Polyvinyl alcohol manufacturing method and polyvinyl alcohol manufacturing apparatus

Abstract

The present invention addresses the problem of providing a method for producing polyvinyl alcohol that can efficiently and stably produce biomass-derived polyvinyl alcohol. [Solution] The system includes a carbonization process for producing carbonized material from biomass, a reformed gasification process for producing reformed gas by gasifying the carbonized material with water vapor and carbon dioxide, an ethanol production process for producing ethanol by contacting the reformed gas with a catalyst, an ethylene production process for producing ethylene by dehydrating ethanol, an acetic acid production process for producing acetic acid by oxidizing ethanol, a vinyl acetate production process for producing vinyl acetate by an oxidative esterification reaction between ethylene and acetic acid, a polyvinyl acetate production process for producing polyvinyl acetate by polymerizing the vinyl acetate obtained in the vinyl acetate production process, and a polyvinyl alcohol production process for saponifying the polyvinyl acetate obtained in the polyvinyl acetate production process.

Description

[Technical Field]

[0001] The present invention relates to a method for producing polyvinyl alcohol and an apparatus for producing polyvinyl alcohol. [Background technology]

[0002] Biomass, which includes agricultural products such as thinned wood, rice straw, and bagasse, food products made from these products, processed products such as cotton cloth, clothing fibers, and furniture, construction waste, and organic waste such as household garbage, is a biological material that can be used as an energy source or industrial raw material. Such biomass is a renewable, neutral carbon material that is cyclically generated by the action of solar energy, air, water, carbon dioxide, soil, etc.

[0003] As a method for utilizing such biomass, for example, ethanol production using food biomass such as rice, corn, sugarcane, and taro, as well as non-food biomass raw materials such as thinned wood and agricultural and industrial waste, has been developed. In particular, producing ethanol from non-food biomass is useful as a technology for reducing the volume of agricultural and industrial waste and for recycling it into resources, and there are high hopes for the development of ethanol production technology that will broaden the range of raw material options.

[0004] One method for converting non-food biomass into ethanol is the hydrothermal decomposition of biomass, which involves extracting sugar components from biomass by pyrolysis in the presence of acid or alkali, and then fermenting the sugar components to produce ethanol. This method of hydrothermal decomposition of biomass has the problem of low ethanol yield and high production costs.

[0005] Another known method for producing ethanol is to gasify biomass and obtain ethanol from the gas. One example of a technique for gasifying biomass is a technique in which the biomass is directly gasified by a thermochemical gasification reaction using air and steam in a gasifier such as a fixed bed or a fluidized bed (Patent Documents 1 to 4). Furthermore, the gas produced by such biomass gasification technology (also called "biomass gas" or "reformed gas") is known to be used as a feedstock for gas engine power generation, hydrogen production, alcohol fuels such as methanol and ethanol, and synthetic fuels such as Fischer-Tropsch (FT) synthetic oil. For example, Non-Patent Documents 1 and 2 disclose technologies for gasifying biomass and using it for power generation.

[0006] However, even with these conventional biomass pyrolysis carbonization technologies, the carbonization of biomass does not proceed efficiently and uniformly, resulting in an insufficient carbonization rate of the char and an insufficient yield of reformed gas during gasification of the char. Additionally, there is a problem in that ethanol cannot be efficiently and stably produced in the ethanol production process using the reformed gas.

[0007] On the other hand, as an effective utilization of other biomass, there is a technology for producing hydrolyzable cellulose by mixing cellulose obtained from cellulosic biomass with a polyvinyl alcohol polymer (Patent Document 5). Such hydrolyzable materials have attracted attention as materials for food, fibers, various industrial products, etc., due to their low environmental impact. For example, if polyvinyl alcohol could be efficiently obtained from biomass, it could be used as a raw material with even lower environmental impact. Therefore, it is expected that polyvinyl alcohol can be efficiently and stably obtained from ethanol obtained from biomass. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-88434 [Patent Document 2] Patent No. 5342664 [Patent Document 3] International Publication No. 2020 / 166659 [Patent Document 4] International Publication No. 2010 / 092819 [Patent Document 5] International Publication No. 2011 / 158795 [Non-patent literature]

[0009] [Non-Patent Document 1] Kenichi Sasauchi, "Power Generation by Pyrolysis Gasification of Biomass," Journal of the Combustion Society of Japan, Vol. 47, No. 139 (2005), pp. 31-39 [Non-patent document 2] Masaru 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 [Problem to be solved by the invention]

[0010] The present invention has been made in consideration of the above-mentioned problems of the conventional art, and provides a method and an apparatus for producing polyvinyl alcohol, which can efficiently and stably produce polyvinyl alcohol using biomass. [Means for solving the problem]

[0011] The present invention relates to a method for producing polyvinyl alcohol, a carbonization step of carbonizing the biomass to produce a carbonized product; a reforming-gasification step of gasifying the carbide, steam, and carbon dioxide to generate a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide; an ethanol production step of contacting the reformed gas with a C2 oxygenation catalyst and a hydrogenation catalyst to produce ethanol; an ethylene production step in which ethanol obtained in the ethanol production step is subjected to a dehydration reaction to produce ethylene; an acetic acid production step in which the ethanol obtained in the ethanol production step is subjected to an oxidation reaction to produce acetic acid; a vinyl acetate production step in which the ethylene obtained in the ethylene production step and the acetic acid obtained in the acetic acid production step are subjected to an oxidative esterification reaction to produce vinyl acetate; a polyvinyl acetate production step in which the vinyl acetate obtained in the vinyl acetate production step is polymerized to produce polyvinyl acetate; a polyvinyl alcohol production step in which the polyvinyl acetate obtained in the polyvinyl acetate production step is subjected to a saponification reaction to produce polyvinyl alcohol; a mixing step of separating and recovering a metal-containing residue generated in the reformed gasification step from the reformed gas and mixing the metal-containing residue with the biomass; a shift reaction step in which the gas generated in the ethanol production step is separated and carbon monoxide, methane, and water vapor contained in the separated gas are subjected to a shift reaction to produce hydrogen and carbon dioxide; and a carbon dioxide / hydrogen separation process in which carbon dioxide is separated and recovered from the mixed gas of hydrogen and carbon dioxide generated in the shift reaction process, the recovered carbon dioxide is supplied to the reformed gasification process, and the recovered hydrogen is mixed with the reformed gas obtained in the reformed gasification process.

[0012] In the present invention, the metal-containing residue may contain at least one element selected from the group consisting of alkali metals, alkaline earth metals, metalloids, aluminum, iron, and nickel.

[0013] In the present invention, the shift reaction 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.

[0014] In the present invention, the combustion gas generated by air combustion of the dry distillation gas generated together with the carbonized material in the carbonization process may be used as a heat source for heating in at least one of the carbonization process, the reformed gasification process, the ethanol production process, the shift reaction process, the ethylene production process, the vinyl acetate production process, the mixing process, and the polyvinyl alcohol production process.

[0015] In the present invention, the C2 oxygenation catalyst may contain rhodium, at least one element selected from the group consisting of 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.

[0016] In the present invention, the hydrogenation catalyst may contain at least one element selected from the group consisting of palladium, iron, nickel, platinum, copper, chromium, zinc, potassium, sodium, cerium, and titanium, and a porous support.

[0017] In the present invention, in the ethanol production process, a composite catalyst prepared by mixing the C2 oxygenated catalyst and the hydrogenation catalyst may be used, and the volume ratio of the C2 oxygenated catalyst to the hydrogenation catalyst in the composite catalyst (C2 oxygenated catalyst / hydrogenation catalyst) may be 0.1 or more and 5 or less.

[0018] The present invention relates to an apparatus for producing polyvinyl alcohol, a carbonization furnace for carbonizing biomass to generate a carbonized product; a reforming gasification furnace into which the carbonized material is introduced from the carbonization furnace and into which the carbonized material, water vapor, and carbon dioxide are subjected to a gasification reaction to generate a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide; an ethanol production facility that introduces reformed gas from the reforming gasification furnace and brings the reformed gas into contact with a C2 oxygenation catalyst and a hydrogenation catalyst to produce ethanol; an ethylene production facility into which ethanol is introduced from the ethanol production facility and which dehydrates the ethanol to produce ethylene; an acetic acid production facility into which ethanol is introduced from the ethanol production facility and which generates acetic acid by oxidizing the ethanol; a vinyl acetate production facility into which ethylene from the ethylene production facility and acetic acid from the acetic acid production facility are introduced, and which produces vinyl acetate by subjecting the ethylene and acetic acid to an oxidative esterification reaction; a polyvinyl acetate production facility into which vinyl acetate is introduced from the vinyl acetate production facility and which polymerizes the vinyl acetate to produce polyvinyl acetate; a polyvinyl alcohol production facility into which polyvinyl acetate is introduced from the polyvinyl acetate production facility and which saponifies the polyvinyl acetate to produce polyvinyl alcohol; a shift reaction facility into which gas generated in the ethanol production facility is introduced and into which carbon monoxide, methane, and steam contained in the gas are subjected to a shift reaction to produce hydrogen and carbon dioxide; a mixing means for separating and recovering a metal-containing residue generated in the reforming gasification furnace from the reformed gas and mixing the metal-containing residue with the biomass; and a supply means for separating and recovering carbon dioxide from the mixed gas of hydrogen and carbon dioxide generated in the shift reaction facility, supplying the recovered carbon dioxide to the reforming gasification furnace, and supplying the recovered hydrogen to the reforming gasification furnace.

[0019] In the present invention relating to the apparatus for producing polyvinyl alcohol, the metal-containing residue may contain at least one element selected from the group consisting of alkali metals, alkaline earth metals, metalloids, aluminum, iron, and nickel.

[0020] In the present invention relating to an apparatus for producing polyvinyl alcohol, the shift reaction facility 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.

[0021] The present invention relating to the polyvinyl alcohol production apparatus may also include a combustion gas piping system that supplies combustion gas generated by air combustion of the dry distillation gas generated together with the carbonized material in the carbonization furnace as a heat source for heating to at least one of the carbonization furnace, the reforming gasification furnace, the ethanol production facility, the shift reaction facility, the ethylene production facility, the vinyl acetate production facility, and the polyvinyl alcohol production facility.

[0022] In the present invention relating to an apparatus for producing polyvinyl alcohol, the C2 oxygenation catalyst may contain rhodium and at least one element selected from the group consisting of 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.

[0023] In the present invention relating to an apparatus for producing polyvinyl alcohol, the hydrogenation catalyst may contain at least one element selected from the group consisting of palladium, iron, nickel, platinum, copper, chromium, zinc, potassium, sodium, cerium, and titanium, and a porous support.

[0024] In the present invention relating to a polyvinyl alcohol production apparatus, the ethanol production facility may include a composite catalyst prepared by mixing the C2 oxygenated catalyst and the hydrogenation catalyst, and the volume ratio of the C2 oxygenated catalyst to the hydrogenation catalyst in the composite catalyst (C2 oxygenated catalyst / hydrogenation catalyst) may be 0.1 or more and 5 or less.

[0025] The present invention relating to the polyvinyl alcohol production apparatus may further include a water electrolysis facility and a hydrogen holder, and may include piping equipment for introducing hydrogen generated in the ethanol production facility and / or hydrogen generated in the water electrolysis facility into the hydrogen holder. [Effects of the Invention]

[0026] According to the present invention, it is possible to provide a method and an apparatus for producing polyvinyl alcohol that can efficiently and stably produce polyvinyl alcohol using biomass. [Brief explanation of the drawings]

[0027] [Figure 1]FIG. 1 is a schematic diagram showing an apparatus according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, embodiments of a method for producing polyvinyl alcohol and an apparatus for producing polyvinyl alcohol (hereinafter simply referred to as a production method and a production apparatus) according to the present invention will be described. In addition, when the specification uses "~" 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 by "above" and "below"). In this specification, the terms "bioethanol" and "biopolyvinyl alcohol" refer to ethanol and polyvinyl alcohol, respectively, produced using biomass as a raw material.

[0029] (First embodiment: Method for producing biopolyvinyl alcohol) In this embodiment, a method for producing polyvinyl alcohol from biomass (a method for producing biopolyvinyl alcohol) will be described. The method for producing biopolyvinyl alcohol of this embodiment is as follows: a carbonization process for carbonizing biomass to produce a carbonized product; a reformed-gasification process for gasifying the carbonized product with steam and carbon dioxide to produce a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide; an ethanol production process for contacting the reformed gas with a C2 oxygenation catalyst and a hydrogenation catalyst to produce ethanol; an ethylene production process for dehydrating the ethanol produced in the ethanol production process to produce ethylene; an acetic acid production process for oxidizing the ethanol produced in the ethanol production process to produce acetic acid; a vinyl acetate production process for oxidatively esterifying the ethylene produced in the ethylene production process with the acetic acid produced in the acetic acid production process to produce vinyl acetate; and a polyvinyl acetate production process for polymerizing the vinyl acetate produced in the vinyl acetate production process to produce polyvinyl acetate. a polyvinyl alcohol production process in which polyvinyl acetate obtained in the polyvinyl acetate production process is subjected to a saponification reaction to produce polyvinyl alcohol; a mixing process in which a metal-containing residue generated in the reformed-gasification process is separated and recovered from the reformed gas and mixed with the biomass; a shift reaction process in which gas generated in the ethanol production process is separated and carbon monoxide, methane, and water vapor contained in the gas are subjected to a shift reaction to produce hydrogen and carbon dioxide; and a carbon dioxide / hydrogen separation process in which carbon dioxide is separated and recovered from the mixed gas of hydrogen and carbon dioxide generated in the shift reaction process, the recovered carbon dioxide is supplied to the reformed-gasification process, and the recovered hydrogen is mixed with the reformed gas obtained in the reformed-gasification process.

[0030] [biomass] The biomass used as the raw material in 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 wood such as cedar, pine, and bamboo; agricultural products such as rice straw, sugarcane, napia, and sweet sorghum; waste by-products (such as bagasse); construction waste; industrial waste such as cotton and textile products; natural materials such as 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, 10 to 100 mm. One type of biomass may be used alone, or two or more types may be used in combination.

[0031] The biomass used as the raw material in this embodiment may be dried using a dryer or the like to adjust the moisture content before being subjected to the carbonization step described below.

[0032] In addition to carbon, the biomass of this embodiment may contain elements such as alkali metals or alkaline earth metals including sodium, potassium, lithium, cesium, calcium, magnesium, barium, etc., metalloids such as boron, silicon, germanium, antimony, tellurium, aluminum, iron, nickel, etc. Furthermore, these elements and compounds containing them may be added and mixed. When these elements are contained in biomass, it is possible to reduce tar production in the carbonization process and improve the carbonization rate of the carbonized product, and to more efficiently generate reformed gas in the subsequent reformed gasification process.

[0033] The amounts of the above elements contained in the biomass are not particularly limited and can be adjusted as appropriate. In the method of this embodiment, the metal-containing residue generated together with the reformed gas in the reforming-gasification process described below is used as the element source. The metal-containing residue is a residue separated and recovered from the reformed gas generated in the reforming-gasification process. The metal-containing residue can be recovered as a solid material such as a metal oxide, carbide, or metal salt. In order to allow the biomass to contain an appropriate amount of the above elements, in addition to mixing the metal-containing residue, the type and amount of biomass may be adjusted, or substances other than the metal-containing residue, such as metal compounds, may be mixed with the biomass.

[0034] The mixing step of mixing the metal-containing residue with the biomass may be carried out before the carbonization step, or may be carried out simultaneously with the carbonization step, i.e., by directly adding the metal-containing residue to a facility that carries out the carbonization step, such as a carbonization furnace, and mixing the metal-containing residue with the biomass. Details of the mixing step will be described below.

[0035] [Carbonization process] The method of this embodiment includes a carbonization step of carbonizing biomass to produce a carbonized product. In the carbonization process, the raw material biomass is heated under low-oxygen or oxygen-free conditions to cause pyrolysis. Pyrolysis of the biomass produces char and a dry distillation gas containing low-molecular-weight fuel gas and heavy fuel components such as tar. In this embodiment, the carbonization process is performed using a carbonization furnace. The biomass carbonization process may also be performed while stirring the biomass.

[0036] The carbonization furnace can be appropriately selected from known carbonization furnaces, for example, the carbonization furnaces mentioned in the embodiment of the polyvinyl alcohol production apparatus described later can be used. The carbonization conditions for the carbonization step in this embodiment are as follows. The heating temperature in the carbonization step is, for example, 200°C or higher and 650°C or lower, or 250°C or higher and 600°C or lower. The treatment time (residence time) in the carbonization step in this embodiment is, for example, from 5 minutes to 100 minutes, or from 10 minutes to 60 minutes. By pyrolyzing the raw material biomass at the heating temperature and for the heating time, a carbonized product can be obtained more efficiently. In the carbonization step of this embodiment, the biomass may be supplied to the carbonization furnace continuously or intermittently. In addition, when the metal-containing residue is supplied to the carbonization furnace, the supply may also be performed continuously or intermittently.

[0037] [Dry distillation gas combustion process] The method of this embodiment may include a combustion step in which the dry distillation gas generated in the carbonization step is separated from the carbonized material, recovered, and combusted to generate high-temperature combustion gas. Specifically, since the dry distillation gas contains hydrogen, lower hydrocarbons, and heavy fuel components such as tar, it is combusted in an air atmosphere, for example, in an air combustion furnace equipped with an air blower, to obtain high-temperature (1000°C to 1200°C) combustion gas from which heavy fuel components such as tar have been removed.

[0038] The high-temperature combustion gas obtained in this combustion process can be transported to each process of the method of this embodiment, such as the carbonization process, reforming gasification process, and shift reaction production process, or to other heating processes and equipment, such as biomass dryers in external systems, and used as exhaust gas for heating. By utilizing the heat of the combustion gas as exhaust gas for heating in each step of the manufacturing method of this embodiment or for heating in other external systems in a cascade manner, heating can be performed without using external fuels (heavy oil, electricity, etc.), or by using a smaller amount of combustion gas generated by air combustion of an external fuel than conventional methods. This not only improves the yield of the reformed gas obtained by the method of this embodiment, and further improves the yield of bioethanol and bio-polyvinyl alcohol obtained from the reformed gas, thereby reducing the production costs, but also contributes to the suppression of global warming by reducing carbon dioxide emissions.

[0039] [Reformed gasification process] The method of this embodiment includes a reformed gasification process in which carbon dioxide, water vapor, and carbon dioxide are co-gasified to produce a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide (hereinafter also referred to as H2, CO, CH4, and CO2). In the reformed gasification step of this embodiment, the following reactions occur. (1) Reaction of carbide with water vapor: C + H2O → H2 + CO (2) Reaction of carbide with carbon dioxide: C + CO2 → 2CO (3) Shift reaction: CO + H2O → CO2 + H2 (4) Methanation reaction: C + 2H2 → CH4

[0040] In the gasification temperature range (600°C to 1200°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 water vapor in the above-mentioned carbonized material 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 reformed gas is produced using water vapor alone.

[0041] 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 step described below may be introduced into the reforming-gasification furnace.

[0042] The amount of carbonized material supplied to the reforming gasification furnace in the reforming gasification process of this embodiment can be adjusted as appropriate to efficiently produce reformed gas, and may be, for example, 10 kg / h or more and 10,000 kg / h or less, or 50 kg / h or more and 5,000 kg / h or less. The amount of steam supplied to the reforming gasification furnace can be adjusted as appropriate, but for example, the amount of steam supplied per 1 kg / h of carbonized material may be 0.5 kg / h or more and 10 kg / h or less, or 2 kg / h or more and 5 kg / h or less. The amount of carbon dioxide supplied to the reforming gasification furnace can be adjusted as appropriate. For example, the amount of carbon dioxide supplied per 1 kg / h of carbonized material is set to 0.1 Nm 3 / h or more 10Nm 3 / h or less, or 0.5Nm 3 / h or more 5Nm 3 / h or less. Furthermore, the ratio of the carbon dioxide supply amount to the total of the water vapor supply amount and the carbon dioxide supply amount (CO2 supply amount ÷ (water vapor supply amount + carbon dioxide supply amount)) can be, for example, 1 vol% or more and 85 vol% or less, or 10 vol% or more and 60 vol% or less.

[0043] 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 1200° 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.

[0044] For example, water vapor can be obtained by heating clean water in a heat exchanger heated to a temperature in the range of 50°C to 800°C, and then supplying the water vapor to the reforming-gasification furnace. When the clean water is heated by heat exchange using a heat exchanger or the like, a water vapor heat exchange step in which exhaust heat gas from the reforming-gasification furnace is introduced into the heat exchanger for heating may be carried out. Furthermore, the exhaust heat gas from the heat exchanger that heated the clean water may be introduced into another process (e.g., an ethanol production process, a shift reaction process, an ethylene production process, an acetic acid production process, a vinyl acetate production process, a polyvinyl acetate production process, or a polyvinyl alcohol production process) and used for heating.

[0045] 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.

[0046] The reformed gas obtained in the reformed gasification process of this embodiment contains hydrogen (H2) and carbon monoxide (CO), and typically contains hydrogen (H2), carbon monoxide (CO), methane (CH4), and carbon dioxide (CO2). The range of the hydrogen content in the reformed gas is, for example, 25% by volume or more and 75% by volume or less, or 35% by volume or more and 65% by volume or less. The range of the carbon monoxide content in the reformed gas is, for example, 20% by volume or more and 60% by volume or less, or 25% by volume or more and 50% by volume or less. The range of the total content of hydrogen and carbon monoxide in the reformed gas is, for example, 60% by volume or more and 100% by volume or less, or 70% by volume or more and 90% by volume or less. The range of the methane content in the reformed gas is, for example, 0.1% by volume or more and 10% by volume or less, or 0.5% by volume or more and 5% by volume or less. The range of the carbon dioxide content in the reformed gas is, for example, 1% by volume or more and 35% by volume or less, or 10% by volume or more and 25% by volume or less. The content (vol %) of each component is the value at 25°C (room temperature) and 1 atmosphere.

[0047] [Mixing process] The method of this embodiment includes a mixing step of separating and recovering a metal-containing residue generated in the reformed gasification step from the reformed gas, and mixing the metal-containing residue with the biomass. That is, in the reformed gasification step, the metal elements contained in the carbide remain as metal-containing residue, and this 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 into the reformed gas and the metal-containing residue using a dust collector such as a cyclone or a bag filter, and recovering the separated metal-containing residue.

[0048] In the method of this embodiment, the mixing step may be carried out prior to the carbonization step, or may be carried out simultaneously with the carbonization step. When the mixing process is carried out prior to the carbonization process, it is carried out in the biomass before it is introduced into the carbonization furnace, for example, in a place where the biomass is received (receiver, etc.) or in a place where the biomass is mixed and dried (mixer, dryer, etc.). If the mixing step is carried out simultaneously with the carbonization step, the metal-containing residue is mixed with the biomass in the carbonization furnace. In this embodiment, the metal-containing residue may be supplied to the biomass continuously or intermittently.

[0049] Examples of methods for mixing metal-containing residues with biomass include immersing biomass in a solution in which the metal-containing residues are dissolved or dispersed in a solvent such as an acid or alkaline aqueous solution, alcohol, ether, or hydrocarbon, and adding the solution by spraying it onto the biomass to mix and support the metal components on the biomass.

[0050] In the method of the present embodiment, the inclusion of metal elements in the biomass in the carbonization step can promote carbonization in the carbonization step and increase the carbonization rate. The content of each metal element in the metal-containing residue is usually about 0.01 g to 100 g, or about 0.1 g to 50 g, per 1 kg of the metal-containing residue. The mass ratio of the metal-containing residue to be mixed with the biomass (metal-containing residue / biomass) may be in the range of 0.01 to 0.99, or 0.1 to 0.9, for example. In this embodiment, when the metal element content of the metal-containing residue and the mass ratio of the metal-containing residue to the biomass are within the above ranges, the carbonization rate in the biomass carbonization step tends to be further improved.

[0051] Increasing the carbonization rate makes it possible to further increase the production amounts of char, reformed gas, and bioethanol. That is, by mixing the metal-containing residue with biomass, the production amounts of ethylene in the ethylene production process, vinyl acetate monomer produced by the vinyl acetate reaction of ethylene and acetic acid, polyvinyl acetate produced by the polymerization reaction of vinyl acetate monomer, and biopolyvinyl alcohol produced by the saponification reaction of polyvinyl acetate are all increased. Furthermore, the effect of increasing the carbonization rate of biomass and the amount of reformed gas by recycling and supplying the metal-containing residue to the biomass may increase with the number of times the metal-containing residue is recycled in this embodiment.

[0052] Since the metal-containing residue is the metal components contained in the biomass recovered as residue, it includes metal elements contained in the raw material, i.e., elements other than carbon contained in the biomass as described above, such as alkali metals or alkaline earth metals including sodium, potassium, lithium, cesium, calcium, magnesium, barium, etc., metalloids such as boron, silicon, germanium, antimony, tellurium, etc., and elements such as aluminum, iron, nickel, etc. In this embodiment, the metal content in the metal-containing residue can be measured by ion chromatography, ICP emission spectrometry, and X-ray fluorescence analysis.

[0053] The ratio of the supply rate (kg / h) of the metal-containing residue to the supply rate (kg / h) of the biomass (supply rate of the metal-containing residue / supply rate of the biomass) is, for example, 0.01 to 10, or 0.05 to 5, or 0.1 to 1. When the ratio is equal to or greater than the lower limit, the carbonization rate of the carbonized product and the reformed gasification rate increase. When the ratio is equal to or less than the upper limit, the mixing efficiency and mixing uniformity of the biomass and the metal-containing residue are improved.

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

[0055] [Gas purification process] The production method of this embodiment may include a gas purification step for purifying the reformed gas obtained in the reformed gasification step. 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, potentially reducing catalytic activity and impairing stability in each subsequent reaction treatment. Therefore, removing such sulfur-containing components can improve the stability of catalytic activity in each step.

[0056] For example, a known gas purifier can be used for gas purification. For example, a gas purifier equipped with a gas purification element 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 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 chemically removed from the reformed gas.

[0057] 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, the gas purification may remove nitrogen-containing components such as ammonia and NOx, and chlorine-containing components such as HCl, in addition to sulfur-containing components.

[0058] [Ethanol production process] The method of this embodiment includes an ethanol production step of producing bioethanol by contacting the reformed gas with a C2 oxygenation catalyst and a hydrogenation catalyst. In the ethanol production process of this embodiment, the reformed gas is brought into contact with a C2 oxygenation catalyst to produce C2 oxygenated compounds such as acetic acid, acetaldehyde, and ethanol from the H, CO, CO, and CH contained in the reformed gas. At the same time, derivatives of the C2 oxygenated compounds, such as methyl acetate and ethyl acetate, may also be produced as by-products. Furthermore, by contacting the reformed gas with a hydrogenation catalyst, the acetic acid, acetaldehyde, methyl acetate, and ethyl acetate are hydrogenated and converted to ethanol. The reaction using these two types of catalysts increases the amount of ethanol produced and also increases the ethanol selectivity. In the ethanol production process of this embodiment, the reformed gas subjected to the ethanol production process contains CO, H2, CH4, and CO2. Since the reformed gas contains CH4 and CO2 in this manner, the ethanol yield is improved compared to when the reformed gas does not contain CH4 and CO2.

[0059] The C2 oxygenation catalyst is a catalyst for efficiently producing the C2 oxygenated compounds from reformed gas. The C2 oxygenation catalyst contains rhodium, at least one element selected from the group consisting of 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)), and a porous carrier. The element (1) contained in the C2 oxygen-containing catalyst may be one type or two or more types. The atomic ratio of element (1) to rhodium (Rh) is preferably 0.001-10, more preferably 0.01-5. Examples of porous supports include porous oxides such as silica, alumina, and interlayer clay minerals. The supported amount of Rh and element (1) is, for example, 0.01% by mass to 10% by mass, or 0.1% by mass to 5% by mass, etc. Here, the supported amount of Rh and element (1) is the ratio of the total mass of Rh and element (1) to the mass of the porous support.

[0060] The C2 oxygenated catalyst can be prepared by known methods. For example, a catalyst precursor is dissolved in a solvent, the resulting solution is impregnated into a porous support, and then an activation treatment is performed to obtain a C2 oxygenated catalyst. Examples of catalyst precursors include salts of Rh and salts of element (1). Examples of salts include hydrochlorides, nitrates, formates, acetates, alkoxide salts, and oxyacid salts. Examples of the solvent include ethanol, methanol, and water. Examples of activation treatment methods include a method in which the temperature is raised stepwise in an oxygen-containing atmosphere in a temperature range of 250° C. to 600° C., and a method in which the temperature is raised stepwise in a hydrogen gas atmosphere in a temperature range of 100° C. to 450° C. Additionally, reduction treatment using a reducing agent such as hydrazine or boron hydride may be used as the hydrogen activation treatment. The selection of catalyst precursor, catalyst production process and activation treatment conditions are not limited to these.

[0061] When producing a C2 oxygenated catalyst in which Rh is supported on a support, a supporting method can be used in which a Rh solution is applied to a porous support such as porous silica, alumina, or an intercalated clay mineral, and then forced into the pores of the porous support. Examples of the Rh solution used in this step include rhodium chloride, rhodium nitrate solution, hexaamminerhodium acetate solution, and tetraamminerhodium hydroxide solution. When producing a C2 oxygenated catalyst in which Rh and element (1) are supported on a porous support, element (1) may be contained in a Rh solution, or a solution of element (1) may be separately applied to the Rh-supported porous support. The Rh solution and the element (1) solution can be simultaneously or successively supported by immersion, dropping, coating, spraying, or the like in a predetermined temperature range.

[0062] In the production of a C2 oxygenated catalyst containing Rh and element (1), at least one chelating agent selected from the group consisting of oxalic acid, citric acid, tartaric acid, lactic acid, and malic acid may be used. The use of a chelating agent improves the ethanol production activity compared to when no chelating agent is used. A method for producing a C2 oxygenated catalyst using a chelating agent includes, for example, impregnating a porous support with a Rh solution and an element (1) solution, drying the support, and then impregnating the support with a chelating agent solution and activating the support.

[0063] The hydrogenation catalyst contains at least one element selected from the group consisting of palladium, iron, nickel, platinum, copper, chromium, zinc, potassium, sodium, cerium, and titanium (hereinafter also referred to as element (2)), and a porous support. The element (2) contained in the hydrogenation catalyst may be one type or two or more types. Examples of porous supports include porous oxides such as silica, alumina, and interlayer clay minerals. The amount of element (2) supported is, for example, 0.01% by mass to 10% by mass, and preferably 0.1% by mass to 5% by mass, where the amount of element (2) supported is the ratio of the total mass of element (2) to the mass of the porous support.

[0064] The hydrogenation catalyst can be produced by a known method. For example, a catalyst precursor is dissolved in a solvent, the resulting solution is impregnated into a porous support, and the support is subjected to an activation treatment to obtain a hydrogenation catalyst. The catalyst precursor may be, for example, a salt of element (2), such as a hydrochloride, a nitrate, an oxalate, an oxyacid salt, or an organic acid salt. Examples of the solvent include ethanol, methanol, and water. Examples of activation treatment methods include a method in which the temperature is raised stepwise in an oxygen-containing atmosphere in a temperature range of 250° C. to 600° C., and a method in which the temperature is raised stepwise in a hydrogen gas atmosphere in a temperature range of 100° C. to 450° C. Additionally, reduction treatment using a reducing agent such as hydrazine or boron hydride may be used as the hydrogen activation treatment. The selection of catalyst precursor, catalyst production process and activation treatment conditions are not limited to these.

[0065] The C2 oxygenation catalyst and the hydrogenation catalyst may be disposed separately, but from the viewpoint of ethanol yield and ethanol selectivity, it is preferable that the C2 oxygenation catalyst and the hydrogenation catalyst are disposed as a mixed composite catalyst. When the C2 oxygenation catalyst and the hydrogenation catalyst are disposed separately, the hydrogenation catalyst is disposed downstream of the C2 oxygenation catalyst and comes into contact with the gas that has been in contact with the C2 oxygenation catalyst.

[0066] When a composite catalyst prepared by mixing the C2 oxygenated catalyst and the hydrogenation catalyst is used in the ethanol production process, the volume ratio of the C2 oxygenated catalyst to the hydrogenation catalyst in the composite catalyst (C2 oxygenated catalyst / hydrogenation catalyst) can be in the range of 0.1 to 5, or 0.2 to 2. When the C2 oxygenated catalyst / hydrogenation catalyst volume ratio is equal to or greater than the lower limit of the range, the C2 oxygenated compound yield is superior, and when it is equal to or less than the upper limit of the range, the ethanol selectivity is superior.

[0067] The reformed gas supplied to the ethanol production process may be pressurized to a predetermined reaction pressure. The reaction pressure in the ethanol production process may be in the range of, for example, 0.1 MPa to 5 MPa, or 1 MPa to 3.5 MPa. The reaction temperature is, for example, in the range of 200°C to 350°C, or 250°C to 300°C. The space velocity of biomass gas (SV: synthesis gas velocity L / h / catalyst volume L) is, for example, 1000 h -1 ~35000h -1 , or 3000h -1 ~25000h -1 The range includes: The gas volume ratio (H2 / (CO+CO2)) of hydrogen to CO and CO2 in the gas is, for example, 0.1 to 10, or 1 to 5, or the like. In the ethanol production process of this embodiment, for example, the ethanol selectivity is set to 50% to 85%, and the ethanol yield (STY: g / L -cat / h)250g / L -cat / h~850g / L -catBioethanol can be obtained at a rate of / h.

[0068] [Ethanol purification process] The method of this embodiment may optionally include a step of purifying the ethanol. In the ethanol production process, bioethanol is obtained as a liquid ethanol product (crude ethanol: 50 to 63% weight concentration), and is therefore purified using ethanol separation and purification means such as a distillation column or a membrane separator, and gas-liquid separation means. The distillation column concentrates and separates ethanol from the liquid ethanol product, and also separates and recovers low-boiling by-product residues such as acetic acid, acetaldehyde, propanol, and methanol. The purification means used in the purification step may be a known means, for example, a multi-stage Raschig ring system or a silicon membrane separation facility.

[0069] The ethanol concentration (ethanol / (ethanol + water) mass ratio × 100) of the crude ethanol (liquid ethanol product) produced in the ethanol production process of this embodiment is, for example, 50% to 63% by mass. In the purification process, the crude ethanol can be concentrated to a mass ratio of 80% to 85% by mass using, for example, the known distillation column. Furthermore, separation and purification to a higher ethanol concentration can be achieved by using a ceramic membrane separation device, which is the known separation means. The concentration of the purified bioethanol is, for example, 86% to 99% by mass. It is preferable to use such high-purity bioethanol to produce ethylene through a dehydration reaction in the subsequent ethylene purification step. In the method of this embodiment, the gas (residual gas) separated from the liquid ethanol product is supplied to a shift reaction step described below, where carbon monoxide, methane, and water vapor contained in the residual gas are subjected to a shift reaction to produce hydrogen and carbon dioxide.

[0070] [Ethylene production process] The method of this embodiment includes an ethylene production step in which ethanol obtained in the ethanol production step is subjected to a dehydration reaction to produce ethylene. In the ethylene production process of this embodiment, ethylene is produced from high-purity bioethanol using an ethanol dehydration reactor or the like equipped with a silica and alumina carrier that has been treated with phosphoric acid or MgO under conditions of 0.1 to 1 MPa and 250 to 480°C. The ethylene may be further treated to remove impurities, or may be pressurized using a booster and stored in a holder. Known conditions and catalysts can be used as appropriate for the reaction conditions and catalysts used in this ethanol dehydration process.

[0071] [Acetic acid manufacturing process] The method of this embodiment includes an acetic acid production step in which ethanol obtained in the ethanol production step is subjected to an oxidation reaction to produce acetic acid. In this embodiment, ethanol generated in the ethanol production process is used to produce acetic acid at a yield of 85 to 95% by oxidation reaction means. The oxidation reaction may involve, for example, the production of acetic acid by partial oxidation of ethanol using oxygen in the presence of a metal oxide-supported catalyst such as alumina, silica, MgO, ZrO2, TiO2, or MoO3 containing Cu, Pt, Pd, or Rh, at 120 to 300°C and atmospheric pressure to 3 MPa. As the reaction conditions and catalyst for the partial oxidation of ethanol, known conditions and catalysts can be used appropriately.

[0072] [Vinyl acetate manufacturing process] The method further includes a vinyl acetate production step in which the ethylene obtained in the ethylene production step and the acetic acid obtained in the acetic acid production step are subjected to an oxidative esterification reaction to produce vinyl acetate. In this embodiment, vinyl acetate monomer is produced using the ethylene and acetic acid obtained in the ethylene production step and the acetic acid production step. Examples of methods for producing vinyl acetate monomer include oxidative esterification under oxygen using a metal-supported catalyst in which Pd, Cu, and Au are impregnated and supported on a metal oxide support such as silica (SiO), ZrO, HfO, TiO, NbO, TaO, WO, LaO, or MgO, or an interlayer clay mineral support such as kaolinite, saponite, smectite, or montmorillonite. Vinyl acetate monomer can be produced in a yield of 85 to 95% by such oxidative esterification. The reaction conditions include, for example, a reaction temperature of 110 to 125° C. and a reaction pressure of 3 to 4 MPa. As the reaction conditions and catalysts used in the vinyl acetate monomer production process of this embodiment, known conditions and catalysts can be used appropriately.

[0073] [Polyvinyl acetate manufacturing process] The method of this embodiment includes a polyvinyl acetate production step of polymerizing the vinyl acetate obtained in the vinyl acetate production step to produce polyvinyl acetate. In this embodiment, vinyl acetate monomer is polymerized in a methanol / water solution in a polymerization reactor using a catalyst such as a radical initiator, e.g., benzoyl peroxide, through solution polymerization or emulsion polymerization to produce polyvinyl acetate with a yield of 85 to 98%. As the reaction conditions and catalysts used in the production process of polyvinyl acetate in this embodiment, known conditions and catalysts can be used appropriately.

[0074] [Polyvinyl alcohol manufacturing process] The method of this embodiment includes a polyvinyl alcohol production step in which the polyvinyl acetate obtained in the polyvinyl acetate production step is subjected to a saponification reaction to produce polyvinyl alcohol. In this embodiment, polyvinyl acetate is subjected to a saponification reaction in a methanol solution in the presence of an alkali catalyst to cleave the acetate ester, thereby producing methyl acetate and polyvinyl alcohol. Examples of the alkali catalyst include sodium hydroxide, potassium hydroxide, sodium methylate, sodium ethylate, and potassium methylate. In this step, polyvinyl alcohols with different solubility and water resistance can be produced by adjusting the molar ratio of hydroxyl groups (saponification degree: mol %=(hydroxyl groups) / (hydroxyl groups+acetic acid groups)×100). Methyl acetate generated in the polyvinyl alcohol production process may be recovered and separated from the saponification reactor, and then subjected to a hydrolysis reaction to produce acetic acid, which may then be recycled and fed back into the vinyl acetate production process. As the reaction conditions and catalysts for the production process of polyvinyl alcohol in this embodiment, known conditions and catalysts can be appropriately used.

[0075] [Shift reaction process] The method of this embodiment includes a shift reaction step in which gas generated in the ethanol production step is separated as residual gas, and carbon monoxide, methane, and steam contained in the residual gas are subjected to a shift reaction to produce hydrogen and carbon dioxide. The residual gas generated in the ethanol production process is a mixed gas containing CO, methane, and CO. The CO and methane in the gas are brought into contact with a shift reaction catalyst in the presence of steam, and a mixed gas of H and CO is produced through the shift reaction described below. In the shift reaction 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 + H2O → CO2 + H2 (6) Methane reforming reaction: CH4 + 2H2O → 4H2 + CO2

[0076] Examples of the shift reaction 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 (hereinafter also referred to as element (3)) 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 carrier can be appropriately selected from known catalyst carriers, and examples thereof include porous oxides such as silica, alumina, and interlayer clay minerals.

[0077] In the shift reaction 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 gas for heating.

[0078] The treatment conditions for the shift reaction in this embodiment are as follows. The heating temperature may be, for example, in the range of 250°C or higher and 600°C or lower, or 300°C or higher and 450°C or lower. The pressure in the shift reaction step of this embodiment may be, for example, 0.05 MPa or more and 5 MPa or less, or 0.09 MPa or more and 1 MPa or less. The residence time in the shift reaction step of this embodiment is, for example, 1 minute or more and 100 minutes or less, or 5 minutes or more and 50 minutes or less. The gas hourly space velocity (GHSV) of the reformed gas relative to the catalyst is, for example, 100 to 5000 h -1 , or 500~3000h -1 The following can be mentioned: By carrying out the shift reaction step under the above reaction conditions, a mixed gas containing hydrogen and carbon dioxide at high concentrations can be obtained more efficiently.

[0079] As described above, carbon dioxide is produced together with hydrogen in the shift reaction step, and the produced carbon dioxide is separated from the hydrogen and introduced into the reformed gasification step. The step of separating hydrogen and carbon dioxide can be carried out in a hydrogen separation step following the shift reaction hydrogen production step.

[0080] The separated hydrogen may be compressed under high pressure to form a compressed gas, or may be cooled to form a liquefied gas. The hydrogen may then be mixed with the reformed gas obtained in the reforming gasification step by a transfer facility.

[0081] [Carbon dioxide and hydrogen separation process] The method of this embodiment includes a carbon dioxide / hydrogen separation step in which carbon dioxide is separated and recovered from a mixed gas of hydrogen and carbon dioxide generated in the shift reaction step, the recovered carbon dioxide is supplied to the reformed gasification step, and the recovered hydrogen is mixed with the reformed gas obtained in the reformed gasification step. By supplying the carbon dioxide obtained in the shift reaction step to the reformed gasification step, the reformed gas can be generated more efficiently in the reformed gasification step.

[0082] The hydrogen obtained in the shift reaction step may be mixed with the reformed gas and supplied to the ethanol production step. In this embodiment, the hydrogen obtained in the shift reaction process can be used to adjust the H / (CO+CO) volume ratio of the reformed gas to a value suitable for ethanol production. This significantly improves the production yield of bioethanol and the ethanol selectivity. Furthermore, the production yields of ethylene and acetic acid in the subsequent ethylene and acetic acid production processes using ethanol, the production yield of vinyl acetate monomer by oxidative esterification of the ethylene with the acetic acid, the production yield of polyvinyl acetate by polymerization of vinyl acetate monomer, and the production yield of biopolyvinyl alcohol by saponification of polyvinyl acetate can be increased.

[0083] The hydrogen obtained in the shift reaction step may be stored in, for example, a hydrogen holder, etc. In this case, it is easy to mix and supply the hydrogen to the reformed gas using a hydrogen supply amount adjusting means, etc. This allows the H2 / (CO+CO2) volume ratio of the reformed gas to be adjusted to a preferred range, for example, 1 to 5 or 1.5 to 2.5, and then the reformed gas can be introduced into the ethanol production step to carry out the ethanol production reaction.

[0084] In the method of this embodiment, hydrogen generated or supplied by other means may be used in addition to the hydrogen obtained in the shift reaction step. For example, hydrogen may be generated using a water electrolysis device or the like, and this hydrogen may be stored in a hydrogen holder or the like together with the hydrogen obtained in the shift reaction step, and used to adjust the H2 / (CO+CO2) volume ratio of the reformed gas.

[0085] In the manufacturing method of this embodiment, the combustion gas generated by air combustion of the dry distillation gas generated together with the carbonized material in the carbonization process may be used as a heat source for heating in at least one of the carbonization process, the reformed gasification process, the ethanol production process, the shift reaction process, the ethylene production process, the vinyl acetate production process, the mixing process, and the polyvinyl alcohol production process. In this way, by recycling the heat and products generated within the system, such as by using the dry distillation gas as exhaust heat gas in each process and by mixing the metal-containing residue generated in the reforming gasification process with the raw biomass, it is possible to reduce emissions outside the system and reduce the environmental burden.

[0086] (Second embodiment: biopolyvinyl alcohol manufacturing apparatus) An apparatus for producing polyvinyl alcohol (biopolyvinyl alcohol) from biomass (hereinafter also simply referred to as a production apparatus) according to this embodiment will be described with reference to FIG. The production apparatus 100 of this embodiment includes a carbonization furnace 20 that carbonizes biomass 1 to produce carbonized material 2; a reforming gasification furnace 30 that receives the carbonized material 2 from the carbonization furnace 20 and gasifies the carbonized material 2 with steam and carbon dioxide to produce a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide; an ethanol production facility 50 that receives the reformed gas from the reforming gasification furnace 30 and brings the reformed gas into contact with a composite catalyst 63 that is prepared using a catalyst mixture regulator 95 and a C2 oxygenation catalyst 58 and a hydrogenation catalyst 59 and introduced through a composite catalyst introduction pipe to produce ethanol; an ethylene production facility 42 that receives the ethanol from the ethanol production facility 50 and dehydrates the ethanol to produce ethylene; an acetic acid production facility 43 that receives the ethanol from the ethanol production facility 50 and oxidizes the ethanol to produce acetic acid; and a gasification furnace 30 that receives ethylene from the ethylene production facility and acetic acid from the acetic acid production facility 43 and oxidizes the ethylene and acetic acid to produce acetic acid. a polyvinyl acetate production facility 45 to which vinyl acetate is introduced from the vinyl acetate production facility 44 and which polymerizes the vinyl acetate to produce polyvinyl acetate; a polyvinyl alcohol production facility 46 to which polyvinyl acetate is introduced from the polyvinyl acetate production facility 45 and which saponifies the polyvinyl acetate to produce polyvinyl alcohol; and a shift reaction facility 53 to which gas generated in the ethanol production facility 50 is introduced and which generates hydrogen and carbon dioxide by a shift reaction of carbon monoxide, methane, and water vapor contained in the gas. The system is also equipped with a mixing means for separating and recovering a metal-containing residue generated in the reforming gasification furnace 30 from the reformed gas and mixing the metal-containing residue with the biomass, and a supply means for separating and recovering carbon dioxide from the mixed gas of hydrogen and carbon dioxide generated in the shift reaction facility 53, supplying the recovered carbon dioxide to the reforming gasification furnace, and supplying the recovered hydrogen to the reforming gasification furnace.

[0087] More specifically, the polyvinyl alcohol production apparatus 100 of this embodiment includes a biomass supply facility 91 for supplying biomass to the carbonization furnace 20, and a biomass dryer 12. The biomass supply facility 91 includes a biomass receiver 11 that receives biomass 1 supplied from outside, and a rotary kiln-type dryer 12 (biomass dryer) that dries the biomass 1 received in the biomass receiver 11. Furthermore, the biomass supply amount adjustment means 80 is provided that supplies biomass 1 from the receiver 11 to the dryer 12. The biomass supply amount adjustment means 80 includes 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 the carbonization furnace 20, and is configured so that the dried biomass 1 from the dryer 12 is transferred to the carbonization furnace 20. The biomass 1 can be supplied to the carbonization furnace 20 continuously or intermittently.

[0088] The carbonization furnace 20 carbonizes the biomass 1 by pyrolysis. Carbonization by pyrolysis is performed by heating the biomass 1 in a low-oxygen or oxygen-free state to pyrolyze it. The pyrolysis of the biomass 1 produces a char 2. In addition to the char, pyrolysis gases 5 such as decomposition gas and tar are also produced. The carbonization furnace 20 may be equipped with a stirring means for stirring the biomass 1. Examples of the stirring means include known stirring devices such as a turntable type and a moving scree type. An air combustor 60 is connected to the carbonization furnace 20. The air combustor 60 combusts the pyrolysis gas (pyrolysis gas 5) generated in the carbonization furnace 20 with an air blower 41 to generate high-temperature combustion gas 6.

[0089] The reforming gasification furnace 30 gasifies the carbide 2. Specifically, the reforming gasification furnace 30 produces a reformed gas 8 (a mixed gas of H, CO, CH, and CO) through a mixed gasification reaction of the carbide 2 with steam 7 and carbon dioxide 9. The reforming gasification furnace 30 includes an inner cylindrical portion 30a and an outer cylindrical portion 30b surrounding the inner cylindrical portion 30a. The inner cylindrical portion 30a accommodates the carbide 2. The inner cylindrical portion 30a is heated by supplying a heating gas to the gap between the inner cylindrical portion 30a and the outer cylindrical portion 30b, and the carbide, steam, and CO2 are heated by the heat from the inner cylindrical portion 30a, thereby progressing the reforming gasification.

[0090] One end of a steam supply pipe 33 is connected to the bottom of the inner cylindrical portion 30a of the reforming-gasification furnace 30, and the other end of the steam supply pipe 33 is connected to the clean water supply source 4 via the steam heat exchanger 31. A steam supply amount regulator 84 is installed in the steam supply pipe 33.

[0091] One end of a carbon dioxide supply pipe 32 is connected to the bottom of the inner cylindrical portion 30a of the reforming-gasification furnace 30, and the other end of the carbon dioxide supply pipe 32 is connected to the gas separation and purification equipment 54. In addition, a carbon dioxide supply amount regulator 83 is installed in the carbon dioxide supply pipe 32. An example of the carbon dioxide supply amount regulator 83 is a mass flow controller. The regulator is configured to allow carbon dioxide to be supplied to the reforming-gasification furnace 30 continuously or intermittently.

[0092] A reformed gas piping 35 is connected to the reforming gasification furnace 30 via a reformed gas supply facility 93, and the reformed gas piping 35 is connected to a dust collector 34 that separates and recovers the metal-containing residue 3 from the reformed gas 8. The dust collector 34 is configured to supply the reformed gas 8 from which the metal-containing residue 3 has been removed to a gas purifier 36, and to transfer the metal-containing residue 3 to a metal-containing residue separation and recovery device 94. The reformed gas 8 passes through the gas purifier 36 and is connected to the ethanol production facility 50 via a reformed gas supply amount regulator 86, a gas mixture preparer 89, and a pressurized gas circulation supply facility 88. The gas purifier 36 further removes sulfur- and chlorine-containing components from the reformed gas 8 from which the metal-containing residue 3 has been separated and removed in the metal-containing residue separation and recovery device 94.

[0093] The metal-containing residue 3 recovered in the metal-containing residue separation and recovery device 94 is stored in the metal-containing residue receiver 38 via the metal-containing residue discharge pipe 39. The metal-containing residue receiver 38 is connected to the biomass receiver 11 via the metal-containing residue supply amount regulator 82, the metal-containing residue recovery amount regulator 65, and the metal-containing residue supply equipment 37, and is configured so that the stored metal-containing residue can be mixed with the biomass in the biomass receiver 11. The metal-containing residue can be supplied to the biomass 1 continuously or intermittently by the metal-containing residue supply equipment 37.

[0094] The ethanol production facility 50 is connected to a catalyst mixture preparer 57 that prepares a composite catalyst 63 by mixing a C2 oxygenation catalyst 58 and a hydrogenation catalyst 59 . The catalyst mixture amount adjuster 95 is disposed in the catalyst mixture preparer 57 to adjust the amount of the C2 oxygenated catalyst mixed with the hydrogenation catalyst. In addition, the ethanol production facility 50 is connected to a shift reaction facility 53 via a gas-liquid separator 52. The shift reaction facility 53 generates hydrogen and carbon dioxide by shift reaction of carbon monoxide and methane contained in the reaction gas generated in the ethanol production facility 50 with water vapor.

[0095] The gas-liquid separator 52 is connected to an ethanol separation and purification facility 56 via a crude ethanol piping 77. The ethanol separation and purification facility 56 is provided to separate, purify, and concentrate ethanol from a liquid product containing ethanol.

[0096] The shift reaction equipment 53 is connected to the gas separation and purification equipment 54 via an H2 / CO2 gas pipe 64. The hydrogen and carbon dioxide generated in the shift reaction equipment 53 are supplied to the gas separation and purification equipment 54 via the H2 / CO2 gas pipe 64.

[0097] The gas separation and purification equipment 54 is connected to the hydrogen holder 55 via a hydrogen supply pipe 79 and is configured to store hydrogen generated in the shift reaction equipment 53 in the hydrogen holder 55 . The carbon dioxide 9 separated and recovered in the gas separation and purification equipment 54 is supplied to the reforming gasification furnace 30 via the carbon dioxide supply pipe 32. The carbon dioxide supply pipe 32 is provided with a carbon dioxide supply amount regulator 83 that adjusts the amount of carbon dioxide supplied to the reforming gasification furnace 30.

[0098] The apparatus of this embodiment is equipped with a water electrolysis facility 40. The water electrolysis facility 40 receives clean water from a clean water supply source 4 and generates hydrogen by electrolyzing the water. The hydrogen generated in the water electrolysis facility 40 is stored in a hydrogen holder 55 via a hydrogen supply pipe 51 and a water electrolysis hydrogen supply regulator 87. Commercially available electricity can be used as the electricity to operate the water electrolysis equipment 40. However, in order to reduce carbon dioxide emissions in the bioethanol production process, it is preferable to use electricity obtained from renewable energy sources such as solar power generation, wind power generation, and nuclear power generation.

[0099] The hydrogen holder 55 is connected to a gas mixture preparer 89 via a hydrogen supply pipe 78. A hydrogen supply amount regulator 85 is provided on the hydrogen supply pipe 78. The hydrogen supply amount regulator 85 regulates the amount of hydrogen stored in the hydrogen holder 55 that is supplied to the gas mixture preparer 89. The gas mixture adjuster 89 is provided to adjust the mixture of hydrogen from the hydrogen holder 55 with the reformed gas. The pressurized gas circulation supply equipment 88 is configured to pressurize the reformed gas with an adjusted H2 / (CO+CO2) volume ratio and circulate it to the ethanol production equipment 50.

[0100] The apparatus of this embodiment is provided with a combustion gas piping system 70 that supplies the combustion gas generated by air combustion of the dry distillation gas generated together with the carbonized material 2 in the carbonization furnace 20 as a heat source for heating to at least one of the carbonization furnace 20, the reforming gasification furnace 30, the ethanol production equipment 50, the shift reaction equipment 53, the ethylene production equipment 42, the vinyl acetate production equipment 44, and the polyvinyl alcohol production equipment 46. The combustion gas piping equipment 70 is composed of a plurality of combustion gas pipes 71 to 76, and supplies the combustion gas 6 generated by the air combustor 60 to each equipment via the combustion gas pipes and the combustion gas flow regulator 61 as exhaust heat gas. That is, the combustion gas piping equipment 70 is composed of combustion gas piping 71 that supplies combustion gas to the biomass dryer 12, combustion gas piping 72 that supplies combustion gas to the carbonization furnace 20, combustion gas piping 73 that supplies combustion gas to the reforming gasification furnace 30, combustion gas piping 74 that supplies combustion gas to the steam heat exchanger 31, combustion gas piping 75 that supplies combustion gas to the ethanol production equipment 50, combustion gas piping 76 that supplies combustion gas to the shift reaction equipment 53, combustion gas piping 96 that supplies combustion gas to the ethylene production equipment 42, combustion gas piping 97 that supplies combustion gas to the vinyl acetate production equipment 44, combustion gas piping 98 that supplies combustion gas to the polyvinyl acetate production equipment 45, and combustion gas piping 99 that supplies combustion gas to the polyvinyl alcohol production equipment 46.

[0101] The ethylene production facility 42 is connected to the ethanol production facility 50 via a gas-liquid separator 52 and an ethanol separation and purification facility 56, and is configured to receive the separated and purified ethanol. The ethylene production facility 42 is equipped with an ethanol dehydration reactor capable of producing ethylene 66 through a dehydration reaction.

[0102] The acetic acid production facility 43 is connected to the ethanol production facility 50 via a gas-liquid separator 52 and an ethanol separation and purification facility 56, and is provided so that separated and purified ethanol can be introduced therein. The acetic acid production facility 43 is equipped with an oxidation reactor capable of producing acetic acid by an oxidation reaction of ethanol. A metal oxide supported catalyst is disposed in the reactor.

[0103] The vinyl acetate production facility 44 is configured to receive ethylene 66 and acetic acid 67 from the ethylene production facility 42 and the acetic acid production facility 43, respectively. The vinyl acetate production facility 44 is equipped with a reactor capable of producing vinyl acetate monomer 68 by an oxidative esterification reaction.

[0104] The polyvinyl acetate production facility 45 is configured to receive vinyl acetate monomer 68 from the vinyl acetate production facility 44. The polyvinyl acetate production facility 45 is equipped with a polymerization reactor in which a catalyst such as a radical initiator is placed, and is configured to be able to produce polyvinyl acetate by a solution polymerization or emulsion polymerization reaction.

[0105] The polyvinyl alcohol production facility 46 is configured to receive polyvinyl acetate from the polyvinyl acetate production facility 45. The polyvinyl alcohol production facility 46 is equipped with a saponification reactor, which is configured to be able to produce biopolyvinyl alcohol by a saponification reaction through hydrolysis. The saponification reactor is configured to be able to recover acetic acid generated in the saponification reaction and recycle it into the vinyl acetate production facility 44 via acetic acid recovery / recycle piping 48. The biopolyvinyl alcohol 69 obtained in the saponification reactor is stored in a reservoir. In addition, the manufacturing apparatus of this embodiment is configured so that polyvinyl acetate 49 manufactured in the polyvinyl acetate manufacturing equipment 45 is temporarily stored in a polyvinyl acetate container 47 before being introduced into the polyvinyl alcohol manufacturing equipment 46.

[0106] The method for producing polyvinyl alcohol using the biopolyvinyl alcohol production apparatus 100 of this embodiment may be the same as the production method of the first embodiment. Furthermore, the production method may use all or part of the functions of the production apparatus 100 of this embodiment. That is, the embodiment of the production method and the embodiment of the production apparatus are shown as independent and separate embodiments.

[0107] The method and apparatus for producing bio-based polyvinyl alcohol according to the present embodiment are as described above, but the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. 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. [Example]

[0108] 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.

[0109] (Test 1) A test for producing bio-polyvinyl alcohol was carried out using the polyvinyl alcohol production apparatus configured as shown in Figure 1. In this test, 285 kg / h of construction waste chips (moisture content 25% by mass) were fed into the dryer and carbonization furnace, and the carbonization rate (wt%) of the carbonized material in the carbonization furnace and the amount of reformed gas produced in the reforming gasification furnace (Nm 3 / h), reformed gas component composition (vol%), bioethanol production rate (kg / h), and biopolyvinyl alcohol production rate (kg / h) were measured.

[0110] In this test, 120 kg / h of steam and 80 Nm of CO2 were fed into the reforming gasification furnace. 3 / h was fed to the mixed reformer and gasified. Experimental results for the carbonization rate, reformed gas production volume, reformed gas composition, ethanol production volume, and bio-polyvinyl alcohol production volume were shown in Table 1, with and without recycling the metal-containing residue (15 kg / h) separated and recovered by a cyclone dust collector to a construction waste chip receiver. In this experiment, the reaction conditions for ethylene production by ethanol dehydration were 480°C and 0.5 MPa. The oxidative esterification reaction of ethylene with acetic acid was carried out at a reaction temperature of 110–125°C and a reaction pressure of 3.5 MPa, producing vinyl acetate monomer with an 85% yield. Polyvinyl acetate was produced in a 90% yield by emulsion polymerization using vinyl acetate monomer and benzoyl peroxide as a radical polymerization initiator. Bio-vinyl alcohol (bio-PVA) was produced with an 89% degree of saponification by saponification of the polyvinyl acetate in a methanol solution in the presence of NaOH as an alkaline catalyst.

[0111] The reformed gas component composition and the CO, hydrogen, CO2, CH4 in the outlet gas of the shift reaction hydrogen production unit (shift reaction equipment), and the liquid components including ethanol generated in the ethanol production equipment were analyzed using a thermal conductivity gas chromatograph analyzer (Shimadzu GC-14B) filled with Gaskuropack and molecular sieve 13X, and an FID gas chromatograph analyzer (Shimadzu GC-8A). The flow rate of the exhaust gas was measured with 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 per kg of the metal-containing residue obtained in this test were Na 25g / kg, K 85g / kg, Ca 36g / kg, Mg 7.5g / kg, Ba 5g / kg, Fe 7.5g / kg, and Ni 1.8g / kg.

[0112] (C2 oxygenation catalyst 1) The chlorides or nitrates of Rh, Mg, V, Hf, Ir, and Ce were dissolved in a mixed solvent of ethanol and water in an atomic ratio of 1:0.3:0.2:0.5:0.2 to obtain an ethanol aqueous solution. This ethanol aqueous solution was applied to a silica support (specific surface area 315 m 2 After impregnation with 1000 ppm of SiO2 / g, the catalyst was activated by heating the catalyst to 150°C over 1 hour in a stream of a hydrogen and nitrogen gas (1:3 volume ratio), maintaining the temperature for 2 hours, heating the catalyst to 450°C over 2 hours, maintaining the temperature for 2 hours, and then cooling the catalyst to room temperature. This resulted in the preparation of C2 oxygenated catalyst 1, in which Rh, Mg, V, Hf, Ir, and Ce were supported on a silica support.

[0113] (Hydrogenation catalyst 1) Cu and Cr nitrates and Ti and Mo chlorides were dissolved in a mixed solvent of ethanol and water so that the atomic ratio of Cu:Cr:Ti:Mo was 1:0.6:0.3:0.15, to obtain an ethanol aqueous solution. This ethanol aqueous solution was applied to a silica support (specific surface area 365 m). 2After impregnating the catalyst with Cu, Cr, Ti, and Mo, the catalyst was activated by heating it to 100°C over 1 hour in a stream of a mixed gas of hydrogen and nitrogen gas (1:2 volume ratio), maintaining the temperature for 2 hours, heating it to 450°C over 2 hours, maintaining the temperature for 3 hours, and then cooling it to room temperature. This resulted in the preparation of hydrogenation catalyst 1, in which Cu, Cr, Ti, and Mo were supported on a silica support. A composite catalyst prepared by mixing a C2 oxygenation catalyst (100 kg) and a hydrogenation catalyst (200 kg) in a commercially available mixer was packed into a titanium-coated stainless steel reactor. Bioethanol was produced by contacting the reformed gas with the composite catalyst. The bulk density of the prepared catalyst in this test was 0.5 kg / L.

[0114] [Table 1]

[0115] As shown in Table 1, the carbonization rate, amount of reformed gas produced, and amount of ethanol and biopolyvinyl alcohol produced in the carbonization process using construction waste chips were significantly improved when the metal-containing residue was recycled into construction waste chips (Example 1) compared to when it was not recycled (Comparative Example 1).

[0116] (Test 2) Similar to Test 1, tests were conducted using sugarcane bagasse to determine the carbonization rate, reformed gas production volume, ethanol production volume, and bio-polyvinyl alcohol (PVA) production volume. Sugarcane bagasse was fed at a rate of 350 kg per hour. The carbonization operation was carried out at a furnace temperature of 250°C to 420°C. The reformed gasification process of the carbonized material was carried out at a temperature of 900°C, with steam at 150 kg / h and CO2 at 100 Nm3. 3 The reformed gas production amount (Nm m) was measured when the mixture was supplied at 150 kg / h (Example 2) and when steam was supplied alone at 150 kg / h (Comparative Example 2). 3 / h), reformed gas component composition (vol%), and the test results of the ethanol production amount (kg-EtOH / h) and bio-polyvinyl alcohol production amount (kg / h) in the bioethanol production process using the reformed gas are shown in Table 2. In this study, the reaction conditions for ethylene production by dehydration of ethanol were 480°C and 0.5 MPa. The oxidative esterification reaction of ethylene with acetic acid was carried out at a reaction temperature of 110-125°C and a reaction pressure of 3 MPa. The saponification reaction of polyvinyl acetate was carried out in a methanol solution in the presence of potassium methylate. The degree of saponification of the obtained biopolyvinyl alcohol was 85%.

[0117] In this test, the metal-containing residue separated and recovered by the cyclone dust collector was mixed into a rice straw receiver at a rate of 15 kg per hour, and carbonization and gasification were carried out. The metal contents per kg of the metal-containing residue obtained in this test were 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.

[0118] (C2 oxygenation catalyst 2) Chlorides of Rh, Mn, Li, Sc, and Ce were dissolved in a mixed solvent of ethanol and water in an atomic ratio of 1:0.1:0.25:0.10:0.02 to obtain an aqueous ethanol solution. This aqueous ethanol solution was applied to a silica support (specific surface area 385 m). 2 After impregnation with 100°C (1:4 by volume) of SiO2, the catalyst was activated by heating the catalyst to 100°C over 1 hour in a stream of a hydrogen and nitrogen gas mixture (1:4 by volume), maintaining the temperature for 2 hours, then heating the catalyst to 400°C over 2 hours, maintaining the temperature for 2 hours, and then cooling the catalyst to room temperature. This resulted in the preparation of C2 oxygenated catalyst 2, in which Rh, Mn, Li, Sc, and Ce were supported on a silica support.

[0119] (Hydrogenation catalyst 2) 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 to obtain an ethanol aqueous solution. This ethanol aqueous solution was applied to a silica support (specific surface area 265 m). 2After impregnation with Pd, the silica support was activated by heating it to 100°C over 1 hour under a mixed gas flow of hydrogen and nitrogen gas (1:2 volume ratio), maintaining it for 2 hours, then heating it to 400°C over 2 hours, maintaining it for 2 hours, and cooling it to room temperature. 、 A hydrogenation catalyst 2 supporting Cu, Zn, K, and Zr was prepared. Made The bulk density of the catalyst is 0.5 kg / L. The composite catalyst, which was prepared by mixing C2 oxygenation catalyst (160 kg) and hydrogenation catalyst (320 kg) in a mixer, was packed into a titanium-coated stainless steel reactor. Bioethanol was produced by contacting the reformed gas with the composite catalyst.

[0120] [Table 2]

[0121] As shown in Table 2, in the reforming gasification process of carbonized material made from sugarcane bagasse, the amount of reformed gas produced, the amount of ethanol produced, and the amount of biopolyvinyl alcohol produced under the mixed supply conditions of steam and CO2 (Example 2) were shown to be significantly increased compared to the case where steam was supplied alone (Comparative Example 2).

[0122] (Test 3) In a similar embodiment to Test 2, 450 kg / h of cedar chips (35% moisture content) were used as biomass and carbonized and gasified. The resulting reformed gas was contacted with a composite catalyst prepared by mixing a C2 oxygen-containing catalyst 2 and a hydrogenation catalyst 2 to produce bioethanol. In this test, the reaction gas separated by a gas-liquid separator in the ethanol production facility was fed into a shift reactor, and the resulting hydrogen and CO2 mixed gas was separated from the CO2 by a ceramic membrane separation facility. The residual hydrogen was stored in a hydrogen holder. Hydrogen was supplied from the hydrogen holder to the reformed gas by gas mixing and preparation, and the H2 / (CO + CO2) volume ratio in the reformed gas was adjusted to 2.5 (Example 3), and when hydrogen was not supplied (Comparative Example 3). Table 3 shows the reformed gas conversion rate (ethanol / (CO + CO2) molar ratio %), ethanol selectivity (%), ethanol yield (STY: g-EtOH / L-cat / h), and biovinyl alcohol production amount (kg-PVA / h).

[0123] [Table 3]

[0124] As shown in Table 3, when residual hydrogen generated in the shift reactor was supplied to the reformed gas (Example 3), the ethanol selectivity and ethanol yield increased compared to when hydrogen was not supplied (Comparative Example 3). This resulted in a significant increase in the amount of ethylene produced in the subsequent ethylene production process using ethanol and the amount of biopolyvinyl alcohol produced.

[0125] (Test 4) In the same ethanol production apparatus and embodiment as in Example 1, the C2 oxygenated catalyst 1 and the hydrogenation catalyst 1 were mixed in a mass ratio of (volume ratio) The composite catalyst obtained by mixing and preparing the catalyst in a 1:1 ratio using a catalyst mixer was packed into a titanium-coated stainless steel reactor. The reformed gas was then pumped into the reactor at 2.5 MPa, 285°C, and SV=25,000 h. -1Table 4 shows the reformed gas conversion rate, ethanol selectivity, ethanol yield (STY: g-EtOH / L-cat / h), and biopolyvinyl alcohol production amount (kg-PVA / h) in ethanol production when the same amount of C2 oxygenated catalyst 1 was packed in the upper layer and the same amount of hydrogenation catalyst 1 was packed in the lower layer of a reactor (Example 5) as in the case of producing ethanol by catalytic circulation reaction on a composite catalyst (Example 4).

[0126] [Table 4]

[0127] As shown in Table 4, when a composite catalyst prepared by mixing a C2 oxygenated catalyst and a hydrogenation catalyst was used (Example 4), the ethanol yield, ethanol selectivity, and amount of biopolyvinyl alcohol produced were improved compared to when the C2 oxygenated catalyst and the hydrogenation catalyst were packed separately in a layered manner (Example 5). [Explanation of symbols]

[0128] 1. Biomass 2. Carbide 3 Metal-containing residue 4. Source of drinking water 5 Dry distillation gas (including tar) 6 Combustion gas 7. Water Vapor 8. Reformed gas 9. Carbon dioxide 10 Hydrogen 11 Biomass receiver 12 Biomass dryer 20 Carbonization furnace 30 Reforming gasifier 31 Steam heat exchanger 32 Carbon dioxide supply pipe 33 Steam supply piping 34 Dust collector 35 Reformed gas piping 36 Gas Purifier 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 Ethylene production facility 43 Acetic acid production facility 44 Vinyl acetate manufacturing facility 45 Polyvinyl acetate manufacturing facility 46 Polyvinyl alcohol manufacturing facility 47 Polyvinyl acetate containers 48 Acetic acid recovery and recycling piping 49 Polyvinyl acetate 50 Ethanol production facility 51 Hydrogen supply piping 52 Gas-liquid separator 53 Shift reaction hydrogen production equipment (shift reaction equipment) 54 Gas separation and purification equipment 55 Hydrogen Holder 56 Ethanol separation and purification facility 57 Catalyst mixer (catalyst mixer and preparer) 58 C2 oxygenation catalyst 59 Hydrogenation catalyst 60 Air Combustor 61 Combustion gas flow regulator 62 Composite catalyst introduction equipment 63 Composite Catalyst 64 H2 / CO2 gas piping 65 Metal-containing residue recovery amount adjuster 66 Ethylene 67 Acetic Acid 68 Vinyl acetate monomer 69 Biopolyvinyl alcohol (PVA) 70 Combustion gas piping equipment 71 Combustion gas piping (for dryer) 72 Combustion gas piping (for carbonization furnace) 73 Combustion gas piping (for reforming gasification furnace) 74 Combustion gas piping (for steam heat exchanger) 75 Combustion gas piping (for ethanol production equipment) 76 Combustion gas piping (for shift reaction hydrogen production equipment) 77 Crude ethanol piping 78 Hydrogen supply piping 79 Hydrogen supply piping 80 Biomass supply regulator (biomass supply regulator) 81 Carbide supply amount regulator (carbide supply amount adjustment means) 82 Metal-containing residue supply amount adjuster (metal-containing residue separation and recovery means) 83 Carbon dioxide supply regulator (carbon dioxide supply regulator) 84 Steam supply regulator 85 Hydrogen supply regulator 86 Reformed gas supply regulator (reformed gas supply equipment) 87 Water electrolysis hydrogen supply amount regulator 88 Pressurized gas circulation supply equipment 89 Gas Mixture Preparer 90 Bioethanol 91 Biomass supply facility 92 Carbide supply equipment 93 Reformed gas supply equipment 94 Metal-containing residue separation and recovery device (Metal-containing residue separation and recovery means) 95 Catalyst mixture amount regulator (catalyst mixture amount adjustment means) 96 Combustion gas piping (for ethylene production facilities) 97 Combustion gas piping (for vinyl acetate manufacturing equipment) 98 Combustion gas piping (for polymerization reactor) 99 Combustion gas piping (for saponification reactor) 100 Biopolyvinyl alcohol manufacturing equipment

Claims

1. a carbonization step of carbonizing the biomass to produce a carbonized product; a reforming-gasification step of gasifying the carbide, steam, and carbon dioxide to generate a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide; The reformed gas is ２ an ethanol production step of contacting the mixture with an oxygenation catalyst and a hydrogenation catalyst to produce ethanol; an ethylene production step in which ethanol obtained in the ethanol production step is subjected to a dehydration reaction to produce ethylene; an acetic acid production step in which the ethanol obtained in the ethanol production step is subjected to an oxidation reaction to produce acetic acid; a vinyl acetate production step in which the ethylene obtained in the ethylene production step and the acetic acid obtained in the acetic acid production step are subjected to an oxidative esterification reaction to produce vinyl acetate; a polyvinyl acetate production step in which the vinyl acetate obtained in the vinyl acetate production step is polymerized to produce polyvinyl acetate; a polyvinyl alcohol production step in which the polyvinyl acetate obtained in the polyvinyl acetate production step is subjected to a saponification reaction to produce polyvinyl alcohol; a mixing step of separating and recovering a metal-containing residue generated in the reformed gasification step from the reformed gas and mixing the metal-containing residue with the biomass; a shift reaction step in which gas generated in the ethanol production step is separated and carbon monoxide, methane, and water vapor contained in the separated gas are subjected to a shift reaction to produce hydrogen and carbon dioxide; a carbon dioxide / hydrogen separation process in which carbon dioxide is separated and recovered from a mixed gas of hydrogen and carbon dioxide generated in the shift reaction process, the recovered carbon dioxide is supplied to the reformed-gasification process, and the recovered hydrogen is mixed with the reformed gas obtained in the reformed-gasification process.

2. 2. The method for producing polyvinyl alcohol according to claim 1, wherein the metal-containing residue contains at least one element selected from the group consisting of alkali metals, alkaline earth metals, semimetals, aluminum, iron, and nickel.

3. 3. The method for producing polyvinyl alcohol according to claim 1, wherein the shift reaction step uses a shift reaction catalyst comprising 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.

4. 3. The method for producing polyvinyl alcohol according to claim 1 or 2, wherein the combustion gas generated by air combustion of the dry distillation gas generated together with the carbonized material in the carbonization process is used as a heat source for heating in at least one of the carbonization process, the reformed gasification process, the ethanol production process, the shift reaction process, the ethylene production process, the vinyl acetate production process, the mixing process, and the polyvinyl alcohol production process.

5. Said C ２ 3. The method for producing polyvinyl alcohol according to claim 1 or 2, wherein the oxygenation catalyst comprises rhodium, at least one element selected from the group consisting of 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.

6. 3. The method for producing polyvinyl alcohol according to claim 1, wherein the hydrogenation catalyst comprises at least one element selected from the group consisting of palladium, iron, nickel, platinum, copper, chromium, zinc, potassium, sodium, cerium, and titanium, and a porous support.

7. In the ethanol production process, ２ A composite catalyst prepared by mixing an oxygen-containing catalyst and the hydrogenation catalyst is used, and the C relative to the hydrogenation catalyst in the composite catalyst is ２ Mixing volume ratio of oxygenated catalyst (C ２ 3. The method for producing polyvinyl alcohol according to claim 1, wherein the ratio of the oxygenation catalyst to the hydrogenation catalyst is 0.1 or more and 5 or less.

8. a carbonization furnace for carbonizing biomass to generate a carbonized product; a reforming gasification furnace into which the carbonized material is introduced from the carbonization furnace and into which the carbonized material, water vapor, and carbon dioxide are subjected to a gasification reaction to generate a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide; The reformed gas is introduced from the reforming gasification furnace, and the reformed gas is ２ an ethanol production facility that produces ethanol by contacting the ethanol with an oxygenation catalyst and a hydrogenation catalyst; an ethylene production facility into which ethanol is introduced from the ethanol production facility and which dehydrates the ethanol to produce ethylene; an acetic acid production facility into which ethanol is introduced from the ethanol production facility and which generates acetic acid by oxidizing the ethanol; a vinyl acetate production facility into which ethylene from the ethylene production facility and acetic acid from the acetic acid production facility are introduced, and which produces vinyl acetate by subjecting the ethylene and acetic acid to an oxidative esterification reaction; a polyvinyl acetate production facility into which vinyl acetate is introduced from the vinyl acetate production facility and which polymerizes the vinyl acetate to produce polyvinyl acetate; a polyvinyl alcohol production facility into which polyvinyl acetate is introduced from the polyvinyl acetate production facility and which saponifies the polyvinyl acetate to produce polyvinyl alcohol; a shift reaction facility into which gas generated in the ethanol production facility is introduced and into which carbon monoxide, methane, and steam contained in the gas are subjected to a shift reaction to produce hydrogen and carbon dioxide; a mixing means for separating and recovering a metal-containing residue generated in the reforming gasification furnace from the reformed gas and mixing the metal-containing residue with the biomass; a supply means for separating and recovering carbon dioxide from a mixed gas of hydrogen and carbon dioxide generated in the shift reaction facility, supplying the recovered carbon dioxide to the reforming gasification furnace, and supplying the recovered hydrogen to the reforming gasification furnace.

9. 9. The apparatus for producing polyvinyl alcohol according to claim 8, wherein the metal-containing residue contains at least one element selected from the group consisting of alkali metals, alkaline earth metals, semimetals, aluminum, iron, and nickel.

10. 10. The apparatus for producing polyvinyl alcohol according to claim 8 or 9, wherein the shift reaction facility uses a shift reaction catalyst comprising 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.

11. 10. The polyvinyl alcohol production apparatus according to claim 8 or 9, further comprising a combustion gas piping system that supplies combustion gas generated by air combustion of the dry distillation gas generated together with the carbonized material in the carbonization furnace as a heat source for heating to at least one of the carbonization furnace, the reforming gasification furnace, the ethanol production equipment, the shift reaction equipment, the ethylene production equipment, the vinyl acetate production equipment, and the polyvinyl alcohol production equipment.

12. Said C ２ 10. The apparatus for producing polyvinyl alcohol according to claim 8 or 9, wherein the oxygenation catalyst comprises rhodium, at least one element selected from the group consisting of 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.

13. 10. The apparatus for producing polyvinyl alcohol according to claim 8 or 9, wherein the hydrogenation catalyst comprises at least one element selected from the group consisting of palladium, iron, nickel, platinum, copper, chromium, zinc, potassium, sodium, cerium, and titanium, and a porous carrier.

14. The ethanol production facility is ２ A composite catalyst is provided which is prepared by mixing an oxygen-containing catalyst and the hydrogenation catalyst, and the C relative to the hydrogenation catalyst in the composite catalyst is ２ Mixing volume ratio of oxygenated catalyst (C ２ 10. The apparatus for producing polyvinyl alcohol according to claim 8 or 9, wherein the ratio of the oxygenation catalyst to the hydrogenation catalyst is 0.1 or more and 5 or less.

15. Further provided with water electrolysis equipment and a hydrogen holder, 10. The polyvinyl alcohol production apparatus according to claim 8, further comprising piping equipment for introducing hydrogen generated in the ethanol production equipment and / or hydrogen generated in the water electrolysis equipment into the hydrogen holder.

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