JP5230562B2 - Method for producing biodiesel fuel - Google Patents

Description

  The present invention relates to a method for producing biodiesel fuel, a biodiesel fuel, an encapsulated catalyst, and a method for producing the encapsulated catalyst.

  In recent years, biodiesel fuel has attracted attention as a carbon-neutral fuel because it uses as a raw material a biomass resource that is vegetable oil, animal oil, or waste oil.

  Biodiesel fuel can be produced by various production methods. As one of such production methods, there is a method of synthesizing fatty acid methyl ester (FAME) which is a main component of biodiesel fuel by a transesterification reaction between vegetable oil and methanol. Since this manufacturing method uses a catalyst, a catalyst for efficiently producing a fatty acid methyl ester has been developed.

  As such a catalyst, utilization of an alkali solid catalyst such as calcium oxide (CaO) has been studied. Calcium oxide is inexpensive and easily available. However, for example, calcium oxide has a property of low activity, and its improvement has been studied.

  Patent Document 1 discloses a biodiesel oil production comprising calcium oxide having a base strength (H_) of 15 or more and a base amount of 0.1 mmol / g or more as a solid base catalyst. A solid base catalyst is described. The solid base catalyst for producing biodiesel oil is a raw material selected from the group consisting of quick lime, calcium carbonate, calcium acetate and slaked lime at 300 ° C. in a gas atmosphere substantially free of water and carbon dioxide. It is obtained by firing at the above temperature. It is described that when this solid base catalyst is used, extremely high reaction efficiency can be achieved.

  Non-Patent Document 1 introduces research to increase the catalytic activity of CaO in order to develop an effective heterogeneous catalyst used in the production of biodiesel oil by transesterification of vegetable oil and methanol. Specifically, this document describes that CaO is pretreated with methanol and used for transesterification.

  Patent Document 2 discloses a solid catalyst used in the production of biodiesel oil by transesterification of raw material fats and alcohol, and this catalyst includes calcium oxide having a base strength (H_) of 9.3 or more, Or, it is calcium diglyceroxide obtained by reacting this raw material with a methanol solution of glycerin under heating and reflux, using either calcium hydroxide obtained by hydrating this calcium oxide as a raw material. A featured solid catalyst for the production of biodiesel is described. According to this document, a high-quality biodiesel oil with a smaller residual amount of inorganic content can be obtained while achieving a reaction performance comparable to that when using highly active calcium oxide.

WO 2006/134845 (Claim 1, paragraphs 0007, 0011, 0017, 0018)

JP 2008-212772 A (Claim 1, paragraph 0014)

A. Kawashima, K .; Matsubara and K.M. Honda, “Acceleration of catalytic activity of calcium oxide for biodiesel production”, Bioresource Technology 100, 696-700 (2009)

  In Patent Document 1, the raw material needs to be fired in a gas atmosphere substantially free of water and carbon dioxide gas, but the number of steps is increased by the amount necessary to perform such firing treatment, and the firing atmosphere is replaced. The manufacturing cost is increased by the amount necessary for the baking apparatus that can be used. In addition, since the calcined calcium oxide is inactivated by adsorbing with carbon dioxide gas and moisture, it is important that the calcined calcium oxide is not brought into contact with air as much as possible after the calcining. In this respect, also in this document, an airtight container is used as a reactor for producing biodiesel oil. The use of such special containers also causes an increase in manufacturing costs. Thus, in patent document 1, the increase in the number of processes and the raise of manufacturing cost are caused, and there exists a subject that it is hard to put into practical use (industrial production).

  In Non-Patent Document 1, CaO is pretreated with methanol. In Patent Document 2, calcium diglyceroxide is obtained by reacting a methanol solution of CaO and glycerin with heating under reflux. However, in such a pretreatment method, when CaO powder is used as a molded body in order to facilitate separation and recovery, only the surface of solid CaO is activated, and internal CaO cannot be used. For this reason, there exists a subject that the activity of a catalyst cannot fully be raised.

  Further, in these documents, there is a problem that, when trying to obtain a composite material in which activated CaO is immobilized on a silica carrier or the like, it takes time to adjust the composite material and it is difficult to put it into practical use (industrial production). That is, in Patent Document 2, the carrier material is coated with calcium oxide in order to facilitate separation and recovery. According to paragraph 0019 of the same document, “Calcium oxide is easy to react with common carrier materials such as silica and alumina, and forms inactive calcium silicate and aluminum silicate during the firing operation in the pretreatment process of the composite material. For this reason, the "immobilization operation is repeated a plurality of times", so that "a large amount of calcium compound as a catalyst precursor is supported on the surface of the support, and the active compound particles remain at the expense of the calcium compound near the surface." "I have done that." However, such a repetitive operation of the fixing operation and the subsequent baking operation are complicated, and it takes time and effort to adjust the composite material.

  The present invention has been made in order to solve the above-mentioned problems. The first object of the present invention is to improve the activity of the catalyst while facilitating practical application (industrial production) by facilitating separation and recovery. It is to provide a method for producing diesel fuel.

  The present invention has been made to solve the above-mentioned problems, and its second object is to increase the activity of the catalyst while facilitating practical application (industrial production) by facilitating separation and recovery. It is providing the biodiesel fuel manufactured by the manufacturing method of diesel fuel.

  The present invention has been made to solve the above-described problems, and a third object of the present invention is to provide an encapsulated catalyst capable of enhancing the activity of the catalyst.

  The present invention has been made to solve the above problems, and a fourth object of the present invention is to provide a method for producing an encapsulated catalyst capable of enhancing the activity of the catalyst.

  The present inventors diligently studied a method for producing a biodiesel fuel that can increase the activity of the catalyst and increase the reaction efficiency while facilitating industrial production by facilitating separation and recovery of the catalyst. As a result, when synthesizing biodiesel fuel, the present inventors use a catalyst encapsulated in a capsule to perform catalytic activity by performing synthesis using a minute space inside the capsule. (Reaction efficiency) can be increased, and separation and recovery of the encapsulated catalyst can be facilitated, so that it has been found that a method for producing biodiesel fuel suitable for industrial production can be obtained. Furthermore, the present inventors have also found a biodiesel fuel produced by the method for producing biodiesel fuel, an encapsulated catalyst, and a method for producing the encapsulated catalyst.

  The method for producing a biodiesel fuel of the present invention for solving the above-mentioned problems is characterized by using a catalyst present in a capsule when producing a biodiesel fuel by transesterification of raw oil and fat and lower alcohol. .

  According to the present invention, when producing biodiesel fuel, since the raw oil and fat and lower alcohol are produced by a transesterification reaction in the production of biodiesel fuel, the catalyst used in the capsule is used. While using a general-purpose synthesis method, it is possible to effectively achieve contact between the catalyst and the raw material in the minute space in the capsule, and as a result, separation and recovery are facilitated while enhancing the activity of the catalyst. A method for producing biodiesel fuel that can be easily put into practical use (industrial production) can be provided.

  In a preferred embodiment of the method for producing biodiesel fuel according to the present invention, raw oil and fat is further present in the capsule.

  According to this invention, since the raw material fats and oils are further present in the capsule, the raw material is present in the capsule from the beginning of the synthesis, which facilitates the synthesis.

  In a preferred embodiment of the method for producing biodiesel fuel of the present invention, the material constituting the capsule is at least one selected from the group consisting of alginic acids, pectins, carrageenans, polyacrylic acids, polyvinyl alcohol, and agars. One.

  According to this invention, since the material constituting the capsule is at least one selected from the group consisting of alginic acids, pectins, carrageenans, polyacrylic acids, polyvinyl alcohol, and agars, it can be easily treated with a crosslinking solution. Gelation can be performed quickly, and as a result, the double tube nozzle method described later can be easily applied.

  In a preferred embodiment of the method for producing biodiesel fuel according to the present invention, the catalyst is selected from the group consisting of an alkali solid catalyst, an anion exchange resin, a hydrotalcite compound, and a solid base catalyst in which an alkali metal is supported on a metal oxide. At least one selected.

  According to this invention, the catalyst is at least one selected from the group consisting of an alkali solid catalyst, an anion exchange resin, a hydrotalcite compound, and a solid base catalyst having an alkali metal supported on a metal oxide. Therefore, a solid catalyst having a low activity is used, and the significance of the present invention to be used in an encapsulated form is increased.

  The biodiesel fuel of the present invention for solving the above-mentioned problems is produced using the method for producing a biodiesel fuel of the present invention.

  According to this invention, since biodiesel fuel is produced using the method for producing biodiesel fuel of the present invention, it is possible to utilize effective contact between the catalyst and the raw material in a minute space in the capsule, As a result, it is possible to provide a biodiesel fuel produced by a method for producing a biodiesel fuel that is easy to put into practical use (industrial production) by increasing the catalyst activity and facilitating separation and recovery.

  The encapsulated catalyst of the present invention for solving the above-described problems is an alkaline solid comprising at least one selected from the group consisting of alginic acids, pectins, carrageenans, polyacrylic acids, polyvinyl alcohol, and agars as a capsule wall. The capsule contains at least one catalyst selected from the group consisting of a catalyst, an anion exchange resin, a hydrotalcite compound, and a solid base catalyst in which an alkali metal is supported on a metal oxide.

  According to this invention, at least one selected from the group consisting of alginic acids, pectins, carrageenans, polyacrylic acids, polyvinyl alcohol, and agars is used as the capsule wall, and the alkali solid catalyst, anion exchange resin, hydrotalcite An encapsulated catalyst containing at least one catalyst selected from the group consisting of a compound compound and a solid base catalyst in which an alkali metal is supported on a metal oxide, in the capsule. As a result, it is possible to provide an encapsulated catalyst capable of enhancing the activity of the catalyst.

  The method for producing an encapsulated catalyst of the present invention for solving the above problems is characterized by being produced by a double tube nozzle method.

  According to this invention, since the encapsulated catalyst of the present invention is produced by a double tube nozzle method, it is easy to control the thickness of the capsule film and to easily obtain a monodispersed capsule, and as a result, A method for producing an encapsulated catalyst capable of increasing the activity of the catalyst can be provided.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the biodiesel fuel which is easy to put into practical use (industrial production) can be provided by making separation and collection | recovery easy etc., raising the activity of a catalyst.

  ADVANTAGE OF THE INVENTION According to this invention, the biodiesel fuel manufactured by the manufacturing method of the biodiesel fuel which is easy to put into practical use (industrial production) by making separation and collection | recovery easy etc., improving the activity of a catalyst can be provided.

  According to the present invention, an encapsulated catalyst capable of enhancing the activity of the catalyst can be provided.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the encapsulated catalyst which can improve the activity of a catalyst can be provided.

It is a typical conceptual diagram which shows an example of the manufacturing apparatus of an encapsulation catalyst. It is the graph which showed the change of the outflow amount (diffusion amount) of rapeseed oil after a measurement start. It is a graph which shows the time-dependent change of the FAME yield after reaction start.

  Next, embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the present invention.

(Method for producing biodiesel fuel)
The biodiesel fuel production method of the present invention uses a catalyst present in a capsule when producing biodiesel fuel by transesterification of raw oil and fat and lower alcohol. As a result, it is possible to effectively achieve contact between the catalyst and the raw material in the minute space in the capsule while using a general-purpose synthesis method using transesterification reaction. It is possible to provide a method for producing biodiesel fuel that can be easily put into practical use (industrial production) by, for example, facilitating separation and recovery.

  The method for producing biodiesel fuel is not particularly limited as long as it is a production method using a catalyst, but in the present invention, biodiesel fuel is synthesized by synthesizing biodiesel fuel using raw oil and lower alcohol. Thereby, as above-mentioned, it can be set as the versatile synthesis method using transesterification, and it becomes easier to produce industrially. More specifically, examples of the synthesis method using the transesterification include an alkali catalyst method using an alkali catalyst and an acid catalyst method using an acid catalyst. The alkali catalyst method can be roughly divided into a method using a homogeneous alkali catalyst and a method using a heterogeneous alkali catalyst. Among these production methods, the heterogeneous alkali catalyst method using a heterogeneous alkali catalyst generally having a low catalytic activity is required to increase the catalyst activity, so that the significance of applying the present invention is increased.

  When synthesizing biodiesel fuel using raw material fats and lower alcohols, the raw material fats and oils are not particularly limited as long as they can produce biodiesel fuel. Examples of such raw oils and fats include vegetable oils and animal fats. Examples of vegetable oils include rapeseed oil, sesame oil, soybean oil, canola oil, sunflower oil, corn oil, cottonseed oil, and palm oil. Examples of animal fats include pork fat, beef tallow, and sardine oil. The raw material fats and oils may be a mixture of a plurality of types of fats and oils at an arbitrary mixing ratio within the scope of the present invention. Moreover, the waste oil used for cooking of foodstuffs may be sufficient as raw material fats and oils. When waste oil is used, it is preferable to remove the dust and the like in the waste oil by filtration in order to industrially smoothly react the biodiesel fuel. Furthermore, when the raw material fat is solid at room temperature, it is preferably used after being liquefied by heat treatment or the like. Among these raw oils and fats, it is preferable to use vegetable oils and fats in view of improvement in low-temperature properties based on the difference in saturated fatty acid content.

  When synthesizing biodiesel fuel using raw material fats and lower alcohol, the lower alcohol is not particularly limited as long as it can produce biodiesel fuel. The lower alcohol usually means an alcohol having a small number of carbon atoms (for example, an alcohol having 5 or less carbon atoms). Examples of such lower alcohols include methanol, ethanol, butanol and the like. Of these lower alcohols, considering reactivity, it is preferable to use methanol having a short alkyl chain. That is, usually, the longer the alkyl chain of the lower alcohol, the more difficult it is to react. Therefore, it is preferable to use a lower alcohol having a short alkyl chain from the viewpoint of keeping the reaction temperature low and keeping the reaction pressure low.

  As described above, in the present invention, it is preferable to use a heterogeneous alkaline catalyst method using vegetable oils and fats among raw oils and fats and methanol as a lower alcohol. The reaction formula of biodiesel fuel in this case can be expressed as the following reaction formula (1).

In the above reaction formula (1), FAME is a fatty acid methyl ester and is a main component of biodiesel fuel. In the reaction formula (1), R ¹ , R ² , and R ³ are long-chain alkyl groups, and the structure such as the number of carbons is determined by the chemical structure of the vegetable oil used.

  In the method for producing biodiesel fuel of the present invention, a catalyst present in a capsule is used. More specifically, an encapsulated catalyst in which the catalyst is present in a capsule is used. As a result, it is possible to effectively realize contact between the catalyst and the raw material in a minute space in the capsule, and as a result, the production of biodiesel fuel is facilitated by increasing the activity of the catalyst and facilitating separation and recovery. It is possible to provide an encapsulated catalyst that facilitates the process. The reason why the catalytic activity is increased by using the encapsulated catalyst has not been completely elucidated, but is considered as follows. That is, when raw material fats and methanol are used as the raw material, it is presumed that the activity of the catalyst is more effectively enhanced by contacting the methanol and the catalyst in a minute space in the capsule. Furthermore, it is presumed that the activity of the catalyst is further enhanced when alcohol such as glycerin as a by-product of the produced biodiesel fuel (FAME) comes into contact with the catalyst in a minute space in the capsule. In addition, since the raw fats and oils and methanol do not dissolve each other, the produced FAME becomes both solvents that dissolve in both the raw fats and oils and methanol, so the production of FAME promotes the contact between the raw fats and oils and methanol. Furthermore, it is estimated that reaction efficiency increases. By competing with each other as described above, it is presumed that the catalytic activity and the reaction efficiency are improved when the encapsulated catalyst is used.

  The encapsulated catalyst is usually composed of a capsule and a catalyst contained therein. The material constituting the capsule film (also referred to as “capsule wall” in this specification) may be any material that can permeate raw materials such as raw oils and fats and lower alcohols, and is not particularly limited. Absent. As such a material, it is preferable to use at least one selected from the group consisting of alginic acids, pectins, carrageenans, polyacrylic acids, polyvinyl alcohol, and agars. As a result, gelation can be easily and quickly performed with a crosslinking solution (curing solution), and as a result, the double tube nozzle method described later can be easily applied. The capsule wall is usually formed by polymerizing the above material.

  The alginic acid used as the capsule material is not particularly limited within the scope of the present invention, and examples thereof include alginic acid, alginates, and esterified alginic acid. Examples of alginates include potassium alginate, ammonium alginate, sodium alginate and the like. Examples of esterified alginic acid include esterified sodium alginate and propylene glycol alginate (PGA) provided with lipophilic propylene glycol. Although PGA tends to not gelate because the carboxyl group is substituted with propylene glycol, it can be expected to form a gel that makes use of the lipophilicity of PGA by mixing it arbitrarily with sodium alginate or the like. .

  The pectins used as the capsule material are not particularly limited within the scope of the present invention. For example, polysaccharides composed of a linear polymer of D-galacturonic acid, the carboxyl group of which is partly methyl ester and And polysaccharides that form salts with metal ions.

  The carrageenans used as the capsule material are not particularly limited within the scope of the present invention, and examples thereof include κ (kappa) -carrageenan and ι (iota) -carrageenan. Carrageenan is based on β-D-galactose sulfate and 3,6-anhydro-α-D-galactose, and there are three main types: κ (kappa), λ (lambda), and ι (iota). There are different binding sites and contents of sulfate and 3,6-anhydro-α-D-galactose. Further, commercially available carrageenan is a mixture of the above three types.

  The polyacrylic acid used as the capsule material is not particularly limited within the scope of the present invention, but refers to a polymer of acrylic acid and derivatives thereof, such as polyacrylic acid, polyacrylic acid ester, polyacrylic acid. A salt etc. can be mentioned.

  The agar used as the material for the capsule is not particularly limited within the scope of the present invention, and examples thereof include those made of red algae such as agus (Amakusa). Agar has the property of gelling when such red algae are melted and hardened, so that it can be encapsulated by cooling at high temperature to a liquid form. For example, when the double tube nozzle method described later is used, the double tube nozzle may be heated so that the agar is in a liquid state and flows in the nozzle.

  Among these materials, it is preferable to use alginic acids from the viewpoint of imparting hydrophobicity and facilitating the permeation of raw material fats and oils, and it is more preferable to use sodium alginate and esterified sodium alginate. Here, methanol, ethanol, butanol, pentanol, etc. can be mentioned as alcohol used in order to esterify sodium alginate and to obtain esterified alginic acid. Of these, butanol from the standpoint of stably producing an encapsulated catalyst by securing the gelation rate when forming a gel in the presence of a divalent cation such as calcium ion, and the standpoint of ensuring hydrophobicity. Is preferably used. However, although details will be described later, even if the material has hydrophilicity, it becomes easy to permeate the raw material fat by performing drying after encapsulation, so that it can be used sufficiently even if the material itself is not hydrophobic. is there.

  The film thickness of the capsule may be a thickness that allows the raw material fat or alcohol to permeate well, and is usually 1 μm or more, preferably 5 μm or more, more preferably 10 μm or more, and usually 2 mm or less, preferably 1 mm or less, more preferably. Is 500 μm or less, more preferably 100 μm or less, and most preferably 50 μm or less.

  The outer diameter of the capsule may be a size capable of forming a minute space inside, and is usually 50 μm or more and 3 mm or less, although it is related to the thickness of the capsule film. The inner diameter is determined by controlling the outer diameter and the thickness of the capsule coating.

  As described above, it is preferable to hydrophobize the capsule wall membrane as the capsule wall from the viewpoint of facilitating the permeation of raw oil and fat, lower alcohol, the product biodiesel fuel (FAME) and the like. The method for hydrophobizing the capsule wall membrane is not particularly limited. For example, a hydrophobic material is used as the material constituting the capsule, or the moisture on the surface is evaporated by performing a drying process after the capsule is formed. Just do it.

  A catalyst is present inside the capsule. Such a catalyst is not particularly limited within the scope of the present invention, but from the group consisting of an alkali solid catalyst, an anion exchange resin, a hydrotalcite compound, and a solid base catalyst in which an alkali metal is supported on a metal oxide. It is preferable that at least one selected. As a result, a solid catalyst having a low activity is generally used, and the significance of the present invention to be encapsulated is increased.

The alkali solid catalyst is not particularly limited within the scope of the present invention. For example, CaO, Ca (OH) ₂ , BaO, Ba (OH) ₂ , MgO, CaCO ₃ , SrO, SnO, PbO, ZnO , PbO ₂ , Ti ₂ O ₃ , Pb ₃ O _4, and complex oxides thereof. The alkali solid catalyst can be used as a catalyst in combination with other oxides, and examples thereof include CaO—La ₂ O ₃ and CaO—TiO ₂ . The anion exchange resin is not particularly limited within the scope of the present invention, and examples thereof include CaO / Zeolite HY. The hydrotalcite compound is not particularly limited within the scope of the present invention, and examples thereof include MgAl hydrotalcite. The solid base catalyst in which an alkali metal is supported on a metal oxide is not particularly limited within the scope of the gist of the present invention. For example, an alkali metal such as K, Na, Sr, or Li that exhibits strong basicity is alumina. And silica, cation exchange zeolite, zirconium oxide, zinc oxide, calcium oxide and the like.

Among these materials, the catalyst is more preferably at least one selected from the group consisting of CaO, SrO, CaO—La ₂ O ₃ , CaO—TiO ₂ , Ca (OH) ₂ , MgO, PbO, and BaO. preferable. As a result, an alkali solid catalyst having a low activity is generally used, and the significance of the present invention to be used after encapsulating is further increased. Of these catalysts, CaO and Ca (OH) ₂ are more preferably used, and CaO is particularly preferably used. Since these catalysts have particularly low activity, the significance of adopting the present invention is further increased.

  In the present invention, since a powdered catalyst is used in the capsule, the advantage is that the catalyst powder existing inside the capsule can be effectively contributed to the reaction, compared to the case where the catalyst is used as a molded body. There is. Further, when using the reaction represented by the above reaction formula (1) and using CaO as a catalyst, a highly active CaO composite can be obtained by encapsulating CaO powder previously activated with methanol or glycerin in a capsule. It is expected that separation and recovery of the encapsulated catalyst will be facilitated while ensuring the effectiveness of the body. In addition, considering the environment outside the capsule, the by-product (eg, glycerin) is difficult to diffuse from the capsule, so that activation of CaO is effective inside the capsule without being activated with glycerin as described above. Expect to get up. Of course, a complex of CaO and glycerin may be encapsulated in advance. By using the encapsulated catalyst, the above-described various variations for enhancing the activity of the catalyst can be applied while facilitating separation and recovery.

The average particle diameter of the catalyst present inside the capsule is not particularly limited as long as the average particle diameter does not leak from the capsule. The average particle diameter of the catalyst can be measured by, for example, a scanning microscope (SEM), an X-ray diffraction method (XRD), or an optical microscope. The specific surface area of the catalyst is from the standpoint of increasing the activity, usually 0.01 m ² / g, and 100 m ² / g or less. The specific surface area of the catalyst can be measured using the BET method.

  When using raw material fats and oils for manufacture, it is preferable that raw material fats and oils exist further inside a capsule. Thereby, a raw material exists in a capsule from the beginning of synthesis, and it becomes easier to promote synthesis. As the raw material fats and oils, any of those described above may be used, and the point that a mixture or waste oil can be used is also as described above. The raw oil / fat to be encapsulated in the capsule may be the same as or different from the raw oil / fat used for the production of biodiesel fuel, but from the viewpoint of unifying the materials used for the reaction, the same raw oil / fat is used. It is preferable.

  Within the scope of the gist of the present invention, the capsule may further contain a material such as an additive, in addition to the catalyst and the raw material fat to be included as necessary.

  The content of the catalyst with respect to the raw material fat inside the capsule is usually 0.1% by weight or more and 50% by weight or less, but when the encapsulated catalyst is produced by the double tube nozzle method described later, the nozzle is clogged. In consideration of the above, it is preferably 40% by weight or less, more preferably 30% by weight or less, and still more preferably 10% by weight or less. However, as for nozzle clogging, there is clogging due to aggregates of catalyst powder. In order to avoid such clogging, in addition to controlling the content of the catalyst with respect to the raw oil and fat inside the capsule, it is only necessary to take measures such as quickly dropping by increasing the flow rate of the nozzle.

  The production of the encapsulated catalyst is not particularly limited within the scope of the present invention, but is usually performed by a chemical production method, a physicochemical production method, or a mechanical / physical production method. Among these, examples of the chemical production method include an interfacial polymerization method, an in situ polymerization method, and an orifice method (double tube nozzle method). Examples of the physicochemical production method include a coacervation method. Examples of the mechanical / physical production method include a spray drying method and an air suspension coating method. Of these various methods, the orifice method (double tube nozzle method) is preferably used as the method for producing the encapsulated catalyst. This makes it easy to control the capsule film thickness and to easily obtain a monodisperse capsule with a particle size, and as a result, an encapsulated catalyst that facilitates industrial production of biodiesel fuel while enhancing the activity of the catalyst. A manufacturing method can be provided. More specifically, the double-tube nozzle method can control the thickness of the capsule film by a simple method of changing the flow rate between the outer tube and the inner tube, and the particle size is also easily monodispersed. There are advantages.

  When the encapsulated catalyst is produced by the double tube nozzle method, the wall material and the core material are simultaneously flowed from the outer tube and the inner tube of the nozzle, respectively, and the resulting droplet having a two-phase structure is crosslinked. An encapsulated catalyst is produced by receiving the solution (curing solution). Here, the wall material is usually a solution obtained by dissolving the above-mentioned capsule forming material in a solvent, and the core material is dispersed in the raw oil or fat as necessary as the core material. Use a liquid. An example of the solvent used for the wall material is water, and in this case, the wall material is an aqueous solution.

  FIG. 1 is a schematic conceptual diagram showing an example of an encapsulated catalyst manufacturing apparatus. The encapsulated catalyst manufacturing apparatus 1 includes a double pipe nozzle 2, a syringe pump 3A connected to the inner pipe 5 of the double pipe nozzle via a tube 4A, and an outer pipe 6 of the double pipe nozzle via a tube 4B. The syringe pump 3B and the reservoir 7 are connected. The reservoir 7 is composed of a container 9 filled with a curable solution, a stirrer (magnetic stirrer) 10 disposed at the bottom of the container 9, and a stirrer 8. Can be stirred.

In the encapsulated catalyst manufacturing apparatus 1, the core material is pushed out from the syringe pump 3 </ b> A through the inner tube 5 of the double tube nozzle at a constant flow rate, and at the same time, the wall material is introduced from the syringe pump 3 </ b> B through the outer tube 6 of the double tube nozzle. By extruding at a constant flow rate, a droplet surrounded by a wall material is formed around the core material. The droplets fall into the cured solution in the container 9, whereby the wall material is cured (gelled) to form a capsule. Here, as the curing solution, a solution capable of curing the wall agent substance may be used. For example, when sodium alginate or esterified sodium alginate is used as the wall material, a divalent cation such as calcium ion is used. What is necessary is just to use the solution which exists. Examples of such a solution include a calcium chloride (CaCl ₂ ) solution.

  In the encapsulated catalyst manufacturing apparatus 1, the flow rate between the outer tube and the inner tube is controlled by adjusting the speed at which the core material and the wall material are pushed out from the syringe pumps 3A and 3B, respectively, thereby controlling the thickness of the capsule film. The capsule outer diameter, the capsule formation rate (yield), and the like can be controlled. From this point of view, the flow rate of the wall material flowing in the outer tube 6 of the double tube nozzle relative to the flow rate of the core material flowing in the inner tube 5 of the double tube nozzle is controlled by the thickness and outer diameter of the capsule film described above. However, from the standpoint of maintaining a good formation rate, it is usually set to be twice or more. The upper limit of the flow rate of the wall material flowing in the outer tube 6 of the double tube nozzle relative to the flow rate of the core material flowing in the inner tube 5 of the double tube nozzle is not particularly limited, but the core needs to be mononuclear Is preferably 6 times or less. In addition, the linear velocity of the wall material flowing in the outer tube 6 of the double tube nozzle relative to the linear velocity of the core material flowing in the inner tube 5 of the double tube nozzle is usually 1 time or more from the same viewpoint as described above. Good. The upper limit of the linear velocity of the wall material flowing in the outer tube 6 of the double tube nozzle relative to the linear velocity of the core material flowing in the inner tube 5 of the double tube nozzle is not particularly limited, but the core needs to be mononuclear. In some cases, it is preferably 4 times or less.

  Production of the encapsulated catalyst in the encapsulated catalyst production apparatus 1 may be performed at room temperature, but the temperature of the cured solution may be controlled depending on the type of the wall material and the type of the cured solution. In this case, the temperature of the curing solution may be controlled to usually 0 ° C. or more and 80 ° C. or less from the viewpoint of satisfactory curing of the capsule in the curing solution. For example, since carrageenans and agars have a property of gelling even when the temperature is lowered, it is preferable that the hardening solution has a low temperature. On the other hand, for example, when polymer polymerization is used, it is preferable to set the curing solution to a high temperature. Specifically, temperature control is effective when a capsule film is formed / reinforced or a function is imparted by polymer polymerization. For example, when a temperature-responsive polymer is introduced into an alginate gel, a method may be used in which a monomer is placed in droplets and polymerized in a curing solution at about 60 ° C. containing a polymerization initiator or a crosslinking agent. .

  In the manufacturing apparatus 1 of the encapsulated catalyst, it is preferable that after forming the encapsulated catalyst with the curing solution, the encapsulated catalyst is taken out from the cured solution and the encapsulated catalyst is dried. The drying process makes it easy to increase the strength of the capsule, and as described above, it becomes easy to remove the moisture on the capsule surface and make it hydrophobic. The drying temperature may be appropriately controlled depending on the capsule material, the encapsulated catalyst, and the like, but is usually 30 ° C. or higher and 70 ° C. or lower. Further, the drying time is not particularly limited as long as the capsule is dried well. For example, if reduced-pressure drying is used, the drying time can be shortened.

  Using the encapsulated catalyst obtained as described above, production is carried out by synthesizing biodiesel fuel using raw oil and fat and lower alcohol. Such a production method is not particularly limited. For example, after introducing the raw material fat into a reaction vessel such as a reaction vessel, nitrogen substitution is performed as necessary, and then the encapsulated catalyst is introduced into the raw material fat and oil. What is necessary is just to start reaction by adding alcohol. Further, for example, the raw oil and fat and the encapsulated catalyst may be simultaneously added to the reaction can and then the lower alcohol may be added to start the reaction.

  The temperature at the time of synthesis is not particularly limited as long as the production reaction of biodiesel fuel proceeds satisfactorily in consideration of the heat resistance of the encapsulated catalyst, but is usually 30 ° C. or more and 100 ° C. or less, preferably Is 40 ° C. or higher and 80 ° C. or lower. In the synthesis, it is preferable to stir the reaction solution from the viewpoint of efficiently proceeding the reaction.

  The time for the synthesis (reaction time) may be performed until the biodiesel fuel has a desired yield. In industrial production, the reaction time varies depending on the production volume of biodiesel fuel (raw material charge) and the scale of reaction vessels such as reaction cans, so it is difficult to specify the reaction time specifically. However, in the present invention, since the catalytic activity can be enhanced by using the encapsulated catalyst, the reaction time is shortened by about 30 to 80% compared to the conventional method in which the catalyst is used without being encapsulated. It becomes easy to do.

  After completion of the reaction, the encapsulated catalyst may be recovered through a net or the like, and the remaining lower alcohol may be removed by removal under reduced pressure or the like to purify the biodiesel fuel. Thus, separation and collection are facilitated by employing the encapsulated catalyst.

  In the present invention, the encapsulated catalyst can be reused. Various methods for such reuse can be proposed.

  As a first method, after the encapsulated catalyst is recovered by a net or the like, the biodiesel fuel and by-products such as glycerin in the reactor are recovered. After that, the raw oil and capsules are charged again into the reactor, and when the reactor is heated to a predetermined temperature (for example, 60 ° C.), lower alcohol (for example, methanol) is charged to perform the biodiesel synthesis reaction. Just start again. By repeating such a procedure, the encapsulated catalyst can be reused a plurality of times.

  In the first method, there are no particular restrictions on the order of charging the raw material for biodiesel fuel and the encapsulated catalyst, the heating method, and the like. For example, the encapsulated catalyst, the lower alcohol, and the raw oil and fat may be put into the reactor before heating. Further, for example, the raw material oil may be added after the encapsulated catalyst and the lower alcohol are heated to a predetermined temperature. In this case, when methanol is used as the lower alcohol and calcium oxide (CaO) is used as the catalyst, the biodiesel fuel synthesis reaction starts in the state where a large amount of active calcium methoxide is present due to the reaction between methanol and CaO. Will be.

  As a second method, a method in which an encapsulated catalyst is packed in a column and used as a continuous reactor can be exemplified. More specifically, the capsule is packed in a column wound with a ribbon heater and heated to a predetermined temperature (for example, about 60 ° C.). Separately, a mixed solution of raw oil and fat and lower alcohol (for example, methanol) is prepared and stirred. Here, you may heat this mixed solution so that it may become predetermined | prescribed temperature (for example, 60 degreeC). Then, the mixed solution is fed into the column using a pump or the like, the reaction solution flowing out from the column outlet is returned to the original mixed solution and circulated, and the circulation may be continued until the reaction is completed.

(Biodiesel fuel)
The biodiesel fuel of the present invention is produced using the method for producing biodiesel fuel of the present invention. This makes it possible to use effective contact between the catalyst and the raw material in the minute space inside the capsule, and as a result, it is put to practical use by increasing the activity of the catalyst and facilitating separation and recovery (industrial production). It is possible to provide a biodiesel fuel produced by a method for producing a biodiesel fuel that is easy to perform.

  More specifically, the biodiesel fuel of the present invention has an advantage that a biodiesel fuel having almost no residual catalyst can be easily obtained by a simple method. That is, since biodiesel fuel is produced using an encapsulated catalyst in the present invention, the reaction liquid after completion of the reaction has a biodiesel fuel layer in the upper layer and a by-product layer (for example, glycerin) in the lower layer. it can. The encapsulated catalyst then sinks to the bottom of the reactor and will be present in the byproduct layer. When left for a while, the biodiesel fuel layer and the by-product layer completely separate into two phases. Therefore, even if processing such as centrifugation is not performed, there is no residual catalyst in the biodiesel fuel layer, and a biodiesel fuel having a very high purity can be obtained.

  On the other hand, when the catalyst is used as a powder without encapsulating, the reaction liquid after completion of the reaction is such that the powdered catalyst is composed of an upper biodiesel fuel layer and a lower by-product layer. Both are suspended. Here, if it is left for a long time, it is expected that the powdered catalyst will also settle, but the remaining catalyst powder remains at the interface between the biodiesel fuel layer and the by-product layer. However, it is difficult to remove the catalyst from the biodiesel fuel layer. However, if treatment such as centrifugation can be performed, the catalyst can be removed from the biodiesel fuel layer, but the number of steps increases industrially, which is disadvantageous in practice.

(Encapsulated catalyst and production method thereof)
The encapsulated catalyst of the present invention comprises at least one selected from the group consisting of alginic acids, pectins, carrageenans, polyacrylic acids, polyvinyl alcohol, and agars as a capsule wall, an alkali solid catalyst, an anion exchange resin, The capsule contains at least one catalyst selected from the group consisting of a talcite compound and a solid base catalyst in which an alkali metal is supported on a metal oxide. As a result, it is possible to effectively realize contact between the catalyst and the raw material in a minute space within the capsule, and as a result, it is possible to provide an encapsulated catalyst capable of enhancing the activity of the catalyst.

  The encapsulated catalyst of the present invention can be preferably used in the above-described method for producing the biodiesel fuel of the present invention. However, the use of the encapsulated catalyst of the present invention is not limited to the production of biodiesel fuel. That is, the encapsulated catalyst of the present invention can be applied to other uses.

  As the details (materials, production method, other components, etc.) of the encapsulated catalyst of the present invention, those described in the above-mentioned “method for producing biodiesel fuel” can be used as they are. For this reason, in order to avoid duplication of explanation, explanation here is omitted.

  The production method of the encapsulated catalyst of the present invention is preferably produced by a double tube nozzle method. This makes it easy to control the capsule film thickness and to easily obtain a monodispersed capsule with a particle size, and as a result, it is possible to provide a method for producing an encapsulated catalyst capable of enhancing the activity of the catalyst. .

  As the double-tube nozzle method (apparatus, production method, etc.) used in the method for producing an encapsulated catalyst of the present invention, those described in the above-mentioned “method for producing biodiesel fuel” can be used as they are. For this reason, in order to avoid duplication of explanation, explanation here is omitted.

  EXAMPLES Next, although an Example demonstrates this invention further more concretely, this invention is not limited to description of a following example, unless the summary is exceeded.

(Example 1: Production of encapsulated catalyst)
An attempt was made to produce an encapsulated catalyst using sodium alginate and esterified sodium alginate. As sodium alginate, the thing made by Kanto Chemical Co., Ltd. was used.

  Esterified sodium alginate was prepared as follows. That is, 1.5 g of sodium alginate was added to 5 ml of 1-butanol (1-BuOH) solution, and a few concentrated sulfuric acids were added as a catalyst, and the reaction was allowed to proceed overnight at room temperature. After the reaction, it was washed several times with 1-BuOH, the solvent was removed by filtration, and then naturally dried in air to obtain esterified sodium alginate.

An aqueous solution in which 2% by weight of each of sodium alginate and esterified sodium alginate obtained as described above was dissolved was prepared, and this was used as a wall material. On the other hand, rapeseed oil in which 10% by weight of commercially available CaO powder (manufactured by Wako Pure Chemical Industries, Ltd.) was dispersed was used as the core substance. In addition, the specific surface area of CaO was 4.14 m < ² > / g as a result of measuring by BET method. And the core substance was manufactured by making CaO into a rapeseed oil after making it fine with a mortar beforehand. The reason why CaO was used after it was fined with a mortar in advance was that commercially available CaO was agglomerated and agglomerated, and if this was suspended and used, the flow path of the double tube nozzle might be clogged. . As a result of measurement by the BET method, there was no change in the measured value of the specific surface area before and after making CaO fine. This is thought to be due to the fact that the particles are crushed and a new surface is hardly formed because of pulverization using a mortar.

Next, using the encapsulated catalyst manufacturing apparatus 1 shown in FIG. 1, the core material was filled into the syringe pump 3A, and the wall material was filled into the syringe pump 3B. Then, using the double tube nozzle 2, a droplet in which the periphery of the core material was covered with a wall material was dropped into a 0.4 M CaCl ₂ solution (cured solution). At this time, the stirrer 10 was used to stir the cured solution at 300 rpm. In addition, the flow rate condition of the double tube nozzle during the dropping is 20 ml / h (linear velocity: 0.78 cm / s) for the outer tube and 5 ml / h (linear velocity: 0.58 cm / s) for the inner tube. I did it. After completion of dropping, the gelled capsule was taken out from the CaCl ₂ solution and washed with water to obtain an encapsulated catalyst. This encapsulated catalyst is referred to as a pre-drying sample. On the other hand, a part of the encapsulated catalyst washed with water was dried in an oven set at 50 ° C. This encapsulated catalyst is referred to as a sample after drying. The properties of the capsule film were observed for the obtained sample before drying and sample after drying. The results are shown in Table-1.

  Using the encapsulated catalyst obtained as described above, it was examined whether the rapeseed oil contained permeated through the capsule and flowed out (diffused) to the outside. Specifically, 20 ml of 1-butanol (1-BuOH) was charged into a vial, and then 0.1 g of the encapsulated catalyst was charged. Next, after stirring at 200 to 300 rpm, a solution of 1-butanol is collected after a lapse of a certain time, and the absorbance at 284 nm, which is the absorption wavelength of rapeseed oil, is measured, and rapeseed oil flows out (diffuses) out of the capsule. It was measured whether or not. The results are shown in Table-1.

  Moreover, about the sample after drying, the solution of 1-butanol is periodically collected from the start of stirring, the absorbance is measured, and the amount of rapeseed oil diffused using a calibration curve measured in advance (flow rate: μl) Was calculated. The results are shown in FIG. 2 and Table-2. FIG. 2 is a graph showing changes in the amount of rapeseed oil flowing out (diffusion amount) after the start of measurement. In the same graph, the data shown as a square as “dried esterified Alg” is the case where esterified sodium alginate was used as the capsule material and the sample after drying was used as the encapsulation catalyst. The data indicated by black circles are the cases where sodium alginate was used as the capsule material and the sample after drying was used as the encapsulation catalyst. For the measurement of absorbance, UV-vis Spectrophotometer V-560 manufactured by JASCO Corporation was used. Table 2 shows data plotted in the graph of FIG.

  From Table 1, the encapsulated catalyst using sodium alginate as the capsule material does not allow the rapeseed oil to flow out (diffuse) to the outside of the capsule before drying. It turns out that is possible. This is presumably because the moisture of the capsule film was removed by drying. On the other hand, an encapsulated catalyst using esterified sodium alginate as a capsule material allows rapeseed oil to flow out (diffuse) to the outside of the capsule regardless of before and after drying. This is presumably because rapeseed oil can permeate the capsule because sodium alginate is hydrophobized by esterification. Moreover, it turns out that a capsule becomes hard by drying, regardless of the material of a capsule, and the intensity | strength of an encapsulation catalyst improves.

  Next, from FIG. 2 and Table 2, it can be seen that the permeation rate of rapeseed oil is increased by using esterified sodium alginate as the material of the capsule as compared with the case of sodium alginate. From this result, it can be said that the encapsulation catalyst using the esterified sodium alginate as the capsule material is more suitable for industrial production.

(Example 2: Production of biodiesel fuel)
100 ml of rapeseed oil and 4.78 g of encapsulated catalyst as raw material fats and oils were put into a separable flask and covered with a cover fitted with a Dimroth cooler, thermocouple, stirring blades, and nitrogen tube. After fixing with a fixture, the stirring speed was set to 150 rpm, and the reaction solution was set to 60 ° C. using a temperature controller. As the encapsulated catalyst, among the various encapsulated catalysts produced in Example 1, those obtained by performing a drying treatment using esterified sodium alginate as a capsule material (sample after drying) were used.

  Next, 50 ml of methanol as a lower alcohol was added to start synthesis of biodiesel fuel. Then, the reaction solution was periodically sampled after the synthesis was started. The sampled reaction liquid was centrifuged and phase-separated to recover a layer of synthesized fatty acid methyl ester (FAME) and rapeseed oil. Here, since methanol dissolves in FAME and slightly dissolves in the raw oil and fat, methanol is dissolved in the recovered FAME / rapeseed oil layer. Therefore, the remaining methanol was distilled off under reduced pressure. The FAME thus obtained was analyzed by a gas chromatograph with a flame ionization detector (GC-FID). The GC-FID analysis was performed using GC-4000 manufactured by GL Science.

The column used for GC was Capillary column InsertCapPure-WAX (0.53 mmI> D.x30m df = 1 μm) manufactured by GL Science. The analysis conditions were as follows.
Column Temp. : 50 ° C. (5 min) → 5 ° C./min→230° C. (30 min)
Carrier Gas: Nitrogen Detection: FID 250 ° C

  The obtained results are shown in FIG. 3 and Table 3 (data shown as “CaO-encapsulated capsule”). FIG. 3 is a graph showing the change with time of the FAME yield after the start of the reaction. Table 3 shows data plotted in the graph of FIG. 3, and also shows data after 12 hours in addition to the data shown in the graph.

  When the catalyst was separated and recovered after completion of the reaction, the encapsulated catalyst could be easily separated from the reaction solution with a net.

(Comparative Example 1)
A biodiesel fuel was produced in the same manner as in Example 2 except that a commercially available CaO powder was used as a catalyst without using an encapsulated catalyst. However, it was not possible to collect the CaO powder after completion of the reaction with a net. For this reason, in order to collect | recover CaO powder from a reaction liquid, it was necessary to perform pressure reduction filtration using a filter (0.5 micrometer). In Example 2, the centrifugation was performed at the time of sampling the reaction solution in order to obtain a phase-separated solution. In Comparative Example 1, the centrifugation at the time of sampling the reaction solution was Not only to obtain a phase separated solution, but also to remove the CaO catalyst.

  The time-dependent change in FAME yield after the start of the reaction is shown in FIG. 3 and Table 3 (data shown as “CaO powder”). Here, Table 3 shows the data plotted in the graph of FIG. 3. In addition to the data shown in the graph, the data after 12 hours and after 24 hours are also shown.

  As can be seen from FIG. 3, the induction period of the reaction is about 1 hour and 25 minutes when using the encapsulated catalyst (CaO-encapsulated capsule), and about 4 hours and 45 minutes when using the catalyst itself (CaO powder). ing. Here, as can be seen from the solid line drawn in the graph of FIG. 3, the induction period of the reaction draws a tangent at a point where the amount of change in the yield (reaction rate) with respect to time is maximum, and this tangent is the time axis ( (X axis) is a value defined by the time at the point of intersection. Thus, it can be seen that the use of the encapsulated catalyst shortens the induction period of the reaction and increases the activity of the catalyst. In addition, the time when the FAME yield reaches 75% or more is about 5 hours when the encapsulated catalyst is used, and about 8 hours when the catalyst itself is used. It can be seen that can be shortened by about 40%.

DESCRIPTION OF SYMBOLS 1 Manufacturing apparatus of encapsulated catalyst 2 Double pipe nozzle 3A, 3B Syringe pump 4A, 4B Tube 5 Double pipe nozzle inner pipe 6 Double pipe nozzle outer pipe 7 Reservoir 8 Stirrer 9 Container 10 Stirrer

Claims (3)

  When manufacturing biodiesel fuel by transesterification of raw oil and fat and lower alcohol, use capsules with an alkali solid catalyst dispersed in raw oil and fat as the core material and alginic acids cured with divalent cations as the wall material A method for producing biodiesel fuel characterized by the above. The method for producing biodiesel fuel according to claim 1, wherein the alkali solid catalyst is CaO or Ca (OH) ₂ . A biodiesel fuel produced using the biodiesel fuel production method according to claim 1 or 2.

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