Gas production method and gas production apparatus

Abstract

To provide a method and an apparatus for efficiently producing a gas such as a reformed gas and hydrogen by gasifying a carbide obtained in a carbonization process using sewage sludge and organic waste.SOLUTION: The present inventors have focused on improvement in production efficiency of gas such as reformed gas and hydrogen, reduction in production cost, and reduction in environmental load based on reduction in carbon dioxide emission, and as means for solving the problem, the present invention provides a method for producing a gas, comprising: Disclosed is a method for producing a gas, which is provided with a reforming gasification step wherein a reformed gas containing hydrogen, carbon monoxide, methane and carbon dioxide is produced, or a method which is further provided with a shift reaction hydrogen production step wherein steam is reacted with carbon monoxide and methane in the reformed gas produced in the reforming gasification step to produce hydrogen.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for producing gases such as reformed gas and hydrogen gas, and an apparatus for producing these gases. [Background technology]

[0002] Large amounts of organic waste, such as sewage sludge, household garbage, and industrial waste, are discharged as biomass waste, and their disposal has become an environmental problem. For this reason, there is an increasing need to develop technologies to reduce the volume of sewage sludge and organic waste and to utilize them as energy resources, such as methane fermentation technology and gasification power generation. Until now, sewage sludge has generally been used as a fuel for combustion or disposed of as waste by burial. In recent years, technologies have been developed for pyrolysis and gasification of sewage sludge at high temperatures using oxygen, air, and steam, for producing charcoal by carbonizing sewage sludge, and for using sewage sludge as an alternative fuel for thermal power generation (Patent Documents 1-3, Non-Patent Documents 1-2).

[0003] Specifically, Patent Document 1 discloses a sewage sludge pyrolysis gasification power generation system that generates power using pyrolysis gas produced by pyrolyzing sewage sludge. Patent Document 2 discloses a method for producing a carbonized product by heating sewage sludge or biomass containing sewage sludge to 250°C or higher while passing a heated gas through it to remove volatile components in the biomass, and then carbonizing it by indirect heating at 400 to 500°C. Patent Document 3 discloses a method for converting sludge into fuel, which involves drying sewage sludge, adding woody biomass to the dried sewage sludge, and carbonizing the sludge to produce pyrolysis gas and charcoal. Non-Patent Document 1 discloses a sewage sludge carbonization system in which sewage sludge is dewatered to a moisture content of about 80%, is further dried, and then is introduced into a carbonization furnace for carbonization. Non-Patent Document 2 discloses a method for producing carbonized sewage sludge fuel, in which sewage sludge is dehydrated, further dried to a moisture content of 25%, and then heated and pyrolyzed in a rotary kiln to produce a carbonized product, which is then used as carbonized fuel.

[0004] On the other hand, other technologies that have been developed include the direct reformed gas production method, in which organic waste such as grass, wood, rice straw, and bagasse, as well as peat, construction wood, cotton, paper, and food waste, is reacted directly with steam, oxygen, and air at high temperatures to produce reformed gas, and the two-stage gas production technology, in which biomass raw materials are carbonized by dry distillation and the resulting carbonized material is reacted with steam to produce reformed gas. The reformed gas produced by these biomass gasification technologies is a mixed gas containing carbon monoxide (CO), hydrogen (H2), methane (CH4), ethane (C2H6), carbon dioxide (CO2), etc. Conventional methods for using reformed gas include as fuel for gas engine power generation and hydrogen production by applying hydrogen extraction technology from reformed gas (Patent Documents 4-6, Non-Patent Documents 3-5).

[0005] Specifically, Patent Document 4 discloses a reformed gas produced from biomass that can be used in gas engines and gas turbines. Patent Document 5 discloses purifying gas obtained from biomass gas and using the purified gas as fuel to drive a gas turbine. Patent Document 6 discloses obtaining a carbonized product from biomass or organic waste as a raw material, and further pyrolyzing it with steam and air to generate water gas, which is then used as fuel for an internal combustion engine that can easily be started and shut down daily. Non-Patent Documents 3 and 4 disclose technologies and issues related to gasifying biomass and using it for power generation. Non-Patent Document 5 discloses a technology in which woody biomass, such as forest resources, is used as a raw material to produce biogas in a reformed gas furnace, and the hydrogen in the biogas is stored in methylhexane and used for hydrogen stations and hydrogen power generation.

[0006] However, in conventional technologies, in addition to low-molecular-weight fuel gas, heavy components such as oily components and tar are generated in the carbonization process, which may cause serious loads and obstacles to the subsequent production of reformed gas and hydrogen.In addition, in recent years, from the perspectives of economics and environmental impact, there has been a demand for energy savings in the reformed gasification of the carbonized material and hydrogen production, reductions in the production costs of reformed gas and hydrogen, and reductions in emissions of global warming factors such as carbon dioxide resulting from the consumption of external fuels such as heavy oil, kerosene, and electricity. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2002-256884 [Patent Document 2] Patent Publication No. 2007-84728 [Patent Document 3] Patent No. 3861093 [Patent Document 4] International Publication No. WO2008 / 050727 [Patent Document 5] Patent No. 4295793 [Patent Document 6] JP 2004-35837 A [Non-patent literature]

[0008] [Non-Patent Document 1] Susumu Shimura, Tadatoshi Ko, Makoto Kitabayashi, Kenji Shimizu, "Utilization of sewage sludge charcoal as biomass fuel," Electric Steel Manufacturing, Vol. 78, No. 1, pp. 73-78 (2007) [Non-patent document 2] Takeshi Amari, Mizuhiko Tanaka, Yoichi Koga, Satoshi Okuno, Akira Tajima, "Sewage Sludge Carbonized Fuel Production and Biomass Power Generation," Proceedings of the 16th Environmental Engineering General Symposium 2006, Japan Society of Mechanical Engineers, pp. 151-153 (2006) [Non-patent document 3] Masaru Ichikawa, editor, "New Developments in Biomass Refinery Catalyst Technology", CMC Publishing (2011), pp. 70-77, pp. 99-106 [Non-patent document 4] Kenichi Sasauchi, "Power Generation by Pyrolysis Gasification of Biomass," Journal of the Combustion Society of Japan, Vol. 47, No. 139 (2005), pp. 31-39 [Non-Patent Document 5] Masaru Ichikawa, "New Developments in Hydrogen Energy Technology Utilizing Biomass Resources," Life and Environment, pp. 27-32, Vol. 61, No. 1 (2016) Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention has been made in consideration of the problems of the prior art as described above, and an object of the present invention is to provide a gas production method and production apparatus that can efficiently produce gases such as reformed gas and hydrogen by gasifying carbonized material obtained in a carbonization process using sewage sludge and organic waste. [Means for solving the problem]

[0010] The gas production method of the present invention comprises a carbonization step of carbonizing sewage sludge and organic waste to produce a carbonized product, and a reformed gasification step of gasifying the carbonized product in the presence of water vapor and carbon dioxide to produce a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide.

[0011] In the present invention, a metal-containing residue generated together with the reformed gas in the reformed gasification step may be separated and recovered from the reformed gas, and the recovered metal-containing residue may be mixed with the sewage sludge and organic waste.

[0012] The metal-containing residue may contain at least one element selected from the group consisting of alkali metals and alkaline earth metals, including sodium, potassium, lithium, calcium, magnesium, and barium, boron, aluminum, iron, and nickel.

[0013] The system may further include a shift reaction hydrogen production step in which carbon monoxide and methane in the reformed gas generated in the reformed gasification step are reacted with steam to produce hydrogen.

[0014] In the shift reaction hydrogen production step, carbon dioxide may be produced together with hydrogen, and the produced carbon dioxide may be separated from the hydrogen and introduced into the reformed gasification step.

[0015] In the shift reaction hydrogen production step, a composite catalyst containing at least one element selected from the group consisting of iron, ruthenium, nickel, copper, zinc, potassium, lithium, magnesium, chromium, cobalt, molybdenum, zirconia, titanium, cerium, lanthanum, and neodymium, and a porous oxide support may be used.

[0016] The dry distillation gas generated together with the carbonized material in the carbonization step may be combusted with air and introduced into at least one of the carbonization step and the reformed gasification step to be used as exhaust heat gas.

[0017] The dry distillation gas generated together with the carbonized material in the carbonization process may be combusted with air and introduced into at least one of the carbonization process, the reformed gasification process, and the shift reaction hydrogen production process, and used as exhaust heat gas.

[0018] The present invention relates to a gas production apparatus that includes a carbonization furnace that carbonizes sewage sludge and organic waste to produce a carbonized product, a reforming gasification furnace that gasifies the carbonized product in the presence of water vapor and carbon dioxide to produce a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide, a piping system that introduces carbon dioxide into the reforming gasification furnace, a recovery system that separates and recovers metal-containing residue generated in the reforming gasification furnace from the reformed gas, and a mixing system that mixes the recovered metal-containing residue with the sewage sludge and organic waste.

[0019] In the present invention relating to a gas production apparatus, the apparatus may include a combustion furnace that burns the dry distillation gas generated in the carbonization furnace, and a heat exchanger that heats the steam to be introduced into the reforming gasification furnace, and may also include a means for supplying the combustion gas generated in the combustion furnace to at least one of the carbonization furnace, the reforming gasification furnace, and the heat exchanger as a heating gas.

[0020] The gas production apparatus of the present invention may further include a shift reaction hydrogen production facility that produces hydrogen by reacting carbon monoxide and methane in the reformed gas generated in the reforming gasification furnace with steam.

[0021] The gas production apparatus of the present invention may include a combustion furnace that burns the dry distillation gas generated in the carbonization furnace, and a heat exchanger that heats steam to be introduced into the reforming gasification furnace, and may also include a means for supplying the combustion gas generated in the combustion furnace as heating gas to at least one of the carbonization furnace, the reforming gasification furnace, the heat exchanger, and the shift reaction hydrogen production equipment.

[0022] The gas production apparatus of the present invention may be provided with a blower that controls the temperature and / or exhaust flow rate of the combustion gas combusted in the combustion furnace, a carbonized material supply amount adjustment means that adjusts the amount of carbonized material supplied to the reforming gasification furnace, and a water vapor and carbon dioxide supply amount adjustment means that adjusts the amount of water vapor and carbon dioxide supplied to the reforming gasification furnace.

[0023] In the present invention relating to a gas production apparatus, the shift reaction hydrogen production equipment may further include a booster that pressurizes the reformed gas inside to a predetermined pressure, and a gas separation and purification equipment that separates the hydrogen and carbon dioxide produced in the shift reaction hydrogen production equipment.

[0024] The gas production apparatus of the present invention may further include a hydrogen holder for storing hydrogen separated in the shift reaction hydrogen production equipment, and piping equipment for introducing carbon dioxide separated in the shift reaction hydrogen production equipment into the reforming gasification furnace. [Effects of the Invention]

[0025] According to the present invention, it is possible to provide a gas production method and production apparatus that can efficiently produce gases such as reformed gas, hydrogen, etc. from carbonized material obtained in a carbonization process using sewage sludge and organic waste with water vapor and carbon dioxide. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a schematic diagram showing an apparatus according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, embodiments of a gas production method and a gas production apparatus (hereinafter simply referred to as a production method and a production apparatus) according to the present invention will be described. Furthermore, when "~" is used to indicate a numerical range, it means that the numerical values ​​before and after it are included as the lower and upper limits (i.e., the range is between the values ​​indicated as above and below).

[0028] (First embodiment: method for producing hydrogen) In this embodiment, a method for producing hydrogen as a gas is shown. The gas production method of this embodiment includes a carbonization process in which sewage sludge and organic waste are carbonized to produce a carbonized product, and a reformed gasification process in which the carbonized product is gasified in the presence of water vapor and carbon dioxide to produce a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide.

[0029] [Sewage sludge and organic waste] The sewage sludge and organic waste materials used as raw materials in this embodiment will be described. Examples of sewage sludge include sewage sludge generally generated in sewage treatment facilities and the like. When used in the method of this embodiment, sewage sludge can be dehydrated to a moisture content of about 80%. Furthermore, sewage sludge generated in sewage treatment facilities and the like may be used to produce methane gas by methane fermentation or the like, and the method of this embodiment can use sewage sludge before or after methane fermentation treatment. Sewage sludge is typically dehydrated to about 80% by mass, and then crushed into a dehydrated cake. It may then be dried in a kiln dryer or the like to a moisture content of about 15% to 30% by mass.

[0030] Examples of organic waste include forest timber such as cedar, pine, and bamboo, agricultural produce and by-products such as rice straw and sugarcane, construction waste, industrial waste such as cotton and textile products, natural materials such as peat and driftwood, and crushed materials obtained by crushing these (hereinafter also referred to as raw material chips). The size of the raw material chips is, for example, 5 to 100 mm. One type of organic waste may be used alone, or two or more types may be used in combination.

[0031] The organic waste may also be dried in the kiln dryer, etc., in the same manner as the sewage sludge. In this case, the organic waste may be dried together with the sewage sludge, or may be dried in a dryer separate from the sewage sludge, and then mixed with the sewage sludge and subjected to the carbonization step.

[0032] The exhaust heat discharged from such a dryer may be utilized as exhaust heat gas in the production method of this embodiment or may be transferred to a system separate from the production method. Generally, dried sewage sludge contains only a relatively small amount of carbon (e.g., about 25 to 35% by mass), while organic waste contains a relatively large amount of carbon (e.g., 35 to 45% by mass). Therefore, by adding organic waste to sewage sludge, the amount of carbonized material obtained in the carbonization process can be increased. The mixing ratio of sewage sludge to organic waste can be adjusted as appropriate, and for example, the mass ratio of sewage sludge to organic waste may be in the range of 0.01 to 99.

[0033] In addition to carbon, sewage sludge and organic waste may contain alkali metals and alkaline earth metals including sodium, potassium, lithium, cesium, calcium, magnesium, barium, etc., as well as metals such as boron, aluminum, iron, and nickel, and these metals may also be added and mixed in. If these metals are contained in the raw material, this is preferred because it can promote carbonization in the carbonization step and more efficiently generate reformed gas in the reformed gasification step described below.

[0034] In this embodiment, in order to allow the sewage sludge and organic waste to contain appropriate amounts of metals, the types and amounts of the sewage sludge and organic waste may be adjusted. Alternatively, compounds or other substances that serve as sources of the above-mentioned metals may be mixed with the sewage sludge and organic waste. For example, metal-containing residues generated together with the reformed gas in the reforming-gasification process may be used as such metal sources. Such metal-containing residues are residues that are separated and recovered from the reformed gas generated in the reforming-gasification process.

[0035] Regarding the timing for mixing the metal source such as the metal-containing residue with the sewage sludge and the organic waste, a mixing step may be provided before the carbonization step, or the metal-containing residue and / or the metal source may be directly charged into the carbonization furnace. When the metal source is mixed before the carbonization step, for example, it may be charged into a dryer that dries the sewage sludge and the organic waste.

[0036] Examples of methods for mixing metals with sewage sludge and organic waste include a method in which the sewage sludge and organic waste are immersed in a solution in which a metal source such as a metal-containing residue is dissolved in a solvent such as water, alcohol, ether, or hydrocarbon, and a method in which the solution is sprayed onto the sewage sludge and organic waste to support the metals on the sewage sludge and organic waste.

[0037] In the carbonization step of this embodiment, the presence of each of the metals in the raw material promotes carbonization and increases the carbonization rate. The content of the metal in the metal-containing residue is usually about 0.01 to 100 g, or about 0.1 to 50 g, per 1 kg of the metal-containing residue. The weight ratio of the metal-containing residue to the total of the sewage sludge and organic waste (metal-containing residue / sewage sludge+organic waste) may be in the range of 0.01 to 0.99, or 0.1 to 0.9, for example. When the metal element content of the metal-containing residue and the weight ratio of the metal-containing residue to the total of sewage sludge and organic waste are within the above ranges, the carbonization rate and tar removal rate in the carbonization process of the sewage sludge and organic waste tend to be better. The increased carbonization rate ultimately makes it possible to further increase the production amounts of char, reformed gas, and hydrogen. In this embodiment, the content of the metal can be measured by ion chromatography, ICP emission spectrometry, and X-ray fluorescence analysis.

[0038] [Carbonization process] In the method of this embodiment, a carbonization step is carried out in which sewage sludge and organic waste are carbonized to produce a char. In the carbonization step, the raw materials, sewage sludge and organic waste, are heated under low-oxygen or oxygen-free conditions to cause pyrolysis. Pyrolysis of the raw materials produces a char and a dry distillation gas containing a low-molecular-weight fuel gas and heavy fuel components such as tar. The carbonization step of this embodiment is carried out using a carbonization furnace.

[0039] The carbonization furnace can be appropriately selected from known carbonization furnaces, for example, a carbonization furnace equipped with an external or internal heating device, or a carbonization furnace equipped with a device for transporting heated material such as a screw or rotary.

[0040] The carbonization conditions for the carbonization step of this embodiment are as follows. The heating temperature in the carbonization step is, for example, 200°C or higher and 600°C or lower, or 230°C or higher and 500°C or lower. The residence time in the carbonization step of this embodiment is, for example, 5 minutes or more and 100 minutes or less, or 10 minutes or more and 60 minutes or less. By pyrolyzing the raw materials, sewage sludge and organic waste, at the heating temperature and heating time described above, carbonized materials can be efficiently obtained.

[0041] In the carbonization step of this embodiment, the raw material may be supplied to the carbonization furnace continuously or intermittently. The metal-containing residue may be supplied to the carbonization furnace continuously or intermittently.

[0042] [Dry distillation gas combustion process] In the production method of this embodiment, the dry distillation gas generated together with the carbonized material in the carbonization step may be separated from the carbonized material, recovered, and combusted to generate high-temperature combustion gas. Such combustion gas may be introduced into at least one of the carbonization step, the reforming gasification step described below, and the shift reaction hydrogen production step, and used as exhaust gas for heating. Specifically, since dry distillation gas usually contains heavy fuel components such as tar, it is transferred to an air combustion furnace or the like and burned in an air atmosphere at a temperature of, for example, 1000°C to 1200°C to obtain high-temperature combustion gas from which the heavy fuel components have been removed. Because such combustion gas is hot, it can be transferred via various piping facilities or the like to each step of the manufacturing method of this embodiment or to a heating step in an external system, such as a dryer for sewage sludge and organic waste, and used as exhaust heat gas for heating each step.

[0043] By cascading the heat of the combustion gas as exhaust heat gas for heating in each step of the production method of this embodiment, heating can be performed without using external fuel (heavy oil, electricity, etc.) or by using a smaller amount of combustion gas generated by air combustion of external fuel than conventional methods. Steps in the production method of this embodiment that can use such exhaust heat gas include, for example, drying of sewage sludge and organic waste, a carbonization step (heating of the carbonization furnace), a reforming gasification step (heating of the reforming gasification furnace), and a shift reaction hydrogen production step (heating of the shift reaction hydrogen production facility). This will not only reduce the cost of gas production, but will also have the effect of curbing global warming by reducing CO2 emissions.

[0044] [Reformed gasification process] The method of this embodiment includes a reforming gasification process in which the carbonized material obtained in the carbonization process is gasified in the presence of water vapor and carbon dioxide to produce a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide (hereinafter also referred to as H2, CO, CH4, and CO2). In the reforming-gasification process of this embodiment, the carbide is heated and reformed into gas in a reforming-gasification furnace in which both water vapor and carbon dioxide are present. In the reforming-gasification furnace, the carbide is reformed into gas through the following reaction: (1) Reaction of carbide with water vapor: C + H2O → H2 + CO (2) Methanation reaction: C + 2H2 → CH4 (3) Shift reaction: CO + H2O → CO2 + H2 (4) Reaction of carbide with carbon dioxide: C + CO2 → 2CO

[0045] In the reformed gasification process of this embodiment, reactions (1) to (4) occur efficiently because carbon dioxide is supplied together with water vapor, and reaction (4), which requires CO2, is particularly promoted. Therefore, reformed gas can be produced efficiently, and the amount of reformed gas produced can be increased. By using carbon dioxide together with water vapor in the above reactions, it is possible to increase the amount of reformed gas produced, for example, by 1.2 to 2.5 times, compared to reformed gas produced using water vapor alone.

[0046] The water vapor used in the reforming-gasification step of this embodiment can be water vapor generated by heating water such as tap water. The carbon dioxide used in the reforming-gasification step of this embodiment may be introduced into the reforming-gasification furnace from a system separate from the production method of this embodiment, or carbon dioxide discharged from a shift reaction hydrogen production step described below may be introduced into the reforming-gasification furnace.

[0047] The amount of carbonized material supplied to the reforming gasification furnace in the reforming gasification process of this embodiment can be adjusted as appropriate to efficiently produce reformed gas, and may be, for example, 10 kg / h or more and 10,000 kg / h or less, or 50 kg / h or more and 5,000 kg / h or less. The amount of steam supplied to the reformed gas furnace can be adjusted as appropriate, but for example, the amount of steam supplied per 1 kg / h of carbonized material may be 0.5 kg / h or more and 10 kg / h or less, or 2 kg / h or more and 5 kg / h or less. The amount of carbon dioxide supplied to the reformed gas furnace can be adjusted as appropriate. For example, the amount of carbon dioxide supplied per 1 kg / h of carbide is set to 0.1 Nm 3 / h or more 10Nm 3 / h or less, or 0.5Nm 3 / h or more 5Nm 3 / h or less. Furthermore, the ratio of the carbon dioxide supply amount to the total of the water vapor supply amount and the carbon dioxide supply amount (CO2 supply amount ÷ (water vapor supply amount + carbon dioxide supply amount)) can be, for example, 1 vol% or more and 85 vol% or less, or 10 vol% or more and 60 vol% or less.

[0048] In the reformed gasification step of the embodiment, the temperature of the reformed gasification furnace can be appropriately adjusted to efficiently produce the reformed gas, and may be, for example, 800° C. or higher and 900° C. or lower. As a heating means for the reformed gasification furnace, for example, the combustion gas obtained by burning the dry distillation gas described above may be used as exhaust heat gas for heating.

[0049] The steam is heated, for example, in a heat exchanger that heats clean water to a temperature in the range of 350°C to 800°C, and then supplied to the reforming-gasification furnace. When a heat exchanger or the like is used to heat the clean water, the heat exchanger may be heated by introducing exhaust heat gas from the reforming-gasification furnace. Furthermore, the exhaust heat gas from the heat exchanger that heated the clean water may be introduced into another process (for example, a shift reaction hydrogen production process) and used for heating.

[0050] The pressure in the reforming-gasification furnace in the reforming-gasification step can be adjusted as appropriate, and may be, for example, 0.05 MPa or more and 0.5 MPa or less.

[0051] The reformed gas obtained in the reformed gasification process of this embodiment contains hydrogen (H2) and carbon monoxide (CO), and typically contains hydrogen (H2), carbon monoxide (CO), methane (CH4), and carbon dioxide (CO2). The range of the hydrogen content in the reformed gas is, for example, 25% by volume or more and 75% by volume or less, or 35% by volume or more and 65% by volume or less. The range of the carbon monoxide content in the reformed gas is, for example, 20% by volume or more and 60% by volume or less, or 25% by volume or more and 50% by volume or less. The range of the total content of hydrogen and carbon monoxide in the reformed gas is, for example, 60% by volume or more and 100% by volume or less, or 70% by volume or more and 90% by volume or less. The range of the methane content in the reformed gas is, for example, 0.1% by volume or more and 10% by volume or less, or 0.5% by volume or more and 5% by volume or less. The range of the carbon dioxide content in the reformed gas is, for example, 1% by volume or more and 35% by volume or less, or 10% by volume or more and 25% by volume or less. The content (vol %) of each component is the value at 25°C (room temperature) and 1 atmosphere.

[0052] [Separation and recovery process] In this embodiment, a separation and recovery step may be provided in which a metal-containing residue generated together with the reformed gas in the reformed gasification step is separated and recovered from the reformed gas, and the recovered metal-containing residue is mixed with the sewage sludge and organic waste. That is, in the reforming-gasification step, the metals contained in the carbide remain as a metal-containing residue, and this metal-containing residue is separated and recovered from the reformed gas. Examples of the recovery method include separating the reformed gas containing the metal-containing residue discharged from the reforming-gasification furnace using a separation device such as a cyclone dust collector, and recovering the separated metal-containing residue. Such metal-containing residue can be recycled to a process prior to the carbonization process or to the carbonization process, and mixed with sewage sludge and organic waste as described above, thereby reducing emissions from within the system of the manufacturing method of this embodiment.

[0053] The metal-containing residue is formed by recovering metals contained in sewage sludge and organic waste as residue, and therefore contains at least one element selected from the group consisting of metals contained in the raw materials, i.e., metals contained in the above-mentioned sewage sludge and organic waste, such as alkali metals and alkaline earth metals such as sodium, potassium, lithium, calcium, magnesium, and barium, boron, aluminum, iron, and nickel.

[0054] The reformed gas from which the metal-containing residue has been removed in the separation device is transferred to the shift reaction hydrogen production process described below and used for hydrogen production, or it may be used for other purposes, such as power generation in a gasification power generation facility.

[0055] [Shift reaction hydrogen production process] The production method of this embodiment includes a shift reaction hydrogen production step in which carbon monoxide and methane in the reformed gas generated in the reformed gasification step are reacted with steam, i.e., carbon monoxide is reacted with steam, and methane is reacted with steam, respectively, to produce hydrogen. In the shift reaction hydrogen production process, in addition to the shift reaction (reaction 5 below), a methane reforming reaction (reaction 6 below) is carried out using steam and methane contained in the reformed gas, producing a mixed gas containing hydrogen and carbon dioxide at higher concentrations than the reformed gas. (5) Shift reaction: CO + H2O → CO2 + H2 (6) Methane reforming reaction: CH4 + 2H2O = 4H2 + CO2

[0056] In the hydrogen production process of the present embodiment, a composite catalyst containing a shift reaction hydrogenation catalyst may be used. By performing the shift reaction and the methane reforming reaction in the presence of the composite catalyst, a mixed gas of hydrogen and carbon dioxide can be efficiently produced at a relatively low temperature.

[0057] Examples of composite catalysts include those containing at least one element selected from iron, ruthenium, nickel, copper, zinc, potassium, lithium, magnesium, chromium, cobalt, molybdenum, zirconia, titanium, cerium, lanthanum, and neodymium, and a porous oxide support. Any of these elements can be selected, and examples include composite catalysts containing at least one element that serves as a catalyst for the shift reaction, such as lithium, magnesium, chromium, copper, zinc, or potassium, and at least one element that serves as a catalyst for the methane reforming reaction, such as iron, ruthenium, nickel, cobalt, molybdenum, zirconia, titanium, cerium, lanthanum, or neodymium. The carrier can be appropriately selected from known catalyst carriers, and examples thereof include ceramics containing alumina, magnesium oxide, silicon oxide, etc., and porous oxides such as titanium oxide.

[0058] In the shift reaction hydrogen step of this embodiment, the high-temperature combustion gas obtained in the combustion step of the dry distillation gas described above may be introduced and used as exhaust heat gas for heating.

[0059] The treatment conditions for the shift reaction in this embodiment are as follows. The heating temperature may be, for example, in the range of 250°C or higher and 600°C or lower, or 300°C or higher and 450°C or lower. The pressure of the shift reaction in this embodiment is, for example, 0.05 MPa or more and 5 MPa or less, or 0.09 MPa or more and 1 MPa or less. The residence time of the shift reaction in this embodiment is, for example, 1 minute or more and 100 minutes or less, or 5 minutes or more and 50 minutes or less. The gas hourly space velocity (GHSV) of the reformed gas relative to the catalyst is, for example, 100 to 5000 h -1 , or 500~3000h -1 etc. By carrying out the shift reaction under the above-mentioned shift reaction conditions, a mixed gas containing hydrogen and carbon dioxide at high concentrations can be obtained more efficiently.

[0060] As described above, carbon dioxide is produced together with hydrogen in the shift reaction hydrogen production step, and the produced carbon dioxide may be separated from the hydrogen and introduced into the reformed gasification step. The step of separating hydrogen and carbon dioxide can be carried out in a hydrogen separation step following the shift reaction hydrogen production step.

[0061] [Hydrogen separation process] This embodiment includes a hydrogen separation process. In the hydrogen separation process, the mixed gas containing high concentrations of hydrogen and carbon dioxide obtained in the shift reaction hydrogen production process is separated into hydrogen and carbon dioxide using a gas separation and purification device or the like as gas separation and purification equipment to obtain hydrogen. Through the treatment in this hydrogen separation process, it is possible to refine hydrogen and carbon dioxide to high purity (for example, purity of 90 to 99.998%).

[0062] The obtained hydrogen may be compressed under high pressure to form a compressed gas, or may be cooled to liquefy. The carbon dioxide separated in the gas separation and purification unit is transferred to the reforming-gasification step by a transfer facility and can be recycled as carbon dioxide to be used in the reforming-gasification.

[0063] In the hydrogen production method of this embodiment, the yield of carbide can be increased by using a metal-containing residue in the carbonization step. Furthermore, the yield of reformed gas can be increased by reforming the carbide using carbon dioxide together with water vapor in the reformed-gasification step. As a result, the yield of reformed gas and the amount of hydrogen produced are increased, the hydrogen gas production cost can be reduced, and hydrogen gas can be produced efficiently.

[0064] In the hydrogen production method of this embodiment, high-temperature gases generated from heat exchangers for heating clean water, combustion equipment for combustion gas, etc. are used as exhaust heat gas in each process. Metal-containing residues generated in the reforming-gasification process are also used to mix with the raw material. Alternatively, carbon dioxide emitted in the shift reaction hydrogen production process is used in the reforming-gasification process. By recycling and utilizing heat and products generated within the same system in this way, it is possible to reduce emissions outside the system and alleviate the environmental burden.

[0065] (Second embodiment: method for producing reformed gas) In this embodiment, a method for producing a reformed gas as the gas will be described. The method for producing reformed gas of this embodiment uses the sewage sludge and organic waste shown in the first embodiment and includes a carbonization process, a reformed gasification process, and optionally a separation and recovery process. The resulting reformed gas can be transferred to and used in gasification power generation using a gas turbine, gas engine, or the like.

[0066] In the reformed gas production method of this embodiment, high-temperature gas generated from a combustion device for combustion gas or the like is used as exhaust heat gas in each process. Metal-containing residue generated in the reformed gasification process is also used to mix with the raw material. By recycling the heat and products generated within the same system in this way, it is possible to reduce emissions outside the system and alleviate the environmental burden.

[0067] (Third embodiment: hydrogen production device) The hydrogen production device of this embodiment will be described with reference to FIG. The manufacturing apparatus 100 of this embodiment is a gas manufacturing apparatus comprising: a carbonization furnace 20 that carbonizes sewage sludge 1 and organic waste 2 to produce a carbonized product; and a reforming gasification furnace 30 that gasifies the carbonized product in the presence of water vapor and carbon dioxide to produce a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide. The gas manufacturing apparatus also comprises a piping system 51 that introduces carbon dioxide into the reforming gasification furnace 30; recovery systems 35 and 38 that separate and recover metal-containing residues generated in the reforming gasification furnace from the reformed gas; and a metal-containing residue introduction system 37 that mixes the recovered metal-containing residues with the sewage sludge 1 and organic waste 2.

[0068] The manufacturing apparatus 100 is equipped with receivers 10, 11 for storing sewage sludge 1 and organic waste 2, and a rotary kiln-type dryer 12 for introducing the sewage sludge 1 and organic waste 2 from the receivers 10, 11 and drying them, which is connected to a carbonization furnace, and is configured so that the dried mixture of sewage sludge 1 and organic waste 2 from the dryer 12 is transferred to the carbonization furnace 20.

[0069] The carbonization furnace 20 is equipped with a screw-type transfer facility 13 and a heating device (not shown) inside. The carbonization furnace 20 is equipped with a lower outlet 14 for discharging the produced carbonized material, and an upper outlet 15 for discharging the dry distillation gas 5 generated in the carbonization furnace 20. The upper outlet 15 is connected to an air combustion furnace 60 via a pipe. A carbonized material supply pipe 21 is connected to the lower outlet 14, and the carbonized material C1 can be fed into the reforming gasification furnace 30 via the carbonized material supply pipe 21. A controller is disposed in the carbide supply pipe 21 as carbide supply amount adjusting means for adjusting the amount of the carbide C1 supplied to the reforming gasification furnace 30.

[0070] The air combustion furnace 60 burns the dry distillation gas 5 containing tar and other substances generated during the pyrolysis dry distillation process in the carbonization furnace 20 while introducing air 7 using an air blower 61, thereby generating high-temperature combustion gas 6 from which tar and other substances have been removed. Piping equipment 70 comprising multiple paths is connected to the air combustion furnace 60. The piping equipment 70 connected to the air combustion furnace 60 is composed of a combustion gas pipe 71 that transfers the combustion gas 6 to the rotary kiln-type dryer 12, a combustion gas pipe 72 that transfers the combustion gas 6 to the carbonization furnace 20, and a combustion gas pipe 73 that transfers the combustion gas 6 to the reforming gasification furnace 30. Each combustion gas pipe is configured to heat each device with combustion gas.

[0071] The reforming gasification furnace 30 includes an inner cylindrical portion 30a and an outer cylindrical portion 30b arranged to surround the inner cylindrical portion. A carbide supply pipe 21 for introducing carbide C1 into the inner cylindrical portion 30a is connected to the reforming gasification furnace 30, and a steam supply port 31 and a carbon dioxide supply port 32 for introducing steam and carbon dioxide into the inner cylindrical portion 30a, respectively. The carbide supply pipe 21 is connected to an upper portion or a middle portion of the reforming gasification furnace 30. The steam supply port 31 is configured to introduce steam into the lower portion of the reforming gasification furnace 30 from a heat exchanger 33 that heats clean water 4 to generate steam.

[0072] A controller that controls the flow rate of steam introduced into the reforming-gasification furnace 30 from the steam supply port 31 is disposed in the heat exchanger 33 as steam supply amount adjusting means. The carbon dioxide supply port 32 is connected to a carbon dioxide recycling piping system 51 that supplies the carbon dioxide separated and recovered in a gas separation and purification system 50 (described later) to the reformed gas furnace 30. The piping system 51 is equipped with a flow rate controller as carbon dioxide supply amount adjustment means that adjusts the flow rate of carbon dioxide introduced into the reformed gasification furnace 30. The supply of carbon dioxide to the reformed gasification furnace 30 may be continuous or intermittent. The combustion gas pipe 73 is connected to the gap between the inner cylindrical portion 30a and the outer cylindrical portion 30b to introduce the combustion gas 6 for heating.

[0073] A reformed gas flow path 34 for discharging the reformed gas 8 and metal-containing residue generated in the inner cylindrical portion 30a is connected to the top of the reforming gasification furnace 30. The reformed gas flow path 34 is connected to a shift reaction hydrogen production facility 40 via a dust collector 35 as a recovery facility for the metal-containing residue.

[0074] The dust remover 35 is a device for separating and recovering the reformed gas and the metal-containing residue 3, and examples thereof include a cyclone and a bag filter. The dust remover 35 is connected to a metal-containing residue receiver 38 that collects the metal-containing residue 3 separated from the reformed gas, and is configured to feed a portion or all of the metal-containing residue 3 into the rotary kiln-type dryer 12 via a metal-containing residue introduction device 37. The metal-containing residue introduction device 37 and the dryer 12 constitute a mixing device that mixes the metal-containing residue with sewage sludge and organic waste. The receiver 38, together with the dust remover 35, constitutes a metal-containing residue recovery device. The dust remover 35 is also connected to a pipe that introduces the reformed gas from which the metal-containing residue has been removed into a shift reaction hydrogen production facility 40 via a desulfurization and deoxidation gas purifier (desulfurization and deoxidation gas purifier) ​​36.

[0075] The shift reaction hydrogen production facility 40 comprises a reaction vessel in which a shift reaction and a methane reforming reaction are carried out, and in which a composite catalyst 41 containing a shift reaction hydrogenation catalyst is disposed. A pipe for introducing the reformed gas that has passed through the de-S, O gas purifier 36 is connected to the reaction vessel of the shift reaction hydrogen production facility 40, and the reaction vessel is configured to carry out a shift reaction of carbon monoxide in the reformed gas with steam and a methane reforming reaction in the presence of the shift reaction hydrogenation catalyst. The shift reaction hydrogen production facility also includes a booster (not shown) that pressurizes the reformed gas inside to a predetermined pressure.

[0076] The composite catalyst 41 may be, for example, a catalyst in which one or more of elements acting as a catalyst for a shift reaction, elements acting as a catalyst for a methane reforming reaction, etc. are supported on a carrier made of a porous oxide, as described in the first embodiment.

[0077] The shift reaction hydrogen production facility 40 is equipped with a heating device that heats the inside of the reaction vessel to a temperature required for the shift reaction and the methane reforming reaction. The facility of this embodiment is equipped with a heating device that introduces, via a combustion gas piping 75, the combustion gas discharged from the heat exchanger 33 that converts the clean water 4 into steam. The shift reaction hydrogen production facility 40 is equipped with an outlet that discharges the mixed gas produced by the reaction and transfers it to the gas separation and purification device 50.

[0078] The gas separation and purification apparatus 50 is a hydrogen separation apparatus that separates the mixed gas used into hydrogen and carbon dioxide and is appropriately selected from known gas separation and purification apparatuses (gas separation and purification facilities), and examples thereof include a PSA (pressure swing adsorption) gas separation apparatus and a gas separation membrane gas separation apparatus. Any one or more of these separation apparatuses may be used. A hydrogen holder 80 that discharges and stores the separated hydrogen 9 is connected to the gas separation and purification apparatus 50. In addition, a piping system 51 for recycling carbon dioxide is connected to the gas separation and purification apparatus 50. In this embodiment, the piping system 51 for recycling carbon dioxide constitutes a means for recovering the carbon dioxide separated in the gas separation and purification apparatus 50 and recycling and supplying the carbon dioxide to the reforming gasification furnace 30. The carbon dioxide recycling piping equipment 51 may be provided with a controller for adjusting the amount of carbon dioxide supplied.

[0079] In the apparatus 100 of this embodiment, the piping equipment is composed of a combustion gas pipe 71 for heating the dryer 12, a combustion gas pipe 72 for heating the carbonization furnace 20, a combustion gas pipe 73 for heating the reforming gasification furnace 30, a combustion gas pipe 74 for heating steam, and a combustion gas pipe 75 for heating the shift reaction hydrogen production facility 40. In other words, the high-temperature gas generated within the apparatus can be recycled and reused for heating each apparatus.

[0080] The method for producing hydrogen using the production apparatus 100 of this embodiment may be a method similar to the production method of the first embodiment. Furthermore, the production method may use all or part of the functions of the production apparatus 100 of this embodiment. That is, the embodiment of the production method and the embodiment of the production apparatus are shown as separate and distinct embodiments.

[0081] (Fourth embodiment: reformed gas production device) This embodiment shows an apparatus for producing a reformed gas as a gas. Similar to the production apparatus 100 shown in the third embodiment, the reformed gas production apparatus of this embodiment includes a carbonization furnace 20 that carbonizes sewage sludge 1 and organic waste 2 to produce a carbonized product, and a reformed gasification furnace 30 that gasifies the carbonized product in the presence of water vapor and carbon dioxide to produce a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide. The reformed gasification furnace 30 also includes a piping system 51 that introduces carbon dioxide into the reformed gasification furnace 30, recovery systems 35 and 38 that separate and recover metal-containing residues generated in the reformed gasification furnace from the reformed gas, and a metal-containing residue introduction system 37 that mixes the recovered metal-containing residues with the sewage sludge 1 and organic waste 2. That is, this is an apparatus that essentially includes the part for obtaining the reformed gas in the apparatus 100 described in the third embodiment, and optionally includes (or does not include) the part for obtaining hydrogen. The obtained reformed gas can be transferred to and used in gasification power generation using a gas turbine, gas engine, or the like, as in the third embodiment.

[0082] The method for producing a reformed gas using the production apparatus 100 of this embodiment may be the same as the production method of the second embodiment. Also, the production method may use all or part of the functions of the production apparatus 100 of this embodiment. That is, the embodiment of the production method and the embodiment of the production apparatus are shown as independent and separate embodiments.

[0083] The gas production method and apparatus according to the present embodiment are as described above, but the embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims rather than the above description, and it is intended to include all modifications within the meaning and scope of the claims. [Example]

[0084] Next, examples of the present invention will be described together with comparative examples, but the present invention should not be construed as being limited to the following examples.

[0085] (Test 1) A hydrogen production test was conducted using the equipment configured as shown in Figure 1. In this test, sewage sludge and organic waste were fed into a dryer and a carbonization furnace, and hydrogen was produced through carbonization in the carbonization furnace, a reforming gasification reaction in the reforming gasification furnace, a shift reaction and methane reforming reaction in the shift reaction hydrogen production facility, and gas separation and purification in the PSA gas separation and purification unit. Carbon dioxide separated in the gas separation unit was recycled and supplied to the reforming gasification furnace. Metal-containing residue separated and recovered in the cyclone dust collector was recycled and supplied to the dryer for sewage sludge and organic waste. The results of the reforming gasification and hydrogen production experiments in which the metal-containing residue was recycled and not supplied to the sewage sludge are shown in Example 1 and Comparative Example 1.

[0086] The test method is as follows. Sewage sludge (80% moisture content by mass) was fed at a rate of 30 kg per hour. Construction waste chips were fed as organic waste at a rate of 10 kg per hour. Carbonization was performed at a furnace temperature of 250-450°C. Reforming gasification was performed at a steam / carbide (mass ratio) of 1.5, CO2 / carbide (molar ratio) of 0.5, and a temperature of 860°C. The shift reaction hydrogen production process was carried out at a temperature of 350°C and a pressure of 0.1 MPa using a composite catalyst consisting of Fe, Ru, Ni, Cu, Zn, Mg, Zr, Ti, and Ce supported on porous oxides. Metal-containing residue separated and recovered in a cyclone dust collector was fed into the dryer at a rate of 3 kg per hour.

[0087] The reformed gas component composition and the concentrations of CO, hydrogen, CO2, CH4, and other components in the outlet gas of the shift reaction hydrogen production unit were measured using a thermal conductivity gas chromatograph analyzer (Shimadzu Corporation, GC-14B) filled with Gaskuropack and molecular sieve 13X, and an FID gas chromatograph analyzer (Shimadzu Corporation, GC-8A). The flow rate of the exhaust gas was measured using a wet gas flow meter. The metal element contents of the metal-containing residue were measured using an ICP optical emission spectrometer (Shimadzu Corporation, ICPS-8100) and an X-ray fluorescence analyzer (Hitachi High-Tech Corporation, EA1400). The metal contents of the metal-containing residue obtained in this test were Na 35g / kg, K 85g / kg, Ca 46g / kg, Mg 27g / kg, Ba 5g / kg, Fe 7.5g / kg, and Ni 3.8g / kg. The results are shown in Table 1.

[0088] [Table 1] Note 1) Modified gasification process: Steam / carbonized material = 1.5 (weight ratio), CO2 / carbonized material = 0.5 (mole ratio), reaction temperature 860°C *2) Hydrogen purity: 99.8%

[0089] These results showed that the amount of reformed gas and hydrogen produced using sewage sludge and construction waste materials as raw materials was significantly improved when the metal-containing residue was recycled and supplied (Example 1) compared to when it was not recycled and supplied (Comparative Example 1).

[0090] (Test 2) Carbonization, reforming gasification, and hydrogen production tests were conducted in the same manner as in Test 1 using sewage sludge and rice straw, which is agricultural waste. Sewage sludge (80% moisture content) was fed at a rate of 45 kg per hour. Rice straw was fed as organic waste at a rate of 20 kg per hour. The carbonization was carried out at a furnace temperature of 250 to 420°C. The reformed gasification process of the carbonized material was carried out at a temperature of 900°C. o Table 2 shows the reformed gas production amount, reformed gas component composition, and hydrogen production amount measured in Example 2, which was carried out under mixed supply conditions of steam and CO2 at a steam / carbide (mass ratio) of 1.7 and CO2 / carbide (molar ratio) of 0.35 at C, and in Comparative Example 2, which was carried out under single supply conditions of steam / carbide = 1.7.

[0091] The shift reaction hydrogen production process was carried out at a temperature of 350°C and a pressure of 0.3 MPa using a composite catalyst consisting of Ru, Cu, Cr, K, Li, La, and Nd supported on a porous oxide. The metal-containing residue separated and recovered in a cyclone dust collector was mixed and fed to a dryer for sewage sludge and rice straw at a rate of 5 kg per hour and carbonized. The metal contents of the metal-containing residue obtained in this test were Na 23 g / kg, K 65 g / kg, Ca 50 g / kg, Mg 15 g / kg, Ba 2.5 g / kg, Li 0.5 g / kg, Fe 8.2 g / kg, and Ni 2.5 g / kg. The results are shown in Table 2.

[0092] [Table 2]

[0093] These results showed that in the reforming gasification process of carbonized material made from sewage sludge and rice straw, the amount of reformed gas and hydrogen produced under mixed steam and CO2 supply conditions (Example 2) was significantly increased compared to the amount of steam alone supply conditions (Comparative Example 2). [Industrial Applicability]

[0094] In the present invention, in a carbonization process using sewage sludge and organic waste, and in a method and apparatus for producing reformed gas and hydrogen, the efficiency of producing reformed gas and hydrogen can be improved by recycling and supplying the metal-containing residue in the reformed gasification process and the carbon dioxide in the hydrogen production process, thereby reducing the cost of hydrogen production and the environmental load by reducing carbon dioxide emissions. [Explanation of symbols]

[0095] 1. Sewage sludge 2. Organic waste 3 Metal-containing residue 4 Water supply 5. Dry distillation gas 6 Combustion gas 7. Air 8. Reformed gas 9. Hydrogen 10 Sewage sludge receiver 11 Organic waste receptacle 12 Rotary kiln dryer 13 Screw-type transfer equipment 14 Lower outlet (carbide discharge) 15 Upper outlet (carbonization gas discharge) 20 Carbonization furnace 21 Carbide supply piping 30 Reforming gasifier 31 Steam supply port 32 Carbon dioxide supply port 33 Heat exchanger 34 Reformed gas flow path 35 Dust remover 36 S and O gas purifier 37 Metal-containing residue introduction equipment 38 Metal-containing residue receiver 40 Shift reaction hydrogen production facility 41 Composite catalyst 50 Gas separation and purification equipment 51 CO2 recycling piping equipment 60 Air-fired furnace 61 Air Blower 70 Plumbing equipment 71 Combustion gas piping (for heating dryer) 72 Combustion gas piping (for heating carbonization furnace) 73 Combustion gas piping (for heating reforming gasification furnace) 74 Combustion gas piping (for steam heating) 75 Combustion gas piping (for heating shift reaction hydrogen production equipment) 80 Hydrogen Holder 100 Reformed gas and hydrogen production equipment C1 carbide

Claims

1. a carbonization step of carbonizing the sewage sludge and organic waste to produce a carbonized product; a reformed gasification step of gasifying the carbonized material in the presence of water vapor and carbon dioxide to produce a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide.

2. 2. The gas production method according to claim 1, wherein a metal-containing residue generated together with the reformed gas in the reformed gasification step is separated and recovered from the reformed gas, and the recovered metal-containing residue is mixed with the sewage sludge and organic waste.

3. 3. The gas production method according to claim 2, wherein the metal-containing residue contains at least one element selected from the group consisting of alkali metals and alkaline earth metals including sodium, potassium, lithium, calcium, magnesium, and barium, boron, aluminum, iron, and nickel.

4. 4. The gas production method according to claim 1, further comprising a shift reaction hydrogen production step of producing hydrogen by reacting carbon monoxide and methane in the reformed gas generated in the reformed gasification step with steam.

5. In the shift reaction hydrogen production step, carbon dioxide is produced together with hydrogen, The method for producing a gas according to claim 4, wherein the produced carbon dioxide is separated from hydrogen and introduced into the reforming-gasification step.

6. 5. The gas production method according to claim 4, wherein the shift reaction hydrogen production step uses a composite catalyst containing at least one element selected from the group consisting of iron, ruthenium, nickel, copper, zinc, potassium, lithium, magnesium, chromium, cobalt, molybdenum, zirconia, titanium, cerium, lanthanum, and neodymium, and a porous oxide support.

7. The method for producing a gas according to any one of claims 1 to 3, wherein the dry distillation gas generated together with the carbonized material in the carbonization step is subjected to air combustion and introduced into at least one of the carbonization step and the reformed gasification step to be used as exhaust heat gas.

8. The gas production method according to claim 4, wherein the dry distillation gas generated together with the carbonized material in the carbonization process is subjected to air combustion and introduced into at least one of the carbonization process, the reformed gasification process, and the shift reaction hydrogen production process, and used as exhaust heat gas.

9. a carbonization furnace for carbonizing sewage sludge and organic waste to produce carbonized material; a reforming gasification furnace for gasifying the carbonized material in the presence of water vapor and carbon dioxide to produce a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide; a piping facility for introducing carbon dioxide into the reforming gasification furnace; a recovery facility for separating and recovering metal-containing residue generated in the reforming gasification furnace from the reformed gas; and mixing equipment for mixing the recovered metal-containing residue with the sewage sludge and organic waste.

10. a combustion furnace that burns the dry distillation gas generated in the carbonization furnace; a heat exchanger that heats the steam to be introduced into the reforming-gasification furnace; 10. The gas production apparatus according to claim 9, further comprising a means for supplying the combustion gas generated in the combustion furnace to at least one of the carbonization furnace, the reforming gasification furnace, and the heat exchanger as a heating gas.

11. 10. The gas production apparatus according to claim 9, further comprising a shift reaction hydrogen production facility that produces hydrogen by reacting carbon monoxide and methane in the reformed gas generated in the reforming gasification furnace with steam.

12. a combustion furnace that burns the dry distillation gas generated in the carbonization furnace; a heat exchanger that heats the steam to be introduced into the reforming-gasification furnace; The gas production apparatus according to claim 11, further comprising a means for supplying the combustion gas generated in the combustion furnace as heating gas to at least one of the carbonization furnace, the reforming gasification furnace, the heat exchanger, and the shift reaction hydrogen production facility.

13. a blower for controlling the temperature and / or the discharge flow rate of the combustion gas combusted in the combustion furnace; a carbonized material supply amount adjusting means for adjusting the amount of carbonized material supplied to the reforming gasification furnace; 13. The gas production apparatus according to claim 10, further comprising: a steam and carbon dioxide supply amount adjusting means for adjusting the amounts of steam and carbon dioxide supplied to the reforming-gasification furnace.

14. 13. The gas production apparatus according to claim 11 or 12, wherein the shift reaction hydrogen production facility further comprises a booster that pressurizes the reformed gas therein to a predetermined pressure, and a gas separation and purification facility that separates the hydrogen and carbon dioxide produced in the shift reaction hydrogen production facility.

15. 15. The gas production apparatus according to claim 14, further comprising: a hydrogen holder for storing hydrogen separated in the shift reaction hydrogen production facility; and piping equipment for introducing carbon dioxide separated in the shift reaction hydrogen production facility into the reforming gasification furnace.

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