Alcohol production apparatus and alcohol production method

Abstract

To provide an alcohol production apparatus and method that can produce alcohol while reducing raw material costs. [Solution] A raw material gas supply unit that supplies raw material gas containing CO2 and H2 to the alcohol production unit, and an alcohol production unit that produces alcohol using an alcohol production catalyst, Alcohol production apparatus and method comprising: a gas-liquid separation unit for separating gaseous and liquid components from effluent discharged from an alcohol production unit; a water supply unit for supplying H2O to a steam reforming unit; a steam reforming unit for generating H2 and CO from the gaseous components separated in the gas-liquid separation unit and H2O supplied from the water supply unit; a water-gas shift unit for generating CO2 and H2 from effluent discharged from the steam reforming unit; and a gas-water separation unit for separating CO2, H2, and H2O from effluent discharged from the water-gas shift unit, wherein the alcohol production unit produces alcohol from a raw material gas containing CO2 and H2 separated in the gas-water separation unit.

Description

[Technical Field]

[0001] The present invention relates to an alcohol production apparatus and an alcohol production method. [Background technology]

[0002] In recent years, concern about global warming has increased, and the Conference of the Parties (COP) to the United Nations Framework Convention on Climate Change, which discusses international frameworks for reducing greenhouse gas emissions, aims to keep the rise in average temperature since the pre-industrial era well below 2°C as a common long-term global goal, aiming to suppress peak emissions as early as possible and to reduce them rapidly in accordance with the latest science. The COP21 Paris Agreement states that all countries should strive to formulate and submit long-term low-emission greenhouse gas development strategies. The European Green Deal is also moving to strengthen policies through legislation, such as carbon neutrality by 2050 and raising reduction targets at the midpoint. In Japan, the government has also declared carbon neutrality by 2050. In response to these developments, the development of countermeasures technologies for reducing carbon dioxide is being vigorously carried out in various places. As one countermeasure technology, several attempts have been proposed to convert emitted carbon dioxide into useful substances, but a large amount of energy is required to convert carbon dioxide into another substance, and the development of effective catalysts to accelerate the reaction is desired.

[0003] Furthermore, in order for a technology to contribute to carbon dioxide reduction, it is necessary to produce useful substances that are in high demand. Alcohols, a form of hydrocarbon, are useful substances that can be produced using carbon dioxide (CO2) and hydrogen (H2) as raw materials, and are therefore positioned as a technology for reducing carbon dioxide.

[0004] The following documents describe technologies for producing alcohol by chemical reaction. For example, Patent Document 1 discloses a method for producing organic oxygenated substances, comprising: a production step of contacting a synthesis gas containing hydrogen and carbon monoxide with a synthesis catalyst to obtain a product gas containing organic oxygenated substances and hydrocarbons; a separation step of separating at least a portion of the organic oxygenated substances from the product gas to obtain a separated gas containing hydrocarbons; and a reforming step of contacting the separated gas and water vapor with a reforming catalyst to obtain a reformed gas having higher concentrations of hydrogen and carbon monoxide than those contained in the separated gas, wherein the content of the organic oxygenated substances in the separated gas used in the reforming step is less than 1000 ppm on a molar basis. Patent Document 1 also discloses a method for producing organic oxygenated substances, comprising a reuse step of contacting the reformed gas with the synthesis catalyst to obtain the product gas. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] International Public Gazette No. 2017 / 195817 [Overview of the project] [Problems that the invention aims to solve]

[0006] In alcohol production from CO2, low raw material costs are desirable. For carbon neutrality, the H2 used as raw material must be derived from renewable energy, but this is very costly. The lower the raw material costs, the lower the total production costs can be. On the other hand, equipment for producing alcohol from CO2 with low raw material costs needs improvement in terms of efficiency and stability.

[0007] Therefore, the purpose of this disclosure is to provide an alcohol manufacturing apparatus and an alcohol manufacturing method that can produce alcohol while reducing raw material costs. [Means for solving the problem]

[0008] The present inventors have discovered that alcohol can be produced with low raw material costs by using an alcohol production apparatus and alcohol production method that include specific steps, and have come to this disclosure.

[0009] In other words, the alcohol manufacturing apparatus and alcohol manufacturing method related to this disclosure are as follows:

[0010] <1> A raw material gas supply unit that supplies raw material gas containing CO2 and H2 to the alcohol production unit described below, An alcohol production unit having an alcohol production catalyst that is brought into contact with the raw material gas supplied from the raw material gas supply unit to produce alcohol, and producing alcohol using the alcohol production catalyst, A gas-liquid separation unit separates a gaseous component containing CO2, H2, CO, and gaseous hydrocarbons from the effluent discharged from the alcohol production unit, and a liquid component containing H2O and alcohol. A water supply unit that supplies H2O to the steam reforming unit described below, A steam reforming unit that generates H2 and CO from the gaseous components separated in the gas-liquid separation unit and H2O supplied from the water supply unit, A water-gas shift unit that generates CO2 and H2 from the effluent discharged from the aforementioned steam reforming unit, A gas-water separation unit separates CO2 and H2 from the effluent discharged from the aforementioned water-gas shift unit, Equipped with, The alcohol production unit is an alcohol production apparatus that produces alcohol from the raw material gas containing CO2 and H2 separated in the gas-water separation unit. <2> The gaseous components separated in the gas-liquid separation unit are further provided with a raw material gas separation unit that separates CO2 and H2, and CO and gaseous hydrocarbons. The steam reforming unit generates H2 and CO from the CO and gaseous hydrocarbons separated in the raw material gas separation unit and H2O supplied from the water supply unit. The alcohol production unit produces the alcohol from the raw material gas, which includes CO2 and H2 separated in the raw material gas separation unit and CO2 and H2 separated in the gas-water separation unit. <1> The alcohol manufacturing apparatus described above. <3> The system includes an alcohol / water separation unit that separates H2O and alcohol from the liquid component separated in the gas-liquid separation unit, and recovers the alcohol separated in the alcohol / water separation unit. The steam reforming unit generates H2 and CO from the gaseous component separated in the gas-liquid separation unit and H2O supplied from the water supply unit, or from the gaseous component separated in the gas-liquid separation unit, H2O supplied from the water supply unit, H2O separated in the alcohol / water separation unit, and H2O separated in the gas-water separation unit. <1> The alcohol manufacturing apparatus described above. <4> The system includes an alcohol / water separation unit that separates H2O and alcohol from the liquid component separated in the gas-liquid separation unit, and recovers the alcohol separated in the alcohol / water separation unit. The steam reforming unit generates H2 and CO from the CO and gaseous hydrocarbons separated in the raw material gas separation unit and H2O supplied from the water supply unit, or from the CO and gaseous hydrocarbons separated in the raw material gas separation unit, H2O supplied from the water supply unit, H2O separated in the alcohol / water separation unit and H2O separated in the gas-water separation unit. <2> The alcohol manufacturing apparatus described above. <5> The raw material gas supply unit includes a raw material gas preparation unit that prepares a raw material gas with a predetermined molar ratio (H2 / CO2), and supplies the raw material gas prepared in the raw material gas preparation unit to the alcohol production unit. <1> ~ <4> An alcohol manufacturing apparatus as described in any one of the items. <6> The system includes a purge section for purging a portion of the CO2 and H2 separated in the aforementioned gas-liquid separation section. <1> , <3> , or <5> The alcohol manufacturing apparatus described above. <7> The alcohol production apparatus according to <2>, <4>, or <5>, comprising a purge section that purges part of CO₂ and H₂ separated in the raw material gas separation section and the steam-water separation section. <8> The alcohol production apparatus according to any one of <1> to <7>, wherein the alcohol selectivity for reaction products excluding CO generated in the alcohol production section is 20 to 80%, and the hydrocarbon selectivity for hydrocarbons having 5 or more carbon atoms is 35% or less. <9> a raw material gas supply step of supplying a raw material gas containing CO₂ and H₂ to the following alcohol production step; an alcohol production step having an alcohol production catalyst that is brought into contact with the raw material gas supplied from the raw material gas supply step to produce alcohol, and produces alcohol by the alcohol production catalyst; a gas-liquid separation step of separating an effluent flowing out from the alcohol production step into a gas component containing CO₂, H₂, CO and gaseous hydrocarbons, and a liquid component containing H₂O and alcohol; a water supply step of supplying H₂O to the following steam reforming step; a steam reforming step of producing H₂ and CO from the gas component separated in the gas-liquid separation step and H₂O supplied from the water supply step; a water-gas shift step of producing CO₂ and H₂ from an effluent flowing out from the steam reforming step; a steam-water separation step of separating CO₂ and H₂, and H₂O from an effluent flowing out from the water-gas shift step; comprising, an alcohol production method, wherein the alcohol production step produces the alcohol from the raw material gas containing CO₂ and H₂ separated in the steam-water separation step. <10> comprising a raw material gas separation step of separating CO₂ and H₂, and CO and gaseous hydrocarbons from the gas component separated in the gas-liquid separation step, wherein the steam reforming step produces H₂ and CO from CO and gaseous hydrocarbons separated in the raw material gas separation step and H₂O supplied from the water supply step, The alcohol production method according to <9>, wherein the alcohol production step produces the alcohol from the source gas comprising CO₂ and H₂ separated in the source gas separation step and CO₂ and H₂ separated in the gas-water separation step. <11> comprising an alcohol / water separation step of separating H₂O and alcohol from the liquid component separated in the gas-liquid separation step, and recovering the alcohol separated in the alcohol / water separation step, The alcohol production method according to <9>, wherein the steam reforming step generates H₂ and CO from the gas component separated in the gas-liquid separation step and H₂O supplied from the water supply step, or from the gas component separated in the gas-liquid separation step, H₂O supplied from the water supply step, H₂O separated in the alcohol / water separation step, and H₂O separated in the gas-water separation step. <12> comprising an alcohol / water separation step of separating H₂O and alcohol from the liquid component separated in the gas-liquid separation step, and recovering the alcohol separated in the alcohol / water separation step, The alcohol production method according to claim 10>, wherein the steam reforming step generates H₂ and CO from CO and gaseous hydrocarbons separated in the source gas separation step and H₂O supplied from the water supply step, or from CO and gaseous hydrocarbons separated in the source gas separation step, H₂O supplied from the water supply step, H₂O separated in the alcohol / water separation step, and H₂O separated in the gas-water separation step. <13> The alcohol production method according to any one of <9> to <12>, wherein the source gas supply step comprises a source gas preparation step of preparing a source gas having a predetermined molar ratio (H₂ / CO₂), and supplies the source gas prepared in the source gas preparation step to the alcohol production step. <14> The alcohol production method according to <9>, <11> or <13>, comprising a purging step of purging a part of CO₂ and H₂ separated in the gas-water separation step. <15> The system includes a purging step for purging a portion of the CO2 and H2 separated in the aforementioned raw material gas separation step and the aforementioned gas-water separation step. <10> , <12> , or <13> The alcohol manufacturing method described below. <16> In the aforementioned alcohol production process, the alcohol selectivity among the reaction products excluding CO is 20-80%, and the hydrocarbon selectivity with 5 or more carbon atoms is 35% or less. <9> ~ <15> The method for manufacturing alcohol described in any one of the items in item 1. [Effects of the Invention]

[0011] According to this disclosure, it is possible to provide an alcohol production apparatus and an alcohol production method that can produce alcohol at a lower raw material cost compared to conventional apparatuses and methods for producing alcohol from CO2. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a flow chart of an example of the alcohol production apparatus of this disclosure (alcohol production apparatus of Example 1). [Figure 2] Figure 2 is a flow chart of another example of the alcohol production apparatus of this disclosure (the alcohol production apparatus of Example 2). [Figure 3] Figure 3 is a flow chart of another example of the alcohol production apparatus of this disclosure (the alcohol production apparatus of Example 2). [Figure 4] Figure 4 is a flow chart of the alcohol production apparatus in Comparative Example 1. [Modes for carrying out the invention]

[0013] An example embodiment of this disclosure will be described. These descriptions and examples are illustrative and do not limit the scope of the invention. In this specification, a numerical range represented by "~" means a range that includes the numbers before and after "~" as lower and upper limits, unless those numbers are preceded by "greater than" or "less than". If the numbers before and after "~" are preceded by "greater than" or "less than", the numerical range means a range that does not include those numbers as lower or upper limits. In the numerical ranges described stepwise in this specification, the upper limit of one stepwise numerical range may be replaced with the upper limit of another stepwise numerical range, or with the values ​​shown in the examples. Similarly, the lower limit of one stepwise numerical range may be replaced with the lower limit of another stepwise numerical range, or with the values ​​shown in the examples. Furthermore, unless otherwise specified, the percentage ("%) in relation to the content refers to "mass%". A percentage of "0" indicates that the ingredient is optional and does not need to be included.

[0014] Each component may contain multiple types of the relevant substance. When referring to the amount of each component in a composition, if there are multiple substances corresponding to each component in the composition, unless otherwise specified, it refers to the total amount of those multiple substances present in the composition. The term "process" includes not only independent processes, but also any process that cannot be clearly distinguished from other processes, as long as its intended function is achieved.

[0015] <Alcohol production equipment> The alcohol manufacturing apparatus disclosed herein, A raw material gas supply unit that supplies raw material gas containing CO2 and H2 to the alcohol production unit, An alcohol production unit has an alcohol production catalyst that is brought into contact with a raw material gas supplied from a raw material gas supply unit to produce alcohol, and produces alcohol using the alcohol production catalyst. A gas-liquid separation unit separates gaseous components containing CO2, H2, CO, and gaseous hydrocarbons from spills discharged from the alcohol production section, and liquid components containing H2O and alcohol. A water supply unit that supplies H2O to the steam reforming unit, A steam reforming unit generates H2 and CO from the gaseous components separated in the gas-liquid separation unit and H2O supplied from the water supply unit. A water-gas shift section generates CO2 and H2 from the effluent discharged from the steam reforming section, A gas-water separation unit separates CO2 and H2 from H2O in the effluent discharged from the water-gas shift unit. It is equipped with. The alcohol production section then produces alcohol from the raw material gas containing CO2 and H2 separated in the gas-water separation section.

[0016] In the alcohol production apparatus disclosed herein, A raw material gas supply process that supplies raw material gas containing CO2 and H2 to the alcohol production process, An alcohol production process includes an alcohol production catalyst that is brought into contact with a raw material gas supplied from a raw material gas supply process to produce alcohol, and an alcohol production process that produces alcohol using the alcohol production catalyst. A gas-liquid separation process separates gaseous components containing CO2, H2, CO, and gaseous hydrocarbons from effluent discharged from the alcohol manufacturing process, and liquid components containing H2O and alcohol. A water supply process that supplies H2O to the steam reforming process, A steam reforming process that generates H2 and CO from the gaseous components separated in the gas-liquid separation process and H2O supplied from the water supply process, A water-gas shift process that generates CO2 and H2 from the effluent discharged from the steam reforming process, A gas-water separation process separates CO2 and H2 from H2O in the effluent discharged from the water-gas shift process. The alcohol production method of this disclosure is carried out, comprising the above. The alcohol production process then produces alcohol from the raw material gas containing CO2 and H2 separated in the gas-water separation process.

[0017] In the alcohol production apparatus and alcohol production method of this disclosure, the alcohol production section and alcohol production process produce alcohol from a raw material gas containing CO2 and H2 separated in the gas-water separation section and gas-water separation process. Therefore, the alcohol production apparatus and alcohol production method of this disclosure make it possible to produce alcohol while keeping raw material costs down.

[0018] Hereinafter, as an example of the alcohol manufacturing apparatus of this disclosure, the details of an alcohol manufacturing apparatus (see Figure 1) comprising a raw material gas supply unit having a raw material gas preparation unit, an alcohol manufacturing unit, a gas-liquid separation unit, a raw material gas separation unit, an alcohol / water separation unit, a water supply unit, a water vapor reforming unit, a water-gas shift unit, a gas-water separation unit, and a purging unit will be described together with the alcohol manufacturing method of this disclosure. In the following description, since each step of the alcohol manufacturing method described herein is carried out in each part of the alcohol manufacturing apparatus described herein, the description of each step will be omitted.

[0019] In Figure 1, 10 is the raw material gas supply unit, 10A is the raw material gas preparation unit, 12 is the alcohol production unit, 14 is the gas-liquid separation unit, 16 is the raw material gas separation unit, 18 is the alcohol / water separation unit, 20 is the steam reforming unit, 22 is the water-gas shift unit, 24 is the gas-water separation unit, 26 is the purging unit, and 28 is the water supply unit. Also, in Figure 1, C 1-4 ROH indicates a gaseous hydrocarbon, and ROH indicates an alcohol.

[0020] <Raw Gas Supply Department> The raw material gas supply unit supplies raw material gas containing CO2 and H2 to the alcohol production unit. Specifically, the raw material gas supply unit receives CO2 and H2 from an external source. In addition, the raw material gas supply unit receives CO2 and H2 separated in the raw material gas separation unit and the gas-liquid separation unit. The raw material gas supply unit then supplies raw material gas containing CO2 and H2 to the alcohol production unit.

[0021] Here, the raw material gas supply unit includes a raw material gas preparation unit that prepares a raw material gas with a predetermined CO2 / H2 ratio and gas flow rate. The raw material gas supply unit then supplies the raw material gas prepared in the raw material gas preparation unit to the alcohol production unit. The raw material gas supply unit receives CO2 and H2 supplied from an external source, along with CO2 and H2 separated in the raw material gas separation unit and the gas-water separation unit. The raw material gas supply unit then prepares the raw material gas from the supplied CO2 and H2 to a predetermined molar ratio (H2 / CO2). By preparing a raw material gas with a predetermined CO2 / H2 ratio in the raw material gas preparation unit, the productivity of alcohol production is improved.

[0022] The molar ratio (H2 / CO2) of the raw material gas prepared in the raw material gas preparation unit is preferably, for example, 1.0 to 4.0. When the molar ratio of H2 to CO2 is 1.0 or higher, the amount of H2 in the raw material gas is sufficient, so the hydrogenation reaction of CO2 proceeds easily, and productivity is high. On the other hand, when the molar ratio of H2 to CO2 is 4.0 or lower, the amount of CO2 in the raw material gas is sufficient, so productivity is high.

[0023] The raw material gas preparation unit is optional. In other words, the CO2 and H2 separated in the raw material gas separation unit and the gas-water separation unit, along with the CO2 and H2 supplied from an external source, may be supplied to the alcohol production unit as raw material gas without adjusting the CO2 / H2 ratio.

[0024] Here, the CO2 supplied to the raw material gas preparation unit from an external source is not particularly limited, but examples include CO2 directly recovered from the atmosphere by DAC (Direct Air Capture) technology, and CO2 captured from exhaust gas of steel mills or chemical plants using chemical adsorption methods, etc. Furthermore, while there are no particular restrictions on the H2 supplied from an external source to the raw material gas preparation unit, examples include green hydrogen and blue hydrogen. Furthermore, the CO2 and H2 supplied from external sources refer to CO2 and H2 supplied from devices other than the alcohol production apparatus described in this disclosure.

[0025] <Alcohol Manufacturing Department> The alcohol production unit has an alcohol production catalyst that is brought into contact with a raw material gas supplied from the raw material gas supply unit to produce alcohol, and alcohol is produced using the alcohol production catalyst. In other words, the alcohol production unit produces alcohol from the raw material gas supplied from the raw material gas supply unit. Specifically, the alcohol production unit receives raw material gas containing CO2 and H2 from the raw material gas supply unit. As mentioned above, the raw material gas also includes CO2 and H2 separated in the gas-liquid separation unit and CO2 and H2 separated in the raw material gas separation unit. Then, in the alcohol production section, the raw material gas comes into contact with the catalyst, causing the reaction shown in equation (1) below, and through this reaction, the target product, alcohol, is produced from the raw material gas.

[0026] In the reaction shown in equation (1) below, an alcohol with a hydroxyl group (-OH) is produced, and H2O is produced as a by-product. In addition, in this reaction, gaseous hydrocarbons with 1 to 4 carbon atoms are also produced as by-products, for example, through the reaction shown in equation (2) below. nCO2 + 3nH2 → C n H 2n+1 OH + 2n - 1H2O - (1) nCO2 + 3n + 1H2 → C n H 2n+2 +2nH2O -(2)

[0027] The alcohol production section consists of known reactors (fixed-bed reactors, slurry-bed reactors, etc.).

[0028] The reaction conditions are not particularly limited, but a reaction temperature of 150-350°C and a reaction pressure of 1.0-10 MPa are preferred, and 180-320°C and 3.0-7.0 MPa are more preferred. Setting the reaction temperature above 150°C makes it easier to achieve sufficient catalytic activity. Setting the reaction temperature below 350°C suppresses the increase in selectivity of by-products such as methane and the decrease in catalyst lifetime. Therefore, it is preferable to set the reaction temperature within the range of 150 to 350°C. On the other hand, setting the reaction pressure to 1.0 MPa or higher makes it easier to achieve sufficient catalytic activity. Setting the reaction pressure to 10 MPa eliminates the need to set a high pressure resistance design for the plant, thus suppressing increases in equipment costs. Therefore, it is preferable to set the reaction pressure in the range of 1.0 to 10 MPa.

[0029] <Gas-liquid separation section> In the gas-liquid separation section, gaseous components containing CO2, H2, CO, and gaseous hydrocarbons are separated from the effluent discharged from the alcohol production section, and liquid components containing H2O and alcohol are separated. Specifically, the gas-liquid separation unit receives the effluent from the alcohol production unit. It then separates the gaseous component, containing CO2, H2, CO, and gaseous hydrocarbons, from the effluent from the alcohol production unit, into a liquid component containing H2O and alcohol. Examples of alcohols include methanol and ethanol, which are hydrophilic and therefore readily dissolve in the by-product H2O.

[0030] The gas-liquid separation unit is composed of a known gas-liquid separator and can be operated at, for example, 0 to 80°C. Furthermore, by using the effluent from the alcohol production unit at high pressure without depressurization, gas-liquid separation can be achieved more efficiently.

[0031] <Raw material gas separation section> The raw material gas separation unit separates CO2 and H2 from CO and gaseous hydrocarbons from the gaseous components separated in the gas-liquid separation unit. Specifically, the raw material gas separation unit receives the gaseous components. It then separates CO2 and H2 from CO and gaseous hydrocarbons. CO2 is separated using at least one of the following methods: chemical adsorption, PSA, and membrane separation. H2 is separated using at least one of the following methods: PSA and membrane separation.

[0032] Here, the CO2 and H2 separated in the raw material gas separation section are sent to the raw material gas supply section via the purging section and supplied to the alcohol production section as raw material gas. In the alcohol production section, the CO2 and H2 separated in the raw material gas separation section are also used as raw material gas in the production of alcohol. This increases the utilization rate of the raw material gas, thereby reducing raw material costs.

[0033] The raw material gas separation unit is optional. In other words, even without a raw material gas separation unit, the gaseous components separated in the gas-liquid separation unit can be supplied directly to the steam reforming unit, where H2 and CO can be produced from the gaseous components separated in the gas-liquid separation unit and H2O supplied from the water supply unit and alcohol / water separation unit, or from the water supply unit, alcohol / water separation unit and gas-liquid separation unit (see Figure 3). The symbols in Figure 3 are the same as those in Figure 1.

[0034] <Alcohol / Water Separation Section> The alcohol / water separation unit separates H2O and alcohol from the liquid component. Specifically, the alcohol / water separation unit receives a supply of liquid components, including H2O and alcohol, which have been separated in the gas-liquid separation unit. The alcohol / water separation unit then separates H2O and alcohol from the liquid component. The alcohol / water separation section consists of a known distillation separator or a membrane separator.

[0035] The alcohol separated in the alcohol / water separation unit is recovered as the target product. On the other hand, the H2O separated in the alcohol / water separation unit is sent to the steam reforming unit. The H2O separated in the alcohol / water separation unit is vaporized by a vaporizer (not shown) and sent to the steam reforming unit. The H2O separated in the alcohol / water separation unit may be supplied directly to the steam reforming unit, or it may be sent to the water supply unit before being supplied to the steam reforming unit. However, Figure 1 shows a configuration in which the H2O separated in the alcohol / water separation unit is sent to the water supply unit before being supplied to the steam reforming unit.

[0036] Here, the alcohol / water separation unit is optional. In other words, even without an alcohol / water separation unit, the liquid component separated in the gas-liquid separation unit can be recovered directly as the target product (see Figure 2). However, if an alcohol / water separation unit is not provided, the steam reforming unit generates H2 and CO from the gaseous hydrocarbons separated in the raw material gas separation unit and the H2O supplied from the water supply unit and the H2O separated in the gas-water separation unit. Note that the symbols in Figure 2 are the same as those in Figure 1.

[0037] <Steam reforming section> The steam reforming unit generates H2 and CO from the CO and gaseous hydrocarbons separated in the raw material gas separation unit, H2O supplied from the water supply unit, H2O separated in the alcohol / water separation unit, and H2O separated in the gas-water separation unit. Specifically, the steam reforming unit receives CO and gaseous hydrocarbons from the raw material gas separation unit, H2O supplied from the water supply unit, H2O separated in the alcohol / water separation unit, and H2O separated in the gas-water separation unit. The H2O separated in the alcohol / water separation section and the vapor-water separation section, as well as the H2O supplied from the water supply section, are vaporized by a vaporizer (not shown) and supplied to the steam reforming section. Figure 1 shows a configuration in which H2O separated in the alcohol / water separation unit and the gas-water separation unit is sent to the water supply unit, and the H2O is supplied in bulk from the water supply unit to the steam reforming unit. However, the H2O separated in the alcohol / water separation unit and the gas-water separation unit may also be supplied directly to the steam reforming unit. In the steam reforming section, H2 and CO are produced from gaseous hydrocarbons and H2O through a steam reforming reaction. This increases the utilization rate of the raw material gas and reduces raw material costs. Furthermore, CO2 is also produced during the steam reforming reaction, i.e., in the steam reforming section.

[0038] Here, as an example, the steam reforming reaction of methane, a gaseous hydrocarbon, is shown in equation (3) below. CH4 + H2O → CO + 3H2 - (3)

[0039] Furthermore, if gaseous hydrocarbons are sent to the steam reforming section without a raw material gas separation section, unreacted CO2 and H2 are also sent to the steam reforming section. Since CO2 and H2 are products in the steam reforming reaction, they act unfavorably in equilibrium, leading to a decrease in the conversion rate of gaseous hydrocarbons. In addition, when raising the temperature of the steam reforming section to the reaction temperature, CO2 and H2 are also heated, increasing the required energy. In contrast, the above problem can be avoided by separating CO2 and H2 from CO and gaseous hydrocarbons in the raw material gas separation section.

[0040] The steam reforming section is composed of a known steam reformer and may be carried out in two stages, for example. In this case, by carrying out the first reaction at 450-600°C and the second reaction at 700-1000°C, the amount of unreacted gaseous hydrocarbons can be reduced, and H2 and CO can be efficiently obtained.

[0041] When gaseous hydrocarbons with two or more carbon atoms are used in a steam reforming reaction, coking due to CO disproportionation is likely to occur. To prevent this, a methanation stage may be provided before the steam reforming stage, and the gaseous hydrocarbon may be converted to methane before being used in the steam reforming reaction. This makes it possible to obtain H2 and CO while suppressing coking.

[0042] Another method to suppress coking is to set a high S / C ratio (supplied steam / carbon ratio). This suppresses coking by consuming CO, which is the cause of coking, by reacting it with H2O through the reaction shown in (4). On the other hand, setting the S / C ratio too high increases the energy required to heat the water, so it is preferable to set the S / C ratio between 1.0 and 4.0 considering economic efficiency. CO + H2O → CO2 + H2 - (4)

[0043] The catalyst used in the steam reforming reaction is not particularly limited, but it is preferable to use at least one from the group consisting of nickel (Ni), ruthenium (Ru), and rhodium (Rh), and at least one from the group consisting of activated carbon (C), alumina (Al2O3), silica (SiO2), titania (TiO2), and zirconia (ZrO2).

[0044] <Water-gas shift section> The water-gas shift section generates CO2 and H2 from the effluent discharged from the steam reforming section. Specifically, the water-gas shift section receives a supply of effluent from the steam reforming section, which includes CO2, H2, CO, and H2O. The water-gas shift section then generates CO2 and H2 from CO and H2O. The water-gas shift reaction is the reaction described in (4) above.

[0045] The CO2 and H2 generated in the water-gas shift section are sent to the raw material gas supply section via the purging section and supplied to the alcohol production section as raw material gas. The alcohol production section receives the CO2 and H2 generated in the water-gas shift section and uses this CO2 and H2 in the production of alcohol. This increases the utilization rate of the raw material gas, thereby reducing raw material costs.

[0046] The water-gas shift section is composed of a known water-gas shift reactor and may be carried out in two stages, for example. In that case, by carrying out the first reaction at 450°C and the second reaction at 200°C, unreacted CO can be reduced and CO2 and H2 can be obtained efficiently.

[0047] CO, like CO2, can be used in reactions, but an increase in CO in the reaction gas leads to a higher H / O ratio (hydrogen / CO2 and oxygen in CO), meaning an excess of H2 and an increase in gaseous hydrocarbons such as CH4. By providing a water-gas shift section to generate H2 from CO and convert it back to CO2, the H / O ratio can be controlled to a constant level, stabilizing alcohol production.

[0048] The catalyst used in the water-gas shift reaction is not particularly limited, but it is preferable to use a known high-temperature catalyst such as an Fe-Cr catalyst or a known low-temperature catalyst such as Cu / Zn / Al2O3.

[0049] <Sea water separation section> The gas-water separation unit separates CO2 and H2 from H2O from the effluent discharged from the water-gas shift unit. Specifically, the gas-water separation unit receives the effluent from the water-gas shift unit. It then separates CO2, H2, and H2O from the effluent from the water-gas shift unit. The gas-liquid separation unit is composed of a known gas-liquid separator.

[0050] If CO2 and H2 generated in the water-gas shift section are supplied to the alcohol production section without a gas-water separation section, H2O will also be supplied to the alcohol production section. If a large amount of H2O is supplied to the catalyst, degradation due to oxidation of metal active species will occur, leading to a decrease in productivity. Also, if a large amount of H2O is contained in the reaction gas, the amount of CO2 and H2 flowing per unit time will decrease, also leading to a decrease in productivity. In contrast, separating CO2 and H2 from H2O in a gas-water separation section can avoid the above problems.

[0051] Here, the H2O separated in the steam-water separation unit may be supplied directly to the steam reforming unit, or it may be sent to the water supply unit before being supplied to the steam reforming unit. Figure 1 shows an example in which the H2O separated in the steam-water separation unit is sent to the water supply unit before being supplied to the steam reforming unit. Alternatively, the H2O separated in the steam-water separation unit may be disposed of rather than supplied to the water supply unit or steam reforming unit (see Figure 2).

[0052] <Purge section> The purging section purges a portion of the CO2 and H2 separated in the raw gas separation section and the gas-water separation section. Specifically, the purging section receives CO2 and H2 separated in the raw material gas separation section and the gas-water separation section. The purging section then purges a portion of the CO2 and H2 separated in the raw material gas separation section and the gas-water separation section. This controls the amount of impurity gas in the CO2 and H2 gas sent to the raw material gas supply section to be below a certain percentage.

[0053] The purging section can be provided at any time. However, the CO2 and H2 separated in the raw material gas separation section and the gas-water separation section may contain impurity gases such as gaseous hydrocarbons and H2O that cannot be completely removed. Therefore, if the CO2 and H2 separated in the raw gas separation unit and the gas-water separation unit are continuously recycled, impurity gases will accumulate, leading to a decrease in productivity. In contrast, the above problem can be avoided by purging a portion of the recycled CO2 and H2 in a purging section and controlling the amount of impurity gas to below a certain percentage.

[0054] <Reaction Products> In the alcohol production apparatus and production method of this disclosure, in addition to alcohol, H2O, and optionally CO, gaseous hydrocarbons (hydrocarbons with 1 to 4 carbon atoms), and liquid hydrocarbons (hydrocarbons with 5 or more carbon atoms) may also be produced as by-products in the alcohol production section and the alcohol production process. CO is converted to CO2 and H2 in the water-gas shift section and can be reused as a raw material gas. The alcohol production apparatus and method disclosed herein can improve the apparent alcohol selectivity and reduce raw material costs by converting by-product hydrocarbons into raw material gas and reusing them in alcohol production. On the other hand, if the original alcohol selectivity is sufficiently high, it is more advantageous to reuse the by-product hydrocarbons directly without converting them into raw material gas, as this reduces the power costs associated with the conversion. Furthermore, if the original alcohol selectivity is extremely low, it would actually result in the production of a large amount of other hydrocarbons, making it unsuitable for alcohol production. Specifically, the alcohol selectivity among the reaction products, excluding CO, generated in the alcohol production process of the alcohol production section is preferably 20-80%.

[0055] In the basic configuration of the alcohol production apparatus and production method disclosed herein, there is no oil component separation section or separation process, so liquid hydrocarbons (hydrocarbons with 5 or more carbon atoms) may be mixed into the steam reforming section or the final product. Furthermore, in the steam reforming reaction, liquid hydrocarbons are highly likely to cause coking, and in order to suppress this, it is necessary to set a high S / C ratio, for example, but this increases the energy required to heat the water and becomes a factor that reduces production efficiency. Therefore, it is preferable to avoid generating liquid hydrocarbons as much as possible. Specifically, in the alcohol production section and the alcohol production process, the selectivity for hydrocarbons with 5 or more carbon atoms in the products excluding CO is preferably 35% or less.

[0056] <Catalyst for alcohol production> The catalyst for alcohol production is a catalyst used for producing alcohol from CO2 and H2, and can be a precious metal catalyst such as iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), molybdenum (Mo), rhodium (Rh), palladium (Pd), iridium (Ir), or platinum (Pt), which are active in the hydrogenation reaction. Among these precious metal catalysts, it is preferable to use cobalt, copper, rhodium, palladium, or platinum, which are suitable for the alcohol production apparatus and production method of this disclosure and can suppress the generation of liquid hydrocarbons.

[0057] Furthermore, the catalyst used for alcohol production from CO2 and H2 preferably contains cobalt, at least one element from the group consisting of copper, molybdenum, rhodium, palladium, iridium, and platinum, and at least one element from the group consisting of magnesium (Mg), aluminum (Al), titanium (Ti), manganese (Mn), zinc (Zn), gallium (Ga), and zirconium (Zr). More preferably, the catalyst contains cobalt, at least one element from the group consisting of copper, palladium, rhodium, and platinum, and at least one element from the group consisting of aluminum, titanium, zinc, gallium, and zirconium. By using the above catalyst, alcohol can be produced efficiently.

[0058] In the alcohol production apparatus and production method of this disclosure, if the generation of liquid hydrocarbons is a problem, an oil-water separation unit and an oil-water separation step may be provided between the gas-liquid separation unit and the alcohol / water separation unit to separate liquid hydrocarbons from H2O and alcohol. [Examples]

[0059] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to these examples.

[0060] (Method for producing catalysts) -Fe-based catalyst (Na-ZnFe@C)- To 30 mL of a dimethylformamide (DMF) solution containing 10 mmol of iron(III) chloride hexahydrate, 30 mL of a DMF solution containing 5 mmol of terephthalic acid was added dropwise, and the mixture was stirred for 1 hour. The resulting solution was then transferred to an autoclave and reacted at 110°C for 36 hours. The resulting solid was centrifuged, washed three times with pure water, and dried overnight at 80°C under reduced pressure. Next, zinc nitrate hexahydrate was impregnated to a Zn load of 6.2% by mass, and treated at 550°C for 3 hours under an N2 atmosphere to obtain ZnFe@C. Na-ZnFe@C was obtained by impregnating sodium carbonate to a Na load of 2% by mass.

[0061] -Co-based catalyst (Co / Silicalite-1) Tetrabutylammonium bromide and sodium hydroxide were ground into a fine powder using an agate mortar. Colloidal silica was then added and kneaded until a gel was formed. At this time, the molar ratios of the components were colloidal silica: 1.00, tetrabutylammonium bromide: 0.12, sodium hydroxide: 0.16, and water: 7.78. The resulting gel was transferred to an autoclave and reacted at 170°C for 24 hours. The resulting solid was separated by filtration, washed with pure water until the pH of the solid was 7, and then dried overnight at 110°C. Subsequently, Silicalite-1 was obtained by calcining at 550°C for 4 hours. Next, Co / Silicalite-1 was obtained by loading cobalt nitrate hexahydrate using the incipient wetness method so that the amount of Co loaded was 5.3% by mass.

[0062] -Cu·Precious metal catalyst (Pd / CeO2) To 140 mL of an aqueous solution containing 38.4 g of sodium hydroxide, 20 mL of an aqueous solution containing 3.47 g of cerium nitrate hexahydrate was added dropwise, and the mixture was stirred for 30 minutes. The resulting solution was then transferred to an autoclave and reacted at 100°C for 24 hours. The resulting solid was centrifuged, washed three times each with pure water and ethanol, and dried at 80°C for 8 hours. CeO2 was then obtained by calcining at 400°C for 4 hours. Next, CeO2 was added to an aqueous solution of palladium nitrate reduced with sodium borohydride so that the Pd load was 1.9 wt%, and the mixture was stirred at room temperature for 2 hours. The resulting solid was separated by filtration and dried at 60°C for 12 hours to obtain Pd / CeO2.

[0063] (Evaluation of the response) The following apparatus was prepared as the reaction device. A tubular fixed-bed reactor was used as the reactor for the alcohol production section. After filling each reactor with 0.5g of the three catalysts mentioned above, a reduction treatment was carried out at 400°C for 8 hours under a flow of pure H2 to produce alcohol. However, the reaction conditions for each catalyst were as follows: • Fe-based catalyst: Under the conditions of 320°C and 5.0 MPa, adjust F (flow rate of raw material gas (H2 / CO2=3.0)) in the reactor so that W (catalyst mass) / F (raw material gas flow rate); (g·h / mol) = 5.0. • Co-based catalyst: Under the conditions of 250°C and 2.0 MPa, adjust F (flow rate of raw material gas (H2 / CO2=3.0)) in the reactor so that W (catalyst mass) / F (raw material gas flow rate); (g·h / mol) = 5.0. • Cu-noble metal catalyst: Under the conditions of 240°C and 3.0 MPa, adjust F (flow rate of raw material gas (H2 / CO2=3.0)) in the reactor so that W (catalyst mass) / F (raw material gas flow rate); (g·h / mol) = 5.0.

[0064] Then, the compositions of the raw material gas and the gas at the outlet of the reactor were determined by online GC-TCD, and the CO2 conversion rate and CO selectivity were evaluated. On the other hand, the liquid components in the ice trap recovered after the completion of the reaction were determined by offline GC-FID, and the methane selectivity, selectivity for C2 hydrocarbons (C2), selectivity for C3 hydrocarbons (C3), selectivity for C4 hydrocarbons (C4), C5+ hydrocarbons (C 5+ 5+) selectivity, methanol (MeOH) selectivity, selectivity for alcohols with 2 or more carbon atoms (C 2+ 2+OH) selectivity were evaluated. In addition, a vertical tubular reactor was used, and the raw material gas was introduced from the upper part of the reactor.

[0065] Here, the CO2 conversion rate, CO selectivity, and selectivity for each product (methane selectivity, selectivity for C2 hydrocarbons (C2), selectivity for C3 hydrocarbons (C3), selectivity for C4 hydrocarbons (C4), C5+ hydrocarbons (C 5+ 5+) selectivity, methanol (MeOH) selectivity, selectivity for alcohols with 2 or more carbon atoms (C 2+ 2+OH) selectivity) were calculated as follows. • CO2 conversion rate (%) = (number of moles of CO2 reduced / number of moles of supplied CO2) × 100 • CO selectivity (%) = (number of moles of CO produced / number of moles of CO2 reduced) × 100 • Selectivity of each product (%) = (moles of carbon in each produced product / (total amount of produced products - number of moles of produced CO)) × 100 However, the number of carbon moles produced by each product (C-mol / kg-cat·h) = the number of moles of molecules produced by each product × the number of carbon atoms in each product.

[0066] (Comparative Examples 1A-1C, Examples 1A-1C, Examples 2A-2C, Examples 3A-3C) Next, based on the evaluation results of the reactions obtained for each catalyst, we estimated the raw material costs in the alcohol production apparatus. Specifically, the amount of raw material gas supplied was adjusted so that the raw material gas ratio flowing through the alcohol production section remained constant at H2 / CO2 = 3.0. Subsequently, the reaction in the steam reforming section was carried out at 900°C and 1.0 MPa, and the reaction in the water-gas shift section was carried out at 200°C and atmospheric pressure, and the reaction was allowed to proceed until the equilibrium composition was reached. At this time, the raw material cost was calculated from (amount of H2 and CO2 consumed or lost as products in the production process out of the supplied raw material gas / amount of H2 and CO2 converted to alcohol). The raw material cost was set to 1.0, with Comparative Example 1 as the baseline.

[0067] Here, Figure 1 is a flow chart of the alcohol production apparatus for Examples 1A to 1C. Figure 2 is a flow chart of the alcohol production apparatus for Examples 2A to 2C. Figure 3 is a flow chart of the alcohol production apparatus for Examples 3A to 3C. Figure 4 shows the flow diagrams for the alcohol production apparatus of Comparative Examples 1A to 1C. Note that the details of the symbols shown in Figure 4 are the same as the details of the symbols shown in Figure 1.

[0068] -Examples 1A~1C- As shown in Figure 1, the alcohol production apparatus of Examples 1A to 1C comprises a raw material gas supply unit having a raw material gas preparation unit, an alcohol production unit, a gas-liquid separation unit, a raw material gas separation unit, an alcohol / water separation unit, a water vapor reforming unit, a water-gas shift unit, a gas-water separation unit, and a purging unit.

[0069] -Examples 2A~2C- As shown in Figure 2, the alcohol production apparatus of Examples 2A to 2C is a modified version of the alcohol production apparatus of Examples 1A to 1C, with the alcohol / water separation unit removed and a separate water supply unit provided to supply H2O to the steam reforming unit described below.

[0070] -Examples 3A~2C- As shown in Figure 3, the alcohol production apparatus of Examples 3A to 3C is a device that removes the raw material gas separation unit from the alcohol production apparatus of Examples 1A to 1C and supplies the gaseous components separated in the gas-liquid separation unit to the steam reforming unit.

[0071] -Comparative Examples 1A~1C- As shown in Figure 4, the alcohol production apparatuses of Comparative Examples 1A to 1C are apparatuses obtained by removing the hydrogen reforming section, water-gas shift section, and gas-water separation section from the alcohol production apparatuses of Figures 1A to 1C. In other words, the alcohol production apparatus of Comparative Examples 1A to 1C does not include a hydrogen reforming section, a water-gas shift section, or a gas-water separation section. Therefore, in the alcohol production apparatus of Comparative Examples 1A to 1C, gaseous hydrocarbons and H2O are not converted to CO2 and H2 and reused as raw material gas.

[0072] Table 1 shows the CO2 conversion rate, CO selectivity, selectivity of each product, and raw material cost for the alcohol production apparatus of Comparative Examples 1A-1C, Examples 1A-1C, Examples 2A-2C, and Examples 3A-3C described above.

[0073] [Table 1]

[0074] As shown in Table 1, it was confirmed that the alcohol reaction apparatus of the example, equipped with a steam reforming section and a water-gas shift section, can produce alcohol with low raw material costs. [Explanation of Symbols]

[0075] 10. Raw Material Gas Supply Department 10A Raw material gas preparation section 12. Alcohol Manufacturing Department 14. Gas-liquid separation section 16. Raw material gas separation section 18. Alcohol / Water Separation Section 20 Steam reforming section 22 Water-gas shift section 24 Air-water separation section 26 Purge section 28 Water supply section

Claims

1. CO ２ and H ２ A raw material gas supply unit supplies raw material gas containing the following to the alcohol production unit, An alcohol production unit having an alcohol production catalyst that is brought into contact with the raw material gas supplied from the raw material gas supply unit to produce alcohol, and producing alcohol using the alcohol production catalyst, From the spilled material from the aforementioned alcohol manufacturing section, CO ２ H ２ , CO and gaseous hydrocarbons, and H ２ A gas-liquid separation unit that separates the liquid component containing O and alcohol, H ２ A water supply unit that supplies O to the steam reforming unit below, The gaseous component separated in the gas-liquid separation unit and H supplied from the water supply unit ２ O and, from H ２ and a steam reforming unit that generates CO, From the effluent flowing out of said steam reforming section, CO ２ and H ２ a water-gas shift section for producing From the spilled material from the aforementioned water-gas shift section, CO ２ and H ２ And, H ２ A gas-water separation unit that separates O and, Equipped with, The alcohol production section is separated from the CO2 separated in the gas-water separation section. ２ and H ２ An alcohol production apparatus that produces the alcohol from the raw material gas containing the above.

2. From the gaseous components separated in the gas-liquid separation unit, CO ２ and H ２ It is equipped with a raw material gas separation unit that separates CO and gaseous hydrocarbons, The steam reforming unit processes CO and gaseous hydrocarbons separated in the raw material gas separation unit, and H supplied from the water supply unit. ２ O and, from H ２ and CO is produced, The alcohol production section is separated from the CO2 in the raw material gas separation section. ２ and H ２ And the CO separated in the gas-water separation section ２ and H ２ The alcohol production apparatus according to claim 1, comprising producing the alcohol from the raw material gas containing the above.

3. From the liquid component separated in the gas-liquid separation section, H ２ It comprises an alcohol / water separator that separates O and alcohol, and recovers the alcohol separated in the alcohol / water separator. The steam reforming unit separates the gaseous component from the gas-liquid separation unit and H supplied from the water supply unit. ２ O, or the gaseous component separated in the gas-liquid separation unit, and H supplied from the water supply unit. ２ O and H separated in the alcohol / water separation unit. ２ O and H separated in the gas-water separation section. ２ O and, from H ２ The alcohol production apparatus according to claim 1, which also generates CO.

4. From the liquid component separated in the gas-liquid separation section, H ２ It comprises an alcohol / water separator that separates O and alcohol, and recovers the alcohol separated in the alcohol / water separator. The steam reforming unit processes CO and gaseous hydrocarbons separated in the raw material gas separation unit, and H supplied from the water supply unit. ２ O, or CO and gaseous hydrocarbons separated in the raw material gas separation unit, and H supplied from the water supply unit. ２ O and H separated in the alcohol / water separation unit. ２ O and H separated in the gas-water separation section. ２ O and, from H ２ The alcohol production apparatus according to claim 2, which also generates CO.

5. The raw material gas supply unit uses a predetermined molar ratio (H ２ / CO ２ The alcohol manufacturing apparatus according to claim 1 or claim 2, comprising a raw material gas preparation unit for preparing a raw material gas, and supplying the raw material gas prepared in the raw material gas preparation unit to the alcohol manufacturing unit.

6. CO separated in the aforementioned gas-liquid separation unit ２ and H ２ The alcohol production apparatus according to claim 1, further comprising a purging section for purging a portion of the alcohol.

7. CO separated in the raw material gas separation unit and the gas-water separation unit ２ and H ２ The alcohol production apparatus according to claim 2, further comprising a purging section for purging a portion of the alcohol.

8. The alcohol production apparatus according to claim 1 or claim 2, wherein the alcohol selectivity among the reaction products excluding CO produced in the alcohol production section is 20 to 80%, and the hydrocarbon selectivity with 5 or more carbon atoms is 35% or less.

9. CO ２ and H ２ A raw material gas supply process that supplies raw material gas containing the following to the alcohol manufacturing process, An alcohol production process comprising an alcohol production catalyst that is brought into contact with the raw material gas supplied from the raw material gas supply process to produce alcohol, and an alcohol production process that produces alcohol using the alcohol production catalyst, From the effluent that leaked out of the aforementioned alcohol manufacturing process, CO ２ H ２ , CO and gaseous hydrocarbons, and H ２ A gas-liquid separation step to separate the liquid component containing O and alcohol, H ２ A water supply process that supplies O to the steam reforming process described below, The gaseous component separated in the gas-liquid separation step and H supplied from the water supply step ２ O and, from H ２ and a steam reforming process that generates CO, From the effluent released from the aforementioned steam reforming process, CO ２ and H ２ A water-gas shift process that generates, From the effluent that flowed out of the aforementioned water-gas shift process, CO ２ and H ２ And, H ２ A gas-water separation process to separate O and, Equipped with, The alcohol production process involves the CO2 separated in the gas-water separation process. ２ and H ２ A method for producing alcohol, comprising producing the alcohol from the raw material gas containing the above.

10. From the gaseous components separated in the gas-liquid separation step, CO ２ and H ２ It includes a raw material gas separation process that separates CO and gaseous hydrocarbons, The steam reforming step involves using CO and gaseous hydrocarbons separated in the raw material gas separation step, and H supplied from the water supply step. ２ O and, from H ２ and CO is produced, The alcohol production process involves the CO2 separated in the raw material gas separation process. ２ and H ２ And the CO separated in the aforementioned gas-water separation step ２ and H ２ The method for producing alcohol according to claim 9, comprising producing the alcohol from the raw material gas containing the above.

11. From the liquid component separated in the gas-liquid separation step, H ２ It includes an alcohol / water separation step for separating O and alcohol, and recovers the alcohol separated in the alcohol / water separation step. The steam reforming step involves the gaseous components separated in the gas-liquid separation step and H supplied from the water supply step. ２ O, or the gaseous component separated in the gas-liquid separation step, and H supplied from the water supply step. ２ O and H separated in the alcohol / water separation step. ２ O and H separated in the gas-water separation step. ２ O and, from H ２ The method for producing alcohol according to claim 9, wherein CO is generated.

12. From the liquid component separated in the gas-liquid separation step, H ２ It includes an alcohol / water separation step for separating O and alcohol, and recovers the alcohol separated in the alcohol / water separation step. The steam reforming step involves using CO and gaseous hydrocarbons separated in the raw material gas separation step, and H supplied from the water supply step. ２ O, or CO and gaseous hydrocarbons separated in the raw material gas separation step, and H supplied from the water supply step. ２ O and H separated in the alcohol / water separation step. ２ O and H separated in the gas-water separation step. ２ O and, from H ２ The method for producing alcohol according to claim 10, comprising generating CO.

13. The raw material gas supply process involves a predetermined molar ratio (H ２ / CO ２ The alcohol production method according to claim 9 or claim 10, comprising a raw material gas preparation step for preparing a raw material gas, and supplying the raw material gas prepared in the raw material gas preparation step to the alcohol production step.

14. CO separated in the aforementioned gas-water separation step ２ and H ２ The method for producing alcohol according to claim 9, comprising a purging step of purging a portion of the alcohol.

15. CO separated in the aforementioned raw material gas separation step and the aforementioned gas-water separation step ２ and H ２ The method for producing alcohol according to claim 10, comprising a purging step of purging a portion of the alcohol.

16. The method for producing alcohol according to claim 9 or claim 10, wherein the alcohol selectivity among the reaction products, excluding CO, produced in the alcohol production step is 20 to 80%, and the hydrocarbon selectivity with 5 or more carbon atoms is 35% or less.

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