Method for producing ethanol and apparatus for producing ethanol

Abstract

Conventional thermal decomposition and carbonization technologies for plastics have resulted in inefficient and uniform carbonization of plastics, leading to low carbonization rates of the carbides and low yields of reformed gas during gasification of the carbides. Consequently, ethanol could not be efficiently and stably obtained in ethanol production processes using the reformed gas. [Solution] The present invention provides an ethanol production method and apparatus comprising: a carbonization step of co-carbonizing plastic and biomass to produce a carbide; a reforming gasification step of generating a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide through a mixed gasification reaction of the carbide with water vapor and carbon dioxide; and an ethanol production step of supplying the reformed gas to an ethanol production step and producing ethanol by contacting it with a C2 oxygenation catalyst and a hydrogenation catalyst in the ethanol production step; separating and recovering a metal-containing residue generated together with the reformed gas in the reforming gasification step, and mixing the recovered metal-containing residue with the plastic and biomass.

Description

[Technical Field]

[0001] This invention relates to a method for producing ethanol and an apparatus for producing ethanol. [Background technology]

[0002] Plastic waste (hereinafter also referred to as waste plastic) is generated in large quantities as household and industrial waste, posing an environmental problem. In particular, micro-shredded waste plastic causes serious environmental damage to the survival of marine life. For this reason, there is a growing need for the development of technologies to reduce the volume of waste plastic and to recycle it.

[0003] Until now, waste plastics have generally been used as combustion fuel or disposed of as waste in landfills. In recent years, however, waste plastics have been converted into decomposed oil through high-temperature pyrolysis and into reformed gas (hydrogen (H2), carbon monoxide (CO), methane, and other lower hydrocarbons (C)) through pyrolysis gasification technology. n H 2n+2 Technologies have been developed for generating electricity using engines with a mixed gas containing carbon dioxide (CO2) and for producing carbides by the thermal decomposition and carbonization of plastics (see Patent Documents 1-2 and Non-Patent Documents 1-4).

[0004] On the other hand, direct gas production technology has been developed for organic biomass such as wood (cedar, pine, bamboo, etc.), agricultural waste (rice straw, bagasse, etc.), construction waste, sewage sludge, peat, cotton, paper, and food waste), which is directly reacted with steam, oxygen, or air at high temperatures to produce pyrolysis gas. Two-stage gasification technology has also been developed for biomass, which involves pyrolysis carbonization of the biomass and then reacting the resulting carbonized material with steam to produce reformed gas. The reformed gas produced by biomass gasification technology is a mixed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide. Known uses for reformed gas include gas engine power generation and the production of hydrogen, alcohols such as methanol and ethanol, and FT synthetic oil (see Patent Documents 3-5 and Non-Patent Documents 5-7). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2016-23240 [Patent Document 2] Japanese Patent Publication No. 2002-20533 [Patent Document 3] Japanese Patent Publication No. 2008-88434 [Patent Document 4] Patent No. 5342664 [Patent Document 5] International Publication No. 2020 / 166659 [Non-patent literature]

[0006] [Non-Patent Document 1] Narimitsu Kasaoka, Yusaku Sakata, Atsuyuki Mimura, Hideo Yamato, Production of Activated Carbon from Various Plastics, Journal of the Chemical Society of Japan, Vol. 10 (1976), pp. 1631-1640. [Non-Patent Document 2] Takayoshi Yagasaki, Yuji Kimura, and Kozo Sato, Characterization of carbides produced by carbonization treatment of plastic waste, Journal of the Japan Society for Environmental Systems Measurement and Control, Vol. 5, No. 2 (2000), pp. 119-124. [Non-Patent Document 3] Hattori, Masashi. Utilization Technology of Waste Plastics as Carbon Materials. Electric Steelmaking, Vol. 76, No. 1 (2005), pp. 27-32. [Non-Patent Document 4] Kenji Kato, Makoto Nomura, Koichi Fukuda, Hiroshi Uematsu, Hirotoshi Kondo, Chemical raw material conversion technology for waste plastics using a coke oven, Shin-Nippon Fe Technical Report, Vol. 384 (2006), pp. 69-73. [Non-Patent Document 5] Masaru Ichikawa (supervisor), "New Developments in Biomass Refinery Catalyst Technology," CMC Publishing (2011), pp. 70-77. [Non-Patent Document 6] Kenichi Sasauchi, Power Generation Utilization by Pyrolysis Gasification of Biomass, Journal of the Combustion Society of Japan, Vol. 47, No. 139 (2005), pp. 31-39. [Non-Patent Document 7] Katsushi Ichikawa, "New Developments in Hydrogen Energy Technology Utilizing Biomass Resources", Life and Environment, Vol. 61, No. 1 (2016), pp. 27-32

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in the conventional thermal decomposition carbonization technology of plastics, due to the inefficient and non-uniform progress of plastic carbonization, the carbonization rate of the carbide is low, the yield of reformed gas in the gasification of the carbide is low, and in addition, there is a technical problem that ethanol cannot be efficiently and stably obtained in the ethanol production process using the reformed gas.

[0008] The present invention has been made in view of the problems of the prior art as described above, and aims to increase the carbonization rate of the carbide obtained in the co-carbonization process using plastic and biomass, improve the yield of reformed gas by gasifying the carbide, and provide a method for producing ethanol and an ethanol production apparatus capable of efficiently and stably producing ethanol.

Means for Solving the Problems

[0009] The present invention has the following embodiments.

[0010] The ethanol production method of the present invention comprises a carbonization step of co-carbonizing plastic and biomass to produce carbide, and a reformed gasification step of producing a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide by a mixed gasification reaction of the carbide with water vapor and carbon dioxide.

[0011] The present invention further comprises an ethanol production step of supplying the reformed gas to an ethanol production process and contacting it with a composite catalyst prepared by mixing a C2 oxygenated catalyst and a hydrogenation catalyst in the ethanol production process to produce ethanol.

[0012] Separate and recover the metal-containing residue generated together with the reformed gas in the reforming gasification step from the reformed gas, and the recovered metal-containing residue may be mixed with the plastic and biomass. In the present invention, the supply of the metal-containing residue to the plastic and biomass may be performed continuously or intermittently a number of times.

[0013] The metal-containing residue may contain at least one element selected from the group consisting of alkali metals and alkaline earth metals including Na, K, Li, Ca, Mg, Ba, and B, Al, Fe, Ni.

[0014] A shift reaction hydrogen production step may be provided in which carbon monoxide, methane, and steam in the residual gas after separating the liquid product containing ethanol by a gas-liquid separator from the reaction gas generated in the ethanol production step are subjected to a shift reaction to produce hydrogen and CO2.

[0015] CO2 may be separated and recovered from the hydrogen and CO2 generated in the shift reaction hydrogen production step by gas separation equipment, the residual hydrogen may be supplied to the reformed gas, and the recovered CO2 may be supplied to the reforming gasification step.

[0016] In the shift reaction hydrogen production step, a shift reaction catalyst containing at least one element selected from the group consisting of Fe, Ru, Ni, Cu, Zn, K, Li, Mg, Cr, Co, Mo, Zr, Ti, Ce, La, and Nd and a porous oxide carrier may be used.

[0017] The dry distillation gas generated together with the carbide in the carbonization step may be burned in air, and the generated high-temperature exhaust gas may be used as a heat source for heating the carbonization step, the reforming gasification step, the steam heat exchange step, the shift reaction hydrogen production step, and the ethanol production step.

[0018] The C2 oxygenated catalyst may contain Rh and at least one element selected from the group consisting of Mn, Sc, Li, Na, K, Cs, Mg, Ba, Pt, Pd, Ir, Mo, W, V, Zr, Hf, Ti, Y, Ce, and La and a porous carrier.

[0019] The hydrogenation catalyst may include at least one element selected from the group consisting of Pd, Fe, Ni, Zn, Cr, Pt, Cu, K, Na, Ce, and Ti, and a porous support.

[0020] The ethanol production process may include a composite catalyst that physically mixes the C2 oxygenation catalyst and the hydrogenation catalyst, and the volume ratio of the C2 oxygenation catalyst to the hydrogenation catalyst in the composite catalyst may be 0.1 to 5.

[0021] The system may also include: a supply facility for plastics and biomass and means for adjusting the supply amounts thereof; a mixing dryer equipped with means for adjusting and controlling the biomass dryness to a predetermined degree and mixing and preparing the plastics and biomass; a carbonization furnace equipped with a temperature adjustment means; a carbonization supply facility and carbonization supply amount adjustment means for connecting and supplying the carbonized material to the reforming gasification furnace; a supply facility and supply amount adjustment means for supplying steam and carbon dioxide to the gasification furnace; a reforming gas supply facility for supplying the reformed gas to the ethanol production process; a gas purification facility and gas mixing adjustment facility and pressurized gas circulation facility for the reformed gas; a separation and recovery means for separating and recovering metal-containing residue generated together with the reformed gas in the reforming gasification process; a metal residue supply facility and metal residue supply amount adjustment means for supplying and mixing the recovered metal-containing residue with the plastics and biomass; and a catalyst mixing and preparation facility and catalyst mixing amount adjustment means for mixing and preparing a C2 oxygenation catalyst and a hydrogenation catalyst in the ethanol production process.

[0022] The system may also include a shift reaction hydrogen production process in which the reaction gas generated in the ethanol production process is separated into a liquid product containing ethanol using a gas-liquid separator, and then carbon monoxide and methane in the residual gas are shift-reacted with water vapor to produce hydrogen and CO2; a gas separation facility for separating and recovering CO2 from the generated hydrogen and CO2, and piping equipment and supply amount adjustment means for supplying the recovered CO2 to the reforming gasification furnace; piping equipment and hydrogen supply amount adjustment means for supplying residual hydrogen to a hydrogen holder; piping equipment and hydrogen supply amount adjustment means for supplying hydrogen generated in a water electrolysis facility to the hydrogen holder; piping equipment and hydrogen supply amount adjustment means for supplying hydrogen from the hydrogen holder to the reformed gas; pressurized and circulating supply equipment and reformed gas circulation amount adjustment means for contacting the reformed gas with the composite catalyst; pressurized and circulating supply equipment and supply amount adjustment means for contacting the reformed gas with the composite catalyst; and ethanol separation and purification equipment for separating and purifying ethanol from the liquid product containing ethanol.

[0023] The system may also include a combustion furnace for burning the carbonization gas generated in the carbonization furnace, and a heat exchanger for heating the steam introduced into the reforming gasification furnace, and may also include piping and gas flow rate adjustment means for supplying the combustion gas generated in the combustion furnace as heating gas to at least one of the mixing dryer, the carbonization furnace, the reforming gasification furnace, the steam heat exchanger, the shift reaction hydrogen production equipment, and the ethanol production process. [Effects of the Invention]

[0024] The present invention provides a method for producing ethanol and an ethanol production apparatus that can efficiently produce reformed gas by co-carbonizing plastic and biomass to improve the carbonization rate of the carbide, and subsequently produce ethanol economically and stably. [Brief explanation of the drawing]

[0025] [Figure 1] This is a schematic diagram of an ethanol production apparatus for carrying out an ethanol production method according to one embodiment of the present invention. [Modes for carrying out the invention]

[0026] In this specification, the "~" indicating a numerical range means that the values ​​before and after it are included as the lower and upper limits, respectively. Also, below, "Pressure Swing Adsorption" will be referred to as PSA. The reference numerals for raw materials, products, catalysts, equipment, machinery, and piping related to this embodiment are the same as those described in paragraph 0126 and Figure 1.

[0027] Figure 1 is a schematic diagram of an ethanol production apparatus 100 according to an embodiment of the present invention. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0028] Examples of plastic 1 (including waste plastics) include polyolefins such as polyethylene (PE) and polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyacrylonitrile (PAN), acrylic butadiene styrene resin (ABS, AS, etc.), phenolic resin, vinyl acetate resin, epoxy resin, polycarbonate, polyimide resin, melamine resin, polyurethane, organic polymer rubber, tires, organic polymer fibers, organic polymer paints, organic polymer adhesives, and organic polymer films. Plastic 1 may contain additives. The organic polymer material P may be a molded article or a crushed product obtained by crushing a molded article. The crushed plastic 1 is preferably 0.1 to 10 cm, and more preferably 1 to 5 cm.

[0029] Examples of biomass 2 (or biomass itself) include forest timber such as cedar, pine, and bamboo; agricultural waste and by-products such as rice straw, sugarcane, nepier, and sweet sorghum; organic waste such as sewage sludge, peat, construction waste, cotton, and textile products. Preferably, the biomass is obtained by compressing or crushing biomass produced or discarded in forestry or agriculture, and then drying the resulting pulverized material. The dimensions of the pulverized material are, for example, 10 to 100 mm. Biomass 2 may be used alone or in combination of two or more types.

[0030] Biomass 2 may contain, in addition to carbon, alkali metals and alkaline earth metals such as Na, K, Li, Cs, Ca, Mg, Ba, etc., as well as metals such as B, Al, Fe, and Ni. These metals may also be added and mixed. When these metals are present in biomass and plastic, it is preferable because they promote the co-carbonization reaction in the carbonization process of plastic and biomass, thereby generating reformed gas more efficiently in the subsequent reformed gasification process and increasing the amount of reformed gas produced.

[0031] In this embodiment, in order to include an appropriate amount of metal in the crushed chips of plastic 1 and biomass 2, in addition to adjusting the type and amount of plastic and biomass, a substance such as a metal compound that serves as a separate source of each of the above-mentioned metals may be mixed with the plastic and biomass. As such a metal source, it is preferable to use, for example, the metal-containing residue 4 that is generated together with the reformed gas 8 in the reformed gasification process. Such metal-containing residue is the residue that is separated and recovered from the reformed gas generated in the reformed gasification process. The metal-containing residue 4 may normally be recovered as solid matter such as metal oxides, carbides, and metal salts.

[0032] The timing for mixing the metal source, such as metal-containing residue, with the plastic 1 and biomass 2 is as follows: a mixing step may be provided before the carbonization process, or the metal-containing residue and / or metal source may be directly introduced into the carbonization furnace 20 that performs the co-carbonization process of the plastic and biomass. When mixing the metal-containing residue and / or metal source with the plastic and biomass before the carbonization process, for example, the metal-containing residue may be introduced into the receiving container 11 for the plastic 1 and the receiving container 12 for the biomass 2, or into the screw-type mixing dryer 13 that mixes and dries the biomass 2 and the plastic 1.

[0033] Methods for mixing metal-containing residue 4 with plastic 1 and biomass 2 include, for example, immersing and mixing biomass in a solution obtained by dissolving and dispersing a metal source such as metal-containing residue in an acid or alkaline aqueous solution, alcohol, ethers, or hydrocarbons, or adding the solution by spraying it onto the plastic and biomass to support the metal-containing residue on the plastic and biomass.

[0034] In the carbonization process of this embodiment, the inclusion of the metal and metal-containing residue 4 in the plastic 1 and biomass 2 promotes co-carbonization of the plastic and biomass, thereby increasing the carbonization rate of the carbonized product 3 and increasing the amount of carbonized product produced.

[0035] The metal content in the metal-containing residue is typically around 0.01 to 100 g, or 0.1 to 50 g, per 1 kg of metal-containing residue. The weight ratio of metal-containing residue 4 to plastic 1 and biomass 2 (metal-containing residue ÷ (plastic + biomass)) is typically in the range of 0.01 to 0.99, or 0.1 to 0.9. In this embodiment, the supply of metal-containing residue to plastic and biomass may be continuous or intermittent.

[0036] In embodiments of the present invention, when the weight ratio of metal-containing residue 4 to plastic 1 and biomass 2 is within the aforementioned range, the carbonization rate of the char in the co-carbonization process of plastic and biomass is significantly improved, and the tar removal rate tends to be superior. As a result of the increased carbonization rate, it becomes possible to increase the production volume of reformed gas and ethanol.

[0037] In this embodiment, the metal content of the metal-containing residue can be measured by ion chromatography, ICP emission spectrometry, and X-ray fluorescence analysis. The content of the metal element in the biomass body varies depending on the type of biomass body, but is approximately 0.01 to 2 g per 1 kg of biomass body.

[0038] [Co-carbonization process] In the method of this embodiment, a carbonization step is carried out to produce charred material 3 by co-carbonizing plastic 1 and biomass 2. In the co-carbonization step, the mixture of raw materials, plastic and biomass, is heated in a low-oxygen or oxygen-free state to cause thermal decomposition. By co-carbonizing the plastic and biomass, charred material and a carbonization gas 5 containing low-molecular-weight fuel gas and heavy component fuels such as tar are produced. The carbonization step of this embodiment is carried out using a carbonization furnace 20.

[0039] As the carbonization furnace, one can be appropriately selected from known carbonization furnaces. Examples include carbonization furnaces equipped with external or internal heating devices, and carbonization furnaces equipped with heating material transfer devices such as screws and rotary furnaces.

[0040] In this embodiment, the carbonization conditions for the co-carbonization process of plastic 1 and biomass 2 include, for example, a heating temperature of 200°C to 650°C, or 250°C to 550°C, and a residence time of 5 minutes to 100 minutes, or 10 minutes to 60 minutes. By co-carbonizing the raw materials, plastic and biomass, at these heating temperatures and times, carbonized material can be efficiently obtained.

[0041] In the carbonization process of this embodiment, the mass ratio of plastic 1 to biomass 2 (biomass / plastic) is preferably 0.05 to 10, and more preferably 0.1 to 5, in the production of carbonized material. If the mass ratio of biomass / plastic is within the above range, the carbonization rate of plastic and biomass will be higher. A higher carbonization rate will increase the amount of carbonized material produced, the amount of reformed gas produced, and the amount of ethanol produced. The raw materials, plastic and biomass, may be supplied to the carbonization furnace continuously or intermittently.

[0042] [Air combustion process of carbonized gas] In the manufacturing method of this embodiment, the carbonization gas 5 generated together with the carbonized material 3 in the co-carbonization process of the plastic 1 and biomass 2 may be separated from the carbonized material, recovered, and burned in air to produce a high-temperature combustion gas 6. This combustion gas 6 may be introduced into at least one of the carbonization process, the reforming gasification process described later, the steam heat exchanger, the ethanol production equipment, the shift reaction hydrogen production process, and the mixing dryer and used as waste heat gas for heating.

[0043] Specifically, since the carbonized gas 5 contains hydrogen, lower hydrocarbons, and heavy fuel components such as tar, it is transferred to an air combustion furnace 60 equipped with an air blower 41, and, for example, by combustion in an air atmosphere, a high-temperature (1000-1200°C) combustion gas 6 is obtained from which heavy fuel components such as tar have been removed. This combustion gas can be used as a heat source and transferred via various piping systems to each step of the manufacturing method of this embodiment, or to heating steps of other external systems such as biomass dryers, and used as waste heat gas for heating each step.

[0044] By using the heat from the combustion gas 6 as waste heat gas and cascading it for heating in each step of the manufacturing method of this embodiment, heating can be performed without using external fuel (heavy oil, electricity, etc.), or with a smaller amount of combustion gas generated by burning external fuel in air than in conventional methods. Steps in the manufacturing method of this embodiment that can utilize such waste heat gas include, for example, the mixing dryer for plastics and biomass, the carbonization step (heating of the carbonization furnace), the reforming gasification step (heating of the reforming gasification furnace), the steam heat exchanger, the ethanol production step, and the shift reaction hydrogen production step. This not only reduces the cost of reforming gas and ethanol production, but also improves the environment by reducing CO2 emissions and mitigating global warming.

[0045] [Reformed Gasification Process] The method of this embodiment includes a reforming gasification step in which the carbide 3 obtained in the carbonization furnace 20 is subjected to a mixed gasification reaction with water vapor 7 and carbon dioxide 9 in the inner cylinder 30a of a reforming gasifier 30 to produce a reformed gas 8 containing hydrogen, carbon monoxide, methane, and carbon dioxide (hereinafter also referred to as H2, CO, CH4, and CO2).

[0046] In the reforming gasification process of this embodiment, it is believed that reformed gas is produced by the following reforming gasification reaction between carbide, water vapor, and carbon dioxide. (1) Reaction of carbides with water vapor: [ka] (2) Reaction of carbides with carbon dioxide: [ka] (3) Shift reaction: [ka] (4) Methanation reaction: [ka]

[0047] In the reforming gasification process of this embodiment, the reactions (1) and (2) described above are particularly accelerated because carbon dioxide is supplied in a mixed manner along with water vapor. Therefore, the reformed gas can be produced efficiently. In this embodiment, by using carbon dioxide mixed with water vapor in the above reaction, it is possible to increase the amount of reformed gas produced by, for example, 1.2 to 2.5 times compared to reforming gas with water vapor or CO2 alone.

[0048] In this embodiment, the steam 7 used in the reforming gasification process can be generated by heating tap water 14, and this steam can be used. The carbon dioxide 9 used in the reforming gasification process in this embodiment may be introduced into the reforming gasifier from a system separate from the manufacturing method of this embodiment, or carbon dioxide 9 discharged from the shift reaction hydrogen production equipment 53, which will be described later, may be introduced into the reforming gasifier 30.

[0049] The amount of carbide supplied to the reforming gas furnace in the reforming gasification process of this embodiment can be adjusted as appropriate to efficiently produce reformed gas, but examples include 10 kg / h or more and 10,000 kg / h or less, or 50 kg / h or more and 5,000 kg / h or less. The amount of steam supplied to the reforming gas furnace can be adjusted as appropriate, but examples include 0.5 kg / h or more and 10 kg / h or less, or 2 kg / h or more and 5 kg / h or less, as the amount of steam supplied per 1 kg / h of carbide supplied. The amount of carbon dioxide supplied to the reforming gas furnace can be adjusted as appropriate, but examples include 0.1 Nm³ as the amount of carbon dioxide supplied per 1 kg / h of carbide supplied. 3 / h or more 10Nm 3 / h or less, or 0.5Nm 3 / h or more 5Nm 3 Examples include being less than or equal to / h. Furthermore, the ratio of the carbon dioxide supply to the total of the water vapor supply and carbon dioxide supply (CO2 supply ÷ (water vapor supply + carbon dioxide supply)) is, for example, between 1 volume% and 85 volume%, or between 10 volume% and 60 volume%, etc.

[0050] In the reforming gasification process of this embodiment, the temperature of the reforming gasification furnace can be adjusted as appropriate to efficiently produce the reformed gas, but for example, it can be between 800°C and 1000°C. As a means of heating the reforming gasification furnace, for example, the combustion gas obtained by burning the above-mentioned carbonization gas may be used as waste heat gas for heating.

[0051] The steam is heated in a heat exchanger, for example, by heating tap water 14 to a range of 350°C to 800°C, and then supplied to the reforming gasification furnace. When heating tap water using a heat exchanger or the like, the steam may be heated in the steam heat exchanger 31 via the exhaust heat gas piping 74 from the reforming gasification furnace 30.

[0052] The pressure of the reforming gasifier 30 in the reforming gasification process can be adjusted as appropriate, but for example, it can be set to between 0.05 MPa and 0.5 MPa.

[0053] The reformed gas 8 obtained in the reformed gasification process of this embodiment contains hydrogen (H2) and carbon monoxide (CO), and typically contains hydrogen (H2), carbon monoxide (CO), methane (CH4), and carbon dioxide (CO2).

[0054] [Separation and recovery process of metal-containing residue] In this embodiment, the metal-containing residue 4 generated together with the reformed gas 8 in the reformed gasification process may be separated from the reformed gas and recovered, and the recovered metal-containing residue 4 may be supplied to the plastic 1 and biomass 2. The embodiment may also include a separation and recovery process for metal-containing residue, discharge and supply equipment 37 and supply amount adjustment means 82.

[0055] In other words, in the reforming gasification process, the metal contained in the carbide 3 remains as metal-containing residue 4, and this metal-containing residue is separated from the reformed gas 8 and recovered. As a recovery method, for example, the reformed gas containing the metal-containing residue discharged from the reforming gasification furnace is separated from the metal-containing residue using a dust remover 34 such as a cyclone and a bag filter and a metal-containing residue separator and recoverer 94, and the separated metal-containing residue 4 is recovered.

[0056] The metal-containing residue 4 is recycled and supplied to the plastic receiver 11 and biomass receiver 12, the mixing dryer 13, or the carbonization furnace 20 before the carbonization process. By uniformly mixing the metal-containing residue with the plastic and biomass as described above, the carbonization rate of the plastic and biomass and the yield of carbonized material in the carbonization process of this embodiment can be increased, and in addition, the amount of reformed gas produced in the reformed gasification process can be increased. The effect of increasing the carbonization rate of the plastic and biomass and the amount of reformed gas produced may increase along with the number of recycling supplies of the metal-containing residue in this embodiment.

[0057] The metal-containing residue contains metals from the biomass, which are recovered as residue in the gasification process. Therefore, it contains at least one element selected from the group consisting of alkali metals and alkaline earth metals such as Na, K, Li, Ca, Mg, and Ba, and B, Al, Fe, and Ni. The metal-containing residue 4 may normally be recovered as solid matter such as metal oxides, carbides, and metal salts.

[0058] The reformed gas 8, from which metal-containing residue has been removed by the separation device 34, is transferred to the ethanol production process described later and used for ethanol production. It may also be used for other purposes, such as hydrogen production, methanol production, and power generation in gasification power plants.

[0059] [Gas purification process for reformed gas] The gas purification equipment 36 removes sulfur-containing components from the reformed gas. The reformed gas generated during the gasification of carbide C1 contains sulfur-containing substances such as hydrogen sulfide and COS. These sulfur-containing substances act as catalyst poisons and may reduce the catalytic activity and impair the stability of the ethanol production equipment. By removing the sulfur-containing components, the stability of the catalytic activity in the ethanol production equipment is improved.

[0060] The gas purification equipment 36 is preferably equipped with a gas purification member in which at least one metal selected from the group consisting of Cu, Zn, Cr, Ce, Fe, Mo, and Co is supported on a porous carrier such as silica, alumina, or zeolite. When such a gas purification member is brought into contact with the reformed gas, sulfur-containing components bind to the metal and the porous carrier and are chemically removed from the reformed gas.

[0061] However, the gas purification equipment 36 is not limited to those using the chemical methods described above. For example, other common technologies, such as gas purification techniques using gas adsorbents like activated carbon or various zeolites, can also be used in combination. Furthermore, the gas purification equipment may remove not only the sulfur-containing components but also nitrogen-containing components such as ammonia and NOx, and chlorine-containing components such as HCl.

[0062] [Ethanol manufacturing process] The ethanol production equipment 50 is equipped with a C2 oxygenation catalyst 58 and a hydrogenation catalyst 59. When the reformed gas 8 is brought into contact with the C2 oxygenation catalyst 58, C2 oxygenated compounds such as acetic acid, acetaldehyde, and ethanol are produced from H2, CO, CO2, and CH4 contained in the reformed gas. Derivatives of C2 oxygenated compounds such as methyl acetate and ethyl acetate may also be produced as by-products. When the hydrogenation catalyst 59 is brought into contact with the gas, acetic acid, acetaldehyde, methyl acetate, ethyl acetate, etc. are hydrogenated and efficiently converted into ethanol. This increases the amount of ethanol produced and also improves the selectivity of ethanol.

[0063] The C2 oxygenation catalyst 58 can be improved by combining various metal components in addition to Rh, depending on its intended use, thereby increasing the yield and selectivity of the C2 oxygenated product. For example, a catalyst containing Rh and at least one element selected from the group consisting of Mn, Sc, Li, Na, K, Cs, Mg, Ba, Pt, Pd, Ir, Mo, W, V, Zr, Hf, Ti, Y, Ce, and La (hereinafter also referred to as element (1)) can be used. The C2 oxygenation catalyst may contain two or more elements (1).

[0064] The atomic ratio of element (1) to Rh is preferably 0.001 to 10, and more preferably 0.01 to 5. Rh and element (1) may be supported on a carrier. Examples of carriers include porous oxides such as silica and alumina. The amount of Rh and element (1) supported is, for example, 0.01 to 10 mass%, preferably 0.1 to 5 mass%. Here, the amount of Rh and element (1) supported is the ratio of the total mass of Rh and element (1) to the mass of the carrier.

[0065] C2 oxygenation catalysts can be produced by known methods. For example, a catalyst precursor can be dissolved in a solvent, the resulting solution can be impregnated into a support, and the catalyst can be activated to obtain a C2 oxygenation catalyst. Examples of catalyst precursors include salts of Rh and salts of element (1). Examples of salts include hydrochloride salts, nitrates, formates, acetates, oxalic acid, citric acid, lactic acid, malate salts, alkoxide salts, and oxygenate salts.

[0066] Examples of solvents include ethanol, methanol, ethers, and water. Methods for activation include, for example, gradually increasing the temperature in the 250-600°C range in an oxygen-containing atmosphere, or gradually increasing the temperature in the 100-450°C range under a hydrogen gas atmosphere. In addition, as a hydrogen activation treatment, reduction treatment with reducing agents such as hydrazine or boron hydride may be performed.

[0067] The selection of catalyst precursors, catalyst manufacturing processes, and activation conditions are not limited to these.

[0068] When producing a C2 oxygenation catalyst in which Rh is supported on a carrier, a supporting method is recommended in which an Rh salt solution is applied to a porous carrier such as silica or alumina and then injected and permeated into the pores of the carrier. Preferred Rh solutions used in this process include, for example, rhodium chloride, rhodium nitrate solution, hexaamminerhodium acetate solution, or tetraamminerhodium hydroxylate solution.

[0069] When producing a C2 oxygenation catalyst in which Rh and element (1) are supported on a carrier, a mixed solution containing Rh and element (1) may be used, or a separate solution of element (1) may be applied to the porous carrier supporting Rh. The Rh solution and element (1) solution can be simultaneously or sequentially supported by methods such as immersion, dropwise addition, coating, or spraying within a predetermined temperature range.

[0070] Various types of hydrogenation catalysts 59 can be selected depending on their intended use. For example, a catalyst containing at least one element selected from the group consisting of Pd, Fe, Ni, Pt, Cu, Zn, Cr, K, Na, Ce, and Ti (hereinafter also referred to as element (2)) can be used. The hydrogenation catalyst may contain two or more elements (2). Element (2) may be supported on a support. Examples of supports include porous oxides such as silica and alumina.

[0071] Hydrogenation catalysts can be manufactured by known methods. For example, a hydrogenation catalyst can be obtained by dissolving a catalyst precursor in a solvent, impregnating a support with the resulting solution, and performing an activation treatment. Examples of catalyst precursors include salts of element (2). Examples of salts include hydrochloride salts, nitrates, oxalates, and oxyacid salts.

[0072] Examples of solvents include ethanol, methanol, and water. Methods of activation include, for example, gradually increasing the temperature in the 250-600°C range in an oxygen-containing atmosphere, or gradually increasing the temperature in the 100-450°C range under a hydrogen gas atmosphere. In addition, as a hydrogen activation treatment, reduction treatment with reducing agents such as hydrazine or boron hydride may be performed.

[0073] The selection of catalyst precursors, catalyst manufacturing processes, and activation conditions are not limited to these.

[0074] The C2 oxygenation catalyst 58 and the hydrogenation catalyst 59 may be arranged separately, but from the viewpoint of ethanol yield and ethanol selectivity, it is preferable to prepare a composite catalyst 63 in which the C2 oxygenation catalyst 58 and the hydrogenation catalyst 59 are physically mixed. In this embodiment, compared to the case in which the C2 oxygenation catalyst 58 and the hydrogenation catalyst 59 are packed into separate reactors, the amount of ethanol produced and the ethanol selectivity are improved when a composite catalyst 63 is prepared by mixing the C2 oxygenation catalyst 58 and the hydrogenation catalyst 59 in a catalyst mixing and preparing device 57 is used.

[0075] In the composite catalyst 63, the volume ratio of the C2 oxygenation catalyst 58 to the hydrogenation catalyst 59 (C2 oxygenation catalyst / hydrogenation catalyst volume ratio) is preferably 0.1 to 5, and more preferably 0.2 to 3. When the C2 oxygenation catalyst / hydrogenation catalyst volume ratio is above the lower limit of the above range, the yield of C2 oxygenated compounds is better, and when it is below the upper limit of the above range, the ethanol selectivity and ethanol production volume are better.

[0076] Next, the reformed gas 8 is pressurized in a booster in a booster gas circulation supply equipment 88 to a predetermined reaction pressure, and then continuously circulated and supplied to the ethanol production equipment 50. The reformed gas supplied to the ethanol production equipment comes into contact with a composite catalyst 63, which is a mixture of the C2 oxygenation catalyst 58 and the hydrogenation catalyst 59, to produce ethanol.

[0077] The reaction pressure in the ethanol production facility 50 is preferably 0.1 to 5 MPa, and more preferably 1 to 3.5 MPa. The reaction temperature is preferably 200 to 350°C, and more preferably 250 to 300°C. The airtime velocity of the biomass gas (SV: velocity of synthesis gas L / h / volume of catalyst L) is 1000 to 35000 h -1 Preferably, 3000-25000h -1 This is more preferable. In the ethanol production equipment 50 of this embodiment, for example, ethanol can be obtained with an ethanol selectivity of 50 to 85% and an ethanol yield (STY: kg / L (C2 oxygenation catalyst) / h) of 0.25 to 0.85 kg / L / h.

[0078] [Production of H2 and CO2] The reaction gas separated by the gas-liquid separator may be circulated and supplied to the ethanol production equipment via the pressurized gas circulation supply equipment 88. However, in this embodiment, the reaction gas (a mixed gas containing CO, methane, and CO2) may also be introduced into the shift reaction hydrogen production equipment 53 to produce H2 and CO2.

[0079] The shift reaction hydrogen production equipment 53 produces a mixed gas of H2 and CO2 by bringing the CO and methane in the reaction gas separated in the gas-liquid separator 52 into contact with a shift reaction hydrogen production catalyst in the presence of water vapor, as described below, through the shift reaction. [ka] [ka]

[0080] In this implementation, various types of shift reaction hydrogen production catalysts can be selected depending on their intended use. For example, a catalyst containing at least one element selected from the group consisting of Fe, Ru, Ni, Cu, Zn, K, Li, Mg, Cr, Co, Mo, Zr, Ti, Ce, La, and Nd (hereinafter also referred to as element (3)) can be used. The shift reaction hydrogen production catalyst may contain two or more elements (3). Element (3) may be supported on a carrier. Examples of carriers include porous oxides such as silica and alumina.

[0081] [CO2 supply] The mixed gas of H2 and CO2 generated in the shift reaction hydrogen production facility 53 may be separated into CO2 in the gas separation and purification unit 54, and the recovered CO2 may be supplied to the reforming gasification furnace 30 via the CO2 supply adjustment unit 84.

[0082] [Hydrogen supply] Residual hydrogen is supplied to the hydrogen holder 55 via the hydrogen supply pipe 79. The reformed gas 8 and hydrogen 10 may be gas-adjusted in the gas mixing regulator 89 and supplied to the ethanol production equipment. In this embodiment, by adjusting the H2 / CO mixing ratio of the reformed gas, which is preferable for ethanol production, via the gas mixing regulator, the amount of ethanol produced and the ethanol selectivity can be significantly improved.

[0083] The gas separation and purification equipment 54 separates CO2 from the mixed gas of H2 and CO2 generated in the shift reaction hydrogen production equipment 53. Examples of the gas separation and purification equipment 54 include a PSA type gas separator and a ceramic membrane type gas separator. Either one of these gas separators may be used, or both may be used.

[0084] In this embodiment, the water electrolysis equipment 40 is also connected to the hydrogen holder 55 via a hydrogen supply adjustment equipment 87. H2 discharged from the water electrolysis equipment 40 is supplied to the hydrogen holder 36. Commercially available electricity can be used as the power source for the water electrolysis equipment, but it is preferable to use electricity obtained from renewable energy sources such as solar and wind power generation, as well as nuclear reactor power generation, for water electrolysis in order to reduce CO2 emissions in the ethanol production process.

[0085] The hydrogen holder 55 is connected to the gas mixing and adjusting unit 89 via hydrogen piping 79. Hydrogen supplied from the hydrogen holder 55, with the supply amount adjusted by the hydrogen supply rate regulator 85, is mixed and supplied to the reformed gas. This increases the hydrogen / CO volume ratio in the reformed gas 8, adjusting it to a preferred H2 / CO volume ratio of 1 to 3, more preferably 1.5 to 2.5, for the ethanol production process. The gas is then pressurized and circulated in the pressurized gas circulation equipment 88 and introduced into the ethanol production equipment 50 to carry out the ethanol production reaction.

[0086] [Ethanol purification process] In this embodiment, crude ethanol separated in the gas-liquid separator 52 is purified via an ethanol separation and purification facility 56 equipped with a distillation column and a membrane separator. The distillation column concentrates and separates ethanol from the ethanol liquid product (crude ethanol), and also separates and recovers low-boiling point by-product residues such as acetic acid, acetaldehyde, propanol, and methanol from the liquid product. The distillation column may be a known type, such as a multi-stage Raschig ring distillation column and a silicon membrane separator. In this embodiment, the ethanol concentration of the crude ethanol produced in the ethanol production facility 50 is, for example, 53-60% by weight. It is concentrated to 65-85% using a commercially available distillation column. For example, it can be separated and purified to an even higher ethanol concentration using a commercially available ceramic membrane separator. The ethanol concentration of the purified product is, for example, 86-99%.

[0087] [Ethanol production apparatus 100] The ethanol production apparatus 100 of this embodiment includes a carbonization furnace 20 that carbonizes plastic 1 and biomass 2 by co-carbonization to produce carbonized material 3, a plastic receiver 11 that receives plastic 1 from the outside and a biomass receiver 12 that receives biomass 2, a biomass supply rate regulator 80 equipped with means for adjusting the supply rate and measuring the water content for supplying biomass to the receiver 11, a plastic supply rate regulator 42, a screw-type mixing dryer 13 for mixing and drying plastic 1 and biomass 2, means for supplying carbonized material 3 to a reforming gasifier 30 connected to the carbonization furnace 20 via a carbonized material supply rate regulator 81 and a carbonized material supply equipment 92, an air combustor 60 that generates high-temperature combustion gas 6 by air combustion of carbonization gas 5 (including pyrolysis light gas and tar) generated in the carbonization furnace 20 with an air blower 41, and a reforming gas 8 (H2, CO, C) of carbonized material 2 by a mixed gasification reaction with water vapor 7 and CO2 9. A reforming gasifier 30 that produces a mixed gas of H4 and CO2, a first steam supply pipe 33 that supplies steam to the reforming gasifier 30, a CO2 supply pipe 32 that supplies CO2 to the reforming gasifier 30, a dust collector 34 that separates and recovers metal-containing residue 4 from the reformed gas 8 discharged from the reforming gasifier, a metal-containing residue separator and recoverer 94 that separates and recovers the metal-containing residue 4, and a system that circulates and supplies the metal-containing residue 4 to a plastic receiver 14 and a biomass receiver 11 to adjust the supply amount. The ethanol production apparatus comprises a metal-containing residue supply equipment 37 equipped with a regulating mechanism and a metal-containing residue supply amount regulator 82; a gas purifier 36 that removes sulfur-containing and chlorine-containing components from the reformed gas 8 obtained by separating and removing metal-containing residue 4 with a dust collector 34; a catalyst mixing and preparing equipment 57 that prepares a composite catalyst 63 by mixing the reformed gas with a C2 oxygenation catalyst 58 and a hydrogenation catalyst 59; and an ethanol production equipment 50 that produces ethanol by contacting the reformed gas with the composite catalyst 63.

[0088] Furthermore, the system includes a shift reaction hydrogen production facility 53 that generates hydrogen and CO2 by shift reaction between carbon monoxide and methane and water vapor in the residual reaction gas after separating the liquid product containing ethanol from the reaction gas generated in the ethanol production process using a gas-liquid separator 52, a gas separation and purification facility 54 that supplies the generated hydrogen and CO2 via an H2 / CO2 gas pipe 64, a CO2 supply pipe 32 and a CO2 supply rate regulator 83 that supply the separated and recovered CO29 from the gas separation and purification facility 54 to the reforming gasification furnace 30, and a water tank for separating the hydrogen 10. The ethanol production apparatus comprises a hydrogen supply pipe 79 that supplies hydrogen to a hydrogen holder 55, a hydrogen supply amount regulator 87 that supplies hydrogen generated in a water electrolysis equipment 40 to the hydrogen holder 55, a gas mixing and adjusting equipment 89 that mixes and supplies hydrogen from the hydrogen holder 55 to the reformed gas 8 via a hydrogen pipe 78, a gas circulation supply equipment 88 that pressurizes and circulates the reformed gas with the adjusted H2 / CO volume ratio, and an ethanol separation and purification equipment 56 that separates and purifies ethanol from the liquid product (crude ethanol) containing ethanol.

[0089] The reforming gasifier 30 produces reformed gas through a mixed gasification reaction of carbide 2 with steam and CO2. In this embodiment, the reforming gasifier 30 comprises an inner cylinder 30a and an outer cylinder surrounding an outer cylinder 30b. The carbide 2 is contained within the inner cylinder 30a. The inner cylinder is heated by supplying combustion gas 6 for heating into the gap between the inner cylinder and the outer cylinder, and the carbide 2, steam 7, and CO2 9 are heated by the heat from the inner cylinder, allowing the mixed reforming gasification process to proceed efficiently.

[0090] One end of the steam supply pipe 33 is connected to the bottom of the inner cylinder 30a of the gasification furnace 30. The other end of the steam supply pipe 33 is connected to the tap water 13 via the heat exchanger 31. A steam supply rate regulator 84 may be installed in the steam supply pipe 33.

[0091] One end of the CO2 supply pipe 32 is connected to the bottom of the inner cylinder 30a of the gasifier 30. The other end of the CO2 supply pipe 32 is connected to the gas separation equipment 54. A CO2 supply rate regulator 83 is also installed in the CO2 supply pipe 32. An example of the CO2 supply rate regulator 83 is a mass flow controller. The supply of CO2 to the gasifier 30 may be continuous or intermittent.

[0092] A reformed gas supply unit 93 and a reformed gas piping unit 35 are connected to the top of the reformed gasification furnace 30. The reformed gas piping unit 35 leads the reformed gas 8 out of the reformed gasification furnace 30. The reformed gas 8 can be supplied to the gas purification unit 36 ​​via a dust collection unit 34. The reformed gas is connected to the ethanol production unit 50 via the gas purification unit 36, a reformed gas supply rate regulator 86, a gas mixing and adjusting unit 89, and a pressurized gas circulation unit 88.

[0093] The dust collector 34, equipped with a metal-containing residue separator and recovery unit 94, is installed in the middle of the reformed gas piping 35, upstream of the gas purifier 36. From the reformed gasification furnace 30, metal-containing residue 4 is discharged along with the reformed gas. The dust collector 34 separates the reformed gas 8 from the metal-containing residue 4 and recovers the separated metal-containing residue 4. Since the metal-containing residue 4 contains useful metal elements derived from biomass, the recovered metal-containing residue 4 is fed into the biomass receiver 12 and the plastic receiver 11 via the metal-containing residue discharge pipe 39, the metal-containing residue supply amount regulator 82, and the metal-containing residue supply equipment 37 to be mixed and prepared with biomass and plastic.

[0094] The gas purification equipment 36 is installed in the middle of the reformed gas piping 35. Downstream of the gas purification equipment 36, a gas mixing and adjusting device 89 is installed via a reformed gas supply rate regulator 86.

[0095] Multiple combustion gas pipes supply combustion gas to waste heat utilization equipment via combustion gas pipe 70 and combustion gas flow regulator 61, including combustion gas pipe 71 which supplies combustion gas 6 generated by the air combustor 60 to the mixing dryer 12, combustion gas pipe 72 which supplies to the carbonization furnace, combustion gas pipe 73 which supplies to the reforming gasifier 30, combustion gas pipe 74 which supplies to the steam heat exchanger 31, combustion gas pipe 75 which supplies to the ethanol production equipment 50, and combustion gas pipe 76 which supplies to the shift reaction hydrogen production equipment 53.

[0096] According to the ethanol production method and production equipment of this embodiment, the carbonization rate and the amount of carbonized material produced in the co-carbonization process using plastic and biomass can be increased, as can the amount of reformed gas produced, and ethanol can be produced efficiently and stably thereafter.

[0097] Although the present invention has been described above with reference to examples of embodiments, the present invention is not limited to the above-described examples of embodiments, and can be freely modified within the scope of the present invention.

[0098] Test 1 was conducted to produce ethanol using plastic and biomass with an ethanol production apparatus 100 having the configuration shown in Figure 1. [Examples]

[0099] [Test 1] As plastic, 30 kg per hour of crushed plastic (PP+PET) consisting of 50% polypropylene (PP) containers and 50% PET bottles was added. As biomass, 20 kg per hour of construction waste chips was added. Carbonization was carried out under conditions of temperature 250-500°C. A mixed gasification reaction of carbon with water vapor and CO2 was carried out under conditions of water vapor / carbon (mass ratio) = 1.5, CO2 / carbon (molar ratio) = 0.5, and temperature 860°C. Ethanol production was carried out under conditions of temperature 285°C and pressure 2.5 MPa using a composite catalyst prepared by mixing C2 oxygen-containing catalyst 1 and hydrogenation catalyst 1.

[0100] [Example 1, Comparative Example 1] The production amount (kg-C / h) and carbonization rate (wt%) of carbide in the co-carbonization process using plastic and biomass in the carbonization furnace, the reformed gas production amount (Nm 3 / h) in the reformed gasification furnace, the reformed gas component composition (VOL%), and the ethanol production amount (kg / h) were measured. The experimental results of reformed gasification and ethanol production when the metal-containing residue (5 kg / h) separated and recovered by the cyclone dust collector was recycled and supplied to the receivers of plastic (PP + PET) and construction waste chips and when it was not supplied are shown in Example 1 and Comparative Example 1.

[0101] In this test, the analysis of the reformed gas component composition and the liquid components including CO, hydrogen, CO2, CH4 in the outlet gas of the shift reaction hydrogen production device and ethanol generated in the ethanol production facility was measured using a gas chromatograph packed with Gaskuropack and molecular sieve 13X, a thermal conductivity type gas chromatograph analyzer (GC-14B manufactured by Shimadzu Corporation), and an FID gas chromatograph analyzer (GC-8A manufactured by Shimadzu Corporation). The flow rate of the exhaust gas was measured by a wet gas flow meter.

[0102] The content of the metal elements in the metal-containing residue was measured by an ICP emission spectroscopic analyzer (ICPS-8100 manufactured by Shimadzu Corporation) and a fluorescent X-ray analyzer (EA1400 manufactured by Hitachi High-Tech Corporation). The metal content per 1 kg of the metal-containing residue obtained in this test is 25 g / kg of Na, 85 g / kg of K, 36 g / kg of Ca, 7.5 g / kg of Mg, 5 g / kg of Ba, 7.5 g / kg of Fe, and 1.8 g / kg of Ni.

[0103] [Preparation of C2 oxygenated catalyst 1] Chlorides or nitrates of Rh, Mn, V, Hf, Ir, and Ce were dissolved in a mixed solvent of ethanol and water so that the atomic ratio of each element was 1:0.25:0.2:0.1:0.3:0.1 to obtain an ethanol aqueous solution. This ethanol aqueous solution was used on a silica carrier (specific surface area 315 m 2After impregnation with ( / g), the material was heated to 150°C over 1 hour under a gas stream of hydrogen and nitrogen gas (1:3 volume ratio), held for 2 hours, heated to 450°C over 2 hours, held for 2 hours, and then cooled to room temperature in an activation treatment. This prepared C2 oxygenated catalyst 1 in which Rh, Mn, V, Hf, Ir, and Ce were supported on a silica support.

[0104] [Preparation of hydrogenation catalyst 1] Cu, Cr, Zn nitrate, Ti, and Mo chloride were dissolved in a mixed solvent of ethanol and water in an atomic ratio of Cu:Cr:Zn:Ti:Mo of 1:0.8:0.5:0.2:0.15 to obtain an aqueous ethanol solution. This aqueous ethanol solution was then used to prepare a silica support (specific surface area 365 m²). 2 After impregnation with ( / g), the material was heated to 100°C over 1 hour under a gas stream of hydrogen and nitrogen gas (1:2 volume ratio), held for 2 hours, heated to 450°C over 2 hours, held for 3 hours, and then cooled to room temperature in an activation treatment. This prepared hydrogenation catalyst 1 in which Cu, Cr, Zn, Ti, and Mo were supported on a silica support.

[0105] A composite catalyst prepared by mixing C2 oxygenation catalyst 1 (35 kg) and hydrogenation catalyst 1 (70 kg) in a commercially available mixing and preparing device was packed into a Ti-coated stainless steel reactor. Ethanol was produced by contacting the composite catalyst with reformed gas adjusted to an H2 / CO volume ratio of 2.5. The bulk density of the C2 oxygenation catalyst and hydrogenation catalyst used in this test was 0.5 kg / L.

[0106] [Table 1]

[0107] These results demonstrate that, in a co-carbonization process using plastic and biomass raw materials, the carbonization rate, reformed gas production volume, and ethanol production volume are significantly improved when metal-containing residue is recycled and supplied to the plastic and biomass (Example 1) compared to when metal-containing residue is not recycled and supplied (Comparative Example 1).

[0108] [Exam 2] Except for adding 45 kg per hour of crushed plastic [PE+PAN+PVC] consisting of 40% polyethylene containers, 40% acrylic resin containers, and 20% polyvinyl chloride containers as the plastic, and 25 kg per hour of sugarcane bagasse chips as the biomass, the same ethanol production apparatus as in Test 1 was used to conduct co-carbonization, reforming gasification, and ethanol production tests of plastic and biomass.

[0109] [Example 2, Comparative Example 2] Co-carbonization tests similar to those in Test 1 were conducted using plastic and sugarcane bagasse at a carbonization furnace temperature range of 250 to 450°C. The carbonization process involved adding 30 kg / h of steam and 15 Nm³ of CO2 at an internal temperature of 860 to 900°C in the reforming gasifier furnace. 3 When introduced at / h and carried out under mixed gasification conditions of steam and CO2 (Example 2), and when 30 kg / h of steam was supplied alone (Comparative Example 2), the amount of reformed gas produced (Nm³) 3 Table 2 shows the test results for the reformed gas component composition (vol%) and the amount of ethanol produced in the ethanol production facility using the reformed gas (kg / h).

[0110] In this experiment, metal-containing residue separated and recovered by a cyclone dust collector was mixed and fed into a biomass and plastic receiving container at a rate of 5 kg per hour, and then subjected to carbonization and gasification operations. The metal content per 1 kg of metal-containing residue obtained in this experiment was as follows: Na 45 g / kg, K 65 g / kg, Ca 50 g / kg, Mg 15 g / kg, Ba 2.5 g / kg, Li 1.5 g / kg, Fe 2.8 g / kg, and Ni 0.5 g / kg.

[0111] [Preparation of C2 oxygenated catalyst 2] The chlorides of Rh, Mn, Li, Sc, and Mg were dissolved in a mixed solvent of ethanol and water in an atomic ratio of 1:0.05:0.30:0.10:0.05 to obtain an aqueous ethanol solution. This aqueous ethanol solution was then applied to a silica support (specific surface area 385 m²). 2After impregnation with ( / g), the catalyst was heated to 100°C over 1 hour under a gas stream of hydrogen and nitrogen gas (1:4 volume ratio), held for 2 hours, heated to 400°C over 2 hours, held for 2 hours, and then cooled to room temperature. This prepared C2 oxygenated catalyst 2 in which Rh, Mn, Li, Sc, and Mg were supported on a silica support.

[0112] [Preparation of Hydrogenation Catalyst 2] The nitrates of Pd, Cu, Zn, K, and Zr were dissolved in a mixed solvent of ethanol and water in an atomic ratio of 1:0.8:0.2:0.15:0.08 to obtain an aqueous ethanol solution. This aqueous ethanol solution was then used to prepare a silica support (specific surface area 265 m²). 2 After impregnation with ( / g), the catalyst was heated to 100°C over 1 hour under a gas stream of hydrogen and nitrogen gas (1:2 volume ratio), held for 2 hours, then heated to 400°C over 2 hours, held for 2 hours, and cooled to room temperature in an activation treatment. This prepared hydrogenation catalyst 2, on which Pd, Cu, Zn, K, and Zr were supported on a silica support. The bulk density of the C2 oxygenated catalyst and hydrogenation catalyst used in this test was 0.5 kg / L.

[0113] A composite catalyst prepared by mixing C2 oxygenation catalyst 2 (38 kg) and hydrogenation catalyst 2 (95 kg) in a mixing and preparing device was packed into a Ti-coated stainless steel reactor. Ethanol was produced by contacting the composite catalyst with reformed gas.

[0114] [Table 2]

[0115] These results show that the amount of reformed gas and ethanol produced in the reformed gasification process using carbides generated in a co-carbonization process with plastic and sugarcane bagasse as raw materials, under mixed supply conditions of water vapor and CO2 (Example 2), is significantly increased compared to the supply condition of water vapor alone (Comparative Example 2).

[0116] [Exam 3] In an embodiment similar to that of Test 2, co-carbonization and gasification were performed using 50 kg / h of crushed plastic chips (PS+PAN) made of polystyrene (PS) and polyaminonitrile (PAN) (PS:PAN = 1:1 weight ratio) and 25 kg / h of biomass (cedar chips (moisture content 35%)). The resulting reformed gas was then contacted with a composite catalyst prepared by mixing C2 oxygen-containing catalyst 2 (35 kg) and hydrogenation catalyst 2 (70 kg) to produce ethanol.

[0117] In this experiment, the reaction gas separated by a gas-liquid separator in the ethanol production facility was fed into a shift reaction hydrogen production facility to generate a hydrogen and CO2 mixed gas. In addition to the residual hydrogen obtained by separating CO2 from this mixed gas using a ceramic membrane separator, hydrogen generated in a water electrolysis facility was stored in a hydrogen holder.

[0118] Table 3 shows the CO conversion rate (ethanol / CO molar ratio %), ethanol selectivity (%), and ethanol yield (STY: g-EtOH / L-cat / h) for two cases: when hydrogen was supplied to the reformed gas from a hydrogen holder via a hydrogen supply regulator to adjust the reformed gas composition to an H2 / CO volume ratio of 2.5 (Example 3), and when the ethanol production test was performed using only the reformed gas without hydrogen supply (Example 4).

[0119] [Table 3]

[0120] These results demonstrate that when hydrogen generated in the shift reaction hydrogen production facility and the water electrolysis facility is supplied to the reformed gas (Example 3), the CO conversion rate, ethanol selectivity, and ethanol yield (STY) increase significantly compared to when hydrogen is not supplied (Example 4).

[0121] [Exam 4] In an ethanol production apparatus and embodiment similar to that of Test 1, a composite catalyst obtained by mixing C2 oxygenation catalyst 1 (35 kg) and hydrogenation catalyst 1 (35 kg) in a volume ratio of 1:1 was packed into a Ti-coated stainless steel reaction tube. Table 4 shows the CO conversion rate, ethanol selectivity, and ethanol yield (STY: g-EtOH / L-cat / h) in ethanol production when ethanol is produced by contacting the composite catalyst with reformed gas at 2.5 MPa, 285°C, and SV = 25,000 h-1 (Example 5), and when the same amount of C2 oxygenation catalyst 1 (35 kg) and hydrogenation catalyst 1 (35 kg) are separately stacked and packed into the reactor (Example 6).

[0122] [Table 4]

[0123] This demonstrated that when a composite catalyst prepared by mixing a C2 oxygenation catalyst and a hydrogenation catalyst was used (Example 5), the CO conversion rate, ethanol selectivity, and ethanol yield (STY) were significantly improved compared to when the C2 oxygenation catalyst and the hydrogenation catalyst were stacked separately (Example 6).

[0124] [Industrial applicability]

[0125] The present invention provides a method for producing ethanol and an ethanol production apparatus that can increase the carbonization rate of carbides obtained in a co-carbonization process using plastics and biomass, improve the yield of reformed gas obtained by gasification of carbides, and produce ethanol efficiently and stably. [Explanation of symbols]

[0126] 1 Plastic 2. Biomass 3. Carbides 4 Metal-containing residue 5. Drying gas (containing tar) 6. Combustion gases 7. Water vapor 8. Reformed gas 9 CO2 10 Hydrogen 11 Plastic receiver 12 Biomass receiver 13 Mixing dryer 14 Josui 20 Carbonization furnace 30 Reforming Gasifier 31. Steam heat exchanger 32 CO2 supply piping 33 Steam supply piping 34. Dust collector (cyclone, etc.) 35. First reformed gas piping 36 Gas purification equipment 37 Metal-containing residue supply equipment 38 Metal-containing residue receiver 39 Metal-containing residue discharge piping 40 Water electrolysis equipment 41 Air blower 42 Plastic supply regulator 50 Ethanol production equipment 51 Water electrolysis hydrogen supply piping 52 Gas-liquid separator 53 Shift Reaction Hydrogen Production Equipment 54. Gas separation and purification equipment (ceramic membrane separator, PSA) 55 Hydrogen holder 56 Ethanol separation and purification equipment (distillation apparatus, ceramic membrane separator) 57 Catalyst Mixing Preparator 58 C2 oxygenation catalyst 59 Hydrogenation catalyst 60 Air Combustor 61 Combustion gas supply regulator 62. Combined catalyst introduction piping 63. Compound catalyst 64 H2 / CO2 introduction piping 70 Combustion gas piping equipment 71. First heat exhaust piping (dryer) 72. Second heat exhaust piping (carbonization furnace) 73. Third waste heat piping (reformed gasification furnace) 74. Fourth heat exhaust piping (steam heat exchanger) 75. Fifth heat exhaust piping (ethanol production equipment) 76. No. 6 waste heat piping (shift reaction hydrogen production facility) 77 Crude ethanol piping 78. Hydrogen piping (gas mixing regulator) 79. Hydrogen piping (hydrogen cylinders) 80 Biomass supply regulator 81 Carbide supply amount regulator 82 Metal-containing residue supply amount regulator 83 CO2 supply amount regulator 84. Steam supply regulator 85 Hydrogen supply regulator 86. Reformed gas supply rate regulator 87 Water electrolysis hydrogen supply amount regulator 88 Pressurized circulating gas supply equipment 89 Gas Mixing Regulator 90 ethanol 91 Biomass supply facilities 92 Carbide supply amount regulator 93 Reformed gas supply device 94 Metal-containing residue separation and recovery equipment 95 Catalyst mixing amount regulator 96 Plastic supply equipment 100 Ethanol Production Equipment

Claims

1. A carbonization process involves co-carbonizing plastic and biomass to produce a carbonized product; a reforming gasification process involves a mixed gasification reaction of the carbonized product with water vapor and carbon dioxide to produce a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide; and supplying the reformed gas to an ethanol production process, where C is produced in the ethanol production process. ２ An ethanol production method comprising an ethanol production step of producing ethanol by contacting an oxygenation catalyst and a hydrogenation catalyst, wherein a metal-containing residue generated together with the reformed gas in the reformed gas step is separated from the reformed gas and recovered, and the recovered metal-containing residue is mixed with the plastic and biomass.

2. The ethanol production method according to claim 1, wherein the metal-containing residue comprises at least one element selected from the group consisting of alkali metals and alkaline earth metals including Na, K, Li, Ca, Mg, and Ba, and B, Al, Fe, and Ni.

3. The method for producing ethanol according to claims 1 and 2, further comprising a shift reaction hydrogen production step in which carbon monoxide and methane in the residual gas after separating the liquid product containing ethanol from the reaction gas generated in the ethanol production step using a gas-liquid separator are shift-reacted with water vapor to produce hydrogen and carbon dioxide.

4. The ethanol production method according to claim 3, wherein the hydrogen and carbon dioxide generated in the shift reaction hydrogen production step are separated and recovered in a gas separation facility, the residual hydrogen is supplied to the reformed gas, and the recovered carbon dioxide is supplied to the reformed gasification step.

5. The ethanol production method according to claims 3 and 4, wherein in the shift reaction hydrogen production step, a shift reaction hydrogen production catalyst comprising at least one element selected from the group consisting of Fe, Ru, Ni, Cu, Zn, K, Li, Mg, Cr, Co, Mo, Zr, Ti, Ce, La, and Nd, and a porous oxide support is used.

6. The method for producing ethanol according to claim 1 to 5, wherein the carbonization gas generated together with the carbide in the carbonization step is combusted with air, and the resulting high-temperature exhaust gas is used as a heat source to heat and use at least one of the steps of the carbonization step, the reforming gasification step, the shift reaction hydrogen production step, and the ethanol production step.

7. Said C ２ The method for producing ethanol according to claims 1 to 6, wherein the oxygenation catalyst comprises Rh, at least one element selected from the group consisting of Mn, Sc, Li, Na, K, Cs, Mg, Ba, Pt, Pd, Ir, Mo, W, V, Zr, Hf, Ti, Y, Ce, and La, and a porous support.

8. The method for producing ethanol according to claims 1 to 7, wherein the hydrogenation catalyst comprises at least one element selected from the group consisting of Pd, Fe, Ni, Pt, Cu, Cr, Zn, K, Na, Ce, and Ti, and a porous support.

9. The ethanol manufacturing process is C ２ The composite catalyst comprises an oxygen-containing catalyst and a hydrogenation catalyst, wherein the C in the composite catalyst is relative to the hydrogenation catalyst. ２ The method for producing ethanol according to claims 1 to 8, wherein the mixed volume ratio of the oxygen-containing catalyst is 0.1 to 5.

10. The aforementioned supply equipment for plastics and biomass, means for adjusting the supply amount of plastics and biomass, a mixing dryer equipped with means for adjusting and controlling the biomass dryness to a predetermined degree, a carbonization furnace equipped with a temperature adjustment means, a carbonization supply equipment and carbonization supply amount adjustment means for connecting and supplying the carbonized material to the reforming gasification furnace, a supply equipment and supply amount adjustment means for supplying steam and carbon dioxide to the gasification furnace, a reforming gas supply equipment for supplying the reformed gas to the ethanol production process, a gas purification equipment and gas mixing adjustment equipment for the reformed gas, a separation and recovery means for separating and recovering metal-containing residue generated together with the reformed gas in the reforming gasification process, a metal residue supply equipment and metal residue supply amount adjustment means for supplying and mixing the recovered metal-containing residue with the plastics and biomass, and in the ethanol production process C ２ Ethanol production equipment comprising catalyst mixing and preparation equipment for mixing and preparing an oxygenation catalyst and a hydrogenation catalyst, and catalyst mixing amount adjustment means.

11. The ethanol production apparatus according to claim 10, further comprising: a shift reaction hydrogen production step which generates hydrogen and carbon dioxide by shift reaction between carbon monoxide and methane and water vapor in the residual gas after separating the liquid product containing ethanol from the reaction gas generated in the ethanol production step using a gas-liquid separator; a gas separation facility for separating and recovering carbon dioxide, and a piping facility and carbon dioxide supply adjustment means for supplying the recovered carbon dioxide to the reforming gasification furnace; a piping facility and supply adjustment means for supplying residual hydrogen to a hydrogen holder; a piping facility and hydrogen supply adjustment means for supplying hydrogen generated in a water electrolysis facility to the hydrogen holder; a supply facility and hydrogen supply adjustment means for supplying hydrogen from the hydrogen holder to the reformed gas; a pressurized and circulating supply facility and reformed gas circulation amount adjustment means for contacting the reformed gas with the composite catalyst; and a distillation column and ceramic membrane separation facility for separating and purifying ethanol from the liquid product containing ethanol.

12. The ethanol production apparatus according to claims 10 and 11, further comprising: a combustion furnace for burning the carbonization gas generated in the carbonization furnace; a heat exchanger for heating steam introduced into the reforming gasification furnace; and piping equipment and gas temperature and gas flow rate adjustment means for supplying the combustion gas generated in the combustion furnace as heating gas to at least one of the mixing dryer, the carbonization furnace, the reforming gasification furnace, the steam heat exchanger, the shift reaction hydrogen production equipment, and the ethanol production process.

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