exit stream and recycled.

[0025] As used herein, the term "MoVOx catalyst" refers to a catalyst having an empirical formula of Mo 6.5-7.0 V3O d where d is a number that satisfies at least the valence of the metals; 6.25-7.25 V3O d where d is a number that at least satisfies the valence of the metals, or a combination thereof.

[0026] As used herein, the term "olefinic monomer" includes, but is not limited to, α-olefins, and in certain embodiments, ethylene, propylene, 1-butene, 1-hexene, 1-octene, and combinations thereof.

[0027] As used herein, the term "oxidative dehydrogenation" or "ODH" refers to a process that couples the endothermic dehydration of alkanes with the strongly exothermic oxidation of hydrogen, as further described herein.

[0028] As used herein, the term "polyolefin" refers to a material prepared by polymerizing a monomer composition that includes at least one or more olefinic monomers.

[0029] As used herein, the term "polyethylene" includes, but is not limited to, homopolymers of ethylene and copolymers of ethylene with one or more α-olefins.

[0030] As used herein, the term "polypropylene" includes, but is not limited to, homopolymers of propylene, including isotactic polypropylene and syndiotactic polypropylene, and copolymers of propylene and one or more α-olefins.

[0031] As used herein, the term "polymer" refers to a macromolecule composed of repeating structural units joined by covalent chemical bonds, and is meant to include, but not be limited to, homopolymers, random copolymers, block copolymers, and graft copolymers.

[0032] As used herein, the term "short chain branching" refers to copolymers of ethylene and α-olefins or copolymers having branches of less than about 40 carbon atoms. Often, the α-olefins or branches are present at less than 20% by weight of the polyethylene, and in some cases less than 15% by weight. Often, the presence of short chain branches disrupts the formation of the polyethylene crystal structure and is observed as a lower density compared to linear (no short chain branches) polyethylene of the same molecular weight.

[0033] As used herein, the term "solution polyethylene process" refers to a process for polymerizing ethylene and one or more optional α-olefins in a mixture of lower alkane hydrocarbons in the presence of one or more catalysts. In some embodiments, two or more individual reactors can be arranged in parallel or series, each under slightly different conditions, so that different polyethylene properties from the reactors will be present in the resulting polyethylene blend. Often the catalysts include, but are not limited to, chromium catalysts, Ziegler-Natta catalysts, zirconocene catalysts, hafnocene catalysts, phosphinimine catalysts and metallocene catalysts, and combinations thereof.

[0034] As used herein, the term "slurry polyethylene process" refers to a single tube loop reactor, twin tube loop reactor or autoclave (stirred tank reactor) used to polymerize ethylene and any α-olefins in the presence of a catalyst system and a diluent. Non-limiting examples of diluents include isobutane, n-hexane or n-heptane. In some embodiments, two or more individual reactors can be placed in parallel or series, each under slightly different conditions, so that different polyethylene properties from the reactors will be present in the resulting polyethylene blend. Often, catalyst systems include, but are not limited to, chromium catalysts, Ziegler-Natta catalysts, zirconocene catalysts, hafnocene catalysts, phosphinimine catalysts and metallocene catalysts, and combinations thereof.

[0035] As used herein, the term "substantially acetylene-free" means that the amount of acetylene remaining in the process streams described herein, if any, is undetectable or is zero ppmv using the analytical techniques described herein.

[0036] As used herein, the term "swing bed reactor configuration" is a gas phase reactor system in which a first vessel effectively operates as a reactor and a second vessel effectively operates as a regenerator for regenerating the catalyst system. This configuration can be used with fluidized bed gas phase polyethylene reactors as well as with fixed bed gas phase polyethylene reactors.

[0037] As used herein, the term "thermoplastic" refers to a class of polymers that soften or become liquid when heated and harden when cooled. Thermoplastics are often high molecular weight polymers that can be repeatedly heated and reshaped. In many embodiments of the present disclosure, thermoplastics include polyolefins and elastomers that have thermoplastic properties.

[0038] As used herein, the terms "thermoplastic elastomer" and "TPE" refer to a class of copolymers or blends of polymers (often blends of thermoplastics and rubbers) that contain materials that have both thermoplastic and elastomeric properties.

[0039] As used herein, the term "thermoplastic olefin" or "TPO" refers to a polymer / filler blend that includes polyethylene, polypropylene, block copolymers of polypropylene, rubber, and a portion of reinforcing fillers. The fillers can include, but are not limited to, talc, glass fiber, carbon fiber, wollastonite, and / or metal oxysulfates. The rubbers can include, but are not limited to, ethylene-propylene rubber, EPDM (ethylene-propylene-diene rubber), ethylene-butadiene copolymer, styrene-ethylene-butadiene-styrene block copolymer, styrene-butadiene copolymer, ethylene-vinyl acetate copolymer, ethylene-alkyl (meth)acrylate copolymer, very low density polyethylene (VLDPE) (such as those sold under the trade name FLEXOMER® resins by Dow Chemical Co, Midland, Michigan), styrene-ethylene-ethylene-propylene-styrene (SEEPS). These can also be used as materials modified by interpolymers to adjust the rheological properties.

[0040] As used herein, the term "VLDPE" refers to very low density polyethylene, which is a polyethylene having a high level of short chain branching and a typical density in the range of 0.880 to 0.915 g / cc. In many cases, VLDPE is a substantially linear polymer. VLDPE is typically produced by the copolymerization of ethylene and α-olefins. VLDPE is often produced using metallocene catalysts.

[0041] As used herein, the term "weight hourly space velocity (WHSV)" refers to the gas flow in an ODH reactor in terms of the weight, rather than the volume, of gas flowing through a weight of active catalyst per hour. In calculating WHSV, the weight of gas may include only reactants, but may also include diluents added to the gas mixture. In many embodiments of the present disclosure, when including the weight of diluent, if used, WHSV is calculated as 0.5 h -1 ~50h -1 In most cases, the range is 1.0 to 25.0 h -1 The range may be:

[0042] Unless otherwise specified, all molecular weight values ​​are determined using gel permeation chromatography (GPC). Molecular weights are expressed as polyethylene equivalents with relative standard deviations of 2.9% for number average molecular weight ("Mn") and 5.0% for weight average molecular weight ("Mw"). Unless otherwise specified, molecular weight values ​​given herein are weight average molecular weight (Mw). [Brief description of the drawings]

[0043] [Figure 1] FIG. 1 is a schematic diagram of a chemical complex for an oxidative dehydrogenation process according to embodiments described herein. [Diagram 2] Figure 2 is a schematic diagram of the experimental setup used to generate the results shown in Table 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0044] In some embodiments disclosed herein, the extent to which carbon monoxide is produced during the ODH process can be mitigated by converting it to carbon dioxide, which can then act as an oxidant. The process can be operated to control the emission of carbon dioxide from the process to a desired level. Using the methods described herein, users can choose to operate under carbon dioxide neutral conditions so that excess carbon dioxide does not have to be flared or vented to the atmosphere.

[0045] In some embodiments disclosed herein, the extent to which acetylene is produced during the ODH process can be mitigated by converting it to other compounds.

[0046] In some embodiments disclosed herein, the extent to which oxygen is retained in the stream after the ODH process can be mitigated by converting it to other compounds.

[0047] Disclosed herein are methods for mitigating the formation of carbon monoxide and / or acetylene in an ODH process, by minimizing the amount of oxygen, if any, in the post-ODH process stream. Aspects of these methods include introducing a gas mixture of lower alkanes, oxygen, and optionally carbon dioxide to at least one ODH reactor under conditions that allow for the production of the corresponding alkenes and small amounts of various by-products. In the case of multiple ODH reactors, each reactor contains the same or different ODH catalyst. In some embodiments, steam with an optional diluent may also be introduced into the reactor as part of the gas mixture.

[0048] In some embodiments, the lower alkane is ethane and the corresponding alkene is ethylene.

[0049] In further embodiments, at least one ODH reactor is a fixed bed reactor. In some embodiments, at least one ODH reactor is a fixed bed reactor that includes heat dissipative particles within the fixed bed. In some embodiments, the heat dissipative particles have a greater thermal conductivity than the catalyst. In alternative embodiments, at least one ODH reactor is a fluidized bed reactor.

[0050] In some embodiments, the at least one ODH catalyst is a mixed metal oxide catalyst. In certain embodiments, the at least one ODH catalyst is a catalyst represented by the formula: Mo a V b Te c Nb d Pd e O f (wherein a, b, c, d, e, and f are the relative atomic weights of the elements Mo, V, Te, Nb, Pd, and O, respectively; a=1, b=0.01-1.0, c=0.01-1.0, d=0.01-1.0, 0.00≦e≦0.10, and f is a number that at least satisfies the valence states of the metals in the catalyst).

[0051] In other particular embodiments, the at least one ODH catalyst is a mixed metal oxide of the formula: Mo 6.25-7.25 V3O d (wherein d is a number that at least satisfies the valence of the metal).

[0052] Various embodiments relate to the oxidative dehydrogenation (ODH) of lower alkanes to their corresponding alkenes. Lower alkanes are saturated hydrocarbons having 2-4 carbons, and the corresponding alkenes include hydrocarbons having the same number of carbons but with one carbon-carbon double bond. While the methods disclosed herein can be used to convert any lower alkane to its corresponding alkene, one particular embodiment is the ODH of ethane to produce its corresponding alkene, ethylene.

[0053] <ODHプロセス> ODH of alkanes involves contacting a mixture of one or more alkanes and oxygen with an ODH catalyst in an ODH reactor under conditions that promote the oxidation of the alkanes to the corresponding alkenes. The conditions in the reactor are controlled by an operator and include parameters such as, but are not limited to, temperature, pressure, and flow rate. Conditions can be varied and optimized for a particular alkane, a particular catalyst, or whether a diluent is used in the reactant mix.

[0054] The use of an ODH reactor to carry out an ODH process consistent with the present disclosure is within the knowledge of one of ordinary skill in the art. For best results, the oxidative dehydrogenation of the one or more alkanes may be carried out at a temperature of 300° C. to 500° C., or 300° C. to 450° C., or 330° C. to 425° C., at a pressure of 0.5 to 100 psig (3.447 to 689.47 kPag), or 15 to 50 psig (103.4 to 344.73 kPag), and the residence time of the one or more alkanes in the reactor may be 0.002 to 30 seconds, or 1 to 10 seconds.

[0055] In some embodiments, the process has a selectivity of greater than 95%, or for example greater than 98%, for the corresponding alkene (ethylene in the case of ethane ODH). The gas hourly space velocity (GHSV) is about 400 to about 30,000 h -1 , or 1000h -1 In some embodiments, the gas velocity can be described in terms of weight hourly space velocity (WHSV) and is about 0.4 h -1 About 30 hours from -1 In some embodiments, the gas velocity can be described in terms of linear velocity and can be from about 5 cm / sec to about 500 cm / sec. In some embodiments, the space-time yield (productivity) of the corresponding alkene in g / hr per kg of catalyst can be at least 50 or more, or more than 1500, or more than 3000, or more than 3500 at 330-500° C., depending on the temperature profile of the catalyst bed. In some embodiments, the productivity of the catalyst will increase with increasing temperature until selectivity decreases.

[0056] <ODH catalyst> None of the ODH catalysts known in the art are suitable for use in the methods disclosed herein. Non-limiting examples of suitable oxidative dehydrogenation catalysts include those containing one or more mixed metal oxides selected from the following: i) A catalyst of the following formula: Mo a V b Te c Nb d Pd e O f (wherein a, b, c, d, e, and f are the relative atomic weights of the elements Mo, V, Te, Nb, Pd, and O, respectively; a = 1, b = 0.01 to 1.0, c = 0.01 to 1.0, d = 0.01 to 1.0, 0.00 ≦ e ≦ 0.10, and f is a number that satisfies at least the valence state of the metals in the catalyst); ii) A catalyst of the following formula: Ni g A h B i D j O f (wherein g is a number from 0.1 to 0.9, often from 0.3 to 0.9, in other cases from 0.5 to 0.85, and in some cases from 0.6 to 0.8; h is a number from 0.04 to 0.9; i is a number from 0 to 0.5; j is a number from 0 to 0.5; f is a number that satisfies at least the valence state of the catalyst; A is selected from Ti, Ta, V, Nb, Hf, W, Y, Zn, Zr, Si, and Al or mixtures thereof; B is selected from La, Ce, Pr, Nd, Sm, Sb, Sn, Bi, Pb, Tl, In, Te, Cr, Mn, Mo, Fe, Co, Cu, Ru, Rh, Pd, Pt, Ag, Cd, Os, Ir, Au, Hg, and mixtures thereof; D is selected from Ca, K, Mg, Li, Na, Sr, Ba, Cs, Rb, and mixtures thereof; O is oxygen); iii) A catalyst of the following formula: Mo a E k G l O f (wherein E is selected from Ba, Ca, Cr, Mn, Nb, Ta, Ti, Te, V, W, and mixtures thereof; G is selected from Bi, Ce, Co, Cu, Fe, K, Mg, V, Ni, P, Pb, Sb, Si, Sn, Ti, U, and mixtures thereof; a=1; k is 0-2; l=0-2, with the proviso that the sum of l for Co, Ni, Fe, and mixtures thereof is less than 0.5; and f is a number that at least satisfies the valence states of the metals in the catalyst); iv) a catalyst of the formula: V m Mo n Nb o Te p Me q O f (wherein Me is selected from Ta, Ti, W, Hf, Zr, Sb and mixtures thereof; m is 0.1 to 3; n is 0.5 to 1.5; o is 0.001 to 3; p is 0.001 to 5; q is 0 to 2; and f is a number that at least satisfies the valence state of the metal in the catalyst); v) a catalyst of the formula: Mo a V r X s Y t Z u M v O f (wherein X is at least one of Nb and Ta; Y is at least one of Sb and Ni; Z is at least one of Te, Ga, Pd, W, Bi and Al; M is at least one of Fe, Co, Cu, Cr, Ti, Ce, Zr, Mn, Pb, Mg, Sn, Pt, Si, La, K, Ag and In; a=1.0 (normalized); r=0.05-1.0; s=0.001-1.0; t=0.001-1.0; u=0.001-0.5; v=0.001-0.3; f is a number that satisfies at least the valence state of the metal of the catalyst). When selecting a catalyst, one skilled in the art can understand that catalysts can vary in selectivity and activity. Some embodiments of ethane ODH in the present disclosure use mixed metal oxide catalysts that can provide high selectivity to ethylene without significant loss of activity. A non-limiting example catalyst is a catalyst of the formula: Mo a V b Te c Nb d Pd e O f (wherein a, b, c, d, e, and f are the relative atomic weights of the elements Mo, V, Te, Nb, Pd, and O, respectively; a=1, b=0.01-1.0, c=0.01-1.0, d=0.01-1.0, 0.00≦e≦0.10, and f is a number that satisfies at least the valence state of the metal in the catalyst). vi) A mixed metal oxide having the empirical formula: Mo 6.5-7.0 V3O d (wherein d is a number that at least satisfies the valence of the metal in the catalyst); vii) A mixed metal oxide having the empirical formula: Mo 6.25-7.25 V3O d (where d is a number that at least satisfies the valence of the metal in the catalyst).

[0057] In some embodiments, the catalyst may be supported / agglomerated with a binder. Some binders include acidic, basic, or neutral binder slurries of TiO2, ZrO2, Al2O3, AlO(OH) and mixtures thereof. Another useful binder includes Nb2O5. The agglomerated catalyst may be extruded into suitable shapes (rings, spheres, saddles, etc.) of sizes typically used in fixed bed reactors. When extruding the catalyst, various extrusion aids known in the art may be used. In some cases, the resulting support has a cumulative surface area, as measured by BET, of 35 m2 or more. 2 / g, in some cases 20m 2Less than / g, or 3 m in other cases 2 It may be less than / g, and the cumulative pore volume may be 0.05 - 0.50 cm 3 / g.

[0058] <ODH Reactor> Any of the known reactor types applicable to the ODH of alkanes can be used in the method disclosed herein. In some embodiments, this method can be used in a conventional fixed-bed reactor. In a typical fixed-bed reactor, the reactants are introduced into the reactor at one end, flow through the immobilized catalyst, products are formed, and exit from the other end of the reactor. The design of the fixed-bed reactor suitable for the method disclosed herein can follow the techniques known for this type of reactor. Those skilled in the art will know which features are required regarding the shape and dimensions, input of reactants, discharge of products, temperature and pressure control, and means for immobilizing the catalyst.

[0059] In some embodiments, inert non-catalytic heat-dissipating particles can be used within one or more ODH reactors. In various embodiments, the heat-dissipating particles are present in the bed and include one or more non-catalytic inert fine particles having a melting point at least 30 °C, in some cases at least 100 °C, in some embodiments at least 250 °C, and in further embodiments at least 500 °C higher than the temperature upper limit control temperature of the reaction, and the particle size ranges from about 0.1 mm to about 50 mm, in some embodiments from 0.5 mm to 15 mm, in further embodiments from 0.5 mm to 8 mm, and in other embodiments from 0.5 mm to 5 mm, and having a thermal conductivity exceeding 10 W / mK (watts / meter·kelvin) within the reaction temperature management limit. In some embodiments, the fine particles are metal alloys and compounds having a thermal conductivity exceeding 10 W / mK (watts / meter·kelvin) within the reaction temperature control limit. Non-limiting examples of suitable metals that can be used in these embodiments include silver, copper, gold, aluminum, steel, stainless steel, molybdenum, and tungsten, but are not limited thereto.

[0060] The heat dissipative particles can have a particle size of about 1 mm to about 15 mm. In some embodiments, the particle size can be in the range of about 0.1 mm to about 50 mm, in some embodiments 0.5 mm to 15 mm, in other embodiments 0.5 mm to 8 mm, and in further embodiments 0.5 mm to 5 mm. The heat dissipative particles can be added to the fixed bed in an amount of 5 to 95% by weight, in some embodiments 30 to 70% by weight, and in other embodiments 45 to 60% by weight, based on the total weight of the fixed bed. The particles are used to potentially improve the cooling uniformity and reduction of hot spots in the fixed bed by transferring heat directly to the reactor walls.

[0061] Additional embodiments include the use of a fluidized bed reactor, where the catalyst bed is supported by a porous structure or distribution plate located near the bottom of the reactor, and the reactants flow at a velocity sufficient to fluidize the bed (e.g., the catalyst rises and begins to swirl fluidly). The reactants are converted to products upon contact with the fluidized catalyst, and the reactants are then removed from the top of the reactor. Design considerations that one skilled in the art can modify and optimize include, but are not limited to, reactor geometry, distribution plate shape and size, input temperature, output temperature, and reactor temperature and pressure controls.

[0062] Embodiments of the present disclosure include using a combination of both fixed bed and fluidized bed reactors, each reactor having the same or different ODH catalyst. Multiple reactors can be arranged in series or parallel configurations, the design of which is within the knowledge of one of ordinary skill in the art.

[0063] <Oxygen / alkane mixture> In many embodiments, a mixture of one or more alkanes and oxygen should be utilized with a ratio that is outside the flammability envelope of the one or more alkanes and oxygen. In some embodiments, the ratio of alkanes to oxygen may be outside the upper flammability envelope. In these embodiments, the percentage of oxygen in the mixture may be less than 30% by volume, in some cases less than 25% by volume, or in other cases less than 20% by volume, but may be greater than zero or at least 0.1% by volume.

[0064] In embodiments with a high percentage of oxygen, the percentage of alkane can be adjusted to keep the mixture outside the flammability envelope. The appropriate ratio level can be determined by one of skill in the art, but in many cases the percentage of oxygen is less than about 40% by volume and greater than zero or at least 0.1% by volume. As a non-limiting example, if the mixture of gases before the ODH contains 10% by volume of oxygen and 15% by volume of alkanes, the remainder can be made up with a diluent. Non-limiting examples of diluents useful in this embodiment include, but are not limited to, one or more of nitrogen, carbon dioxide, and steam. In some embodiments, the diluent must be present in a gaseous state at the conditions in the reactor and must not increase the flammability of the hydrocarbons added to the reactor, such characteristics being understood by one of skill in the art when determining which diluent to use. The diluent can be added to either the alkane-containing gas or the oxygen-containing gas before entering the ODH reactor, or can be added directly to the ODH reactor.

[0065] In embodiments of the present disclosure, the volumetric feed ratio of oxygen to ethane (O2 / C2H6) fed to the one or more ODH reactors is at least about 0.1, in some cases about 0.2, in other cases about 0.3, in some cases at least about 0.4, and in other cases at least about 0.5, and may be up to about 1, in some cases up to about 0.9, in other cases up to about 0.8, in some cases up to about 0.7, and in other cases up to about 0.6. The volumetric feed ratio of oxygen to ethane may be any of the values ​​recited above, or may range between any of the values ​​recited above.

[0066] In some embodiments, mixtures that fall within the flammable envelope may be used when the mixture exists under conditions that prevent uncontrolled process propagation, as a non-limiting example. In these non-limiting examples, a flammable mixture is generated in a medium where ignition is immediately stopped. As a further non-limiting example, a user may design a reactor where oxygen and one or more alkanes are mixed at a point surrounded by flame suppression material. Ignition would be suppressed by the surrounding material. Flame suppression materials include, but are not limited to, metal or ceramic components such as stainless steel walls or ceramic supports. In some embodiments, oxygen and alkanes may be mixed at a low temperature such that an ignition event would not lead to an uncontrolled process, and then introduced into the reactor before increasing the temperature. Flammable conditions do not exist until the mixture is surrounded by flame suppression material inside the reactor.

[0067] <Carbon monoxide emissions> Carbon monoxide may be produced as a by-product of the oxidation of one or more alkanes in the ODH reaction. Carbon monoxide emissions are a function of the amount of carbon monoxide produced in the oxidation process.

[0068] Measuring the amount of carbon monoxide exiting the ODH reactor can be done by any means known in the art. For example, one or more detectors, such as a GC, IR, or Rahman detector, are placed immediately downstream of the reactor to measure the carbon monoxide emissions. Although not required, the emissions of other components can also be measured. These include, but are not limited to, the amounts of by-products such as ethylene, unreacted ethane, acetylene, carbon dioxide, oxygen, and acetic acid.

[0069] Carbon monoxide output may be expressed using any metric commonly used in the art. For example, carbon monoxide output may be expressed as mass flow rate (g / min) or volume flow rate (cm 3The selectivity can be expressed in units of CO / min. In some embodiments, the normalized selectivity can be used to assess the extent to which carbon monoxide is produced or consumed. In that case, the net mass flow rate of CO (the difference between the mass flow rate of CO entering the ODH reactor and the mass flow rate of CO leaving the ODH reactor) is normalized to the conversion of ethane, essentially describing what proportion of ethane is converted to carbon monoxide rather than ethylene or other by-products such as acetic acid.

[0070] In addition to ODH, many industrial processes produce carbon monoxide, which must be captured or combusted where it contributes to greenhouse gas emissions. Using the carbon monoxide abatement step disclosed herein, most, if not all, of the carbon monoxide resulting from the ODH process is converted to carbon dioxide. The advantage here is that it can be combined with other processes, such as pyrolysis, to reduce or eliminate the amount of carbon monoxide produced in the ODH process. In some cases, the carbon dioxide can be captured in an amine scrubber.

[0071] <Acetylene emissions> Acetylene may be produced as a by-product of the oxidation of one or more alkanes in the ODH reaction. Acetylene emissions are a function of the amount of acetylene produced in the oxidation process.

[0072] Measuring the amount of acetylene exiting the ODH reactor can be done by any means known in the art. For example, one or more detectors, such as a GC, IR, or Rahman detector, are placed immediately downstream of the reactor to measure acetylene emissions. Although not required, emissions of other components can also be measured. These include, but are not limited to, the amount of by-products such as ethylene, unreacted ethane, carbon monoxide, carbon dioxide, oxygen, and acetic acid.

[0073] The acetylene output can be expressed using any metric commonly used in the art. For example, the acetylene output can be expressed as mass flow rate (g / min), volume flow rate (cm3 The selectivity can be expressed in parts per million by volume (ppmv) or parts per million by volume (ppmv). In some embodiments, normalized selectivity can be used to assess the extent to which acetylene is produced or consumed. In that case, the net mass flow rate of acetylene (the difference between the mass flow rate of acetylene entering the ODH reactor and the mass flow rate of acetylene leaving the ODH reactor) is normalized to the conversion of ethane, essentially describing what percentage of ethane is converted to acetylene rather than ethylene or other by-products such as acetic acid.

[0074] Using the acetylene abatement step disclosed herein, most, if not all, of the acetylene is reacted with the acetylene resulting from the ODH process. The advantage in this case is that it can be combined with other processes, such as pyrolysis, to reduce or eliminate the amount of acetylene produced in the ODH process and eliminate downstream unit operations in the ODH type process.

[0075] <Removal of carbon monoxide, acetylene, and oxygen> Carbon monoxide, oxygen, and acetylene are contaminants that can affect the performance of equipment downstream of one or more ODH reactors and / or adversely affect the purity of the final ethylene product. A reactor located downstream of one or more ODH reactors that includes a catalytic material including CuO and ZnO removes all or a portion of the carbon monoxide, oxygen, and acetylene in the process stream passing therethrough. In some embodiments, the material including CuO and ZnO can act as an adsorbent for carbon monoxide, oxygen, and acetylene. In other embodiments, the material including CuO and ZnO can function as a selective carbon monoxide oxidation catalyst.

[0076] In some embodiments, after a bed of material comprising CuO and ZnO is depleted of chemisorbed oxygen, the material can initiate a chemical reaction in which oxygen and acetylene are removed or eliminated without removing carbon monoxide from the process stream. Without being limited to a single theory, in this embodiment, it is believed that CuO and ZnO are reduced to their corresponding elemental metallic forms via the reaction.

[0077] When the above reactor containing the catalytic material containing CuO and ZnO is placed downstream of one or more ODH reactors, this mode of operation may be beneficial in certain integration options of ODH with various plants where carbon monoxide is the preferred feedstock of the downstream plants compared to carbon dioxide.

[0078] <Carbon dioxide emissions> Carbon dioxide is produced in the ODH reaction as a by-product of alkane oxidation and can be recycled from carbon monoxide oxidation. Carbon dioxide can also be added to the ODH reactor when used as an inert diluent. Conversely, carbon dioxide can be consumed when acting as an oxidant in the dehydrogenation reaction. Thus, carbon dioxide emissions are a function of the amount of carbon dioxide added and produced minus the amount of carbon dioxide consumed in the oxidation process. In some embodiments, the disclosed methods control the degree to which carbon dioxide acts as an oxidant to affect the overall carbon dioxide emissions coming out of the ODH process.

[0079] Measuring the amount of carbon dioxide exiting the ODH process can be done by any means known in the art. For example, one or more detectors, such as a GC, IR, or Rahman detector, are placed immediately downstream of the reactor to measure the carbon dioxide emissions. Although not required, the emissions of other components can also be measured. These include, but are not limited to, the amount of ethylene, unreacted ethane, carbon monoxide, oxygen, and by-products such as acetic acid. It should also be noted that depending on the metric selected for carbon dioxide emissions, the emission levels of other components (e.g., ethane) may actually be required.

[0080] Carbon dioxide output can be expressed using any metric commonly used in the art. For example, carbon dioxide output can be expressed as mass flow rate (g / min) or volumetric flow rate (cm 3 The selectivity can be expressed in units of CO2 / min. In some embodiments, the normalized selectivity can be used to assess the extent to which carbon dioxide is produced or consumed. In that case, the net mass flow rate of CO2 (the difference between the mass flow rate of CO2 entering the ODH reactor and the mass flow rate of CO2 leaving the ODH reactor) is normalized to the conversion of ethane, essentially describing what percentage of ethane is converted to carbon dioxide rather than ethylene or other by-products such as acetic acid. A carbon selectivity of zero indicates that the amount of carbon dioxide entering the reactor is the same as the amount of carbon dioxide output. In other words, the process is carbon dioxide neutral. A positive carbon dioxide selectivity alerts the user that carbon dioxide is being produced and that the oxidation of carbon dioxide occurring is insufficient to offset its production, which can result in the process being carbon dioxide positive and reduced selectivity to olefins.

[0081] In some embodiments of the present disclosure, the product selectivity for carbon dioxide is less than about 10 wt%, in some cases less than about 7.5 wt%, and in other cases less than about 5 wt%. The product selectivity for carbon dioxide can be any value recited above, or can range between any of the values ​​recited above.

[0082] In some embodiments, the total amount of carbon dioxide in the stream exiting one or more ODH reactors can be essentially the same as the total amount of carbon dioxide in the stream entering one or more ODH reactors. In this case, essentially the same means that the difference in the amount of carbon dioxide in the stream exiting the ODH reactor is within 2 volume percent (+2 vol%) of the amount of carbon dioxide entering the ODH reactor. In certain embodiments of the present disclosure, the amount of carbon dioxide in the stream exiting the ODH reactor can be about +5 vol%, in some cases about +7.5 vol%, in other cases about +10 vol%, and can be about -5 vol%, in some cases about -7.5 vol%, in other cases about -10 vol% of the amount of carbon dioxide in the stream entering the ODH reactor. The difference between the amount of carbon dioxide in the stream exiting the ODH reactor and the amount of carbon dioxide entering the ODH reactor can be any of the values ​​above, or a range between any of the values ​​above.

[0083] In some embodiments, the methods and apparatus disclosed herein provide the possibility of a carbon dioxide negative process. In this case, carbon dioxide is consumed at a faster rate than it is produced, resulting in a negative carbon selectivity. The ODH process may produce carbon dioxide, but the extent to which it is consumed while acting as an oxidant offsets the production that is occurring. In addition to ODH, many industrial processes produce carbon dioxide, which must be captured or burned off where it contributes to greenhouse gas emissions. With a carbon dioxide negative process, excess carbon dioxide from other processes can be captured and used as a diluent for the ODH process under conditions of negative carbon selectivity. The advantage in this case is that it can be combined with other processes, such as pyrolysis, to reduce the amount of carbon dioxide produced in the ODH process. Furthermore, the consumption of carbon dioxide is endothermic, and by increasing the extent to which carbon dioxide acts as an oxidant, the heat produced from the ODH of ethane is partially offset by the consumption of carbon dioxide, reducing the extent to which heat needs to be removed from the reactor. In some embodiments, when acting as an oxidant, carbon dioxide can produce carbon monoxide, which can be captured and used as an intermediate in the production of other chemical products, such as methanol or formic acid.

[0084] <Removal of acetic acid> The stream exiting the one or more ODH reactors can optionally be directed to a quench tower or acetic acid scrubber before being fed to the second reactor, which facilitates removal of oxygenates such as acetic acid, ethanol and water via a bottom outlet. A stream containing unconverted lower alkanes (such as ethane), the corresponding alkenes (such as ethylene), and one or more of unreacted oxygen, carbon dioxide, carbon monoxide, acetylene, and inert diluent exits the scrubber and is fed downstream.

[0085] In an embodiment of the disclosure, the stream from one or more ODH reactors is cooled to a lower temperature before being fed to the acetic acid scrubber (described below). The temperature of the stream prior to entering the acetic acid scrubber can be at least about 40° C., in some cases at least about 45° C., and in other cases at least about 50° C., and can be up to about 90° C., in some cases up to about 85° C., in other cases up to about 80° C., in some cases up to about 75° C., and in other cases up to about 70° C. The temperature of the ODH reactor product stream fed to the acetic acid scrubber can be cooled to any of the above temperature values, or to a range between any of the above temperature values.

[0086] Oxygenates removed via the quench tower or acetic acid scrubber can include carboxylic acids (e.g., acetic acid), aldehydes (e.g., acetaldehyde), alcohols (e.g., thanol), and ketones (e.g., acetone). The amount of oxygenates remaining in the stream exiting the scrubber is often zero, i.e., below the detection limit of the analytical test methods typically used to detect such compounds. If oxygenates can be detected, they may be present at levels up to about parts per million by volume (ppmv), in some cases up to about 5 ppmv, in other cases less than about 10 ppmv, in some cases up to about 50 ppmv, in other cases up to about 100 ppmv, and may be present at up to about 2% by volume, in some cases up to about 1% by volume, and in other cases up to about 1,000 ppm. The amount of oxygenates or acetic acid in the stream exiting the scrubber may be any of the values ​​recited above, or may range between any of the values ​​recited above.

[0087] <Second Reactor> In many embodiments, the ODH reactor (or reactors) can provide a stream containing at least a small amount of oxygen that remains as the reactor effluent. In embodiments of the present disclosure, the oxygen can be beneficial to the ODH reactor product gas. In some embodiments, if the ODH catalyst is exposed to an oxygen-free reducing environment at high temperatures, the catalyst can be permanently decomposed. In other embodiments, when the level of oxygen in the product gas from the ODH reactor contains less than about 1 ppmv of oxygen, most, if not all, of the one or more alkanes are converted to one or more alkenes in the inlet portion of the reactor, and most of the catalyst bed of the reactor is not utilized.

[0088] In other embodiments, oxygen in the ODH reactor product gas creates serious operational problems for downstream equipment, as a non-limiting example, in the first compression stage of the ODH process. This process consideration dictates that oxygen must be removed to very low or undetectable levels before the product gas is compressed.

[0089] One method used to reduce / remove oxygen in the ODH product gas focuses on catalytically combusting a small portion of the ODH product gas to completely consume the residual oxygen. While this approach is viable, it is often undesirable because it increases the overall oxygen consumption in the ODH process and, in a non-limiting example where the alkane is ethane, reduces the overall process selectivity to ethylene.

[0090] As described above, a reactor located downstream of one or more ODH reactors comprising a catalytic material containing CuO and ZnO removes all or a portion of the carbon monoxide, oxygen, and acetylene in the process stream passing therethrough. In some embodiments, the material comprising CuO and ZnO can act as an adsorbent for carbon monoxide, oxygen, and acetylene. In other embodiments, the material comprising CuO and ZnO can function as a selective carbon monoxide oxidation catalyst.

[0091] In embodiments of the present disclosure, the amount of oxygen in the stream exiting the one or more ODH reactors can be at least about 80 ppmv, in some cases at least about 100 ppmv, in other cases at least about 150 ppmv, in some cases at least about 200 ppmv, and in some cases up to about 5 vol.%, in some cases up to about 4 vol.%, in other cases up to about 3 vol.%, in some cases up to about 2 vol.%, in other cases up to about 1 vol.%, and in certain circumstances up to about 500 ppmv. The amount of oxygen in the stream exiting the one or more ODH reactors can be any of the values ​​recited above, or can range between any of the values ​​recited above.

[0092] In embodiments of the present disclosure, if oxygen is present in the stream exiting the second reactor (in some cases, the amount of oxygen is undetectable or zero pmpv), the amount of oxygen in the stream exiting the second reactor can be at least about 1 ppmv, in some cases at least about 2 ppmv, in other cases at least about 3 ppmv, in some cases at least about 5 ppmv, and can be up to about 1 vol.%, in some cases up to about 0.9 vol.%, in other cases up to about 0.8 vol.%, in some cases up to about 0.7 vol.%, in other cases up to about 0.6 vol.%, and in certain circumstances up to about 0.5 vol.%. The amount of oxygen in the stream exiting the second reactor can be any of the values ​​recited above, or can range between any of the values ​​recited above.

[0093] In embodiments of the present disclosure, the amount of carbon monoxide in the stream exiting the one or more ODH reactors can be at least about 100 ppmv, in some cases at least about 200 ppmv, in other cases at least about 300 ppmv, and in some cases at least about 400 ppmv, and can be up to about 10% by volume, in some cases up to about 9% by volume, in other cases up to about 8% by volume, in some cases up to about 7% by volume, in other cases up to about 6% by volume, and in certain circumstances up to about 5% by volume. The amount of carbon monoxide in the stream exiting the one or more ODH reactors can be any of the values ​​recited above, or can range between any of the values.

[0094] In embodiments of the present disclosure, if carbon monoxide is present in the stream exiting the second reactor (in some cases, the amount of carbon monoxide is undetectable or zero ppmv), the amount of carbon monoxide in the stream exiting the second reactor can be at least about 1 ppmv, in some cases at least about 2 ppmv, in other cases at least about 3 ppmv, in some cases at least about 5 ppmv, and up to about 8% by volume, in some cases up to about 7% by volume, in other cases up to about 6% by volume, in some cases up to about 5% by volume, in other cases up to about 4% by volume, and in certain circumstances up to about 3% by volume. The amount of carbon monoxide in the stream exiting the second reactor can be any of the values ​​recited above, or can range between any of the values ​​recited above.

[0095] In embodiments of the present disclosure, when acetylene is present in the stream exiting the one or more ODH reactors (in some cases, the amount of acetylene is undetectable or is zero ppmv), the amount of acetylene in the stream exiting the one or more ODH reactors can be at least about 1 ppmv, in some cases at least about 2 vppm, in other cases at least about 5 ppmv, in some cases at least about 10 ppmv, and up to about 1000 ppmv, in some cases up to about 750 ppmv, in other cases up to about 500 ppmv, in some cases up to about 400 ppmv, in other cases up to about 300 ppmv, and in certain circumstances up to about 300 ppmv. The amount of acetylene in the stream exiting the one or more ODH reactors can be any of the values ​​recited above, or can range between any of the values ​​recited above.

[0096] In embodiments of the present disclosure, the amount of acetylene in the stream exiting the second reactor will be less than the amount entering the second reactor, and in many cases the stream exiting the second reactor will be substantially free of acetylene.

[0097] In embodiments of the present disclosure, if acetylene is present in the stream exiting the second reactor (often the amount of acetylene is undetectable, less than 1 ppmv, or zero ppmv), the amount of acetylene in the stream exiting the second reactor can be at least about 1 ppmv, in some cases at least about 2 ppmv, in other cases at least about 3 ppmv, in some cases at least about 5 ppmv, and up to about 100 ppmv, in some cases up to about 50 ppmv, in other cases up to about 25 ppmv, in some cases up to about 20 ppmv, in other cases up to about 15 ppmv, and in certain circumstances up to about 10 ppmv. The amount of acetylene in the stream exiting the second reactor can be any of the values ​​recited above, or can range between any of the values ​​recited above.

[0098] In embodiments of the present disclosure, the temperature in the second reactor can be at least about 100° C., in some cases at least about 110° C., in other cases at least about 115° C., in some cases at least about 120° C., and can be up to about 200° C., in some cases up to about 190° C., in other cases up to about 180° C., in some circumstances up to about 175° C., and in other circumstances up to about 170° C. The temperature of the second reactor can range between any of the above temperature values, including the temperature gradient in the second reactor described above.

[0099] In various embodiments of the present disclosure, fixed bed reactors loaded with catalytic materials containing CuO and ZnO can be placed at three different locations in the ODH process. At the ODH reactor outlet (the product from the reactor outlet can be cooled to below 200°C before entering the second reactor). At the outlet of the acetic acid scrubber / quench tower (the gaseous feed to the second reactor may be preheated to at least 100°C). At the outlet of the first stage compression of the gaseous ODH product, downstream of the acetic acid scrubber, the feed to the second reactor can be at least partially preheated by the energy of compression.

[0100] <ODHコンプレックス> In the following description of the present disclosure with reference to the drawings, it should be noted that like parts are indicated by like reference numerals.

[0101] In an embodiment of the present disclosure, the chemical complex of the present disclosure, shown as one embodiment in schematic form in FIG. 1, comprises in a cooperative arrangement: ODH reactor 10, quench tower or acetic acid scrubber 20, second reactor 25 (described herein), amine wash tower 30 (which may include a caustic tower), dryer 40, and distillation tower 50 (which is a C1 column). A separate column is required to separate ethylene and ethane because the conversion of ethane is not 100%. ODH reactor 10 contains an ODH catalyst capable of catalyzing the oxidative dehydrogenation of alkanes introduced via alkane line 80 in the presence of oxygen, which may be introduced via oxygen line 70. Although second reactor 25 is shown immediately after quench tower or acetic acid scrubber 20, it is often more efficiently utilized after the gas stream has been compressed, often before amine wash tower 30. Therefore, in many cases, locating the second reactor 25 after the input stream is compressed can make the process configuration more energy efficient.

[0102] The ODH reaction may also occur in the presence of an inert diluent, such as carbon dioxide, nitrogen, or steam, which is added to ensure that the mixture of oxygen and hydrocarbon is outside the flammability limits. Determining whether a mixture is outside the flammability limits for a given temperature and pressure is within the knowledge of one of ordinary skill in the art. The ODH reaction occurring in the ODH reactor 10 may also produce a variety of other products, which may include carbon dioxide, carbon monoxide, oxygenates, and water, depending on the catalyst and conditions within the ODH reactor 10. These products, along with unreacted alkanes, the corresponding alkenes, residual oxygen, carbon monoxide, acetylene, and the inert diluent (if added), exit the ODH reactor 10 via the ODH reactor product line 90.

[0103] The ODH reactor product line 90 is directed to a quench tower or acetic acid scrubber 20 which quenches the product from product line 90 to facilitate removal of oxygenates and water via quench tower bottom outlet 100. The unconverted lower alkanes, corresponding alkenes, unreacted oxygen, carbon dioxide, carbon monoxide, acetylene and inert diluent added to the quench tower 20 exit through quench tower overhead line 110 and are directed to the second reactor 25.

[0104] The second reactor 25, which can be variously configured as described above, contains a catalytic material containing CuO and ZnO to remove all or a portion of the carbon monoxide, oxygen, and acetylene. In the second reactor 25, most or all of the unreacted oxygen and acetylene are consumed. The remaining unconverted lower alkane, the corresponding alkene, unreacted oxygen (if present), all or a portion of the carbon dioxide, carbon monoxide (if present), acetylene (if present), and inert diluent are conveyed via line 115 to the amine scrubber 30.

[0105] Any carbon dioxide present in line 115 is separated by amine scrub column 30 and may be captured and sold via carbon dioxide bottom outlet 120 or recycled back to ODH reactor 10 as described above. Components introduced to amine scrub column 30 via line 115 other than carbon dioxide exit amine scrub column 30 through amine scrub column overhead line 130 and pass through dryer 40 before being directed to distillation column 50 where the C2 / C2+ hydrocarbons are isolated and removed via C2 / C2+ hydrocarbon bottom outlet 150.

[0106] In many embodiments, the C2 / C2+ hydrocarbon bottom outlet 150 is fed to a C2 splitter (not shown) that separates ethane from ethylene.

[0107] In many embodiments of the present disclosure, the olefins produced using one or more ODH reactors or any of the processes or complexes described herein can be used to produce a variety of olefin derivatives, including, but not limited to, polyethylene, polypropylene, ethylene oxide, propylene oxide, polyethylene oxide, polypropylene oxide, vinyl acetate, polyvinyl chloride, acrylic esters (e.g., methyl methacrylate), thermoplastic elastomers, thermoplastic olefins and blends, and combinations thereof.

[0108] <Derivative> In many embodiments of the present disclosure, the olefins produced using one or more ODH reactors or any of the processes or complexes described herein can be used to produce a variety of olefin derivatives, including, but not limited to, polyethylene, polypropylene, ethylene oxide, propylene oxide, polyethylene oxide, polypropylene oxide, vinyl acetate, polyvinyl chloride, acrylic esters (e.g., methyl methacrylate), thermoplastic elastomers, thermoplastic olefins and blends, and combinations thereof.

[0109] In many embodiments of the present disclosure, ethylene and optionally α-olefins are produced in one or more ODH reactors or any of the processes or complexes described herein and used to make polyethylene. The polyethylenes made from ethylene and optional α-olefins described herein can include homopolymers of ethylene, copolymers of ethylene and α-olefins, resulting in HDPE, MDPE, LDPE, LLDPE, and VLDPE.

[0110] The polyethylenes produced using the ethylene and optional α-olefins described herein can be produced using any suitable polymerization process and equipment. Suitable ethylene polymerization processes include, but are not limited to, gas phase polyethylene processes, high pressure polyethylene processes, low pressure polyethylene processes, solution polyethylene processes, slurry polyethylene processes, and suitable combinations of the above arranged in parallel or series.

[0111] The present disclosure also contemplates the use of various tools commonly used in chemical reactors, including flow meters, compressors, and sensors for measuring parameters such as temperature, pressure, and flow rate. One skilled in the art is expected to include these components as deemed necessary for operation. (Aspect)

[0112] A first aspect of the present disclosure is directed to a method for converting one or more alkanes to one or more alkenes, comprising: a. providing a first stream comprising one or more alkanes and oxygen to an oxidative dehydrogenation reactor; b. converting at least a portion of the one or more alkanes to one or more alkenes in said oxidative dehydrogenation reactor to provide a second stream exiting the oxidative dehydrogenation reactor comprising one or more alkanes, one or more alkenes, and one or both of oxygen and acetylene; c. feeding the second stream to a second reactor comprising a catalyst comprising CuO and ZnO and reacting the second stream to provide a third stream exiting the second reactor comprising one or more alkanes, one or more alkenes, and lower or undetectable levels of oxygen and acetylene compared to the second stream.

[0113] A second aspect of the present disclosure is directed to the first aspect, wherein the one or more alkanes comprises ethane. A third aspect of the present disclosure is directed to the second aspect, wherein the one or more alkenes comprise ethylene.

[0114] A fourth aspect of the present disclosure is directed to one or more of the first to third aspects, wherein the oxidative dehydrogenation reactor comprises an oxidative dehydrogenation catalyst containing one or more mixed metal oxides selected from the following: i) a catalyst of the formula: Mo a V b Te c Nb d Pd e O f (wherein a, b, c, d, e, and f are the relative atomic weights of the elements Mo, V, Te, Nb, Pd, and O, respectively; a=1, b=0.01 to 1.0, c=0.01 to 1.0, d=0.01 to 1.0, 0.00≦e≦0.10, and f is a number that satisfies at least the valence state of the metal present in the catalyst); ii) a catalyst of the formula: Ni g A h B i D j O f (In the formula, g is a number of 0.1 to 0.9, sometimes 0.3 to 0.9, in other cases 0.5 to 0.85, and sometimes 0.6 to 0.8; h is a number of 0.04 to 0.9; i is a number of 0 to 0.5; j is a number of 0 to 0.5; f is a number that satisfies at least the valence state of the catalyst; and A is Ti, Ta, V, Nb, Hf, W, Y, Zn, Zr, Si, and Al or any of them. B is selected from La, Ce, Pr, Nd, Sm, Sb, Sn, Bi, Pb, Tl, In, Te, Cr, Mn, Mo, Fe, Co, Cu, Ru, Rh, Pd, Pt, Ag, Cd, Os, Ir, Au, Hg, and mixtures thereof; D is selected from Ca, K, Mg, Li, Na, Sr, Ba, Cs, Rb, and mixtures thereof; O is oxygen; iii) a catalyst of the formula: Mo a E k G l O f (wherein E is selected from Ba, Ca, Cr, Mn, Nb, Ta, Ti, Te, V, W, and mixtures thereof; G is selected from Bi, Ce, Co, Cu, Fe, K, Mg, V, Ni, P, Pb, Sb, Si, Sn, Ti, U, and mixtures thereof; a=1; k is 0-2; l=0-2, with the proviso that the sum of l for Co, Ni, Fe, and mixtures thereof is less than 0.5; and f is a number that at least satisfies the valence states of the metals present in the catalyst); iv) a catalyst of the formula: V m Mo n Nb o Te p Me q O f (wherein Me is selected from Ta, Ti, W, Hf, Zr, Sb and mixtures thereof; m is 0.1 to 3; n is 0.5 to 1.5; o is 0.001 to 3; p is 0.001 to 5; q is 0 to 2; and f is a number that satisfies at least the valence state of the metal present in the catalyst); v) a catalyst of the formula: Mo a V r X s Y t Z u M v O f (wherein X is at least one of Nb and Ta; Y is at least one of Sb and Ni; Z is at least one of Te, Ga, Pd, W, Bi and Al; M is at least one of Fe, Co, Cu, Cr, Ti, Ce, Zr, Mn, Pb, Mg, Sn, Pt, Si, La, K, Ag and In; a=1.0 (normalized); r=0.05-1.0; s=0.001-1.0; t=0.001-1.0; u=0.001-0.5; v=0.001-0.3; f is a number that at least satisfies the valence state of the catalyst); vi) A mixed metal oxide having the empirical formula: Mo 6.5-7.0 V3O d (wherein d is a number that at least satisfies the valence of the metal in the catalyst); vii) A mixed metal oxide having the empirical formula: Mo 6.25-7.25 V3O d (where d is a number that at least satisfies the valence of the metal in the catalyst).

[0115] A fifth aspect of the present disclosure is directed to one or more of the first to fourth aspects, wherein the first stream comprises one or more diluents, an oxygen-containing gas, and a gas containing one or more lower alkanes.

[0116] A sixth aspect of the present disclosure is directed to one or more of the first to fifth aspects, wherein the second stream comprises one or more unreacted lower alkanes, one or more lower alkenes, oxygen, one or more diluents, and water.

[0117] A seventh aspect of the present disclosure is directed to one or more of the first to sixth aspects, wherein the oxidative dehydrogenation reactor comprises a single fixed bed reactor.

[0118] An eighth aspect of the present disclosure is directed to one or more of the first to sixth aspects, wherein the oxidative dehydrogenation reactor comprises a single fluidized bed reactor and / or a moving bed reactor.

[0119] A ninth aspect of the present disclosure is directed to one or more of the first to sixth aspects, wherein the oxidative dehydrogenation reactor comprises a swing bed reactor configuration.

[0120] A tenth aspect of the present disclosure is directed to one or more of the first to ninth aspects, wherein an acetic acid scrubber is disposed between the oxidative dehydrogenation reactor and the second reactor.

[0121] An eleventh aspect of the present disclosure is directed to one or more of the first to tenth aspects, wherein the temperature in the second reactor is 100 to 200°C.

[0122] A twelfth aspect of the present disclosure is directed to one or more of the first to eleventh aspects, wherein the second stream comprises carbon monoxide, and the amount of carbon monoxide in the third stream is less than the amount of carbon monoxide in the second stream.

[0123] A thirteenth aspect of the present disclosure is directed to one or more of the first to twelfth aspects, wherein the gas hourly space velocity (GHSV) is about 400 to about 3000. 0 h -1 It is.

[0124] A fourteenth aspect of the present disclosure is directed to one or more of the first to twelfth aspects, wherein the weight hourly space velocity (WHSV) is about 0.4 h -1 ~about 30h -1 It is.

[0125] A fifteenth aspect of the present disclosure is directed to one or more of the first to twelfth aspects, wherein the linear velocity is from about 5 cm / sec to about 500 cm / sec.

[0126] A sixteenth aspect of the present disclosure is directed to a method of converting ethane to ethylene, comprising: a) feeding a first stream comprising ethane and oxygen to an oxidative dehydrogenation reactor; b) converting at least a portion of the ethane to ethylene in the oxidative dehydrogenation reactor to provide a second stream exiting the oxidative dehydrogenation reactor comprising ethane, ethylene, and one or both of oxygen and acetylene; and c) feeding the second stream to a second reactor comprising a catalyst comprising CuO and ZnO to provide a third stream exiting the second reactor comprising ethane, ethylene, and lower or undetectable levels of oxygen and acetylene as compared to the second stream.

[0127] A seventeenth aspect of the present disclosure is directed to the sixteenth aspect, wherein the oxidative dehydrogenation reactor comprises an oxidative dehydrogenation catalyst containing one or more mixed metal oxides selected from: i) a catalyst of the formula: Mo a V b Te c Nb d Pd e O f (wherein a, b, c, d, e, and f are the relative atomic weights of the elements Mo, V, Te, Nb, Pd, and O, respectively; a=1, b=0.01-1.0, c=0.01-1.0, d=0.01-1.0, 0.00≦e≦0.10, and f is a number that at least satisfies the valence state of the catalyst); ii) a catalyst of the formula: Ni g A h B i D j O f (In the formula, g is a number of 0.1 to 0.9, sometimes 0.3 to 0.9, in other cases 0.5 to 0.85, and sometimes 0.6 to 0.8; h is a number of 0.04 to 0.9; i is a number of 0 to 0.5; j is a number of 0 to 0.5; f is a number that satisfies at least the valence state of the catalyst; and A is Ti, Ta, V, Nb, Hf, W, Y, Zn, Zr, Si, and Al or any of them. B is selected from La, Ce, Pr, Nd, Sm, Sb, Sn, Bi, Pb, Tl, In, Te, Cr, Mn, Mo, Fe, Co, Cu, Ru, Rh, Pd, Pt, Ag, Cd, Os, Ir, Au, Hg, and mixtures thereof; D is selected from Ca, K, Mg, Li, Na, Sr, Ba, Cs, Rb, and mixtures thereof; O is oxygen; iii) a catalyst of the formula: Mo a E k G l O f (wherein E is selected from Ba, Ca, Cr, Mn, Nb, Ta, Ti, Te, V, W, and mixtures thereof; G is selected from Bi, Ce, Co, Cu, Fe, K, Mg, V, Ni, P, Pb, Sb, Si, Sn, Ti, U, and mixtures thereof; a=1; k is 0-2; l=0-2, with the proviso that the sum of l for Co, Ni, Fe, and mixtures thereof is less than 0.5; and f is a number that at least satisfies the valence states of the metals in the catalyst); iv) a catalyst of the formula: V m Mo n Nb o Te p Me q Of (wherein Me is selected from Ta, Ti, W, Hf, Zr, Sb and mixtures thereof; m is 0.1 to 3; n is 0.5 to 1.5; o is 0.001 to 3; p is 0.001 to 5; q is 0 to 2; and f is a number that at least satisfies the valence state of the metal in the catalyst); v) a catalyst of the formula: Mo a V r X s Y t Z u M v O f (wherein X is at least one of Nb and Ta; Y is at least one of Sb and Ni; Z is at least one of Te, Ga, Pd, W, Bi and Al; M is at least one of Fe, Co, Cu, Cr, Ti, Ce, Zr, Mn, Pb, Mg, Sn, Pt, Si, La, K, Ag and In; a=1.0 (normalized); r=0.05-1.0; s=0.001-1.0; t=0.001-1.0; u=0.001-0.5; v=0.001-0.3; f is a number that satisfies at least the valence state of the metal of the catalyst); vi) A mixed metal oxide having the empirical formula: Mo 6.5-7.0 V3O d (wherein d is a number that at least satisfies the valence of the metal in the catalyst); vii) A mixed metal oxide having the empirical formula: Mo 6.25-7.25 V3O d (where d is a number that at least satisfies the valence of the metal in the catalyst).

[0128] An eighteenth aspect of the present disclosure is directed to one or more of the sixteenth and seventeenth aspects, wherein the first stream comprises one or more diluents, an oxygen-containing gas, and a gas containing ethane.

[0129] A nineteenth aspect of the present disclosure is directed to one or more of the sixteenth to eighteenth aspects, wherein the second stream comprises one or more of ethane, ethylene, oxygen, one or more diluents, acetic acid, and water.

[0130] A twentieth aspect of the present disclosure is directed to one or more of the sixteenth to nineteenth aspects, wherein the oxidative dehydrogenation reactor comprises a single fixed bed reactor.

[0131] A twenty-first aspect of the present disclosure is directed to one or more of the sixteenth to eighteenth aspects, wherein the oxidative dehydrogenation reactor comprises a single fluidized bed reactor and / or a moving bed reactor.

[0132] A twenty-second aspect of the present disclosure is directed to one or more of the sixteenth to eighteenth aspects, wherein the oxidative dehydrogenation reactor comprises a swing bed reactor configuration.

[0133] A twenty-third aspect of the present disclosure is directed to one or more of the sixteenth to twenty-second aspects, wherein an acetic acid scrubber is disposed between the oxidative dehydrogenation reactor and the second reactor.

[0134] A twenty-fourth aspect of the present disclosure is directed to one or more of the sixteenth to twenty-third aspects, wherein the temperature in the second reactor is 100 to 200°C.

[0135] A twenty-fifth aspect of the present disclosure is directed to one or more of the sixteenth to twenty-fourth aspects, wherein the gas hourly space velocity (GHSV) is about 400 to about 3000. 0 h -1 It is.

[0136] A twenty-sixth aspect of the present disclosure is directed to one or more of the sixteenth to twenty-fourth aspects, wherein the weight hourly space velocity (WHSV) is about 0.4 h -1 ~about 30h -1 It is.

[0137] A twenty-seventh aspect of the present disclosure is directed to one or more of the sixteenth to twenty-fourth aspects, wherein the linear velocity is from about 5 cm / sec to about 500 cm / sec.

[0138] A twenty-eighth aspect of the present disclosure is directed to a chemical complex for the oxidative dehydrogenation of lower alkanes, the chemical complex comprising: i) at least one oxidative dehydrogenation reactor, comprising an oxidative dehydrogenation catalyst, adapted to receive an oxygen-containing gas and a lower alkane-containing gas, optionally in the presence of a diluent, and to produce the corresponding alkene and one or more of the following components: a. Unreacted lower alkanes; B.Oxygen; c. diluent; D. Acetylene; e. oxygenates; f. water; an oxidative dehydrogenation reactor designed to produce a product stream comprising: ii) a quench tower for quenching the product stream and removing water and soluble oxygenates therefrom; iii) a second reactor comprising a catalyst comprising CuO and ZnO for providing a second product stream exiting the second reactor comprising unreacted lower alkanes, alkenes, and lower or undetectable levels of oxygen and acetylene compared to the product stream; iv) an optional amine wash to remove carbon dioxide from the second product stream; v) a dryer for removing water from the second product stream; vi) a distillation column for removing C2 / C2+ hydrocarbons from said second product stream to produce an overhead stream enriched in C1 hydrocarbons; in a cooperative arrangement, Components i) through vi) are connected in series in the order listed.

[0139] A twenty-ninth aspect of the present disclosure is directed to the twenty-eighth aspect, and includes a non-flammable liquid flood-type gas mixer for premixing the oxygen-containing gas, the lower alkane-containing gas, and the heat removal gas prior to introduction into the at least one oxidative dehydrogenation reactor.

[0140] A thirtieth aspect of the present disclosure is directed to one or more of the twenty-eight and twenty-ninth aspects, wherein the oxidative dehydrogenation catalyst comprises a mixed metal oxide selected from: i) a catalyst of the formula: Mo a V b Te c Nb d Pd e O f (wherein a, b, c, d, e, and f are the relative atomic weights of the elements Mo, V, Te, Nb, Pd, and O, respectively; a=1, b=0.01-1.0, c=0.01-1.0, d=0.01-1.0, 0.00≦e≦0.10, and f is a number that at least satisfies the valence state of the catalyst); ii) a catalyst of the formula: Ni g A h B i D j O f (In the formula, g is a number of 0.1 to 0.9, sometimes 0.3 to 0.9, in other cases 0.5 to 0.85, and sometimes 0.6 to 0.8; h is a number of 0.04 to 0.9; i is a number of 0 to 0.5; j is a number of 0 to 0.5; f is a number that satisfies at least the valence state of the catalyst; and A is Ti, Ta, V, Nb, Hf, W, Y, Zn, Zr, Si, and Al or any of them. B is selected from La, Ce, Pr, Nd, Sm, Sb, Sn, Bi, Pb, Tl, In, Te, Cr, Mn, Mo, Fe, Co, Cu, Ru, Rh, Pd, Pt, Ag, Cd, Os, Ir, Au, Hg, and mixtures thereof; D is selected from Ca, K, Mg, Li, Na, Sr, Ba, Cs, Rb, and mixtures thereof; O is oxygen; iii) a catalyst of the formula: Mo a E k G l O f (wherein E is selected from Ba, Ca, Cr, Mn, Nb, Ta, Ti, Te, V, W, and mixtures thereof; G is selected from Bi, Ce, Co, Cu, Fe, K, Mg, V, Ni, P, Pb, Sb, Si, Sn, Ti, U, and mixtures thereof; a=1; k is 0-2; l=0-2, with the proviso that the sum of l for Co, Ni, Fe, and mixtures thereof is less than 0.5; and f is a number that at least satisfies the valence state of the catalyst); iv) a catalyst of the formula: V m Mo n Nb o Te p Me q O f (wherein Me is a metal selected from Ta, Ti, W, Hf, Zr, Sb and mixtures thereof; m is 0.1 to 3; n is 0.5 to 1.5; o is 0.001 to 3; p is 0.001 to 5; q is 0 to 2; and f is a number that at least satisfies the valence state of the catalyst); v) a catalyst of the formula: Mo a V r X s Y t Z u M v O f (wherein X is at least one of Nb and Ta; Y is at least one of Sb and Ni; Z is at least one of Te, Ga, Pd, W, Bi and Al; M is at least one of Fe, Co, Cu, Cr, Ti, Ce, Zr, Mn, Pb, Mg, Sn, Pt, Si, La, K, Ag and In; a=1.0 (normalized); r=0.05-1.0; s=0.001-1.0; t=0.001-1.0; u=0.001-0.5; v=0.001-0.3; f is a number that at least satisfies the valence state of the catalyst); vi) A mixed metal oxide having the empirical formula: Mo 6.5-7.0 V3O d (wherein d is a number that at least satisfies the valence of the metal in the catalyst); vii) A mixed metal oxide having the empirical formula: Mo 6.25-7.25 V3O d (where d is a number that at least satisfies the valence of the metal in the catalyst). 30. The chemical complex of claim 28, wherein at least one oxidative dehydrogenation reactor comprises a single fixed bed reactor.

[0141] A thirty-first aspect of the present disclosure is directed to one or more of the twenty-eighth to thirtieth aspects, wherein the at least one oxidative dehydrogenation reactor comprises a single fluidized bed reactor and / or a moving bed reactor.

[0142] A thirty-second aspect of the present disclosure is directed to one or more of the twenty-eighth to thirtieth aspects, wherein at least one oxidative dehydrogenation reactor comprises a swing bed reactor configuration.

[0143] A thirty-third aspect of the present disclosure is directed to one or more of the twenty-eighth to thirtieth aspects, wherein the at least one oxidative dehydrogenation reactor includes a plurality of oxidative dehydrogenation reactors connected in series, each reactor containing the same or a different oxidative dehydrogenation catalyst, and a product stream from each oxidative dehydrogenation reactor except for the last oxidative dehydrogenation reactor in the series is fed to a downstream oxidative dehydrogenation reactor.

[0144] A thirty-fourth aspect of the present disclosure is directed to one or more of the twenty-eighth to thirtieth aspects, wherein the at least one oxidative dehydrogenation reactor comprises a plurality of oxidative dehydrogenation reactors connected in parallel, each reactor containing the same or a different oxidative dehydrogenation catalyst.

[0145] A thirty-fifth aspect of the present disclosure is directed to one or more of the twenty-eighth to thirty-fourth aspects, wherein the chemical complex further comprises at least one heat exchanger immediately upstream of said quench tower.

[0146] A thirty-sixth aspect of the present disclosure is directed to one or more of the twenty-eighth to thirty-sixth aspects, wherein the chemical complex further comprises a caustic wash tower immediately downstream of said amine wash tower.

[0147] A thirty-seventh aspect of the present disclosure is directed to one or more of the twenty-eight through thirty-sixth aspects, wherein the C2 / C2+ hydrocarbons exit the distillation column and are sent to a second distillation column for separation of unreacted lower alkanes and corresponding alkenes into an unreacted lower alkane stream and a corresponding alkene stream.

[0148] A thirty-eighth aspect of the present disclosure is directed to the thirty-seventh aspect, further providing that the second distillation column separates the C2 / C2+ hydrocarbon portion of the product stream into an unreacted lower alkane stream and a corresponding alkene stream.

[0149] A thirty-ninth aspect of the present disclosure is directed to one or more of the thirty-seventh to thirty-eighth aspects, wherein the unreacted lower alkane stream is returned to the at least one oxidative dehydrogenation reactor as part of the lower alkane-containing gas.

[0150] A fortieth aspect of the present disclosure is directed to one or more of the twenty-eighth to thirty-ninth aspects, wherein the oxygenates include one or more selected from acetic acid, ethanol, acrylic acid, acetaldehyde, maleic acid, and maleic anhydride.

[0151] A forty-first aspect of the present disclosure is directed to one or more of the twenty-eight to fortieth aspects, 0 h -1 It is.

[0152] A 42nd aspect of the present disclosure is directed to one or more of the 28th to 40th aspects, wherein the weight hourly space velocity (WHSV) is about 0.4 h -1 ~about 30h -1 It is.

[0153] A 43rd aspect of the present disclosure is directed to one or more of the 28th to 40th aspects, wherein the linear velocity is from about 5 cm / sec to about 500 cm / sec. EXAMPLES

[0154] The following examples are intended to aid in the understanding of the present disclosure, but these examples should not be construed as limiting the scope of the disclosure.

[0155] The ODH catalyst was prepared as follows: (NH4)6Mo7O in 600 mL of distilled water. 24 A solution of VOSO4·3.46H2O (44.20 g, 35.77 mmol, white solid) in 600 mL of distilled water was prepared in a 2 L RBF equipped with a magnetic stir bar. A solution of VOSO4·3.46H2O (14.07 g, 62.95 mmol, light blue solid) in 600 mL of distilled water was prepared in a 1 L beaker equipped with a magnetic stir bar. Both solutions were stirred in a 60 °C water bath until homogeneous. The blue vanadium solution was then added to the clear, colorless molybdenum solution. This resulted in a dark purple solution with a fine suspension. Sodium dodecyl sulfate (SDS) (13.57 g, 47.06 mmol, white solid) was added to the reaction mixture. The purple slurry was stirred at 60 °C for 1 h.

[0156] The reaction mixture was transferred to a glass liner and the total volume measured after rinsing was approximately 1380 mL. The liner was loaded into a 2 L pressure reactor (Parr Instrument Company, Moline, IL) and the gap was filled with distilled water. The reactor was sealed and the headspace was evacuated and filled with nitrogen gas 10 times. The headspace was placed under 15 psig nitrogen gas and sealed. The reactor was transferred to a programmable oven and heated at 230°C for 24 hours (1 hour ramp to 230°C and 24 hours cool to room temperature). After cooling to room temperature, the reactor was evacuated and the contents were filtered using a Büchner funnel and four sheets of quantitative filter paper. The oily mother liquor was decanted off and the filter paper was replaced. The filter cake was rinsed with 1250 mL of distilled water. The filtrate was dark blue and the product was charcoal / gray purple in color.

[0157] The filter cake was dried overnight in a 90°C oven and 15.29g of product was recovered (estimated yield 37%). The uncalcined catalyst was crushed with a spatula and then loaded into a programmable muffle furnace. The program was set to ramp to 280°C over 1 hour and hold there for 9 hours before naturally cooling to room temperature. The air treated product was crushed with a mortar and pestle and submitted for CHN analysis. Carbon and nitrogen contents were found to be less than 1% by weight. The material was loaded into a quartz boat and centered in the quartz tube of a QRU furnace. The quartz tube was purged with bulk nitrogen (400sccm) for 8 hours, after which the nitrogen feed was fed to an oxygen scrubbing bed to further purify the nitrogen to less than 4ppmv oxygen. This ultra-high purity (UHP) nitrogen was purged through the quartz tube overnight. The next morning the furnace was turned on and ramped to 400°C over 4 hours. The catalyst was calcined at 400° C. for 2 hours and then allowed to cool naturally to ambient temperature.

[0158] 5.0 g of calcined catalyst (92 wt%) and 0.44 g of beryllium oxide (8 wt%) were placed in a 100 mL beaker (92%). Approximately 30 mL of distilled water was added to the beaker and stirred manually. The beaker was placed in an oil bath at approximately 100 °C with an overhead stirrer positioned so that the paddle was slightly off the bottom of the beaker. The mixture was stirred at 80 rpm for approximately 1.5 hours until it formed a paste, and the beaker with the paste was placed in a 90 °C oven to dry overnight. The solid catalyst chunks were broken up with a spatula and placed in a muffle furnace at 350 °C for 3.5 hours to form the ODH catalyst.

[0159] The catalyst composition for the second reactor in these examples is a reduced form of an oxide precursor composition containing 70 wt% CuO, 20 wt% ZnO, and 10 wt% ZrO2. To prepare this oxide precursor composition, a Cu-Zn-Zr nitrate solution (metal content 15.2 wt%, Cu:Zn:Zr ratio corresponding to a CuO:ZnO:ZrO2 weight ratio of 7:2:1) was precipitated with a soda solution (20 wt%) at pH 6.5 and 70°C. After the precipitation was completed, the suspension was stirred for another 120 minutes at pH 6.5 and 70°C. The solution was then filtered and the filter cake was washed with demineralized water until it was free of nitrates and dried at 120°C. The dried powder was calcined in a forced air oven at 300°C for 240 minutes to form the second reactor catalyst.

[0160] The ODH catalysts were evaluated in the apparatus shown in Figure 2. The ODH reactor 200 was a laboratory-scale dehydrogenation reactor (ODH microreactor unit).

[0161] The feed to the ODH reactor 200 contained oxygen, ethane and nitrogen in a weight ratio of 18% by volume / 36% by volume / 46% by volume, respectively, at 8.4 psig with a gas flow rate of 32.8 sccm, fed through a ¼ inch OD tube. The ODH catalyst / beryllium oxide described above was placed in the ODH reactor 200 and the gas feed was processed through the ODH reactor 200 at 327° C. The effluent from the ODH reactor 200 was passed through a condenser 210 where an aqueous solution containing 18.5 wt % acetic acid was condensed and the remaining effluent gas was passed to a second reactor 220 at 14 psig.

[0162] The second reactor 220 was placed in a temperature controlled oven 230 and loaded with 2 g of the second reactor catalyst. The effluent gas from the condenser 210 was introduced into the second reactor 220 at a pressure of 14 psig and a flow rate of 32.8 sccm and contacted with the second reactor catalyst in the second reactor 220 at various temperatures before exiting the second reactor 220 at ambient pressure. Samples of the effluent gas after exiting the second reactor 220 were collected and subsequently evaluated by gas chromatograph 240.

[0163] Table 1 summarizes the composition of the effluent gas samples taken after exiting the second reactor. These samples include two original samples taken when the temperature controlled oven 320 was set to "off," representing ambient temperature. Subsequent samples were taken after the temperature was increased to specific temperatures and held at those temperatures for the times indicated.

[0164] [Table 1]

[0165] The data in Table 1 show that the second reactor catalyst removes O2, CO, and acetylene at temperatures above 120° C. It is also clear from the data shown in Table 1 that all compounds are reacting with either oxygen from the catalyst or oxygen in the gas stream rather than being chemisorbed. The constant presence of oxygen in the feed stream was sufficient to oxidize all of the acetylene, resulting in the continued removal of acetylene and O2 even after the catalyst material had exhausted the chemisorbed oxygen.

[0166] Although the present disclosure has been particularly described with respect to certain embodiments thereof, it will be understood in light of the present disclosure that numerous variations of the disclosure are presently possible and still fall within the scope of the present disclosure. Accordingly, the present disclosure should be broadly construed and limited only by the scope and spirit of the claims appended hereto. [Industrial Applicability]

[0167] The process is applicable to the oxidative dehydrogenation (ODH) of light alkanes. The process can be applied to control the emission levels of carbon monoxide, oxygen, and / or acetylene from the ODH process.

Claims

1. 1. A process for converting one or more alkanes to one or more alkenes, comprising the steps of: a. providing a first stream comprising one or more alkanes, carbon dioxide, and oxygen to an oxidative dehydrogenation reactor; b. converting at least a portion of the one or more alkanes to one or more alkenes in the oxidative dehydrogenation reactor in a carbon dioxide negative process to provide a second stream exiting the oxidative dehydrogenation reactor comprising one or more alkanes, one or more alkenes, and one or both of oxygen and acetylene, wherein the amount of carbon dioxide in the second stream exiting the oxidative dehydrogenation reactor is in the range of −5% to −10% by volume of the amount of carbon dioxide in the first stream provided to the oxidative dehydrogenation reactor; c) feeding the second stream to a second reactor comprising a catalyst comprising CuO and ZnO and reacting the second stream to provide a third stream exiting the second reactor comprising one or more alkanes, one or more alkenes, and lower or undetectable levels of oxygen and acetylene compared to the second stream; The above method.

2. 2. The process of claim 1 , wherein the one or more alkanes comprises ethane.

3. 10. The process of claim 1 , wherein the one or more alkenes comprises ethylene.

4. 10. The method of claim 1 , wherein the oxidative dehydrogenation reactor comprises an oxidative dehydrogenation catalyst containing one or more mixed metal oxides selected from the following: i) a catalyst of the formula: Mo ａ V ｂ The ｃ Nb ｄ P$ ｅ Oh ｆ (wherein a, b, c, d, e, and f are the relative atomic weights of the elements Mo, V, Te, Nb, Pd, and O, respectively; a=1, b=0.01-1.0, c=0.01-1.0, d=0.01-1.0, 0.00≦e≦0.10, and f is a number that satisfies at least the valence states of the metals present in the catalyst); ii) a catalyst of the formula: Ni ｇ A ｈ B ｉ D ｊ O ｆ wherein g is a number between 0.1 and 0.9; h is a number between 0.04 and 0.9; i is a number between 0 and 0.5; j is a number between 0 and 0.5; f is a number that satisfies at least the valence states of the catalyst; A is selected from Ti, Ta, V, Nb, Hf, W, Y, Zn, Zr, Si and Al or mixtures thereof; B is selected from La, Ce, Pr, Nd, Sm, Sb, Sn, Bi, Pb, Tl, In, Te, Cr, Mn, Mo, Fe, Co, Cu, Ru, Rh, Pd, Pt, Ag, Cd, Os, Ir, Au, Hg, and mixtures thereof; D is selected from Ca, K, Mg, Li, Na, Sr, Ba, Cs, Rb, and mixtures thereof; and O is oxygen. iii) a catalyst of the formula: Mo ａ E ｋ G ｌ O ｆ wherein E is selected from Ba, Ca, Cr, Mn, Nb, Ta, Ti, Te, V, W, and mixtures thereof; G is selected from Bi, Ce, Co, Cu, Fe, K, Mg, V, Ni, P, Pb, Sb, Si, Sn, Ti, U, and mixtures thereof; a=1; k is 0-2; l=0-2, with the sum of l for Co, Ni, Fe, and mixtures thereof being less than 0.5; and f is a number that at least satisfies the valence states of the metals present in the catalyst; iv) a catalyst of the formula: V ｍ Mo ｎ Nb ｏ The ｐ Me ｑ Oh ｆ wherein Me is selected from Ta, Ti, W, Hf, Zr, Sb and mixtures thereof; m is from 0.1 to 3; n is from 0.5 to 1.5; o is from 0.001 to 3; p is from 0.001 to 5; q is from 0 to 2; and f is a number that satisfies at least the valence states of the metals present in the catalyst; v) a catalyst of the formula: Mo ａ V ｒ X ｓ Y ｔ Z ｕ M ｖ O ｆ where X is at least one of Nb and Ta; Y is at least one of Sb and Ni; Z is at least one of Te, Ga, Pd, W, Bi and Al; M is at least one of Fe, Co, Cu, Cr, Ti, Ce, Zr, Mn, Pb, Mg, Sn, Pt, Si, La, K, Ag and In; a=1.0 (normalized); r=0.05-1.0; s=0.001-1.0; t=0.001-1.0; u=0.001-0.5; v=0.001-0.3; f is a number that satisfies at least the valence states of the catalyst; vi) a mixed metal oxide having the empirical formula: Mo ６．５－７．０ V ３ O ｄ where d is a number that at least satisfies the valence of the metal in the catalyst; vii) a mixed metal oxide different from vi) above, having the empirical formula: Mo ６．２５－７．２５ V ３ O ｄ (where d is a number that at least satisfies the valence of the metal in the catalyst).

5. 2. The method of claim 1, wherein the first stream comprises one or more diluents, an oxygen-containing gas, and a gas containing one or more lower alkanes.

6. 10. The method of claim 1, wherein the second stream comprises one or more unreacted lower alkanes, one or more lower alkenes, oxygen, one or more diluents, and water.

7. 10. The method of claim 1 , wherein the oxidative dehydrogenation reactor comprises a single fixed bed reactor.

8. 10. The process of claim 1, wherein the oxidative dehydrogenation reactor comprises a single fluidized bed reactor and / or a moving bed reactor.

9. 10. The method of claim 1 , wherein the oxidative dehydrogenation reactor comprises a swing bed reactor configuration.

10. 10. The method of claim 1 , wherein an acetic acid scrubber is disposed between the oxidative dehydrogenation reactor and the second reactor.

11. The process of claim 1, wherein the temperature in the second reactor is from 100 to 200° C.

12. 2. The method of claim 1, wherein said second stream comprises carbon monoxide, and the amount of carbon monoxide in said third stream is less than the amount of carbon monoxide in said second stream.

13. The gas hourly space velocity (GHSV) of the first stream in the oxidative dehydrogenation reactor is 400 to 30,000 h －１ The method of claim 1, wherein

14. The weight hourly space velocity (WHSV) of the first stream in the oxidative dehydrogenation reactor is 0.4 h －１ ~30h －１ The method of claim 1, wherein 15. The method of claim 1, wherein the linear velocity of the first stream in the oxidative dehydrogenation reactor is from 5 cm / sec to 500 cm / sec.

16. 1. A process for converting ethane to ethylene, comprising the steps of: a. feeding a first stream comprising ethane, carbon dioxide, and oxygen to an oxidative dehydrogenation reactor; b. converting at least a portion of the ethane to ethylene in the oxidative dehydrogenation reactor in a carbon dioxide negative process to provide a second stream exiting the oxidative dehydrogenation reactor comprising ethane, ethylene, and one or both of oxygen and acetylene, wherein the amount of carbon dioxide in the second stream exiting the oxidative dehydrogenation reactor is in the range of −5% to −10% by volume of the amount of carbon dioxide in the first stream provided to the oxidative dehydrogenation reactor; c) feeding the second stream to a second reactor comprising a catalyst comprising CuO and ZnO to provide a third stream exiting the second reactor comprising ethane, ethylene, and lower or undetectable levels of oxygen and acetylene as compared to the second stream; The above method.

17. 17. The method of claim 16, wherein the oxidative dehydrogenation reactor comprises an oxidative dehydrogenation catalyst containing one or more mixed metal oxides selected from the following: i) a catalyst of the formula: Mo ａ V ｂ The ｃ Nb ｄ P$ ｅ Oh ｆ (wherein a, b, c, d, e, and f are the relative atomic weights of the elements Mo, V, Te, Nb, Pd, and O, respectively; a=1, b=0.01-1.0, c=0.01-1.0, d=0.01-1.0, 0.00≦e≦0.10, and f is a number that at least satisfies the valence state of the catalyst); ii) a catalyst of the formula: Ni ｇ A ｈ B ｉ D ｊ O ｆ wherein g is a number between 0.1 and 0.9; h is a number between 0.04 and 0.9; i is a number between 0 and 0.5; j is a number between 0 and 0.5; f is a number that satisfies at least the valence states of the catalyst; A is selected from Ti, Ta, V, Nb, Hf, W, Y, Zn, Zr, Si and Al or mixtures thereof; B is selected from La, Ce, Pr, Nd, Sm, Sb, Sn, Bi, Pb, Tl, In, Te, Cr, Mn, Mo, Fe, Co, Cu, Ru, Rh, Pd, Pt, Ag, Cd, Os, Ir, Au, Hg, and mixtures thereof; D is selected from Ca, K, Mg, Li, Na, Sr, Ba, Cs, Rb, and mixtures thereof; and O is oxygen. iii) a catalyst of the formula: Mo ａ E ｋ G ｌ O ｆ wherein E is selected from Ba, Ca, Cr, Mn, Nb, Ta, Ti, Te, V, W, and mixtures thereof; G is selected from Bi, Ce, Co, Cu, Fe, K, Mg, V, Ni, P, Pb, Sb, Si, Sn, Ti, U, and mixtures thereof; a=1; k is 0-2; l=0-2, with the sum of l for Co, Ni, Fe, and mixtures thereof being less than 0.5; and f is a number that at least satisfies the valence states of the metals in the catalyst; iv) a catalyst of the formula: V ｍ Mo ｎ Nb ｏ The ｐ Me ｑ Oh ｆ wherein Me is selected from Ta, Ti, W, Hf, Zr, Sb and mixtures thereof; m is 0.1 to 3; n is 0.5 to 1.5; o is 0.001 to 3; p is 0.001 to 5; q is 0 to 2; and f is a number that at least satisfies the valence states of the metals in the catalyst; v) a catalyst of the formula: Mo ａ V ｒ X ｓ Y ｔ Z ｕ M ｖ O ｆ where X is at least one of Nb and Ta; Y is at least one of Sb and Ni; Z is at least one of Te, Ga, Pd, W, Bi and Al; M is at least one of Fe, Co, Cu, Cr, Ti, Ce, Zr, Mn, Pb, Mg, Sn, Pt, Si, La, K, Ag and In; a=1.0 (normalized); r=0.05-1.0; s=0.001-1.0; t=0.001-1.0; u=0.001-0.5; v=0.001-0.3; f is a number that satisfies at least the valence states of the metals of the catalyst; vi) a mixed metal oxide having the empirical formula: Mo ６．５－７．０ V ３ O ｄ where d is a number that at least satisfies the valence of the metal in the catalyst; vii) a mixed metal oxide different from vi) above, having the empirical formula: Mo ６．２５－７．２５ V ３ O ｄ (where d is a number that at least satisfies the valence of the metal in the catalyst).

18. 17. The method of claim 16, wherein the first stream comprises one or more of a diluent, an oxygen-containing gas, and an ethane-containing gas.

19. 17. The method of claim 16, wherein the second stream comprises one or more of ethane, ethylene, oxygen, one or more diluents, acetic acid, and water.

20. 17. The method of claim 16, wherein the oxidative dehydrogenation reactor comprises a single fixed bed reactor.

21. 17. The method of claim 16, wherein the oxidative dehydrogenation reactor comprises a single fluidized bed reactor and / or a moving bed reactor.

22. 17. The method of claim 16, wherein the oxidative dehydrogenation reactor comprises a swing bed reactor configuration.

23. 17. The method of claim 16, wherein an acetic acid scrubber is disposed between the oxidative dehydrogenation reactor and the second reactor.

24. The process of claim 16, wherein the temperature in the second reactor is from 100 to 200° C.

25. The gas hourly space velocity (GHSV) of the first stream in the oxidative dehydrogenation reactor is 400 to 30,000 h －１ 17. The method of claim 16, wherein:

26. The method of claim 25, wherein the weight hourly space velocity (WHSV) of the first stream in the oxidative dehydrogenation reactor is 0.4 h －１ ~30h －１ 17. The method of claim 16, wherein:

27. The method of claim 16, wherein the linear velocity of the first stream in the oxidative dehydrogenation reactor is from 5 cm / sec to 500 cm / sec.

28. A chemical complex for the oxidative dehydrogenation of lower alkanes, comprising i) at least one oxidative dehydrogenation reactor in a carbon dioxide negative process, comprising an oxidative dehydrogenation catalyst, receiving an oxygen-containing gas, a lower alkane-containing gas, and carbon dioxide, optionally in the presence of a diluent, and producing the corresponding alkenes and one or more of the following components: a. unreacted lower alkanes; b. oxygen; c. a diluent; d. acetylene; e. oxygenates; f. water; wherein the amount of carbon dioxide in the product stream exiting the oxidative dehydrogenation reactor is in the range of −5% to −10% by volume of the amount of carbon dioxide accepted by the oxidative dehydrogenation reactor; ii) a quench tower for quenching the product stream and removing water and soluble oxygenates therefrom; iii) a second reactor comprising a catalyst comprising CuO and ZnO for providing a second product stream exiting the second reactor comprising unreacted lower alkanes, alkenes, and lower or undetectable levels of oxygen and acetylene as compared to the product stream; iv) an optional amine wash to remove carbon dioxide from the second product stream; v) a dryer for removing water from said second product stream; vi) a distillation column for removing C2 / C2+ hydrocarbons from said second product stream to produce an overhead stream enriched in C1 hydrocarbons; in a coordinated arrangement, The above chemical complex, wherein components i) to vi) are connected in series in the order listed.

29. 30. The chemical complex of claim 28, further comprising a non-flammable liquid flood-type gas mixer for premixing the oxygen-containing gas, the lower alkane-containing gas and the heat removal gas prior to introduction into the at least one oxidative dehydrogenation reactor.

30. 29. The chemical complex of claim 28, wherein the oxidative dehydrogenation catalyst comprises a mixed metal oxide selected from: i) a catalyst of the formula: Mo ａ V ｂ The ｃ Nb ｄ P$ ｅ Oh ｆ (wherein a, b, c, d, e, and f are the relative atomic weights of the elements Mo, V, Te, Nb, Pd, and O, respectively; a=1, b=0.01-1.0, c=0.01-1.0, d=0.01-1.0, 0.00≦e≦0.10, and f is a number that at least satisfies the valence state of the catalyst); ii) a catalyst of the formula: Ni ｇ A ｈ B ｉ D ｊ O ｆ wherein g is a number between 0.1 and 0.9; h is a number between 0.04 and 0.9; i is a number between 0 and 0.5; j is a number between 0 and 0.5; f is a number that satisfies at least the valence states of the catalyst; A is selected from Ti, Ta, V, Nb, Hf, W, Y, Zn, Zr, Si and Al or mixtures thereof; B is selected from La, Ce, Pr, Nd, Sm, Sb, Sn, Bi, Pb, Tl, In, Te, Cr, Mn, Mo, Fe, Co, Cu, Ru, Rh, Pd, Pt, Ag, Cd, Os, Ir, Au, Hg, and mixtures thereof; D is selected from Ca, K, Mg, Li, Na, Sr, Ba, Cs, Rb, and mixtures thereof; and O is oxygen. iii) a catalyst of the formula: Mo ａ E ｋ G ｌ O ｆ wherein E is selected from Ba, Ca, Cr, Mn, Nb, Ta, Ti, Te, V, W, and mixtures thereof; G is selected from Bi, Ce, Co, Cu, Fe, K, Mg, V, Ni, P, Pb, Sb, Si, Sn, Ti, U, and mixtures thereof; a=1; k is 0-2; l=0-2, with the proviso that the sum of l for Co, Ni, Fe, and mixtures thereof is less than 0.5; and f is a number that at least satisfies the valence states of the catalyst; iv) a catalyst of the formula: V ｍ Mo ｎ Nb ｏ The ｐ Me ｑ Oh ｆ where Me is a metal selected from Ta, Ti, W, Hf, Zr, Sb and mixtures thereof; m is 0.1 to 3; n is 0.5 to 1.5; o is 0.001 to 3; p is 0.001 to 5; q is 0 to 2; and f is a number that at least satisfies the valence states of the catalyst; v) a catalyst of the formula: Mo ａ V ｒ X ｓ Y ｔ Z ｕ M ｖ O ｆ where X is at least one of Nb and Ta; Y is at least one of Sb and Ni; Z is at least one of Te, Ga, Pd, W, Bi and Al; M is at least one of Fe, Co, Cu, Cr, Ti, Ce, Zr, Mn, Pb, Mg, Sn, Pt, Si, La, K, Ag and In; a=1.0 (normalized); r=0.05-1.0; s=0.001-1.0; t=0.001-1.0; u=0.001-0.5; v=0.001-0.3; f is a number that satisfies at least the valence states of the catalyst; vi) a mixed metal oxide having the empirical formula: Mo ６．５－７．０ V ３ O ｄ where d is a number that at least satisfies the valence of the metal in the catalyst; vii) a mixed metal oxide different from vi) above, having the empirical formula: Mo ６．２５－７．２５ V ３ O ｄ (where d is a number that at least satisfies the valence of the metal in the catalyst).

31. 30. The chemical complex of claim 28, wherein said at least one oxidative dehydrogenation reactor comprises a single fixed bed reactor.

32. 30. The chemical complex of claim 28, wherein the at least one oxidative dehydrogenation reactor comprises a single fluidized bed reactor and / or a moving bed reactor.

33. 30. The chemical complex of claim 28, wherein said at least one oxidative dehydrogenation reactor comprises a swing bed reactor configuration.

34. 30. The chemical complex of claim 28, wherein the at least one oxidative dehydrogenation reactor comprises a plurality of oxidative dehydrogenation reactors connected in series, each reactor containing the same or a different oxidative dehydrogenation catalyst, and wherein a product stream from each oxidative dehydrogenation reactor except for the last oxidative dehydrogenation reactor in the series is fed to a downstream oxidative dehydrogenation reactor.

35. 30. The chemical complex of claim 28, wherein the at least one oxidative dehydrogenation reactor comprises a plurality of oxidative dehydrogenation reactors connected in parallel, each reactor containing the same or a different oxidative dehydrogenation catalyst.

36. 30. The chemical complex of claim 28, wherein said chemical complex further comprises at least one heat exchanger immediately upstream of said quench tower.

37. 30. The chemical complex of claim 28, wherein said chemical complex further comprises a caustic wash tower immediately downstream of said amine wash.

38. 30. The chemical complex of claim 28, wherein the C2 / C2+ hydrocarbons exit the distillation column and are sent to a second distillation column for separating unreacted lower alkanes and corresponding alkenes into an unreacted lower alkane stream and a corresponding alkene stream.

39. 40. The chemical complex of claim 38, wherein the second distillation column further provides for separating the C2 / C2+ hydrocarbon portion of the product stream into an unreacted lower alkane stream and a corresponding alkene stream.

40. 40. The chemical complex of claim 39, wherein said unreacted lower alkane stream is returned to said at least one oxidative dehydrogenation reactor as part of a lower alkane-containing gas.

41. 30. The chemical complex of claim 28, wherein the oxygenates include one or more selected from acetic acid, ethanol, acrylic acid, acetaldehyde, maleic acid, and maleic anhydride.

42. The gas hourly space velocity (GHSV) of the first stream in the oxidative dehydrogenation reactor is 400 to 30,000 h －１ 30. The chemical complex of claim 28, 43. The method of claim 42, wherein the weight hourly space velocity (WHSV) of the first stream in the oxidative dehydrogenation reactor is 0.4 h －１ ~30h －１ 30. The chemical complex of claim 28, 44. The chemical complex of claim 28, wherein the linear velocity of the first stream in the oxidative dehydrogenation reactor is from 5 cm / sec to 500 cm / sec.

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