Method for producing bioethanol, apparatus for producing bioethanol

Abstract

A carbonization step of carbonizing biomass to produce a carbide, a reforming gasification step of performing a mixed gasification reaction of the carbide with steam and carbon dioxide to produce a reformed gas containing hydrogen, carbon monoxide, methane and carbon dioxide, and the reformed gas is C 2 An ethanol production step of producing ethanol by bringing it into contact with an oxygen-containing catalyst and a hydrogenation catalyst, and separating and recovering a metal-containing residue generated together with the reformed gas in the reforming gasification step from the reformed gas, and mixing the metal-containing residue with the biomass. A method for producing bioethanol having a mixing step.

Description

Technical Field

[0001] The present invention relates to a method for producing bioethanol and an apparatus for producing bioethanol. This application claims priority based on Japanese Patent Application No. 2024-048238 filed in Japan on March 25, 2024, and incorporates its content herein by reference.

Background Art

[0002] Generally, biomass is a substance derived from organisms that can be used as an energy source or industrial raw material. Biomass includes, for example, thinned wood, agricultural products, processed products such as food, cotton cloth, clothing fibers, and furniture made from them, construction waste, and organic waste such as household waste. Since biomass is cyclically generated by the action of solar energy, air, water, carbon dioxide gas, soil, etc., it is an infinitely renewable neutral carbon substance.

[0003] Fermentation methods for bioethanol, manufacturing technologies for bioethanol, manufacturing systems for bioethanol, etc. using food biomass such as rice, corn, sugarcane, and taro as raw materials have been developed. On the other hand, manufacturing methods for bioethanol that utilize non-food biomass raw materials such as thinned wood and agricultural / industrial waste are useful as technologies for reducing the volume and recycling of agricultural / industrial waste. Currently, the development of manufacturing technologies for bioethanol that expand the range of raw material selection is desired.

[0004] Conventionally, as a method for converting non-food biomass into bioethanol, a hydrothermal decomposition method of biomass is known. The hydrothermal decomposition method of biomass is a method of extracting sugar components in the presence of acid or alkali and fermenting the obtained sugar components to obtain bioethanol. The hydrothermal decomposition method of biomass has technical and economic problems related to the production of bioethanol, such as low yield of bioethanol and high production cost.

[0005] On the one hand, technologies for gasifying biomass have been proposed. As technologies for gasifying biomass, for example, technologies for directly gasifying biomass by thermochemical gasification reaction using air and steam in a gasification furnace such as a fixed bed or a fluidized bed have been reported. Further, as technologies for gasifying biomass, for example, technologies for gasifying carbides obtained by thermal decomposition reaction of biomass with steam have been reported. As utilization methods of the gas generated by the biomass gasification technology (hereinafter sometimes referred to as "biomass gas" or "reformed gas"), production technologies such as gas engine power generation, hydrogen production, production of alcohols such as methanol and ethanol, and Fischer-Tropsch (FT) hydrocarbon fuel production are known (see Patent Documents 1 to 4, Non-Patent Documents 1 to 3).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Non-Patent Documents

[0007]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, in the conventional biomass pyrolysis carbonization technology, the carbonization of biomass does not proceed efficiently and uniformly, resulting in a low carbonization rate of the carbide, a low yield of reformed gas in the gasification of the carbide, and in addition, there is a problem that bioethanol cannot be efficiently and stably obtained in the bioethanol production process using the reformed gas.

[0009] The present invention has been made in view of the above problems, and aims to provide a method for producing bioethanol and a bioethanol production apparatus that can improve the carbonization rate of the carbide obtained in the carbonization process using biomass, improve the yield of reformed gas by gasifying the carbide, and efficiently and stably produce bioethanol.

Means for Solving the Problems

[0010] The present invention has the following aspects. [1] A carbonization step of carbonizing biomass to produce a carbide, A reformed gasification step of performing a mixed gasification reaction of the carbide with a mixed gas of steam and carbon dioxide to produce a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide, An ethanol production step of producing ethanol by bringing the reformed gas into contact with an oxygen-containing catalyst and a hydrogenation catalyst, 2 A bioethanol production method having a mixing step of separating and recovering a metal-containing residue generated together with the reformed gas in the reformed gasification step from the reformed gas and mixing the metal-containing residue with the biomass. [2] The method for producing bioethanol according to [1], wherein the metal-containing residue contains at least one element selected from the group consisting of an alkali metal, an alkaline earth metal, a metalloid, aluminum, iron, and nickel. [2] The method for producing bioethanol according to [1], wherein the metal-containing residue contains at least one element selected from the group consisting of an alkali metal, an alkaline earth metal, a metalloid, aluminum, iron, and nickel. [3] A shift reaction step of subjecting carbon monoxide, methane, and steam contained in the residual gas after separating the liquid product containing ethanol from the gas generated in the ethanol production step to a shift reaction to produce hydrogen and carbon dioxide, the method for producing bioethanol according to [1] or [2]. [4] A supply step of separating and recovering carbon dioxide from the mixed gas of hydrogen and carbon dioxide generated in the shift reaction step, supplying the recovered carbon dioxide to the reforming gasification step, and supplying the hydrogen to the reforming gas, the method for producing bioethanol according to [3]. [5] In the shift reaction step, using 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 carrier, the method for producing bioethanol according to [3] or [4]. [6] Air-combusting the dry distillation gas generated together with the carbide in the carbonization step, and using the generated combustion gas as a heat source for heating at least one of the carbonization step, the reforming gasification step, the ethanol production step, and the shift reaction step, the method for producing bioethanol according to any one of [1] to [5]. [7] The C 2 The oxygen-containing catalyst contains Rh, at least one element selected from the group consisting of Mn, Sc, Li, Na, K, Cs, Mg, Ba, Pt, Pd, Ir, Mo, W, V, Zr, Hf, Ti, Y, Ce, and La, and a porous carrier, the method for producing bioethanol according to any one of [1] to [6]. [8] 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, and a porous carrier, the method for producing bioethanol according to any one of [1] to [7]. [9] In the ethanol production step, using a composite catalyst prepared by mixing the oxygen-containing catalyst and the hydrogenation catalyst, and in the composite catalyst, the C with respect to the hydrogenation catalyst 2 ​2 Volume ratio of the oxygenated catalyst (C 2 The method for producing bioethanol according to any one of [1] to [8], wherein the volume ratio of the oxygenated catalyst / hydrogenated catalyst) is 0.1 or more and 5 or less.

[10] A reforming gasification furnace, A biomass supply facility, Biomass supply amount adjusting means, A biomass dryer having means for adjusting and controlling the dryness of the biomass, A carbonization furnace having means for adjusting the temperature rise, A carbide supply facility for supplying carbide to the reforming gasification furnace, Carbide supply amount adjusting means for adjusting the supply amount of the carbide to the reforming gasification furnace, A supply facility for supplying steam and carbon dioxide to the reforming gasification furnace, Carbon dioxide supply amount adjusting means for adjusting the supply amounts of the steam and the carbon dioxide to the reforming gasification furnace, A reformed gas supply facility for supplying reformed gas to the reforming gasification furnace, The reformed gas to C 2 An ethanol production facility for producing bioethanol by bringing the reformed gas into contact with an oxygenated catalyst and a hydrogenated catalyst, Separation and recovery means for separating and recovering metal-containing residues generated together with the reformed gas from the reformed gas, A metal residue supply facility for supplying and mixing the recovered metal-containing residues to the biomass, Metal-containing residue supply amount adjusting means for adjusting the supply amount of the metal-containing residues to the biomass, In the ethanol production facility C 2 A catalyst mixing and preparation facility for mixing and preparing an oxygenated catalyst and the hydrogenated catalyst, The C with respect to the hydrogenated catalyst 2 Catalyst mixing amount adjusting means for adjusting the mixing amount of the oxygenated catalyst, comprising a production apparatus for bioethanol.

[11] Gas separation equipment for separating carbon dioxide from the reaction gas generated in the bioethanol production equipment from the mixed gas of hydrogen and carbon dioxide contained in the residual gas after separating the liquid product containing ethanol, A first piping facility for supplying carbon dioxide recovered by the gas separation facility to the reforming gasification furnace; A carbon dioxide supply amount adjusting means for adjusting the supply amount of the recovered carbon dioxide to the reforming gasification furnace; A second piping facility for supplying residual hydrogen remaining in the gas separation facility to a hydrogen holder; A hydrogen supply amount adjusting means for adjusting the supply amount of the residual hydrogen to the hydrogen holder; A third piping facility for supplying hydrogen generated by the water electrolysis facility to the hydrogen holder; A supply facility for supplying the residual hydrogen and the hydrogen from the hydrogen holder to the reforming gasification furnace; A hydrogen supply amount adjusting means for adjusting the supply amount of the residual hydrogen and the hydrogen to the reforming gasification furnace; A pressurization and circulation supply facility for bringing the reforming gas into contact with a composite catalyst; A reforming gas circulation amount adjusting means for adjusting the circulation amount of the reforming gas to the composite catalyst; A separation and purification facility for separating and purifying bioethanol from a liquid product containing ethanol, the bioethanol production apparatus according to

[10] .

[12] A combustion furnace for burning the dry distillation gas generated in the carbonization furnace; A heat exchanger for heating the steam introduced into the reforming gasification furnace; A piping facility for supplying the combustion gas generated in the combustion furnace as a heating gas to at least one of the reforming gasification furnace, the biomass dryer, the carbonization furnace, and the shift reaction facility; A gas temperature adjusting means for adjusting the temperature of the gas; A gas flow rate adjusting means for adjusting the flow rate of the gas, the bioethanol production apparatus according to

[10] or

[11] .

Advantages of the Invention

[0011] According to the present invention, it is possible to provide a method for producing bioethanol and a bioethanol production apparatus capable of economically and stably producing reforming gas using biomass, and then efficiently and stably producing bioethanol.

Brief Description of the Drawings

[0012]

Figure 1

Modes for Carrying Out the Invention

[0013] In this specification, "bioethanol" means ethanol produced using biomass as a raw material. In this specification, "~" indicating a numerical range means including the numerical values described before and after it as the lower limit value and the upper limit value.

[0014] [Bioethanol Production Apparatus] FIG. 1 is a schematic diagram of a bioethanol production apparatus for implementing a method for producing bioethanol according to an embodiment of the present invention. The bioethanol production apparatus 100 of this embodiment includes a biomass dryer 12, a carbonization furnace 20, a reforming gasification furnace 30, a metal-containing residue supply facility 37, an ethanol production facility 50, a catalyst mixing and preparation device (catalyst mixing and preparation facility) 57, a biomass supply amount adjuster (biomass supply amount adjusting means) 80, a carbide supply amount adjuster (carbide supply amount adjusting means) 81, a carbon dioxide supply amount adjusting means (carbon dioxide supply amount adjusting means) 83, a reformed gas supply amount adjuster (reformed gas supply facility) 86, a biomass supply facility 91, a carbide supply facility 92, a supply facility 93, a metal-containing residue separation and recovery device (metal-containing residue separation and recovery means) 94, and a catalyst mixing amount adjuster (catalyst mixing amount adjusting means) 95.

[0015] The biomass receiver 11 is disposed in front of the carbonization furnace 20 and receives biomass 1 from the outside.

[0016] The biomass dryer 12 has means for adjusting and controlling the degree of drying of the biomass 1. As the biomass dryer 12, a rotary kiln dryer can be used. The rotary kiln dryer dries the biomass 1 in the biomass receiver 11 and feeds it into the carbonization furnace 20. The supply of the biomass 1 to the carbonization furnace 20 may be continuous or intermittent.

[0017] The carbonization furnace 20 carbonizes the biomass 1 by means of a pyrolytic carbonization operation. The carbonization furnace 20 has means for adjusting the temperature rise when carbonizing the biomass 1. In the carbonization by the pyrolytic carbonization operation, the biomass 1 is heated and pyrolyzed in a low oxygen state or an oxygen-free state. When the biomass 1 is pyrolyzed, the carbide 2 is produced. Also, dry distillation gases 5 other than the carbide such as decomposition gas and tar are also produced. The carbonization furnace 20 may be provided with stirring means for stirring the biomass 1. As the stirring means, known ones such as a turntable method and a screw movement method may be used.

[0018] The reforming gasification furnace 30 gasifies the carbide 2. Specifically, the reforming gasification furnace 30 produces reformed gas 8 (H 2 , CO, CH 4 and CO 2 mixed gas) by co-gasification reaction of the carbide 2 with steam 7 and carbon dioxide 9. The reforming gasification furnace 30 includes an inner cylinder part 30a and an outer cylinder part 30b surrounding the inner cylinder part 30a. The carbide 2 is accommodated in the inner cylinder part 30a. By supplying heating gas to the gap between the inner cylinder part 30a and the outer cylinder part 30b, the inner cylinder part 30a is heated, and the carbide, steam and CO 2 are heated, and the reforming gasification proceeds.

[0019] The reforming gasifier 30 is connected to a first steam supply pipe 33 for supplying steam via a steam supply amount adjuster 84. Further, the reforming gasifier 30 is connected to a carbon dioxide supply pipe 32 via a carbon dioxide supply amount adjuster 83. A dust collector 34 for separating and recovering the metal-containing residue 3 from the reformed gas 8 discharged from the reforming gasifier 30 is connected to the reforming gasifier 30 via a first reformed gas pipe 35.

[0020] A gas purifier 36 for removing sulfur-containing and chlorine-containing components is connected to the dust collector 34 from the reformed gas 8 from which the metal-containing residue 3 has been separated and removed by the dust collector 34.

[0021] The metal residue supply facility 37 supplies and mixes the metal-containing residue recovered by the metal-containing residue separator 94 to the biomass 1. The supply of the metal-containing residue to the biomass 1 may be continuous or intermittent. Here, the ratio of the supply rate (kg / h) of the metal-containing residue to the supply rate (kg / h) of the biomass 1 (supply rate of metal-containing residue / supply rate of biomass) is preferably 0.01 or more and 10 or less, more preferably 0.05 or more and 5 or less, and even more preferably 0.1 or more and 1 or less. When the ratio is equal to or higher than the lower limit value, the carbonization rate of the carbide and the reforming gasification rate increase. When the ratio is equal to or lower than the upper limit value, the mixing efficiency and mixing uniformity of the biomass and the metal-containing residue are more excellent. The metal-containing residue receiver 38 receives the metal-containing residue recovered by the metal-containing residue separator 94.

[0022] The ethanol production facility 50 produces bioethanol by bringing the reformed gas into contact with a composite catalyst 63 which is a mixture of an oxygen-containing catalyst 58 and a hydrogenation catalyst 59. 2 The ethanol production facility 50 is provided with an oxygen-containing catalyst and a hydrogenation catalyst. When the biomass gas is brought into contact with the oxygen-containing catalyst, H, CO, CO, CH contained in the biomass gas The ethanol production facility 50 2 is provided with an oxygen-containing catalyst and a hydrogenation catalyst. When the biomass gas is brought into contact with the oxygen-containing catalyst, H 2 contained in the biomass gas 2 CO, CO 2 CH 4From acetic acid, acetaldehyde, ethanol, etc. 2 Oxygen-containing compounds are produced. Methyl acetate, ethyl acetate, etc. 2 Derivatives of oxygen-containing compounds may also be produced. Furthermore, when a hydrogenation catalyst is used, ethanol is produced from acetic acid, acetaldehyde, methyl acetate, ethyl acetate, etc., increasing the ethanol selectivity. In this embodiment, the biomass gas supplied to the ethanol production facility 50 is a gas mixture of CO, H 2 , C.H. 4 and CO 2 Contains. CH 4 and CO 2 By including 4 and CO 2 The ethanol yield is improved compared to when it is not included.

[0023] C 2 The oxygen-containing catalyst is a catalyst that efficiently converts the above-mentioned C 2 It is a catalyst for producing oxygen-containing compounds. 2 The oxygen-containing catalyst contains Rh, at least one element selected from the group consisting of Mn, Sc, Li, Na, K, Cs, Mg, Ba, Pt, Pd, Ir, Mo, W, V, Zr, Hf, Ti, Y, Ce and La (hereinafter also referred to as element (1)), and a porous carrier. 2 The oxygen-containing catalyst may contain two or more kinds of element (1). The atomic ratio of the element (1) to Rh is preferably 0.001-10, and more preferably 0.01-5. Examples of the porous support include porous oxides such as silica and alumina. The amount of Rh and element (1) 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 Rh and element (1) supported is the ratio of the total mass of Rh and element (1) to the mass of the porous support.

[0024] C 2 The oxygen-containing 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 an activation treatment is performed to obtain a C 2 oxygen-containing catalyst. Examples of the catalyst precursor include salts of Rh and salts of element (1). Examples of the salts include hydrochloride, nitrate, formate, acetate, alkoxide salt, and oxyacid salt. Examples of the solvent include ethanol, methanol, and water. Examples of the activation treatment method include a method of gradually increasing the temperature in the temperature range of 250°C to 600°C in an oxygen-containing atmosphere and a method of gradually increasing the temperature in the temperature range of 100°C to 450°C in a hydrogen gas atmosphere. In addition, as the hydrogen activation treatment, reduction treatment may be performed with a reducing agent such as hydrazine or borohydride. The selection of the catalyst precursor, the process of catalyst production, and the activation treatment conditions are not limited to these.

[0025] C with Rh supported on the carrier 2 When producing an oxygen-containing catalyst, a supporting method of applying an Rh solution to a porous support such as silica or alumina having a porous structure and press-fitting and infiltrating it into the pores of the porous support is recommended. Examples of the Rh solution used in this step include rhodium chloride, rhodium nitrate solution, hexaammine rhodium acetate solution, or tetraammine rhodium hydroxide solution, etc. C with Rh and element (1) supported on the porous support 2 When producing an oxygen-containing catalyst, element (1) may be contained in the Rh solution, or alternatively, an element (1) solution may be applied to the porous support supporting Rh. The Rh solution and the element (1) solution can also be supported simultaneously or sequentially by methods such as immersion, dropping, coating, or spraying in a predetermined temperature range.

[0026] C containing Rh and element (1) 2In the production of the oxygenated catalyst, it is preferable to use at least one chelating agent selected from the group consisting of oxalic acid, citric acid, tartaric acid, lactic acid, and malic acid. By using the chelating agent, the ethanol production activity is improved as compared with the case where no chelating agent is used. Using a chelating agent, C 2 As a method for producing the oxygenated catalyst, for example, a method of impregnating a porous carrier with a Rh solution and an element (1) solution, drying, further impregnating with a chelating agent solution, and performing an activation treatment can be mentioned.

[0027] The hydrogenation catalyst includes at least one element (hereinafter also referred to as element (2)) selected from the group consisting of palladium, iron, nickel, platinum, copper, chromium, zinc, potassium, sodium, cerium, and titanium, and a porous carrier. Two or more kinds of element (2) may be contained in the hydrogenation catalyst. Examples of the porous carrier include porous oxides such as silica and alumina. The supported amount of element (2) is, for example, 0.01% by mass to 10% by mass, preferably 0.1% by mass to 5% by mass. Here, the supported amount of element (2) is the ratio of the total mass of element (2) to the mass of the porous carrier.

[0028] The hydrogenation catalyst can be produced by a known method. For example, a hydrogenation catalyst can be obtained by dissolving a catalyst precursor in a solvent, impregnating the obtained solution into a porous carrier, and performing an activation treatment. Examples of the catalyst precursor include salts of element (2). Examples of the salts include hydrochlorides, nitrates, oxygen acid salts, and organic acid salts such as oxalates. Examples of the solvent include ethanol, methanol, and water. Examples of the activation treatment method include a method of gradually raising the temperature in the temperature range of 250°C to 600°C in an oxygen-containing atmosphere, and a method of gradually raising the temperature in the temperature range of 100°C to 450°C in a hydrogen gas atmosphere. In addition, as the hydrogen activation treatment, reduction treatment may be performed with a reducing agent such as hydrazine or borohydride. The selection of the catalyst precursor, the process of catalyst production, and the activation treatment conditions are not limited to these.

[0029] C 2 The oxygen-containing catalyst and the hydrogenation catalyst may be arranged separately, but from the viewpoints of ethanol yield and ethanol selectivity, it is preferable that they are arranged as a composite catalyst in which the oxygen-containing catalyst and the hydrogenation catalyst are mixed. 2 In addition, when the oxygen-containing catalyst and the hydrogenation catalyst are arranged separately, the hydrogenation catalyst is arranged downstream of the oxygen-containing catalyst and contacts the biomass gas after contacting the oxygen-containing catalyst. 2 C 2 C 2

[0030] In the composite catalyst, the volume ratio of the oxygen-containing catalyst to the hydrogenation catalyst (oxygen-containing catalyst / hydrogenation catalyst) is preferably 0.1 to 5, more preferably 0.2 to 2. When the volume ratio (oxygen-containing catalyst / hydrogenation catalyst) is equal to or higher than the lower limit value of the above range, the yield of the oxygen-containing compound is more excellent, and when it is equal to or lower than the upper limit value of the above range, the ethanol selectivity is more excellent. 2 C 2 C 2 C 2

[0031] In the ethanol production facility 50, a catalyst mixing and preparation device 57 for adjusting the reformed gas 8 into a composite catalyst 63 by mixing the oxygen-containing catalyst 58 and the hydrogenation catalyst 59 is connected via a composite catalyst introduction facility 62. The composite catalyst 63 prepared by the catalyst mixing and preparation device 57 is introduced into the ethanol production facility 50 by the composite catalyst introduction facility 62. 2

[0032] In the ethanol production facility 50, a shift reaction hydrogen production facility (shift reaction facility) 53 is connected via a gas-liquid separator 52. The shift reaction hydrogen production facility 53 subjects the reaction gas generated in the ethanol production facility 50 to a shift reaction of carbon monoxide, methane, and steam contained in the residual gas after separating the liquid product containing ethanol by the gas-liquid separator 52 to produce hydrogen and carbon dioxide (shift reaction step).

[0033] The shift reaction hydrogen production facility 53 is connected to the gas separation facility 54 via the H 2 / CO 2 gas pipe 64. The hydrogen and carbon dioxide generated in the shift reaction hydrogen production facility 53 are supplied to the gas separation facility 54 via the H 2 / CO 2 gas pipe 64.

[0034] The gas separation facility 54 is connected to the hydrogen holder 55 via the hydrogen supply pipe (second piping facility) 79. The carbon dioxide 9 separated and recovered in the gas separation facility 54 is supplied to the reforming gasification furnace 30 via the carbon dioxide supply pipe (first piping facility) 32. The carbon dioxide supply pipe 32 is provided with a carbon dioxide supply amount adjuster 83 for adjusting the supply amount of carbon dioxide supplied to the reforming gasification furnace 30. The hydrogen holder 55 is connected to the gas mixing and preparation device 89 via the hydrogen supply pipe 78. The hydrogen supply pipe 78 is provided with a hydrogen supply amount adjuster (hydrogen supply amount adjusting means) 85. The hydrogen supply amount adjuster 85 adjusts the supply amount of hydrogen generated in the water electrolysis facility 40 and supplied to the hydrogen holder 55 via the hydrogen supply pipe (third piping facility) 51.

[0035] The gas mixing and preparation device 89 mixes and adjusts hydrogen from the hydrogen holder 55 into the reforming gas.

[0036] The pressure boosting gas circulation supply facility 88 pressurizes and circulates the reforming gas with the adjusted H 2 / CO 2 volume ratio.

[0037] The ethanol separation and purification facility 56 separates and purifies bioethanol 90 from the liquid product containing ethanol.

[0038] The ethanol production facility 50 is connected to the gas-liquid separator 52. The gas-liquid separator 52 is connected to the ethanol separation and purification facility 56 via the crude ethanol pipe 77.

[0039] One end of the steam supply pipe 33 is connected to the bottom of the inner cylinder portion 30a of the reforming gasifier 30. The other end of the steam supply pipe 33 is connected to the make-up water 4 via the heat exchanger 31. A steam supply amount adjuster 84 may be installed in the steam supply pipe 33.

[0040] One end of the carbon dioxide supply pipe 32 is connected to the bottom of the inner cylinder portion 30a of the reforming gasifier 30. The other end of the carbon dioxide supply pipe 32 is connected to the gas separation facility 54. Also, a carbon dioxide supply amount adjuster 83 is installed in the carbon dioxide supply pipe 32. Examples of the carbon dioxide supply amount adjuster 83 include a mass flow controller. The supply of carbon dioxide to the reforming gasifier 30 may be continuous or intermittent.

[0041] A first reformed gas pipe 35 is connected to the top of the reforming gasifier 30. The first reformed gas pipe 35 leads out the reformed gas 8 from the reforming gasifier 30. The reformed gas 8 is supplied to the gas purifier 36 via the first reformed gas pipe 35. The reformed gas 8 is connected to the ethanol production facility 50 via the gas purifier 36, the reformed gas supply amount adjuster 86, the gas mixing and preparation device 89, and the boosted gas circulation facility 88.

[0042] The dust collector 34 equipped with a metal-containing residue separation and recovery means is installed in the middle of the first reformed gas pipe 35, on the upstream side of the gas purifier 36. From the reforming gasifier 30, together with the reformed gas 8, the metal-containing residue 3 is discharged. The dust collector 34 separates the reformed gas 8 from the metal-containing residue 3 and recovers the separated metal-containing residue 3. Since the metal-containing residue 3 contains useful metal elements derived from biomass, the recovered metal-containing residue 3 is put into the biomass receiver 11 via the metal-containing residue discharge pipe 39, the metal-containing residue supply amount adjuster (metal-containing residue supply means) 82, and the metal-containing residue supply facility 37 and mixed and prepared with the biomass.

[0043] The gas purifier 36 is installed in the middle of the first reformed gas pipe 35. On the downstream side of the gas purifier 36, a gas mixing and preparation device 89 is installed via a reformed gas supply amount adjuster 86.

[0044] The plurality of combustion gas pipes supply the combustion gas 6 generated by the air combustor 60 to the waste heat utilization equipment described below via the combustion gas pipe 70 and the combustion gas flow rate adjuster 61. It includes a combustion gas pipe 71 for supplying combustion gas to the biomass dryer 12, a combustion gas pipe 72 for supplying combustion gas to the carbonization furnace, a combustion gas pipe 73 for supplying combustion gas to the reforming gasification furnace 30, a combustion gas pipe 74 for supplying combustion gas to the steam heat exchanger 31, a combustion gas pipe 75 for supplying combustion gas to the ethanol production facility 50, and a combustion gas pipe 76 for supplying combustion gas to the shift reaction hydrogen production facility 53. Further, it may include a gas temperature adjustment means for adjusting the temperature of the combustion gas and a gas flow rate adjustment means for adjusting the flow rate of the combustion gas.

[0045] The biomass supply amount adjuster 80 is provided between the biomass receiver 11 and the biomass dryer 12, and adjusts the supply amount of the biomass 1 to the biomass dryer 12. The biomass supply amount adjuster 80 has a water content measurement means.

[0046] The carbide supply amount adjuster 81 is provided between the carbonization furnace 20 and the reforming gasification furnace 30, and adjusts the supply amount of the carbide 2 to the reforming gasification furnace 30.

[0047] The carbon dioxide supply amount adjuster 83 adjusts the supply amounts of steam and carbon dioxide to the reforming gasification furnace 30.

[0048] The reformed gas supply amount adjuster 86 adjusts the supply amount of the reformed gas to the reforming gasification furnace 30.

[0049] The biomass supply facility 91 adjusts the supply amount of the biomass 1 to the carbonization furnace 20.

[0050] The carbide supply facility 92 adjusts the supply amount of the carbide 2 to the reforming gasification furnace 30.

[0051] The reformed gas supply facility 93 supplies steam and carbon dioxide to the reforming gasifier 30.

[0052] The metal-containing residue separator 94 separates and recovers the metal-containing residue generated together with the reformed gas from the reformed gas.

[0053] The catalyst mixing amount adjuster 95 adjusts the supply amount of the metal-containing residue to the biomass 1.

[0054] The air combustor 60 is connected to the carbonization furnace 20. The air combustor 60 air-combusts the pyrolysis gas (dry distillation gas 5) generated in the carbonization furnace 20 with an air blower 41 to generate high-temperature combustion gas 6.

[0055] According to the bioethanol production facility of the present embodiment, the carbonization rate of the biomass can be increased, the reformed gas can be made efficient, and subsequent bioethanol can be produced economically and stably.

[0056] [Method for Producing Bioethanol] The method for producing bioethanol of the present embodiment includes a carbonization step of carbonizing biomass to produce a carbide, a reforming gasification step of performing a mixed gasification reaction of the carbide with steam and carbon dioxide to produce a reformed gas containing hydrogen, carbon monoxide, methane, and carbon dioxide, and a step of contacting the reformed gas with an oxygen-containing catalyst and a hydrogenation catalyst to produce ethanol, and a mixing step of separating and recovering the metal-containing residue generated together with the reformed gas in the reforming gasification step from the reformed gas and mixing the metal-containing residue with the biomass. 2 The method for producing bioethanol of the present embodiment uses the bioethanol production apparatus 100. The method for producing bioethanol of the present embodiment uses the bioethanol production apparatus 100.

[0057] (Biomass) Examples of the biomass (or the biomass main body) used in this embodiment include forest logging materials such as cedar, pine, and bamboo, agricultural products and by-products such as rice straw and sugarcane, construction waste, and industrial waste such as cotton and fiber products.

[0058] As the biomass (or the biomass main body), preferably, the biomass produced or discarded in forestry or agriculture is pulverized and dried. The size of the pulverized material is, for example, 10 mm to 100 mm. The biomass may be used alone or in combination of two or more.

[0059] In addition to carbon, Biomass 1 may contain alkali metals and alkaline earth metals such as sodium, potassium, lithium, cesium, calcium, magnesium, and barium, metalloids such as boron, and metals such as aluminum, iron, and nickel. However, these metals may be further added and mixed. When these metals are contained in the biomass, it is preferable because it can reduce tar generation in the carbonization process and promote the carbonization reaction, or generate reformed gas more efficiently in the subsequent reforming gasification process.

[0060] In this embodiment, in order to make the biomass crushing chips contain an appropriate amount of metal, in addition to adjusting the type and amount of the biomass, substances such as metal compounds serving as sources of the above-mentioned respective metals may be separately mixed with the biomass. As such a metal supply source, for example, it is preferable to use the metal-containing residue 3 generated together with the reformed gas 8 in the reforming gasification process of the biomass. Such a metal-containing residue is a residue separated and recovered from the reformed gas generated in the reforming gasification process. The metal-containing residue may usually be recovered as solids such as metal oxides, carbides, and metal salts.

[0061] As the timing of mixing a metal source such as a metal-containing residue with biomass, a mixing step may be provided and mixed before subjecting it to a carbonization step, or at least one of the metal-containing residue and the metal source may be directly charged into a carbonization furnace. When mixing at least one of the metal-containing residue 3 and the metal source before subjecting it to the carbonization step, examples include charging and mixing into a biomass receiver and / or a dryer for drying biomass. In the present embodiment, the supply of the metal-containing residue to the biomass may be performed continuously or intermittently.

[0062] As a method of mixing a metal with biomass, for example, there are a method of immersing biomass in a solution in which a metal source such as a metal-containing residue is dissolved or dispersed in a solvent such as an acid or an aqueous alkali solution, alcohol, ethers, or hydrocarbons, and a method of spraying the solution onto the biomass to mix and support the metal component on the biomass.

[0063] In the carbonization step of the present embodiment, the presence of each of the above metals in the biomass raw material can promote carbonization and increase the carbonization rate. The metal content in the metal-containing residue is usually about 0.01 g to 100 g, or 0.1 g to 50 g, per 1 kg of the metal-containing residue. The mass ratio of the metal-containing residue to biomass (metal-containing residue ÷ biomass) may be in the range of 0.01 to 0.99, or 0.1 to 0.9, etc. In the present embodiment, when the metal element content of the metal-containing residue and the mass ratio of the metal-containing residue to biomass are within the above ranges, the carbonization rate in the carbonization step of the biomass is more improved, and in addition, the tar removal rate tends to be more excellent. By increasing the carbonization rate, it becomes possible to increase the production amount of carbide, reformed gas, and bioethanol as a result. The metal content of the metal-containing residue in the present embodiment can be measured by ion chromatography, ICP emission spectrometry, and fluorescent X-ray analysis.

[0064] (Carbonization step) In the method for producing bioethanol according to this embodiment, a carbonization step is carried out in which biomass 1 is carbonized to produce carbide 2. In the carbonization step, the biomass as a raw material is heated and pyrolyzed in a low oxygen state or an oxygen-free state. By pyrolyzing the biomass, carbide and dry distillation gas containing heavy component fuels such as low molecular fuel gas and tar are produced. In the method for producing bioethanol according to this embodiment, the carbonization step is carried out using a carbonization furnace 20.

[0065] As the carbonization furnace, it can be appropriately selected and used from known carbonization furnaces. For example, a carbonization furnace equipped with an external heat type or internal heat type heating device, a carbonization furnace equipped with a transfer device for heated materials such as a screw or a rotary, etc. can be mentioned.

[0066] The carbonization conditions of the carbonization step in the method for producing bioethanol according to this embodiment are as follows. The heating temperature in the carbonization step is preferably, for example, 200°C or higher and 600°C or lower, and more preferably 250°C or higher and 500°C or lower, etc. The residence time in the carbonization step in the method for producing bioethanol according to this embodiment is preferably, for example, 5 minutes or longer and 100 minutes or shorter, and more preferably 10 minutes or longer and 60 minutes or shorter, etc. By pyrolyzing the biomass as a raw material at the above heating temperature and heating time, carbide can be efficiently obtained.

[0067] In the carbonization step of the method for producing bioethanol according to this embodiment, the supply of the raw material to the carbonization furnace may be continuous or intermittent. The supply of the metal-containing residue to the carbonization furnace may be continuous or intermittent.

[0068] (Air combustion step of dry distillation gas) In the method for producing bioethanol according to this embodiment, the dry distillation gas 5 generated together with the carbide in the carbonization step may be separated from the carbide, recovered, and burned to generate high-temperature combustion gas 6. Such combustion gas may be introduced into at least one of the carbonization step, the reforming gasification step described later, the bioethanol production step, and the shift reaction hydrogen production step and used as waste heat gas for heating. Specifically, since the pyrolysis gas contains heavy component fuels such as hydrogen, lower hydrocarbons, and tar, it is transferred to an air combustion furnace 60 equipped with an air blower and burned, for example, in an air atmosphere to remove heavy component fuels such as tar, and high-temperature combustion gas (1000°C to 1200 o C) is obtained. Using such combustion gas as a heat source, it can be transferred to each process of the production method of the present embodiment in each piping facility, etc., and to the heating process of a biomass dryer of other external systems, etc., and used as exhaust heat gas for heating each process.

[0069] By using the heat of the combustion gas as exhaust heat gas and cascading heat utilization for heating in each process of the bioethanol production method of the present embodiment, heating can be performed without using external fuel (such as heavy oil, electricity, etc.) or with a smaller amount of combustion gas generated by burning external fuel than before. The production process of the present embodiment where such exhaust heat gas can be utilized includes, for example, drying of biomass, carbonization process (heating of the carbonization furnace 20), reforming gasification process (heating of the reforming gasification furnace 30), bioethanol production process, heating of the steam heat exchanger 31 and the shift reaction hydrogen production facility 53, etc. Thereby, in the bioethanol production method of the present embodiment, in addition to the economic effect of reducing the cost of reforming gas and bioethanol production, it can contribute to the effect of suppressing global warming by reducing carbon dioxide emissions.

[0070] (Reforming gasification process) The bioethanol production method of the present embodiment includes a reforming gasification process in which the carbide obtained in the carbonization process is put into a gasification furnace for connecting the carbides, and a co-gasification reaction of the carbide with steam and carbon dioxide is carried out to generate reforming gas containing hydrogen, carbon monoxide, methane, and carbon dioxide (hereinafter, H 2 , CO, CH 4 and CO 2 are also denoted).) In the reforming gasification process of the bioethanol production method of the present embodiment, it is considered that reforming gas is generated by the following reforming gasification reaction of carbide with steam and carbon dioxide. (1) Reaction of carbide with steam: C + H2 O→H 2 +CO (2) Reaction of carbide and carbon dioxide: C + CO 2 →2CO (3) Shift reaction: CO + H 2 O→CO 2 +H 2 (4) Methanation reaction: C + 2H 2 →CH 4 In the reforming gasification step of the method for producing bioethanol according to the present embodiment, in order to mix and supply carbon dioxide together with steam, the reactions (1) and (2) are particularly promoted. Therefore, the production of reformed gas can be efficiently carried out, and the production amount of reformed gas can be increased. By using carbon dioxide mixed with steam in the above reactions, the production amount of reformed gas can be improved, for example, 1.2 to 2.5 times compared with the case of reforming gasification with steam alone.

[0071] As the steam used in the reforming gasification step of the method for producing bioethanol according to the present embodiment, water such as city water 4 can be heated to generate steam 7, and such steam can be used. The carbon dioxide 9 used in the reforming gasification step of the method for producing bioethanol according to the present embodiment may be introduced into the reforming gasification furnace from a system different from the system of the method for producing bioethanol according to the present embodiment, or the carbon dioxide discharged from the shift reaction hydrogen production facility 53 described later may be introduced into the reforming gasification furnace 30.

[0072] The supply of the carbide 2 to the reforming gasification furnace 30 connected in the reforming gasification step of the method for producing bioethanol according to the present embodiment can be appropriately adjusted by the carbide supply amount adjuster 81 in order to efficiently produce reformed gas. For example, it may be 10 kg / h or more and 10000 kg / h or less, or 50 kg / h or more and 5000 kg / h or less. The supply amount of steam to the reforming gas furnace can be appropriately adjusted. For example, the supply rate of steam per 1 kg / h of the carbide supply rate 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, etc. The supply rate of carbon dioxide to the reforming gas furnace can be adjusted as appropriate. For example, as the supply rate of carbon dioxide per 1 kg / h of the carbide supply rate, it is 0.1 Nm 3 / h or more and 10 Nm 3 / h or less, or 0.5 Nm 3 / h or more and 5 Nm 3 / h or less, etc. Also, the ratio of the supply rate of carbon dioxide to the total of the supply rate of steam 7 and the supply rate of carbon dioxide 9 (CO 2 supply rate ÷ (supply rate of steam + supply rate of carbon dioxide)) may be, for example, 1 volume % or more and 85 volume % or less, or 10 volume % or more and 60 volume % or less, etc.

[0073] In the reforming gasification step of the method for producing bioethanol of the present embodiment, the temperature of the reforming gasification furnace 30 can be adjusted as appropriate to efficiently produce reforming gas. For example, it may be 600°C to 1200°C, preferably 800°C to 900°C. As the heating means of the reforming gasification furnace 30, for example, the combustion gas obtained by burning the above-mentioned dry distillation gas may be used as the exhaust heat gas for heating.

[0074] Steam 7, for example, is heated in a steam heat exchanger 31 that heats raw water 4 in the range of 50°C or more and 800°C or less, and is supplied to the reforming gasification furnace 30. When heating the raw water using a heat exchanger or the like, the exhaust heat gas from the reforming gasification furnace may be introduced into the heat exchanger for heating. Further, the exhaust heat gas from the steam heat exchanger 31 that has heated the raw water may be introduced into another process (for example, the ethanol production facility 50 and the shift reaction hydrogen production facility 53, etc.) and used for heating.

[0075] The pressure of the reforming gasification furnace 30 in the reforming gasification step can be adjusted as appropriate. For example, it may be 0.05 MPa or more and 0.5 MPa or less, etc.

[0076] The reformed gas 8 obtained in the reforming gasification step of the method for producing bioethanol according to this embodiment contains hydrogen (H 2 ), and carbon monoxide (CO). Typically, it contains hydrogen (H 2 ), carbon monoxide (CO), methane (CH 4 ), and carbon dioxide (CO 2 ).

[0077] (Separation and recovery step of metal-containing residue) In this embodiment, a separation and recovery step of metal-containing residue, a discharge and supply facility, and a supply amount adjustment means for separating and recovering the metal-containing residue generated together with the reformed gas 8 in the reforming gasification step from the reformed gas and supplying the recovered metal-containing residue to the biomass may be provided. That is, in the reforming gasification step, the metal contained in the carbide remains as the metal-containing residue 3, but the metal-containing residue 3 is separated from the reformed gas 8 and recovered. As a recovery method, for example, the reformed gas containing the metal-containing residue discharged from the reforming gasification furnace is separated into the reformed gas and the metal-containing residue using a dust collector 34 such as a cyclone and a bag filter, and the separated metal-containing residue is recovered. The metal-containing residue 3 is recycled and supplied to the biomass receiver 11, the biomass dryer 12 before the carbonization step, or recycled and supplied to the carbonization step, and mixed and utilized with the biomass as described above, thereby increasing the carbonization rate and the reformed gas production amount in the carbonization step and the gasification step of the method for producing bioethanol according to this embodiment. The effect of increasing the carbonization rate of the biomass and the amount of reformed gas by recycling and supplying the metal-containing residue 3 to the biomass 1 may increase with the number of recycling times in this embodiment.

[0078] Since the metal-containing residue 3 is the metal contained in the biomass recovered as the residue of the gasification step, it contains at least one element selected from the group consisting of alkali metals and alkaline earth metals such as sodium, potassium, lithium, calcium, magnesium, and barium, metalloids such as boron, and aluminum, iron, and nickel, which are the metals contained in the biomass.

[0079] The reformed gas 8 from which the metal-containing residue 3 has been removed by the separation device is transferred to the bioethanol production process described below and used for bioethanol production. In addition, it may be used for other purposes, for example, hydrogen production and power generation in a gasification power generation facility.

[0080] (Gas purification process of reformed gas) The gas purifier 36 removes sulfur-containing components from the reformed gas 8. The reformed gas 8 generated by the mixed gasification of the carbide 2 with steam 7 and carbon dioxide 9 contains sulfur-containing substances such as hydrogen sulfide and COS. These sulfur-containing substances act as catalyst poisons and may reduce the catalytic activity and stability in the bioethanol production facility. By removing the sulfur-containing components, the stability of the catalytic activity in the bioethanol production facility is improved.

[0081] Preferably, the gas purifier 36 includes a gas purification member in which at least one metal selected from the group consisting of Cu, Zn, Cr, Ce, Fe, Mo, and Co is supported on a porous carrier such as silica, alumina, or zeolite. When such a gas purification member is brought into contact with the biomass gas, the sulfur-containing components bind to the metal and the porous carrier and are chemically removed from the reformed gas 8.

[0082] However, the gas purifier 36 is not limited to the one based on the chemical method as described above. For example, other general techniques such as gas purification techniques using gas adsorbents such as activated carbon and various zeolites can also be used in combination. The gas purification facility may remove nitrogen-containing components such as ammonia and NOx and chlorine-containing components such as HCl in addition to desulfurization.

[0083] (Bioethanol production process) The ethanol production facility 50 is equipped with an oxygen-containing catalyst 58 and a hydrogenation catalyst 59. 2 When the reformed gas 8 is brought into contact with the oxygen-containing catalyst 58, the H contained in the reformed gas 8 2 CO, CO 2 、CO 2 、CH 4From this, oxygen-containing compounds such as acetic acid, acetaldehyde, and ethanol are produced. Derivatives of oxygen-containing compounds such as methyl acetate and ethyl acetate may also be by-produced. Further, when the hydrogenation catalyst 59 is brought into contact, acetic acid, acetaldehyde, methyl acetate, ethyl acetate, etc. are hydrogenated and efficiently converted to ethanol. As a result, the amount of ethanol produced increases and in addition, the ethanol selectivity increases. 2 Next, the reformed gas 8 is pressurized to a predetermined reaction pressure by a booster in a pressure-up gas circulation supply facility (reformed gas circulation amount adjusting means) 88 and continuously circulated and supplied to the ethanol production facility 50. In the pressure-up gas circulation supply facility 88, the amount (circulation amount) of the reformed gas circulated to the composite catalyst 63 is adjusted. 2 The reformed gas supplied to the ethanol production facility 50 comes into contact with a composite catalyst 63 prepared by mixing an oxygen-containing catalyst 58 and a hydrogenation catalyst 59 to produce a liquid product containing bioethanol.

[0084] The reaction pressure in the ethanol production facility 50 is preferably 0.1 MPa to 5 MPa, more preferably 1 MPa to 3.5 MPa. The reaction temperature is preferably 200°C to 350°C, more preferably 250°C to 300°C. The space velocity (SV: velocity of synthesis gas L / h / volume of catalyst L) of the biomass gas is 1000 h ~35000 h 2 is preferable, and 3000 h

[0085] ~25000 h -1 is more preferable. In the ethanol production facility 50 of this embodiment, for example, bioethanol can be obtained with an ethanol selectivity of 50% to 85% and an ethanol yield (STY: kg / L-cat / h) of 0.25 kg / L-cat / h to 0.85 kg / L-cat / h. -1 Connected to the outlet of the ethanol production facility 50 is a gas-liquid separator 52. A liquid product containing ethanol (also called crude ethanol) and a reaction gas are separated. The gas-liquid separator may be a known one. -1 ~25000 h -1 The reaction pressure in the ethanol production facility 50 is preferably 0.1 MPa to 5 MPa, more preferably 1 MPa to 3.5 MPa. The reaction temperature is preferably 200°C to 350°C, more preferably 250°C to 300°C. The space velocity (SV: velocity of synthesis gas L / h / volume of catalyst L) of the biomass gas is 1000 h

[0086] Connected to the outlet of the ethanol production facility 50 is a gas-liquid separator 52. A liquid product containing ethanol (also called crude ethanol) and a reaction gas are separated. The gas-liquid separator may be a known one.

[0087] (H 2 and CO 2 production) The reaction gas separated by the gas-liquid separator may be circulated and supplied to the bioethanol production facility. However, in this embodiment, the reaction gas (CO, methane, CO 2 containing mixed gas) is introduced into the shift reaction hydrogen production facility 53 to produce H 2 and CO 2 .

[0088] The shift reaction hydrogen production facility 53 brings the CO and methane in the reaction gas separated by the gas-liquid separator 52 into contact with a shift reaction catalyst in the coexistence of steam, and produces a mixed gas of H 2 and CO 2 by the shift reaction described below. 1. CO + H 2 O = H 2 + CO 2 2. CH 4 + 2H 2 O = 4H 2 + CO 2

[0089] In this embodiment, various shift reaction catalysts can be selected according to their usage purposes. For example, those 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 (hereinafter also referred to as element (3)). The shift reaction catalyst may contain two or more elements (3). Element (3) may be supported on a carrier. Examples of the carrier include porous oxides such as silica and alumina (porous oxide carriers).

[0090] (CO 2 supply) In the shift reaction hydrogen production facility 53, the mixed gas of H 2 and CO 2 is separated from carbon dioxide 9 by the gas separation facility 54, and the recovered CO2 It may be supplied to the reforming gasifier 30 via the carbon dioxide supply amount adjuster 83 (supply step).

[0091] (Hydrogen supply) The residual hydrogen is supplied to the hydrogen holder 55 via the hydrogen supply pipe 79. The reformed gas and hydrogen may be mixed and adjusted and supplied to the bioethanol production facility (supply step). In this embodiment, the H of the reformed gas preferable for bioethanol production 2 / CO mixing ratio can be adjusted via the gas mixing and preparation device, and the production amount of bioethanol production and the ethanol selectivity can be significantly improved.

[0092] The gas separation facility 54 separates CO 2 and CO 2 from the mixed gas of 2 Examples of the gas separation facility 54 include a PSA type gas separation device and a ceramic membrane type gas separation device. Any one of these gas separation devices may be used alone, or both may be used.

[0093] In this embodiment, the shift reaction hydrogen production facility 53 and the gas separation facility 54 are connected via the H 2 / CO 2 pipe 64. The CO 2 discharged from the gas separation facility 54 is supplied to the reforming gasifier 30 via the carbon dioxide supply pipe 32. Further, hydrogen is supplied to the hydrogen holder 55 via the gas separation facility 54 and the hydrogen supply pipe 79.

[0094] In this embodiment, in addition, it is connected to the hydrogen holder 55 via the water electrolysis facility 40, the hydrogen supply pipe 51, and the water electrolysis hydrogen supply amount adjuster 87. Commercial power can be used as the power of the water electrolysis facility, but it is preferable to use solar power and wind power, which are renewable energy sources, and in addition, power obtained from nuclear power generation, for the reduction of carbon dioxide emissions in the bioethanol production process.

[0095] The hydrogen holder 55 is connected to the gas mixing and preparation device 89 via the hydrogen supply pipe 79. Hydrogen 10 whose supply amount is adjusted by the hydrogen supply amount adjuster 85 is mixed and supplied from the hydrogen holder 55 to the reformed gas 8. Thereby, the hydrogen / CO volume ratio in the reformed gas 8 is increased, and preferably H 2 after adjusting the / CO volume ratio to 1-3, and more preferably after adjusting it to 1.5-2.5, it is pressurized and circulated by the pressurized gas circulation supply facility 88 and introduced into the ethanol production facility 50 to carry out the ethanol production reaction.

[0096] (Purification process of bioethanol) In this embodiment, the crude ethanol separated by the gas-liquid separator 52 is purified through the ethanol separation and purification facility 56 equipped with a distillation column and a membrane separation device. 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 from the liquid product. The distillation column may be a known one, and examples include a multi-stage Raschig ring distillation column and a silicon membrane separation facility. In this embodiment, the ethanol concentration of the crude ethanol liquid product produced by the bioethanol production facility is, for example, 53% to 60% by mass ratio. It is concentrated to 80% - 85% using a commercially available distillation column. For example, a higher ethanol concentration can be separated and purified in a commercially available ceramic membrane separation device. The ethanol concentration of the purified product is, for example, 86% - 99%.

[0097] According to the method for producing bioethanol of this embodiment, the carbonization rate of biomass can be increased, the reformed gas can be made efficient, and subsequently, bioethanol can be produced economically and stably.

[0098] As described above, the present invention has been described by showing embodiment examples, but the present invention is not limited to the above embodiment examples, and can be freely changed within the scope of the present invention.

Examples

[0099] Examples of the present invention are shown below. The following examples are merely illustrative of the invention, and the content of the present invention is not limited by the following examples.

[0100] (Test 1) A test was conducted to produce bioethanol using a bioethanol production apparatus having the configuration shown in FIG. 1. In this test, 250 kg / h of construction waste chips (moisture content 27% by mass ratio) were used and fed into a dryer and a carbonization furnace, and the carbonization rate (wt%) of the carbide in the carbonization furnace, the production amount of reformed gas (Nm 3 / h), the reformed gas component composition (vol%), and the production amount of bioethanol (kg / h) were measured. In this test, 105 kg / h of steam and CO 2 were fed at 70 Nm 3 / h into the reformed gasification furnace for mixed gasification. The experimental results of reformed gasification and bioethanol production when the metal-containing residue (10 kg / h) separated and recovered by a cyclone dust collector was recycled and supplied to the receiver of the construction waste chips and when it was not supplied are shown in Example 1 and Comparative Example 1.

[0101] The reformed gas component composition and the CO, hydrogen, CO 2 , CH 4 in the outlet gas of the shift reaction hydrogen production apparatus, and the liquid components including ethanol generated in the ethanol production facility were analyzed using a gas chromatograph analyzer (GC-14B manufactured by Shimadzu Corporation) filled with Gaskuropack and molecular sieve 13X and an FID gas chromatograph analyzer (GC-8A manufactured by Shimadzu Corporation). The flow rate of the exhaust gas was measured using a wet gas flow meter. The content of the metal elements in the metal-containing residue was measured using an ICP emission spectroscopic analyzer (ICPS-8100 manufactured by Shimadzu Corporation) and a fluorescent X-ray analyzer (EA1400 manufactured by Hitachi High-Tech Corporation). The metal content per 1 kg of the metal-containing residue obtained in this test is 25 g / kg of Na, 85 g / kg of K, 36 g / kg of Ca, 7.5 g / kg of Mg, 5 g / kg of Ba, 7.5 g / kg of Fe, and 1.8 g / kg of Ni.

[0102] (C2 Oxygen-containing catalyst 1) Chlorides or nitrates of Rh, Mg, V, Hf, Ir, and Ce were dissolved in a mixed solvent of ethanol and water so that the atomic ratio of each element was 1:0.3:0.2:0.5:0.3 to obtain an ethanol aqueous solution. This ethanol aqueous solution was impregnated on a silica carrier (specific surface area 315 m 2 / g). After that, the temperature was raised to 150 °C over 1 hour under a mixed gas stream of hydrogen and nitrogen gas (volume ratio 1:3), held for 2 hours, raised to 450 °C over 2 hours, held for 2 hours, and then cooled to room temperature for an activation treatment. As a result, an oxygen-containing catalyst 1 in which Rh, Mg, V, Hf, Ir, and Ce were supported on the silica carrier was prepared. 2 Oxygen-containing catalyst 1 was prepared.

[0103] (Hydrogenation catalyst 1) Cu, Cr nitrate, Ti, and Mo chloride were dissolved in a mixed solvent of ethanol and water so that the atomic ratio of Cu:Cr:Ti:Mo was 1:0.8:0.2:0.15 to obtain an ethanol aqueous solution. This ethanol aqueous solution was impregnated on a silica carrier (specific surface area 365 m 2 / g). After that, the temperature was raised to 100 °C over 1 hour under a mixed gas stream of hydrogen and nitrogen gas (volume ratio 1:2), held for 2 hours, raised to 450 °C over 2 hours, held for 3 hours, and then cooled to room temperature for an activation treatment. As a result, a hydrogenation catalyst 1 in which Cu, Cr, Ti, and Mo were supported on the silica carrier was prepared. C 2 A composite catalyst prepared by mixing and preparing an oxygen-containing catalyst (100 kg) and a hydrogenation catalyst (200 kg) in a commercially available mixing apparatus was filled into a reactor made of titanium-coated stainless steel. The reformed gas was brought into contact with the composite catalyst to produce bioethanol. The bulk specific gravity of the adjusted catalyst in this test was 0.5 kg / L.

[0104]

Table 1

[0105] From these results, it was shown that for the carbonization rate, the amount of reformed gas produced, and the amount of ethanol produced in the carbonization process using biomass raw materials, when the metal-containing residue was recycled and supplied (Example 1), there was a significant improvement compared to the case where it was not recycled and supplied (Comparative Example 1).

[0106] (Test 2) Using rice straw, an agricultural waste, tests of carbonization, reformed gasification, and ethanol production similar to those in Test 1 were conducted. The rice straw was fed at 350 kg per hour. The carbonization operation was carried out under the condition that the temperature of the carbonization furnace was 250°C to 420°C. When the reformed gasification process of the carbide was carried out at a temperature of 900°C under the mixed supply conditions of 150 kg / h of steam and 100 Nm 2 100 Nm 3 / h (Example 2), and when it was supplied alone with 150 kg / h of steam (Comparative Example 2), the test results of the amount of reformed gas produced (Nm 3 / h), the reformed gas component composition (vol%), and the ethanol production (kg-EtOH / h) in bioethanol production using the reformed gas are shown in Table 2.

[0107] In this test, the metal-containing residue separated and recovered by the cyclone dust collector was mixed and fed into the rice straw receiver at 15 kg per hour, and the carbonization and gasification operations were carried out. The metal content per 1 kg of the metal-containing residue obtained in this test is 45 g / kg of Na, 65 g / kg of K, 50 g / kg of Ca, 15 g / kg of Mg, 2.5 g / kg of Ba, 1.5 g / kg of Li, 2.8 g / kg of Fe, and 0.5 g / kg of Ni.

[0108] (C 2 Oxygen-containing catalyst 2) Chlorides of Rh, Mn, Li, Sc, and Ce were dissolved in a mixed solvent of ethanol and water so that the atomic ratio of each element was 1:0.05:0.30:0.10:0.05 to obtain an ethanol aqueous solution. This ethanol aqueous solution was used on a silica carrier (specific surface area 385 m 2After impregnating it in / g), it was heated to 100 °C over 1 hour under a mixed gas stream of hydrogen and nitrogen gas (volume ratio of 1:4), held for 2 hours, heated to 400 °C over 2 hours, held for 2 hours, and then cooled to room temperature for activation treatment. As a result, C with Rh, Mn, Li, Sc, and Ce supported on the silica carrier was obtained. 2 The oxygen-containing catalyst 2 was prepared.

[0109] (Hydrogenation catalyst 2) Nitrates of Pd, Cu, Zn, K, and Zr were dissolved in a mixed solvent of ethanol and water so that the atomic ratio of each element was 1:0.8:0.2:0.15 to obtain an ethanol aqueous solution. This ethanol aqueous solution was impregnated into a silica carrier (specific surface area 265 m 2 / g), and then activated by heating to 100 °C over 1 hour under a mixed gas stream of hydrogen and nitrogen gas (volume ratio of 1:2), holding for 2 hours, heating to 400 °C over 2 hours, holding for 2 hours, and then cooling to room temperature. As a result, a hydrogenation catalyst 2 with Pd, Cu, Zn, K, and Zr supported on the silica carrier was prepared. The bulk specific gravity of the adjusted catalyst in this test is 0.5 kg / L. C 2 A composite catalyst prepared by mixing an oxygen-containing catalyst (160 kg) and a hydrogenation catalyst (320 kg) in a mixing preparation device was filled into a reactor made of titanium-coated stainless steel. The reformed gas was brought into contact with the composite catalyst to produce bioethanol.

[0110]

Table 2

[0111] From these results, in the reformed gasification process of the carbide using rice straw as a raw material, the reformed gas composition, gas production amount, and ethanol production amount under the mixed supply conditions of steam and CO (Example 2) were significantly increased compared to the case of single supply of steam (Comparative Example 2). 2 It was shown that.

[0112] (Test 3) In an embodiment similar to Test 2, carbonization and gasification were carried out using 450 kg / h of cedar chips (moisture content 35%) as biomass, and the produced reformed gas was C 2 contacted with a composite catalyst prepared by mixing an oxygen-containing catalyst and a hydrogenation catalyst 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 reaction hydrogen production facility, and hydrogen and CO generated 2 from the mixed gas were separated by a ceramic membrane separation facility to obtain CO 2 The residual hydrogen separated was stored in a hydrogen holder. Hydrogen was supplied from the hydrogen holder to the reformed gas in gas mixing preparation to adjust the H 2 / CO volume ratio to 2.5 (Example 3), and when hydrogen was not supplied ( Reference Example ), the CO conversion rate (ethanol / CO molar ratio %), ethanol selectivity (%) and ethanol yield (STY: g-EtOH / L-cat / h) are shown in Table 3.

[0113]

Table 3

[0114] From these results, it was shown that when hydrogen generated in the shift reaction hydrogen production facility was supplied to the reformed gas (Example 3), the ethanol selectivity and ethanol yield increased compared to the case where hydrogen was not supplied ( Reference Example ).

[0115] (Test 4) In the ethanol production apparatus and embodiment similar to Example 1, C 2 The composite catalyst obtained by mixing and preparing an oxygen-containing catalyst 1 and a hydrogenation catalyst 1 in a mass ratio of 1:1 using a catalyst mixing preparation device was filled into a reaction tube made of titanium-coated stainless steel. Therein, the reformed gas was contacted and circulated with the composite catalyst at 2.5 MPa, 285 °C, and SV = 25,000 h -1 to produce ethanol (Example 5) in the same amount of C 2When the oxygenated catalyst 1 is separately stacked and filled in the upper layer of the reactor and the hydrogenated catalyst 1 is stacked and filled in the lower layer (Example 6), the CO conversion rate, ethanol selectivity, and bioethanol yield (STY: g-EtOH / L-cat / h) in ethanol production are shown in Table 4.

[0116]

Table 4

[0117] As a result, C 2 When a composite catalyst prepared by mixing an oxygenated catalyst and a hydrogenated catalyst is used (Example 5), C 2 It was shown that the ethanol yield and ethanol selectivity were improved compared to the case where the oxygenated catalyst and the hydrogenated catalyst were separately stacked and filled (Example 6).

Industrial Applicability

[0118] According to the present invention, it is possible to provide a method for producing bioethanol and a bioethanol production apparatus that can efficiently produce reformed gas using biomass and then stably produce bioethanol economically.

Explanation of Signs

[0119] 1 Biomass 2 Carbide 3 Metal-containing residue 4 Makeup water 5 Pyrolysis gas (including tar) 6 Combustion gas 7 Steam 8 Reformed gas 9 Carbon dioxide 10 Hydrogen 11 Biomass receiver 12 Biomass dryer 20 Carbonization furnace 30 Reformed gasification furnace 31 Steam heat exchanger 32 Carbon dioxide supply pipe 33 Steam supply pipe 34 Dust collector 35 First reformed gas pipe 36 Gas purifier 37 Metal-containing residue supply facility 38 Metal-containing residue receiver 39 Metal-containing residue discharge pipe 40 Water electrolysis facility 41 Air blower 50 Ethanol production facility 51 Hydrogen supply pipe 52 Gas-liquid separator 53 Shift reaction hydrogen production facility 54 Gas separation facility 55 Hydrogen holder 56 Ethanol separation and purification facility 57 Catalyst mixing and preparation unit (catalyst mixing and preparation facility) 58 C 2 Oxygen-containing catalyst 59 Hydrogenation catalyst 60 Air combustor 61 Combustion gas flow regulator 62 Composite catalyst introduction facility 63 Composite catalyst 64 H 2 / CO 2 Gas pipe 70 Combustion gas pipe 71 Combustion gas pipe 72 Combustion gas pipe 73 Combustion gas pipe 74 Combustion gas pipe 75 Combustion gas pipe 76 Combustion gas pipe 77 Pipe for crude ethanol 78 Hydrogen supply pipe 79 Hydrogen supply pipe 80 Biomass supply amount regulator (biomass supply amount adjustment means) 81 Carbide supply amount regulator (carbide supply amount adjustment means) 82 Metal-containing residue supply amount regulator (metal-containing residue supply amount adjustment means) 83 Carbon dioxide supply amount regulator (carbon dioxide supply amount adjustment means) 84 Steam supply amount regulator 85 Hydrogen supply regulator 86 Reformed gas supply regulator (reformed gas supply facility) 87 Water electrolysis hydrogen supply regulator 88 Boosted gas circulation supply facility 89 Gas mixing and preparation device 90 Bioethanol 91 Biomass supply facility 92 Carbide supply facility 93 Reformed gas supply facility 94 Metal-containing residue separator and recycler (metal-containing residue separation and recycling means) 95 Catalyst mixing amount regulator (catalyst mixing amount adjustment means) 100 Bioethanol production device

Claims

1. a carbonization step of carbonizing the biomass to generate a carbonized material; a reforming gasification process in which a mixed gasification reaction of the carbide with steam and carbon dioxide is carried out to generate a reformed gas containing hydrogen, carbon monoxide, methane and carbon dioxide; The reformed gas is C ２ an ethanol production step of contacting the mixture with an oxygenation catalyst and a hydrogenation catalyst to produce ethanol; a mixing step of separating and recovering a metal-containing residue generated together with the reformed gas in the reformed gasification step from the reformed gas, and mixing the metal-containing residue with the biomass; a shift reaction step in which carbon monoxide and methane contained in the residual gas remaining after separation of a liquid product containing ethanol from the gas produced in the ethanol production step are subjected to a shift reaction with water vapor to produce hydrogen and carbon dioxide; a supply step of separating and recovering carbon dioxide from the mixed gas of hydrogen and carbon dioxide generated in the shift reaction step, supplying the recovered carbon dioxide to the reforming gasification step, and supplying the hydrogen to the reformed gas.

2. The method for producing bioethanol 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, metalloids, aluminum, iron and nickel.

3. 2. The method for producing bioethanol according to claim 1, wherein the shift reaction step uses a shift reaction catalyst containing at least one element selected from the group consisting of iron, ruthenium, nickel, copper, zinc, potassium, lithium, magnesium, chromium, cobalt, molybdenum, zirconia, titanium, cerium, lanthanum, and neodymium, and a porous oxide support.

4. The method for producing bioethanol according to any one of claims 1 to 3, wherein the dry distillation gas generated together with the carbonized material in the carbonization step is subjected to air combustion, and the generated combustion gas is used as a heat source for heating at least one of the carbonization step, the reformed gasification step, the ethanol production step, and the shift reaction step.

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

6. 2. The method for producing bioethanol 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 carrier.

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 The volume ratio of the oxygenated catalyst (C ２ The method for producing bioethanol according to claim 1, wherein the ratio of oxygenation catalyst to hydrogenation catalyst is 0.1 or more and 5 or less.

8. A reforming gasifier; Biomass supply equipment; A biomass supply adjustment means; A biomass dryer having a means for adjusting and controlling the dryness of the biomass; A carbonization furnace having a temperature rise adjustment means; A carbonized material supplying facility for supplying carbonized material to the reforming gasification furnace; a carbonized material supply amount adjusting means for adjusting the amount of the carbonized material supplied to the reforming gasification furnace; A supply facility for supplying water steam and carbon dioxide to the reforming gasification furnace; a carbon dioxide supply amount adjustment means for adjusting the amount of the water steam and the carbon dioxide supplied to the reforming gasification furnace; a reformed gas supply facility that supplies a reformed gas to the reforming gasification furnace; The reformed gas is C ２ a bioethanol production facility for producing bioethanol by contacting the oxygenation catalyst and the hydrogenation catalyst; a separation and recovery means for separating and recovering a metal-containing residue generated together with the reformed gas from the reformed gas; A metal residue supplying facility that supplies and mixes the recovered metal-containing residue with the biomass; a metal-containing residue supply amount adjustment means for adjusting the amount of the metal-containing residue supplied to the biomass; In the bioethanol production facility, ２ A catalyst mixing and preparation facility for mixing and preparing an oxygenation catalyst and the hydrogenation catalyst; The hydrogenation catalyst ２ A catalyst mixing amount adjustment means for adjusting the mixed amount of the oxygen-containing catalyst; A gas separation facility that separates carbon dioxide from a mixed gas of hydrogen and carbon dioxide contained in a residual gas after separating a liquid product containing ethanol from the reaction gas generated in the bioethanol production facility; a first piping facility that supplies the carbon dioxide recovered in the gas separation facility to the reforming gasification furnace; a carbon dioxide supply amount adjustment means for adjusting the amount of the recovered carbon dioxide supplied to the reforming gasification furnace; a second piping system that supplies residual hydrogen remaining in the gas separation system to a hydrogen holder; a hydrogen supply amount adjusting means for adjusting the amount of the residual hydrogen supplied to the hydrogen holder; a third piping facility that supplies hydrogen generated in the water electrolysis facility to the hydrogen holder; a supply facility for supplying the residual hydrogen and the hydrogen from the hydrogen holder to the reforming gasification furnace; a hydrogen supply amount adjusting means for adjusting the amount of the residual hydrogen and the hydrogen supplied to the reforming gasification furnace; a pressurizing and circulating supply facility for contacting the reformed gas with a composite catalyst; a reformed gas circulation amount adjusting means for adjusting the amount of the reformed gas circulated to the composite catalyst; A bioethanol production apparatus comprising: a separation and purification facility that separates and purifies bioethanol from a liquid product containing ethanol.

9. a combustion furnace for burning the dry distillation gas generated in the carbonization furnace; a heat exchanger for heating the steam to be introduced into the reforming gasification furnace; A piping facility that supplies the combustion gas generated in the combustion furnace to at least one of the reforming gasification furnace, the biomass dryer, the carbonization furnace, and the shift reaction facility as a heating gas; A gas temperature adjusting means for adjusting the temperature of the gas; The bioethanol production apparatus according to claim 8 , further comprising: a gas flow rate adjusting means for adjusting a flow rate of the gas.