JP2015157735A - Hydrogen supply system, and hydrogen supply method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress hydrogenation reaction heat while stabilizing a hydrogen supply amount, in a configuration for supplying hydrogen to hydrogen users from an off gas generated in petroleum plants or the like, by an organic chemical hydride method.SOLUTION: A hydrogen supply system 1 includes: an off gas storage device 11 for storing an off gas collected from a plurality of plants 2A-2C, as a mixed off gas; a hydrogenation apparatus 13 for adding hydrogen contained in the mixed off gas to an aromatic compound by a hydrogenation reaction to produce a hydrogenated aromatic compound; and a hydrogen supply body storage device 15 for storing the hydrogenated aromatic compound as a hydrogen supply body. A lower hydrocarbon generated as the off gas from at least one of the plurality of plants is contained in the mixed off gas at a predetermined ratio.

Description

  The present invention relates to a hydrogen supply system and a hydrogen supply method for recovering hydrogen contained in a by-product gas generated from an oil plant or the like and supplying the hydrogen to a hydrogen demand destination.

  Oil and petrochemical plants produce by-product gas (hereinafter referred to as off-gas) mainly composed of hydrogen derived from fossil fuels and lower hydrocarbons (low-boiling hydrocarbons such as methane, ethane, propane and butane). The About this type of off-gas, the generation amount varies greatly depending on the operation status of the plant, and it is not sufficient in quantity to be used for a specific application, so it is generally consumed as private fuel. .

  Conventionally, a hydrogen purification technology for obtaining high purity hydrogen from a mixed gas containing hydrogen as a main component such as off-gas has been developed. For example, in the presence of a hydrogenation catalyst, a hydrogen-containing mixed gas and an aromatic compound The hydrogenated aromatic compound (organic hydride) is recovered by gas-liquid separation of the hydrogenated reaction mixture obtained by hydrogenation of the aromatic compound by contacting with hydrogen, and the presence of a dehydrogenation catalyst. Below, there is a hydrogen purification method in which the hydrogenated aromatic compound is dehydrogenated and the hydrogen obtained by the dehydrogenation is recovered (see Patent Document 1).

  A technique for storing and transporting hydrogen in the state of a hydrogenated aromatic compound by hydrogenating the aromatic compound is known as an organic chemical hydride method. According to this method, hydrogen is transported in the form of hydrogenated aromatic compounds, and hydrogen and aromatics are dehydrogenated by hydrogenated aromatic compounds at a plant or hydrogen station adjacent to a hydrogen use site in a city or the like. A compound is produced. The aromatic compound produced by the dehydrogenation reaction is transported again to the hydrogen production site and used for the hydrogenation reaction (hydrogenation reaction).

  In addition, in the past, technologies for utilizing hydrogen contained in off-gas from refineries and steelworks in hydrogenation reactions such as organic chemical hydride methods have been developed. There is a technique using a hydrogenation catalyst having high anti-toxicity to carbon oxide or the like (see Patent Document 2).

Japanese Patent No. 4740564 JP 2011-83701 A

  However, in the conventional techniques described in Patent Documents 1 and 2, when the operation status of the plant that generates off-gas changes (for example, the operation is stopped) and the hydrogen supply amount is insufficient, or the demand for hydrogen is temporarily There was a case where the hydrogen supply amount became excessive due to the decrease.

  In the conventional technique described in Patent Document 2, an inert gas (such as nitrogen) for dilution is mixed with the raw material hydrogen in order to control the temperature of the hydrogenation reaction with a large exotherm. In order to perform stable dilution of hydrogen, it is necessary to secure a sufficient inert gas by separately providing an inert gas production apparatus in the plant.

  Furthermore, according to the prior art described in Patent Documents 1 and 2, the hydrogen can be effectively used in off-gas. However, Patent Document 1 mainly aims to obtain high-purity hydrogen, Since the above-mentioned Patent Document 2 mainly aims to improve the anti-poisoning properties of the catalyst against hydrogen source impurities, the use of components other than hydrogen (such as lower hydrocarbons) in the off-gas has not been specifically considered.

  The present invention was devised in view of such problems of the prior art, and in a configuration for supplying hydrogen contained in off-gas generated from a petroleum plant or the like to a hydrogen customer based on an organic chemical hydride method, The main object is to provide a hydrogen supply system and a hydrogen supply method that can suppress the heat of hydrogenation reaction without requiring an inert gas for dilution while stabilizing the hydrogen supply amount.

  In the first aspect of the present invention, a hydrogen supply system (1) that supplies hydrogen contained in off-gas generated from a plurality of plants (2A to 2C) including an oil plant to a hydrogen demand destination based on an organic chemical hydride method. An off-gas storage device (11) for storing off-gas collected from the plurality of plants as a mixed off-gas, and adding hydrogen contained in the mixed off-gas to the aromatic compound by a hydrogenation reaction, A hydrogenation reaction device (13) for producing a fluorinated aromatic compound, and a hydrogen supplier storage device (15) for storing the hydrogenated aromatic compound as a hydrogen supplier. It is characterized in that lower hydrocarbons generated as off-gas from at least one of the plants are contained in a predetermined ratio.

  In the hydrogen supply system according to the first aspect, hydrogen contained in off-gas generated from an oil plant or the like is supplied to a hydrogen demand destination based on the organic chemical hydride method, and off-gas generated from a plurality of plants is used. The amount of lower hydrocarbons in the off-gas is determined by stabilizing the hydrogen supply amount without the need for an inert gas for dilution (that is, the inert gas for dilution is replaced with lower hydrocarbons). It is possible to suppress the heat of hydrogenation reaction.

  The second aspect of the present invention relates to the first aspect, further comprising a lower hydrocarbon recovery device (14) for recovering the lower hydrocarbon after the hydrogenation reaction in the hydrogenation reaction device. And

  In the hydrogen supply system according to the second aspect, it is possible to effectively utilize the lower hydrocarbon after the hydrogenation reaction while suppressing the heat of reaction in the hydrogenation reaction by the lower hydrocarbon contained in the offgas.

  According to a third aspect of the present invention, there is further provided a reformer (22) for generating a reformed gas containing hydrogen and carbon monoxide by a reforming reaction of the recovered lower hydrocarbon, with respect to the second aspect. It is characterized by having.

  In the hydrogen supply system according to the third aspect, the lower hydrocarbon contained in the offgas is obtained by reforming the lower hydrocarbon contained in the offgas to obtain a reformed gas (a mixed gas containing hydrogen and carbon monoxide). Can be used as a raw material for the chemical industry (for example, for the production of C1 chemical products, etc.).

  According to a fourth aspect of the present invention, with respect to the third aspect, a shift reaction apparatus (23) that generates a shift gas containing carbon dioxide and hydrogen by a shift reaction that shifts carbon monoxide in the reformed gas to carbon dioxide. Is further provided.

  In the hydrogen supply system according to the fourth aspect, it is possible to effectively use lower hydrocarbons contained in the offgas as hydrogen and carbon dioxide.

  The fifth aspect of the present invention further relates to the fourth aspect, further comprising a carbon dioxide separation device (25) for separating the carbon dioxide in the shift gas, wherein the hydrogenation reaction device is separated from the carbon dioxide. Hydrogen in shift gas is used for the hydrogenation reaction.

  In the hydrogen supply system according to the fifth aspect, hydrogen derived from lower hydrocarbons contained in the offgas can be effectively used in the hydrogenation reaction.

  According to a sixth aspect of the present invention, there is further provided a carbon dioxide separator (25) for separating carbon dioxide in the shift gas with respect to the fourth and fifth aspects, wherein the reformer further converts the carbon dioxide into the carbon dioxide gas. It is used for the reforming reaction.

  In the hydrogen supply system according to the sixth aspect, the carbon dioxide gas derived from the lower hydrocarbon contained in the offgas can be effectively used in the reforming reaction.

  According to a seventh aspect of the present invention, there is further provided an impurity removing device (12) for removing impurities contained in off-gas generated from the plurality of plants, according to any one of the first to sixth aspects. And

  In the hydrogen supply system according to the seventh aspect, the impurities (sulfur components, etc.) contained in the off-gas mainly composed of hydrogen and lower hydrocarbons are removed to thereby poison the hydrogenation catalyst used in the hydrogenation reaction. It becomes possible to prevent (or suppress).

  The eighth aspect of the present invention relates to any one of the first to seventh aspects, wherein the predetermined ratio is set based on a reaction temperature of the hydrogenation reaction in the hydrogenation reaction apparatus. To do.

  In the hydrogen supply system according to the eighth aspect, it is possible to easily suppress an extreme temperature increase in the hydrogenation reaction apparatus by determining the content ratio of the lower hydrocarbon in the mixed off gas based on the reaction temperature of the hydrogenation reaction. It becomes possible.

  According to a ninth aspect of the present invention, there is provided a hydrogen supply method for supplying hydrogen contained in off-gas generated from a plurality of plants including an oil plant to a hydrogen demand destination based on an organic chemical hydride method. Off-gas storage step of storing off-gas collected from the plant as mixed off-gas, and hydrogenation reaction step of generating hydrogenated aromatic compound by adding hydrogen contained in the mixed off-gas to the aromatic compound by hydrogenation reaction And a hydrogen supplier storage step of storing the hydrogenated aromatic compound as a hydrogen supplier, and the mixed off gas includes lower hydrocarbons generated as off gas from at least one of the plurality of plants. , The content ratio of the lower hydrocarbon in the mixed off gas is the hydrogenation reaction in the hydrogenation reaction step Characterized in that it is set on the basis of the reaction temperature.

  As described above, according to the present invention, in the configuration in which hydrogen contained in off-gas generated from a petroleum plant or the like is supplied to a hydrogen customer based on the organic chemical hydride method, the hydrogen supply amount is stabilized, and the inerting for dilution is performed. It is possible to suppress the heat of hydrogenation reaction without requiring gas or the like.

The block diagram which shows schematic structure of the hydrogen supply system which concerns on 1st Embodiment. The block diagram which shows schematic structure of the hydrogen supply system which concerns on 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram showing a schematic configuration of a hydrogen supply system 1 according to the first embodiment of the present invention. The hydrogen supply system 1 supplies hydrogen contained in off-gas generated from a plurality of plants to nearby or remote hydrogen demand destinations (a plant, a hydrogen station, etc., not shown) based on the organic chemical hydride method. .

  In the present embodiment, as an example of a plurality of plants, first to third oil plants 2A to 2C (hereinafter collectively referred to as “petroleum plant 2”) are shown. As long as an off-gas having a necessary composition, which will be described in detail later, can be obtained, the plant may be configured to include not only a petroleum plant but also other plants (for example, a petrochemical plant for producing petrochemical products). In addition, the number and scale of plants constituting the hydrogen supply system 1 (off gas discharge amount, etc.) can be changed as appropriate.

  The oil plant 2 constitutes oil storage, refinery, and other various incidental facilities in refineries and the like, for example, an atmospheric distillation device that separates crude oil into gas, LPG, naphtha, kerosene, light oil, residual oil fraction, and the like. And hydrodesulfurization equipment that removes sulfur compounds, etc., reformers that obtain high-octane reformed gasoline by reforming gasoline fractions, heavy fractions with lighter distillation with lower boiling point It is equipped with a known device such as a cracking device that converts it into minutes.

  The off-gas is a by-product gas generated in each processing step such as a distillation apparatus, a reforming apparatus, and a cracking apparatus in the petroleum plant 2, and mainly contains hydrogen and lower hydrocarbons. The average composition (volume ratio) of off-gas in the petroleum plant 2 is, for example, hydrogen: 51 vol%, methane: 21 vol%, ethane, propane, and butane: 27 vol%. In addition, for off-gas, as a trace amount of impurities other than the main component, for example, hydrogen sulfide generated in the heavy fraction decomposition process by fluid catalytic cracking method, hydrochloric acid treatment for catalyst regeneration by continuous regeneration platform method Examples include chlorine generated in the process, ammonia generated in a hydrodesulfurization process in which a petroleum fraction is reacted with hydrogen in the presence of a catalyst.

  The hydrogen supply system 1 includes an offgas storage device 11 that stores offgas collected from the first to third oil plants 2A to 2C, and an offgas stored in the offgas storage device 11 (hereinafter, “mixed offgas”). And an impurity removing device 12 that removes impurities contained in the mixture, and hydrogen contained in the mixed off-gas from which the impurities have been removed are added to toluene (aromatic compound) by hydrogenation reaction to produce methylcyclohexane (hydrogenated aromatic compound). ) For producing lower hydrocarbons from a mixture of methylcyclohexane (hereinafter referred to as “MCH”) and lower hydrocarbons sent from the hydrogenation device 13. Lower hydrocarbon) recovery device 14 and M for storing MCH recovered by LHC recovery device 14 as a hydrogen supplier And H storage device (hydrogen donor storage unit) 15, a dehydrogenation reactor 16 for obtaining hydrogen is provided primarily by the dehydrogenation of MCH.

  Between the 1st-3rd oil plants 2A-2C and the off-gas storage apparatus 11, the transport line L1 for collect | recovering off-gas is provided, and similarly between each apparatus 11-16, each apparatus Transport lines L2 to L6 are provided for transporting the processing objects (gas, liquid, etc.) used for the processing in the above. Although detailed description is omitted, these transport lines L1 to L6 have a well-known configuration including pipes, valves, pumps, and the like.

  Off-gas is supplied to the off-gas storage device 11 via a transportation line L1 connected to the first to third oil plants 2A to 2C, and these off-gas (mixed off-gas) is stored in an off-gas storage tank (not shown). (Off-gas storage process). A plurality of off-gas storage devices 11 may be provided. Further, the mixed off gas does not contain a gas component containing oxygen atoms (carbon monoxide, carbon dioxide gas, oxygen, etc.) or even if it is contained, it does not affect the hydrogenation reaction in the hydrogenation device 13 (1 vol% or less). , Preferably 0.5 vol% or less).

  As will be described in detail later, the mixed off gas needs to contain lower hydrocarbons at a predetermined ratio. Accordingly, when the off-gas from each of the oil plants 2A to 2C is supplied to the off-gas storage device 11 as it is, there is a possibility that the content ratio of the lower hydrocarbon is out of the desired range, the off-gas storage device from each of the oil plants 2A to 2C. A flow rate adjusting valve (not shown) for individually adjusting the amount of off gas supplied to the transport gas L1 is provided in the transport line L1, and the content ratio of lower hydrocarbons in the mixed off gas can be adjusted by adjusting the flow rate. In that case, a well-known analyzer for quantitatively analyzing the gas composition is the off-gas storage device 11, the first to third oil plants 2A to 2C (or the branch piping of the transportation line L1 corresponding to each of the oil plants 2A to 2C. ) And the like, and the supply amount of off-gas from each of the oil plants 2A to 2C is controlled based on the analysis result. In addition, methane is particularly suitable as the lower hydrocarbon in the present invention, but is not limited to methane, and may be ethane, propane, butane, or a mixture of two or more thereof.

  The mixed off-gas is supplied from the off-gas storage device 11 to the impurity removing device 12 via the transport line L2. The impurity removing device 12 removes sulfur compounds (such as hydrogen sulfide), chlorine, ammonia, and the like contained in the mixed off gas as impurities based on a well-known adsorption method. For example, the impurity removal apparatus 12 can employ a moving bed adsorption method, and a known adsorbent (physical adsorbent or chemical adsorbent) corresponding to the impurity can be used for the adsorption treatment.

  Impurities to be removed by the impurity removal device 12 are determined from the viewpoint of preventing (or suppressing) poisoning of the hydrogenation catalyst used in the hydrogenation device 13. Therefore, the impurity removal device 12 does not necessarily need to remove all impurities contained in the mixed off-gas, but sufficiently removes gas components related to the poisoning of the hydrogenation catalyst (for example, hydrogen sulfide is 1 ppm or less). There is a need to. Further, when there is no component that poisons the hydrogenation catalyst in the off-gas of each plant constituting the hydrogen supply system 1 (or the presence can be ignored), or a catalyst having excellent poisoning resistance is used as the hydrogenation catalyst. In such a case, the impurity removing step by the impurity removing device 12 can be omitted.

In the hydrogenation device 13, in the presence of a hydrogenation catalyst, hydrogen contained in the mixed off-gas is chemically added to toluene (C ₇ H ₈ ) by a hydrogenation reaction based on the following chemical reaction formula (1) (hydrogen Reaction step). Thus, toluene is converted to _MCH (C _{7 H 14)} is a hydrogenated aromatic compound.

  The hydrogenation reaction is an exothermic reaction that proceeds from left to right in the chemical reaction formula (1). When the content ratio of hydrogen contained in the mixed off gas supplied to the hydrogenation device 13 is high, the calorific value (that is, the reaction temperature) becomes excessive, and it is difficult to appropriately perform the hydrogenation reaction. Therefore, in the hydrogen supply system 1, the content ratio of lower hydrocarbons in the mixed off gas stored in the off gas storage device 11 is controlled to suppress an extreme increase in the reaction temperature. In other words, in the hydrogen supply system 1, the composition of the mixed off gas stored in the off gas storage device 11 (the content ratio of hydrogen and lower hydrocarbons because the impurities are very small) is the hydrogenation in the hydrogenation device 13. It is set in order to control the reaction temperature of the reaction within a desired range. In this case, the lower hydrocarbons in the mixed off gas may be generated as off gas from at least one plant constituting the hydrogen supply system 1.

  About reaction temperature in the hydrogenation apparatus 13, it is preferable to set it as 120-250 degreeC, for example. In order to achieve this reaction temperature, in the hydrogen supply system 1, the content ratio (volume ratio) of the lower hydrocarbon (here, methane) in the mixed off-gas is in the range of 5 to 70 vol%, preferably 10 to 30 vol%. Within the range of When the content ratio of the lower hydrocarbon is higher than 30 vol% (especially 70 vol%), an increase in the reaction temperature can be easily suppressed, but the total supply gas amount necessary for supplying a predetermined amount of hydrogen increases. Become. As a result, pressure loss in the reactor and the catalyst layer increases, and problems such as promotion of catalyst pulverization and the need to add a compressor for boosting the supply gas may occur. Further, when the content of lower hydrocarbons is lower than 10 vol% (especially 5 vol%), the hydrogenation reaction becomes easier in equilibrium, but the effect of suppressing the extreme temperature rise at the reactor inlet is reduced, and MCH and The progress of side reactions that must not be ignored can result in inferior economic efficiency.

  The aromatic compound that functions as a hydrogen supplier is not particularly limited to toluene, and examples thereof include monocyclic aromatic compounds such as benzene and xylene, and bicyclic aromatic compounds such as naphthalene, tetralin, and methylnaphthalene. Group compounds and tricyclic aromatic compounds such as anthracene can be used alone or as a mixture of two or more.

  The hydrogenated aromatic compound is obtained by hydrogenating the above organic substance, and a monocyclic hydrogenated aromatic compound such as cyclohexane or dimethylcyclohexane, or a bicyclic hydrogenated aromatic compound such as tetralin, decalin, or methyldecalin. It becomes a compound, a tricyclic hydrogenated aromatic compound such as tetradecahydroanthracene, or a mixture of two or more. As a hydrogenated aromatic compound, it is preferable to select a hydrogenated aromatic compound that can be handled as a liquid that is stable at normal temperature and normal pressure, for convenience of storage and transportation.

  As the hydrogenation catalyst, a known catalyst used for hydrogenating aromatic compounds can be employed. For example, alumina or silica is used as a carrier, and active metals such as platinum (Pt), palladium (Pd), A material on which nickel (Ni) or the like is supported can be used.

  In the LHC recovery device 14, the MCH and lower hydrocarbons sent from the hydrogenation device 13 are separated by a known gas-liquid separator, and the separated lower hydrocarbons are recovered. The recovered lower hydrocarbon can be effectively used as a raw material used in the C1 chemical process. Further, the MCH storage device 15 stores the MCH from which the lower hydrocarbons have been separated in the LHC recovery device 14 in an MCH storage tank (not shown) at normal temperature and normal pressure (hydrogen supplier storage step). The MCH stored in the MCH storage device 15 can be appropriately supplied not only to the dehydrogenation reaction device 16 described later but also to a hydrogen demand destination in a remote place through a tanker, a pipeline, or the like.

  In the dehydrogenation reaction apparatus 16, hydrogen and toluene are produced from MCH by dehydrogenation reaction in the presence of a dehydrogenation catalyst. The dehydrogenation reaction proceeds from right to left in the chemical reaction formula (1). Hydrogen and toluene are separated by a known gas-liquid separator (not shown). The obtained hydrogen is supplied to hydrogen customers, and is used as, for example, chemical raw materials, additives in metal heat treatment, fuel for fuel cell vehicles, and the like. On the other hand, toluene is supplied (circulated) again to the hydrogenation device 13 via a transport line (not shown). It should be noted that hydrogen is also obtained by the same dehydrogenation reaction at the above-described hydrogen demand destination in the remote place, and the separated toluene is circulated to the hydrogen supply system 1 again.

  In the hydrogen supply system 1, the hydrogenation of toluene in the hydrogenation device 13, the storage of MCH in the MCH storage device 15, the transport of MCH, and the production of hydrogen from MCH in the dehydrogenation reaction device 16, etc. Performed based on the hydride method.

  For details on the organic chemical hydride method, see, for example, Yoshitsugu Okada et al., Development of dehydrogenation catalyst for organic chemical hydride method, Catalyst, 2004, 46 (6), p510-512, ISSN. 05598958, Yoshida Okada et al., Development of organic chemical hydride dehydrogenation catalyst and hydrogen energy chain vision, Catalyst, 2009, 51 (6), p496-498 , ISSN 05598958., Yoshida Okada et al., Development of organic chemical hydride dehydrogenation catalyst aiming at establishment of large-scale long-distance storage and transport technology of hydrogen energy, Chemical Engineering, 2010, 74 (9), p468-470, ISSN 03759253. Yoshida Okada et al., Development of organic chemical hydride dehydrogenation catalyst for hydrogen storage and transport (New Year Special GSC Symposium 2005), Fine Chemicals, 2006, 35 (1), p5-13, I Reference can be made to SSN 09136150.

  As described above, in the hydrogen supply system 1, the hydrogen supply amount is stabilized by using the offgas generated from the plurality of petroleum plants 2 </ b> A to 2 </ b> C, and the content ratio of lower hydrocarbons in the offgas is determined by diluting. The heat of hydrogenation reaction can be suppressed without requiring an inert gas. Moreover, since it is the structure which stores a hydrogenated aromatic compound as a hydrogen supply body based on the organic chemical hydride method, the response | compatibility when the demand for hydrogen falls temporarily is easy. Further, since the lower hydrocarbon after the hydrogenation reaction is recovered by the LHC recovery device 14, the lower hydrocarbon contained in the offgas can be effectively used. In addition, the hydrogen supply system 1 has an advantage that a large amount of hydrogen can be supplied without discharging carbon dioxide gas.

(Second Embodiment)
FIG. 2 is a block diagram showing a schematic configuration of the hydrogen supply system 1 according to the second embodiment of the present invention. FIG. 2 shows only the configuration related to the processing of the lower hydrocarbon (here, methane) sent from the LHC recovery device 14 in FIG. 1, and the other configuration is the same as that of the first embodiment. Therefore, detailed description is omitted. In addition, between each apparatus 14, 22-25, the transport lines L7-L10 for enabling the process target (gas, liquid, etc.) used for the process by each apparatus to be transported are provided.

The hydrogen supply system 1 according to the second embodiment includes a reformer 22 that generates a reformed gas containing hydrogen and carbon monoxide by a reforming reaction of methane from the LHC recovery device 14, and monoxide in the reformed gas. A shift reaction device 23 that generates a shift gas containing carbon dioxide gas and hydrogen by a shift reaction that shifts carbon to carbon dioxide gas, and a carbon dioxide gas (CO ₂ ) separation device 25 that separates the carbon dioxide gas in the shift gas are mainly provided.

In the reformer 22, a steam reforming process is performed by reacting methane with steam in the presence of a catalyst (for example, a nickel-based catalyst) at a high temperature (for example, 800 ° C.). Steam reforming is mainly based on the following chemical reaction formulas (2) and (3).

Further, the shift reaction device 23 shifts carbon monoxide in the reformed gas to carbon dioxide gas based on a predetermined temperature condition in the presence of a catalyst in order to increase the hydrogen concentration in the reformed gas generated by the reformer 22. To do. The reaction temperature of the shift reaction device 23 can be appropriately set in consideration of the reaction rate of the shift reaction and the composition ratio of the product. Here, the concentration of carbon monoxide is lowered in two stages: a shift reaction at a relatively high temperature (about 350 to 420 ° C.) and a shift reaction at a relatively low temperature (about 200 to 300 ° C.). The shift reaction is mainly based on the following chemical reaction formula (4).

  At least a part of the gas mainly composed of hydrogen and carbon monoxide generated in the reformer 22 is sent to a neighboring petrochemical plant 24 and used as a raw material for the chemical industry (for example, a C1 chemical product). Used for manufacturing).

As the steam reforming process as described above, well-known techniques such as ICI (Imperial Chemical Industries, Ltd.) method and Topso (Haldor Topsoe) method can be used. In the reformer 22, partial oxidation reforming may be used as a method for converting the hydrocarbon component into a gas mainly composed of hydrogen and carbon monoxide. The partial oxidation reaction is mainly based on the following chemical reaction formula (5).

Further, as the reforming process, CO ₂ reforming mainly based on the following chemical reaction formula (6) can be used together with steam reforming.

  In this way, the lower hydrocarbon contained in the offgas is chemically reformed by the reformer 22 to obtain the reformed gas (mixed gas containing hydrogen and carbon monoxide), whereby the lower hydrocarbon contained in the offgas is chemically treated. It can be used as an industrial raw material. Furthermore, it becomes possible to effectively utilize lower hydrocarbons contained in the offgas as hydrogen and carbon dioxide gas by the shift reaction of the reformed gas. In this case, the use of lower hydrocarbons in off-gas generated from a plurality of petroleum plants 2A to 2C does not cause a problem that the amount of lower hydrocarbons is insufficient.

The carbon dioxide separator 25 separates hydrogen and carbon dioxide from each other. The separated hydrogen is used in the hydrogenation reaction in the hydrogenation apparatus 13 described above. On the other hand, the separated carbon dioxide gas is sent to the reformer 22 via the transport line L10 and used in the CO ₂ reforming reaction there.

  In the carbon dioxide separator 25, a zeolite membrane having high selective permeability to carbon dioxide is used as a separation membrane. The zeolite membrane is obtained by forming a hydrophilic zeolite membrane on a porous substrate such as alumina or silica. The hydrophilic zeolite membrane is heat-treated at a temperature of about 100 to 800 ° C. The separation membrane used in the carbon dioxide separator 25 is not limited to a zeolite membrane, and other inorganic membranes such as an aluminum oxide (alumina) membrane and a zirconium oxide (zirconia) membrane can be used.

In the carbon dioxide separator 25, the CO ₂ permeable membrane is not limited to the zeolite membrane, and an inorganic membrane (ceramic membrane or the like) made of another inorganic material can be used. As the inorganic material, ceramic is suitable, and examples thereof include aluminum oxide (alumina) and zirconium oxide (zirconia). In some cases, an organic film (polymer film or the like) made of an organic material may be used as the CO ₂ permeable film. Examples of the organic material include cellulose acetate, polysulfone, polyethylene, polypropylene, polyacrylonitrile and the like.

  The carbon dioxide separation by the carbon dioxide separator 25 is not necessarily performed by a membrane separation method, but may be a chemical absorption method (for example, carbon dioxide is absorbed by a reaction with an alkaline solution such as an amine or an aqueous solution of potassium carbonate) or physical adsorption. Other well-known separation techniques such as a method (for example, carbon dioxide is contacted and adsorbed on an adsorbent such as zeolite) may be used.

  As mentioned above, although this invention was demonstrated based on specific embodiment, these embodiment is an illustration to the last, Comprising: This invention is not limited by these embodiment. It should be noted that not all the components of the hydrogen supply system and the hydrogen supply method according to the present invention shown in the above-described embodiment are necessarily essential, and can be appropriately selected as long as they do not depart from the scope of the present invention. It is. In addition, a composite apparatus having the functions of a plurality of apparatuses shown in the above embodiments can be used.

DESCRIPTION OF SYMBOLS 1 Hydrogen supply system 2A-2C Petroleum plant 11 Off-gas storage apparatus 12 Impurity removal apparatus 13 Hydrogenation apparatus (hydrogenation reaction apparatus)
14 LHC recovery unit (lower hydrocarbon recovery unit)
15 MCH storage device (hydrogen supplier storage device)
16 Dehydrogenation reactor 22 Reformer 23 Shift reactor 24 Petrochemical plant 25 Carbon dioxide separator

Claims (9)

A hydrogen supply system that supplies hydrogen contained in off-gas generated from a plurality of plants including an oil plant to a hydrogen customer based on an organic chemical hydride method,
An offgas storage device for storing offgas collected from the plurality of plants as a mixed offgas;
A hydrogenation reaction apparatus for producing a hydrogenated aromatic compound by adding hydrogen contained in the mixed off gas to the aromatic compound by a hydrogenation reaction;
A hydrogen supplier storage device for storing the hydrogenated aromatic compound as a hydrogen supplier,
The mixed off gas contains a lower hydrocarbon generated as an off gas from at least one of the plurality of plants at a predetermined ratio.   The hydrogen supply system according to claim 1, further comprising a lower hydrocarbon recovery device that recovers the lower hydrocarbon after the hydrogenation reaction in the hydrogenation reaction device.   The hydrogen supply system according to claim 2, further comprising a reformer that generates a reformed gas containing hydrogen and carbon monoxide by a reforming reaction of the recovered lower hydrocarbon.   The hydrogen supply system according to claim 3, further comprising a shift reaction device that generates a shift gas containing carbon dioxide and hydrogen by a shift reaction that shifts carbon monoxide in the reformed gas to carbon dioxide. Further comprising a carbon dioxide separator for separating carbon dioxide in the shift gas,
5. The hydrogen supply system according to claim 4, wherein the hydrogenation reaction apparatus uses hydrogen in the shift gas from which the carbon dioxide gas is separated for the hydrogenation reaction. Further comprising a carbon dioxide separator for separating carbon dioxide in the shift gas,
The hydrogen supply system according to claim 4, wherein the reformer uses the carbon dioxide gas for the reforming reaction.   The hydrogen supply system according to any one of claims 1 to 6, further comprising an impurity removal device that removes impurities contained in off-gas generated from the plurality of plants.   The hydrogen supply system according to any one of claims 1 to 7, wherein the predetermined ratio is set based on a reaction temperature of the hydrogenation reaction in the hydrogenation reaction apparatus. A hydrogen supply method for supplying hydrogen contained in off-gas generated from a plurality of plants including an oil plant to a hydrogen customer based on an organic chemical hydride method,
An offgas storage step of storing offgas collected from the plurality of plants as a mixed offgas;
A hydrogenation reaction step of producing a hydrogenated aromatic compound by adding hydrogen contained in the mixed off gas to the aromatic compound by a hydrogenation reaction;
A hydrogen supplier storage step of storing the hydrogenated aromatic compound as a hydrogen supplier,
The mixed off gas includes lower hydrocarbons generated as off gas from at least one of the plurality of plants, and the content ratio of the lower hydrocarbons in the mixed off gas is the amount of the hydrogenation reaction in the hydrogenation reaction step. A hydrogen supply method, which is set based on a reaction temperature.

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