JP5488871B2 - Energy gas production method - Google Patents

Description

The present invention relates to an energy gas production how, more particularly, relates biomass, carbon hydrogen and oxygen-containing compounds, such as plastic waste hydrogen, methane, and how to produce energy gas such as carbon monoxide.

Biomass refers to organic resources derived from renewable organisms, excluding fossil resources. Biofuel refers to fuel that uses the energy of biomass (for example, ethanol, methanol, butanol, diethyl ether, hydrogen gas, methane gas, synthesis gas, etc.). Biofuels can be used in a wide variety of raw materials such as corn, sugarcane, edible oil, wood, manure, sawdust, corn stalk, and organic waste that cannot be used for food and feed.
Biofuels that are in an alcoholic state can be used as fuel for diesel engines and are commonly used in some countries. Synthetic oils of biofuels and petroleum fuels are called biomass fuels, and their use is being studied mainly in the United States as an alternative fuel for gasoline.

In addition, various proposals have been made for methods for obtaining gas fuel or solid fuel from biomass.
For example, Non-Patent Document 1 discloses a hydrogen generation method in which Ca (OH) ₂ and Ni (OH) ₂ are added to cellulose, mixed and pulverized, and the mixed pulverized product is heated.
This document describes that hydrogen can be selectively obtained at around 400 ° C. by such a method.

Patent Document 1 discloses a method for producing hydrogen in which a mixture of cellulose and iron powder is milled.
This document describes that hydrogen can be produced at room temperature and pressure by such a method.

Patent Document 2 discloses a hydrogen production method in which cedar wood, Ca (OH) ₂ and water are introduced into an autoclave and maintained at 650 ° C. and 3 to 25 atm for 10 minutes.
In the same document,
(1) The gas component obtained by such a method is mostly hydrogen, and
(2) At a reaction temperature of 650 ° C., the conversion rate of water into hydrogen by biomass is maximized near 6 atm.
Is described.

Furthermore, in Patent Document 3, cellulose, water, and a nickel metal catalyst are placed in a pressurized reaction vessel, and the inside of the vessel is heated to 350 ° C. (saturated vapor pressure of water: 170 atm or higher) to produce hydrogen that is held for 60 minutes. A method is disclosed.
This document describes that hydrogen can be produced by such a method, and that the amount of hydrogen produced increases as the number of metal catalysts increases.

JP 2006-31690 A JP 2005-041733 A JP-A-8-059202

Zhang, Taketake et al., "Hydrogen generation from cellulose combining mechanochemical treatment and heating method", Proceedings of the 39th Autumn Meeting of the Chemical Society of Japan

  Around 2030, oil mining peaks, and the economic development of developing countries is predicted to cause a shortage of oil-dependent energy on a global scale. Therefore, in several decades, securing energy sources other than fossil resources and their stable storage will be important issues. One such candidate is the active use of hydrogen-based energy. Since hydrogen energy can be produced from other sources than fossil resources, the expectations are high.

As disclosed in Patent Documents 2 and 3, when water vapor or oxygen is added to a pulverized biomass raw material and reacted under high temperature and high pressure, the raw material is gasified to obtain hydrogen gas with relatively high purity. it can.
However, this method requires a reaction at a high temperature and a high pressure, and therefore requires a large-scale device and an exhaust gas purification device. In addition, since necessary heat is obtained by burning a part of the raw material, there is a problem that the efficiency of the entire process is low. Furthermore, tar may be generated depending on the reaction conditions.

On the other hand, as disclosed in Non-Patent Document 1, a method of adding mechanochemical treatment by adding additives such as Ca (OH) ₂ and Ni (OH) ₂ to a biomass raw material uses a large-scale apparatus. Therefore, relatively high purity hydrogen can be produced under normal pressure.
However, in order to obtain a relatively large amount of hydrogen, it is necessary to heat the mechanochemically processed product to a high temperature of about 400 ° C. In addition, depending on the type of additive, a mixed gas containing a gas other than hydrogen can be obtained, so that gas separation may be necessary depending on the application. In order to efficiently use various resources including biomass raw materials, a technique capable of selectively extracting a larger amount of energy gas at a lower temperature is desired.

An object of the present invention is to provide more at low temperature to provide a more energy gas production how capable of producing a large amount of energy gas.
Another problem to be solved by the present invention is to provide an energy gas production how capable of simultaneously or selectively produce a single or multiple energy gas.
Furthermore, another problem to be solved by the present invention is that a single or a plurality of energy gases can be simultaneously or selectively produced without generating tar and without using steam reforming. It is to provide an energy gas production how.

Energy gas production how according to the present invention in order to solve the above problems,
A mixing step of obtaining a mixture (A) comprising a carbon-hydrogen-oxygen-containing compound (A) and an alkali metal or a compound thereof;
As heating engineering and heating the mixture (A) under inert atmosphere (A),
The heated product obtained in the heating step (A) or the separated product containing the alkali metal compound separated from the heated product is added to the carbon-hydrogen-oxygen-containing compound (B), and the mixture (B A remixing step to obtain
A heating step (B) of heating the mixture (B) under an inert atmosphere .

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When extracting an energy gas from a carbon hydrogen oxygen-containing compound, when an alkali metal or a compound thereof is added to the carbon hydrogen oxygen containing compound, a single or a plurality of energy gases can be extracted. In addition, there is no need to use steam reforming at that time, and there is no generation of tar.
Further, by optimizing the kind of additive, the amount added, and the mixing method, the generation temperature of energy gas (particularly hydrogen gas) can be lowered, or a plurality of energy gases can be selectively extracted.
Furthermore, when a transition metal or a compound thereof coexists in addition to an alkali metal or a compound thereof, the generation temperature of energy gas (particularly hydrogen gas) can be further lowered.

2 is a mass spectrum of gases released from cellulose / KOH mixtures with different blending ratios obtained in Reference Example 1. FIG. It is a high temperature XRD pattern of the cellulose / KOH mixture (weight ratio of cellulose / KOH = 1/3) obtained in Reference Example 1 . Mass spectrum of H ₂ released from different cellulose / NaOH mixture of mixing ratio obtained in Reference Example 2 (upper left panel) and mass spectra (bottom left diagram) of CH _4, and, cellulose obtained in Reference Example 1 / is a mass spectrum of H ₂ released from KOH mixture (top right figure). Mass spectrum of H ₂ Reference Example obtained MG (mechanical grinding) 3 treated cellulose / KOH mixture (top left diagram), mass spectrum of H ₂ cellulose / KOH mixture was mixed and stirred obtained in Reference Example 4 (upper right diagram), and mixing conditions of the cellulose / KOH mixture - a diagram (below) showing a heating temperature -H ₂ gas yield relationships. Mass spectrum of H ₂ Example Wet (upper left diagram) obtained in 4 or dry cellulose / KOH mixture was mixed and stirred (the upper right diagram), and it is these XRD patterns (see below). It is a mass spectrum of a cellulose / KOH mixture ( Reference Example 5 ) treated with MG. It is a mass spectrum of a cellulose / KOH mixture ( Reference Example 6 ) mixed with water. MG-treated cellulose / K ₂ CO ₃ mixture is a mass spectrum of the mass spectrum and mixed and stirred cellulose / K ₂ CO ₃ mixture (Example 7) (Reference Example 8). Mixture stirred cellulose / K ₂ CO ₃ mixture is a mass spectrum of (Example 8). It is a mass spectrum of H ₂ of a cellulose / KOH mixture ( Reference Example 9 ) mixed with water. It is a mass spectrum of a cellulose / K ₂ CO ₃ / Ni (OH) ₂ mixture ( Reference Example 10 ) that has been mixed and stirred. Cellulose, MG-treated cellulose / Na ₂ CO ₃ mixture, MG-treated cellulose / Na ₂ CO ₃ / Ni (HCOO) ₂ mixture, and MG-treated cellulose / Na ₂ CO ₃ / Ni (OH) ₂ mixture Spectrum. It is a mass spectrum of the mixture which added various additives to the cellulose and mixed and stirred. It is a mass spectrum of the mixture which mixed and stirred acetic acid to the cellulose. It is a mass spectrum of a cellulose / K ₂ CO ₃ / Ni (OH) ₂ mixture (first time), and a mass spectrum of a mixture obtained by adding cellulose to a 500 ° C. baking residue (second time and third time).

Hereinafter, an embodiment of the present invention will be described in detail.
[1. Energy gas production method (1)]
The energy gas manufacturing method according to the first embodiment of the present invention includes a mixing step and a heating step.

[1.1 Mixing process]
The mixing step is a step of obtaining a mixture containing a carbon hydrogen oxygen-containing compound and an alkali metal or a compound thereof.

[1.1.1 Carbon-hydrogen oxygen-containing compound]
The carbon hydrogen oxygen-containing compound (hereinafter referred to as “CHO compound”) refers to all organic compounds composed of C, H, and O. That is, the CHO compound includes not only organic resources derived from renewable organisms (so-called biomass), but also organic compounds generally not classified as biomass and wastes thereof. The CHO compound includes not only natural products and wastes thereof, but also organic compounds synthesized, extracted or purified, organic compounds derived from fossil fuels, wastes thereof, and the like.
Specifically, as the CHO compound,
(1) Products produced in agriculture, livestock industry, fishery industry or forestry and their waste (for example, agricultural products such as wheat, corn, potato, sweet potato, and plants other than parts used for food use or livestock feed) Part, livestock excrement, wood and its waste, sawdust, fallen leaves)
(2) Food waste discharged from the food processing industry, kitchens, etc. (for example, coffee grounds)
(3) Waste paper,
(4) Organic substances such as oils, fats, natural polymers, synthetic polymers and wastes thereof (for example, polyethylene (PE), polyvinyl chloride (PVC), etc.),
(5) Sewage sludge,
and so on.
The CHO compound may be in a wet state or in a dry state. When a wet CHO compound is used as a starting material, it is preferably dried before the heating step.

[1.1.2 Alkali metals or compounds thereof]
Alkali metals or their compounds (hereinafter collectively referred to as “alkali additives”) are considered to have an action of decomposing CHO compounds into CO, CO ₂ , H ₂ , CH ₄ and the like. Further, it is considered that certain alkali additives have an action of fixing the decomposed CO ₂ in the form of carbonate.
Alkali metals (Li, Na, K, Rb, Cs, Fr) may be used in the form of a pure metal or an alloy containing an alkali metal, or in the form of a compound.
As an alkali additive, for example,
(1) Pure metal made of alkali metal, or alloy containing two or more kinds of alkali metals,
(2) Alkali metals such as LiCoO ₂ , LiNiO, LiFeO, LiMn ₂ O ₄ , K ₂ CrO ₄ , K ₃ [Fe (CN) ₆ ], K ₄ [Fe (CN) ₆ ], K ₄ Nb ₆ O ₁₇ Oxides or complex salts containing,
(3) hydroxides such as LiOH, NaOH, KOH,
(4) carbonates such as Li ₂ CO ₃ , Na ₂ CO ₃ , K ₂ CO ₃ ,
(5) acetates such as CH ₃ COOLi, CH ₃ COONa, CH ₃ COOK,
(6) benzoates such as C ₇ H ₅ O ₅ Li, C ₇ H ₅ O ₅ Na, C ₇ H ₅ O ₅ K,
(7) Formates such as HCOOLi, HCOONa, HCOOK,
and so on. Any one of the alkali additives described above may be used, or two or more may be used in combination.
Among these, metals, alloys or compounds containing K and / or Na have a large effect of lowering the generation temperature of energy gas (particularly hydrogen). Further, unlike Na, K or a compound thereof has a feature that the amount of CH ₄ generated is small.

The addition amount of the alkali additive is selected in accordance with the type of CHO compound, the type and amount of other additives described later, and the like. Generally, when the amount of the alkali additive added is too small, the generation temperature of energy gas (particularly hydrogen gas) becomes high. Moreover, the mixed gas containing energy gas other than hydrogen gas is obtained, so that the addition amount of an alkali additive decreases.
On the other hand, as the amount of the alkali additive added increases, the proportion of hydrogen gas in the generated energy gas increases. However, if the amount of the alkali additive added is too large, the proportion of the CHO compound in the entire raw material is reduced, and the amount of energy gas released is reduced. Further, excessive addition of the alkali additive may increase the temperature at which the energy gas is generated.

For example, when cellulose (C ₆ (H ₂ O) ₅ ) is decomposed in the presence of K or a compound thereof, in order to generate high purity hydrogen gas, 2 K or a compound thereof is added to 1 mol of cellulose. It is preferable to add 0.0 to 10 mol. The addition amount of K or a compound thereof is more preferably 3 to 8 mol per 1 mol of cellulose.
For example, when cellulose is decomposed in the presence of K or a compound thereof, in order to obtain a mixed gas of hydrogen and CO, 0.03 to 5 mol of K or a compound thereof is added to 1 mol of cellulose. Is preferred. The amount of K or its compound added is more preferably 0.3 to 1 mol.

For example, when cellulose is decomposed in the presence of Na or a compound thereof, in order to generate high purity hydrogen gas, it is preferable to add 2 to 10 mol of Na or a compound thereof with respect to 1 mol of cellulose. The addition amount of Na or a compound thereof is more preferably 3 to 8 mol with respect to 1 mol of cellulose.
For example, when cellulose is decomposed in the presence of Na or a compound thereof, in order to obtain a mixed gas of hydrogen and CO, 0.03 to 5 mol of Na or a compound thereof is added to 1 mol of cellulose. Is preferred. The amount of Na or its compound added is more preferably 0.3 to 1 mol.

[1.1.3 Transition metals or compounds thereof]
Transition metals or compounds thereof (hereinafter collectively referred to as “transition metal additives”) are considered to have a catalytic function for reactions that decompose CHO compounds to generate various energy gases. Therefore, a transition metal additive is not always necessary, but when used in combination with an alkali additive, generation of various energy gases can be promoted.

In the present invention, “transition metal” refers to Group 3 to 11 elements ( ₂₁ Sc to ₂₉ Cu, ₃₉ Y to ₄₇ Ag, ₅₇ La to ₇₉ Au, ₈₉ Ac to ₁₁₁ Rg). The transition metal may be added in the state of a metal or an alloy, or may be added in the state of a compound.
The transition metal additive preferably contains the first transition element ( ₂₁ Sc to ₂₉ Cu). In addition, among the first transition elements, a metal, an alloy, or a compound including any one or more of Mn, Fe, Co, Ni, and Cu has a high catalytic function. In particular, the Ni compound is particularly suitable as an additive because it is highly dispersible in a nano-level state in the CHO compound.

As a transition metal additive, specifically,
(1) Ni, Ni-Cu, Ni-Fe, Ni-Mo, Ni-Cr, Ni-Cr-Fe, Ni-Mo-Cr, Ni-Si, Fe-Ni-Co, Ni-Zn, Ni-Ti Metals or alloys such as
(2) Nickel acetate ((CH ₃ COO) ₂ Ni), cobalt acetate (II) ((CH ₃ COO) ₂ Co), copper acetate (II) ((CH ₃ COO) ₂ Cu), iron acetate (II) (C ₄ H ₆ FeO ₄ ), acetates such as copper acetate (I) (C ₂ H ₃ CuO ₂ ),
(3) Halides such as nickel bromide (II) (NiBr ₂ ), cobalt bromide (II) (CoBr ₂ ), copper bromide (CuBr, CuBr ₂ ), iron bromide (II) anhydrous (FeBr ₂ ) ,
(4) formates such as nickel formate (II) ((HCOO) ₂ Ni), copper formate (II) ((HCOO) ₂ Cu),
(5) lactate such as nickel lactate (C ₆ H ₁₀ NiO ₆ ), iron (II) lactate (Fe (CH ₃ CHOHCOO) ₂ ),
(6) oxalates such as nickel oxalate (NiC ₂ O ₄ ), iron oxalate (FeC ₂ O ₄ ), copper oxalate (CuC ₂ O ₄ ),
(7) hydroxides such as nickel hydroxide (Ni (OH) ₂ ), copper hydroxide (II) (Cu (OH) ₂ ), cobalt hydroxide (Co (OH) ₂ ),
(8) oxides such as nickel oxide (NiO), iron oxide (Fe ₃ O ₄ ), copper oxide (CuO), cobalt oxide (CoO),
(9) carbonates such as nickel carbonate (NiCO ₃ ) and cobalt carbonate (CoCO ₃ );
and so on.
Any one of the various transition metal additives described above may be used, or two or more may be used in combination.

  The addition amount of the transition metal additive is selected in accordance with the type of CHO compound, the type and amount of the alkali metal additive, and the like. In general, if the amount of transition metal additive added is too small, a sufficient catalytic function cannot be obtained. On the other hand, when the addition amount of the transition metal additive is too large, the proportion of the CHO compound in the entire raw material is reduced, and the amount of energy gas released is reduced.

  For example, in the case of decomposing cellulose in the presence of K or a compound thereof, in order to lower the generation temperature of hydrogen gas, it is preferable to add 0.1 to 1 mol of a transition metal additive with respect to 1 mol of cellulose. . The addition amount of the transition metal additive is more preferably 0.2 to 0.6 mol with respect to 1 mol of cellulose.

  Further, for example, when cellulose is decomposed in the presence of Na or a compound thereof, in order to lower the generation temperature of hydrogen gas, 0.1 to 1 mol of a transition metal additive is added to 1 mol of cellulose. Is preferred. The addition amount of the transition metal additive is more preferably 0.2 to 0.6 mol with respect to 1 mol of cellulose.

[1.1.4 Mixing method]
For the mixing method of raw materials,
(1) A method of subjecting the mixture to MG treatment (a method of vigorously stirring),
(2) A method of mixing and stirring the mixture (a method of weakly stirring),
There is. Any method may be used in the present invention.
When an alkali additive is used as an additive for decomposing the CHO compound, the CHO compound can be decomposed even when the input energy during mixing is small.

[1.1.4.1. MG treatment]
MG treatment means mechanically mixing and grinding a mixture of a CHO compound and various additives. One means for causing a mechanochemical reaction between the raw material and the additive is MG treatment. A form in which a mechanochemical reaction is generated by applying pressure and temperature and kneading (using a twin-screw extruder or the like) may be used. Here, it demonstrates as MG processing for convenience. The MG treatment has a disadvantage that a large amount of power energy is input, but has an advantage that an energy gas having a high hydrogen gas concentration can be easily obtained.

The mixing and pulverizing method is not particularly limited, and a pulverizing method in which various solid raw materials are powdered can be used. Specific examples of the mixing and pulverizing method include a method in which raw materials are mixed and pulverized using various pulverizers such as a planetary ball mill, a vibrating ball mill, and a rotating ball mill.
The MG treatment is preferably performed until at least an additive other than the CHO compound is highly dispersed to several tens of nm or less. Further, the MG treatment is preferably performed until both the CHO compound and other additives are highly dispersed to several tens of nm or less.
In general, as the energy (for example, acceleration, pulverization time, etc.) applied to the raw material during pulverization increases, an MG processed product in which finely pulverized raw material is uniformly mixed is obtained, so that the mechanochemical reaction is more likely to proceed. .

The optimum MG treatment conditions are selected according to the composition of the raw material mixture.
For example, when the mixture does not contain a transition metal additive, a sufficient effect can be obtained even with MG treatment with relatively low energy. This is presumably because the alkali additive itself functions as a decomposition catalyst for the CHO compound.
In this case, the MG treatment is preferably performed so that the sizes of the CHO raw material and various additives are 50 nm or less. The size of the CHO raw material and various additives is preferably as small as possible, and it is desirable that the CHO raw material and each additive are highly dispersed.

For example, when the MG treatment is performed using a planetary ball mill, the acceleration is preferably 3G or more when no transition metal additive is included. The acceleration is more preferably 5G or more.
Further, the rotational speed is preferably 200 rpm or more. The number of rotations is more preferably 400 rpm or more.
Further, the grinding time is preferably 0.5 hr or more. The pulverization time is more preferably 1 hr or longer.

On the other hand, when adding the transition metal additive to the raw material, it is preferable to perform MG treatment with relatively strong energy and disperse the transition metal additive as uniformly and finely as possible in the CHO compound. This is presumably because the transition metal additive has a catalytic function for the decomposition reaction of the CHO compound.
In this case, it is preferable to perform the MG treatment so that the size of the CHO raw material and various additives is not more than 50 nm, and the size of the transition metal additive is not more than 10 nm. The size of the transition metal additive is more preferably 5 nm or less.
In particular, it is preferable to perform strong mixing and grinding to such an extent that the transition metal additive cannot be confirmed when the MG-treated product is observed with a TEM. In other words, it is preferable to perform the MG treatment until the size of the transition metal additive becomes 5 nm or less. When a transition metal compound (particularly a hydroxide) is used as the transition metal additive, such uniform and fine dispersion is further facilitated.

For example, when the MG treatment is performed using a planetary ball mill, the acceleration is preferably 5 G or more when a transition metal additive is included. The acceleration is more preferably 8G or more.
The rotation speed is preferably 400 rpm or more. The number of rotations is more preferably 700 rpm or more.
Furthermore, the grinding time is preferably 2 hours or more. The pulverization time is more preferably 5 hours or more.

[1.1.4.2. Mixing and stirring]
Mixing stirring refers to mixing a mixture of a CHO compound and various additives with relatively small energy. The mixing and stirring does not necessarily involve the pulverization of the raw material.
Specifically, as a mixing and stirring method,
(1) A method of mixing the mixture in a mortar under dry or wet conditions,
(2) A method of propeller mill mixing (for example, a stirrer or the like) at a low acceleration and / or a low rotation speed without pulverization in a dry or wet process,
(3) A method in which a solution in which various additives are dissolved or dispersed is sprinkled over the CHO compound, or a method in which the CHO compound is dissolved or dispersed in a solution in which various additives are dissolved or dispersed (no stirring operation),
and so on.

In such weak stirring, when the amount of the alkali metal additive is relatively large, an energy gas having a high hydrogen gas concentration can be obtained.
On the other hand, when performing weak stirring, when the amount of the alkali metal additive is relatively small, an energy gas containing hydrogen gas and CO gas at a predetermined ratio is obtained. Further, when the amount of the alkali additive added is controlled, the ratio of hydrogen gas and CO gas contained in the energy gas can be controlled.

[1.2 Heating process]
The heating step is a step of heating the mixture obtained in the mixing step under an inert atmosphere.
The heating is performed in an inert atmosphere (for example, in Ar, N ₂ , etc.) in order to facilitate removal of the combustible gas contained in the mixture (collect gas with high efficiency).
As the heating temperature, an optimum temperature is selected according to the composition of the mixture and the mixing conditions. Further, depending on the mixing conditions such as the type of alkali additive, the amount added, and the mixing method, different energy gases may be generated at different temperatures. In such a case, when the heating temperature is changed stepwise, a relatively high purity gas can be separated and extracted. Further, it may be gasified by rapid thermal decomposition (utilization of microwave or the like) at a high temperature (500 to 600 ° C.) in a short time of several seconds or less.
In the present invention, “energy gas” refers to a combustible gas containing C, H, or O such as H ₂ , CH ₄ , and CO.

[2. Energy gas production method (2)]
The energy gas manufacturing method according to the second embodiment of the present invention includes a remixing step and a heating step.

[2.1. Remixing process]
In the remixing step, the product after heating obtained in the heating step according to the first embodiment of the present invention, or the separated product containing the alkali metal compound separated from the product after heating is converted into a compound containing oxyhydrogen. In addition to the step, a mixture of these is obtained.

[2.1.1. Product after heating]
The “post-heating product” refers to a residue remaining after heating a mixture containing a CHO compound and an alkali additive to release energy gas. The product after heating is ideally considered a mixture comprising carbon and an alkali metal compound (mainly alkali metal carbonate).
In the decomposition of the CHO compound performed before the remixing step, when a transition metal additive is added, the product after heating contains the transition metal additive. In the remixing step, the post-heating product containing such a transition metal additive may be added again to a new CHO compound.

The product after heating may be added to the CHO compound as it is, or the alkali metal compound (and transition metal compound) may be separated from the product after heating, and the separated product may be added to the CHO compound.
Since the alkali metal compound is dissolved in water, it can be easily separated from the product after heating. Further, when the transition metal compound is dissolved in water, the transition metal additive can be separated simultaneously with the alkali metal compound.

The addition amount of the product or separated product after heating is selected in accordance with the type of CHO compound, the type and amount of other additives, and the like.
Usually, it is preferable to add the product or separated product after heating so that the alkali metal compound or the transition metal compound contained in the product or separated product after heating becomes a predetermined ratio with respect to the CHO compound. Details regarding the addition amount of the alkali compound and the transition metal compound contained in the product or separated product after heating are the same as those in the first embodiment, and thus the description thereof is omitted.

[2.1.2. Carbon hydrogen oxygen-containing compound (CHO compound)]
The details of the CHO compound are the same as those in the first embodiment, and a description thereof will be omitted.

[2.1.3. Transition metal or compound thereof (transition metal additive)]
Regardless of whether or not the transition metal additive was added in the decomposition of the CHO compound before the remixing step, in the remixing step, a new transition metal additive was added in addition to the product after heating or the separated product. May be.
In general, repeated use of a product after heating or a separated product containing a transition metal additive reduces the activity of the transition metal additive as a catalyst. This is considered to be because the grain growth of the transition metal additive proceeds by repeating the heating. In such a case, it is preferable to newly add a transition metal additive to the CHO compound.
Other points regarding the transition metal additive, such as the addition amount of the transition metal additive, are the same as those in the first embodiment, and a description thereof will be omitted.

[2.1.4. Remixing method]
For the method of remixing raw materials,
(1) A method of subjecting the mixture to MG treatment (a method of vigorously stirring),
(2) A method of mixing and stirring the mixture (a method of weakly stirring),
There is. Any method may be used in the present embodiment.
Since the other points regarding the mixing method are the same as those of the first embodiment, description thereof will be omitted.

[2.2. Heating process]
The heating step is a step of heating the mixture obtained in the remixing step in an inert atmosphere.
The details of the heating process are the same as those in the first embodiment, and thus description thereof is omitted.

[3. Energy gas storage material]
The energy gas storage material which concerns on this invention consists of a mixture containing a carbon hydrogen oxygen containing compound, an alkali metal, or its compound. The energy gas storage material may further contain a transition metal or a compound thereof.

The alkali metal or a compound thereof (alkali additive) may be newly added to the carbon hydrogen oxygen-containing compound (CHO compound), or may be added as a product after heating or a separated product thereof. .
Similarly, when a transition metal or a compound thereof (transition metal additive) is included, the transition metal additive may be newly added to the CHO compound, or the product after heating or a separated product thereof It may be added as.

Furthermore, the mixture
(1) A method of subjecting the mixture to MG treatment (a method of vigorously stirring),
(2) A method of mixing and stirring the mixture (a method of weakly stirring),
It may be obtained by any of these methods.

When transition metal additives are included in the mixture, they are preferably uniformly and finely dispersed in the CHO compound. Specifically, the size of the transition metal additive contained in the mixture is preferably 5 nm or less. Such a mixture can be obtained by strongly mixing and grinding the raw material mixture. Further, when a transition metal compound (particularly a hydroxide) is used as the transition metal additive, such uniform and fine dispersion is further facilitated.
Further, the material may be used in such a form that these mixtures are densified (pressed) to give an activation function that further improves the catalytic function of the additive. A plurality of mixtures having different energy gas generation profiles can be densified and combined to obtain an optimum energy gas in a necessary temperature range.

When such a mixture is heated under an inert atmosphere, various energy gases are generated at various temperatures depending on the type and composition of the CHO compound and additives.
In particular, when an alkali additive containing K and / or Na is used, energy gas (particularly hydrogen gas) can be taken out at a lower temperature.
Moreover, when the addition amount and mixing method of the alkali additive are optimized, each energy gas is generated at a different temperature. Therefore, when the mixing conditions are optimized, not only can the energy gas be taken out at a lower temperature, but also the energy gas can be separated and taken out, or the energy gas having a different composition can be easily taken out.
Furthermore, after releasing a specific energy gas at a specific temperature, the product after heating can be heated at a higher temperature to release another energy gas. Further, two or more kinds of post-heating products having different histories may be further mixed and heated to a predetermined temperature.
Furthermore, since the transition metal additive has a catalytic function for the decomposition reaction of the CHO compound, when they are added, energy gas (especially hydrogen gas) at a lower temperature than a mixture not containing them. Can be taken out.

  Since the other points regarding the CHO compound, the alkali additive, the transition metal additive, and the mixing method are as described above, the description thereof is omitted.

[4. Energy gas production method and action of energy gas storage material]
When mixing the CHO compound and heating the mixture to take out the energy gas, if an alkali additive is allowed to coexist at the time of mixing, it is possible to take out a single or a plurality of energy gases simply by heating the mixture. In addition, it is not necessary to use steam reforming that requires high energy, expensive equipment or the like, and tar is not generated. Furthermore, high energy MG treatment is not necessarily required during mixing. This is presumably because the alkali additive itself functions as a decomposition catalyst for decomposing the CHO compound.

Further, when the type and amount of additive are optimized, the generation temperature of energy gas (particularly hydrogen gas) can be lowered or a plurality of energy gases can be selectively extracted. In particular, among the alkali additives, those containing K can generate H ₂ gas at a lower temperature (specifically, lower the hydrogen generation start temperature to around 200 ° C.). Further, the K-based additive has an action of suppressing generation of CH ₄ gas. Therefore, when a K-based additive is added to the mixture, a relatively high purity H ₂ gas or a mixed gas of H ₂ gas and CO gas can be taken out simply by heating.
Furthermore, when a transition metal additive coexists in addition to the alkali additive, the generation temperature of energy gas (particularly hydrogen gas) can be further lowered. This is presumably because the transition metal additive has a catalytic function for the decomposition reaction of the CHO compound.

For example, assuming a hypothetical reaction in which CO ₂ and H ₂ are generated from cellulose, and various hydroxides absorb the generated CO ₂ , K is likely to absorb CO ₂ at a low temperature to become a carbonate, and at a low temperature. Hydrogen generation can be expected.
In actual experiments, when KOH [K ₂ CO ₃ (H ₂ O) _1.5 ] was added to cellulose by mixing solids in air (a method of weak stirring), high-purity hydrogen was generated from a low temperature of about 200 ° C. It has been found that it can occur. In addition, since the mixing and stirring for a short time can be used instead of the conventional MG processing, the processing energy can be greatly reduced. Further, since the alkali salt is an exothermic reaction (confirmed by TG / DTA or the like), the input energy accompanying heating is extremely small.

Further, when hydrogen is generated from cellulose / KOH [K ₂ CO ₃ (H ₂ O) _1.5 ], K ₂ CO ₃ is generated in the product after heating. When a small amount of K ₂ CO ₃ is added to cellulose and heated, CO _x gas can be generated from a low temperature of about 200 ° C. (H ₂ can be generated from about 500 ° C.). Since K ₂ CO ₃ has a melting point of 891 ° C., it can be used repeatedly as long as the heating temperature is about 700 ° C. Furthermore, in order to further promote the generation of energy gas (particularly hydrogen gas), it is effective to add a small amount of a transition metal additive such as Ni.

(Reference Example 1)
[1. Preparation of sample]
Cellulose and KOH are blended so that the weight ratio is 1/3 to 2/1 (1 / 8.6 to 1 / 1.4 in molar ratio), tablet-like KOH is crushed, and mixed with cellulose. did. A magnetic stirrer was used for mixing and stirring, and the mixing time was 1 minute.

[2. Test method]
[2.1 Mass spectrometry]
The mixture was heated using a mass spectrometer, and the generated gas was qualitatively analyzed. Mass spectrometry was performed by automatic measurement using an automatic temperature programmed desorption analyzer (TP-5000, RG-102P) manufactured by Okura Riken Co., Ltd., setting MS measurement conditions and automatic sequence conditions.
[2.2 High temperature XRD measurement]
The mixture was subjected to high temperature XRD (X-ray diffraction) measurement.

[3. result]
FIG. 1 shows mass spectra of gases released from cellulose / KOH mixtures having different blending ratios.
From FIG.
(1) When the weight ratio of cellulose / KOH is 1/1 or more (molar ratio of cellulose / KOH is 1 / 2.8 or more), high-purity hydrogen gas is obtained at about 200 ° C.,
(2) When the weight ratio of cellulose / KOH is 2/1 (molar ratio of cellulose / KOH is 1 / 1.4), a mixed gas of hydrogen, CO, and CO ₂ is obtained at about 300 ° C.
I understand that.

FIG. 2 shows a high temperature XRD pattern (Ar atmosphere) of a mixture having a cellulose / KOH weight ratio of 1/3.
From FIG.
(1) After mixing and drying (25 ° C.), KOH is K ₂ CO ₃ (H ₂ O) _1.5 ,
(2) K ₂ CO ₃ (H ₂ O) _1.5 becomes K ₂ CO _{3 when} heated to 150 ° C. and changes with increasing temperature (to a compound that is difficult to identify), but when cooled to 30 ° C. after heating, K ₂ again CO ₃
I understand that.

(Reference Example 2)
[1. Preparation of sample]
A mixture was obtained according to the same procedure as in Reference Example 1 except that cellulose and NaOH were blended in a weight ratio of 1/3 to 1/1.
[2. Test method]
Qualitative analysis of the generated gas was performed in the same manner as in Reference Example 1 .

[3. result]
The left figure of FIG. 3 shows mass spectra of H ₂ and CH ₄ released from cellulose / NaOH mixtures having different blending ratios. 3 also shows the mass spectrum of H ₂ released from the cellulose / KOH mixture obtained in Reference Example 1 .
From FIG.
(1) The cellulose / NaOH mixture releases hydrogen gas at about 250 ° C.
(2) The cellulose / NaOH mixture has the largest CH ₄ generation when the cellulose / NaOH weight ratio is 1/2.
(3) The cellulose / KOH mixture hardly generates CH ₄ when the weight ratio of cellulose / KOH is in the range of 1/3 to 1/1.
I understand that.

(Reference Examples 3 and 4)
[1. Preparation of sample]
Cellulose and KOH were blended so as to have a weight ratio of 1/3 and subjected to MG treatment with a planetary ball mill (Reference Example 3) . The MG treatment was performed at a rotation speed of 400 rpm for 5 minutes to 8 hours using a planetary ball mill device P5 manufactured by Fritche.
Further, cellulose and KOH were blended so that the weight ratio was 1/3, and were mixed and stirred by wet or dry method (Reference Example 4) . A magnetic stirrer was used for mixing and stirring, and the mixing time was 1 hour or 12 hours. For the wet-mixed mixture, the mixture was dried at 120 ° C. after mixing.

[2. Test method]
[1. Mass spectrometry]
Qualitative analysis of the generated gas was performed in the same manner as in Reference Example 1 .
[2. XRD measurement]
XRD (X-ray diffraction) measurement of the mixture was performed.

[3. result]
FIG. 4 shows an H ₂ mass spectrum (upper left) of the MG-treated mixture obtained in Reference Example 3, an H ₂ mass spectrum (upper right) of the mixed and stirred mixture obtained in Reference Example 4 , and The relationship between the mixing conditions-heating temperature-H ₂ gas generation amount (below) is shown.
From FIG.
(1) In the cellulose / KOH mixture, the amount of H ₂ generated increases as the heating temperature increases, regardless of the mixing method and mixing time.
(2) The cellulose / KOH mixture shows almost the same H ₂ release characteristics regardless of the mixing method and mixing time.
I understand that.

FIG. 5 shows a mass spectrum of H ₂ of a cellulose / KOH mixture mixed and stirred by a wet method or a dry method, and their XRD patterns (in the atmosphere).
From FIG.
(1) The XRD pattern of the wet-mixed mixture is different from the XRD pattern of the dry-mixed mixture.
(2) The mass spectrum of H ₂ of the wet-mixed mixture shows a mass spectrum almost equivalent to that of the dry-mixed mixture.
I understand that.

(Reference Examples 5 and 6)
[1. Preparation of sample]
Cellulose and KOH were blended so as to have a weight ratio of 1/1 to 1 / 0.05 and subjected to MG treatment with a planetary ball mill (Reference Example 5) . The MG treatment was performed for 0.5 hour at a rotation speed of 400 rpm using a planetary ball mill device P5 manufactured by Fritche.
Cellulose and KOH were blended so that the weight ratio was 1/1 to 1 / 0.1, and water was added and mixed and stirred (Reference Example 6) . A magnetic stirrer was used for mixing and stirring, and the mixing time was 1 minute.
[2. Test method]
Qualitative analysis of the generated gas was performed in the same manner as in Reference Example 1 .

[3. result]
FIG. 6 shows the mass spectrum of the MG-treated cellulose / KOH mixture. FIG. 7 shows a mass spectrum of a cellulose / KOH mixture obtained by adding water.
From FIG. 6 and FIG.
(1) In the case of MG treatment, CO and CO ₂ are generated at 200 to 300 ° C.
(2) In the case of MG treatment, when the amount of KOH added is small (when the weight ratio of cellulose / KOH is 1 / 0.5 or less), the generation of CO becomes significant.
(3) In the case of water addition mixing, CO and CO ₂ are generated at a low temperature of 100 to 300 ° C., and when KOH is in the range of 1 to 0.5, the generation of CO ₂ becomes significant at 100 to 200 ° C.,
(4) In the case of water addition mixing, when the amount of KOH added is small (when the weight ratio of cellulose / KOH is 1/1 or less), the generation of CO and CO ₂ becomes significant.
I understand that.

(Reference Examples 7 and 8)
[1. Preparation of sample]
Cellulose and K ₂ CO ₃ were blended so as to have a weight ratio of 1/2 to 1/3, and subjected to MG treatment with a planetary ball mill (Reference Example 7) . The MG treatment was performed for 0.5 hour at a rotation speed of 400 rpm using a planetary ball mill device P5 manufactured by Fritche.
Cellulose and K ₂ CO ₃ were blended so that the weight ratio was 1 / 0.05 to 1/3, and mixed and stirred in a dry manner (Reference Example 8) . A magnetic stirrer was used for mixing and stirring, and the mixing time was 1 minute.
[2. Test method]
Qualitative analysis of the generated gas was performed in the same manner as in Reference Example 1 .

[3. result]
FIG. 8 shows a mass spectrum of the MG-treated cellulose / K ₂ CO ₃ mixture and a mass spectrum of the cellulose / K ₂ CO ₃ mixture after mixing and stirring.
From FIG.
(1) When K ₂ CO ₃ is added to cellulose, CO and CO ₂ are generated at a low temperature (from 200 ° C.).
(2) When K ₂ CO ₃ is added to cellulose, H ₂ is slightly generated at 400 to 600 ° C.
(3) Mass spectrum is slightly different between MG treatment and mixed stirring.
I understand that.

FIG. 9 shows an enlarged H ₂ mass spectrum of the cellulose / K ₂ CO ₃ mixture that has been mixed and stirred.
From FIG. 9, it can be seen that H ₂ is generated at 400 to 600 ° C. and shows a peak of the generated temperature at about 500 ° C. regardless of the amount of K ₂ CO ₃ added.

(Reference Example 9)
[1. Preparation of sample]
KOH was blended in a weight ratio of 1 / 0.1 to 1/1 with respect to 1 g of cellulose. 10 cc of water was added thereto and mixed and stirred (Reference Example 9) . A magnetic stirrer was used for mixing and stirring, and the mixing time was 1 minute.
[2. Test method]
Qualitative analysis of the generated gas was performed in the same manner as in Reference Example 1 .

[3. result]
FIG. 10 shows a mass spectrum of H ₂ of a cellulose / KOH mixture mixed with water.
From FIG. 10, it can be seen that H ₂ is generated at 400 to 600 ° C. and shows a peak of the generated temperature at about 500 ° C. regardless of the amount of KOH added.

(Reference Example 10)
[1. Preparation of sample]
Cellulose, K ₂ CO ₃ and Ni (OH) ₂ were blended in a weight ratio of 1 / 0.5 / 0 to 0.3 and mixed and stirred in a dry manner (Reference Example 10) . A magnetic stirrer was used for mixing and stirring, and the mixing time was 1 minute.
[2. Test method]
Qualitative analysis of the generated gas was performed in the same manner as in Reference Example 1 .

[3. result]
FIG. 11 shows a mass spectrum of a mixture / stirred cellulose / K ₂ CO ₃ / Ni (OH) ₂ mixture.
From FIG. 11, it can be seen that increasing the amount of Ni (OH) ₂ shows a tendency to lower the generation of H _2, CO, and CO ₂ , indicating the catalytic function of the transition metal Ni. .

(Reference Example 11)
[1. Preparation of sample]
Cellulose and Na ₂ CO ₃ were blended so as to have a weight ratio of 1 / 0.5 and subjected to MG treatment with a planetary ball mill. The MG treatment was performed for 1 hour at a rotation speed of 700 rpm using a planetary ball mill device P7 manufactured by Fritche.
Further, MG treatment was performed in the same manner as above except that cellulose / Na ₂ CO ₃ / Ni (HCOO) ₂ was blended so as to have a weight ratio of 2/1 / 0.2.
Furthermore, MG treatment was performed in the same manner as above except that cellulose / Na ₂ CO ₃ / Ni (OH) ₂ was blended so as to have a weight ratio of 2/1 / 0.2.
[2. Test method]
Qualitative analysis of the generated gas was performed in the same manner as in Reference Example 1 .

[3. result]
FIG. 12 shows cellulose, MG-treated cellulose / Na ₂ CO ₃ mixture, MG-treated cellulose / Na ₂ CO ₃ / Ni (HCOO) ₂ mixture, and MG-treated cellulose / Na ₂ CO ₃ / Ni (OH). ₂ shows the mass spectrum of the mixture.
From FIG. 12, the addition of Na ₂ CO ₃ shows a decrease in the generation temperature of CO and CO ₂ from the cellulose and the generation of H ₂ . It can be seen that when an additive based on transition metal (Ni) is further added to cellulose / Na ₂ CO ₃ , the H ₂ generation temperature is lowered.

(Reference Example 12)
[1. Preparation of sample]
Cellulose, Na ₂ CO ₃ and Ni (OH) ₂ were blended so as to have a weight of ₂ to 2.9 g / 1 to 0.1 g / 0.2 g and subjected to MG treatment with a planetary ball mill. The MG treatment was performed for 1 hour at a rotation speed of 700 rpm using a planetary ball mill device P7 manufactured by Fritche.
[2. Test method]
Qualitative analysis of the generated gas was performed in the same manner as in Reference Example 1 .

[3. result]
Table 1 shows the composition of the generated gas.
Table 1 shows that even if the blending ratio of cellulose and Na ₂ CO ₃ is changed within a range of ₂ to 29 times, the product gas ratio does not fluctuate significantly.

(Reference Example 13, Comparative Example 1)
[1. Preparation of sample]
Various alkali additives were added to cellulose, and mixed and stirred in a dry manner (Reference Example 13) . A magnetic stirrer was used for mixing and stirring, and the mixing time was 1 minute.
Further, as Comparative Example 1, mixing and stirring were performed in the same manner as above except that acetic acid was added to cellulose.
[2. Test method]
Qualitative analysis of the generated gas was performed in the same manner as in Reference Example 1 .

[3. result]
13 and 14 show mass spectra of a mixture obtained by adding various additives to cellulose and mixing and stirring.
From FIG. 13 and FIG. 14, it can be seen that CO (CO ₂ ) can be generated at a low temperature and H ₂ can be generated at a high temperature by adding a K compound to cellulose.

(Example 14)
[1. Preparation of sample]
Cellulose, K ₂ CO ₃ and Ni (OH) ₂ were blended in a weight ratio of 1 / 0.5 / 0 to 0.1 and mixed and stirred in a dry manner (Example 14 ). A magnetic stirrer was used for mixing and stirring, and the mixing time was 1 minute. The obtained mixture was heated to 500 ° C. to generate energy gas (first time).
Next, cellulose was added so that the cellulose and the residue after heating at 500 ° C. (carbon + K ₂ CO ₃ ) became 1/2 in weight ratio, and a mixture was obtained in the same manner as described above. The resulting mixture was heated to 500 ° C. to generate energy gas (second time).
Furthermore, the cellulose was added so that cellulose and the residue after the second firing were 2/1 in weight ratio, and a mixture was obtained in the same manner as described above. The resulting mixture was heated to 500 ° C. to generate energy gas (third time).
[2. Test method]
Qualitative analysis of the generated gas was performed in the same manner as in Reference Example 1 .

[3. result]
FIG. 15 shows a mass spectrum of a cellulose / K ₂ CO ₃ / Ni (OH) ₂ mixture (first time) and a mass spectrum of a mixture obtained by adding cellulose to a baked residue at 500 ° C. (second time and third time).
From FIG.
(1) Even when cellulose is added to the baking residue at 500 ° C., energy gas can be generated by heating.
(2) As the number of times of addition increases, the temperature at which H ₂ gas is generated increases.
I understand that.
The reason why the generation temperature of the H ₂ gas becomes higher as the number of times of cellulose addition is increased is considered that the sintering of the Ni-based catalyst proceeds by repeated firing.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention.

The energy gas production method according to the present invention can be used as a method for producing various energy gases such as combustible gas and fuel gas supplied to a fuel cell.
Moreover, the energy gas storage material which concerns on this invention can be used as a material for taking out various energy gas by a simple method.

Claims (7)

A mixing step of obtaining a mixture (A) comprising a carbon-hydrogen-oxygen-containing compound (A) and an alkali metal or a compound thereof;
As heating engineering and heating the mixture (A) under inert atmosphere (A),
The heated product obtained in the heating step (A) or the separated product containing the alkali metal compound separated from the heated product is added to the carbon-hydrogen-oxygen-containing compound (B), and the mixture (B A remixing step to obtain
A method for producing an energy gas, comprising: a heating step (B) in which the mixture (B) is heated in an inert atmosphere .   The energy gas production method according to claim 1, wherein the alkali metal or a compound thereof is K or a compound thereof. The energy gas production method according to claim 1 or 2, wherein in the mixing step, a transition metal or a compound thereof is further added to the mixture (A) . The energy gas production method according to any one of claims 1 to 3 , wherein in the mixing step, the mixture (A) is subjected to MG treatment. The energy gas production method according to any one of claims 1 to 3 , wherein in the mixing step, the mixture (A) is mixed and stirred. The energy gas production method according to any one of claims 1 to 5 , wherein the remixing step is an MG treatment of the mixture (B) . The energy gas production method according to any one of claims 1 to 5 , wherein the remixing step is a step of mixing and stirring the mixture (B) .

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