JP7323305B2 - ethanol - Google Patents

Description

TECHNICAL FIELD The present invention relates to ethanol, and more particularly to ethanol in which the content of specific minor components is adjusted. Furthermore, the present invention relates to a novel resource-recycling type ethanol that uses a gas containing carbon monoxide and hydrogen as a substrate and is not derived from conventional petroleum resources or biomass resources.

Petrochemical products are used in various places in our lives. On the other hand, since it is a familiar product, it has become a big problem on a global scale that it causes various environmental problems due to mass production and mass consumption. For example, polyethylene and polyvinyl chloride, which are typical products of the petrochemical industry, are consumed in large amounts and thrown away, and their waste is a major cause of environmental pollution. In addition, in the mass production of petrochemical industrial products, global environmental problems such as the depletion of fossil fuel resources and the increase of carbon dioxide in the atmosphere are being discussed.

Due to the growing global awareness of such environmental problems, in recent years, techniques for producing various organic substances using raw materials other than naphtha, which is a raw material for petrochemical products, have been investigated. For example, a method of producing bioethanol from edible raw materials such as corn by sugar fermentation has attracted attention. However, since the sugar fermentation method using such edible raw materials uses a limited farmland area for production other than food, it has been pointed out that it causes a problem such as soaring food prices.

In order to solve this problem, the use of non-edible raw materials, which have conventionally been discarded, has been investigated. Specifically, there is a method of producing alcohols by a fermentation method using cellulose derived from waste materials and waste paper as non-edible raw materials, and a method of gasifying the above biomass raw materials and producing alcohol from synthesis gas using a catalyst. There have been proposals for methods for producing the same, but the current situation is that they have not yet been put into practical use. Moreover, even if various petrochemical products can be produced from these petroleum-free raw materials, they will eventually become waste plastics that do not decompose naturally, so it can be said that they are not effective as a drastic solution to environmental problems. .

By the way, the amount of combustible waste currently discarded in Japan amounts to about 60 million tons/year. The amount of energy is equivalent to about 200 trillion kilocalories, which greatly exceeds the amount of energy possessed by naphtha, which is used as a raw material for plastics in Japan. If these waste resources can be converted into petrochemical products, it will be possible to realize an ultimate resource recycling society that does not rely on petroleum resources. From the above point of view, Patent Documents 1 and 2, etc. disclose techniques for producing synthesis gas (gas mainly composed of CO and _H2 ) from waste, and producing ethanol from the synthesis gas by fermentation. there is

However, as pointed out in Patent Document 3, synthesis gas produced from waste contains a wide variety of unexplained impurities, some of which are toxic to microorganisms. Therefore, productivity has been a major issue in the production of alcohol from synthesis gas by microbial fermentation. Alcohol obtained by microbial fermentation of synthesis gas also contains various components resulting from impurities in the synthesis gas, and these components cannot be completely removed by purification treatment such as distillation. Therefore, the development of derivatives from alcohol obtained by microbial fermentation of syngas has been a major technical issue.

JP 2016-059296 A International publication 2015-037710 JP 2018-058042 A

According to the studies of the present inventors, for example, conventional C2 raw materials represented by ethanol are known as starting materials for various chemical products, but as described above, they are not based on petroleum resources or biomass resources. It has been found that alcohol produced from resources (recyclable resources) contains various trace amounts of unknown substances, unlike chemical raw materials derived from naphtha. However, in the prior art, the characteristics of substances are also unknown, and conventionally, sufficient consideration has not been made as to whether all substances should be removed or only specific substances should be removed. Therefore, even if alcohol produced from recyclable resources is proposed in the above-mentioned patent document, the current situation is that there is still room for technical improvement in order to put the alcohol into practical use.

On the other hand, according to the above document, although the general fermentation/distillation method and the optimum synthesis gas composition are disclosed, the details of the process, etc. are not described, and even the identification of the obtained alcoholic substance is not described. Not even.

Therefore, the present invention has been made in view of such background art, and an object thereof is to provide a practical novel alcohol and its derivatives that are more industrially valuable than existing petrochemical raw materials.

As a result of intensive studies to solve the above problems, the present inventors identified a wide variety of trace substances contained in alcohol produced from recyclable resources, and further measured the content by a new production method. It was found that it became possible to control the concentration within a specific range, and in addition, various derivatives thereof exhibited superior effects compared to existing petrochemical-derived alcohols. For example, in the process of synthesizing butadiene from ethanol, the conversion rate of ethanol is improved compared to the case of using conventional petrochemical-derived ethanol, and a practical level of alcohol equal to or higher than that of petrochemical-derived alcohol can be obtained. The discovery led to the present invention.

More specifically, when ethanol is produced from a gas substrate containing carbon monoxide and hydrogen using waste as a carbon source, synthesis of butadiene from the ethanol improves the ethanol conversion rate. Upon detailed investigation, it was found that the content of specific metal elements is extremely low in ethanol derived from a recyclable resource that uses a gas containing carbon monoxide and hydrogen as a substrate. The present invention is based on such findings.

That is, the present invention includes the following gists.
[1] Ethanol having a chromium content of 0.6 mg/L or less.
[2] The ethanol according to [1], wherein the substrate is a gas containing carbon monoxide and hydrogen.
[3] The ethanol according to [1] or [2], which is derived from microbial fermentation.
[4] The ethanol according to [2], wherein the gas containing carbon monoxide and hydrogen is derived from waste.
[5] converting the carbon source to a synthesis gas comprising carbon monoxide and hydrogen;
a microbial fermentation step of supplying the synthesis gas containing carbon monoxide and hydrogen to a microbial fermentation tank to obtain an ethanol-containing liquid through microbial fermentation;
a separation step of separating the ethanol-containing liquid into a liquid or solid component containing microorganisms and a gas component containing ethanol;
a liquefying step of condensing and liquefying the gas component;
a purification step of purifying ethanol from the liquid obtained in the liquefaction step;
including
A method for producing ethanol, wherein the purified ethanol has a chromium content of 0.6 mg/L or less.
[6] The method of [5], further comprising the step of purifying the synthesis gas.
[7] The method of [5] or [6], wherein the carbon source is derived from waste.
[8] The ethanol according to any one of [1] to [4], which is for chemical products.
[9] The ethanol according to any one of [1] to [4], which is for fuel.
[10] The ethanol according to any one of [1] to [4], which is used as a raw material for polymers.
[11] A chemical product made from ethanol according to any one of [1] to [4].
[12] A fuel containing ethyl-t-butyl ether made from the ethanol according to any one of [1] to [4] and/or the ethanol according to any one of [1] to [4].
[13] A polymer raw material made from ethanol according to any one of [1] to [4].
[14] The polymer raw material according to [13], which is selected from the group consisting of ethylene, propylene, butadiene, ethyl acetate, isobutene, methyl (meth)acrylate, acrylic acid, aminohexanoic acid, and diethyl carbonate.
[15] A polymer whose raw material is the polymer raw material according to [13] or [14].
[16] A molded article made of the polymer according to [15].

According to the present invention, by using ethanol with an extremely low content of a specific metal element, it is possible to obtain various different effects compared to commercially available industrial ethanol. For example, according to the present invention, it is possible to improve the conversion rate of ethanol when synthesizing butadiene using ethanol as a raw material, improve the reaction rate when synthesizing a carboxylic acid ester by adding ethanol to a carboxylic acid, and improve the reaction rate when ethanol is added. It is possible to improve combustion efficiency when used as fuel. In addition, even with existing alcohols, it is expected that similar effects can be obtained by adjusting the content of specific metal elements to an extremely low content.

Ethanol according to the present invention is, for example, butadiene, ethylene, propylene, isobutene, acetaldehyde, acetic acid, ethyl acetate, methyl (meth)acrylate, ethyl-t-butyl ether ethylene glycol, ester composition, polyester, acrylic acid, amino Hexanoic 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), it can be used as a raw material for manufacturing polyurethane (PU), etc. In addition, ethanol according to the present invention can be used in cosmetics, perfumes, fuels, antifreeze, bactericides, disinfectants, cleaning agents, mold removers, detergents, hair cleansers, soaps, antiperspirants, facial cleansing sheets, solvents, paints, adhesives, It can be used for various uses of chemical products such as diluents and food additives.

An example of a preferred mode for carrying out the present invention will be described below. However, the following embodiments are examples for explaining the present invention, and the present invention is not limited to the following embodiments.

<Definition>
In the present invention, "ethanol" does not mean pure ethanol as a compound (ethanol represented by the chemical formula: CH ₃ CH ₂ OH), but is inevitably contained in ethanol produced through synthesis or purification. It is intended to mean a composition that contains impurities (contaminant components).

<Ethanol>
The content of Cr (chromium) in the ethanol according to the invention is 0.6 mg/L or less, preferably 0.5 mg/L or less. The content of Cr is the amount of Cr compound converted to Cr element. When the Cr content is within the above numerical range, the ethanol conversion rate is improved when ethanol is used as a raw material to synthesize butadiene, and the reaction rate is improved when ethanol is added to a carboxylic acid to synthesize a carboxylic acid ester. It is also possible to improve the combustion efficiency when ethanol is used as fuel.

The content of chromium in ethanol can be measured by a conventionally known method. As a method for measuring the content of chromium, for example, there is a method of analysis using an inductively coupled plasma mass spectrometry (ICP-MS). In the method of analysis using ICP-MS, the standard solution for atomic absorption is analyzed after concentration adjustment to create a calibration curve, and the chromium content is determined by analyzing the sample to be measured based on this calibration curve. is.

Ethanol according to the present invention is preferably ethanol using a gas containing carbon monoxide and hydrogen as a substrate, or ethanol derived from microbial fermentation. This is because, with these ethanols, adjusting the content of chromium to the above concentration is simple in the production process. In addition, commercially available industrial ethanol derived from fossil fuels usually contains chromium in excess of the above concentration, but the chromium content may be adjusted to the above concentration by further refining.

Although not bound by theory, in the present invention, by reducing the content of a specific metal in ethanol to an extremely low value, the ethanol conversion rate when synthesizing butadiene using ethanol as a raw material is improved. Also, it is thought that the reaction rate when adding ethanol to a carboxylic acid to synthesize a carboxylic acid ester can be improved, and the combustion efficiency can be improved when ethanol is used as a fuel.

The ethanol according to the invention may contain inorganic components other than Cr. For example, it may contain inorganic components such as Si, K and Na. Compounds containing these elements may be inorganic compounds or organometallic compounds.

When Si is contained in ethanol, the content of Si is preferably 10 mg/L or more, more preferably 20 mg/L or more, still more preferably 30 mg/L or more, relative to ethanol, and , preferably 100 mg/L or less, more preferably 90 mg/L or less, and even more preferably 80 mg/L or less. The content of Si is the Si element equivalent amount of the Si compound. When the Si content is within the above numerical range, the ethanol conversion rate when synthesizing butadiene using ethanol as a raw material is improved, and the reaction rate when adding ethanol to a carboxylic acid to synthesize a carboxylic acid ester is improved. It is also possible to improve the combustion efficiency when ethanol is used as fuel.

When K is contained in ethanol, the content of K is preferably 1.0 mg/L or more, more preferably 1.5 mg/L or more, and still more preferably 2.0 mg/L, relative to ethanol. L or more, more preferably 2.5 mg/L or more, preferably 10 mg/L or less, more preferably 7 mg/L or less, still more preferably 5 mg/L or less. The content of K is the amount of the K compound in terms of K element. When the content of K is within the above numerical range, the ethanol conversion rate when synthesizing butadiene using ethanol as a raw material is improved, or the reaction rate when synthesizing a carboxylic acid ester by adding ethanol to a carboxylic acid is improved. It is also possible to improve the combustion efficiency when ethanol is used as fuel.

When Na is contained in ethanol, the content of Na is preferably 150 mg/L or more, more preferably 170 mg/L or more, still more preferably 190 mg/L or more, relative to ethanol, and , preferably 1000 mg/L or less, more preferably 500 mg/L or less, still more preferably 400 mg/L or less, and more preferably 300 mg/L or less. The content of Na is the amount of Na compound converted to Na element. When the content of Na is within the above numerical range, it improves the ethanol conversion rate when synthesizing butadiene using ethanol as a raw material, or improves the reaction rate when synthesizing a carboxylic acid ester by adding ethanol to a carboxylic acid. It is also possible to improve the combustion efficiency when ethanol is used as fuel.

When Fe is contained in ethanol, the content of Fe is preferably 2.0 mg/L or less, more preferably 1.5 mg/L or less, and still more preferably 1.0 mg/L, relative to ethanol. or less, and more preferably 0.5 mg/L or less. The content of Fe is the Fe element equivalent amount of the Fe compound. When the Fe content is within the above numerical range, the ethanol conversion rate is improved when ethanol is used as a raw material to synthesize butadiene, and the reaction rate is improved when ethanol is added to a carboxylic acid to synthesize a carboxylic acid ester. It is also possible to improve the combustion efficiency when ethanol is used as fuel.

The ethanol of the present invention is obtained by extracting and further purifying the ethanol-containing liquid obtained from the microbial fermentation tank as described later, but it contains other components in addition to the above-mentioned unavoidable substances. good too. For example, trace amounts of aromatic compounds may be included. Examples of aromatic compounds include toluene, ethylbenzene, o-xylene, m-xylene, and p-xylene, and only one of these may be included, or two or more thereof may be included. Ethylbenzene is preferably included as the aromatic compound.

The content (sum total) of aromatic compounds contained in ethanol is preferably 0.4 mg/L or more, more preferably 0.5 mg/L or more, and still more preferably 0.5 mg/L or more, based on the total amount of ethanol. 7 mg/L or more, more preferably 1.0 mg/L or more, preferably 10 mg/L or less, more preferably 7 mg/L or less, still more preferably 5 mg/L or less, Even more preferably, it is 3 mg/L or less. When the content of the aromatic compound is in the above numerical range, the ethanol conversion rate when synthesizing butadiene using ethanol as a raw material is improved, or the reaction rate when synthesizing a carboxylic acid ester by adding ethanol to a carboxylic acid. can be improved, and the combustion efficiency can be improved when ethanol is used as fuel.

When ethylbenzene is contained in ethanol, the content of ethylbenzene is preferably 0.1 mg/L or more, more preferably 0.2 mg/L or more, and still more preferably 0.3 mg with respect to the whole ethanol. /L or more, still more preferably 0.5 mg/L or more, preferably 5 mg/L or less, more preferably 3 mg/L or less, still more preferably 2 mg/L or less, Even more preferably, it is 1 mg/L or less. When the content of ethylbenzene is within the above numerical range, it improves the ethanol conversion rate when synthesizing butadiene using ethanol as a raw material, or improves the reaction rate when synthesizing a carboxylic acid ester by adding ethanol to a carboxylic acid. It is also possible to improve the combustion efficiency when ethanol is used as fuel.

When toluene is contained in ethanol, the content of toluene is preferably 0.01 mg/L or more, more preferably 0.02 mg/L or more, and still more preferably 0.03 mg with respect to the whole ethanol. /L or more, still more preferably 0.05 mg/L or more, preferably 1 mg/L or less, more preferably 0.5 mg/L or less, still more preferably 0.2 mg/L or less, and more preferably 0.1 mg/L or less. When the toluene content is within the above numerical range, the ethanol conversion rate is improved when ethanol is used as a raw material to synthesize butadiene, and the reaction rate is improved when ethanol is added to a carboxylic acid to synthesize a carboxylic acid ester. It is also possible to improve the combustion efficiency when ethanol is used as fuel.

When o-xylene is contained in ethanol, the content of o-xylene is preferably 0.1 mg/L or more, more preferably 0.2 mg/L or more, and still more preferably, based on the total ethanol. is 0.3 mg/L or more, still more preferably 0.5 mg/L or more, preferably 5 mg/L or less, more preferably 3 mg/L or less, and still more preferably 2 mg/L or less, and more preferably 1 mg/L or less. When the content of o-xylene is in the above numerical range, the ethanol conversion rate when synthesizing butadiene using ethanol as a raw material is improved, or the reaction rate when synthesizing a carboxylic acid ester by adding ethanol to a carboxylic acid. can be improved, and the combustion efficiency can be improved when ethanol is used as fuel.

When m-xylene and/or p-xylene is contained in ethanol, the content (total) of m-xylene and/or p-xylene is preferably 0.2 mg/L or more with respect to the whole ethanol. , more preferably 0.3 mg/L or more, still more preferably 0.4 mg/L or more, still more preferably 0.5 mg/L or more, and preferably 5 mg/L or less, and more preferably It is preferably 3 mg/L or less, more preferably 2 mg/L or less, and even more preferably 1 mg/L or less. When the content of m-xylene and/or p-xylene is within the above numerical range, the ethanol conversion rate when synthesizing butadiene using ethanol as a raw material is improved, or ethanol is added to a carboxylic acid to produce a carboxylic acid ester. It is possible to improve the reaction rate during synthesis and improve the combustion efficiency when ethanol is used as fuel.

Also, the ethanol according to the present invention may further contain trace amounts of aliphatic hydrocarbons. Examples of aliphatic hydrocarbons include n-hexane, n-heptane, n-octane, n-decane, n-dodecane, n-tetradecane, hexadecane and the like, and only one of these may be included. , may be included. Aliphatic hydrocarbons preferably include one or more of n-hexane, n-decane, and n-dodecane.

The content (total) of aliphatic hydrocarbons contained in ethanol is preferably 0.16 mg/L or more, preferably 0.2 mg/L or more, more preferably 0.3 mg/L, based on the total amount of ethanol. L or more, more preferably 0.5 mg/L or more, and 10 mg/L or less, preferably 7 mg/L or less, more preferably 5 mg/L or less, still more preferably 3 mg/L or less. When the content of the aliphatic hydrocarbon is in the above numerical range, the ethanol conversion rate when synthesizing butadiene using ethanol as a raw material is improved, or the reaction when synthesizing a carboxylic acid ester by adding ethanol to a carboxylic acid It is possible to improve the rate of combustion and improve the combustion efficiency when ethanol is used as fuel.

When n-hexane is contained in ethanol, the content of n-hexane is preferably 0.1 mg/L or more, more preferably 0.2 mg/L or more, more preferably 0.2 mg/L or more, based on the total ethanol. is 0.3 mg/L or more, still more preferably 0.5 mg/L or more, preferably 5 mg/L or less, more preferably 3 mg/L or less, and still more preferably 2 mg/L or less, and more preferably 1 mg/L or less. When the content of n-hexane is within the above numerical range, the ethanol conversion rate when synthesizing butadiene using ethanol as a raw material is improved, or the reaction rate when synthesizing a carboxylic acid ester by adding ethanol to a carboxylic acid. can be improved, and the combustion efficiency can be improved when ethanol is used as fuel.

When n-heptane is contained in ethanol, the content of n-heptane is preferably 0.01 mg/L or more, more preferably 0.02 mg/L or more, more preferably 0.02 mg/L or more, based on the total ethanol. is 0.03 mg/L or more, still more preferably 0.05 mg/L or more, preferably 1 mg/L or less, more preferably 0.5 mg/L or less, and still more preferably 0 .2 mg/L or less, and even more preferably 0.1 mg/L or less. When the content of n-heptane is within the above numerical range, the ethanol conversion rate when synthesizing butadiene using ethanol as a raw material is improved, or the reaction rate when synthesizing a carboxylic acid ester by adding ethanol to a carboxylic acid. can be improved, and the combustion efficiency can be improved when ethanol is used as fuel.

When n-octane is contained in ethanol, the content of n-octane is preferably 0.01 mg/L or more, more preferably 0.02 mg/L or more, more preferably 0.02 mg/L or more, based on the total ethanol. is 0.03 mg/L or more, still more preferably 0.05 mg/L or more, preferably 1 mg/L or less, more preferably 0.5 mg/L or less, and still more preferably 0 .2 mg/L or less, and even more preferably 0.1 mg/L or less. When the content of n-octane is within the above numerical range, the ethanol conversion rate when synthesizing butadiene using ethanol as a raw material is improved, or the reaction rate when synthesizing a carboxylic acid ester by adding ethanol to a carboxylic acid. can be improved, and the combustion efficiency can be improved when ethanol is used as fuel.

When n-decane is contained in ethanol, the content of n-decane is preferably 0.01 mg/L or more, more preferably 0.02 mg/L or more, more preferably 0.02 mg/L or more, based on the total ethanol. is 0.03 mg/L or more, still more preferably 0.05 mg/L or more, preferably 1 mg/L or less, more preferably 0.5 mg/L or less, and still more preferably 0 .2 mg/L or less, and even more preferably 0.1 mg/L or less. When the content of n-decane is within the above numerical range, the ethanol conversion rate when synthesizing butadiene using ethanol as a raw material is improved, or the reaction rate when synthesizing a carboxylic acid ester by adding ethanol to a carboxylic acid. can be improved, and the combustion efficiency can be improved when ethanol is used as fuel.

When n-dodecane is contained in ethanol, the content of n-dodecane is preferably 0.01 mg/L or more, more preferably 0.02 mg/L or more, and still more preferably, based on the total ethanol. is 0.03 mg/L or more, still more preferably 0.05 mg/L or more, preferably 1 mg/L or less, more preferably 0.5 mg/L or less, and still more preferably 0 .2 mg/L or less, and even more preferably 0.1 mg/L or less. When the content of n-dodecane is within the above numerical range, the ethanol conversion rate when synthesizing butadiene using ethanol as a raw material is improved, or the reaction rate when synthesizing a carboxylic acid ester by adding ethanol to a carboxylic acid. can be improved, and the combustion efficiency can be improved when ethanol is used as fuel.

When n-tetradecane is contained in ethanol, the content of n-tetradecane is preferably 0.01 mg/L or more, more preferably 0.02 mg/L or more, and still more preferably, based on the total ethanol. is 0.03 mg/L or more, still more preferably 0.05 mg/L or more, preferably 1 mg/L or less, more preferably 0.5 mg/L or less, and still more preferably 0 .2 mg/L or less, and even more preferably 0.1 mg/L or less. When the content of n-tetradecane is within the above numerical range, the ethanol conversion rate when synthesizing butadiene using ethanol as a raw material is improved, or the reaction rate when synthesizing a carboxylic acid ester by adding ethanol to a carboxylic acid. can be improved, and the combustion efficiency can be improved when ethanol is used as fuel.

When hexadecane is contained in ethanol, the content of hexadecane is preferably 0.01 mg/L or more, more preferably 0.02 mg/L or more, and still more preferably 0.03 mg with respect to the whole ethanol. /L or more, still more preferably 0.05 mg/L or more, preferably 1 mg/L or less, more preferably 0.5 mg/L or less, still more preferably 0.2 mg/L or less, and more preferably 0.1 mg/L or less. When the content of hexadecane is within the above numerical range, it improves the ethanol conversion rate when synthesizing butadiene using ethanol as a raw material, or improves the reaction rate when synthesizing a carboxylic acid ester by adding ethanol to a carboxylic acid. It is also possible to improve the combustion efficiency when ethanol is used as fuel.

Also, the ethanol according to the present invention may further contain a trace amount of dialkyl ether. Examples of dialkyl ethers include dimethyl ether, diethyl ether, dipropyl ether, dibutyl ether, and dipentyl ether, and only one of these may be included, or two or more thereof may be included. The dialkyl ether preferably includes dibutyl ether.

The content (total) of dialkyl ether contained in ethanol is preferably 0.001 mg/L or more, preferably 0.01 mg/L or more, and more preferably 0.1 mg/L or more with respect to the whole ethanol. , more preferably 1.0 mg/L or more, and 100 mg/L or less, preferably 80 mg/L or less, more preferably 50 mg/L or less, and still more preferably 30 mg/L or less. When the dialkyl ether content is within the above numerical range, the ethanol conversion rate when synthesizing butadiene using ethanol as a raw material can be improved, or the reaction rate when adding ethanol to a carboxylic acid to synthesize a carboxylic acid ester can be increased. It is also possible to improve the combustion efficiency when ethanol is used as fuel.

When dibutyl ether is contained in ethanol, the content of dibutyl ether is preferably 1 mg/L or more, more preferably 2 mg/L or more, and still more preferably 5 mg/L or more, relative to ethanol. , still more preferably 10 mg/L or more, preferably 50 mg/L or less, more preferably 40 mg/L or less, still more preferably 30 mg/L or less, still more preferably 25 mg/L It is below. When the content of dibutyl ether is within the above numerical range, the ethanol conversion rate when synthesizing butadiene using ethanol as a raw material is improved, or the reaction rate when synthesizing a carboxylic acid ester by adding ethanol to a carboxylic acid is increased. It is also possible to improve the combustion efficiency when ethanol is used as fuel.

The ethanol of the present invention contains inorganic components as described above and, if desired, trace amounts of organic components such as aromatic hydrocarbons and aliphatic hydrocarbons. Pure ethanol) has a concentration of 75% by volume or more, preferably 80% by volume or more, more preferably 90% by volume or more, still more preferably 95% by volume or more, and even more preferably 98% by volume, based on the total ethanol % or more, 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.

The ethanol concentration in the ethanol of the present invention may be set according to the intended use. For example, for cosmetics, the concentration is 90% by volume or more, and for ethanol for disinfectants, the concentration is 75% by volume or more. It is preferably used, and the upper limit can also be conveniently set according to the application. The higher the concentration of ethanol in the product, the better, considering transportation costs and the like.

<Method for producing ethanol>
As a method for producing ethanol having a characteristic gas chromatographic peak as described above, for example, ethanol can be produced by microbial fermentation of synthesis gas containing carbon monoxide derived from waste or exhaust gas. In such a method, the amount of aromatic compounds contained in the final product may be controlled by controlling the content of aromatic compounds in the raw material gas derived from the waste or exhaust gas and the purification conditions. As an example, a method for producing ethanol by microbial fermentation of synthetic gas containing carbon monoxide derived from waste or exhaust gas will be described below.

A method for producing ethanol includes the steps of converting a carbon source into a synthetic gas containing carbon monoxide and hydrogen, and supplying the synthetic gas containing carbon monoxide and hydrogen to a microbial fermentation tank to ferment the microorganisms to obtain an ethanol-containing liquid. A fermentation step, a separation step of separating the ethanol-containing liquid into a liquid or solid component containing microorganisms and a gas component containing ethanol, a liquefaction step of condensing and liquefying the gas component, and a liquefaction step. and a purifying step of purifying ethanol from a liquid, and may include a source gas generation step, a synthesis gas preparation step, a waste water treatment step, and the like, if necessary. Each step will be described below.

<Raw material gas generation process>
The raw material gas generating step is a step of generating a raw material gas by gasifying the carbon source in the gasification section. A gasification furnace may be used in the source gas generation step. A gasification furnace is a furnace that burns (incompletely burns) a carbon source, and examples thereof include shaft furnaces, kiln furnaces, fluidized bed furnaces, and gasification reforming furnaces. The gasification furnace is preferably of the fluidized bed type because partial combustion of the waste enables a high hearth load and excellent operational operability. By gasifying the waste in a low-temperature (approximately 450-600°C) and low-oxygen fluidized bed furnace, it decomposes into gases (carbon monoxide, carbon dioxide, hydrogen, methane, etc.) and char containing a large amount of carbon. do. Furthermore, since the incombustibles contained in the waste are separated from the furnace bottom in a hygienic and low-oxidation state, it is possible to selectively recover valuables such as iron and aluminum in the incombustibles. Therefore, gasification of such waste enables efficient resource recycling.

The gasification temperature in the source gas generation step is not particularly limited, but is usually 100 to 2500°C, preferably 200 to 2100°C.

The gasification reaction time in the raw material gas generation step is usually 2 seconds or longer, preferably 5 seconds or longer.

The carbon source used in the raw material gas generation process is not particularly limited, and examples include coke ovens in ironworks, blast furnaces (blast furnace gas), coal used in converters and coal-fired power plants, and incinerators (particularly gasifiers). Various carbon-containing materials can also be suitably used for the purpose of recycling, such as general wastes and industrial wastes introduced into industrial wastes, carbon dioxide by-produced by various industries, and the like.

More specifically, the carbon source is preferably waste, specifically plastic waste, garbage, municipal solid waste (MSW), industrial solid waste, waste tires, biomass waste, futon and paper, waste such as building materials, coal, petroleum, petroleum-derived compounds, natural gas, and shale gas. Municipal solid waste is more preferred.

A raw material gas obtained by gasifying a carbon source contains carbon monoxide and hydrogen as essential components, but may further contain carbon dioxide, oxygen, and nitrogen. As other components, the source gas may further contain components such as soot, tar, nitrogen compounds, sulfur compounds, phosphorus compounds, and aromatic compounds.

In the raw material gas generating step, the raw material gas is subjected to a heat treatment (commonly known as gasification) for burning (incomplete combustion) of the carbon source, that is, by partially oxidizing the carbon source to convert carbon monoxide, particularly Although not limited, it may be generated as a gas containing 0.1% by volume or more, preferably 10% by volume or more, more preferably 20% by volume or more.

<Synthesis gas refining process>
A synthesis gas purification process is a process that removes or reduces certain substances, such as various contaminants, dust particles, impurities, and undesirable amounts of chemical compounds, from the feed gas. When the raw material gas is derived from waste, the raw material gas usually contains 0.1% to 80% by volume of carbon monoxide, 0.1% to 70% by volume of carbon dioxide, and 0% of hydrogen. .1% by volume or more and 80% by volume or less, and further nitrogen compounds of 1 mg/L or more, sulfur compounds of 1 mg/L or more, phosphorus compounds of 0.1 mg/L or more, and/or aromatic compounds of 10 mg/L or more. tend to include It may also contain substances such as other environmental pollutants, dust particles, and impurities. Therefore, when supplying synthesis gas to the microbial fermentation tank, substances unfavorable for the stable culture of microorganisms and compounds in unfavorable amounts are reduced or removed from the source gas, and the content of each component contained in the source gas is preferably in a range suitable for stable culture of microorganisms.

In particular, in the synthesis gas refining process, a pressure swing adsorption device filled with the above regenerated adsorbent is used to adsorb carbon dioxide gas in the syngas to the regenerated adsorbent (zeolite), and the carbon dioxide gas concentration in the syngas is to reduce Additionally, the syngas may be subjected to other conventionally known processing steps to remove impurities and adjust the gas composition. Other treatment processes include, for example, a gas chiller (moisture separator), a low-temperature separation system (cryogenic system) separator, a cyclone, a particulate (soot) separator such as a bag filter, and a scrubber (water-soluble impurity separator). , desulfurization equipment (sulfide separation equipment), membrane separation equipment, deoxygenation equipment, pressure swing adsorption equipment (PSA), temperature swing adsorption equipment (TSA), pressure temperature swing adsorption equipment It can be treated using one or more of a separation device (PTSA), a separation device using activated carbon, a deoxidizing catalyst, specifically a separation device using a copper catalyst or a palladium catalyst, and the like.

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

The synthesis gas used in the method for producing ethanol of the present invention contains at least carbon monoxide as an essential component, and may further contain hydrogen, carbon dioxide and nitrogen.

The synthesis gas used in the present invention is produced by gasifying a carbon source to produce a raw material gas (raw material gas generation step), and then adjusting the concentration of each component of carbon monoxide, carbon dioxide, hydrogen and nitrogen from the raw material gas. In addition, a gas obtained through a process of reducing or removing substances and compounds as described above may be used as synthesis gas.

The carbon monoxide concentration in the synthesis gas is usually 20% by volume or more and 80% by volume or less, preferably 25% by volume or more and 50% by volume, based on the total concentration of carbon monoxide, carbon dioxide, hydrogen and nitrogen in the synthesis gas. % by volume or less, more preferably 35% by volume or more and 45% by volume or less.

The hydrogen concentration in the synthesis gas is usually 10% by volume or more and 80% by volume or less, preferably 30% by volume or more and 55% by volume, with respect to the total concentration of carbon monoxide, carbon dioxide, hydrogen and nitrogen in the synthesis gas. or less, more preferably 40% by volume or more and 50% by volume or less.

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

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

The concentrations of carbon monoxide, carbon dioxide, hydrogen, and nitrogen can be adjusted by changing the elemental composition of hydrocarbons (carbon and hydrogen) and nitrogen as carbon sources in the raw material gas generation process, and by changing the combustion temperature and the oxygen concentration of the gas supplied during combustion. A predetermined range can be obtained by appropriately changing the combustion conditions such as. For example, if you want to change the concentration of carbon monoxide or hydrogen, you can change to a carbon source with a high ratio of hydrocarbons (carbon and hydrogen) such as waste plastic. There is a method of supplying a gas with a high

The synthesis gas used in the present invention may contain sulfur compounds, phosphorus compounds, nitrogen compounds, etc., in addition to the above components, although there are no particular restrictions. The content of each of these compounds is preferably 0.05 mg/L or more, more preferably 0.1 mg/L or more, still more preferably 0.5 mg/L or more, and preferably 2000 mg/L or less, It is more preferably 1000 mg/L or less, still 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. to the lower limit or more, there is an advantage that microorganisms can be suitably cultured, and by setting the content to the upper limit or less, microorganisms do not consume. There is an advantage that the medium is not contaminated with various nutrient sources.

Sulfur compounds generally include sulfur dioxide, CS ₂ , COS, and H ₂ S. Among them, H ₂ S and sulfur dioxide are preferred because they are easily consumed as nutrients for microorganisms. Therefore, it is more preferable that the sum of H ₂ S and sulfur dioxide be contained in the synthesis gas within the above range.
As the phosphorus compound, phosphoric acid is preferable because it is easily consumed as a nutrient source for microorganisms. Therefore, it is more preferable that the synthesis gas contains phosphoric acid within the above range.
Nitrogen compounds include nitric oxide, nitrogen dioxide, acrylonitrile, acetonitrile, HCN, and the like, and HCN is preferred because it is easily consumed as a nutrient source for microorganisms. Therefore, it is more preferable that the synthesis gas contains HCN within the above range.

In addition, the synthesis gas may contain aromatic compounds of 0.01 mg/L or more and 90 mg/L or less, preferably 0.03 mg/L or more, more preferably 0.05 mg/L or more, and still more preferably 0.1 mg/L or more. 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. When the content is equal to or higher than the lower limit, microorganisms tend to be able to be cultured properly, and when the content is equal to or lower than the upper limit, the medium tends to be less likely to be contaminated with various nutrients that have not been consumed by the microorganisms. It is in.

<Microbial fermentation process>
The microbial fermentation step is a step of microbially fermenting the synthesis gas described above to produce ethanol in a microbial fermentation tank. The microbial fermenter is preferably a continuous fermentation apparatus. In general, a microbial fermenter of any shape can be used, including agitation type, airlift type, bubble column type, loop type, open bond type, and photobio type. In the present invention, a microbial fermenter However, a known loop reactor having a main tank section and a reflux section can be preferably used. In this case, it is preferable to further include a circulation step of circulating the liquid culture medium between the main tank portion and the reflux portion.

As long as the synthesis gas to be supplied to the microbial fermentation tank satisfies the above-mentioned conditions for the composition of the synthesis gas, the gas obtained through the raw material gas generation process may be used as it is as the synthesis gas, or impurities, etc., may be reduced from the raw material gas. Alternatively, another predetermined gas may be added to the removed gas before using the synthesis gas. As another 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 synthesis gas.

The microbial fermenter may be continuously supplied with the synthesis gas and the microbial culture solution, but it is not necessary to supply the synthesis gas and the microbial culture solution at the same time. Syngas may be supplied. Certain types of anaerobic microorganisms are known to produce ethanol and the like from substrate gases such as syngas through fermentation, and this type of gas-assimilating microorganisms is cultured in a liquid medium. For example, a liquid medium and gas-assimilating bacteria may be supplied and stored, and synthetic gas may be supplied into the microbial fermentation tank while stirring the liquid medium in this state. As a result, the gas-utilizing bacteria can be cultured in the liquid medium, and ethanol can be produced from the synthesis gas by its fermentation action.

In the microbial fermenter, the temperature of the medium (culture temperature) may be any temperature, preferably about 30 to 45° C., more preferably about 33 to 42° C., still more preferably 36.5 to 37° C. It can be about 0.5°C. In addition, the culture time is preferably 12 hours or more in continuous culture, more preferably 7 days or more, particularly preferably 30 days or more, and most preferably 60 days or more. From this point of view, it is preferably 720 days or less, more preferably 365 days or less. In addition, the culture time means the time from adding the inoculum to the culture tank until the entire amount of the culture solution in the culture tank is discharged.

Microorganisms (seeds) contained in the microbial culture solution are not particularly limited as long as ethanol can be produced by microbial fermentation of synthesis gas using carbon monoxide as a main raw material. For example, the microorganism (seed) is preferably one that produces ethanol from synthesis gas by the fermentation action of a gas-utilizing bacterium, particularly a microorganism that has an acetyl-COA metabolic pathway. Among gas-utilizing bacteria, the genus Clostridium is more preferable, and Clostridium autoethanogenum is particularly preferable, but the bacteria are not limited thereto. Further examples are given below.

Gassing bacteria include both eubacteria and archaea. Eubacteria include, for example, Clostridium bacteria, Moorella bacteria, Acetobacterium bacteria, Carboxydocella bacteria, Rhodopseudomonas bacteria, Eubacterium bacteria of the genus Eubacterium, bacteria of the genus Butyribacterium, bacteria of the genus Oligotropha, bacteria of the genus Bradyrhizobium, aerobic hydrogen-oxidizing bacteria of the genus Rassotonia, and the like.

On the other hand, archaebacteria include, for example, Methanobacterium, Methanobrevibacter, Methanocalculus, Methanococcus, Methanosarcina, Methanosphaera, Methanothermobacter, Methanothrix, Methanoculleus, Methanofollis, and Methanogenium. Bacteria, 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, preferable archaea are Methanosarcina, Methanococcus, Methanothermobacter, Methanothrix, Thermococcus, Thermofilum, and Archaeoglobus.

Furthermore, the archaea are preferably bacteria of the genus Methanosarcina, bacteria of the genus Methanothermobactor, or bacteria of the genus Methanococcus, and bacteria of the genus Methanosarcina or bacteria of the genus Methanococcus are particularly preferred as the archaea, since they are excellent in assimilation of carbon monoxide and carbon dioxide. Specific examples of bacteria of the genus Methanosarcina include Methanosarcina barkeri, Methanosarcina mazei, and Methanosarcina acetivorans.

Bacteria having a high ability to produce the desired ethanol are selected and used from among the gas-utilizing bacteria as described above. For example, gas-utilizing bacteria with high ethanol-producing ability include Clostridium autoethanogenum, Clostridium ljungdahlii, Clostridium aceticum, and Clostridium carboxidivorans. , Moorella thermoacetica, Acetobacterium woodii, etc. Among these, Clostridium autoethanogenum is particularly preferred.

The medium used for culturing the above microorganisms (seeds) is not particularly limited as long as it has an appropriate composition according to the bacteria. phosphoric acid, etc.). The composition of such a medium is prepared so that gas-utilizing bacteria can grow well. For example, for the culture medium when Clostridium is used as a microorganism, US Patent Application Publication No. 2017/260552, "0097" to "0099", etc. can be referred to.

The ethanol-containing liquid obtained by the microbial fermentation process can be obtained as a suspension containing microorganisms, their dead bodies, proteins derived from microorganisms, and the like. The protein concentration in the suspension is usually 30-1000 mg/L, depending on the type of microorganism. The protein concentration in the ethanol-containing liquid can be measured by the Kjeldahl method.

<Separation process>
The ethanol-containing liquid obtained by the microbial fermentation process is then subjected to a separation process. In the present invention, an ethanol-containing liquid is heated to room temperature to 500° C. under conditions of 0.01 to 1000 kPa (absolute pressure) to separate into a liquid or solid component containing microorganisms and a gas component containing ethanol. . In the conventional method, the ethanol-containing liquid obtained by the microbial fermentation process was distilled to separate and purify the desired ethanol. If the liquid is distilled as it is, foaming may occur in the distillation apparatus and hinder continuous operation. It is also known to use a membrane evaporator as a method for purifying foamy liquids, but membrane evaporators have low concentration efficiency and are not suitable for purifying liquids containing solid components. In the present invention, before separating and purifying the desired ethanol from the ethanol-containing liquid obtained by the microbial fermentation process by distillation or the like, the ethanol-containing liquid is heated to obtain a liquid or solid component containing microorganisms and a gas containing ethanol. The desired ethanol is separated and purified only from the separated gaseous component containing ethanol. By carrying out the separation step, foaming does not occur in the distillation apparatus during the distillation operation during the separation and purification of ethanol, so the distillation operation can be performed continuously. In addition, since the concentration of ethanol contained in the gas component containing ethanol is higher than the concentration of ethanol in the ethanol-containing liquid, ethanol can be efficiently separated and purified in the purification step described later.

In the present invention, from the viewpoint of efficiently separating into liquid or solid components containing microorganisms, their dead bodies, proteins derived from microorganisms, etc., and gaseous components containing ethanol, conditions of preferably 10 to 200 kPa are more preferable. Heating the ethanol-containing liquid at a temperature of preferably 50 to 200 ° C., more preferably 80 to 180 ° C., still more preferably 100 to 150 ° C. under conditions of 50 to 150 kPa, more preferably normal pressure. I do.

The heating time in the separation step is not particularly limited as long as it can obtain the gas component, but from the viewpoint of efficiency or economy, it is usually 5 seconds to 2 hours, preferably 5 seconds to 1 hour, or more. It is preferably 5 seconds to 30 minutes.

The above separation process is not particularly limited as long as it is an apparatus that can efficiently separate the ethanol-containing liquid into liquid or solid components (microorganisms, their dead bodies, proteins derived from microorganisms, etc.) and gaseous components (ethanol) by thermal energy. For example, a drying apparatus such as a rotary dryer, a fluidized bed dryer, a vacuum dryer, or a conduction heating dryer can be used. It is preferable to use a conduction heating dryer from the viewpoint of efficiency when separating into a solid component and a gaseous component. Examples of conductive heating dryers include drum dryers and disk dryers.

<Liquefaction process>
The liquefaction step is a step of liquefying the gaseous component containing ethanol obtained in the separation step by condensation. The device used in the liquefaction step is not particularly limited, but it is preferable to use a heat exchanger, particularly a condenser (condenser). Examples of condensers include water-cooled, air-cooled, and evaporative types, among which the water-cooled type is preferred. The condenser may have one stage or may have multiple stages.

It can be said that it is preferable that the liquefied material obtained by the liquefaction step does not contain components contained in the ethanol-containing liquid, such as microorganisms, their dead bodies, and proteins derived from microorganisms. It does not exclude the inclusion of protein therein. Even if the liquefied substance contains protein, its concentration is preferably 40 mg/L or less, more preferably 20 mg/L or less, and even more preferably 15 mg/L or less.

The heat of condensation of the gaseous component obtained by the condenser may be reused as a heat source in the refining process described below. Ethanol can be produced efficiently and economically by reusing the heat of condensation.

<Purification process>
Next, ethanol is purified from the liquefied product obtained in the liquefying step. The ethanol-containing liquid obtained in the microbial fermentation process can be supplied to the purification process without going through the above-described separation process when components such as microorganisms have already been removed. The refining step is a step of separating the ethanol-containing liquid obtained in the liquefaction step into a distillate with an increased target ethanol concentration and a bottom product with a decreased target ethanol concentration. The equipment used in the purification process includes, for example, a distillation apparatus, a treatment apparatus including a pervaporation membrane, a treatment apparatus including a zeolite dehydration membrane, a treatment apparatus for removing low boiling point substances with a boiling point lower than that of ethanol, and a treatment apparatus with a boiling point higher than that of ethanol. A processing device for removing substances, a processing device including an ion exchange membrane, and the like can be mentioned. These devices may be used alone or in combination of two or more. Heated distillation or membrane separation may be preferably used as the unit operation.

In the heating distillation, a distillation apparatus can be used to obtain desired ethanol as a distillate with high purity. The temperature in the distiller during distillation of ethanol is not particularly limited, but is preferably 100°C or less, more preferably about 70 to 95°C. By setting the temperature in the distiller to the above range, the separation of ethanol from other components, that is, distillation of ethanol can be carried out more reliably. In particular, after introducing the ethanol-containing liquid obtained in the liquefaction step into a distillation apparatus equipped with a heater using steam of 100 ° C. or higher, and raising the temperature of the bottom of the distillation column to 90 ° C. or higher within 30 minutes. High-purity ethanol can be obtained by introducing the above ethanol-containing liquid from the middle part of the distillation column and performing the distillation process in such a manner that the temperature difference between the bottom part, the middle part, and the top part is within ±15 ° C. . The distillation temperature difference is preferably ±13°C, more preferably ±11°C. With the above distillation temperature difference, separation from other components, that is, ethanol can be distilled more reliably.

The pressure in the distillation apparatus during distillation of ethanol may be normal pressure, but is preferably less than atmospheric pressure, more preferably about 60 to 95 kPa (absolute pressure). By setting the pressure in the distillation apparatus within the above range, it is possible to improve the separation efficiency of ethanol and, in turn, to improve the yield of ethanol. The yield of ethanol (concentration of ethanol contained in the distillate after distillation) is preferably 90% by volume or more, more preferably 95% by volume or more.

In membrane separation, a known separation membrane can be used as appropriate, and for example, a zeolite membrane can be preferably used.

The concentration of ethanol contained in the distillate separated in the purification step is preferably 20% to 99.99% by volume, more preferably 60% to 99.9% by volume.
On the other hand, the concentration of ethanol contained in the bottoms is preferably 0.001% by volume to 10% by volume, more preferably 0.01% by volume to 5% by volume.

The bottoms separated in the refining process are substantially free of nitrogen compounds. In the present invention, "substantially free" does not mean that the concentration of nitrogen compounds is 0 mg / L, but to the extent that the bottoms obtained in the refining process do not require a wastewater treatment process. is the nitrogen compound concentration of In the separation step, instead of purifying the desired ethanol from the ethanol-containing liquid obtained in the microbial fermentation step, the ethanol-containing liquid is separated into a liquid or solid component containing microorganisms and a gas component containing ethanol as described above. separate into At that time, the nitrogen compounds remain on the side of the liquid or solid component containing the microorganisms, so that the gas component containing ethanol contains almost no nitrogen compounds. Therefore, it is considered that the bottoms obtained when purifying ethanol from a liquefied product obtained by liquefying gaseous components does not substantially contain nitrogen compounds. Even when the bottoms contain nitrogen compounds, the concentration of the nitrogen compounds is 0.1 to 200 mg/L, preferably 0.1 to 100 mg/L, more preferably 0.1 to 50 mg/L. be.

Also, for the same reason as above, the bottoms separated in the refining process are substantially free of phosphorus compounds. In addition, "substantially free" does not mean that the concentration of the phosphorus compound is 0 mg / L, but the phosphorus compound to the extent that the bottoms obtained in the purification process does not require a wastewater treatment process. concentration. Even when the bottoms contain the phosphorus compound, the concentration of the phosphorus compound is 0.1 to 100 mg/L, preferably 0.1 to 50 mg/L, more preferably 0.1 to 25 mg/L. be. Thus, according to the method of the present invention, the bottoms discharged in the ethanol refining process do not substantially contain nitrogen compounds or phosphorus compounds, and hardly contain other organic substances. Therefore, it is possible to simplify the wastewater treatment process that has been conventionally required.

<Wastewater treatment process>
The bottoms separated in the refining process may be supplied to the wastewater treatment process. In the wastewater treatment process, organic substances such as nitrogen compounds and phosphorus compounds can be further removed from the bottoms. In this step, organic matter may be removed by subjecting the bottoms to anaerobic treatment or aerobic treatment. The removed organic matter may be used as a fuel (heat source) in the refining process.

The treatment temperature in the waste water treatment step is usually 0 to 90°C, preferably 20 to 40°C, more preferably 30 to 40°C.

Since the liquid or solid components including microorganisms have been removed from the bottoms obtained through the separation process, the bottoms are more suitable for wastewater treatment than the bottoms directly supplied from the microbial fermentation process to the refining process. load is reduced.

In the wastewater treatment process, the nitrogen compound concentration in the treated liquid obtained by treating the bottoms is preferably 0.1 to 30 mg/L, more preferably 0.1 to 20 mg/L, and still more preferably 0.1. ~10 mg/L and no nitrogen compounds are particularly preferred. Further, the phosphorus compound concentration in the treatment liquid is preferably 0.1 to 10 mg/L, more preferably 0.1 to 5 mg/L, and still more preferably 0.1 to 1 mg/L. It is particularly preferred that no phosphorus compounds are included.

<Uses of ethanol>
Ethanol according to the present invention can be used as a raw material for producing various organic compounds. For example, ethanol according to the invention includes 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 ), can be used as a raw material for manufacturing polyurethane (PU), etc. Hereinafter, the method for synthesizing butadiene and the method for producing polyethylene and polyester using ethanol as a raw material of the present invention will be described as an example, but it goes without saying that the method can also be used for other chemical products and polymer raw materials.

<Method for synthesizing butadiene>
Butadiene is mainly produced by refining the C4 fraction by-produced when ethylene is synthesized from petroleum (that is, naphtha cracking), and is a raw material for synthetic rubber. However, in recent years, there has been a strong demand for a technology for converting ethanol not derived from fossil fuels (ethanol derived from microbial fermentation) into 1,3-butadiene instead of raw materials for the chemical industry obtained from petroleum. Known methods for synthesizing butadiene using such ethanol derived from microbial fermentation as a raw material include a method using MgO as a catalyst, a method using a mixture of Al ₂ O ₃ and ZnO, a catalyst having a magnesium silicate structure, and the like. ing. As the catalyst, vanadium, manganese, iron, cobalt, nickel, copper, zinc, gallium, niobium, silver, indium, cerium, etc. are used in addition to those mentioned above.

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

The heating temperature for advancing the conversion reaction is such that the temperature in the reaction system is, for example, 300 to 450°C, preferably 350 to 400°C. If the temperature in the reaction system is lower than the above range, sufficient catalytic activity cannot be obtained, the reaction rate tends to decrease, and the production efficiency tends to decrease. On the other hand, if the temperature in the reaction system exceeds the above range, the catalyst may easily deteriorate.

The reaction can be carried out by a conventional method such as a batch system, a semi-batch system, or a continuous system. When a batch system or a semi-batch system is adopted, the conversion rate of ethanol can be increased, but with the ethanol according to the present invention, even if a continuous system is adopted, ethanol can be converted more efficiently than before. can do. Although the reason for this is not clear, in the ethanol derived from a recyclable resource using a gas containing carbon monoxide and hydrogen as a substrate, as in the present invention, in a gas chromatograph measured by gas chromatograph mass spectrometry, It is thought that this is due to the presence of a unique peak not seen in ethanol.

Examples of methods for bringing the raw material into contact with the catalyst include a suspended bed method, a fluidized bed method, and a fixed bed method. Moreover, either a vapor phase method or a liquid phase method may be used. In view of the ease of recovering and regenerating the catalyst, a fixed-bed gas phase continuous flow reactor is used in which the above catalyst is filled in a reaction tube to form a catalyst layer, and the raw material is circulated as a gas and reacted in the gas phase. It is preferable to use 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 being diluted. may be supplied.

After the ethanol conversion reaction is completed, the reaction product (1,3-butadiene) can be separated and purified by, for example, separation means such as filtration, concentration, distillation and extraction, or a combination of these separation means.

<Polyethylene>
Ethanol according to the present invention can also be suitably used as a raw material for polyethylene, which is widely used as a general-purpose plastic. Conventional polyethylene was produced by synthesizing ethylene from petroleum and polymerizing ethylene monomers. By producing polyethylene using the ethanol of the present invention, it becomes possible to realize an ultimate resource recycling society that does not depend on petroleum resources.

First, ethylene, which is a raw material for polyethylene, is synthesized using ethanol according to the present invention as a raw material. The method for producing ethylene is not particularly limited, and it can be obtained by a conventionally known method. As an example, ethylene can be obtained by a dehydration reaction of ethanol. A catalyst is usually used to obtain ethylene by the dehydration reaction of ethanol, but the catalyst is not particularly limited, and conventionally known catalysts can be used. Advantageous in terms of process is a fixed bed flow reaction in which the catalyst and product can be easily separated, and for example, γ-alumina is preferred.

Since the dehydration reaction is an endothermic reaction, it is usually carried out under heating conditions. Although the heating temperature is not limited as long as the reaction proceeds at a commercially useful reaction rate, a temperature of preferably 100° C. or higher, more preferably 250° C. or higher, and even more preferably 300° C. or higher is suitable. Although the upper limit is not particularly limited, it is preferably 500° C. or lower, more preferably 400° C. or lower from the viewpoint of energy balance and equipment.

The reaction pressure is also not particularly limited, but a pressure equal to or higher than normal pressure is preferable in order to facilitate subsequent gas-liquid separation. Industrially, a fixed bed flow reaction is suitable for easy separation of the catalyst, but a liquid phase suspension bed, a fluidized bed, or the like may also be used.

In the dehydration reaction of ethanol, the yield of the reaction depends on the amount of water contained in ethanol supplied as a raw material. In general, when a dehydration reaction is performed, it is preferable that there is no water, considering the removal efficiency of water. However, in the case of ethanol dehydration using a solid catalyst, the absence of water tends to increase the amount of other olefins, especially butenes. The lower limit of the allowable water content is 0.1% by mass or more, preferably 0.5% by mass or more. Although the upper limit is not particularly limited, it is preferably 50% by mass or less, more preferably 30% by mass or less, and still more preferably 20% by mass or less from the viewpoint of material balance and heat balance.

By carrying out the dehydration reaction of ethanol as described above, a mixed portion of ethylene, water and a small amount of unreacted ethanol is obtained. By separation, ethylene can be obtained by removing water and ethanol. This method may be performed by a known method. Subsequently, the ethylene obtained by the gas-liquid separation is further distilled, and the distillation method, operating temperature, residence time, etc. are not particularly limited except that the operating pressure at this time is normal pressure or higher.

Ethanol derived from a recyclable resource that uses a gas containing carbon monoxide and hydrogen as a substrate, such as the present invention, has a unique There is a peak of Therefore, ethylene obtained from ethanol is considered to contain a very small amount of impurities. Depending on the use of ethylene, these trace amounts of impurities may pose a problem, so they may be removed by refining. The purification method is not particularly limited, and a conventionally known method can be used. A suitable purification operation is, for example, an adsorption purification method. The adsorbent to be used is not particularly limited, and conventionally known adsorbents can be used. For example, caustic water treatment may be used in combination as a method for purifying impurities in ethylene. If caustic water is to be treated, it is desirable to do so before adsorption purification. In that case, after the caustic treatment, it is necessary to apply moisture removal treatment before adsorption purification.

The method for polymerizing the ethylene-containing monomer is not particularly limited, and conventionally known methods can be used. The polymerization temperature and polymerization pressure should be appropriately adjusted according to the polymerization method and polymerization apparatus. The polymerization apparatus is also not particularly limited, and a conventionally known apparatus can be used. An example of a method for polymerizing a monomer containing ethylene is described below.

Polymerization methods for polyolefins, particularly ethylene polymers and copolymers of ethylene and α-olefins, vary depending on the type of polyethylene desired, for example, high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE). ), and linear low-density polyethylene (LLDPE) can be appropriately selected depending on the difference in density and branching. For example, using a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst as a polymerization catalyst, by any method of gas phase polymerization, slurry polymerization, solution polymerization, and high pressure ion polymerization, It is preferable to carry out in one stage or in multiple stages of two or more stages.

The above-mentioned single-site catalyst is a catalyst capable of forming uniform active species, and is usually prepared by contacting a metallocene-based transition metal compound or a non-metallocene-based transition metal compound with an activating cocatalyst. . A single-site catalyst has a more uniform active site structure than a multi-site catalyst, and is therefore preferable because it can polymerize a polymer having a high molecular weight and a highly uniform structure. As the single-site catalyst, it is particularly preferable to use a metallocene-based catalyst. The metallocene catalyst is a catalyst containing a transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton, a cocatalyst, an organometallic compound if necessary, and each catalyst component of a carrier. be.

In the transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton, the cyclopentadienyl skeleton is a cyclopentadienyl group, a substituted cyclopentadienyl group, or the like. The substituted cyclopentadienyl group is one having a substituent such as a hydrocarbon group having 1 to 30 carbon atoms. Examples of transition metals include zirconium, titanium and hafnium, with zirconium and hafnium being particularly preferred. The transition metal compound usually has two ligands having a cyclopentadienyl skeleton, and each ligand having a cyclopentadienyl skeleton is preferably bonded to each other by a bridging group. One or a mixture of two or more of the above transition metal compounds can be used as a catalyst component.

The co-catalyst is one that can make the above-described transition metal compound effective as a polymerization catalyst, or one that can balance the ionic charges in a catalytically activated state. Examples of co-catalysts include benzene-soluble aluminoxanes of organoaluminumoxy compounds, benzene-insoluble organoaluminumoxy compounds, ion-exchange layered silicates, boron compounds, cations containing or not containing active hydrogen groups, and non-coordinating anions. ionic compounds, lanthanide salts such as lanthanum oxide, tin oxide, and phenoxy compounds containing a fluoro group.

The transition metal compound described above may be supported on an inorganic or organic compound carrier before use. As the carrier, porous oxides of inorganic or organic compounds are preferred, and specific examples include ion-exchange layered silicates such as montmorillonite, SiO ₂ , Al ₂ O ₃ , MgO, ZrO ₂ , TiO ₂ and B ₂ O. ₃ , CaO, ZnO, BaO, _ThO2 , etc. or mixtures thereof.

Examples of organometallic compounds that are used as necessary include organoaluminum compounds, organomagnesium compounds, and organozinc compounds. Of these, organic aluminum is preferably used.

As the polyolefin, an ethylene polymer or an ethylene/α-olefin copolymer may be used alone, or two or more of them may be mixed and used.

<acetaldehyde>
Acetaldehyde is an important chemical as an industrial raw material. Acetaldehyde is useful, for example, as a raw material for acetic acid and ethyl acetate.

Acetaldehyde can be produced by oxidizing ethanol by a conventionally known method. For example, ethanol can be oxidized by chlorine to produce acetaldehyde. Chlorine is usually reacted with ethanol in the gaseous state. Chlorine may be supplied at a concentration of approximately 100%, or diluted with an inert gas (eg, nitrogen, helium, neon, argon, etc.). In this case, the degree of dilution is 50% by weight or less, preferably 25% by weight or less, in consideration of reaction efficiency. Ethanol and chlorine are preferably reacted at a supply rate of 25 to 100 sccm with respect to 100 g of an ethanol aqueous solution, for example.

The oxidation of ethanol with chlorine is preferably carried out using chlorine gas, hydrogen chloride, phosphorus pentachloride, phosphorus trichloride, phosphorus oxychloride, thionyl chloride, and chlorine-containing compounds such as hypochlorous acid compounds. This oxidation can be achieved by, for example, photoreaction, thermal reaction, catalytic reaction, or the like. Among these, photochlorination of ethanol with chlorine gas and oxidation by thermal chlorination are preferred, and oxidation by photochlorination with chlorine gas is more preferred. Examples of the photoreaction include a method of irradiating with light of various wavelengths such as ultraviolet rays and visible light. Among these, it is preferable to irradiate light from a light source having a wavelength of about 300 to 500 nm to cause the reaction. . The light source is not particularly limited, and fluorescent lamps, mercury lamps, halogen lamps, xenon lamps, metal halide lamps, excimer lamps, LED lamps, and the like can be used. A suitable reaction temperature is about 0 to 80°C, preferably about 0 to 50°C. A suitable reaction time is about 1 to 5 hours.

As another example, ethanol can be oxidized in the gas phase in the presence of molecular oxygen and a catalyst to produce acetaldehyde. As such a catalyst, for example, a base metal oxide in which fine gold particles are dispersed and fixed can be used. Examples of base metal oxides include La ₂ O ₃ , MoO ₃ , Bi ₂ O ₃ , SrO, Y ₂ O ₃ , MgO, BaO, WO ₃ , CuO, and composite oxides containing one or more thereof.

The oxidation reaction of ethanol is carried out by bringing a gas containing ethanol and oxygen molecules into contact with the catalyst at, for example, 100-280.degree. Oxygen molecules used for the reaction may be supplied as oxygen gas, or air may be used. Further, the raw material gas, which is the gas, may contain a diluent gas (carrier gas) if necessary. The apparatus used for the reaction at this time may be a general apparatus that is usually used for gas phase reactions. For example, a catalyst is filled in a reaction tube, and a gas containing ethanol and oxygen gas or air is fed into the reaction tube in a state where the reaction tube is heated to a predetermined temperature, and these raw material gases are brought into contact with the catalyst, and the reaction gas is This is done by collecting The reaction pressure may be normal pressure, and if necessary, about 0.5 to 5 Pa (atmospheric pressure) may be increased. As the diluent gas, so-called inert gas such as nitrogen, argon, helium, carbon dioxide is used. The amount of diluent gas to be used may be appropriately determined in consideration of the composition, flow rate, reaction heat, etc. of the raw material gas, but it is usually preferably 1 to 100 times the volume of ethanol.

The ratio of ethanol and oxygen molecules (oxygen gas) supplied to the reaction tube is not particularly limited, but is usually 0.5 to 100% by volume of oxygen gas or oxygen gas in the air with respect to ethanol, It is preferably 1 to 10% by volume, more preferably 2 to 5% by volume. The amount of the catalyst to be used is not particularly limited, either, but if the inner diameter of the reaction tube is 6 to 10 mm, it may generally be about 0.1 to 1.0 g. Practically, it is preferable to use an amount that gives a space velocity (SV) in the range of about 10,000 to 40,000 hr ⁻¹ ·ml·g _cat ⁻¹ in relation to the gas flow rate.

Furthermore, acetaldehyde can also be produced by dehydrogenating ethanol in the presence of a catalyst. As such a catalyst, for example, a solid catalyst containing copper as an active species can be used. Copper as an active species may be in any form as long as it has the activity of converting ethanol into acetaldehyde. , inorganic acid salts such as copper carbonate; organic acid salts such as copper salts of carboxylic acids, etc.). The solid catalyst should just contain at least 1 type selected from such an elemental copper and a copper compound. Copper as the active species is preferably in the form of metallic copper. Moreover, copper may be used as it is in the form of metallic copper or a copper compound, or may be used in the form of being supported on a carrier. Note that copper as an active species may act as a main catalyst of the solid catalyst, and may be used in combination with a co-catalyst or the like. Moreover, the solid catalyst may be in a form in which both copper and co-catalyst are supported on a carrier.

The dehydrogenation reaction may be a liquid phase reaction as long as the ethanol can be brought into contact with the solid catalyst, but it is often a gas phase reaction in which gaseous ethanol and the solid catalyst are brought into contact with each other in the gas phase. From the viewpoint of the equilibrium relationship between ethanol and acetaldehyde, catalyst life, etc., the temperature may be about 150 to 350°C, preferably 170 to 300°C, more preferably about 200 to 280°C. The higher the reaction temperature, the more the equilibrium shifts to the acetaldehyde side, so the conversion rate can be improved. Although the reaction may be carried out under pressure, it may be carried out under normal pressure for convenience. Moreover, it can be carried out under reduced pressure because it is advantageous for the ethanol conversion rate.

<acetic acid>
Acetic acid is an important chemical as an industrial raw material. Acetic acid is useful, for example, as a starting material for vinyl acetate monomers, acetic anhydride, acetic acid esters, and the like.

Acetic acid can be produced by oxidation of acetaldehyde by a conventionally known method. For example, acetic acid can be produced by air oxidation of acetaldehyde in the presence of a catalyst. Catalysts include manganese acetate and cobalt acetate.

<Ethyl-t-butyl ether>
Ethyl-t-butyl ether (ETBE) is an important chemical as an industrial raw material. ETBE is useful, for example, as an alternative fuel to gasoline, particularly as a high-octane fuel.

ETBE can be synthesized from ethanol and isobutene by a conventionally known method. For example, it can be produced by reacting ethanol and isobutene in the presence of a reaction catalyst. The molar ratio of isobutene to the raw material ethanol is preferably 0.1 to 10 mol, more preferably 0.5 to 2 mol.

A cation exchange resin is preferably used as the reaction catalyst, and a strongly acidic cation exchange resin is more preferably used. As such a strongly acidic cation exchange resin, a porous type (MR type) styrenic resin into which a strong acid group such as a sulfonic acid group (--SO ₃ H) is introduced as an ion exchange group is preferable. The particle size of the strongly acidic cation exchange resin is preferably 0.5 to 1.0 mm. The amount of the reaction catalyst to be used is preferably 1 to 90 g, more preferably 1 to 90 g, even more preferably 4 to 9 g, relative to 1 mol of ethanol.

In addition, the method of using the reaction catalyst is not particularly limited, and it can be used in the reaction in the form of a fixed bed, a fluidized bed, or a suspended bed. The form of reaction between isobutene and ethanol is not particularly limited, but it is preferable to use a pressurized gas-liquid mixed phase reaction system in which ethanol can maintain a liquid phase. In this case, the yield of ETBE obtained is further improved.

<Ester>
A wide variety of esters can be synthesized by reacting ethanol with various carboxylic acids. For example, ethyl benzoate can be obtained from ethanol and benzoic acid, and diethylene glycol, which is a raw material for polyester, can also be obtained from ethanol via ethylene. By producing polyethylene using the ethanol of the present invention, it becomes possible to realize an ultimate resource recycling society that does not depend on petroleum resources.

Polyester is composed of diol units and dicarboxylic acid units, and is obtained by a polycondensation reaction using ethylene glycol as the diol unit and terephthalic acid and isophthalic acid as the dicarboxylic acid unit. Ethylene glycol is obtained from the ethanol of the present invention. For example, ethylene glycol can be obtained by a method of producing ethylene glycol via ethylene oxide from ethanol by a conventionally known method.

As dicarboxylic acids, aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and derivatives thereof can be used without limitation. Examples of aromatic dicarboxylic acids include terephthalic acid and isophthalic acid. Examples of derivatives of aromatic dicarboxylic acids include lower alkyl esters of aromatic dicarboxylic acids, specifically methyl esters, ethyl esters, propyl esters and butyl esters. Ester etc. are mentioned. Among these, terephthalic acid is preferred, and dimethyl terephthalate is preferred as the aromatic dicarboxylic acid derivative. Further, as the aliphatic dicarboxylic acid, specifically, oxalic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dodecanedioic acid, dimer acid, cyclohexanedicarboxylic acid and the like usually having 2 to 40 carbon atoms. Chain or alicyclic dicarboxylic acids can be mentioned. In addition, derivatives of aliphatic dicarboxylic acids include lower alkyl esters such as methyl esters, ethyl esters, propyl esters and butyl esters of the above aliphatic dicarboxylic acids, and cyclic acid anhydrides of the above aliphatic dicarboxylic acids such as succinic anhydride. is mentioned. Among these, adipic acid, succinic acid, dimer acid, or mixtures thereof are preferred, and those containing succinic acid as the main component are particularly preferred. More preferred derivatives of aliphatic dicarboxylic acids are methyl esters of adipic acid and succinic acid, or mixtures thereof.

The polyester can be obtained by a conventionally known method of polycondensing the above diol units and dicarboxylic acid units. Specifically, after performing the esterification reaction and / or transesterification reaction of the dicarboxylic acid component and the diol component, a general method of melt polymerization such as performing a polycondensation reaction under reduced pressure, or an organic solvent can be produced by a known solution heating dehydration condensation method using

The polycondensation reaction is preferably carried out in the presence of a polymerization catalyst, and examples of the polymerization catalyst include titanium compounds, zirconium compounds and germanium compounds.

The reaction temperature for the esterification reaction and/or transesterification reaction between the dicarboxylic acid component and the diol component is usually in the range of 150 to 260° C., and the reaction atmosphere is usually an atmosphere of an inert gas such as nitrogen or argon. .

In the polycondensation reaction step, a chain extender (coupling agent) may be added to the reaction system. After completion of the polycondensation, the chain extender is added to the reaction system in a uniformly molten state without a solvent, and reacted with the polyester obtained by the polycondensation.

After solidifying the obtained polyester, if necessary, solid state polymerization may be carried out in order to further increase the degree of polymerization or to remove oligomers such as cyclic trimers.

In the production process of polyester, various additives may be added as long as the properties are not impaired. Weather stabilizers, antistatic agents, friction reducers, mold release agents, antioxidants, ion exchange agents, color pigments, and the like can be added.

The ethanol according to the present invention is not limited to the above-mentioned polymers, and can be used as a raw material for various other polymers, and the resulting molded articles of the polymer are carbon-neutral materials. It becomes possible to realize a resource recycling society.

<Products containing ethanol>
Ethanol according to the present invention can be used not only as a raw material for polymers as described above, but also for various products. Examples of products include cosmetics, perfume, fuel, antifreeze, disinfectant, disinfectant, cleaning agent, mold remover, detergent, hair wash, soap, antiperspirant, facial cleansing sheet, solvent, paint, adhesive, diluent. , chemical products such as food additives. By using it for these uses, it is possible to exhibit an appropriate effect according to the use.

<Fuel>
Ethanol according to the present invention can also be used as a raw material for fuels (eg, jet fuel, kerosene, diesel oil, gasoline). Since ethanol has a high sterilizing ability, it can also function as a sterilant to prevent the growth of bacteria and the like in fuel systems such as engines and piping.

The Society of Automotive Engineers of Japan standard (2006) stipulates that the concentration of ethanol in fuel ethanol is 99.5% by volume or more. In other countries as well (eg India) the concentration of ethanol in fuel ethanol is stipulated to be at least 99.5% by volume. Therefore, ethanol with a purity of 99.5 to 99.9% by volume can be suitably used for ethanol vehicles. In addition, since fuel ethanol can be used for applications other than ethanol-only vehicles, ethanol with a purity of 99.5 to 99.9% by volume has particularly high versatility.

Ethanol according to the invention can also be mixed with gasoline and used as ethanol-blended gasoline. Environmental load can be reduced by using ethanol mixed gasoline. Ethanol used in the ethanol-blended gasoline has a purity of 92.0% by volume or more, preferably 95.0% by volume or more, and more preferably 99.5% by volume or more.

The content of ethanol in the ethanol-blended gasoline is preferably 1% by volume or more and 15% by volume or less, more preferably 2% by volume or more and 12% by volume or less, and still more preferably 3% by volume or more and 10% by volume or less. . If the content of ethanol is 1% by volume or more, the advantage of increasing the octane value due to ethanol blending can be obtained, and if it is 15% by volume or less, the azeotropic phenomenon with other gasoline base materials will significantly change the evaporation characteristics. Therefore, proper drivability of a gasoline vehicle can be ensured.

The water content in the ethanol-blended gasoline is preferably 0.01% by mass or more and 0.9% by mass or less, more preferably 0.01% by mass or more and 0.7% by mass or less. The lower limit of the water content depends on the saturated water content of the gasoline base material and the water content in ethanol, but is substantially about 0.01% by mass. When the upper limit is 0.9% by mass or less, phase separation can be prevented, and even when phase separation occurs, the gasoline layer enables proper operation of the gasoline engine. The water content can be measured according to "Crude oil and petroleum products-Moisture test method" described in JIS K 2275, for example, Karl Fischer coulometric titration can be used.

As the gasoline base material, any commonly used gasoline base material can be used without particular limitation. Gasoline base materials include, for example, light naphtha obtained by atmospheric distillation of crude oil, preferably desulfurized light naphtha obtained by desulfurizing it, catalytically reformed gasoline obtained by catalytically reforming heavy naphtha after desulfurization, and Debenzene catalytically reformed gasoline, debenzene light catalytically reformed gasoline, debenzene heavy catalytically reformed gasoline, mixtures thereof, cracked gasoline obtained by catalytic cracking or hydrocracking, etc. , light cracked gasoline, heavy cracked gasoline, mixtures thereof, and isomerized gasoline obtained by isomerizing light naphtha.

Furthermore, the ethanol-based ETBE according to the invention can be mixed with gasoline and used as an ETBE-blended gasoline. By using ETBE blended gasoline, the environmental load can be reduced. The ETBE content of the ETBE-blended gasoline is preferably 1% to 15% by volume, more preferably 2% to 12% by volume, and still more preferably 3% to 10% by volume. If the content of ETBE is 1% by volume or more, the advantage of increasing the octane value due to ETBE blending is obtained, and if it is 15% by volume or less, the azeotropic phenomenon with other gasoline base materials will significantly change the evaporation characteristics. Therefore, proper drivability of a gasoline vehicle can be ensured.

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples as long as the gist of the present invention is not exceeded.

<Ethanol component evaluation method>
In the following examples and comparative examples, the content of chromium in ethanol was measured using an inductively coupled plasma mass spectrometer (ICP-MS) ELAN DRC II manufactured by PerkinElmer.

<How to quantify butadiene>
Quantitative evaluation of butadiene was performed by analysis using a gas chromatograph (GC-2014, manufactured by SHIMADZU). 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, 11.5 minutes → 10°C/minute → 100°C, 14.5 minutes → 10°C/minute → 250°C
Sampling time: 5 minutes Carrier gas: He (30 cm/s)
Split ratio: 75

<Ethyl benzoate quantitative method>
Quantitative evaluation of ethyl benzoate was performed by analysis using a gas chromatography device. The measurement conditions were as follows.
<Analysis conditions for GC/MS method>
Column: DB-1 (length 30.0 m, inner diameter 0.254 mm, film thickness 0.25 m)
Temperature rising conditions: 30°C-300°C 15°C/min
Carrier gas: He 100 kPa
Split ratio: 50

<Combustion efficiency quantification method>
Quantitative evaluation of the combustion efficiency of ethanol was performed by total calorific value analysis using a cone calorimeter manufactured by FTT.

[Example 1]
<Preparation of ethanol>
Ethanol was produced as follows.
(Raw material gas generation process)
The gas discharged after burning general waste in a garbage incineration facility was used. The components of the source gas were about 30% by volume carbon monoxide, about 30% by volume carbon dioxide, about 30% by volume hydrogen and about 10% by volume nitrogen.

(Syngas refining process)
The raw material gas produced above was heated to 80° C. using a PSA device, which is an impurity removal device, to reduce the carbon dioxide contained in the synthesis gas to the original content. (About 30% by volume) was removed to 60 to 80% by volume, and then the temperature of the gas was raised and cooling water was used at 25°C in a double-tube heat exchanger using steam at 150°C. A synthesis gas was produced by re-cooling using a double-tube heat exchanger, precipitating impurities, and removing the precipitated impurities with a filter.

(Microbial fermentation process)
An inoculum of Clostridium autoethanogenum (microorganism) equipped with a main reactor, a synthesis gas supply hole, and a discharge hole, and a liquid medium for culturing the fungus (containing appropriate amounts of phosphorus compounds, nitrogen compounds, various minerals, etc.) The synthetic gas obtained as described above was continuously supplied to the filled continuous fermentation apparatus (microbial fermenter), and culture (microbial fermentation) was continuously performed for 300 hours. After that, about 8000 L of culture solution containing ethanol was extracted from the discharge hole.

(Separation process)
An ethanol-containing liquid was obtained from the culture solution obtained in the above fermentation step using a solid-liquid separation filter device under conditions of a culture solution introduction pressure of 200 kPa or more.

(Distillation process)
Subsequently, the ethanol-containing liquid was introduced into a distillation apparatus equipped with a heater using steam at 170°C. After raising the temperature of the bottom of the distillation column to 101°C within 8 to 15 minutes, the ethanol-containing liquid is introduced from the middle of the distillation column. The top of the head was continuously operated at 91° C. and 15 seconds/L to obtain purified ethanol. The content of chromium in the obtained ethanol was less than 0.5 mg/L.

(Method for producing butadiene)
Butadiene was produced using the ethanol obtained as described above. First, in order to use the obtained ethanol as a gas for the reaction, the ethanol was passed through a single tube heated to 90° C. and vaporized, and the vaporized ethanol gas was combined with nitrogen. At this time, by controlling the flow rate of ethanol gas at SV360L/hr/L and nitrogen at SV840L/hr/L by mass flow, a mixture of 30% by volume of ethanol (converted to gas) and 70% by volume of nitrogen (converted to gas) was obtained. A mixed gas was used. Subsequently, a 1/2 inch (1.27 cm) diameter, 15.7 inch (40 cm) long stainless steel cylinder was filled with 0.85 g of a butadiene synthesis catalyst based on Hf, Zn and Ce. While maintaining the temperature of the reaction tube at 350° C. and the pressure (reaction bed pressure) at 0.1 MPa, the mixed gas was continuously supplied to obtain a butadiene-containing gas. The content of butadiene in the resulting butadiene-containing gas was quantified using a gas chromatograph of GC-2014 (manufactured by SHIMADZU). The results were as shown in Table 1.

[Comparative Example 1]
Butadiene was produced in the same manner as in Example 1 using 99-degree ethanol (manufactured by Amakusu Kagaku Sangyo Co., Ltd.), which is fossil fuel-derived ethanol, and the content of butadiene was quantified in the same manner as in Example 1. The results were as shown in Table 1. The content of chromium in 99-degree ethanol, which is fossil fuel-derived ethanol, was 0.7 mg/L.

[Comparative Example 2]
Butadiene was produced in the same manner as in Example 1 using 99° ethanol (manufactured by Amakusu Kagaku Sangyo Co., Ltd.) derived from saccharification and fermentation of plants, and the content of butadiene was quantified in the same manner as in Example 1. The results were as shown in Table 1. The content of chromium in 99° ethanol derived from saccharification and fermentation of plants was 0.7 mg/L.

As shown in Table 1, the ethanol produced using the gas emitted after burning general waste in a garbage incineration facility is more efficient than conventional ethanol derived from fossil fuels and ethanol derived from saccharification fermentation from plants. , the conversion efficiency to butadiene was found to be high.

[Example 2]
(Production of ethyl benzoate)
Using the same ethanol as the ethanol used in Example 1, ethyl benzoate was produced as follows. First, 36.8 g of benzoic acid and 200 ml of ethanol were mixed under an argon stream, 9 ml of concentrated sulfuric acid was added, and the mixture was stirred for 5 hours while refluxing. Thereafter, the mixture was allowed to cool to room temperature, unreacted ethanol was removed under reduced pressure, and ethyl benzoate synthesized with 100 ml of diethyl ether was recovered. The recovered liquid was washed with distilled water, dried with magnesium sulfide, filtered and concentrated.
The obtained filtrate was subjected to component analysis using a gas chromatograph to quantify the amount of ethyl benzoate synthesized. The analysis conditions at that time are shown below. The analysis results were as shown in Table 2.
Column: DB-1 (length 30.0 m, inner diameter 0.254 mm, film thickness 0.25 m)
Temperature rising conditions: 30-300°C 15°C/min
Carrier gas: He 100 kPa
Split ratio: 50

[Comparative Example 3]
Ethyl benzoate was produced and quantified in the same manner as in Example 2 except that the petrochemical-derived ethanol used in Comparative Example 1 was used. The analysis results were as shown in Table 2.

[Comparative Example 4]
Ethyl benzoate was produced and quantified in the same manner as in Example 2 except that the petrochemical-derived ethanol used in Comparative Example 2 was used. The analysis results were as shown in Table 2.

As shown in Table 2, the ethanol produced using the gas emitted after burning general waste at the garbage incineration facility is more efficient than conventional ethanol derived from fossil fuels and ethanol derived from saccharification fermentation from plants. , the conversion efficiency to ethyl benzoate was found to be high.

[Example 3]
Using the same ethanol as the ethanol used in Example 1, the ethanol combustion efficiency was quantified. Fuel efficiency is measured under non-heated conditions by adding 30 g of ethanol to a heat-resistant container of length 60 mm x width 60 mm x height 30 mm, igniting it, and burning it completely in a cone calorimeter (manufactured by FTT). It was quantified by measuring the oxygen loss and calculating the total calorific value based on the oxygen loss. The quantitative results were as shown in Table 3.

[Comparative Example 5]
The ethanol combustion efficiency was quantified in the same manner as in Example 3, except that the ethanol used in Comparative Example 1 was used. The quantitative results were as shown in Table 3.

[Comparative Example 6]
The combustion efficiency of ethanol was quantified in the same manner as in Example 3, except that the ethanol used in Comparative Example 2 was used. The quantitative results were as shown in Table 3.

As shown in Table 3, the ethanol produced using the gas emitted after burning general waste at the garbage incineration facility is more efficient than conventional ethanol derived from fossil fuels and ethanol derived from saccharification and fermentation from plants. was found to have high combustion efficiency.

Claims (13)

A step of gasifying waste as a carbon source to produce a raw material gas containing carbon monoxide, carbon dioxide, hydrogen and nitrogen; and purifying the raw material gas using a pressure swing adsorption type separator. , a step of obtaining a synthesis gas containing carbon monoxide, carbon dioxide, hydrogen and nitrogen, and a step of microbial fermentation of supplying the synthesis gas to a fermenter containing Clostridium as microorganisms to obtain an ethanol-containing liquid by microbial fermentation; a separation step of separating the ethanol-containing liquid into a liquid or solid component containing microorganisms and a gas component containing ethanol; a liquefaction step of condensing and liquefying the gas component; Ethanol obtained by a method comprising a purification step of purifying ethanol,
Ethanol having a chromium content of 0.6 mg/L or less. gasifying waste as a carbon source to produce a feedstock gas comprising carbon monoxide, carbon dioxide, hydrogen and nitrogen;
a step of purifying the raw material gas using a pressure swing adsorption type separator to obtain a synthesis gas containing carbon monoxide, carbon dioxide, hydrogen and nitrogen;
a microbial fermentation step of supplying the synthesis gas to a fermenter containing Clostridium as a microorganism to obtain an ethanol-containing liquid by microbial fermentation;
a separation step of separating the ethanol-containing liquid into a liquid or solid component containing microorganisms and a gas component containing ethanol;
a liquefying step of condensing and liquefying the gas component;
a purification step of purifying ethanol from the liquid obtained in the liquefaction step;
including
A method for producing ethanol, wherein the purified ethanol has a chromium content of 0.6 mg/L or less. For the total concentration of carbon monoxide, carbon dioxide, hydrogen and nitrogen in said synthesis gas,
The carbon monoxide concentration is 20% by volume or more and 50% by volume or less,
The concentration of carbon dioxide is 0.1% by volume or more and 40% by volume or less,
The hydrogen concentration is 10% by volume or more and 55% by volume or less,
3. The method for producing ethanol according to claim 2, wherein the nitrogen concentration is 1% by volume or more and 40% by volume or less. 4. The method for producing ethanol according to claim 2, wherein the pressure swing adsorption type separator is used to reduce the carbon dioxide concentration in the source gas. The ethanol according to claim 1 , which is for chemical products. 2. The ethanol of claim 1 , which is used as a fuel. 2. Ethanol according to claim 1 , which is used as a raw material for polymers. A chemical product using the ethanol according to claim 1 as a raw material. A fuel comprising the ethanol according to claim 1 and/or the ethanol-derived ethyl-t-butyl ether according to claim 1 . A polymer raw material using the ethanol according to claim 1 as a raw material. 11. The polymer feedstock of claim 10 selected from the group consisting of ethylene, propylene, butadiene, ethyl acetate, isobutene, methyl (meth)acrylate, acrylic acid, aminohexanoic acid, and diethyl carbonate. 12. The ethanol-based polymer of claim 10 or 11 . A molded article comprising the polymer of claim 12 .