JP4814537B2 - Hydrogen production method and apparatus - Google Patents

Description

TECHNICAL FIELD The present invention relates to a hydrogen production method and an apparatus therefor, and more particularly, hydrogen production that produces carbon monoxide (CO) and carbon dioxide (CO ₂ ) free hydrogen that can directly supply the produced hydrogen to a fuel cell. The present invention relates to a method and an apparatus thereof.

  From the viewpoint of preventing electrode poisoning of a fuel cell, it is necessary to supply hydrogen that does not contain carbon monoxide to a fuel cell, particularly a polymer electrolyte fuel cell (PEFC) that has recently attracted attention. In a conventional hydrogen production process, hydrogen is generated from a fossil fuel such as natural gas, petroleum, or coal by a steam reforming reaction. At this time, most of the carbon contained in the fossil fuel is discharged into the atmosphere as carbon dioxide. However, as a party to the Kyoto Protocol, suppression of emissions of carbon dioxide, a greenhouse gas, is urgent.

  In addition, in the above hydrogen production process, it is impossible to avoid the residual (1 to 3%) of the electrode poisonous substance CO. Therefore, hydrogen depth purification (CO <20 ppm) is unavoidable by a large and high-cost facility using a pressure swing adsorption method (PSA method) or the like. In addition, the steam reforming reaction needs to be heated to a very high temperature of about 800 ° C.

Therefore, as a method for generating neither CO nor CO ₂ , a UT-3 cycle using solar heat and a method disclosed in JP 07-267601 A have been proposed. However, since these methods use solar heat, there is a problem that a large-scale system is required and the cost is very high.

On the other hand, Japanese Patent Laid-Open No. 10-25001 proposes a method for producing hydrogen by using sodium hydroxide as a reaction medium by a thermochemical decomposition reaction between water and carbon. Although this method has an advantage that sodium hydroxide can be made to act catalytically by supplying a large excess of carbon to sodium hydroxide, CO and CO ₂ are produced as by-products. There is a problem.
JP 07-267601 A Japanese Patent Laid-Open No. 10-25001

In view of the above problems, an object of the present invention is to provide a hydrogen production method and apparatus capable of producing hydrogen without producing CO _x such as carbon monoxide and carbon dioxide.

In order to achieve the above object, a hydrogen production method according to the present invention comprises a natural organic compound or a natural organic compound in an inert gas atmosphere and under heating conditions and in the presence of a metal or metal oxide catalyst. A hydrogen production method for producing hydrogen without producing carbon monoxide and carbon dioxide by reacting a carbon-containing material, which is a biomass or a synthetic polymer compound, with an alkali, and generating carbon without producing carbon monoxide and carbon dioxide . The molar ratio is 2 to 5 mol / (alkali valence) with respect to 1 mol of carbon contained in the carbon-containing material. For example, the reaction when carbon contained in the carbon-containing material is C and the alkali is NaOH is shown in the following formula 1.

C + 4NaOH → 2H ₂ + Na ₂ CO ₃ + Na ₂ O (Formula 1)

As shown in Formula 1, carbon (C) contained in the carbon-containing material reacts with an alkali to produce a carbonate, so that the production of CO and CO ₂ is avoided, is CO _x- free and has high purity of hydrogen. Can be obtained.

The obtained gas may contain a little methane in addition to hydrogen. The reaction formula for methane production is shown in the following formula 2. However, methane unlike CO and CO _2, does not result in electrode poisoning and greenhouse.

2C + 4NaOH → CH ₄ + Na ₂ CO ₃ + Na ₂ O (Formula 2)

  In the hydrogen production method according to the present invention, it is preferable to carry out the above reaction by further adding water or water vapor. Thereby, for example, the reaction of the following formula 3 occurs together with the above formula 1.

Na ₂ O + H ₂ O → 2NaOH (Formula 3)

  As shown in Formula 3, since the reaction by-product (oxide) of Formula 1 is regenerated to the raw material alkali, the hydrogen generation rate can be increased. That is, the reaction in which water or water vapor is added can be expressed by the following formula 4 from the above formulas 1 and 3.

C + 2NaOH + H ₂ O → 2H ₂ + Na ₂ CO ₃ (Formula 4)

In Formula 4, similarly to Formula 1, since carbon (C) contained in the carbon-containing material reacts with an alkali to generate a carbonate, CO and CO ₂ are not generated. Water or water vapor can be added during the reaction between the carbon-containing material and the alkali.

  In addition, when water or water vapor is added, the resulting gas may contain a little methane in addition to hydrogen. The reaction of methane generation in this case can be expressed by the following formula 5 from the above formulas 2 and 3.

2C + 2NaOH + H ₂ O → CH ₄ + Na ₂ CO ₃ (Formula 5)

  In the hydrogen production method according to the present invention, the reaction is preferably performed in the presence of a metal or metal oxide catalyst, or a catalyst in which a metal is supported on a metal oxide or carbon material. Thereby, the said reaction is accelerated | stimulated and a hydrogen production rate can be raised. Furthermore, the production of methane can be reduced to 1% or less of hydrogen.

As the carbon-containing material, it is preferable to use natural organic compounds or biomass containing natural organic compounds. As a result, biomass resources such as woody biomass such as waste wood and newspapers and food biomass such as food residue that have not been effectively used can be effectively used as energy sources. For example, the production reaction formula of hydrogen and sodium carbonate in the unit structure (C ₆ H ₁₀ O ₅ ) of cellulose, which is the main component of woody biomass, can be expressed as the following formula 6.

(C ₆ H ₁₀ O ₅ ) + 12NaOH + H ₂ O → 12H ₂ + 6Na ₂ CO ₃ (Formula 6)

  Moreover, it is preferable to use a synthetic polymer compound as the carbon-containing material. This makes it possible to effectively use waste plastic that has not been effectively used as an energy source and to detoxify the waste plastic.

Another aspect of the present invention is a hydrogen production apparatus comprising a natural organic compound or a biomass containing a natural organic compound or a carbon-containing material that is a synthetic polymer compound and an alkali, and a metal or metal oxide. A reaction vessel that further contains a catalyst , reacts the carbon-containing material with the alkali in an inert gas atmosphere, and produces hydrogen without producing carbon monoxide and carbon dioxide, and heats the reaction vessel A hydrogen production apparatus comprising a heater and a pipe for discharging hydrogen generated in the reaction vessel, wherein the molar ratio of the carbon-containing material and the alkali contained in the reaction vessel is a carbon-containing material. The alkali is 2 to 5 mol / (alkali valence) with respect to 1 mol of carbon contained in.

  It is preferable that the reaction vessel further includes a pipe for supplying water or water vapor. The reaction vessel preferably further contains a metal or metal oxide catalyst, or a catalyst having a metal supported on a metal oxide or carbon material.

As described above, according to the present invention, it is possible to provide a hydrogen production method and apparatus for producing hydrogen without producing CO _x such as carbon monoxide and carbon dioxide.

  First, an embodiment of the hydrogen production method according to the present invention will be described. The hydrogen production method according to the present invention is characterized in that hydrogen is generated by reacting a carbon-containing material, an alkali, and, if necessary, water or water vapor under heating conditions.

  As the carbon-containing material, it is particularly preferable to use carbon materials, natural organic compounds or biomass containing natural organic compounds, or synthetic polymer compounds. Other alcohols such as methanol and ethanol, ethers such as dimethyl ether and diethyl ether, ketones such as acetone and methyl ethyl ketone, aldehydes such as formaldehyde and acetaldehyde, organic acids such as formic acid and acetic acid, and natural gas, oil and coal Such fossil fuels may be used.

  The carbon material is not particularly limited, but for example, amorphous carbon such as charcoal, activated carbon, carbon black, coke, soot, graphite (graphite), carbon fiber, carbon naofiber, fullerene, carbon nanotube, etc. should be used. Is preferred. As charcoal or activated carbon, charcoal of woody biomass, such as charcoal, bamboo charcoal, bincho charcoal, coconut husk charcoal, coffee bean husk, chaff, rice bran, buckwheat husk etc. be able to.

Although it does not specifically limit as a natural organic compound, For example, it is preferable to use saccharides, such as a monosaccharide, a disaccharide, an oligosaccharide, and a polysaccharide, lignin, a fatty acid, etc. In addition, glucose, fructose, galactose, etc. can be used as a monosaccharide, sucrose, maltose, lactose, etc. can be used as a disaccharide, and starch, cellulose, glycogen etc. can be used as a polysaccharide. Natural organic compounds are finite resources and, unlike fossil fuels that emit large amounts of CO ₂ into the atmosphere, are reproducible and carbon neutral. The present invention can efficiently generate hydrogen from such natural organic compounds.

  Although it does not specifically limit as biomass containing a natural organic compound, For example, sugar-type biomass, such as sugarcane and sugar beet, starch-type biomass, such as rice, wheat, corn, and a potato, rapeseed, soybean, peanut, edible oil, etc. It is preferable to use oily biomass, woody biomass such as wood, grass, wood, wood waste, straw, natural fiber, paper products, and resource waste biomass such as newspaper, wrapping paper, toilet paper, and cardboard. Since the present invention can generate hydrogen directly from biomass resources, it can be efficiently used from bioresources such as waste biomass and woody biomass such as newspapers and food biomass such as food residues that have not been effectively used conventionally. Hydrogen can be produced.

  In addition, woody biomass such as wood and vegetation has cellulose, hemicellulose, and lignin as main components. However, cellulose is mainly used, and about 50% of the wood is cellulose. Therefore, a large amount of lignin is contained in the waste liquid of pulp mills, and about 50 million tons are discharged annually. Lignin was dumped into rivers, but is now being burned. Lignin begins to thermally decompose at around 200 ° C, but does not complete at 600 ° C or higher, and cellulose (starting at around 300 ° C and almost complete at around 360 ° C) or hemicellulose (below 200 ° C) The material was difficult to be treated by thermal decomposition as compared with the case where the thermal decomposition started at about 300 ° C.). According to the present invention, hydrogen can be easily generated using lignin, so that lignin can be used effectively. Moreover, according to this invention, even when it is a case where hydrogen is produced | generated using woody biomass, lignin can also be decomposed | disassembled easily with a cellulose.

  The synthetic polymer compound is not particularly limited. For example, saturated polyester (SP) such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), polycarbonate (PC), polyvinyl chloride (PVC), and polyamide (PA). , Polyarylate (PAR), polyacetal (POM), polysulfone (PSU), polyimide (PI), polyamideimide (PAI), polyetherimide (PEI), polyetheretherketone (PEEK), polybenzimidazole (PBI), etc. Thermoplastic resin, phenol resin (PF), urea resin (UF), melamine resin (MF), diallyl phthalate resin (DAP), unsaturated polyester resin (UP), silicone resin (SI), epoxy resin (EP) Thermosetting trees such as , Polyamide, polyester, synthetic fibers such as polyurethane, the use of synthetic rubber or the like. In particular, polyesters such as PET and polycarbonate are more preferable. Thus, according to the present invention, waste plastic that has not been effectively used can be effectively used as an energy source, and waste plastics can be rendered harmless.

  Even in the case where chlorine is contained in the polymer compound, in the present invention, chlorine reacts with an alkali to produce a salt such as NaCl, so that the chlorine is prevented from being mixed into hydrogen gas. Can do. In addition, a chlorine-based polymer compound such as polyvinyl chloride that generates dioxin by combustion can be converted into a harmless salt such as NaCl in the present invention, and therefore can be used as an energy source without any environmental load.

Although it does not specifically limit as an alkali, It is preferable to use the hydroxide or oxide of an alkali metal or alkaline-earth metal. For example, hydroxides of alkali metals such as sodium hydroxide (NaOH), lithium hydroxide (LiOH), potassium hydroxide (KOH), rubidium hydroxide (RbOH), calcium oxide (CaO), magnesium oxide (MgO) An alkaline earth metal oxide such as NaOH can be used, and among these, NaOH is particularly preferable. When NaOH is used, it is used as a raw material for glass or the like by the reaction of the present invention, and sodium carbonate (Na ₂ CO ₃ ) having a higher industrial value than NaOH is generated. Therefore, reaction by-products can also be effectively used.

As the addition amount of alkali, it is preferable to add 0.5 mol / (alkali valence) or more of alkali to 1 mol of carbon (C) contained in the carbon-containing material. By making such an addition amount, carbon (C) in the carbon-containing material surely generates alkali and carbonate, so that the generation of CO and CO ₂ due to thermal decomposition of the carbon-containing material is surely prevented. Can do. Moreover, the hydrogen production | generation speed | rate can also be improved by setting it as such addition amount. In addition, it is preferable that the alkali is present in a larger amount than carbon, but even if it is added excessively exceeding 10 mol / (alkali valence), the effect becomes saturated, so the upper limit of the amount of alkali added is 10 mol / (alkali valence) is preferred. A more preferable range is 2 to 5 mol / (alkali valence).

  The heating conditions vary depending on the raw materials used, but it is preferable to heat the carbon-containing material and the alkaline raw material to about 200 ° C. or higher. Thus, the target hydrogen can be produced | generated reliably by making the minimum of heating temperature into about 200 degreeC. On the other hand, the upper limit of the heating temperature is preferably about 700 ° C. When the heating temperature exceeds about 700 ° C., generation and volatilization of alkali metal and decomposition of alkali carbonate occur, which is not preferable.

  In particular, when a carbon material is used as the carbon-containing material, the lower limit of the heating temperature is preferably about 400 ° C, more preferably about 500 ° C, and even more preferably about 600 ° C in order to further improve the hydrogen production rate. . In addition, this reaction needs to be performed in an inert gas atmosphere, a water vapor atmosphere, or an atmosphere of water vapor and an inert gas in order to prevent combustion of the carbon-containing material. As the inert gas, a group 0 element gas such as argon (Ar) or nitrogen gas is preferably used. As for content of the water vapor | steam in an inert gas, the range with more preferable 1-100 volume% is 50-100 volume%.

  In addition, when using a natural organic compound or biomass containing a natural organic compound as a carbon-containing material, an excellent hydrogen generation rate is exhibited even when the lower limit of the heating temperature is about 200 ° C., but in order to further improve the lower limit, More preferably, the temperature is 250 ° C. In addition, when using lignin, the production | generation rate of hydrogen can be improved by making a minimum into about 400 degreeC. Thus, when using a natural organic compound or biomass containing a natural organic compound, an excellent hydrogen production rate can be obtained even at a low temperature.

  In addition, when a synthetic polymer compound is used as the carbon-containing material, depending on the type of compound, many exhibit an excellent hydrogen production rate when the lower limit of the heating temperature is about 250 ° C. Thus, when a synthetic polymer compound is used, an excellent hydrogen generation rate can be obtained even at a low temperature. Some compounds such as polycarbonate can obtain an excellent hydrogen production rate by setting the lower limit of the heating temperature to about 475 ° C.

  The reaction of the present invention can increase the hydrogen production rate by using a catalyst. As the catalyst, it is preferable to use a metal or metal oxide catalyst or a catalyst in which a metal is supported on a metal oxide or carbon material. Although the addition amount of a catalyst is not specifically limited, It is preferable to add in 0.1-100 weight% with respect to a carbon containing material.

  Examples of metal catalysts include ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), platinum (Pt) and other platinum groups, iron (Fe), nickel (Ni), etc. The iron group is preferred. In particular, ruthenium and rhodium can dramatically improve the hydrogen generation rate.

Examples of the metal oxide catalyst include magnesium (Mg), aluminum (Al), silicon (Si), calcium (Ca) titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), Metal oxides such as iron (Fe), zinc (Zn), zirconium (Zr), molybdenum (Mo), lanthanum (La), cerium (Ce), and praseodymium (Pr) are preferable. Specifically, magnesium oxide (MgO), aluminum oxide (Al ₂ O ₃ ), silicon dioxide (SiO ₂ ), calcium oxide (CaO), titanium dioxide (TiO ₂ ), vanadium pentoxide (V ₂ O ₅ ), Chromium trioxide (Cr ₂ O ₃ ), manganese dioxide (MnO ₂ ), triiron tetroxide (Fe ₃ O ₄ ), zinc oxide (ZnO), zirconium dioxide (ZrO ₂ ), molybdenum trioxide (MoO ₃ ), oxidation Examples thereof include lanthanum (La ₂ O ₃ ), cerium oxide (CeO ₂ ), and praseodymium oxide (Pr ₆ O ₁₁ ). In particular, aluminum oxide can dramatically improve the hydrogen generation rate.

Further, as a catalyst in which a metal is supported on a metal oxide or a carbon material, examples of the metal oxide as a carrier include magnesium (Mg), aluminum (Al), silicon (Si), calcium (Ca) titanium (Ti). , Vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), zinc (Zn), zirconium (Zr), molybdenum (Mo), lanthanum (La), cerium (Ce), praseodymium (Pr) Each oxide of metals such as is preferable. Specifically, magnesium oxide (MgO), aluminum oxide (Al ₂ O ₃ ), silicon dioxide (SiO ₂ ), calcium oxide (CaO), titanium dioxide (TiO ₂ ), vanadium pentoxide (V ₂ O ₅ ), Chromium trioxide (Cr ₂ O ₃ ), manganese dioxide (MnO ₂ ), triiron tetroxide (Fe ₃ O ₄ ), zinc oxide (ZnO), zirconium dioxide (ZrO ₂ ), molybdenum trioxide (MoO ₃ ), oxidation Examples thereof include lanthanum (La ₂ O ₃ ), cerium oxide (CeO ₂ ), and praseodymium oxide (Pr ₆ O ₁₁ ). In particular, aluminum oxide and silicon dioxide can dramatically improve the hydrogen production rate.

  The carbon material as a carrier is not particularly limited, but examples thereof include amorphous carbon such as charcoal, activated carbon, carbon black, coke, and soot, graphite (graphite), carbon fiber, carbon naofiber, fullerene, and carbon nanotube. It is preferable to use it. As charcoal or activated carbon, charcoal of woody biomass, such as charcoal, bamboo charcoal, bincho charcoal, coconut husk charcoal, coffee bean husk, chaff, rice bran, buckwheat husk etc. be able to.

  Examples of the active component metal include ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), platinum (Pt) and other platinum groups, iron (Fe), cobalt ( First transition metals such as Co), nickel (Ni), copper (Cu), and zinc (Zn) are preferred. In particular, a catalyst supporting nickel, cobalt, ruthenium, rhodium or the like can dramatically improve the hydrogen generation rate.

  The carbon-containing material and the alkali are not particularly limited as long as they are mixed so that the reaction occurs, but the carbon-containing material is preferably formed in various shapes depending on the shape of the reaction vessel so that the reaction is accelerated. For example, it is preferable to use powder, granule, pellet, flake, chip, piece, or porous. Further, depending on the type of carbon-containing material, it may be liquid or slurry. The alkali is preferably supported on a carbon-containing material as an aqueous solution.

  Next, an embodiment of the hydrogen generator according to the present invention will be described. The hydrogen production apparatus according to the present invention is not particularly limited as long as it is an apparatus that can generate hydrogen by the above-described hydrogen production method, but a reaction container containing a carbon-containing material and an alkali, and heating for heating the reaction container. It is preferable that the apparatus is equipped with a vessel and a pipe for discharging the hydrogen produced in the reaction vessel.

  The reaction vessel is preferably made of a material excellent in heat resistance and alkali resistance such as metals such as stainless steel and aluminum, ceramics such as alumina and zirconia, and heat resistant plastics such as phenol resin and polyphenylene sulfide. Moreover, when a reaction container becomes high temperature, it is preferable to cover with a heat insulating material. As the heat insulating material, glass fiber, silica fiber, silica powder molded body and the like can be used.

  In order to accelerate the reaction, this reaction vessel preferably further contains at least one catalyst selected from metals and metal oxides. The catalyst is preferably stored in a reaction vessel by selecting a shape suitable for the reaction such as powder, pellet, cylinder, honeycomb structure, and nonwoven fabric.

  As the heater, a heater by resistance heating, a positive temperature coefficient thermistor (PTC heater), a heater using oxidation heat of chemical reaction, a heater by catalytic combustion, a heater by induction heating, or the like can be used.

  In the case of performing the reaction with the addition of water vapor, it is preferable to further provide piping for supplying water or water vapor to the reaction vessel. Although water can be vaporized in the reaction vessel by the heater, a vaporizer or the like provided outside the reaction vessel to supply water vapor can be supplied into the reaction vessel. In addition, a certain amount of water can be stored in the reaction vessel.

  It is preferable that the piping for discharging hydrogen is configured so as to be supplied to a device using hydrogen such as a fuel cell. Moreover, since the hydrogen production apparatus according to the present invention is provided in combination with a fuel cell for a personal computer, a fuel cell for a mobile phone, and the like, it can be a small portable device.

  The carbon-containing material and alkali can be accommodated in the reaction vessel by either a fixed bed method or a fluidized bed method. In addition, a means for continuously supplying the carbon-containing material and alkali as raw materials may be provided in the reaction vessel so that hydrogen is continuously generated. Thereby, a certain amount of hydrogen can be generated over a long period of time.

(Hydrogen production from carbon materials)
( Experimental example 1)
Activated carbon (hereinafter abbreviated as activated carbon (W)) manufactured by Wako Pure Chemical Industries, Ltd. was weighed on an alumina board, and a 50 wt% NaOH aqueous solution (manufactured by Wako Pure Chemical Industries, Ltd.) was dropped onto the activated carbon. Then, activated carbon and NaOH aqueous solution were mixed with the spatula. The amounts of activated carbon and NaOH were 0.10 g (8.3 mmol) for activated carbon and 0.66 g (16.6 mmol) for NaOH so that the molar ratio of carbon: alkali = 1: 2.

Next, using the fixed bed flow reactor shown in FIG. 1, an experiment for generating hydrogen from the above sample was performed. First, the sample placed on the alumina board was placed in the alumina reaction tube 3, and Ar purge (50 ml / min, 101 kPa) was performed for 30 minutes. Thereafter, the reaction tube 3 was heated by the electric furnace 4 and dried at 100 ° C. for 20 minutes in an Ar (20 ml / min, 101 kPa) atmosphere. And the temperature in the reaction tube 3 was further heated up to 400 degreeC. After reaching a temperature of 400 ° C., water vapor was introduced from the microfeeder 1 through the vaporizer 2 and measurement described later was started. The water vapor was introduced at a water vapor supply rate of 9.4 ml / min, an Ar flow rate of 40 ml / min, and partial pressures of H ₂ O = 19.3 kPa and Ar = 81.7 kPa. The temperature of the vaporizer 2 was 100 ° C.

The gas generated in the alumina reaction tube 3 was introduced into the sampling device 6 through the trap device 5 maintained at 0 ° C. with ice. In order to analyze the gas phase product, a part of the gas phase is further introduced into the gas chromatograph 7 (GL Sciences, GC323, column: activated carbon), while the gas phase flow rate is measured. Was introduced into the soap film flow meter 8. The production rate (μmol / min) of each component such as hydrogen, methane, CO, and CO ₂ in the gas phase was determined from the gas phase composition and flow rate.

  The analysis of the gas phase product and the measurement of the flow rate were performed at a temperature of 400 ° C. for 1 hour, then the temperature was raised to 500 ° C. and again for 1 hour, and the temperature was further raised to 600 ° C. for 1 hour. These series of measurement results are shown in FIGS.

As shown in FIG. 2, it was confirmed that hydrogen was generated by the reaction of activated carbon (W), NaOH, and water vapor at a temperature of 400.degree. In addition, the hydrogen generation rate dramatically improved at temperatures of 500 ° C. and 600 ° C. As shown in FIG. 3, in addition to hydrogen, methane was produced in a very small amount (about 1 to 3 μmol / min at 500 ° C. and 600 ° C.), but no production of CO and CO ₂ was observed.

( Experimental example 2)
Instead of the activated carbon (W) in Experimental Example 1, low temperature carbonized bamboo charcoal (manufactured by Shiramoto Co., Ltd., hereinafter abbreviated as bamboo charcoal (L)), high temperature carbonized bamboo charcoal (manufactured by Shiramoto Co., Ltd., hereinafter, bamboo charcoal (H)) ), Bamboo charcoal (manufactured by Tsurugame, hereinafter abbreviated as bamboo charcoal (T)), Bincho charcoal (manufactured by Hinomaru Carbo Techno Co., Ltd.), carbon nanofiber (silica-supported Ni—Pd catalyst (silica by methane decomposition at 530 ° C.) : Carbon produced on the product name Cab-O-Sil, Ni-Pd: 30 wt%) manufactured by Cabot, hereinafter abbreviated as CNF), carbon black (manufactured by Wako Pure Chemical Industries, Ltd.), coconut shell activated carbon ( Experiments were performed in the same procedure as in Experimental Example 1 except that Hakugen Co., Ltd. (low temperature carbonization) was used. These measurement results are shown in FIGS. 2 and 3 together with the measurement results of Experimental Example 1.

As shown in Fig. 2, even when using charcoal such as bamboo charcoal, Bincho charcoal, coconut husk charcoal, or carbon materials such as CNF or carbon black, it is confirmed that hydrogen is generated as in the case of activated carbon (W). did. In particular, coconut husk activated carbon, bamboo charcoal (H), and bamboo charcoal (L) showed excellent hydrogen generation rates at 600 ° C. Further, as shown in FIG. 3, even in these carbon materials, a small amount of methane was produced, but no production of CO and CO ₂ was observed.

( Experimental example 3)
Instead of activated carbon (W) in Experimental Example 1, carbonized coffee bean husk (Shiramoto Co., Ltd., hereinafter abbreviated as coffee carbon), carbonized rice husk (Shiramoto Co., Ltd., hereinafter, rice husk) Abbreviated as shell carbon), carbonized rice bran (manufactured by Hakugen Co., Ltd., hereinafter abbreviated as rice bran carbon), carbonized buckwheat shell (manufactured by Shiramoto Co., Ltd., hereinafter abbreviated as buckwheat carbon) Except for this, the experiment was performed in the same procedure as in Experimental Example 1. The measurement results are shown in FIG.

As shown in FIG. 4, it was confirmed that even when a carbon material obtained by carbonizing woody biomass such as coffee carbon was used, hydrogen was generated as in the case of the activated carbon (W) and the like. In particular, coffee carbon and buckwheat carbon showed excellent hydrogen generation rates at 600 ° C. In these carbon materials, a small amount of methane was produced, but no production of CO and CO ₂ was observed.

Hydrogen production amount (mmol) calculated by accumulating each hydrogen production amount obtained when each carbon material of Experimental Example 1 to Experimental Example 3 was reacted at reaction temperatures of 400 ° C., 500 ° C., and 600 ° C. for 1 hour each. Is shown in FIG. Also, from this hydrogen production amount, the theoretically consumed carbon amount (mol) and NaOH amount (mol) are calculated based on the above-mentioned formula 4 (note that the methane production amount is not taken into account), and from this, carbon The consumption rate (= consumed carbon amount / introduced carbon amount × 100 (%)) and NaOH consumption rate (= consumed NaOH amount / introduced NaOH amount × 100 (%)) were calculated. These calculation results are shown in FIGS. 6 and 7, respectively. Furthermore, the ratio (H ₂ / C) of the amount of hydrogen generation to the amount of introduced carbon is shown in FIG.

Further, the surface area of each carbon material used in Experiment 1 to Experiment Example 3 (m ² / g), was measured according to the BET method. The result is shown in FIG. As shown in FIG. 9, the carbon material having a larger surface area tends to have a higher hydrogen production rate. However, some carbon materials with a small surface area, such as bamboo charcoal (L), have a good hydrogen generation rate.

(Influence of the amount of alkali added)
( Experimental example 4)
The NaOH amount of Experimental Example 1 was not added (carbon: alkali = 1: 0), 33 mg (carbon: alkali = 1: 0.1), 83 mg (carbon: alkali = 1: 0.25), 664 mg (carbon: Alkali = 1: 2), 1000 mg (carbon: alkali = 1: 3), the molar ratio of the amount of alkali added to the amount of carbon introduced was changed, and the measurement time was 500 to 60 minutes at 400 ° C. The experiment was performed by the same procedure as in Experimental Example 1 except that the temperature was changed to 60 ° C. for 60 to 200 minutes and 600 ° C. for 60 to 200 minutes. The measurement results are shown in FIGS.

When no alkali was added, as shown in FIG. 10, not only the generation of hydrogen was hardly observed, but it was also confirmed that CO and CO ₂ were generated as shown in FIGS. 11 and 12. . In addition, when the alkali was added at a molar ratio of 0.1 or 0.25, generation of hydrogen was confirmed as shown in FIG. 10, but CO and CO ₂ were also generated as shown in FIGS. Confirmed to do. On the other hand, when alkali is added at a molar ratio of 2 or 3, as shown in FIG. 10, the hydrogen production rate is good, and as shown in FIGS. 11 and 12, the production of CO and CO ₂ is observed. There wasn't.

Also for Experimental Example 4, from the hydrogen generation amount (mmol) calculated by accumulating each hydrogen generation amount obtained at each reaction temperature, the ratio of hydrogen generation amount to the introduced carbon amount (H ₂ / C), Carbon consumption rate (%) and NaOH consumption rate (%) were calculated. These calculation results are shown in FIGS.

As shown in FIG. 13, when alkali was added in a molar ratio of 2 or more, it was confirmed that the amount of hydrogen generation was higher than the amount of carbon introduced. Further, as shown in FIG. 14, it was confirmed that when the alkali was added in a molar ratio of 2 or more, the carbon consumption rate was also high. On the other hand, as shown in FIG. 15, the NaOH consumption rate was higher when the alkali was added at a molar ratio of 0.1 and 0.25, exceeding 100%. When the consumption rate of NaOH exceeds 100%, it is considered that H ₂ , CO, and CO ₂ were generated by the reaction shown below.

C + H ₂ O → CO + H ₂ (Formula 7)

CO + H ₂ O → CO ₂ + H ₂ (Formula 8)

(Total hydrogen production)
( Experimental example 5)
In Experimental Example 1, carbon black and coconut husk activated carbon were used, and after measuring for 1 hour each at a reaction temperature of 400 ° C. and 500 ° C., measurement was performed until almost no hydrogen generation was observed at a reaction temperature of 600 ° C. Except for this, the experiment was performed in the same procedure as in Experimental Example 1. The results at 600 ° C. are extracted and shown in FIG.

  As shown in FIG. 16, it was confirmed that carbon black and coconut husk activated carbon continue to generate hydrogen even when the reaction temperature exceeds 600 ° C. for more than 1 hour. At the initial stage of the reaction at a temperature of 600 ° C., coconut husk activated carbon had a higher hydrogen production rate than carbon black. In both coconut husk activated carbon and carbon black, the hydrogen production rate gradually decreased with the passage of time, and coconut husk activated carbon almost disappeared in about 2 hours after heating up to 600 ° C. Hydrogen was produced for more than an hour.

Also for Experimental Example 5, the hydrogen production amount (mmol), the carbon consumption rate (%), and the NaOH consumption rate (%) obtained by accumulating each hydrogen production amount obtained at each reaction temperature were calculated. These results are shown in FIG. Since carbon black produced hydrogen for a longer time than coconut shell activated carbon, as shown in FIG. 17, the hydrogen production amount, carbon consumption rate, and NaOH consumption rate of carbon black were almost the same values as coconut shell activated carbon.

( Experimental example 6)
In Experimental Example 1, bamboo charcoal (H), coconut shell activated carbon was used, and the temperature was raised to 600 ° C. in about 15 minutes under an Ar atmosphere. After reaching 600 ° C., water vapor was introduced and measurement was started. The experiment was performed by the same procedure as in Experimental Example 1 except that the measurement was performed until no hydrogen production was observed. The result is shown in FIG.

  As shown in FIG. 18, it was confirmed that bamboo charcoal (H) and coconut husk activated carbon produced hydrogen by continuing the reaction even after 300 minutes from the introduction of water vapor. At the beginning of the reaction, bamboo charcoal (H) had a higher hydrogen production rate than coconut shell activated carbon. Both the coconut husk activated carbon and bamboo charcoal (H) gradually decreased in hydrogen generation rate over time, but the hydrogen generation rate increased again from about 80 minutes to about 180 minutes after the introduction of steam.

For Experimental Example 6, the amount of hydrogen produced, the carbon consumption rate, and the NaOH consumption rate were also calculated. In Experimental Example 6, each consumption rate was calculated in consideration of the amount of methane produced. These results are shown in FIG. As shown in FIG. 19, when water vapor introduction was started at a temperature of 600 ° C., the hydrogen production amount, carbon consumption rate, and NaOH consumption rate of bamboo charcoal (H) exceeded that of coconut shell activated carbon.

(Adsorption component content of coconut shell activated carbon)
As a sample, 0.1028 g (8.57 mmol) of coconut shell activated carbon was placed on an alumina board and heated at 600 ° C. for 2 hours in an Ar atmosphere. It was 0.0831g when the weight of the sample after a heating was measured. Therefore, the weight 0.0831 g (6.93 mmol) of the sample after heating is the amount contained in the sample as pure carbon, and 0.0197 g (19.19 as the weight ratio) which is the difference in the sample weight before and after heating. 2%) was the amount contained in the sample as an adsorbing component (water, carbon dioxide, etc.) or a decomposition component (—OH, —COOH, —CHO group, etc.). Thereafter, the calculation is performed considering the content of adsorbed components or surface decomposition components in coconut shell activated carbon as 19.2 wt%.

( Experimental example 7)
In Experimental Example 1, 0.1002 g (8.35 mmol) of coconut shell activated carbon and 0.6678 g (16.7 mmol) of NaOH were used, and the temperature was raised to 600 ° C. in an Ar atmosphere. (100 ° C. to 600 ° C.) was also measured using the same procedure as in Experimental Example 1 except that the generated gas phase was measured and water vapor was introduced from 600 ° C. until hydrogen generation was not observed. Went. The results are shown in FIGS.

  As shown in FIG. 20, it was confirmed that hydrogen was generated at a temperature of about 350 ° C. or higher even in the temperature rising process in which no water vapor was introduced. In particular, at a temperature of 500 ° C. or higher, the hydrogen production rate was dramatically improved. In addition, as shown in FIG. 21, the hydrogen production rate gradually decreased with the passage of time after the introduction of water vapor, but the hydrogen production rate significantly increased between about 80 minutes and about 180 minutes after the introduction of water vapor.

As shown in FIG. 22, a small amount of methane was produced in the temperature raising process, but no production of CO and CO ₂ was observed. Further, as shown in FIG. 23, the methane production rate was remarkably reduced after the introduction of water vapor, but the methane production rate slightly increased between about 80 minutes and about 180 minutes after the introduction of water vapor.

In Experimental Example 7, in addition to the amount of hydrogen produced, the amount of methane produced and the rate of adsorbed components in the sample were taken into account, and the amounts of carbon and NaOH consumed and the rates of consumption, as well as the hydrogen production for the introduced carbon The amount ratio (H ₂ / C) was calculated. These results are shown in Table 1. In addition, the amount of carbon (the amount of carbon introduced) contained in 0.1002 g of coconut shell activated carbon was set to 0.0810 g (6.74 mmol) using the above-described adsorption and surface decomposition component ratio of 19.2 wt%.

As shown in Table 1, about 81% of the introduced carbon was consumed after the introduction of steam, but about 14% was consumed in the temperature rising process, so the carbon consumption rate of the entire reaction was about 95%. there were. Therefore, it was found that most of the introduced carbon was consumed by the hydrogen generation reaction. Further, H ₂ / C of the whole reaction was about 1.8, which was very close to the theoretical value of 2.

(Influence of water vapor introduction)
( Experimental example 8)
In Experimental Example 1, use of coconut husk activated carbon, and heating up to 600 ° C. in an Ar atmosphere, with or without introducing water vapor from 600 ° C. The experiment was conducted by the same procedure as in Experimental Example 1 except that the measurement was performed until no more was observed. The results are shown in FIG.

  As shown in FIG. 24, it was confirmed that hydrogen was generated at a reaction temperature of 600 ° C. for about 300 minutes with or without introduction of water vapor. In addition, in the case where water vapor was introduced or not introduced at all, the hydrogen production rate gradually decreased with the passage of time. However, when water vapor was introduced, hydrogen was introduced between about 80 minutes and about 180 minutes after the introduction of water vapor. The production rate increased significantly. On the other hand, such an increase was not observed when no water vapor was introduced.

Further, as shown in Table 2, the amount of hydrogen produced when no steam was introduced was 26.6% lower than when steam was introduced. This is presumably because the introduction of water vapor promotes hydrogen production by reacting the water vapor with Na ₂ O to regenerate NaOH as shown in Equation 3 above. Note that the NaOH consumption when water vapor was introduced was calculated based on the above equation 4, and the NaOH consumption when water vapor was not introduced at all was calculated based on the above equation 1. is there. Therefore, as shown in Table 2, the NaOH consumption when steam was introduced was about 65%, whereas the NaOH consumption when steam was not introduced was as high as about 95%. .

( Experimental example 9)
In Experimental Example 1, coconut shell activated carbon was used, and when the temperature was raised to 600 ° C. under an Ar atmosphere and steam was introduced after the temperature was raised to 600 ° C. and when steam was introduced after reacting at 600 ° C. for 200 minutes. The experiment was conducted by the same procedure as in Experimental Example 1 except that the measurement was performed until no hydrogen generation was observed from the temperature raising process (100 ° C. to 600 ° C.). The results are shown in FIG.

  As shown in FIG. 25, both when the steam was introduced after the temperature was raised to 600 ° C. and when the steam was introduced after reacting at 600 ° C. for 200 minutes, the hydrogen production rate immediately after the temperature rise was 600 ° C. was the highest. The hydrogen production rate gradually decreased. When water vapor was introduced after the temperature was raised to 600 ° C., the hydrogen production rate increased significantly between about 80 minutes and about 180 minutes after the introduction of the water vapor. In addition, when water vapor was introduced after the reaction for 200 minutes, the hydrogen production rate was not increased before the introduction of water vapor, but the hydrogen production rate was about 60 minutes to about 180 minutes after the water vapor was introduced. It rose significantly.

Moreover, as shown in Table 3, both when the steam is introduced after the temperature is raised to 600 ° C. and when the steam is introduced after reacting at 600 ° C. for 200 minutes, the hydrogen production amount, the methane production amount, the carbon consumption after the completion of the reaction. Rate, NaOH consumption rate, and H ₂ / C were almost the same value.

(Hydrogen production from biomass resources)
( Experimental example 10)
In Experimental Example 1, in place of 0.10 g (8.3 mmol) of activated carbon (W), D-glucose (manufactured by Wako Pure Chemical Industries, Ltd.), sucrose (manufactured by Wako Pure Chemical Industries, Ltd.), cellulose (manufactured by Aldrich) ) Was used in such a weight that the carbon content in the sample was 0.20 g (16.7 mmol), 1.33 g (33.3 mmol) of NaOH was used, no water vapor was introduced, and an Ar atmosphere. Example 1 except that the temperature was raised to 600 ° C. at a substantially constant rate of temperature increase (1.9 ° C./min) and the temperature was measured between 100 ° C. and 600 ° C. The experiment was conducted according to the same procedure. The results are shown in FIG.

As shown in FIG. 26, it was confirmed that all saccharides of glucose, sucrose, and cellulose exhibited an excellent hydrogen generation rate in a low temperature range of about 250 ° C. to about 350 ° C. Sucrose produced hydrogen even at a low temperature of about 175 ° C. Cellulose exhibited a high hydrogen production rate at a low temperature of about 250 ° C. Glucose produced the largest amount of hydrogen among these sugars. In addition, although a relatively large amount of methane was produced, no production of CO and CO ₂ was observed.

( Experimental example 11)
In Experimental Example 10, the experiment was performed in the same procedure as in Experimental Example 10 except that water vapor was introduced at 100 ° C. The results are shown in FIG.

  As shown in FIG. 27, when water vapor is introduced, as in the case where water vapor is not introduced, all saccharides of glucose, sucrose, and cellulose have excellent hydrogen generation rates in a low temperature range of about 250 ° C. to about 350 ° C. Confirmed to show. When steam was introduced, the hydrogen production amount of cellulose was the largest. In addition, when water vapor | steam was introduce | transduced, compared with the case where water vapor | steam was not introduce | transduced, the hydrogen production rate rose in the temperature range of about 350 degreeC-about 450 degreeC.

( Experimental example 12)
In Experimental Example 11, an experiment was performed in the same procedure as Experimental Example 11 except that lignin (manufactured by Aldrich) and starch (manufactured by Wako Pure Chemical Industries, Ltd.) were used. The results are shown in FIGS. 28 and 29 and Table 6.

As shown in FIG. 28, it was confirmed that starch, which is a saccharide, exhibits an excellent hydrogen production rate in a low temperature range of about 200 ° C. to about 350 ° C., similar to the above glucose. On the other hand, lignin, unlike these saccharides, showed an excellent hydrogen production rate at about 400 ° C. or higher. As shown in FIG. 29, in the starch and lignin, methane was produced in a trace amount, but no production of CO and CO ₂ was observed.

( Experimental example 13)
In Experiment 10, absorbent cotton (commercial product) and Japanese paper (commercial product) were used in an amount such that the carbon content was 0.20 g (16.7 mmol) on the assumption that the sample was composed entirely of cellulose. Except for the above, the experiment was performed in the same procedure as in Experimental Example 10. The results are shown in FIGS. In the figure, the cellulose of Experimental Example 10 is also shown for comparison.

As shown in FIG. 30, it was confirmed that the absorbent cotton and Japanese paper, which are cellulosic products, exhibited excellent hydrogen generation rates in a low temperature range of about 250 ° C. to about 350 ° C. as in the case of cellulose. As shown in FIG. 31, absorbent cotton and Japanese paper also produced trace amounts of methane, but no CO or CO ₂ was observed. Moreover, as shown in FIG. 32, the production amounts of hydrogen and methane of absorbent cotton and Japanese paper were almost the same as those of cellulose.

( Experimental example 14)
The paper of Example 13, except that was measured by introducing steam from 100 ° C., an experiment was conducted by a procedure similar to that of Example 13. The results are shown in FIG. 33 and Table 7. In the figure and table, for comparison, the case of not introducing the water vapor in Experimental Example 13 is also shown.

As shown in FIG. 33, when water vapor is introduced, the hydrogen production rate is slightly reduced at about 280 ° C. to about 300 ° C., but an excellent hydrogen production rate is exhibited in the temperature range of about 220 ° C. to about 350 ° C. It was. In addition, the hydrogen production rate increased again in the temperature range of about 400 ° C to about 450 ° C. When water vapor was not introduced, some carbon remained after the reaction. However, when water vapor was introduced, there was no black material that appeared to be carbon, and only a white material of Na ₂ CO ₃ remained. As shown in Table 7, when water vapor was introduced, the amount of hydrogen generation increased compared to the case where water vapor was not introduced. Thus, when water vapor is introduced, the remaining unreacted carbon reacts again to generate hydrogen.

( Experimental example 15)
In Experiment 11, rice straw, except that cedar, bamboo, assuming the sample is composed of all cellulose was used the amount of carbon content is 0.20 g (16.7 mmol), Experiment The experiment was conducted according to the same procedure as in No.11. The results are shown in FIG. 34 and Table 8.

The main component of woody biomass is cellulose, but it also contains a lot of lignin as other components. In general, the content of lignin is about 18 to 36 wt% for wood and 15 to 25 wt% for plants. Therefore, as shown in FIG. 34, the woody biomass of rice straw, cedar and bamboo shows an excellent hydrogen generation rate in a low temperature range of about 250 ° C. to about 350 ° C. as in the case of cellulose, and similarly to lignin. An excellent hydrogen production rate was exhibited even in a temperature range of about 400 ° C. or higher. These woody biomass also produced a small amount of methane, but no CO or CO ₂ was produced.

( Experimental example 16)
In Experimental Example 10, newspaper (commercially available) was used in an amount of 0.20 g (16.7 mmol) of carbon, assuming that the sample was composed entirely of cellulose, and from 100 ° C. to water vapor. The experiment was performed according to the same procedure as in Experimental Example 10 except that the measurement was carried out in the case where no water vapor was introduced and the case where no water vapor was introduced. The results are shown in FIG. 35 and Table 9.

As shown in FIG. 35, it was confirmed that the newspaper, which is a cellulose product, showed an excellent hydrogen production rate in a low temperature range of about 250 ° C. to about 350 ° C., similar to cellulose. In addition, the newspaper also produced a small amount of methane, but no CO or CO ₂ was produced.

( Experimental example 17)
The paper of Example 13, except that measured in the case of adding the case and NaOH without the addition of NaOH at all, an experiment was conducted by a procedure similar to that of Example 13. The results are shown in FIGS. 36 and 37.

When no NaOH was added at all, as shown in FIG. 36, it was confirmed that CO and CO ₂ were generated at around 300 to 350 ° C., and thermal decomposition of the Japanese paper started. Moreover, since water was trapped by the trap device 5 from around this temperature and a yellowish brown liquid (tar) adhered to the vicinity of the outlet of the reaction tube 3, it was also confirmed that water vapor and tar were generated. In addition, hydrogen was generated in a trace amount (about 0.4 μmol / min) at about 500 ° C. On the other hand, when NaOH was added, as shown in FIG. 37, an excellent hydrogen production rate was exhibited at around 250 to 400 ° C., and the production of CO and CO ₂ was not observed. Further, since no tar was adhered, it is considered that when NaOH was added, hydrogen was generated not by thermal decomposition of Japanese paper but by reaction of NaOH and Japanese paper.

(Hydrogen generation from synthetic polymer compounds)
( Experiment 18)
In Experimental Example 1, instead of 0.10 g (8.3 mmol) of activated carbon (W), polyethylene terephthalate (commercial product, hereinafter abbreviated as PET), polycarbonate (commercial product, hereinafter abbreviated as PC), carbon in the sample The amount used was 0.20 g (16.7 mmol), the use of 1.33 g (33.3 mmol) of NaOH, no introduction of water vapor, and almost 600 ° C. under Ar atmosphere. The experiment was conducted in the same procedure as in Experimental Example 1 except that the temperature was raised at a constant rate of temperature increase (1.9 ° C./min) and the measurement was performed between 100 ° C. and 600 ° C., which is the temperature raising process. went. The results are shown in FIGS. 38 and 39.

As shown in FIG. 38, it was confirmed that both PET and PC plastics showed excellent hydrogen production rates. PET produced hydrogen at a low temperature of about 250 ° C., and showed the highest hydrogen production rate at about 300 ° C. In addition, PC produced hydrogen at a high temperature of about 475 ° C., and showed the highest hydrogen production rate at about 500 ° C. In both PET and PC plastics, a small amount of methane was produced in addition to hydrogen, but no production of CO and CO ₂ was observed. As shown in FIG. 39, the amount of hydrogen produced by PC was larger than that by PET.

  Further, in order to examine the total hydrogen production amount and the total methane production amount in both PET and PC plastics, measurement was performed until no hydrogen production was observed while maintaining the temperature at 600 ° C. The results are shown in FIGS. 40 and 41. As shown in FIG. 40, after both PET and PC reached 600 ° C. (in the figure, about 260 minutes), the hydrogen production rate gradually decreased with the passage of time. Further, as shown in FIG. 41, the total amount of hydrogen generated was about 7 mmol for PET, whereas about 20 mmol for PC was able to obtain a very large amount of hydrogen.

(Promotion of hydrogen production reaction by catalyst)
( Experimental example 19)
Carbon black (0.100 g) was used instead of the activated carbon of Experimental Example 1, 0.025 g of a metal catalyst of iron, nickel, ruthenium, platinum, and rhodium was added as a catalyst, and the temperature was raised to 500 ° C. and, by introducing steam after reaching the temperature of 500 ° C., was measured at a temperature 500 ° C. 40 min, except that the temperature was further raised to a temperature 600 ° C., it measured 100 minutes again temperature 600 ° C., as in experimental example 1 The experiment was conducted according to the same procedure. The results are shown in FIGS. In addition, in the figure, in order to compare the effect of the metal catalyst, the result of not adding the catalyst is also shown.

  As shown in FIGS. 42 and 43, in the case of using the metal catalyst, the hydrogen generation rate and the hydrogen generation amount were remarkably improved as compared with the case where the catalyst was not added. In particular, a dramatic improvement was shown at a temperature of 600 ° C. Of these metal catalysts, ruthenium showed the most excellent hydrogen production rate and hydrogen production.

( Experiment 20)
Instead of the metal catalyst of Experimental Example 19, magnesium oxide, aluminum oxide, silicon dioxide, calcium oxide, titanium dioxide, vanadium pentoxide, chromium trioxide, manganese dioxide, triiron tetroxide, zinc oxide, zirconium dioxide, molybdenum trioxide The experiment was conducted in the same procedure as in Experimental Example 19 except that 0.025 g of a metal oxide catalyst of lanthanum oxide, cerium oxide, and praseodymium oxide was added. The results are shown in FIGS. 44 and 45. In addition, in the figure, in order to compare the effect of the metal oxide catalyst, the result of not adding the catalyst is also shown.

  As shown in FIGS. 44 and 45, those using a metal oxide catalyst significantly improved the hydrogen generation rate and the amount of hydrogen generation compared to the case where no catalyst was added. In particular, a dramatic improvement was shown at a temperature of 600 ° C. Among these metal catalysts, aluminum oxide showed the best hydrogen production rate and hydrogen production.

( Experimental example 21)
First, aluminum oxide is immersed in an aqueous solution containing nickel metal ions, dried, calcined at 600 ° C. in air, and subjected to hydrogen reduction treatment at 500 ° C., whereby a catalyst in which nickel metal is supported on aluminum oxide (Ni / Al ₂ O ₃ ) was obtained. The metal loading was 20% by weight.

Next, in Experimental Example 1, instead of activated carbon (W), 0.45 g of cellulose (manufactured by Aldrich) was used (carbon content in cellulose was 16.7 mmol), 1.33 g (33.3 mmol) of NaOH. ) Used, 0.18 g of Ni / Al ₂ O ₃ catalyst, almost constant temperature increase from 100 ° C. to 600 ° C. under Ar and water vapor (40.0 and 9.4 ml / min, 101 kPa) atmosphere The experiment was performed in the same procedure as in Experimental Example 1 except that the temperature was increased at a rate (2 ° C./min) and the measurement was performed between 100 ° C. and 600 ° C., which is the temperature increasing process. The result is shown in FIG. In the figure, in order to compare the effect of this catalyst, the result of not adding the catalyst is also shown.

As shown in FIG. 46, when the Ni / Al ₂ O ₃ catalyst was used, the hydrogen generation rate was remarkably improved as compared with the case where the catalyst was not used. Further, when the catalyst was not used, a small amount of methane was produced at 350 to 500 ° C. (about 100 μmol / min at about 400 ° C.), but when the Ni / Al ₂ O ₃ catalyst was used, the temperature increased to 600 ° C. Methane formation was not confirmed even when heated.

( Experimental example 22)
In Experimental Example 21, an experiment was performed in the same procedure as in Experimental Example 21, except that each catalyst in which cobalt, iron, copper, rhodium, ruthenium, platinum, and palladium were supported on aluminum oxide was used instead of nickel. . The results are shown in FIGS. 47 and 48. Note that the amount of metal supported was 20% by weight.

As shown in FIG. 47 and FIG. 48, it was confirmed that the hydrogen production rate was improved when each catalyst having the above metal supported on aluminum oxide was used as compared with the case where no catalyst was used. Further, in any case where any of these catalysts was used, methane formation was not confirmed as in Experimental Example 21 (not shown).

  Furthermore, the obtained hydrogen production amount was also compared. Assuming that the hydrogen yield obtained when the reaction formula shown in Formula 6 proceeds completely is 100%, the amount of hydrogen produced should be 33.3 mmol. When the catalyst was not used, the amount of hydrogen produced was 20.7 mmol, so the hydrogen yield was 62%. On the other hand, as shown in FIG. 49, the hydrogen yield was improved from 62% when the above-described catalysts each having a metal supported on aluminum oxide were used. In particular, a hydrogen yield of almost 100% was obtained with a catalyst in which cobalt, nickel, ruthenium, and rhodium were supported on aluminum oxide.

( Experimental example 23)
In Experimental Example 21, the experiment was performed in the same procedure as in Experimental Example 21 except that each catalyst in which nickel was supported on titanium dioxide, chromium trioxide, zirconium dioxide, cerium oxide, or silicon dioxide was used instead of aluminum oxide. went. The result is shown in FIG. Note that the amount of metal supported was 20% by weight.

  As shown in FIG. 50, even when the above metal oxide was used in addition to aluminum oxide as the support, a hydrogen yield of almost 100% could be obtained.

It is a schematic diagram which shows the outline of the fixed bed flow reaction apparatus used by the experiment example . It is a graph which shows the hydrogen production rate in the reaction temperature of each carbon material. It is a graph which shows the methane production | generation rate in the reaction temperature of each carbon material. It is a graph which shows the hydrogen and methane production | generation rate in the reaction temperature of each carbon material. It is a graph which shows the hydrogen production amount of each carbon material. It is a graph which shows the carbon consumption rate of each carbon material. It is a graph which shows the NaOH consumption rate of each carbon material. It is a graph showing the H ₂ / C of each carbon material. It is a graph which shows the surface area of each carbon material. It is a graph which shows the hydrogen production | generation rate at the time of changing the molar ratio of NaOH. It is a graph which shows CO production | generation rate at the time of changing the molar ratio of NaOH. It is a graph showing the CO ₂ production rate in the case of changing the molar ratio of NaOH. It is a graph showing the H ₂ / C in the case of changing the molar ratio of NaOH. It is a graph which shows the carbon consumption rate at the time of changing the molar ratio of NaOH. It is a graph which shows the NaOH consumption rate at the time of changing the molar ratio of NaOH. It is a graph which shows the hydrogen production | generation rate at the time of making it react until it stops producing hydrogen production at 600 degreeC. It is a result at the time of making it react at 400 degreeC and 500 degreeC for 1 hour each, and making it react until it stops producing hydrogen production at 600 degreeC, Comprising: (a) is the amount of hydrogen production, (b) is consumption of carbon and NaOH It is a graph which shows a rate. It is a graph which shows the hydrogen production | generation rate at the time of introduce | transducing water vapor | steam from 600 degreeC. It is a result at the time of introduce | transducing water vapor | steam from 600 degreeC, Comprising: (a) is a hydrogen production amount, (b) is a graph which shows the consumption rate of carbon and NaOH. It is a graph which shows the hydrogen production rate of a temperature rising process. It is a graph which shows the hydrogen production rate at the time of a temperature rising process, and when water vapor | steam is introduce | transduced at 600 degreeC. It is a graph which shows the methane production | generation rate of a temperature rising process. It is a graph which shows the methane production | generation rate | velocity | rate when water vapor | steam is introduce | transduced at a temperature rising process and 600 degreeC. It is a graph which shows the methane production | generation rate at the time of not introducing water vapor | steam at all. It is a graph which shows the hydrogen production | generation rate at the time of introduce | transducing water vapor | steam after making it react at 600 degreeC for 200 minutes. It is a graph which shows the production | generation rate of hydrogen and methane of each saccharide | sugar when water vapor | steam is not introduce | transduced. It is a graph which shows the production | generation rate of hydrogen and methane of each saccharide | sugar when water vapor | steam is introduce | transduced. It is a graph which shows the hydrogen production rate of lignin and starch. It is a graph which shows the methane production rate of lignin and starch. It is a graph which shows the hydrogen production | generation rate of a cellulose, absorbent cotton, and Japanese paper. It is a graph which shows the methane production | generation rate of a cellulose, absorbent cotton, and Japanese paper. It is a graph which shows the production amount of hydrogen and methane of cellulose, absorbent cotton, Japanese paper. It is a graph which shows the production | generation rate | velocity | rate of hydrogen and a methane when the water vapor | steam is introduce | transduced and it does not introduce | transduce. It is a graph which shows the production | generation rate of hydrogen and methane of rice straw, cedar, bamboo. It is a graph which shows the production | generation rate | velocity of the hydrogen and methane of a newspaper when the water vapor | steam was introduce | transduced and it was not introduce | transduced. Hydrogen when not adding NaOH, is a graph showing methane generation rate of CO and CO _2. Is a graph showing the hydrogen in the case of addition of NaOH, methane, the formation rate of CO and CO _2. It is a graph which shows the production | generation speed | velocity of hydrogen and methane of PET and PC. It is a graph which shows the production amount of hydrogen and methane of PET and PC. It is a graph which shows the production | generation rate | velocity of hydrogen and methane of PET, PC at the time of performing reaction until hydrogen production is no longer seen. It is a graph which shows the production amount of hydrogen of PET, PC, and methane when it reacts until hydrogen production is not seen. It is a graph showing of H ₂ production rate and H ₂ O conversion in the case of using a metal catalyst. It is a graph showing of H ₂ generation amount and the carbon conversion rate in the case of using a metal catalyst. It is a graph showing of H ₂ production rate and H ₂ O conversion in the case of using a metal oxide catalyst. It is a graph showing of H ₂ generation amount and the carbon conversion rate in the case of using a metal oxide catalyst. Metal is a graph showing of H ₂ production rate and CH ₄ production rate in the case of using the catalyst supported on metal oxides. Metal is a graph showing of H ₂ production rate in the case of using the catalyst supported on metal oxides. Metal is a graph showing of H ₂ production rate in the case of using the catalyst supported on metal oxides. Metal is a graph showing of H ₂ yields when using a catalyst supported on metal oxides. Metal is a graph showing of H ₂ yields when using a catalyst supported on metal oxides.

1 Microfeeder 2 Vaporizer 3 Alumina reaction tube 4 Electric furnace 5 Trap device 6 Sampling device 7 Gas chromatograph 8 Soap film flow meter

Claims (2)

A reaction between a natural organic compound or a biomass containing a natural organic compound or a carbon-containing material that is a synthetic polymer compound and an alkali in an inert gas atmosphere and under heating conditions and in the presence of a metal or metal oxide catalyst. A hydrogen production method for producing hydrogen without producing carbon monoxide and carbon dioxide , wherein the molar ratio of the carbon-containing material to the alkali is set to an alkali with respect to 1 mol of carbon contained in the carbon-containing material. A hydrogen production method of 2 to 5 mol / (alkali valence). A natural organic compound or a biomass containing a natural organic compound or a carbon-containing material that is a synthetic polymer compound and an alkali are contained, and a metal or metal oxide catalyst is further contained , and the carbon-containing material is contained in an inert gas atmosphere. A reaction vessel for producing hydrogen without producing carbon monoxide and carbon dioxide, a heater for heating the reaction vessel, and discharging the hydrogen produced in the reaction vessel. A hydrogen production apparatus comprising: a pipe, wherein the molar ratio of the carbon-containing material and the alkali contained in the reaction vessel is 2-5 mol / alkali per 1 mol of carbon contained in the carbon-containing material. A hydrogen production apparatus that is (alkali valence).

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