JP2005255896A - Desulfurizer, desulfurization system, hydrogen manufacturing apparatus, and fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a desulfurizer and a desulfuriztion system both of which are suitable for subjecting a liquid fuel to thermal liquid-phase desulfurization and capable of controlling bumping and pressure fluctuations, and to provide a hydrogen manufacturing apparatus and a fuel cell system both of which can be operated more stably. <P>SOLUTION: In the desulfurizer which performs desulfurization while heating the liquid fuel by a heating medium in the presence of a desulfurizing agent, at least one desulfurizing chamber which has an area for containing the desulfurizing agent and forms the passage of the liquid fuel and a plurality of tubes which, penetrating the above area and arranged almost horizontally, forms the passage of the heating medium are equipped; and in at least one desulfurizing chamber, a liquid fuel outlet is formed above a liquid fuel supply inlet. The desulfurization system is equipped with the desulfurizer and a heat exchanger which preheats the liquid fuel supplied to the desulfurizer with the heating medium discharged from the desulfurizer and which lets the heating medium flow into the shell side and the liquid fuel into the tube side. A hydrogen manufacturing apparatus having this desulfurization system and a fuel cell system having this hydrogen manufacturing apparatus are also provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a desulfurizer and a desulfurization system for reducing the sulfur content in a liquid fuel such as kerosene. The present invention also relates to a hydrogen production apparatus for producing a gas containing hydrogen by reforming after desulfurizing a liquid fuel. Furthermore, the present invention relates to a fuel cell system using a hydrogen-containing gas obtained from such a hydrogen production apparatus as a fuel.

  Development of fuel cells has been actively promoted as a power generation system with high energy utilization efficiency. Among them, the polymer electrolyte fuel cell is particularly attracting attention because of its high power density and ease of handling.

  Since a fuel cell is a system that generates electricity by an electrochemical reaction between hydrogen and oxygen, it is essential to establish a hydrogen supply means. As one of the methods, there is a method of producing hydrogen by reforming a raw material for hydrogen production such as a hydrocarbon fuel, and a method using pure hydrogen in that a hydrocarbon fuel supply system has already been socially established. More advantageous.

  Examples of the hydrocarbon fuel include city gas, gasoline, kerosene, and light oil. Liquid fuels such as gasoline, kerosene, and light oil are attracting attention as fuel cells because they are easy to handle, store and transport, and are inexpensive. In order to use these hydrocarbon fuels in fuel cells, it is necessary to produce hydrogen from hydrocarbons. For this purpose, hydrocarbons are reacted with water in a reformer, mainly into carbon monoxide and hydrogen. In the shift reactor, where most of the carbon monoxide reacts with water to convert it to hydrogen and carbon dioxide, and finally in the selective oxidation reactor, a small amount of residual carbon monoxide reacts with oxygen to form carbon dioxide. Things have been done. Further, since sulfur becomes a poisoning substance such as a reforming catalyst, a desulfurizer for removing sulfur in the raw material for hydrogen production is often provided. Such a fuel cell system is disclosed in Patent Document 1, for example.

  The desulfurizing agent used in the desulfurizer has an appropriate operating temperature range, and the desulfurizing agent is heated to this temperature range. Patent Document 2 discloses that combustion exhaust gas from a burner of a fuel reformer is guided to a desulfurizer, and thereby heats a catalyst in the desulfurizer.

As a technique for desulfurizing liquid fuel, for example, Patent Document 3 describes desulfurization of part or all of kerosene in a liquid phase state.
JP 2003-187832 A Japanese Patent Laid-Open No. 5-3043 JP 2002-2014478 A

  When the liquid fuel is heated and desulfurized while in the liquid phase, the liquid fuel may locally boil even if the liquid fuel does not vaporize in terms of the overall heat balance. When bumping occurs, the pressure in the system fluctuates greatly, making it difficult to control the flow rate. Therefore, it is desirable to reduce the possibility of bumping as much as possible. It is also desirable to make the pressure fluctuation difficult even if there is some bumping.

  In particular, in a fuel cell system, fluctuations in the pressure of the fuel supplied to the fuel cells appear as fluctuations in voltage, so it is desirable to suppress the fluctuations in the pressure of the fuel.

  An object of the present invention is to provide a desulfurizer and a desulfurization system that can suppress bumping and pressure fluctuation and can be operated more stably, which is suitable for desulfurization of liquid fuel in a liquid phase under heating.

  Another object of the present invention is to provide a hydrogen production apparatus that obtains a hydrogen-containing gas by desulfurization after liquid fuel is desulfurized, and a fuel cell system that uses the hydrogen-containing gas obtained from the hydrogen production apparatus as fuel. It is possible to suppress bumping and pressure fluctuation, and to enable more stable operation.

According to the present invention, in a desulfurizer for desulfurizing while heating a liquid fuel with a heating medium in the presence of a desulfurizing agent,
At least one desulfurization chamber having a region for containing a desulfurization agent and forming a flow path for the liquid fuel;
A plurality of tubes that form channels of the heating medium that are disposed substantially horizontally through the region;
A desulfurizer is provided in which at least one of the desulfurization chambers has a liquid fuel discharge port formed above the liquid fuel supply port.

In the desulfurizer, the desulfurization chamber is the whole or a part of a cylindrical container,
The plurality of tubes are preferably arcuate.

In the desulfurizer, a plurality of the desulfurization chambers are connected in series to form one liquid fuel flow path,
In the desulfurization chamber on the most downstream side of the flow path of the liquid fuel, it is preferable that a liquid fuel discharge port is formed above the liquid fuel supply port.

In the desulfurizer, a plurality of the desulfurization chambers are connected in series to form one liquid fuel flow path,
In the desulfurization chamber on the most upstream side of the flow path of the liquid fuel, it is preferable that a liquid fuel discharge port is formed above the liquid fuel supply port.

According to the present invention, a desulfurizer for desulfurizing while heating a liquid fuel with a heating medium in the presence of a desulfurizing agent, and a liquid fuel supplied to the desulfurizer for preheating with a heating medium discharged from the desulfurizer. A heat exchanger,
The desulfurizer has at least one desulfurization chamber having a region for containing a desulfurizing agent and forming a flow path for the liquid fuel, and a flow path for the heating medium disposed substantially horizontally through the region. A liquid fuel discharge port formed above the liquid fuel supply port in at least one of the desulfurization chambers,
The heat exchanger is provided with a desulfurization system including a cylinder that forms a flow path for the heating medium and a pipe that forms a flow path for the liquid fuel and penetrates the cylinder.

  In the desulfurization system, it is preferable that the liquid fuel flow path downstream of the desulfurizer further has a capillary.

In the desulfurization system, in the desulfurizer, the desulfurization chamber is a whole or a part of a cylindrical container, and the plurality of tubes are arc-shaped,
It is preferable that the heat exchanger has an annular column shape and is provided on the outer periphery of the cylindrical container.

According to the present invention, a desulfurizer for desulfurizing while heating a liquid fuel with a heating medium in the presence of a desulfurizing agent, and a liquid fuel supplied to the desulfurizer for preheating with a heating medium discharged from the desulfurizer. A heat exchanger, and a reformer that produces a gas containing hydrogen using the desulfurized liquid fuel as a raw material,
The reformer includes a reforming reaction unit including a reforming catalyst and a burner that performs combustion for heating the reforming reaction unit.
The desulfurizer has at least one desulfurization chamber having a region for containing a desulfurizing agent and forming a flow path for the liquid fuel, and a flow path for the heating medium disposed substantially horizontally through the region. A liquid fuel discharge port formed above the liquid fuel supply port in at least one of the desulfurization chambers,
The heat exchanger has a cylinder that forms a flow path for the heating medium, and a tube that forms a flow path for the liquid fuel and penetrates the cylinder.
There is provided a hydrogen production apparatus having means for guiding the combustion exhaust gas of the burner discharged from the reformer to the flow path of the heating medium of the desulfurizer.

  According to the present invention, there is provided a fuel cell system comprising the above-described hydrogen production apparatus and a fuel cell using as a fuel a gas containing hydrogen produced by the hydrogen production apparatus.

  ADVANTAGE OF THE INVENTION According to this invention, the desulfurizer and desulfurization system which can suppress bumping and a pressure fluctuation suitable for desulfurizing liquid fuel with a liquid phase under heating, and can operate more stably are provided. Further, in a hydrogen production apparatus that obtains a hydrogen-containing gas by reforming liquid fuel after desulfurization, and a fuel cell system that uses hydrogen-containing gas obtained from the hydrogen production apparatus as fuel, bumping and pressure fluctuations during desulfurization are prevented. Suppresses and more stable operation is possible.

  Further, by making the desulfurizer substantially cylindrical, it is possible to easily dispose and integrate with a heat exchanger for preheating liquid fuel. By such adjacent arrangement and further integration, heat loss can be reduced and space can be saved.

  Hereinafter, the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto.

  FIG. 1 shows a schematic configuration of one embodiment of the fuel cell system of the present invention. In this fuel cell system, the desulfurization system of the present invention is applied to a polymer electrolyte fuel cell system using kerosene, and kerosene is used as a liquid fuel, and combustion exhaust gas of a reformer burner is used as a heating fluid.

  The fuel cell system includes a desulfurizer 1, a heat exchanger 11 that preheats liquid fuel supplied to the desulfurizer (hereinafter, referred to as “liquid fuel preheater” in some cases), hydrogen from the desulfurized liquid fuel and steam. It has a reformer 31 that produces a hydrogen-containing gas that is a gas to be contained, and a fuel cell 42 that uses this hydrogen-containing gas as fuel. The desulfurization system of the present invention includes a desulfurizer 1 and a heat exchanger 11. The hydrogen production apparatus of the present invention has this desulfurization system and the reformer 31. The hydrogen production apparatus or the fuel cell system is provided with a vaporizer 41 for vaporizing the liquid fuel desulfurized as necessary.

  The desulfurizer 1 has a desulfurization chamber 2 that forms a flow path for liquid fuel. The desulfurization vessel has a region for accommodating the desulfurizing agent 6 (hereinafter, sometimes referred to as “desulfurizing agent accommodating region”). The liquid fuel supply port 7 is provided in the lower part of the desulfurization chamber, and the liquid fuel discharge port 8 is provided in the upper part of the desulfurization chamber. The desulfurizer includes a plurality of pipes 5 that form a flow path for the heating medium, which are disposed substantially horizontally through the desulfurization agent storage region, and two headers (entrance on the inlet side 3) that respectively communicate with both ends of the plurality of pipes. And an outlet side header 4). The heat exchanger 11 has a cylinder 12 and a tube 13 that passes through the cylinder 12. The desulfurization agent accommodation region may be the entire region of the desulfurization chamber excluding the region occupied by the pipe 5 or a part thereof.

  Kerosene is supplied from a kerosene tank (not shown) to a liquid fuel preheater pipe 13 via a line 51 by a pump (not shown) and heated by heat exchange with combustion exhaust gas flowing on the cylinder 12 side, and desulfurized via a line 52. The chamber 2 is supplied from a liquid fuel supply port 7. Kerosene rises in the desulfurization chamber while being heated by the pipe 5 through which the heating medium flows while being in contact with the desulfurizing agent 6, and desulfurized kerosene is obtained from the liquid fuel discharge port 8 via the line 53. A capillary 21 is connected to the liquid fuel discharge port 8.

  This kerosene is mixed with steam necessary for the steam reforming reaction through the vaporizer 41, reformed by the reformer 31, and supplied to the anode chamber 42 </ b> A of the polymer electrolyte fuel cell 42. Although not shown, a CO shift reactor and a selective oxidation reactor are provided between the reformer and the anode chamber. The reformer 31 is an external heat type reformer that burns kerosene with a burner 33 and heats the reforming reaction section 32 from the outside by the combustion heat. The reforming reaction section is formed by a reforming reaction tube filled with a reforming catalyst. The burner and the reforming reaction section are provided in the reforming furnace 34.

  On the other hand, the combustion exhaust gas from the burner 33 heats and vaporizes the kerosene desulfurized in the vaporizer 41, and then supplies it from the line 61 to the heating medium inlet side header 3 of the desulfurizer. Then, the desulfurizing agent 6 and the liquid fuel are heated while passing through the pipe 5 and are discharged from the header 4. Thereafter, it is supplied to the cylinder 12 of the liquid fuel preheater via the line 62, the kerosene flowing through the pipe 13 is heated, and is discharged from the line 63.

  Air is humidified and supplied to the cathode chamber 42C of the fuel cell as necessary. The anode off-gas discharged from the anode chamber and the cathode off-gas discharged from the cathode chamber are discharged using heat as appropriate. Since the anode off gas contains unburned combustible components, it is appropriately used, for example, as burner fuel.

  The main factors affecting bumping are temperature difference and space. When the local temperature difference ΔT between the high-temperature fluid and the low-temperature fluid related to heat exchange is about 130 to 140 ° C., bumping (a phenomenon called evaporation vibration) tends to occur, and therefore ΔT does not change even if the operating conditions slightly change. Preventing such a temperature from being reached is effective in suppressing bumping. Further, if there is a large space, bumping tends to occur easily, and bumping is difficult to occur inside a thin tube, for example.

  In order to make it difficult for the pressure to fluctuate even when bumping occurs, it is effective to increase the capacity of the flow path and further to increase the cross-sectional area of the flow path. Such a flow path acts as a buffer to relieve pressure fluctuations. In addition, when a capillary (portion in which the diameter of the passage is narrowed) is provided in the flow path, pressure fluctuation is less likely to be transmitted downstream from the capillary due to the resistance of that portion.

  In the above configuration, kerosene is heated in two stages by the liquid fuel preheater 11 and the desulfurizer 1. In a liquid fuel preheater that supplies kerosene at approximately room temperature (not heated), ΔT tends to increase. However, in the liquid fuel preheater, kerosene flows through the pipe 13, so that the cross-sectional area of the flow path is reduced to cause bumping. It can be easily suppressed. On the other hand, the fact that the combustion exhaust gas supplied to the liquid fuel preheater is cooled by the desulfurizer 1 is also useful for reducing the ΔT in the heat exchanger and suppressing bumping. Further, by exchanging heat with kerosene and combustion exhaust gas as counterflows in at least a part of the liquid fuel preheater, ΔT can be reduced and bumping can be suppressed.

  In the desulfurizer, combustion exhaust gas is flowed to the tube side, and kerosene is flowed to the body side. Since preheated kerosene is supplied to the desulfurizer, ΔT can be reduced to suppress bumping. Since kerosene flows on the barrel side, the capacity of the region where kerosene is heated in the desulfurizer can be increased, functioning as a buffer, and pressure fluctuation can be easily reduced. Furthermore, by extending the tube almost horizontally and flowing kerosene upward in the vertical direction, it is easy to increase the flow passage cross-sectional area of kerosene in the desulfurizer and easily reduce pressure fluctuations. is there. In addition, by making the kerosene flow vertically upward, fine bubbles can be easily removed by the pressure caused by the weight of kerosene, which is effective in preventing bumping and suppressing pressure fluctuations.

  The plurality of tubes that form the flow path of the heating medium are arranged substantially horizontally. “Substantially horizontal” includes not only strictly horizontal but also substantially horizontal.

  Further, the presence of the capillary 21 downstream of the liquid fuel discharge port of the desulfurizer can suppress the pressure fluctuation from being transmitted downstream from the capillary. The capillary is a channel cross-sectional area that is smaller than the channel cross-sectional area up to that time, and is intended to rapidly increase the differential pressure (in-pipe pressure), and the cross-sectional area is 1/50 of that upstream of the capillary. The ratio is preferably 1/2 or less and more preferably 1/10 or more and 1/3 or less. If the cross-sectional area is smaller than 1/50, the pressure loss of the pipe increases, which is disadvantageous in that it tends to increase the operating power energy of the pump that sends out kerosene. This is disadvantageous in that the suppression effect tends to be small. The length of the capillary can be appropriately designed to suppress pressure fluctuation.

  In the form shown in FIG. 1, the desulfurizer has only one desulfurization chamber. The liquid fuel supply port is provided in the lower part of the desulfurization chamber. The position can be the bottom surface or the bottom of the desulfurization chamber, but is not necessarily required as long as the liquid fuel flows upward in the desulfurization chamber. The liquid fuel discharge port is provided in the upper part of the desulfurization chamber. The position can be the upper surface or the top of the desulfurization chamber, but it is not necessarily required as long as the liquid fuel flows upward in the desulfurization chamber. In other words, since the flow of the liquid fuel in the desulfurization chamber becomes an upward flow, the liquid fuel discharge port only needs to be above the liquid fuel supply port, but in order to distribute the liquid fuel in a wider region in the desulfurization chamber, It is desirable to provide the supply port at a position as low as possible and the liquid fuel discharge port as high as possible.

  The cross-sectional area of the flow path through which the liquid fuel flows in the liquid fuel preheater is such that the fluid velocity is preferably 0.1 cm / s to 50 cm / s, more preferably 0.5 cm / s to 10 cm / s. Can be set.

  Thus, by suppressing bumping and suppressing pressure fluctuation, it becomes possible to stably control the flow rate of kerosene, and it becomes easy to desulfurize stably.

[Liquid fuel]
As the liquid fuel, petroleum fuels such as gasoline, naphtha and kerosene, alcohols such as methanol and the like, hydrocarbon fuels which are liquid at 0.1 MPa and 25 ° C., or liquefied petroleum gas can be used. Of these, kerosene is preferable because it is easily available for industrial use and consumer use, and is easy to handle.

  The sulfur concentration in the liquid fuel after desulfurization is preferably 0.1 mass ppm or less, more preferably 50 mass ppb or less, from the viewpoint of suppressing poisoning of the reforming catalyst when the liquid fuel is supplied to the reformer. And

  There is no restriction | limiting in particular in the sulfur concentration in the liquid fuel with which it uses for desulfurization, If it is a liquid fuel which can be converted into the said sulfur concentration in a desulfurization process, it can be used. However, from the viewpoint of the life of the desulfurizing agent, the sulfur concentration of the liquid fuel is preferably 150 ppm by mass or less, and more preferably 50 ppm by mass or less.

[Desulfurization agent]
As the desulfurizing agent, a known desulfurizing agent such as a sorption type desulfurizing agent may be used. For example, it contains at least one metal selected from Ni, Cu, Zn and Fe, and the carrier is silica, alumina, titania, zirconia. In addition, one using at least one selected from magnesia and complex oxides thereof, or one produced by coprecipitation of these components can be used. Among them, a sorbent containing at least Ni is preferable from the viewpoint of catalyst life.

  The shape of the desulfurizing agent is not particularly limited, but an extruded molded body such as a cylinder, a trefoil, and a four leaf, a cylinder, a dome-shaped tablet molded body, and a spherical molded body are preferable.

[Desulfurization conditions]
The supply amount of the liquid fuel to the desulfurizing agent, the device size, in terms of economy and desulfurization rate, preferably 0.05Hr ^-1 or more 5.0Hr ^-1 or less at LHSV (liquid hourly space velocity), 0.1 hr ^-1 or more It is more preferably 3.0 hr ⁻¹ or less.

  The temperature for desulfurization, that is, the desulfurization temperature is preferably 100 ° C to 300 ° C, more preferably 100 ° C to 220 ° C, and further preferably 130 ° C to 200 ° C from the viewpoint of the desulfurization ability or life of the desulfurization agent. When the sorption type desulfurizing agent is used at low temperature, the sulfur compound in the liquid fuel is adsorbed on the surface as it is without chemical reaction and desorption does not occur, and the desulfurizing agent life is shortened. This is disadvantageous in that the desulfurization ability or life of the steel tends to be reduced. A high temperature is disadvantageous in that the desulfurization ability or life of the desulfurization agent tends to be reduced, such as carbon deposition resulting in a decrease in desulfurization sites on the desulfurization agent and a shortened life.

  Desulfurization is performed under conditions that do not boil even under heating. From this viewpoint, the desulfurization is preferably 100 kPa-G (G indicates a gauge pressure) or more. From the viewpoint of suppressing energy required for boosting, it is preferably 500 kPa-G or less. In order to realize such a pressure, liquid fuel may be supplied to the desulfurizer at a predetermined pressure by appropriately using a boosting means such as a pump.

[Heat exchange conditions]
Reducing the temperature difference between the desulfurizer inlet header and the outlet header of the heating medium is also effective in reducing the horizontal temperature distribution of the liquid fuel in the desulfurization vessel and preventing bumping. In this respect, the temperature difference is preferably 100 ° C. or less, more preferably 50 ° C. or less, and further preferably 30 ° C. or less. From the viewpoint of increasing the amount of heat exchange with the liquid fuel, this temperature difference is preferably 5 ° C or higher, more preferably 10 ° C or higher, and further preferably 20 ° C or higher.

  When kerosene is used as the liquid fuel, for example, in order to increase the kerosene entering the desulfurizer to a desulfurizer set temperature of 130 ° C. or higher and 200 ° C. or lower, the temperature of the heating medium supplied to the desulfurizer ( In FIG. 1, the temperature at the heating medium inlet side header 3) is preferably 170 ° C. or more and 300 ° C. or less, and the temperature of kerosene discharged from the desulfurizer (the temperature at the heating medium outlet side header 4 in FIG. 1) is 130 ° C. The temperature is preferably set to 250 ° C. or lower.

(Cylindrical desulfurizer)
FIG. 2 shows an example of the structure when the desulfurizer is cylindrical. FIG. 2A is a schematic plan sectional view, and FIG. 2B is a schematic side sectional view. The inside of the cylindrical container is partitioned, and an inlet side header 103, an outlet side header 104, and a desulfurization chamber 102 are formed. A plurality of pipes 105 communicating with the respective headers and penetrating the desulfurization vessel are all arranged horizontally and arranged in a concentric arc shape. In some cases, the header may be separately provided outside the cylindrical container.

  Kerosene is supplied from the line 152 to the desulfurization chamber through the liquid fuel supply port 107 provided on the lower surface, flows vertically through the desulfurization chamber filled with the desulfurization agent 106, and the liquid fuel discharge port 108 provided on the upper surface. , Discharged from line 153. On the other hand, the combustion exhaust gas (heating medium) of the reformer burner is supplied from the line 161 to the header 103, passes through a plurality of horizontally arranged arcuate tubes 105, and is discharged from the header 104 to the line 162. It is also effective to provide a capillary in the line 153 as in the above-described embodiment.

  If the desulfurizer is made cylindrical in this way, it becomes easy to arrange the cylindrical reformer adjacent to the cylindrical reformer and further to integrate them. In this case, it is possible to exchange burner combustion exhaust gas and kerosene at a very short distance between the desulfurizer and the reformer, which is preferable from the viewpoint of space saving and heat loss suppression.

  Further, since the inlet and outlet of the pipe 105 through which the heating medium flows, that is, the high temperature portion and the low temperature portion can be arranged close to each other, the temperature distribution in the horizontal direction of kerosene can be reduced, which is also effective for preventing bumping. .

  FIG. 3 shows a desulfurization system in which a short cylindrical desulfurizer and a heat exchanger for kerosene preheating are integrated. FIG. 3A is a schematic perspective view showing the outline, and FIG. 3B is a schematic side sectional view. In this desulfurization system, a heat exchanger (liquid fuel preheater) 211 is integrally provided on the outer periphery of a desulfurizer 201 having the same configuration except for the fluid and the portion shown in FIG.

  In the liquid fuel preheater 211, an annular cylindrical container is partitioned to form a cylinder 212 and headers 215 and 216. Thereby, a liquid fuel preheater can be made into an annular column shape. In some cases, the header can be separately provided outside the annular cylindrical container, and the annular cylindrical liquid fuel preheater includes such a form in which pipes and headers are connected to the annular cylindrical container. Arc-shaped pipes 213 penetrating the body of the liquid fuel preheater and communicating at both ends with the headers 215 and 216, respectively, are arranged in parallel on the circumference concentric with the pipe 205 passing through the desulfurization chamber filled with the desulfurization agent 206. Three are provided. Kerosene is passed through the pipe 213, and combustion exhaust gas discharged from the desulfurizer is flowed outside thereof. The structure for fluid coupling between the desulfurizer and the heat exchanger and the supply or discharge of the fluid to or from the desulfurization system can be found in the desulfurizer headers 203, 204 and the liquid fuel preheater headers 215, 216. It is possible to design appropriately such as providing an opening that opens to the outside, or providing a communication port or a communication pipe for communicating between the headers.

  Up to this point, the desulfurizer has a single desulfurization chamber, but the desulfurizer can have a plurality of desulfurization chambers. When there is only one desulfurization chamber, depending on the cross-sectional area of the liquid fuel desulfurization chamber and the supply mode of the liquid fuel to the desulfurization chamber, a relatively good portion and a relatively bad portion of the liquid fuel flow occur, This may affect desulfurization performance. In order to suppress such a phenomenon, for example, a manifold can be provided outside the desulfurization chamber, and liquid fuel can be supplied from the manifold to the desulfurization chamber through a plurality of liquid fuel supply ports. Alternatively, as described below, a plurality of desulfurization chambers can be connected in series to form one liquid fuel flow path.

  FIG. 4 shows a desulfurization configuration in which the shape of the desulfurizer is a rectangular parallelepiped in the desulfurizer shown in FIG. Indicates a vessel. The desulfurization chambers 302a to 302e are sequentially adjacent to each other to form one flow path. Kerosene is supplied from a kerosene supply port 307 provided in the lower part (here, the bottom surface) of the desulfurization chamber 302a located on the most upstream side of the flow path, and rises in the desulfurization chamber 302a, and in the upper part, the baffle plate 390a and the container 399 is discharged from the gap between them and supplied to the desulfurization chamber 302b. This gap is a liquid fuel discharge port of the desulfurization chamber 302a and a liquid fuel supply port of the desulfurization chamber 302b. Kerosene sequentially passes through the desulfurization chamber in a downward flow in the desulfurization chamber 302b, an upward flow in the desulfurization chamber 302c, and a downward flow in the desulfurization chamber 302d. Although not shown, each desulfurization chamber is filled with a desulfurizing agent. In the desulfurization chamber 302e located on the most downstream side of the flow path, the gap between the baffle plate 390d and the container 399 is a liquid fuel supply port, from which kerosene is supplied to rise in the desulfurization chamber 302e, The liquid is discharged from the liquid fuel discharge port 308 provided in the upper portion (here, the top surface) of the chamber 302e and discharged from the desulfurizer.

  The combustion exhaust gas which is a heating medium is supplied from the heating medium inlet header 303 and heats kerosene by heat exchange through the pipe 305 penetrating the desulfurization chambers 302a to 302e in the same manner as shown in FIG. It is discharged from 304.

  FIG. 5 shows a form in which a plurality of desulfurization chambers as described above are provided in a cylindrical desulfurizer. Similar to the desulfurizer shown in FIG. 2, the inside of one cylindrical container 499 is partitioned to form the inlet header 403 and the outlet header 404 for the heating medium. In the form shown in FIG. 2, the portion that was one desulfurization chamber is partitioned by baffle plates 490 a to 490 d in this form, and desulfurization chambers 402 a to 402 e are formed. In the desulfurization chamber 402a located on the most upstream side of the kerosene flow path, an opening 491a formed at the lower end on the outer periphery side of the plate-like member for forming the outlet header 404 is a liquid fuel supply port, and this opening 491a It exists in the lower part of the desulfurization chamber 402a (here, the position of the side surface in contact with the bottom surface). The liquid fuel discharge port of the desulfurization chamber 402a is an opening 491b formed at the upper end on the outer peripheral side of the baffle plate 490a. This opening 491b exists in the upper part of the desulfurization chamber 402a (here, the position of the side surface in contact with the upper surface). Kerosene is supplied from the opening 491a, rises in the desulfurization chamber 402a, is discharged from the opening 491b, and is supplied to the desulfurization chamber 402b at the same time. Kerosene flows downward in the desulfurization chamber 402b and enters the desulfurization chamber 402c through an opening 491c provided at the lower end on the outer periphery of the baffle plate 490b. It enters into the desulfurization chamber 402d, where it descends and is discharged from an opening 491e formed at the lower end on the outer peripheral side of the baffle plate 490d. In the desulfurization chamber 402e located on the most downstream side of the kerosene flow path, the liquid fuel supply port is an opening 491e, and the liquid fuel discharge port is formed at the upper end on the outer peripheral side of the plate-like member for forming the inlet side header 403. It is the formed opening 491f. The opening 491f exists in the upper part of the desulfurization chamber 402e (here, the position of the side surface in contact with the top surface).

  The means for supplying kerosene from the outside of the desulfurizer to the opening 491a and the means for discharging the kerosene from the opening 491f to the outside of the desulfurizer are not shown in the figure, but piping is used and the headers 403 and 404 are further partitioned. Can be designed as appropriate. For example, if the pipe passes through the header 404 and is connected to the opening 491a, kerosene can be supplied from the outside of the desulfurizer to the opening 491a.

  In the form shown in FIG. 5, although not shown, a pipe (shown by the pipe 105 in FIG. 2) for flowing the heating medium is provided in the same manner as the form shown in FIG.

  As described above, in the form in which the flow path of the liquid fuel is formed by the plurality of desulfurization chambers, the liquid fuel becomes an upward flow in the desulfurization chamber located most downstream of the liquid fuel flow channel among these desulfurization chambers. Is preferred. As described in the case of a single desulfurization chamber, setting the flow of liquid fuel vertically upward tends to eliminate minute bubbles due to the pressure of the liquid fuel due to its own weight, and is effective in preventing bumping and suppressing pressure fluctuations. In a configuration in which a plurality of desulfurization chambers are connected in series, the pressure fluctuation in the most downstream desulfurization chamber has the strongest influence on the downstream side of the desulfurizer, so the flow in the most downstream desulfurization chamber is directed vertically upward. It is preferable. Therefore, it is preferable to dispose the liquid fuel discharge port above the liquid fuel supply port in the most downstream desulfurization chamber.

  Furthermore, in a form in which the flow path of the liquid fuel is formed by a plurality of desulfurization chambers, the liquid fuel discharge is located above the liquid fuel supply port in the desulfurization chamber located upstream of the liquid fuel flow path among these desulfurization chambers. An outlet is preferably arranged. This is because the flow of the liquid fuel in the desulfurizer becomes smooth even when bubbles are mixed in the liquid fuel supplied to the desulfurizer.

  The shape of the desulfurizer can be cylindrical or polygonal, and the shape of the desulfurization chamber is cylindrical (the central axis of the cylinder is the vertical direction) or the cylindrical container has its central axis as described above. It can be made into the sector-shaped column shape, rectangular parallelepiped, etc. which were divided by two surfaces to include, and can also be made into a polygonal column shape.

  When the desulfurizer is cylindrical, the L / D (height / diameter ratio) is preferably 0.1 or more and 2 or less, and more preferably 0.3 or more and 1.0 or less. When L / D is larger than 2, it is disadvantageous in that the vertical temperature distribution tends to be larger. When L / D is smaller than 0.1, the effect of preventing bumping due to kerosene upflow tends to be smaller. It is disadvantageous in that there is.

[Hydrogen production equipment]
The hydrogen production apparatus of the present invention includes the above-described desulfurizer, liquid fuel preheater, and reformer, and a vaporizer, a CO shift reactor, and a selective oxidation reactor are provided as necessary.

  When a plurality of tubes forming the flow path of the heating medium are formed in an arc shape and the inside of the cylindrical vessel is partitioned to form a desulfurization vessel, the outer shape of the desulfurizer may be made substantially cylindrical as shown in FIG. If such a desulfurizer is used, it can be arranged compactly in contact with a reformer having a cylindrical reforming furnace. In some cases, as shown in FIG. 3, a desulfurization system in which a desulfurizer and a liquid fuel desulfurizer are integrated can be formed in a compact manner in contact with the reformer. Such a hydrogen production apparatus is easy to suppress heat loss and miniaturize.

  The liquid fuel is mixed with steam for steam reforming reaction (in some cases, oxygen-containing gas such as air is also mixed), and the reformer burner is fuel for combustion and oxygen-containing gas ( Air or the like) can be supplied as appropriate.

  The hydrogen production apparatus of the present invention has means for guiding the combustion exhaust gas of the burner discharged from the reformer to the heating medium flow path of the desulfurizer. For this purpose, the burner combustion exhaust gas discharge port of the reformer and the heating medium inlet header of the desulfurizer can be connected by a pipe, and a booster such as a blower can be provided in the pipe as necessary. In the form shown in FIG. 1, a line from the reformer furnace 34 to the header 61 through the vaporizer 41 corresponds to this means. Further, when the desulfurizer and the reformer are installed adjacent to each other or integrated as described above, it may be sufficient to provide an opening that communicates a predetermined portion of the desulfurizer and the reformer.

[Reformer]
The reformer is an apparatus for producing a reformed gas containing hydrogen by reacting a raw material for hydrogen production with water and / or oxygen. In this apparatus, the raw material for hydrogen production is mainly decomposed into hydrogen and carbon monoxide. Usually, carbon dioxide and methane are also contained in the cracked gas.

  The reformer used in the present invention is an externally heated reformer that heats the reforming reaction section from the outside, and the hydrogen production apparatus of the present invention is suitably applied when the reforming reaction is a steam reforming reaction. it can. Further, even when the reforming reaction is an autothermal reforming reaction, it can be applied when heating from the outside is required.

The steam reforming reaction is a reaction between steam and hydrocarbon, but usually involves heating from the outside because it involves a large endotherm. Usually, the reaction is carried out in the presence of a metal catalyst typified by a Group VIII metal such as nickel, cobalt, iron, ruthenium, rhodium, iridium and platinum. The reaction temperature can be 450 ° C to 900 ° C, preferably 500 ° C to 850 ° C, more preferably 550 ° C to 800 ° C. The amount of steam introduced into the reaction system is defined as the ratio of the number of moles of water molecules to the number of moles of carbon atoms contained in the raw material for hydrogen production (steam / carbon ratio), and this value is preferably 0.5-10. Preferably it is 1-7, More preferably, it is 2-5. When the raw material for hydrogen production is liquid, the space velocity (LHSV) at this time is A / B when the flow rate in the liquid state of the raw material for hydrogen production is A (L / h) and the volume of the catalyst layer is B (L). This value is preferably set in the range of 0.05 to 20 h ⁻¹ , more preferably 0.1 to 10 h ⁻¹ , and still more preferably 0.2 to 5 h ⁻¹ .

  Autothermal reforming reaction is a method of reforming while balancing the reaction heat by advancing the steam reforming reaction with the heat generated at this time while oxidizing part of the raw material for hydrogen production, Since it has a relatively short start-up time and is easy to control, it has recently attracted attention as a hydrogen production method for fuel cells. Also in this case, the reaction is usually carried out in the presence of a metal catalyst, typically a Group VIII metal such as nickel, cobalt, iron, ruthenium, rhodium, iridium and platinum. The amount of steam introduced into the reaction system is preferably 0.3 to 10, more preferably 0.5 to 5, and still more preferably 1 to 3 as a steam / carbon ratio.

  In autothermal reforming, oxygen is added to the raw material in addition to steam. The oxygen source may be pure oxygen, but in many cases air is used. Usually, oxygen is added to such an extent that it can generate an amount of heat that can balance the endothermic reaction associated with the steam reforming reaction, but the amount of addition is appropriately determined in relation to heat loss and external heating installed as necessary. The amount is preferably from 0.05 to 1, more preferably from 0.1 to 0.75, even more preferably as the ratio of the number of moles of oxygen molecules to the number of moles of carbon atoms contained in the raw material for hydrogen production (oxygen / carbon ratio). Is set to 0.2 to 0.6. The reaction temperature of the autothermal reforming reaction is set in the range of 450 ° C. to 900 ° C., preferably 500 ° C. to 850 ° C., more preferably 550 ° C. to 800 ° C., as in the case of the steam reforming reaction. When the raw material for hydrogen production is liquid, the space velocity (LHSV) at this time is preferably selected in the range of 0.1 to 30, more preferably 0.5 to 20, and still more preferably 1 to 10.

  As the structure of the reformer, a known external heat reformer including a burner for external heat can be appropriately adopted. In particular, a reformer in which a burner and a reforming reaction section are provided in a cylindrical reforming furnace is preferable because it can be easily disposed adjacent to or integrated with the cylindrical desulfurizer as described above.

[CO shift reactor]
Depending on the type of fuel cell, the reformed gas, which is a hydrogen-containing gas generated in the reformer, may be supplied to the fuel cell with the same composition. For example, the performance of solid polymer fuel cells is degraded by carbon monoxide. Therefore, in the polymer electrolyte fuel cell system, it is preferable to provide a CO shift reactor downstream of the reformer, and it is preferable to provide a selective oxidation reactor downstream of the CO shift reactor. Accordingly, it is preferable to provide a CO shift reactor and a selective oxidation reactor in a hydrogen production apparatus for producing a hydrogen-containing gas used in such a fuel cell.

  The gas generated in the reformer contains carbon monoxide, carbon dioxide, methane, and water vapor in addition to hydrogen. Further, nitrogen is also contained when air is used as an oxygen source in the autothermal reforming. Among these, the CO conversion reactor performs the step of reacting carbon monoxide with water to convert it into hydrogen and carbon dioxide. Usually, the reaction proceeds in the presence of a catalyst, and a catalyst containing a noble metal such as a mixed oxide of Fe—Cr, a mixed oxide of Zn—Cu, platinum, ruthenium, and iridium is used. Mol%) is preferably reduced to 2% or less, more preferably 1% or less, and even more preferably 0.5% or less. The shift reaction can also be carried out in two stages, in which case a high temperature CO shift reactor and a low temperature CO shift reactor are used.

[Selective oxidation reactor]
When producing a hydrogen-containing gas used as a fuel for a polymer electrolyte fuel cell, it is preferable to further reduce the carbon monoxide concentration. For this purpose, it is preferable to treat the outlet gas of the CO shift reactor with a selective oxidation reaction. . In this step, a catalyst containing iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, platinum, copper, silver, gold, etc. is used, preferably 0.5 to the number of moles of carbon monoxide remaining. The carbon monoxide concentration is preferably increased by selectively converting carbon monoxide to carbon dioxide by adding 10 moles, more preferably 0.7-5 moles, and even more preferably 1-3 moles of oxygen. Is reduced to 10 ppm (on a molar basis of the dry base) or less. In this case, the carbon monoxide concentration can be reduced by reacting with the coexisting hydrogen simultaneously with the oxidation of carbon monoxide to generate methane.

〔Fuel cell〕
As the fuel cell, a fuel cell of a type in which hydrogen is a reactant of the electrode reaction in the fuel electrode can be appropriately employed. For example, a fuel cell of a solid polymer type, a phosphoric acid type, a molten carbonate type, or a solid oxide type can be employed. Hereinafter, the configuration of the polymer electrolyte fuel cell will be described.

  The fuel cell electrode consists of an anode (fuel electrode) and cathode (air electrode) and a solid polymer electrolyte sandwiched between them. A hydrogen-containing gas is required on the anode side, and an oxygen-containing gas such as air is required on the cathode side. If so, it is introduced after appropriate humidification treatment.

  At this time, a reaction in which hydrogen gas becomes protons and emits electrons proceeds at the anode, and a reaction in which oxygen gas obtains electrons and protons to become water proceeds at the cathode. In order to promote these reactions, platinum black and Pt catalyst or Pt-Ru alloy catalyst supported on activated carbon are used for the anode, and platinum black and Pt catalyst supported on activated carbon are used for the cathode. Usually, both the anode and cathode catalysts are formed into a porous catalyst layer together with Teflon, a low molecular weight polymer electrolyte membrane material, activated carbon or the like as necessary.

  As solid polymer electrolytes, Nafion (Nafion, manufactured by DuPont), Gore (Gore, manufactured by Gore), Flemion (Flemion, manufactured by Asahi Glass), Aciplex (Aciplex, manufactured by Asahi Kasei), etc. A molecular electrolyte membrane is usually used, and the porous catalyst layer is laminated on both sides thereof to form an MEA (Membrane Electrode Assembly). Further, the fuel cell is assembled by sandwiching the MEA with a separator having a gas supply function, a current collecting function, particularly an important drainage function in the cathode, and the like made of a metal material, graphite, carbon composite and the like. The electric load is electrically connected to the anode and the cathode.

[Composition of hydrogen-containing gas]
When the steam reforming reaction is used in the reformer, the composition of the gas that has passed through the reformer (mol% in dry base) is typically, for example, 63 to 73% hydrogen, 0.1 to 5% methane, 5 to 5 carbon dioxide. 20%, carbon monoxide 5-20%. On the other hand, the composition when using the autothermal reforming reaction (mol% in dry base) is usually 23 to 37% hydrogen, 0.1 to 5% methane, 5 to 25% carbon dioxide, 5 carbon monoxide, for example. -25%, nitrogen 30-60%.

  In addition, the composition of the gas that has passed through the reformer and shift reactor (mol% or mol ppm of dry base) is usually, for example, 65 to 75% of hydrogen, 0. 1 to 5%, carbon dioxide 20 to 30%, carbon monoxide 1000 ppm to 10000 ppm. On the other hand, the composition when using the autothermal reforming reaction (mol% or mol ppm of dry base) is usually 25 to 40% hydrogen, 0.1 to 5% methane, 20 to 40% carbon dioxide, one Carbon oxide is 1000 ppm to 10000 ppm and nitrogen is 30 to 54%.

  The composition of the gas that has passed through the reformer, shift reactor, and selective oxidation reactor (mol% of the dry base) is usually, for example, 65 to 75% hydrogen, 0. 1 to 5%, carbon dioxide 20 to 30%, nitrogen 1 to 10%. On the other hand, the composition (dry base mol%) when using the autothermal reforming reaction is usually, for example, 25 to 40% hydrogen, 0.1 to 5% methane, 20 to 40% carbon dioxide, and 30 to 54 nitrogen. %.

[Other equipment]
Known components of the desulfurization system, the hydrogen production apparatus, or the fuel cell system can be appropriately provided as necessary. Specific examples include a means for supplying an oxygen-containing gas such as air to the cathode of the fuel cell, a steam generator for generating steam for humidifying the gas supplied to the fuel cell, and various devices such as the fuel cell. Cooling system, pressurizing means such as pumps, compressors and blowers for pressurizing various fluids, flow regulating means such as valves for regulating the flow rate of fluids, or shutting off / switching the flow of fluids Channel shut-off / switching means, heat exchanger for heat exchange / recovery, vaporizer for vaporizing liquid, condenser for condensing gas, heating / heat-retaining means for externally heating various devices with steam, etc. Storage means, instrumentation air and electrical systems, control signal systems, control devices, output and power electrical systems, and the like.

  Kerosene was desulfurized using the combustion exhaust gas from the burner of the reformer as the heating medium.

(Example)
The desulfurization system of the form which integrated the short cylindrical desulfurizer and the heat exchanger for kerosene preheating shown in FIG. 3 was used. In other words, the desulfurizer and heat exchanger have a double cylindrical structure, and the exhaust gas as the heating medium and the kerosene as the heated medium exchange heat in the outer annular portion, and the desulfurization catalyst is filled in the inner cylinder. Therefore, the same heat exchange occurs and desulfurization reaction occurs at the same time.

  In the annular part (heat exchanger), kerosene as the heated medium passes through the three pipes (inner diameter 21.7 mm), and exhaust gas as the heating medium passes through the outside (shell side in terms of shells and tubes). To do.

  The outer size of the desulfurizer was 350 mm × 125 mm in diameter. The desulfurizer has the structure shown in FIG. 5, and five desulfurization chambers are connected in series to form one kerosene flow path. In this flow path, the kerosene supply port is located in the most upstream and the most downstream desulfurization chambers. A discharge port is formed further upward. Nine pipes (inner diameter 21.7 mm) on the heating medium side are arranged, and exhaust gas passes through them, while kerosene passes through the desulfurization catalyst layer filled on the shell side while exchanging heat. Five desulfurization chambers were filled with approximately equal amounts of a total of 6 L of Ni-based desulfurization catalyst.

The fuel used was kerosene pretreated with No. 1 kerosene (the sulfur content was 2 ppm on a mass basis), and the flow rate was circulated at a rate of 2 kg / h. As a method for raising the temperature of the reactor, exhaust gas heating (230 ° C., 25 Nm ³ / h) was used, and the temperature of the desulfurizer inlet catalyst layer was set to 180 ° C. The temperature distribution of the desulfurizer at that time was small as shown in FIG. The sulfur content in kerosene after desulfurization was 0.05 ppm (mass basis) or less, and desulfurization was performed well. In FIG. 6, for example, DS (60 °) indicates a portion of 60 ° in the clockwise direction of the cylindrical surface, where the center of the kerosene inlet is 0 °. “Nm ³ / h” represents “m ³ / h” at 0 ° C.

  Further, the pressure fluctuation of the desulfurizer is small as shown in FIG. 7, and when a capillary (length 50 mm) having a pipe inner diameter of 3 mm is provided in the kerosene passage downstream pipe (9 mm inner diameter) of the desulfurizer, the pressure fluctuation is further reduced. became.

  FIG. 7 shows the pressure (gauge pressure) in the desulfurizer for a certain period, and the upper graph in the figure shows the pressure fluctuation in the desulfurizer when the capillary is not installed (right vertical axis). The graph shows the pressure fluctuation in the desulfurizer when the capillary is installed (left vertical axis). When no capillary is installed, the pressure fluctuates with a width of about 10 kPa between 136 kPa-G and 146 kPa-G. When a capillary is installed, the pressure fluctuates with a width of about 3 kPa between 246 kPa-G and 249 kPa-G. there were.

(Comparative example)
The desulfurizer used here was a cylindrical container having a diameter of 350 mm × 125 mm filled with 6 L of a Ni-based desulfurization catalyst. As fuel, kerosene pretreated from JIS No. 1 kerosene (sulfur content was 2 ppm by mass) was used, and the flow rate was 2 kg / h. Kerosene was supplied from one location near the outer periphery of the bottom surface of the cylindrical container, and discharged from a location symmetrical about the central axis of the cylinder. As a method for raising the temperature of the reactor, an external heater was used, and the temperature was set to 180 ° C.

  The temperature distribution of the desulfurizer at that time is shown in FIG. 8, and the change over time in pressure fluctuation is shown in FIG. The temperature distribution and pressure fluctuation were large, the desulfurization performance was not good, and the S content in kerosene after desulfurization was 0.5 ppm. In FIG. 8, for example, DS (60 °) indicates a location of 60 ° in the clockwise direction of the cylindrical surface with the center of the kerosene inlet being 0 °. FIG. 9 shows the pressure (gauge pressure) in the desulfurizer for a certain period. Since the pressure fluctuation of the desulfurizer is large, the instantaneous S / C cannot be controlled accurately and the S / C becomes low. There is a risk of coking in the catalyst.

It is a flowchart which shows the outline of one form of the fuel cell system of this invention. It is a schematic diagram which shows the outline of one form of the desulfurizer of this invention. (A) is a top sectional view, (b) is a side sectional view. It is a schematic diagram which shows the outline of one form of the desulfurization system of this invention. (A) is a perspective view, (b) is a side sectional view. It is a schematic diagram which shows the outline of the other form of the desulfurizer of this invention. It is a schematic diagram which shows the outline of other form of the desulfurizer of this invention. It is a graph which shows the desulfurizer temperature distribution in an Example. It is a graph which shows a time-dependent change of the pressure in a desulfurizer in an Example. It is a graph which shows the desulfurizer temperature distribution in a comparative example. It is a graph which shows a time-dependent change of the pressure in a desulfurizer in a comparative example.

Explanation of symbols

1, 201: Desulfurizer 2, 102: Desulfurization chamber 3, 103, 203, 303, 403: Heating medium inlet side header 4, 104, 204, 403, 404: Heating medium outlet side header 5, 105, 205, 305: Tube (heating medium flow path)
6, 106, 206: Desulfurization agent 7, 107, 307: Liquid fuel supply port 8, 108, 308: Liquid fuel discharge port 11, 211: Heat exchanger (liquid fuel preheater)
12: Body 13, 213: Tube (liquid fuel flow path)
21: capillary 31: reformer 32: reforming reaction section 33: burner 34: reforming furnace 41: liquid fuel vaporizer 42: fuel cell, 42A: anode chamber, 42C: cathode chambers 51, 52, 53, 152, 153: liquid fuel lines 61, 62, 63, 161, 162: heating medium line 215: liquid fuel inlet side header 216: liquid fuel outlet side headers 302a-e, 402a-e: desulfurization chambers 390a-d, 490a- d: baffle plates 399, 499: containers 491a-f: opening

Claims (9)

In a desulfurizer for desulfurizing while heating a liquid fuel with a heating medium in the presence of a desulfurizing agent,
At least one desulfurization chamber having a region for containing a desulfurization agent and forming a flow path for the liquid fuel;
A plurality of tubes that form channels of the heating medium that are disposed substantially horizontally through the region;
A desulfurizer characterized in that a liquid fuel discharge port is formed above the liquid fuel supply port in at least one of the desulfurization chambers. The desulfurization chamber is the whole or a part of a cylindrical container,
The desulfurizer according to claim 1, wherein the plurality of pipes have an arc shape. A plurality of the desulfurization chambers are connected in series to form one liquid fuel flow path,
The desulfurizer according to claim 1 or 2, wherein a liquid fuel discharge port is formed above the liquid fuel supply port in the desulfurization chamber on the most downstream side of the flow path of the liquid fuel. A plurality of the desulfurization chambers are connected in series to form one liquid fuel flow path,
The desulfurizer according to any one of claims 1 to 3, wherein a liquid fuel discharge port is formed above the liquid fuel supply port in the desulfurization chamber on the most upstream side of the flow path of the liquid fuel. A desulfurizer for desulfurizing while heating the liquid fuel with a heating medium in the presence of a desulfurizing agent; and a heat exchanger for preheating the liquid fuel supplied to the desulfurizer with the heating medium discharged from the desulfurizer. With
The desulfurizer has at least one desulfurization chamber having a region for containing a desulfurizing agent and forming a flow path for the liquid fuel, and a flow path for the heating medium disposed substantially horizontally through the region. A liquid fuel discharge port formed above the liquid fuel supply port in at least one of the desulfurization chambers,
The heat exchanger includes a cylinder that forms a flow path for the heating medium, and a pipe that forms a flow path for the liquid fuel and penetrates the cylinder.   The desulfurization system according to claim 5, further comprising a capillary in the liquid fuel flow path downstream of the desulfurizer. In the desulfurizer, the desulfurization chamber is the whole or a part of a cylindrical container, and the plurality of tubes are arc-shaped,
The desulfurization system according to claim 5 or 6, wherein the heat exchanger has an annular column shape and is provided on an outer periphery of the cylindrical container. A desulfurizer for desulfurizing while heating the liquid fuel with a heating medium in the presence of a desulfurizing agent; and a heat exchanger for preheating the liquid fuel supplied to the desulfurizer with the heating medium discharged from the desulfurizer. A reformer for producing a gas containing hydrogen using the desulfurized liquid fuel as a raw material,
The reformer includes a reforming reaction unit including a reforming catalyst and a burner that performs combustion for heating the reforming reaction unit.
The desulfurizer has at least one desulfurization chamber having a region for containing a desulfurizing agent and forming a flow path for the liquid fuel, and a flow path for the heating medium disposed substantially horizontally through the region. A liquid fuel discharge port formed above the liquid fuel supply port in at least one of the desulfurization chambers,
The heat exchanger has a cylinder that forms a flow path for the heating medium, and a tube that forms a flow path for the liquid fuel and penetrates the cylinder.
A hydrogen production apparatus comprising means for guiding combustion exhaust gas of a burner discharged from the reformer to a flow path of a heating medium of the desulfurizer.   9. A fuel cell system comprising: the hydrogen production apparatus according to claim 8; and a fuel cell using as a fuel a gas containing hydrogen produced by the hydrogen production apparatus.

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