JP7195169B2 - Method and apparatus for regenerating calcium oxide (CaO) - Google Patents

Description

The present invention relates to a method and apparatus for regenerating calcium oxide (CaO).

Conventionally, as a method for regenerating particulate calcium oxide (CaO), there is a method disclosed in Patent Document 1, for example. The technique disclosed in Patent Document 1 uses particulate calcium oxide (particle size 0.2 to 0.8 mm) obtained by calcining limestone or calcium carbonate. Then, the particulate calcium oxide is reacted with water,
CaO+ _H2O →Ca(OH) ₂ (A)
When the reaction represented by is carried out, the reaction (A) is allowed to proceed under steam conditions of 650 to 700° C. at a pressure of 1 atm or ^more , so that Ca(OH ) ₂ , followed by thermal decomposition at 850-900°C.

Patent No. 5286480

However, in the method described in Patent Document 1, additional equipment such as a heat source is required in order to satisfy the reaction conditions for advancing the formula (A). Therefore, there is a problem that the cost is high.

A main object of one aspect of the present invention is to provide a calcium oxide (CaO) regeneration method and a calcium oxide (CaO) regeneration apparatus that do not require additional equipment such as a heat source and are inexpensive.

In order to solve the above problems, a method for regenerating calcium oxide according to one aspect of the present invention includes a pyrolyzer for pyrolyzing a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam; A combustion device that burns the pyrolysis products obtained in the device, and steam reforming using calcium oxide from the combustible gas obtained in the pyrolysis device to reform the gas with a higher hydrogen concentration than the combustible gas. A calcium oxide regeneration method for regenerating calcium oxide using a facility comprising a reformer for producing a reformed gas and a power generation facility for generating power using hydrogen contained in the reformed gas as a fuel, At least part of the power generation exhaust gas discharged from the power generation equipment is supplied to the combustion device, and at least part of the power generation exhaust gas is converted to at least part of the calcium carbonate produced in the pyrolysis device in the combustion device. to regenerate calcium oxide.

In order to solve the above problems, a method for regenerating calcium oxide according to one aspect of the present invention includes a pyrolyzer for pyrolyzing a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam; A combustion device that burns the pyrolysis products obtained in the device, and steam reforming using calcium oxide from the combustible gas obtained in the pyrolysis device to reform the gas with a higher hydrogen concentration than the combustible gas. A calcium oxide regeneration method for regenerating calcium oxide using a facility comprising a reformer for producing a raw gas, wherein at least part of the calcium carbonate generated in the thermal decomposition device is burned. a first regeneration step of calcining in the presence of at least part of the combustion gas discharged from the device to regenerate calcium oxide; and a recycling step of returning to at least one of the apparatus and the reformer.

In order to solve the above problems, a method for regenerating calcium oxide according to one aspect of the present invention includes a pyrolyzer for pyrolyzing a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam; A combustion device that burns the pyrolysis products obtained in the device, and steam reforming using calcium oxide from the combustible gas obtained in the pyrolysis device to reform the gas with a higher hydrogen concentration than the combustible gas. A calcium oxide regeneration method for regenerating calcium oxide using a facility comprising a reformer for producing a raw gas, wherein at least part of the calcium carbonate generated in the thermal decomposition device is replaced by the reformer. a second regeneration step of calcining in the presence of at least part of the reformed gas discharged from the reforming device to regenerate calcium oxide; and a return step of returning to at least one of the combustion device and the reformer.

In order to solve the above problems, a method for regenerating calcium oxide according to one aspect of the present invention includes a pyrolyzer for pyrolyzing a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam; A combustion device that burns the pyrolysis products obtained in the device, and steam reforming using calcium oxide from the combustible gas obtained in the pyrolysis device to reform the gas with a higher hydrogen concentration than the combustible gas. A calcium oxide regeneration method for regenerating calcium oxide using a facility comprising a reformer for producing a reformed gas and a power generation facility for generating power using hydrogen contained in the reformed gas as a fuel, a third regeneration step of calcining at least part of the calcium carbonate produced in the thermal decomposition device in the presence of at least part of the power generation exhaust gas discharged from the power generation equipment to regenerate calcium oxide; 3 a returning step of returning the calcium oxide regenerated in the regenerating step to at least one of the thermal decomposition device, the combustion device and the reforming device.

In order to solve the above-described problems, a calcium oxide regeneration device according to one aspect of the present invention includes a thermal decomposition device that thermally decomposes a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam; A combustion device for burning the pyrolysis product obtained in , and steam reforming using calcium oxide from the combustible gas obtained in the pyrolysis device to reform the gas with a higher hydrogen concentration than the combustible gas. A reforming device for producing gas and power generation equipment for generating power using hydrogen contained in the reformed gas as a fuel are provided, and power generation exhaust gas discharged from the power generation equipment is supplied to the combustion device.

In order to solve the above-described problems, a calcium oxide regeneration device according to one aspect of the present invention includes a thermal decomposition device that thermally decomposes a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam; A combustion device for burning the pyrolysis product obtained in , and steam reforming using calcium oxide from the combustible gas obtained in the pyrolysis device to reform the gas with a higher hydrogen concentration than the combustible gas. A reformer for producing gas, and a regeneration furnace for regenerating calcium carbonate contained in the pyrolysis products generated in the pyrolysis device into calcium oxide, wherein the regeneration furnace is discharged from the combustion device. The exhausted combustion gas or the reformed gas discharged from the reformer is supplied.

In order to solve the above-described problems, a calcium oxide regeneration device according to one aspect of the present invention includes a thermal decomposition device that thermally decomposes a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam; A combustion device for burning the pyrolysis product obtained in , and steam reforming using calcium oxide from the combustible gas obtained in the pyrolysis device to reform the gas with a higher hydrogen concentration than the combustible gas. A reformer that produces gas, a power generation facility that generates power using hydrogen contained in the reformed gas as a fuel, and calcium carbonate contained in the thermal decomposition product generated by the thermal decomposition device to regenerate calcium oxide. and a regeneration furnace, wherein power generation exhaust gas discharged from the power generation equipment is supplied to the regeneration furnace.

ADVANTAGE OF THE INVENTION According to one aspect of the present invention, it is possible to regenerate calcium oxide (CaO) without the need to separately provide equipment for regenerating calcium oxide and without incurring costs.

1 is a block diagram showing a schematic configuration of a calcium oxide regeneration device according to Embodiment 1 of the present invention; FIG. Fig. 2 is a block diagram showing a schematic configuration of a calcium oxide regeneration device according to Embodiment 2 of the present invention; FIG. 3 is a block diagram showing a schematic configuration of a calcium oxide regeneration device according to Embodiment 3 of the present invention; FIG. 4 is a block diagram showing a schematic configuration of a calcium oxide regeneration device according to Embodiment 4 of the present invention;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to this, and various modifications are possible within the scope described, and embodiments obtained by appropriately combining technical means disclosed in different embodiments are also present. included in the technical scope of In this specification, unless otherwise specified, "A to B" representing a numerical range means "A or more and B or less". Also, "mass" and "weight" are considered synonymous.

[Embodiment 1] Method for Regenerating Calcium Oxide The method and apparatus for regenerating calcium oxide according to the present embodiment are characterized in that various facilities of the hydrogen production apparatus are used for regenerating calcium oxide. As a result, there is no need to separately provide equipment for regenerating calcium oxide, and various equipment of the hydrogen production apparatus are effectively used, so calcium oxide (CaO) can be regenerated without incurring costs.

[Hydrogen production equipment]
The hydrogen production apparatus used in one embodiment of the present invention includes a thermal decomposition apparatus that thermally decomposes a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam, and heat obtained in the thermal decomposition apparatus. A combustion device that burns decomposition products, and a reformer that produces a reformed gas having a higher hydrogen concentration than the combustible gas by steam reforming using calcium oxide from the combustible gas obtained in the thermal decomposition device. with quality equipment.

Examples of the phosphorus-containing biomass supplied to the hydrogen production apparatus include phosphorus-containing biomass such as sewage sludge generated in sewage treatment plants, night soil sludge generated in human waste treatment plants, meat and bone meal, and livestock manure. The form of phosphorus contained in the phosphorus-containing biomass includes, for example, organic phosphorus derived from living organisms, phosphoric acid-form phosphorus, and the like. However, the phosphorus-containing biomass is not limited to the phosphorus-containing biomass exemplified above. In the following description, sludge slurry, which is sewage sludge and night soil sludge, is taken as an example of phosphorus-containing biomass.

As shown in FIG. 1, the hydrogen production apparatus according to one embodiment of the present invention includes a dehydrator 1 that also serves as a mixing device, a drying device 2, a thermal decomposition device 3 that also serves as a moisture adjusting device, and a reformer 4. , a combustion device 5 and an ash separator 6 . Each device is connected to each other by a device (not shown) having a transport function so that phosphorus recovery can be performed continuously. That is, the hydrogen production apparatus is composed of a plurality of fluidized bed apparatuses so that phosphorus can be continuously recovered. However, the hydrogen production device is not limited to a fluidized bed recovery device.

Hereinafter, each device constituting the hydrogen production device used in one embodiment of the present invention will be described with reference to FIG.

<Dehydrator 1>
The dehydrator 1 removes a separated liquid containing water from the sludge slurry (phosphorus-containing biomass) supplied through the sludge slurry supply channel 11 to obtain dehydrated sludge, and then passes the obtained dehydrated sludge through the dehydrated sludge supply channel 12. It is supplied to the drying device 2 .

The dehydrator 1 may be any device capable of removing a separated liquid containing water from the sludge slurry, and examples thereof include a pressurized dehydrator such as a belt press or a mechanical dehydrator such as a centrifugal dehydrator. Moreover, when the water content of the phosphorus-containing biomass is a desired amount, the dehydrator 1 does not necessarily have to be provided. In that case, the phosphorus-containing biomass may be supplied to the direct drying device 2 and the thermal decomposition device 3 .

Further, the dehydrator 1 preferably also functions as a mixing device for mixing the sludge slurry with an inorganic calcium compound supplied from an inorganic calcium compound supply channel (not shown). In that case, the dehydrated sludge supplied to the drying device 2 is a mixture of sludge slurry and inorganic calcium compounds.

The timing of mixing the inorganic calcium compound with the sludge slurry may be before the separation liquid is removed from the sludge slurry, during the removal, or after the removal. Multiple times may be combined. However, as shown below, since the inorganic calcium compound acts as a dehydration aid, it is more preferable to mix the inorganic calcium compound with the sludge slurry before removing the separated liquid.

(Inorganic calcium compound)
The inorganic calcium compound serves as a calcium source for tricalcium phosphate “Ca ₃ (PO ₄ ) ₂ ” and also acts as a dehydration aid that promotes dehydration of sludge slurry. Therefore, by adding an inorganic calcium compound to the sludge slurry, it is possible to improve the dehydration property more than the normal dehydration method.

The inorganic calcium compound is preferably at least one selected from calcium carbonate “CaCO ₃ ”, slaked lime “Ca(OH) ₂ ”, quicklime “CaO”, and dolomite “Ca.Mg(CO ₃ ) ₂ ”. . The particle size of the inorganic calcium compound is preferably 200 μm to 500 μm.

In addition to acting as a dehydration aid, inorganic calcium compounds play multiple roles such as fluid media, carbon dioxide absorption media, heat sources for the gasification process (sensible heat media and carbon dioxide absorption reaction heat) and phosphorus melting inhibitors. . Furthermore, inorganic calcium compounds also have a secondary function of contributing to the production of high-concentration hydrogen.

The inorganic calcium compound may be supplied to the dehydrator 1 in its entirety supplied to the hydrogen production apparatus, and a part thereof may be supplied to any of the thermal decomposition apparatus 3, the reforming apparatus 4, and the combustion apparatus 5, as described later. may be supplied to

The amount W (mol/kg-dry weight (DS)) of the inorganic calcium compound to be mixed with the sludge slurry is stoichiometrically represented by the following formula (1). That is, the amount W to be added should be at least the amount that can recover the phosphorus and sulfur contents in the sludge slurry as tricalcium phosphate "Ca ₃ (PO ₄ ) ₂ " and gypsum "CaSO ₄ ".

W (mol/kg-DS) ≧ (3/2)×P (mol/kg-DS) + S (mol/kg-DS) (1)
Therefore, the amount of the inorganic calcium compound added to the sludge slurry is not particularly limited as long as it satisfies the formula (1). Specifically, 0.06 kg to 0.8 kg, more preferably 0.1 kg to 0.5 kg of inorganic calcium compound may be mixed with 1 kg of dry weight of sludge slurry (phosphorus-containing biomass). In particular, by mixing an excessive amount of the inorganic calcium compound with the sludge slurry, it is possible to more effectively prevent adhesion of the phosphorous compound to the incinerator due to melting and clogging of the incinerator.

<Drying device 2>
The drying device 2 heats the dehydrated sludge supplied from the dewatering device 1 and evaporates water to obtain dried sludge. The drying device 2 then supplies the dried sludge to the thermal decomposition device 3 through the dried sludge supply channel 13 . In addition, the drying device 2 supplies part of the dried sludge to the combustion device 5 through the dry sludge supply path 14 for heat source as needed. The dried sludge supplied to the combustion device 5 is combusted as a heat source.

The drying device 2 is not particularly limited as long as it can dry the dewatered sludge. Moreover, when the amount of water in the mixture obtained by the dehydrator 1 is small, the drying device 2 does not necessarily have to be provided. In that case, the mixture may be supplied from the dehydrator 1 to the thermal cracker 3 .

<Pyrolyzer 3>
Gasification steam is supplied to the pyrolyzer 3 . The thermal decomposition device 3 heats the dried sludge at 400° C. to 900° C., more preferably 600° C. to 800° C. in the presence of water vapor for 0.1 hour to 2 hours, more preferably 0.5 hours to It is thermally decomposed by staying for 1 hour. The thermal decomposition device 3 supplies thermal decomposition products obtained by thermal decomposition to the combustion device 5 through the thermal decomposition product supply passage 15 . Then, the thermal decomposition device 3 supplies the combustible gas, which is the thermal decomposition gas among the thermal decomposition products obtained by thermal decomposition, to the reformer 4 through the combustible gas supply passage 19 . Calcium oxide "CaO" is supplied (circulated) from the reformer 4 to the thermal decomposition apparatus 3 through the supply channel 18, and, if necessary, a part of the new inorganic calcium compound is supplied to the thermal decomposition apparatus 3. .

The thermal decomposition device 3 is not particularly limited as long as it can thermally decompose the dried sludge.

In the thermal decomposition apparatus 3, thermal decomposition is performed by the following reaction to generate combustible gas. That is, the dry sludge is thermally decomposed in the presence of water vapor by the reaction represented by the following formula (2) and converted into thermal decomposition gas and solid residue. The pyrolysis gases _are hydrogen "H2", carbon monoxide "CO", carbon dioxide " _CO2 ", hydrogen sulfide " _H2S " and ammonia " _NH3 ", as well as methane " _CH4 ", a hydrocarbonaceous It contains as a main component a hydrocarbon-based gas “C _m H _n ” containing gas and tar components. Solid residues include charcoal and ash.

Dry sludge (C, H, O, _N , S) + _H2O → Thermal decomposition gas (H2, CO, _CO2 , _CmHn , _H2S , _NH3 ) ₊ C (charcoal) + ash … (2)
Here, ash is a compound containing P, Si, Al, Fe, Mg, Ca, Na, K and the like.

A portion of the charcoal also reacts with water vapor and is converted to carbon dioxide and hydrogen as shown in formula (3) below.

C(charcoal) + 2H2O → _{CO2 + 2H2} (3)
Further, carbon monoxide contained in the pyrolysis gas reacts with water vapor and is converted to carbon dioxide as shown in the following formula (4).

CO + H ₂ O → CO ₂ + H ₂ (4)
Most of the hydrogen sulfide contained in the pyrolysis gas reacts with inorganic calcium compounds in the dry sludge and calcium oxide mainly generated by heating, and becomes calcium sulfide as shown in the following formula (5), which is fixed. become. Most of the hydrogen sulfide contained in the pyrolysis gas is thus immobilized as calcium sulfide, resulting in an increase in the concentration of hydrogen in the pyrolysis gas.

CaO+ _H2S →CaS+ _H2O (5)
Then, the carbon dioxide generated by the reactions represented by the above formulas (2) to (4) reacts with calcium oxide to become calcium carbonate “CaCO ₃ ” as represented by the following formula (6), and is immobilized. Since only carbon dioxide is absorbed by calcium oxide and extracted from the pyrolysis gas by the reaction shown in formula (6), a rightward equilibrium shift occurs in the reactions shown in formulas (2) to (4), resulting in a high A combustible gas containing a concentration of hydrogen is produced.

CaO+ _CO2 → _CaCO3 (6)
On the other hand, the phosphorus contained in the ash of the solid residue reacts with the inorganic calcium compound in the thermal decomposition apparatus 3 to become tricalcium phosphate "Ca ₃ (PO ₄ ) ₂ ". In the present embodiment, the amount of inorganic calcium compound added to the sludge slurry is extremely large, and a large amount of calcium exists inside the thermal decomposition device 3 (reaction field). Phosphorus can therefore be converted to tricalcium phosphate, a high-melting phosphorus compound with a melting point of 1390°C.

Therefore, by thermal decomposition in the thermal decomposition apparatus 3, solid components (solid residues) such as tricalcium phosphate, calcium sulfide, charcoal, calcium carbonate, unreacted inorganic calcium compounds, and ash are extracted from the dried sludge. A pyrolysis product containing is obtained.

Since the tricalcium phosphate is a main component of phosphate ore resources, it can be reused as ore resources. In addition, since the melting point of tricalcium phosphate is as high as 1390° C., it is possible to prevent adhesion of the phosphorus compound to the incinerator due to melting of the phosphorus compound in the thermal decomposition device 3 and the combustion device 5 and clogging of the incinerator. Therefore, it becomes possible to operate the phosphorus recovery apparatus more stably and continuously.

<Reformer 4>
The reformer 4 performs steam reforming using calcium oxide from the combustible gas supplied from the thermal cracker 3 to produce a second combustible gas having a hydrogen concentration higher than that of the combustible gas. The second combustible gas is discharged through the combustible gas discharge path 22 . The second combustible gas containing such high-concentration hydrogen is supplied to a power generation facility 7 such as a solid oxide fuel cell (SOFC) or a gas engine, and used for power generation.

In addition, calcium oxide “CaO” is supplied (circulated) from the ash separator 6 to the reforming device 4 through the circulating calcium oxide supply path 17, and if necessary, a part of the new inorganic calcium compound is supplied. supplied. Further, the reformer 4 supplies (circulates) calcium oxide to the pyrolyzer 3 through the supply path 18 .

The reformer 4 is not particularly limited as long as it is a device capable of steam reforming the combustible gas.

In the reformer 4, the combustible gas is steam-reformed by the following reaction to produce hydrogen of high concentration. That is, the combustible gas includes hydrogen and carbon monoxide, as well as methane " _CH4 ", a hydrocarbon-based gas " _CmHn " containing _hydrocarbon -based gas and tar components. The hydrocarbon-based gas contained in the combustible gas is reformed into hydrogen and carbon dioxide by steam reforming using calcium oxide as a catalyst, as shown in the above formula (4) and the following formula (7).

C _m H _n + H ₂ O → H ₂ + CO ₂ (7)
The produced carbon dioxide is absorbed by calcium oxide as shown in the above formula (6). As a result, a second combustible gas (reformed gas) in which the concentration of hydrogen is further increased, that is, a gas containing a high concentration of hydrogen is obtained from the combustible gas.

<Combustion device 5>
The combustion device 5 burns the pyrolysis solid product supplied from the pyrolysis device 3 . Combustion device 5 supplies combustion solid products among combustion products obtained by combustion to ash separation device 6 through combustion solid product supply passage 16 . Air is supplied to the combustion device 5 from the outside. In addition, part of the new inorganic calcium compound is supplied to the pyrolyzer 3 as needed.

The combustion device 5 heats the pyrolysis solid product supplied from the pyrolysis device 3 at 850° C. to 1200° C., more preferably 900° C. to 1150° C., more preferably about 1100° C. for 0.1 hour. It is combusted with a residence time of ˜2 hours, more preferably 0.5 hours to 1 hour.

Further, the combustion device 5 is supplied with dry sludge from the drying device 2 through the heat source dry sludge supply path 14 as required. The dried sludge is combusted as a heat source when it is difficult to combust the pyrolysis solid products only with the heat quantity from combustion of the combustion gas in the combustor 5 . By burning the dried sludge, the amount of combustion gas supplied from the outside can be reduced, so that the amount of energy used can be reduced.

The combustion device 5 is not particularly limited as long as it is a device capable of burning the pyrolysis solid product.

In the combustion device 5, combustion solid products and combustion gas are produced by the following reactions. That is, as shown in the following equation (8), the charcoal contained in the pyrolysis solid product is combusted into carbon dioxide by air or an oxygen-containing gas. Moreover, as shown in the following formula (9), calcium carbonate contained in the thermal decomposition solid product is regenerated by becoming calcium oxide. Further, as shown in the following formula (10), the calcium sulfide contained in the thermal decomposition solid product is converted into gypsum (calcium sulfate) "CaSO ₄ " by air or an oxygen-containing gas.

C(charcoal)+ _O2 → _CO2 (8)
_CaCO3 →CaO+ _CO2 (9)
CaS+ _2O2 → _CaSO4 (10)
The reactions represented by the above formulas (8) and (10) are exothermic reactions, and the reaction heat generated by the reactions becomes sensible heat of the circulated calcium oxide, and the thermal decomposition device 3, the reformer 4, and the It is used as a heat source for the combustion device 5 .

In the combustion device 5, calcium oxide, tricalcium phosphate, gypsum, ash, etc. are produced by the reactions shown in the above formulas (8) to (10) and, if necessary, by combustion of the dried sludge supplied from the drying device 2. A combustion solid product is obtained which is a solid component comprising Also, a combustion gas containing a high concentration of carbon dioxide is obtained along with the combustion solid product. Combustion device 5 discharges combustion gas, which is one of combustion products obtained by combustion, through combustion gas discharge path 20 .

<Ash separator 6>
The ash separator 6 separates particles containing calcium oxide as a main component from the combustion solid product supplied from the combustion device 5, and phosphorus-containing ash (calcium oxide combustion solid products other than The ash separator 6 then discharges the phosphorus-containing ash through the phosphorus-containing ash discharge path 21 . The phosphorus _- containing ash contains, as calcium phosphate compounds, tricalcium phosphate " _{Ca3 (} PO4) ₂ ", _P2O5 , _{CaPO4 ,} Ca _{( PO3)2 , Ca2P2O7} , _CaHPO4 and the like are included. The phosphorus-containing ash has a smaller particle size than particles containing calcium oxide as a main component.

On the other hand, the ash separator 6 supplies particles containing calcium oxide as a main component to the reformer 4 through the circulation calcium oxide supply path 17 . As a result, the calcium oxide circulates through the reformer 4, the pyrolyzer 3, the combustion device 5 and the ash separator 6, is used repeatedly, and performs the multiple functions described above.

The ash separation device 6 may be any device that can separate the combustion solid product into particles containing calcium oxide as a main component and other combustion solid products, such as a cyclone. The configuration is not particularly limited.

The hydrogen production apparatus according to the present embodiment may recover phosphorus-containing ash containing tricalcium phosphate. Therefore, the hydrogen production apparatus according to the present embodiment adds an acid to the phosphorus-containing ash containing tricalcium phosphate, which is supplied from the phosphorus-containing ash discharge passage 21, reacts with the tricalcium phosphate, and produces phosphoric acid. and a phosphoric acid production device (not shown) for producing a soluble phosphoric acid compound such as calcium dihydrogen phosphate.

[Calcium oxide regeneration device]
A calcium oxide regeneration device (hereinafter referred to as a regeneration device) according to the present embodiment utilizes various facilities of the hydrogen production device described above to convert calcium oxide into active calcium oxide, more specifically, thermal decomposition. It is a device that regenerates particulate calcium oxide (hereinafter referred to as active calcium oxide) that has a large effect of promoting reaction in equipment and reforming equipment.

As shown in FIG. 1, the regeneration device according to this embodiment includes a small regeneration furnace 8 . In this embodiment, the pyrolyzer 3 is configured to supply part of the pyrolysis products obtained by pyrolysis to the regeneration furnace 8 . In addition, the combustion device 5 supplies combustion gas containing high-concentration carbon dioxide to the regeneration furnace 8 through a combustion gas supply path 23 branching to the combustion gas discharge path 20 . The regeneration furnace 8 returns the combustion gas supplied from the combustion device 5 to the combustion gas discharge passage 20 through the combustion gas return passage 25 . Further, fuel is supplied to the regeneration furnace 8 from the outside through the fuel supply path 24 .

The regeneration furnace 8 regenerates calcium carbonate contained in the thermal decomposition products obtained by thermal decomposition into calcium oxide. More specifically, the regeneration furnace 8 heats the pyrolyzed solid product supplied from the pyrolyzer 3 at 600°C to 1200°C, more preferably 750°C to 1100°C, and even more preferably 800°C to 950°C. 0.1 hour to 2 hours, more preferably 0.5 hour to 1 hour. The inside of the regeneration furnace 8 has an atmosphere containing a large amount of carbon dioxide due to the combustion gas supplied from the combustion device 5 .

In the regeneration furnace 8, the calcium carbonate contained in the supplied pyrolysis solid product is calcined in a carbon dioxide atmosphere to be regenerated into active calcium oxide. Then, the activated calcium oxide regenerated in the regeneration furnace 8 is returned to the thermal decomposition device 3 . Note that the regeneration device according to this embodiment is not limited to the configuration shown in FIG. Any configuration is acceptable as long as it is returned to at least one.

In the regenerating apparatus according to this embodiment, part of the pyrolyzed solid product produced in the pyrolyzing apparatus 3 is regenerated into active calcium oxide by the regenerating furnace 8 . The combustion gas discharged from the combustion device 5 is used for regeneration of this active calcium oxide. Therefore, there is no need to separately provide facilities for regenerating calcium oxide, and various facilities of the hydrogen production apparatus are effectively used, so calcium oxide (CaO) can be regenerated without incurring costs.

[Calcium oxide regeneration method]
In the calcium oxide regeneration method (hereinafter simply referred to as the regeneration method) in the present embodiment, calcium oxide is regenerated using, for example, various equipment in the hydrogen production apparatus described above. The equipment used in the regeneration method according to the present embodiment is not limited to the hydrogen production apparatus described above, and includes a thermal decomposition apparatus that thermally decomposes a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam, and the thermal decomposition A combustion device that burns the pyrolysis products obtained in the device, and steam reforming using calcium oxide from the combustible gas obtained in the pyrolysis device to reform the gas with a higher hydrogen concentration than the combustible gas. and a reformer for producing a raw gas, and capable of discharging combustion gas that can be used to regenerate calcium oxide from the combustion device.

The regeneration method according to the present embodiment includes, for example, a thermal decomposition step of thermally decomposing a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam, and a thermal decomposition product obtained in the thermal decomposition step. and a reforming step of producing a reformed gas having a hydrogen concentration higher than that of the combustible gas by steam reforming using calcium oxide from the combustible gas obtained in the pyrolysis step. and calcining at least part of the calcium carbonate produced in the thermal decomposition step in the presence of at least part of the combustion gas discharged from the combustion step. , a regeneration step A of regenerating calcium oxide; and a returning step of returning the calcium oxide regenerated in the regeneration step A to at least one of the thermal decomposition step, the combustion step and the reforming step. .

More specifically, the hydrogen production method used in this embodiment mainly includes a mixing process, a dehydration process, a drying process, a thermal decomposition process, a reforming process, a combustion process, and an ash separation process. . Further, the hydrogen production method includes a transfer step between each step so that hydrogen can be produced continuously.

Each step constituting the hydrogen production method and regeneration method used in this embodiment will be described below. However, with respect to the content that overlaps with the content described in the above-described hydrogen production device and regeneration device, the description will be simplified or omitted.

<Mixing process and dehydration process>
In the mixing step, the sludge slurry (phosphorus-containing biomass) is mixed with the inorganic calcium compound described above. The order of performing the mixing step and the dehydration step is not particularly limited, but by performing the mixing step before the dehydration step, the dehydration property can be improved more than the normal dehydration method. The amount of the inorganic calcium compound added to the sludge slurry is as described above. The mixing process and the dehydration process are performed before the drying process and the moisture adjustment process.

In the dehydration step, the mixture of the sludge slurry obtained in the mixing step and the inorganic calcium compound is dehydrated. That is, the separated liquid containing water is removed from the sludge slurry. The mixture from which the separated liquid has been removed is subjected to the next drying step.

A specific mixing method for mixing the sludge slurry and the inorganic calcium compound and a specific dewatering method for dewatering the mixture of the sludge slurry and the inorganic calcium compound are not particularly limited.

When the hydrogen production method does not include a dehydration step, it is preferable to use a sludge slurry having a water content within the range of the water content of the mixture described above.

<Drying process>
In the drying step, part of the mixture obtained through the dehydration step is taken out, and part of the moisture contained in the taken out mixture is evaporated. Part of the evaporated moisture (dry steam) is condensed by cooling and discharged as removed water. The remainder is used as a heat source in the drying and combustion processes.

A specific drying method for drying the mixture is not particularly limited, but a method using an indirect heating dryer is preferable. By using an indirect heating dryer, high-temperature steam generated in the reforming process and the combustion process can be used as a heat medium, so that the thermal efficiency can be improved.

<Thermal decomposition process>
In the thermal decomposition step, the mixture obtained through the drying step is heated in the presence of water vapor at 400° C. to 900° C., more preferably 600° C. to 800° C., more preferably about 700° C., and heated for 0.1 hour to It is thermally decomposed by staying for 2 hours, more preferably 0.5 to 1 hour. That is, the heating temperature of the mixture in the thermal decomposition step is 400° C. to 900° C., more preferably 600° C. to 800° C., still more preferably about 700° C., and the residence time is 0.1 hour to 2 hours, more preferably 0.5 hours to 1 hour.

In the thermal decomposition step, thermal decomposition is performed by the reaction described above to produce a thermal decomposition solid product and a combustible gas, which is a thermal decomposition gas. A pyrolysis solid product obtained by pyrolysis is subjected to a combustion process. Then, the combustible gas obtained by thermal decomposition is subjected to the next reforming process. In addition, in the thermal decomposition step, the calcium oxide “CaO” used in the reforming step is supplied (circulated), and if necessary, a part of the new inorganic calcium compound is supplied.

A specific thermal decomposition method for thermally decomposing the moisture-adjusted substance is not particularly limited.

Since the melting point of tricalcium phosphate contained in the pyrolysis solid product is as high as 1390°C, it prevents adhesion of the phosphorus compound to the incinerator due to melting and clogging of the incinerator during the pyrolysis process and the following combustion process. be able to. Therefore, it becomes possible to operate the hydrogen production method more stably and continuously.

<Reforming process>
In the reforming step, the combustible gas obtained in the pyrolysis step is subjected to steam reforming using calcium oxide to perform the above-described reaction, and a second combustible gas having a hydrogen concentration higher than that of the combustible gas manufactures natural gas. The produced second combustible gas is cooled and recovered as gas containing high concentration of hydrogen. Heat recovered from the second combustible gas is supplied to the combustion process.

In the reforming step, the combustible gas obtained through the thermal decomposition step is heated at 800° C. to 1200° C., more preferably 900° C. to 1150° C., more preferably about 950° C. for 0.5 hours to 3 hours. Steam reforming is carried out by staying for 0 hours, more preferably 1.0 to 2.5 hours. That is, the heating temperature of the combustible gas in the reforming step is 800° C. to 1200° C., more preferably 900° C. to 1150° C., still more preferably about 950° C., and the residence time is 0.5 hours to 3.0 hours. , more preferably 1.0 to 2.5 hours.

In addition, in the reforming step, the calcium oxide “CaO” separated in the ash separation step is supplied (circulated), and if necessary, a part of the new inorganic calcium compound is supplied. Furthermore, the calcium oxide used in the reforming step is supplied (circulated) to the thermal decomposition step.

A specific reforming method for steam reforming the combustible gas is not particularly limited.

<Combustion process>
In the combustion step, the above reaction is performed by burning the pyrolysis solid products obtained in the pyrolysis step, and combustion solid products and combustion gas are obtained as combustion products. The combustion solids products and combustion gases are fed to the subsequent ash separation step. The combustion gas contains a high concentration of carbon dioxide. In the combustion process, a combustion gas serving as a heat source is supplied from the outside together with air or an oxygen-containing gas. Moreover, in the combustion process, a part of the fresh inorganic calcium compound is supplied as necessary.

In the combustion step, the thermal decomposition solid product obtained through the thermal decomposition step is heated at 850° C. to 1200° C., more preferably 900° C. to 1150° C., more preferably about 1100° C., and heated for 0.1 hour to 2 hours. Combustion by dwelling for a period of time, more preferably 0.5 hours to 1 hour. That is, the heating temperature of the thermal decomposition solid product in the combustion step is 850° C. to 1200° C., more preferably 900° C. to 1150° C., still more preferably about 1100° C., and the residence time is 0.1 hour to 2 hours. More preferably, it is 0.5 hours to 1 hour.

Furthermore, in the combustion step, the mixture described above is supplied from the drying step as required. The mixture is combusted as a heat source when it is difficult to combust the pyrolysis solid products only by the amount of heat generated by combusting the combustion gas in the combustion process. By burning the mixture, the amount of combustion gas supplied from the outside can be reduced, so that the amount of energy used can be reduced.

A specific combustion method for burning the pyrolysis solid product is not particularly limited.

<Ash separation process>
In the ash separation process, particles containing calcium oxide as a main component and phosphorus-containing ash (a solid component containing tricalcium phosphate, gypsum, ash, etc.) (other than calcium oxide) are separated from the combustion solid product obtained in the combustion process. Combustion solid products) are separated.

On the other hand, particles containing calcium oxide as a main component are supplied to the modification step. As a result, the calcium oxide circulates through the reforming process, thermal decomposition process, combustion process and ash separation process, is repeatedly used, and performs the multiple functions described above.

Although a specific separation method for separating the combustion solid product into particles containing calcium oxide as a main component and other combustion solid products is not particularly limited, a separation method using a cyclone, for example, is preferable. .

<Regeneration process A>
In the regeneration step A, at least part of the calcium carbonate produced in the thermal decomposition step is calcined in the presence of at least part of the combustion gas discharged from the combustion step to regenerate calcium oxide.

In the regeneration step A, the thermal decomposition solid product supplied from the thermal decomposition step is heated at 600° C. to 1200° C., more preferably 750° C. to 1100° C., more preferably 800° C. to 950° C. for 0.1 hour. Firing is performed by dwelling for ˜2 hours, more preferably 0.5 to 1 hour. In addition, the combustion gas discharged from the combustion process contains a high concentration of carbon dioxide. In the regeneration step, the combustion gas calcines the pyrolysis solid product in an atmosphere containing a large amount of carbon dioxide.

Here, it is known that calcium carbonate is thermally decomposed by firing in the presence of high-temperature carbon dioxide to produce active calcium oxide.

Therefore, in the regeneration step A, at least part of the calcium carbonate produced in the pyrolysis step is removed under high-temperature conditions in the presence of the combustion gas discharged from the combustion step, i.e., a gas containing carbon dioxide. By calcining, the calcium carbonate is thermally decomposed and active calcium oxide is regenerated.

<Return process>
In the returning step, the calcium oxide regenerated in the regenerating step is returned to at least one of the thermal decomposition step, the combustion step and the reforming step. The calcium oxide returned in the returning process circulates among the thermal decomposition process, the combustion process and the reforming process.

[Embodiment 2]
Other embodiments of the present invention will be described in detail below. For convenience of explanation, members having the same functions as the members explained in the above embodiment are given the same reference numerals, and the explanation thereof will not be repeated. FIG. 2 is a block diagram showing a schematic configuration of the calcium oxide regeneration device according to this embodiment.

[Calcium oxide regeneration device]
As shown in FIG. 2, the regeneration device according to the present embodiment uses the second combustible gas discharged from the reformer 4, that is, the reformed gas containing high-concentration hydrogen, to regenerate calcium oxide. It differs from the first embodiment in that it is used. More specifically, the regeneration device according to the present embodiment includes a thermal decomposition device 3, a combustion device 5, a reformer 4, and a regeneration furnace 8, and the second gas discharged from the reformer 4 of combustible gas, that is, a reformed gas containing a high concentration of hydrogen is supplied to the regeneration furnace 8 .

In the regeneration device according to the present embodiment, the reformer 4 supplies the second combustible gas containing high-concentration hydrogen to the regeneration furnace 8 through the second combustible gas supply passage 26 branched from the combustible gas discharge passage 22. supply to The regeneration furnace 8 returns the second combustible gas supplied from the reformer 4 to the combustible gas discharge line 22 through the second combustible gas return line 27 .

The regeneration furnace 8 heats the pyrolyzed solid product supplied from the pyrolyzer 3 at 600° C. to 1200° C., more preferably 750° C. to 1100° C., more preferably 800° C. to 950° C. It is fired by allowing it to stay for 1 hour to 2 hours, more preferably 0.5 hour to 1 hour. Further, the inside of the regeneration furnace 8 has an atmosphere containing a large amount of hydrogen due to the second combustible gas (reformed gas) supplied from the reformer 4 .

In the regeneration furnace 8, the calcium carbonate contained in the supplied pyrolysis solid product is calcined in a hydrogen atmosphere, whereby the hydrogen functions as a reducing gas to regenerate calcium oxide. Regenerated calcium oxide is active calcium oxide. Then, the activated calcium oxide regenerated in the regeneration furnace 8 is returned to the thermal decomposition device 3 .

In the regeneration device according to this embodiment, the second combustion gas discharged from the reformer 4 is used to regenerate the active calcium oxide. Therefore, there is no need to separately provide facilities for regenerating calcium oxide, and various facilities of the hydrogen production apparatus are effectively used, so calcium oxide (CaO) can be regenerated without incurring costs.

[Method for Regenerating Calcium Oxide]
Equipment used in the regeneration method according to the present embodiment includes a pyrolysis device that pyrolyzes a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam, and a pyrolysis product obtained by the pyrolysis device. a combustion device that burns, a reformer that produces a reformed gas having a hydrogen concentration higher than that of the combustible gas by steam reforming the combustible gas obtained in the pyrolysis device using calcium oxide; and capable of discharging a combustible gas that can be used to regenerate calcium oxide from the reformer.

The regeneration method according to the present embodiment includes, for example, a thermal decomposition step of thermally decomposing a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam, and a thermal decomposition product obtained in the thermal decomposition step. and a reforming step of producing a reformed gas having a hydrogen concentration higher than that of the combustible gas by steam reforming using calcium oxide from the combustible gas obtained in the pyrolysis step. and at least part of the calcium carbonate produced in the thermal decomposition step in the presence of at least part of the reformed gas discharged from the reforming step. a regeneration step B of calcining and regenerating calcium oxide; a returning step of returning the calcium oxide regenerated in the regeneration step B to at least one of the thermal decomposition step, the combustion step and the reforming step; including.

<Regeneration process B>
In the regeneration step B, at least a portion of the calcium carbonate generated in the thermal decomposition step is calcined in the presence of at least a portion of the reformed gas obtained in the reforming step to regenerate calcium oxide. A regeneration step B is included.

In the regeneration step B, the thermal decomposition solid product supplied from the thermal decomposition step is heated at 600° C. to 1200° C., more preferably 750° C. to 1100° C., more preferably 800° C. to 950° C. for 0.1 hour. Firing is performed by dwelling for ˜2 hours, more preferably 0.5 to 1 hour.

Here, it is known that the thermal decomposition reaction of calcium carbonate proceeds favorably in a reducing atmosphere. Further, the reformed gas contains a high concentration of hydrogen “H ₂ ” gas, which is a reducing gas.

Therefore, in the regeneration step B, at least part of the calcium carbonate produced in the thermal decomposition step is removed under high temperature and pressure conditions in the presence of the reformed gas containing a high concentration of hydrogen, which is a reducing gas. By calcining, the calcium carbonate is thermally decomposed to regenerate calcium oxide.

[Embodiment 3]
Further embodiments of the present invention will be described in detail below. For convenience of explanation, members having the same functions as the members explained in the above embodiment are given the same reference numerals, and the explanation thereof will not be repeated. FIG. 3 is a block diagram showing a schematic configuration of the calcium oxide regeneration device according to this embodiment.

[Calcium oxide regeneration device]
As shown in FIG. 3, the regenerating apparatus according to this embodiment differs from the first embodiment in that the power generation exhaust gas discharged from the power generation equipment 7 is used to regenerate calcium oxide. More specifically, the regeneration device according to the present embodiment includes a thermal decomposition device 3, a combustion device 5, a reformer 4, and a power generation facility 7, and the power generation exhaust gas discharged from the power generation device 7 is It is configured to be supplied to the combustion device 5 .

The regeneration device according to this embodiment includes a power generation exhaust gas supply path 28 for supplying power generation exhaust gas discharged from the power generation equipment 7 . The power generation exhaust gas supply channel 28 has a branch channel 29 connected to the combustion device 5 and a branch channel 30 connected to the combustion gas discharge channel 20 . The power generation equipment 7 supplies the exhaust gas from the power generation exhaust gas supply line 28 to the combustion device 5 through the branch line 29 . Further, the exhaust gas discharged from the power generation equipment 7 is discharged outside from the power generation exhaust gas supply passage 28 through the branch passage 30 and the combustion gas discharge passage 20 .

The combustion device 5 heats the pyrolyzed solid product supplied from the pyrolyzer 3 at 850° C. to 1200° C., more preferably 900° C. to 1150° C., still more preferably 1100° C., while heating for 0.1 hour to It is fired by staying for 2 hours, more preferably 0.5 to 1 hour. Further, the inside of the combustion device 5 has an atmosphere containing a large amount of carbon dioxide and water vapor due to the power generation exhaust gas supplied from the power generation equipment 7 .

In the combustion device 5, the calcium carbonate contained in the supplied pyrolysis solid product is burned in an atmosphere containing carbon dioxide and water vapor to regenerate calcium oxide. Regenerated calcium oxide is active calcium oxide. The combustion device 5 then supplies the produced activated calcium oxide to the ash separation device 6 through the combustion solid product supply channel 16 .

In the regeneration device according to the present embodiment, the power generation exhaust gas discharged from the power generation equipment 7 is used to regenerate the active calcium oxide. Therefore, there is no need to separately provide facilities for regenerating calcium oxide, and various facilities of the hydrogen production apparatus are effectively used, so calcium oxide (CaO) can be regenerated without incurring costs.

[Method for Regenerating Calcium Oxide]
Equipment used in the regeneration method according to the present embodiment includes a pyrolysis device that pyrolyzes a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam, and a pyrolysis product obtained by the pyrolysis device. a combustion device that burns, a reformer that produces a reformed gas having a hydrogen concentration higher than that of the combustible gas by steam reforming the combustible gas obtained in the pyrolysis device using calcium oxide; and a power generation facility that generates power using the hydrogen contained in the reformed gas as a fuel, and is capable of discharging power generation exhaust gas that can be used to regenerate calcium oxide from the power generation facility.

The regeneration method according to the present embodiment includes, for example, a thermal decomposition step of thermally decomposing a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam, and a thermal decomposition product obtained in the thermal decomposition step. and a reforming step of producing a reformed gas having a hydrogen concentration higher than that of the combustible gas by steam reforming using calcium oxide from the combustible gas obtained in the pyrolysis step. and a power generation step of generating power using the hydrogen contained in the reformed gas obtained in the reforming step as a fuel, wherein the power generation discharged from the power generation step At least part of the exhaust gas is supplied to the combustion step, and in the combustion step, at least part of the calcium carbonate generated in the thermal decomposition step is calcined in the presence of at least part of the power generation exhaust gas to produce calcium oxide. is a way to play

In the combustion step, the pyrolysis solid product supplied from the pyrolysis step is heated at 850° C. to 1200° C., more preferably 900° C. to 1150° C., still more preferably 1100° C., for 0.1 hour to 2 hours. , more preferably for 0.5 to 1 hour.

<Power generation process>
In the power generation step, power is generated using hydrogen contained in the reformed gas obtained in the reforming step as fuel. Specifically, it is a step of rotating a turbine using the amount of heat obtained by burning the reformed gas, more specifically, the hydrogen gas contained in the reformed gas, and converting the heat amount into electricity.

In the power generation step, power generation exhaust gas is generated. The power generation exhaust gas contains water vapor "H ₂ O" produced by combustion of hydrogen. In addition, since the reformed gas supplied to the power generation process may contain carbon "C", the power generation exhaust gas may contain carbon dioxide.

Examples of the power generation equipment 7 used in the power generation process include a solid oxide fuel cell (SOFC) or a gas engine (GE).

[Embodiment 4]
Further embodiments of the present invention will be described in detail below. For convenience of explanation, members having the same functions as the members explained in the above embodiment are given the same reference numerals, and the explanation thereof will not be repeated. FIG. 4 is a block diagram showing a schematic configuration of a calcium oxide regeneration device according to this embodiment.

[Calcium oxide regeneration device]
As shown in FIG. 4, the regenerating apparatus according to this embodiment differs from the first embodiment in that the power generation exhaust gas discharged from the power generation equipment 7 is used to regenerate calcium oxide. Moreover, it differs from the third embodiment in that a regeneration furnace 8 is provided. More specifically, the regeneration device according to the present embodiment includes a pyrolysis device 3, a combustion device 5, a reformer 4, a regeneration furnace 8, and a power generation facility 7. generated exhaust gas is supplied to the regeneration furnace 8.

In the regeneration device according to this embodiment, the power generation equipment 7 discharges the power generation exhaust gas from the combustion gas discharge passage 20 to the outside through the power generation exhaust gas discharge passage 31 . Further, the power generation equipment 7 supplies the power generation exhaust gas to the regeneration furnace 8 through the power generation exhaust gas supply path 32 branching off from the power generation exhaust gas discharge path 31 . The regeneration furnace 8 returns the power generation exhaust gas supplied from the power generation equipment 7 to the power generation exhaust gas discharge path 31 through the power generation exhaust gas return path 33 .

The regeneration furnace 8 heats the pyrolyzed solid product supplied from the pyrolyzer 3 at 600° C. to 1200° C., more preferably 750° C. to 1100° C., more preferably 800° C. to 950° C. It is fired by allowing it to stay for 1 hour to 2 hours, more preferably 0.5 hour to 1 hour. Further, the inside of the regeneration furnace 8 has an atmosphere containing a large amount of carbon dioxide and water vapor due to the power generation exhaust gas supplied from the power generation equipment 7 .

In the regeneration furnace 8, calcium carbonate contained in the supplied pyrolysis solid product is calcined in an atmosphere containing carbon dioxide and water vapor to regenerate calcium oxide. Regenerated calcium oxide is active calcium oxide. Then, the activated calcium oxide regenerated in the regeneration furnace 8 is returned to the thermal decomposition device 3 .

In the regeneration device according to the present embodiment, the power generation exhaust gas supplied from the power generation equipment 7 is used to regenerate the active calcium oxide. Therefore, there is no need to separately provide facilities for regenerating calcium oxide, and various facilities of the hydrogen production apparatus are effectively used, so calcium oxide (CaO) can be regenerated without incurring costs.

In this embodiment, in the configuration shown in FIG. 4 , the power generation equipment 7 may further supply the power generation exhaust gas to the combustion device 5 . In such a configuration, regeneration of calcium oxide takes place in at least one of regeneration furnace 8 and combustion device 5 . In this case, it is preferable to provide a switching unit for switching between regeneration of calcium oxide in the regeneration furnace 8 and regeneration of calcium oxide in the combustion device 5 .

[Method for Regenerating Calcium Oxide]
Equipment used in the regeneration method according to the present embodiment includes a pyrolysis device that pyrolyzes a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam, and a pyrolysis product obtained by the pyrolysis device. a combustion device that burns, a reformer that produces a reformed gas having a hydrogen concentration higher than that of the combustible gas by steam reforming the combustible gas obtained in the pyrolysis device using calcium oxide; and a power generation facility that generates power using the hydrogen contained in the reformed gas as a fuel, and is capable of discharging power generation exhaust gas that can be used to regenerate calcium oxide from the power generation facility.

The regeneration method according to the present embodiment includes, for example, a thermal decomposition step of thermally decomposing a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam, and a thermal decomposition product obtained in the thermal decomposition step. a combustion step of burning, and a reforming step of producing a reformed gas having a hydrogen concentration higher than that of the combustion gas by steam reforming using calcium oxide from the combustion gas obtained in the pyrolysis step; and a power generation step of generating power using the hydrogen contained in the reformed gas obtained in the reforming step as a fuel, wherein the calcium carbonate produced in the thermal decomposition step is a regeneration step C of regenerating calcium oxide by calcining at least a portion thereof in the presence of at least a portion of the power generation exhaust gas discharged from the power generation step; and a recycling step of returning to at least one of the decomposition step, the combustion step and the reforming step.

<Regeneration process C>
In the regeneration step C, at least part of the calcium carbonate produced in the thermal decomposition step is calcined in the presence of at least part of the power generation exhaust gas discharged from the power generation step to regenerate calcium oxide.

In the regeneration step C, the thermal decomposition solid product supplied from the thermal decomposition step is heated at 600° C. to 1200° C., more preferably 750° C. to 1100° C., more preferably 800° C. to 950° C. for 0.1 hour. Firing is performed by dwelling for ˜2 hours, more preferably 0.5 to 1 hour.

It is now known that in the pyrolysis reaction of pyrolyzing calcium carbonate to form (regenerate) calcium oxide, the reaction is favorably accelerated in the presence of a gas containing water vapor and optionally carbon dioxide. there is In addition, the power generation exhaust gas contains water vapor and may contain carbon dioxide.

Therefore, in the regeneration step C, at least part of the calcium carbonate produced in the pyrolysis step is calcined under high temperature conditions in the presence of the power generation exhaust gas containing water vapor and optionally carbon dioxide. The calcium carbonate is thermally decomposed to regenerate calcium oxide.

The present invention is not limited to the above-described embodiments, but can be modified in various ways within the scope of the claims, and can be obtained by appropriately combining technical means disclosed in different embodiments. is also included in the technical scope of the present invention.

〔summary〕
The present invention includes the following configurations.

<1>
A pyrolyzer that thermally decomposes a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam, a combustion device that burns the pyrolysis products obtained in the pyrolyzer, and A reformer for producing a reformed gas having a hydrogen concentration higher than that of the combustible gas by steam reforming using calcium oxide from the combustible gas obtained, and generating power using the hydrogen contained in the reformed gas as fuel. A calcium oxide regeneration method for regenerating calcium oxide using a facility equipped with a power generation facility that performs
At least part of the power generation exhaust gas discharged from the power generation equipment is supplied to the combustion device, and at least part of the calcium carbonate generated in the thermal decomposition device is converted to at least one of the power generation exhaust gas in the combustion device. A method for regenerating calcium oxide, wherein the calcium oxide is regenerated by firing in the presence of a part.

<2>
A pyrolyzer that thermally decomposes a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam, a combustion device that burns the pyrolysis products obtained in the pyrolyzer, and and a reformer for producing a reformed gas having a hydrogen concentration higher than that of the combustible gas by steam reforming the combustible gas using calcium oxide. A calcium oxide regeneration method comprising:
a first regeneration step of calcining at least part of the calcium carbonate produced in the thermal decomposition device in the presence of at least part of the combustion gas discharged from the combustion device to regenerate calcium oxide;
a returning step of returning the calcium oxide regenerated in the first regeneration step to at least one of the thermal decomposition device, the combustion device and the reformer;
A calcium oxide regeneration method comprising:

<3>
A pyrolyzer that thermally decomposes a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam, a combustion device that burns the pyrolysis products obtained in the pyrolyzer, and and a reformer for producing a reformed gas having a hydrogen concentration higher than that of the combustible gas by steam reforming the combustible gas using calcium oxide. A calcium oxide regeneration method comprising:
a second regeneration step of calcining at least part of the calcium carbonate produced in the thermal decomposition device in the presence of at least part of the reformed gas discharged from the reformer to regenerate calcium oxide; ,
a returning step of returning the calcium oxide regenerated in the second regeneration step to at least one of the thermal decomposition device, the combustion device and the reformer;
A calcium oxide regeneration method comprising:

<4>
A pyrolyzer that thermally decomposes a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam, a combustion device that burns the pyrolysis products obtained in the pyrolyzer, and A reformer for producing a reformed gas having a hydrogen concentration higher than that of the combustible gas by steam reforming using calcium oxide from the combustible gas obtained, and generating power using the hydrogen contained in the reformed gas as fuel. A calcium oxide regeneration method for regenerating calcium oxide using a facility equipped with a power generation facility that performs
a third regeneration step of calcining at least part of the calcium carbonate produced in the thermal decomposition device in the presence of at least part of the power generation exhaust gas discharged from the power generation equipment to regenerate calcium oxide;
a returning step of returning the calcium oxide regenerated in the third regeneration step to at least one of the thermal decomposition device, the combustion device and the reformer;
A calcium oxide regeneration method comprising:

<5>
The method for regenerating calcium oxide according to any one of <1> to <4>, wherein the equipment is used to produce hydrogen.

<6>
a pyrolyzer for pyrolyzing a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam;
a combustion device for burning the pyrolysis products obtained in the pyrolysis device;
A reformer for producing a reformed gas having a hydrogen concentration higher than that of the combustible gas by steam reforming using calcium oxide from the combustible gas obtained in the thermal cracker;
and a power generation facility that generates power using the hydrogen contained in the reformed gas as a fuel,
A calcium oxide regeneration device, wherein power generation exhaust gas discharged from the power generation facility is supplied to the combustion device.

<7>
a pyrolyzer for pyrolyzing a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam;
a combustion device for burning the pyrolysis products obtained in the pyrolysis device;
A reformer for producing a reformed gas having a hydrogen concentration higher than that of the combustible gas by steam reforming using calcium oxide from the combustible gas obtained in the thermal cracker;
a regeneration furnace for regenerating calcium carbonate contained in the pyrolysis product generated in the pyrolyzer into calcium oxide,
A calcium oxide regeneration device, wherein the regeneration furnace is supplied with combustion gas discharged from the combustion device or reformed gas discharged from the reformer.

<8>
a pyrolyzer for pyrolyzing a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam;
a combustion device for burning the pyrolysis products obtained in the pyrolysis device;
A reformer for producing a reformed gas having a hydrogen concentration higher than that of the combustible gas by steam reforming using calcium oxide from the combustible gas obtained in the thermal cracker;
a power generation facility that generates power using the hydrogen contained in the reformed gas as a fuel;
a regeneration furnace for regenerating calcium carbonate contained in the pyrolysis product generated in the pyrolyzer into calcium oxide,
A calcium oxide regeneration device, wherein power generation exhaust gas discharged from the power generation equipment is supplied to the regeneration furnace.

The method and apparatus for regenerating calcium oxide according to one embodiment of the present invention use phosphorus-containing biomass such as sewage sludge generated in sewage treatment plants, night soil sludge generated in night soil treatment plants, meat-and-bone meal, livestock manure, etc. as raw materials. It is preferably used in the production of hydrogen to

1 Dewatering device (mixing device)
2 drying device 3 pyrolysis device 4 reforming device 5 combustion device 6 ash separation device

Claims (8)

A pyrolyzer that thermally decomposes a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam, a combustion device that burns the pyrolysis products obtained in the pyrolyzer, and A reformer for producing a reformed gas having a hydrogen concentration higher than that of the combustible gas by steam reforming using calcium oxide from the combustible gas obtained, and generating power using the hydrogen contained in the reformed gas as fuel. A calcium oxide regeneration method for regenerating calcium oxide using a facility equipped with a power generation facility that performs
At least part of the power generation exhaust gas discharged from the power generation equipment is supplied to the combustion device, and at least part of the calcium carbonate generated in the thermal decomposition device is converted to at least one of the power generation exhaust gas in the combustion device. A method for regenerating calcium oxide, wherein the calcium oxide is regenerated by firing in the presence of a part. A pyrolyzer that thermally decomposes a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam, a combustion device that burns the pyrolysis products obtained in the pyrolyzer, and and a reformer for producing a reformed gas having a hydrogen concentration higher than that of the combustible gas by steam reforming the combustible gas using calcium oxide. A calcium oxide regeneration method comprising:
a first regeneration step of calcining at least part of the calcium carbonate produced in the thermal decomposition device in the presence of at least part of the combustion gas discharged from the combustion device to regenerate calcium oxide;
a returning step of returning the calcium oxide regenerated in the first regeneration step to at least one of the thermal decomposition device, the combustion device and the reformer;
A calcium oxide regeneration method comprising: A pyrolyzer that thermally decomposes a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam, a combustion device that burns the pyrolysis products obtained in the pyrolyzer, and and a reformer for producing a reformed gas having a hydrogen concentration higher than that of the combustible gas by steam reforming the combustible gas using calcium oxide. A calcium oxide regeneration method comprising:
a second regeneration step of calcining at least part of the calcium carbonate produced in the thermal decomposition device in the presence of at least part of the reformed gas discharged from the reformer to regenerate calcium oxide; ,
a returning step of returning the calcium oxide regenerated in the second regeneration step to at least one of the thermal decomposition device, the combustion device and the reformer;
A calcium oxide regeneration method comprising: A pyrolyzer that thermally decomposes a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam, a combustion device that burns the pyrolysis products obtained in the pyrolyzer, and A reformer for producing a reformed gas having a hydrogen concentration higher than that of the combustible gas by steam reforming using calcium oxide from the combustible gas obtained, and generating power using the hydrogen contained in the reformed gas as fuel. A calcium oxide regeneration method for regenerating calcium oxide using a facility equipped with a power generation facility that performs
a third regeneration step of calcining at least part of the calcium carbonate produced in the thermal decomposition device in the presence of at least part of the power generation exhaust gas discharged from the power generation equipment to regenerate calcium oxide;
a returning step of returning the calcium oxide regenerated in the third regeneration step to at least one of the thermal decomposition device, the combustion device and the reformer;
A calcium oxide regeneration method comprising: The method for regenerating calcium oxide according to any one of claims 1 to 4, wherein the equipment is used for producing hydrogen. a pyrolyzer for pyrolyzing a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam;
a combustion device for burning the pyrolysis products obtained in the pyrolysis device;
A reformer for producing a reformed gas having a hydrogen concentration higher than that of the combustible gas by steam reforming using calcium oxide from the combustible gas obtained in the thermal cracker;
and a power generation facility that generates power using the hydrogen contained in the reformed gas as a fuel,
A calcium oxide regeneration device, wherein power generation exhaust gas discharged from the power generation facility is supplied to the combustion device. a pyrolyzer for pyrolyzing a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam;
a combustion device for burning the pyrolysis products obtained in the pyrolysis device;
A reformer for producing a reformed gas having a hydrogen concentration higher than that of the combustible gas by steam reforming using calcium oxide from the combustible gas obtained in the thermal cracker;
a regeneration furnace for regenerating calcium carbonate contained in the pyrolysis product generated in the pyrolyzer into calcium oxide,
A calcium oxide regeneration device, wherein the regeneration furnace is supplied with combustion gas discharged from the combustion device or reformed gas discharged from the reformer. a pyrolyzer for pyrolyzing a dehydrated mixture of phosphorus-containing biomass and inorganic calcium in the presence of steam;
a combustion device for burning the pyrolysis products obtained in the pyrolysis device;
A reformer for producing a reformed gas having a hydrogen concentration higher than that of the combustible gas by steam reforming using calcium oxide from the combustible gas obtained in the thermal cracker;
a power generation facility that generates power using the hydrogen contained in the reformed gas as a fuel;
a regeneration furnace for regenerating calcium carbonate contained in the pyrolysis product generated in the pyrolyzer into calcium oxide,
A calcium oxide regeneration device, wherein power generation exhaust gas discharged from the power generation equipment is supplied to the regeneration furnace.

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