Method for producing conjugated diene polymers

Abstract

This invention provides a method for producing non-petrogenic conjugated diene polymers using non-petrogenic alcohols as raw materials. [Solution] The present invention is characterized by producing a non-petrified conjugated diene polymer using a non-petrified raw material-derived alcohol having an iron content of 0.0001 mg / L or more and 2 mg / L or less as a raw material.

Description

[Technical Field]

[0001] The present invention relates to a method for producing a conjugated diene polymer. More specifically, the present invention relates to a method for producing a non-fossil-derived conjugated diene polymer using, as a raw material, an alcohol derived from a non-fossil raw material such as ethanol in which the content of a specific trace component has been adjusted. [Background Art]

[0002] Petrochemical products are used in various aspects of our daily life. On the other hand, precisely because these are familiar products, the various environmental problems caused by mass production and mass consumption have become a major issue on a global scale. For example, polyethylene and polyvinyl chloride, which are representative products of the petrochemical industry, are mass-consumed and disposed of after single use, and their waste has become a major cause of environmental pollution. In addition, in relation to the mass production of petrochemical products, concerns about the depletion of fossil fuel resources and the global environmental issue of increased carbon dioxide in the atmosphere have also been discussed.

[0003] In recent years, in response to the growing global awareness of such environmental issues, methods for producing various organic substances using raw materials other than naphtha, which is the raw material for petrochemical products, have been studied. For example, a method of producing bioethanol from edible raw materials such as corn by a sugar fermentation method has attracted attention. However, it has been pointed out that such a sugar fermentation method using edible raw materials uses limited agricultural land for production other than food, thereby causing problems such as soaring food prices.

[0004] To address this problem, the use of non-edible raw materials that were previously discarded is being considered. Specifically, methods such as producing alcohols by fermentation using waste materials and cellulose derived from recycled paper as non-edible raw materials, or gasifying the aforementioned biomass raw materials and producing alcohols from the synthesis gas using a catalyst have been proposed, but none of these have yet been put into practical use. Furthermore, even if various petrochemical products could be manufactured from these de-petrification raw materials, they would ultimately become waste plastics that do not decompose naturally, and therefore cannot be considered an effective fundamental solution to environmental problems.

[0005] Incidentally, the amount of combustible waste currently discarded in Japan amounts to approximately 60 million tons per year. Its energy content is equivalent to approximately 200 trillion kilocalories, far exceeding the energy content of naphtha used as a raw material for plastics in Japan, and thus this waste can be considered a valuable resource. If these waste resources can be converted into petrochemical products, it will be possible to realize the ultimate resource-recycling society that does not rely on petroleum resources. From the above perspective, Patent Documents 1 and 2 disclose a technology for producing synthesis gas (a gas mainly composed of CO and H2) from waste, and then producing ethanol from that synthesis gas by fermentation.

[0006] However, as pointed out in Patent Document 3, synthesis gas produced from waste contains a wide variety of unidentified impurities, some of which are toxic to microorganisms. Therefore, productivity has been a major challenge in producing alcohol from synthesis gas through microbial fermentation. Furthermore, the alcohol obtained by microbial fermentation of synthesis gas also contains various components resulting from the impurities in the synthesis gas, and these components cannot be completely removed even by purification processes such as distillation. For this reason, developing derivative products from alcohol obtained by microbial fermentation of synthesis gas has been a major technical challenge.

[0007] Further, conventionally, as rubber compositions for tires, synthetic rubbers such as butadiene rubber (BR) and styrene-butadiene rubber (SBR), and fillers such as carbon black have been used, but these were highly dependent on raw materials derived from petroleum resources. However, in recent years, environmental issues have come to be emphasized, and regulations on carbon dioxide emissions have been tightened. Furthermore, since the amount of existing petroleum is finite and there is a limit to the use of raw materials derived from petroleum resources, development of rubber compositions for tires in which part or all of the currently used raw materials derived from petroleum resources are replaced with raw materials derived from non-petroleum resources is demanded. Accordingly, Patent Document 4 proposes increasing the proportion of natural rubber as a rubber component. Patent Document 5 proposes using modified natural rubber as a rubber component. Furthermore, Patent Document 6 proposes using renewable (biomass-derived) butadiene and isoprene as butadiene and isoprene, which are raw materials for rubber components. Patent Documents 7 and 8 propose synthesizing 1,3-butadiene from commercially available bioethanol. [PRIOR ART DOCUMENT] [PATENT DOCUMENTS]

[0008] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2016-059296 [Patent Document 2] International Publication No. 2015-037710 [Patent Document 3] Japanese Unexamined Patent Application Publication No. 2018-058042 [Patent Document 4] Japanese Unexamined Patent Application Publication No. 2007-246712 [Patent Document 5] Japanese Unexamined Patent Application Publication No. 2012-122016 [Patent Document 6] Japanese National Publication of International Patent Application No. 2012-518658 [Patent Document 7] International Publication No. 2012 / 102290 [Patent Document 8] Japanese Unexamined Patent Application Publication No. 2014-148683 [SUMMARY OF THE INVENTION] [Problems that the invention aims to solve]

[0009] According to the inventors' research, while C2 raw materials, such as conventional ethanol, are known to be used as starting materials for various chemical products, as mentioned above, alcohol produced from resources other than petroleum or biomass resources (recyclable resources) contains various trace amounts of unknown substances, unlike chemical raw materials derived from naphtha. However, in conventional technology, the properties of these substances are unknown, and it has not been sufficiently investigated whether it is sufficient to remove all substances or only specific substances. Therefore, even though alcohol produced from recycled resources has been proposed in the above-mentioned patent documents, there is still much room for technological improvement before such alcohol can be put into practical use.

[0010] On the other hand, while the above-mentioned literature discloses general fermentation and distillation methods and the optimal composition of synthesis gas, it does not describe the details of the process, nor does it even identify the resulting alcoholic substance.

[0011] Therefore, the present invention has been made in view of the above background art, and its objective is to provide a novel alcohol and its derivatives that have industrial value compared to existing petrochemical raw materials and are practical.

[0012] Furthermore, Patent Document 6 describes a method for producing renewable butadiene, in which alcohol obtained by fermenting biomass-derived sugars is used as a starting material. In addition, Patent Documents 7 and 8 propose the synthesis of 1,3-butadiene from commercially available bioethanol. However, the commercially available alcohols or equivalent products (described in the comparative examples) described in such prior art documents are not specifically manufactured for practical chemical applications, and there was a need to develop raw material alcohols that could withstand the physical properties and characteristics of various practical products (e.g., resins and products using those resins). Therefore, a broader range of technologies was required to optimize the application range of alcohols. [Means for solving the problem]

[0013] The inventors of this invention conducted diligent research to solve the above problems and found that they were able to identify a wide variety of trace substances contained in alcohol produced from recycled resources, and that it was possible to control the content within a specific range using a novel manufacturing method. Furthermore, they found that the various derivatives thereof exhibit superior effects compared to existing alcohols. For example, in the process of synthesizing butadiene from ethanol, they found that the selectivity for butadiene was improved compared to when conventional ethanol was used, and that chemicals derived from alcohol or products using such alcohols could be obtained at a practical level equivalent to or better than existing alcohols, leading to the present invention.

[0014] More specifically, we discovered that when ethanol is produced from a gas substrate containing carbon monoxide and hydrogen using waste as a carbon source, synthesizing butadiene from the ethanol improves the conversion rate of the ethanol. Upon investigating the reason for this in detail, we found that ethanol derived from recycled resources using gases containing carbon monoxide and hydrogen as substrates has an extremely low content of certain metal elements. This invention is based on these findings.

[0015] Furthermore, the inventors conducted diligent studies to solve the above problems and found that by using alcohols such as ethanol derived from non-petrochemical raw materials, which have an iron content within a specific range, as a starting material to produce a conjugated diene system such as butadiene, and then polymerizing it to produce a non-petrochemical-derived conjugated diene polymer, a suitable rubber composition for tires can be obtained. The present invention is based on this finding.

[0016] In other words, the present invention includes the following gist. [1] A method for producing a non-petrogenic conjugated diene polymer using non-petrogenic alcohol as a raw material, Using an alcohol derived from non-petrochemical raw materials having an iron content of 0.0001 mg / L or more and 2 mg / L or less as a raw material, the alcohol is brought into contact with a catalyst and heated, thereby generating a catalyst with a carbon number of C4~C 12a step of producing a conjugated diene, a step of polymerizing a monomer containing the conjugated diene to produce a non-petrochemical-derived conjugated diene-based polymer, and A method comprising: [2] The method according to [1], wherein the non-petrochemical feedstock-derived alcohol comprises ethanol. [3] The method according to [1] or [2], wherein the conjugated diene comprises at least one selected from the group consisting of 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 4,5-diethyl-1,3-octadiene, and 3-butyl-1,3-octadiene. [4] The method according to any one of [1] to [3], wherein the non-petrochemical feedstock-derived alcohol uses a gas containing carbon monoxide and hydrogen as a substrate. [5] The method according to any one of [1] to [4], wherein the non-petrochemical feedstock-derived alcohol is derived from microbial fermentation. [6] The method according to [4], wherein the gas containing carbon monoxide and hydrogen is derived from waste. [7] The method according to any one of [1] to [6], wherein an aromatic hydrocarbon is further polymerized as the monomer. [8] The method according to [7], wherein the aromatic hydrocarbon is at least one selected from the group consisting of styrene, methylstyrene, ethylstyrene, t-butylstyrene, α-methylstyrene, α-methyl-p-methylstyrene, chlorostyrene, bromostyrene, methoxystyrene, dimethylaminomethylstyrene, dimethylaminoethylstyrene, diethylaminomethylstyrene, diethylaminoethylstyrene, cyanoethylstyrene, and vinylnaphthalene. [9] The method according to any one of [1] to [8], wherein the conjugated diene-based polymer comprises at least one selected from the group consisting of isoprene rubber, butadiene rubber, styrene-butadiene rubber, chloroprene rubber, and acrylonitrile-butadiene rubber.

[10] A method for producing a crosslinked rubber product, comprising: A method comprising the step of kneading the non-petrochemical conjugated diene polymer obtained by any of the methods in [1] to [9] as a rubber component with a filler and crosslinking. A method for manufacturing a tire, using a rubber crosslinked product obtained by the method described in

[11]

[10] .

[0017] According to the present invention, by using an alcohol with an extremely low content of a specific metal element, preferably ethanol, various unique effects can be obtained compared to commercially available industrial alcohols. For example, according to the present invention, it is possible to improve the selectivity of butadiene when synthesizing butadiene using ethanol as a raw material, improve the yield when synthesizing SBR, and control the glass transition temperature of SBR and the butadiene / styrene ratio. In addition, it is expected that similar effects can be obtained even with existing alcohols by adjusting the content of a specific metal element to an extremely low level.

[0018] Furthermore, the alcohol used in the present invention, preferably ethanol, can be used as a raw material for the manufacture of, for example, butadiene, ethylene, propylene, isobutene, acetaldehyde, acetic acid, ethyl acetate, methyl (meth)acrylate, ethyl-t-butyl ether ethylene glycol, ester compositions, polyesters, acrylic acid, aminohexanoic acid, diethyl carbonate, polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), polyisobutylene, polymethyl methacrylate (PMMA), ethylene propylene diene rubber (EPDM), polybutylene terephthalate (PBT), polyethylene furanoate (PEF), polyurethane (PU), etc. In addition, the alcohol used in the present invention can be used in a variety of applications for chemical products such as cosmetics, perfumes, fuels, antifreeze, disinfectants, sterilizers, cleaning agents, mold removers, detergents, shampoos, soaps, antiperspirants, facial cleansing sheets, solvents, paints, adhesives, diluents, and food additives. [Modes for carrying out the invention]

[0019] Hereinafter, an example of a preferred embodiment for carrying out the present invention will be described. However, the following embodiment is an illustration for describing the present invention, and the present invention is not limited to the following embodiment in any way.

[0020] <Definition> In the present invention, the term "alcohol" refers to a compound obtained by substituting a hydroxy group (-OH) for a hydrogen atom of a hydrocarbon. Specifically, examples of lower alcohols include methanol (methyl alcohol), ethanol (ethyl alcohol), 2-propanol, ethylene glycol, glycerin, phenol, and the like, with ethanol being preferred. Higher alcohols generally have 8 to 22 carbon atoms, and specific examples thereof include capryl alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol (cetanol), stearyl alcohol, oleyl alcohol, linolyl alcohol, and the like. In addition, in the present invention, the term "ethanol" does not mean pure ethanol as a compound (ethanol represented by the chemical formula: CH3CH2OH), but shall mean a composition containing water and unavoidably contained impurities (contaminant components) in ethanol produced through synthesis or purification. In addition, in the present invention, the content of each component such as inorganic components and organic components in an alcohol raw material refers to the amount (mg) of each component per 1 L of alcohol.

[0021] <Non-petroleum raw material-derived alcohol> In the present invention, a non-petroleum raw material-derived alcohol in which the content of Fe (iron) is controlled is used. Specifically, the content of Fe (iron) relative to the alcohol is 0.0001 mg / L or more and 2 mg / L or less, preferably 0.0005 mg / L or more, more preferably 0.001 mg / L or more, still more preferably 0.01 mg / L or more, preferably 1.5 mg / L or less, more preferably 1.0 mg / L or less, and still more preferably 0.5 mg / L or less. Note that the Fe content refers to the amount of Fe element in the Fe compound. Having the Fe content within the above numerical range improves the selectivity of butadiene when synthesizing butadiene using ethanol as a raw material, improves the yield when synthesizing SBR, and allows for control of the glass transition temperature of SBR and the butadiene / styrene ratio.

[0022] The iron content in alcohol can be measured by conventionally known methods. One such method is analysis using an inductively coupled plasma mass spectrometer (ICP-MS). In the ICP-MS method, a calibration curve is created by analyzing atomic absorption standard solutions after adjusting their concentration, and the iron content is determined by analyzing the sample to be measured based on this calibration curve.

[0023] The alcohol used in the present invention, preferably ethanol, is not particularly limited, but it is preferably an alcohol produced using a gas containing carbon monoxide and hydrogen as a substrate, or an alcohol produced using microbial fermentation or a metal catalyst with sugar or cellulose as raw materials. This is because it is easy to adjust the iron content to the above concentration in the manufacturing process if these alcohols are used. Furthermore, it has been found that commercially available non-fossil fuel-derived alcohols, such as sugar ethanol, and especially small-scale reagent ethanol as described in the publicly available literature, do not contain Fe, as shown in the comparative example. Therefore, for industrial use as a chemical raw material, strict control of the Fe content becomes necessary. In such cases, the iron content may be adjusted to the above concentration by further purification, preferably by the purification method described herein. If the iron content does not exceed the above concentration, it is sufficient to include it during the process of producing ethanol from the raw materials and / or the process of converting ethanol to a conjugated diene. The timing of inclusion is not particularly limited, but includes storage, transportation, and delivery. The method of inclusion is not particularly limited, but may include, for example, addition or elution in contact with a metal containing Fe.

[0024] While not bound by theory, in this invention, by reducing the content of specific metals in ethanol to extremely low levels, it becomes possible to improve the selectivity of butadiene when synthesizing butadiene using ethanol as a raw material, improve the yield when synthesizing SBR, and control the glass transition temperature of SBR and the butadiene / styrene ratio.

[0025] The alcohol used in the present invention, particularly ethanol, may contain inorganic components other than Fe. For example, it may contain inorganic components such as Si, K, and Na. Compounds containing these elements may be inorganic compounds or organometallic compounds.

[0026] When alcohol, particularly ethanol, contains Si, the Si content is preferably 10 mg / L or more, more preferably 20 mg / L or more, even more preferably 30 mg / L or more, and also preferably 100 mg / L or less, more preferably 90 mg / L or less, and even more preferably 80 mg / L or less, relative to ethanol. The Si content refers to the amount of Si element in the Si compound. By having a Si content within the above numerical range, it is possible to capture the water produced by the butadiene synthesis reaction, thereby improving the selectivity of butadiene when synthesizing butadiene using ethanol as a raw material, and improving the yield of the butadiene polymerization reaction.

[0027] The silicon (Si) content in alcohol, particularly ethanol, can be measured by conventionally known methods. One method for measuring Si content is analysis using an inductively coupled plasma mass spectrometer (ICP-MS). In the ICP-MS method, a calibration curve is created by analyzing atomic absorption standard solutions after adjusting their concentration, and the Si content is determined by analyzing the sample to be measured based on this calibration curve.

[0028] The alcohol of the present invention, particularly ethanol, is obtained by extracting and further purifying an ethanol-containing liquid obtained from a microbial fermentation tank, as described below. However, other components may be present in addition to the unavoidable substances mentioned above. For example, trace amounts of aromatic compounds may be present. Examples of aromatic compounds include toluene, ethylbenzene, o-xylene, m-xylene, and p-xylene, and only one of these may be present, or two or more may be present. It is preferable that ethylbenzene is included as the aromatic compound.

[0029] The total amount of aromatic compounds contained in alcohol, particularly ethanol, is preferably 0.4 mg / L or more, more preferably 0.5 mg / L or more, even more preferably 0.7 mg / L or more, even more preferably 1.0 mg / L or more, and also preferably 10 mg / L or less, more preferably 7 mg / L or less, even more preferably 5 mg / L or less, and even more preferably 3 mg / L or less. Having the aromatic compound content within the above numerical range allows for smooth mixing of styrene and ethanol during the polymerization reaction, improving the yield of the polymerization reaction.

[0030] The content of aromatic compounds in alcohol, particularly ethanol, can be measured by conventionally known methods. One such method is analysis using gas chromatography-mass spectrometry (GC-MS). In the GC-MS method, a calibration curve is created by analyzing standard gases, and the content of aromatic compounds is determined by analyzing the sample to be measured based on this calibration curve.

[0031] When ethylbenzene is present in the alcohol, particularly ethanol, the ethylbenzene content is preferably 0.1 mg / L or more, more preferably 0.2 mg / L or more, even more preferably 0.3 mg / L or more, even more preferably 0.5 mg / L or more, and also preferably 5 mg / L or less, more preferably 3 mg / L or less, even more preferably 2 mg / L or less, and even more preferably 1 mg / L or less, relative to the total ethanol. Having the ethylbenzene content within the above numerical range allows for smooth mixing of styrene and ethanol during the polymerization reaction, improving the yield of the polymerization reaction.

[0032] The ethylbenzene content in alcohols, particularly ethanol, can be measured by conventionally known methods. One method for measuring ethylbenzene content is analysis using gas chromatography-mass spectrometry (GC-MS). In the GC-MS method, a calibration curve is created by analyzing standard gases, and the ethylbenzene content is determined by analyzing the sample to be measured based on this calibration curve.

[0033] When toluene is present in the alcohol, particularly ethanol, the toluene content is preferably 0.01 mg / L or more, more preferably 0.02 mg / L or more, even more preferably 0.03 mg / L or more, even more preferably 0.05 mg / L or more, and also preferably 1 mg / L or less, more preferably 0.5 mg / L or less, even more preferably 0.2 mg / L or less, and even more preferably 0.1 mg / L or less. Having the toluene content within the above numerical range allows for smooth mixing of styrene and ethanol during the polymerization reaction, improving the yield of the polymerization reaction.

[0034] The toluene content in ethanol can be measured by conventionally known methods. One such method is analysis using gas chromatography-mass spectrometry (GC-MS). In the GC-MS method, a calibration curve is created by analyzing standard gases, and the toluene content is determined by analyzing the sample to be measured based on this calibration curve.

[0035] When o-xylene is present in alcohol, particularly ethanol, the o-xylene content is preferably 0.1 mg / L or more, more preferably 0.2 mg / L or more, even more preferably 0.3 mg / L or more, even more preferably 0.5 mg / L or more, and also preferably 5 mg / L or less, more preferably 3 mg / L or less, even more preferably 2 mg / L or less, and even more preferably 1 mg / L or less, relative to the total ethanol. Having the o-xylene content within the above numerical range allows for smooth mixing of styrene and ethanol during the polymerization reaction, improving the yield of the polymerization reaction.

[0036] The o-xylene content in alcohol, particularly ethanol, can be measured by conventionally known methods. One such method is analysis using gas chromatography-mass spectrometry (GC-MS). In the GC-MS method, a calibration curve is created by analyzing standard gases, and the o-xylene content is determined by analyzing the sample to be measured based on this calibration curve.

[0037] When m-xylene and / or p-xylene are present in alcohol, particularly ethanol, the total content of m-xylene and / or p-xylene is preferably 0.1 mg / L or more, more preferably 0.2 mg / L or more, preferably 5 mg / L or less, more preferably 3 mg / L or less, even more preferably 2 mg / L or less, and even more preferably 1 mg / L or less, relative to the total ethanol. Having the m-xylene and / or p-xylene content within the above numerical range allows for smooth mixing of styrene and ethanol during the polymerization reaction, improving the yield of the polymerization reaction.

[0038] The m- or p-xylene content in alcohol, particularly ethanol, can be measured by conventionally known methods. One such method is analysis using gas chromatography-mass spectrometry (GC-MS). In the GC-MS method, a calibration curve is created by analyzing standard gases, and the m- or p-xylene content is determined by analyzing the sample to be measured based on this calibration curve.

[0039] When alcohol, especially ethanol, contains chlorine, it is preferable that the concentration be less than 2 mg / L. If the chlorine content exceeds this range, the catalyst for the reaction to synthesize butadiene from ethanol will be deactivated, and the conversion rate of ethanol will decrease.

[0040] The chlorine content in alcohol, particularly ethanol, can be measured by conventionally known methods. One such method is analysis using ion chromatography. In this method, a calibration curve is created by analyzing standard solutions, and the chlorine content is determined by analyzing the sample to be measured based on this calibration curve.

[0041] The alcohol of the present invention, particularly ethanol, contains the inorganic components described above, and optionally trace amounts of organic components such as aromatic hydrocarbons and aliphatic hydrocarbons. The concentration of ethanol (pure ethanol as a compound), which is the main component of ethanol, is 75% by volume or more, preferably 80% by volume or more, more preferably 90% by volume or more, even more preferably 95% by volume or more, even more preferably 98% by volume or more, and also preferably 99.999% by volume or less, more preferably 99.99% by volume or less, even more preferably 99.9% by volume or less, and even more preferably 99.5% by volume or less.

[0042] <Method for producing alcohol> As for the method of producing alcohol, particularly ethanol, which has the characteristic inorganic and organic compounds described above, there are no particular limitations as long as they are within the content range specified in the present invention, but as raw materials for alcohol, biomass resources, specifically, for example, cellulosic plants (pulp, waste paper, papermaking, etc.), wood, charcoal, compost, natural rubber, cotton, sugarcane, okara, oils and fats, plants (corn, cassava, bagasse, etc.), fishery residues, livestock excrement, waste, algae, etc., can be used. The biomass resources may be extracted and purified from the above biomass resources or biomass resources that have undergone the above treatment (i.e., biomass-derived substances). For example, sugar ethanol purified from these biomass resources may also be used. Preferably, ethanol can be produced by microbial fermentation of synthesis gas containing carbon monoxide derived from waste or exhaust gas. In such a method, the content of aromatic compounds, etc. in the raw material gas derived from waste or exhaust gas and the purification conditions may be controlled to control the amount of aromatic compounds, etc. in the final product. Below, as an example, a method for producing ethanol by microbial fermentation of synthesis gas containing carbon monoxide derived from waste or exhaust gas will be described.

[0043] A method for producing alcohol, particularly ethanol, includes the steps of: converting a carbon source into synthesis gas containing carbon monoxide and hydrogen; supplying the synthesis gas containing carbon monoxide and hydrogen to a microbial fermentation tank to obtain an ethanol-containing liquid by microbial fermentation; separating the ethanol-containing liquid into a liquid or solid component containing microorganisms and a gaseous component containing ethanol; liquefaction, condensing the gaseous component into a liquid; and purification, purifying the ethanol from the liquid obtained in the liquefaction step. However, it may also include, as necessary, a raw material gas generation step, a synthesis gas preparation step, a wastewater treatment step, etc. Each step will be described below.

[0044] <Raw material gas generation process> The raw material gas generation process is a process in which raw material gas is generated in the gasification section by gasifying a carbon source. A gasification furnace may be used in the raw material gas generation process. A gasification furnace is a furnace that burns (incompletely combusts) a carbon source, and examples include shaft furnaces, kiln furnaces, fluidized bed furnaces, and gasification reforming furnaces. A fluidized bed furnace is preferred for the gasification furnace because it allows for high hearth load and excellent operability by partially burning the waste. By gasifying the waste in a fluidized bed furnace at a low temperature (approximately 450-600°C) and a low-oxygen atmosphere, it is decomposed into gases (carbon monoxide, carbon dioxide, hydrogen, methane, etc.) and char containing a large amount of carbon. Furthermore, since non-combustible materials contained in the waste are separated from the bottom of the furnace in a hygienic and low-oxidation state, it is possible to selectively recover valuable materials such as iron and aluminum from the non-combustible materials. Therefore, such gasification of waste enables efficient resource recycling.

[0045] The temperature of the gasification process in the raw material gas generation process is not particularly limited, but is usually 100 to 2500°C, and preferably 200 to 2100°C.

[0046] The reaction time for gasification in the raw material gas generation process is usually 2 seconds or more, preferably 5 seconds or more.

[0047] The carbon sources used in the raw material gas generation process are not particularly limited, and various carbon-containing materials can be suitably used for recycling purposes, such as coke ovens and blast furnaces (blast furnace gas) in steel mills, coal used in converters and coal-fired power plants, general waste and industrial waste introduced into incinerators (especially gasifiers), and carbon dioxide produced as a by-product by various industries.

[0048] More specifically, carbon sources are preferably waste materials, including plastic waste, food waste, municipal solid waste (MSW), industrial solid waste, discarded tires, biomass waste, household waste such as bedding and paper, building materials, coal, petroleum, petroleum-derived compounds, natural gas, and shale gas. Among these, various types of waste are preferred, and from the perspective of sorting costs, unsorted municipal solid waste is even more preferred.

[0049] Furthermore, carbon sources can include, for example, waste tires as combustion material, specifically, gases generated when waste tires are burned and the resulting thermal energy is recovered, such as in thermal recycling. The combustion equipment is not particularly limited, but examples include blast furnaces in steel mills, blast furnaces (blast furnace gas), converters, coal used in coal-fired power plants, incinerators, and boilers. In particular, about 60% of the raw materials of tires are suitable as combustion material, and tire chips obtained from waste tires have a total calorific value of 35,000 kJ per kg, which is almost the same as petroleum products such as light oil and heavy oil, making them suitable as an alternative fuel to coal. In other words, if the gas generated in these processes is primarily CO2, it is preferable to convert it to CO using known technology and use it, as this can achieve resource-recycling recycling as an effective measure to reduce CO2 emissions.

[0050] The raw material gas obtained by gasifying a carbon source contains carbon monoxide and hydrogen as essential components, but may also contain carbon dioxide, oxygen, and nitrogen. Other components that may be included in the raw material gas include soot, tar, nitrogen compounds, sulfur compounds, phosphorus compounds, and aromatic compounds.

[0051] The raw material gas may be produced in the raw material gas production process by performing a heat treatment (commonly known as gasification) that burns (incompletely burns) the carbon source, that is, by partially oxidizing the carbon source, resulting in a gas containing carbon monoxide, although not particularly limited, 0.1 volume% or more, preferably 10 volume% or more, and more preferably 20 volume% or more.

[0052] <Synthesis gas purification process> The synthesis gas purification process is a process of removing or reducing specific substances from the raw material gas, such as various pollutants, particulate matter, impurities, and undesirable amounts of compounds. When the raw material gas is derived from waste, it typically contains 0.1% to 80% by volume of carbon monoxide, 0.1% to 70% by volume of carbon dioxide, and 0.1% to 80% by volume of hydrogen, and also tends to contain 1 mg / L or more of nitrogen compounds, 1 mg / L or more of sulfur compounds, 0.1 mg / L or more of phosphorus compounds, and / or 10 mg / L or more of aromatic compounds. In addition, other environmental pollutants, particulate matter, and impurities may also be present. Therefore, when supplying synthesis gas to a microbial fermentation tank, it is preferable to reduce or remove substances and undesirable amounts of compounds from the raw material gas so that the content of each component in the raw material gas is within a range suitable for stable microbial cultivation.

[0053] In particular, in the synthesis gas purification process, a pressure swing adsorption device filled with the above-mentioned regenerative adsorbent is used to adsorb carbon dioxide gas in the synthesis gas onto the regenerative adsorbent (zeolite), thereby reducing the carbon dioxide gas concentration in the synthesis gas. Furthermore, the synthesis gas may be subjected to other conventionally known treatment processes to remove impurities and adjust the gas composition. Other treatment processes include, for example, gas chillers (moisture separators), cryogenic separators, cyclones, particulate matter (soot) separators such as bag filters, scrubbers (water-soluble impurity separators), desulfurization devices (sulfide separators), membrane separators, deoxygenation devices, pressure swing adsorption (PSA), temperature swing adsorption (TSA), pressure-temperature swing adsorption (PTSA), activated carbon separators, and deoxygenation catalysts, specifically, separators using copper catalysts or palladium catalysts, one or more of which can be used for treatment.

[0054] In this invention, the concentrations of iron and chromium derived from the raw material gas can be controlled by adjusting the conditions of the above processing steps. For example, by adjusting conditions such as the residence time of the scrubber and membrane separation, these concentrations can be reduced to below the detection limit. By reducing the concentrations of iron and chromium in the raw material gas in this way, the iron and chromium content in the final alcohol, particularly ethanol, can be reduced to below the detection limit.

[0055] The synthesis gas used in the method for producing alcohol, particularly ethanol, according to the present invention, contains at least carbon monoxide as an essential component, and may further contain hydrogen, carbon dioxide, and nitrogen.

[0056] The synthesis gas used in the present invention may be obtained by first generating a raw material gas by gasifying a carbon source (raw material gas generation step), and then by adjusting the concentrations of carbon monoxide, carbon dioxide, hydrogen, and nitrogen from the raw material gas, as well as by reducing or removing the above-mentioned substances and compounds.

[0057] The carbon monoxide concentration in the synthesis gas is typically 20% to 80% by volume, preferably 25% to 50% by volume, and more preferably 35% to 45% by volume, relative to the total concentration of carbon monoxide, carbon dioxide, hydrogen, and nitrogen in the synthesis gas.

[0058] The hydrogen concentration in the synthesis gas is typically 10% to 80% by volume, preferably 30% to 55% by volume, and more preferably 40% to 50% by volume, relative to the total concentration of carbon monoxide, carbon dioxide, hydrogen, and nitrogen in the synthesis gas.

[0059] The carbon dioxide concentration in the synthesis gas is typically 0.1% to 40% by volume, preferably 0.3% to 30% by volume, more preferably 0.5% to 10% by volume, and particularly preferably 1% to 6% by volume, relative to the total concentration of carbon monoxide, carbon dioxide, hydrogen, and nitrogen in the synthesis gas.

[0060] The nitrogen concentration in the synthesis gas is typically 40% by volume or less, preferably 1% to 20% by volume, and more preferably 5% to 15% by volume, relative to the total concentration of carbon monoxide, carbon dioxide, hydrogen, and nitrogen in the synthesis gas.

[0061] The concentrations of carbon monoxide, carbon dioxide, hydrogen, and nitrogen can be kept within a predetermined range by changing the elemental composition of hydrocarbons (carbon and hydrogen) and nitrogen in the raw material gas production process, or by appropriately changing combustion conditions such as combustion temperature and oxygen concentration of the gas supplied during combustion. For example, to change the carbon monoxide or hydrogen concentration, one can switch to a carbon source with a high ratio of hydrocarbons (carbon and hydrogen), such as waste plastics, and to decrease the nitrogen concentration, one can supply gas with a high oxygen concentration in the raw material gas production process.

[0062] The synthesis gas used in the present invention is not particularly limited in that it contains sulfur compounds, phosphorus compounds, nitrogen compounds, etc., in addition to the components described above. The content of each of these compounds is preferably 0.05 mg / L or more, more preferably 0.1 mg / L or more, even more preferably 0.5 mg / L or more, and also preferably 2000 mg / L or less, more preferably 1000 mg / L or less, even more preferably 80 mg / L or less, even more preferably 60 mg / L or less, and particularly preferably 40 mg / L or less. By setting the content of sulfur compounds, phosphorus compounds, nitrogen compounds, etc. above the lower limit, there is the advantage that microorganisms can be cultured suitably, and by setting the content below the upper limit, there is the advantage that the culture medium is not contaminated by various nutrients that were not consumed by the microorganisms.

[0063] Examples of sulfur compounds include sulfur dioxide, CS2, COS, and H2S, with H2S and sulfur dioxide being preferred because they are easily consumed as nutrients by microorganisms. Therefore, it is more preferable that the sum of H2S and sulfur dioxide in the synthesis gas is within the above range. As for phosphorus compounds, phosphoric acid is preferred because it is easily consumed as a nutrient source by microorganisms. Therefore, it is more preferable that phosphoric acid is contained in the synthesis gas within the above range. Examples of nitrogen compounds include nitric oxide, nitrogen dioxide, acrylonitrile, acetonitrile, and HCN, with HCN being preferred because it is easily consumed as a nutrient source by microorganisms. Therefore, it is more preferable that the synthesis gas contains HCN within the above range.

[0064] Furthermore, the synthesis gas may contain aromatic compounds in an amount of 0.01 mg / L to 90 mg / L, preferably 0.03 mg / L or more, more preferably 0.05 mg / L or more, even more preferably 0.1 mg / L or more, and preferably 70 mg / L or less, more preferably 50 mg / L or less, and even more preferably 30 mg / L or less. By setting the content above the lower limit, microorganisms tend to be able to be cultured suitably, and by setting the content below the upper limit, the culture medium tends to be less contaminated by various nutrients that were not consumed by the microorganisms.

[0065] <Microbial fermentation process> The microbial fermentation process is a process of producing alcohol, particularly ethanol, by microbial fermentation of the above-mentioned synthesis gas in a microbial fermentation tank. The microbial fermentation tank is preferably a continuous fermentation apparatus. In general, any shape of microbial fermentation tank can be used, including agitated type, airlift type, bubble tower type, loop type, open bond type, and photobio type. However, in the present invention, a known loop reactor having a main tank section and a reflux section can be suitably used as the microbial fermentation tank. In this case, it is preferable to further include a circulation process in which the above-mentioned liquid culture medium is circulated between the main tank section and the reflux section.

[0066] The synthesis gas supplied to the microbial fermentation tank may be the gas obtained through the raw material gas production process, as long as it satisfies the above-mentioned synthesis gas component conditions, or it may be the raw material gas from which impurities have been reduced or removed, to which another predetermined gas is added before using as synthesis gas. As the other predetermined gas, for example, at least one compound selected from the group consisting of sulfur compounds such as sulfur dioxide, phosphorus compounds, and nitrogen compounds may be added to form the synthesis gas.

[0067] A microbial fermenter may be continuously supplied with synthesis gas and microbial culture medium, but it is not necessary to supply them simultaneously. Alternatively, synthesis gas may be supplied to a microbial fermenter that has already been supplied with microbial culture medium. Certain anaerobic microorganisms are known to produce alcohol, particularly ethanol, from substrate gases such as synthesis gas through fermentation, and these gas-assimilating microorganisms are cultured in liquid culture media. For example, a liquid culture medium and gas-assimilating bacteria may be supplied and contained within the microbial fermenter, and synthesis gas may be supplied to the microbial fermenter while stirring the liquid culture medium. This allows gas-assimilating bacteria to be cultured in liquid culture media and produce ethanol from synthesis gas through fermentation.

[0068] In a microbial fermentation tank, the temperature of the culture medium (culture temperature) can be any temperature, but it is preferably around 30-45°C, more preferably around 33-42°C, and even more preferably around 36.5-37.5°C. The culture time is preferably 12 hours or more for continuous culture, more preferably 7 days or more, particularly preferably 30 days or more, and most preferably 60 days or more. There is no upper limit, but from the viewpoint of equipment maintenance, it is preferably 720 days or less, and more preferably 365 days or less. The culture time refers to the time from when the starter culture is added to the culture tank until the entire amount of culture solution in the culture tank is drained.

[0069] The microorganisms (species) contained in the microbial culture medium are not particularly limited, as long as they can produce ethanol by microbial fermentation of synthesis gas using carbon monoxide as the main raw material. For example, it is preferable that the microorganisms (species) produce ethanol from synthesis gas through the fermentation action of gas-assimilating bacteria, and are particularly likely to be microorganisms that have an acetyl-CoA metabolic pathway. Among gas-assimilating bacteria, the genus Clostridium is more preferred, and Clostridium autoethanogenum is particularly preferred, but is not limited thereto. Further examples are given below.

[0070] Gas-assimilating bacteria include both eubacteria and archaea. Examples of eubacteria include bacteria of the genera Clostridium, Moorella, Acetobacterium, Carboxydocella, Rhodopseudomonas, Eubacterium, Butyribacterium, Oligotropha, Bradyrhizobium, and the aerobic hydrogen-oxidizing bacteria Ralsotonia.

[0071] On the other hand, examples of archaea include bacteria of the genus Methanobacterium, bacteria of the genus Methanobrevibacter, bacteria of the genus Methanocalculus, bacteria of the genus Methanococcus, bacteria of the genus Methanosarcina, bacteria of the genus Methanosphaera, bacteria of the genus Methanothermobacter, Metha Examples include bacteria of the genus Nothrix, bacteria of the genus Methanoculleus, bacteria of the genus Methanofollis, bacteria of the genus Methanogenium, bacteria of the genus Methanospirillium, bacteria of the genus Methanosaeta, bacteria of the genus Thermococcus, bacteria of the genus Thermofilum, bacteria of the genus Arcaheoglobus, and the like. Among these, as archaea, bacteria of the genus Methanosarcina, bacteria of the genus Methanococcus, bacteria of the genus Methanothermobacter, bacteria of the genus Methanothrix, bacteria of the genus Thermococcus, bacteria of the genus Thermofilum, and bacteria of the genus Archaeoglobus are preferred.

[0072] Furthermore, due to their excellent assimilation capabilities of carbon monoxide and carbon dioxide, archaeons of the genera Methanosarcina, Methanothermobacter, or Methanococcus are preferred, with Methanosarcina or Methanococcus being particularly preferred. Specific examples of Methanosarcina bacteria include Methanosarcina barkeri, Methanosarcina mazei, and Methanosarcina acetivorans.

[0073] From among the gas-utilizing bacteria described above, bacteria with high ethanol production capacity are selected and used. For example, gas-utilizing bacteria with high ethanol production capacity include Clostridium autoethanogenum, Clostridium... Examples include Clostridium ljungdahlii, Clostridium aceticum, Clostridium carboxidivorans, Moorella thermoacetica, and Acetobacterium woodii, with Clostridium autoethanogenum being particularly preferred among them.

[0074] The culture medium used when culturing the above-mentioned microorganisms (species) is not particularly limited as long as it has an appropriate composition for the bacteria, but it is a liquid containing water as the main component and nutrients (e.g., vitamins, phosphoric acid, etc.) dissolved or dispersed in this water. The composition of such a culture medium is prepared so that gas-assimilating bacteria can grow well. For example, when using Clostridium species as the microorganism, the culture medium can be referenced from "0097" to "0099" of U.S. Patent Application Publication 2017 / 260552.

[0075] Alcohol-containing liquids, particularly ethanol-containing liquids, obtained through microbial fermentation processes can be acquired as suspensions containing microorganisms, their remains, and microbial-derived proteins. The protein concentration in the suspension varies depending on the type of microorganism, but is typically between 30 and 1000 mg / L. The protein concentration in the ethanol-containing liquid can be measured using the Kjeldahl method.

[0076] <Separation process> The alcohol-containing liquid, particularly the ethanol-containing liquid, obtained from the microbial fermentation process is then subjected to a separation process. In this invention, the ethanol-containing liquid is heated to room temperature to 500°C under conditions of 0.01 to 1000 kPa (absolute pressure) to separate it into a liquid or solid component containing microorganisms and a gaseous component containing ethanol. In conventional methods, the ethanol-containing liquid obtained from the microbial fermentation process was distilled to separate and purify the desired ethanol. However, since the ethanol-containing liquid contains microorganisms and proteins derived from microorganisms, distilling the ethanol-containing liquid as is could cause foaming in the distillation apparatus, hindering continuous operation. Furthermore, while membrane evaporators are known to be used as a method for purifying foaming liquids, membrane evaporators have low concentration efficiency and are not suitable for purifying liquids containing solid components. In this invention, before separating and purifying the desired ethanol from the ethanol-containing liquid obtained from the microbial fermentation process by distillation or other means, the ethanol-containing liquid is heated to separate it into a liquid or solid component containing microorganisms and a gaseous component containing ethanol, and the desired ethanol is separated and purified only from the separated gaseous component containing ethanol. By implementing the separation process, foaming is prevented in the distillation apparatus during the distillation operation for the separation and purification of ethanol, allowing for continuous distillation. Furthermore, since the concentration of ethanol in the gaseous component containing ethanol is higher than the concentration of ethanol in the ethanol-containing liquid, the separation and purification of ethanol can be performed efficiently in the purification process described later.

[0077] In the present invention, from the viewpoint of efficiently separating a liquid or solid component containing microorganisms, their remains, microbial-derived proteins, etc., from a gaseous component containing ethanol, the ethanol-containing liquid is heated preferably under conditions of 10 to 200 kPa, more preferably under conditions of 50 to 150 kPa, even more preferably under atmospheric pressure, at a temperature of preferably 50 to 200°C, more preferably 80 to 180°C, and even more preferably 100 to 150°C.

[0078] The heating time in the separation process is not particularly limited as long as it is sufficient to obtain the gaseous component, but from the viewpoint of efficiency or economy, it is usually 5 seconds to 2 hours, preferably 5 seconds to 1 hour, and more preferably 5 seconds to 30 minutes.

[0079] The separation process described above can be carried out without particular limitations, as long as it is an apparatus capable of efficiently separating an ethanol-containing liquid into liquid or solid components (microorganisms and their remains, proteins derived from microorganisms, etc.) and gaseous components (ethanol) using thermal energy. For example, drying apparatuses such as rotary dryers, fluidized bed dryers, vacuum dryers, and conduction-type dryers can be used. However, from the viewpoint of efficiency when separating an ethanol-containing liquid with a low solid component concentration into liquid or solid components and gaseous components, it is preferable to use a conduction-type dryer. Examples of conduction-type dryers include drum-type dryers and disc-type dryers.

[0080] <Liquefaction process> The liquefaction step is a process of liquefying the gaseous components, particularly ethanol, obtained in the separation step by condensation. The apparatus used in the liquefaction step is not particularly limited, but it is preferable to use a heat exchanger, especially a condenser. Examples of condensers include water-cooled, air-cooled, and evaporative types, with water-cooled condensers being preferred among them. The condenser may consist of one stage or multiple stages.

[0081] It is preferable that the liquefied product obtained by the liquefaction process does not contain components that were present in the ethanol-containing solution, such as microorganisms, their remains, and proteins derived from microorganisms. However, the present invention does not exclude the possibility of proteins being present in the liquefied product. Even if proteins are present in the liquefied product, their concentration is preferably 40 mg / L or less, more preferably 20 mg / L or less, and even more preferably 15 mg / L or less.

[0082] The heat of condensation of the gaseous components obtained by the condenser may be reused as a heat source in the purification process described later. By reusing the heat of condensation, ethanol can be produced efficiently and economically.

[0083] <Purification process> Next, the alcohol is purified from the liquefied product obtained in the liquefaction step. The method of production varies depending on the alcohol, but there are no particular restrictions as long as the specific compounds defined in this invention are limited to a specific content. The purification step for ethanol is described in detail below. The ethanol-containing liquid obtained in the microbial fermentation step can be supplied to the purification step without going through the separation step described above if components such as microorganisms have already been removed. The purification step is a step of separating the ethanol-containing liquid obtained in the liquefaction step into a distillate with a higher concentration of the target ethanol and a bottom-extracted liquid with a lower concentration of the target ethanol. Furthermore, the purification step described herein may also be performed to produce the ethanol defined in this invention in ethanol produced from sources other than synthesis gas as described above, or in commercially available bioethanol. Examples of equipment used in the purification step include distillation apparatus, processing apparatus including permeable vaporization membrane, processing apparatus including zeolite dehydration membrane, processing apparatus for removing low-boiling point substances with a boiling point lower than ethanol, processing apparatus for removing high-boiling point substances with a boiling point higher than ethanol, and processing apparatus including ion exchange membrane. These apparatuses may be used individually or in combination of two or more types. As unit operations, heating distillation or membrane separation may be suitably used.

[0084] In heated distillation, the desired ethanol can be obtained as a distillate with high purity using a distillation apparatus. The temperature inside the distillation apparatus during ethanol distillation is not particularly limited, but it is preferably 100°C or lower, and more preferably around 70-95°C. By setting the temperature inside the distillation apparatus within the above range, the separation of ethanol from other components, i.e., the distillation of ethanol, can be performed more reliably. In particular, by introducing the ethanol-containing liquid obtained in the liquefaction step into a distillation apparatus equipped with a heater using steam at 100°C or higher, raising the temperature at the bottom of the distillation column to 90°C or higher within 30 minutes, then introducing the ethanol-containing liquid from the middle of the distillation column, and performing the distillation process with a temperature difference of ±15°C or less between the bottom, middle, and top of the column, high-purity ethanol can be obtained. The distillation temperature difference is preferably ±13°C, and more preferably ±11°C. With the above distillation temperature difference, the separation from other components, i.e., the distillation of ethanol, can be performed more reliably, and is preferable for producing the ethanol defined in the present invention.

[0085] While not bound by theory, it is believed that the above ethanol-containing liquid contains Si in the form of organosiloxanes with a boiling point of 100°C or less (e.g., 1,1,3,3-tetramethyldisiloxane, hexamethyldisiloxane, etc.). By distilling such ethanol, the ethanol obtained can contain trace amounts of Si by leaving behind organosiloxanes with boiling points close to those of ethanol. In the present invention, the Si content in the ethanol contained in the distillate can be adjusted by adjusting the above distillation conditions. As a result, the Si content in the final ethanol can be adjusted. Furthermore, in the above separation step, the Si content in the final ethanol can also be adjusted by maintaining the gas introduction temperature to the separation apparatus at 20°C to 40°C to stabilize the organosiloxane in the synthesis gas.

[0086] In the above-mentioned distillation apparatus, it is preferable to use multiple distillation columns. In this case, it is preferable to use a processing device including an ion exchange membrane between the distillation columns. In the present invention, by controlling the concentration of sodium ions and potassium ions by passing through the ion exchange membrane, the sodium and potassium content in the final ethanol can be adjusted to a suitable range.

[0087] The above ethanol-containing liquid is thought to contain aliphatic hydrocarbons with boiling points higher than ethanol (e.g., heptane, octane, decane, dodecane, tetradecane, etc.), aromatic compounds (e.g., toluene, ethylbenzene, xylene, etc.), and dialkyl ethers (e.g., dibutyl ether, dipentyl ether, etc.). In the present invention, by adjusting the above distillation conditions, for example, by raising the temperature at the top of the distillation column to a temperature 5 to 10°C or higher than usual, aromatic compounds can also be distilled out, thereby adjusting the aromatic compounds in the ethanol contained in the distillate. As a result, the content of aromatic compounds in the final ethanol can be adjusted.

[0088] The pressure inside the distillation apparatus during ethanol distillation may be atmospheric pressure, but is preferably less than atmospheric pressure, and more preferably around 60 to 95 kPa (absolute pressure). Setting the pressure inside the distillation apparatus within this range improves the separation efficiency of ethanol and, consequently, the yield of ethanol, which is preferable for producing the ethanol specified in the invention. The yield of ethanol (the concentration of ethanol contained in the distillate after distillation) is preferably 90% by volume or more, and more preferably 95% by volume or more.

[0089] In membrane separation, known separation membranes can be used as appropriate, and for example, zeolite membranes can be suitably used.

[0090] The concentration of ethanol in the distillate separated in the purification process is preferably 20% to 99.99% by volume, and more preferably 60% to 99.9% by volume. On the other hand, the concentration of ethanol in the canned liquid is preferably 0.001% to 10% by volume, and more preferably 0.01% to 5% by volume.

[0091] The bottom liquid separated in the purification process is substantially free of nitrogen compounds. In this invention, "substantially free" does not mean that the concentration of nitrogen compounds is 0 mg / L, but rather that the nitrogen compound concentration in the bottom liquid obtained in the purification process is such that a wastewater treatment process is not required. In the separation process, instead of purifying the desired ethanol from the ethanol-containing liquid obtained in the microbial fermentation process, the ethanol-containing liquid is separated into a liquid or solid component containing microorganisms and a gaseous component containing ethanol, as described above. At this time, the nitrogen compounds remain on the liquid or solid component side containing microorganisms, so the gaseous component containing ethanol contains almost no nitrogen compounds. Therefore, it is considered that the bottom liquid obtained when purifying ethanol from the liquefied product obtained by liquefying the gaseous component is substantially free of nitrogen compounds. Even if the bottom liquid contains nitrogen compounds, the concentration of nitrogen compounds is 0.1 to 200 mg / L, preferably 0.1 to 100 mg / L, and more preferably 0.1 to 50 mg / L.

[0092] Furthermore, for the same reasons as above, the bottom liquid separated in the purification process is substantially free of phosphorus compounds. Note that "substantially free" does not mean that the concentration of phosphorus compounds is 0 mg / L, but rather that the phosphorus compound concentration in the bottom liquid obtained in the purification process is low enough that a wastewater treatment process is not required. Even if the bottom liquid contains phosphorus compounds, the concentration of phosphorus compounds is 0.1 to 100 mg / L, preferably 0.1 to 50 mg / L, and more preferably 0.1 to 25 mg / L. Thus, according to the method of the present invention, the bottom liquid discharged in the ethanol purification process is substantially free of nitrogen compounds and phosphorus compounds, and is considered to contain almost no other organic matter, thus simplifying the wastewater treatment process that was conventionally required.

[0093] <Wastewater Treatment Process> The bottom effluent separated in the purification process may be supplied to the wastewater treatment process. In the wastewater treatment process, organic matter such as nitrogen compounds and phosphorus compounds can be further removed from the bottom effluent. In this process, organic matter may be removed by anaerobic or aerobic treatment of the bottom effluent. The removed organic matter may be used as fuel (heat source) in the purification process.

[0094] The treatment temperature in the wastewater treatment process is usually 0 to 90°C, preferably 20 to 40°C, and more preferably 30 to 40°C.

[0095] The bottom liquid obtained through the separation process has had liquid or solid components, including microorganisms, removed, thus reducing the burden of wastewater treatment and other processes compared to bottom liquid obtained by directly supplying it from the microbial fermentation process to the purification process.

[0096] In the wastewater treatment process, the concentration of nitrogen compounds in the treated liquid obtained by treating the bottom effluent is preferably 0.1 to 30 mg / L, more preferably 0.1 to 20 mg / L, and even more preferably 0.1 to 10 mg / L, and it is particularly preferable that no nitrogen compounds are present. Furthermore, the concentration of phosphorus compounds in the treated liquid is preferably 0.1 to 10 mg / L, more preferably 0.1 to 5 mg / L, and even more preferably 0.1 to 1 mg / L, and it is particularly preferable that no phosphorus compounds are present in the bottom effluent.

[0097] <Uses of alcohol> The following describes, as an example, a method for synthesizing butadiene using alcohol, particularly ethanol, as a raw material, and a method for producing styrene-butadiene rubber (SBR) according to the present invention. It goes without saying that this method can also be used for chemical products and polymer raw materials using other conjugated diene compounds.

[0098] <Method for synthesizing 1,3-butadiene> Butadiene is mainly produced by refining the C4 fraction, a by-product of ethylene synthesis from petroleum (i.e., naphtha cracking), and is a raw material for synthetic rubber. However, in recent years, there has been a strong demand for technologies to convert ethanol that is not derived from fossil fuels (ethanol derived from microbial fermentation) into 1,3-butadiene, as an alternative to chemical industrial raw materials obtained from petroleum. Methods for synthesizing butadiene using ethanol derived from microbial fermentation as a raw material include methods using MgO as a catalyst, methods using a mixture of Al2O3 and ZnO, and catalysts having a magnesium silicate structure. In addition to those mentioned above, hafnium, vanadium, manganese, iron, cobalt, nickel, copper, zinc, gallium, niobium, silver, indium, and cerium are also used as catalysts.

[0099] By contacting the ethanol of the present invention with the catalyst described above and heating it, an ethanol conversion reaction occurs, and 1,3-butadiene can be synthesized. By synthesizing 1,3-butadiene using the ethanol of the present invention as a raw material, it becomes possible to realize the ultimate resource-recycling society that does not rely on petroleum resources.

[0100] The heating temperature required to carry out the conversion reaction is, for example, 200 to 450°C, preferably 300 to 400°C, within the reaction system. If the temperature within the reaction system falls below this range, sufficient catalytic activity cannot be obtained, the reaction rate decreases, and the production efficiency tends to decline. On the other hand, if the temperature within the reaction system exceeds this range, the catalyst may deteriorate easily.

[0101] The reaction can be carried out by conventional methods such as batch, semi-batch, or continuous reactions. While batch or semi-batch reactions can increase the ethanol conversion rate, the ethanol produced according to the present invention can be converted more efficiently than conventional methods, even when using a continuous reaction. Although the reason for this is unclear, it is thought to be due to the presence of unique peaks in the gas chromatograph, measured by gas chromatography-mass spectrometry, that are not observed in ethanol derived from fossil fuels, in ethanol derived from recycled resources using gas containing carbon monoxide and hydrogen as a substrate, as in the present invention.

[0102] Methods for bringing the raw materials into contact with the catalyst include, for example, a suspension bed method, a fluidized bed method, and a fixed bed method. Furthermore, either a gas-phase or liquid-phase method may be used. For ease of catalyst recovery and regeneration, it is preferable to use a fixed-bed gas-phase continuous flow reactor in which the catalyst is packed into a reaction tube to form a catalyst layer, and the raw materials are flowed as a gas to react in the gas phase. When the reaction is carried out in the gas phase, the ethanol of the present invention may be gasified and supplied to the reactor without dilution, or it may be appropriately diluted with an inert gas such as nitrogen, helium, argon, or carbon dioxide before being supplied to the reactor.

[0103] After the ethanol conversion reaction is complete, the reaction product (1,3-butadiene) can be separated and purified by, for example, gas-liquid separation at 10°C and extraction of only the gas, contact with a drying agent such as calcium chloride or molecular sieves, filtration, concentration, distillation, extraction, or a combination of these separation methods.

[0104] The purity of the obtained butadiene is preferably 70% or higher, more preferably 75% or higher, even more preferably 80% or higher, and even more preferably 82% or higher. This is because it improves the yield of the polymerization reaction. The purity of butadiene can be calculated using the following formula. Butadiene purity = Butadiene concentration / Total organic compound purity The ratio of the concentration of the obtained butadiene to the concentration of the oxygen-containing compound is preferably 3 or higher. This is to prevent the deactivation of the catalyst used in the polymerization reaction. The ratio of the concentration of butadiene to the concentration of the oxygen-containing compound can be calculated using the following formula. Butadiene / oxygen-containing compound = Butadiene concentration / (ethanol concentration + acetaldehyde concentration + acetic acid concentration + ethyl acetate concentration + diethyl ether concentration) The ratio of the concentration of butadiene to the concentration of the hydrocarbon compound obtained is preferably 5 or higher. This is to increase the purity of the polymer. The ratio of the concentration of butadiene to the concentration of the hydrocarbon compound can be calculated using the following formula. Butadiene / Hydrogen Compound = Butadiene Concentration / (Ethylene Concentration + Butene Concentration + Propylene Concentration + Butane Concentration)

[0105] <Method for producing conjugated diene polymers> The method for producing a conjugated diene polymer of the present invention is: Using an alcohol derived from non-petrochemical raw materials having an iron content of 0.0001 mg / L or more and 2 mg / L or less as a raw material, the alcohol is brought into contact with a catalyst and heated, thereby generating a catalyst with a carbon number of C4~C 12 The process for producing a conjugated diene, A step of polymerizing a monomer containing the aforementioned conjugated diene to produce a non-petrogenic conjugated diene polymer. It includes.

[0106] The raw materials used in the manufacturing process of conjugated dienes are not particularly limited, as long as they are non-petrochemical raw material-derived alcohols with an iron content of 0.0001 mg / L or more and 2 mg / L or less. For example, the ethanol mentioned above can be used.

[0107] The carbon number obtained in the manufacturing process of conjugated dienes is C4~C 12Examples of conjugated dienes include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 4,5-diethyl-1,3-octadiene, and 3-butyl-1,3-octadiene. Among these, 1,3-butadiene is preferred. These conjugated dienes may be used individually or in combination of two or more in the manufacturing process of non-petrogenic conjugated diene polymers.

[0108] In the manufacturing process of conjugated diene polymers, the monomer has a carbon number of C4 to C4. 12 Only conjugated dienes may be used, or aromatic hydrocarbons other than said conjugated dienes may be used. Examples of aromatic hydrocarbons that can be used as monomers include styrene, methylstyrene, ethylstyrene, t-butylstyrene, α-methylstyrene, α-methyl-p-methylstyrene, chlorostyrene, bromostyrene, methoxystyrene, dimethylaminomethylstyrene, dimethylaminoethylstyrene, diethylaminomethylstyrene, diethylaminoethylstyrene, cyanoethylstyrene, and vinylnaphthalene. Among these, styrene is preferred.

[0109] In the manufacturing process of conjugated diene polymers, the polymerization method of the monomers is not particularly limited and can be carried out by conventionally known methods. The polymerization method may be emulsion polymerization or solution polymerization. Emulsion polymerization is a method in which a monomer that is poorly soluble in the solvent and an emulsifier (surfactant) are mixed in a conventionally known solvent such as water, and a polymerization initiator that is soluble in the solvent is added to carry out polymerization. Solution polymerization is a method in which a monomer and a polymerization initiator are added to an inert solvent to carry out polymerization.

[0110] The surfactant used in the manufacturing process of conjugated diene polymers is not particularly limited, as long as it is one that is commonly used in emulsion polymerization. Specific examples of surfactants that can be used include cationic surfactants and anionic surfactants.

[0111] In the manufacturing process of conjugated dienes, the catalyst is not particularly limited, and conventionally known catalysts can be used. For example, as polymerization catalysts, it is preferable to use coordination catalysts that contain rare earth element compounds or metallocene-based catalysts, or anionic polymerization catalysts that use organometallic compounds.

[0112] The inert solvent used in the manufacturing process of conjugated diene polymers is not particularly limited as long as it is not inhibited and is commonly used in solution polymerization. Specific examples of inert solvents include linear aliphatic hydrocarbons such as butane, pentane, hexane, and heptane; alicyclic hydrocarbons such as cyclopentane and cyclohexane; and aromatic hydrocarbons such as benzene, toluene, and xylene. These inert solvents may be used individually or in combination of two or more.

[0113] Polymerization initiators used in the manufacturing process of conjugated diene polymers include those with a carbon number of C4 to C 12The catalyst is not particularly limited as long as it can polymerize monomers containing a conjugated diene. Specific examples include polymerization initiators that primarily use organoalkali metal compounds, organoalkaline earth metal compounds, and lanthanum series metal compounds as catalysts. Examples of organoalkali metal compounds include organomonolithium compounds such as n-butyllithium, sec-butyllithium, t-butyllithium, hexyllithium, phenyllithium, and stilbenithium; organopolyvalent lithium compounds such as dilithiomethane, 1,4-dilithiobutane, 1,4-dilithio-2-ethylcyclohexane, 1,3,5-trilithiobenzene, and 1,3,5-tris(lithiomethyl)benzene; organosodium compounds such as sodium naphthalene; and organopotassium compounds such as potassium naphthalene. Examples of organic alkaline earth metal compounds include di-n-butylmagnesium, di-n-hexylmagnesium, diethoxycalcium, calcium distearate, di-t-butoxystrontium, diethoxybarium, diisopropoxybarium, diethylmercaptobarium, di-t-butoxybarium, diphenoxybarium, diethylaminobarium, barium distearate, and diketilbarium. Examples of polymerization initiators using lanthanum series metal compounds as the main catalyst include a salt of a lanthanum series metal, such as lanthanum, cerium, praseodymium, neodymium, samarium, or gadolinium, with a carboxylic acid or phosphorus-containing organic acid as the main catalyst, and a polymerization initiator consisting of this and co-catalysts such as alkylaluminum compounds, organoaluminum hydride compounds, and organoaluminum halide compounds. Among these polymerization initiators, organic monolithium compounds and organic polyvalent lithium compounds are preferably used, organic monolithium compounds are more preferably used, and n-butyllithium is particularly preferably used. The organic alkali metal compounds may also be used as organic alkali metal amide compounds by reacting them beforehand with secondary amine compounds such as dibutylamine, dihexylamine, dibenzylamine, pyrrolidine, piperidine, hexamethyleneimine, and heptamethyleneimine.By using organic alkali metal amide compounds as polymerization initiators, the resulting rubber crosslinked products can be made to exhibit lower heat generation and superior wet grip properties. These polymerization initiators may be used individually or in combination of two or more.

[0114] The amount of polymerization initiator used can be determined according to the molecular weight of the target conjugated diene polymer, but is typically in the range of 1 to 50 mmol, preferably 1.5 to 20 mmol, and more preferably 2 to 15 mmol per 1000 g of monomer.

[0115] The polymerization temperature is typically in the range of -80 to +150°C, preferably 0 to 100°C, and more preferably 30 to 90°C. Any polymerization method, such as batch or continuous, can be used, but when copolymerizing a conjugated diene compound with an aromatic vinyl compound, the batch method is preferred because it allows for easier control of the randomness of the bonding between the conjugated diene monomer units and the aromatic vinyl monomer units.

[0116] Examples of conjugated diene polymers obtainable by the manufacturing method of the present invention include isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), and acrylonitrile butadiene rubber (NBR). Among these, styrene-butadiene rubber is preferred as the rubber component used in tires.

[0117] The weight-average molecular weight (Mw) of the conjugated diene polymer obtained by the production method of the present invention is not particularly limited, but is preferably 100,000 to 2,000,000, more preferably 150,000 to 1,500,000, and particularly preferably 200,000 to 1,000,000, as measured by gel permeation chromatography on a polystyrene basis. By setting the weight-average molecular weight (Mw) of the conjugated diene polymer having an active end within the above range, the resulting rubber crosslinked product can be made to have a good balance between wet grip and low heat generation.

[0118] The molecular weight distribution of the conjugated diene polymer obtained by the production method of the present invention, expressed as the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) (Mw / Mn), is not particularly limited, but is preferably 4.0 to 6.0, and more preferably 4.7 to 6.0. When the molecular weight distribution (Mw / Mn) of the conjugated diene polymer is within the above range, the low heat generation properties of the resulting rubber crosslinked product can be further improved.

[0119] The glass transition temperature (Tg) of the conjugated diene polymer obtained by the manufacturing method of the present invention is not particularly limited, but is preferably -40°C to -50°C, and more preferably -41°C to -47°C. The glass transition temperature of the conjugated diene polymer obtained by the manufacturing method of the present invention can be adjusted, for example, by changing the blending ratio of the conjugated diene monomer and the aromatic hydrocarbon monomer in the conjugated diene polymer.

[0120] The conjugated diene polymer obtained by the manufacturing method of the present invention can be suitably used for various applications after adding fillers and crosslinking agents. In particular, when silica is added as a filler, a rubber composition can be obtained that provides a rubber crosslinked product with low heat generation and excellent wet grip properties.

[0121] <Rubber composition> The rubber composition of the present invention contains, as rubber components, a conjugated diene polymer obtained by the manufacturing method of the present invention described above, and a filler. The filler is not particularly limited and includes silica, carbon black, calcium carbonate, talc, and the like.

[0122] Examples of silica to be incorporated into the rubber composition include dry-process white carbon, wet-process white carbon, colloidal silica, and precipitated silica. Among these, wet-process white carbon, which mainly consists of hydrated silicic acid, is preferred. Alternatively, a carbon-silica dual-phase filler, in which silica is supported on the surface of carbon black, may be used. These silicas can be used individually or in combination of two or more types. The nitrogen adsorption specific surface area of ​​the silica used (measured by the BET method in accordance with ASTM D3037-81) is preferably 50 to 300 m². 2 / g, more preferably 80-220m 2 The concentration is / g. Furthermore, the pH of the silica is preferably between 5 and 10.

[0123] The amount of silica in the rubber composition is 10 to 200 parts by weight, preferably 30 to 150 parts by weight, and more preferably 50 to 100 parts by weight, per 100 parts by weight of the rubber component in the rubber composition. By setting the amount of silica within the above range, the processability of the rubber composition is improved, and the wet grip and low heat generation properties of the resulting crosslinked rubber can be further enhanced.

[0124] Furthermore, there are no particular limitations on the method of adding silica to the rubber composition. Methods such as adding silica to a solid conjugated diene polymer and kneading it (dry kneading method) or adding silica to a solution containing a conjugated diene polymer and allowing it to solidify and dry (wet kneading method) can be applied.

[0125] The carbon black used in the rubber composition is not particularly limited and includes, for example, furnace black, acetylene black, thermal black, channel black, and graphite. The inclusion of carbon black provides reinforcement, and in particular, can improve wear resistance.

[0126] The rubber composition of the present invention may further contain a silane coupling agent from the viewpoint of further improving low heat generation. The silane coupling agent is not particularly limited, and various silane coupling agents can be used. Any silane coupling agent that has been conventionally used in combination with silica in the rubber industry can be used as the silane coupling agent, for example, bis(3-triethoxysilylpropyl)tetrasulfide, bis(2-triethoxysilylethyl)tetrasulfide, bis(4-triethoxysilylbutyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(2-trimethoxysilylethyl)tetrasulfide, bis(4-trimethoxysilylbutyl)tetrasulfide, bis(3-triethoxysilylpropyl)trisulfide, bis(2-triethoxysilylethyl)trisulf Examples of sulfide-based crosslinking accelerators include bis(4-triethoxysilylbutyl) trisulfide, bis(3-trimethoxysilylpropyl) trisulfide, bis(2-trimethoxysilylethyl) trisulfide, bis(4-trimethoxysilylbutyl) trisulfide, bis(3-triethoxysilylpropyl) disulfide, bis(2-triethoxysilylethyl) disulfide, bis(4-triethoxysilylbutyl) disulfide, bis(3-trimethoxysilylpropyl) disulfide, bis(2-trimethoxysilylethyl) disulfide, and bis(4-trimethoxysilylbutyl) disulfide. Among these, bis(3-triethoxysilylpropyl) disulfide is preferred from the viewpoint of processability. These silane coupling agents may be used individually or in combination of two or more.

[0127] The rubber composition preferably further contains a crosslinking agent. Examples of crosslinking agents include sulfur, sulfur halides, organic peroxides, quinone dioximes, organic polyvalent amine compounds, and alkylphenol resins having methylol groups. Among these, sulfur is preferably used. The amount of crosslinking agent is preferably 0.1 to 15 parts by weight, more preferably 0.5 to 5 parts by weight, and particularly preferably 1 to 4 parts by weight, per 100 parts by weight of the rubber component in the rubber composition.

[0128] Furthermore, in addition to the above components, the rubber composition may contain, in accordance with conventional methods, compounding agents such as crosslinking accelerators, crosslinking activators, antioxidants, surfactants, process oils, plasticizers, and lubricants in the required amounts.

[0129] When sulfur or a sulfur-containing compound is used as a crosslinking agent, it is preferable to use a crosslinking accelerator and a crosslinking activator in combination. Examples of crosslinking accelerators include sulfenamide-based crosslinking accelerators; guanidine-based crosslinking accelerators; thiourea-based crosslinking accelerators; thiazole-based crosslinking accelerators; thiram-based crosslinking accelerators; dithiocarbamate-based crosslinking accelerators; xanthogenic acid-based crosslinking accelerators; and the like. Among these, those containing sulfenamide-based crosslinking accelerators are preferred. These crosslinking accelerators can be used individually or in combination of two or more. The amount of crosslinking accelerator added is preferably 0.1 to 15 parts by weight, more preferably 0.5 to 5 parts by weight, and particularly preferably 1 to 4 parts by weight, per 100 parts by weight of the rubber component in the rubber composition.

[0130] Examples of crosslinking activators include higher fatty acids such as stearic acid; zinc oxide; and the like. These crosslinking activators can be used individually or in combination of two or more. The amount of crosslinking activator added is preferably 0.05 to 20 parts by weight, and particularly preferably 0.5 to 15 parts by weight, per 100 parts by weight of the rubber component in the rubber composition.

[0131] Furthermore, the rubber composition of the present invention may also contain resins in addition to the rubber component. By incorporating resins, it is possible to impart tackiness to the rubber composition or improve the dispersibility of fillers in the rubber composition. As a result, improvements in the wet grip and abrasion resistance of the resulting crosslinked rubber can be expected. In addition, as an effect similar to that of plasticizers, the processability of the rubber composition can also be improved. Examples of resins include C5 petroleum resins, C5 / C9 petroleum resins, C9 petroleum resins, dicyclopentadiene resins, terpene resins, terpene phenol resins, aromatically modified terpene resins, alkylphenol-acetylene resins, rosin resins, rosin ester resins, indene resins, C9 resins containing indene, α-methylstyrene-indene copolymer resins, coumaron-indene resins, farnesene resins, and polylimonene resins. These resins may be modified or hydrogenated. These resins can be used individually or in combination of two or more. The amount of resin added is preferably 25 parts by weight or less per 100 parts by weight of the rubber component in the rubber composition.

[0132] To obtain the rubber composition of the present invention, each component can be kneaded according to a conventional method. For example, a compounding agent excluding heat-unstable components such as crosslinking agents and crosslinking accelerators can be kneaded with a rubber component containing a conjugated diene polymer obtained by the manufacturing method of the present invention. Then, the heat-unstable components such as crosslinking agents and crosslinking accelerators can be mixed into the kneaded mixture to obtain the desired composition. The kneading temperature between the compounding agent excluding heat-unstable components and the rubber component containing a conjugated diene polymer obtained by the manufacturing method of the present invention is preferably 80 to 200°C, more preferably 120 to 180°C, and the kneading time is preferably 30 seconds to 30 minutes. Furthermore, the mixing of the kneaded mixture with the heat-unstable components is usually carried out after cooling to 100°C or lower, preferably 80°C or lower.

[0133] <Rubber Crosslinked Products> The crosslinked rubber product of the present invention is obtained by crosslinking (vulcanizing) the rubber composition of the present invention described above. The crosslinked rubber product can be manufactured by using the rubber composition of the present invention and molding it using a molding machine corresponding to the desired shape, such as an extruder, injection molding machine, compressor, or roll, and then heating it to perform a crosslinking reaction and fix the shape as a crosslinked product. In this case, crosslinking may be performed either after molding or simultaneously with molding. The molding temperature is usually 10 to 200°C, preferably 25 to 120°C. The crosslinking temperature is usually 100 to 200°C, preferably 130 to 190°C, and the crosslinking time is usually 1 minute to 24 hours, preferably 2 minutes to 12 hours, and particularly preferably 3 minutes to 6 hours.

[0134] Furthermore, depending on the shape and size of the crosslinked rubber material, even if the surface is crosslinked, the interior may not be sufficiently crosslinked. In such cases, further heating may be performed to carry out secondary crosslinking.

[0135] For heating, you can appropriately select a common method used for crosslinking rubber, such as press heating, steam heating, oven heating, or hot air heating.

[0136] The crosslinked rubber product of the present invention obtained in this manner is obtained using a conjugated diene polymer obtained by the manufacturing method of the present invention described above, and therefore has excellent low heat generation and wet grip properties, making it suitable for use in tires. In particular, the crosslinked rubber product can be used in a variety of applications, taking advantage of these properties, such as materials for various parts of tires, including the cap tread, base tread, carcass, sidewall, and bead; materials for hoses, belts, mats, vibration-damping rubber, and other various industrial products; impact resistance modifiers for resins; resin film cushioning agents; shoe soles; rubber shoes; golf balls; toys; and more. In particular, the crosslinked rubber product of the present invention can be suitably used in various parts of tires, such as the tread, carcass, sidewall, and bead, in all-season tires, high-performance tires, and studless tires, and is especially suitable for use as a tread material for fuel-efficient tires because of its excellent low heat generation properties.

Examples

[0137] Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention.

[0138] <Method for Evaluating Ethanol Component> In the following examples and comparative examples, the contents of iron and Si in ethanol were measured using an inductively coupled plasma mass spectrometer (Inductively Coupled Plasma Mass Spectrometry: ICP-MS) ELAN DRCII manufactured by PerkinElmer Co., Ltd. The content of aromatic compounds in ethanol was measured using a gas chromatography apparatus (GC-2014, manufactured by SHIMADZU Corporation).

[0139] <Quantitative Determination Method for 1,3-Butadiene> Quantitative evaluation of 1,3-butadiene was performed by analysis using a gas chromatography apparatus (GC-2014, manufactured by SHIMADZU Corporation). The measurement conditions were as follows. <Analysis Conditions for GC / MS Method> Column: Rt-Q-BOND (length 30 m, inner diameter 0.32 mm, film thickness 10 μm) Oven temperature: 60°C for 11.5 minutes → 10°C / min → 100°C for 14.5 minutes → 10°C / min → 250°C Sampling time: 5 minutes Carrier gas: He (30 cm / s) Split ratio: 75

[0140] [Reference Example 1] <Preparation of Ethanol> Ethanol was produced as follows. (Raw Material Gas Generation Step) The gas discharged after combusting general waste in a waste incineration facility was used. The components of the raw material gas were approximately 30% by volume of carbon monoxide, approximately 30% by volume of carbon dioxide, approximately 30% by volume of hydrogen, and approximately 10% by volume of nitrogen.

[0141] (Synthesis gas purification process) The raw material gas produced as described above was heated to 80°C using a PSA (Pressure Sequestration) device to remove carbon dioxide from the synthesis gas, reducing its content to 60-80% of the original amount (approximately 30% by volume). Then, the gas was heated again using a double-tube heat exchanger with 150°C steam and recooled using a double-tube heat exchanger with 25°C cooling water to precipitate impurities. These precipitated impurities were then removed using a filter to produce synthesis gas.

[0142] (Microbial fermentation process) A continuous fermentation apparatus (microbial fermentation tank) equipped with a main reactor, a synthesis gas supply port, and an exhaust port, was filled with Clostridium autoethanogenum (microorganism) inoculum and a liquid culture medium for bacterial cultivation (containing appropriate amounts of phosphorus compounds, nitrogen compounds, and various minerals, etc.). Synthesis gas obtained as described above was continuously supplied to the apparatus, and cultivation (microbial fermentation) was carried out continuously for 300 hours. After that, approximately 8,000 liters of the culture solution containing ethanol were withdrawn from the exhaust port.

[0143] (separation process) The culture solution obtained in the above fermentation process was subjected to a solid-liquid separation filter device under conditions of a culture solution introduction pressure of 200 kPa or higher to obtain an ethanol-containing solution.

[0144] (Distillation process) Next, the ethanol-containing liquid was introduced into a distillation apparatus equipped with a heater using 170°C steam. After raising the temperature at the bottom of the distillation column to 101°C within 8 to 15 minutes, the ethanol-containing liquid was introduced from the middle of the distillation column. During continuous operation, the column was operated continuously at 101°C at the bottom, 99°C in the middle, and 91°C at the top, at a rate of 15 seconds / L, to obtain purified ethanol. The iron content in the obtained ethanol was 0.1 mg / L, and the Si content was 50 mg / L. In addition, the toluene content in the obtained ethanol was 0.07 mg / L, the ethylbenzene content was 0.8 mg / L, and the total content of m-xylene and p-xylene was 0.2 mg / L.

[0145] The obtained ethanol contained 0.1 mg / L of n-hexane, 0.04 mg / L of n-heptane, 0.02 mg / L of n-octane, 0.32 mg / L of n-decane, 0.1 mg / L of n-dodecane, and 0.03 mg / L of tetradecane. The obtained ethanol also contained 20 mg / L of dibutyl ether.

[0146] (Method for producing 1,3-butadiene) 1,3-butadiene was produced using the ethanol obtained as described above. First, the obtained ethanol was vaporized by passing it through a single tube heated to 90°C to be used as a gas for the reaction, and the vaporized ethanol gas was combined with nitrogen. The flow rate of the ethanol gas was controlled by mass flow so that it was SV360 L / hr / L and the nitrogen was SV840 L / hr / L to obtain a mixed gas of 30 vol% ethanol (gas equivalent) and 70 vol% nitrogen (gas equivalent). Subsequently, a 1,3-butadiene-containing gas was obtained by continuously supplying the above mixed gas through a stainless steel cylindrical reaction tube with a diameter of 1 / 2 inch (1.27 cm) and a length of 15.7 inches (40 cm), which was filled with 0.85 g of a 1,3-butadiene synthesis catalyst mainly composed of Hf and Zn, while maintaining the temperature at 325°C and the pressure (reaction bed pressure) at 0.1 MPa. The 1,3-butadiene content of the obtained 1,3-butadiene-containing gas was quantified using a GC-2014 gas chromatography apparatus (manufactured by SHIMADZU). The results are shown in Table 1.

[0147] [Reference Comparison Example 1] Using 99-degree ethanol (manufactured by Amakasu Chemical Industry Co., Ltd.), which is derived from fossil fuels, 1,3-butadiene was produced by the same method as in Reference Example 1, and the content of 1,3-butadiene was quantified in the same manner as in Reference Example 1. The results are shown in Table 1. The iron content in the 99-degree ethanol, which is derived from fossil fuels, was 2.8 mg / L, and the Si content was unmeasurable (below the detection limit, less than 10 mg / L). In addition, the toluene content in the obtained ethanol was unmeasurable (below the detection limit, less than 0.01 mg / L), the ethylbenzene content was unmeasurable (below the detection limit, less than 0.1 mg / L), and the total content of m-xylene and p-xylene was unmeasurable (below the detection limit, less than 0.2 mg / L).

[0148] [Reference Comparison Example 2] Using 99-degree ethanol derived from plant saccharification and fermentation (manufactured by Amakasu Chemical Industry Co., Ltd.), 1,3-butadiene was produced by the same method as in Reference Example 1, and the 1,3-butadiene content was quantified in the same manner as in Reference Example 1. The results are shown in Table 1. The iron content in the 99-degree ethanol derived from plant saccharification and fermentation was below the detection limit (less than 0.0001 mg / L), and the Si content was unmeasurable (below the detection limit, less than 10 mg / L). In addition, the toluene content in the obtained ethanol was unmeasurable (below the detection limit, less than 0.01 mg / L), the ethylbenzene content was unmeasurable (below the detection limit, less than 0.1 mg / L), and the total content of m-xylene and p-xylene was unmeasurable (below the detection limit, less than 0.2 mg / L).

[0149] [Table 1]

[0150] As shown in Table 1, ethanol produced using gas emitted after burning general waste in a waste incineration facility was found to have a higher conversion efficiency to 1,3-butadiene compared to conventional ethanol derived from fossil fuels or ethanol derived from saccharification and fermentation of plants.

[0151] (SBR evaluation method) The styrene-butadiene rubber (SBR) synthesized as described below was evaluated using the method described below. • Average molecular weight and degree of dispersion Number-average molecular weight (Mn) and weight-average molecular weight (Mw) were determined by GPC measurement using an HLC-8420GPC (Tosoh Corporation) column with a Shodex GPC KF-806L (Showa Denko Corporation) column. A 0.2 w / v% sample solution was prepared using THF as the eluent and polystyrene as the standard. 100 μL of the prepared sample was injected at a flow rate of 1.0 mL / min. The column temperature was 40°C. The degree of dispersion was determined as Mw / Mn. • Glass transition temperature (Tg) Using a thermal analyzer EXSTAR DSC7020 (manufactured by Hitachi High-Tech Science), the glass transition temperature was measured at a temperature range of -100 to 100°C, a heating rate of 20°C / min, and under a nitrogen atmosphere.

[0152] [Example 1] (SBR synthesis) 1,3-butadiene prepared in Reference Example 1 (iron content in raw material ethanol: 0.1 mg / L) was cooled to 10°C as a gas and purified by gas-liquid separation to obtain purified butadiene. At this time, the purity of the butadiene was 70%, butadiene / oxygen-containing compound = 3.6, and butadiene / hydrocarbon compound = 6.2. 129 g of water was added to a 1 L pressure-resistant reaction vessel, and then 3 L of nitrogen gas was bubbled in (approximately 50 mL / min x 1 hour). Next, 11.6 g of 25% potassium rosinate aqueous solution, 0.097 g of potassium oleate, 0.52 g of sodium phosphate, 0.097 g of rongalit, 0.13 g of paramentane hydroperoxide, and 16.2 g of styrene were added. The reaction vessel was immersed in a water bath cooled to 5°C, and 48.4 g of purified butadiene was added while stirring. Subsequently, 0.032 g of ferric sulfate and 0.045 g of EDTA-4Na were added as initiators. After 20 hours, 0.13 g of N,N'-dimethyldithiocarbamate was added to stop the reaction, yielding latex (styrene-butadiene rubber).

[0153] A few drops of sulfuric acid were added to the obtained latex, and the mixture was stirred in water. After filtering the water, the mixture was washed with water until the washing solution was neutral, and then dissolved in THF. The solution was washed with methanol, and then dried under reduced pressure to obtain solid rubber (emulsion polymerized SBR). The yield was 44%. Analysis revealed that the obtained polymer had a Mn of 91,800, a Mw of 492,000, and a Mw / Mn ratio of 5.36. The glass transition temperature was -46.5°C.

[0154] [Comparative Example 1] Solid rubber (emulsion polymerized SBR) was obtained in the same manner as in Example 1, except that 1,3-butadiene prepared in Reference Comparative Example 1 (iron content in raw material ethanol: less than 2.8 mg / L) was used as the 1,3-butadiene. The yield was 29%. Analysis revealed that the obtained polymer had a Mn of 82,400, a Mw of 382,000, and a Mw / Mn ratio of 4.64. The glass transition temperature was -40.3°C.

[0155] [Comparative Example 2] Solid rubber (emulsion polymerized SBR) was obtained in the same manner as in Example 1, except that 1,3-butadiene prepared in Reference Comparative Example 2 (iron content in raw material ethanol: below the detection limit (less than 0.0001 mg / L)) was used as 1,3-butadiene. The yield was 43%. Analysis revealed that the obtained polymer had a Mn of 67,200, a Mw of 297,000, and a Mw / Mn ratio of 4.42. The glass transition temperature was -47.1°C.

[0156] (Effect of iron content) From the examples and comparative examples, it can be seen that when the iron content of ethanol is in the range of 0.0001 to 2 mg / L, the Mw / Mn ratio falls within the range of 4.7 to 6.0. The presence of iron in ethanol in the range of 0.0001 to 2 mg / L can adsorb trace amounts of oxygen, preventing polymerization reactions that proceed as side reactions during butadiene synthesis and improving the selectivity of butadiene. By using high-purity butadiene, the ratio of styrene to butadiene can be precisely controlled, and the Mw / Mn ratio can fall within the range of 4.7 to 6.0. If the presence of iron in ethanol is 2 mg / L or more, the amount of butane mixed into the butadiene gas produced during the butadiene synthesis reaction increases. It is thought that the presence of butane that does not act on the polymerization reaction during emulsion polymerization lowers the proportion of butadiene in the polymer and increases the Mw / Mn value.

[0157] From the examples and comparative examples, it can be seen that the polymerization yield is high when the iron content of ethanol is in the range of 0.0001 to 2 mg / L. It is thought that the presence of iron in ethanol in the range of 0.0001 to 2 mg / L can adsorb trace amounts of oxygen, preventing catalyst deactivation by oxygen during emulsion polymerization and thus increasing the polymerization yield. On the other hand, when ethanol contains more than 2 mg / L of iron, the amount of butane mixed into the butadiene gas produced during the butadiene synthesis reaction increases. It is thought that the presence of butane, which does not act on the polymerization reaction during emulsion polymerization, lowers the proportion of butadiene in the polymer and thus lowers the polymerization yield.

[0158] From the examples and comparative examples, it can be seen that when the iron content of ethanol is in the range of 0.0001 to 2 mg / L, the glass transition temperature falls within the range of -41 to -47°C. The presence of iron in ethanol increases the amount of ethyl acetate mixed into the butadiene gas produced during the butadiene synthesis reaction. It is thought that the presence of ethyl acetate during emulsion polymerization leads to some of the ethyl acetate being incorporated into the rubber, resulting in lower molecular crystallinity and a lower glass transition temperature. On the other hand, it is thought that when ethanol contains more than 2 mg / L of iron, the amount of ethyl acetate mixed into the butadiene gas produced during the butadiene synthesis reaction increases too much, resulting in an excessively high glass transition temperature.

Claims

[Claim 1] A method for producing a non-petrogenic conjugated diene polymer using non-petrogenic alcohol as a raw material, Using an alcohol derived from non-petrochemical raw materials having an iron content of 0.0001 mg / L or more and 2 mg / L or less as a raw material, the alcohol is brought into contact with a catalyst and heated, thereby producing a catalyst with a carbon number of C ４ ~C １２ The process for producing a conjugated diene, A step of polymerizing a monomer containing the aforementioned conjugated diene to produce a non-petrogenic conjugated diene polymer. Methods that include...

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