JP2006315922A - Fuel reformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel reformer capable of efficiently accelerating a reforming reaction, even at a temperature lower than a conventional reforming temperature. <P>SOLUTION: The fuel reformer comprises a reforming part 10, a shift reaction part 20, a CO removal part 30 and an unreformed fuel recovery part 70. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel reformer, and more particularly to a fuel reformer for reforming raw fuel into a gas containing hydrogen.

  Since hydrogen gas is used for fuel cells, hydrogenation of various organic compounds, or various industrial applications, various research and development relating to the production of hydrogen gas have been actively conducted. As raw fuel for producing hydrogen gas, hydrocarbons such as methane and gasoline, alcohols such as methanol and ethanol, and the like are used. Steam reforming, partial oxidation reforming, and autothermal reforming are used as fuel reforming means for obtaining hydrogen-containing gas (hereinafter referred to as reformed gas) using these raw fuels.

  Autothermal reforming is a combination of partial oxidation reforming, which is an exothermic reaction, and steam reforming, which is an endothermic reaction and has better reforming efficiency than partial oxidation reforming. It is said that the reforming reaction can be performed efficiently without adding.

  As a structure of the conventional fuel reformer for performing autothermal reforming, the structure shown to the codes | symbols 10-30 of FIG. 1 is mentioned.

  A system for fuel reforming by a conventional fuel reformer and fuel consumption by a battery when ethanol is used as a raw fuel will be described with reference to FIG. The raw fuel 100 is introduced into the reforming unit 10 together with air 120 and water vapor 140. In the reforming unit 10, the reaction shown in the following chemical formulas 1 to 3 proceeds through the fuel reforming catalyst by autothermal reforming, so that hydrogen is contained from the raw fuel 100, oxygen contained in the air 120, and water vapor 140. A reformed gas 110 is obtained. At this time, the reforming temperature of the reforming unit 10 is adjusted to a high temperature in order to maintain fuel reforming efficiency. The obtained reformed gas 110 is introduced into the shift reaction unit 20.

  In the shift reaction unit 20, the CO concentration in the reformed gas 110 is lowered to about 1 vol% by the reaction shown in the following chemical formula 4. The reformed gas 110 whose CO concentration has been lowered in the shift reaction unit 20 is introduced into the CO removal unit 30 together with the air 120.

  When used in a fuel cell that operates at a low temperature such as a polymer electrolyte fuel cell, it is preferable to reduce the CO concentration to 10 ppm or less. Therefore, in the CO removal unit 30, the reformed gas 110 is reacted by the reaction shown in the following chemical formula 5. The CO concentration inside is reduced to the ppm order. The reformed gas 110 having the CO concentration lowered to the ppm order by the CO removing unit 30 is supplied to the fuel cell 40 and used as fuel for power generation.

  Inside the fuel cell 4, a power generation reaction using the reformed gas 110 and oxygen 130 proceeds, and spent fuel (hydrogen) 160 and oxidant (air) 170 are discharged to the combustion unit 50. In the combustion unit 50, spent fuel (hydrogen) 160 and oxidant (air) 170 are combusted, and in the evaporation unit 60, water 150 is evaporated using the combustion heat 200 and supplied to the reforming unit 10. By generating the generated steam 140, the energy efficiency can be measured.

In autothermal reforming performed through the above-described process, generally, as shown in Patent Document 1, the reforming temperature of the reforming section is set to 600 to 900 ° C. in order to maintain the efficiency of fuel reforming. It is done with adjustment.
Patent Publication 2002-12408 (Claim 8)

  When the fuel reforming reaction is performed under a conventional reforming temperature condition of 600 to 900 ° C., the CO concentration in the resulting reformed gas becomes high. This is based on the equilibrium composition, and the higher the temperature, the higher the CO concentration. For this reason, there is a problem that the shift reaction unit and the CO removal unit for removing CO installed at the subsequent stage of the reforming unit are increased in size, and the startup time and startup energy of these apparatuses are increased. In particular, the shift reaction section is generally composed of a high temperature shift reaction section and a low temperature shift reaction section in order to cope with the high concentration CO gas introduced from the reforming section. Occupy volume.

  Even when autothermal reforming is used, the container filled with the catalyst must be heated by a heating device until the reforming reaction is thermally stabilized. The higher the reforming temperature, the higher the heating device. Increases startup time and startup energy. Furthermore, since the temperature of the reformed gas obtained also rises with the reforming temperature, the heat exchanger for cooling the reformed gas is increased in size, and the startup time and startup energy are increased.

  On the other hand, when the reforming temperature is lowered, the reforming rate of the raw fuel is lowered, so that the proportion of raw fuel that has not been reformed (hereinafter referred to as unreformed fuel) in the reformed gas increases.

  In order to solve the above problems, an object of the present invention is to provide a fuel reformer that does not lower the reforming efficiency even at a temperature lower than the conventional reforming temperature.

  The present inventors have found that the above problem can be solved by recovering unreformed fuel from the reformed gas and supplying it to the reforming section, and have completed the present invention.

  That is, the present invention is a fuel reforming apparatus including a reforming section, a shift reaction section, and a CO removal section, and further includes an unreformed fuel recovery section.

  A first aspect of the present invention is a fuel reformer including a reforming unit, a shift reaction unit, and a CO removing unit, and further includes an unreformed fuel recovery unit. It is.

  The difference between the conventional fuel reformer and the fuel reformer of the present invention is that the fuel reformer of the present invention includes an unreformed fuel recovery unit.

  Even if unreformed fuel is contained in the reformed gas, the unreformed fuel can be recovered by the unreformed fuel recovery unit and supplied to the reforming unit. Even if the quality is improved, a high fuel reforming effect can be obtained as viewed in the entire fuel reforming apparatus. Since the fuel reforming can be performed even at a low temperature, the burden on the heating device, the shift reaction unit, and the CO removal unit can be reduced, and these devices can be made more compact than before. In particular, the shift reaction unit, which has conventionally been composed of the high temperature shift reaction unit and the low temperature shift reaction unit, can be configured with only the low temperature shift reaction unit by reducing the CO concentration discharged from the reforming unit. .

Hereinafter, details of the unreformed fuel recovery unit will be described. In order to recover unreformed fuel from the reformed gas, the unreformed fuel recovery unit can perform two-stage separation. When an easily liquefied material such as ethanol is used as a raw fuel, gas-liquid separation is performed in the first stage to separate water and unreformed fuel from H ₂ , CO and CO ₂ , In two stages, liquid-liquid separation is performed, and it is desirable to separate water and unreformed fuel.

As a gas-liquid separation method performed in the first stage, cooling is preferably mentioned. Depending on the raw fuel used, for example, when ethanol is used as the raw fuel, water and unreformed fuel are liquefied by cooling the gas introduced from the reforming section or shift reaction section to 70 ° C or lower. Which can be separated from H ₂ , CO and CO ₂ .

  As a cooling method, a method of arranging a heat exchanger using a refrigerant, a method of increasing the distance of piping, and the like are effective.

When the water and unreformed fuel in the reformed gas and H ₂ , CO and CO ₂ are separated by cooling, a conventional heat exchanger is not disposed in the unreformed fuel recovery unit. In the fuel reformer, the heat reforming may be usually performed using a heat exchanger provided between the reforming unit and the shift reaction unit or between the shift reaction unit and the CO removal unit. It is preferable to use a heat exchanger provided in a conventional fuel reforming apparatus because it is not necessary to increase the volume of the unreformed fuel recovery unit.

  When using liquefied methane gas or other liquefied water as raw fuel, the first step is to apply unreformed fuel separation method using molecular sieve instead of gas-liquid separation. Is preferred. As the molecular sieve, a zeolite membrane made of Ca-mordenite or the like is preferably used.

  As a method for separating water and unreformed fuel, a conventionally known separation method can be appropriately selected, but it is particularly preferable to use a membrane separation method. As the membrane separation method, a conventionally known method such as a reverse osmosis method, a membrane distillation method, a vapor permeation method, or a vaporization method can be appropriately selected.

  Examples of membranes used in the membrane separation method include zeolite membranes, silicone rubber membranes, polymer membranes such as trimethylsilylpropylene, cellulose acetate membranes, polyvinyl alcohol membranes, polyethyleneimine-based crosslinked membranes, polyimide membranes, and chitosan membranes. Among these membranes, a zeolite membrane is particularly preferable.

When the zeolite membrane contains hydrophilic zeolite, H ₂ O is preferentially adsorbed in the pores of the zeolite to permeate the zeolite membrane over the unreformed fuel, so that the unreformed fuel accumulates on the supply side, Water accumulates on the opposite permeate side through the membrane, so that unreformed fuel and H ₂ O can be separated. Conventionally known various zeolites can be appropriately used as the hydrophilic zeolite, but A-type zeolite, Y-type zeolite, X-type zeolite and MFI-type zeolite are preferable, and the molecular size of the raw fuel and H ₂ O is taken into consideration. More preferably, it is A-type zeolite.

When the A-type zeolite is used, the separation selectivity between the unreformed fuel and H ₂ O is very excellent. Therefore, the unreformed fuel recovery unit can be reduced in size, and the A-type zeolite is used. In this case, it is preferable because the zeolite membrane can be easily produced. In particular, when ethanol is used as a raw fuel, the molecular size of ethanol is 0.445 nm and the molecular size of H ₂ O is 0.265 nm, whereas the pore size of A-type zeolite is 0.41 nm. Therefore, only H ₂ O can be passed through very effectively.

When the zeolite membrane contains hydrophobic zeolite, the unreformed fuel is adsorbed into the pores of the zeolite preferentially over H ₂ O and permeates the zeolite membrane, so that water accumulates on the supply side and is opposed through the membrane. The unreformed fuel accumulates on the permeate side, and as a result, the unreformed fuel and H ₂ O can be separated. Various conventionally known zeolites can be appropriately used as the hydrophobic zeolite. When alcohol is used as the raw fuel, it is particularly suitable for separating unreformed fuel and H ₂ O.

Use of a hydrophobic zeolite is preferable because H ₂ O contained in the raw fuel can be extremely reduced.

  As a method for promoting the separation, a method of lowering the pressure on the permeate side with a vacuum pump or the like can be mentioned. The pressure on the transmission side is preferably 10.6 to 26.6 Pa (0.08 to 0.2 Torr).

  The film thickness of the zeolite membrane is not particularly limited and can be appropriately determined according to the raw fuel, the scale of the fuel reformer, etc. When using a zeolite membrane containing A-type zeolite, the film thickness is 10 to 15 μm. preferable.

  As the zeolite, natural zeolite or artificially synthesized zeolite may be used. There are various methods for artificially synthesizing zeolite, and in the present invention, conventionally known techniques can be appropriately used. Examples of methods for artificially synthesizing zeolite include the following methods.

  A liquid mixture containing water, Na source, Si source, and Al source is prepared, and a support charged with seed crystals is immersed in the liquid mixture to perform hydrothermal synthesis. The zeolite deposited on the support can be obtained by washing and drying with water after the synthesis.

Examples of the Na source include sodium hydroxide, sodium silicate, and sodium aluminate. Examples of the Si source include sodium silicate, silica gel, silica sol, colloidal silica, and silica powder. Examples of the Al source include , Sodium aluminate, and aluminum hydroxide. Water, Na source, Si source, and Al source are adjusted so that the composition ratios of H ₂ O / Na ₂ O, Na ₂ O / SiO ₂ , and SiO ₂ / Al ₂ O ₃ are in an appropriate range. These composition _{ratios, H 2 O / Na 2 O} = 20~300, Na 2 O / SiO 2 = 0.3~2, SiO 2 / Al 2 O 3 = 2~4 is preferable. The liquid mixture may be gelled by, for example, stirring at room temperature for 2 to 3 hours before immersing the support.

  Commercially available zeolite crystal powder or the like can be used as the seed crystal. As a method for preparing the seed crystal on the support, there is a method in which water is added to the seed crystal to form a paste, which is then applied thinly and uniformly on the support and dried.

  As the support, a porous support is preferable. Porous supports include ceramics such as alumina, silica, zirconia, silicon nitride, and silicon carbide; metals such as aluminum, copper, and stainless steel; and polyethylene, polypropylene, polytetrafluoroethylene, polystyrene, polysulfone, and Examples thereof include those made of polyimide. The average pore diameter of the porous support is preferably 0.05 to 10 μm, and the porosity is preferably 10 to 70%. The shape of the porous support is not particularly limited, but is preferably tubular or lotus root. Hydrothermal synthesis is preferably performed 1 to 5 times at 60 to 150 ° C. for 1 to 24 hours.

  The unreformed fuel recovery part of the present invention is preferably provided at the rear stage of the shift reaction part. FIG. 2 shows an example of a fuel reforming system using the fuel reforming apparatus of the present invention and a fuel consuming system using a battery in which an unreformed fuel recovery unit is arranged after the shift reaction unit, but the present invention is not limited to this. .

  A fuel reforming system using the fuel reforming apparatus of the present invention when ethanol is used as a raw fuel will be described with reference to FIG. The raw fuel 100 is introduced into the reforming unit 10 together with air 120 and water vapor 140. In the reforming unit 10, the reactions shown in the following chemical formulas 1 to 3 proceed through the fuel reforming catalyst by autothermal reforming, so that the oxygen contained in the raw fuel 100, the air 120, and the hydrogen contained from the steam 140 One reformed gas 111 is obtained. The obtained first reformed gas 111 is introduced into the shift reaction unit 20.

  In the shift reaction unit 20, the CO concentration in the first reformed gas 111 is lowered to about 1% by volume by the reaction shown in the following chemical formula 4. The second reformed gas 112 whose CO concentration has been lowered in the shift reaction unit 20 is introduced into the unreformed fuel recovery unit 70.

In the second reformed gas 112, CO ₂ , CO, H ₂ , H ₂ O, and unreformed fuel are mixed, but these are cooled in the unreformed fuel recovery unit 70, and H ₂ O and Unreformed fuel is condensed and liquefied. CO ₂ , CO, and H ₂ are introduced into the CO removing unit 30 together with the air 120 as the third reformed gas 113. On the other hand, the condensed liquefied mixture of H ₂ O and unreformed fuel is separated into water and unreformed fuel in the unreformed fuel recovery unit 70. The separated unreformed fuel is supplied to the reforming unit 10 as the raw fuel 100. The separated water can be supplied to the evaporator 60, and the water tank can be made compact by reusing the water. Since other parts are the same as those in FIG.

As described in the section of the unreformed fuel recovery section, the separation of CO ₂ , CO and H ₂ contained in the second reformed gas 112 from H ₂ O and unreformed fuel is performed by the shift reaction section. It can also carry out using the conventionally well-known heat exchanger for cooling the gas discharged | emitted from 20. FIG.

  It is preferable to provide the unreformed fuel recovery unit 70 after the shift reaction unit 20 because the burden on the CO removal unit can be reduced and the CO removal unit can be made compact.

  The unreformed fuel recovery part of the present invention can also be provided at the subsequent stage of the CO removal part. FIG. 3 shows an example of a fuel reforming system using the fuel reforming apparatus of the present invention in which an unreformed fuel recovery unit is arranged at the subsequent stage of the CO removing unit and a fuel consumption system using a battery, but the present invention is not limited to this.

  In the case where the unreformed fuel recovery unit is arranged at the subsequent stage of the CO removal unit, the second reformed gas 112 whose CO concentration has been lowered in the shift reaction unit 20 is introduced into the CO removal unit 30 together with the air 120, The CO concentration in the third reformed gas 113 is lowered to the ppm order by the reaction shown in the following chemical formula 5. The third reformed gas 113 whose CO concentration has been lowered by the CO removal unit 30 is introduced into the unreformed fuel recovery unit 70.

The third reformed gas 113 contains CO ₂ , CO, H ₂ , H ₂ O, and unreformed fuel, which are cooled in the unreformed fuel recovery unit 70, and H ₂ O and unreformed fuel is condensed liquefied coagulation. CO ₂ , CO, and H ₂ are introduced into the polymer electrolyte fuel cell 40 as the fourth reformed gas 114. On the other hand, the condensed liquefied H ₂ O and unreformed fuel mixture is separated into water and unreformed fuel in the unreformed fuel recovery section 70. The separated unreformed fuel is supplied to the reforming unit 10 as the raw fuel 100. The separated water can be supplied to the evaporator 60, and the water tank can be made compact by reusing the water. Since other parts are the same as those in FIGS.

As described in the section of the unreformed fuel recovery unit, the separation of CO ₂ , CO and H ₂ contained in the third reformed gas 113 from H ₂ O and unreformed fuel is performed by the CO removal unit. It can also carry out using the conventionally well-known heat exchanger for cooling the gas discharged | emitted from 30. FIG.

  It is preferable to provide the unreformed fuel recovery unit 70 at the subsequent stage of the CO removal unit 30 in that the influence of the unreformed fuel on the electrolytic catalyst of the fuel cell can be more effectively prevented.

When the unreformed fuel recovery unit is arranged after the shift reaction unit or the CO removal unit, the above-mentioned water and unreformed fuel and the gas-liquid separation stage for separating H ₂ , CO and CO ₂ are shifted. It can also be carried out in the reaction section or the CO removal section.

  The second of the present invention is a fuel reforming method characterized by reforming raw fuel using the above-described fuel reformer.

  For fuel reforming using the fuel reformer of the present invention, natural gas such as methane or city gas; hydrocarbons such as naphtha and gasoline; and alcohols such as methanol, ethanol and propanol, etc. are used as raw fuel. A well-known raw fuel can be preferably used, More preferably, it is alcohol, such as methanol, ethanol, and a propanol, More preferably, it is ethanol.

  Alcohol is preferable because it can be easily separated from water by a membrane containing A-type zeolite. As described above, the advantage of using a membrane containing A-type zeolite is that the zeolite membrane can be easily manufactured. Ethanol is considered to be a renewable energy source because it has low toxicity and can be produced from cereals such as potatoes and corn and plants such as sugar cane.

  The fuel reforming apparatus of the present invention can be applied to various apparatuses for producing reformed gas. However, since the apparatus size can be made smaller than that of the conventional apparatus, mounting of the apparatus is possible. It is particularly preferred for use in vehicles with very limited space. Applications for vehicles include a method of connecting to a polymer electrolyte fuel cell as described above, a method of connecting to an engine, and the like.

  EXAMPLES Next, although an Example is given and this invention is demonstrated concretely, these Examples do not restrict | limit this invention at all.

(Example 1)
(Preparation of fuel reforming catalyst)
A rhodium nitrate solution was dissolved in a dilute nitric acid aqueous solution to a concentration of 11.4% by mass to prepare an Rh catalyst preparation solution. The Rh catalyst adjustment solution was impregnated with alumina (average specific surface area 200 m ² / g). Next, after drying at 150 ° C. for 4 hours, firing was performed at 500 ° C. for 1 hour to obtain an Rh-supported powder. Rh loading time was 4 mass% (in metal conversion).

  200 g of the above Rh-supported powder, 6 g of alumina sol, and 0.3 liter of water were placed in a magnetic ball mill pot and mixed and ground for 2 hours to form a slurry.

  The slurry was applied to a honeycomb made of cordierite using a suction coating apparatus, dried by ventilation at 130 ° C., and then fired at 400 ° C. for 1 hour to obtain a fuel reforming catalyst.

(Preparation of shift reforming catalyst)
A dinitrodiamine platinum solution was dissolved in a dilute nitric acid aqueous solution to a concentration of 8.5% by mass to prepare a Pt catalyst preparation solution. The Pt catalyst adjustment solution was impregnated with ceria (average specific surface area 100 m ² / g). Next, after drying at 150 ° C. for 4 hours, firing was performed at 500 ° C. for 1 hour to obtain a Pt-supported powder. The amount of Pt supported was 5% by mass (metal conversion).

  200 grams of the Pt-supported powder, 6 grams of alumina sol, and 0.3 liter of water were placed in a magnetic ball mill pot and mixed and ground for 2 hours to form a slurry.

  The slurry was applied to a honeycomb made of cordierite using a suction coating apparatus, dried by ventilation at 130 ° C., and then fired at 400 ° C. for 1 hour to obtain a shift reforming catalyst.

(Preparation of CO removal catalyst)
A dinitrodiamine platinum solution is dissolved in dilute nitric acid aqueous solution to a concentration of 8.5% by mass, and further Fe (III) nitrate nonahydrate is dissolved to a concentration of 7% by mass to prepare a Pt-Fe catalyst preparation solution. Was made. The Pt—Fe catalyst adjustment solution was impregnated with alumina (average specific surface area 200 m ² / g). Next, after drying at 150 ° C. for 4 hours, baking was performed at 500 ° C. for 1 hour to obtain a Pt—Fe-supported powder. The amount of Pt supported was 5% by mass (metal conversion), and the amount of Fe supported was 0.8% by mass (metal converted).

  200 grams of the Pt-supported powder, 6 grams of alumina sol, and 0.3 liter of water were placed in a magnetic ball mill pot and mixed and ground for 2 hours to form a slurry.

  The slurry was applied to a honeycomb made of cordierite using a suction coating apparatus, dried by ventilation at 130 ° C., and then fired at 400 ° C. for 1 hour to obtain a CO removal catalyst.

(Production of zeolite membrane)
The composition ratio of H ₂ O, Na ₂ O, SiO ₂ , and Al ₂ O ₃ is H ₂ O / Na ₂ O = 60, Na ₂ O / SiO ₂ = 1, SiO ₂ / Al ₂ O ₃ = 2. As described above, 1 liter of a mixed solution composed of a 20 mass% sodium silicate aqueous solution, sodium hydroxide, and aluminum hydroxide was prepared, and the mixed solution was transferred to a glass container. After immersing a tubular porous alumina support (outer diameter 10 mm, length 200 mm, wall thickness 1 mm, pore diameter 1 μm, gas efficiency 40%) with a seed crystal composed of A-type zeolite microcrystals on the surface of the glass container Hydrothermal synthesis was performed while evaporating water at 100 ° C. for 3 hours. Next, it was washed with water and dried at 70 ° C. to obtain an A-type zeolite membrane. The thickness of the obtained A-type zeolite membrane was 10 μm.

(Fuel reforming)
The above-described fuel reforming catalyst 60 g is disposed in the fuel reforming section having a capacity of 1 liter, the shift catalyst 500 g is disposed in the shift reaction section having a capacity of 2.5 liters, and the CO removal catalyst 150 g is removed from the volume of 1.5 liters of CO. The 300 g A-type zeolite membrane was placed in the unreformed fuel recovery part with a volume of 3 liters. The fuel reformer was arranged in the order of the fuel reforming section, the shift reaction section, the CO removal section, and the unreformed fuel recovery section.

After treating with 10% H ₂ / N ₂ balance gas at 500 ° C. for 1 hour as a pretreatment of the catalyst, steam / carbon ratio (S / C) = 2.0, O ₂ /C=0.4, LHSV ( liquid hourly space ^velocity) = 20h -1, GHSV (and adjusted to a gas hourly space velocity) = 93000h ^-1.

  In the unreformed fuel recovery section, the pressure on the permeate side of the A-type zeolite membrane was maintained at 13.3 Pa (0.1 Torr) by a vacuum pump. Unreformed fuel was recovered at 75 ° C.

Analyze the ethanol concentration, CO concentration, and CH ₄ concentration at the outlet of the fuel reforming section when reforming ethanol at a reforming inlet gas temperature of 350 ° C., and obtain the ethanol conversion rate from the following equation. It was.

After 30 minutes from the start of fuel reforming, the ethanol conversion rate in the fuel reforming section was 95%, the CO concentration at the fuel reforming section outlet was 4%, and the CH ₄ concentration was 1%. The CO remover subsequent ethanol 6% aqueous solution containing obtained with CO concentration 30ppm of containing _{H 2} gas, and _{H 2} containing gas CO concentration 30ppm in unreformed fuel recovery unit, and ethanol 6% aqueous solution containing isolated The aqueous solution containing 6% ethanol was separated into water and 99.5% ethanol.

  Although the ethanol conversion rate in the fuel reforming unit is 95%, since the unreformed fuel is supplied again to the fuel reforming unit by the unreformed fuel recovery unit, the ethanol conversion rate is seen from the whole fuel reformer. Became 100%.

(Comparative Example 1)
180 g of the reforming catalyst is disposed in the fuel reforming section having a capacity of 3 liters, 600 g of the shift catalyst is disposed in the first shift reaction section having a capacity of 3 liters, and 900 g of the shift catalyst is disposed in the second shift reaction section having a capacity of 4.5 liters. , S / C = 2.0, O ₂ /C=0.4, LHSV (liquid space velocity) = 5 h ⁻¹ , GHSV (gas space The same procedure as in Example 1 was performed except that the reforming reaction was performed at a gas velocity of 600 ° C. at the reforming section inlet at a speed of 23000 h ⁻¹ .

The ethanol conversion rate of the fuel reforming section 30 minutes after the start of fuel reforming was 100%, the CO concentration at the fuel reforming section outlet was 11%, and the CH ₄ concentration was 4%. In the latter part of the CO removal unit, an H ₂ -containing gas having a CO concentration of 30 ppm was obtained.

It is a figure which shows the fuel reforming system by the conventional fuel reformer, and the fuel consumption system by a battery. It is a figure which shows an example of the system of the fuel reforming by the fuel reformer of this invention, and the fuel consumption by a battery. It is a figure which shows an example of the system of the fuel reforming by the fuel reformer of this invention, and the fuel consumption by a battery.

Explanation of symbols

10 reforming section,
20 shift reaction part,
30 CO removal section,
40 solid polymer fuel cell,
50 combustion section,
60 evaporation section,
70 Unreformed fuel recovery unit,
100 raw fuel,
110 reformed gas,
111 first reformed gas,
112 second reformed gas,
113 third reformed gas,
114 fourth reformed gas,
120 air,
130 oxygen,
140 water vapor,
150 water,
160 spent fuel,
170 oxidizing agent,
200 Combustion heat.

Claims (10)

A fuel reformer comprising a reforming section, a shift reaction section, and a CO removal section,
A fuel reformer comprising an unreformed fuel recovery unit. _2. The fuel reforming according to claim 1, wherein the unreformed fuel recovery unit separates the unreformed fuel and the H ₂ O from a mixture of unreformed fuel and H ₂ O. 3. apparatus.   The fuel reformer according to claim 1 or 2, wherein the unreformed fuel recovery unit includes a zeolite membrane.   The fuel reformer according to claim 3, wherein the zeolite membrane contains hydrophilic zeolite.   The fuel reformer according to claim 4, wherein the hydrophilic zeolite is an A-type zeolite.   The fuel reformer according to claim 3, wherein the zeolite membrane contains hydrophobic zeolite.   The fuel reformer according to any one of claims 1 to 6, wherein the unreformed fuel recovery unit is provided at a stage subsequent to the shift reaction unit.   The fuel reformer according to claim 1, wherein the unreformed fuel recovery unit is provided at a stage subsequent to a CO removal unit.   A fuel reforming method comprising reforming a raw fuel using the fuel reforming apparatus according to claim 1.   The fuel reforming method according to claim 9, wherein the raw fuel is ethanol.

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