JP2018003797A - Fuel reforming system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel reforming system capable of suppressing clogging due to deposition of a component hard to dissolve in fuel occurring from reforming reaction or reformed fuel.SOLUTION: A fuel reforming system 1 includes: a reformer 15 having a reforming catalyst 151 for reforming gasoline with air to generate alcohol; and an esterification device 30 arranged on a downstream side of the reformer 15, and having a solid acid catalyst for esterifying benzoic acid generated with reforming reaction of the reforming catalyst 151 to form benzoic acid ester.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fuel reforming system. More specifically, the present invention relates to a fuel reforming system that can improve the octane number of fuel by reforming a fuel mainly composed of hydrocarbons to produce alcohol.

  In a gasoline engine that burns a premixed fuel / air mixture by spark ignition with an ignition plug, it is known that knocking occurs when the unburned mixture (end gas) separated from the ignition plug self-ignites. Yes. Since knocking is likely to occur when the compression ratio of the engine is increased, suppression of knocking is strongly demanded in recent high compression ratio engines.

  As a method for suppressing knocking, there is a method of retarding the ignition timing. However, if the ignition timing is retarded, the thermal efficiency of the engine decreases. Therefore, it is desired to develop a technology capable of obtaining high thermal efficiency while suppressing knocking even in a high compression ratio engine.

  By the way, since knocking can be suppressed by increasing the octane number of the fuel, an alcohol-containing fuel in which alcohol such as ethanol is mixed in advance with gasoline is widely used as a fuel having a high octane number in some areas. In addition, with the widespread use of such alcohol-containing fuels, development of technology for separating alcohol-containing fuel supplied from the outside into a fuel with a high gasoline concentration and a fuel with a high alcohol concentration on a vehicle is underway. There are various differences in fuel properties such as octane number and calorific value between gasoline and alcohol. For example, gasoline and alcohol are separated on the vehicle rather than using the alcohol-containing fuel supplied from the outside as it is. This is because it is preferable to properly use alcohol and alcohol. However, at present, separation according to engine requirements is not easy.

  On the other hand, a synthesis method has been proposed in which hydrocarbons are converted into alcohols using a carbon radical-generating catalyst such as N-hydroxyphthalimide (NHPI) (for example, see Non-Patent Document 1). If this synthesis method can be used on a vehicle, it is considered that hydrocarbons contained in gasoline can be converted into alcohol having a high octane number and alcohol having a high octane number can be supplied to the engine according to the demand of the engine.

S. Sakaguchi, S. Kato, T. Iwahama, Y. Ishii, Bull. Chem. Soc. Jpn. 71 (1998) p. 1237-1240

  However, in the fuel reforming system using the synthesis method described above, the reforming reaction generates a fuel or a component that is difficult to dissolve in the reformed fuel, and the component is precipitated by a downstream filter or injector, thereby clogging. There was a risk of it occurring.

  The present invention has been made in view of the above, and an object of the present invention is to provide a fuel reforming system capable of suppressing clogging due to precipitation of components that are difficult to dissolve in fuel generated by reforming reaction or reformed fuel. .

  In order to achieve the above object, the present inventors have conducted intensive research and found that benzoic acid produced by the reforming reaction is the cause of clogging, and this benzoic acid is esterified and dissolved in fuel and reformed fuel. The present inventors have found that clogging can be suppressed by converting to a benzoic acid ester that is easy to do, and have completed the present invention.

  Specifically, the present invention relates to a reforming catalyst (for example, a later-described reforming catalyst) for reforming a hydrocarbon-based fuel (for example, later-described gasoline) using air to generate alcohol. 151) and a benzoic acid ester formed by esterifying benzoic acid, which is disposed downstream of the reformer and formed by a reforming reaction using the reforming catalyst. There is provided a fuel reforming system (for example, a fuel reforming system 1 described later) including an esterification apparatus (for example, an esterification apparatus 30 described later) having a solid acid catalyst.

In the present invention, benzoic acid produced by the reforming reaction is esterified on the downstream side of the reformer having a reforming catalyst for reforming the fuel mainly composed of hydrocarbon using air to produce alcohol. An esterification apparatus having a solid acid catalyst for converting to a benzoic acid ester is provided.
As a result, the benzoic acid that is not easily dissolved in the reformed fuel or the fuel that is generated when the fuel is reformed is reacted with the alcohol generated in the reforming reaction to be converted into a benzoic acid ester that is soluble in the fuel or the reformed fuel. Thereby, precipitation of benzoic acid can be suppressed. Therefore, according to the fuel reforming system of the present invention, clogging of the filter and the injector can be suppressed, and the fuel can be reformed more efficiently.

  It is preferable that the esterification apparatus is disposed close to the downstream end of the reformer.

  In the present invention, the esterification apparatus is disposed close to the downstream end of the reformer. That is, the esterification apparatus is disposed immediately below the reformer. Thereby, since heat generated by the reforming reaction can be used for the esterification reaction, benzoic acid can be esterified more efficiently.

  The solid acid catalyst is preferably at least one selected from the group consisting of sulfated zirconia, heteropolyacid, activated alumina, and zeolite.

  In the present invention, as the solid acid catalyst, at least one selected from the group consisting of sulfated zirconia, heteropolyacid, activated alumina, and zeolite is used. Thereby, benzoic acid can be reliably esterified in the esterification apparatus.

  The reforming catalyst preferably includes a main catalyst composed of an N-hydroxyimide group-containing compound and a promoter composed of a transition metal compound.

  In this invention, a reforming catalyst including a main catalyst composed of an N-hydroxyimide group-containing compound and a promoter composed of a transition metal compound is used as the reforming catalyst. Thereby, benzoic acid can be esterified more reliably using the alcohol generated by the reforming reaction.

  ADVANTAGE OF THE INVENTION According to this invention, the fuel reforming system which can suppress the clogging by precipitation of the component which is hard to melt | dissolve in the fuel produced | generated by reforming reaction or reformed fuel can be provided.

It is a figure which shows the fuel reformer which concerns on one Embodiment of this invention.

An embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing a configuration of a fuel reforming system 1 according to an embodiment of the present invention. The fuel reforming system 1 according to this embodiment is mounted on a vehicle (not shown), and reforms hydrocarbons contained in the fuel into alcohol according to the demand of the engine (not shown) on the vehicle and supplies the alcohol to the engine.

  In the fuel reforming system 1 of the present embodiment, gasoline is used as the fuel and air is used as the oxidant. That is, since the fuel reforming system 1 of the present embodiment reforms gasoline using an oxidation reaction by oxygen in the air, for example, under conditions that are milder at a lower temperature than reforming using a decomposition reaction or the like. Modification is possible. Therefore, the system configuration can be simplified and it is suitable for on-demand driving on a vehicle.

  As shown in FIG. 1, the fuel reforming system 1 according to the present embodiment includes an air introduction unit 11, a fuel tank 12, a fuel introduction unit 13, a mixer 14, a reformer 15, and an esterification device. 30, a condenser 16, a fuel supply unit 17, a gas-liquid separator 18, a gas phase supply unit 19, a reformed fuel tank unit 20, and a reformed fuel supply unit 21. . In the fuel reforming system 1, as will be described later, a reformer 15 reforms a fuel mainly composed of hydrocarbons using air to generate alcohol. The generated reformed fuel is stored in the reformed fuel tank unit 20 via the condenser 16, and is transferred from the reformed fuel tank unit 20 to the engine fuel supply system through the reformed fuel supply pipe 212 by the reformed fuel pump 211. Supplied.

The air introduction unit 11 is provided upstream of the mixer 14 described later, and introduces air as an oxidant into the mixer 14.
The air introduction unit 11 includes an air filter 111, an air pump 112, an air flow meter 113, and an air valve 114 in order from the upstream side of the air introduction pipe 110.
The air introduction unit 11 takes in air from the outside air via the air filter 111 by driving the air pump 112. The air introduction unit 11 opens the air valve 114 to introduce the taken-in air into the mixer 14.

  Based on the air flow rate detected by the air flow meter 113, the opening degree of the air valve 114 is adjusted by an electronic control unit (hereinafter referred to as “ECU”) (not shown). The amount of air introduced is adjusted.

  The fuel supply unit 17 includes a fuel pump 171, a fuel supply pipe 172, and an injector (not shown). The fuel supply unit 17 drives the fuel pump 171 to supply gasoline stored in the fuel tank 12 into a cylinder or an intake port of an engine (not shown) via the fuel supply pipe 172 and the injector. The gasoline supply amount to the engine is controlled by adjusting the injection amount of the injector by the ECU.

The fuel introduction unit 13 is provided upstream of a mixer 14 described later, and introduces fuel gasoline into the mixer 14.
The fuel introduction unit 13 includes a reforming pump 131, a fuel flow meter 132, and a fuel valve 133 in order from the upstream side of the fuel introduction pipe 130. The fuel introduction unit 13 drives the reforming pump 131 and opens the fuel valve 133 to introduce the gasoline stored in the fuel tank 12 into the mixer 14.

  Based on the fuel flow rate detected by the fuel flow meter 132, the opening degree of the fuel valve 133 is adjusted by the ECU, and the amount of gasoline introduced into the mixer 14 is adjusted by this opening degree adjustment.

In the fuel reforming system 1, the air introduction unit 11 and the fuel introduction unit 13 described above constitute a supply device 10 that supplies air and fuel to the mixer 14.
In the supply device 10, the air introduction unit 11 and the fuel introduction unit 13 operate in cooperation with each other under the control of the ECU, and the introduction amount of air and fuel supplied to the mixer 14 is adjusted.

  Since this adjustment is performed, the ratio of the fuel and the air and fuel supplied to the mixer 14 is 22 weight percent or more. This ratio corresponds to a region where the fuel is richer than the explosion limit. Therefore, the risk of an excessively rapid reaction is minimized, and the conversion process for converting gasoline to alcohol becomes stable.

The mixer 14 is provided on the upstream side of the reformer 15. Moreover, the mixer 14 may be comprised so that a small air bubble may be produced | generated by forming the connection part of the air introduction pipe | tube 110 and the mixer 14 in a small hole, for example. Moreover, the mixer 14 may be comprised so that a vortex may be generated with the strong flow of air. Alternatively, the mixer 14 has a particulate material or a porous material disposed therein, and the particulate material or the porous material allows the air and fuel supplied from the supply device 10 to flow. You may be comprised so that dispersion | distribution, transformation, conversion (rotation) may be produced and it may mix uniformly.
Furthermore, the mixer 14 may include a static mixer so that air and fuel are uniformly mixed.
The mixer 14 includes a heater (not shown), and generates a mixed fluid of gasoline and air by mixing gasoline and air while raising the temperature to a predetermined temperature.

  The reformer 15 reforms the hydrocarbon, which is the main component of gasoline in the gas mixture supplied from the mixer 14, using the air in the gas mixture to generate alcohol. Specifically, the reformer 15 may be either a flow reactor or a complete mixing reactor.

Here, the flow reactor is a mixture of gasoline and air introduced from the mixer 14 while being swept away like a piston without being mixed with the mixture supplied before and after the mixture in the reactor. It means a reactor that is reformed and flows out. Therefore, in the flow reactor, the composition of the fluid flowing out from the reactor and the composition of the fluid inside the reactor are different, and the variation in the residence time of the air-fuel mixture in the reactor is small.
On the other hand, the complete mixing reactor means a reactor in which a mixture of gasoline and air introduced from the mixer 14 is uniformly mixed with a reactant in the reformer and reformed. Therefore, in the complete mixing reactor, the composition of the fluid flowing out from the reactor and the composition of the fluid inside the reactor are the same, and the residence time inside the reactor of the mixer has a large variation.

  As shown in FIG. 1, the reformer 15 is provided with a temperature sensor (not shown) and a cooling unit 153 for cooling the interior of the reformer 15. The cooling unit 153 is controlled by the ECU based on the temperature detected by the temperature sensor, and cools the reformer 15 by supplying engine coolant (not shown) to the reformer 15. The engine cooling water temperature is preferably 70 ° C to 100 ° C. If the temperature of the engine cooling water is less than 70 ° C., the reforming reaction rate is small, and if it exceeds 100 ° C., it becomes difficult to use the engine cooling water. The cooling unit 153 cools the reformer 15 with engine cooling water when the reforming reaction proceeds and the temperature in the reformer 15 is high. When the temperature in 15 is low, the reformer 15 is warmed with engine cooling water.

  The reformer 15 also includes a reforming catalyst 151 that reforms hydrocarbons mainly contained in gasoline using air as an oxidant to generate alcohol. Specifically, the reformer 15 includes a cylindrical casing 152 and a solid reforming catalyst 151 filled in the casing 152.

  The solid reforming catalyst 151 includes a small spherical porous carrier, and a main catalyst and a cocatalyst supported on the surface of the porous carrier. The main catalyst and the cocatalyst are supported on the surface of a small spherical porous support in a uniformly mixed state. As described above, the reforming catalyst 151 of the present embodiment has a small spherical porous carrier, which increases the surface area of the main catalyst and the promoter supported on the surface of the reforming catalyst 151. The contact area increases.

  As the small spherical porous carrier, for example, silica beads, alumina beads, silica alumina beads and the like are used. Of these, silica beads are preferably used. The particle size of the porous carrier is preferably 3 μm to 500 μm.

  The main catalyst has the ability to extract alkyl atoms from hydrocarbons in gasoline to generate alkyl radicals. Specifically, an N-hydroxyimide group-containing compound having an N-hydroxyimide group is used as the main catalyst. Among these, N-hydroxyphthalimide (hereinafter referred to as “NHPI”) or an NHPI derivative is preferably used.

  The cocatalyst has the ability to reduce an alkyl hydroperoxide generated from an alkyl radical to produce an alcohol. Specifically, a transition metal compound is used as the promoter. Among these, a compound selected from the group consisting of a cobalt compound, a manganese compound, and a copper compound is preferably used. Cobalt acetate (II) or the like is used as the cobalt compound, manganese (II) acetate or the like is used as the manganese compound, and copper (I) chloride or the like is used as the copper compound.

  As a method for supporting the main catalyst and the cocatalyst on the porous carrier, a conventionally known impregnation method or the like is employed. For example, after preparing a slurry containing a main catalyst and a promoter in a predetermined mixing ratio, a small spherical porous carrier is immersed in the prepared slurry. Next, the porous carrier is pulled up from the slurry to remove excess slurry adhering to the surface of the porous carrier, and then dried under predetermined conditions. Thereby, the reforming catalyst 151 in which the main catalyst and the promoter are uniformly supported on the surface of the porous carrier is obtained.

Here, the reforming reaction that proceeds in the reformer 15 will be described in detail below.
First, as shown in the following reaction formula (1), the reforming reaction of the present embodiment is initiated by a hydrogen abstraction reaction in which hydrogen atoms are extracted from hydrocarbons in gasoline to generate alkyl radicals. This hydrogen abstraction reaction proceeds by the action of the main catalyst, radicals, oxygen molecules and the like.

［反応式（１）中、ＲＨは炭化水素を表し、Ｒ・はアルキルラジカルを表す。］

[In Reaction Formula (1), RH represents a hydrocarbon, and R. represents an alkyl radical. ]

  Next, as shown in the following reaction formula (2), the alkyl radical generated by the hydrogen abstraction reaction is combined with oxygen molecules to generate an alkyl peroxy radical.

［反応式（２）中、Ｏ_２は酸素分子を表し、ＲＯＯ・はアルキルペルオキシラジカルを表す。］

[In Reaction Formula (2), O ₂ represents an oxygen molecule, and ROO · represents an alkyl peroxy radical. ]

  Next, as shown in the following reaction formula (3), the alkyl peroxy radical generated by the reaction formula (2) pulls out hydrogen atoms from hydrocarbons contained in gasoline to generate an alkyl hydroperoxide.

［反応式（３）中、ＲＯＯＨはアルキルヒドロペルオキシドを表す。］

[In reaction formula (3), ROOH represents alkyl hydroperoxide. ]

  Next, as shown in the following reaction formula (4), the alkyl hydroperoxide produced by the reaction formula (3) is reduced to an alcohol by the action of a promoter.

［反応式（４）中、ＲＯＨはアルコールを表す。］

[In the reaction formula (4), ROH represents an alcohol. ]

  Moreover, the alkyl hydroperoxide produced | generated by Reaction formula (3) decomposes | disassembles into an alkoxy radical and a hydroxy radical by the effect | action of a promoter or a heat | fever, as shown in following Reaction formula (5).

［反応式（５）中、ＲＯ・はアルコキシラジカルを表し、・ＯＨはヒドロキシラジカルを表す。］

[In the reaction formula (5), RO · represents an alkoxy radical, and · OH represents a hydroxy radical. ]

  Subsequently, the alkoxy radical produced | generated by Reaction formula (5) draws out a hydrogen atom from the hydrocarbon contained in gasoline, and produces | generates alcohol.

  As described above, hydrocarbons mainly contained in gasoline are oxidized and reformed and converted to alcohol. More specifically, since hydrocarbons contained in gasoline are hydrocarbons having 4 to 10 carbon atoms, these hydrocarbons are converted into alcohols having 4 to 10 carbon atoms. Thus, in the fuel reforming system 1 of this embodiment, the octane number of gasoline can be improved.

  The condenser 16 is provided downstream of the reformer 15 and separates the product gas generated by the reformer 15 into a condensed phase mainly composed of reformed fuel and a gas phase. The condenser 16 separates the condensed phase and the gas phase by cooling the product gas flowing out from the outlet of the reformer 15 with the outside air traveling wind generated by the traveling of the vehicle. The condensed phase material includes by-product water in addition to the reformed fuel mainly composed of alcohol, and the gas phase material includes nitrogen, oxygen, and other by-product gas components. Etc. are included.

  A filter 160 that prevents permeation of the solid phase substance is disposed upstream of the condenser 16. As this filter 160, metal nets, such as a nonwoven fabric and a stainless steel mesh, can be used, for example. The filter 160 prevents the solid phase material from being mixed into the liquid phase material (reformed fuel).

Of the produced gas flowing into the gas-liquid separator 18, the reformed fuel (fuel containing alcohol as a main component) that has become a liquid phase (condensed phase) is set on the bottom side of the gas-liquid separator 18 by gravity. It is stored in the reformed fuel tank unit 20.
The reformed fuel stored in the reformed fuel tank unit 20 is supplied to the engine fuel supply system through the reformed fuel supply unit 21 as required under the control of the ECU.

On the other hand, the substance in the gas phase out of the generated gas flowing into the gas-liquid separator 18 is supplied to the combustion in the cylinder of the engine from the gas-phase supply unit 19 provided above the gas-liquid separator 18. Is done.
The gas phase supply unit 19 supplies the gas phase material separated by the condenser 16 into the intake port of the engine. The gas phase supply unit 19 includes a gas phase supply pipe 191 connected to the intake port of the engine. The gas phase material separated by the condenser 16 is supplied into the intake port of the engine via the gas phase supply pipe 191.

  The reformed fuel tank unit 20 stores the reformed fuel in the condensed phase separated by the condenser 16. The reformed fuel tank unit 20 functions as a buffer tank that temporarily stores the reformed fuel alcohol generated by reforming gasoline by the reformer 15.

  The reformed fuel supply unit 21 supplies the reformed fuel stored in the reformed fuel tank unit 20 into an engine cylinder or an intake port. The reformed fuel supply unit 21 includes a reformed fuel pump 211, a reformed fuel supply pipe 212, and an injector (not shown). The reformed fuel supply unit 21 drives the reformed fuel pump 211 to supply the reformed fuel into an intake port of an engine (not shown) via the reformed fuel supply pipe 212 and the injector. The alcohol supply amount is controlled by adjusting the injection amount of the injector by the ECU.

  By the way, in the fuel reforming system 1 of the present embodiment, the esterification apparatus 30 is disposed on the downstream side of the reformer 15. More specifically, the esterification apparatus 30 is disposed at a position close to the downstream end of the reformer 15, that is, immediately below the reformer 15. The esterification apparatus 30 esterifies the benzoic acid contained in the product gas produced by the reformer 15 to convert it into a benzoic acid ester.

The esterification apparatus 30 includes a solid acid catalyst for esterifying benzoic acid produced by the reforming reaction by the reforming catalyst 151 into a benzoic acid ester. By using the solid acid catalyst, filling into the esterification apparatus 30 is facilitated.
As the solid acid catalyst, it is preferable to use at least one selected from the group consisting of sulfated zirconia, heteropolyacid, activated alumina, and zeolite.

  When the product gas generated by the reformer 15 flows into the esterification apparatus 30 having the above-described solid acid catalyst, benzoic acid and alcohol contained in the product gas react by the action of the solid acid catalyst. Specifically, the esterification reaction shown in the following reaction formula (7) proceeds. Thereby, benzoic acid which is difficult to dissolve in the fuel and the reformed fuel is converted into a benzoic acid ester which is easily dissolved in the fuel and the reformed fuel. At this time, the esterification reaction does not proceed unless it is under a predetermined high temperature condition. However, in this embodiment, since the esterification apparatus 30 is arranged directly under the reformer 15, the heat generated by the reforming reaction is directly used as the ester. It can be used for chemical reaction. Further, as shown in the reaction formula (7), water is simultaneously generated in addition to the benzoic acid ester, and there is no problem even if the generated water is supplied to the engine fuel supply system together with the reformed fuel.

The fuel reforming system 1 of the present embodiment having the above configuration is controlled by the ECU and operates as follows.
First, when it is determined that gasoline reform is required according to the operating state of the engine, it is determined whether or not the temperature of the engine cooling water is equal to or higher than a predetermined temperature. Immediately after the engine is started, when the temperature of the engine cooling water is lower than the predetermined temperature, the reformed fuel stored in the reformed fuel tank 20 of the condenser 16 at the previous reforming is supplied to the engine intake by the reformed fuel pump 211. Supply in the port.

  When the temperature of the engine cooling water is equal to or higher than a predetermined temperature, the fuel valve 133 and the air valve 114 are opened. Next, the reforming pump 131 pumps gasoline from the fuel tank 12 and introduces it into the mixer 14. At the same time, air that has passed through the air filter 111 is introduced into the mixer 14 by the air pump 112.

  Next, the gasoline and air introduced into the mixer 14 are uniformly mixed while being heated to a predetermined temperature to obtain a mixed fluid, and then supplied into the reformer 15. The hydrocarbon, which is the main component of gasoline in the mixed fluid supplied into the reformer 15, is converted into alcohol as the above reaction formulas (1) to (6) proceed by the action of the reforming catalyst 151. Is done. At this time, supply of engine cooling water is controlled based on the temperature monitored by the temperature sensor. Thereby, the temperature in the reformer 15 is maintained at a desired appropriate temperature.

  Next, the reformed product gas generated in the reformer 15 is introduced into the esterification apparatus 30, and benzoic acid and alcohol contained in the product gas undergo an esterification reaction by the action of the solid acid catalyst. Thereby, benzoic acid which is difficult to dissolve in the fuel and the reformed fuel is converted into a benzoic acid ester which is easily dissolved in the fuel and the reformed fuel, and clogging of the filter 160 and the like is suppressed.

  Next, the reformed product gas generated by the reformer 15 is separated into a condensed phase and a gas phase by the condenser 16, and this reformed fuel is stored in the reformed fuel tank unit 20. The reformed fuel in the reformed fuel tank unit 20 is supplied into the intake port of the engine by the reformed fuel pump 211. On the other hand, the separated gas phase substance is introduced into the intake port of the engine through the gas phase supply unit 19 to be used for combustion in the cylinder of the engine.

  If it is determined that gasoline reforming is not necessary according to the operating state of the engine, first, the air pump 112 is stopped and the air valve 114 is closed. Thereafter, after the reformer 15 is filled with gasoline, the reforming pump 131 is stopped, the fuel valve 133 is closed, and the supply of gasoline into the mixer 14 is stopped. This avoids a situation in which the reforming reaction proceeds due to oxygen remaining in the reformer 15 while the system is stopped.

According to the fuel reforming system 1 of the present embodiment, the following effects are exhibited.
In this embodiment, benzoic acid produced by the reforming reaction is esterified on the downstream side of the reformer 15 having the reforming catalyst 151 for reforming gasoline using air to produce alcohol. An esterification apparatus 30 having a solid acid catalyst for forming an ester was provided.
As a result, the benzoic acid that is not easily dissolved in the reformed fuel or the fuel that is generated when the fuel is reformed is reacted with the alcohol generated in the reforming reaction to be converted into a benzoic acid ester that is soluble in the fuel or the reformed fuel. Thereby, precipitation of benzoic acid can be suppressed. Therefore, according to the fuel reforming system 1 according to the present embodiment, clogging of the filter 160 provided in the condenser 16 and the injector provided in the reformed fuel supply unit 21 can be suppressed, and the fuel is reformed more efficiently. it can.

  In the present embodiment, the esterification apparatus 30 is disposed in the vicinity of the downstream end of the reformer 15. That is, the esterification apparatus 30 was disposed immediately below the reformer 15. Thereby, since heat generated by the reforming reaction can be used for the esterification reaction, benzoic acid can be esterified more efficiently.

In this embodiment, at least one selected from the group consisting of sulfated zirconia, heteropolyacid, activated alumina, and zeolite is used as the solid acid catalyst, and the main catalyst composed of an N-hydroxyimide group-containing compound is used as the reforming catalyst. A reforming catalyst comprising a catalyst and a promoter composed of a transition metal compound was used.
Thereby, benzoic acid can be more reliably esterified in the esterification apparatus 30 by the action of the above-described solid acid catalyst effective for esterification using alcohol generated in the reforming reaction.

  It should be noted that the present invention is not limited to the above-described embodiment, and modifications, improvements, etc. within a scope that can achieve the object of the present invention are included in the present invention.

  In the above embodiment, gasoline is used as the fuel, but the present invention is not limited to this. For example, even when alcohol-containing gasoline containing alcohol such as ethanol is used, the same effects as those of the above-described embodiment can be obtained.

  Moreover, in the said embodiment, although the esterification apparatus 30 for esterifying benzoic acid was arrange | positioned directly under the modifier 15, it is not limited to this. For example, the esterification device may be integrated with the outlet (downstream end) of the reformer. Specifically, for example, when a reformer including a plurality of reaction tubes filled with a reforming catalyst is used, a solid acid catalyst is disposed in a porous body disposed like a lid at the outlet of the reaction tube. May be. In this case, it is not necessary to provide a separate space for the esterification apparatus, the space can be used effectively, and the system can be downsized.

DESCRIPTION OF SYMBOLS 1 Fuel reforming system 15 Reformer 100 Esterification apparatus 151 Reforming catalyst

Claims (4)

A reformer having a reforming catalyst for reforming hydrocarbon-based fuel using air to produce alcohol;
A fuel reformer, comprising: an esterification device which is disposed downstream of the reformer and has a solid acid catalyst for esterifying benzoic acid produced by a reforming reaction by the reforming catalyst into a benzoic acid ester system.   The fuel reforming system according to claim 1, wherein the esterification device is disposed in proximity to a downstream end of the reformer.   The fuel reforming system according to claim 1 or 2, wherein the solid acid catalyst is at least one selected from the group consisting of sulfated zirconia, heteropolyacid, activated alumina, and zeolite.   The fuel reforming system according to any one of claims 1 to 3, wherein the reforming catalyst includes a main catalyst composed of an N-hydroxyimide group-containing compound and a promoter composed of a transition metal compound.

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