WO2020213701A1 - Methane fermentation method, methane fermentation system, waste material recycling method, and waste material recycling system - Google Patents
Methane fermentation method, methane fermentation system, waste material recycling method, and waste material recycling system Download PDFInfo
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- WO2020213701A1 WO2020213701A1 PCT/JP2020/016795 JP2020016795W WO2020213701A1 WO 2020213701 A1 WO2020213701 A1 WO 2020213701A1 JP 2020016795 W JP2020016795 W JP 2020016795W WO 2020213701 A1 WO2020213701 A1 WO 2020213701A1
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- containing liquid
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- alkyl ester
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/02—Biological treatment
- C02F11/04—Anaerobic treatment; Production of methane by such processes
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- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
- C12P5/00—Preparation of hydrocarbons or halogenated hydrocarbons
- C12P5/02—Preparation of hydrocarbons or halogenated hydrocarbons acyclic
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E50/00—Technologies for the production of fuel of non-fossil origin
- Y02E50/30—Fuel from waste, e.g. synthetic alcohol or diesel
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/54—Improvements relating to the production of bulk chemicals using solvents, e.g. supercritical solvents or ionic liquids
Definitions
- the present invention relates to a methane fermentation method, and in particular, a by-product containing glycerin (also referred to as “waste glycerin” in the present specification) obtained in the process of producing biodiesel fuel, a soap factory, an oil / fat factory, and a cosmetics factory.
- a by-product containing glycerin also referred to as “waste glycerin” in the present specification
- Efficient biogas containing methane from glycerin-containing waste produced by-products in processing processes using fats and oils as raw materials in pharmaceutical factories, waste cooking oil, high acid value oil, and other fatty acid glycerin ester-containing waste. It relates to a well-produced methane fermentation method.
- the present invention also relates to a methane fermentation system capable of realizing the above-mentioned methane fermentation method, a waste recycling method and a recycling system containing at least one of glycerin and a fatty acid glycerin ester.
- Examples of methods for industrially producing free fatty acids from fats and oils include high-temperature and high-pressure decomposition methods, enzymatic decomposition methods, etc., all of which hydrolyze fats and oils derived from animals and plants to liberate fatty acids. .. Even in such hydrolysis, a by-product containing glycerin is produced.
- Waste containing glycerin contains a large amount of impurities such as catalysts and unreacted fats and oils. Therefore, although glycerin itself has a use as a raw material for pharmaceuticals and cosmetics, the above-mentioned glycerin-containing waste must be purified at a great cost in order to be used as a raw material for pharmaceuticals and cosmetics. , Was not practical. Therefore, glycerin-containing waste was often disposed of as industrial waste.
- oils and fats such as edible oils deteriorate, they become hydrolyzed or the carbon chains are broken and further oxidized, resulting in oils with high acid value (high acid value oil). Further, in the deoxidizing step in the refining of vegetable oils and fats, oil slag is separated from the oils and fats (crude oil). These high acid oils and slags are wastes containing fatty acid glycerin esters.
- Japanese Unexamined Patent Publication No. 2007-098239 Japanese Patent No. 5036938 JP-A-2010-193767 Japanese Unexamined Patent Publication No. 2006-348191 Japanese Unexamined Patent Publication No. 2012-39912 Japanese Unexamined Patent Publication No. 2005-279411 Japanese Unexamined Patent Publication No. 2012-039975
- Patent Documents 2 to 6 merely use the glycerin-containing waste as an auxiliary raw material, and are still insufficient from the viewpoint of effective utilization of the glycerin-containing waste. Further, also in the method disclosed in Patent Document 7, the glycerin-containing waste is only used for solubilizing the raw material. On the other hand, in the method disclosed in Patent Document 8, sugar must be added to waste glycerin in order to promote methane fermentation, which is not yet sufficient from the viewpoint of production cost and practical use.
- the present invention has been made in view of the above problems, and is a methane fermentation method for efficiently producing biogas containing methane from a raw material containing waste containing glycerin and waste containing fatty acid glycerin ester.
- the purpose is to provide.
- the present inventor adjusts the raw material containing at least one of glycerin and fatty acid glycerin ester to an appropriate pH, separates and removes oil from the raw material, and performs this separation and removal step. They have found that methane-containing biogas can be efficiently produced by performing methane fermentation using the obtained glycerin-containing liquid, and have completed the present invention. Specifically, the present invention is as follows.
- a methane fermentation method for producing biogas containing methane from a raw material containing at least one of glycerin and a fatty acid glycerin ester The first separation step of mixing the raw material and the inorganic acid to separate the first oil and the first glycerin-containing liquid, A neutralization step of neutralizing the first glycerin-containing liquid with an alkaline substance, and A second separation step of separating the second oil and the precipitated inorganic salt from the neutralized first glycerin-containing liquid to obtain a second glycerin-containing liquid.
- auxiliary raw material containing nitrogen and / or phosphorus is charged into the methane fermentation tank in addition to the second glycerin-containing liquid.
- the methane fermentation method according to item 1.
- the auxiliary raw material is one or more selected from the group consisting of food waste, livestock manure, phosphoric acid, phosphate, ammonia, and ammonium salt [5].
- the described methane fermentation method [7] The auxiliary raw material is added so that the total nitrogen (TN) concentration of the digested sludge in the methane fermentation tank is 100 to 10,000 mg / L [5] or [6]. ]
- the second glycerin-containing liquid is characterized in that the supply amount of the second glycerin-containing liquid to the methane fermentation step is adjusted according to the demand for applications other than methane fermentation [1] to [1] to [ The methane fermentation method according to any one of 8].
- a method other than the alkali catalyst method which is selected from the group consisting of an acid catalyst method, an acid alkali catalyst method, a biocatalyst method, an ion exchange resin method, a supercritical method, a subcritical method and a solid catalyst method. It comprises an esterification step of producing a fatty acid alkyl ester by one method.
- the esterification step is characterized in that the first oil separated in the first separation step and / or the second oil separated in the second separation step is used as a raw material [1].
- the methane fermentation method according to any one of [9].
- the supply amount of the second glycerin-containing liquid to the methane fermentation step is adjusted according to the demand for applications other than methane fermentation of the second glycerin-containing liquid, and the demand for the fatty acid alkyl ester is met.
- the methane fermentation method according to [11] wherein the supply amount of the fatty acid alkyl ester to the power generation step is adjusted accordingly.
- a methane fermentation system for producing biogas containing methane from a raw material containing at least one of glycerin and a fatty acid glycerin ester.
- a first separation device that mixes the raw material and an inorganic acid to separate the first oil and the first glycerin-containing liquid.
- a neutralizer that neutralizes the first glycerin-containing liquid with an alkaline substance,
- a second separation device that separates the second oil and the precipitated inorganic salt from the neutralized first glycerin-containing liquid to obtain a second glycerin-containing liquid.
- a methane fermentation apparatus that performs methane fermentation using the second glycerin-containing liquid, and A methane fermentation system characterized by being equipped with.
- a glycerin storage tank for storing the second glycerin-containing liquid is provided after the second separation device.
- the glycerin storage tank includes a detector that detects the amount of the second glycerin-containing liquid stored.
- a method other than the alkali catalyst method which is selected from the group consisting of an acid catalyst method, an acid alkali catalyst method, a biocatalyst method, an ion exchange resin method, a supercritical method, a subcritical method and a solid catalyst method.
- Esterifying equipment for producing fatty acid alkyl esters by one method The first oil separated in the first separation step and / or the second oil separated in the second separation step is supplied to the esterification apparatus as a raw material [13]. ] Or [14].
- the methane fermentation system [16]
- a fatty acid alkyl ester storage tank for storing the fatty acid alkyl ester is provided after the esterification device.
- a power generation device that generates electricity using the fatty acid alkyl ester is provided after the fatty acid alkyl ester storage tank.
- the fatty acid alkyl ester storage tank includes a detector that detects the amount of the stored fatty acid alkyl ester.
- a method for reusing waste containing at least one of glycerin and fatty acid glycerin ester The first separation step of mixing the waste and the inorganic acid to separate the first oil and the first glycerin-containing liquid, A neutralization step of neutralizing the first glycerin-containing liquid with an alkaline substance, and A second separation step of separating the second oil and the precipitated inorganic salt from the neutralized first glycerin-containing liquid to obtain a second glycerin-containing liquid.
- a method other than the alkali catalyst method which is selected from the group consisting of an acid catalyst method, an acid alkali catalyst method, a biocatalyst method, an ion exchange resin method, a supercritical method, a subcritical method and a solid catalyst method. It comprises an esterification step of producing a fatty acid alkyl ester by one method.
- the esterification step is characterized in that the first oil separated in the first separation step and / or the second oil separated in the second separation step is used as a raw material [17].
- a power generation step of generating electricity using at least a part of the fatty acid alkyl ester obtained in the esterification step is provided.
- the supply amount of the second glycerin-containing liquid to the methane fermentation step is adjusted according to the demand for applications other than methane fermentation of the second glycerin-containing liquid, and the fatty acid alkyl ester is used according to the demand.
- the waste recycling method according to [19] wherein the supply amount of the fatty acid alkyl ester to the power generation step is adjusted.
- a system for reusing waste containing at least one of glycerin and fatty acid glycerin ester A first separation device that mixes the waste with an inorganic acid and separates the first oil and the first glycerin-containing liquid.
- a neutralizer that neutralizes the first glycerin-containing liquid with an alkaline substance,
- a second separation device that separates the second oil and the precipitated inorganic salt from the neutralized first glycerin-containing liquid to obtain a second glycerin-containing liquid.
- a methane fermentation apparatus that performs methane fermentation using the second glycerin-containing liquid, and A waste recycling system characterized by being equipped with.
- a glycerin storage tank for storing the second glycerin-containing liquid is provided after the second separation device.
- the glycerin storage tank includes a detector that detects the amount of the stored second glycerin-containing liquid.
- the waste reuse according to [21], wherein the second glycerin-containing liquid is supplied to the methane fermentation apparatus when the amount of the second glycerin-containing liquid exceeds a predetermined amount. system.
- a method other than the alkali catalyst method which is selected from the group consisting of an acid catalyst method, an acid alkali catalyst method, a biocatalyst method, an ion exchange resin method, a supercritical method, a subcritical method and a solid catalyst method.
- Esterifying equipment for producing fatty acid alkyl esters by one method The first oil separated in the first separation step and / or the second oil separated in the second separation step is supplied to the esterification apparatus as a raw material [21]. ] Or [22].
- the waste recycling system [24] A fatty acid alkyl ester storage tank for storing the fatty acid alkyl ester is provided after the esterification device. A power generation device that generates electricity using the fatty acid alkyl ester is provided after the fatty acid alkyl ester storage tank.
- the fatty acid alkyl ester storage tank includes a detector that detects the amount of the stored fatty acid alkyl ester.
- the waste recycling system according to [23], wherein the fatty acid alkyl ester is supplied to the power generation device when the amount of the fatty acid alkyl ester exceeds a predetermined amount.
- biogas containing methane can be efficiently produced from glycerin-containing waste and fatty acid glycerin ester-containing waste.
- the recovery rate of methane from glycerin-containing waste is dramatically increased as compared with the conventional method.
- the methane fermentation method is a method for producing a biogas containing methane from a raw material containing at least one of glycerin and a fatty acid glycerin ester, in which the raw material and an inorganic acid are mixed. From the first separation step of separating the first oil and the first glycerin-containing liquid; and the neutralization step of neutralizing the first glycerin-containing liquid with an alkaline substance; from the neutralized glycerin-containing liquid. It comprises a second separation step of separating the second oil and the precipitated inorganic salt to obtain a second glycerin-containing liquid; and a fermentation step of performing methane fermentation using the second glycerin-containing liquid.
- FIG. 1 is a diagram showing a flow in a particularly preferable embodiment of the methane fermentation method according to the present embodiment.
- a first separation step of mixing an inorganic acid with a raw material containing glycerin-containing waste or fatty acid glycerin ester-containing waste to separate and remove a first oil component, followed by a first glycerin-containing liquid.
- the neutralization step, the second separation step of separating and removing the second oil and the inorganic salt from the neutralized glycerin-containing liquid, and the subsequent alcohol removing step of separating and removing alcohol from the second glycerin-containing liquid are performed. It is illustrated.
- the alcohol removing step is an optional step, and the second glycerin-containing liquid may be supplied to the methane fermentation step without going through the alcohol removing step.
- the raw material used in the present embodiment is not particularly limited as long as it contains at least one of glycerin and fatty acid glycerin ester.
- the raw material containing glycerin include waste containing glycerin.
- the raw material containing the fatty acid glycerin ester produces glycerin by an acid-catalyzed transesterification reaction or the like in the first separation step described later, these can also be preferably used.
- the glycerin-containing waste and the fatty acid glycerin ester-containing waste will be described in some detail.
- Glycerin-containing waste used in the present embodiment includes waste glycerin produced as a by-product in the production process of biodiesel fuel, glycerin waste liquid produced as a by-product in the production process of free fatty acids, and sweetness. Water, washing waste water of fatty acid alkyl ester, etc. can be used.
- the glycerin waste liquid produced as a by-product in the process of producing free fatty acids is waste produced as a by-product when hydrolyzing fats and oils of animals and plants to produce free fatty acids.
- Examples of the method for producing free fatty acid by hydrolysis include a high temperature and high pressure decomposition method and an enzymatic decomposition method.
- the glycerin waste liquid produced as a by-product in such a production process includes unreacted fats and oils, partially hydrolyzed fats and oils, and the like, in addition to glycerin.
- sweet water is a by-product in the case of saponifying (alkaline hydrolysis) fats and oils to produce fatty acid salts (for example, in the manufacturing process of soap), and contains glycerin, water, alkali and the like.
- Washing wastewater of fatty acid alkyl ester is wastewater generated when a reactant is washed in the process of producing fatty acid alkyl ester such as biodiesel fuel, and is produced as a by-product in the production reaction of fatty acid alkyl ester in addition to water. It contains glycerin, and further contains unreacted free fatty acids and salts thereof, monohydric alcohols and the like.
- the fatty acid alkyl ester used as a biodiesel fuel can be obtained by adding a monohydric alcohol such as methanol and an alkaline catalyst such as potassium hydroxide to a raw material fat such as vegetable oil and performing a transesterification reaction.
- Raw oils and fats for biodiesel fuel include vegetable oils such as rapeseed oil, palm oil, olive oil, sunflower oil, soybean oil, rice oil and cannabis oil; animal fats such as fish oil, lard and cow pig; waste cooking oil such as tempura oil; Can be used.
- vegetable oils such as rapeseed oil, palm oil, olive oil, sunflower oil, soybean oil, rice oil and cannabis oil
- animal fats such as fish oil, lard and cow pig
- waste cooking oil such as tempura oil
- Can be used As the monohydric alcohol, methanol, ethanol, 1-propanol, ethylhexanol and the like can be used, and methanol and ethanol are preferable, and methanol is particularly preferable.
- Potassium hydroxide, sodium hydroxide, calcium oxide and the like can be used as the alkali catalyst, but potassium hydroxide is preferable from the viewpoint of precipitation property and ease of reuse of the salt separated and recovered in the present embodiment. ..
- the fatty acid glycerin ester contained in the raw material fat and oil reacts with the monohydric alcohol to produce the fatty acid alkyl ester and glycerin.
- the obtained reaction solution is separated into a fatty acid alkyl ester phase and a waste glycerin phase, and in the production of biodiesel fuel, the obtained fatty acid alkyl ester phase is recovered and washed to obtain the biodiesel fuel. To do.
- the waste glycerin phase contains unreacted monohydric alcohol (especially methanol), unreacted fats and oils, fatty acids and salts thereof, alkaline catalysts, and impurities derived from raw material fats and oils, in addition to containing a high concentration of glycerin. included.
- the waste glycerin may be liquid waste glycerin or solid waste glycerin, but from the viewpoint of workability, handling and the like, liquid waste glycerin is preferable.
- the content of glycerin, monohydric alcohol, fats and oils, fatty acids and salts thereof in waste glycerin is not particularly limited, but usually, glycerin is 25% by mass or more and 65% by mass or less, and monohydric alcohol is 2% by mass with respect to the whole waste glycerin. In many cases, the total amount of fats and oils, fatty acids and salts thereof is 30% by mass or more and 50% by mass or less.
- the pH is often 9 or more, and in this embodiment, it may be 9 to 13.
- the water content in the waste glycerin shall be 5% by mass or less from the viewpoint of facilitating the acid-catalyzed esterification reaction with the unreacted fats and oils and the monohydric alcohol contained in the waste glycerin. Is preferable, and 3% by mass or less is particularly preferable.
- the water content of the waste glycerin can be appropriately adjusted by heating, reducing the pressure, using a desiccant or the like, or permeating the purified glycerin.
- waste glycerin can be used as a raw material for pharmaceuticals and cosmetics, but in order to use glycerin contained in waste glycerin for such purposes, it is necessary to purify it with high purity, which requires a great deal of cost and energy. Therefore, waste glycerin has a considerably low utility value as glycerin, and has been difficult to process in the past.
- waste glycerin can be used as a main raw material for methane fermentation, and the environmental load can be reduced from the viewpoint of effectively utilizing waste glycerin, which is an industrial waste.
- waste glycerin produced as a by-product in the biodiesel fuel production process and free fatty acids It is preferable to use at least one kind of glycerin waste liquid produced as a by-product in the production process of the above, and it is particularly preferable to use waste glycerin produced as a by-product in the production process of biodiesel fuel.
- fatty acid glycerin ester-containing waste can also be used as a raw material.
- a raw material containing a fatty acid glycerin ester is used, and the acid catalyst ester in the first separation step is used.
- the chemical reaction can also increase the yield of glycerin.
- Wastes containing fatty acid glycerin ester include, for example, waste cooking oil, foods containing expired fats and oils (temple oil, mayonnaise, dressing, butter, cream, cheese, etc.), animal and vegetable oils, high acid value oils (gristrap oil, sewage). Examples thereof include oils and fats containing fatty acid glycerin ester as a main component of oils, gutter oil, waste liquid treated recycled oil, etc.; and compositions containing fatty acid salts such as oil slag and soap as main components.
- the main component means the component having the highest content in the composition (however, when the most abundant component is water, the component having the second highest content). This means that the content is preferably 40% by mass or more, more preferably 50% by mass or more.
- the high acid value oil refers to an oil or fat having an acid value of 10 mgKOH / g or more, and contains free fatty acids and the like in addition to the fatty acid glycerin ester which is the main component of the oil and fat.
- the acid value may be 20 mgKOH / g or more, and further may be 50 mgKOH / g or more.
- the upper limit of the acid value is usually 200 mgKOH / g or less.
- the oil residue is a by-product separated from the oil (crude oil) in the deoxidizing step in the refining of vegetable oil, and contains fatty acid salts, fatty acid glycerin esters, alkalis, water and the like.
- auxiliary raw materials food waste, livestock manure, sludge, domestic wastewater (sewage / sewage), industrial wastewater, deodorized wastewater, and other chemical substances containing phosphorus and nitrogen, such as , Phosphoric acid, phosphate, ammonia, ammonium salt, specifically, ammonium phosphate, ammonium chloride, ammonium sulfate, phosphoric acid, potassium phosphate, magnesium phosphate and the like can be added.
- the auxiliary raw material is used in the methane fermentation step described later, and when the second glycerin-containing liquid obtained by performing the neutralization step and the separation step of waste glycerin or the like as the main raw material is put into the methane fermentation tank. Put it in the fermenter according to.
- a raw material containing at least one of glycerin and a fatty acid glycerin ester is mixed with an inorganic acid, and the first oil and the first glycerin-containing liquid are phased.
- the oil content separated in this step includes fatty acid glycerin ester and free fatty acid in addition to fatty acid alkyl ester.
- the salt of the fatty acid contained in the waste glycerin or the like is converted into a free fatty acid by an inorganic acid.
- the fatty acid and its salt use an inorganic acid as an acid catalyst and produce a fatty acid alkyl ester by an esterification reaction with an unreacted monohydric alcohol contained in waste glycerin.
- a fatty acid alkyl ester and glycerin are produced by a transesterification reaction with a monohydric alcohol.
- the monohydric alcohol in this case can be added separately, and for example, the monohydric alcohol recovered in the alcohol separation step described later can be used. Further, the unreacted monohydric alcohol contained in the waste glycerin may be utilized by treating the waste glycerin at the same time as the fatty acid glycerin ester-containing waste.
- this step can also be referred to as an acid-catalyzed esterification step. In comparison with the second esterification reaction described later, the first separation step may be referred to as the "first esterification step".
- the fatty acid glycerin ester produces free fatty acid and glycerin in the presence of an acid in the first separation step.
- the fatty acid salt is converted into a free fatty acid by the acid and easily separated from glycerin. Therefore, even when the raw material does not contain monohydric alcohol, the present embodiment can be suitably applied.
- the first separation step since the first separation step is performed in the presence of the inorganic acid, various raw materials can be processed at the same time.
- wastes containing glycerin and fatty acid glycerin esters such as waste glycerin, waste cooking oil, and high acid value oil can be effectively utilized, which can contribute to reduction of environmental load. it can.
- high acid value oil has a high acid value of 10 mgKOH / g or more, so that it is difficult to use it as a raw material for the transesterification reaction using the alkali catalyst described above.
- high acid value oil can also be suitably used as a raw material.
- the fatty acid alkyl ester and free fatty acid produced in the first separation step move to the oil phase consisting of the first oil, so that the first glycerin It can be separated from the containing liquid.
- the obtained first oil fatty acid alkyl ester, free fatty acid, etc.
- the first glycerin-containing liquid is acidified by the addition of an inorganic acid.
- the first glycerin-containing liquid may contain an inorganic salt generated from an inorganic acid and an alkali contained in the glycerin-containing waste.
- a part of the inorganic salt may be precipitated, that is, the first glycerin-containing liquid may contain an acidic glycerin phase and the precipitated inorganic salt.
- the raw material that can be used in the first separation step preferably has a water content of 10% by mass or less, and preferably 5% by mass or less.
- a raw material having a low water content for example, waste glycerin having a low water content
- the water content of the raw material can be appropriately adjusted by heating, reducing the pressure, using a desiccant or the like, or permeating the purified glycerin.
- Examples of the inorganic acid used in the first separation step include concentrated sulfuric acid, phosphoric acid, concentrated nitric acid, hydrogen chloride and the like, but concentrated sulfuric acid and phosphoric acid having a low water content are preferable, and concentrated sulfuric acid is particularly preferable.
- the pH of the mixed solution (reaction solution) of the raw material and the inorganic acid is preferably 3 or less, and particularly preferably 1 or less.
- the pH of the reaction solution can be adjusted by the amount of the above-mentioned inorganic acid added.
- the reaction solution preferably has a water content of 10% by mass or less, and particularly preferably 0.5% by mass or less.
- the water content of the reaction solution can be appropriately adjusted by adjusting the water content and input amount of each raw material, using a desiccant in the reaction solution, and the like.
- the efficiency of the acid-catalyzed esterification reaction can be enhanced, and the first oil component and the first glycerin-containing solution (containing an acidic glycerin phase and an inorganic salt) can be contained. ) And can be separated well.
- the temperature of the reaction solution in the first separation step can be 30 to 64 ° C, and further can be 50 to 60 ° C.
- the reaction time can be 0.5 to 12 hours, and further can be 4 to 12 hours. During this time, it is preferable to stir the reaction solution.
- the mixture is allowed to stand for 0.2 to 12 hours to contain the first oil containing fatty acid alkyl ester, unreacted fat and oil, and the first containing an acidic glycerin phase and an inorganic salt. Separates from the glycerin-containing liquid.
- the first oil can be used for the production of fatty acid alkyl esters by further subjecting it to an acid-catalyzed esterification reaction.
- the first glycerin-containing liquid is subjected to the subsequent neutralization step.
- the neutralization step is a step of neutralizing the first glycerin-containing liquid obtained in the first separation step with an alkaline substance.
- an alkaline substance hydroxides such as potassium hydroxide and sodium hydroxide can be used.
- a substance containing glycerin can be used as the alkaline substance.
- glycerin-containing alkaline substances include the above-mentioned waste glycerin and other by-products of the alkali-catalyzed transesterification reaction of fats and oils. Since these can not only neutralize acidic glycerin but also increase the yield of glycerin, the use of a glycerin-containing alkaline substance is preferable from this viewpoint as well.
- the glycerin-containing alkaline substance may contain a fatty acid salt or a fatty acid glycerin ester.
- the glycerin-containing alkaline substance preferably has a glycerin content of 25% by mass or more, and particularly preferably 50% by mass or more.
- the upper limit is not particularly limited, but may be, for example, 99% by mass or less, or 90% by mass or less.
- the pH of the glycerin-containing alkaline substance is preferably 9 or more, and particularly preferably 9 to 13.
- alkaline substance a composition containing a fatty acid salt as a main component may be used.
- alkaline substances containing fatty acid salts as main components include oil slags and alkaline soaps.
- the pH of the glycerin-containing liquid is 4.0 to 8.0, further 4.5 to 7.0, and particularly 5.0 to 6.5. It is preferable to neutralize to.
- the pH of the glycerin-containing liquid can be appropriately adjusted by controlling the amount of the alkaline substance added.
- the neutralization step it is preferable to add the above alkaline substance while stirring the acidic glycerin-containing liquid so that the liquid property shifts from acidic to near neutral.
- a substance containing a fatty acid salt may be used as the alkaline substance used for neutralization, but the fatty acid salt is converted into a free fatty acid by the acid by the addition order as described above.
- the free fatty acid shifts from the glycerin-containing liquid to the phase-separated oil phase, and even if the pH of the glycerin-containing liquid becomes high, it becomes difficult to redissolve in the glycerin-containing liquid. This makes the separation in the subsequent second separation step even easier.
- the fatty acid salt is contained not only in the above-mentioned substance containing a fatty acid salt as a main component, but also in a by-product of an alkali catalytic transesterification reaction of fats and oils and alkali hydrolysis.
- the alkaline substance neutralizes the first glycerin-containing liquid obtained in the first separation step.
- the neutralized glycerin-containing solution is subjected to the subsequent second separation step.
- Second Separation Step the second oil and the precipitated inorganic salt are separated from the neutralized glycerin-containing liquid obtained in the neutralization step, and the second glycerin is contained. This is the process of obtaining the liquid.
- the second oil to be separated includes fats and oils and fatty acids that were not separated even in the first separation step and remained in the first glycerin-containing liquid, as well as fats and oils derived from alkaline substances added in the neutralization step. And free fatty acids are included.
- the inorganic salt separated in the second separation step is a salt of an inorganic acid (concentrated sulfuric acid, etc.) added in the first separation step and an alkali (potassium, sodium, etc.), preferably potassium sulfate.
- the alkali is contained in a raw material (waste glycerin, etc.) added to the first separation step or an alkaline substance added in the neutralization step, and an inorganic salt is contained in the first separation step or neutralization step. It is precipitated.
- the glycerin-containing liquid contains, in addition to glycerin, monohydric alcohol derived from waste glycerin, water, and the like. Since oil and inorganic salts have low solubility in such a glycerin-containing liquid, they are separated from the glycerin-containing liquid.
- the upper liquid (oil) and the lower liquid (glycerin-containing liquid) are separately recovered, and the glycerin-containing liquid to be the lower liquid is collected.
- the separation rate by centrifugation or the like.
- a three-phase separation type centrifuge capable of separating the upper liquid (that is, oil content), the lower liquid (that is, glycerin-containing liquid) and the solid matter (that is, an inorganic salt) can be preferably used. ..
- a centrifuge capable of solid-liquid separation such as a decanter type
- the liquid phase portion is further separated by a three-phase separation type centrifuge. It is preferable to separate by.
- the second oil content obtained in the second separation step is, for example, combined with the first oil content separated in the first separation step and subjected to a further acid-catalyzed esterification reaction (esterification step described later). It can be used to produce fatty acid alkyl esters.
- the second oil content obtained in the second separation step can be used as a raw material for producing fatty acid methyl ester (FAME) as a biodiesel fuel. That is, methanol and a catalyst are added to this oil to cause a methyl esterification reaction.
- the inorganic salt can be used as a raw material for an inorganic fertilizer or the like through, for example, a washing step or the like.
- the second glycerin-containing liquid obtained as described above can be used as it is as a carbon source for methane fermentation in the methane fermentation step described later, but when removing the monohydric alcohol derived from the raw material or the like. May be further subjected to an alcohol removing step. Further, the alcohol removal step may be preferable from the viewpoint of improving the efficiency of methane fermentation, the viewpoint of workability, and the viewpoint of avoiding the need to treat it as a dangerous substance. On the other hand, from the viewpoint of reducing the operating cost required for alcohol removal, or when the presence of the monohydric alcohol does not matter in the second glycerin-containing liquid (for example, the raw material does not contain the monohydric alcohol and contains the second glycerin). If the liquid does not contain monohydric alcohol, for example), the second glycerin-containing liquid may be supplied to the methane fermentation step as it is without being subjected to the alcohol removal step.
- the alcohol removing step is a step of removing monovalent alcohol (methanol, etc.) from the second glycerin-containing liquid obtained in the second separation step, and is an optional step carried out as necessary.
- the second glycerin-containing liquid may contain a monohydric alcohol derived from waste glycerin and remaining in the first separation step (acid-catalyzed esterification reaction).
- the monohydric alcohol can be used for methane fermentation even if it remains, but the efficiency of methane fermentation can be improved by removing it.
- a vacuum distillation method is a method in which a glycerin-containing liquid is heated (for example, about 60 ° C.) to evaporate a monohydric alcohol such as methanol, and then the pressure is reduced to separate the monohydric alcohol or the like.
- the separated monohydric alcohol or the like can be cooled and recovered.
- the gas-liquid contact method is a method in which a glycerin-containing liquid is brought into contact with the gas phase as fine droplets, and a monohydric alcohol having a low boiling point is transferred to the gas phase for separation.
- the membrane separation method is a method using a membrane that preferentially permeates a monohydric alcohol.
- the monohydric alcohol such as methanol recovered by distilling the second glycerin-containing liquid can be positively used for the production of biodiesel fuel.
- the second glycerin-containing liquid may further contain water.
- water does not interfere with the effect as a carbon source in methane fermentation and may remain in the purified glycerin, but in, for example, in a vacuum distillation method or a gas-liquid contact method, the water moves to the gas phase together with the monohydric alcohol. Therefore, water can be removed.
- further purification treatment may be performed using an ion exchange method, activated clay, diatomaceous earth, carbon, zeolite or the like.
- the monohydric alcohol separated in this step can be purified as it is or by redistillation or the like if necessary, and can be reused as a raw material for an alkali-catalyzed transesterification reaction or an acid-catalyzed esterification reaction. Further, it may be used as a cleaning liquid or the like for the inorganic salt or the like separated in the second separation step.
- the glycerin obtained by the above method has a high purity.
- the purity of glycerin can be 85% by mass or more, 90% by mass or more, 97% by mass or more, and further 99% by mass or more.
- waste glycerin or the like is a raw material, it is a relatively simple method, but the above method is used. Purified glycerin with high purity as in the numerical range can be obtained.
- the second glycerin-containing liquid obtained by the above method is subjected to a methane fermentation step described later, and is also a release agent for asphalt-containing compositions and cement-containing compositions; as an organic carbon source in biological nitrification denitrification treatment.
- Denitrifying agents used can be used in a variety of applications such as industrial raw materials (eg, raw materials for fatty acid glycerin esters). Further, by further subjecting it to a process such as distillation, it can be applied to applications that require higher purity (for example, cosmetics, foods and drinks, pharmaceuticals, etc.).
- the methane fermentation step can be carried out according to a conventional method except that methane fermentation is carried out using the second glycerin-containing liquid obtained through the above-mentioned steps. More specifically, the above-mentioned second glycerin-containing liquid is put into the methane fermentation tank, and at this time, it is preferable to add the above-mentioned auxiliary raw material.
- the methane fermentation tank is a closed reaction tank, and the inside is filled with methane bacteria, which are anaerobic microorganisms, and is maintained under anaerobic conditions. Further, in the methane fermentation tank, a stirrer is installed so that methane bacteria uniformly disperse and act in a mixture of sludge, main raw material, auxiliary raw material, and other organic substances and essential elements that promote methane fermentation. In the methane fermentation tank, the above-mentioned mixture is decomposed by anaerobic microorganisms, and methane gas and digestive juice are produced as the methane fermentation progresses.
- biogas mainly composed of methane gas produced by methane fermentation stays in the uppermost cavity of the fermentation tank, and digestive juice is stored in the lower part.
- methane fermentation is performed while keeping the inside of the fermenter at around 37 ° C. or high-temperature fermentation performed while maintaining the temperature at around 55 ° C. may be used, and methane fermentation is performed while stirring the contents in an anaerobic atmosphere. It is preferable to carry out.
- the second glycerin-containing liquid used in the present embodiment preferably contains an n-hexane extractant (n-Hex) of 10,000 mg / kg or less, more preferably 5,000 mg / kg or less. It is particularly preferably 2,000 mg / kg or less.
- n-hexane extract substance is a general term for non-volatile substances extracted by n-hexane, which is an organic solvent, and is used as an index showing the amount of "oil, etc.” in water.
- the second glycerin-containing liquid used in the present embodiment has a small value of n-Hex because oil is removed from the glycerin-containing waste. By using the second glycerin-containing liquid from which such oil is removed, the efficiency of methane fermentation (particularly the methane production rate) can be improved.
- the CODcr load in the methane fermentation tank in the methane fermentation step falls within the range of 2 to 20 kg / m 3 ⁇ day. .. More preferably, the CODcr load in the methane fermentation tank is 5 to 10 kg / m 3 ⁇ day. If the CODcr load is applied too much, it becomes difficult for methane fermentation to proceed quickly. By adjusting the inside of the fermenter to the range of the CODcr load as described above, it becomes easy to maintain the rate of methane fermentation.
- auxiliary raw materials is for the purpose of supplementing nutrients (nitrogen, phosphorus, and other essential elements) necessary for the activity of methane bacteria.
- the amount of the auxiliary raw material input is preferably adjusted so that the total nitrogen (TN) concentration of the digested sludge in the methane fermentation tank is 100 to 10,000 mg / liter. More preferably, it is added so that the TN concentration is 500 to 5,000 mg / liter.
- TN total nitrogen
- the methane gas produced in the methane fermentation tank is appropriately recovered and used as fuel for power generation, etc., and after purification, it is used for various purposes as high-purity methane gas.
- the first and second oil components are recovered from the separated oil phases, respectively. It is conceivable that these are circulated and supplied as raw materials in the production of fatty acid alkyl esters by the alkali catalyst method, but since the purity is not necessarily high, if they are used as raw materials as they are, fatty acid alkyl esters can be efficiently produced. It can be difficult to do.
- the first and / or second oils contain fats and oils having a high acid value such as free fatty acids, and in particular, the first oil can be said to be an esterification reaction using an acid catalyst. Since it was separated in one separation step (first esterification step), it has an acidic oil content. Therefore, it becomes more difficult to use the first and second oils as they are as a raw material for producing a fatty acid alkyl ester using an alkali catalyst.
- esterification step of producing a fatty acid alkyl ester by a method other than the alkali catalyst method.
- this step may be referred to as "second esterification step”.
- the first oil separated in the first separation step and / or the second oil separated in the second separation step are preferable to use as raw materials.
- the same raw material (high acid value oil or the like) as in the above acid reaction step (first esterification step) can be used.
- the second esterification step it is preferable to use the monohydric alcohol separated in the alcohol separation step as a raw material.
- the monohydric alcohol separated in the alcohol separation step as a raw material.
- the method that can be adopted in the second esterification step is a method other than the alkali catalyst method, and more specifically, an acid catalyst method, an acid alkali catalyst method, a biocatalyst method, an ion exchange resin method, a supercritical method, Subcritical methods and solid catalyst methods are exemplified. With these methods, transesterification reactions can be carried out with monohydric alcohols such as methanol even for waste cooking oils and fats and oils having a high acid value, and even for fats and oils containing unreacted free fatty acids. ..
- glycerin is produced as a by-product together with the oil containing the fatty acid alkyl ester.
- the oil content obtained in the second esterification step and the glycerin-containing liquid can be phase-separated by standing, centrifuging or the like.
- the separated oil can be used as a biodiesel fuel by recovering the fatty acid alkyl ester.
- the by-produced glycerin can be supplied to the neutralization step together with the first glycerin-containing liquid obtained in the first separation step (first esterification step), for example.
- the glycerin produced as a by-product in the second esterification step can also be made into a part of the second glycerin-containing liquid through the neutralization step, the second separation step, and the like. It can be recycled more efficiently.
- the second esterification step it is particularly preferable to adopt the acid catalyst method among the methods other than the alkaline catalyst method described above.
- the acid catalyst method when adopted as the second esterification step, the first oil component and / or the second oil component is used as a raw material.
- the other raw material monovalent alcohol recovered in the alcohol removal step can be used, and further, the same raw material (high acid value oil, etc.) as in the first separation step (first esterification step) can be used. May be used.
- the reaction solution obtained in the second esterification step is separated into an oil component containing a fatty acid alkyl ester and a glycerin-containing solution containing by-produced glycerin, an acid catalyst and a salt thereof. Both the obtained oil and the glycerin-containing liquid are acidic, and the acidic glycerin-containing liquid can be supplied to the neutralization step or the like.
- waste glycerin produced as a by-product in the production process of biodiesel fuel is preferably exemplified. Specifically, waste glycerin produced as a by-product in the manufacturing process of biodiesel fuel is dealcoholicized and stored in a tank or the like, and neutralizing oil is added from the lower part of the tank to bring it into contact with waste glycerin. ..
- the acidic oil is neutralized by the alkali of the waste glycerin, and the water and the monohydric alcohol contained in the oil are absorbed by the waste glycerin solution. Then, the oil charged from the lower part overflows from the upper part due to the difference in specific gravity, so that it can be easily recovered.
- neutralization, dehydration and dealcoholization can be performed at the same time, and high quality oil can be easily obtained.
- the waste glycerin solution that has absorbed water and monohydric alcohol can be supplied to the above-mentioned neutralization step, and can be made into a part of the second glycerin-containing solution through the second separation step and the like.
- a biocatalyst method As a method other than the acid catalyst method, a biocatalyst method, a supercritical method, and a subcritical method can be preferably exemplified.
- the biocatalytic method is a method of promoting a transesterification reaction by using a lipase or a phospholipase having a catalytic activity of an ester conversion reaction.
- the biocatalytic method has a characteristic that the reaction conditions are mild, but the transesterification reaction can be promoted even with a fat or oil having a high acid value, and there are few by-products.
- the phase state of a substance is changed from two phases of gas and liquid to two phases of liquid and liquid, and further, by changing the raw material to a supercritical state or a subcritical state by adjusting the temperature and pressure.
- This is a method of promoting hydrolysis by lowering the reaction system to one phase and changing the reaction system that originally required the use of a catalyst to a non-catalytic system.
- the obtained fatty acid alkyl ester can be shipped as biodiesel fuel, bioheavy oil, etc., and energy can be recovered by subjecting it to power generation or the like. That is, it may further include a power generation step of generating electricity using the fatty acid alkyl ester obtained in the second esterification step.
- the methane fermentation method can be "a method of reusing waste containing at least one of glycerin and fatty acid glycerin ester".
- the second glycerin-containing liquid obtained in the second separation step or the glycerin-containing liquid obtained by separating and removing alcohol in the alcohol removing step can be applied to various uses as purified glycerin. Therefore, in the present invention, the obtained second glycerin-containing liquid (purified glycerin) may be used for purposes other than methane fermentation, and the balance may be subjected to the methane fermentation step. That is, the obtained second glycerin-containing liquid (purified glycerin) is provided with the above-mentioned first separation step, neutralization step and second separation step (including, if necessary, the alcohol removal step).
- the method of this embodiment can be "a method of purifying glycerin from a raw material containing at least one of glycerin and fatty acid glycerin ester".
- Applications other than methane fermentation include, for example, asphalt-containing compositions and cement-containing composition strippers; denitrifying agents used as organic carbon sources in biological nitrification denitrification treatments; industrial raw materials (eg, fatty acid glycerin esters). ); Applications that require high purity of glycerin (for example, cosmetics, foods and drinks, pharmaceuticals, etc.) and the like.
- the amount of the second glycerin-containing liquid to be subjected to methane fermentation may be adjusted according to the demand for applications other than methane fermentation.
- glycerin-containing waste and fatty acid glycerin ester-containing waste can be used as raw materials, and a second glycerin-containing liquid (purified glycerin) and an oil component (first and) can be used. / Or a second oil) can be obtained.
- the second glycerin-containing liquid can be used for applications other than methane fermentation, while the oil content can be subjected to the above-mentioned second esterification step to produce a fatty acid alkyl ester.
- the glycerin-containing waste and the fatty acid glycerin ester-containing waste which are raw materials, have various origins and compositions, and the content ratio of glycerin and fatty acid glycerin ester varies greatly depending on the raw material. Therefore, the ratio of the ratio of the glycerin-containing liquid separated by the above method to the oil content (first and / or second oil content) also differs depending on the raw material, and the obtained second glycerin-containing liquid
- the ratio of (purified glycerin) to fatty acid alkyl ester also varies depending on the raw material. In this case, it may be difficult to adjust the production amount according to the demand for refined glycerin (uses other than methane fermentation) and the demand for fatty acid alkyl esters (biodiesel fuel, etc.).
- the supply amount of the second glycerin-containing liquid to the methane fermentation process is adjusted according to the demand for applications other than methane fermentation, and the fatty acid alkyl ester power generation process is started according to the demand for the fatty acid alkyl ester.
- Supply amount can be adjusted. That is, it is provided with the above-mentioned first separation step, neutralization step, second separation step and methane fermentation step, and further provided with the above-mentioned second esterification step and power generation step, and is obtained in the second separation step.
- the supply amount of the second glycerin-containing liquid to the methane fermentation step is adjusted according to the demand for applications other than methane fermentation of the second glycerin-containing liquid, and the fatty acid alkyl obtained in the second esterification step is adjusted.
- the aspect of adjusting the supply amount of the fatty acid alkyl ester to the power generation process according to the demand for the ester is one of the modifications of the present invention.
- the demand for the second glycerin-containing liquid for applications other than methane fermentation can be rephrased as the shipment amount of the second glycerin-containing liquid that is not supplied to the methane fermentation step.
- the demand for fatty acid alkyl esters can be rephrased as the shipment amount of fatty acid alkyl esters that are not supplied to the power generation process.
- the method of this embodiment is particularly suitable as a method for reusing waste containing at least one of glycerin and fatty acid glycerin ester.
- methane fermentation system A methane fermentation system according to an embodiment of the present invention, which can realize the methane fermentation method according to the above-described embodiment, will be described. Similar to the methane fermentation method described above, the methane fermentation system described below can be a system for reusing waste containing at least one of glycerin and fatty acid glycerin ester.
- the methane fermentation system (waste recycling system) 100 includes a first separation device 101, a neutralization device 102, a second separation device 103, and a methane fermentation device 104. It is configured.
- the methane fermentation system 100 illustrated in FIG. 3 further includes storage tanks 105 and 107 for storing glycerin-containing liquids, an alcohol removing device 106, a second esterification device 111, and a storage tank 112 for storing fatty acid alkyl esters. And are illustrated to include a power generator 113.
- the raw material composition containing glycerin or fatty acid glycerin ester (FIG. 3 shows glycerin-containing waste and fatty acid glycerin ester-containing waste) is charged into the first separation device 101 together with the inorganic acid, and the acid is added. A catalytic transesterification reaction or the like is carried out. After a certain period of time, the reaction solution is phase-separated into an acidic glycerin phase (first glycerin-containing solution) and an oil phase (first oil component).
- the first glycerin-containing liquid contains glycerin, an inorganic salt, a monohydric alcohol and the like, and the first glycerin-containing liquid is supplied to the neutralizing device 102, and an alkaline substance is added to neutralize the liquid.
- the neutralized glycerin-containing liquid obtained by neutralizing with the neutralizing device 102 is supplied to the second separation device 103 and separated into a second glycerin-containing liquid, an oil component (second oil component), and an inorganic salt. Will be done.
- a three-phase separation type centrifuge or the like can be preferably used, and a decanter type or other solid-liquid separable centrifuge or the like may be provided in front of the three-phase separation type centrifuge or the like.
- the inorganic salt separated from the second separation device 103 can be used as fertilizer or the like.
- the second glycerin-containing liquid separated by the second separation device 103 is supplied to the methane fermentation device 104.
- a storage tank 105 for storing the second glycerin-containing liquid may be provided between the second separation device 103 and the methane fermentation device 104.
- the monohydric alcohol may be separated and removed by the alcohol removing device 106.
- the second glycerin-containing liquid from which the alcohol has been removed is stored in the glycerin storage tank 107 and can be used for purposes other than methane fermentation. Further, the separated and removed monohydric alcohol may be configured to be supplied to the second esterification apparatus 111 described later.
- the second glycerin-containing liquid may be configured to bypass the alcohol removing device 106 and be supplied to the storage tank 107.
- the content ratio of glycerin and fatty acid glycerin ester in the raw material varies greatly depending on the raw material.
- the production amount of the second glycerin-containing liquid is larger than the demand for applications other than methane fermentation of the second glycerin-containing liquid (the shipment amount of the second glycerin-containing liquid not supplied to the methane fermentation apparatus 104)
- the second glycerin-containing liquid is produced.
- the amount of storage of the second glycerin-containing liquid increases. Therefore, in a preferred embodiment, the glycerin storage tank 107 includes a level meter L1 for detecting the level of the second glycerin-containing liquid.
- the methane fermentation system 100 opens the valve V1 and uses the second glycerin-containing liquid in the methane fermentation apparatus 104.
- the glycerin storage tank 107 may be provided with a detector capable of detecting the amount of the second glycerin-containing liquid, and for example, a weighing scale may be used instead of the level meter.
- the second glycerin-containing liquid separated by the second separating device 103 is separately supplied to the methane fermentation device 104 and the alcohol removing device 106.
- the embodiment is not limited to this.
- the glycerin-containing liquid from which the alcohol has been removed by the alcohol removing device 106 may be supplied to the methane fermentation device 104.
- a valve V1 is provided in a path for supplying a second glycerin-containing liquid from the alcohol removing device 106 (or the glycerin storage tank 107) to the methane fermentation device 104.
- the valve V1 can be opened and closed according to the level of the glycerin-containing liquid detected by the level meter L1.
- the alcohol removing device 106 has an arbitrary configuration and can be omitted in this system.
- the storage tank 105 can also be omitted.
- a valve V1 is provided in the path for supplying the second glycerin-containing liquid from the glycerin storage tank 107 to the methane fermentation apparatus 104, and the valve V1 is detected by the level meter L1.
- the valve V1 may be opened and closed according to the level of the second glycerin-containing liquid.
- the methane fermentation system 100 further includes a second esterification device 111.
- the second esterification apparatus 111 is composed of an esterification reaction tank for producing a fatty acid alkyl ester by a method other than the alkali catalyst method.
- the oil content separated by the first separation device 101 first oil content
- the oil content separated by the second separation device 103 second oil content
- the monohydric alcohol separated / removed by the alcohol removing device 106 may be supplied.
- a method other than the alkali catalyst method more specifically, an acid catalyst method, an acid alkali catalyst method, a biocatalyst method, an ion exchange resin method, a supercritical method, a subcritical method or a solid.
- the catalytic method is carried out.
- An esterification reaction (including a transesterification reaction) is carried out by any of these methods to separate the oil containing the fatty acid alkyl ester from the glycerin-containing liquid.
- the by-produced glycerin-containing liquid can be, for example, supplied to the above-mentioned neutralization device 102, neutralized and separated, and recycled as a raw material for methane fermentation and the like.
- the oil component containing the fatty acid alkyl ester is acidic.
- Such acidic oil may be neutralized, dehydrated, and dealcoholicized at the same time by injecting the acidic oil from the lower part of a tank or the like (not shown) storing waste glycerin and overflowing it to the upper part of the glycerin phase.
- the fatty acid alkyl ester thus obtained is stored in the fatty acid alkyl ester storage tank 112.
- the methane fermentation system 100 may be provided with a power generation device 113 that generates power using a fatty acid alkyl ester after the storage tank 112.
- a power generation device 113 that generates power using a fatty acid alkyl ester after the storage tank 112.
- the content ratio of glycerin and fatty acid glycerin ester in the raw material varies greatly depending on the raw material.
- the production amount of the fatty acid alkyl ester is larger than the demand for the fatty acid alkyl ester (the shipment amount of the fatty acid alkyl ester not supplied to the power generation 113)
- the storage amount of the fatty acid alkyl ester is large. Therefore, in a preferred embodiment, the fatty acid alkyl ester storage tank 112 includes a level meter L2 for detecting the level of the fatty acid alkyl ester.
- the methane fermentation system 100 is configured to open the valve V2 and supply the fatty acid alkyl ester to the power generation device 113. be able to. With this configuration, even if the content ratio of glycerin or fatty acid glycerin ester fluctuates greatly depending on the raw material, it is possible to flexibly respond to the demand for fatty acid alkyl ester.
- a biodiesel fuel was produced by transesterifying waste cooking oil and methanol by an alkaline catalyst method using potassium hydroxide as a catalyst.
- the by-product containing glycerin produced at this time was recovered as waste glycerin.
- waste material waste glycerin 20 g of zeolite was added to this waste glycerin per 1 kg of waste glycerin to remove water.
- the zeolite-added waste glycerin was passed through a 250 mesh filter to remove zeolite and solid impurities.
- the composition and physical properties of the waste glycerin as a raw material thus obtained (hereinafter, referred to as “raw material waste glycerin”) are as shown in Table 1.
- first oil content an oil phase
- acidic glycerin phase first glycerin-containing liquid
- first glycerin-containing liquid including the acidic glycerin phase and precipitated potassium sulfate
- the neutralized glycerin was treated with a decanter type centrifuge (product name: Z18HV, manufactured by Tanabe Wiltec) at 5,500 rpm for 180 minutes, and the precipitated potassium sulfate was separated and recovered.
- the liquid phase was further treated with a three-phase separation type centrifuge (manufactured by Alfa Laval) at 8,000 rpm for 180 minutes, and the second oil, the second glycerin-containing liquid, and potassium sulfate were separated and recovered.
- the second glycerin-containing liquid obtained in this step was used as sample 1.
- the second glycerin-containing liquid obtained in the second separation step was distilled in a batch system at a distillation temperature of 110 ° C. for 10 minutes using a vacuum distillation apparatus, and methanol and water were separated and removed.
- the obtained second glycerin-containing solution (glycerin-containing solution after removing methanol and water) was used as Sample 2.
- the first obtained raw material waste glycerin was used as Sample 3.
- COD Chemical Oxygen Demand
- COD Mn total nitrogen
- n-Hex (n-hexane extractant) was measured by the extraction / gravimetric method in Appendix Table 4 of Notification No. 64 of the Ministry of the Environment in 1974.
- n-Hex is a general term for non-volatile substances extracted by n-hexane, which is an organic solvent, and is used as an index showing the amount of "oil, etc.” in water.
- the oil content and the like include animal and vegetable fats and oils, fatty acids, fatty acid esters, fatty acid derivatives such as phospholipids, waxes, greases, petroleum hydrocarbons and the like.
- TOP total phosphorus
- Total chlorine is the total amount of chlorine and chloride contained in water as measured by combustion ion chromatography.
- the methanol concentration was measured by a gas chromatograph method, and the glycerin concentration was measured by a liquid chromatograph method.
- the methane fermentation apparatus 1 includes a fermentation tank 2, a stirrer 4, a heating apparatus 6, a thermometer 8, a raw material input port 10, a drain 12, and a gas outlet 14.
- the fermenter 2 is a closed cylindrical tank made of SUS with a capacity of 20 L.
- a gas tube 16 is attached to the gas outlet 14 of the fermenter 2, and the gas tube 16 is connected to a flow meter 18 (volumetric flow meter).
- the flow meter 18 has a built-in data logging device, which enables monitoring and recording of the amount of gas generated continuously for 24 hours.
- an aluminum gas pack 22 for collecting the generated gas is connected to the flow meter 18 via another gas tube 20.
- FIG. 5 shows the change over time in the amount of gas generated for each of the samples 1 to 3.
- the biogas production rate is higher than that when waste glycerin is used (when sample 3 is used).
- the speed is much faster and the amount of biogas produced is also increasing.
- the carbon source that can be a raw material for biogas is similar in samples 1 to 3 regardless of any of BOD, TOC, and CODcr as an index, but the biogas production rate in samples 1 and 2 is high. Since the speed is increased and the amount of production is also increased, it is recognized that the efficiency of methane fermentation has been dramatically improved by removing the oil from the glycerin-containing waste.
- biogas containing methane can be efficiently produced by methane fermentation using waste glycerin or the like, which is an industrial waste, as a raw material.
- waste glycerin-containing waste such as waste glycerin, which was conventionally considered to have low utility value, can be actively utilized, and there are some that have great industrial utility value.
- the biogas produced by the method according to the present invention can be sent to a desulfurization step, and the obtained gas can be supplied to a gas engine to generate electricity. It is also possible to remove carbon dioxide contained in a separation membrane or the like and supply it as a household gas.
- the oil content obtained in the separation step during the methane fermentation method according to the present invention can be used as a raw material for producing biodiesel fuel.
- the glycerin-containing liquid obtained as an intermediate product in the method of the present invention can be appropriately diluted and used as a water treatment denitrifying agent and an asphalt adhesion inhibitor.
- glycerin-containing waste such as waste glycerin, which has been treated as waste, can be used in various uses and fields, and is stable by securing many usage destinations. Recycling flow becomes possible. As a result, the industrial utility value is great.
Abstract
Description
具体的には、本発明は以下のとおりである。 As a result of diligent research to solve the above problems, the present inventor adjusts the raw material containing at least one of glycerin and fatty acid glycerin ester to an appropriate pH, separates and removes oil from the raw material, and performs this separation and removal step. They have found that methane-containing biogas can be efficiently produced by performing methane fermentation using the obtained glycerin-containing liquid, and have completed the present invention.
Specifically, the present invention is as follows.
前記原料と無機酸とを混合し、第一の油分と第一のグリセリン含有液とを分離する第一の分離工程と、
前記第一のグリセリン含有液をアルカリ性物質により中和する中和工程と、
中和された前記第一のグリセリン含有液から、第二の油分および析出した無機塩を分離して第二のグリセリン含有液を得る第二の分離工程と、
前記第二のグリセリン含有液を用いてメタン発酵を行う発酵工程と、
を備えることを特徴とするメタン発酵方法。
〔2〕 前記第二の分離工程の後に前記第二のグリセリン含有液からアルコールを除去し、アルコールを分離除去した第二のグリセリン含有液を用いて前記メタン発酵を行うことを特徴とする〔1〕に記載のメタン発酵方法。
〔3〕 前記第一の分離工程において、前記原料と前記無機酸との混合液のpHが3以下であることを特徴とする〔1〕または〔2〕に記載のメタン発酵方法。
〔4〕 前記中和工程において、前記第一のグリセリン含有液のpHが4~8となるように中和することを特徴とする〔1〕~〔3〕のいずれか一項に記載のメタン発酵方法。
〔5〕 前記メタン発酵工程において、前記第二のグリセリン含有液に加え、窒素及び/又はリンを含む副原料をメタン発酵槽に投入することを特徴とする〔1〕~〔4〕のいずれか一項に記載のメタン発酵方法。
〔6〕 前記副原料が、生ごみ、畜糞尿、リン酸、リン酸塩、アンモニア、及びアンモニウム塩からなる群より選択される1種または2種以上であることを特徴とする〔5〕に記載のメタン発酵方法。
〔7〕 前記メタン発酵槽内の消化汚泥の総窒素(T-N)濃度が100~10,000mg/Lとなるように、前記副原料を添加することを特徴とする〔5〕または〔6〕に記載のメタン発酵方法。
〔8〕 前記メタン発酵槽内のCODcr負荷が2~20kg/m3・dayとなるように、前記第二のグリセリン含有液の投入量を調節することを特徴とする〔1〕~〔7〕のいずれか一項に記載のメタン発酵方法。
〔9〕 前記第二のグリセリン含有液のメタン発酵以外の用途の需要に応じて、前記第二のグリセリン含有液のメタン発酵工程への供給量を調整することを特徴とする〔1〕~〔8〕のいずれか一項に記載のメタン発酵方法。
〔10〕 アルカリ触媒法以外の方法であって、酸触媒法、酸アルカリ触媒法、生体触媒法、イオン交換樹脂法、超臨界法、亜臨界法および固体触媒法からなる群より選択される少なくとも一つの方法により、脂肪酸アルキルエステルを製造するエステル化工程を備え、
前記エステル化工程においては、前記第一の分離工程で分離された第一の油分および/または前記第二の分離工程で分離された第二の油分を原料として用いる
ことを特徴とする〔1〕~〔9〕のいずれか一項に記載のメタン発酵方法。
〔11〕 前記エステル化工程で得られた脂肪酸アルキルエステルの少なくとも一部を用いて発電する発電工程を備えることを特徴とする〔10〕に記載のメタン発酵方法。
〔12〕 前記第二のグリセリン含有液のメタン発酵以外の用途の需要に応じて、前記第二のグリセリン含有液の前記メタン発酵工程への供給量を調整するとともに、前記脂肪酸アルキルエステルの需要に応じて、前記脂肪酸アルキルエステルの前記発電工程への供給量を調整することを特徴とする〔11〕に記載のメタン発酵方法。
〔13〕 グリセリンおよび脂肪酸グリセリンエステルの少なくとも1種を含有する原料からメタンを含むバイオガスを製造するメタン発酵システムであって、
前記原料と無機酸とを混合し、第一の油分と第一のグリセリン含有液とを分離する第一の分離装置と、
前記第一のグリセリン含有液をアルカリ性物質により中和する中和装置と、
中和された前記第一のグリセリン含有液から、第二の油分および析出した無機塩を分離して第二のグリセリン含有液を得る第二の分離装置と、
前記第二のグリセリン含有液を用いてメタン発酵を行うメタン発酵装置と、
を備えることを特徴とするメタン発酵システム。
〔14〕 前記第二の分離装置の後段に、前記第二のグリセリン含有液を貯留するグリセリン貯留タンクを備え、
前記グリセリン貯留タンクは、貯留された前記第二のグリセリン含有液の量を検知する検知計を備え、
前記第二のグリセリン含有液の量が所定量以上となった場合に、前記第二のグリセリン含有液が前記メタン発酵装置へ供給される
ことを特徴とする〔13〕に記載のメタン発酵システム。
〔15〕 アルカリ触媒法以外の方法であって、酸触媒法、酸アルカリ触媒法、生体触媒法、イオン交換樹脂法、超臨界法、亜臨界法および固体触媒法からなる群より選択される少なくとも一つの方法により、脂肪酸アルキルエステルを製造するエステル化装置を備え、
前記第一の分離工程で分離された第一の油分および/または前記第二の分離工程で分離された第二の油分が、原料として前記エステル化装置に供給される
ことを特徴とする〔13〕または〔14〕に記載のメタン発酵システム。
〔16〕 前記エステル化装置の後段に、前記脂肪酸アルキルエステルを貯留する脂肪酸アルキルエステル貯留タンクを備えるともに、
前記脂肪酸アルキルエステル貯留タンクの後段に、前記脂肪酸アルキルエステルを用いて発電する発電装置を備え、
前記脂肪酸アルキルエステル貯留タンクは、貯留された前記脂肪酸アルキルエステルの量を検知する検知計を備え、
前記脂肪酸アルキルエステルの量が所定量以上となった場合に、前記脂肪酸アルキルエステルが前記発電装置へ供給される
ことを特徴とする〔15〕に記載のメタン発酵システム。
〔17〕 グリセリンおよび脂肪酸グリセリンエステルの少なくとも1種を含有する廃棄物を再利用する方法であって、
前記廃棄物と無機酸とを混合し、第一の油分と第一のグリセリン含有液とを分離する第一の分離工程と、
前記第一のグリセリン含有液をアルカリ性物質により中和する中和工程と、
中和された前記第一のグリセリン含有液から、第二の油分および析出した無機塩を分離して第二のグリセリン含有液を得る第二の分離工程と、
前記第二のグリセリン含有液を用いてメタン発酵を行う発酵工程と、
を備えることを特徴とする廃棄物再利用方法。
〔18〕 前記第二のグリセリン含有液のメタン発酵以外の用途の需要に応じて、前記第二のグリセリン含有液のメタン発酵工程への供給量を調整することを特徴とする〔17〕に記載の廃棄物再利用方法。
〔19〕 アルカリ触媒法以外の方法であって、酸触媒法、酸アルカリ触媒法、生体触媒法、イオン交換樹脂法、超臨界法、亜臨界法および固体触媒法からなる群より選択される少なくとも一つの方法により、脂肪酸アルキルエステルを製造するエステル化工程を備え、
前記エステル化工程においては、前記第一の分離工程で分離された第一の油分および/または前記第二の分離工程で分離された第二の油分を原料として用いる
ことを特徴とする〔17〕または〔18〕に記載の廃棄物再利用方法。
〔20〕 前記エステル化工程で得られた脂肪酸アルキルエステルの少なくとも一部を用いて発電する発電工程を備え、
前記第二のグリセリン含有液のメタン発酵以外の用途の需要に応じて、前記第二のグリセリン含有液の前記メタン発酵工程への供給量を調整するとともに、前記脂肪酸アルキルエステルの需要に応じて、前記脂肪酸アルキルエステルの前記発電工程への供給量を調整することを特徴とする〔19〕に記載の廃棄物再利用方法。
〔21〕 グリセリンおよび脂肪酸グリセリンエステルの少なくとも1種を含有する廃棄物を再利用するシステムであって、
前記廃棄物と無機酸とを混合し、第一の油分と第一のグリセリン含有液とを分離する第一の分離装置と、
前記第一のグリセリン含有液をアルカリ性物質により中和する中和装置と、
中和された前記第一のグリセリン含有液から、第二の油分および析出した無機塩を分離して第二のグリセリン含有液を得る第二の分離装置と、
前記第二のグリセリン含有液を用いてメタン発酵を行うメタン発酵装置と、
を備えることを特徴とする廃棄物再利用システム。
〔22〕 前記第二の分離装置の後段に、第二のグリセリン含有液を貯留するグリセリン貯留タンクを備え、
前記グリセリン貯留タンクは、貯留された前記第二のグリセリン含有液の量を検知する検知計を備え、
前記第二のグリセリン含有液の量が所定量以上となった場合に、前記第二のグリセリン含有液が前記メタン発酵装置へ供給される
ことを特徴とする〔21〕に記載の廃棄物再利用システム。
〔23〕 アルカリ触媒法以外の方法であって、酸触媒法、酸アルカリ触媒法、生体触媒法、イオン交換樹脂法、超臨界法、亜臨界法および固体触媒法からなる群より選択される少なくとも一つの方法により、脂肪酸アルキルエステルを製造するエステル化装置を備え、
前記第一の分離工程で分離された第一の油分および/または前記第二の分離工程で分離された第二の油分が、原料として前記エステル化装置に供給される
ことを特徴とする〔21〕または〔22〕に記載の廃棄物再利用システム。
〔24〕 前記エステル化装置の後段に、前記脂肪酸アルキルエステルを貯留する脂肪酸アルキルエステル貯留タンクを備えるともに、
前記脂肪酸アルキルエステル貯留タンクの後段に、前記脂肪酸アルキルエステルを用いて発電する発電装置を備え、
前記脂肪酸アルキルエステル貯留タンクは、貯留された前記脂肪酸アルキルエステルの量を検知する検知計を備え、
前記脂肪酸アルキルエステルの量が所定量以上となった場合に、前記脂肪酸アルキルエステルが前記発電装置へ供給される
ことを特徴とする〔23〕に記載の廃棄物再利用システム。 [1] A methane fermentation method for producing biogas containing methane from a raw material containing at least one of glycerin and a fatty acid glycerin ester.
The first separation step of mixing the raw material and the inorganic acid to separate the first oil and the first glycerin-containing liquid,
A neutralization step of neutralizing the first glycerin-containing liquid with an alkaline substance, and
A second separation step of separating the second oil and the precipitated inorganic salt from the neutralized first glycerin-containing liquid to obtain a second glycerin-containing liquid.
A fermentation step in which methane fermentation is performed using the second glycerin-containing liquid, and
A methane fermentation method characterized by comprising.
[2] After the second separation step, alcohol is removed from the second glycerin-containing liquid, and the methane fermentation is carried out using the second glycerin-containing liquid from which the alcohol has been separated and removed [1]. ] The methane fermentation method described in.
[3] The methane fermentation method according to [1] or [2], wherein in the first separation step, the pH of the mixed solution of the raw material and the inorganic acid is 3 or less.
[4] The methane according to any one of [1] to [3], which comprises neutralizing the first glycerin-containing liquid so that the pH becomes 4 to 8 in the neutralization step. Fermentation method.
[5] Any of [1] to [4], wherein in the methane fermentation step, an auxiliary raw material containing nitrogen and / or phosphorus is charged into the methane fermentation tank in addition to the second glycerin-containing liquid. The methane fermentation method according to
[6] The auxiliary raw material is one or more selected from the group consisting of food waste, livestock manure, phosphoric acid, phosphate, ammonia, and ammonium salt [5]. The described methane fermentation method.
[7] The auxiliary raw material is added so that the total nitrogen (TN) concentration of the digested sludge in the methane fermentation tank is 100 to 10,000 mg / L [5] or [6]. ] The methane fermentation method described in.
[8] It is characterized in that the input amount of the second glycerin-containing liquid is adjusted so that the CODcr load in the methane fermentation tank is 2 to 20 kg / m 3 · day [1] to [7]. The methane fermentation method according to any one of the above.
[9] The second glycerin-containing liquid is characterized in that the supply amount of the second glycerin-containing liquid to the methane fermentation step is adjusted according to the demand for applications other than methane fermentation [1] to [1] to [ The methane fermentation method according to any one of 8].
[10] A method other than the alkali catalyst method, which is selected from the group consisting of an acid catalyst method, an acid alkali catalyst method, a biocatalyst method, an ion exchange resin method, a supercritical method, a subcritical method and a solid catalyst method. It comprises an esterification step of producing a fatty acid alkyl ester by one method.
The esterification step is characterized in that the first oil separated in the first separation step and / or the second oil separated in the second separation step is used as a raw material [1]. The methane fermentation method according to any one of [9].
[11] The methane fermentation method according to [10], which comprises a power generation step of generating electricity using at least a part of the fatty acid alkyl ester obtained in the esterification step.
[12] The supply amount of the second glycerin-containing liquid to the methane fermentation step is adjusted according to the demand for applications other than methane fermentation of the second glycerin-containing liquid, and the demand for the fatty acid alkyl ester is met. The methane fermentation method according to [11], wherein the supply amount of the fatty acid alkyl ester to the power generation step is adjusted accordingly.
[13] A methane fermentation system for producing biogas containing methane from a raw material containing at least one of glycerin and a fatty acid glycerin ester.
A first separation device that mixes the raw material and an inorganic acid to separate the first oil and the first glycerin-containing liquid.
A neutralizer that neutralizes the first glycerin-containing liquid with an alkaline substance,
A second separation device that separates the second oil and the precipitated inorganic salt from the neutralized first glycerin-containing liquid to obtain a second glycerin-containing liquid.
A methane fermentation apparatus that performs methane fermentation using the second glycerin-containing liquid, and
A methane fermentation system characterized by being equipped with.
[14] A glycerin storage tank for storing the second glycerin-containing liquid is provided after the second separation device.
The glycerin storage tank includes a detector that detects the amount of the second glycerin-containing liquid stored.
The methane fermentation system according to [13], wherein the second glycerin-containing liquid is supplied to the methane fermentation apparatus when the amount of the second glycerin-containing liquid exceeds a predetermined amount.
[15] A method other than the alkali catalyst method, which is selected from the group consisting of an acid catalyst method, an acid alkali catalyst method, a biocatalyst method, an ion exchange resin method, a supercritical method, a subcritical method and a solid catalyst method. Esterifying equipment for producing fatty acid alkyl esters by one method
The first oil separated in the first separation step and / or the second oil separated in the second separation step is supplied to the esterification apparatus as a raw material [13]. ] Or [14]. The methane fermentation system.
[16] A fatty acid alkyl ester storage tank for storing the fatty acid alkyl ester is provided after the esterification device.
A power generation device that generates electricity using the fatty acid alkyl ester is provided after the fatty acid alkyl ester storage tank.
The fatty acid alkyl ester storage tank includes a detector that detects the amount of the stored fatty acid alkyl ester.
The methane fermentation system according to [15], wherein the fatty acid alkyl ester is supplied to the power generation device when the amount of the fatty acid alkyl ester exceeds a predetermined amount.
[17] A method for reusing waste containing at least one of glycerin and fatty acid glycerin ester.
The first separation step of mixing the waste and the inorganic acid to separate the first oil and the first glycerin-containing liquid,
A neutralization step of neutralizing the first glycerin-containing liquid with an alkaline substance, and
A second separation step of separating the second oil and the precipitated inorganic salt from the neutralized first glycerin-containing liquid to obtain a second glycerin-containing liquid.
A fermentation step in which methane fermentation is performed using the second glycerin-containing liquid, and
A waste recycling method characterized by providing.
[18] The second glycerin-containing liquid according to [17], wherein the supply amount of the second glycerin-containing liquid to the methane fermentation step is adjusted according to the demand for applications other than methane fermentation. How to reuse waste.
[19] A method other than the alkali catalyst method, which is selected from the group consisting of an acid catalyst method, an acid alkali catalyst method, a biocatalyst method, an ion exchange resin method, a supercritical method, a subcritical method and a solid catalyst method. It comprises an esterification step of producing a fatty acid alkyl ester by one method.
The esterification step is characterized in that the first oil separated in the first separation step and / or the second oil separated in the second separation step is used as a raw material [17]. Alternatively, the waste recycling method according to [18].
[20] A power generation step of generating electricity using at least a part of the fatty acid alkyl ester obtained in the esterification step is provided.
The supply amount of the second glycerin-containing liquid to the methane fermentation step is adjusted according to the demand for applications other than methane fermentation of the second glycerin-containing liquid, and the fatty acid alkyl ester is used according to the demand. The waste recycling method according to [19], wherein the supply amount of the fatty acid alkyl ester to the power generation step is adjusted.
[21] A system for reusing waste containing at least one of glycerin and fatty acid glycerin ester.
A first separation device that mixes the waste with an inorganic acid and separates the first oil and the first glycerin-containing liquid.
A neutralizer that neutralizes the first glycerin-containing liquid with an alkaline substance,
A second separation device that separates the second oil and the precipitated inorganic salt from the neutralized first glycerin-containing liquid to obtain a second glycerin-containing liquid.
A methane fermentation apparatus that performs methane fermentation using the second glycerin-containing liquid, and
A waste recycling system characterized by being equipped with.
[22] A glycerin storage tank for storing the second glycerin-containing liquid is provided after the second separation device.
The glycerin storage tank includes a detector that detects the amount of the stored second glycerin-containing liquid.
The waste reuse according to [21], wherein the second glycerin-containing liquid is supplied to the methane fermentation apparatus when the amount of the second glycerin-containing liquid exceeds a predetermined amount. system.
[23] A method other than the alkali catalyst method, which is selected from the group consisting of an acid catalyst method, an acid alkali catalyst method, a biocatalyst method, an ion exchange resin method, a supercritical method, a subcritical method and a solid catalyst method. Esterifying equipment for producing fatty acid alkyl esters by one method
The first oil separated in the first separation step and / or the second oil separated in the second separation step is supplied to the esterification apparatus as a raw material [21]. ] Or [22]. The waste recycling system.
[24] A fatty acid alkyl ester storage tank for storing the fatty acid alkyl ester is provided after the esterification device.
A power generation device that generates electricity using the fatty acid alkyl ester is provided after the fatty acid alkyl ester storage tank.
The fatty acid alkyl ester storage tank includes a detector that detects the amount of the stored fatty acid alkyl ester.
The waste recycling system according to [23], wherein the fatty acid alkyl ester is supplied to the power generation device when the amount of the fatty acid alkyl ester exceeds a predetermined amount.
〔メタン発酵方法〕
本発明の一実施形態に係るメタン発酵方法は、グリセリンおよび脂肪酸グリセリンエステルの少なくとも1種を含有する原料からメタンを含むバイオガスを製造する方法であって、前記原料と無機酸とを混合し、第一の油分と第一のグリセリン含有液とを分離する第一の分離工程と;前記第一のグリセリン含有液をアルカリ性物質により中和する中和工程と;中和されたグリセリン含有液から、第二の油分および析出した無機塩を分離して第二のグリセリン含有液を得る第二の分離工程と;前記第二のグリセリン含有液を用いてメタン発酵を行う発酵工程と;を備える。 Hereinafter, embodiments of the present invention will be described.
[Methane fermentation method]
The methane fermentation method according to the embodiment of the present invention is a method for producing a biogas containing methane from a raw material containing at least one of glycerin and a fatty acid glycerin ester, in which the raw material and an inorganic acid are mixed. From the first separation step of separating the first oil and the first glycerin-containing liquid; and the neutralization step of neutralizing the first glycerin-containing liquid with an alkaline substance; from the neutralized glycerin-containing liquid. It comprises a second separation step of separating the second oil and the precipitated inorganic salt to obtain a second glycerin-containing liquid; and a fermentation step of performing methane fermentation using the second glycerin-containing liquid.
本実施形態において用いる原料は、グリセリンおよび脂肪酸グリセリンエステルの少なくとも1種を含むものであれば、特に限定されない。
グリセリンを含む原料としては、例えば、グリセリンを含有する廃棄物が例示される。また、脂肪酸グリセリンエステルを含む原料は、後述する第一の分離工程において、酸触媒エステル交換反応等によりグリセリンを生成するため、これらも好適に利用することができる。
以下、グリセリン含有廃棄物および脂肪酸グリセリンエステル含有廃棄物についてやや詳しく説明する。 (1) Raw Material The raw material used in the present embodiment is not particularly limited as long as it contains at least one of glycerin and fatty acid glycerin ester.
Examples of the raw material containing glycerin include waste containing glycerin. Further, since the raw material containing the fatty acid glycerin ester produces glycerin by an acid-catalyzed transesterification reaction or the like in the first separation step described later, these can also be preferably used.
Hereinafter, the glycerin-containing waste and the fatty acid glycerin ester-containing waste will be described in some detail.
本実施形態で用いられるグリセリン含有廃棄物としては、バイオディーゼル燃料の製造過程で副生される廃グリセリン、遊離脂肪酸の製造工程で副生されるグリセリン廃液、甘水、脂肪酸アルキルエステルの洗浄廃水などを用いることができる。 (1-1) Glycerin-containing waste The glycerin-containing waste used in the present embodiment includes waste glycerin produced as a by-product in the production process of biodiesel fuel, glycerin waste liquid produced as a by-product in the production process of free fatty acids, and sweetness. Water, washing waste water of fatty acid alkyl ester, etc. can be used.
また、甘水は、油脂を鹸化(アルカリ加水分解)して脂肪酸塩を生成させる場合(例えば、石鹸の製造過程など)における副生成物であり、グリセリン、水分、アルカリ等を含む。
脂肪酸アルキルエステルの洗浄廃水は、バイオディーゼル燃料をはじめとする脂肪酸アルキルエステルの製造過程において、反応物を洗浄したときに生じる廃水であり、水分の他、脂肪酸アルキルエステルの製造反応において副生されるグリセリンが含まれ、さらに未反応の遊離脂肪酸およびその塩、1価アルコール等が含まれる。 Here, the glycerin waste liquid produced as a by-product in the process of producing free fatty acids is waste produced as a by-product when hydrolyzing fats and oils of animals and plants to produce free fatty acids. Examples of the method for producing free fatty acid by hydrolysis include a high temperature and high pressure decomposition method and an enzymatic decomposition method. The glycerin waste liquid produced as a by-product in such a production process includes unreacted fats and oils, partially hydrolyzed fats and oils, and the like, in addition to glycerin.
In addition, sweet water is a by-product in the case of saponifying (alkaline hydrolysis) fats and oils to produce fatty acid salts (for example, in the manufacturing process of soap), and contains glycerin, water, alkali and the like.
Washing wastewater of fatty acid alkyl ester is wastewater generated when a reactant is washed in the process of producing fatty acid alkyl ester such as biodiesel fuel, and is produced as a by-product in the production reaction of fatty acid alkyl ester in addition to water. It contains glycerin, and further contains unreacted free fatty acids and salts thereof, monohydric alcohols and the like.
バイオディーゼル燃料となる脂肪酸アルキルエステルは、植物油などの原料油脂に、メタノール等の1価アルコールと、水酸化カリウム等のアルカリ触媒とを加え、エステル交換反応を行うことで得られる。 Next, the waste glycerin produced as a by-product in the manufacturing process of biodiesel fuel will be described in a little more detail.
The fatty acid alkyl ester used as a biodiesel fuel can be obtained by adding a monohydric alcohol such as methanol and an alkaline catalyst such as potassium hydroxide to a raw material fat such as vegetable oil and performing a transesterification reaction.
1価アルコールとしては、メタノール、エタノール、1-プロパノール、エチルヘキサノール等を用いることができ、メタノールおよびエタノールが好ましく、メタノールが特に好ましい。
アルカリ触媒としては、水酸化カリウム、水酸化ナトリウム、酸化カルシウム等を用いることができるが、本実施形態で分離回収される塩の析出性や再利用容易性等の観点から、水酸化カリウムが好ましい。 Raw oils and fats for biodiesel fuel include vegetable oils such as rapeseed oil, palm oil, olive oil, sunflower oil, soybean oil, rice oil and cannabis oil; animal fats such as fish oil, lard and cow pig; waste cooking oil such as tempura oil; Can be used.
As the monohydric alcohol, methanol, ethanol, 1-propanol, ethylhexanol and the like can be used, and methanol and ethanol are preferable, and methanol is particularly preferable.
Potassium hydroxide, sodium hydroxide, calcium oxide and the like can be used as the alkali catalyst, but potassium hydroxide is preferable from the viewpoint of precipitation property and ease of reuse of the salt separated and recovered in the present embodiment. ..
廃グリセリンにおけるグリセリン、1価アルコール、油脂並びに脂肪酸およびその塩の含有量は特に限定されないが、通常、廃グリセリン全体に対して、グリセリンは25質量%以上65質量%以下、1価アルコールは2質量%以上20質量%以下、油脂ならびに脂肪酸およびその塩の合計は30質量%以上50質量%以下となる場合が多い。 On the other hand, the waste glycerin phase contains unreacted monohydric alcohol (especially methanol), unreacted fats and oils, fatty acids and salts thereof, alkaline catalysts, and impurities derived from raw material fats and oils, in addition to containing a high concentration of glycerin. included. The waste glycerin may be liquid waste glycerin or solid waste glycerin, but from the viewpoint of workability, handling and the like, liquid waste glycerin is preferable.
The content of glycerin, monohydric alcohol, fats and oils, fatty acids and salts thereof in waste glycerin is not particularly limited, but usually, glycerin is 25% by mass or more and 65% by mass or less, and monohydric alcohol is 2% by mass with respect to the whole waste glycerin. In many cases, the total amount of fats and oils, fatty acids and salts thereof is 30% by mass or more and 50% by mass or less.
第一の分離工程において、廃グリセリンに含まれる未反応の油脂および1価アルコールによる酸触媒エステル化反応を進行させやすくする観点から、廃グリセリンにおける水分の含有量は、5質量%以下であることが好ましく、3質量%以下であることが特に好ましい。廃グリセリンにおける水分含有量は、加熱、減圧、乾燥剤等の使用、精製グリセリン中を透過させることなどにより適宜調整することができる。 Since waste glycerin contains a large amount of alkaline catalyst, the pH is often 9 or more, and in this embodiment, it may be 9 to 13.
In the first separation step, the water content in the waste glycerin shall be 5% by mass or less from the viewpoint of facilitating the acid-catalyzed esterification reaction with the unreacted fats and oils and the monohydric alcohol contained in the waste glycerin. Is preferable, and 3% by mass or less is particularly preferable. The water content of the waste glycerin can be appropriately adjusted by heating, reducing the pressure, using a desiccant or the like, or permeating the purified glycerin.
しかし、本実施形態によれば、廃グリセリンをメタン発酵の主原料として用いることができ、産業廃棄物である廃グリセリンを有効活用できる観点からも、環境負荷を低減することができる。 Here, glycerin can be used as a raw material for pharmaceuticals and cosmetics, but in order to use glycerin contained in waste glycerin for such purposes, it is necessary to purify it with high purity, which requires a great deal of cost and energy. Therefore, waste glycerin has a considerably low utility value as glycerin, and has been difficult to process in the past.
However, according to the present embodiment, waste glycerin can be used as a main raw material for methane fermentation, and the environmental load can be reduced from the viewpoint of effectively utilizing waste glycerin, which is an industrial waste.
本実施形態においては、脂肪酸グリセリンエステルを含有する廃棄物も原料として用いることができる。本実施形態においては、無機酸を用いた第一の分離工程、中和工程および第二の分離工程にて行うため、脂肪酸グリセリンエステルを含有する原料を用い、第一の分離工程における酸触媒エステル化反応によりグリセリンの収量を高めることもできる。
脂肪酸グリセリンエステルを含有する廃棄物としては、例えば、廃食油や賞味期限切れ油脂含有食品(天ぷら油、マヨネーズ、ドレッシング、バター、クリーム、チーズ等)、動植物油、高酸価油(グリストラップ油、下水油、地溝油、廃液処理再生油等)の脂肪酸グリセリンエステルを主成分とする油脂;油滓、石鹸等の脂肪酸塩を主成分とする組成物;などが挙げられる。
なお、本明細書において「主成分とする」とは、当該組成物において含有量が最も多い成分(ただし最も多い成分が水である場合には2番目に含有量が多い成分)であることを意味し、好ましくは含有量が40質量%以上、より好ましくは50質量%以上である。 (1-2) Fatty Acid Glycerin Ester-Containing Waste In this embodiment, fatty acid glycerin ester-containing waste can also be used as a raw material. In the present embodiment, since the first separation step, the neutralization step and the second separation step using an inorganic acid are carried out, a raw material containing a fatty acid glycerin ester is used, and the acid catalyst ester in the first separation step is used. The chemical reaction can also increase the yield of glycerin.
Wastes containing fatty acid glycerin ester include, for example, waste cooking oil, foods containing expired fats and oils (temple oil, mayonnaise, dressing, butter, cream, cheese, etc.), animal and vegetable oils, high acid value oils (gristrap oil, sewage). Examples thereof include oils and fats containing fatty acid glycerin ester as a main component of oils, gutter oil, waste liquid treated recycled oil, etc.; and compositions containing fatty acid salts such as oil slag and soap as main components.
In addition, in this specification, "the main component" means the component having the highest content in the composition (however, when the most abundant component is water, the component having the second highest content). This means that the content is preferably 40% by mass or more, more preferably 50% by mass or more.
油滓は、植物油脂の精製における脱酸工程において油脂(原油)から分離される副生成物であり、脂肪酸塩、脂肪酸グリセリンエステル、アルカリ、水分等を含む。 Here, the high acid value oil refers to an oil or fat having an acid value of 10 mgKOH / g or more, and contains free fatty acids and the like in addition to the fatty acid glycerin ester which is the main component of the oil and fat. The acid value may be 20 mgKOH / g or more, and further may be 50 mgKOH / g or more. The upper limit of the acid value is usually 200 mgKOH / g or less.
The oil residue is a by-product separated from the oil (crude oil) in the deoxidizing step in the refining of vegetable oil, and contains fatty acid salts, fatty acid glycerin esters, alkalis, water and the like.
本実施形態においては、副原料として、生ごみ、畜糞尿、汚泥、生活排水(し尿・下水)、産業排水、脱臭廃水等、その他リンや窒素を含む化学物質、例えば、リン酸、リン酸塩、アンモニア、アンモニウム塩、具体的には、リン酸アンモニウム、塩化アンモニウム、硫酸アンモニウム、リン酸、リン酸カリウム、リン酸マグネシウム等を加えることができる。なお、副原料は後述するメタン発酵工程において用いるものであり、主原料となる廃グリセリン等を中和工程、分離工程を施して得られた第二のグリセリン含有液をメタン発酵槽に投入する際に合わせて発酵槽に投入する。 (1-3) Auxiliary raw materials In the present embodiment, as auxiliary raw materials, food waste, livestock manure, sludge, domestic wastewater (sewage / sewage), industrial wastewater, deodorized wastewater, and other chemical substances containing phosphorus and nitrogen, such as , Phosphoric acid, phosphate, ammonia, ammonium salt, specifically, ammonium phosphate, ammonium chloride, ammonium sulfate, phosphoric acid, potassium phosphate, magnesium phosphate and the like can be added. The auxiliary raw material is used in the methane fermentation step described later, and when the second glycerin-containing liquid obtained by performing the neutralization step and the separation step of waste glycerin or the like as the main raw material is put into the methane fermentation tank. Put it in the fermenter according to.
第一の分離工程は、グリセリンおよび脂肪酸グリセリンエステルの少なくとも1種を含む原料と、無機酸とを混合し、第一の油分と第一のグリセリン含有液とを相分離する工程である。
本工程で分離される油分には、脂肪酸アルキルエステルの他、脂肪酸グリセリンエステル、遊離脂肪酸が含まれる。 (2) First Separation Step In the first separation step, a raw material containing at least one of glycerin and a fatty acid glycerin ester is mixed with an inorganic acid, and the first oil and the first glycerin-containing liquid are phased. This is the process of separation.
The oil content separated in this step includes fatty acid glycerin ester and free fatty acid in addition to fatty acid alkyl ester.
1価アルコールの存在下で第一の分離工程を行う場合、本工程は酸触媒エステル化工程ということもできる。なお、後述する第二のエステル化反応との対比において、第一の分離工程を「第一のエステル化工程」という場合がある。 When a fatty acid glycerin ester-containing waste is used as a raw material, a fatty acid alkyl ester and glycerin are produced by a transesterification reaction with a monohydric alcohol. The monohydric alcohol in this case can be added separately, and for example, the monohydric alcohol recovered in the alcohol separation step described later can be used. Further, the unreacted monohydric alcohol contained in the waste glycerin may be utilized by treating the waste glycerin at the same time as the fatty acid glycerin ester-containing waste.
When the first separation step is carried out in the presence of a monohydric alcohol, this step can also be referred to as an acid-catalyzed esterification step. In comparison with the second esterification reaction described later, the first separation step may be referred to as the "first esterification step".
そのため、原料に1価アルコールが含まれない場合であっても、本実施形態を好適に適用することができる。 Even when the monohydric alcohol is not contained, the fatty acid glycerin ester produces free fatty acid and glycerin in the presence of an acid in the first separation step. When the raw material contains a fatty acid salt, the fatty acid salt is converted into a free fatty acid by the acid and easily separated from glycerin.
Therefore, even when the raw material does not contain monohydric alcohol, the present embodiment can be suitably applied.
なかでも高酸価油は、酸価が10mgKOH/g以上と高いことから前述したアルカリ触媒によるエステル交換反応の原料としての利用は困難である。しかし、酸触媒エステル化反応ともいうべき第一の分離工程においては、高酸価油も原料として好適に用いることができる。 In the present embodiment, since the first separation step is performed in the presence of the inorganic acid, various raw materials can be processed at the same time. In addition, by performing the first separation step, wastes containing glycerin and fatty acid glycerin esters such as waste glycerin, waste cooking oil, and high acid value oil can be effectively utilized, which can contribute to reduction of environmental load. it can.
Among them, high acid value oil has a high acid value of 10 mgKOH / g or more, so that it is difficult to use it as a raw material for the transesterification reaction using the alkali catalyst described above. However, in the first separation step, which can be called an acid-catalyzed esterification reaction, high acid value oil can also be suitably used as a raw material.
一方、第一のグリセリン含有液は、無機酸の添加により酸性化されている。また、第一のグリセリン含有液は、無機酸とグリセリン含有廃棄物に含まれるアルカリとから生成した無機塩を含有する場合がある。なお、無機塩の一部は析出していてもよく、すなわち第一のグリセリン含有液は、酸性グリセリン相と析出した無機塩とを含んでいてもよい。 When waste glycerin or fatty acid glycerin ester-containing waste is used as a raw material, the fatty acid alkyl ester and free fatty acid produced in the first separation step move to the oil phase consisting of the first oil, so that the first glycerin It can be separated from the containing liquid. When the oil phase is recovered, the obtained first oil (fatty acid alkyl ester, free fatty acid, etc.) is subjected to a further esterification reaction (esterification step described later), and finally biodiesel fuel, etc. Can be used as a raw material for.
On the other hand, the first glycerin-containing liquid is acidified by the addition of an inorganic acid. In addition, the first glycerin-containing liquid may contain an inorganic salt generated from an inorganic acid and an alkali contained in the glycerin-containing waste. A part of the inorganic salt may be precipitated, that is, the first glycerin-containing liquid may contain an acidic glycerin phase and the precipitated inorganic salt.
反応液は、水分含有量を10質量%以下とすることが好ましく、0.5質量%以下とすることが特に好ましい。反応液の水分含有量は、各原料の水分含有量および投入量の調整、反応液への乾燥剤の使用などにより適宜調整することができる。
反応液のpHおよび水分含有量を上記範囲とすることで、酸触媒エステル化反応の効率を高めることができ、また第一の油分と第一のグリセリン含有液(酸性グリセリン相、無機塩を含む)とを良好に分離させることができる。 In the first separation step, the pH of the mixed solution (reaction solution) of the raw material and the inorganic acid is preferably 3 or less, and particularly preferably 1 or less. The pH of the reaction solution can be adjusted by the amount of the above-mentioned inorganic acid added.
The reaction solution preferably has a water content of 10% by mass or less, and particularly preferably 0.5% by mass or less. The water content of the reaction solution can be appropriately adjusted by adjusting the water content and input amount of each raw material, using a desiccant in the reaction solution, and the like.
By setting the pH and water content of the reaction solution within the above ranges, the efficiency of the acid-catalyzed esterification reaction can be enhanced, and the first oil component and the first glycerin-containing solution (containing an acidic glycerin phase and an inorganic salt) can be contained. ) And can be separated well.
上記反応(あるいは攪拌)が終了したのち、0.2~12時間静置することで、脂肪酸アルキルエステルや未反応の油脂等を含む第一の油分と、酸性グリセリン相や無機塩を含む第一のグリセリン含有液とが分離する。第一の油分は、さらなる酸触媒エステル化反応に付すことで、脂肪酸アルキルエステルの生成に用いることができる。一方、第一のグリセリン含有液は、続く中和工程に付される。 The temperature of the reaction solution in the first separation step can be 30 to 64 ° C, and further can be 50 to 60 ° C. The reaction time can be 0.5 to 12 hours, and further can be 4 to 12 hours. During this time, it is preferable to stir the reaction solution.
After the above reaction (or stirring) is completed, the mixture is allowed to stand for 0.2 to 12 hours to contain the first oil containing fatty acid alkyl ester, unreacted fat and oil, and the first containing an acidic glycerin phase and an inorganic salt. Separates from the glycerin-containing liquid. The first oil can be used for the production of fatty acid alkyl esters by further subjecting it to an acid-catalyzed esterification reaction. On the other hand, the first glycerin-containing liquid is subjected to the subsequent neutralization step.
中和工程は、第一の分離工程で得られた第一のグリセリン含有液を、アルカリ性物質により中和する工程である。
かかるアルカリ性物質としては、水酸化カリウム、水酸化ナトリウム等の水酸化物、を用いることができる。 (3) Neutralization Step The neutralization step is a step of neutralizing the first glycerin-containing liquid obtained in the first separation step with an alkaline substance.
As such an alkaline substance, hydroxides such as potassium hydroxide and sodium hydroxide can be used.
上記グリセリン含有アルカリ性物質は、グリセリン含有量が25質量%以上であることが好ましく、50質量%以上であることが特に好ましい。上限は特に限定されないが、例えば99質量%以下であってよく、90質量%以下であってよい。
また、上記グリセリン含有アルカリ性物質は、pHが9以上であることが好ましく、9~13であることが特に好ましい。 Further, as the alkaline substance, a substance containing glycerin can be used. Examples of such glycerin-containing alkaline substances include the above-mentioned waste glycerin and other by-products of the alkali-catalyzed transesterification reaction of fats and oils. Since these can not only neutralize acidic glycerin but also increase the yield of glycerin, the use of a glycerin-containing alkaline substance is preferable from this viewpoint as well. The glycerin-containing alkaline substance may contain a fatty acid salt or a fatty acid glycerin ester.
The glycerin-containing alkaline substance preferably has a glycerin content of 25% by mass or more, and particularly preferably 50% by mass or more. The upper limit is not particularly limited, but may be, for example, 99% by mass or less, or 90% by mass or less.
The pH of the glycerin-containing alkaline substance is preferably 9 or more, and particularly preferably 9 to 13.
第二の分離工程は、中和工程にて得られた中和されたグリセリン含有液から、第二の油分および析出した無機塩を分離し、第二のグリセリン含有液を得る工程である。 (4) Second Separation Step In the second separation step, the second oil and the precipitated inorganic salt are separated from the neutralized glycerin-containing liquid obtained in the neutralization step, and the second glycerin is contained. This is the process of obtaining the liquid.
また、無機塩は、例えば、洗浄工程等を経て無機肥料等の原料とすることができる。
一方、以上のようにして得られた第二のグリセリン含有液は、そのままでもメタン発酵の炭素源として後述するメタン発酵工程に用いることができるが、原料等に由来する1価アルコールを除去する場合には、さらにアルコール除去工程に付してもよい。
さらにアルコール除去工程に付すことで、メタン発酵の効率性向上の観点、作業性の観点、さらには危険物として取り扱う必要を回避する観点から、好ましい場合がある。一方、アルコール除去に要する運転コストを節減する観点からは、あるいは第二のグリセリン含有液において1価アルコールの存在が問題とならない場合(例えば、原料に1価アルコールが含まれず、第二のグリセリン含有液にも1価アルコールが含まれない場合など)は、アルコール除去工程に付さずに上記第二のグリセリン含有液をそのままメタン発酵工程に供給してもよい。 The second oil content obtained in the second separation step is, for example, combined with the first oil content separated in the first separation step and subjected to a further acid-catalyzed esterification reaction (esterification step described later). It can be used to produce fatty acid alkyl esters. Specifically, the second oil content obtained in the second separation step can be used as a raw material for producing fatty acid methyl ester (FAME) as a biodiesel fuel. That is, methanol and a catalyst are added to this oil to cause a methyl esterification reaction.
Further, the inorganic salt can be used as a raw material for an inorganic fertilizer or the like through, for example, a washing step or the like.
On the other hand, the second glycerin-containing liquid obtained as described above can be used as it is as a carbon source for methane fermentation in the methane fermentation step described later, but when removing the monohydric alcohol derived from the raw material or the like. May be further subjected to an alcohol removing step.
Further, the alcohol removal step may be preferable from the viewpoint of improving the efficiency of methane fermentation, the viewpoint of workability, and the viewpoint of avoiding the need to treat it as a dangerous substance. On the other hand, from the viewpoint of reducing the operating cost required for alcohol removal, or when the presence of the monohydric alcohol does not matter in the second glycerin-containing liquid (for example, the raw material does not contain the monohydric alcohol and contains the second glycerin). If the liquid does not contain monohydric alcohol, for example), the second glycerin-containing liquid may be supplied to the methane fermentation step as it is without being subjected to the alcohol removal step.
アルコール除去工程は、第二の分離工程で得られた第二のグリセリン含有液から1価アルコール(メタノール等)を除去する工程であって、必要に応じて実施する任意工程である。
上記第二のグリセリン含有液には、廃グリセリンに由来し、第一の分離工程(酸触媒エステル化反応)においても残存した1価アルコールが含まれ得る。かかる1価アルコールが残存したままでもメタン発酵に用いることができるが、除去することでメタン発酵の効率を向上させることができる。 (5) Alcohol Removal Step The alcohol removing step is a step of removing monovalent alcohol (methanol, etc.) from the second glycerin-containing liquid obtained in the second separation step, and is an optional step carried out as necessary. Is.
The second glycerin-containing liquid may contain a monohydric alcohol derived from waste glycerin and remaining in the first separation step (acid-catalyzed esterification reaction). The monohydric alcohol can be used for methane fermentation even if it remains, but the efficiency of methane fermentation can be improved by removing it.
減圧蒸留法は、グリセリン含有液を加温(例えば、60℃程度)してメタノール等の1価アルコールを蒸発させ、その後減圧することで1価アルコール等を分離する方法である。分離した1価アルコール等は冷却して回収することができる。
気液接触法は、グリセリン含有液を微細な液滴として気相と接触させ、沸点の低い1価アルコールを気相に移行させて分離する方法であり、具体的にはスプレードライ法等を好適に採用することができる。
膜分離法は、1価アルコールを優先的に透過させる膜を用いる方法である。
ちなみに、第二のグリセリン含有液を蒸留して回収されたメタノール等の1価アルコールは、バイオディーゼル燃料の製造に積極的に用いることができる。 In the step of separating / removing the monohydric alcohol, a vacuum distillation method, a gas-liquid contact method, a membrane separation method and the like can be adopted.
The vacuum distillation method is a method in which a glycerin-containing liquid is heated (for example, about 60 ° C.) to evaporate a monohydric alcohol such as methanol, and then the pressure is reduced to separate the monohydric alcohol or the like. The separated monohydric alcohol or the like can be cooled and recovered.
The gas-liquid contact method is a method in which a glycerin-containing liquid is brought into contact with the gas phase as fine droplets, and a monohydric alcohol having a low boiling point is transferred to the gas phase for separation. Specifically, a spray-dry method or the like is preferable. Can be adopted for.
The membrane separation method is a method using a membrane that preferentially permeates a monohydric alcohol.
By the way, the monohydric alcohol such as methanol recovered by distilling the second glycerin-containing liquid can be positively used for the production of biodiesel fuel.
また、上記1価アルコールを分離するアルコール分離工程の前または後に、イオン交換法や、活性白土、珪藻土、炭素、ゼオライト等を用い、さらなる精製処理を行ってもよい。 The second glycerin-containing liquid may further contain water. Such water does not interfere with the effect as a carbon source in methane fermentation and may remain in the purified glycerin, but in, for example, in a vacuum distillation method or a gas-liquid contact method, the water moves to the gas phase together with the monohydric alcohol. Therefore, water can be removed.
Further, before or after the alcohol separation step of separating the monohydric alcohol, further purification treatment may be performed using an ion exchange method, activated clay, diatomaceous earth, carbon, zeolite or the like.
メタン発酵工程では、上述した工程を経て得られた第二のグリセリン含有液を用いてメタン発酵を行う以外、常法に従って行うことができる。
より具体的には、上述した第二のグリセリン含有液をメタン発酵槽に投入するが、この時、上述した副原料を加えるのが好ましい。 (6) Methane Fermentation Step The methane fermentation step can be carried out according to a conventional method except that methane fermentation is carried out using the second glycerin-containing liquid obtained through the above-mentioned steps.
More specifically, the above-mentioned second glycerin-containing liquid is put into the methane fermentation tank, and at this time, it is preferable to add the above-mentioned auxiliary raw material.
本実施形態においては、発酵槽内を37℃付近に保ちながら行う中温発酵、および55℃付近に保ちながら行う高温発酵のいずれでもよく、嫌気牲の雰囲気下で内容物を攪拌しながらメタン発酵を実行するのが好ましい。 The methane fermentation tank is a closed reaction tank, and the inside is filled with methane bacteria, which are anaerobic microorganisms, and is maintained under anaerobic conditions. Further, in the methane fermentation tank, a stirrer is installed so that methane bacteria uniformly disperse and act in a mixture of sludge, main raw material, auxiliary raw material, and other organic substances and essential elements that promote methane fermentation. In the methane fermentation tank, the above-mentioned mixture is decomposed by anaerobic microorganisms, and methane gas and digestive juice are produced as the methane fermentation progresses. Specifically, in the methane fermentation tank, biogas mainly composed of methane gas produced by methane fermentation stays in the uppermost cavity of the fermentation tank, and digestive juice is stored in the lower part.
In the present embodiment, either medium-temperature fermentation performed while keeping the inside of the fermenter at around 37 ° C. or high-temperature fermentation performed while maintaining the temperature at around 55 ° C. may be used, and methane fermentation is performed while stirring the contents in an anaerobic atmosphere. It is preferable to carry out.
上述した第一および第二の分離工程においては、分離した油相より第一および第二の油分がそれぞれ回収される。これらは、アルカリ触媒法による脂肪酸アルキルエステルの製造における原料として循環供給することも考えられるが、純度が必ずしも高くないため、そのままの状態で原料として用いようとすると、脂肪酸アルキルエステルを効率的に製造することが困難な場合がある。また、第一および/または第二の油分には、遊離脂肪酸等の酸価の高い油脂が含まれており、とりわけ第一の油分は、酸触媒を用いたエステル化反応ともいうことができる第一の分離工程(第一のエステル化工程)にて分離されたものであるため、酸性の油分となっている。そのため、第一および第二の油分をそのままアルカリ触媒による脂肪酸アルキルエステルの製造の原料として用いることはより一層困難となる。 (7) Esterification Step In the first and second separation steps described above, the first and second oil components are recovered from the separated oil phases, respectively. It is conceivable that these are circulated and supplied as raw materials in the production of fatty acid alkyl esters by the alkali catalyst method, but since the purity is not necessarily high, if they are used as raw materials as they are, fatty acid alkyl esters can be efficiently produced. It can be difficult to do. Further, the first and / or second oils contain fats and oils having a high acid value such as free fatty acids, and in particular, the first oil can be said to be an esterification reaction using an acid catalyst. Since it was separated in one separation step (first esterification step), it has an acidic oil content. Therefore, it becomes more difficult to use the first and second oils as they are as a raw material for producing a fatty acid alkyl ester using an alkali catalyst.
なお、前述した第一の分離工程(第一のエステル化工程)との対比において、本工程を「第二のエステル化工程」ということがある。 However, if it is a method other than the alkali catalyst method, it is possible to produce a fatty acid alkyl ester even with a fat or oil having a high acid value. Therefore, in the present embodiment, it is preferable to include an esterification step of producing a fatty acid alkyl ester by a method other than the alkali catalyst method.
In comparison with the above-mentioned first separation step (first esterification step), this step may be referred to as "second esterification step".
その他の原料としては、上記酸反応工程(第一のエステル化工程)と同様の原料(高酸価油等)を用いることができる。 In the second esterification step, it is preferable to use the first oil separated in the first separation step and / or the second oil separated in the second separation step as raw materials.
As the other raw material, the same raw material (high acid value oil or the like) as in the above acid reaction step (first esterification step) can be used.
図2に示すように、第二のエステル化工程として酸触媒法を採用する場合には、上記第一の油分および/または第二の油分を原料として用いる。その他の原料としては、アルコール除去工程で回収された1価のアルコールを用いることができ、さらには、第一の分離工程(第一のエステル化工程)と同様の原料(高酸価油等)を用いても良い。
第二のエステル化工程で得られた反応液は、脂肪酸アルキルエステルを含む油分と、副生したグリセリンや酸触媒およびその塩等を含むグリセリン含有液とに分離させる。得られる油分およびグリセリン含有液はいずれも酸性となっており、このうち酸性グリセリン含有液は上記中和工程などに供給することができる。 As the second esterification step, it is particularly preferable to adopt the acid catalyst method among the methods other than the alkaline catalyst method described above.
As shown in FIG. 2, when the acid catalyst method is adopted as the second esterification step, the first oil component and / or the second oil component is used as a raw material. As the other raw material, monovalent alcohol recovered in the alcohol removal step can be used, and further, the same raw material (high acid value oil, etc.) as in the first separation step (first esterification step) can be used. May be used.
The reaction solution obtained in the second esterification step is separated into an oil component containing a fatty acid alkyl ester and a glycerin-containing solution containing by-produced glycerin, an acid catalyst and a salt thereof. Both the obtained oil and the glycerin-containing liquid are acidic, and the acidic glycerin-containing liquid can be supplied to the neutralization step or the like.
生体触媒法は、エステル変換反応の触媒活性を備えたリパーゼやホスホリパーゼを用いて、エステル交換反応を促す方法である。生体触媒法は、反応条件が穏やかであるが、酸価値の高い油脂であってもエステル交換反応を促進でき、副生物が少ないという特性がある。
超臨界法や亜臨界法は、温度や圧力を調整して、原材料を超臨界状態または亜臨界状態に変えることで、物質の相状態を気液二相から液液二相、さらに誘電率を下げて一相へと変化させて、本来触媒を用いる必要があった反応系を無触媒系へと変えて、加水分解を促進する方法である。 In the second esterification step, as a method other than the acid catalyst method, a biocatalyst method, a supercritical method, and a subcritical method can be preferably exemplified.
The biocatalytic method is a method of promoting a transesterification reaction by using a lipase or a phospholipase having a catalytic activity of an ester conversion reaction. The biocatalytic method has a characteristic that the reaction conditions are mild, but the transesterification reaction can be promoted even with a fat or oil having a high acid value, and there are few by-products.
In the supercritical method and subcritical method, the phase state of a substance is changed from two phases of gas and liquid to two phases of liquid and liquid, and further, by changing the raw material to a supercritical state or a subcritical state by adjusting the temperature and pressure. This is a method of promoting hydrolysis by lowering the reaction system to one phase and changing the reaction system that originally required the use of a catalyst to a non-catalytic system.
本発明に係る方法は、上記実施形態に限定されるものではなく、実施段階ではその要旨を逸脱しない範囲で種々に変形することができる。
例えば、上記メタン発酵方法は、「グリセリンおよび脂肪酸グリセリンエステルの少なくとも1種を含む廃棄物を再利用する方法」とすることができる。 (8) Modification Example The method according to the present invention is not limited to the above embodiment, and can be variously modified at the implementation stage without departing from the gist thereof.
For example, the methane fermentation method can be "a method of reusing waste containing at least one of glycerin and fatty acid glycerin ester".
そのため、本発明においては、得られた第二のグリセリン含有液(精製されたグリセリン)をメタン発酵以外の用途に用い、残部を上記メタン発酵工程に付す構成を採用してもよい。
すなわち、前述した第一の分離工程、中和工程および第二の分離工程を備え(必要に応じて、さらに上記アルコール除去工程を備える)、得られた第二のグリセリン含有液(精製されたグリセリン)をメタン発酵以外の用途に用い、第二のグリセリン含有液の残部を上記メタン発酵工程に付す、との態様は、本発明の変形例の一つである。
なお、精製されたグリセリンの一部をメタン発酵以外の用途に用いる場合、本態様の方法は「グリセリンおよび脂肪酸グリセリンエステルの少なくとも1種を含む原料からグリセリンを精製する方法」とすることができる。 Further, as described above, the second glycerin-containing liquid obtained in the second separation step or the glycerin-containing liquid obtained by separating and removing alcohol in the alcohol removing step can be applied to various uses as purified glycerin.
Therefore, in the present invention, the obtained second glycerin-containing liquid (purified glycerin) may be used for purposes other than methane fermentation, and the balance may be subjected to the methane fermentation step.
That is, the obtained second glycerin-containing liquid (purified glycerin) is provided with the above-mentioned first separation step, neutralization step and second separation step (including, if necessary, the alcohol removal step). ) Is used for applications other than methane fermentation, and the remainder of the second glycerin-containing liquid is subjected to the methane fermentation step, which is one of the modifications of the present invention.
When a part of the purified glycerin is used for an application other than methane fermentation, the method of this embodiment can be "a method of purifying glycerin from a raw material containing at least one of glycerin and fatty acid glycerin ester".
この変形例においては、メタン発酵以外の用途の需要に応じて、メタン発酵に付す第二のグリセリン含有液の量を調整することとしてもよい。 Applications other than methane fermentation include, for example, asphalt-containing compositions and cement-containing composition strippers; denitrifying agents used as organic carbon sources in biological nitrification denitrification treatments; industrial raw materials (eg, fatty acid glycerin esters). ); Applications that require high purity of glycerin (for example, cosmetics, foods and drinks, pharmaceuticals, etc.) and the like.
In this modification, the amount of the second glycerin-containing liquid to be subjected to methane fermentation may be adjusted according to the demand for applications other than methane fermentation.
ここで、原料となるグリセリン含有廃棄物や脂肪酸グリセリンエステル含有廃棄物は、由来や組成等が多様であり、原料によってグリセリンや脂肪酸グリセリンエステルの含有比率が大きく異なる。そのため、上記方法で分離されるグリセリン含有液と、油分(第一および/または第二の油分)との比率との比率も、原料に依存して異なるものとなり、得られる第二のグリセリン含有液(精製されたグリセリン)と脂肪酸アルキルエステルとの比率も、原料に依存して変動する。この場合、精製グリセリンの需要(メタン発酵以外の用途)や、脂肪酸アルキルエステルの需要(バイオディーゼル燃料等)に応じた製造量の調整が困難となる場合がある。 Further, as described above, in the above-mentioned method, glycerin-containing waste and fatty acid glycerin ester-containing waste can be used as raw materials, and a second glycerin-containing liquid (purified glycerin) and an oil component (first and) can be used. / Or a second oil) can be obtained. The second glycerin-containing liquid can be used for applications other than methane fermentation, while the oil content can be subjected to the above-mentioned second esterification step to produce a fatty acid alkyl ester.
Here, the glycerin-containing waste and the fatty acid glycerin ester-containing waste, which are raw materials, have various origins and compositions, and the content ratio of glycerin and fatty acid glycerin ester varies greatly depending on the raw material. Therefore, the ratio of the ratio of the glycerin-containing liquid separated by the above method to the oil content (first and / or second oil content) also differs depending on the raw material, and the obtained second glycerin-containing liquid The ratio of (purified glycerin) to fatty acid alkyl ester also varies depending on the raw material. In this case, it may be difficult to adjust the production amount according to the demand for refined glycerin (uses other than methane fermentation) and the demand for fatty acid alkyl esters (biodiesel fuel, etc.).
すなわち、前述した第一の分離工程、中和工程、第二の分離工程およびメタン発酵工程を備えるとともに、前述した第二のエステル化工程および発電工程をさらに備え、第二の分離工程で得られた第二のグリセリン含有液のメタン発酵以外の用途の需要に応じて、第二のグリセリン含有液のメタン発酵工程への供給量を調整するとともに、第二のエステル化工程で得られた脂肪酸アルキルエステルの需要に応じて、脂肪酸アルキルエステルの発電工程への供給量を調整する、との態様は、本発明の変形例の一つである。
なお、第二のグリセリン含有液のメタン発酵以外の用途の需要とは、上記メタン発酵工程に供給されない第二のグリセリン含有液の出荷量と言い換えることができる。また、脂肪酸アルキルエステルの需要とは、上記発電工程に供給されない脂肪酸アルキルエステルの出荷量と言い換えることができる。 On the other hand, the supply amount of the second glycerin-containing liquid to the methane fermentation process is adjusted according to the demand for applications other than methane fermentation, and the fatty acid alkyl ester power generation process is started according to the demand for the fatty acid alkyl ester. Supply amount can be adjusted.
That is, it is provided with the above-mentioned first separation step, neutralization step, second separation step and methane fermentation step, and further provided with the above-mentioned second esterification step and power generation step, and is obtained in the second separation step. The supply amount of the second glycerin-containing liquid to the methane fermentation step is adjusted according to the demand for applications other than methane fermentation of the second glycerin-containing liquid, and the fatty acid alkyl obtained in the second esterification step is adjusted. The aspect of adjusting the supply amount of the fatty acid alkyl ester to the power generation process according to the demand for the ester is one of the modifications of the present invention.
The demand for the second glycerin-containing liquid for applications other than methane fermentation can be rephrased as the shipment amount of the second glycerin-containing liquid that is not supplied to the methane fermentation step. In addition, the demand for fatty acid alkyl esters can be rephrased as the shipment amount of fatty acid alkyl esters that are not supplied to the power generation process.
上述した実施形態に係るメタン発酵方法を実現することのできる、本発明の一実施形態に係るメタン発酵システムについて説明する。
なお、前述したメタン発酵方法と同様に、以下に説明するメタン発酵システムは、グリセリンおよび脂肪酸グリセリンエステルの少なくとも1種を含む廃棄物を再利用するシステムとすることができる。 [Methane fermentation system]
A methane fermentation system according to an embodiment of the present invention, which can realize the methane fermentation method according to the above-described embodiment, will be described.
Similar to the methane fermentation method described above, the methane fermentation system described below can be a system for reusing waste containing at least one of glycerin and fatty acid glycerin ester.
なお、図3に例示されるメタン発酵システム100は、さらにグリセリン含有液を貯留する貯留タンク105および107、アルコール除去装置106、第二のエステル化装置111、脂肪酸アルキルエステルを貯留する貯留タンク112、および発電装置113を備えるように図示されている。 As shown in FIG. 3, the methane fermentation system (waste recycling system) 100 includes a first separation device 101, a
The methane fermentation system 100 illustrated in FIG. 3 further includes
第一のグリセリン含有液には、グリセリン、無機塩、1価アルコール等が含まれており、第一のグリセリン含有液は中和装置102に供給され、アルカリ性物質が投入されて中和される。 The raw material composition containing glycerin or fatty acid glycerin ester (FIG. 3 shows glycerin-containing waste and fatty acid glycerin ester-containing waste) is charged into the first separation device 101 together with the inorganic acid, and the acid is added. A catalytic transesterification reaction or the like is carried out. After a certain period of time, the reaction solution is phase-separated into an acidic glycerin phase (first glycerin-containing solution) and an oil phase (first oil component).
The first glycerin-containing liquid contains glycerin, an inorganic salt, a monohydric alcohol and the like, and the first glycerin-containing liquid is supplied to the
なお、第二の分離装置103より分離された無機塩は、肥料などに用いることができる。 The neutralized glycerin-containing liquid obtained by neutralizing with the neutralizing
The inorganic salt separated from the
なお、第二のグリセリン含有液において1価アルコールの存在が問題とならない場合(例えば、原料に1価アルコールが含まれず、第二のグリセリン含有液にも1価アルコールが含まれない場合など)は、図3中の一点鎖線で示すように、第二のグリセリン含有液を、アルコール除去装置106をバイパスして貯留タンク107に供給されるように構成してもよい。 If the monohydric alcohol remains in the second glycerin-containing liquid separated by the
When the presence of monohydric alcohol does not matter in the second glycerin-containing liquid (for example, when the raw material does not contain monohydric alcohol and the second glycerin-containing liquid does not contain monohydric alcohol) , As shown by the alternate long and short dash line in FIG. 3, the second glycerin-containing liquid may be configured to bypass the alcohol removing device 106 and be supplied to the
そこで、好ましい態様において、グリセリン貯留タンク107は、第二のグリセリン含有液のレベルを検知するレベル計L1を備える。そして、第二のグリセリン含有液のレベルが所定値以上となったことがレベル計L1によって検知されると、メタン発酵システム100は、バルブV1を開き、第二のグリセリン含有液をメタン発酵装置104へ供給するように構成することができる。
このように構成することで、原料によってグリセリンや脂肪酸グリセリンエステルの含有比率が大きく変動しても、精製グリセリンの需要に応じて柔軟に対応することができる。
この場合において、グリセリン貯留タンク107は、第二のグリセリン含有液の量を検知できる検知計を備えていればよく、例えば、レベル計の代わりに重量計を用いてもよい。 By the way, as described above, the content ratio of glycerin and fatty acid glycerin ester in the raw material varies greatly depending on the raw material. When the production amount of the second glycerin-containing liquid is larger than the demand for applications other than methane fermentation of the second glycerin-containing liquid (the shipment amount of the second glycerin-containing liquid not supplied to the methane fermentation apparatus 104), the second glycerin-containing liquid is produced. The amount of storage of the second glycerin-containing liquid increases.
Therefore, in a preferred embodiment, the
With this configuration, even if the content ratio of glycerin or fatty acid glycerin ester fluctuates greatly depending on the raw material, it is possible to flexibly respond to the demand for purified glycerin.
In this case, the
かかる構成において、さらにグリセリン貯留タンク107がレベル計L1を備える場合には、アルコール除去装置106(またはグリセリン貯留タンク107)からメタン発酵装置104へ第二のグリセリン含有液を供給する経路にバルブV1を設け、レベル計L1により検知されるグリセリン含有液のレベルに応じてバルブV1を開閉する構成とすることができる。 Although it is shown in FIG. 3 that the second glycerin-containing liquid separated by the
In such a configuration, when the
なお、第二のエステル化装置111において酸触媒法によりエステル化反応が行われる場合は、脂肪酸アルキルエステルを含む油分は酸性となっている。かかる酸性の油分は、廃グリセリンを貯留したタンク等(図示しない)の下部から注入してグリセリン相の上部にオーバーフローさせることで、中和・脱水・脱アルコール化を同時に行ってもよい。
このようにして得られた脂肪酸アルキルエステルは、脂肪酸アルキルエステル貯留タンク112にて貯留される。 In the
When the esterification reaction is carried out by the acid catalyst method in the
The fatty acid alkyl ester thus obtained is stored in the fatty acid alkyl
そこで、好ましい態様において、脂肪酸アルキルエステル貯留タンク112は、脂肪酸アルキルエステルのレベルを検知するレベル計L2を備える。そして、脂肪酸アルキルエステルのレベルが所定値以上となったことがレベル計L2によって検知されると、メタン発酵システム100は、バルブV2を開き、脂肪酸アルキルエステルを発電装置113へ供給するように構成することができる。
このように構成することで、原料によってグリセリンや脂肪酸グリセリンエステルの含有比率が大きく変動しても、脂肪酸アルキルエステルの需要に応じて柔軟に対応することができる。 Further, as described above, the content ratio of glycerin and fatty acid glycerin ester in the raw material varies greatly depending on the raw material. When the production amount of the fatty acid alkyl ester is larger than the demand for the fatty acid alkyl ester (the shipment amount of the fatty acid alkyl ester not supplied to the power generation 113), the storage amount of the fatty acid alkyl ester is large.
Therefore, in a preferred embodiment, the fatty acid alkyl
With this configuration, even if the content ratio of glycerin or fatty acid glycerin ester fluctuates greatly depending on the raw material, it is possible to flexibly respond to the demand for fatty acid alkyl ester.
水酸化カリウムを触媒とするアルカリ触媒法により、廃食油とメタノールとをエステル交換させてバイオディーゼル燃料を製造した。このとき生成したグリセリンを含む副生成物を廃グリセリンとして回収した。 (Preparation of waste glycerin)
A biodiesel fuel was produced by transesterifying waste cooking oil and methanol by an alkaline catalyst method using potassium hydroxide as a catalyst. The by-product containing glycerin produced at this time was recovered as waste glycerin.
こうして得られた原料としての廃グリセリン(以下、「原料廃グリセリン」という。)の組成および物性は表1に示すとおりであった。 20 g of zeolite was added to this waste glycerin per 1 kg of waste glycerin to remove water. The zeolite-added waste glycerin was passed through a 250 mesh filter to remove zeolite and solid impurities.
The composition and physical properties of the waste glycerin as a raw material thus obtained (hereinafter, referred to as “raw material waste glycerin”) are as shown in Table 1.
加温冷却機能を有する容量1,000L(リットル)の反応タンクに、原料廃グリセリン500kg、高酸価油(150mgKOH/g)300kgを投入し、攪拌(120rpm)しながら55℃まで加温した。この状態で、濃硫酸32Lを反応容器中に15分かけて添加した。濃硫酸の添加にあたり、反応容器中の混合物の温度が65℃を超えないように留意した。濃硫酸を全量添加した後の反応液のpHは1であった。濃硫酸の添加終了後、240分間攪拌を継続した。その後10時間静置し、油相(第一の油分)と酸性グリセリン相(第一のグリセリン含有液)とに分離させ、第一のグリセリン含有液(酸性グリセリン相,析出した硫酸カリウムを含む)を回収した。以上の操作を繰り返すことにより、第一のグリセリン含有液5,000kgを得た。 (First separation step)
500 kg of raw material waste glycerin and 300 kg of high acid value oil (150 mgKOH / g) were put into a reaction tank having a capacity of 1,000 L (liter) having a heating / cooling function, and heated to 55 ° C. with stirring (120 rpm). In this state, 32 L of concentrated sulfuric acid was added into the reaction vessel over 15 minutes. When adding concentrated sulfuric acid, care was taken so that the temperature of the mixture in the reaction vessel did not exceed 65 ° C. The pH of the reaction solution after the total amount of concentrated sulfuric acid was added was 1. After the addition of concentrated sulfuric acid was completed, stirring was continued for 240 minutes. After that, it is allowed to stand for 10 hours to separate it into an oil phase (first oil content) and an acidic glycerin phase (first glycerin-containing liquid), and the first glycerin-containing liquid (including the acidic glycerin phase and precipitated potassium sulfate). Was recovered. By repeating the above operation, 5,000 kg of the first glycerin-containing liquid was obtained.
容量15,000Lの反応タンクに、攪拌しながら第一のグリセリン含有液5,000kg、廃グリセリン5,000kgを投入した。pHは7.1であった。その後も4時間攪拌を継続し、その後24時間静置した。 (Neutralization process)
A reaction tank having a capacity of 15,000 L was charged with 5,000 kg of the first glycerin-containing liquid and 5,000 kg of waste glycerin with stirring. The pH was 7.1. After that, stirring was continued for 4 hours, and then the mixture was allowed to stand for 24 hours.
中和されたグリセリンを、デカンタ型遠心分離機(製品名:Z18H-V,タナベウィルテック社製)にて5,500rpm、180分間処理し、析出した硫酸カリウムを分離回収した。液相について、さらに三相分離型遠心分離機(アルファ・ラバル社製)にて8,000rpm、180分間処理し、第二の油分、第二のグリセリン含有液、硫酸カリウムをそれぞれ分離回収した。この工程で得られた第二のグリセリン含有液を試料1とした。 (Second separation step)
The neutralized glycerin was treated with a decanter type centrifuge (product name: Z18HV, manufactured by Tanabe Wiltec) at 5,500 rpm for 180 minutes, and the precipitated potassium sulfate was separated and recovered. The liquid phase was further treated with a three-phase separation type centrifuge (manufactured by Alfa Laval) at 8,000 rpm for 180 minutes, and the second oil, the second glycerin-containing liquid, and potassium sulfate were separated and recovered. The second glycerin-containing liquid obtained in this step was used as
上記第二の分離工程で得られた第二のグリセリン含有液を、真空蒸留装置を用いて蒸留温度110℃で10分のバッチ式で蒸留し、メタノールおよび水を分離除去した。得られた第二のグリセリン含有液(メタノール及び水の除去後のグリセリン含有液)を試料2とした。
なお、比較の目的で、最初に得られた原料廃グリセリンを試料3とした。 (Alcohol removal process)
The second glycerin-containing liquid obtained in the second separation step was distilled in a batch system at a distillation temperature of 110 ° C. for 10 minutes using a vacuum distillation apparatus, and methanol and water were separated and removed. The obtained second glycerin-containing solution (glycerin-containing solution after removing methanol and water) was used as
For the purpose of comparison, the first obtained raw material waste glycerin was used as Sample 3.
ここで、以下に述べる各項目は、JIS K0102に準拠して測定した。BOD(生物化学的酸素要求量)とは、水中の有機物などの量を、その酸化分解のために微生物が必要とする酸素の量で表したものである。TOC(全有機炭素)とは、水中の有機物の総量を「有機物中に含まれる炭素量」として表現する指標である。また、COD(化学的酸素要求量)とは、水中の有機物量を、「酸化剤により分解した時の酸素消費量」として表現する指標であり、使用する酸化剤の種類や反応条件に応じて複数の種類がある。本実施形態では、COD指標として、酸化剤に二クロム酸カリウムを用いる「CODCr」を好適に用いることができる。酸化剤に過マンガン酸カリウムを使う「CODMn」は実際の有機物量に対する捕捉率が低いためである。また、T-N(全窒素)は水中に含まれる窒素化合物の総量を示すものである。次に、n-Hex(n-ヘキサン抽出物質)は、昭和49年環境省告示64号付表4抽出・重量法により測定した。n-Hexは、有機溶剤であるn-ヘキサンによって抽出される不揮発性の物質の総称であり、水中の「油分等」の量を表す指標として用いられているものである。ここで油分等とは動植物油脂、脂肪酸、脂肪酸エステル、リン脂質などの脂肪酸誘導体、ワックス、グリース、石油系炭化水素等を含む。また、T-P(総リン)は水中に含まれるリン化合物の総量である。全塩素は、燃焼イオンクロマトグラフ法で測定し、水中に含まれる塩素及び塩化物の総量である。
また、メタノール濃度はガスクロマトグラフ法、グリセリン濃度は液体クロマトグラフ法により測定した。 For each of
Here, each item described below was measured in accordance with JIS K0102. BOD (Biochemical Oxygen Demand) is the amount of organic matter in water expressed by the amount of oxygen required by microorganisms for its oxidative decomposition. TOC (total organic carbon) is an index that expresses the total amount of organic matter in water as "the amount of carbon contained in organic matter". In addition, COD (Chemical Oxygen Demand) is an index that expresses the amount of organic matter in water as "oxygen consumption when decomposed by an oxidant", depending on the type of oxidant used and the reaction conditions. There are multiple types. In the present embodiment, "COD Cr " using potassium dichromate as an oxidizing agent can be preferably used as the COD index. This is because "COD Mn ", which uses potassium permanganate as an oxidizing agent, has a low capture rate with respect to the actual amount of organic matter. Further, TN (total nitrogen) indicates the total amount of nitrogen compounds contained in water. Next, n-Hex (n-hexane extractant) was measured by the extraction / gravimetric method in Appendix Table 4 of Notification No. 64 of the Ministry of the Environment in 1974. n-Hex is a general term for non-volatile substances extracted by n-hexane, which is an organic solvent, and is used as an index showing the amount of "oil, etc." in water. Here, the oil content and the like include animal and vegetable fats and oils, fatty acids, fatty acid esters, fatty acid derivatives such as phospholipids, waxes, greases, petroleum hydrocarbons and the like. In addition, TOP (total phosphorus) is the total amount of phosphorus compounds contained in water. Total chlorine is the total amount of chlorine and chloride contained in water as measured by combustion ion chromatography.
The methanol concentration was measured by a gas chromatograph method, and the glycerin concentration was measured by a liquid chromatograph method.
ここで、バイオガスの原料となり得る炭素源は、BOD、TOC、CODcrのいずれを指標としても、試料1~3で同程度であるにもかかわらず、試料1及び2においてバイオガスの生成速度が速くなっており、生成量も多くなっていることから、グリセリン含有廃棄物から油分を除去することで、メタン発酵の効率が飛躍的に高まったものと認められる。 FIG. 5 shows the change over time in the amount of gas generated for each of the
Here, the carbon source that can be a raw material for biogas is similar in
また、本発明によるメタン発酵方法の途中の分離工程で得られた油分は、バイオディーゼル燃料を製造する際の原材料として用いることができる。さらにまた、本発明の方法において中間生成物として得られたグリセリン含有液は、適宜希釈して水処理脱窒剤、及びアスファルト付着防止剤としても利用することができる。
このように、本発明によれば、これまで廃棄物として処理されていた廃グリセリン等のグリセリン含有廃棄物は種々の用途・分野において利用が可能となり、多くの利用先を確保することにより、安定的なリサイクルフローが可能になる。この結果、産業上の利用価値は大なるものがある。 According to the present invention, biogas containing methane can be efficiently produced by methane fermentation using waste glycerin or the like, which is an industrial waste, as a raw material. Glycerin-containing waste such as waste glycerin, which was conventionally considered to have low utility value, can be actively utilized, and there are some that have great industrial utility value. For example, the biogas produced by the method according to the present invention can be sent to a desulfurization step, and the obtained gas can be supplied to a gas engine to generate electricity. It is also possible to remove carbon dioxide contained in a separation membrane or the like and supply it as a household gas.
In addition, the oil content obtained in the separation step during the methane fermentation method according to the present invention can be used as a raw material for producing biodiesel fuel. Furthermore, the glycerin-containing liquid obtained as an intermediate product in the method of the present invention can be appropriately diluted and used as a water treatment denitrifying agent and an asphalt adhesion inhibitor.
As described above, according to the present invention, glycerin-containing waste such as waste glycerin, which has been treated as waste, can be used in various uses and fields, and is stable by securing many usage destinations. Recycling flow becomes possible. As a result, the industrial utility value is great.
Claims (24)
- グリセリンおよび脂肪酸グリセリンエステルの少なくとも1種を含有する原料からメタンを含むバイオガスを製造するメタン発酵方法であって、
前記原料と無機酸とを混合し、第一の油分と第一のグリセリン含有液とを分離する第一の分離工程と、
前記第一のグリセリン含有液をアルカリ性物質により中和する中和工程と、
中和された前記第一のグリセリン含有液から、第二の油分および析出した無機塩を分離して第二のグリセリン含有液を得る第二の分離工程と、
前記第二のグリセリン含有液を用いてメタン発酵を行う発酵工程と、
を備えることを特徴とするメタン発酵方法。 A methane fermentation method for producing biogas containing methane from a raw material containing at least one of glycerin and a fatty acid glycerin ester.
The first separation step of mixing the raw material and the inorganic acid to separate the first oil and the first glycerin-containing liquid,
A neutralization step of neutralizing the first glycerin-containing liquid with an alkaline substance, and
A second separation step of separating the second oil and the precipitated inorganic salt from the neutralized first glycerin-containing liquid to obtain a second glycerin-containing liquid.
A fermentation step in which methane fermentation is performed using the second glycerin-containing liquid, and
A methane fermentation method characterized by comprising. - 前記第二の分離工程の後に前記第二のグリセリン含有液からアルコールを除去し、アルコールを分離除去した第二のグリセリン含有液を用いて前記メタン発酵を行うことを特徴とする請求項1に記載のメタン発酵方法。 The first aspect of claim 1, wherein after the second separation step, alcohol is removed from the second glycerin-containing liquid, and the methane fermentation is carried out using the second glycerin-containing liquid from which the alcohol has been separated and removed. Methan fermentation method.
- 前記第一の分離工程において、前記原料と前記無機酸との混合液のpHが3以下であることを特徴とする請求項1または2に記載のメタン発酵方法。 The methane fermentation method according to claim 1 or 2, wherein in the first separation step, the pH of the mixed solution of the raw material and the inorganic acid is 3 or less.
- 前記中和工程において、前記第一のグリセリン含有液のpHが4~8となるように中和することを特徴とする請求項1~3のいずれか一項に記載のメタン発酵方法。 The methane fermentation method according to any one of claims 1 to 3, wherein in the neutralization step, the first glycerin-containing liquid is neutralized so as to have a pH of 4 to 8.
- 前記メタン発酵工程において、前記第二のグリセリン含有液に加え、窒素及び/又はリンを含む副原料をメタン発酵槽に投入することを特徴とする請求項1~4のいずれか一項に記載のメタン発酵方法。 The invention according to any one of claims 1 to 4, wherein in the methane fermentation step, an auxiliary raw material containing nitrogen and / or phosphorus is charged into the methane fermentation tank in addition to the second glycerin-containing liquid. Methane fermentation method.
- 前記副原料が、生ごみ、畜糞尿、リン酸、リン酸塩、アンモニア、及びアンモニウム塩からなる群より選択される1種または2種以上であることを特徴とする請求項5に記載のメタン発酵方法。 The methane according to claim 5, wherein the auxiliary raw material is one or more selected from the group consisting of food waste, livestock manure, phosphoric acid, phosphate, ammonia, and ammonium salt. Fermentation method.
- 前記メタン発酵槽内の消化汚泥の総窒素(T-N)濃度が100~10,000mg/Lとなるように、前記副原料を添加することを特徴とする請求項5または6に記載のメタン発酵方法。 The methane according to claim 5 or 6, wherein the auxiliary raw material is added so that the total nitrogen (TN) concentration of the digested sludge in the methane fermenter is 100 to 10,000 mg / L. Fermentation method.
- 前記メタン発酵槽内のCODcr負荷が2~20kg/m3・dayとなるように、前記第二のグリセリン含有液の投入量を調節することを特徴とする請求項1~7のいずれか一項に記載のメタン発酵方法。 Any one of claims 1 to 7, wherein the input amount of the second glycerin-containing liquid is adjusted so that the CODcr load in the methane fermentation tank is 2 to 20 kg / m 3 days. The methane fermentation method described in.
- 前記第二のグリセリン含有液のメタン発酵以外の用途の需要に応じて、前記第二のグリセリン含有液のメタン発酵工程への供給量を調整することを特徴とする請求項1~8のいずれか一項に記載のメタン発酵方法。 Any of claims 1 to 8, wherein the supply amount of the second glycerin-containing liquid to the methane fermentation step is adjusted according to the demand for applications other than methane fermentation of the second glycerin-containing liquid. The methane fermentation method according to item 1.
- アルカリ触媒法以外の方法であって、酸触媒法、酸アルカリ触媒法、生体触媒法、イオン交換樹脂法、超臨界法、亜臨界法および固体触媒法からなる群より選択される少なくとも一つの方法により、脂肪酸アルキルエステルを製造するエステル化工程を備え、
前記エステル化工程においては、前記第一の分離工程で分離された第一の油分および/または前記第二の分離工程で分離された第二の油分を原料として用いる
ことを特徴とする請求項1~9のいずれか一項に記載のメタン発酵方法。 At least one method other than the alkali catalyst method, which is selected from the group consisting of an acid catalyst method, an acid alkali catalyst method, a biocatalyst method, an ion exchange resin method, a supercritical method, a subcritical method and a solid catalyst method. With an esterification step to produce a fatty acid alkyl ester
Claim 1 is characterized in that, in the esterification step, the first oil component separated in the first separation step and / or the second oil component separated in the second separation step is used as a raw material. The methane fermentation method according to any one of 9 to 9. - 前記エステル化工程で得られた脂肪酸アルキルエステルの少なくとも一部を用いて発電する発電工程を備えることを特徴とする請求項10に記載のメタン発酵方法。 The methane fermentation method according to claim 10, further comprising a power generation step of generating electricity using at least a part of the fatty acid alkyl ester obtained in the esterification step.
- 前記第二のグリセリン含有液のメタン発酵以外の用途の需要に応じて、前記第二のグリセリン含有液の前記メタン発酵工程への供給量を調整するとともに、前記脂肪酸アルキルエステルの需要に応じて、前記脂肪酸アルキルエステルの前記発電工程への供給量を調整することを特徴とする請求項11に記載のメタン発酵方法。 The supply amount of the second glycerin-containing liquid to the methane fermentation step is adjusted according to the demand for applications other than methane fermentation of the second glycerin-containing liquid, and the fatty acid alkyl ester is used according to the demand. The methane fermentation method according to claim 11, wherein the supply amount of the fatty acid alkyl ester to the power generation step is adjusted.
- グリセリンおよび脂肪酸グリセリンエステルの少なくとも1種を含有する原料からメタンを含むバイオガスを製造するメタン発酵システムであって、
前記原料と無機酸とを混合し、第一の油分と第一のグリセリン含有液とを分離する第一の分離装置と、
前記第一のグリセリン含有液をアルカリ性物質により中和する中和装置と、
中和された前記第一のグリセリン含有液から、第二の油分および析出した無機塩を分離して第二のグリセリン含有液を得る第二の分離装置と、
前記第二のグリセリン含有液を用いてメタン発酵を行うメタン発酵装置と、
を備えることを特徴とするメタン発酵システム。 A methane fermentation system that produces biogas containing methane from raw materials containing at least one of glycerin and fatty acid glycerin ester.
A first separation device that mixes the raw material and an inorganic acid to separate the first oil and the first glycerin-containing liquid.
A neutralizer that neutralizes the first glycerin-containing liquid with an alkaline substance,
A second separation device that separates the second oil and the precipitated inorganic salt from the neutralized first glycerin-containing liquid to obtain a second glycerin-containing liquid.
A methane fermentation apparatus that performs methane fermentation using the second glycerin-containing liquid, and
A methane fermentation system characterized by being equipped with. - 前記第二の分離装置の後段に、前記第二のグリセリン含有液を貯留するグリセリン貯留タンクを備え、
前記グリセリン貯留タンクは、貯留された前記第二のグリセリン含有液の量を検知する検知計を備え、
前記第二のグリセリン含有液の量が所定量以上となった場合に、前記第二のグリセリン含有液が前記メタン発酵装置へ供給される
ことを特徴とする請求項13に記載のメタン発酵システム。 A glycerin storage tank for storing the second glycerin-containing liquid is provided after the second separation device.
The glycerin storage tank includes a detector that detects the amount of the second glycerin-containing liquid stored.
The methane fermentation system according to claim 13, wherein the second glycerin-containing liquid is supplied to the methane fermentation apparatus when the amount of the second glycerin-containing liquid exceeds a predetermined amount. - アルカリ触媒法以外の方法であって、酸触媒法、酸アルカリ触媒法、生体触媒法、イオン交換樹脂法、超臨界法、亜臨界法および固体触媒法からなる群より選択される少なくとも一つの方法により、脂肪酸アルキルエステルを製造するエステル化装置を備え、
前記第一の分離工程で分離された第一の油分および/または前記第二の分離工程で分離された第二の油分が、原料として前記エステル化装置に供給される
ことを特徴とする請求項13または14に記載のメタン発酵システム。 At least one method other than the alkali catalyst method, which is selected from the group consisting of an acid catalyst method, an acid alkali catalyst method, a biocatalyst method, an ion exchange resin method, a supercritical method, a subcritical method and a solid catalyst method. Esterifying equipment for producing fatty acid alkyl esters
The claim is characterized in that the first oil separated in the first separation step and / or the second oil separated in the second separation step is supplied to the esterification apparatus as a raw material. The methane fermentation system according to 13 or 14. - 前記エステル化装置の後段に、前記脂肪酸アルキルエステルを貯留する脂肪酸アルキルエステル貯留タンクを備えるともに、
前記脂肪酸アルキルエステル貯留タンクの後段に、前記脂肪酸アルキルエステルを用いて発電する発電装置を備え、
前記脂肪酸アルキルエステル貯留タンクは、貯留された前記脂肪酸アルキルエステルの量を検知する検知計を備え、
前記脂肪酸アルキルエステルの量が所定量以上となった場合に、前記脂肪酸アルキルエステルが前記発電装置へ供給される
ことを特徴とする請求項15に記載のメタン発酵システム。 A fatty acid alkyl ester storage tank for storing the fatty acid alkyl ester is provided after the esterification apparatus, and
A power generation device that generates electricity using the fatty acid alkyl ester is provided after the fatty acid alkyl ester storage tank.
The fatty acid alkyl ester storage tank includes a detector that detects the amount of the stored fatty acid alkyl ester.
The methane fermentation system according to claim 15, wherein the fatty acid alkyl ester is supplied to the power generation device when the amount of the fatty acid alkyl ester exceeds a predetermined amount. - グリセリンおよび脂肪酸グリセリンエステルの少なくとも1種を含有する廃棄物を再利用する方法であって、
前記廃棄物と無機酸とを混合し、第一の油分と第一のグリセリン含有液とを分離する第一の分離工程と、
前記第一のグリセリン含有液をアルカリ性物質により中和する中和工程と、
中和された前記第一のグリセリン含有液から、第二の油分および析出した無機塩を分離して第二のグリセリン含有液を得る第二の分離工程と、
前記第二のグリセリン含有液を用いてメタン発酵を行う発酵工程と、
を備えることを特徴とする廃棄物再利用方法。 A method of reusing waste containing at least one of glycerin and fatty acid glycerin ester.
The first separation step of mixing the waste and the inorganic acid to separate the first oil and the first glycerin-containing liquid,
A neutralization step of neutralizing the first glycerin-containing liquid with an alkaline substance, and
A second separation step of separating the second oil and the precipitated inorganic salt from the neutralized first glycerin-containing liquid to obtain a second glycerin-containing liquid.
A fermentation step in which methane fermentation is performed using the second glycerin-containing liquid, and
A waste recycling method characterized by providing. - 前記第二のグリセリン含有液のメタン発酵以外の用途の需要に応じて、前記第二のグリセリン含有液のメタン発酵工程への供給量を調整することを特徴とする請求項17に記載の廃棄物再利用方法。 The waste according to claim 17, wherein the supply amount of the second glycerin-containing liquid to the methane fermentation step is adjusted according to the demand for uses other than the methane fermentation of the second glycerin-containing liquid. Reuse method.
- アルカリ触媒法以外の方法であって、酸触媒法、酸アルカリ触媒法、生体触媒法、イオン交換樹脂法、超臨界法、亜臨界法および固体触媒法からなる群より選択される少なくとも一つの方法により、脂肪酸アルキルエステルを製造するエステル化工程を備え、
前記エステル化工程においては、前記第一の分離工程で分離された第一の油分および/または前記第二の分離工程で分離された第二の油分を原料として用いる
ことを特徴とする請求項17または18に記載の廃棄物再利用方法。 At least one method other than the alkali catalyst method, which is selected from the group consisting of an acid catalyst method, an acid alkali catalyst method, a biocatalyst method, an ion exchange resin method, a supercritical method, a subcritical method and a solid catalyst method. With an esterification step to produce a fatty acid alkyl ester
17. The esterification step is characterized in that the first oil separated in the first separation step and / or the second oil separated in the second separation step is used as a raw material. Alternatively, the waste recycling method according to 18. - 前記エステル化工程で得られた脂肪酸アルキルエステルの少なくとも一部を用いて発電する発電工程を備え、
前記第二のグリセリン含有液のメタン発酵以外の用途の需要に応じて、前記第二のグリセリン含有液の前記メタン発酵工程への供給量を調整するとともに、前記脂肪酸アルキルエステルの需要に応じて、前記脂肪酸アルキルエステルの前記発電工程への供給量を調整することを特徴とする請求項19に記載の廃棄物再利用方法。 A power generation step for generating electricity using at least a part of the fatty acid alkyl ester obtained in the esterification step is provided.
The supply amount of the second glycerin-containing liquid to the methane fermentation step is adjusted according to the demand for applications other than methane fermentation of the second glycerin-containing liquid, and the fatty acid alkyl ester is used according to the demand. The waste recycling method according to claim 19, wherein the supply amount of the fatty acid alkyl ester to the power generation step is adjusted. - グリセリンおよび脂肪酸グリセリンエステルの少なくとも1種を含有する廃棄物を再利用するシステムであって、
前記廃棄物と無機酸とを混合し、第一の油分と第一のグリセリン含有液とを分離する第一の分離装置と、
前記第一のグリセリン含有液をアルカリ性物質により中和する中和装置と、
中和された前記第一のグリセリン含有液から、第二の油分および析出した無機塩を分離して第二のグリセリン含有液を得る第二の分離装置と、
前記第二のグリセリン含有液を用いてメタン発酵を行うメタン発酵装置と、
を備えることを特徴とする廃棄物再利用システム。 A system for reusing waste containing at least one of glycerin and fatty acid glycerin ester.
A first separation device that mixes the waste with an inorganic acid and separates the first oil and the first glycerin-containing liquid.
A neutralizer that neutralizes the first glycerin-containing liquid with an alkaline substance,
A second separation device that separates the second oil and the precipitated inorganic salt from the neutralized first glycerin-containing liquid to obtain a second glycerin-containing liquid.
A methane fermentation apparatus that performs methane fermentation using the second glycerin-containing liquid, and
A waste recycling system characterized by being equipped with. - 前記第二の分離装置の後段に、第二のグリセリン含有液を貯留するグリセリン貯留タンクを備え、
前記グリセリン貯留タンクは、貯留された前記第二のグリセリン含有液の量を検知する検知計を備え、
前記第二のグリセリン含有液の量が所定量以上となった場合に、前記第二のグリセリン含有液が前記メタン発酵装置へ供給される
ことを特徴とする請求項21に記載の廃棄物再利用システム。 A glycerin storage tank for storing the second glycerin-containing liquid is provided after the second separation device.
The glycerin storage tank includes a detector that detects the amount of the second glycerin-containing liquid stored.
The waste reuse according to claim 21, wherein the second glycerin-containing liquid is supplied to the methane fermentation apparatus when the amount of the second glycerin-containing liquid exceeds a predetermined amount. system. - アルカリ触媒法以外の方法であって、酸触媒法、酸アルカリ触媒法、生体触媒法、イオン交換樹脂法、超臨界法、亜臨界法および固体触媒法からなる群より選択される少なくとも一つの方法により、脂肪酸アルキルエステルを製造するエステル化装置を備え、
前記第一の分離工程で分離された第一の油分および/または前記第二の分離工程で分離された第二の油分が、原料として前記エステル化装置に供給される
ことを特徴とする請求項21または22に記載の廃棄物再利用システム。 At least one method other than the alkali catalyst method, which is selected from the group consisting of an acid catalyst method, an acid alkali catalyst method, a biocatalyst method, an ion exchange resin method, a supercritical method, a subcritical method and a solid catalyst method. Esterifying equipment for producing fatty acid alkyl esters
The claim is characterized in that the first oil separated in the first separation step and / or the second oil separated in the second separation step is supplied to the esterification apparatus as a raw material. 21 or 22. The waste recycling system. - 前記エステル化装置の後段に、前記脂肪酸アルキルエステルを貯留する脂肪酸アルキルエステル貯留タンクを備えるともに、
前記脂肪酸アルキルエステル貯留タンクの後段に、前記脂肪酸アルキルエステルを用いて発電する発電装置を備え、
前記脂肪酸アルキルエステル貯留タンクは、貯留された前記脂肪酸アルキルエステルの量を検知する検知計を備え、
前記脂肪酸アルキルエステルの量が所定量以上となった場合に、前記脂肪酸アルキルエステルが前記発電装置へ供給される
ことを特徴とする請求項23に記載の廃棄物再利用システム。 A fatty acid alkyl ester storage tank for storing the fatty acid alkyl ester is provided after the esterification apparatus, and
A power generation device that generates electricity using the fatty acid alkyl ester is provided after the fatty acid alkyl ester storage tank.
The fatty acid alkyl ester storage tank includes a detector that detects the amount of the stored fatty acid alkyl ester.
The waste recycling system according to claim 23, wherein the fatty acid alkyl ester is supplied to the power generation device when the amount of the fatty acid alkyl ester exceeds a predetermined amount.
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Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010065154A (en) * | 2008-09-11 | 2010-03-25 | Central Res Inst Of Electric Power Ind | Solid fuel and method for producing the same |
CN103772149A (en) * | 2012-10-28 | 2014-05-07 | 青岛嘉能节能环保技术有限公司 | Method for refining crude glycerine being by-product of biodiesel |
WO2017174775A1 (en) * | 2016-04-07 | 2017-10-12 | A & C Freeman | Process for recovery of glycerol from biodiesel production streams |
WO2019039531A1 (en) * | 2017-08-23 | 2019-02-28 | バイオ燃料技研工業株式会社 | Water treatment method, water treatment system, method for producing denitrifying agent, and apparatus for producing denitrifying agent |
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Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010065154A (en) * | 2008-09-11 | 2010-03-25 | Central Res Inst Of Electric Power Ind | Solid fuel and method for producing the same |
CN103772149A (en) * | 2012-10-28 | 2014-05-07 | 青岛嘉能节能环保技术有限公司 | Method for refining crude glycerine being by-product of biodiesel |
WO2017174775A1 (en) * | 2016-04-07 | 2017-10-12 | A & C Freeman | Process for recovery of glycerol from biodiesel production streams |
WO2019039531A1 (en) * | 2017-08-23 | 2019-02-28 | バイオ燃料技研工業株式会社 | Water treatment method, water treatment system, method for producing denitrifying agent, and apparatus for producing denitrifying agent |
Non-Patent Citations (2)
Title |
---|
SILES LOPEZ, J. A. ET AL.: "Anaerobic digestion of glycerol derived from biodiesel manufacturing", BIORESOURCE TECHNOLOGY, vol. 100, 2009, pages 5609 - 5615, XP026469458, DOI: 10.1016/j.biortech.2009.06.017 * |
TAKESHITA, TOSHIHIRO: "Application of Dilution and Neutralization to Recycling of Glycerol Waste Fluid Left after Manufacturing Bio-diesel Fuel", OLEOSCIENCE, vol. 17, no. 7, 2017, pages 305 - 311, XP055751568 * |
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