Production of liquid hydrocarbons from methane

FIELD: chemistry.

SUBSTANCE: invention relates to methods of producing liquid hydrocarbons from methane. Disclosed is a method of converting methane into liquid hydrocarbons, in which material containing methane is brought into contact with a dehydrocyclisation catalyst under conditions suitable for conversion of said methane to aromatic hydrocarbons, including naphthalene, and obtaining a first effluent containing hydrogen and at least 5 wt % aromatic hydrocarbons more than said starting material. At least a portion of aromatic hydrocarbons from the first effluent then reacts with hydrogen to form a second effluent having lower content of benzene compared to said first effluent, and at least a portion of hydrogen from the first effluent reacts with carbon monoxide, carbon dioxide or mixture thereof to obtain an additional effluent containing water and a hydrocarbon, and at least a portion of the hydrocarbon in said additional effluent is returned to said contact step.

EFFECT: improved method of converting methane to liquid hydrocarbons when methane is contained in a stream of natural gas with large amount of carbon dioxide.

32 cl, 3 dwg, 4 ex

The technical FIELD TO WHICH the INVENTION RELATES.

This application describes a method of obtaining liquid hydrocarbons from methane and, in particular, from natural gas.

BACKGROUND of INVENTION

The transported liquid hydrocarbons, such as cyclohexane and decalin, are important products of mass production for use in fuel and chemical industries. Currently, liquid hydrocarbons are most often receive a variety of methods from starting materials based on crude oil. However, as the world's supply of raw materials based on crude oil decreases, there is an increasing need to find alternative sources of liquid hydrocarbons.

One possible alternative source of liquid hydrocarbons is methane, which is the main component of natural gas and biogas. The volume of proven world reserves of natural gas is constantly increasing, and at present open up more natural gas than oil. Because of the problems associated with transporting large volumes of natural gas, most of the natural gas produced along with oil, especially in remote areas, flared and sent to waste. Therefore, a particularly attractive method of increasing grade natural gas which is the transformation of alkanes, contained in the natural gas directly into heavier hydrocarbons provided that can be overcome related technical difficulties.

A significant part of the main ways of converting methane to liquid hydrocarbons includes first conversion of methane into synthesis gas, a mixture of N₂and WITH the. Obtaining synthesis gas is associated with high capital costs and is energy-intensive; therefore, preferred paths, which do not require the generation of synthesis gas.

Proposed a number of alternative ways of converting methane directly into heavier hydrocarbons. One such method involves the catalytic oxidation the combination of methane to olefins and subsequent catalytic conversion of olefins to liquid hydrocarbons, including aromatic hydrocarbons. For example, in US No. 5336825 described two-step method for oxidative conversion of methane into hydrocarbons boiling within the gasoline fraction comprising aromatic hydrocarbons. At the first stage in the presence of free oxygen using a modified rare earth metal catalyst oxide of alkaline earth metal at a temperature in the range from 500 to 1000°C, the methane into ethylene and a small quantity of₃- and₄olefins. Then the ethylene and the more high molecular weight olefins, formed in the first stage, over an acidic solid catalyst, comprising pentasyllabic zeolite with a high content of silicon dioxide is converted into liquid hydrocarbons within the gasoline boiling fraction.

As ways to improve the grade of methane to heavier hydrocarbons, particularly ethylene, benzene and naphthalene, also proposed dehydroaromatization methane through high-temperature recovery combination. For example, in US No. 4727206 described a method of producing a liquid product rich in aromatic hydrocarbons, the introduction of methane at a temperature in the range from 600 to 800°C in the absence of oxygen in contact with a catalytic composition comprising an aluminosilicate having a molar ratio of silica to alumina of at least 5:1, and the above-mentioned aluminosilicate enter (I) gallium or its compound and (II) a metal of group VIIB of the Periodic table of elements or its connection.

In US no 5026937 described by way of aromatization of methane, which includes phase flow of raw materials, which includes more than 0.5 mol.% hydrogen and 50 mol.% methane in the reaction zone containing at least one layer of a solid catalyst comprising ZSM-5 and a phosphorus-containing alumina, in the conditions of transformation, which include a temperature of from 550 to 750°C, bolotnoe pressure below 10 at (1000 kPa) and hourly average gas flow rate from 400 to 7500 h ^-1. The waste stream products includes, as stated, methane, hydrogen, at least 3 mol.% With₂hydrocarbons and at least 5 mol.% aromatic With₆-C₈of hydrocarbons. After condensation removal fraction₄+ to identify the hydrogen and light hydrocarbons (methane, ethane, ethylene and so on)contained in the exhaust stream of products offered cryogenic methods.

In US no 5936135 described low-temperature non-oxidizing way of transformation of a lower alkane, such as methane and ethane, in aromatic hydrocarbons. In this way the lower alkane mix with more high-molecular olefin or paraffin, such as propylene and butene, and the mixture is introduced into contact with the pretreated bifunctional pentesilea zeolite catalyst, such as GaZSM-5, at a temperature of from 300 to 600°C, an average hourly rate of gas supply from 1000 to 100000 cm³·g^-1h^-1and under pressure from 1 to 5 at (from 100 to 500 kPa). Pre-treatment of the catalyst includes the contacting of the catalyst with a mixture of hydrogen and water vapor at a temperature of from 400 to 800°C, under a pressure from 1 to 5 at (from 100 to 500 kPa) and at an average hourly rate of gas supply at least 500 cm³·g^-1h^-1during a period of at least 0.5 h, and then the contacting of the catalyst with air or oxygen in the is the temperature value from 400 to 800°C, average hourly rate of gas supply at least 200 cm³·g^-1h^-1and under pressure from 1 to 5 at (from 100 to 500 kPa) for a period of at least 0,2 o'clock

In US no 6239057 and 6426442 described a method of producing hydrocarbons from a higher number of carbon atoms, such as benzene, hydrocarbons with a low number of carbon atoms, such as methane, the introduction of the latter into contact with a catalyst comprising a porous carrier, such as ZSM-5, which contains dispersed therein a rhenium promoter and a metal, such as iron, cobalt, vanadium, manganese, molybdenum, tungsten, or their mixture. Adding CO or CO₂in the source material increases, as it is written, the output of benzene and stability of the catalyst.

In US no 6552243 describes how non-oxidative aromatization of methane, in which the catalytic composition comprising a crystalline aluminosilicate molecular sieve with the metal initially activated by treatment with a mixture of hydrogen and alkane with₂With₄preferably butane, and then the activated catalyst is introduced into contact with the stream of starting materials comprising at least 40 mol.% methane, at a temperature of from 600 to 800°C., under an absolute pressure below 5 at (500 kPa) and average hourly feed rate of raw material (JCSS) from 0.1 to 10 h^-1.

In RU # 2135441 described method is not the stop of methane to heavier hydrocarbons, in which the methane is mixed with at least 5 wt.% hydrocarbon With₃+such as benzene, and then in multitudinous reactor system is introduced into contact with a catalyst comprising platinum metal with under a partial pressure of methane of at least 0.05 MPa and at a temperature of at least 440°C the oxidation state above zero. The hydrogen generated in the process, may be introduced into contact with the oxides of carbon with additional methane, which after removal of simultaneous water can be added to the methane source material. The products of conversion of methane are gaseous phase With a₃-C₄and the liquid phase With₅+ but, in accordance with the examples, with little (less than 5 wt.%) or there is no actual increase in the number of aromatic rings in comparison with the source material.

Existing proposals for the conversion of methane into aromatic hydrocarbons suffer from several problems that limit their technical potential. Methods for oxidizing combinations usually include vysokoekonomichnyj and potentially dangerous combustion reaction of methane, often requiring expensive equipment to generate oxygen and producing large amounts of environmentally undesirable carbon oxides. On the other hand, am the current methods of rehabilitation combinations are often characterized by low selectivity for aromatic compounds and may require costly joint source materials to improve conversion and/or selectivity in respect of aromatic compounds. Moreover, in any process of rehabilitation combinations receive large amounts of hydrogen, resulting in the economic viability path required for effective utilization of hydrogen as a by-product. Because natural gas deposits are often located in remote areas, effective utilization of hydrogen can be a daunting task.

Another disadvantage of these methods is that they are characterized by the tendency to form as a product mainly of benzene and naphthalene. Although benzene has potential value as a chemical raw material, it finds limited sales on the market of chemicals and is not a reliable fuel source due to the challenges posed to health and the environment. Naphthalene finds even more limited sales on the market of chemicals, and its use as a fuel is more difficult due to the challenges posed to health and the environment, in addition to which its melting point greater than room temperature.

A particular difficulty when using natural gas as a source of liquid hydrocarbons lies in the fact that many natural gas fields around the world contain a large amount, sometimes more than 50%, diox is Yes carbon. Carbon dioxide is not only the object of tightening government requirements because of its potential liability for global climate change, but probably economically forbidden is any way, the implementation of which requires allocation of natural gas and removing large quantities of carbon dioxide. In fact, some natural gas deposits are characterized by sufficiently high concentrations of carbon dioxide, which is currently considered as economically irretrievably lost.

Therefore, there is still a need to develop an improved method for converting methane to liquid hydrocarbons, particularly when the methane contained in the natural gas stream, containing large quantities of carbon dioxide.

SUMMARY of the INVENTION

In one respect, this application describes a method for converting methane to heavier hydrocarbons, including:

(a) contacting the starting material containing methane and at least one of the N₂N₂Oh, co and CO₂with catalyst dehydrocyclization under conditions effective to convert the mentioned methane to aromatic hydrocarbons, including benzene and/or naphthalene, and the receipt of the first exhaust stream, is with aromatic hydrocarbons and hydrogen, where mentioned, the first exhaust stream comprises at least 5 wt.% aromatic hydrocarbons is greater than the source material, and

(b) communicating at least part of the aforementioned aromatic hydrocarbons of the above-mentioned first exhaust stream with hydrogen to obtain a second exhaust stream having a reduced content of benzene and/or naphthalene in comparison with the first-mentioned exhaust stream.

In a suitable embodiment, the aforementioned source material in (a) contains less than 5 wt.% hydrocarbons With₃+. Used in the present description the term "hydrocarbons₃+” means hydrocarbons containing 4 or more carbon atoms.

In a suitable embodiment, the above-mentioned conditions (a) are non-oxidizing conditions. The term "non-oxidizing" indicate that oxidants (such as O₂, NO_xand metal oxides, which are capable of releasing oxygen for the oxidation of methane in CO_x) are contained in concentrations below 5%, preferably below 1%, most preferably below 0.1%, the amount required for stoichiometric oxidation of methane.

Typically, the above-mentioned conditions (a) include a temperature of from 400 to 1200°C., in particular from 500 to 975°C., for example from 600 to 950°C.

In a suitable embodiment, the above-mentioned interaction (b) preframe is at least part of the benzene and/or naphthalene in said first exhaust stream into one or more of cyclohexane, cyclohexene, dihydronaphthalene (benzylchloride), tetrahydronaphthalene (tetralin), hexahydronaphthalen (dicyclohexano), octahydronaphthalene and decahydronaphthalene (decalin).

In a suitable embodiment, when the above-mentioned interaction (b) at least a portion of the naphthalene in the above-mentioned first exhaust stream is subjected to hydrogenation and hydrocracking with getting alkyl monocyclic aromatic materials such as benzene, xylenes, cumene, trimethylbenzene, butylbenzoyl, diethylbenzene, methylethylbenzene and other typical isomers.

In one embodiment, when the above-mentioned interaction (b) at least part of the benzene and/or naphthalene in said first waste stream is subjected to hydrocracking to normal and/or isoparaffins.

In a suitable embodiment, at least part of the benzene and/or naphthalene in said first exhaust flow can participate in further reactions with cyclohexanol successfully get mentioned reaction (b), before the formation respectively of cyclohexylbenzene and/or cyclohexylaniline.

In a suitable embodiment, the method also includes the selection of the above-mentioned first exhaust stream from at least one aromatic hydrocarbons, typically benzene and/or naphthalene. Before or after the above allocation of aromatic compounds in the above paragraph is ditch the exhaust stream can be alkylated with alkylating agent. In one embodiment, the alkylating agent is an ethylene obtained by the above-mentioned contacting (a). In another embodiment, the alkylating agent comprises carbon monoxide and hydrogen, or the product of their interaction, where the carbon monoxide receive as a result of these interactions (b).

In another respect, this application describes a method for converting methane to heavier hydrocarbons, including:

(a) contacting the starting material containing methane and CO, and/or CO₂with catalyst dehydrocyclization in a non-oxidizing conditions effective to convert the mentioned methane to aromatic hydrocarbons, including benzene and/or naphthalene, and the formation of the first exhaust stream comprising aromatic hydrocarbons and hydrogen, where the first mentioned exhaust stream comprises at least 5 wt.% aromatic hydrocarbons is greater than said source material;

(b) communicating at least part of the aforementioned aromatic hydrocarbons of the above-mentioned first exhaust stream with at least part of the hydrogen from the first mentioned exhaust stream to obtain a second exhaust stream having a reduced content of benzene and/or naphthalene in comparison with the first-mentioned exhaust flow;

(C) interaction at measures which part of the hydrogen from the mentioned second exhaust stream oxygen-containing materials with obtaining third exhaust stream, comprising water and a hydrocarbon, and

(g) returning at least part of the hydrocarbon in said third exhaust stream to the said contacting (a).

It must be borne in mind that in the present description refer to the first exhaust stream comprising at least 5 wt.% aromatic rings more than the source material, should be taken as meaning that the total number of aromatic rings in the first exhaust flow must exceed the total number of aromatic rings in the source material by at least 5 wt.%. For example, if the source material contains 1 wt.% aromatic rings, the first exhaust stream typically contains at least 6 wt.% aromatic rings. Changes among the substituents on any of the aromatic rings in the transition from the source material to the first exhaust stream these calculations are not covered.

BRIEF DESCRIPTION of DRAWINGS

Figure 1 presents the block diagram of the method of conversion of methane to heavier hydrocarbons in accordance with the first example according to the invention.

Figure 2 presents the block diagram of the method of conversion of methane to heavier hydrocarbons in accordance with the second example according to the invention.

Figure 3 presents the block diagram of the method of conversion of methane in the more high molecular weight hydrocarbons in accordance with the fourth example according to the invention.

DETAILED DESCRIPTION of embodiments of the INVENTION

This application describes a method of converting methane to liquid hydrocarbons processing of raw material containing methane, as a rule, together with at least one of the N₂N₂Oh, co and CO₂at the stage of dehydrocyclization under conditions effective to convert the methane to aromatic hydrocarbons and the formation of the first exhaust stream comprising aromatic hydrocarbons and hydrogen, where the first exhaust stream comprises at least 5 wt.% aromatic hydrocarbons larger than the source material.

Then the first waste stream is processed at the stage of hydrogenation, in which at least part of the benzene or naphthalene mentioned first exhaust flow interacts with hydrogen, preferably at least part of the hydrogen from the first mentioned exhaust flow, with the formation of the second exhaust stream having a reduced content of the benzene or naphthalene in comparison with the first exhaust flow. From the second exhaust flow allocate at least one liquid hydrocarbon fraction, in particular cyclohexane, cyclohexene, dihydronaphthalene (benzylchloride), tetrahydronaphthalene (tetralin), hexahydronaphthalen (DICYCLOHEXYL), octahydronaphthalene or decahydronaphthalene (akalin). If necessary, before or after hydrogenation of one or more fractions of aromatic hydrocarbons the first exhaust stream may be subjected to processing at the stage of alkylation of aromatic compounds.

Source material

In the method according to the invention can use any metadatabase source material, but in General the proposed method is provided for use with a source of natural gas. Other acceptable metastorage source materials include those derived from such sources as coal seams, disposal of waste, fermentation of agricultural or municipal waste and/or gas flows downstream.

Metastorage source materials, such as natural gas, usually contain, in addition to methane, carbon dioxide and ethane. Ethane and other aliphatic hydrocarbons which may be contained in the original material on stage dehydrocyclization can be, of course, turned into a target of aromatic products. In addition, as discussed below, carbon dioxide can be converted into useful aromatic products either directly on the stage of dehydrocyclization or indirectly, by conversion to methane and/or other hydrocarbons at a stage of reduction of hydrogen content.

Before applying monstergame flows in the method according to the invention, the nitrogen and/or sulfur-containing impurities, also, as a rule, are found in these streams, in the preferred embodiment, is removed or their number can be reduced to low concentrations. Usually the source material supplied to the stage of dehydrocyclization, contains less than 100 ppm million, for example less than 10 ppm million, in particular less than 1 ppm million, each of nitrogen and sulphur compounds.

In addition to methane, with the aim of helping to reduce coke formation in the source material supplied to the stage of dehydrocyclization, you can add at least one of hydrogen, water, carbon monoxide and carbon dioxide. These additives can be incorporated in a separate jointly supplied raw materials or may be present in the methane stream, for example, such as when the methane flow derivateservlet from natural gas, including carbon dioxide. Other sources of carbon dioxide include exhaust gases, LPG plant, hydrogen unit, ammonia plant, picoline installation and paleoamerican installation.

In one embodiment, the source material supplied to the stage of dehydrocyclization contains carbon dioxide and comprises from 90 to 99.9 mol.%, in particular, from 97 to 99 mol.%, methane and 0.1 to 10 mol.%, in particular from 1 to 3 mol.%, CO₂. In another embodiment, the source material supplied to the stage of dehydrocyclization, keep the carbon monoxide and includes from 80 to 99.9 mol.%, in particular, from 94 to 99 mol.%, methane and 0.1 to 20 mol.%, in particular from 1 to 6 mol.%, WITH. In the third embodiment, the source material supplied to the stage of dehydrocyclization contains water vapor and contains from 90 to 99.9 mol.%, in particular, from 97 to 99 mol.%, methane and 0.1 to 10 mol.%, in particular from 1 to 5 mol.%, water vapour. In the fourth embodiment, the source material supplied to the stage of dehydrocyclization, contains hydrogen and includes from 80 to 99.9 mol.% hydrocarbons, in particular from 95 to 99 mol.%, methane and 0.1 to 20 mol.%, in particular from 1 to 5 mol.%, of hydrogen.

The source material supplied to the stage of dehydrocyclization may also include heavier hydrocarbons than methane, including aromatic hydrocarbons. Such heavier hydrocarbons can be added as a separate jointly supplied raw materials or may be present in the methane stream, such as, for example, in the case when the source of natural gas contains ethane. However, usually the source material supplied to the stage of dehydrocyclization, contains less than 5 wt.%, in particular less than 3 wt.%, hydrocarbons With₃+.

Dehydrocyclization

At the stage of dehydrocyclization proposed method metadatabase source material is introduced into contact with the catalyst dehydrocyclization, usually in a non-oxidizing conditions, and predpochtitel is about reducing conditions, effective for the conversion of methane to heavier hydrocarbons, including benzene and naphthalene. In principle, carry out the following net reaction:

Monoxide and/or carbon dioxide which may be present in the source material, increases the activity and stability of catalyst for promoting reaction processes, such as:

but negatively affects the balance, enabling the flow parallel to the resulting reaction such as:

.

In the method according to the invention can be any catalyst dehydrocyclization, effective for the conversion of methane into aromatic compounds, although typically, the catalyst includes a metal component, in particular a transition metal or its compound on an inorganic carrier. In a suitable embodiment, a metal component is contained in a quantity ranging from 0.1 to 20 wt.%, in particular in the range from 1 to 10 wt.%, in terms of the weight of the catalyst.

Acceptable to the catalyst metal components include calcium, magnesium, barium, yttrium, lanthanum, scandium, cerium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, rhenium, iron, ruthenium, cobalt, rhodium, ride, Nickel, palladium, copper, silver, gold, zinc, aluminum, gallium, silicon, germanium, indium, tin, lead, bismuth and transuranic metals. These metal components may be contained in the form of free elements or compounds of metals, such as oxides, carbides, nitrides and/or phosphides, and they can be used independently or in combination. As one of the metal components can also be used platinum and osmium, but they are usually not preferred.

The inorganic carrier may be either amorphous or crystalline and, in particular, can be an oxide, carbide or nitride of boron, aluminum, silicon, phosphorus, titanium, scandium, chromium, vanadium, magnesium, manganese, iron, zinc, gallium, germanium, yttrium, zirconium, niobium, molybdenum, indium, tin, barium, lanthanum, hafnium, cerium, tantalum, tungsten or other transuranic elements. In addition, the carrier may be a porous material, such as microporous crystalline material and mesoporous material. Acceptable microporous crystalline materials include silicates, aluminosilicates, titanosilicates, alumophosphate, metallophosphates, kriminaalreformi and mixtures thereof. Such microporous crystalline materials include materials having armatures types MFI (for example, ZSM-5 and silicalite), MEL (for example, ZSM-11), MTW (EmOC is emer, ZSM-12), TON (for example, ZSM-22), MTT (e.g., ZSM-23), FER (for example, ZSM-35), MFS (for example, ZSM-57), MWW (e.g., MCM-22, PSH-3, SSZ-25, ERB-1, ITQ-1, ITQ-2, MCM-36, MCM-49 and MCM-56), IWR (for example, ITQ-24), KFI (for example, ZK-5), WEAH (for example, beta-zeolite), ITH (for example, ITQ-13), MOR (e.g., mordenite), FAU (for example, zeolites X, Y, ultrastabilized Y and dealuminated Y), LTL (for example, zeolite L), IWW (for example, ITQ-22), VFI (for example, VPI-5), AEL (for example, SAPO-11), AFI (e.g., ALPO-5) and AFO (SAPO-41), as well as materials such as MSM-68, EMM-1, EMM-2, ITQ-23, ITQ-24, ITQ-25, ITQ-26, ETS-2, ETS-10, SAPO-17, SAPO-34 and SAPO-35. Acceptable mesoporous materials include MCM-41, MCM-48, MCM-50 and SBA-15.

Examples of preferred catalysts include molybdenum, tungsten, rhenium and compounds and combinations on ZSM-5, silica or aluminum oxide.

The metal component may be dispersed on an inorganic carrier by any means well known in the art, such as coprecipitation, impregnation to the initial humidity, evaporation, conventional impregnation, spray drying, Sol-gel, ion exchange, chemical vapor deposition, diffusion, and physical mixing. In addition, the inorganic carrier may be modified by known methods such as, for example, treatment with water vapor, acid washing, washing with caustic soda and/or processing of silicon-containing compounds, phosphorus is terashima compounds and/or elements or compounds of elements of groups 1, 2, 3 and 13 of the Periodic table of elements. Such modifications can be used to change the surface activity of the media and obstacles or improve access to any internal porous structure of the media.

Stage dehydrocyclization can be implemented in a wide range of conditions, including a temperature of from 400 to 1200°C., in particular from 500 to 975°C., for example from 600 to 950°C, a pressure from 1 to 1000 kPa, in particular from 10 to 500 kPa, for example from 50 to 200 kPa, and the average hourly feed rate from 0.01 to 1000 h^-1in particular from 0.1 to 500 h^-1for example from 1 to 20 h^-1. In a suitable embodiment, the stage of dehydrocyclization carried out in the absence of O₂.

Stage dehydrocyclization can be carried out in reactors with one or more fixed bed, moving layers or fluid layers with regenerierung catalyst, carried out in-situ or ex-situ air, oxygen, carbon dioxide, carbon monoxide, water, hydrogen, or their combinations.

The reaction dehydrocyclization is endothermic, and therefore, when this reaction is carried out in several stages, to revert to the original material to the desired reaction temperature may be necessary to use miladinova heating. The fuel required to ensure mistakenly heating may be the success obtained by removing and burning of run-off flow of exhaust from dehydrocyclization stream after separation of the aromatic components. In addition, when the reaction proceeds in the presence of rolling catalyst layer, part or all of the heat can be provided by removing from the layer side of the catalyst by heating the catalyst by, for example, the combustion of coke on the catalyst and then returning the heated catalyst in moving the catalytic layer.

The main components of the waste from the stage of dehydrocyclization flow are hydrogen, benzene, naphthalene, carbon monoxide, ethylene and unreacted methane. This waste stream typically comprises at least 5 wt.%, in particular at least 10 wt.%, for example at least 20 wt.%, aromatic hydrocarbons larger than the source material.

Selection/processing of aromatic products

Benzene and naphthalene can be separated from the waste from dehydrocyclization flow, usually by solvent extraction and subsequent separation into fractions, and then delivered for sale directly as chemical products of mass production. In addition, before or after separation of the waste from dehydrocyclization flow a certain amount or all of the benzene and/or naphthalene can be alkylated with obtaining, for example, toluene, xylenes and alkylnaphthalenes. However, in accordance with the invention at least part of the aromatic components of exhaust from de is eroticization stream is subjected to hydrogenation to yield useful liquid products, such as cyclohexane, cyclohexene, dihydronaphthalene (benzylchloride), tetrahydronaphthalene (tetralin), hexahydronaphthalen (DICYCLOHEXYL), octahydronaphthalene and/or decahydronaphthalene (decalin). These products can be used as fuels and chemical intermediates, and in the case of tetralin and decalin these can be used as solvent for the extraction of waste from dehydrocyclization flow of aromatic components.

When the process of dehydrocyclization carried out in remote regions, hydrogenation of aromatic components can also be used as an effective method of translating a certain number of hydrogen as a side product in liquid form, namely in the liquid products of the process of hydrogenation, to facilitate the transportation of hydrogen in the region in which it usually has a higher value. In this case, after the transportation of the liquid product may be economically viable re-conversion of liquid product again in the original aromatic components and hydrogen.

Hydrogenation of aromatic compounds

In a suitable embodiment, at least part of the benzene and/or naphthalene reacts with hydrogen from the first exhaust stream to form one or more of cyclohexane, cyclohexene is, dihydronaphthalene (benzylchloride), tetrahydronaphthalene (tetralin), hexahydronaphthalen (dicyclohexano), octahydronaphthalene and decahydronaphthalene (decalin). Illustrative reactions are reactions get cyclohexene as follows:

With₆H₆+2H₂→₆H₁₀;

get dihydronaphthalene as follows:

With₁₀H₈+H₂→₁₀H₁₀;

receiving tetrahydronaphthalene as follows:

C₁₀H₈+2H₂→C₁₀H₁₂;

get hexahydronaphthalen as follows:

C₁₀H₈+3H₂→₁₀H₁₄and

get decahydronaphthalene as follows:

With₁₀H₈+5H₂→₁₀H₁₈.

Part of naphthalene may also be subjected to hydrogenation in the one ring followed by hydrocracking of the ring to produce different alkyl monocyclic aromatic materials such as benzene, xylenes, cumene, trimethylbenzene, butylbenzoyl, diethylbenzene, methylethylbenzene and other typical isomers. Although, as a rule, less valuable, benzene and/or naphthalene can be hydrocracked to the distribution of carbon numbers and normal isomers and isoparaffins.

In a suitable embodiment, at least part of the benzene and/or naphthalene can do is to actavate further reaction with received cyclohexanol education respectively cyclohexylbenzene or cyclohexylaniline.

There are several main reasons why it is advisable to carry out the hydrogenation of the benzene and naphthalene: combustion of part of the simultaneous hydrogen reduces the need for other methods of hydrogen - far neskazanny the hydrogen is transformed into chemically linked transported hydrogen;

fuels with higher hydrogen content is preferred because of possible reduced emissions of CO₂the energy component;

get fuel with very low sulfur content, both for consumers and for use in fuel cells, in which sulfur is especially harmful;

The benzene is converted into a material with:

reduced problems for human health and the environment

cyclohexane has a high value as a starting material for polymers

cyclohexen can be used directly as a monomer for polymer products, or it can be easily introduced into the reaction with the obtaining of materials such as cyclohexanone and cyclohexanol

Naphthalene is converted into a material with:

reduced problems for human health and the environment

with the exception of the possibility of curing at room temperature

cyclohexane has a high value as source material for the teaching of polymers

dihydronaphthalene (benzylchloride), hexahydronaphthalen (DICYCLOHEXYL), octahydronaphthalene can be used directly as a monomer for polymer products, or they can be easily introduced into the reaction with the receipt of such materials, as benzylchloride and dicyclohexano

decalin may have a high value as a fuel for jet engines, in particular as a fuel of high density for military aircraft, hydrocracked for the distribution of carbon numbers and normal isomers and isoparaffins can produce diesel fuel and fuel for jet engines with low aromatic content and low sulfur content by hydrogenation of one ring followed by hydrocracking of the ring to produce different alkyl monocyclic aromatic materials such as benzene, xylenes, cumene, trimethylbenzene, butylbenzoyl, diethylbenzene, methylethylbenzene and other typical isomers, receive a stream of products that can be used for the recovery of chemicals or high octane and low sulfur fuel for internal combustion engines.

The hydrogenation is advisable, but not necessarily, carried out after discharge from the exhaust from dehydrocyclization thread aromatic components is tov and it is advisable to use a portion of the hydrogen, formed by the reaction of dehydrocyclization. If the source material includes nitrogen and/or sulfur-containing impurities, may be necessary in the handling of hydrogen produced by the reaction of dehydrocyclization, to reduce the concentration of sulfur and nitrogen in hydrogen before the hydrogen for hydrogenation of aromatic components from the exhaust of dehydrocyclization flow. You may also need to remove at least part of the unreacted methane and other light hydrocarbons from the stream of hydrogen. The hydrogen content in this stream can also be improved reforming process stream with water vapor before you apply for hydrogenation. The flow of hydrogen after applying for hydrogenation can be enriched With₁-C₅the paraffins that are acceptable for return to the reactor dehydrocyclization.

Acceptable methods of hydrogenation of aromatic compounds in the art is well-known, and they typically use a catalyst comprising Ni, Pd, Pt, Ni/Mo or sulfatirovanne Ni/Mo supported on alumina or silica as the carrier or other inorganic media with high specific surface area. Acceptable to the hydrogenation process operating conditions include a temperature of from 300 to 1000°F (150 to 540°C), in particular the t 500 to 700°F (260 to 370°C), gauge pressure of from 50 to 2000 psig (445 to 13890 kPa), in particular from 100 to 500 psig (790 to 3550 kPa), and JCSS from 0.5 to 50 h^-1in particular from 2 to 10 h^-1.

In order to obtain materials that are acceptable for polymerization or other subsequent chemical transformations, it may be also necessary partial hydrogenation in order to leave the product one or more olefinic carbon-carbon bonds. Acceptable forms of partial hydrogenation in the art is well-known, and they typically use a catalyst comprising noble metals, and ruthenium in the preferred embodiment, is applied to the metal oxides, such as La₂O₃/ZnO. Can also be used homogeneous catalytic systems with noble metals. Examples of how partial hydrogenation described in patents US№№4678861, 4734536, 5457251, 5656761, 5969202 and 5973218, the contents of which in full is included in the present description as a reference.

An alternative method of hydrogenation involves hydrocracking naphthalene component with getting alkyl benzenes over this catalyst, as sulfatirovanne Ni/W or sulpicianus Ni deposited on amorphous aluminosilicate or zeolite, such as zeolite X, zeolite Y, beta zeolite, or other inorganic media with you the Oka specific surface area. Acceptable for hydrocracking low-pressure operating conditions include a temperature of from 300 to 1000°F (150 to 540°C), in particular from 500 to 700°F (260 to 370°C)gauge pressure of from 50 to 2000 psig (445 to 13890 kPa), in particular from 100 to 500 psig (790 to 3550 kPa), and JCSS from 0.5 to 50 h^-1in particular from 2 to 10 h^-1.

An alternative method of hydrogenation involves hydrocracking of the benzene or naphthalene component with obtaining a normal or branched paraffins over the catalyst as the metal of group VIII, preferably Pt and Ir deposited on amorphous aluminosilicate or zeolite, such as zeolite X, zeolite Y, beta zeolite, or other inorganic media with high specific surface area. Acceptable for hydrocracking low-pressure operating conditions include a temperature of from 300 to 1000°F (150 to 540°C), in particular from 500 to 700°F (260 to 370°C)gauge pressure of from 50 to 2000 psig (445 to 13890 kPa), in particular from 100 to 500 psig (790 to 3550 kPa), and JCSS from 0.5 to 50 h^-1in particular from 2 to 10 h^-1.

Alkylation of aromatic compounds

Alkylation of aromatic compounds such as benzene and naphthalene, in the art are well known and generally involves the reaction of an olefin, alcohol or alkylhalogenide with aromatic mothers who Lamy in gaseous or liquid phase in the presence of an acid catalyst. Acceptable acid catalysts include zeolites with medium-sized pores (i.e. those who have a limiting rate from 2 to 12, as defined in US no 4016218), including materials, with frames types MFI (for example, ZSM-5 and silicalite), MEL (for example, ZSM-11), MTW (for example, ZSM-12), TON (for example, ZSM-22), MTT (e.g., ZSM-23), MFS (for example, ZSM-57) and FER (for example, ZSM-35), and ZSM-48, and zeolites with larger pores (i.e. those who have a limiting indicator is less than 2), such as materials, with frames types WEAH (for example, beta-zeolite), FAU (for example, ZSM-3, ZSM-20, zeolite X, Y, ultrastabilized Y and dealuminated Y), MOR (e.g., mordenite), MAZ (for example, ZSM-4), MEI (for example, ZSM-18) and MWW (e.g., MCM-22, PSH-3, SSZ-25, ERB-1, ITQ-1, ITQ-2, MCM-36, MCM-49 and MCM-56).

In one embodiment, the proposed method benzene is recovered from the exhaust of dehydrocyclization thread and then alkylate the olefin, such as ethylene, obtained as a by-product at the stage of reduction of hydrogen content using tonirovania/mahanirvana. Typical conditions for vapor-phase alkylation of benzene with ethylene include a temperature of from 650 to 900°F (343 to 482°C)gauge pressure from atmospheric to 3000 psig (100 to 20800 kPa), JCSS in terms of ethylene and from 0.5 to 2.0 h^-1and the molar ratio of benzene to ethylene from 1/1 to 30/1. Liquid-phase alkali the Finance of benzene with ethylene can be carried out at a temperature in the range from 300 to 650°F (150 to 340°C), under a gauge pressure of up to about 3000 psig (20800 kPa), when JCSS in terms of ethylene, from 0.1 to 20 h^-1and a molar ratio of benzene to ethylene from 1/1 to 30/1.

In a preferred embodiment, atilirovanie benzene is carried out in conditions at least partially liquid phase using a catalyst comprising at least one beta zeolite, zeolite Y, MCM-22, PSH-3, SSZ-25, ERB-1, ITQ-1, ITQ-2, ITQ-13, ZSM-5, MCM-36, MCM-49 and MCM-56.

Atilirovanie benzene can be carried out at the place of the process of dehydrocyclization/reduction of hydrogen content or benzene can be transported to another region to become ethylbenzene. Then the resulting ethylbenzene can be supplied for sale, used as a precursor, for example, upon receipt of styrene, or Samaritan by methods well known in the art, in mixed xylenes.

In another embodiment of the proposed method alkylating agent is a methanol or dimethyl ether (DME), it is used for the alkylation of benzene and/or naphthalene, emitted from the exhaust of dehydrocyclization flow, obtaining toluene, xylenes, methylnaphthalene and/or dimethylnaphthalene. When methanol or dimethyl ether is used for the alkylation of benzene, in a useful embodiment, this is carried out in the presence of a catalyst comprising a zeolite with rednie pores, such as ZSM-5, beta-zeolite, ITQ-13, MCM-22, MCM-49, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35 and ZSM-48, which is pre-modified by treatment with water vapor so that he had a diffusion parameter for 2,2-Dimethylbutane from about 0.1 to 15^-1when it is determined at a temperature of 120°C and a pressure of 2.2-Dimethylbutane 60 Torr (8 kPa). This method is selective in obtaining para-xylene, he stated, for example, in US patent No. 6504272 included in the present description by reference. When methanol is used for the alkylation of naphthalene, in a useful embodiment, this is carried out in the presence of a catalyst comprising ZSM-5, MCM-22, PSH-3, SSZ-25, ERB-1, ITQ-1, ITQ-2, ITQ-13, MCM-36, MCM-49 or MCM-56. This method can be applied for selective receipt of 2,6 - dimethylnaphthalene, he stated, for example, in US patents No. 4795847 and 5001295 included in this description as a reference.

When the method according to the invention as alkylating agent use methanol or DME, it can enter into the process as a separate source material or it may be at least partially received in situ by adding containing carbon dioxide gaseous source material, such as a natural gas stream, in part or whole exhaust from the stage of dehydrocyclization stream. Thus, in particular, the exhaust from dehydrocyclization stream before or after the ejecta is aromatic components can be sent back into the reactor conversion and to carry out the reaction containing carbon dioxide source material in terms of increasing the content of carbon monoxide in the exhaust stream, i.e. such reactions as the reaction of 5 and the following reaction is reversed conversion of water gas:

In addition, the reactor inverse conversion can be sent methane and CO₂and/or water vapor to obtain synthesis gas, which can then be mixed with a part of the exhaust from dehydrocyclization flow to regulate the ratio of N₂/CO/CO₂depending on the needs for phase alkylation.

Typically, the reactor inverse conversion contains a catalyst comprising a transition metal on a carrier, such as Fe, Ni, Cr, Zn and si aluminum oxide, silicon dioxide or titanium dioxide, and working conditions including a temperature of from 500 to 1200°C., in particular from 600 to 1000°C., for example from 700 to 950°C and a pressure of from 1 to 10000 kPa, in particular from 2000 to 10000 kPa, for example from 3000 to 5000 kPa. Average hourly rate of gas flow can be varied depending on the type of way, but usually hourly average gas flow rate in the gas flow through the catalytic layer is in the range from 50 to 50000 h^-1in particular from 250 to 25000 h^-1, more preferably from 500 to 10000 h^-1.

Then the exhaust from the reactor inverse conversion of the flow can be directed to the alkylation reactor operating under conditions ensuring the reactions as the following:

Acceptable for such a reactor alkylation conditions include, apparently, a temperature of from 100 to 700°C., a pressure of from 1 to 300 at (from 100 to 30,000 kPa) and JCSS for aromatic hydrocarbons from 0.01 to 100 h^-1. Acceptable catalyst includes, apparently, molecular sieve, with the limiting rate from 1 to 12, such as ZSM-5, usually together with one of the metals or oxides of metals such as copper, chromium and/or zinc oxide.

When in the preferred embodiment, the alkylation catalyst comprises a molecular sieve, this is the last change to change its diffusion characteristics so that the predominant isomer of xylene obtained by reaction 11 was para-xylene. Acceptable means of diffusion modification includes the deposition of ex-situ or in-situ coke, silicon, metal oxide on the surface or at the entrances to the pores of the molecular sieve. Preferably also the fact that the active metal is introduced into the molecular sieve thus, to ensure saturation of the more highly reactive materials such as olefins, which may be formed as by-products and which otherwise would cause deactivation of the catalyst.

Then the exhaust from the reactor alkylation stream could b the guide section division in which aromatic products were first separated from the hydrogen and other low molecular weight materials, suitable extraction solvent. Further aromatic products can be divided into a benzene fraction, a toluene fraction, With₈fraction and a heavy fraction comprising naphthalene and alkylated naphthalenes. Then scented With₈the fraction could be directed to the process of crystallization or adsorption to separate valuable p-xylene component, and the remaining mixed xylenes or delivered for sale as a product, or directed into a path of isomerization for an additional amount of p-xylene. Toluene fraction could be either removed as finding the marketing of the product, or returned to the alkylation reactor or directed in the installation of the disproportionation of toluene, and preferably in the installation of selective disproportionation of toluene to obtain an additional amount of p-xylene.

The reduction of hydrogen content

Hydrogen is a major component of the waste from dehydrocyclization flow, and, although part of the hydrogen used in the hydrogenation of aromatics and possibly an optional stage of alkylation, the waste stream is subjected to processing at a stage of reduction of hydrogen content in order to lower nigerianisation in the exhaust stream before returning unreacted methane on stage dehydrocyclization and maximize the utilization of the source material. Stage reduction of hydrogen content, as a rule, involves the reaction of at least part of the hydrogen in the exhaust from dehydrocyclization the flow of oxygen-containing materials to produce water and a second exhaust stream having a lower content of hydrogen in comparison with the first exhaust (from dehydrocyclization) thread.

In a suitable embodiment, the stage of reduction of hydrogen content includes (I) mahanirvana and/or tonirovanie, (II) the Fischer-Tropsch process, (III) synthesis of alcohols from C₁With₃in particular methanol and other oxygenates, (IV) synthesis of light olefins by means of methanol or dimethyl ether as an intermediate product and/or (V) selective combustion of hydrogen. For best performance, these stages can be performed sequentially; for example, initially, there may be performed the Fischer-Tropsch process of obtaining enriched With₂+ stream with subsequent mahanirvana to achieve a high degree of conversion of N₂.

Mahanirvana/tonirovanie

In one embodiment, the stage of reducing the content of hydrogen involves the reaction of at least part of the hydrogen in the exhaust from dehydrocyclization stream with carbon dioxide to obtain methane and/or ethane in accordance with the following reactions result:

In an expedient variant used carbon dioxide is part of the natural gas stream, and preferably of the same stream of natural gas, which is used as the source material supplied to the stage of dehydrocyclization. When carbon dioxide is part metadatareader flow, CO₂/CH₄this thread in the appropriate variant retain in the range from 1/1 to 0.1/1. A mixture containing carbon dioxide stream and the exhaust from dehydrocyclization thread in the appropriate option to achieve the gaseous source materials into the inlet fixture jet pump.

At a stage of reduction of hydrogen content with the capture of methane or ethane, as a rule, use the molar ratio of N₂/CO₂close to the stoichiometric proportions required for the target reaction 10 or reactions 11, though, if you want to get containing CO₂or containing H₂the second exhaust stream, the stoichiometric ratio can be made small changes. Stage reduction of hydrogen content with the capture of methane or ethane in an expedient embodiment is carried out in the presence of a bifunctional catalyst comprising a metal component, in particular a transition metal or its compound on an inorganic carrier. Acceptable metal is omponent include copper, iron, vanadium, chromium, zinc, gallium, Nickel, cobalt, molybdenum, ruthenium, rhodium, palladium, silver, rhenium, tungsten, iridium, platinum, gold, gallium and combinations thereof, and connections. The inorganic carrier may be an amorphous material such as silicon dioxide, aluminum oxide and silicon dioxide/aluminum oxide or similar to those listed for catalyst dehydroaromatization. In addition, the inorganic carrier may be a crystalline material, such as microporous or mesoporous crystalline material. Acceptable porous crystalline materials include silicates, alumophosphate and kriminaalreformi listed above for catalyst dehydrocyclization.

Stage reduction of hydrogen content with the capture of methane and/or ethane can be implemented in a wide range of conditions, including a temperature of from 100 to 900°C., in particular from 150 to 500°C., for example from 200 to 400°C., a pressure of from 200 to 20,000 kPa, in particular from 500 to 5000 kPa, and the average hourly feed rate of 0.1 to 10000 h^-1in particular from 1 to 1000 h^-1. The values of the degree of conversion of CO₂as a rule, are in the range from 20 to 100%, and more preferably 90%, in particular more than 99%. This exothermic reaction can be conducted in many catalytic layers of heat between the layers. In addition, in order to cabinetvision kinetic speed, the process in the front layer (layers) can be performed at higher temperatures, and in order to maximize thermodynamic transformation in the last layer (layers) it can be done at lower temperatures.

The main products of the reaction are water and, depending on the molar ratio of H₂/CO₂, methane, ethane and heavier alkanes together with some unsaturated C₂- and heavier hydrocarbons. In addition, some preferred partial hydrogenation of carbon dioxide to carbon monoxide. After removal of water, methane, carbon monoxide, all unreacted carbon dioxide and heavier hydrocarbons can be sent directly to the stage of dehydrocyclization for more aromatic products.

The process of Fischer-Tropsch

In another embodiment, the stage of reducing the content of hydrogen involves the reaction of at least part of the hydrogen in the exhaust from dehydrocyclization stream with carbon monoxide in accordance with the Fischer-Tropsch process of obtaining paraffins and olefins with₂C₅.

the Fischer-Tropsch process in this area is well known in the art (see, for example, US patents No. 5348982 and 5545674 included in this description as references). This process, usually including the AET reaction of hydrogen and carbon monoxide in a molar ratio of from 0.5/1 to 4/1, preferably from 1.5/1 to 2.5/1, at a temperature of from 175 to 400°C., preferably from 180 to 240°C and a pressure of from 1 to 100 bar (100 to 10,000 kPa), preferably from 10 to 40 bar (1000 to 4000 kPa), in the presence of a catalyst Fischer-Tropsch process, usually applied or not applied to the bearer of the element of group VIII base metal such as Fe, Ni, Ru, Co, promoter or without it, for example ruthenium, rhenium, hafnium, zirconium, titanium. The media, when used, can serve as refractory metal oxides, such as group IVB, i.e. titanium dioxide, zirconium dioxide or silicon dioxide, aluminum oxide or silicon dioxide/aluminum oxide. In one embodiment, the catalyst includes non-conversion catalyst, such as cobalt or ruthenium, preferably cobalt, rhenium or zirconium as a promoter, preferably cobalt, and rhenium deposited on a silicon dioxide or titanium dioxide, preferably titanium dioxide.

In another embodiment, the catalyst for synthesis of hydrocarbons includes a metal such as si, Cu/Zn and Cr/Zn, ZSM-5, and the process is carried out to obtain significant quantities of monocyclic aromatic hydrocarbons. An example of such a process is described in the work of Jose Erena Study of Physical Mixtures of Cr₂O₃-ZnO and ZSM-5 Catalysts for the Transformation of Syngas into Liquid Hydrocarbons; Ind.Eng.Chem.Res. 1998, 37, 1211-1219 included in this description as with Alki.

Emit liquid Fischer-Tropsch process, i.e. With₅+and heavier hydrocarbons to separate light gases such as unreacted hydrogen and CO, C₁With₃or₄and the water. Then heavier hydrocarbons can be selected as products or aimed at the stage of dehydrocyclization for more aromatic products.

The presence of carbon monoxide required for the reaction of the Fischer-Tropsch process may be fully or partially achieved with existing or supplied together with matenadarani source material and obtained as a by-product at the stage of dehydrocyclization the carbon monoxide. If necessary, additional carbon monoxide can be generated by supplying carbon dioxide is contained, for example, in natural gas, in the reaction of the Fischer-Tropsch process, allowing carbon dioxide into carbon monoxide reverse reaction is the conversion of water gas.

Synthesis of alcohols

In yet another embodiment, the stage of reducing the content of hydrogen involves the reaction of at least part of the hydrogen in the exhaust from dehydrocyclization stream with carbon monoxide to obtain alcohols with C₁With₃in particular methanol. Obtaining methanol and other oxygenates from synthesis gas is well known and shown, for example, in atento US No. 6114279, 6054497, 5767039, 5045520, 5254520, 5610202, 4666945, 4455394, 4565803, 5385949, descriptions which are included in the present description as a reference. Used synthesis gas typically has a molar ratio of hydrogen (H₂) to oxides of carbon (CO+CO₂) in the range of from 0.5/1 to 20/1, preferably in the range of from 2/1 to 10/1, and carbon dioxide is not necessarily contained in an amount of not more than 50 wt.% in terms of the total weight of the synthesis gas.

The catalyst used in the methanol synthesis process typically includes the oxide of at least one element selected from the group comprising copper, silver, zinc, boron, magnesium, aluminum, vanadium, chromium, manganese, gallium, palladium, osmium and zirconium. In a suitable embodiment, the catalyst is a catalyst based on copper, in particular in the form of copper oxide, optionally in the presence of oxide of at least one element selected from silver, zinc, boron, magnesium, aluminum, vanadium, chromium, manganese, gallium, palladium, osmium and zirconium. In a suitable embodiment, the catalyst contains copper oxide and an oxide of at least one element selected from zinc, magnesium, aluminum, chromium and zirconium. In one embodiment, the catalyst for methanol synthesis are selected from the group comprising the oxides of copper, oxides of zinc and aluminium oxides. In a more preferred embodiment, the catalyst contains oxides of copper and zinc is.

The process of methanol synthesis can be carried out in a wide range of temperatures and pressures. Acceptable temperature in the range from 150 to 450°C., in particular from 175 to 350°C., for example from 200 to 300°C. Acceptable pressure in the range from 1500 up to 12,500 kPa, in particular from 2000 to 10000 kPa, for example from 2500 to 7500 kPa. Average hourly rate of gas supply vary depending on the type of procedure done, but usually hourly average gas flow rate in the gas flow through the catalytic layer is in the range from 50 to 50000 h^-1in particular from 250 to 25000 h^-1, more preferably from 500 to 10000 h^-1. This exothermic reaction can be carried out either in a fixed or fluid layers, including many catalytic layers with heat between the layers. In addition, in order to maximize the kinetic speed the process in the front layer (layers) can be performed at higher temperatures, and in order to maximize thermodynamic transformation in the last layer (layers) it can be done at lower temperatures.

The resulting methanol and/or other oxygenates may be directed to sell as a standalone product, they can be used for alkylation of aromatic compounds formed at the stage of dehydrocyclization to more Wysokie the different products, such as xylenes, or can be used as source material for more low molecular weight olefins, particularly ethylene and propylene. The conversion of methanol to olefins is a well-known process and is described, for example, in US patent No. 4499327 included in the present description by reference.

Selective combustion of hydrogen

However, in another embodiment, stage reduction of hydrogen content includes selective combustion of hydrogen, which is a process in which hydrogen is mixed stream interacts with oxygen to produce water or water vapor without substantial interaction in the flow of hydrocarbons with oxygen from getting monoxide, carbon dioxide and/or oxygenated hydrocarbons. Usually selective combustion of hydrogen is carried out in the presence of oxygen-containing particulate material, such as a mixed metal oxide, which usually releases a part of the bound oxygen to hydrogen.

One acceptable method of selective combustion of hydrogen is described in US patent No. 5430210 included in this description as a reference, it includes contacting under reaction conditions a first stream comprising hydrocarbons and hydrogen and a second stream comprising oxygen, with separate surfaces of the membrane, cont. niceboy for not containing oxygen gas, where said membrane includes a metal oxide, a selective towards hydrogen burning, and the selection of product selective combustion of hydrogen. This metal oxide, as a rule, is a mixed metal oxide of bismuth, indium, antimony, thallium and/or zinc.

In US patent No. 5527979 included in the present description by reference, describes how clean catalytic oxidative dehydrogenization alkanes with getting alkenes. This method involves the simultaneous equilibrium dehydrogenization alkanes to alkenes and selective burning the resulting hydrogen for carrying out equilibrium reactions dehydrogenization obtaining alkenes. Thus, in particular, alkanoyl source material digitalout over the catalyst equilibrium dehydrogenization in the first reactor, and then the exhaust from the first reactor flow together with oxygen is directed to the second reactor, containing a catalyst of a metal oxide, which is used for catalysis of the selective combustion of hydrogen. The catalyst equilibrium dehydrogenization may include platinum, as a catalyst for the selective combustion of the metal oxide may include bismuth, antimony, indium, zinc, thallium, lead and tellurium or a mixture.

In the application for US patent No. 2004/0152586, published on August 5, 2004 GI included in the present description by reference, describes a method to decrease the value of hydrogen content in the exhaust from the cracking installation thread. In this method using a catalytic system comprising (1) at least one solid acidic cracking component and (2) at least one component of the selective combustion of hydrogen on a metal basis, consisting essentially of (a) combination of metals selected from the group including:

I) at least one metal from group 3, and at least one metal from groups 4 through 15 of the Periodic table of elements;

II) at least one metal from groups 5 to 15 of the Periodic table of elements and at least one metal from at least one of the groups 1, 2 and 4 of the Periodic table of elements;

III) at least one metal from groups 1 and 2, at least one metal from group 3, and at least one metal from groups 4 through 15 of the Periodic table of elements and

IV) two or more metals from groups 4-15 of the Periodic table of elements;

and (b) at least one of oxygen and sulfur, where the at least one of oxygen and sulfur are chemically bound both within and between the metals.

The reaction of the selective combustion of hydrogen according to the present invention is generally carried out at a temperature in the range from 300 to 850°C and under a pressure in the range from 1 to 20 at (from 100 to 2000 kPa).

Further, the invention is more specifically represented with reference to the following examples and accompanying drawings.

PR is measures 1

In the first example according to the invention, which is schematically illustrated in figure 1, the source material 11 including 100 kg of methane sent to the reactor 12 dehydrocyclization, which contains a catalyst comprising 3 wt.% Mo on HZSM-5 (molar ratio of silicon dioxide to aluminum oxide 25), and operates at a temperature of about 800°C, JCSS 1 and under an absolute pressure of 20 psi (138 kPa). The exhaust from the reactor 12 dehydrocyclization stream 13 comprises an aromatic component comprising 10,78 kg of benzene and 2.45 kg naphthalene, and gaseous fuel component, including 79,62 kg of unreacted methane, 4,01 kg of hydrogen and 0.85 kg of ethylene.

The exhaust stream 13 is sent to the first separator 14, where the exhaust stream is separated by suitable extraction solvent, an aromatic component 15 and the fuel gas component 16. Then gaseous fuel component is directed to the second separator 17 where the component 16 is removed stream 18 of hydrogen, including 1.05 kg of hydrogen, to give the fuel gas product 19, including 79,62 kg of unreacted methane, 2,96 kg of hydrogen and 0.85 kg of ethylene. Further, the thread 18 of hydrogen and an aromatic component 15 is directed to the hydrogenation reactor 21 where the aromatic component hydronaut to form a liquid hydrocarbon product 22, which includes 11,6 to the cyclohexane and 2.7 kg of decline.

Liquid hydrocarbon product 22 may be selected for use as, for example, fuel or can be delivered in a more desired region, such as a chemical plant, where the product can be fed into the dehydrogenation reactor 23 for turning and reverse split stream 24 aromatic products, including 10,78 kg of benzene and 2.45 kg of naphthalene, and the thread 25 of hydrogen produced, including 1.05 kg of hydrogen.

Example 2

In the second example according to the invention, schematically illustrated in figure 2, the source material 31 includes, in addition to 100 kg of methane, 114 kg of carbon dioxide, it is initially directed into the reactor 32 mahanirvana, which contains a catalyst of Cu/Zn and operates at a temperature of 300°C, JCSS 1 and under an absolute pressure of 350 psig (2413 kPa). The exhaust from the reactor 32 mahanirvana stream 33 is sent to the condenser 34, where isolated 94 kg of water, and then the remaining waste stream is sent to the reactor 35 dehydrocyclization, which contains a catalyst comprising 3 wt.% Mo on HZSM-5 (molar ratio of silicon dioxide to aluminum oxide 25), and operates at a temperature of about 800°C, JCSS 1 and under an absolute pressure of 20 psi (138 kPa). The exhaust from the reactor 35 dehydrocyclization stream 36 consists of an aromatic component comprising 78.8 kg of benzene and 17.2 kg naphthalene, and t is plungo gaseous component, including unreacted methane, hydrogen and ethylene.

The exhaust stream 36 is sent to the first separator 37, where the exhaust stream is separated by suitable extraction solvent, an aromatic component 38 and light gaseous component 39. Next light gaseous component is directed to the second separator 41, in which the light gaseous component is removed stream 42 of hydrogen, and the balance of light gas return as stream 43 in the reactor 32 mahanirvana. Then, the thread 42 of hydrogen and an aromatic component 38 is directed to the hydrogenation reactor 44, where the aromatic component hydronaut to form a liquid hydrocarbon product 45, including 84,9 kg of cyclohexane and 18.7 kg decline.

As in example 1, the liquid hydrocarbon product 45 can be selected for use as, for example, fuel or can be delivered in a more desired region, such as a chemical plant, where the product can be fed into the dehydrogenation reactor 46 to turn and reverse split stream 47 aromatic products, including 78.8 kg of benzene and 17.2 kg of naphthalene, and the thread 48 of hydrogen generated.

Example 3 (comparative)

In this comparative example, the process of example 2 is repeated, but without hydrogenation of the aromatic component 38 and return to the reactor 32 mahanirvana the entire lung is gazoobraznogo component 39. In this case, using source material including 100 kg of methane and 114 kg of carbon dioxide in the condenser 34 emit 149 kg of water, and an aromatic component 38 includes 93 kg of benzene and 22 kg of naphthalene.

Example 4

In the fourth example according to the invention, schematically illustrated in figure 3, the source material 51 includes 100 kg of methane and 70 kg of carbon dioxide, it is initially directed into the reactor 52 mahanirvana, which contains a catalyst of Cu/Zn and operates at a temperature of 300°C, JCSS 1 and under an absolute pressure of 350 psig (2413 kPa). The exhaust from the reactor 52 mahanirvana stream 53 is sent to the condenser 54, where isolated 57 kg of water, and then the remaining waste stream is sent to the reactor 55 dehydrocyclization, which contains a catalyst comprising 3 wt.% Mo on HZSM-5 (molar ratio of silicon dioxide to aluminum oxide 25), and operates at a temperature of about 800°C, JCSS 1 and under an absolute pressure of 20 psi (138 kPa). The exhaust from the reactor dehydrocyclization stream 56 consists of an aromatic component comprising 69,8 kg of benzene and 15.9 kg naphthalene, and gaseous fuel component comprising unreacted methane, hydrogen and ethylene.

The exhaust stream 56 is sent to the first separator 57, where the waste stream is separated into a stream 58 of the obtained benzene, which is marked, the thread 5 of naphthalene and light gaseous component 61. Then light gaseous component 61 is directed to the second separator 62, where light gaseous component is removed, respectively, the first and second threads 63, 64 of hydrogen, and the balance of light gas return in the form of flow 65 in the reactor 52 mahanirvana. Then the first thread 63 of hydrogen and the flow 59 naphthalene sent to the hydrogenation reactor 66, in which the flow of naphthalene hydronaut with receiving stream 67 tetraline, including 16,4 kg of tetralin. Then the stream 67 tetralin and a second thread 64 of the hydrogen is sent to the installation 68 hydrocracking, in which tetralin subjected to hydrocracking with receiving stream 69 products, including 3.2 kg benzene, 3.8 kg of toluene, 4,4 kg xylenes, 5.5 kg of propane and 11.2 kg of ethane.

Although the present invention is described and illustrated with reference to specific ways of its implementation, for the usual specialists in the art it is obvious that the invention leads to variants that it is not necessary to illustrate in the present description. For this reason, in order to determine the actual scope of the present invention should be handled only by the attached claims.

1. The method of conversion of methane to heavier hydrocarbons, including
(a) contacting the starting material containing methane and at least one of the N₂N ₂Oh, co and CO₂with catalyst dehydrocyclization under conditions effective to convert the mentioned methane to aromatic hydrocarbons, including naphthalene, and receiving the first exhaust stream comprising aromatic hydrocarbons and hydrogen, where the first mentioned exhaust stream comprises at least 5 wt.% aromatic hydrocarbons is greater than said source material;
(b) reaction of at least part of the aforementioned aromatic hydrocarbons of the above-mentioned first exhaust stream with hydrogen to obtain a second exhaust stream having a reduced content of naphthalene comparing with the first-mentioned exhaust stream, in which at least part of naphthalene in said first exhaust flow mentioned reaction hydronaut and hydrocracking obtaining monocyclic alkyl aromatic compounds; and
(C) the reaction of at least part of the hydrogen from the first mentioned exhaust stream with carbon monoxide, carbon dioxide or a mixture of carbon monoxide and carbon dioxide additional waste stream comprising water and a hydrocarbon, and returning at least part of the hydrocarbon in said additional exhaust flow to the said contacting (a).

2. The method according to claim 1, in which at least part of toroda, used in (b), is mentioned first exhaust stream.

3. The method according to claim 1, in which carbon dioxide is used in stage (b) and specified carbon dioxide is introduced into the process as part of the natural gas stream.

4. The method according to claim 3 in which the said natural gas stream also contains at least part of the methane in the source material in (a).

5. The method according to claim 1, in which said additional exhaust stream includes water and methane, ethane or a mixture of methane and ethane.

6. The method according to claim 1, in which carbon monoxide is used in stage (b), and said additional exhaust stream includes one or more of paraffins and olefins with₂C₅, monocyclic aromatic hydrocarbons and alcohols with C₁With₃.

7. The method according to claim 1, in which said reaction of at least part of the hydrogen from the first mentioned exhaust stream with carbon monoxide, carbon dioxide or a mixture of carbon monoxide and carbon dioxide includes selective combustion of hydrogen.

8. The method according to claim 1, in which the mentioned source material in (a) contains less than 5 wt.% hydrocarbons With₃+.

9. The method according to claim 1, in which the above-mentioned conditions (a) are non-oxidizing conditions.

10. The method according to claim 1, in which the above-mentioned conditions (a) include a temperature of from primer the 400 to about 1200°C. the pressure from about 1 to about 1000 kPa and average hourly feed rate from about 0.1 to about 1000 h^-1.

11. The method according to claim 1 in which the said catalyst dehydrocyclization in (a) includes at least one of molybdenum, tungsten, rhenium, molybdenum compounds, compounds of tungsten and compounds of rhenium on ZSM-5, silica or aluminum oxide.

12. The method according to claim 1, wherein in reaction (b) at least a portion of the naphthalene in said first exhaust flow hydrocracking with getting normal and isoparaffins.

13. The method according to claim 1, further comprising an allotment of the said first exhaust flow of at least one aromatic hydrocarbon.

14. The method according to item 13, in which part of the above mentioned first waste stream remaining after the allocation of at least one aromatic hydrocarbons, used as fuel to supply heat mentioned contacting (a).

15. The method according to claim 1, further comprising the alkylation of at least one aromatic hydrocarbon in said first exhaust flow alkylating agent.

16. The method according to item 15, in which the aforementioned alkylating agent comprises ethylene, obtained by the above-mentioned contacting (a).

17. The method according to item 15, in which the aforementioned alkylating agent includes carbon monoxide and water the od or the product of their interaction.

18. The method of conversion of methane to heavier hydrocarbons and hydrogen, including
(a) contacting the starting material containing methane with a catalyst dehydrocyclization in a non-oxidizing conditions effective to convert the mentioned methane to aromatic hydrocarbons, including naphthalene, and receiving the first exhaust stream comprising aromatic hydrocarbons and hydrogen, in which the first mentioned exhaust stream comprises at least 5 wt.% aromatic hydrocarbons is greater than said source material;
(b) reaction of at least part of the aforementioned aromatic hydrocarbons of the above-mentioned first exhaust stream with at least part of the hydrogen from the first mentioned exhaust flow, and the reaction is performed at a first site and get the second exhaust stream having a reduced content of naphthalene comparing with the first-mentioned exhaust flow;
(C) transporting at least part of the mentioned second exhaust stream at a second site, remote from the first section; and
(g) dehydrogenization at least the said second exhaust flow at the above-mentioned second site to produce hydrogen and the third exhaust flow with a high content of naphthalene in than the AI with said second exhaust stream; and
(d) the reaction of at least part of the hydrogen from the first mentioned exhaust stream with carbon monoxide, carbon dioxide or a mixture of carbon monoxide and carbon dioxide additional waste stream comprising water and a hydrocarbon, and returning at least part of the hydrocarbon in said additional exhaust flow to the said contacting (a).

19. The method according to p, in which carbon dioxide is used in stage (d) and the carbon dioxide is introduced into the process as part of the natural gas stream.

20. The method according to claim 19, in which the said natural gas stream also contains at least part of the methane in the source material in (a).

21. The method according to p, in which said additional exhaust stream includes water and methane, ethane or a mixture of methane and ethane.

22. The method according to p, in which carbon monoxide is used in stage (d), and said additional exhaust stream includes one or more of paraffins and olefins with₂C₅, monocyclic aromatic hydrocarbons and alcohols with C₁With₃.

23. The method according to p, which mentioned the reaction of at least part of the hydrogen from the first mentioned exhaust stream with carbon monoxide, carbon dioxide or a mixture of carbon monoxide and carbon dioxide includes the selective combustion of hydrogen.

24. The method according to p, in which the mentioned source material in (a) also contains at least one of the N₂N₂Oh, co and CO₂.

25. The method according to p, in which the mentioned source material in (a) contains less than 5 wt.% hydrocarbons With₃+.

26. The method according to p, in which the above-mentioned conditions (a) include a temperature of from about 400 to about 1200°C., a pressure from about 1 to about 1000 kPa and average hourly feed rate from about 0.1 to about 1000 h^-1.

27. The method according to p, in which the said catalyst dehydrocyclization in (a) includes at least one of molybdenum, tungsten, rhenium, molybdenum compounds, compounds of tungsten and compounds of rhenium on ZSM-5, silica or aluminum oxide.

28. The method according to p, further comprising an allotment of the said first exhaust flow of at least one aromatic hydrocarbon.

29. The method according to p, in which part of the above mentioned first waste stream remaining after the allocation of at least one aromatic hydrocarbons, used as fuel to supply heat mentioned contacting (a).

30. The method according to p, further comprising the alkylation of at least one aromatic hydrocarbon in said first exhaust flow alkylating agent.

31. The method according to item 30, kotoromuty alkylating agent comprises ethylene, obtained by the above-mentioned contacting (a).

32. The method according to item 30, in which the aforementioned alkylating agent includes carbon monoxide and hydrogen, or the product of their interaction.