Method and apparatus for producing gas, and method and apparatus for producing bio-jet fuel

Abstract

In a carburization process using biomass, a method for producing reformed gas, hydrogen, and bio-jet fuel, and an apparatus for producing bio-jet fuel according to the present invention, metal-containing residues from a reforming gasification process are recycled and supplied to biomass, and carbon dioxide emitted during a shift reaction hydrogen production process is recycled and supplied to a reforming gasification furnace, thereby making it possible to improve the production efficiency of reformed gas, hydrogen, and bio-jet fuel. Accordingly, it is possible to achieve a reduction in the production costs of reformed gas, hydrogen, and bio-jet fuel, and a reduction in environmental load due to reduced carbon dioxide emissions.

Description

Gas production method and production device, and biojet fuel production method and production device

[0001] The present invention relates to a gas production method and a gas production apparatus, and a biojet fuel production method and a biojet fuel production apparatus.

[0002] Organic waste, such as sewage sludge, peat, household garbage, and industrial waste, is discharged in large quantities as biomass waste, and the disposal of such waste has become an environmental problem. For this reason, there is an increasing need for the development of technologies for reducing the volume of sewage sludge and organic waste and utilizing them as energy resources, such as methane fermentation and gasification power generation. Until now, sewage sludge has generally been used as combustion fuel or buried as waste. In recent years, technologies for pyrolysis and gasification of sewage sludge at high temperatures using oxygen, air, and steam, technologies for producing charcoal by carbonizing sewage sludge, and technologies for using it as an alternative fuel for thermal power generation have been developed (Patent Documents 1 to 3, Non-Patent Documents 1 and 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 char by heating sewage sludge or biomass containing sewage sludge to 250°C or higher while passing 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 sewage sludge into fuel by drying the sewage sludge, adding woody biomass to the dried sewage sludge, and carbonizing it to produce pyrolysis gas and a char. Non-Patent Document 1 discloses a sewage sludge carbonization system in which sewage sludge dehydrated to a moisture content of about 80% is further dried and then 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, there have been developed direct reformed gas production methods in which organic waste such as grass, wood, rice straw, bagasse, and other agricultural waste, peat, construction wood, cotton, paper, and food waste are directly reacted with steam, oxygen, and air at high temperatures to produce reformed gas, and two-stage gas production techniques 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 contains carbon monoxide (CO), hydrogen (H ２ ), methane (CH ４ ), ethane (C ２ H ６ ), carbon dioxide (CO ２ Conventional methods for using reformed gas include as fuel for gas engine power generation and for producing hydrogen by applying hydrogen extraction technology from reformed gas (Patent Documents 4 to 6, Non-Patent Documents 3 to 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 is easy to operate daily starting and shutting down. 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 biogas is produced in a reformed gasifier using woody biomass, such as forest resources, as a raw material, 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.

[0007] Furthermore, from the perspective of reducing emissions of substances that contribute to global warming, achieving carbon neutrality in jet fuel has become an important theme, particularly in the aviation industry. Biojet fuels produced from biomass and the like have attracted attention as a way to achieve such carbon neutrality (Patent Documents 7 and 8). Patent Documents 7 and 8 disclose methods for producing biojet fuels consisting of isomerized hydrocarbons with 7 to 14 carbon atoms by heating and catalytically reforming biomass-derived oil. However, these conventional methods for producing biojet fuels using biomass as a raw material are insufficient for efficient and stable production of biojet fuels.

[0008] Japanese Patent Publication No. 2002-256884, Japanese Patent Publication No. 2007-84728, Japanese Patent No. 3861093, International Publication No. WO2008 / 050727, Japanese Patent No. 4295793, Japanese Patent Publication No. 2004-35837, International Publication No. WO2023 / 085337, International Publication No. W2024 / 071264

[0009] Susumu Shimura, Tadatoshi Ko, Makoto Kitabayashi, Kenji Shimizu, "Use of sewage sludge carbonized fuel as biomass fuel", Electric Steel Manufacturing, Vol. 78, No. 1, pp. 73-78 (2007); Takeshi Amari, Mizuhiko Tanaka, Yoichi Koga, Satoshi Okuno, Akira Tajima, "Production of carbonized sewage sludge fuel and use of biomass power generation", Proceedings of the 16th Environmental Engineering General Symposium 2006 of the Japan Society of Mechanical Engineers, pp. 151-153 (2006); Masaru Ichikawa, editor, "Biomass "New Developments in Refinery Catalyst Technology," CMC Publishing (2011), pp. 70-77, pp. 99-106; Kenichi Sasauchi, "Power Generation from Biomass Pyrolysis Gasification," Journal of the Combustion Society of Japan, Vol. 47, No. 139 (2005), pp. 31-39; Masaru Ichikawa, "New Developments in Hydrogen Energy Technology Utilizing Biomass Resources," Life and Environment, Vol. 61, No. 1 (2016), pp. 27-32

[0010] The present invention was made in consideration of the problems of the prior art described above, and aims to efficiently utilize sewage sludge and organic waste to obtain gases for use as fuel, etc. Specifically, the present invention aims 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. It also aims to provide a biojet fuel production method and production apparatus that can efficiently and stably produce biojet fuel using biomass such as sewage sludge and organic waste.

[0011] 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.

[0012] 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.

[0013] 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.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] The dry distillation gas generated together with the carbonized material in the carbonization step may be 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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 carbide supply amount adjustment means that adjusts the amount of carbide 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.

[0024] 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.

[0025] 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.

[0026] The present invention relates to a method for producing biojet fuel, and includes the steps of: a carbonization step of carbonizing biomass to produce a carbonized product; a reformed-gasification step of gasifying the carbonized product with steam and carbon dioxide to produce a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide; an olefin production step of contacting the reformed gas with a methanol synthesis catalyst and a mesoporous catalyst to produce olefins having 2 to 4 carbon atoms; an oligomerization reaction step of oligomerizing the olefins to produce iso-oligomers having 6 to 16 carbon atoms; a hydrogenation step of hydrogenating the iso-oligomers to produce isoparaffins and producing a biojet fuel containing the isoparaffins; and a separation and recovery step of separating and recovering from the reformed gas a metal-containing residue generated together with the reformed gas in the reformed-gasification step, and mixing the recovered metal-containing residue with the biomass.

[0027] In the present invention, 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.

[0028] In the present invention, the olefin production step may include a separation step of contacting the reformed gas with a methanol synthesis catalyst and a mesoporous catalyst to generate a reaction gas, and separating the reaction gas into a mixed gas containing carbon monoxide and methane and olefins having 2 to 4 carbon atoms.

[0029] The present invention may further comprise a shift reaction hydrogen production step in which carbon monoxide and methane in the reaction gas generated in the olefin production step are reacted with steam to produce hydrogen and carbon dioxide.

[0030] In the present invention, carbon dioxide generated in the shift reaction hydrogen production step may be introduced into the reformed gasification step, and hydrogen generated in the shift reaction hydrogen production step may be mixed with the reformed gas obtained from the reformed gasification step.

[0031] In the present invention, the shift reaction hydrogen production step may use a shift reaction 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.

[0032] In the present invention, the dry distillation gas generated together with the carbonized material in the carbonization process may be combusted and introduced into at least one of the carbonization process, the reforming gasification process, the steam heat exchange process, the steam heat exchange process, the olefin production process, and the oligomerization reaction process.

[0033] In the present invention, the dry distillation gas generated together with the carbonized material in the carbonization process may be combusted and introduced into at least one of the carbonization process, the reforming gasification process, the steam heat exchange process, the shift reaction hydrogen production process, the olefin production process, and the oligomerization reaction process.

[0034] In the present invention, the methanol synthesis catalyst may contain at least one element selected from the group consisting of copper, zinc, chromium, manganese, scandium, lithium, sodium, potassium, cesium, magnesium, barium, platinum, palladium, iridium, molybdenum, tungsten, vanadium, zirconium, hafnium, titanium, yttrium, cerium, and lanthanum, and a porous support.

[0035] In the present invention, the mesoporous catalyst may contain a porous support made of a mesoporous zeolite and a mesoporous clay mineral.

[0036] In the present invention, the olefin production step may use a composite catalyst prepared by mixing the methanol synthesis catalyst and the mesoporous catalyst, and the volume ratio of the methanol synthesis catalyst to the mesoporous catalyst in the composite catalyst may be 0.1 to 5.

[0037] The present invention relates to an apparatus for producing biojet fuel, and includes: a carbonization furnace that introduces biomass and produces a carbonized product; a reforming-gasification furnace that introduces the carbonized product obtained in the carbonization furnace and gasifies it with water vapor and carbon dioxide to produce a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide; an olefin production facility that introduces the reformed gas obtained in the reforming-gasification furnace and brings it into contact with a methanol synthesis catalyst and a mesoporous catalyst to produce olefins having 2 to 4 carbon atoms; an oligomerization reaction facility that introduces the olefins and oligomerizes them to produce iso-oligomers having 6 to 16 carbon atoms; and a hydrogenation facility that introduces the iso-oligomers obtained in the oligomerization reaction facility and hydrogenates them to produce a biojet fuel containing paraffin. The apparatus also includes a separation and recovery means that separates and recovers from the reformed gas a metal-containing residue generated together with the reformed gas in the reforming-gasification furnace; and a means for introducing the metal-containing residue recovered by the separation and recovery means into the biomass.

[0038] The present invention may further comprise a shift reaction facility for producing hydrogen and carbon dioxide by reacting carbon monoxide and methane in the reaction gas generated in the olefin production facility with steam.

[0039] In the present invention, the olefin production facility may be equipped with a separation means for separating the generated reaction gas into olefins having 2 to 4 carbon atoms and a gas containing carbon monoxide and methane.

[0040] In the present invention, the shift reaction facility may include a transfer means for transferring the produced carbon dioxide to the reforming gasification furnace.

[0041] In the present invention, a combustion device is provided that burns the dry distillation gas discharged from the carbonization furnace, and the combustion device may be provided with a supply means that supplies the combusted gas as a heating gas to at least one of the carbonization furnace, the reforming gasification furnace, the olefin production equipment, the oligomerization reaction equipment, and the hydrogenation equipment.

[0042] In the present invention, a combustion device is provided that burns the dry distillation gas discharged from the carbonization furnace, and the combustion device may be provided with a supply means that supplies the combusted gas as a heating gas to at least one of the carbonization furnace, the reforming gasification furnace, the olefin production equipment, the oligomerization reaction equipment, the hydrogenation equipment, and the shift reaction equipment.

[0043] According to the present invention, it is possible to efficiently use sewage sludge and organic waste to obtain gases for use as fuel, etc. That is, it is possible to provide a gas production method and production apparatus that can efficiently produce gases such as hydrogen and reformed gases from carbonized materials obtained in a carbonization process using sewage sludge and organic waste with water vapor and carbon dioxide. It is also possible to provide a biojet fuel production method and production apparatus that can efficiently and stably produce biojet fuel using biomass such as sewage sludge and organic waste.

[0044] Fig. 1 is a schematic diagram showing an apparatus according to an embodiment of the present invention. Fig. 2 is a schematic diagram showing an apparatus according to an embodiment of the present invention.

[0045] Below, we will explain embodiments of a gas production method and gas production apparatus (hereinafter simply referred to as a production method and production apparatus) and a biojet fuel production method and production apparatus (hereinafter simply referred to as a fuel production method and fuel production apparatus) according to the present invention. Note that when "to" 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 above and below).

[0046] (First embodiment: hydrogen production method) This embodiment describes a method for producing hydrogen as a gas. The gas production method of this embodiment is a production method including a carbonization step of carbonizing sewage sludge and organic waste to produce a charcoal, and a reformed-gasification step of gasifying the charcoal in the presence of water vapor and carbon dioxide to produce a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide.

[0047] [Sewage Sludge and Organic Waste] The sewage sludge and organic waste 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, the sewage sludge can be dehydrated to a moisture content of approximately 80%. Sewage sludge generated in sewage treatment facilities and the like is sometimes used to produce methane gas by methane fermentation, and the method of this embodiment can use sewage sludge before or after methane fermentation. Sewage sludge is typically dehydrated to approximately 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 approximately 15% to 30% by mass.

[0048] Examples of organic waste include forest harvested materials such as cedar, pine, and bamboo, agricultural products 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.

[0049] 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.

[0050] The exhaust heat emitted from such a dryer may be used 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, adding organic waste to sewage sludge can increase the amount of carbonized material obtained in the carbonization step. The mixing ratio of sewage sludge to organic waste can be adjusted as appropriate, and examples of such ranges include a sewage sludge to organic waste mass ratio of 0.01 to 99.

[0051] 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.

[0052] 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, a metal-containing residue generated together with the reformed gas in the reforming-gasification process may be used as such a metal source. The metal-containing residue is a residue separated and recovered from the reformed gas generated in the reforming-gasification process.

[0053] 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.

[0054] 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.

[0055] In the carbonization process of this embodiment, the inclusion of each metal in the raw material promotes carbonization and increases the carbonization rate. The metal content in the metal-containing residue is typically approximately 0.01 to 100 g, or 0.1 to 50 g, per 1 kg of the metal-containing residue. Furthermore, the weight ratio of the metal-containing residue to the total of sewage sludge and organic waste (metal-containing residue / sewage sludge + organic waste) can range from 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. An increased carbonization rate ultimately enables increased production of char, reformed gas, and hydrogen. The metal content in this embodiment can be measured by ion chromatography, ICP atomic emission spectroscopy, and X-ray fluorescence analysis.

[0056] [Carbonization Process] In the method of this embodiment, a carbonization process is carried out in which sewage sludge and organic waste are carbonized to produce a char. In the carbonization process, 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 low-molecular-weight fuel gas and heavy fuel components such as tar. The carbonization process of this embodiment is carried out using a carbonization furnace.

[0057] 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.

[0058] 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 higher and 100 minutes or lower, or 10 minutes or higher and 60 minutes or lower. By pyrolyzing the raw materials, sewage sludge and organic waste, at the above heating temperatures and heating times, a carbonized product can be efficiently obtained.

[0059] 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.

[0060] [Combustion Process of Carbonized Gas] In the production method of this embodiment, the carbonized gas generated together with the carbonized material in the carbonization process may be separated from the carbonized material, recovered, and combusted to generate high-temperature combustion gas. This combustion gas may be introduced into at least one of the carbonization process, the reforming gasification process (described later), and the shift reaction hydrogen production process to be used as exhaust heat gas for heating. Specifically, since the carbonized gas typically contains heavy fuel components such as tar, it is transferred to an air combustion furnace or the like and combusted in an air atmosphere at a temperature of 1000°C to 1200°C to obtain high-temperature combustion gas from which the heavy fuel components have been removed. Because this combustion gas is hot, it can be transferred via various piping systems or other devices to the various processes of the production method of this embodiment or to heating processes such as sewage sludge and organic waste dryers in external systems, and used as exhaust heat gas for heating these processes.

[0061] 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 an external fuel (heavy oil, electricity, etc.) or by using a smaller amount of combustion gas generated by air combustion of an external fuel than in the past. 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 not only reduces the cost of gas production, but also reduces CO ２ It can help curb global warming by reducing emissions.

[0062] [Reforming-Gasification Step] In the method of this embodiment, the carbonized material obtained in the carbonization step is subjected to a gasification reaction in the presence of water vapor and carbon dioxide to produce hydrogen, carbon monoxide, methane, and carbon dioxide (hereinafter, referred to as H ２ , CO, CH ４ and CO ２The reformed gasification process of this embodiment includes a reformed gasification process for producing a reformed gas containing carbon dioxide. In the reformed gasification process of this embodiment, the carbonized material is heated in a reformed gasification furnace where water vapor and carbon dioxide are both present, and reformed gasification is performed. In the reformed gasification furnace, the carbonized material is reformed and gasified by the following reaction: (1) Reaction between the carbonized material and water vapor: C+H ２ O → H ２ + CO (2) Methanation reaction: C + 2H ２ →CH ４ (3) Shift reaction: CO + H ２ O → CO ２ +H ２ (4) Reaction of carbide with carbon dioxide: C + CO ２ →2CO

[0063] In the reforming gasification process of this embodiment, the reactions (1) to (4) occur efficiently because carbon dioxide is supplied together with water vapor. ２ The reaction (4), which requires the addition of water vapor, is particularly promoted. Therefore, the 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 reaction, the amount of reformed gas produced can be increased, for example, by 1.2 to 2.5 times compared to when water vapor is used alone to produce the reformed gas.

[0064] 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.

[0065] The amount of carbide supplied to the reforming gasification furnace in the reforming gasification step of this embodiment can be adjusted as appropriate to efficiently produce the reformed gas, and may be, for example, 10 kg / h to 10,000 kg / h, or 50 kg / h to 5,000 kg / h. The amount of steam supplied to the reforming gas furnace can be adjusted as appropriate, and may be, for example, 0.5 kg / h to 10 kg / h, or 2 kg / h to 5 kg / h, as the amount of steam supplied per kg / h of carbide. The amount of carbon dioxide supplied to the reforming gas furnace can be adjusted as appropriate, and may be, for example, 0.1 Nm ３ / h or more 10Nm ３ / h or less, or 0.5 Nm ３ / h or more 5Nm ３ / h or less. In addition, the ratio of the supply amount of carbon dioxide to the total supply amount of water vapor and carbon dioxide (CO ２ The supply amount divided by (the supply amount of water vapor plus the supply amount of carbon dioxide) is, for example, 1% by volume or more and 85% by volume or less, or 10% by volume or more and 60% by volume or less.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] The reformed gas obtained in the reformed gasification process of this embodiment is hydrogen (H ２ ) and carbon monoxide (CO), typically hydrogen (H ２ ), carbon monoxide (CO), methane (CH ４ ) and carbon dioxide (CO ２ ). The hydrogen content in the reformed gas can range, for example, from 25% to 75% by volume, or from 35% to 65% by volume. The carbon monoxide content in the reformed gas can range, for example, from 20% to 60% by volume, or from 25% to 50% by volume. The total hydrogen and carbon monoxide content in the reformed gas can range, for example, from 60% to 100% by volume, or from 70% to 90% by volume. The methane content in the reformed gas can range, for example, from 0.1% to 10% by volume, or from 0.5% to 5% by volume. The carbon dioxide content in the reformed gas can range, for example, from 1% to 35% by volume, or from 10% to 25% by volume. The content (volume %) of each component is a value at 25°C (room temperature) and 1 atmosphere.

[0070] [Separation and Recovery Step] This embodiment may include a separation and recovery step in which a metal-containing residue generated together with the reformed gas in the reformed-gasification step is separated from the reformed gas and recovered, and the recovered metal-containing residue is mixed with the sewage sludge and organic waste. That is, in the reformed-gasification step, metals contained in the carbonized product remain as a metal-containing residue, and the metal-containing residue is separated from the reformed gas and recovered. Examples of recovery methods include separating the reformed gas containing the metal-containing residue discharged from the reformed-gasification furnace using a separation device such as a cyclone dust collector, and recovering the separated metal-containing residue. The metal-containing residue can be recycled to a step prior to the carbonization step or to the carbonization step, and then mixed with the sewage sludge and organic waste as described above, thereby reducing emissions from the production system of this embodiment.

[0071] The metal-containing residue is formed by recovering metals contained in sewage sludge and organic waste as residue, and therefore contains metals contained in the raw materials, i.e., at least one element selected from the group consisting of alkali metals and alkaline earth metals such as sodium, potassium, lithium, calcium, magnesium, and barium, boron, aluminum, iron, and nickel, which are metals contained in the sewage sludge and organic waste described above.

[0072] 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.

[0073] [Shift Reaction Hydrogen Production Step] 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 step, 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 to produce a mixed gas containing hydrogen and carbon dioxide at higher concentrations than the reformed gas. (5) Shift Reaction: CO + H ２ O → CO ２ +H ２ (6) Methane reforming reaction: CH ４ +2H ２ O=4H ２ +CO ２

[0074] 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.

[0075] 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 support can be appropriately selected from known catalyst supports, and examples include ceramics containing alumina, magnesium oxide, or silicon oxide, and porous oxides such as titanium oxide.

[0076] 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.

[0077] The treatment conditions for the shift reaction of this embodiment are as follows. The heating temperature is, for example, in the range of 250°C to 600°C, or 300°C to 450°C. The pressure for the shift reaction of this embodiment is, for example, in the range of 0.05 MPa to 5 MPa, or 0.09 MPa to 1 MPa. The residence time for the shift reaction of this embodiment is, for example, in the range of 1 minute to 100 minutes, or 5 minutes to 50 minutes. The gas hourly space velocity (GHSV) of the reformed gas relative to the catalyst is, for example, 100 to 5000 h －１ , or 500 to 3000 hours －１ 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.

[0078] 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 reforming-gasification step. The step of separating hydrogen and carbon dioxide can be carried out in the hydrogen separation step following the shift reaction hydrogen production step.

[0079] [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%).

[0080] 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.

[0081] 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.

[0082] 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.

[0083] (Second embodiment: method for producing reformed gas) This embodiment describes a method for producing reformed gas as a gas. 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 obtained reformed gas can be transported and used in gasification power generation using a gas turbine, a gas engine, or the like.

[0084] 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.

[0085] (Third embodiment: hydrogen production apparatus) A hydrogen production apparatus of this embodiment will be described with reference to Figure 1. The production apparatus 100 of this embodiment is a gas production 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 production 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 residue generated in the reforming gasification furnace from the reformed gas, and a metal-containing residue introduction system 37 that mixes the recovered metal-containing residue with the sewage sludge 1 and organic waste 2.

[0086] 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.

[0087] 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 introduced into the reforming gasification furnace 30 via the carbonized material supply pipe 21. A controller is arranged in the carbonized material supply pipe 21 as a carbonized material supply amount adjustment means for adjusting the amount of the carbonized material C1 supplied to the reforming gasification furnace 30.

[0088] The air combustion furnace 60 burns the dry distillation gas 5 containing tar and the like generated in the pyrolysis dry distillation process in the carbonization furnace 20 while introducing air 7 with an air blower 61, thereby generating a high-temperature combustion gas 6 from which the tar and the like have been removed. A piping system 70 comprising a plurality of paths is connected to the air combustion furnace 60. The piping system 70 connected to the air combustion furnace 60 is composed of a combustion gas piping 71 that transfers the combustion gas 6 to the rotary kiln-type dryer 12, a combustion gas piping 72 that transfers the combustion gas 6 to the carbonization furnace 20, and a combustion gas piping 73 that transfers the combustion gas 6 to the reforming gasification furnace 30. Each combustion gas piping is configured to heat each device with combustion gas.

[0089] 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.

[0090] A controller that controls the flow rate of water vapor introduced from the water vapor supply port 31 into the reforming gasification furnace 30 is disposed in the heat exchanger 33 as water vapor supply amount adjustment means. The carbon dioxide supply port 32 is connected to a carbon dioxide recycling piping system 51 that supplies carbon dioxide separated and recovered in a gas separation and purification system 50 (described later) to the reforming gas furnace 30. The piping system 51 is equipped with a flow rate controller that adjusts the flow rate of carbon dioxide introduced into the reforming gasification furnace 30 as carbon dioxide supply amount adjustment means. The supply of carbon dioxide to the reforming gasification furnace 30 may be continuous or intermittent. The combustion gas piping 73 is connected to the gap between the inner and outer cylindrical portions 30a and 30b to introduce combustion gas 6 for heating.

[0091] 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 serving as a recovery facility for the metal-containing residue.

[0092] 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 facility 37. The metal-containing residue introduction facility 37 and the dryer 12 constitute a mixing facility 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 facility. 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 oxygenation gas purifier (desulfurization and deoxygenation gas purifier) ​​36.

[0093] 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 desulfurization and oxygen 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 between carbon monoxide in the reformed gas and 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.

[0094] The composite catalyst 41 may be, for example, a catalyst in which one or more of an element acting as a catalyst for a shift reaction, an element acting as a catalyst for a methane reforming reaction, or the like is supported on a carrier made of a porous oxide, as described in the first embodiment.

[0095] 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, 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.

[0096] The gas separation and purification apparatus 50 is a hydrogen separation apparatus appropriately selected from known gas separation and purification apparatuses (gas separation and purification facilities) that separates the mixed gas used into hydrogen and carbon dioxide. Examples include a PSA (pressure swing adsorption) gas separation apparatus and a gas separation membrane gas separation apparatus. 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. A carbon dioxide recycling piping system 51 is also connected to the gas separation and purification apparatus 50. In this embodiment, the carbon dioxide recycling piping system 51 constitutes a means for recovering the carbon dioxide separated by the gas separation and purification apparatus 50 and recycling and supplying the carbon dioxide to the reforming gasification furnace 30. A controller that adjusts the amount of carbon dioxide supplied may be provided in the carbon dioxide recycling piping system 51.

[0097] 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 in the apparatus can be recycled and reused for heating each apparatus.

[0098] The method for producing hydrogen using the production apparatus 100 of this embodiment may be the same as the production method in the first embodiment. Furthermore, the method may use all or some 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.

[0099] (Fourth Embodiment: Reformed Gas Production Apparatus) This embodiment illustrates 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 gas production apparatus 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 residue generated in the reformed gasification furnace from the reformed gas, and a metal-containing residue introduction system 37 that mixes the recovered metal-containing residue with the sewage sludge 1 and organic waste 2. That is, the reformed gas production apparatus of this embodiment essentially includes the portion for obtaining the reformed gas in the apparatus 100 described in the third embodiment, but optionally includes (or does not include) the portion 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.

[0100] 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. Furthermore, the 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.

[0101] Fifth Embodiment: Method for Producing Biojet Fuel This embodiment describes a method for producing biojet fuel. The method for producing biojet fuel in this embodiment includes: a carbonization step of carbonizing biomass to produce a char; a reformed-gasification step of gasifying the char, steam, and carbon dioxide to produce a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide; an olefin production step of contacting the reformed gas with a methanol synthesis catalyst and a mesoporous catalyst to produce olefins having 2 to 4 carbon atoms; an oligomerization reaction step of oligomerizing the olefins to produce isoparaffins having 6 to 16 carbon atoms; and a hydrogenation step of hydrogenating the isoparaffins to obtain biojet fuel. This method for producing biojet fuel is characterized in that 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 biomass.

[0102] [Biomass] The biomass used as a raw material in the fuel production method of this embodiment will be described. The biomass used in this embodiment is a reusable organic resource derived from plants and animals, and is not particularly limited as long as it is not a fossil fuel such as petroleum. Examples include sewage sludge and organic waste. Examples of the sewage sludge and organic waste that can be used are similar to those described in the first embodiment. That is, the sewage sludge can be sewage sludge generally generated in sewage treatment facilities, etc. When used in the method of this embodiment, the sewage sludge can be dehydrated to a moisture content of approximately 80%. Furthermore, sewage sludge generated in sewage treatment facilities, etc., can be used to produce methane gas by methane fermentation, etc., but the method of this embodiment can use sewage sludge before or after methane fermentation. Sewage sludge is typically dehydrated to approximately 80% by mass, and then crushed into a dehydrated cake. It may then be further dried in a kiln dryer or the like to a moisture content of approximately 15% to 30% by mass.

[0103] Examples of organic waste include forest harvested materials such as cedar, pine, and bamboo, agricultural products 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.

[0104] 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.

[0105] The exhaust heat gas discharged from such a dryer may be used as exhaust heat gas in the production method of this embodiment, or may be transferred to a system separate from the production method and utilized as exhaust heat gas. 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., about 35 to 45% by mass). Therefore, by adding organic waste to sewage sludge, the amount of carbonized material obtained in the carbonization step can be increased. The mixing ratio of sewage sludge to organic waste can be adjusted as appropriate, but examples of such ranges include a sewage sludge to organic waste mass ratio of 0.01 to 99.

[0106] In this embodiment, the biomass as a raw material may be either the sewage sludge or the organic waste, or both of the sewage sludge and the organic waste. In this embodiment, a case where both the sewage sludge and the organic waste are used as the biomass will be described.

[0107] As in the first embodiment, the sewage sludge and organic waste may contain, in addition to carbon, 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 materials, this is preferable because it promotes carbonization in the carbonization step and enables more efficient generation of reformed gas in the reformed gasification step described below.

[0108] 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, a metal-containing residue generated together with the reformed gas in the reforming-gasification process may be used as such a metal source. The metal-containing residue is a residue separated and recovered from the reformed gas generated in the reforming-gasification process.

[0109] 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.

[0110] 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.

[0111] In the carbonization process of this embodiment, the inclusion of each of the metals in the raw material promotes carbonization and increases the carbonization rate. The metal content in the metal-containing residue is typically approximately 0.01 to 100 g, or 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 sewage sludge and organic waste (metal-containing residue / sewage sludge + organic waste) can range from 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. An increased carbonization rate ultimately enables increased production of char, reformed gas, olefins (described below), isoparaffins, and the final product, biojet fuel. In this embodiment, the content of the metal can be measured by ion chromatography, ICP emission spectrometry, and X-ray fluorescence analysis.

[0112] [Carbonization Process] In the fuel production method of this embodiment, a carbonization process is carried out in which sewage sludge and organic waste are carbonized to produce a char. In the carbonization process, the raw materials, sewage sludge and organic waste, are heated in a low-oxygen or oxygen-free state 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 process of this embodiment is carried out using a carbonization furnace.

[0113] 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.

[0114] 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 higher and 100 minutes or lower, or 10 minutes or higher and 60 minutes or lower. By pyrolyzing the raw materials, sewage sludge and organic waste, at the above heating temperatures and heating times, a carbonized product can be efficiently obtained.

[0115] 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.

[0116] [Combustion Process of Carbonized Gas] In the fuel production method of this embodiment, the carbonized gas generated together with the carbonized product in the carbonization process may be separated from the carbonized product, recovered, and combusted to generate high-temperature combustion gas. This combustion gas may be introduced into at least one of the following processes: the carbonization process, the reforming-gasification process (described later), the olefin production process, the oligomerization reaction process, the hydrogenation process, or the process of heating steam by heat exchange, and used as exhaust heat gas for heating. Specifically, since the carbonized gas typically contains heavy fuel components such as tar, it can be transferred to an air combustion furnace or the like and combusted in an air atmosphere at a temperature of 1000°C to 1200°C to obtain high-temperature combustion gas from which the heavy fuel components have been removed. Because this combustion gas is hot, it can be transported via various piping systems or the like to the respective processes of the fuel production method of this embodiment, or to heating processes such as sewage sludge and organic waste dryers in external systems, and used as exhaust heat gas for heating these processes.

[0117] By cascading the heat of the combustion gas as exhaust heat gas for heating in each step of the fuel production method of this embodiment, heating can be performed without using an external fuel (heavy oil, electricity, etc.) or by using a smaller amount of combustion gas generated by air combustion of the external fuel than in the past. The steps of the fuel 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), a step of heat exchanging steam for heating (steam heat exchange step), a shift reaction hydrogen production step (heating of the shift reaction hydrogen production facility), an olefin production step (olefin production facility), an oligomerization reaction step (oligomerization reaction facility), and a hydrogenation step (hydrogenation facility). This not only reduces the cost of gas production, but also reduces CO ２ It can help curb global warming by reducing emissions.

[0118] [Reforming-Gasification Step] In the fuel production method of this embodiment, the carbonized material obtained in the carbonization step is subjected to a gasification reaction in the presence of water vapor and carbon dioxide to produce hydrogen, carbon monoxide, methane, and carbon dioxide (hereinafter, referred to as H ２ , CO, CH ４ and CO ２ The present invention also includes a reformed gasification process for producing a reformed gas containing carbon dioxide. In the reformed gasification process of this embodiment, the following reactions occur: (1) Reaction between carbon dioxide and water vapor: C+H ２ O → H ２ + CO (2) Reaction of carbide with carbon dioxide: C + CO ２ → 2CO (3) Shift reaction: CO + H ２ O → CO ２ +H ２ (4) Methanation reaction: C + 2H ２ →CH ４

[0119] In the gasification temperature range (600°C to 10,000°C) in the reformed gas process of this embodiment, the gasification reactions (1) and (2) between the carbide, steam, and carbon dioxide are particularly promoted. In addition, the reactions (3) and (4) occur concomitantly to produce the reformed gas. In this embodiment, when the gasification temperature is high, the proportion of hydrogen in the reformed gas increases relatively. Furthermore, by using carbon dioxide together with steam in the above-mentioned carbide gasification reactions (1) and (2), it is possible to increase the amount of reformed gas produced, for example, by 1.2 to 2.5 times, compared to when steam alone is used for reforming the gas.

[0120] 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 fuel 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.

[0121] The amount of carbide supplied to the reforming gasification furnace in the reforming gasification step of this embodiment can be adjusted as appropriate to efficiently produce the reformed gas, and examples of such amounts include 10 kg / h to 10,000 kg / h, or 50 kg / h to 5,000 kg / h. The amount of steam supplied to the reforming gasification furnace can be adjusted as appropriate, and examples of such amounts include 0.5 kg / h to 10 kg / h, or 2 kg / h to 5 kg / h, as the amount of steam supplied per kg / h of carbide. The amount of carbon dioxide supplied to the reforming gasification furnace can be adjusted as appropriate, and examples of such amounts include 0.1 Nm3 as the amount of carbon dioxide supplied per kg / h of carbide. ３ / h or more 10Nm ３ / h or less, or 0.5 Nm ３ / h or more 5Nm ３ / h or less. In addition, the ratio of the supply amount of carbon dioxide to the total supply amount of water vapor and carbon dioxide (CO ２The supply amount divided by (the supply amount of water vapor plus the supply amount of carbon dioxide) is, for example, 1% by volume or more and 85% by volume or less, or 10% by volume or more and 60% by volume or less.

[0122] In the reformed gasification step of the embodiment, the temperature of the reformed gasification furnace can be adjusted as appropriate to efficiently produce the reformed gas, and may be, for example, 600° C. or higher and 1000° C. or lower, or 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.

[0123] 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 the clean water is heated by heat exchange using a heat exchanger or the like, exhaust heat gas from the reforming-gasification furnace may be introduced into the heat exchanger for heating (steam heat exchange process). Furthermore, the exhaust heat gas from the heat exchanger that heated the clean water may be introduced into another process (e.g., an olefin production process, an oligomerization reaction process, a shift reaction hydrogen production process, etc.) and used for heating. In the biojet fuel production method of this embodiment, using the exhaust heat gas for heating in other processes not only has the economic effect of reducing the production costs of reformed gas, olefins, and biojet fuel, but also contributes to the suppression of global warming by reducing carbon dioxide emissions.

[0124] 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.

[0125] The reformed gas obtained in the reformed gasification process of this embodiment is hydrogen (H ２ ) and carbon monoxide (CO), typically hydrogen (H ２ ), carbon monoxide (CO), methane (CH ４ ) and carbon dioxide (CO ２). The hydrogen content in the reformed gas can range, for example, from 25% to 75% by volume, or from 35% to 65% by volume. The carbon monoxide content in the reformed gas can range, for example, from 20% to 60% by volume, or from 25% to 50% by volume. The total hydrogen and carbon monoxide content in the reformed gas can range, for example, from 60% to 100% by volume, or from 70% to 90% by volume. The methane content in the reformed gas can range, for example, from 0.1% to 10% by volume, or from 0.5% to 5% by volume. The carbon dioxide content in the reformed gas can range, for example, from 1% to 35% by volume, or from 10% to 25% by volume. The content (volume %) of each component is a value at 25°C (room temperature) and 1 atmosphere.

[0126] [Separation and Recovery Step] This embodiment includes a separation and recovery step in which a metal-containing residue generated together with the reformed gas during the reforming-gasification step is separated from the reformed gas and recovered, and the recovered metal-containing residue is mixed with the biomass. That is, in the reforming-gasification step, metals contained in the carbonized product remain as a metal-containing residue, and the metal-containing residue is separated from the reformed gas and recovered. Examples of recovery methods include separating the reformed gas containing the metal-containing residue discharged from the reforming-gasification furnace using a separator such as a cyclone dust collector, and then recovering the separated metal-containing residue. The metal-containing residue can be recycled and supplied to a biomass receiving section (e.g., a receiver), a biomass mixing and drying section (e.g., a mixer, dryer), or the carbonization furnace before being introduced into the carbonization step. By mixing the metal-containing residue with sewage sludge and organic waste as described above, emissions from the system of the fuel production method of this embodiment can be reduced.

[0127] The metal-containing residue is formed by recovering metals contained in sewage sludge and organic waste as residue, and therefore contains metals contained in the raw materials, i.e., at least one element selected from the group consisting of alkali metals and alkaline earth metals such as sodium, potassium, lithium, calcium, magnesium, and barium, boron, aluminum, iron, and nickel, which are metals contained in the sewage sludge and organic waste described above.

[0128] The reformed gas from which the metal-containing residue has been removed in the separation device may be used to produce biojet fuel, or may be used for other purposes, such as power generation and hydrogen production in a gasification power generation facility.

[0129] [Gas Purification Step] The fuel production method of this embodiment may include a gas purification step in which the reformed gas obtained in the reforming / gasification step is purified. In the gas purification step, it is preferable to remove components such as sulfur-containing components contained in the reformed gas. The reformed gas may contain sulfur-containing components such as hydrogen sulfide and COS derived from the biomass feedstock. These sulfur-containing components can act as catalyst poisons and may reduce catalytic activity and impair stability in the olefin production step and oligomerization reaction step described below. Therefore, removing such sulfur-containing components can improve the stability of catalytic activity in each step.

[0130] For example, a known gas purifier can be used for gas purification. For example, a gas purification element comprising at least one metal selected from the group consisting of Cu, Zn, Cr, Ce, Fe, Mo, and Co supported on a porous carrier such as silica, alumina, or zeolite is preferred. By contacting the reformed gas with such a gas purification element, sulfur-containing components are bonded to the metal and the porous carrier, and are chemically removed from the reformed gas. The gas purifier is not limited to those using chemical adsorption as described above, and may be a gas purifier equipped with a known gas adsorbent such as activated carbon or various zeolites. Furthermore, gas purification may also remove nitrogen-containing components such as ammonia and NOx, and chlorine-containing components such as HCl, in addition to sulfur-containing components.

[0131] [Olefin Production Step] The fuel production method of this embodiment includes an olefin production step in which the reformed gas is brought into contact with a methanol synthesis catalyst and a mesoporous catalyst to produce olefins having 2 to 4 carbon atoms. In the olefin production step, the reformed gas obtained in the reforming gasification step (which may be a reformed gas purified through a gas purification step) is first brought into contact with a methanol synthesis catalyst to remove H contained in the reformed gas. ２ , CO, CO ２ , C.H. ４ Further, by contacting the methanol with a mesoporous catalyst, ethylene (C ２ H ４ ), propylene (C ３ H ６ ) and butene (C ４ H ８ ), that is, a gas containing olefins having 2 to 4 carbon atoms (hereinafter also referred to as C2 to C4 olefins).

[0132] Known methanol synthesis catalysts can be used as the methanol synthesis catalyst. Examples include catalysts containing at least one element selected from the group consisting of copper, zinc, chromium, manganese, scandium, lithium, sodium, potassium, cesium, magnesium, barium, platinum, palladium, iridium, molybdenum, tungsten, vanadium, zirconium, hafnium, titanium, yttrium, cerium, and lanthanum (hereinafter also referred to as element (1)). These elements (1) may be supported on a carrier. Examples of the carrier include porous carriers made of porous oxides such as silica and alumina. Selecting an appropriate element (1), or in some cases selecting multiple elements (1), from the above-mentioned elements (1) can improve the methanol production yield and selectivity. When a methanol synthesis catalyst using a carrier is used, the amount of element (1) supported is, for example, 0.01 to 10 mass%, preferably 0.1 to 5 mass%. Here, the amount of element (1) supported is the ratio of the total mass of element (1) to the mass of the carrier.

[0133] Methanol synthesis catalysts can be produced by known methods. When producing a methanol synthesis catalyst in which element (1) is supported on a carrier, a solution containing element (1) may be supported on the carrier. The element (1) solution can be simultaneously or sequentially supported by methods such as immersion, dripping, coating, or spraying at a predetermined temperature range. A specific example of a method for producing a methanol synthesis catalyst includes impregnating a carrier with a catalyst precursor containing element (1) dissolved in a solvent, followed by activation treatment to produce a methanol synthesis catalyst. Examples of catalyst precursors include salts of element (1). Examples of salts include hydrochloride, nitrate, formate, acetate, oxalic acid, citric acid, lactic acid, malate, and alkoxide salts. Examples of solvents include ethanol, methanol, ethers, and water. Examples of activation treatment methods include a method in which the temperature is raised stepwise in an oxygen-containing atmosphere over a temperature range of 250 to 600°C, and a method in which the temperature is raised stepwise in a hydrogen gas atmosphere over a temperature range of 100 to 450°C. In addition, hydrogen activation treatment may be performed by reduction treatment using a reducing agent such as hydrazine, boron hydride, etc. The selection of catalyst precursor, catalyst production process, and activation treatment conditions are not limited to these.

[0134] Known catalysts can be used as the mesoporous catalyst, but examples include mesoporous zeolites such as ZSM-5, ZSM-11, SAPO-34, and erionite, which are characterized by a pore diameter of 0.36 to 0.55 nm x 0.50 to 0.56 nm, and mesoporous catalysts containing mesointercalated clay minerals characterized by an interlayer distance of 0.35 to 0.56 nm. In this embodiment, the mesoporous catalyst is preferably treated with a salt of at least one element selected from phosphoric acid, boric acid, and alkali metals and alkaline earth metals such as lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, and barium. This can improve the selectivity and production yield of olefins.

[0135] Mesoporous catalysts can be produced by known methods. Specific production methods include dissolving a catalyst precursor containing the above-mentioned elements in a solvent, impregnating a support with the resulting solution, and performing activation and reactivation treatments to obtain an activated mesoporous catalyst. Examples of catalyst precursors include salts of the above-mentioned elements. Examples of salts include hydrochlorides, nitrates, and organic acid salts such as acetic acid, oxalic acid, citric acid, and lactic acid. Examples of solvents include ethanol, methanol, and water. Examples of catalyst activation and reactivation treatment methods include a stepwise temperature increase in an oxygen-containing atmosphere over a temperature range of 250 to 600°C, and a stepwise temperature increase in a hydrogen gas atmosphere over a temperature range of 100 to 450°C. The selection of catalyst precursors, the process for producing activated catalysts, and the activation and reactivation treatment conditions are not limited to these.

[0136] The methanol synthesis catalyst and the mesoporous catalyst can be used separately or as a composite catalyst in which both are mixed. In this embodiment, from the viewpoint of olefin yield and selectivity, it is preferable to use a composite catalyst in which the methanol synthesis catalyst and the mesoporous catalyst are physically mixed. When a composite catalyst is used, the olefin production amount and olefin selectivity can be improved.

[0137] The volume ratio of the methanol synthesis catalyst to the mesoporous catalyst in the composite catalyst (methanol synthesis catalyst / mesoporous catalyst volume ratio) is, for example, 0.1 to 5, or 0.2 to 2. When the methanol synthesis catalyst / mesoporous catalyst volume ratio is within the above range, the methanol yield can be improved, and the olefin selectivity and olefin production amount can be improved. The composite catalyst can be installed and used in a fixed bed, a fluidized bed, or a slurry-type catalytic reactor in which the catalyst is dispersed in an organic solvent such as hexane, heptane, or octane. In particular, when the composite catalyst is installed in a slurry-type catalytic reactor, the uniformity of the reaction bed temperature is increased, improving the stabilization of olefin production activity.

[0138] The reformed gas introduced into the olefin production process may be pressurized to a predetermined reaction pressure using a pressure booster or other pressure boosting device, and may be continuously circulated and supplied. The reaction pressure of the reformed gas in the olefin production process may be, for example, 0.1 to 5 MPa or 1 to 3.5 MPa. The reaction temperature may be, for example, 200 to 500°C or 250 to 450°C. The space velocity of the reformed gas (SV: synthesis gas velocity L / h / catalyst volume L) may be, for example, 1,000 to 35,000 h －１ , or 3000 to 25000 hours －１ In the olefin production process of this embodiment, for example, an olefin selectivity of 65 to 95% and an olefin yield (STY: kg / L-cat / h) of 0.25 to 1.5 kg / L-cat / h can be obtained. Under the normal reaction conditions of this embodiment, the production selectivity of each of the olefins having 2 to 4 carbon atoms is 25 to 50% ethylene (C ２ ), 25-45% propylene (C ３ ) and 10-20% butene (C ４ ) can be obtained.

[0139] In the olefin production process, the reaction gas may be cooled by an internal cooling device 56 to condense and separate the water generated in the reaction, and then discharged outside the system. In this case, improvement of olefin production efficiency and stabilization of catalyst activity can be ensured.

[0140] The reaction gas generated in the olefin production process contains light gases (carbon monoxide, methane, and carbon dioxide) in addition to the C2 to C4 olefins. The light gases can be separated by the distillation separator 52, and the separated carbon monoxide and methane can be used in the shift reaction hydrogen production process.

[0141] [Oligomerization Reaction Step] The fuel production method of this embodiment includes an oligomerization reaction step in which the olefins are subjected to an oligomerization reaction to produce iso-oligomers having 6 to 16 carbon atoms (hereinafter also referred to as C6 to C16 iso-oligomers). In the oligomerization reaction step, the olefins generated in the olefin production step are heated and pressurized in the presence of a metal complex catalyst to produce iso-oligomers having 6 to 16 carbon atoms. Specifically, C6 to C16 iso-oligomers are obtained by iso-oligomerizing ethylene (C2), propylene (C3), and butene (C4).

[0142] The catalyst and reaction conditions in the oligomerization reaction step of this embodiment can be appropriately selected from known catalysts and reaction conditions within a range, and are not particularly limited. For example, the C6 to C16 iso-oligomers can be obtained in a reactor under heating and pressure conditions of 120 to 250°C and 2 to 5 MPa in the presence of a metal complex catalyst containing a metal such as Co, Ti, Zr, or Al. In this embodiment, light olefins having 2 to 5 carbon atoms, which are generated simultaneously with the iso-oligomers in the oligomerization reaction step, can be separated and recovered from the iso-oligomers using a separation and recovery means such as a distiller, and then returned to the oligomerization reaction step. Recycling these recovered light olefins back into the oligomerization reaction step can improve the production amount and yield of the target iso-oligomers having 6 to 16 carbon atoms.

[0143] [Hydrogenation Step] The fuel production method of this embodiment includes a hydrogenation step in which the iso-oligomers are hydrogenated to produce isoparaffins and a biojet fuel containing the isoparaffins is produced. In the hydrogenation step, the iso-oligomers produced in the oligomerization reaction step are hydrotreated to produce isoparaffins having 6 to 16 carbon atoms. The catalyst and reaction conditions in the hydrogenation step of this embodiment can be appropriately selected from known catalysts and reaction conditions within a range, and are not particularly limited. For example, in the presence of a noble metal catalyst containing platinum, palladium, iridium, or the like, the C6 to C16 iso-oligomers are hydrogenated in a reactor under reaction conditions such as 250 to 350°C and 1 to 5 MPa to produce C6 to C16 isoparaffins. Such isoparaffins are preferably produced at a conversion rate of 85 to 90%. Such C6 to C16 isoparaffins are used as biojet fuel.

[0144] [Biojet Fuel] The biojet fuel produced by the fuel production method of this embodiment is isoparaffin having 6 to 16 carbon atoms.

[0145] In the fuel production method of this embodiment, the dry distillation gas generated together with the carbonized material in the carbonization step may be combusted and introduced into at least one of the carbonization step, reforming-gasification step, steam heat exchange step, olefin production step, and oligomerization reaction step. In this way, by using the dry distillation gas as exhaust heat gas in each step, or by using it to mix the metal-containing residue generated in the reforming-gasification step with the raw material, the heat and products generated within the system can be recycled, thereby reducing emissions outside the system and making it possible to alleviate the environmental burden.

[0146] In the fuel production method of this embodiment, the yield of char can be increased by using a metal-containing residue in the carbonization step. Furthermore, the yield of reformed gas can be increased by performing mixed reformed-gasification of the char using water vapor and carbon dioxide in the reforming-gasification step. As a result, the yield of iso-oligomers with 6 to 16 carbon atoms obtained by oligomerizing olefins with 2 to 4 carbon atoms for biojet fuel and isoparaffins obtained by hydrogenating the iso-oligomers is increased. Consequently, the production cost of biojet fuel can be reduced, and biojet fuel can be produced efficiently.

[0147] (Sixth embodiment: Method for producing biojet fuel) The method for producing biojet fuel of this embodiment is similar to the method for producing biojet fuel shown in the fifth embodiment above, but further includes a shift reaction hydrogen production step in which carbon monoxide and methane in the reaction gas generated in the olefin production step are reacted with steam to produce hydrogen and carbon dioxide.

[0148] [Shift Reaction Hydrogen Production Step] The fuel production method of this embodiment may include a shift reaction hydrogen production step in which carbon monoxide and methane in the reaction gas generated in the olefin production step are reacted with steam to produce hydrogen and carbon dioxide. In the shift reaction hydrogen production step, a shift reaction (reaction 5 below) and a methane reforming reaction (reaction 6 below) are carried out to produce a mixed gas containing hydrogen and carbon dioxide. (5) Shift reaction: CO + H ２ O → CO ２ +H ２ (6) Methane reforming reaction: CH ４ +2H ２ O=4H ２ +CO ２

[0149] In the fuel production method of this embodiment, light gases (carbon monoxide, methane, and carbon dioxide) separated and recovered from the olefins produced in the olefin production step are introduced into a shift reaction hydrogen production step, where the light gases are brought into contact with a shift reaction hydrogen production catalyst in the presence of steam, whereby a mixed gas containing hydrogen and carbon dioxide is produced by the shift reaction and methane reforming reaction.

[0150] In the shift reaction hydrogen production process of this embodiment, a mixed gas consisting of hydrogen and carbon dioxide can be produced efficiently at a relatively low temperature by performing a shift reaction and a methane reforming reaction in the presence of a shift reaction hydrogen production catalyst.

[0151] Examples of the shift reaction hydrogen production catalyst 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 acting as a catalyst for the shift reaction, such as lithium, magnesium, chromium, copper, zinc, or potassium, and at least one element acting as a catalyst for the methane reforming reaction, such as iron, ruthenium, nickel, cobalt, molybdenum, zirconia, titanium, cerium, lanthanum, or neodymium. The support can be appropriately selected from known catalyst supports, and examples include ceramics containing alumina, magnesium oxide, or silicon oxide, and porous oxides such as titanium oxide.

[0152] In the shift reaction hydrogen production step of this embodiment, the high-temperature combustion gas obtained in the above-mentioned combustion step of the dry distillation gas may be introduced and used as exhaust heat gas for heating.

[0153] The processing conditions for the shift reaction of this embodiment are as follows. The heating temperature is, for example, in the range of 250°C to 600°C, or 300°C to 450°C. The pressure in the shift reaction hydrogen production step of this embodiment is, for example, in the range of 0.05 MPa to 5 MPa, or 0.09 MPa to 1 MPa. The residence time in the shift reaction hydrogen production step of this embodiment is, for example, in the range of 1 minute to 100 minutes, or 5 minutes to 50 minutes. The gas hourly space velocity (GHSV) of the reformed gas relative to the catalyst is, for example, 100 to 5000 h －１ , or 500 to 3000 hours －１ By carrying out the shift reaction hydrogen production process under the above reaction conditions, a mixed gas containing hydrogen and carbon dioxide at high concentrations can be obtained more efficiently.

[0154] 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 reforming-gasification step. The step of separating hydrogen and carbon dioxide can be carried out in the hydrogen separation step following the shift reaction hydrogen production step.

[0155] The obtained hydrogen may be compressed under high pressure to form a compressed gas, or may be cooled to liquefy the hydrogen. The separated carbon dioxide may be transferred to the reforming-gasification step by a transfer facility and recycled as carbon dioxide for use in the reforming-gasification.

[0156] [Hydrogen Separation Step] This embodiment may include a hydrogen separation step. In the hydrogen separation step of this embodiment, hydrogen is obtained by separating a mixed gas containing high concentrations of hydrogen and carbon dioxide obtained in the shift reaction hydrogen production step into hydrogen and carbon dioxide using a gas separation and purification apparatus or the like as a gas separation and purification means. This hydrogen may be stored in a hydrogen holder or the like. Alternatively, hydrogen may be mixed with a reformed gas, the concentration of which may be adjusted, and then supplied to the olefin production step. Examples of gas separation and purification means include a PSA gas separation apparatus and a ceramic membrane gas separation apparatus. Either one of these gas separation apparatuses may be used, or both may be used.

[0157] When the hydrogen obtained in the shift reaction hydrogen production process of this embodiment is supplied as a mixed gas to the olefin production process, H in the mixed gas ２ By adjusting the / CO volume ratio to, for example, 1 to 3, or 1.5 to 2.5, the amount of olefin produced and the selectivity for olefin production in the olefin production process can be significantly improved.

[0158] In the fuel production method of this embodiment, the H of the reformed gas supplied to the olefin production process is ２ To obtain hydrogen necessary for adjusting the CO / CO gas ratio, a water electrolysis step using water electrolysis equipment may be provided. Commercially available electricity can be used as the power for such water electrolysis equipment. ２ To reduce emissions, electricity obtained from renewable energy sources such as solar and wind power, or nuclear reactor-generated energy may be used.

[0159] The fuel production method of this embodiment provides all of the same advantages as the production method of the fifth embodiment, and further provides the following advantage by including a shift reaction hydrogen production step. That is, by introducing carbon dioxide generated in the shift reaction hydrogen production step into the reformed-gasification step, the yield of reformed gas generated in the reformed-gasification step can be increased. As a result, the production cost of biojet fuel can be reduced, and biojet fuel can be produced efficiently.

[0160] Furthermore, in the fuel production method of this embodiment, the dry distillation gas generated together with the carbonized material in the carbonization step may be combusted to generate combustion gas, and the combustion gas may be used as a heat source in at least one of the following steps: the carbonization step, the reformed-gasification step, the steam heat exchange step, the shift reaction hydrogen production step, the olefin production step, and the oligomerization reaction step. In this way, the dry distillation gas may be used as an exhaust heat gas as a heat source in each step, or the metal-containing residue generated in the reformed-gasification step may be recycled and mixed with the biomass feedstock to improve the carbonization rate of the carbonized material. By recycling the combustion gas and metal-containing residue generated in the system, the yield of the reformed gas can be improved. As a result, the production yield of biojet fuel can be increased and production costs can be reduced.

[0161] Seventh Embodiment: Biojet Fuel Production Apparatus An apparatus for producing biojet fuel according to this embodiment will be described with reference to FIG. 2. The production apparatus 100' of this embodiment comprises a carbonization furnace 20' into which biomass 1' (sewage sludge and organic waste) is introduced to produce a carbonized product; a reforming-gasification furnace 30' into which the carbonized product 2' obtained in the carbonization furnace 20' is introduced and which performs a mixed gasification reaction with steam and carbon dioxide to produce a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide; an olefin production facility 50' into which the reformed gas obtained in the reforming-gasification furnace 30' is introduced and which produces olefins having 2 to 4 carbon atoms by bringing the reformed gas into contact with a methanol synthesis catalyst and a mesoporous catalyst; and an olefin production facility 50' into which the olefins are introduced and the olefins are mixed and gasified. The biojet fuel production system includes an oligomerization reaction system (42') that produces iso-oligomers by a distillation purification system (43') that introduces the iso-oligomers and separates iso-oligomers having 6 to 16 carbon atoms by distillation; a light olefin recycle pipe (45') that recycles and supplies residual light olefins (C2 to C5 olefins) to the oligomerization reaction system (42'); and a hydrogenation system (44') that introduces the C6 to C16 iso-oligomers and hydrogenates them to produce a biojet fuel (90') consisting of isoparylene having 6 to 16 carbon atoms.

[0162] (Biojet fuel production equipment) The production apparatus 100' of this embodiment is equipment for carbonizing biomass and includes a biomass receiver 11' that receives biomass 1' supplied from outside and a rotary kiln dryer 12' (dryer) that dries the biomass 1' received in the biomass receiver 11'. The biomass receiver 11' is equipped with a biomass supply device 91' that supplies the biomass 1' into the receiver 11' and a biomass supply amount adjustment means 80' that supplies the biomass 1' from the receiver 11' to the dryer 12'. The biomass supply amount adjustment means 80' is equipped with a means for adjusting the amount of biomass 1' supplied to the dryer 12' and for measuring the moisture content. The dryer 12' is connected to a carbonization furnace 20', and the dried biomass 1' from the dryer 12' is transferred to the carbonization furnace 20'.

[0163] The carbonization furnace 20' is equipped inside with a transfer device such as a screw-type biomass transfer facility and a heating section (not shown) that uses combustion gas as a heat source via a combustion gas piping 72'. The carbonization furnace 20' is equipped with a lower outlet for discharging the produced carbonized material 2' and an upper outlet for discharging the dry distillation gas generated in the carbonization furnace 20. The upper outlet is connected to an air combustion furnace 60' via a piping. A carbonized material supply piping is connected to the lower outlet, and the carbonized material can be introduced into the reforming gasification furnace 30' via a carbonized material supply amount regulator 81' and a carbonized material supply device 92' provided on the carbonized material supply piping.

[0164] The air combustion furnace 60' is configured to combust the dry distillation gas 5' (containing tar) generated in the carbonization furnace 20' with an air blower 41' to generate high-temperature combustion gas 6'.

[0165] Next, a reforming gasification furnace 30' that generates a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide by gasifying the carbide with steam and carbon dioxide will be described. The reforming gasification furnace 30' that performs reforming gasification generates a reformed gas 8' (H ２ , CO, CH ４ , CO ２The reforming gasification furnace 30' is configured to produce a mixture gas (a gas containing carbon dioxide). The reforming gasification furnace 30' includes an inner cylindrical portion 30a' and an outer cylindrical portion 30b' that surrounds the inner cylindrical portion. The inner cylindrical portion 30a' contains carbide 2'. A combustion gas pipe (reforming gasification furnace) 73' from the air-fuel furnace 60' is connected to the gap between the inner cylindrical portion 30a' and the outer cylindrical portion 30b, and heating combustion gas is supplied via the combustion gas pipe 73'. The inner cylindrical portion 30a' is heated by the combustion gas, and the carbide, water vapor, and carbon dioxide are heated by the heat from the inner cylindrical portion 30a', thereby progressing reforming gasification.

[0166] The reforming gasification furnace 30' has a steam supply pipe 33' for supplying steam to the inside thereof and a CO ２ The supply pipe 32' is connected to the CO ２ The supply pipe 32' is ２ A supply amount adjuster 83' is provided to adjust the amount of CO supplied to the reforming gasification furnace 30'. ２ The steam supply pipe is provided with a steam heat exchanger 31' and a steam supply amount regulator 84', which regulate the temperature and amount of steam supplied to the reforming-gasification furnace 30'.

[0167] The production apparatus 100' of this embodiment includes a separation and recovery means for separating and recovering from the reformed gas a metal-containing residue generated together with the reformed gas in the reforming-gasification furnace 30', and an introduction means for introducing the metal-containing residue recovered by the separation and recovery means into the biomass introduced into the carbonization furnace 20'. Specifically, a reformed gas pipe 35' is connected to the upper part of the reforming-gasification furnace 30', and the reformed gas is discharged via a reformed gas supply device 93'. The reformed gas is transported to a dust collector 34'. A gas purifier 36', a reformed gas supply regulator 86', a gas mixture preparer 89', and a pressurized gas circulation system 88' are connected to the dust collector 34' via pipes, and the reformed gas is introduced into the olefin production facility 50'. The gas purifier 36' is configured to remove sulfur- and chlorine-containing components from the reformed gas, and a known gas adsorbent such as that described above is used. The reformed gas discharged from the dust collector 34' is pressurized by a pressurized gas circulation system 88' such as a pressure booster to reach the reaction pressure required in the olefin production facility 50'.

[0168] The dust collector 34' is equipped with a metal-containing residue separation and recovery facility 94' that separates and recovers the metal-containing residue contained in the reformed gas from the reformed gas. A metal-containing residue receiver 38' that stores the metal-containing residue after separation and recovery in the dust collector 34' is connected via a metal-containing residue discharge pipe 39'. A metal-containing residue supply facility 37' that transfers the recovered metal-containing residue to the biomass receiver 11' is connected to the metal-containing residue receiver 38'. A metal-containing residue supply amount adjuster 82' is connected to the metal-containing residue supply facility 37' and is configured to adjust the amount of metal-containing residue supplied to the biomass receiver 11'.

[0169] Next, a C2-C4 olefin production facility 50' (hereinafter also referred to as an olefin production facility) for producing olefins having 2 to 4 carbon atoms from a reformed gas will be described. The above-described composite catalyst 63' is disposed inside the olefin production facility 50' so as to be able to come into contact with the reformed gas introduced therein. The olefin production facility 50' is also provided with an internal cooling device 56' for adjusting the temperature inside the facility to a temperature suitable for the reaction. The composite catalyst 63' is supplied to the olefin production facility 50' from a catalyst mixture preparer 57', which prepares the composite catalyst 63' by mixing a methanol synthesis catalyst 58' and a mesoporous catalyst 59', via a catalyst mixture adjuster 95' and a composite catalyst supply pipe 62'.

[0170] The olefin production facility 50' is configured to separate olefins generated as a result of the reaction therein and transfer the olefins to the oligomerization reaction facility 42' via a distillation separator 52'. A reaction gas pipe 77' is connected to the distillation separator 52' ​​and transfers gas containing carbon monoxide and methane separated from the olefins to a shift reaction hydrogen production facility 53'.

[0171] Next, we will explain the oligomerization reaction equipment that oligomerizes olefins having 2 to 4 carbon atoms to produce iso-oligomers having 6 to 16 carbon atoms. The oligomerization reaction equipment 42' is configured to oligomerize olefins introduced into the equipment via a C2-C4 olefin piping 47' to produce iso-oligomers having 6 to 16 carbon atoms. The oligomerization reaction equipment 42' contains the oligomerization catalyst described above, and is equipped with a heating and pressurizing device that can adjust the temperature, pressure, and other conditions to be appropriate for the oligomerization reaction. The oligomerization reaction equipment 42' is connected to a C6-C16 iso-oligomer piping 48' that transfers the iso-oligomers produced by the reaction to a hydrogenation equipment 44' via a distillation purification equipment 43'.

[0172] Next, we will explain the hydrogenation equipment 44' that hydrogenates the iso-oligomers to produce isoparaffins and then produces a biojet fuel containing the isoparaffins. The hydrogenation equipment 44' contains the hydrogenation catalyst described above and is equipped with a heating and pressurizing device that can adjust the temperature, pressure, and other conditions to be appropriate for the hydrogenation reaction. The hydrogenation equipment 44' produces a biojet fuel 90' consisting of C6 to C16 isoparaffins, which is then discharged from a C6 to C16 isoparaffin pipe 49'.

[0173] [Hydrogen and Carbon Dioxide Circulation Equipment] Of the fuel production apparatus of this embodiment, equipment for circulating hydrogen and carbon dioxide produced during the production of biojet fuel will be described. The biojet fuel production apparatus 100' of this embodiment further includes a shift reaction hydrogen production equipment 53' that produces hydrogen and carbon dioxide by reacting carbon monoxide and methane in the reaction gas generated in the olefin production equipment 50' with steam. The inclusion of such a shift reaction hydrogen production equipment 53' is optional. The shift reaction hydrogen production equipment 53' is configured so that light gas containing carbon monoxide and methane, which has been separated from the C2-C4 olefins in the distillation separator 52' ​​from the reaction gas discharged from the olefin production equipment 50', is introduced into the shift reaction hydrogen production equipment 53' via the distillation separator 52'. A shift reaction hydrogenation catalyst is disposed inside the shift reaction hydrogen production equipment 53', and the shift reaction hydrogen production equipment 53' is configured to generate a mixed gas containing hydrogen and carbon dioxide by the shift reaction described above. The shift reaction hydrogen production equipment 53' includes a H 2 O 4 catalyst that transfers the generated mixed gas to the gas separation and purification equipment 54'. ２ / CO ２ A gas pipe 64' is connected.

[0174] The gas separation and purification equipment 54' separates CO from the mixed gas generated in the shift reaction hydrogen production equipment 53'. ２ and CO ２ CO 2 is introduced into the reforming gasification furnace 30' via a supply regulator 83'. ２A supply pipe 32' is provided. As the gas separation and purification equipment 54', a separation device such as a PSA (Pressure Swing Adsorption) gas separation device or a ceramic membrane gas separation device is used.

[0175] The hydrogen separated in the gas separation and purification equipment 54' is transferred to the hydrogen holder 55' via the hydrogen supply pipe 79'. The hydrogen holder 55' is connected to the gas mixture preparer 89' and the water electrolysis equipment 40'. The water electrolysis equipment 40' electrolyzes the clean water 4' to generate hydrogen. The hydrogen generated in the water electrolysis equipment 40' is transferred to the hydrogen holder 55' via the hydrogen supply pipe 51' and the water electrolysis hydrogen supply regulator 87', and the H in the reformed gas is transferred to the hydrogen holder 55' via the hydrogen supply pipe 51' and the water electrolysis hydrogen supply regulator 87'. ２ Hydrogen is supplied to the gas mixture adjuster 89' to adjust the H / CO gas ratio. ２ It is configured to increase the CO / volume ratio.

[0176] [Equipment for Circulating Exhaust Heat Gas] Next, we will explain the equipment used to circulate the exhaust heat gas, which is provided to utilize the heat generated in the fuel production apparatus of this embodiment in each process. The biojet fuel production apparatus 100' of this embodiment is provided with multiple combustion gas pipes to utilize the heat generated in each process as exhaust heat gas for heating within the apparatus. The multiple combustion gas pipes of this embodiment are composed of pipes that transport the combustion gas 6' generated by the air-fuel furnace 60', which combusts the dry distillation gas discharged from the carbonization furnace 20', to each device. The multiple combustion gas pipes include a combustion gas pipe 71' that supplies combustion gas to the dryer 12' via a combustion gas pipe 70' connected to the air-fuel furnace 60' and a combustion gas flow regulator 61', a combustion gas pipe 72' that supplies combustion gas to the carbonization furnace, a combustion gas pipe 73' that supplies combustion gas to the reforming-gasification furnace 30', a combustion gas pipe 75' that supplies combustion gas to the olefin production facility 50', a combustion gas pipe 96' that supplies combustion gas to the oligomerization reactor, a combustion gas pipe 97' that supplies combustion gas to the hydrogenation reactor, and a combustion gas pipe 76' that supplies combustion gas to the shift reaction hydrogen production facility 53'. Also included is a combustion gas pipe 74' that supplies combustion gas generated in the reforming-gasification furnace 30' to the steam heat exchanger 31'. This configuration for transferring combustion gas to each device allows the high-temperature gas generated in the device 100' of this embodiment to be recycled and reused for heating each device.

[0177] The method for producing biojet fuel using the biojet fuel production apparatus 100' of this embodiment may be a method similar to the production methods in the first and second embodiments. Furthermore, the production method may use all or some of the functions of the production apparatus 100' of this embodiment. In other words, the embodiment of the production method and the embodiment of the production apparatus are shown as separate and distinct embodiments.

[0178] The gas production method and production 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.

[0179] Furthermore, the method and apparatus for producing biojet fuel according to this embodiment have been 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 is intended to include all modifications within the meaning and scope of the claims.

[0180] 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.

[0181] (Test 1) A hydrogen production test was conducted using the apparatus 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.

[0182] The test method was as follows: Sewage sludge (80% by mass moisture content) 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 carried out at a carbonization furnace temperature of 250 to 450°C. Reformed gasification was carried out using a steam / carbonized material (mass ratio) of 1.5 and CO ２The shift reaction hydrogen production process was carried out under conditions of a molar ratio of 0.5 to carbide 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 in the presence of a composite catalyst in which Fe, Ru, Ni, Cu, Zn, Mg, Zr, Ti, and Ce were supported on a porous oxide. The metal-containing residue separated and recovered in a cyclone dust collector was fed into a dryer at a rate of 3 kg per hour.

[0183] Reformed gas component composition and CO, hydrogen, CO in the outlet gas of the shift reaction hydrogen production unit ２ The concentrations of CH4 and other components were measured using a thermal conductivity gas chromatograph analyzer (Shimadzu GC-14B) and an FID gas chromatograph analyzer (Shimadzu GC-8A) filled with Gaskuropack and molecular sieve 13X. 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 ICPS-8100) and an X-ray fluorescence analyzer (Hitachi High-Tech EA1400). The metal contents of the metal-containing residue obtained in this test were 35 g / kg of Na, 85 g / kg of K, 46 g / kg of Ca, 27 g / kg of Mg, 5 g / kg of Ba, 7.5 g / kg of Fe, and 3.8 g / kg of Ni. The results are shown in Table 1.

[0184] Note 1) Modified gasification process: Steam / carbonized material = 1.5 (weight ratio), CO ２ / Carbide = 0.5 (mole ratio), reaction temperature 860°C Note 2) Hydrogen purity 99.8%

[0185] These results show that the production amounts of reformed gas and hydrogen using sewage sludge and construction waste materials as raw materials are significantly improved when the metal-containing residue is recycled and supplied (Example 1) compared to when it is not recycled and supplied (Comparative Example 1).

[0186] (Test 2) Using sewage sludge and rice straw from agricultural waste, a test of carbonization, reformed gasification, and hydrogen production was conducted in the same manner as in Test 1. 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. Carbonization was carried out at a carbonization furnace temperature of 250 to 420°C. The reformed gasification process of the carbonized material was carried out at a temperature of 900°C with a steam / carbonized material (mass ratio) of 1.7 and CO ２ Water vapor and CO at a molar ratio of 0.35 / carbon ２ 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 the mixed supply condition of steam / carbide = 1.7, and in Comparative Example 2, which was carried out under the condition of steam alone supply at a steam / carbide = 1.7.

[0187] 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 at a rate of 5 kg per hour into a dryer for sewage sludge and rice straw raw materials, and carbonized. The metal contents of the metal-containing residue obtained in this test were 23 g / kg Na, 65 g / kg K, 50 g / kg Ca, 15 g / kg Mg, 2.5 g / kg Ba, 0.5 g / kg Li, 8.2 g / kg Fe, and 2.5 g / kg Ni. The results are shown in Table 2.

[0188]

[0189] From these results, it is clear that the amount of water vapor and CO2 generated during the reforming gasification process of charcoal made from sewage sludge and rice straw is ２ It was shown that the amounts of reformed gas and hydrogen produced under the mixed supply condition (Example 2) were significantly increased compared to the condition where only steam was supplied (Comparative Example 2).

[0190] (Test 3) A test was conducted to produce jet fuel using the biojet fuel production system configured as shown in Figure 2. In this test, sewage sludge and organic waste as biomass were fed into a dryer and a carbonization furnace, and carbonization was carried out in the carbonization furnace, reforming gasification reaction in the reforming gasification furnace, 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. The recovered hydrogen was supplied to the reformed gas to produce H２ The reformed gas composition was adjusted to a CO / CO ratio of 2.5 (volume ratio). Carbon dioxide separated in the gas separator was recycled and supplied to the reforming gasifier. Metal-containing residue separated and recovered in the cyclone dust collector was recycled and supplied to a dryer for sewage sludge and organic waste. Experimental results for the carbonization rate, reformed gas production amount, gas composition (volume %), and biojet fuel production amount when the metal-containing residue was recycled and not supplied to the sewage sludge and organic waste are shown in Example 3 and Comparative Example 3.

[0191] The specific test method is as follows: Sewage sludge (80% by mass moisture content) 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 carried out at a carbonization furnace temperature of 250 to 450°C. Reformed gasification was carried out with a steam / carbonized material (mass ratio) of 1.5 and CO ２ The experiment was carried out under conditions of a molar ratio of 0.5 to carbide and a temperature of 860°C. The shift reaction hydrogen production process was carried out at a temperature of 450°C and a pressure of 3.5 MPa using a shift reaction hydrogen production catalyst prepared by supporting Fe, Ru, Ni, Cu, Zn, Mg, Zr, Ti, and Ce on a porous oxide. The metal-containing residue separated and recovered in a cyclone dust collector was fed at a rate of 3 kg per hour into a kiln-type dryer that mixed sewage sludge and construction waste chips. The olefin production process using the reformed gas in this test was carried out using a composite catalyst prepared by mixing a methanol synthesis catalyst (Cu / ZnO) and a mesoporous catalyst (SAPO-34). The reaction conditions were 380°C and 2.5 MPa. The olefin oligomerization reaction was carried out at a temperature of 120 to 250°C and a pressure of 2.5 to 5 MPa. Hydrogenation after the oligomerization reaction was carried out under reaction conditions of 0.1 to 2.5 MPa and 250 to 450°C. The reformed gas component composition and the CO, hydrogen, and CO in the outlet gas of the shift reaction hydrogen production unit ２ , C.H. ４The concentrations of these and other components were measured using a thermal conductivity gas chromatograph analyzer (Shimadzu GC-14B) and an FID gas chromatograph analyzer (Shimadzu GC-8A) filled with Gaskuropack and molecular sieve 13X. 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 ICPS-8100) and an X-ray fluorescence analyzer (Hitachi High-Tech EA1400). The metal contents of the metal-containing residue obtained in this test were 35 g / kg of Na, 85 g / kg of K, 46 g / kg of Ca, 27 g / kg of Mg, 5 g / kg of Ba, 7.5 g / kg of Fe, and 3.8 g / kg of Ni. The yield of biojet fuel in the table indicates the weight (per hour) of liquid oil consisting of C6 to C16 isoparaffins obtained after hydrogenation. The results are shown in Table 3.

[0192] Note 1) Reformed gasification process: steam / carbide = 1.5 (weight ratio), CO ２ / Carbide = 0.5 (mole ratio), reaction temperature 860°C

[0193] From these results, the production volume of reformed gas (Nm ３ It was shown that the production capacity (kg / h) and the production rate (kg / h) of biojet fuel consisting of C6 to C16 isoparaffins were significantly improved when the metal-containing residue was recycled and supplied (Example 3) compared to when it was not recycled and supplied (Comparative Example 3).

[0194] (Test 4) Using sewage sludge and rice straw from agricultural waste as biomass, tests of carbonization, reformed gasification, and biojet fuel production were conducted in the same manner as in Test 3. 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. Carbonization was carried out at a carbonization furnace temperature of 250 to 420°C. The reformed gasification process of the carbonized material was carried out at a temperature of 900°C with a steam / carbonized material (mass ratio) of 1.7 and CO ２ Water vapor and CO at a molar ratio of 0.35 / carbon ２Table 4 shows the reformed gas production amount, reformed gas component composition, and biojet fuel production amount measured in Example 4, which was carried out under the mixed supply condition of steam / carbide = 1.7, and in Comparative Example 4, which was carried out under the condition of steam alone at a steam / carbide ratio of 1.7.

[0195] 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 composed of Ru, Cu, Cr, K, Li, La, and Nd supported on a porous oxide. In this test, the olefin production process using the reformed gas was carried out under the reaction conditions of 380°C and 2.5 MPa, using a composite catalyst consisting of a methanol synthesis catalyst (Cu-Pd / ZnO) and a mesoporous catalyst (ZMS-11). The olefin oligomerization reaction was carried out at 120-250°C and 2.5-5 MPa. Hydrogenation after the oligomerization reaction was carried out at 0.1-2.5 MPa and 250-450°C. The metal-containing residue separated and recovered in the cyclone dust collector was mixed and fed at a rate of 5 kg per hour into a dryer for sewage sludge and rice straw as raw materials, and carbonization was performed. The metal contents of the metal-containing residue obtained in this test were 23 g / kg Na, 65 g / kg K, 50 g / kg Ca, 15 g / kg Mg, 2.5 g / kg Ba, 0.5 g / kg Li, 8.2 g / kg Fe, and 2.5 g / kg Ni. The results are shown in Table 4.

[0196]

[0197] From these results, it is clear that the amount of water vapor and CO2 generated during the reforming gasification process of charcoal made from sewage sludge and rice straw is ２ Reformed gas (Nm) under mixed supply conditions (Example 4) ３ / h) and the production amount of biojet fuel (kg / h) were shown to be significantly increased compared to the condition where only steam was supplied (Comparative Example 4).

[0198] 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.

[0199] Furthermore, in the present invention, in the carbonization process using biomass, the method for producing reformed gas and biojet fuel, and the biojet fuel production apparatus, the production efficiency of reformed gas and biojet fuel can be improved by recycling the metal-containing residue from the reformed-gasification process back to the biomass and by recycling the carbon dioxide emitted in the shift reaction hydrogen production process back to the reformed-gasification furnace, thereby reducing the production cost of biojet fuel and the environmental load by reducing carbon dioxide emissions.

Claims

1. A gas production method comprising: 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, 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.

2. The method for producing a gas according to claim 1, 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.

3. The gas production method according to claim 1 or 2, further comprising 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.

4. The gas production method according to claim 3, wherein carbon dioxide is produced together with hydrogen in the shift reaction hydrogen production step, and the produced carbon dioxide is separated from the hydrogen and introduced into the reforming gasification step.

5. The gas production method according to claim 3, 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.

6. A method for producing a gas according to claim 1 or 2, in which the dry distillation gas generated together with the carbonized material in the carbonization process is combusted with air and introduced into at least one of the carbonization process and the reformed gasification process, and used as exhaust heat gas.

7. A method for producing gas as described in claim 3, in which the dry distillation gas generated together with the carbonized material in the carbonization process is 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.

8. A gas production device comprising: 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; piping equipment that introduces carbon dioxide into the reforming gasification furnace; recovery equipment that separates and recovers metal-containing residue generated in the reforming gasification furnace from the reformed gas; and mixing equipment that mixes the recovered metal-containing residue with the sewage sludge and organic waste.

9. A gas production apparatus as described in claim 8, comprising: 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 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.

10. The gas production system according to claim 8, further comprising a shift reaction hydrogen production facility for producing hydrogen by reacting carbon monoxide and methane in the reformed gas generated in the reforming gasification furnace with steam.

11. A gas production apparatus as described in claim 10, comprising: 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 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.

12. A gas production apparatus as described in claim 9 or 11, comprising: 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.

13. A gas production apparatus according to claim 10 or 11, wherein the shift reaction hydrogen production equipment further comprises a booster that pressurizes the reformed gas therein 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.

14. The gas production apparatus according to claim 13, further comprising 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.

15. A method for producing biojet fuel, comprising: a carbonization step of carbonizing biomass to produce a carbonized product; a reformed-gasification step of gasifying the carbonized product with steam and carbon dioxide to produce a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide; an olefin production step of contacting the reformed gas with a methanol synthesis catalyst and a mesoporous catalyst to produce olefins having 2 to 4 carbon atoms; an oligomerization reaction step of oligomerizing the olefins to produce iso-oligomers having 6 to 16 carbon atoms; a hydrogenation step of hydrogenating the iso-oligomers to produce isoparaffins, and producing a biojet fuel containing the isoparaffins; and a separation and recovery step of separating and recovering from the reformed gas a metal-containing residue generated together with the reformed gas in the reformed-gasification step, and mixing the recovered metal-containing residue with the biomass.

16. The method for producing biojet fuel according to claim 15, 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.

17. The method for producing biojet fuel according to claim 15 or 16, wherein the olefin production step includes a separation step in which the reformed gas is brought into contact with a methanol synthesis catalyst and a mesoporous catalyst to generate a reaction gas, and the reaction gas is separated into a mixed gas containing carbon monoxide and methane and olefins having 2 to 4 carbon atoms.

18. A method for producing a biojet fuel according to claim 15 or 16, further comprising a shift reaction hydrogen production process in which carbon monoxide and methane in the reaction gas generated in the olefin production process are reacted with steam to produce hydrogen and carbon dioxide.

19. The method for producing biojet fuel according to claim 18, wherein carbon dioxide generated in the shift reaction hydrogen production process is introduced into the reformed gasification process, and hydrogen generated in the shift reaction hydrogen production process is mixed with the reformed gas obtained from the reformed gasification process.

20. The method for producing biojet fuel according to claim 18, wherein the shift reaction hydrogen production step uses a shift reaction 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.

21. A method for producing a biojet fuel as described in claim 15 or 16, in which the dry distillation gas generated together with the carbonized material in the carbonization process is combusted and introduced into at least one of the carbonization process, the reforming gasification process, the steam heat exchange process, the olefin production process, and the oligomerization reaction process.

22. A method for producing a biojet fuel as described in claim 18, wherein the dry distillation gas generated together with the carbonized material in the carbonization process is combusted and introduced into at least one of the carbonization process, the reforming gasification process, the steam heat exchange process, the shift reaction hydrogen production process, the olefin production process, and the oligomerization reaction process.

23. The method for producing biojet fuel according to claim 15 or 16, wherein the methanol synthesis catalyst comprises at least one element selected from the group consisting of copper, zinc, chromium, manganese, scandium, lithium, sodium, potassium, cesium, magnesium, barium, platinum, palladium, iridium, molybdenum, tungsten, vanadium, zirconium, hafnium, titanium, yttrium, cerium, and lanthanum, and a porous carrier.

24. A method for producing a biojet fuel according to claim 15 or 16, wherein the mesoporous catalyst comprises a porous support made of mesoporous zeolite and a mesoporous clay mineral.

25. A method for producing biojet fuel according to claim 15 or 16, wherein the olefin production step uses a composite catalyst prepared by mixing the methanol synthesis catalyst and the mesoporous catalyst, and the volume ratio of the methanol synthesis catalyst to the mesoporous catalyst in the composite catalyst is 0.1 to 5.

26. A biojet fuel production system comprising: a carbonization furnace for introducing biomass and producing a carbonized product; a reforming-gasification furnace for introducing the carbonized product from the carbonization furnace and subjecting it to a gasification reaction with water vapor and carbon dioxide to produce a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide; an olefin production facility for introducing the reformed gas from the reforming-gasification furnace and bringing it into contact with a methanol synthesis catalyst and a mesoporous catalyst to produce olefins having 2 to 4 carbon atoms; an oligomerization reaction facility for introducing the olefins and subjecting them to an oligomerization reaction to produce iso-oligomers having 6 to 16 carbon atoms; and a hydrogenation facility for introducing the iso-oligomers produced in the oligomerization reaction facility and hydrogenating them to produce a biojet fuel containing isoparaffins; a separation and recovery means for separating and recovering from the reformed gas a metal-containing residue generated together with the reformed gas in the reforming-gasification furnace; and a means for introducing the metal-containing residue recovered by the separation and recovery means into the biomass.

27. The biojet fuel production apparatus according to claim 26, further comprising a shift reaction facility that reacts carbon monoxide and methane in the reaction gas generated in the olefin production facility with steam to produce hydrogen and carbon dioxide.

28. The biojet fuel production device according to claim 26 or 27, wherein the olefin production facility is equipped with a separation means for separating the generated reaction gas into olefins having 2 to 4 carbon atoms and a gas containing carbon monoxide and methane.

29. The biojet fuel production apparatus according to claim 27, wherein the shift reaction facility is equipped with a transfer means for transferring the produced carbon dioxide to the reforming gasification furnace.

30. A biojet fuel production apparatus as described in claim 26, comprising a combustion device that burns the dry distillation gas discharged from the carbonization furnace, the combustion device comprising a supply means that supplies the combusted gas as a heating gas to at least one of the carbonization furnace, the reforming gasification furnace, the olefin production equipment, the oligomerization reaction equipment, and the hydrogenation equipment.

31. A biojet fuel production apparatus as described in claim 27, comprising a combustion device that combusts the dry distillation gas discharged from the carbonization furnace, the combustion device comprising a supply means that supplies the combusted gas as a heating gas to at least one of the carbonization furnace, the reforming gasification furnace, the olefin production equipment, the oligomerization reaction equipment, the hydrogenation equipment, and the shift reaction equipment.

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