JP2009040980A - Method for liquefying and recovering fatty acid and oil-and-fat from waste oil-and-fat containing water and fatty acid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for selectively dehydrating and recovering fatty acids and/or oils and fats from a material containing water and the fatty acids and/or the oils and fats. <P>SOLUTION: Fatty acids and/or oils and fats are selectively dehydrated and recovered from the material containing water and the fatty acids and/or the oils and fats by adding liquefied dimethyl ether (DME) as an extraction medium to the material containing water and the fatty acids and/or oils and fats to bring the fatty acids and the oils and fats to be a liquefied DME solution and selectively dehydrating and recovering the components. The method can be applied to water-containing edible oils and fats, waste edible oils and fats containing water and/or non-oils and fats, waste oils and fats except the waste edible oils and fats, and the like used as the raw material for producing a biodiesel fuel (BDF). By the method, water and the like which are factors inhibiting generation reaction of the BDF can easily and rapidly be removed with low energy from the raw material oils and fats used for producing the BDF. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for selectively dehydrating and recovering fatty acids and / or fats and oils from substances containing water and fatty acids and / or fats and oils, and in particular, in the production of diesel fuel, water and fatty acids and / or fats and oils are included. The present invention relates to a method for selectively dehydrating and recovering fatty acids and / or fats and oils from a substance containing water and fatty acids and / or fats and oils in order to prepare a raw material oil for producing diesel fuel from the substances.

  In recent years, from the viewpoint of global warming prevention and resource circulation, attention has been focused on technological development related to manufacturing technology of biofuels such as waste biomass, bioethanol and biodiesel fuel (BDF). Biodiesel fuel is rapeseed oil, palm oil, olive oil, sunflower oil, coconut oil, soybean oil, rice oil, and other vegetable oils, beef tallow and other animal fats, fish oil, and edible oils such as waste edible oil, or trap grease. Diesel fuel (fatty acid methyl ester) synthesized from low-quality waste oils and fats (such as mud oils floating on the surface of drainage), and is already spreading in Europe, North America, Latin America, Southeast Asia, etc. .

  Biodiesel fuel (BDF) is produced by subjecting monoglycerides, diglycerides, and monoglycerides, which are the main components of fats and oils, to transesterification with lower alcohols such as ethanol. A method has been proposed. For example, in general, an alkali catalyst method is used in which a fat or oil is subjected to a transesterification reaction using a lower alcohol such as methanol in the presence of an alkali catalyst such as NaOH or KOH (Japanese Patent Laid-Open No. 7-1993). 197047, JP-A-10-245586, JP-A-2005-350630, JP-A-2005-350631, JP-A-2005-350632).

  Further, a method for producing an alkyl ester of a fatty acid by keeping the alcohol in a supercritical state at a temperature of 250 to 300 ° C. and a pressure of 3 to 15 MPa (supercritical method) (JP 2000-109833, JP 2000-143586), a method using a solid catalyst comprising a potassium compound and zirconium oxide, or a fixed catalyst such as a catalyst comprising a composite metal oxide having a perovskite structure (Japanese Patent Laid-Open No. 2000-44984) Various methods such as a method using a volatile catalyst composed of a volatile amine such as methylamine and dimethylamine (Japanese Patent Laid-Open No. 2002-167356) have been proposed. Yes.

  As described above, various methods are known for producing biodiesel fuel (BDF). When producing biodiesel fuel (BDF) using these methods, waste oil used as a raw material is used. It is necessary to remove substances that inhibit the biodiesel fuel (BDF) production reaction. In particular, as an inhibitor of the biodiesel fuel (BDF) production reaction, water, free fatty acids, and the like contained in waste oils and fats are problematic. For example, in the United States, instead of waste cooking oil, use of lower-quality waste fats and oils such as trap grease as BDF raw materials has been studied (Trans. ASAE, 44, 1429-1436, 2001). Trap grease is a muddy oil that floats on the surface of drainage in a collector installed before public sewer drainage, and contains a large amount of free fatty acid (FFA) and water. In the investigation by the present inventors, the FFA content in the fat and oil of the trap grease was as high as about 40 to 100% by mass, and the water content was as high as about 20 to 60% by mass of the entire trap grease.

  Incidentally, moisture and free fatty acids (FFA) inhibit the biodiesel fuel (BDF) production reaction. For example, in the above-mentioned homogeneous alkali method, which is currently the mainstream as a BDF production method, free fatty acids of fats and oils that can be used as raw materials Standards for (FFA) content and water content are set (Journal of the Waste Society, 17, 193-203, 2006). However, these reference values are set to a level one digit or more lower than the values of free fatty acid (FFA) content and moisture content in the trap grease. Therefore, low-quality waste oils and fats such as trap grease cannot be used as they are in place of relatively high-quality waste oils and fats such as waste edible oil. In order to use for the manufacturing method of BDF, pre-treatments such as dehydration from low-quality waste oils and fats and removal of free fatty acids (FFA) are required.

  In inhibitors of biodiesel fuel (BDF) production reactions, for example, removal of free fatty acids (FFA) can be achieved by reacting free fatty acids (FFA) with alcohols such as methanol to produce fatty acid alkyl esters. It is known. On the other hand, as a conventional method for dewatering waste oil and sludge with a high water content, (decompression) heating dehydration method, filter press method, centrifugation method, etc. are known. However, it cannot be dehydrated to a level that can be used in a method for producing biodiesel fuel (BDF), and it is necessary to use a (depressurized) heating dehydration method. Moreover, in order to remove free fatty acid from raw material oil, a method of providing a step of distilling free fatty acid under reduced pressure at a temperature of 50 to 150 ° C. is known (Japanese Patent Laid-Open No. 2005-350631). Issue gazette).

  However, when biodiesel fuel (BDF) is produced on a practical scale, the amount of raw material fats and oils becomes a considerable amount, and when applying the (depressurization) heating dehydration method to the raw material fats and oils, it is enormous. It is necessary to input latent heat of vaporization. For this reason, it has not been practical enough in terms of impact on the global environment and cost. Of the low-quality waste oils and fats, trap grease, in particular, is often in the form of mud or gel, and even if it can be dehydrated, it often becomes a solid. Therefore, in order to apply low-quality waste oils and fats to reaction systems such as the production of biodiesel fuel (BDF), it is also necessary to dehydrate and further liquefy with an appropriate solvent. Thus, in the practical production of biodiesel fuel (BDF), separation of water, free fatty acids, and the like, which are inhibitors of the production reaction of biodiesel fuel (BDF), is an important issue. However, the effective removal method applicable to various raw oils and fats can be effectively separated from the raw oils and fats in the production of biodiesel fuel (BDF) with low energy and low cost. Not developed.

  On the other hand, dimethyl ether (DME) is known as a substance that is a kind of ether compound, is a gas under normal temperature and normal pressure (about 0.1 MPa), and becomes liquid under a pressure of about 0.5 MPa. Dimethyl ether is currently used as an aerosol propellant, and has recently attracted attention as an alternative diesel and alternative propane. Recently, a technique using this dimethyl ether for dehydration has been disclosed. For example, in the pamphlet of International Publication No. WO2003 / 101579, a liquefied product of dimethyl ether (DME) is brought into contact with a water-containing solid (such as coal), and the solid-containing water is dissolved in the liquefied dimethyl ether (DME) to obtain a solid. A method for removing the moisture is disclosed.

  In addition, JP 2007-83122 A discloses a liquefied substance of a substance which is a gas under normal temperature and normal pressure conditions such as dimethyl ether to a water-containing substance such as sanitary goods, disposable diapers, or wood chips and leftover rice, A method of dehydrating a water-containing material by dissolving water in the water-containing material in a liquefied product is disclosed. However, the target field of the disclosed method is completely different from the raw oils and fats used for biodiesel fuel (BDF) production, and the dehydration method itself is also biodiesel fuel (BDF) production. It is different from those applied to the raw oils and fats used in the above.

JP-A-7-197047. JP-A-10-245586. JP 2000-44984 A. JP 2000-109833 A. JP 2000-143586 A. JP 2002-167356 A. JP 2002-294277 A. JP-A-2005-350630. Japanese Patent Laying-Open No. 2005-350631. JP-A-2005-350632. JP 2007-83122 A. International Publication WO2003 / 101579 Pamphlet Trans. ASAE, 44, 1429-1436, 2001. Journal of Japan Society for Waste Management, 17, 193-203, 2006.

  An object of the present invention is to provide a method for selectively dehydrating and recovering fatty acids and / or fats and oils from a substance containing water and fatty acids and / or fats and oils, in particular, in the production of biodiesel fuel, water and fatty acids and / or fats and oils. In order to prepare a raw material oil that can be effectively used for the production of biodiesel fuel from a substance containing, the fatty acid and / or fat from the substance containing water and fatty acid and / or fat, The object is to provide a method for selective dehydration and recovery quickly and with low energy.

  The present inventor, in the production of biodiesel fuel (BDF), from waste oils and fats and the like containing water and fatty acids and / or fats and oils, such as water that becomes a factor that inhibits the production reaction of biodiesel fuel (BDF), As a method for preparing a raw material oil that can be easily and effectively removed and effectively used for the production of biodiesel fuel (BDF), a substance containing water and fatty acids and / or fats and oils has been studied. , By adding liquefied dimethyl ether (DME) as an extraction solvent, and selectively dehydrating and collecting fatty acids and / or fats and oils as liquefied dimethyl ether (DME) solutions, from substances containing water and fatty acids and / or fats and oils, It has been found that selective dehydration and recovery of fatty acids and / or fats and oils can be performed, and the present invention has been completed.

  In the present invention, as a substance containing water and fatty acid and / or fats and oils for selective dehydration / recovery of fatty acids and / or fats and oils, edible water containing water used as a raw material for producing biodiesel fuel (BDF) Examples include waste edible fats and oils containing oils and fats, water and / or non-fats, and waste fats and oils other than waste edible fats and oils. The method for selective dehydration / recovery of fats and oils of the present invention is also effectively applied to oils and fats containing water containing mud or gel fatty acids and / or solids of fats and oils. be able to.

  The method of selectively dehydrating and recovering fatty acids and / or fats and oils from a substance containing water and fatty acids and / or fats and oils according to the present invention includes liquefied dimethyl ether (DME) to a substance containing water and fatty acids and / or fats and oils. Is added as an extraction solvent and stirred to form a homogeneous liquid phase, and then allowed to stand to form a two-liquid phase consisting of a liquefied dimethyl ether (DME) phase and an aqueous phase. ) By separating the phases. In the present invention, liquefied dimethyl ether (DME) is added as an extraction solvent to a substance containing water and fatty acids and / or fats and oils, and the fatty acids and / or fats and oils are selectively dehydrated and recovered as a liquefied dimethyl ether (DME) solution. In doing so, by adding a light oil component to the extraction solvent, the dehydration efficiency can be increased, and the water content of the separated fatty acids and / or fats and oils can be set to a very low water content of 1 wt% or less. Examples of the light oil component in such a case include hydrocarbons such as hexadecane. Moreover, as addition amount of a light oil component, it is preferable to add in 10-50 volume% with respect to the extraction processing liquid whole quantity.

  In the present invention, liquefied dimethyl ether (DME) is added as an extraction solvent to a substance containing water and fatty acids and / or fats and oils, and the fatty acids and / or fats and oils are selectively dehydrated and recovered as a liquefied dimethyl ether (DME) solution. The treatment is preferably performed at a temperature in the range of 10 to 35 ° C. In particular, the temperature in the selective dehydration and recovery treatment is adjusted to the range of 30 to 35 ° C. to increase the dehydration efficiency, and the water content of the separated fatty acid and / or fat is reduced by 1 to 3 wt%. It can be.

  Further, the present invention provides a method for selectively dehydrating and recovering fatty acids and / or fats and oils from substances containing water and fatty acids and / or fats and oils of the present invention, and dehydrated fatty acids and / or fats and liquefied dimethyl ether (DME). And a method for preparing a feedstock for the production of biodiesel fuel (BDF). A method for producing the biodiesel fuel (BDF) is not particularly limited, but a method for preparing a raw material oil in a method for producing a biodiesel fuel in which a transesterification reaction is performed in a homogeneous phase system to which liquefied dimethyl ether (DME) is added (separately , Patent application: Japanese Patent Application No. 2007-210501), extremely advantageous effects can be obtained. That is, the fatty acids and / or fats and oils selectively dehydrated and recovered in the present invention can be recovered as a solution of liquefied dimethyl ether (DME), and these fats and oils can be directly used for producing biodiesel fuel (BDF). This is because it can be used as a raw material oil, and the liquefied dimethyl ether (DME) contained can be used as it is for the production of biodiesel fuel (BDF).

  Furthermore, the method for preparing a raw material oil for the production of biodiesel fuel (BDF) of the present invention can be carried out in combination with an esterification reaction of free fatty acid using an acid catalyst and a lower alcohol. By esterifying the free fatty acid using the acid catalyst and lower alcohol, the free fatty acid contained in the raw fats and oils used in the production of biodiesel fuel (BDF) is esterified (biodiesel fuel), It is possible to simultaneously remove water and free fatty acids that are factors that inhibit the production reaction of biodiesel fuel (BDF).

Specifically, the present invention specifically comprises (1) adding a liquefied dimethyl ether as an extraction solvent to a substance containing water and a fatty acid and / or fat, and selectively dehydrating the fatty acid and / or fat as a liquefied dimethyl ether solution. A method for selectively dehydrating and recovering fatty acids and / or fats and oils from substances containing water and fatty acids and / or fats and oils,
(2) Substances containing water and fatty acids and / or fats and oils are edible fats and oils containing water, waste edible fats and oils containing water and / or non-fats or waste fats and oils other than waste edible fats and oils The method for selective dehydration and recovery of fatty acids and / or fats and oils from substances containing water and fatty acids and / or fats and oils as described in (1) above,
(3) The substance according to (1) or (2) above, wherein the substance containing water and fatty acids and / or fats and oils contains a solid matter of mud or gel fatty acids and / or fats and oils A method for selective dehydration and recovery of fatty acids and / or fats and oils from substances containing water and fatty acids and / or fats and oils;
(4) Add liquefied dimethyl ether as an extraction solvent to a substance containing water and fatty acids and / or fats and oils, and stir to form a uniform liquid phase; And / or a fatty acid from a substance containing water and a fatty acid and / or an oil and fat according to any one of the above (1) to (3), wherein the liquefied dimethyl ether phase is separated from the phase. A method for selective dehydration and recovery of fats and oils,
(5) When a liquefied dimethyl ether is added as an extraction solvent to a substance containing water and fatty acids and / or fats and oils, and the fatty acids and / or fats and oils are selectively dehydrated and recovered as a liquefied dimethyl ether solution, A method for selectively dehydrating and recovering fatty acids and / or fats and oils from substances containing water and fatty acids and / or fats and oils according to any one of (1) to (4) above,
(6) The substance containing water and fatty acids and / or fats and oils according to (5) above, wherein the light oil component is added in an amount of 10 to 50% by volume based on the total amount of the extraction treatment liquid. For selective dehydration and recovery of fatty acids and / or fats from
(7) A process in which liquefied dimethyl ether is added as an extraction solvent to a substance containing water and fatty acids and / or fats and oils, and the fatty acid and / or fats and oils are selectively dehydrated and recovered as a liquefied dimethyl ether solution at a temperature of 10 to 35. The method for selective dehydration and recovery of fatty acids and / or fats and oils from substances containing water and fatty acids and / or fats and oils according to any one of (1) to (6),
(8) A process in which liquefied dimethyl ether is added as an extraction solvent to a substance containing water and fatty acids and / or fats and oils, and the fatty acid and / or fats and oils are selectively dehydrated and recovered as a liquefied dimethyl ether solution at a temperature of 30 to 35. The method comprises the method for selective dehydration / recovery of fatty acids and / or fats and oils from a substance containing water and fatty acids and / or fats and oils according to the above (7), which is carried out by adjusting the temperature to a range of ° C.

Further, the present invention is (9) dehydrated by the method for selective dehydration / recovery of fatty acids and / or fats from substances containing water and fatty acids and / or fats and oils according to any one of (1) to (8) above. A method for preparing a raw material oil for biodiesel fuel production, characterized in that a substance containing fatty acid and / or fat and oil and liquefied dimethyl ether is prepared,
(10) The feedstock for producing biodiesel fuel according to (9) above, wherein the biodiesel fuel is produced by a method of transesterification in a homogeneous phase system to which liquefied dimethyl ether is added The preparation method of
(11) The above (9) or (10), wherein the preparation of the raw material oil for the production of biodiesel fuel is carried out in combination with an esterification reaction of a free fatty acid using an acid catalyst and a lower alcohol. The method for preparing a feedstock for the production of biodiesel.

  According to the present invention, in the production of biodiesel fuel (BDF), water and the like that are factors that inhibit the production reaction of biodiesel fuel (BDF) from waste oils and fats containing water and fatty acids and / or fats and oils. It can be removed easily and effectively with low energy without using conventional heat treatment and decompression treatment, and it is extremely useful as a practical technology in the production of biodiesel fuel (BDF). Have In particular, the method of the present invention is applicable to edible fats and oils containing water, used as a raw material for producing biodiesel fuel (BDF), waste edible fats and oils or waste edible fats and oils containing water and / or non-fats. It can be applied to a wide range of fats and oils such as waste oils and fats, and raw oils that can produce biodiesel fuel from waste oils and fats of particularly low quality such as trap greases can be quickly and low-energy It is also very useful in terms of environmental measures.

  Furthermore, the raw material oil for production of biodiesel fuel (BDF) prepared by the method of the present invention can easily and effectively remove moisture and the like that inhibit the biodiesel fuel (BDF) formation reaction. In addition to that, the biodiesel fuel (BDF) production reaction using the raw oil is promoted, and further, the biodiesel fuel (BDF) produced from the reaction liquid produced by the biodiesel fuel (BDF) production reaction ( The BDF component can be easily and easily separated and recovered, and this has a very high practical effect in the production of biodiesel fuel (BDF). Therefore, the technology of the present invention has a great contribution to the practical application of biodiesel fuel (BDF).

  The present invention is characterized in that liquefied dimethyl ether is added as an extraction solvent to a substance containing water and fatty acids and / or fats and oils, and the fatty acids and / or fats and oils are selectively dehydrated and recovered as a liquefied dimethyl ether solution. And a method for selective dehydration and recovery of fatty acids and / or fats and oils from substances containing fatty acids and / or fats and oils. The “dehydration” in the present invention includes not only the case where moisture is completely removed but also the case where moisture is reduced.

The substance containing water and fatty acid and / or fat used in the dehydration method of the present invention is not particularly limited as long as it is a substance containing water and fatty acid and / or fat,
Examples include edible fats and oils containing water used as a raw material for producing biodiesel fuel (BDF), waste edible fats and oils containing water and / or non-fats, and waste fats and oils other than waste edible fats and oils, etc. The Further, as the waste oils and fats, any of the above-mentioned substances such as solid, liquid, gel, and mud can be used. Specifically, trap grease (installed before public sewer drainage) Examples thereof include muddy oils and fats floating on the drainage surface in the interceptor and waste edible oil (liquid, solid, gel, etc.) containing water.

  The fatty acid is not particularly limited and may be any of saturated fatty acid, unsaturated fatty acid, branched fatty acid, hydroxyl fatty acid and the like, but one or more selected from the group consisting of C12 to C28 fatty acids. Fatty acids can be preferably exemplified, and specifically, lauric acid, myristic acid, pentadecylic acid, palmitic acid, palmitoyl acid, stearic acid, linoleic acid, linolenic acid, arachidonic acid and the like can be suitably exemplified.

  The oil and fat is not particularly limited and may be any of triglyceride, diglyceride, monoglyceride, etc., but is preferably triglyceride, and the constituent fatty acid of triglycerin is selected from the group consisting of C12 to C28 fatty acids. A triglyceride which is a seed or two or more fatty acids can be exemplified more preferably. Specific examples of the fats and oils include soybean oil, sesame oil, rapeseed oil, rice oil, nutka oil, camellia oil, safflower oil (safflower oil), palm oil, palm shell oil, coconut oil, cottonseed oil, sunflower oil, coconut oil , Olive oil, peanut oil, almond oil, avocado oil, hazelnut oil, walnut oil, grape seed oil, fish oil, liver oil, salmon oil and other oils, lard (pig fat), het (beef tallow), chicken oil, schmalz And fats such as shortening, butter, margarine, cocoa butter, hydrogenated oil, and the like. In addition, non-edible vegetable fats and oils can also be used.

  In addition to water and fatty acids and / or fats and oils, the substance of the present invention may further contain an optional component such as a solid content such as fiber. The water content of the substance of the present invention is not particularly limited, but from the viewpoint of enjoying more benefits of the dehydration method of the present invention, it is preferably 10 wt% or more based on the total amount of the substance of the present invention, 20 wt% % Or more is more preferable, and it is further more preferable that it is 40 wt% or more.

  In the present invention, in order to selectively dehydrate and recover fatty acids and / or fats and oils from substances containing water and fatty acids and / or fats and oils, liquefied dimethyl ether is extracted into substances containing water and fatty acids and / or fats and oils. It is added and stirred as a solvent to form a homogeneous liquid phase, and then allowed to stand to form a two-liquid phase of a liquefied dimethyl ether phase and an aqueous phase, and the liquefied dimethyl ether phase is separated from the phase. However, the formation of the two-liquid phase of the ether phase and the aqueous phase in the process of the dehydration / recovery method of the present invention is, for example, by allowing the substance of the present invention to contain an ether compound, and then allowing it to stand or centrifuge. Although it can be carried out by separating the lower phase water phase and the upper phase ether phase, from the viewpoint of more easily obtaining higher dehydration efficiency, the substance of the present invention is mixed with an ether compound and stirred. The Luo it is preferable to standing. Moreover, when the solid substance is contained in the substance of the present invention, it usually precipitates and shifts to the lower aqueous phase.

  In the step of the dehydration / recovery method, the amount of the ether compound to be contained in the substance of the present invention is not particularly limited, but on the other hand, it should be an amount sufficient to dissolve the fatty acid and fat in the substance of the present invention. On the other hand, if it is too much, the dehydration efficiency may be slightly reduced. Therefore, it is preferable to balance both, and the amount that dissolves fatty acids and fats and oils in the substance of the present invention near the saturation concentration is the most. preferable.

  The method for removing the aqueous phase in the process of the dehydration / recovery method of the present invention is not particularly limited, and the ether phase may be recovered from the two liquid phases, or the aqueous phase may be removed from the two liquid phases. By removing the aqueous phase from the two-liquid phase, the substance of the present invention can be dehydrated simply, rapidly and with low energy without using heat treatment or reduced pressure treatment. Moreover, in the ether phase obtained by removing the aqueous phase, fatty acids and / or fats and oils in the substance of the present invention can be extracted with a very high yield.

  The dehydration method of the present invention can be suitably used as a pretreatment method for raw oils and / or raw fatty acids for producing biodiesel fuel (BDF). That is, by adding an ether compound to the substance of the present invention to form a two-liquid phase of an ether phase and an aqueous phase and removing the aqueous phase, the raw oil and fat for producing biodiesel fuel (BDF) and / or Alternatively, an ether phase solution as a raw fatty acid solution can be obtained. Biodiesel fuel (BDF) (fatty acid methyl ester) is obtained by carrying out a methyl esterification reaction by adding methanol and a suitable catalyst to the ether phase solution containing the raw oil and fat and / or raw fatty acid obtained by this pretreatment. ) Can be suitably produced.

  As the ether of the ether phase solution in the pretreatment method, the phase separation property is excellent, the toxicity is lower, the cost in the production of biodiesel fuel (BDF) and the environmental measures are superior, and liquefied dimethyl ether. Since (DME) is also used as an alternative light oil, dimethyl ether (DME) is particularly preferable because it is considered that there are few problems even if it is mixed in biodiesel fuel (BDF). For example, when biodiesel fuel (BDF) is produced using a liquefied dimethyl ether (DME) phase containing raw oil and / or fatty acid, dimethyl ether (DME) in a liquefied dimethyl ether (DME) phase containing biodiesel fuel (BDF) ( DME) can be vaporized to easily recover dimethyl ether (DME), and methanol in the glycerin phase containing glycerin as a by-product is distilled under reduced pressure using the recovered liquefied dimethyl ether (DME). It is superior in terms of cost and environmental measures because it can be extracted without any problems.

  In the present invention, in the case of waste oils and fats containing a large amount of free fatty acids and water in the raw material oil used for the transesterification reaction, such as low-quality waste oils and fats, the fatty acids and / or fats and oils of the present invention are selectively used. Combined with the dehydration and recovery method, esterification of free fatty acids using acid catalysts and lower alcohols is performed, and free fatty acids contained in raw oils and fats are esterified (biodiesel fuel) to produce biodiesel It is possible to simultaneously remove moisture and free fatty acids that are factors that inhibit the production reaction of fuel (BDF). That is, waste oils and fats are subjected to an esterification reaction with a lower alcohol in a homogeneous phase in which free fatty acids are added with liquefied dimethyl ether (DME) in the presence of an acid catalyst to produce fatty acid methyl esters from the free fatty acids and the like. The concentration of free fatty acids in the substance can be reduced, and then solvent extraction with liquefied dimethyl ether forms a two-liquid phase of an ether phase (upper phase) and an aqueous phase (lower phase). By removing the dehydration treatment, the raw material is dehydrated at low energy and low cost without adding latent heat of vaporization, and free fatty acids are removed and dehydrated to obtain the raw oil used in the transesterification reaction. Can be prepared.

  EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, the technical scope of this invention is not limited to these illustrations.

[Dehydration of waste oils and fats containing high concentrations of water and fatty acids using liquefied DME, and selective recovery of fatty acids and oils and fats 1]
(experimental method)
In order to investigate whether fatty acids and fats can be recovered from waste oils and fats containing high concentrations of water and fatty acids (high water content and high fatty acid content waste fats and oils) using liquefied DME, which is one of the ether compounds, The following experiment was conducted using the series of apparatuses shown in Fig. 1: First, 9 g of triolein, 6 g of palmitic acid and 3.75 g of water were mixed, and a high oil content and high fatty acid content waste oil model solution (hereinafter, Also referred to as “waste oil / fat model solution”. 18.75 g of this waste oil / fat model solution was added to the pressure-resistant glass cell (A), the cell was immersed in ice water, and the waste oil / fat model solution was cooled to about 10 ° C. or less. Thereafter, the valve (C) is opened, and the liquefied DME in the glass cylinder (B) is introduced into the glass cell (A). When about 11 g of liquefied DME enters the glass cell (A), the valve (C) is closed. It was. Next, the temperature of the temperature controller (D) was set to 25 ° C., and the mixture was heated and stirred until the solution in the glass cell (A) reached the set temperature. After confirming that the aqueous phase was formed and the solid palmitic acid was completely dissolved, the solution in the glass cell (A) was allowed to stand for 15 minutes. The solution in the glass cell (A) was divided into an upper liquefied DME phase and a lower aqueous phase.

  Subsequently, the solid oil and fatty acid extracted to the liquefied DME phase which flowed out from the liquefied DME collection | recovery line (F) by opening a valve | bulb (E) was sampled in the sample bottle (G). Thereafter, the moisture content of the sampled solid (solid sample) was measured with a Karl Fischer moisture meter. On the other hand, the valve (H) was opened, and the aqueous phase flowing out from the aqueous phase recovery line (I) was sampled in a sample bottle (J). The sampled aqueous solution was diluted with isopropanol, and the concentrations of triolein and palmitic acid were measured with a high performance liquid chromatograph.

(result)
As a result of the measurement by the moisture meter, the moisture content of the solid sample was about 2.5 wt% to 3.0 wt%. Compared with the moisture content (20 wt%) of the waste oil model solution before the experiment, the water content was reduced to 1/7 to 1/8, and the waste oil model solution can be efficiently dehydrated by liquefaction extraction with liquefied DME. It became clear. Further, when the experiment was performed in the same procedure except that the temperature of the temperature controller (D) was set to 35 ° C. and the amount of liquefied DME added was 9.75 g, the water content of the solid sample was about 1.4 wt%. Met. Furthermore, when the temperature controller (D) was set to 35 ° C., the amount of liquefied DME added was 7.5 g, and an experiment was performed in the same procedure except that light oil was added in addition to liquefied DME, a solid sample was obtained. The water content was 1.0 wt% or less.
On the other hand, as a result of the measurement by the high performance liquid chromatograph, the triolein concentration in the sampled aqueous solution was 13 ppm, and the palmitic acid concentration was 14 ppm. Based on this result, the recovery rates of triolein and palmitic acid in the solid sample were calculated from the waste oil and fat model solution, and it was found that both were 99.99% or more.

[Dehydration of waste oil containing high concentration of water and fatty acid using liquefied DME and selective recovery of fatty acid and oil 2]
(experimental method)
In the experiment of Example 1, the same method was used to change the amount of liquefied DME to be added from about 11 g to about 16 g. When the moisture content of the solid sample sampled from the liquefied DME phase was measured, the moisture content was 3.8 wt%.

(result)
From this result and the result of Example 1, it was shown that the water content of the solid sample does not decrease as the amount of liquefied DME added increases, and it is preferable to add a relatively small amount.

[Dehydration of waste oils and fats containing water and fatty acids at high concentrations using liquefied DME, and selective recovery of fatty acids and oils and fats 3]
(experimental method)
Instead of the waste oil / fat model solution used in the experiment of Example 1, a waste oil / fat model solution having a higher water content (a mixture of 6 g of triolein, 4 g of palmitic acid and 15 g of water: water content of 60 wt%) was further used. The experiment was conducted in the same manner as the experiment in Example 1 except that the amount of liquefied DME to be added was changed from 18.75 g to 12.4 g.

(result)
When the moisture content of the solid sample sampled from the liquefied DME phase was measured, the moisture content was 3.5 wt%. On the other hand, when the triolein and palmitic acid concentrations in the aqueous phase were measured, the triolein concentration was 32 ppm and the palmitic acid concentration was 33 ppm. Based on this result, the recovery rate of triolein and palmitic acid from the waste oil model solution to the liquefied DME phase was calculated, and it was found that both were 99.99% or more. From the above results, liquefied DME has a water content of 60 wt% and a very high water content of the waste oil and fat model solution. It was shown that.

[Reference Example 1]
[Production of diesel fuel from liquefied DME treated waste oil gel]
In order to investigate whether the dehydration method of the present invention is suitable as a pretreatment method for raw material fats and / or raw material fatty acids for diesel fuel (BDF) production, a series of apparatuses shown in FIG. The experiment was conducted.

(experimental method)
First, 100 mL of triolein and 3 g of a fatty acid-based edible oil solidifying agent were mixed to prepare a waste edible oil model gel. 15 g of waste edible oil model gel was added to the pressure-resistant glass cell (A), the cell was immersed in ice water, and the waste edible oil model gel was cooled to about 10 ° C. or less. Thereafter, the valve (C) is opened, and the liquefied DME in the glass cylinder (B) is introduced into the glass cell (A). When about 13 g of liquefied DME enters the glass cell (A), the valve (C) is opened. Closed. Next, the temperature of the temperature controller (D) was set to 25 ° C., and the mixture was heated and stirred until the solution in the glass cell (A) reached the set temperature.

  After the solution in the glass cell (A) reaches the set temperature, the stirring speed is set to 450 rpm, the valve (E) is opened, and 3.5 g of KOH-containing methanol solution is added to the glass cell (A) by the liquid feed pump (F). ) Was fed into the solution and subjected to a transesterification reaction (BDF production reaction). The amount of the KOH-containing methanol solution fed is the sum of the amount of KOH of 1 wt% with respect to the triolein and the amount capable of neutralizing the fatty acid in the solidifying agent. The amount corresponds to 6 moles of the triolein.

  Immediately after the feeding of the KOH-containing methanol, the valve (G) was opened, and 8.9 g of methanol was added to the glass cell (A) by the feeding pump (H). After 10 minutes, the valve (I) was opened, and liquefied DME was extracted from the glass cell (A) as DME gas. Thereafter, 15 mL of 1N HCl aqueous solution was quickly added into the glass cell (A) to stop the transesterification reaction, and then 10 mL of tetrahydrofuran and 10 mL of hexane were added into the glass cell (A). After stirring the solution in the glass cell (A) for about 15 minutes, the solution was allowed to stand for about 2 hours to separate the phases, and the upper phase was recovered and triolein (TO), diolein (DO), Each concentration of monoolein (MO) and methyl oleate (OAME) which is one kind of BDF was measured.

(result)
As a result, triolein in the upper phase was 0.0 mol%, diolein was 0.0 mol%, monoolein was 1.6 mol%, and methyl oleate was 98.4 mol%. Even for fats and oils that have been gelled with a fatty acid-based solidifying agent, a high reaction yield can be achieved even under low temperature conditions of room temperature by performing a BDF formation reaction after pretreatment by the dehydration treatment method of the present invention. It was shown to be obtained.

  On the other hand, the experiment was performed in the same manner as the experiment of Example 4 except that methanol was not added from the valve (G) and the reaction time of the transesterification reaction (BDF generation reaction) was 15 minutes. Went. When each concentration of triolein (TO), diolein (DO), monoolein (MO), and methyl oleate (OAME), which is one type of BDF, was measured with a high performance liquid chromatograph, Rein was 4.6 mol%, diolein was 2.4 mol%, monoolein was 5.2 mol%, and methyl oleate was 87.8 mol%. As a result, it was found that when more methanol was added, the rate of the BDF production reaction was increased.

It is a figure which shows the experimental apparatus used for the spin-drying | dehydration using the liquefied DME of the waste oil and fat containing water and a fatty acid at high concentration, and the selective collection | recovery experiment of a fatty acid and fat. Each symbol in FIG. 1 indicates the following. A: pressure cell, B: glass cylinder (liquefied DME), C: valve, D: controller (temperature and rotation speed), E: valve, F: liquefied DME phase recovery line, G: sample bottle, H: valve, I : Water phase recovery line, J: sample bottle, K: stirring motor, L: thermocouple, M: stirring blade, N: valve It is a figure which shows the experimental apparatus used for the manufacture experiment of the diesel fuel from the liquefied DME processed material of waste edible oil gel. Each symbol in FIG. 2 indicates the following. A: pressure cell, B: glass cylinder (liquefied DME), C: valve, D: controller (temperature and rotation speed), E: valve, F: liquid pump, G: valve, H: liquid pump, I: Valve, J: stirring motor, K: stirring blade, L: thermocouple, M: methanol solution containing KOH, N: methanol

Claims (11)

Water, fatty acids and / or water and / or fatty acids and / or fats and / or oils are added to a substance containing water and fatty acids and / or fats and oils as an extraction solvent, and the fatty acids and / or fats and oils are selectively dehydrated and recovered as liquefied dimethyl ether solutions. Alternatively, a method for selective dehydration and recovery of fatty acids and / or fats and oils from substances containing fats and oils. The substance containing water and fatty acids and / or fats and oils is edible fats and oils containing water, waste edible fats and oils containing water and / or non-fats or waste fats and oils other than waste edible fats and oils The method for selectively dehydrating and recovering fatty acids and / or fats and oils from substances containing water and fatty acids and / or fats and oils according to claim 1. The substance containing water and fatty acid and / or fat / oil contains a solid matter of mud or gel-like fatty acid and / or fat / oil, according to claim 1 or 2, A method for selective dehydration and recovery of fatty acids and / or fats and oils from substances containing fats and oils. Add liquefied dimethyl ether as an extraction solvent to a substance containing water and fatty acids and / or fats and oils, stir to form a uniform liquid phase, and then let stand, then two liquids of liquefied dimethyl ether phase and aqueous phase Selective dehydration of fatty acids and / or fats from substances containing water and fatty acids and / or fats and oils according to any one of claims 1 to 3, comprising forming a phase and separating a liquefied dimethyl ether phase from the phase Collection method. Add liquefied dimethyl ether as an extraction solvent to substances containing water and fatty acids and / or fats and oils, and add light oil components to the extraction solvent when selectively dehydrating and collecting fatty acids and / or fats and oils as liquefied dimethyl ether solutions. The method for selectively dehydrating and recovering fatty acids and / or fats and oils from substances containing water and fatty acids and / or fats and oils according to any one of claims 1 to 4. The addition of the light oil component is added in a range of 10 to 50% by volume with respect to the total amount of the extraction treatment liquid, and the fatty acid from the substance containing water and the fatty acid and / or oil and fat according to claim 5 and // Selective dehydration / recovery method of fats and oils. A process in which liquefied dimethyl ether is added as an extraction solvent to a substance containing water and fatty acids and / or fats and oils, and the fatty acid and / or fats and oils are selectively dehydrated and recovered as a liquefied dimethyl ether solution within a temperature range of 10 to 35 ° C. The method for selective dehydration / recovery of fatty acids and / or fats and oils from substances containing water and fatty acids and / or fats and oils according to any one of claims 1 to 6. A process in which liquefied dimethyl ether is added as an extraction solvent to a substance containing water and fatty acids and / or fats and oils, and the fatty acid and / or fats and oils are selectively dehydrated and recovered as a liquefied dimethyl ether solution within a temperature range of 30 to 35 ° C. The method for selective dehydration and recovery of fatty acids and / or fats and oils from substances containing water and fatty acids and / or fats and oils according to claim 7, wherein Fatty acid and / or oil and fat dehydrated by a method for selectively dehydrating and recovering fatty acid and / or fat from a substance containing water and fatty acid and / or fat according to any one of claims 1 to 8, and liquefied dimethyl ether A method for preparing a feedstock for biodiesel fuel production, comprising preparing a substance containing The method for preparing a feedstock for biodiesel fuel production according to claim 9, wherein the biodiesel fuel is produced by a method of performing a transesterification reaction in a homogeneous phase system to which liquefied dimethyl ether is added. The biodiesel fuel production process according to claim 9 or 10, wherein the preparation of the raw material oil for biodiesel fuel production is carried out in combination with an esterification reaction of free fatty acid using an acid catalyst and a lower alcohol. For preparing raw material oils for

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